42812354 umts radio access network feature description 1

Chapter 1 About This Manual 1-1.........................................................................

1.1 Overview of This Manual 1-1........................................................................1.2 Organization of This Manual 1-2..................................................................1.3 Reference 1-3...............................................................................................

Chapter 2 UE Idle Mode Behavior 2-1..................................................................

2.1 Introduction 2-1.............................................................................................2.2 Glossary 2-1.................................................................................................

2.2.1 Terms 2-1.............................................................................................2.2.2 Acronyms and Abbreviations 2-3.........................................................

2.3 Application 2-4..............................................................................................2.3.1 Availability 2-4......................................................................................2.3.2 Benefit 2-4............................................................................................2.3.3 Limitation and Restriction 2-4...............................................................

2.4 Technical Description 2-4.............................................................................2.4.1 PLMN Selection[2] 2-4.........................................................................2.4.2 Cell Selection[4] 2-8.............................................................................2.4.3 Cell Reselection 2-15.............................................................................2.4.4 Location Update and Routing Area Update[3] 2-17...............................2.4.5 Paging[4][5] 2-22....................................................................................2.4.6 System Information[5] 2-24....................................................................

2.5 Interaction 2-34...............................................................................................2.6 Implementation 2-35.......................................................................................

2.6.1 Engineering Guideline 2-35....................................................................2.6.2 Parameters 2-39....................................................................................2.6.3 Example 2-45.........................................................................................

2.7 Reference Information 2-45............................................................................

Chapter 3 URA UPDATE 3-1..................................................................................




3.4 Technical Description 3-2.............................................................................3.4.1 Type of URA UPDATE Procedure 3-2.................................................3.4.2 Procedure 3-3......................................................................................

3.5 Interaction 3-4...............................................................................................

3.6 Implementation 3-4.......................................................................................3.6.1 Engineering Guideline 3-4....................................................................3.6.2 Parameter 3-4......................................................................................3.6.3 Example 3-5.........................................................................................


Chapter 4 CELL UPDATE 4-1................................................................................




4.4 Technical Description 4-2.............................................................................4.4.1 Type of CELL UPDATE Procedure 4-2................................................4.4.2 Procedure 4-3......................................................................................


4.6.1 Engineering Guideline 4-6....................................................................4.6.2 Parameter 4-6......................................................................................4.6.3 Example 4-7.........................................................................................


Chapter 5 Soft Handover 5-1.................................................................................




5.4 Technical Description 5-6.............................................................................5.4.1 Handover Measurements and Procedures 5-6....................................5.4.2 Example of a Soft Handover Algorithm 5-7..........................................5.4.3 Typical Soft Handover signaling procedures 5-9.................................


5.6.1 Engineering Guideline 5-16....................................................................

5.6.2 Parameter 5-16......................................................................................5.7 Reference Information 5-30............................................................................

Chapter 6 SRNS Relocation 6-1............................................................................




6.4 Technical Description 6-3.............................................................................6.4.1 Algorism of SRNC Relocation 6-3........................................................6.4.2 Scenarios of SRNC Relocation 6-5......................................................




Chapter 7 Inter-RAT Handover 7-1.......................................................................




7.4 Technical Description 7-4.............................................................................7.4.1 General Procedure of Inter-RAT Handover 7-4...................................7.4.2 UMTS to GSM Inter-MSC Handover 7-5..............................................7.4.3 UMTS to GSM Inter-SGSN Change 7-7..............................................7.4.4 Combined Service Inter-RAT Handover 7-13........................................

7.5 Interaction 7-15...............................................................................................7.5.1 Inter-RAT Cell Reselection in Idle Mode 7-15........................................7.5.2 Inter-RAT Cell Reselection from UTRAN 7-16.......................................7.5.3 Co-exist between Inter-frequency and Inter-RAT 7-16..........................

7.6 Implementation 7-16.......................................................................................

7.6.1 Engineering Guideline 7-16....................................................................7.6.2 Parameters 7-17....................................................................................


Chapter 8 PDCP Header Compression 8-1..........................................................


8.2.1 Terms[RFC2507-2] 8-1........................................................................8.2.2 Acronyms and Abbreviation 8-2...........................................................

8.3 Application 8-3..............................................................................................8.3.1 Availability 8-3......................................................................................8.3.2 Benefit[RFC2507-1] 8-3.......................................................................8.3.3 Limitation and Restriction 8-5...............................................................

8.4 Technical Description 8-5.............................................................................8.4.1 Method of Header Compression [RFC2507-3] 8-5..............................8.4.2 Architecture 8-6....................................................................................8.4.3 Algorithm 8-8........................................................................................


8.6.1 Engineering guideline 8-11....................................................................8.6.2 Parameter[RFC2507 14] 8-11................................................................8.6.3 Example 8-12.........................................................................................


Chapter 9 LoCation Service 9-1............................................................................



9.3 Application 9-3..............................................................................................9.3.1 Availability 9-3......................................................................................9.3.2 Benefit 9-3............................................................................................9.3.3 Limitations and Restrictions 9-3...........................................................

9.4 Technical Description 9-4.............................................................................9.4.1 QoS of LCS 9-5....................................................................................9.4.2 Brief Descriptions of Possible Location Based Services[1] 9-6............9.4.3 LCS Architecture 9-8............................................................................9.4.4 CELL ID + RTT 9-11..............................................................................9.4.5 OTDOA-IPDL 9-13.................................................................................9.4.6 AGPS 9-18.............................................................................................9.4.7 Assistance Data Delivery to UE 9-25.....................................................

9.5 LCS Interaction with Soft Handover 9-26.......................................................9.6 Implementation 9-26.......................................................................................



Chapter 10 Power Control 10-1...............................................................................

10.1 Introduction 10-1...........................................................................................10.2 Glossary 10-2...............................................................................................

10.2.1 Terms 10-2...........................................................................................10.2.2 Acronyms and Abbreviations 10-2.......................................................

10.3 Application 10-2............................................................................................10.3.1 Availability 10-2....................................................................................10.3.2 Benefit 10-2..........................................................................................10.3.3 Limitation and Restriction 10-2.............................................................

10.4 Technical Description 10-2...........................................................................10.4.1 Open-Loop Power Control 10-2...........................................................10.4.2 Inner-Loop Power Control 10-4............................................................10.4.3 Outer-Loop Power Control 10-6...........................................................

10.5 Interaction 10-7.............................................................................................10.6 Implementation 10-7.....................................................................................

10.6.1 Engineering Guideline 10-7..................................................................10.6.2 Parameter 10-7....................................................................................10.6.3 Example 10-7.......................................................................................

10.7 Reference Information 10-7..........................................................................

Chapter 11 DCCC 11-1.............................................................................................




11.4 Technical Description 11-2...........................................................................11.4.1 Architecture 11-2..................................................................................11.4.2 Procedure and Algorism 11-3..............................................................11.4.3 Uplink DCCC 11-4................................................................................11.4.4 Downlink DCCC 11-4...........................................................................

11.4.5 UE State Transition 11-5......................................................................11.5 Interaction 11-6.............................................................................................11.6 Implementation 11-6.....................................................................................



Chapter 12 AMRC 12-1............................................................................................




12.4 Technical description 12-2............................................................................12.4.1 Architecture 12-2..................................................................................12.4.2 Uplink AMRC Algorithm 12-2...............................................................12.4.3 Downlink AMRC Algorithm 12-4...........................................................


12.6.1 Engineering guideline 12-5..................................................................12.6.2 Parameter 12-5....................................................................................12.6.3 Example 12-7.......................................................................................

12.7 Reference information 12-7..........................................................................

Chapter 13 Load Control 13-1.................................................................................




13.4 Technical Description 13-6...........................................................................13.4.1 Architecture 13-6..................................................................................13.4.2 Call Admission Control 13-6.................................................................13.4.3 Potential User Control 13-8..................................................................

13.4.4 Cell Breathing 13-9..............................................................................13.4.5 Inter-frequency Load Balancing 13-10...................................................13.4.6 Directed Retry Decision and Redirection 13-11.....................................13.4.7 Load Congestion Control 13-13.............................................................




Chapter 14 Integrity Protection and Encrypt 14-1................................................


14.2.1 Terms 14-1...........................................................................................14.2.2 Symbol 14-2.........................................................................................14.2.3 Acronyms and Abbreviations 14-2.......................................................

14.3 Application 14-3............................................................................................14.4 Technical Description 14-4...........................................................................

14.4.1 Architecture 14-4..................................................................................14.4.2 Integrity Protection and Ciphering Algorithm 14-4...............................

14.5 Interaction 14-8.............................................................................................14.5.1 Relation and Influence with Authentication Procedure 14-8................14.5.2 Relation and Influence with Intersystem Handover Procedure 14-9....

14.6 Implementation 14-12.....................................................................................14.6.1 Engineering Guideline 14-12..................................................................14.6.2 Parameters 14-12..................................................................................


Chapter 15 Clock 15-1.............................................................................................


15.2.1 Terms 15-1...........................................................................................15.2.2 Acronyms and Abbreviation 15-1.........................................................


15.4 Technical Description 15-3...........................................................................15.4.1 Architecture 15-3..................................................................................15.4.2 Procedure and Algorism 15-5..............................................................

15.5 Relationship and Interaction with Other Features 15-5................................15.6 Implementation 15-6.....................................................................................



Chapter 16 STS 16-1................................................................................................




16.4 Technical Description 16-2...........................................................................16.4.1 Architecture 16-2..................................................................................16.4.2 Measurement Items 16-3.....................................................................




Chapter 17 Interface Tracing 17-1..........................................................................




17.4 Technical Description 17-2...........................................................................17.4.1 RNL Standard Interface Tracing 17-2..................................................17.4.2 TNL Tracing 17-2.................................................................................17.4.3 UE Standard Interface Message Tracing 17-3.....................................17.4.4 Sample Tracing 17-3............................................................................

17.5 Interaction 17-3.............................................................................................

17.6 Implementation 17-3.....................................................................................17.6.1 Engineering Guideline 17-3..................................................................17.6.2 Parameter 17-3....................................................................................17.6.3 Example 17-3.......................................................................................

17.7 Reference information 17-3..........................................................................

Index .................................................................................................................

HUAWEI

HUAWEI UMTS Radio Access Network Feature Description

HUAWEI UMTS Radio Access Network

Feature Description

Manual Version T2-032118-20041001-C-1.22

Product Version BSC6800V100R002 NodeBV100R003

BOM 31210018

Huawei Technologies Co., Ltd. provides customers with comprehensive technical support and service. Please feel free to contact our local office or company headquarters.

Huawei Technologies Co., Ltd.

Address: Administration Building, Huawei Technologies Co., Ltd.,

Bantian, Longgang District, Shenzhen, P. R. China

Postal Code: 518129

Website: http://www.huawei.com

Email: [email protected]

Copyright © 2004 Huawei Technologies Co., Ltd.

All Rights Reserved

No part of this manual may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Technologies Co., Ltd.

Trademarks

, HUAWEI, C&C08, EAST8000, HONET, , ViewPoint, INtess, ETS, DMC,

TELLIN, InfoLink, Netkey, Quidway, SYNLOCK, Radium, M900/M1800, TELESIGHT, Quidview, Musa, Airbridge, Tellwin, Inmedia, VRP, DOPRA, iTELLIN, HUAWEI OptiX, C&C08 iNET, NETENGINE, OptiX, iSite, U-SYS, iMUSE, OpenEye, Lansway, SmartAX, infoX, TopEng are trademarks of Huawei Technologies Co., Ltd.

All other trademarks mentioned in this manual are the property of their respective holders.

Notice

The information in this manual is subject to change without notice. Every effort has been made in the preparation of this manual to ensure accuracy of the contents, but all statements, information, and recommendations in this manual do not constitute the warranty of any kind, express or implied.

Summary of Updates

This section provides the update history of this manual and introduces the contents of subsequent updates.

Update History

This manual is updated for a major product version to maintain consistency with system hardware or software versions and to incorporate customer suggestions.

Manual Version Notes

T2-032118-20041001-C-1.22 Initial commercial release

Updates of Contents

None.

About This Manual

Release Notes

This manual applies to BSC6800 V100R002 and NodeB V100R003.

Organization

This manual consists of 17 chapters as described in the following table.

Chapter Content

1. About This Manual

2. Idle state behavior feature description

3. URA update feature description

4. CELL update feature description

5. Soft handover feature description

6. SRNS Relocation feature description

7. Inter-RAT handover feature description

8. PDCP header compression feature description

9. LCS feature description

10. Power control feature description

11. DCCC feature description

12. AMRC feature description

13. Load control feature description

14. Integrity protection and encrypt feature description

15. Clock feature description

16. STS feature description

17. Interface tracing feature description

Intended Audience

The manual is intended for the following readers:

RAN Network Operator RAN System Engineer

Conventions

This document uses the following conventions:

I. General conventions

Convention Description

Arial Normal paragraphs are in Arial.

Arial Narrow Warnings, cautions, notes and tips are in Arial Narrow.

Bold Headings, Command, Command Description are in boldface.

Terminal Display Terminal Display is in Courier New; message input by the user via the terminal is in boldface.

II. Symbols

Eye-catching symbols are also used in this document to highlight the points worthy of special attention during the operation. They are defined as follows:

Caution, Warning, Danger: Means reader be extremely careful during the

operation.

Note, Comment, Tip, Knowhow, Thought: Means a complementary description.

Feature Description HUAWEI UMTS Radio Access Network Table of Contents

i

Table of Contents

Chapter 1 About This Manual....................................................................................................... 1-1 1.1 Overview of This Manual ................................................................................................... 1-1 1.2 Organization of This Manual.............................................................................................. 1-2 1.3 Reference .......................................................................................................................... 1-3

Chapter 2 UE Idle Mode Behavior................................................................................................ 2-1 2.1 Introduction ........................................................................................................................ 2-1 2.2 Glossary............................................................................................................................. 2-1

2.2.1 Terms ...................................................................................................................... 2-1 2.2.2 Acronyms and Abbreviations .................................................................................. 2-3

2.3 Application ......................................................................................................................... 2-4 2.3.1 Availability ............................................................................................................... 2-4 2.3.2 Benefit ..................................................................................................................... 2-4 2.3.3 Limitation and Restriction........................................................................................ 2-4

2.4 Technical Description ........................................................................................................ 2-4 2.4.1 PLMN Selection [2] ................................................................................................... 2-4 2.4.2 Cell Selection[4]........................................................................................................ 2-8 2.4.3 Cell Reselection .................................................................................................... 2-15 2.4.4 Location Update and Routing Area Update[3]........................................................ 2-17 2.4.5 Paging[4][5] .............................................................................................................. 2-22 2.4.6 System Information[5]............................................................................................. 2-24

2.5 Interaction ........................................................................................................................ 2-34 2.6 Implementation ................................................................................................................ 2-35

2.6.1 Engineering Guideline........................................................................................... 2-35 2.6.2 Parameters............................................................................................................ 2-39 2.6.3 Example ................................................................................................................ 2-45

2.7 Reference Information ..................................................................................................... 2-45

Chapter 3 URA UPDATE ............................................................................................................... 3-1 3.1 Introduction ........................................................................................................................ 3-1 3.2 Glossary............................................................................................................................. 3-1



3.4 Technical Description ........................................................................................................ 3-2 3.4.1 Type of URA UPDATE Procedure .......................................................................... 3-2


ii

3.4.2 Procedure................................................................................................................ 3-3 3.5 Interaction .......................................................................................................................... 3-4 3.6 Implementation .................................................................................................................. 3-4

3.6.1 Engineering Guideline............................................................................................. 3-4 3.6.2 Parameter................................................................................................................ 3-4 3.6.3 Example .................................................................................................................. 3-5

3.7 Reference Information ....................................................................................................... 3-5

Chapter 4 CELL UPDATE.............................................................................................................. 4-1 4.1 Introduction ........................................................................................................................ 4-1 4.2 Glossary............................................................................................................................. 4-1



4.4 Technical Description ........................................................................................................ 4-2 4.4.1 Type of CELL UPDATE Procedure......................................................................... 4-2 4.4.2 Procedure................................................................................................................ 4-3

4.5 Interaction .......................................................................................................................... 4-5 4.6 Implementation .................................................................................................................. 4-6

4.6.1 Engineering Guideline............................................................................................. 4-6 4.6.2 Parameter................................................................................................................ 4-6 4.6.3 Example .................................................................................................................. 4-7

4.7 Reference Information ....................................................................................................... 4-7

Chapter 5 Soft Handover .............................................................................................................. 5-1 5.1 Introduction ........................................................................................................................ 5-1 5.2 Glossary............................................................................................................................. 5-4



5.4 Technical Description ........................................................................................................ 5-6 5.4.1 Handover Measurements and Procedures ............................................................. 5-6 5.4.2 Example of a Soft Handover Algorithm................................................................... 5-7 5.4.3 Typical Soft Handover signaling procedures .......................................................... 5-9


5.6.1 Engineering Guideline........................................................................................... 5-16 5.6.2 Parameter.............................................................................................................. 5-16


iii


Chapter 6 SRNS Relocation ......................................................................................................... 6-1 6.1 Introduction ........................................................................................................................ 6-1 6.2 Glossary............................................................................................................................. 6-1



6.4 Technical Description ........................................................................................................ 6-3 6.4.1 Algorism of SRNC Relocation ................................................................................. 6-3 6.4.2 Scenarios of SRNC Relocation ............................................................................... 6-5


6.6.1 Engineering Guideline........................................................................................... 6-10 6.6.2 Parameter.............................................................................................................. 6-10 6.6.3 Example ................................................................................................................ 6-12


Chapter 7 Inter-RAT Handover..................................................................................................... 7-1 7.1 Introduction ........................................................................................................................ 7-1 7.2 Glossary............................................................................................................................. 7-1



7.4 Technical Description ........................................................................................................ 7-4 7.4.1 General Procedure of Inter-RAT Handover ............................................................ 7-4 7.4.2 UMTS to GSM Inter-MSC Handover....................................................................... 7-5 7.4.3 UMTS to GSM Inter-SGSN Change ....................................................................... 7-7 7.4.4 Combined Service Inter-RAT Handover ............................................................... 7-13

7.5 Interaction ........................................................................................................................ 7-15 7.5.1 Inter-RAT Cell Reselection in Idle Mode............................................................... 7-15 7.5.2 Inter-RAT Cell Reselection from UTRAN.............................................................. 7-16 7.5.3 Co-exist between Inter-frequency and Inter-RAT ................................................. 7-16

7.6 Implementation ................................................................................................................ 7-16 7.6.1 Engineering Guideline........................................................................................... 7-16 7.6.2 Parameters............................................................................................................ 7-17



iv

Chapter 8 PDCP Header Compression........................................................................................ 8-1 8.1 Introduction ........................................................................................................................ 8-1 8.2 Glossary............................................................................................................................. 8-1

8.2.1 Terms[RFC2507-2]......................................................................................................... 8-1 8.2.2 Acronyms and Abbreviation .................................................................................... 8-2

8.3 Application ......................................................................................................................... 8-3 8.3.1 Availability ............................................................................................................... 8-3 8.3.2 Benefit[RFC2507-1]........................................................................................................ 8-3 8.3.3 Limitation and Restriction........................................................................................ 8-5

8.4 Technical Description ........................................................................................................ 8-5 8.4.1 Method of Header Compression [RFC2507-3]............................................................... 8-5 8.4.2 Architecture ............................................................................................................. 8-6 8.4.3 Algorithm ................................................................................................................. 8-8


8.6.1 Engineering guideline............................................................................................ 8-11 8.6.2 Parameter [RFC2507 14] .............................................................................................. 8-11 8.6.3 Example ................................................................................................................ 8-12


Chapter 9 LoCation Service ......................................................................................................... 9-1 9.1 Introduction ........................................................................................................................ 9-1 9.2 Glossary............................................................................................................................. 9-1


9.3 Application ......................................................................................................................... 9-3 9.3.1 Availability ............................................................................................................... 9-3 9.3.2 Benefit ..................................................................................................................... 9-3 9.3.3 Limitations and Restrictions .................................................................................... 9-3

9.4 Technical Description ........................................................................................................ 9-4 9.4.1 QoS of LCS ............................................................................................................. 9-5 9.4.2 Brief Descriptions of Possible Location Based Services [1] ..................................... 9-6 9.4.3 LCS Architecture ..................................................................................................... 9-8 9.4.4 CELL ID + RTT...................................................................................................... 9-11 9.4.5 OTDOA-IPDL ........................................................................................................ 9-13 9.4.6 AGPS .................................................................................................................... 9-18 9.4.7 Assistance Data Delivery to UE ............................................................................ 9-25

9.5 LCS Interaction with Soft Handover................................................................................. 9-26 9.6 Implementation ................................................................................................................ 9-26

9.6.1 Engineering Guideline........................................................................................... 9-26 9.6.2 Parameter.............................................................................................................. 9-27 9.6.3 Example ................................................................................................................ 9-40



v

Chapter 10 Power Control .......................................................................................................... 10-1 10.1 Introduction .................................................................................................................... 10-1 10.2 Glossary......................................................................................................................... 10-2

10.2.1 Terms .................................................................................................................. 10-2 10.2.2 Acronyms and Abbreviations .............................................................................. 10-2

10.3 Application ..................................................................................................................... 10-2 10.3.1 Availability ........................................................................................................... 10-2 10.3.2 Benefit ................................................................................................................. 10-2 10.3.3 Limitation and Restriction.................................................................................... 10-2

10.4 Technical Description .................................................................................................... 10-2 10.4.1 Open-Loop Power Control .................................................................................. 10-2 10.4.2 Inner-Loop Power Control ................................................................................... 10-4 10.4.3 Outer-Loop Power Control .................................................................................. 10-6

10.5 Interaction ...................................................................................................................... 10-7 10.6 Implementation .............................................................................................................. 10-7

10.6.1 Engineering Guideline......................................................................................... 10-7 10.6.2 Parameter............................................................................................................ 10-7 10.6.3 Example .............................................................................................................. 10-7

10.7 Reference Information ................................................................................................... 10-7

Chapter 11 DCCC......................................................................................................................... 11-1 11.1 Introduction .................................................................................................................... 11-1 11.2 Glossary......................................................................................................................... 11-1



11.4 Technical Description .................................................................................................... 11-2 11.4.1 Architecture ......................................................................................................... 11-2 11.4.2 Procedure and Algorism...................................................................................... 11-3 11.4.3 Uplink DCCC....................................................................................................... 11-4 11.4.4 Downlink DCCC .................................................................................................. 11-4 11.4.5 UE State Transition ............................................................................................. 11-5




Chapter 12 AMRC ........................................................................................................................ 12-1 12.1 Introduction .................................................................................................................... 12-1


vi

12.2 Glossary......................................................................................................................... 12-1 12.2.1 Terms .................................................................................................................. 12-1 12.2.2 Acronyms and Abbreviations .............................................................................. 12-1


12.4 Technical description ..................................................................................................... 12-2 12.4.1 Architecture ......................................................................................................... 12-2 12.4.2 Uplink AMRC Algorithm ...................................................................................... 12-2 12.4.3 Downlink AMRC Algorithm.................................................................................. 12-4


12.6.1 Engineering guideline.......................................................................................... 12-5 12.6.2 Parameter............................................................................................................ 12-5 12.6.3 Example .............................................................................................................. 12-7

12.7 Reference information ................................................................................................... 12-7

Chapter 13 Load Control ............................................................................................................ 13-1 13.1 Introduction .................................................................................................................... 13-1 13.2 Glossary......................................................................................................................... 13-3



13.4 Technical Description .................................................................................................... 13-6 13.4.1 Architecture ......................................................................................................... 13-6 13.4.2 Call Admission Control........................................................................................ 13-6 13.4.3 Potential User Control ......................................................................................... 13-8 13.4.4 Cell Breathing...................................................................................................... 13-9 13.4.5 Inter-frequency Load Balancing ........................................................................ 13-10 13.4.6 Directed Retry Decision and Redirection .......................................................... 13-11 13.4.7 Load Congestion Control .................................................................................. 13-13

13.5 Interaction .................................................................................................................... 13-13 13.6 Implementation ............................................................................................................ 13-14

13.6.1 Engineering Guideline....................................................................................... 13-14 13.6.2 Parameter.......................................................................................................... 13-14 13.6.3 Example ............................................................................................................ 13-18

13.7 Reference Information ................................................................................................. 13-19

Chapter 14 Integrity Protection and Encrypt............................................................................ 14-1 14.1 Introduction .................................................................................................................... 14-1


vii

14.2 Glossary......................................................................................................................... 14-1 14.2.1 Terms .................................................................................................................. 14-1 14.2.2 Symbol ................................................................................................................ 14-2 14.2.3 Acronyms and Abbreviations .............................................................................. 14-2

14.3 Application ..................................................................................................................... 14-3 14.4 Technical Description ....................................................................................................... 14-4

14.4.1 Architecture ......................................................................................................... 14-4 14.4.2 Integrity Protection and Ciphering Algorithm ...................................................... 14-4

14.5 Interaction ...................................................................................................................... 14-8 14.5.1 Relation and Influence with Authentication Procedure ....................................... 14-8 14.5.2 Relation and Influence with Intersystem Handover Procedure........................... 14-9

14.6 Implementation ............................................................................................................ 14-12 14.6.1 Engineering Guideline....................................................................................... 14-12 14.6.2 Parameters........................................................................................................ 14-12

14.7 Reference Information ................................................................................................. 14-13

Chapter 15 Clock ......................................................................................................................... 15-1 15.1 Introduction .................................................................................................................... 15-1 15.2 Glossary......................................................................................................................... 15-1

15.2.1 Terms .................................................................................................................. 15-1 15.2.2 Acronyms and Abbreviation ................................................................................ 15-1


15.4 Technical Description .................................................................................................... 15-3 15.4.1 Architecture ......................................................................................................... 15-3 15.4.2 Procedure and Algorism...................................................................................... 15-5

15.5 Relationship and Interaction with Other Features ......................................................... 15-5 15.6 Implementation .............................................................................................................. 15-6



Chapter 16 STS............................................................................................................................ 16-1 16.1 Introduction .................................................................................................................... 16-1 16.2 Glossary......................................................................................................................... 16-1




viii

16.4 Technical Description .................................................................................................... 16-2 16.4.1 Architecture ......................................................................................................... 16-2 16.4.2 Measurement Items ............................................................................................ 16-3




Chapter 17 Interface Tracing...................................................................................................... 17-1 17.1 Introduction .................................................................................................................... 17-1 17.2 Glossary......................................................................................................................... 17-1



17.4 Technical Description .................................................................................................... 17-2 17.4.1 RNL Standard Interface Tracing ......................................................................... 17-2 17.4.2 TNL Tracing......................................................................................................... 17-2 17.4.3 UE Standard Interface Message Tracing............................................................ 17-3 17.4.4 Sample Tracing ................................................................................................... 17-3



17.7 Reference information ................................................................................................... 17-3

Index ................................................................................................................................................ i-1

Feature Description HUAWEI UMTS Radio Access Network Chapter 1 About This Manual

1-1

Chapter 1 About This Manual

1.1 Overview of This Manual

This manual describes the features supported by UMTS Radio Access Network (RAN). From this manual, you can obtain a comprehensive understanding of the features from the following perspectives:

Basic principles Technical realizaiton Engineering considerations

This manual describes the features in Table 1-1.

Table 1-1 RAN feature list

Feature class Feature Basic /Optional Chapter

Idle state behavior Basic 2

URA update Basic 3

CELL update Basic 4

Soft handover Basic 5

SRNS Relocation Basic 6

Inter-RAT handover Optional 7

PDCP header compression Optional 8

Service feature

LCS Optional 9

Power control Basic 10

DCCC Basic 11

AMRC Optional 12

Radio resource management feature

Load control Basic 13

Security feature Integrity protection and encrypt Basic 14

Clock feature Clock Basic 15

STS Basic 16 O&M Feature

Interface tracing Optional 17


1-2

1.2 Organization of This Manual

This manual presents each feature from the following perspectives:

Introduction Glossary Application Technical description Interaction Implementation Reference information

I. Introduction

This part presents feature related knowledge and functions.

II. Glossary

This part presents feature related terms, acronyms and abbreviations.

III. Application

This part describes the application of each feature as follows:

Availability: introducing the product version of a feature Benefit: introducing the benefits for carriers applying the feature Limitation and Restriction: introducing feature related requirements and support

IV. Technical Description

This part describes feature related technical description as follows:

Functional structure Process, feature related interface & procedures, aglorythm & parameter,

calculator and data sheet

V. Interaction

This part describes the relationship between a specific feature and the others.

VI. Implementation

This part present implementation as follows:

Engineering guideline Parameter

VII. Reference Information

This part provides the reference materials related to each feature.


1-3

1.3 Reference

To understand this manual better, you shall look through the technical manuals of UMTS NodeBs and RNC products.

Feature Description HUAWEI UMTS Radio Access Network Chapter 2 UE Idle Mode Behavior

2-1

Chapter 2 UE Idle Mode Behavior

2.1 Introduction

UE in idle mode behavior consists of following parts:

PLMN selection: PLMN selection is to insure that the selected PLMN can provide normal service. When an MS is switched on, it attempts to make contact with a public land mobile network (PLMN). The particular PLMN to be contacted may be selected either automatically or manually.

Cell selection and reselection: Cell selection and reselection is to find a suitable cell to camp on. If a suitable cell is found, the UE shall select this cell to camp on, and report this event to NAS so that the necessary NAS registration procedures can be performed. When the registration is successful, the UE enters in state Camped normally in order to obtain normal service. If the UE is unable to find any suitable cell of selected PLMN the UE shall enter the Any cell selection state.

Location registration (LR): Location registration (LR) includes location update and routing area update, which is used for non-GPRS and GPRS respectively.

Location update: The location updating procedure is a general procedure which is used for the purposes of normal location updating, periodic location updating and IMSI attach.

Routing area updating: The routing area updating procedure is a general procedure, which is used for purpose of normal routing area updating, combined routing area updating and periodic routing area updating.

Paging: Paging is used to transmit paging information to selected UEs in idle mode, CELL_PCH or URA_PCH state to establish a signaling connection or used to trigger a cell update procedure for UEs in CELL_PCH or URA_PCH state or to trigger UE reading updated system information. UTRAN may also initiate paging for UEs in CELL_PCH and URA_PCH state to release the RRC connection.

Receiving system information: System information is used to notify and control the behavior of UEs in a cell, which are broadcasted from the UTRAN by BCCH channel. System information is defined to different blocks with different characteristics named as MIB, SIB and SB and organized as a tree.

2.2 Glossary

2.2.1 Terms

Acceptable Cell: A cell that satisfies certain conditions. A UE can always attempt emergency calls on an acceptable cell.


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Available PLMN: A PLMN for which the UE has found at least one cell and read its PLMN identity.

Barred Cell: A cell a UE is not allowed to camp on.

Camped on a cell: UE is in idle mode and has completed the cell selection/reselection process and has chosen a cell. The UE monitors system information and (in most cases) paging information.

Camped on any cell: UE is in idle mode and has completed the cell selection/reselection process and has chosen a cell irrespective of PLMN identity.

Cell identity: This information element identifies a cell unambiguously within a PLMN.

EPLMN: Equivalent PLMN, A PLMN considered as equivalent to the selected PLMN by the UE for PLMN selection, cell selection, cell reselection and handover according to the information provided by the NAS.

HPLMN: Home PLMN. This is a PLMN where the MCC and MNC of the PLMN identity match the MCC and MNC of the IMSI.

Reserved Cell: A cell on which camping is not allowed, except for particular UEs, if so indicated in the system information.

Restricted Cell: A cell on which camping is allowed, but access attempts are disallowed for UEs whose access classes are indicated as barred.

Serving cell: The cell on which the UE is camped.

Strongest cell: The cell on a particular carrier that is considered strongest according to the layer 1 cell search procedure. As the details of the layer 1 cell search are implementation dependent, the precise definition of 'strongest cell' is also implementation dependent.

Suitable Cell: A cell on which an UE may camp. The criteria for a UTRA cell are defined, so are the criteria for a GSM cell.

VPLMN: Visited PLMN. This is a PLMN, different from the home PLMN.

MP: Mandatory present. A value for that information is always needed, and no information is provided about a particular default value. If ever the transfer syntax allows absence (e.g., due to extension), then absence leads to an error diagnosis.

MD: Mandatory with default value. A value for that information is always needed, and a particular default value is mentioned (in the 'Semantical information' column). This opens the possibility for the transfer syntax to use absence or a special pattern to encode the default value.

CV: Conditional on value. A value for that information is needed (presence needed) or unacceptable (absence needed) when some conditions are met that can be evaluated on the sole basis of the content of the message.


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If conditions for presence needed are specified, the transfer syntax must allow for the presence of the information. If the transfer syntax allows absence, absence when the conditions for presence are met leads to an error diagnosis.

If conditions for absence needed are specified, the transfer syntax must allow to encode the absence. If the information is present and the conditions for absence are met, an error is diagnosed.

When neither conditions for presence or absence are met, the information is treated as optional, as described for 'OP'.

CH: Conditional on history. A value for that information is needed (presence needed) or unacceptable (absence needed) when some conditions are met that must be evaluated on the basis of information obtained in the past (e.g., from messages received in the past from the other party).

If conditions for presence needed are specified, the transfer syntax must allow for the presence of the information. If the transfer syntax allows absence, absence when the conditions for presence are met leads to an error diagnosis.

If conditions for absence needed are specified, the transfer syntax must allow to encode the absence. If the information is present and the conditions for absence are met, an error is diagnosed.

When neither conditions for presence or absence are met, the information is treated as optional, as described for 'OP'.

OP: Optional. The presence or absence is significant and modifies the behaviour of the receiver. However whether the information is present or not does not lead to an error diagnosis.

URA identity: Gives the identity of the UTRAN Registration Area. It can be used to indicate to the UE which URA it shall use in case of overlapping URAs.

2.2.2 Acronyms and Abbreviations

EF Elementary File

GPRS General Packet Radio Service

GSM Global System for Mobile Communications

UMTS Universal Mobile Telecommunications System

LAI Location Area Identity

SFI Short EF Identifier

SIB System Information Block

RSCP Receive Signal Code Power

Ec/No Received energy per chip divided by the power density in the band

LR Location Registration

DRX Discontinuous Reception


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IMSI International Mobile Subscriber Identity

MCC Mobile Country Code

MNC Mobile Network Code

MS Mobile Station

PLMN Public Land Mobile Network

UE User Equipment

VPLMN Visited PLMN

MIB Master Information Block


SB Scheduling Block

PLMN Public Land Mobile Network

UTRAN Universal Terrestrial Radio Access Network

2.3 Application

2.3.1 Availability

This is a basic feature for Huawei UMTS RAN. This feature is available on BSC6800 V100R002 and later generic releases of the BSC6800 system.

2.3.2 Benefit

The feature gives the basic service provider capability such as access to WCDMA network and voice call etc.

2.3.3 Limitation and Restriction

This feature is restricted by UE’s capability and compliance to 3GPP specification.

2.4 Technical Description

2.4.1 PLMN Selection [2]

I. PLMN Selection in HPLMN: at Switch-on or Recovery from Lack of Coverage

At switch on, or following recovery from lack of coverage, the MS selects the registered PLMN or equivalent PLMN (if it is available) using all access technologies that the MS is capable of and if necessary attempts to perform a Location Registration.

If successful registration is achieved, the MS indicates the selected PLMN.

If there is no registered PLMN, or if registration is not possible due to the PLMN being unavailable or registration failure, the MS follows one of the following two procedures depending on its operating mode.


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EXCEPTION: If registration is not possible on recovery from lack of coverage due to the registered PLMN being unavailable, a MS attached to GPRS services may, optionally, continue looking for the registered PLMN for an implementation dependent time.

NOTE: A MS attached to GPRS services should use the above exception only if one or more PDP contexts are currently active.

a) Automatic Network Selection Mode Procedure

The MS selects and attempts registration on other PLMNs, if available and allowable, in the following order:

1) HPLMN (if not previously selected); 2) Each PLMN in the "User Controlled PLMN Selector with Access Technology"

data field in the SIM (in priority order); 3) Each PLMN in the "Operator Controlled PLMN Selector with Access Technology"

data field in the SIM (in priority order); 4) Other PLMN/access technology combinations with received high quality signal in

random order; 5) Other PLMN/access technology combinations in order of decreasing signal

quality.

When following the above procedure the following requirements apply:

6) In 4) and 5), the MS shall search for all access technologies it is capable of, before deciding which PLMN to select.

7) In 1), the MS shall search for all access technologies it is capable of. The MS shall start its search using the access technologies stored in the "HPLMN Selector with Access Technology" data field on the SIM in priority order.

8) In 5), the MS shall order the PLMN/access technology combinations in order of decreasing signal quality within each access technology. The order between PLMN/access technology combinations with different access technologies is an MS implementation issue.

If successful registration is achieved, the MS indicates the selected PLMN.

If registration cannot be achieved because no PLMNs are available and allowable, the MS indicates "no service" to the user, waits until a new PLMN is available and allowable and then repeats the procedure.

If there were one or more PLMNs which were available and allowable, but an LR failure made registration on those PLMNs unsuccessful or an entry in the "forbidden LAs for regional provision of service" list prevented a registration attempt, the MS selects the first such PLMN again and enters a limited service state.

b) Manual Network Selection Mode Procedure

The MS indicates whether there are any PLMNs, which are available using all supported access technologies. This includes PLMNs in the "forbidden PLMNs" list and PLMNs which only offer services not supported by the MS.


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If displayed, PLMNs meeting the criteria above are presented in the following order:

1) HPLMN; 2) PLMNs contained in the "User Controlled PLMN Selector with Access

Technology" data field in the SIM (in priority order); 3) PLMNs contained in the "Operator Controlled PLMN Selector with Access

Technology" data field in the SIM (in priority order); 4) Other PLMN/access technology combinations with received high quality signal in

random order; 5) Other PLMN/access technology combinations in order of decreasing signal

quality.

In 2) and 3), an MS using a SIM without access technology information storage (i.e. the "User Controlled PLMN Selector with Access Technology" and the "Operator Controlled PLMN Selector with Access Technology" data fields are not present) shall instead present the PLMNs contained in the "PLMN Selector" data field in the SIM (in priority order).

The user may select his desired PLMN and the MS then initiates registration on this PLMN using the access technology chosen by the user for that PLMN or using the highest priority available access technology for that PLMN, if the associated access technologies have a priority order. (This may take place at any time during the presentation of PLMNs). For such a registration, the MS shall ignore the contents of the "forbidden LAs for roaming", "forbidden LAs for regional provision of service", "forbidden PLMNs for GPRS service" and "forbidden PLMNs" lists.

If the user does not select a PLMN, the selected PLMN shall be the one that was selected before the PLMN selection procedure started. If no such PLMN was selected or that PLMN is no longer available, then the MS shall attempt to camp on any acceptable cell and enter the limited service state.

II. PLMN Selection in HPLMN: User Reselection

At any time the user may request the MS to initiate reselection and registration onto an available PLMN, according to the following procedures, dependent upon the operating mode.

a) Automatic Network Selection Mode

The MS selects and attempts registration on PLMNs, if available and allowable, in all of its bands of operation in accordance with the following order:

1) HPLMN; 2) PLMNs contained in the "User Controlled PLMN Selector with Access

Technology" data field in the SIM (in priority order) excluding the previously selected PLMN;

3) PLMNs contained in the "Operator Controlled PLMN Selector with Access Technology" data field in the SIM (in priority order) excluding the previously selected PLMN;


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4) Other PLMN/access technology combinations with the received high quality signal in random order excluding the previously selected PLMN;

5) Other PLMN/access technology combinations, excluding the previously selected PLMN in order of decreasing signal quality or, alternatively, the previously selected PLMN may be chosen ignoring its signal quality;

6) The previously selected PLMN

The previously selected PLMN is the PLMN which the MS has selected prior to the start of the user reselection procedure.

NOTE 1: If the previously selected PLMN is chosen, and registration has not been attempted on any other PLMNs, then the MS is already registered on the PLMN, and so registration is not necessary.

b) Manual Network Selection Mode

The Manual Network Selection Mode Procedure is the same as the procedure in Automatic Network Selection Mode.

III. PLMN Selection In VPLMN

If the MS is in a VPLMN, the MS shall periodically attempt to obtain service on its HPLMN or higher priority PLMN listed in "user controlled PLMN selector" or "operator controlled PLMN selector" by scanning in accordance with the requirements as defined in the Automatic Network Selection Mode. In the case that the mobile has a stored "Equivalent PLMNs" list the mobile shall only select a PLMN if it is of a higher priority than those of the same country as the current serving PLMN which are stored in the "Equivalent PLMNs" list. For this purpose, a value T minutes may be stored in the SIM. T is either in the range 6 minutes to 8 hours in 6 minute steps or it indicates that no periodic attempts shall be made. If no value is stored in the SIM, a default value of 60 minutes is used.

The attempts to access the HPLMN or higher priority PLMN shall be as specified below:

1) The periodic attempts shall only be performed in automatic mode when the MS is roaming;

2) After switch on, a period of at least 2 minutes and at most T minutes shall elapse before the first attempt is made;

3) The MS shall make an attempt if the MS is on the VPLMN at time T after the last attempt;

4) Periodic attempts shall only be performed by the MS while in idle mode; 5) If the HPLMN or higher priority PLMN is not found, the MS shall remain on the

VPLMN. 6) In steps 1), 2) and 3) the MS shall limit its attempts to access higher priority

PLMNs to PLMNs of the same country as the current serving VPLMN.


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7) Only the priority levels of Equivalent PLMNs of the same country as the current serving VPLMN shall be taken into account to compare with the priority level of a selected PLMN.

2.4.2 Cell Selection[4]

I. States and State Transitions in Idle Mode

UE Cell selection is controlled by both NAS and AS stratums in idle mode.

The NAS may control the cell selection by:

providing information on RAT(s) associated with the selected PLMN; maintaining lists of forbidden registration areas; providing a list of equivalent PLMNs;

One or several RATs may be associated with the selected PLMN. The “HPLMN Selector with Access Technology”, “User Controlled PLMN Selector with Access Technology” and “Operator Controlled PLMN Selector with Access Technology” data fields in the SIM include associated access technologies for each PLMN entry. The PLMN/access technology combinations are listed in priority order. If an entry includes more than one access technology, then no priority is defined for the preferred access technology and the priority is an implementation issue.

The AS shall attempt to find a suitable cell to camp on.

Figure 2-1 shows the states and procedures in Idle Mode.


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InitialCell Selection

Any CellSelection

go herewhen noUSIM inthe UE

USIM inserted

Camped onany cell

go here whenever anew PLMN is

selected

1no cell information

stored for the PLMNcell information

stored for the PLMN

Storedinformation

Cell Selectionno suitable cell found

no suitablecell found

Cell Selectionwhen leaving

connectedmode

suitable cell found 2

suitablecell found Camped

normally

suitable cell found


leaveidle mode

return toidle mode

Connectedmode Cell

ReselectionEvaluationProcess

suitablecell found

trigger


1

Cell Selectionwhen leaving

connectedmode

no acceptable cell found

acceptablecell found


suitablecell found 2

leaveidle mode

return toidle mode

Connectedmode

(Emergencycalls only)

CellReselectionEvaluationProcess


trigger

no acceptablecell found

NAS indicates thatregistration on selected

PLMN is rejected(except with cause #14

or #15 [5][16])

Figure 2-1 Idle Mode Cell Selection and Reselection

In any state, a new PLMN selection causes an exit to number 1.

In order to complete above state transition, following states for cell selection in idle mode are defined:


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Camped normally state Any cell selection State Camped on any cell State Leaving connected mode

II. Camped Normally State

In this state, the UE obtains normal service and performs the tasks as following:

1) Select and monitor the indicated PICH and PCH of the cell according to information sent in system information;

2) Monitor relevant System Information; 3) Perform necessary measurements for the cell reselection evaluation procedure; 4) UE executes the cell reselection evaluation process on the following

occasions/triggers: UE internal triggers; When information on the BCCH used for the cell reselection evaluation procedure

has been modified

If after a Cell reselection evaluation process a better cell is found, the Cell reselection procedure is performed. If no suitable cell is found, the UE shall enter the state Any cell selection.

If a necessary NAS registration is rejected, the UE shall enter the Any cell selection state, except if the LR is rejected with cause #14 or cause #15. The mobile station shall search for a suitable cell in another location area in the same PLMN if the LR is rejected with cause #15.

When UE leaves idle mode in order to enter the state Connected mode, the UE shall attempt to access the current serving cell. If the access attempt to the serving cell fails, the UE shall use the Cell reselection evaluation procedure.

III. Any Cell Selection State

In this state, the UE shall attempt to find an acceptable cell of any PLMN to camp on, trying all RATs that are supported by the UE and searching first for a high quality cell.

The UE, which is not camped on any cell, shall stay in this state until an acceptable cell is found.

The state Any cell selection is also entered if the NAS indicates that a location registration is rejected except if the LR is rejected with cause #14 or cause #15, or if there is no USIM in the UE.

If an acceptable cell is found, the UE shall inform the NAS and camp on this cell and obtain limited service, state Camped on any cell.

IV. Camped on any Cell State

In this state, the UE shall perform the following tasks:


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1) Select and monitor the indicated PICH and PCH of the cell; 2) Monitor relevant System Information; 3) Perform necessary measurements for the cell reselection evaluation procedure; 4) Execute the cell reselection evaluation process on the following

occasions/triggers: UE internal triggers; When information on the BCCH used for the cell reselection evaluation procedure

has been modified; 5) Regularly attempt to find a suitable cell of the selected PLMN trying all RATs that

are supported by the UE. If a suitable cell is found, this causes an exit to number 2 in Figure 2-1.

V. Leaving Connected Mode

When returning to idle mode, the UE shall use the procedure Cell selection when leaving connected mode in order to find a suitable cell to camp on and enter state Camped normally. Candidate cells for this selection are the cell(s) used immediately before leaving connected mode. If a suitable cell is found, then the AS reports this event to NAS to be capable to perform necessary NAS registration procedures. If no suitable cell is found, the Stored information cell selection procedure shall be used.

If no suitable cell is found in cell reselection evaluation process, the UE enters the state Any cell selection.

When returning to idle mode after an emergency call on any PLMN, the UE shall select an acceptable cell to camp on. Candidate cells for this selection are the cell(s) used immediately before leaving connected mode. If no acceptable cell is found, the UE shall continue to search for an acceptable cell of any PLMN in state Any cell selection.

VI. Cell Selection Process

1) Initial Cell Selection

This procedure requires no prior knowledge of which RF channels are UTRA carriers. The UE shall scan all RF channels in the UTRA bands according to its capabilities to find a suitable cell of the selected PLMN. On each carrier, the UE need only search for the strongest cell. Once a suitable cell is found this cell shall be selected.

2) Stored Information Cell Selection

This procedure requires stored information of carrier frequencies and optionally also information on cell parameters, e.g. scrambling codes, from previously received measurement control information elements. Once the UE has found a suitable cell for the selected PLMN the UE shall select it. If no suitable cell of the selected PLMN is found the Initial cell selection procedure shall be started.

3) Cell selection criteria

The cell selection criterion S is fulfilled when:


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for FDD cells: Srxlev > 0 AND Squal > 0

for TDD cells: Srxlev > 0

Where:

Squal = Qqualmeas – Qqualmin Srxlev = Qrxlevmeas - Qrxlevmin - Pcompensation

Squal Cell Selection quality value (dB). Applicable only for FDD cells.

Srxlev Cell Selection RX level value (dB)

Qqualmeas Measured cell quality value. The quality of the received signal expressed in CPICH Ec/N0 (dB) for FDD cells. CPICH Ec/N0 shall be averaged. Applicable only for FDD cells.

Qrxlevmeas Measured cell RX level value. This is received signal, CPICH RSCP for FDD cells (dBm) and P-CCPCH RSCP for TDD cells (dBm).

Qqualmin Minimum required quality level in the cell (dB). Applicable only for FDD cells.

Qrxlevmin Minimum required RX level in the cell (dBm)

Pcompensation max(UE_TXPWR_MAX_RACH – P_MAX, 0) (dB)

UE_TXPWR_MAX_RACH

Maximum TX power level an UE may use when accessing the cell on RACH (read in system information) (dBm)

P_MAX Maximum RF output power of the UE (dBm)

VII. Cell Status and Cell Reservations

Cell status and cell reservations are indicated with the Cell Access Restriction Information Element in the System Information Message by means of three Information Elements:

Cell barred (IE type: "barred" or "not barred"), Cell Reserved for operator use (IE type: "reserved" or "not reserved"), Cell reserved for future extension (IE type: "reserved" or "not reserved").

When cell status is indicated as "not barred", "not reserved" for operator use and "not reserved" for future extension (Cell Reservation Extension),

The UE may select/re-select this cell during the cell selection and cell re-selection procedures in idle mode and in connected mode.

When cell status is indicated as "not barred", "not reserved" for operator use and "reserved" for future extension (Cell Reservation Extension),


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UEs shall behave as if cell status "barred" is indicated using the value "not allowed" in the IE "Intra-frequency cell re-selection indicator" and the maximum value for Tbarred.

When cell status is indicated as "not barred" and "reserved" for operator use,

UEs assigned to Access Class 11 or 15 may select/re-select this cell if in the home PLMN.

UEs assigned to an Access Class in the range 0 to 9 and 12 to 14 shall behave as if cell status "barred" is indicated using the value "not allowed" in the IE "Intra-frequency cell re-selection indicator" and the maximum value for Tbarred.

When cell status "barred" is indicated, The UE is not permitted to select/re-select this cell, not even for emergency calls. The UE shall ignore the "Cell Reserved for future extension (Cell Reservation

Extension) use" IE. The UE shall select another cell according to the following rule: If the "Intra-frequency cell re-selection indicator" IE in Cell Access Restriction IE

is set to value "allowed", the UE may select another cell on the same frequency if selection/re-selection criteria are fulfilled.

If the UE is camping on another cell, the UE shall exclude the barred cell from the neighbouring cell list until the expiry of a time interval Tbarred. The time interval Tbarred is sent via system information in a barred cell together with Cell status information in the Cell Access Restriction IE.

If the UE does not select another cell, and the barred cell remains to be the "best" one, the UE shall after expiry of the time interval Tbarred again check whether the status of the barred cell has changed.

If the "Intra-frequency cell re-selection indicator" IE is set to "not allowed" the UE shall not re-select a cell on the same frequency as the barred cell. For emergency call, the Intra-frequency cell re-selection indicator IE" shall be ignored, i.e. even if it is set to "not allowed" the UE may select another intra-frequency cell.

If the barred cell remains to be the "best" one, the UE shall after expiry of the time interval Tbarred again check whether the status of the barred cell has changed.

The reselection to another cell may also include a change of RAT.

VIII. Access Control

Information on cell access restrictions associated with the Access Classes is broadcast as system information. Table 2-1 describes cell access restriction information element.

Table 2-1 Cell Access Restriction Information Element

Information Element/Group name

Need Type and Reference Semantics description

Cell Barred MP Enumerated(not barred, barred)


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Need Type and Reference Semantics description

Intra-frequency cell re-selection indicator

CV- Barred

Enumerated(not allowed, allowed)

Tbarred CV- Barred

Integer (10,20,40,80,160,320,640,1280)

[4]

[s]

Cell Reserved for operator use

MP Enumerated(reserved, not reserved)

Cell Reservation Extension

MP Enumerated(reserved, not reserved)

Access Class Barred list

CV -SIB3-MD

Default is no access class barred is applied.

The first instance of the parameter corresponds to Access Class 0, the second to Access Class 1 and so on up to Access Class 15. UE reads this IE of its access class stored in SIM.

>Access Class Barred MP Enumerated (not barred, barred)

Condition Explanation

Barred The IE is mandatory present if the IE "Cell Barred" has the value "Barred"; otherwise the element is not needed in the message.

SIB3-MD The IE is mandatory and has a default value if the IE "Cell Access Restriction" is included in SIB 3. Otherwise the IE is not needed.

The UE shall ignore Access Class related cell access restrictions when selecting a cell to camp on, i.e. it shall not reject a cell for camping on because access on that cell is not allowed for any of the Access Classes of the UE. A change of the indicated access restriction shall not trigger cell re-selection by the UE.

Access Class related cell access restrictions shall be checked by the UE before sending an RRC CONNECTION REQUEST message when entering Connected Mode from UTRAN Idle mode. Cell access restrictions associated with the Access Classes


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shall not apply when the initial access for entering Connected Mode is triggered by an Inter-RAT cell re-selection to UTRAN, and for a UE which already is in Connected Mode.

IX. Emergency Call

Emergency calls shall be allowed in all cells whose barred status is not barred, independent of restrictions due to cell reservations.

A restriction on emergency calls, if needed, shall be indicated in the "Access class barred list" IE. If access class 10 is indicated as barred in a cell, UEs with access class 0 to 9 or without an IMSI are not allowed to initiate emergency calls in this cell. For UEs with access classes 11 to 15, emergency calls are not allowed if both access class 10 and the relevant access class (11 to 15) are barred. Otherwise, emergency calls are allowed for those UEs.

2.4.3 Cell Reselection

I. Measurement Rules for Cell re-Selection when HCS not Used

If the system information broadcast in the serving cell indicates that hierarchy cell structure (HCS) is not used, then for intra-frequency and inter-frequency measurements and inter-RAT measurements, the UE shall:

Use Squal for FDD cells and Srxlev for TDD for Sx and apply the following rules:

If Sx > Sintrasearch, UE need not perform intra-frequency measurements. If Sx <= Sintrasearch, perform intra-frequency measurements. If Sintrasearch is not sent for serving cell, perform intra-frequency measurements.

If Sx > Sintersearch, UE need not perform inter-frequency measurements If Sx <= Sintersearch, perform inter-frequency measurements. If Sintersearch is not sent for serving cell, perform inter-frequency measurements.

If Sx > SsearchRAT m, UE need not perform measurements on cells of RAT "m". If Sx <= SsearchRAT m, perform measurements on cells of RAT "m". If SsearchRAT m is not sent for serving cell, perform measurements on cells of RAT "m".

II. Highest Ranked Cells with Access Restrictions

For the highest ranked cell (including serving cell) according to cell reselection criteria, the UE shall check if the access is restricted according to the rules of cell reservations.

If that cell and other cells have to be excluded from the candidate list, the UE shall not consider these as candidates for cell reselection. This limitation is removed when the highest ranked cell changes.


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III. Cell Reselection Criteria

The following cell re-selection criteria are used for intra-frequency cells, inter-frequency cells and inter-RAT cells:

The quality level threshold criterion H for hierarchical cell structures is used to determine whether prioritized ranking according to hierarchical cell re-selection rules shall apply, and is defined by:

Hs = Qmeas,s - Qhcss

Hn = Qmeas,n - Qhcsn – TOn * Ln

If it is indicated in system information that HCS is not used, the quality level threshold criterion H is not applied.

The cell-ranking criterion R is defined by:

The cell-ranking criterion R is defined by:

Rs = Qmeas,s + Qhysts

Rn = Qmeas,n - Qoffsets,n - TOn * (1 – Ln)

where:

TOn = TEMP_OFFSETn * W(PENALTY_TIMEn – Tn)

Ln = 0 if HCS_PRIOn = HCS_PRIOsLn = 1 if HCS_PRIOn <> HCS_PRIOs

W(x) = 0 for x < 0W(x) = 1 for x >= 0

TEMP_OFFSETn applies an offset to the R criteria for the duration of PENALTY_TIMEn after a timer Tn has started for that neighbouring cell.

TEMP_OFFSETn and PENALTY_TIMEn are only applicable if the usage of HCS is indicated in system information.

The UE shall perform ranking of all cells that fulfil the S criterion among

all cells that have the highest HCS_PRIO among those cells that fulfil the criterion H >= 0. Note that this rule is not valid when UE high-mobility is detected.

all cells, not considering HCS priority levels, if no cell fulfil the criterion H >= 0. This case is also valid when it is indicated in system information that HCS is not used, that is when serving cell does not belong to a hierarchical cell structure.

The cells shall be ranked according to the R criteria specified above, deriving Qmeas,n and Qmeas,s and calculating the R values using CPICH RSCP, P-CCPCH


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RSCP and the averaged received signal level as specified in [10] and [11] for FDD, TDD and GSM cells, respectively.

The offset Qoffset1s,n is used for Qoffsets,n to calculate Rn, the hysteresis Qhyst1s is used for Qhysts to calculate Rs.

If the usage of HCS is indicated in system information, TEMP_OFFSET1n is used for TEMP_OFFSETn to calculate TOn. If it is indicated in system information that HCS is not used, TEMP_OFFSETn is not applied when calculating Rn. The best ranked cell is the cell with the highest R value.

If a TDD or GSM cell is ranked as the best cell, then the UE shall perform cell re-selection to that TDD or GSM cell.

If an FDD cell is ranked as the best cell and the quality measure for cell selection and re-selection is set to CPICH RSCP, the UE shall perform cell re-selection to that FDD cell.

If an FDD cell is ranked as the best cell and the quality measure for cell selection and re-selection is set to CPICH Ec/No, the UE shall perform a second ranking of the FDD cells according to the R criteria specified above, but using the measurement quantity CPICH Ec/No for deriving the Qmeas,n and Qmeas,s and calculating the R values of the FDD cells. The offset Qoffset2s,n is used for Qoffsets,n to calculate Rn, the hysteresis Qhyst2s is used for Qhysts to calculate Rs. If the usage of HCS is indicated in system information, TEMP_OFFSET2n is used to calculate TOn. If it is indicated in system information that HCS is not used, TEMP_OFFSETn is not applied when calculating Rn. Following this second ranking, the UE shall perform cell re-selection to the best ranked FDD cell.

In all cases, the UE shall reselect the new cell, only if the following conditions are met:

The new cell is better ranked than the serving cell during a time interval Treselection.

More than 1 second has elapsed since the UE camped on the current serving cell.

2.4.4 Location Update and Routing Area Update[3]

I. State and State Transition in Location/Routing Area Update

Location registration can be described by a set of states, which are entered depending on responses to location registration (LR) requests. Independent update states exist for GPRS and for non-GPRS operation in MSs capable of GPRS and non-GPRS services. The conditions of when a MS entering corresponding state are described in Table 2-2.


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Table 2-2 UE state list and enter condition

UE State UE enter this state When

Updated An LR request is accepted

Roaming not allowed

MS receives an LR reject message with the cause:

a) PLMN not allowed;

b) Location area not allowed;

c) Roaming not allowed in this location area;

d) No Suitable Cells In Location Area.

non-GPRS

Not Updated

Any LR failure not specified for states ‘Roaming not allowed’ or ‘Idle, No IMSI’ occurs, in which cases the MS is not certain whether or not the network has received and accepted the LR attempt.

Updated Same as non-GPRS

Idle, No IMSI

There is no SIM.

Roaming not allowed






e) illegal ME;

f) illegal MS;

g) GPRS services and non-GPRS services not allowed;

h) GPRS services not allowed in this PLMN;

Not Updated

Same as non-GPRS

GPRS

Roaming not allowed







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Table 2-3 below summarizes the events in each state that trigger a new LR request. The actions that may be taken while being in the various states are also outlined in this table.

Table 2-3 LR Process States and Allowed Actions

Location registration New LR request when

state Changing

Cell Changing

registration area (6)Changing PLMN(8)

Other

Updated, (5) No Yes Yes (2)

Idle, No IMSI (7) No No No No

Roaming not allowed:

a) Idle, PLMN not allowed No No Yes No

b) Idle, LA not allowed No Yes(7) Yes No

c) Idle, Roaming not allowed in this LA

No Yes(7) Yes No

d) No Suitable Cells In Location Area

No Yes(7) Yes No

Not updated Yes(1) Yes Yes (2)&(3)&(4)&(5)


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Location registration New LR request when

state Changing

Cell Changing

registration area (6)Changing PLMN(8)

Other

1): for MS capable of GPRS and non-GPRS services when at least one of both update states is NOT UPDATED.

2): A new LR is made when the periodic registration timer expires including Periodic Location Updating timer or Periodic Routing Area Update timer.

3): If a normal call request is made, an LR request is made. If successful the updated state is entered and the call may be made.

4): a manual network reselection has been performed, an acceptable cell of the selected PLMN is present, and the MS is not in the UPDATED state on the selected PLMN.

5): An LR request indicating Normal Location Updating is also made when the response to an outgoing request shows that the MS is unknown in the VLR or SGSN, respectively

6): That is to say a new registration area, i.e. the received registration area identity differs from the one stored in the MS, and the LAI or the PLMN identity is not contained in any of the lists "forbidden LAs for roaming", "forbidden LAs for regional provision of service", "forbidden PLMNs for GPRS service" or "forbidden PLMNs" respectively

7): A GPRS MS shall not perform a new LR when the new routing area is part of a LA contained in the list of "forbidden LAs for regional provision of service".

8): If a new PLMN is entered, a MS which is attached for PS services shall perform a routing area update if the LAI or the PLMN identity is not contained in any of the lists "forbidden LAs for roaming", "forbidden LAs for regional provision of service", "forbidden PLMNs for GPRS service" or "forbidden PLMNs"

II. Periodic Location Registration

Periodic updating may be used to notify periodically the availability of the mobile station to the network. A Periodic Location Updating timer (T3212 for non-GPRS operation) and a Periodic Routing Area Update timer (T3312 for GPRS operation) with the following characteristics:

1) Upon switch on of the MS or when the system information indicates that periodic location registration shall be applied, and the timer is not running, the timer shall be loaded with a random value between 0 and the broadcast or signaled time-out value and started. Namely, let t1 be the new T3212 timeout value, the new timer shall be started at a value randomly, uniformly drawn between 0 and t1.

2) The time-out value for T3212 shall be within the range of 1 deci-hour to 255 deci-hours with a granularity of 1 deci-hour.


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3) When the timer reaches its expiry value, it shall be initiated with respect to the relevant time-out value, and the MS shall initiate the Periodic Location Registration corresponding to the expired timer.

4) The Periodic Location Updating timer shall be prevented from triggering Periodic Location Updating during connected mode. When the MS returns to idle mode, the Periodic Location Updating timer shall be initiated with respect to the broadcast time-out value, then started. Thereafter, the procedure in iii) shall be followed.

5) The Periodic Routing Area Update timer shall be prevented from triggering the Periodic Routing Area Update during Ready state. At transition from Ready to Standby state the Periodic Routing Area Update timer shall be initiated with respect to its time-out value, then started. Thereafter, the procedure in iii) shall be followed.

6) If the MS performs a successful combined Routing Area Update the Periodic Location Updating timer shall be prevented from triggering the Periodic Location Updating until the MS starts using Location Updating procedure, for example because of a changed network operation mode or the MS uses non-GPRS services only.

7) When a change in the time-out value occurs (at a change of serving cell or a change in the broadcast time-out value or a change in the signalled time-out value), the related timer shall be reloaded so that the new time to expiry will be: "old time to expiry" modulo "new time-out value".

Let t1 be the new T3212 timeout value and let t be the current timer value at the moment of the change to the new T3212 timeout value; then the timer shall be restarted with the value t modulo t1.

The value of timer T3212 is sent by the network to the MS in SIB 1.

The value of timer T3312 is sent by the network to the MS in the messages ATTACH ACCEPT and ROUTING AREA UPDATE ACCEPT. The value of the timer T3312 shall be unique within a RA.

III. IMSI Attach/Detach Operation

The system information will contain an indicator indicating whether or not IMSI attach/detach operation is mandatory to use in the cell. The MS shall operate in accordance with the received value of the indicator.

When IMSI attach/detach operation applies, a MS shall send the IMSI detach message to the network when the MS is powered down or the SIM is removed while being in the update state UPDATED. The IMSI detach message will not be acknowledged by the network.

When the MS returns to the active state, the MS shall perform an LR request indicating IMSI attach, provided that the MS still is in the same registration area. If the registration area has changed, an LR request indicating Normal Location Updating.


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IMSI attach for non-GPRS services when the MS is IMSI attached for GPRS services. This procedure is used by GPRS MSs in MS operation modes A or B, if the network operates in network operation mode I.

If the network operates in mode I, GPRS MSs that operate in mode A or B and wish to be or are simultaneously IMSI attached for GPRS and non-GPRS services, shall use the combined GPRS attach and the combined and periodic routing area updating procedures instead of the corresponding IMSI attach and normal and periodic location area updating.

If the network operates in mode II, a GPRS MSs that operate in mode A or B and wish to be or are simultaneously IMSI attached for GPRS and non-GPRS services, shall use location updating procedure and routing area updating procedure listed above respectively.

IV. No Suitable Cells in Location Area

If during location registration the LR response "No Suitable Cells In Location Area" is received:

The MS shall attempt to find another LA of the same PLMN on which it received the LR response. If the MS is able to find another LA it shall attempt registration. If the MS is unable to find an LA in the PLMN, Automatic or Manual Mode Selection Procedure of shall be followed, depending on whether the MS is in automatic or manual mode.

2.4.5 Paging[4][5]

I. Discontinuous Reception

The UE may use Discontinuous Reception (DRX) in idle mode in order to reduce power consumption. When DRX is used the UE needs only to monitor one Page Indicator, PI, in one Paging Occasion per DRX cycle.

For FDD, The DRX cycle length shall be 2k frames, where k is an integer and is decided by three parameters: CN domain specific DRX cycle length for CS, CN domain specific DRX cycle length for PS, and UTRAN DRX cycle length coefficient. Their usage is described below.

CN domain specific DRX cycle lengths:The UE may be attached to different CN domains with different CN domain specific DRX cycle lengths. The UE shall store each CN domain specific DRX cycle length for each CN domain the UE is attached to and use the shortest of those DRX cycle lengths. The CS CN specific DRX cycle length coefficient shall be updated locally in the UE using information given in system information. On the other hand, the PS CN specific DRX cycle length coefficient shall be updated after the negotiation between the UE and PS CN by NAS procedure. If no specific value "k" is negotiated in NAS procedure, the UE and PS CN shall use the DRX cycle length given for PS CN domain in system information.


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UTRAN DRX cycle length: The UTRAN DRX cycle length is transferred to UE by RRC CONNECTION SETUP message irrespective of CN domain.

For a UE in idle mode, the DRX cycle length equals to the value or the shortest value of the following:

Any of the stored CN domain specific DRX cycle length for the CN domains the UE is only attached to with no signaling connection established.

For a UE in CELL_PCH state or URA_PCH state, it equals to the shortest value of the following:

UTRAN DRX cycle length; Any of the stored CN domain specific DRX cycle length for the CN domains the

UE is only attached to with no signaling connection established.

In the UTRAN side, based on all the following information to determine the Paging Occasions that is the actual frame number in the paging channel cycle length of 4096 frames:

IMSI the number of available SCCPCHs that carry a PCH (K) the Cell System Frame Number (SFN) the DRX cycle length

The value of the Paging Occasion is determined as follows:

Paging Occasion= {(IMSI div K) mod DRX cycle length} + n * DRX cycle length

Where n = 0, 1, 2… as long as SFN is below its maximum value.

The actual Page Indicator within a Paging Occasion that the UE shall read is similarly determined based on IMSI which is the actual position in the frame.

The Page Indicator to use is calculated by using the following formula:

PI = DRX Index mod Np

where DRX Index = IMSI div 8192

In the UE side, based the same information as UTRAN to determine and monitor its paging indicator in the PICH frame with SFN given by the Paging Occasion.

In FDD mode, Np = (18,36,72,144) is the number of Page Indicators per frame, and is given in IE "Number of PI per frame", part of system information in FDD mode. This parameter describes the number of simultaneous users in a cell which can be paged in the same paging occasion.

If the UE has no IMSI, for instance when making an emergency call without USIM, the UE shall use as default numbers, IMSI = 0 and DRX cycle length = 256 (2.56 s), in the formulas above.


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2.4.6 System Information[5]

I. Structure of System Information

In the tree structure of system information, a master information block gives references and scheduling information to a number of system information blocks in a cell. The system information blocks contain the actual system information. The master information block may optionally also contain reference and scheduling information to one or two scheduling blocks, which give references and scheduling information for additional system information blocks. Scheduling information for a system information block may only be included in either the master information block or one of the scheduling blocks.

Scheduling of each SIB, and SB (if existing) is performed by the RRC layer in UTRAN. If segmentation to a SIB is used, it should be possible to schedule each segment separately.

To allow the mixing of system information blocks with short repetition period and system information blocks with segmentation over many frames, UTRAN may multiplex segments from different system information blocks. Multiplexing and de-multiplexing is performed by the RRC layer.

The scheduling of each system information block broadcast on a BCH transport channel is defined by the following parameters:

the number of segments (SEG_COUNT); integer(1…16),default value 1 The repetition period (SIB_REP). The same value applies to all segments;

integer(4,8,16,32,64,128,256,512,1024,2048,4096) in frames The position (phase) of the first segment within one cycle of the Cell System

Frame Number (SIB_POS(0)). Since system information blocks are repeated with period SIB_REP, the value of SIB_POS(i), i = 0, 1, 2, … SEG_COUNT-1 must be less than SIB_REP for all segments;

The offset of the subsequent segments in ascending index order (SIB_OFF(i), i = 1, 2, … SEG_COUNT-1). The position of the subsequent segments is calculated using the following: SIB_POS(i) = SIB_POS(i-1) + SIB_OFF(i).

The scheduling is based on the Cell System Frame Number (SFN) which has the period of 4096 frames in time. The scheduling information defined above decides the segments of a SIB, the position of each segment, and repetition of each segment. The SFN of a frame at which a particular segment, i, with i = 0, 1, 2, SEG_COUNT-1 of a system information block occurs, fulfils the following relation:

SFN mod SIB_REP = SIB_POS(i)

The scheduling of the master information block is fixed as defined in below.

SEG_COUNT = 1 SIB_POS = 0 SIB_REP = 8 (FDD)


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SIB_OFF=2

It needs to be pointed out that the first two frames in each repetition of 8 frames is used to transmit SFN of the cell.

The system information is continuously broadcast on a regular basis in accordance with the scheduling defined for each system information block.

II. Reception of SYSTEM INFORMATION Messages by the UE

The UE shall read system information broadcast on a BCH transport channel in idle mode and in the connected mode in states CELL_FACH, CELL_PCH, URA_PCH. When switching off, The UE shall consider all stored system information blocks as invalid except those stored in USIM for use in a stored information cell-selection. When switching on, the UE may store system information blocks with cell, PLMN or Equivalent PLMN area scope (including their value tag if applicable) for different cells and different PLMNs, to be used if the UE returns to these cells.

When selecting a new cell within the currently used PLMN, the UE shall consider all current system information blocks with area scope cell to be invalid and store and use the new one.

After selecting a new PLMN, the UE shall consider all current system information blocks with area scope cell and PLMN to be invalid and store and use the new one.

After selecting a new PLMN which is not indicated by higher layers to be equivalent to the identity of the previously selected PLMN, the UE shall consider all system information blocks with area scope Equivalent PLMN to be invalid and store and use the new one.

III. Actions upon Reception of the Master Information Block and Scheduling Block(s)

When selecting a new cell, the UE shall read the master information block. The UE may use the pre-defined scheduling information to locate the master information block in the cell. In the MIB, MIB value tag, PLMN types, PLMN identity, and scheduling information to other SIBs are the most important IEs.

By reading the PLMN type, UE can know the type of PLMN of current network. By reading the PLMN identity, UE can verify that it is the selected PLMN. By comparing the value tag in the master information block with the value tag

stored for this cell and this PLMN, UE can know whether or not to read and store scheduling information.

By reading the scheduling information to each SIB, UE can know the scope of each SIB, the value tag of it, and the actual position of it. By comparing the value tag to each SIB with the value tag stored for this cell and this PLMN, UE can know whether or not to read and store the SIB. When everything is ok, UE is ready to read them. For those SIBs that are not supported by UE, it will skip reading and monitoring them.


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IV. Actions upon Reception of SYSTEM INFORMATION Blocks

The UE may use the scheduling information included within the master information block and the scheduling blocks to locate each system information block to be acquired. If the UE receives a system information block in a position according to the scheduling information and consider the content valid, it will read and store it for future use. Below we will introduce the important IEs in each SIB in more detail.

1) System information block 1

The UE should store all relevant IEs included in this system information block irrespective of UE’s mode. The system information block type 1 contains NAS system information as well as UE timers and counters to be used in idle mode and in connected mode, as described in Table 2-4.

If in idle mode, the UE should store all relevant IEs included in this system information block if the "PLMN Type" in the variable SELECTED_PLMN has the value "GSM-MAP" and the IE "PLMN type" in the Master Information Block has the value "GSM-MAP" or "GSM-MAP and ANSI-41". The UE shall also:

forward the content of the IE "CN domain specific NAS system information" to the non-access stratum entity indicated by the IE "CN domain identity";

use the IE "CN domain specific DRX cycle length coefficient" to calculate frame number for the Paging Occasions and Page indicator as specified in 3GPP TS 25.304;

use the values in the IE "UE Timers and constants in idle mode" for the relevant timers and counters.

If in connected mode the UE shall not use the values of the IEs in this system information block except for the timers and constant values given by the IE "UE timers and constants in connected mode".

Table 2-4 Important IEs in SIB1

Information Element/

Group name Need Multi

Type and reference

Semantics description

CN information elements

CN common GSM-MAP NAS system information

MP Octet string(1..8 )

The first octet contains octet 1 of the NAS system information element, the second octet contains octet 2 of the NAS system information element and so on.

CN domain system information list

MP

1 to <maxCNdomains>

Send CN information for each CN domain.


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Information Element/

Group name Need Multi

Type and reference


>CN domain identity

MP Enumerated (CS domain, PS domain)

>GSM-MAP

>>CN domain specific NAS system information

MP Octet string(1..8 )

The first octet contains octet 1 of the NAS system information element, the second octet contains octet 2 of the NAS system information element and so on.

UE information

UE Timers and constants in idle mode

MD

UE Timers and constants in idle mode, reference to Table 2-6

Default value means that for all timers and constants

- For parameters with need MD, the defaults specified in Table 3 apply and

- For parameters with need OP, the parameters are absent

UE Timers and constants in connected mode

MD

UE Timers and constants in connected mode, reference to 0.0.0

Default value means that for all timers and constants

- For parameters with need MD, the defaults specified in Table 2 apply and

- For parameters with need OP, the parameters are absent

Table 2-5 UE Timers and constants in connected mode

Information Element /

Group name Need Multi Type and reference Semantics description

T302 MD Integer(100, 200... 2000 by step of 200, 3000, 4000, 6000, 8000)

Value in milliseconds. Default value is 4000.

One spare value is needed.

N302 MD Integer(0..7) Default value is 3.


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T304 MD Integer(100, 200, 400, 1000, 2000)

Value in milliseconds. Default value is 2000. Three spare values are needed.

N304 MD Integer(0..7) Default value is 2..

T305 MD Integer(5, 10, 30, 60, 120, 360, 720, infinity)

Value in minutes. Default value is 30.

Infinity means no update

T307 MD Integer(5, 10, 15, 20, 30, 40, 50)

Value in seconds. Default value is 30.


T308 MD Integer(40, 80, 160, 320)


T309 MD Integer(1…8) Value in seconds. Default value is 5.

T310 MD Integer(40 .. 320 by step of 40)


N310 MD Integer(0 .. 7) Default value is 4.

T311 MD Integer(250 .. 2000 by step of 250)


T312 MD Integer (0..15) Value in seconds. Default value is 1. The value 0 is not used in this version of the specification.

N312 MD Integer (1, 2, 4, 10, 20, 50, 100, 200, 400, 600, 800, 1000)

Default value is 1.

T313 MD Integer (0..15) Value in seconds. Default value is 3.

N313 MD Integer (1, 2, 4, 10, 20, 50, 100, 200)

Default value is 20.

T314 MD Integer(0, 2, 4, 6, 8, 12, 16, 20)


T315 MD Integer (0,10, 30, 60, 180, 600, 1200, 1800)



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N315 MD Integer (1, 2, 4, 10, 20, 50, 100, 200, 400, 600, 800, 1000)

Default value is 1.

T316 MD Integer(0, 10, 20, 30, 40, 50, infinity)



Table 2-6 UE Timers and constants in idle mode

Information Element/Group

name Need Multi Type and reference Semantics description

T300 MP Integer(100, 200... 2000 by step of 200, 3000, 4000, 6000, 8000)


N300 MP Integer(0..7) Default value is 3.

T312 MP Integer(0 .. 15) Value in seconds. Default value is 1.

N312 MP Integer (1, 2, 4, 10, 20, 50, 100, 200, 400, 600, 800, 1000)

Default value is 1.


Table 2-7 describes the Important IEs in SIB2. If in connected mode the UE should store all relevant IEs included in this system information block. If in idle mode, the UE shall not use the values of the IEs in this system information block. The system information block type 2 contains the URA identity.



Need Multi Type and reference


UTRAN mobility information elements


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URA identity list MP 1 <max URA>

>URA identity MP bit string(16)


Table 2-8 describes the Important IEs in SIB3. The UE should store all relevant IEs included in this system information block. If in connected mode, and System Information Block 4 is indicated as used in the cell, UE should read and act on information sent in that block. Otherwise, UE should act on information sent in SIB3. The system information block type 3 contains parameters for cell selection and re-selection.



name Need Multi

Type and reference


SIB4 Indicator MP Boolean TRUE indicates that SIB4 is broadcast in the cell.

UTRAN mobility information elements

Cell identity MP bit string(28)

Cell selection and reselection quality measure

MP Enumerated (CPICH Ec/N0, CPICH RSCP)

Choice of measurement (CPICH Ec/N0 or CPICH RSCP) to use as quality measure Q for FDD cells.

This IE is also sent to the UE in SIB11/12. Both occurrences of the IE should be set to the same value.

Sintrasearch OP Integer (-32..20 by step of 2)

If a negative value is received the UE shall consider the value to be 0. [dB]

Sintersearch OP Integer (-32..20 by step of 2)



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name Need Multi

Type and reference


Ssearch,RAT MP Integer (-32..20 by step of 2)

In case the value 20 is received the UE shall consider this IE as if it was absent.


Qqualmin MP Integer (-24..0) Ec/N0, [dB]

Qrxlevmin MP Integer (-115..-25 by step of 2)

RSCP, [dBm]

Qhyst1s MP Integer (0..40 by step of 2)

[dB]

Qhyst2s

CV-FDD-Quality-Measure

Integer (0..40 by step of 2)

Default value is Qhyst1s

[dB]

Treselections MP Integer (0..31) [s]

Maximum allowed UL TX power

MP Integer(-50..33) In dBm

Cell Access Restriction

MP Structure type For future use


Table 2-9 describes the Important IEs in SIB5. UE should store all relevant IEs included in this system information block. If in connected mode, and System Information Block 6 is indicated as used in the cell, UE should read and act on information sent in that block. Otherwise, UE should act on information sent in SIB5. The system information block type 5 contains parameters for the configuration of the common physical channels in the cell.


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Need Multi Type and reference Semantics description


PhyCH information elements

PICH Power offset MP Integer(-10 .. +5)

Offset in dB. This is the power transmitted on the PICH minus power of the Primary CPICH in FDD.

AICH Power offset MP AICH Power offset

This AICH Power offset also indicates the power offset for AP-AICH and for CD/CA-ICH.

Primary CCPCH info OP Primary CCPCH info Note 1

PRACH system information list

MP PRACH system information list

Secondary CCPCH system information

MP Secondary CCPCH system information

CBS DRX Level 1 information

CV-CTCH

CBS DRX Level 1 information


Table 2-10 describes the Important IEs in SIB7. The UE should store all relevant IEs included in this system information block. If in connected mode, and System Information Block 8 is indicated as used in the cell, the UE should store all relevant IEs included in this system information block and act on information sent in SIB8. If in idle mode, the UE shall not use the values of the IEs in SIB8. The system information block type 7 contains the fast changing parameters UL interference and Dynamic persistence level.





CHOICE mode MP


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>FDD

>>UL interference MP UL interference

>TDD (no data)

PhyCH information elements

PRACHs listed in system information block type 5

MP 1 to <max PRACH>

The order of the PRACHs is the same as in system information block type 5.

>Dynamic persistence level MP Dynamic persistence level

PRACHs listed in system information block type 6

OP 1 to <maxPRACH>

The order of the PRACHs is the same as in system information block type 6.

>Dynamic persistence level MP Dynamic persistence level

Expiration Time Factor MD Expiration Time Factor 10.3.3.12

Default is 1.


Table 2-11 describes the important IEs in SIB11. The UE should store all relevant IEs included in this system information block. If in idle mode, the UE shall not use the values of the IEs in this system information block. If in connected mode, the UE shall use the values of the IEs in this system information block. The system information block type 11 contains measurement control information to be used in the cell.


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Need Multi Type and reference Semantics description


Measurement information elements

FACH measurement occasion info

OP FACH measurement occasion info

Measurement control system information

MP Measurement control system information

2.5 Interaction

Figure 2-2 shows interaction between PLMN selection, cell selection/ reselection and location/routing updating.

PLMN Selection and Reselection

Location Registration

PLMNsavailable

PLMN selected

LocationRegistration

response

Registration Area

changes

Indication to user

Manual Mode Automatic mode

CM requests

NAS Control

Radio measurements

Cell Selectionand Reselection

Figure 2-2 Interaction in Idle Mode

PLMN ID, Cell selection/reselection criteria, Location/routing updating timer are broadcast in system information. System information is updated by paging.


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2.6 Implementation

2.6.1 Engineering Guideline

I. PLMN Selection

PLMN selection belongs to UE behavior, which is depending on UE vendor implement and USIM card application. UE shall support variety kinds of PLMN selector with Access Technology and other function e.g. User controlled PLMN selector with Access Technology, Operator controlled PLMN selector with Access Technology, HPLMN selector with Access Technology, HPLMN search period. Above USIM card parameters shall be set according to user requirement.

II. Cell Selection

Cell selection is mostly controlled by two parameters, they are Qqualmin and Qrxlevmin. Here an example is given to illustrate how to configure these two parameters. To increase the possibility for UE to select a cell successfully, Qqualmin and Qrxlevmin should be as low as possible. But some UE maybe couldn’t finish registration or any other RRC signaling procedure when Qqualmin and Qrxlevmin are low enough. So to set Qqualmin and Qrxlevmin to their minimum value is not the best solution. The recommended value of Qqualmin and Qrxlevmin are -18 dB and -115 dBm.

Besides Qqualmin and Qrxlevmin, UE_TXPWR_MAX_RACH which is read in system information is also influence cell selection. UE_TXPWR_MAX_RACH should be set higher in macro-cell and should be set lower in micro-cell or Pico-cell. So UE_TXPWR_MAX_RACH is related to network planning.

III. Cell Reselection

If HCS not used, cell reselection is mostly controlled by following parameters: Sintrasearch, Sintersearch, SsearchRAT m, Treselections, Qoffset1s,n, Qoffset2s,n, Qhyst1s, Qhyst2s.

In order to decrease network signaling load and to increase the possibility for UEs to be paged, it is necessary to decrease the possibility of UE roaming to other cells with different LAC /RAC or RAT. Supposing there was less possibility of same frequency of two cells between different LAC/RAC than cells within same LAC/RAC. So the criteria of cell reselection should make reselection to inter-frequency cells harder than intra-frequency cells, and the hardest to inter-RAT cells.

To ensure good coverage, Sintrasearch, Sintersearch, SsearchRAT m should enable UE to reselect to a better neighboring cell as soon as possible, but Treselections shouldn’t be too short that maybe cause ping-pong cell reselection. The recommended values of these parameters are as following:

Sintrasearch: 10dB


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Sintersearch: 8dB SsearchRAT m: 4dB Treselections: 1s

When cell reselection happens between two intra-frequency cells, Qoffset2s,n and Qhyst2s should be used instead of Qoffset1s,n and Qhyst1s. When cell reselection happens between any two cells of any other type instead of intra-frequency, Qoffset1s,n and Qhyst1s should be used.

IV. Paging

Pay attention to the following aspects for paging in network deployment:

Control of paging success rate Control of paging load

V. Roaming between UMTS and GSM

At the beginning of UMTS network establishment, UMTS cells will be dotted in some important area, i.e. whose coverage will not be better and more continuum than GSM system. If 3G high quality service shall be used as much as possible and normal voice call service shall be guaranteed under such assumption, it is important to support roaming from/to UMTS to/from GSM/GPRS service. Here are 2 scenarios recommended according to PLMN ID planning and GSM capability.

Scenario I: GSM system support UMTS cells reselection. GSM and UMTS use same PLMN ID

Scenario II: GSM system didn’t support UMTS cells reselection. GSM and UMTS use different PLMN ID

1) Technical guideline for Scenario I: For the purposes of UMTS to GSM cell reselection, UMTS network shall not only

configure 2G neighbor cells but also control parameters in Table 2-12 by broadcast them in SIB3 and SIB11.

Table 2-12 Parameters for UMTS to GSM cell reselection

Parameter name

Description Range Recommended Value

Quality measure

(SIB3/11)

Choice of measurement (CPICH Ec/N0 or CPICH RSCP) to use as quality measure Q for FDD cells.

CPICH Ec/N0 or CPICH RSCP

CPICH RSCP

Ssearch,rat

(SIB3)

Squal>Ssearch,rat, do not trigger inter-RAT system measurement, (Squal = Qqualmeas-Qqualmin)(Qqualmin is inSIB3 or 11)

Integer (-32..20 by step of 2)

2

Qhyst1s This specifies the hysteresis value (Qhyst) for service cell in R criteria. It is used for FDD cells if the quality measure for

0~40 by step 2


2-37

Parameter name


(SIB3) cell selection and re-selection is set to CPICH RSCP. of 2 [dB]

Qhyst2s

(SIB3)

This specifies the hysteresis value (Qhyst) for service cell in R criteria. It is used for FDD cells if the quality measure for cell selection and re-selection is set to CPICH Ec/No.

0~40 by step of 2 [dB]

2

Treselection

(SIB3)

In all cases, the UE shall reselect the new cell, only if the following conditions are met:

- the new cell is better ranked than the serving cell during a time interval Treselection.

- more than 1 second has elapsed since the UE camped on the current serving cell.

Which is used to prevent Ping-pong reselection.

Integer (0..31)[s]

5

Inter-RAT cell info list

(SIB11)

Cell id;

Cell individual offset(-50~50 [dB]);

BSIC;

Band indicator(DCS 1800 band used/PCS 1900 band used);

BCCH ARFCN(0~1023)

Cell selection and re-selection info(SIB11)

Qoffset1s,n，Qoffset2s,n，FDD Qqualmin，Qrxlevmin，GSM Qrxlevmin

Qqualmin=-14dB

Qoffset1s,n =0

Qoffset2s,n =0

For the purposes of GSM to UMTS cell reselection, GSM network shall not only configure 3G neighbor cells but also control parameters in Table 2-13 by broadcast them in SI 2quater.

Table 2-13 Parameters for GSM to UMTS cell reselection,

Parameter name


Qsearch_I Search for 3G cells if signal level is below (0-7) or above (8-15) threshold 0 = - 98 dBm, 1 = - 94 dBm, … , 6 = - 74 dBm,

7 = ∞ (always search 3G cells)

0-15 ∞ (always search 3G cells)


2-38

Parameter name


8 = - 78 dBm, 9 = - 74 dBm, … , 14 = - 54 dBm

15 = ∞ (never search 3G cells).

FDD_Qoffset Applies an offset to RLA_C for cell re-selection to access technology/mode FDD (one or more) 0 = - ∞ (always select a 3G cell if acceptable), 1 = -28 dB, 2 = -24 dB, … 7= - 4dB select 3G in case of 2G signal level is higher than 3G RSCP for FDD_Qoffset value;

8 = 0dB, 9= 4dB, 5 = 28 dB. select 3G in case of 2G signal level is lower than 3G RSCP for FDD_Qoffset value

0-15 0 dB.

FDD_Qmin A minimum threshold for Ec/No for UTRAN FDD cell re-selection,

0= -20dB, 1= -6dB, 2= -18dB, 3= -8dB, 4= -16dB, 5= -10dB, 6= -14dB, 7= -12dB.

0-7 -8dB

The MS shall then reselect a suitable UTRAN cell if its measured RSCP value exceeds the value of RLA_C for the serving cell and all of the suitable non-serving GSM cells by the value FDD_Qoffset for a period of 5 seconds and the UTRAN cells measured Ec/No value is equal or greater than the value FDD_Qmin.

In case of a cell reselection occurring within the previous 15 seconds, FDD_Qoffset is increased by 5 dB.

Cell reselection to UTRAN shall not occur within 5 seconds after the MS has reselected a GSM cell from an UTRAN cell if a suitable GSM cell can be found.

In order to reduce Ping-pong inter-RAT cell reselection and keep MS camping on 3G as much as possible, recommended value is listed above.

2) Technical guideline for Scenario II: UMTS to GSM: Same as Scenario I besides that equivalent PLMN shall be

included in Location Updating Accept message so that MS can use it as mentioned to camp on GSM system.

GSM to UMTS: Cell reselection could not be used in this direction if GSM can not support broadcast the UMTS information to MS. In order to ask MS turn back to UMTS cell, HPLMN selection shall be used.

Suppose UMTS PLMN is HPLMN for the user while GSM PLMN is VPLMN. If the MS is in a VPLMN, the MS shall periodically attempt to obtain service on its HPLMN. For this purpose, a value T minutes may be stored in the SIM, T is either in the range 6 minutes to 8 hours in 6 minute steps. Considering to making MS turn back UMTS as early as possible and save MS power consumption, 6 minutes are recommended.


2-39

VI. Standby Power Consumption

Standby power consumption is effected by following parameters:

The UE may use Discontinuous Reception (DRX) in idle mode in order to reduce power consumption. When DRX is used the UE needs only to monitor one Page Indicator, PI, in one Paging Occasion per DRX cycle.

The UE may use HPLMN timer to turn back to home network, the longer timer is, the less PLMN selection is made, which will reduce power consumption.

The UE may try LR when LR timer expired, the longer LR timer is, the less LR procedure is made, which will reduce power consumption.

The Larger LAC area is, the less does power consume. Power will be consumed faster when radio coverage hole is existed or when the

handsets is at the edge of cells.

2.6.2 Parameters

I. PLMN selection[6]

1) EFPLMNwAcT (User Controlled PLMN Selector with Access Technology)

This EF contains the coding for n PLMNs, where n is at least eight. This information is determined by the user and defines the preferred PLMNs of the user in priority order. The first record indicates the highest priority and the nth record indicates the lowest. The EF also contains the Access Technologies for each PLMN in this list.

Identifier: '6F60' Structure: transparent Optional

SFI: '0A'

File size: 5n (where n ≥ 8 bytes) Update activity: low

Bytes Description M/O Length

1 to 3 1st PLMN (highest priority) M 3 bytes

4 to 5 1st PLMN Access Technology Identifier M 2 bytes

6 to 8 2nd PLMN M 3 bytes

9 to 10 2nd PLMN Access Technology Identifier M 2 bytes

: :

36 to 38 8th PLMN M 3 bytes

39 to 40 8th PLMN Access Technology Identifier M 2 bytes

41 to 43 9th PLMN O 3 bytes

44 to 45 9th PLMN Access Technology Identifier O 2 bytes


2-40


: :

(5n-4) to (5n-2) Nth PLMN (lowest priority) O 3 bytes

(5n-1) to 5n Nth PLMN Access Technology Identifier O 2 bytes

PLMN: Mobile Country Code (MCC) followed by the Mobile Network Code (MNC).

Access Technology Identifier: 2 bytes are used to select the access technology where the meaning of each bit is as follows:

bit = 1: access technology selected; bit = 0: access technology not selected.

Byte5n-1:

RFU

RFU

RFU

RFU

RFU

RFU

RFU

UTRAN

Byte 5n:


2-41

RFU

RFU

RFU

RFU

RFU

RFU

GSM COMPACT

GSM

2) EFOPLMNwACT (Operator controlled PLMN selector with Access Technology)

This EF contains the coding for n PLMNs where n is determined by the operator. This information is determined by the operator and defines the preferred PLMNs in priority order. The first record indicates the highest priority and the nth record indicates the lowest. The EF also contains the Access Technologies for each PLMN in this list.


SFI: '11'

File size: 5n (where n ≥ 8 bytes) Update activity: low




: :

36 to 38 8th PLMN M 3 bytes

39 to 40 8th PLMN Access Technology Identifier M 2 bytes

41 to 43 9th PLMN O 3 bytes

44 to 45 9th PLMN Access Technology Identifier O 2 bytes

: :

(5n-4) to (5n-2) Nth PLMN (lowest priority) O 3 bytes


2-42

(5n-1) to 5n Nth PLMN Access Technology Identifier O 2 bytes

PLMN:Mobile Country Code (MCC) followed by the Mobile Network Code (MNC). Access Technology Identifier: See EFPLMNwACT for coding.

3) EFHPLMNwAcT (HPLMN selector with Access Technology)

The HPLMN Selector with access technology data field shall contain the HPLMN code, or codes together with the respected access technology in priority order.

Identifier: '6F62' Structure: Transparent Optional

SFI: '13'

File size: 5n (n ≥ 1) bytes Update activity: low




6 to 8 2nd PLMN O 3 bytes

9 to 10 2nd PLMN Access Technology Identifier O 2 bytes

: :

(5n-4) to (5n-2) nth PLMN (lowest priority) O 3 bytes

(5n-1) to 5n nth PLMN Access Technology Identifier O 2 bytes


Access Technology: The Access Technology of the HPLMN that the ME will assume when searching for the HPLMN, in priority order. The first Access Technology in the list has the highest priority. See EFPLMNwACT for coding.

4) EFFPLMN (Forbidden PLMNs)

This EF contains the coding for n Forbidden PLMNs (FPLMN). It is read by the ME as part of the USIM initialization procedure and indicates PLMNs which the UE shall not automatically attempt to access.

A PLMN is written to the EF if a network rejects a Location Update with the cause "PLMN not allowed". The ME shall manage the list as follows.

When n FPLMNs are held in the EF, and rejection of a further PLMN is received by the ME from the network, the ME shall modify the EF using the UPDATE command. This new PLMN shall be stored in the nth position, and the existing list "shifted" causing the previous contents of the first position to be lost.


2-43

When less than n FPLMNs exist in the EF, storage of an additional FPLMN shall not cause any existing FPLMN to be lost.

Dependent upon procedures used to manage storage and deletion of FPLMNs in the EF, it is possible, when less than n FPLMNs exist in the EF, for 'FFFFFF' to occur in any position. The ME shall analyse all the EF for FPLMNs in any position, and not regard 'FFFFFF' as a termination of valid data.

Identifier: '6F7B' Structure: transparent Mandatory

SFI: '0D'

File size: n*3 bytes (n>3) Update activity: low


1 to 3 PLMN 1 M 3 bytes




(3n-2) to 3n PLMN n O 3 bytes


For instance, using 246 for the MCC and 81 for the MNC and if this is stored in PLMN 3 the contents is as follows:

Bytes 7-9: '42' 'F6' '18'.

If storage for fewer than n PLMNs is required, the unused bytes shall be set to 'FF'.

5) EFHPLMN (HPLMN search period)

This EF contains the interval of time between searches for the HPLMN

Identifier: '6F31' Structure: transparent Mandatory

SFI: '12'

File size: 1 byte Update activity: low


1 Time interval M 1 byte


2-44

Time interval: the time interval between two searches. The time interval is coded in integer multiples of n minutes. The range is from n minutes to a maximum value. The value '00' indicates that no attempts shall be made to search for the HPLMN. The encoding is:

'00': No HPLMN search attempts; '01': n minutes; '02': 2n minutes; : : 'YZ': (16Y+Z)n minutes (maximum value).

All other values shall be interpreted by the ME as a default period.

Only the service provider shall be able to set the timer value. The timer shall have a value between 6 minutes and 8 hours, with a step size of 6 minutes. One value shall be designated to indicate that no periodic attempts shall be made

II. Cell Selection Parameters

Parameters Default value

Qqualmin -18dB

Qrxlevmin -115dBm

UE_TXPWR_MAX_RACH 24dBm

III. Cell Reselection Parameters

Parameters Default value

Sintrasearch 10dB

Sintersearch 8dB

SsearchRAT m 4dB

Qoffset1s,n 0 dB

Qoffset2s,n 0 dB

Qhyst1s 2dB

Qhyst2s 4dB

Treselections 1s


2-45

IV. Period Location Registration Parameter

Period Location Updating T3212 = 6 minutes,

Period Routing Area Updating T3312 = 54minutes.

2.6.3 Example

None

2.7 Reference Information

1) 3GPP, TS 22.011 "Service accessibility" 2) 3GPP, TS 23.122 "NAS Functions related to Mobile Station (MS) in idle mode" 3) 3GPP, TS 24.008 "Mobile radio interface layer 3 specification; Core Network

Protocols - Stage 3" 4) 3GPP, TS 25.304 "UE Procedures in Idle Mode and Procedures for Cell

Reselection in Connected Mode" 5) 3GPP, TS 25.331 "Radio Resource Control (RRC)" 6) 3GPP, TS 31.102 "Characteristics of the USIM Application"

Feature Description HUAWEI UMTS Radio Access Network Chapter 3 URA UPDATE

3-1

Chapter 3 URA UPDATE

3.1 Introduction

The URA update procedure serves several main purposes:

1) To be used as a supervision mechanism in the URA_PCH state by means of periodical URA update;

2) To update UTRAN with the current URA the UE is camping on after URA reselection.

3.2 Glossary

3.2.1 Terms

CELL_DCH: RRC connected mode in which DCCH and, if configured, DTCH are available. DCCH and DTCH are mapped to DCH. The RNC maintains current camping cell of UE.

CELL_FACH: RRC connected mode in which DCCH and, if configured, DTCH are available. DCCH and DTCH are mapped to RACH/FACH. The RNC maintains current camping cell of UE.

CELL_PCH: Neither DCCH nor DTCH are available. The RNC maintains current camping cell of UE.

URA_PCH: Neither DCCH nor DTCH are available. The RNC maintains current camping URA of UE.


DCCH Dedicated Control Channel

DCH Dedicated Channel

DTCH Dedicated Traffic Channel

FACH Forward Access Channel

RRC Radio Resource Control

IE Information element

RB Radio Bearer


MD Mandatory


3-2

3.3 Application

3.3.1 Availability


3.3.2 Benefit

After RRC connection is established successfully, in URA_PCH state, the RNC maintains UE’s current camping URA by means of URA UPDATE procedure. If the RNC receives RANAP PAGING message from the CN, the RNC only need send paging message in corresponding URA.


None


3.4.1 Type of URA UPDATE Procedure

URA UPDATE procedure can be grouped into following types:

1) Periodical URA update: Upon entering URA _PCH state, the UE starts timer T305. If the timer T305 expires, the UE performs URA update using the cause "periodic URA update". Correspondingly, the RNC starts timer T305 for UE in URA _PCH state. Upon receiving URA UPDATE message with cause as “periodical URA update”, the RNC restarts T305 of this UE.

2) URA reselection: if the UE is in URA _PCH state and the UE performs URA re-selection, the UE performs URA update using the cause " change of URA ". Upon receiving URA UPDATE message with cause as “change of URA”, the RNC updates camping URA of the UE.


3-3

3.4.2 Procedure

I. Basic Flow

UTRAN MOBILITY INFORMATION CONFIRM(Note 1)

UE

URA UPDATE

URA UPDATE CONFRIM

RNC

Figure 3-1 URA UPDATE Procedure

Note1: Response of URA UPDATE CONFIRM is optional, and if present, Response message of URA UPDATE CONFIRM is UTRAN MOBILITY INFORMATION CONFIRM.

II. Interaction with SRNS Relocation Procedure

This example shows Inter-RNS URA Update with switching in the CN (SRNS relocation).

SRNC DRNCSGSNUE

RELOCATION REQUIRED

EST PS RAB, in URA_PCH state

RELOCATION REQUEST

RELOCATION REQUEST_ACK

RELOCATION COMMAND

URA UPDATE CONFIRM

RELOCATION DETECT

RELOCATION COMPLETE

URA UPDATE

UPLINK SIGNALLING TRANSFER INDICATION

RELOCATION COMMIT

UTRAN MOBILITY INFORMATION CONFIRM

IU RELEASE COMMAND

IU RELEASE COMPLETE

Figure 3-2 URA UPDATE Procedure with SRNS relocation procedure

Parameters such as T305 are broadcast in SIB 1 and can be updated in UTRAN MOBILITY INFORMATION procedure.


3-4

3.5 Interaction

None

3.6 Implementation


To Tune the URA update functionality within UTRAN, configure all or parts of the parameters described in the following section.

3.6.2 Parameter

UE Timers and Constants in Connected Mode (T302, T305, T307, T314, T315, T317, N302) are broadcast in SIB 1 and can be modified by MML command “SET CONNMODETIMER”. Table 3-1 describes the parameters.

Table 3-1 Timers of connected mode

Information Element

Need Type and reference Semantics description

T301 MD Integer(100, 200 .. 2000 by step of 200, 3000, 4000, 6000, 8000)

Value in milliseconds. Default value is 2000. This IE should not be used by the UE in this release of the protocol.


N301 MD Integer(0..7) Default value is 2. This IE should not be used by the UE in this release of the protocol.





T304 MD Integer(100, 200, 400, 1000, 2000) Value in milliseconds. Default value is 2000. Three spare values are needed.





T307 MD Integer(5, 10, 15, 20, 30, 40, 50) Value in seconds. Default value is 30.


T308 MD Integer(40, 80, 160, 320) Value in milliseconds. Default value is 160.


3-5

Information Element



T310 MD Integer(40 .. 320 by step of 40) Value in milliseconds. Default value is 160.




N312 MD Integer (1, 2, 4, 10, 20, 50, 100, 200, 400, 600, 800, 1000)

Default value is 1.


N313 MD Integer (1, 2, 4, 10, 20, 50, 100, 200)


T314 MD Integer(0, 2, 4, 6, 8, 12, 16, 20) Value in seconds. Default value is 12.

T315 MD Integer (0,10, 30, 60, 180, 600, 1200, 1800)


N315 MD Integer (1, 2, 4, 10, 20, 50, 100, 200, 400, 600, 800, 1000)

Default value is 1.

T316 MD Integer(0, 10, 20, 30, 40, 50, infinity) Value in seconds. Default value is 30.


T317 MD Integer (0,10, 30, 60, 180, 600, 1200, 1800)

Value in seconds


3.6.3 Example

SET CONNMODETIMER: T305=D10;


1) 3GPP TS 25.331 "Radio Resource Control (RRC); protocol specification" 2) 3GPP TS 25.931 “UTRAN Functions, Examples on Signaling Procedures" 3) 3GPP TS 25.413 "UTRAN Iu interface RANAP signaling"

Feature Description HUAWEI UMTS Radio Access Network Chapter 4 CELL UPDATE

4-1

Chapter 4 CELL UPDATE

4.1 Introduction

The cell update procedure serves several purposes:

To be used as a supervision mechanism of UE in the CELL_FACH or CELL_PCH state by means of periodical cell update;

To update the RNC with the current cell the UE is camping on after cell reselection;

When triggered in the URA_PCH or CELL_PCH state, to notify the RNC of a transition to the CELL_FACH state due to the reception of UTRAN originated paging or due to a request to transmit uplink data;

To act on a radio link failure in the CELL_DCH state or RLC unrecoverable error on an AM RLC entity.

To act on the transmission failure of the UE CAPABILITY INFORMATION message.

4.2 Glossary

4.2.1 Terms

CELL_DCH state: RRC connected mode in which DCCH and, if configured, DTCH are available. DCCH and DTCH are mapped to DCH. The RNC maintains current camping cell of UE.

CELL_FACH state: RRC connected mode in which DCCH and, if configured, DTCH are available. DCCH and DTCH are mapped to RACH/FACH. The RNC maintains current camping cell of UE.

CELL_PCH state: Neither DCCH nor DTCH are available. The RNC maintains current camping cell of UE.

URA_PCH state: Neither DCCH nor DTCH are available. The RNC maintains current camping URA of UE.


DCCH Dedicated Control Channel


DTCH Dedicated Traffic Channel




4-2

IE Information Element

RB Radio Bearer


4.3 Application

4.3.1 Availability


4.3.2 Benefit

After RRC connection is established successfully, the RNC maintains UE’s current camping cell by means of CELL UPDATE procedure. If the RNC receives RANAP PAGING message from the CN, the RNC only need send paging message in corresponding cell.

CELL UPDATE procedure in CELL_DCH state enables the UE to re-establish RRC connection after radio link failure.


None


4.4.1 Type of CELL UPDATE Procedure

CELL UPDATE procedure can be grouped into following types:

1) Periodical cell update: Upon entering CELL_FACH or CELL_PCH state, the UE starts timer T305. If the timer T305 expires, the UE performs cell update using the cause "periodical cell update". Correspondingly, the RNC starts timer T305 for UE in CELL_FACH or CELL_PCH state. Upon receiving CELL UPDATE message with cause as “periodical cell update”, the RNC restarts T305 of this UE.

2) Cell reselection: if the UE is in CELL_FACH or CELL_PCH state and the UE performs cell re-selection, the UE performs cell update using the cause "cell reselection". Upon receiving CELL UPDATE message with cause as “cell reselection”, the RNC updates camping cell of the UE.

3) Paging response: if the UE in URA_PCH or CELL_PCH state, receives a PAGING TYPE 1 message, the UE performs cell update using the cause "paging response". Upon receiving CELL UPDATE message with cause as “paging response”, the RNC shall send CELL UPDATE CONFIRM message to the UE and transit UE’s state to CELL_FACH.


4-3

4) Uplink data transmission: if the UE in URA_PCH or CELL_PCH state has uplink RLC data PDU or uplink RLC control PDU on RB1 or upwards to transmit, the UE performs cell update using the cause "uplink data transmission". Upon receiving CELL UPDATE message with cause as “uplink data transmission”, the RNC shall send CELL UPDATE CONFIRM message to the UE and transit UE’s state to CELL_FACH.

5) Radio link failure: if the UE is in CELL_DCH state and the criteria for radio link failure is met, the UE performs cell update using the cause "radio link failure". Because of radio link failure, the RNC shall delete current radio link, establish new radio link and send CELL UPDATE CONFIRM to the UE including parameter of new radio link, then the UE can re-establish RRC connection on new radio link.

6) Re-entering service area: if the UE runs out of service area, and then re-enter service area, the UE performs cell update using the cause "Re-entering service area". Upon receiving CELL UPDATE message with cause as “Re-entering service area”, the RNC updates camping cell of the UE.

7) RLC unrecoverable error: if the UE detects RLC unrecoverable error in an AM RLC entity, the UE performs cell update using the cause "RLC unrecoverable error". If CELL UPDATE message indicates AM_RLC unrecoverable error occurred on RB2, RB3 or RB4 in the UE, the RNC shall release RRC connection of the UE. If CELL UPDATE message indicates AM_RLC unrecoverable error occurred on RB>4 in the UE, the RNC shall re-establish RLC entity of corresponding RB.

4.4.2 Procedure

I. Basic Flow

Figure 4-1 illustrates the basic flow of CELL UPDATE procedure.

UECELL UPDATE

CELL UPDATE CONFRIM

RESPONSE MESSAGE

RNC

Figure 4-1 Basic flow of CELL UPDATE procedure

1) To initiate CELL UPDATE procedure, the UE send CELL UPDATE message to the RNC, and indicates cause of this CELL UPDATE procedure in “Cell update cause” IE.


4-4

2) RNC takes action according to the “Cell update cause” IE of the CELL UPDATE message as described in 4.4.1 "Type of CELL UPDATE Procedure”.

3) The RNC sends CELL UPDATE CONFIRM message to the UE. 4) Response of CELL UPDATE CONFIRM is optional, and if present, response

message may be the follows: UTRAN MOBILITY INFORMATION CONFIRM PHYSICAL CHANNEL RECONFIGURATION COMPLETE TRANSPORT CHANNEL RECONFIGURATION COMPLETE RADIO BEARER RECONFIGURATION COMPLETER RADIO BEARER RELEASE COMPLETE

II. Interaction with Other RRC Procedure

CELL UPDATE may interact with other RRC procedure including:

SECURITY MODE COMMAND RADIO BEARER SETUP RADIO BEARER RECONFIGURATION RADIO BEARER RELEASE PHYSICAL CHANNEL RECONFIGURATION HANDOVER from UTRAN COMMAND

As an example, Figure 4-2 illustrates the CELL UPDATE interacting with RADIO BEARER RELEASE.

UE

CELL UPDATE(New Cell)

CELL UPDATE CONFRIM(New Cell)

PHYSICAL CHANNEL RECONFIGURATOINCOMPLETE(New Cell)

RNC

RADIO BEARER RELEASE

RADIO BEARER RELEASE COMPLETE(New Cell)

Figure 4-2 CELL UPDATE interacts with RADIO BEARER RELEASE

As shown in Figure 4-2, in RADIO BEARER RELEASE procedure, if the UE reselects a new cell after receiving RADIO BEARER RELEASE message, the UE shall initiate CELL UPDATE procedure and then RADIO BEARER RELEASE procedure shall be continued in new cell.


4-5

III. Interaction with SRNS Relocation Procedure

The example in Figure 4-3 shows Inter-RNS Cell Update with SRNS relocation.

1) The UE sends CELL UPDATE to the RNC, after having made cell re-selection. Upon reception of a CCCH message from a UE, target RNC allocates a C-RNTI for the UE.

2) Controlling target RNC forward the received message (on CCCH) via Uplink Signalling Transfer Indication RNSAP message towards the SRNC. Message includes, besides target RNC-ID, also the allocated C-RNTI, which is to be used as UE identification within the C-RNC, and the D-RNTI. Upon reception of the RNSAP message, SRNC decides to perform SRNS Relocation towards the target RNC.

3) Serving RNC relocation procedure is executed. After completing SRNS Relocation, target RNC allocates a new S-RNTI for the UE, and becomes the new serving RNC.

4) Target RNC responds to UE by RRC Cell Update Confirm, including old S-RNTI and SRNC ID as UE identifiers. Message contains also the new S-RNTI, SRNC-ID and C-RNTI.

5) UE acknowledges the RNTI reallocation by sending the RRC message PHYSICAL CHANNEL RECONFIGURATION COMPLETE.

SRNC DRNCSGSNUE

RELOCATION REQUIRED

EST PS RAB, in CELL_FACH CELL_PCH or URA_PCH state

RELOCATION REQUEST

RELOCATION REQUEST_ACK

RELOCATION COMMAND

CELL UPDATE CONFIRM

RELOCATION DETECT

RELOCATION COMPLETE

CELL UPDATE

UPLINK SIGNALLING TRANSFER INDICATION

RELOCATION COMMIT

PHYSICAL CHANNEL RECONFIGURATION COMPLETE

IU RELEASE COMMAND

IU RELEASE COMPLETE

Figure 4-3 Cell Update with SRNS Relocation

4.5 Interaction

None


4-6

4.6 Implementation


To Tune the Cell Update functionality within UTRAN, configure all or parts of the parameters described in the following section.

4.6.2 Parameter

UE Timers and Constants in Connected Mode(T302, T305, T307, T314, T315, T317, N302) are broadcast in SIB 1 and can be modified by MML command “SET CONNMODETIMER”. Table 4-1 describes the parameters.

Table 4-1 Timers of connected mode

Information Element


T301 MD Integer(100, 200 .. 2000 by step of 200, 3000, 4000, 6000, 8000)

Value in milliseconds. Default value is 2000. This IE should not be used by the UE in this release of the protocol.


N301 MD Integer(0..7) Default value is 2. This IE should not be used by the UE in this release of the protocol.





T304 MD Integer(100, 200, 400, 1000, 2000) Value in milliseconds. Default value is 2000. Three spare values are needed.





T307 MD Integer(5, 10, 15, 20, 30, 40, 50) Value in seconds. Default value is 30.


T308 MD Integer(40, 80, 160, 320) Value in milliseconds. Default value is 160.




4-7

Information Element





N312 MD Integer (1, 2, 4, 10, 20, 50, 100, 200, 400, 600, 800, 1000)

Default value is 1.


N313 MD Integer (1, 2, 4, 10, 20, 50, 100, 200)


T314 MD Integer(0, 2, 4, 6, 8, 12, 16, 20) Value in seconds. Default value is 12.

T315 MD Integer (0,10, 30, 60, 180, 600, 1200, 1800)


N315 MD Integer (1, 2, 4, 10, 20, 50, 100, 200, 400, 600, 800, 1000)

Default value is 1.

T316 MD Integer(0, 10, 20, 30, 40, 50, infinity) Value in seconds. Default value is 30.


T317 MD Integer (0,10, 30, 60, 180, 600, 1200, 1800)

Value in seconds


4.6.3 Example

SET CONNMODETIMER: T305=D10;


1) 3GPP TS 25.331 "Radio Resource Control (RRC); protocol specification" 2) 3GPP TS 25.931 "UTRAN Functions, Examples on Signaling Procedures" 3) 3GPP TS 25.413 "UTRAN Iu interface RANAP signaling"

Feature Description HUAWEI UMTS Radio Access Network Chapter 5 Soft Handover

5-1

Chapter 5 Soft Handover

5.1 Introduction

Soft handover was introduced by CDMA technology. Soft handover is different from the traditional hard handover process. Hard handover happens on a time point, while soft handover lasts for a period of time.

With hard handover, a definite decision is made on whether to handover or not and the mobile terminal only communicates with one cell at a time.

With soft handover, a conditional decision is made on whether to handover or not, depending on the changes in pilot signal strength from two or more cells involved. A decision will eventually be made to communicate with only one and this normally happens after it is clear that the signal coming from one cell is considerably stronger than those come from others. In the interim period of soft handover, the UE communicates with all the cells in the active set simultaneously.

Figure 5-1 shows the basic process of hard handover and soft handover. Assuming there is a UE in a car moving from cell 1 to cell 2, Cell1 is the mobile’s original serving Cell. While moving, the UE continuously measures the pilot signal strength received from the nearby cells. With hard handover shown in Figure 5-1, the trigger of the handover can be simply described as:

if (Pilot Ec/I0)cell2 - (Pilot Ec/I0)cell1 > Hm, and cell1is the serving cell

handover to Cell2

else

do not handover

end

Where:

(pilot_ Ec/I0)cell1 and (pilot_ Ec/I0)cell2 are the received pilot Ec/I0 from Cell1 and Cell2 respectively.

Hm is the hysteresis margin.


5-2

Cell 1 Cell 2

Cell 1

Cell 1

Cell 2

Cell 2Sof t handov er

Hard handov er

(Pilot Ec/Io) Cell 1 (Pilot Ec/Io) Cell 2

Figure 5-1 Comparison between hard and soft handover

The reason for introducing the hysteresis margin in the hard handover algorithm is to avoid a “ping-pong effect”, the phenomenon that when a UE moves in and out of the cell’s boundary, frequent hard handovers occur. Apart from the mobility of the UE, fading effects of the radio channel can also make the “ping-pong” effect more seriously. By introducing the hysteresis margin, you can mitigate the “ping-pong” effect because the UE does not handover immediately to the better cell. The bigger the margin is, the less the “ping-pong” effects. However, a big margin introduces more delay. Moreover, the UE causes extra interference to neighboring cells due to the poor quality link during the delay. Therefore, for hard handover, the value of the hysteresis margin is fairly important. When hard handover occurs, the original traffic link with Cell1 is dropped before the setting up of the new link with Cell2.

In the case of soft handover, shown in Figure 5-1, before (pilot_ Ec/I0)cell2 goes beyond (pilot_ Ec/I0)cell1, as long as the soft handover trigger condition is fulfilled, the UE enters the soft handover state and a new link is set up. Before handover-dropping condition is fulfilled and link to Cell1 is dropped, the UE communicates with both Cell1 and Cell2 simultaneously.

The soft handover process is not the same in the uplink and downlink transmission directions. As shown in Figure 5-2, in the uplink, the UE transmits the signals to the air through its omnidirectional antenna. The two cells in the active set receive the signals simultaneously. Then, the signals are passed forward to the RNC for selection combining. The better frame is selected and the other is discarded. Therefore, in the uplink, there is no extra channel needed to support soft handover.


5-3

RNC

NodeB NodeB

UE

No extra uplink channel needed f or SHO,Selection combination in RNC.

Extra downlink channels,Maximum ratio combining in UE

Figure 5-2 Principles of soft handover (2-way case)

In the downlink, the same signals are transmitted through both cells and the UE can coherently combine the signals from the two cells since UE hears them as just additional multipath components. Normally maximum ratio combining (MRC) algorithm is used, which provides an additional benefit called macro diversity gain. However, to support soft handover in the downlink, at least one extra downlink channel is needed in case of 2-way SHO. This extra downlink channel is additional interference for other users in the air interface. Thus, to support soft handover in the downlink, more resource is required. As a result, in the downlink direction, the performance of the soft handover depends on the trade-off between the macro diversity gain and the extra resource consumption.

Compared to the traditional hard handover, soft handover shows some obvious advantages, such as eliminating the “ping-pong” effect, and no break point in soft handover. No “Ping-Pong” effect means lower load on the network signaling and with soft handover, there is no data loss due to the momentary transmission break that happens in hard handover.

Apart from handling mobility, there is another reason for implementing soft handover in CDMA. Together with power control, soft handover is also used as an interference-reduction mechanism. Figure 5-3 shows two scenarios. For hard handover, only power control is applied; for soft handover, power control combining with soft handover is supported. Assume that the UE is moving from Cell1 towards Cell2. At the current position, the pilot signal the UE received from Cell2 is already stronger than that from Cell1. This means Cell2 is “better” than Cell1.


5-4

Cell 1 Cell 2

RNC

HHO

SHO

UE transmit power

Figure 5-3 Interference-reduction by SHO in UL

In hard handover, the power control loop increases the UE transmit power to guarantee the QoS in the uplink when the UE moves away from its serving Cell, Cell1. In soft handover, the UE is in soft handover status: Cell1 and Cell2 both hear the UE simultaneously. The received signals, then, are passed forward to the RNC for combining. In the uplink direction, selection combining is used in soft handover. The stronger frame is selected and the weaker one is discarded. Because Cell2 is “better” than Cell1, to meet the same QoS target, the required transmit power from the UE is lower compared to the power (shown in pink) needed in scenario of hard handover. Therefore, the interference contributed by this UE in the uplink is lower under soft handover because soft handover always keeps the UE linked to the best cell.

In the downlink direction, the situation is more complicated. Although the maximum ratio combining algorithm gives macro diversity gain, extra downlink channels are needed to support soft handover.

5.2 Glossary

5.2.1 Terms

None


ALCAP Access Link Control Application Part

3G 3rd Generation

3GPP 3rd Generation Partnership Project (produces WCDMA


5-5

standard)

CN Core Network

DL Downlink

DRNC Drift RNC

DS-CDMA Direct-Sequence Code Division Multiple Access

FDD Frequency Division Duplex

HHO Hard Handover

HO Handover

IE Information Element

MS Mobile Station

PC Power Control

RNC Radio Network Controller

RRM Radio Resource Management

SHO Soft Handover

SIR Signal to Interference Ratio

SRNC Serving RNC

TPC Transmit Power Control

UE User Equipment

UL Uplink

UTRAN UMTS Terrestrial Radio Access Network

WCDMA Wideband Code Division Multiple Access

5.3 Application

5.3.1 Availability



5-6

5.3.2 Benefit

1) Eliminate the “ping-pong” effect, leading to reduced load on the network signaling and overhead

2) Smoother transmission with no momentary stop during soft handover 3) Reduced overall uplink interference, leading to:

Better communication quality for a given number of users More users (greater capacity) for the same required QoS


Soft handover involves the following limitation:

1) More complexity in implementation than hard handover 2) Additional network resources are consumed in the downlink direction (code

resource and power resource)


5.4.1 Handover Measurements and Procedures

As illustrated in Figure 5-4, the handover procedure can be divided into three phases:

Measurement phase Decision phase Execution phases

In the handover measurement phase, the necessary information needed to make the handover decision is measured. Typical downlink measurements performed by UEs are the Ec/Io of the common pilot channel (CPICH) of its serving cell and neighboring cells. In WCDMA FDD, the relative timing variance between the cells needs to be measured in order to adjust the transmission timing in soft handover to allow coherent combining in the Rake receiver. Otherwise, the transmissions from the different NodeBs would be difficult to combine and the power control in soft handover would suffer additional delay.


5-7

Measurement for handover decision, Including: •Ec/I0 of the CPICH of the serving and neighboring cells,•the relative timing variance between the cells

•Perform handover process•Update relative parameters

Decision phase

Execution phase

Measurement phase

y es

NoIs handover criteria satisfied?

Figure 5-4 Handover procedures

In the handover decision phase, the measurement results are compared against the predefined thresholds and then it is decided whether to initiate the handover or not. Different handover algorithms have different trigger conditions.

In the execution phase, the handover process is completed and the relative parameters are changed according to the different types of handover. For example, in the execution phase of the soft handover, the UE enters or leaves the soft handover state, a new NodeB is added or released, the active set is updated and the power of each channel involved in soft handover is adjusted.

5.4.2 Example of a Soft Handover Algorithm

This section presents an example of soft handover algorithm, which exploits reporting events 1A, 1B, and 1C. It also exploits the hysteresis mechanism and the time to trigger mechanism.

For the description of the soft handover algorithm presented in this section the following parameters are needed:

AS_Th: Threshold for macro diversity (reporting range); AS_Th_Hyst: Hysteresis for the above threshold; AS_Rep_Hyst: Replacement Hysteresis; ßT: Time to Trigger; AS_Max_Size: Maximum size of Active Set.

Figure 5-5 describes this Soft Handover Algorithm.


5-8

Cell 1 Connected Ev ent 1A⇒ Add Cell 2

Ev ent 1C ⇒ Replace Cell 1

with Cell 3

Ev ent 1B ⇒Remov e Cell 3

CPICH 1

CPICH 2

CPICH 3

Ti me

Measurement Quantity ∆T ∆T ∆T

As_Th + As_Th_Hy s

As_Rep_HystAS_Th –AS_Th_Hy st

Figure 5-5 Example of Soft Handover Algorithm

Figure 5-6 shows a flow-chart of the above described Soft Handover algorithm.

Meas_Sign > Best_Ss– As_Th –as_Th_H yst

for a period of ßT

Yes

Yes(Event 1B)

Meas_Sign >Best_Ss –As_Th + as_Th_H yst

for a period of ∆ TNo

Yes(Event 1A)

Add Best_Cellin the Acti ve Set

Best_C and_Ss > Worst_Old_Ss +

As_Rep_H ystfor a period of ßT

Yes(Event 1C)

No

Active Set F ull

No

Yes

Begin

Add Best Cell in Ac tive Set and Remove Worst Cell

from the Acti ve Set

Remove Worst_Bsin the Acti ve Set

Figure 5-6 A flow-chart of Soft Handover algorithm

As described in Figure 5-5 and Figure 5-6:


5-9

If Meas_Sign is below (Best_Ss - As_Th - As_Th_Hyst) for a period of ßT remove Worst cell in the Active Set.

If Meas_Sign is greater than (Best_Ss - As_Th + As_Th_Hyst) for a period of ßT and the Active Set is not full add Best cell outside the Active Set in the Active Set.

If Active Set is full and Best_Cand_Ss is greater than (Worst_Old_Ss + As_Rep_Hyst) for a period of ßT add Best cell outside Active Set and Remove Worst cell in the Active Set.

Where:

Best_Ss: the best measured cell present in the Active Set; Worst_Old_Ss: the worst measured cell present in the Active Set; Best_Cand_Ss: the best measured cell present in the monitored set; Meas_Sign: the measured and filtered quantity.

5.4.3 Typical Soft Handover signaling procedures

There are three types of soft handover:

soft handover or softer handover within a NodeB inter NodeB soft handover within a RNC inter RNC soft handover

I. Soft handover or Softer Handover within a NodeB

Before soft handover After soft handoverIn soft handover

CN

SRNC

NodeB

CELL1 CELL2

CN

SRNC

NodeB

CN

SRNC

NodeB

CELL1 CELL2 CELL1 CELL2

Figure 5-7 soft handover or softer handover within a NodeB

Figure 5-7 shows the soft handover procedure when a UE moves from one cell to another cell. The two cells belong to the same NodeB, and soft handover or softer handover happens between these two cells. Before handover the cell1 have connection with the UE, in handover two cells have connections with UE, after handover the cell2 have connection with UE. The active set of cell1 is removed by network. Whether soft handover or softer handover happens depend on the IUB NBAP IE: Diversity Control Field.


5-10

Figure 5-8 illustrates soft handover or softer handover signaling procedure within a NodeB before soft handover and in soft handover.

UE Node B SRNC

NBAP1. Radio Li nk Addition RequestNBAP

NBAP2. Radio Li nk Addition ResponseNBAP

Start RX

Start TX

RRC

RRC

RRC

RRC

6.DCCH: Acti ve Set Update Command

7. DCCH : Acti ve Set Update Complete

Decision to setupnew RL

3 ALC AP Iub D ata Transport Bearer Setup (SHO)

DCH-FP4. Downlink Synchronization (SHO)DCH-FP

DCH-FP5.Uplink Synchronization (SHO)DCH-FP

Figure 5-8 Soft or softer handover signaling procedure within a NodeB before and in handover

1) SRNC makes a soft handover decision. The decision usually depends on the measurement report from the UE. For example, UE send a 1A measurement report along with information, such as scramble code, time differences information of the target cell. This report triggers the soft handover decision. If the requirements for soft handover are satisfied, SRNC sends NBAP message Radio Link Addition Request message to NodeB.

If the Diversity Control Field IE is set to "Must", the Node B shall combine the RL with one of the other RL, softer handover (SHO) is triggered.

If the Diversity Control Field IE is set to "Must not", the Node B shall not combine the RL with any other existing RL, soft handover is triggered.

If the Diversity Control Field IE is set to "May", it is for NodeB to decide whether soft or softer handover be triggered.

2) Node B configures its physical channel in the target cell and starts receiving the signal from the UE to achieve UL synchronization. Then NodeB send Radio Link Addition Response to SRNC. RNC knows whether the RL is combined or not by Radio Link Addition Response message.

3) For soft handover (SHO), SRNC establishes ALCAP DATA IUB Transport Bearer between SRNC and NodeB for the new connection. Softer handover does not need this procedure.


5-11

4) For soft handover, SRNC sends downlink synchronization frame to NodeB via the new ALCAP DATA IUB Transport Bearer. Softer handover does not need this procedure.

5) For soft handover case: NodeB sends uplink synchronization frame to SRNC via the new ALCAP DATA IUB Transport Bearer. Softer handover does not need this procedure. NodeB starts DL transmission.

6) SRNC sends RRC message Active Set Update (Radio Link Addition) to UE on DCCH.

7) UE acknowledges with RRC message Active Set Update Complete.

Figure 5-9 illustrates soft handover signaling procedure within a NodeB after soft handover.

Decision to delete a RL

UE NodeB SRNC

NBAP3. Radio Li nk Deleti on RequestNBAP

NBAP4. Radio Li nk Deleti on ResponseNBAP

RRC

RRC

RRC

RRC

Stop RX and Tx



5 ALC AP Iub Transport Bearer release (SHO)

Figure 5-9 soft handover or softer handover signaling procedure within a NodeB(after handover)

1) SRNC decides to remove a radio link. SRNC sends RRC message Active Set Update (Radio Link Deletion) to UE on DCCH.

2) UE deactivates DL reception via old branch, and acknowledges with RRC message Active Set Update Complete.

3) SRNC sends NBAP message Radio Link Deletion Request to NodeB. 4) NodeB deallocates radio resources. Successful outcome is reported in NBAP

message Radio Link Deletion Response. 5) For soft handover, SRNC initiates release of Iub Data Transport Bearer using

ALCAP protocol. Softer handover does not need this procedure.

There is not signaling procedure difference between soft handover and softer handover from the UE point of view.


5-12

II. Inter NodeB Soft Handover within a RNC

Figure 10 shows the soft handover procedure when a UE moves from one cell to another cell which is within the same RNC but different NodeB. The IUB connection is changed between RNC and NodeB during soft handover.

Before soft handover After soft handover

CN

SRNC

CN CN

SRNC

In soft handover

NodeB1 NodeB2 NodeB1 NodeB2

SRNC

NodeB1 NodeB2

Figure 5-10 soft handover within a RNC

Figure 5-11 illustrates soft handover signaling procedure within a RNC before soft handover and in soft handover.

UE NodeB (new) SRNC

NBAP1. Radio Li nk Setup Reques tNBAP

NBAP2. Radio Li nk Setup ResponseNBAP

3 ALC AP Iub D ata Transport Bearer Setup

Start RX

DCH-FP4. Downlink SynchronizationDCH-FP

DCH-FP5.Uplink SynchronizationDCH-FP

Start TX

RRC

RRC

RRC

RRC



Decision to setupnew RL

Figure 5-11 soft handover signaling procedure within a RNC(before handover and in handover)

1) SRNC decides to setup a radio link via a new cell of another NodeB. SRNC sends NBAP message Radio Link Setup Request message to NodeB.


5-13

2) NodeB configures its physical channel, starts receiving the signal from the UE to achieve UL synchronization, then NodeB send Radio Link Setup Response to SRNC.

3) SRNC establishes ALCAP DATA IUB Transport Bearer between SRNC and NodeB for the new connection.

4) SRNC sends downlink synchronization frame to NodeB via the new ALCAP DATA IUB Transport Bearer.

5) NodeB sends uplink synchronization frame to SRNC via the new ALCAP DATA IUB Transport Bearer. NodeB starts DL transmission.

6) SRNC sends RRC message Active Set Update (Radio Link Addition) to UE on DCCH.

7) UE acknowledges with RRC message Active Set Update Complete.

Figure 5-12 illustrates soft handover signaling procedure within a RNC after soft handover.

Decision to delete a RL

UE NodeB (old) SRNC

NBAP3. Radio Li nk Deleti on RequestNBAP

NBAP4. Radio Li nk Deleti on ResponseNBAP

RRC

RRC

RRC

RRC

Stop RX and Tx



5 ALC AP Iub Transport Bearer release

Figure 5-12 Soft handover signaling procedure within a RNC after handover

1) SRNC decides to remove a radio link. SRNC sends RRC message Active Set Update (Radio Link Deletion) to UE on DCCH.

2) UE deactivates DL reception via old branch, and acknowledges with RRC message Active Set Update Complete.

3) SRNC sends NBAP message Radio Link Deletion Request to NodeB. NodeB stop its UL reception and downlink transmission.

4) NodeB deallocates radio resources. Successful outcome is reported in NBAP message Radio Link Deletion Response.

5) SRNC initiates release of Iub Data Transport Bearer using ALCAP protocol.


5-14

III. Inter RNC Soft Handover

Figure 13 shows the soft handover procedure when a UE moves from one cell to another cell which belongs to another RNC. There is IUR connection establishment between SRNC and DRNC during soft handover. It is a complex example: UE already have two connections with two NodeB, after SRNC decide to do a soft handover, SRNC establishes a new connection toward UE via another RNC and remove the old connection of left-side NodeB. A normal simple signaling procedure is :

1) First establishes a new connection toward UE via another RNC. 2) Then remove the old connection toward UE. 3) The IUR connection still exits until a RNC relocation procedure happens.

Before soft handover After soft handover

CN CN

NodeB1 NodeB2

SRNC RNC

NodeB2 NodeB1 NodeB2

SRNC DRNC

NodeB2

Figure 5-13 soft handover inter RNC

Figure 5-14 illustrates inter RNC soft handover signaling procedure


5-15

1. Radio Li nk Setup Reques t

4. Radio Li nk Setup Response

2. Radio Li nk Setup RequestRNSAP

RNSAP

NBAP

NBAP

NBAP

NBAP

Start RX

Decision to setup new RL and release old RL

10. Radi o Link Deletion R equest

11. R adio Link Rel ease Response

NBAP

NBAP

Stop RX and TX

12. ALCAP Iub Data Transport Bearer Release

RRC 9. DCCH : Acti ve Set Update Complete

RRC8. DCCH: Acti ve Set Update Command

[Radio Link Addition & Deletion]

UE NodeB of DRNS NodeB of SRNS Drift RNC Servi ng RNC

ALCAP Iur Bearer Setup5. ALCAP Iub Data Transport Bearer Setup

RNSAP

RNSAP

NBAP

RRC

RRC

NBAP

DCH-FP

DCH-FP

Start TX

DCH-FP

DCH-FP

6. Downlink Synchronization

7. Uplink Synchr onizati on

3. Radio Li nk Setup Response

Figure 5-14 Inter RNC soft handover signaling procedure

4) SRNC decides to setup a radio link via a new cell controlled by another RNC. SRNC requests DRNC for radio resources by sending RNSAP message Radio Link Setup Request.

5) If requested resources are available, DRNC sends NBAP message Radio Link Setup Request to NodeB.

6) NodeB allocates requested resources. Successful outcome is reported in NBAP message Radio Link Setup Response.

7) DRNC sends RNSAP message Radio Link Setup Response to SRNC. 8) SRNC initiates setup of Iur/Iub Data Transport Bearer using ALCAP protocol.

This request contains the AAL2 Binding Identity to bind the Iub Data Transport Bearer to DCH.

9) 6/7. NodeB and SRNC establish synchronism for the Data Transport Bearer(s) by means of exchange of the appropriate DCH Frame Protocol frames Downlink Synchronization and Uplink Synchronization, relative already existing radio link(s). Then NodeB starts DL transmission.

10) SRNC sends RRC message Active Set Update (Radio Link Addition & Deletion) to UE on DCCH.

11) UE deactivates DL reception via old branch, activates DL reception via new branch and acknowledges with RRC message Active Set Update Complete.


5-16

12) SRNC sends NBAP message Radio Link Deletion Request to NodeB. NodeB stop its UL reception and downlink transmission.

13) NodeB deallocates radio resources. Successful outcome is reported in NBAP message Radio Link Deletion Response.

14) SRNC initiates release of Iub Data Transport Bearer using ALCAP protocol.

5.5 Interaction

None

5.6 Implementation


Adjacent cell planning and configuration must be made carefully. Intra frequency Neighboring cells should be configured so that the UE can measure the adjacent cells when needed and can handover to the cell in SHO mode.

5.6.2 Parameter

I. Add Intra-frequency Neighboring Cell

1) RNC Command: ADD INTRAFREQCELL 2) Parameters:

ID Name Description

CELLID Cell ID Value range: 0~65535

Physical unit: None

Content: Uniquely identifying a cell.

Recommended value: None

RNCID RNC ID of neighboring cell

Value range: 0~4095

Physical unit: None

Content: Uniquely identifying an RNC.


NCELLID Neighboring cell ID

Value range: 0~65535

Physical unit: None

Content: Uniquely identifying a neighboring cell.


READSFNIND Read SFN indication

Value range: NOT_READ, READ

Physical unit: None


5-17

ID Name Description

Content: Indicating whether to read the destination cell SFN.

Recommended value: NOT_READ

CELLINDIVIDALOFFSET

Cell offset Value range: -20~20

Physical value range: -10~10; step: 0.5

Physical unit: dB

Content: Cell CPICH offset. The sum of this parameter value and the actual value can be used for UE event evaluation. In the handover algorithm, it can be used to change the cell edge. It is configured based on the actual environment during network planning.

Recommended value: 0

CELLSFORBIDDEN1A

Affect 1A threshold flag

Value range: NOT_AFFECT, AFFECT

Physical unit: None

Content: Indicating whether the cell will affect the event 1A relative threshold if it is added into the active set.

Recommended value: AFFECT

CELLSFORBIDDEN1B

Affect 1B threshold flag

Value range: NOT_AFFECT, AFFECT

Physical unit: None

Content: Indicating whether the cell will affect the event 1B relative threshold if it is added into the active set.

Recommended value: AFFECT

3) Example

Add an intra-frequency neighboring cell to a cell:

ADD INTRAFREQCELL: CELLID=1, RNCID=9, NCELLID=100, READSFNIND=READ, CELLINDIVIDALOFFSET=0, CELLSFORBIDDEN1A=AFFECT, CELLSFORBIDDEN1B=AFFECT,;

After the above operation, the cell 100 of RNC 9 is configured as the intra-frequency neighboring cell of the cell 1:

The cell SFN need be read. The cell will affect the event 1A/1B relative thresholds if it is added into the active

set.

II. Add Set RNC Oriented Handover Algorithm Common Parameters

1) RNC Command: SET HOCOMM 2) Parameters


5-18

ID Name Description

MAXCELLINACTIVESET

Max number of cells in active set

Value range: 1~3

Physical unit: none

Content: The maximum number of cells in active set. This parameter is decided by the product specification. Modification is not suggested.


DIVCTRLFIELD Softer handover combination indication switch

Value range: MAY, MUST, MUST_NOT

Physical value range: MAY, MUST, MUST NOT

Physical unit: none

Content: The indicator for the NodeB to do softer combination. If it's set to "MAY", the NodeB can decide whether to do softer combination (the softer combination can be done for the radio links in different cells in the same NodeB). If it's set to "MUST", the NodeB is forced to do softer combination for the radio links in different cells. If it's set to "MUST NOT", the NodeB is not allowed to do softer combination.

Recommended value: MAY

SHOMETHOD SHO method Value range: SHO_METHOD1, SHO_METHOD2

Physical unit: none

Content: There are two soft handover algorithms in this version. Method 1 refers to a loose mode algorithm, which will add a cell into the active set when the event 1A or 1E is received, and delete a cell from the active set only when the events 1B and 1F are received simultaneously. Method 2 refers to a relative threshold algorithm, which will not use the event 1E or 1F, but only use the event 1A for adding a cell, and use the event 1B for removing a cell.

Recommended value: SHO_METHOD2

3) Example:

Set soft handover algorithms to Method 1:

SET HOCOMM: SHOMETHOD=SHO_METHOD1;

After the above operation, the whole RNC ‘s SHO Method is configured as Method 1.


5-19

III. Set RNC Oriented Intra-frequency Handover Measurement Algorithm Parameters

1) RNC Command: SET INTRAFREQHO 2) Parameters

ID Name Description

FILTERCOEF Intra-freq meas L3 filter coeff

Value range: D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D11, D13, D15, D17, D19

Physical value range: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 15, 17, 19

Physical unit: None

Content: The intra-frequency measurement L3 filter coefficient. The greater this parameter is set, the greater the smoothing effect and the higher the anti fast fading capability, but the lower the signal change tracing capability.

Recommended value: D5

PERIODMRREPORTNUMFOR1A

1A event to periodical rpt number

Value range: D1, D2, D4, D8, D16, D32, D64, infinity

Physical value range: 1, 2, 4, 8, 16, 32, 64, infinity

Physical unit: times

Content: The periodical reporting times for the event 1A. When the actual times exceed this parameter, the periodical reporting comes to an end.


REPORTINTERVALFOR1A

1A event to periodical rpt period

Value range: NON_PERIODIC_REPORT, D250, D500, D1000, D2000, D4000, D8000, D16000

Physical value range: NON_PERIODIC_REPORT, 250, 500, 1000, 2000, 4000, 8000, 16000

Physical unit: ms

Content: The reporting period for the event 1A. Generally the event 1A is reported only once. However, to avoid measurement report loss, the event 1A reporting can be turned to periodical report.


PERIODMRREPORTNUMFOR1C

1C event to periodical rpt number




Content: The periodical reporting times for the event 1C. When the actual times exceed this parameter, the periodical reporting comes to an end.


REPORTINTER 1C event to periodical

Value range: NON_PERIODIC_REPORT, D250, D500, D1000, D2000, D4000,


5-20

ID Name Description

VALFOR1C rpt period D8000, D16000


Physical unit: ms

Content: The reporting period for the event 1C. Generally the event 1C is reported only once. However, to avoid measurement report loss, the event 1C reporting can be turned to periodical reporting.


INTRARELTHDFOR1A

1A event relative threshold

Value range: 0~29

Physical value range: 0~14.5; step: 0.5

Physical unit: dB

Content: The relative threshold of the event 1A.


INTRARELTHDFOR1B

1B event relative threshold

Value range: 0~29


Physical unit: dB

Content: The relative threshold of the event 1B.


INTRAABLTHDFOR1E

1E event absolute threshold

Value range: -24~0

Physical unit: dB

Content: The absolute threshold of the event 1E.

Recommended value: -18

INTRAABLTHDFOR1F

1F event absolute threshold

Value range: -24~0

Physical unit: dB

Content: the absolute threshold of the event 1F.


HYSTFOR1A 1A hysteresis

Value range: 0~15


Physical unit: dB

Content: The hysteresis value of the event 1A. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the less ping-pong effect and misjudgement can be caused. However, in this case, the


5-21

ID Name Description

event cannot be triggered in time.


HYSTFOR1B 1B hysteresis

Value range: 0~15


Physical unit: dB

Content: The hysteresis value of the event 1B. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the less ping-pong effect and misjudgement can be caused. However, in this case, the event cannot be triggered in time.


HYSTFOR1C 1C hysteresis

Value range: 0~15


Physical unit: dB

Content: The hysteresis value of the event 1C. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the less ping-pong effect and misjudgement can be caused. However, in this case, the event cannot be triggered in time.


HYSTFOR1D 1D hysteresis

Value range: 0~15


Physical unit: dB

Content: The hysteresis value of the event 1D. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the less ping-pong effect and misjudgement can be caused. However, in this case, the event cannot be triggered in time.


HYSTFOR1E 1E hysteresis

Value range: 0~15


Physical unit: dB

Content: The hysteresis value of the event 1E. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the less ping-pong effect and misjudgement can be caused. However, in this case, the event cannot be triggered in time.



5-22

ID Name Description

HYSTFOR1F 1F hysteresis

Value range: 0~15


Physical unit: dB

Content: The hysteresis value of the event 1F. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the less ping-pong effect and misjudgement can be caused. However, in this case, the event cannot be triggered in time.


WEIGHT Weighted factor

Value range: 0~20

Physical value range: 0~2; step: 0.1

Physical unit: None

Content: This parameter is used to define the soft handover relative threshold based on the measured value of each cell in the active set. The greater this parameter is set, the higher the soft handover relative threshold. When this parameter is set as 0, the soft handover relative threshold is only for the best cell in the active set.


TRIGTIME1A 1A event trigger delay time

Value range: D0, D10, D20, D40, D60, D80, D100, D120, D160, D200, D240, D320, D640, D1280, D2560, D5000

Physical value range: 0, 10, 20, 40, 60, 80, 100, 120, 160, 200, 240, 320, 640, 1280, 2560, 5000

Physical unit: ms

Content: The trigger delay time of the event 1A. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the smaller the misjudgement probability, but the lower the response speed of the event to the measured signal changes.


TRIGTIME1B 1B event trigger delay time


Physical value range: 0, 10,20, 40, 60, 80, 100, 120, 160, 200, 240, 320, 640, 1280, 2560, 5000

Physical unit: ms

Content: The trigger delay time of the event 1B. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the smaller the misjudgement probability, but the lower the response speed of the event to


5-23

ID Name Description

the measured signal changes.


TRIGTIME1C 1C event trigger delay time



Physical unit: ms

Content: The trigger delay time of the event 1C. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the smaller the misjudgement probability, but the lower the response speed of the event to the measured signal changes.


TRIGTIME1D 1D event trigger delay time



Physical unit: ms

Content: The trigger delay time of the event 1D. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the smaller the misjudgement probability, but the lower the response speed of the event to the measured signal changes.


TRIGTIME1E 1E event trigger delay time



Physical unit: ms

Content: The trigger delay time of the event 1E. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the smaller the misjudgement probability, but the lower the response speed of the event to the measured signal changes.


TRIGTIME1F 1F event trigger delay time


Physical value range: 0, 10, 20, 40, 60, 80, 100, 120, 160, 200, 240, 320, 640,


5-24

ID Name Description

1280, 2560, 5000

Physical unit: ms

Content: The trigger delay time of the event 1F. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the smaller the misjudgement probability, but the lower the response speed of the event to the measured signal changes.


3) Example:

Set soft handover 1B event trigger time:

SET INTRAFREQHO: TRIGTIME1B=D2560;

After the above operation, the RNC oriented soft handover 1B event trigger delay time is configured as 2560ms. If theree is a cell oriented soft handover parameter settings for one cell, the cell oriented soft handover parameter is effective for that cell while the RNC oriented soft handover parameter is not effective for that cell.

IV. Modify Cell Oriented Intra-frequency Handover Measurement Algorithm Parameters

1) RNC Command: MOD CELLINTRAFREQHO 2) Parameters:

ID Name Description

CELLID Cell ID Value range: 0~65535

Physical unit: None

Content: Uniquely identifying a cell.


FILTERCOEF Intra-freq meas L3 filter coeff



Physical unit: None

Content: The intra-frequency measurement L3 filter coefficient. The greater this parameter is set, the greater the smoothing effect and the higher the anti fast fading capability, but the lower the signal change tracing capability.


PERIODMRREPO 1A event to periodical rpt



5-25

ID Name Description

RTNUMFOR1A number Physical value range: 1, 2, 4, 8, 16, 32, 64, infinity


Content: The periodical reporting times for the event 1A. When the actual times exceed this parameter, the periodical reporting comes to an end.


REPORTINTERVALFOR1A

1A event to periodical rpt period



Physical unit: ms

Content: The reporting period for the event 1A. Generally the event 1A is reported only once. However, to avoid measurement report loss, the event 1A reporting can be turned to periodical report.


PERIODMRREPORTNUMFOR1C

1C event to periodical rpt number




Content: The periodical reporting times for the event 1C. When the actual times exceed this parameter, the periodical reporting comes to an end.


REPORTINTERVALFOR1C

1C event to periodical rpt period



Physical unit: ms

Content: The reporting period for the event 1C. Generally the event 1C is reported only once. However, to avoid measurement report loss, the event 1C reporting can be turned to periodical reporting.


INTRARELTHDFOR1A

1A event relative threshold

Value range: 0~29


Physical unit: dB

Content: The relative threshold of the event 1A.


5-26

ID Name Description


INTRARELTHDFOR1B

1B event relative threshold

Value range: 0~29


Physical unit: dB

Content: The relative threshold of the event 1B.


INTRAABLTHDFOR1E

1E event absolute threshold

Value range: -24~0

Physical unit: dB

Content: The absolute threshold of the event 1E.


INTRAABLTHDFOR1F

1F event absolute threshold

Value range: -24~0

Physical unit: dB

Content: the absolute threshold of the event 1F.


HYSTFOR1A 1A hysteresis Value range: 0~15


Physical unit: dB

Content: The hysteresis value of the event 1A. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the less ping-pong effect and misjudgement can be caused. However, in this case, the event cannot be triggered in time.


HYSTFOR1B 1B hysteresis Value range: 0~15


Physical unit: dB

Content: The hysteresis value of the event 1B. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the less ping-pong effect and misjudgement can be caused. However, in this case, the event cannot be triggered in time.


HYSTFOR1C 1C hysteresis Value range: 0~15



5-27

ID Name Description

Physical unit: dB

Content: The hysteresis value of the event 1C. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the less ping-pong effect and misjudgement can be caused. However, in this case, the event cannot be triggered in time.


HYSTFOR1D 1D hysteresis Value range: 0~15


Physical unit: dB



HYSTFOR1E 1E hysteresis Value range: 0~15


Physical unit: dB

Content: The hysteresis value of the event 1E. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the less ping-pong effect and misjudgement can be caused. However, in this case, the event cannot be triggered in time.


HYSTFOR1F 1F hysteresis Value range: 0~15


Physical unit: dB



WEIGHT Weighted factor

Value range: 0~20


Physical unit: None

Content: This parameter is used to define the soft handover relative threshold


5-28

ID Name Description

based on the measured value of each cell in the active set. The greater this parameter is set, the higher the soft handover relative threshold. When this parameter is set as 0, the soft handover relative threshold is only for the best cell in the active set.


TRIGTIME1A 1A event trigger delay time



Physical unit: ms

Content: The trigger delay time of the event 1A. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the smaller the misjudgement probability, but the lower the response speed of the event to the measured signal changes.


TRIGTIME1B 1B event trigger delay time


Physical value range: 0, 10,20, 40, 60, 80, 100, 120, 160, 200, 240, 320, 640, 1280, 2560, 5000

Physical unit: ms

Content: The trigger delay time of the event 1B. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the smaller the misjudgement probability, but the lower the response speed of the event to the measured signal changes.


TRIGTIME1C 1C event trigger delay time



Physical unit: ms

Content: The trigger delay time of the event 1C. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the smaller the misjudgement probability, but the lower the response speed of the event to the measured signal changes.



5-29

ID Name Description

TRIGTIME1D 1D event trigger delay time



Physical unit: ms

Content: The trigger delay time of the event 1D. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the smaller the misjudgement probability, but the lower the response speed of the event to the measured signal changes.


TRIGTIME1E 1E event trigger delay time



Physical unit: ms

Content: The trigger delay time of the event 1E. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the smaller the misjudgement probability, but the lower the response speed of the event to the measured signal changes.


TRIGTIME1F 1F event trigger delay time



Physical unit: ms

Content: The trigger delay time of the event 1F. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the smaller the misjudgement probability, but the lower the response speed of the event to the measured signal changes.


3) Example:

Modify soft handover 1B event trigger time of one cell:

MOD CELLINTRAFREQHO: CELLID=10000, TRIGTIME1B=D640;


5-30

After the above operation, the cell 10000’s soft handover 1B event trigger delay time is configured as 640ms.


1) 3GPP, 25.331 "RRC Protocol Specification" 2) 3GPP, 25.931 " UTRAN Functions, Examples on Signalling Procedures" 3) Yue Chen, “Soft Handover Issues in Radio Resource Management for 3G

WCDMA”, Doctor Degree Thesis, September 2003

Feature Description HUAWEI UMTS Radio Access Network Chapter 6 SRNS Relocation

6-1

Chapter 6 SRNS Relocation

6.1 Introduction

Relocation of SRNS is a UMTS functionality used to relocate the serving RNS role from one RNS to another RNS. The SRNS relocation is realized by several elementary procedures executed in several interfaces and by several protocols.

It may involve a change in the radio resources used between UTRAN and UE. It is also possible to relocate the serving RNS role from one RNS within UMTS to another relocation target external to UMTS.

Before SRNC Relocation After SRNC Relocation

CN CN

SRNC DRNC RNC SRNC

Cells Cells

Iu

Iur

Iu

Iur

Figure 6-1 Relocation of SRNS

6.2 Glossary

6.2.1 Terms

Serving RNS (SRNS): role an RNS can take with respect to a specific connection between an UE and UTRAN. There is one serving RNS for each UE that has a connection to UTRAN. The serving RNS is in charge of the radio connection between a UE and the UTRAN. The serving RNS terminates the Iu for this UE.

Serving RNC (SRNC): SRNC is the RNC belonging to SRNS.

Drift RNS: The role an RNS can take with respect to a specific connection between a UE and UTRAN. An RNS that supports the Serving RNS with radio resources when the connection between the UTRAN and the User Equipment need to use cell(s) controlled by this RNS is referred to as Drift RNS.


6-2

Controlling RNC: A role an RNC can take with respect to a specific set of UTRAN access points. There is only one Controlling RNC for any UTRAN access point. The Controlling RNC has the overall control of the logical resources of its UTRAN access points.

Source RNS: A role with respect to a specific connection between UTRAN and CN that RNS takes when it decides to initiate a relocation of SRNS.

Source RNC: source RNC is the RNC belonging to source RNS.

Target RNS: role an RNS gets with respect to a specific connection between UTRAN and CN when it is being a subject of a relocation of SRNS which is being made towards that RNS.

Target RNC: target RNC is the RNC belonging to target RNS.

Iur: A logical interface between two RNC. Whilst logically representing a point to point link between RNC, the physical realization may not be a point to point link.


CN Core Network

UMTS Universal Mobile Telecommunication System



SRNC Serving RNC

CRNC Controlling RNC

DRNC Drift RNC

TRNC Target RNC

UE User Equipment

6.3 Application

6.3.1 Availability


6.3.2 Benefit

1) Benefit with Iur interface

If the SRNC and DRNC are different RNCs, relocating the SRNC to the DRNC can avoid data forwarding over the Iur interface and reduce the traffic over the Iur interface. The benefits in this case are as follows:


6-3

Allowing more subscribers to perform soft handover between different RNCs so as to ensure communication qualities.

Reducing data transit delay. 2) Benefit in case of no Iur interface

When there is no Iur interface and simplex handover process is not available, the relocation procedure can ensure the continuity of the communication when the UE is moving to a cell that belongs to a different RNC.


SRNS relocation VS Soft handover

The static relocation procedure might occur only when all radio links are in the DRNC.

SRNS relocation VS Hard handover

The static relocation procedure might occur only when a radio link is in the DRNC.


6.4.1 Algorism of SRNC Relocation

The BSC6800 supports the SRNS relocation triggered by two kinds of algorithms. You can use the SET CORRMALGOSWITCH MML command in the BSC6800 O&M System to set two parameters:

RELOCATION_FOR_DELAY_OPTIMIZATION_SWITCH IUR_TRANS_OPTIMIZE_TRANSFER_SWITCH

That is, you can set whether to allow SRNS relocation based on delay optimization or Iur transmission optimization.

I. SRNS Relocation Based on Delay Optimization

Figure 6-2 shows the algorism for SRNS relocation based on delay optimization.

If there are only DRNC radio links (RLs), the BSC6800 will calculate the transmission delay of traffic data. If the calculated transmission delay is greater than the corresponding threshold, the BSC6800 will initiate the SRNS relocation procedure. You can use the SET SRNSR command to set this threshold.


6-4

Are all Rls

in the DRNC?

Other Process<for example,Soft

Handover>

Yes

No

Is delay time greaterthan Qos Thd?

Other Process

No

Serving SRNS relocation

process based on delayOptimization

Yes

Figure 6-2 SRNS relocation based on delay optimization

II. SRNS Relocation Based on Transmission Optimization

Figure 6-3 shows the algorism for SRNS relocation based on transmission optimization.

If there are only DRNC RLs, the BSC6800 will calculate the resource occupation of Iur interface. If the resource occupation is greater than the corresponding threshold, the BSC6800 will initiate the SRNS relocation procedure in batches until the resource occupation is less than the threshold or there is no UE in this RNC for relocation. You can use the MOD NRNC command to modify the two parameters, UP SRNSR start threshold and UP SRNSR stop threshold.


6-5

Are all Rls

in the DRNC?

Other Process<for example, Soft

Handover>

Yes

No

Other Process

No

Serving SRNS relocation

Process based on IurTrans Optimization

YesIs Iur Interface

over loading?

Figure 6-3 SRNS relocation based on transmission optimization

6.4.2 Scenarios of SRNC Relocation

There are three cases in which an SRNS relocation can be performed:

SRNS relocation: SRNS relocation serves to move the UTRAN to CN connection point at the UTRAN side from the source SRNC to the target RNC.

Combined Hard Handover and SRNS relocation: This is used to move the UTRAN to CN connection point at the UTRAN side from the source SRNC to the target RNC, while performing a hard handover decided by the UTRAN as shown in Figure 6-4.

Before SRNC Relocation After SRNC Relocation

CN CN

SRNC DRNC RNC SRNC

Cells Cells

Iu Iu

Figure 6-4 Combined Hard Handover and SRNS relocation


6-6

Combined Cell/URA update and SRNS relocation: This is used to move the UTRAN to CN connection point at the UTRAN side from the source SRNC to the target RNC, while performing a cell re-selection in the UTRAN.

I. SRNS Relocation <CS>

The SRNC initiates the SRNS relocation process (CS) shown in Figure 6-5.

SRNC DRNCMSCUE

RELOC_REQUIREDRELOC_REQUEST

RELOC_REQUEST_ACK

RELOC_COMMAND

RELOC_COMMIT

UTRAN MOBILITY INFO(UM)

UTRAN MOBILITY INFO CONF(AM)

RELOC_DETECT

RELOC_COMPLETE

IU_REL_CMD

IU_REL_CMP

EST RAB CS

Figure 6-5 SRNS relocation procedure (CS)

1) The SRNC sends the RELOC_REQUIRED message to the CN when all links are in the DRNC and the SRNC detects that the transmission delay of traffic loading is greater than the corresponding threshold.

2) The CN sends RELOC_REQUEST to the DRNC according to the received request.

3) The DRNC sends RELOC_REQUEST_ACK to the CN after preparing for SRNC relocation.

4) The CN sends RELOC_COMMAND to the SRNC. 5) The SRNC sends RELOC_COMMIT to the DRNC after preparing for the

relocation. 6) The DRNC sends RELOC_DETECT to the CN and then carries out the internal

configuration flow related to the relocation. During this period the DRNC sends


6-7

UTRAN_MOBILITY _INFO to the UE and the UE sends UTRAN_MOBILITY _INFO_CONF to the DRNC.

7) The DRNC sends RELOC_COMPLETE to the CN after the relocation. 8) The CN sends IU_REL_CMD to the SRNC. 9) The SRNC sends IU_REL_CMP to the CN.

II. SRNS Relocation <CS + PS>

Similar to the SRNS relocation (CS), the SRNS relocation process (CS+PS) just adds the interaction between the RNC and SGSN to the SRNS relocation (CS) process, as shown in Figure 6-6.

SRNC SGSN DRNCMSCUE

RELOC_REQUEST

RELOC_REQUIRED


RELOC_REQUEST_ACK

RELOC_COMMAND

RELOC_REQUEST_ACKRELOC_COMMAND

RELOC_COMMIT

UTRAN MOBILITY INFO(UM)


RELOC_DETECT

RELOC_COMPLETE

RELOC_DETECT

RELOC_COMPLETEIU_REL_CMD

IU_REL_CMP

IU_REL_CMD

IU_REL_CMP

EST RAB CS + PS

Figure 6-6 SRNS relocation procedure (CS + PS)

III. Combined Hard Handover and SRNS Relocation (PS)

Figure 6-7 illustrates the combined hard handover and SRNS relocation process (PS).


6-8

SRNC DRNCSGSNUE

RELOC_REQUIRED RELOC_REQUEST

RELOC_REQUEST_ACKRELOC_COMMAND

PHY_CHL_RECFG(AM)

PHY_CHL_RECFG_COMP(AM)

RELOC_DETECT

RELOC_COMPLETE

MEAS_REPORT

NodeB

RL_SETUP_REQ

RL_SETUP_RSP

RL_REST_IND

(PHY_CHL_RECFG)(PHY_CHL_RECFG)

UTRAN MOBILITY INFO(AM)


IU_REL_CMD

IU_REL_CMP

FWD_SRNS_CNXT FWD_SRNS_CNXT

EST RAB, CELL_DCH

Figure 6-7 Combined hard handover and SRNS relocation procedure (PS)

1) The SRNC sends RELOC_REQUIRED to the CN after receiving the hard handover measurement report.

2) The CN sends RELOC_REQUEST to the DRNC according to the received request.

3) The DRNC sends RELOC_REQUEST_ACK with PHY_CHL_RECFG to the CN after preparing for SRNS relocation. During the preparation, the DRNC instructs the NodeB to set up a link (RL_ SETUP_REQ, RL_SETUP_RSP).

4) The CN sends RELOC_COMMAND with PHY_CHL_RECFG to the SRNC. 5) The SRNC sends FWD_SRNS_CNXT to the CN and then PHY_CHL_RECFG to

the UE. 6) If the DRNC first receives FWD_SRNS_CNXT from the CN and then

RL_REST_IND from the NodeB, it sends RELOC_DETECT to the CN. If the DRNC first receives RL_REST_IND from the NodeB and then FWD_SRNS_CNXT from the CN, it will not send RELOC_DETECT to the CN.

7) The UE sends PHY_CHL_RECFG_ COMP to the DRNC. 8) The DRNC sends RELOC_COMPLETE to the CN.

IV. Combined Cell/URA Update and SRNS Relocation

Figure 6-8 and Figure 6-9 illustrate the combined cell/URA update and SRNS relocation process.


6-9

1.URA Update

2.Iur UL Signal Transfer Ind

7. Relocation Commit

UE UE

8.Relocation Detect

3. Relocation Required

6.Relocation Command

9. Iu Release Command

4.Relocation Request

5. Relocation ACK

CN

TRNCSRNC

Figure 6-8 Combined Cell/URA update and SRNS relocation

SRNC DRNCSGSNUE


RELOC_REQUEST_ACK

RELOC_COMMAND

CELL_UPD ATE_CONF / URA_UPDATE_CONF(UM)

RELOC_DETECT

RELOC_COMPLETE

CELL_UPD ATE / URA_UPDATE(TM)

UL_SIG_TRAN_IND

RELOC_COMMIT

PHY_CHL_RECFG_COMP / UTRAN_MOBI_INFO_CONF(AM)

UTRAN MOBILITY INFO(AM)


IU_REL_CMD

IU_REL_CMP

EST RAB PS, CELL_FACH, CELL_PCH, URA_PCH

Figure 6-9 Combined cell/URA update and SRNS relocation procedure


6-10

1) After receiving CELL_UPDATE/URA_UPDATE from the UE, the DRNC sends the SRNC the message UL_SIG_TRAN_IND to instruct the SRNC to initiate the relocation procedure.

2) The relocation procedure is similar to the basic SRNS relocation procedure. 3) The DRNC sends RELOC_DETECT to the CN and then CELL_UPDATE_CONF

or URA_UPDATE_CONF to the UE. 4) The UE sends the corresponding message PHY_CHL_RECFG_COMP or

UTRAN_MOBI_INFO_CONF to the DRNC. 5) The DRNC sends RELOC_COMPLETE to the CN.

6.5 Interaction

Feature Interaction

Combined Hard Handover and SRNS relocation

VS Hard handover

Along with the relocation, the hard handover also proceeds. Where, the PHY_CHL_RECFG message is sent by the originally SRNC to the UE but PHY_CHL_RECFG_COMP is returned to the originally DRNC. The original DRNC becomes SRNC. Finally, the new SRNC sends RELOC_COMPLETE to the CN.

Combined Cell/URA update and SRNS relocation

VS

Cell/URA update

After receiving CELL_UPDATE/URA_UPDATE from the UE, the DRNC instructs the SRNC to initiate the relocation procedure. After the relocation, the new SRNC (originally the DRNC) continues the cell/URA update procedure. Finally, it sends RELOC_COMPLETE to the CN.

6.6 Implementation


None

6.6.2 Parameter

I. RELOCATION_FOR_DELAY_OPTIMIZATION_SWITCH

You can use the SET CORRMALGOSWITCH command to set this parameter to determine whether the BSC6800 allows the SRSN relocation based on delay optimization. This parameter values are as follows:

RELOCATION_FOR_DELAY_OPTIMIZATION_SWITCH-1 (Y) RELOCATION_FOR_DELAY_OPTIMIZATION_SWITCH-0 (N)


6-11

II. IUR_TRANS_OPTIMIZE_TRANSFER_SWITCH

You can use the SET CORRMALGOSWITCH parameter to set this parameter to determine whether the BSC6800 allows the SRNS relocation based on Iur transmission optimization. The parameter values are as follows:

IUR_TRANS_OPTIMIZE_TRANSFER_SWITCH-1 (Y) IUR_TRANS_OPTIMIZE_TRANSFER_SWITCH-0 (N)

III. Estimated Non-Measurement Delay Offset

You can use the SET SRNSR command to set this parameter. In the case of RELOCATION_FOR_DELAY_OPTIMIZATION_SWITCH-1, the value of this parameter represents the allowed transmission delay of traffic data.

Value range: 0–400 ms. Default value: 400 ms.

IV. UP SRNSR Start Threshold

You can use the ADD NRNC command to set this parameter and then use MOD NRNC to modify it. In the case of IUR_TRANS_OPTIMIZE_TRANSFER_SWITCH-1, if the resource occupation of Iur interface is greater than this parameter value, the BSC6800 will relocate the UEs in this RNC to the DRNC in batches.

Value range: 50% – 100%. Default value: 60%.

V. UP SRNSR Stop Threshold

You can use the ADD NRNC command to set this parameter and then use MOD NRNC to modify it. In the case of IUR_TRANS_OPTIMIZE_TRANSFER_SWITCH-1, if the resource occupation of Iur interface is less than this parameter value, the BSC6800 will stop the relocation.

Value range: 50%–100%. Default value: 50%.

VI. SRNSR Iur Reselection Timer

You can use the SET SRNSR command to set this parameter. The value of this parameter specifies the time interval between two SRNS relocation procedures in the case of SRNS relocation in batches.

Value range: 1–100 s. Default value: 100 s.

VII. Max Number of Users in One SRNS

You can use the SET SRNSR command to set this parameter. The value of this parameter represents the number of UEs relocated in one SRNS relocation procedure in the case of SRNS relocation in batches.


6-12

Value range: 1–200. Default value: 100.

6.6.3 Example

Parameter Value MML command example

RELOCATION_FOR_DELAY_OPTIMIZATION_SWITCH

1 SET CORRMALGOSWITCH: HOSWITCH=RELOCATION_FOR_DELAY_OPTIMIZATION_SWITCH-1;

Estimated non-measurement delay offset

400ms SET SRNSR: SRNSRDELAYOFFSET=400;


1) 3GPP TS 25.331 "Radio Resource Control (RRC); protocol specification" 2) 3GPP TS 25.413 “UTRAN Iu interface RANAP signaling” 3) 3GPP TR 21.905 “Vocabulary for 3GPP Specifications”

Feature Description HUAWEI UMTS Radio Access Network Chapter 7 Inter-RAT Handover

7-1

Chapter 7 Inter-RAT Handover

7.1 Introduction

Handover is a critical function in a cellular mobile communication network. Handover enables the continuous session of subscribers while moving around different cells. Besides, handover can also adjust the traffic of the cell, thus allow optimization of the overall performance.

After a connection is established in CS or PS or both CS and PS domain in UMTS, the connection is occasionally required to transfer to another system with different radio access technology (RAT), such as GSM. It can be caused by coverage limitation, or service strategy, or load share, etc. This transfer procedure is defined in UMTS specification as inter-RAT handover. With this procedure, the established connection can be transferred from UMTS to GSM without interruption, which guarantees the continuity of customer service.

7.2 Glossary

7.2.1 Terms

None


ALCAP Access Link Control Application Protocol

BCCH Broadcast Control Channel

BS Base Station

BSC Base Station Controller

BSS Base Station System

CN Core Network

CS Circuit Switched



GGSN Gateway GPRS Support Node

GPRS General Packet Radio System


7-2

GTP GPRS Tunneling Protocol

HHO Hard Handover

HLR Home Location Register

HO Handover


IN Intelligent Network

LAC Link Access Control


MAP Mobile Application Part

MC Measurement Control

MCC Mobile Country Code

MM Mobility Management

MNC Mobile Network Code

MR Measurement Report

MS Mobile Station

MSC Mobile Services Switching Center

NAS Non-Access Stratum

PCH Paging Channel

PDP Packet Data Protocol

PDU Protocol Data Unit

PS Packet Switched

QoS Quality of Service

RAB Radio Access Bearer

RANAP Radio Access Network Application Part

RAT Radio Access Technology



RSCP Received Signal Code Power


7-3

RSSI Received Signal Strength Indicator

RX Receive

SNDCP Sub-Network Dependent Convergence Protocol

SRNC Serving Radio Network Controller

SRNS Serving RNS

TMSI Temporary Mobile Subscriber Identity

UE User Equipment


URA User Registration Area

UTRA UMTS Terrestrial Radio Access



7.3 Application

7.3.1 Availability

This is an optional feature for Huawei UMTS RAN. This feature is available on BSC6800 V100R002 and later generic releases of the BSC6800 system.

7.3.2 Benefit

Inter-RAT handover from UTMS to GSM gives the service provider flexibility in handling both UMTS and GSM network. With this feature, the service provider can :

Make full use of the existing GSM network, and decrease the investment of the equipment.

Provide better service for the customer with no interruption connection. Implement service relocation strategy and load share.


The inter-RAT handover service is restricted by license. The RNC provides inter-RAT handover function only when the “HANDOVER OR CELL CHANGE FROM 3G TO 2G” and “HANDOVER OR CELL RESELECT FROM 2G TO 3G” licenses are purchased.

UE must be dual mode to support inter-RAT handover from UMTS to GSM.


7-4


7.4.1 General Procedure of Inter-RAT Handover

I. Procedure

Generally, the procedure of handover includes the following three phases:

handover preparation, handover decision, Handover execution.

MS should cooperate with CN and RAN to implement this procedure. If the handover procedure fails, penalty will be implemented. The general procedure of handover from UMTS to GSM in UTRAN is illustrated in Figure 7-1.

RANUE

MC (Inter Freq Measurement Control)

MR (2D Event)

Compress Mode (RAN and UE)

MR (Quality of GSM Cell)

MR (Quality of GSM Cell)

Inter RAT HO Command

HO Preparation

HO Decision

HO Execution

MC (inter-RAT Measurement Control)

Figure 7-1 General procedure of inter-RAT HO in UTRAN

II. Handover Preparation

RAN informs UE to measure the quality of current frequency with inter-Frequency Measurement Control, which indicates reporting criteria and threshold for 2D and 2F event. Based on the quality of current frequency, UE will send RAN measurement report including 2D or 2F event. If RAN receives a Measurement Report including 2D event, RAN will optionally notify NodeB and UE to start Compressed Mode in order to measure GSM cell quality. All the adjacent GSM cells information and reporting criteria are sent in another Measurement Control, which is called inter-RAT Measurement Control. Upon reception this Measurement Control, UE knows which GSM cells to be tested, how to test them and how to report the results.


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III. Handover Decision

UE sends the measurement report to RAN with specified period, which is defined by the inter-RAT Measurement Control. Based on the GSM cell's quality satisfying threshold within a period time, RAN will initiate the handover procedure. The related parameters are detailed in clause 7.6.2 .

IV. Handover Execution

After the handover condition is satisfied, RAN will initiate the handover procedure. Firstly, RAN sends Relocation Required to inform source MSC to communicate with the target MSC handling the target GSM cell to prepare resource for the upcoming handover. Source MSC sends Relocation Command to RAN after all the resource is prepared ready. Then RAN sends handover command to MS to execute handover. Then MS gets access into GSM and continue the connection. All the resource that occupied by MS in UMTS should be released after handover execution.

V. Handover Penalty

If the handover fails, penalty will be implemented. Handover penalty is oriented to the handover target cell by a specified period of time, which can be set through OMC.

7.4.2 UMTS to GSM Inter-MSC Handover

This example shows how Hard Handover is performed from UTRAN to GSM/BSS between a UMTS CN and a 2G-MSC. Figure 7-2 shows the process of UMTS to GSM Inter-MSC Handover.


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MAP/E MAP/E2. PrepareHandover

BSSMAP BSSMAP4. HandoverRequest Ack

RANAP RANAP13. Iu Release

Complete

BSSMAP BSSMAP3. Handover

Request

MAP/E MAP/E5. Prepare Handover

Response

RANAP RANAP

6. Relocation Command


Detect


Complete

MAP/E MAP/E11. Send End Signal

Request

MAP/E MAP/E

14. Send End Signal Response

RANAP RANAP1. Relocation

Required

Node B RNCServ ing

CN MSC BSC BTS

7. DCCH : Handover from UTRAN Command

9. Handover CompleteRRC

RANAP RANAP12. Iu Release

Command

RRC

UE

RRC

RRC

Figure 7-2 UTRAN to GSM/BSS Handover

1) Upon detection of a trigger, SRNC sends RANAP message Relocation Required to the CN.

2) The UMTS CN will forward this request to the GSM MSC (indicated in the received message) over the MAP/E interface (MAP message Prepare Handover).

3) Step 3 follow the normal GSM procedures and are shown only for clarity. 4) Step 4 follow the normal GSM procedures and are shown only for clarity. 5) Once initial procedures are complete in GSM MSC/BSS the MSC returns MAP/E

message Prepare Handover Response. 6) CN responds to the initial request from SRNC by sending RANAP message

Relocation Command to the SRNC. 7) Via existing RRC connection, SRNC sends RRC message Handover from

UTRAN command to the UE. One or several message from the other system can be included in this message.

8) Procedures related to synchronisation etc. to GSM BSS are not shown. 9) Steps 8 & 10 follow normal GSM procedures and are shown only for clarity.


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10) Detection of the UE within the GSM coverage results in the MSC sending MAP/E message Send End Signal Request to the CN.

11) CN initiates release of resources allocated by the former SRNC (Iu Release Command).

12) Previously allocated bearer resources are released within UMTS (e.g. using RANAP and ALCAP protocols [ALCAP not shown]) (Iu Release Complete).

13) Procedure is concluded from UMTS point of view by CN sending MAP/E message Send End Signal Response (this message is not sent until the end of the call).

7.4.3 UMTS to GSM Inter-SGSN Change

I. General Procedure for UMTS to GSM Inter-SGSN Change

An inter-SGSN inter-system change from UMTS to GSM takes place when an MS in PMM-IDLE or PMM-CONNECTED state changes from UTRAN to GSM radio access and the GSM radio access node serving the MS is served by a different SGSN. In this case, the RA changes. Therefore, the MS shall initiate a GSM RA update procedure. The RA update procedure is either combined RA / LA update or only RA update. These RA update cases are illustrated in Figure 7-3.

A combined RA /LA update takes place in network operation mode I when the MS enters a new RA or when a GPRS-attached MS performs IMSI attach. The MS sends a Routing Area Update Request indicating that an LA update may also need to be performed, in which case the SGSN forwards the LA update to the VLR. This concerns only idle mode (see 3G TS 23.122), as no combined RA / LA updates are performed during a CS connection.


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MS new2G-SGSN

HLRGGSNold3G-SGSN

BSS SRNS

C3

C1

newMSC/VLR

oldMSC/VLR

C2

1. Intersystem changedecision

2. Routing Area Update Request

10. Update PDP Context Request

10. Update PDP Context Response

11. Update GPRS Location

15. Update GPRS Location Ack

5. SGSN Context Response6. Security Functions

19. Routing Area Update Accept

12. Cancel Location

12. Cancel Location Ack

14. Insert Subscriber Data Ack

14. Insert Subscriber Data

7. SGSN Context Acknowledge

3. SGSN Context Request

13. Iu Release Command

13. Iu Release Complete

8a. Forward Packets

9. Forward Packets

4. SRNS Context Request

4. SRNS Context Response

8. SRNS Data Forward Command

22. BSS Packet Flow Context Procedure

20. Routing Area Update Complete

16. Location Update Request17a. Update Location

17b. Cancel Location

17c. Cancel Location Ack17d. Insert Subscriber Data17e. Insert Subscriber Data Ack

17f. Update Location Ack18. Location Update Accept

21. TMSI Reallocation Complete

Figure 7-3 UMTS to GSM Inter-SGSN Change


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1) The MS or BSS or UTRAN decides to perform an inter-system change, which makes the MS switch to a new cell that supports GSM radio technology, and stops transmission to the network.

2) The MS sends a Routing Area Update Request (old RAI, old P-TMSI Signature, Update Type, MS Network Capability) message to the new 2G-SGSN. Update Type shall indicate RA update or combined RA / LA update, or, if the MS wants to perform an IMSI attach, combined RA / LA update with IMSI attach requested. The BSS shall add the Cell Global Identity including the RAC and LAC of the cell where the message was received before passing the message to the new 2G-SGSN.

3) The new 2G-SGSN sends an SGSN Context Request (old RAI, TLLI, old P-TMSI Signature, and New SGSN Address) message to the old 3G-SGSN to get the MM and PDP contexts for the MS. The old 3G-SGSN validates the old P-TMSI Signature and responds with an appropriate error cause if it does not match the value stored in the old 3G-SGSN. If the received old P-TMSI Signature does not match the stored value, the security functions in the new 2G-SGSN should be initiated. If the security functions authenticate the MS correctly, the new 2G-SGSN shall send an SGSN Context Request (old RAI, TLLI, MS Validated, New SGSN Address) message to the old 3G-SGSN. MS Validated indicates that the new 2G-SGSN has authenticated the MS. If the old P-TMSI Signature was valid or if the new 2G-SGSN indicates that it has authenticated the MS correctly, the old 3G-SGSN starts a timer. If the MS is not known in the old 3G-SGSN, the old 3G-SGSN responds with an appropriate error cause.

4) If the MS is PMM-CONNECTED the old 3G-SGSN sends an SRNS Context Request (IMSI) message to the SRNS. Upon receipt of this message the SRNS buffers and stops sending downlink PDUs to the MS and returns an SRNS Context Response (GTP-SNDs, GTP-SNUs, PDCP-SNDs, PDCP-SNUs) message. The SRNS shall include for each PDP context the next in-sequence GTP sequence number to be sent to the MS and the GTP sequence number of the next uplink PDU to be tunneled to the GGSN. For each active PDP context using lossless PDCP, the SRNS also includes the uplink PDCP sequence number (PDCP-SNU) downlink PDCP sequence number (PDCP-SND). PDCP-SNU shall be the next in-sequence PDCP sequence number expected from the MS. PDCP-SND is the PDCP sequence number for the first downlink packet for which successful transmission has not been confirmed. The 3G-SGSN shall strip off the eight most significant bits of the passed PDCP sequence numbers, thus converting them to SNDCP N-PDU numbers and, subsequently, storing these N-PDU numbers in its PDP contexts.

5) The old 3G-SGSN responds with an SGSN Context Response (MM Context, PDP Contexts) message. For each PDP context the old 3G-SGSN shall include the GTP sequence number for the next uplink GTP PDU to be tunneled to the GGSN and the next donwlink GTP sequence number for the next in-sequence


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N-PDU to be sent to the MS. Each PDP Context also includes the SNDCP Send N-PDU Number (the value is 0) for the next in-sequence downlink N-PDU to be sent in acknowledged mode SNDCP to the MS and the SNDCP Receive N-PDU Number (= converted PDCP-SNU) for the next in-sequence uplink N-PDU to be received in acknowledged mode SNDCP from the MS. The new 3G-SGSN shall ignore the MS Network Capability contained in MM Context of SGSN Context Response only when it has previously received an MS Network Capability in the Routing Area Request.

6) Security functions may be executed. 7) The new 2G-SGSN sends an SGSN Context Acknowledge message to the old

3G-SGSN. This informs the old 3G-SGSN that the new 2G-SGSN is ready to receive data packets belonging to the activated PDP contexts. The old SGSN marks in its context that the MSC/VLR association and the information in the GGSNs and the HLR are invalid. This triggers the MSC/VLR, the GGSNs, and the HLR to be updated if the MS initiates a RA update procedure back to the old SGSN before completing the ongoing RA update procedure.

8) If the MS is PMM-CONNECTED, the old 3G-SGSN sends an SRNS Data Forward Command (RAB ID, Transport Layer Address, Iu Transport Association) message to the SRNS. For each indicated RAB the SRNS starts duplicating and tunneling the buffered GTP PDUs to the old 3G-SGSN. For each radio bearer which uses lossless PDCP, the SRNS shall start tunneling the GTP-U PDUs related to transmitted but not yet acknowledged PDCP-PDUs to the old 3G-SGSN together with the corresponding downlink PDCP sequence numbers. Upon receipt of the SRNS Data Forward Command message from the 3G-SGSN, the SRNS shall start the data-forwarding timer.

9) The old 3G-SGSN tunnels the GTP PDUs to the new 2G-SGSN. In the case of GTPv1, the conversion of PDCP sequence numbers to SNDCP sequence numbers (the eight most significant bits shall be stripped off) shall be done in the new SGSN. No N-PDU sequence numbers shall be indicated for these N-PDUs. If GTPv0 is used between the SGSNs, the conversion of PDCP sequence numbers to SNDCP numbers shall be done in the old 3G-SGSN (by stripping off the eight most significant bits).

10) The new 2G-SGSN sends an Update PDP Context Request (new SGSN Address, TEID, QoS Negotiated) message to each GGSN concerned. Each GGSN updates its PDP context fields and returns an Update PDP Context Response (TEID) message.

11) The new 2G-SGSN informs the HLR of the change of SGSN by sending an Update GPRS Location (SGSN Number, SGSN Address, IMSI) message to the HLR.

12) The HLR sends a Cancel Location (IMSI) message to the old 3G-SGSN. The old 3G-SGSN acknowledges with a Cancel Location Ack (IMSI) message. The old 3G-SGSN removes the MM and PDP contexts if the timer described in step 3 is


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not running. If the timer is running, the MM and PDP contexts shall be removed when the timer expires.

13) When the MS is PMM-CONNECTED, the old 3G-SGSN sends an Iu Release Command message to the SRNS. When the RNC data-forwarding timer has expired, the SRNS responds with an Iu Release Complete message.

14) The HLR sends an Insert Subscriber Data (IMSI, GPRS Subscription Data) message to the new 2G-SGSN. The 2G-SGSN constructs an MM context and PDP contexts for the MS and returns an Insert Subscriber Data Ack (IMSI) message to the HLR.

15) The HLR acknowledges the Update GPRS Location by returning an Update GPRS Location Ack (IMSI) message to the new 2G-SGSN.

16) If the association has to be established i.e., if Update Type indicates combined RA / LA update with IMSI attach requested, or if the LA changed with the routing area update, the new 2G-SGSN sends a Location Update Request (new LAI, IMSI, SGSN Number, Location Update Type) to the VLR. Location Update Type shall indicate IMSI attach if Update Type in step 1 indicated combined RA / LA update with IMSI attach requested. Otherwise, Location Update Type shall indicate normal location update. The VLR number is translated from the RAI by the 2G-SGSN. The 2G-SGSN starts the location update procedure towards the new MSC/VLR upon receipt of the first Insert Subscriber Data message from the HLR in step 14). The VLR creates or updates the association with the 2G-SGSN by storing SGSN Number.

17) If the subscriber data in the VLR is marked as not confirmed by the HLR, the new VLR informs the HLR. The HLR cancels the old VLR and inserts subscriber data in the new VLR (this signaling is not modified from existing GSM signaling and is included here for illustrative purposes):

a) The new VLR sends an Update Location (new VLR) to the HLR.

b) The HLR cancels the data in the old VLR by sending Cancel Location (IMSI) to the old VLR.

c) The old VLR acknowledges with Cancel Location Ack (IMSI).

d) The HLR sends Insert Subscriber Data (IMSI, GSM subscriber data) to the new VLR.

e) The new VLR acknowledges with Insert Subscriber Data Ack (IMSI).

f) The HLR responds with Update Location Ack (IMSI) to the new VLR.

18) The new VLR allocates a new TMSI and responds with Location Update Accept (VLR TMSI) to the 2G-SGSN. VLR TMSI is optional if the VLR has not changed.

19) The new 2G-SGSN validates the MS's presence in the new RA. If due to roaming restrictions the MS is not allowed to be attached in the RA, or if subscription checking fails, the new 2G-SGSN rejects the routing area update with an appropriate cause. If all checks are successful, the new 2G-SGSN constructs MM and PDP contexts for the MS. A logical link is established between the new


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2G-SGSN and the MS. The 2G-SGSN initiates the establishment procedure. The new 2G-SGSN responds to the MS with a Routing Area Update Accept (P-TMSI, P-TMSI Signature, Receive N-PDU Number (= converted PDCP-SNU)) message. Receive N-PDU Number contains acknowledgements for each NSAPI which used lossless PDCP before starting the update procedure, thereby confirming all mobile-originated N-PDUs that were successfully transferred. If Receive N-PDU Number confirms the reception of N-PDUs, the MS shall discard these N-PDUs.

20) The MS acknowledges the new P-TMSI by returning a Routing Area Update Complete (Receive N-PDU Number (= converted PDCP-SND)) message to the SGSN. Receive N-PDU Number contains the acknowledgements for each lossless PDCP used by the MS before starting the update procedure, thereby confirming all mobile-terminated N-PDUs successfully transferred. If Receive N-PDU Number confirms the reception of N-PDUs that were forwarded from the old 3G-SGSN, the new 2G-SGSN shall discard these N-PDUs. The MS deducts Receive N-PDU number from PDCP-SND by stripping off the eight most significant bits. PDCP-SND is the PDCP sequence number for the next expected by the MS in-sequence downlink per radio bearer, which used lossless PDCP. The new 2G-SGSN negotiates with the MS the use of acknowledged or unacknowledged SNDCP for each NSAPI regardless whether the SRNS used lossless PDCP or not.

21) The new 2G-SGSN sends TMSI Reallocation Complete message to the new VLR if the MS confirms the VLR TMSI.

22) The 2G-SGSN and the BSS may execute the BSS Packet Flow Context procedure.

If the new SGSN is unable to update the PDP context in one or more GGSNs, the new SGSN shall deactivate the corresponding PDP contexts. This shall not cause the SGSN to reject the routing area update.

If the new SGSN is unable to support the same number of active PDP contexts as received from old SGSN, the new SGSN shall first update all contexts in one or more GGSNs and then deactivate the context(s). This shall not cause the SGSN to reject the routing area update.

II. Cell DCH

Generally when MS is in Cell DCH state, the inter-SGSN Change from UMTS to GSM is triggered by UTRAN sending cell change order command.

III. Cell FACH/CELL PCH/URA PCH

Generally when MS is in Cell FACH, CELL PCH or URA PCH state, the inter-SGSN Change from UMTS to GSM is triggered by UE cell reselection.


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7.4.4 Combined Service Inter-RAT Handover

I. Inter-RAT Handover with Simultaneous PS and CS Domain Services

For a UE in CELL_DCH state using both CS and PS Domain services the Inter-RAT handover procedure is based on measurement reports from the UE but initiated from UTRAN.

The UE performs the Inter-RAT handover from UTRA RRC Connected Mode to GSM Connected Mode first. When the UE has sent handover complete message to GSM / BSS the UE initiates a temporary block flow towards GPRS and sends a RA update request.

If the Inter-RAT handover from UTRA RRC Connected Mode to GSM Connected Mode was successful the handover is considered as successful regardless if the UE was able to establish a temporary block flow or not towards GPRS.

In case of Inter-RAT handover failure the UE has the possibility to go back to UTRA RRC Connected Mode and re-establish the connection in the state it originated from.

II. Suspension of GPRS Services

The ability for a GPRS user to access circuit-switched services depends on the subscription held, the network capabilities, and the MS capabilities.

The MS shall request the network for suspension of GPRS services when the MS or the network limitations make it unable to communicate on GPRS channels in one or more of the following scenarios:

During CS connection, the MS performs handover from UMTS to GSM, and the MS or the network limitations make it unable to support CS/PS mode of operation, e.g. an MS in CS/PS mode of operation in Iu mode during a CS connection reverts to class-B mode of operation in A/Gb mode.

III. Inter-System (UMTS-GSM) Suspend and Resume Procedure (Intra-SGSN)

The Suspend and Resume procedure for intra SGSN is illustrated in Figure 7-4.

1) During CS connection, the MS performs handover from UMTS to GSM and the MS or the network limitations are unable to support CS/PS mode of operation.


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2. Suspend


MS BSS 2G/3G SGSN MSC/VLR

3. Suspend

4. Resume

5. Channel Release

3. Suspend Ack

4. Resume Nack

SRNS

1. Intersystem Handover

3. SRNS Context Req/Resp.

Figure 7-4 Suspend and Resume Procedure for intra-SGSN

2) The MS sends an RR Suspend (TLLI, RAI) message to the BSS. 3) The BSS sends a Suspend (TLLI, RAI) message to the SGSN.

The SGSN will then request the SRNS to stop sending downlink PDU's by the SRNS Context Request message. The SRNS then starts buffering the downlink PDUs.

The SRNS responds with an SRNS Context Response message. The SGSN then returns Suspend Ack to the BSS.

4) After CS connection is terminated, the BSS may send a Resume (TLLI, RAI) message to the SGSN, but resume is not possible since the MS has changed the radio system, so the SGSN acknowledges the resume by Resume Nack.

5) The BSS sends an RR Channel Release message to the MS, indicating that the BSS has not successfully requested the SGSN to resume GPRS services for the MS.

6) The MS shall resume GPRS services by sending a Routeing Area Update Request message to the SGSN. The Update Type depends on the mode of operation of the network in use e.g. in mode I Combined RA/LA Update is made and in mode II or III Routeing Area Update is made.

IV. Inter-System (UMTS-GSM) Suspend and Resume Procedure (Inter-SGSN)

This section describes the scenario when the suspend message is received in an SGSN that is different from the SGSN currently handling the packet data transmission and would be valid for at least the following cases:

MS performs inter-system handover from UMTS to GSM during CS connection and the SGSN handling the GSM cell is different from the SGSN handling the UMTS cell, i.e. the 2G and 3G SGSNs are separated.

The Suspend and Resume procedure for inter SGSN is illustrated in 2).


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1) During CS connection, the MS performs handover from UMTS to GSM, and the MS or the network limitations make it unable to support CS/PS mode of operation.

BSS 2G SGSN 3G SGSN

3. Suspend

4. Resu me

3. Suspend Ack

4. Resu me Nack

MSC/VLRSRNS

2. Suspend

5. Channel Release

MS

1. Intersystem Handover


Figure 7-5 Suspend and Resume Procedure for inter-SGSN

2) Suspend and Resume Procedure for inter-SGSN 3) The MS sends an RR Suspend (TLLI, RAI) message to the BSS. 4) The BSS sends a Suspend (TLLI, RAI) message to the SGSN.

The 2G SGSN then returns Suspend Ack to the BSS.

5) After CS connection is terminated, the BSS may send a Resume (TLLI, RAI) message to the 2G SGSN, but since resume is not needed against the 3G SGSN the 2G SGSN acknowledges the resume by Resume Nack. (Resume is not needed in this case since the MS always will perform an RA Update for updating of GPRS services when the CS connection is terminated and the MM context will be moved from 3G to 2G SGSN.)

6) The BSS sends an RR Channel Release message to the MS, indicating that the BSS has not successfully requested the SGSN to resume GPRS services for the MS.

7) The MS shall resume GPRS services by sending a Routeing Area Update Request message to the SGSN. The Update Type depends on the mode of operation of the network in use e.g. in mode I Combined RA/LA Update is made and in mode II or III Routeing Area Update is made.

7.5 Interaction

7.5.1 Inter-RAT Cell Reselection in Idle Mode

When the UE based on received system information makes a cell reselection to a radio access technology other than UTRAN, e.g. GSM/GPRS, according to the criteria specified in [3], the UE shall roam to the new cell and initiate a registration in the new cell. This procedure is applicable in idle mode.


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7.5.2 Inter-RAT Cell Reselection from UTRAN

The purpose of the inter-RAT cell reselection procedure from UTRAN is to transfer, under the control of the UE and to some extent the UTRAN, a connection between the UE and UTRAN to another radio access technology (e.g. GSM/GPRS).

This procedure is applicable in states CELL_FACH, CELL_PCH or URA_PCH.

When the UE based on received system information makes a cell reselection to a radio access technology other than UTRAN, e.g. GSM/GPRS, according to the criteria specified in [3], the UE shall:

1) If the NAS procedures associated with inter-system change specified in [2] require the establishment of a connection:

Initiate the establishment of a connection to the target radio access technology according to its specifications.

2) If the inter-RAT cell reselection fails, the UE shall:

Resume the connection to UTRAN using the resources used before initiating the inter-RAT cell reselection procedure.

7.5.3 Co-exist between Inter-frequency and Inter-RAT

Inter-frequency measurement and inter-RAT measurement can co-exist at the same time. When signal of current cell is under 2d threshold, inter-frequency measurement and inter-RAT measurement can be started simultaneously.

UE shall report either inter-frequency measurement report or inter-RAT measurement report to RNC according to the criteria specified in [3].

7.6 Implementation


I. E-interface and Gn Interface Configuration

To process inter-RAT handover, E-interface and Gn interface should be configured. E-interface is the interface between MSC and MSC. Gn interface is the interface between SGSN and SGSN.

II. UE Ability Requirement

To process inter-RAT handover between GSM and WCDMA, the UE should support GSM and WCDMA and the network mode should be set automatic.

III. Adjacent Cell Planning and Configuration

GSM cells should be configured as adjacent Cells to the WCDMA cell. Then the UE can measure the adjacent cells when needed and can handover to the cell.


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IV. Measurement Strategy

Both RSCP and Ec/Io can be measured as the measurement criteria according to the network planning.

7.6.2 Parameters

I. Add a GSM Cell Neighboring to the WCDMA Coverage.

1) RNC Command

ADD GSMCELL: BANDIND=GSM900_DCS1800_BAND_USED;

2) Parameters

ID Name Description

MCC Mobile country code

Value range: 000~999.

Physical unit: None.

Content: The code of the country to which the GSM cell belongs

Recommended value: None.

MNC Mobile network code

Value range: 00~99 or 000~999.


Content: The code of the mobile communication network to which the GSM cell belongs.


LAC Location area code

Value range: H'0000~H'FFFF(0~65535), except for H'0000 and H'FFFE.


Content: The code of the location area to which the GSM cell belongs. Note: H'0000 and H'FFFE are reserved. Recommended value: None.

CID GSM cell ID Value range: H'0000~H'FFFF(0~65535).


Content: Identifying a GSM cell. Recommended value: None.

NCC Network color code

Value range: 0~7.


Content: Uniquely identifying a different network in the neighboring area. Recommended value: None.

BCC BS color code Value range: 0~7.



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ID Name Description

Content: Uniquely identifying a neighboring base station with the same carrier. Recommended value: None.

BCCHARFCN

Inter-RAT cell frequency number



Content: BCCH frequency number of the inter-RAT cell. Recommended value: None.

BANDIND Inter-RAT cell frequency band indicator

Value range: GSM900_DCS1800_BAND_USED, PCS1900_BAND_USED.


Content: Indicating whether the inter-RAT cell frequency number belongs to DCS1800 or PCS1900 when it is between 512 and 810. Recommended value: None.

Value range: GSM, GSM_OR_GPRS


Content: Indicating whether the inter-RAT cell is a GSM or GSM/GPRS cell. Recommended value: None.

3) Examples

Add the basic information of a GSM cell to the RNC.

ADD GSMCELL: MCC="460", MNC="01", LAC=H'1234,CID=H'0002, NCC=1, BCC=1, BCCHARFCN=512, BANDIND=GSM900_DCS1800_BAND_USED,RATCELLTYPE=GSM_OR_GPRS;

After the above operation, a GSM cell is added as follows.

The mobile country code of the cell is 460, mobile network code is 01, and location area code is H'1234.

The GSM cell ID is H'0002. The network color code is 1 and BS color code is 1. The inter-RAT cell frequency number is 512. The inter-RAT cell frequency band indicator is

GSM900_DCS1800_BAND_USED. The inter-RAT cell type is GSM/GPRS.

II. Add the Information of a GSM Neighboring Cell of the WCDMA Cell.

1) RNC Command

ADD INTERRATNCELL:;

2) Parameters


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ID Name Description

CELLID Cell ID Value range: 0~268435455.


Content: Uniquely identifying a WCDMA cell.


MCC Mobile country code



Content: The code of the country to which the inter-RAT cell belongs.


MNC Mobile network code

Value range: 00~99 or 000~999.


Content: The code of the mobile communication network to which the inter-RAT cell belongs. Recommended value: None.

LAC Location area code

Value range: H'0000~H'FFFF(0~65535), except for H'0000 and H'FFFE.


Content: The code of the location area to which the inter-RAT cell belongs. Note: H'0000 and H'FFFE are reserved.


CID GSM cell ID Value range: H'0000~H'FFFF(0~65535).


Content: Identifying a GSM cell.


CELLINDIVIDUALOFFSET

Cell individual offset

Value range: -50~50.

Physical unit: dB.

Content: Cell individual offset based on the geographical features of the GSM cell. It is used in inter-RAT handover decision process. The greater the value is, the higher the priority of handover to the GSM cell. It is generally configured as 0.

Recommended value: 0.

QOFFSET1SN

Qoffset1sn Value range: -50~50.

Physical unit: dB.

Content: Offset between the inter-RAT neighboring cell and the


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ID Name Description

WCDMA cell. It is used for cell selection and reselection. The greater the value is, the less the probability of reselecting the inter-RAT neighboring cell. Default value is 0.


QRXLEVMIN

Min RX level Value range: -58~-13.

Physical value range: -115~-25; step: 2.

Physical unit: dBm.

Content: The minimum required RX level of the inter-RAT neighboring cell.


BLINDHOFLAG

Flag of Blind Handover Cell

Value range: true, false.


Content: The flag blind handover cell of the inter-RAT neighboring cell.


3) Examples

Add the information of an inter-RAT neighboring cell.

ADD INTERRATNCELL: CELLID=1, MCC="460", MNC="01",LAC=H'1234, CID=H'0002, CELLINDIVIDALOFFSET=0,QOFFSET1SN=0, QRXLEVMIN=-55;

After the above operations, a GSM neighboring cell with the following information, is added to the WCDMA cell 1:

The MCC is 460, MNC is 01, and LAC is H'1234. The GSM cell ID is H'0002. The Cell individual offset is 0. The offset is 6 dB. The minimum RX level is -55 (-109 dBm). The cell is not considered as a blind handover cell.

III. Set the Connection Oriented Algorithm Switches.

1) RNC Command

SET CORRMALGOSWITCH: HOSWITCH=INTERRAT_HO_OUT_SUPP_SWITCH-1&INTERRAT_HO_IN_SUPP_SWITCH-1&CMCF_SUPP_SWITCH-1&INTERRAT_PS_HO_SUPP_SWITCH-1;

2) Parameters


7-21

ID Name Description

HOSWITCH Handover algorithm switch

32-bit unsigned integer.

INTERRAT_HO_OUT_SUPP_SWITCH. When it is checked and the license is enabled, inter-RAT handover from UTRAN is allowed.

INTERRAT_HO_IN_SUPP_SWITCH. When it is checked and the license is enabled, inter-RAT handover to UTRAN is allowed.

CMCF_SUPP_SWITCH. When it is checked, Downlink Compressed Mode Configuration control is allowed.

INTERRAT_PS_HO_SUPP_SWITCH. When it is checked, PS traffic inter-RAT handover from UTRAN is allowed.

3) Examples

Set the connection oriented algorithm switches.

SET CORRMALGOSWITCH: PCSWITCH=OLPC_SWITCH-0;

After the above operation, outer loop power control will be disabled.

IV. Set the RNC Oriented Inter-RAT Handover Measurement Algorithm Parameters.

1) RNC Command

SET INTERFREQHO:;

2) Parameters

ID Name Description

FILTERCOEF

Inter-freq meas L3 filter coeff



Physical unit: None

Content: The inter-frequency measurement L3 filtering coefficient. The greater this parameter is set, the greater the filtering effect and the higher the anti fast fading capability, but the lower the signal change tracing capability.


PERIODREPORTINTERVAL

Periodic report interval

Value range: D250, D500, D1000, D2000, D4000, D8000, D16000, D20000, D24000, D28000, D32000, D64000

Physical value range: 250, 500, 1000, 2000, 4000, 8000, 16000, 20000,


7-22

ID Name Description

24000, 28000, 32000, 64000

Physical unit: ms

Content: Inter-frequency measurement reporting period.


HYSTFOR2D

2D hysteresis

Value range: 0~29


Physical unit: dB



HYSTFOR2F

2F hysteresis

Value range: 0~29


Physical unit: dB



HYSTFORHHO

Hard handover hysteresis

Value range: 0~29


Physical unit: dB

Content: The hysteresis value of the hard handover.


WEIGHTFORUSEDFREQ

Weighted factor for used frequency

Value range: 0~20


Physical unit: None

Content: The weighted factor required for comprehensive quality calculation of the used frequency. The greater this parameter is set, the higher the comprehensive quality the active set possesses. When this parameter is set as 0, the comprehensive quality of the active set refers to the quality of the best cell in the set.


7-23

ID Name Description


TRIGTIME2D

2D trigger time



Physical unit: ms

Content: The trigger delay time of the event 2D. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the less the misjudgement probability, but the lower the response speed of the event to the measured signal changes.


TRIGTIME2F

2F trigger time



Physical unit: ms

Content: The trigger delay time of the event 2F. This parameter value is related to the slow fading characteristic. The greater this parameter is set, the less the misjudgement probability, but the lower the response speed of the event to the measured signal changes.


TRIGTIMEHHO

Hard handover trigger time

Value range: 0~64000

Physical unit: ms

Content: The trigger delay time of hard handover .


CELLPROPERTY

Cell property

Value range: NONLAYERED_CELL_CARRIER_FREQUENCY_VERGE, NONLAYERED_CELL_CARRIER_FREQUENCY_CENTER

Physical unit: None

Content: If there are intra-frequency neighboring cells in all directions of the cell, it can be considered that the cell is at the center of the carrier frequency coverage. Otherwise, it is considered that the cell is on the verge of the carrier frequency coverage. This parameter determines whether RSCP or Ec/No will be taken as the measurement object of the events 2D and 2F.



7-24

ID Name Description

INTERFREQTHDFOR2DECNO

Inter-freq measure start Ec/No THD

Value range: -24~0

Physical unit: dB

Content: If Ec/No acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2D and then the RNC will send a signaling to start the compressed mode (CM) and inter-frequency measurement when the measured value is lower than this threshold.


INTERFREQTHDFOR2FECNO

Inter-freq measure end Ec/No THD

Value range: -24~0

Physical unit: dB

Content: If Ec/No acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2F and then the RNC will send a signaling to stop the compressed mode (CM) and inter-frequency measurement when the measured value is higher than this threshold.


INTERRATCSTHDFOR2DECNO

Inter-rat CS measure start Ec/No THD

Value range: -24~0

Physical unit: dB

Content: If Ec/No acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2D and then the RNC will send a signaling to start the compressed mode (CM) and inter-rat measurement when the measured value of CS traffic is lower than this threshold.


INTERRATCSTHDFOR2FECNO

Inter-rat CS measure end Ec/No THD

Value range: -24~0

Physical unit: dB

Content: If Ec/No acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2F and then the RNC will send a signaling to stop the compressed mode (CM) and inter-rat measurement when the measured value of CS traffic is higher than this threshold.


INTERRATPSTHDFOR2DECN

Inter-rat PS measure start Ec/No

Value range: -24~0

Physical unit: dB

Content: If Ec/No acts as the measurement object according to the setting


7-25

ID Name Description

O THD of the parameter [Cell property], the UE will report event 2D and then the RNC will send a signaling to start the compressed mode (CM) and inter-rat measurement when the measured value of PS traffic is lower than this threshold.


INTERRATPSTHDFOR2FECNO

Inter-rat PS measure end Ec/No THD

Value range: -24~0

Physical unit: dB

Content: If Ec/No acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2F and then the RNC will send a signaling to stop the compressed mode (CM) and inter-rat measurement when the measured value of PS traffic is higher than this threshold.


INTERRATSIGTHDFOR2DECNO

Inter-rat SIG measure start Ec/No THD

Value range: -24~0

Physical unit: dB

Content: If Ec/No acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2D and then the RNC will send a signaling to start the compressed mode (CM) and inter-rat measurement when the measured value of signal is lower than this threshold.


INTERRATSIGTHDFOR2FECNO

Inter-rat SIG measure end Ec/No THD

Value range: -24~0

Physical unit: dB

Content: If Ec/No acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2F and then the RNC will send a signaling to stop the compressed mode (CM) and inter-rat measurement when the measured value of signal is higher than this threshold.


INTERFREQTHDFOR2DRSCP

Inter-freq measure start RSCP THD

Value range: -115~-25

Physical unit: dBm

Content: If RSCP acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2D and then the RNC will send a signaling to start the compressed mode (CM) and inter-frequency measurement when the measured value is lower than


7-26

ID Name Description

this threshold.


INTERFREQTHDFOR2FRSCP

Inter-freq measure end RSCP THD


Physical unit: dBm

Content: If RSCP acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2F and then the RNC will send a signaling to stop the compressed mode (CM) and inter-frequency measurement when the measured value is higher than this threshold.


INTERRATCSTHDFOR2DRSCP

Inter-rat CS measure start RSCP THD


Physical unit: dBm

Content: If RSCP acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2D and then the RNC will send a signaling to start the compressed mode (CM) and inter-rat measurement when the measured value of CS traffic is lower than this threshold.


INTERRATCSTHDFOR2FRSCP

Inter-rat CS measure end RSCP THD


Physical unit: dBm

Content: If RSCP acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2F and then the RNC will send a signaling to stop the compressed mode (CM) and inter-rat measurement when the measured value of CS traffic is higher than this threshold.


INTERRATPSTHDFOR2DRSCP

Inter-rat PS measure start RSCP THD


Physical unit: dBm

Content: If RSCP acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2D and then the RNC will send a signaling to start the compressed mode (CM) and inter-rat measurement when the measured value of PS traffic is lower than this threshold.



7-27

ID Name Description

INTERRATPSTHDFOR2FRSCP

Inter-rat PS measure end RSCP THD


Physical unit: dBm

Content: If RSCP acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2F and then the RNC will send a signaling to stop the compressed mode (CM) and inter-rat measurement when the measured value of PS traffic is higher than this threshold.


INTERRATSIGTHDFOR2DRSCP

Inter-rat SIG measure start RSCP THD


Physical unit: dBm

Content: If RSCP acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2D and then the RNC will send a signaling to start the compressed mode (CM) and inter-rat measurement when the measured value of signal is lower than this threshold.


INTERRATSIGTHDFOR2DRSCP

Inter-rat SIG measure start RSCP THD


Physical unit: dBm

Content: If RSCP acts as the measurement object according to the setting of the parameter [Cell property], the UE will report event 2D and then the RNC will send a signaling to start the compressed mode (CM) and inter-rat measurement when the measured value of signal is lower than this threshold.


HHOTHDTOMACROFORECNO

Inter-freq HHO to Macro cell Ec/No THD

Value range: -24~0

Physical unit: dB

Content: If the candidate cell is macro cell, and the measured quality of this cell is higher than this absolute threshold, the cell can serve as the destination cell for inter-frequency hard handover.


HHOTHDTOMACROFORRSCP

Inter-freq HHO to Macro cell RSCP THD


Physical unit: dBm

Content: If the candidate cell is macro cell, and the measured quality of this cell is higher than this absolute threshold, the cell can serve as the


7-28

ID Name Description

destination cell for inter-frequency hard handover.


HHOTHDTOMICROFORECNO

Inter-freq HHO to Micro cell Ec/No THD

Value range: -24~0

Physical unit: dB

Content: If the candidate cell is micro cell, and the measured quality of this cell is higher than this absolute threshold, the cell can serve as the destination cell for inter-frequency hard handover.


HHOTHDTOMICROFORRSCP

Inter-freq HHO to Micro cell RSCP THD


Physical unit: dBm

Content: If the candidate cell is micro cell, and the measured quality of this cell is higher than this absolute threshold, the cell can serve as the destination cell for inter-frequency hard handover.


3) Examples

Set the RNC oriented inter-frequency handover measurement algorithm parameters.

SET INTERFREQHO: FILTERCOEF=D6, CELLPROPERTY=NONLAYERED_CELL_CARRIER_FREQUENCY_CENTER, INTERFREQTHDFOR2DECNO=-18, INTERFREQTHDFOR2FECNO=-15, HHOTHDTOMACROFORECNO=-16, HHOTHDTOMICROFORECNO=-16;

After the above operation, the parameters are set as follows:

The inter-freq meas L3 filter coeff is 6 The cell is at the center of the carrier frequency coverage. The inter-freq measure start Ec/No thresholds is -18 dB. The inter-freq measure end Ec/No thresholds is -15 dB. The inter-freq hard handover RSCP threshold is -85 dBm. The inter-freq hard handover to macro cell Ec/No threshold is -16 dB. The inter-freq hard handover to micro cell Ec/No threshold is -16 dB.

V. Set the RNC Oriented Inter-RAT Handover Measurement Algorithm Parameters

1) RNC Command

SET INTERRATHO:;

2) Parameters


7-29

ID Name Description

FILTERCOEF

Inter-RAT meas L3 filter coeff

Value range: D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D11, D13, D15, D17, D19.

Physical value range: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 15, 17, 19.


Content: The greater this parameter is, the greater the filtering effect and the higher the anti slow fading capability, but the lower the signal change tracing capability.

Recommended value: D4.

RPTINTERVAL

Report interval

Value range: D250, D500, D1000, D2000, D3000, D4000, D6000, D8000, D12000, D16000, D20000, D24000, D28000, D32000, D64000.

Physical value range:

250, 500, 1000, 2000, 3000, 4000, 6000, 8000, 12000, 16000, 20000, 24000, 28000, 32000, 64000.

Physical unit: ms.

Content: Inter-RAT measurement reporting period.

Recommended value: D1000.

GSMRSSICSTHD

GSM RSSI CS Traffic threshold

Value range: 0~63.

Physical value range: -110~-48 (1: -110; 2: -109; ...; 63:-48).

Physical unit: dBm.

Content: Requirement for the quality of the GSM cell in the CS traffic inter-RAT handover. Note: 0 indicates that this threshold is smaller than -110 dBm. Recommended value: 21.

GSMRSSIPSTHD

GSM RSSI PS traffic threshold

Value range: 0~63.


Physical unit: dBm.

Content: Requirement for the quality of the GSM cell in the PS traffic inter-RAT handover. Note: 0 indicates that this threshold is smaller than -110 dBm. Recommended value: 21.

GSMRSSISIGTHD

GSM RSSI signaling threshold

Value range: 0~63.


Physical unit: dBm.

Content: Requirement for the quality of the GSM cell in the signaling inter-RAT handover. Note: 0 indicates that this threshold is smaller


7-30

ID Name Description

than -110 dBm.


HYSTTHD Hysteresis Value range: 0~15.

Physical value range: 0~7.5; step: 0.5.

Physical unit: dB.

Content: Used to decide whether to trigger the inter-RAT handover decision together with [GSM RSSI threshold]. The value can be decreased to some degree in areas with smaller shadow fading and increased in areas with greater shadow fading. Recommended value: 4.

TIMETOTRIGFORNONVERIFY

Time To Trigger For non-verified GSM Cell

Value range: 0~64000, 65535.

Physical unit: ms.

Content: The inter-RAT handover to GSM procedure will be started if the current status of the GSM cell is non-verified and the GSM cell quality always satisfies the inter-RAT handover condition during the specified period of this parameter. Value 65535 means RNC would never initiate inter-Rat handover to non-verified GSM cell.


TIMETOTRIGFORVERIFY

Time To Trigger For Verified GSM Cell


Physical unit: ms.

Content: The inter-RAT handover to GSM procedure will be started if the current status of the GSM cell is verified and the GSM cell quality always satisfies the inter-RAT handover condition during the specified period of this parameter.


PENALTYTIMEFORSYSHO

Penalty Time For Inter-RAT Handover

Value range: 0~60.

Physical unit: s.

Content: If UE fails to perform inter-RAT handover to a GSM cell, RNC shall not initiate handover to the GSM cell again during the specified period of this parameter until the penalty time expire.


3) Examples

Set the RNC oriented inter-RAT handover algorithm parameters.


7-31

SET INTERRATHO: RPTINTERVAL=D1000, GSMRSSICSTHD=26, TIMETOTRIGFORSYSHO=5000;

After the above operations, the inter-RAT handover algorithm parameters are modified as follows:

The reporting period is 1000 ms. The GSM RSSI CS threshold is -85 dBm. The inter-RAT handover trigger time is 5000 ms.


1) 3GPP TS 23.122 "Non Access Stratum functions related to Mobile Station (MS) in idle mode"

2) 3GPP TS 24.008 "Mobile radio interface layer 3 specification; Core Network Protocols – Stage 3"

3) 3GPP TS 25.304 "UE Procedures in Idle Mode and Procedures for Cell Reselection in Connected Mode"

4) 3GPP TS 25.331 "RRC Protocol Specification" 5) 3GPP TS 23.060 “General Packet Radio Service (GPRS); Service description” 6) 3GPP TS 25.931 “UTRAN Functions, Examples on Signalling Procedures”

Feature Description HUAWEI UMTS Radio Access Network Chapter 8 PDCP Header Compression

8-1

Chapter 8 PDCP Header Compression

8.1 Introduction

As the networks evolve to provide more bandwidth, the applications, services and the consumers of those applications all compete for that bandwidth. For the network operators it is important to offer a high quality of service (QoS) in order to attract more customers and encourage them to use their network as much as possible, thus providing higher average revenue per user (ARPU).

As for wireless networks with their high bit error rates (highly prone to interference) and high latency (long round trip times), it is difficult to attain those high bandwidths required. When all these factors are taken into account it means that the available resources must be used as efficiently as possible.

In many services and applications, for example, Voice over IP, interactive games, messaging and so on, the payload of the IP packet is almost of the same size or even smaller than the header. Over the end-to-end connection comprised of multiple hops, these protocol headers are extremely important but over just one link (hop-to-hop) these headers serve no useful purpose. It is possible to compress those headers, providing in many cases more than 90% savings, and thus save the bandwidth and use the expensive resources efficiently.

IP header compression also provides other important benefits, such as reduction in packet loss and improved interactive response time.

In short, IP header compression is the process of compressing excess protocol headers before transmitting them on a link and uncompressing them to their original state on reception at the other end of the link.

It is possible to compress the protocol headers due to the redundancy in header fields of a packet as well as consecutive packets of the same packet stream.

8.2 Glossary

8.2.1 Terms[RFC2507-2]

Subheaders: An IPv6 base header, an IPv6 extension header, an IPv4 header, a UDP header, or a TCP header.

Header: A chain of subheaders.

Compress: The act of reducing the size of a header by removing header fields or reducing the size of header fields. This is done in a way such that a decompressor can reconstruct the header if its context state is identical to the context state used when compressing the header.


8-2

Decompress: The act of reconstructing a compressed header.

Context identifier (CID): A small unique number identifying the context that should be used to decompress a compressed header. Carried in full headers and compressed headers.

Context: The state which the compressor uses to compress a header and the decompressor uses to decompress a header. The context is the uncompressed version of the last header sent (compressor) or received (decompressor) over the link, except for fields in the header that are included "as-is" in compressed headers or can be inferred from, e.g., the size of the link-level frame. The context for a packet stream is associated with a context identifier. The context for non-TCP packet streams is also associated with a generation.

Generation: For non-TCP packet streams, each new version of the context for a given CID is associated with a generation: a small number that is incremented whenever the context associated with that CID changes. Carried by full and compressed non-TCP headers.

Packet stream: A sequence of packets whose headers are similar and share context. For example, headers in a TCP packet stream have the same source and final destination address, and the same port numbers in the TCP header. Similarly, headers in a UDP packet stream have the same source and destination address, and the same port numbers in the UDP header.

Full header (header refresh): An uncompressed header that updates or refreshes the context for a packet stream. It carries a CID that will be used to identify the context. Full headers for non-TCP packet streams also carry the generation of the context they update or refresh.

Regular header: A normal, uncompressed, header. Does not carry CID or generation association.

Incorrect decompression: When a compressed and then decompressed header is different from the uncompressed header. Usually due to mismatching context between the compressor and decompressor or bit errors during transmission of the compressed header.

Differential coding: A compression technique where the compressed value of a header field is the difference between the current value of the field and the value of the same field in the previous header belonging to the same packet stream. A decompressor can thus obtain the value of the field by adding the value in the compressed header to its context. This technique is used for TCP streams but not for non- TCP streams.

8.2.2 Acronyms and Abbreviation

ARPU Average Revenue Per User

BER Bit Error Rate


8-3

CN Core Network

FTP File Transport Protocol HC Header Compression

GGSN Gateway GPRS Support Node

GPRS General Packet Radio Service

GSM Global System for Mobile telecommunication

IP Internet Protocol

MTU Maximum Transfer Unit

PDCP Packet data convergence Protocol


RAB Radio Access Bears

RB Radio Bears

RFC Request For Comments

RLC Radio Link Control


RTP Real-Time Transport Protocol

RTT Round Trip Time

SGSN Serving GPRS Support Node

TCP Transmission Control Protocol

UDP User Datagram Protocol

UE User Equipment



8.3 Application

8.3.1 Availability


Support for IPv6 header is available on BSC6800 V100R005 and later version.

8.3.2 Benefit[RFC2507-1]

I. Decrease Header Overhead

A common size of TCP segments for bulk transfers over medium-speed links is 512 octets today. When TCP segments are tunneled, for example because Mobile IP is


8-4

used, the IPv6/IPv6/TCP header is 100 octets. Header compression will decrease the header overhead for IPv6/TCP from 19.5 per cent, namely 100 divided by 512, to less than 1 per cent, and for tunneled IPv4/TCP from 11.7 to less than 1 per cent. This is a significant gain for line-speeds as high as a few Mbit/s. The IPv6 specification prescribes path MTU discovery, so with IPv6 bulk TCP transfers should use segments larger than 512 octets when possible. Still, with 1400 octet segments (RFC 894 Ethernet encapsulation allows 1500 octet payloads, of which 100 octets are used for IP headers), header compression reduces IPv6 header overhead from 7.1% to 0.4%.

II. Improve Interactive Response Time

For very low-speed links, echoing of characters may take longer than 100-200 ms because of the time required to transmit large headers. 100-200 ms is the maximum time people can tolerate without feeling that the system is sluggish.

III. Allow Using Small Packets for Bulk Data with Good Line Efficiency

This is important when interactive (for example Telnet) and bulk traffic (for example FTP) is mixed because the bulk data should be carried in small packets to decrease the waiting time when a packet with interactive data is caught behind a bulk data packet. Using small packet sizes for the FTP traffic in this case is a global solution to a local problem. It will increase the load on the network as it has to deal with many small packets. A better solution might be to locally fragment the large packets over the slow link.

IV. Allow Using Small Packets for Delay Sensitive Low Data-Rate Traffic

For such applications, for example voice, the time to fill a packet with data is significant if packets are large. To get low end-to-end delay small packets are preferred. Without header compression, the smallest possible IPv6/UDP headers (48 octets) consume 19.2kbit/s with a packet rate of 50packets/s. 50packets/s is equivalent to having 20ms worth of voice samples in each packet. IPv4/UDP headers consume 11.2k bit/s at 50 packets/s. Tunneling or routing headers, for example to support mobility, will increase the bandwidth consumed by headers by 10-20kbit/s. This should be compared with the bandwidth required for the actual sound samples, for example 13kbit/s with GSM encoding. Header compression can reduce the bandwidth needed for headers significantly, in the example to about 1.7kbit/s. This enables higher quality voice transmission over 14.4 and 28.8kbit/s modems.

V. Reduce Packet Loss Rate over Lossy Links

Because fewer bits are sent per packet, the packet loss rate will be lower for a given bit-error rate. This results in higher throughput for TCP as the sending window can open up more between losses, and in fewer lost packets for UDP.


8-5


This function is restricted by license. The RNC provide PDCP header compression function only when “PDCP HEADER COMPRESSED” license is purchased.

RFC3095 is not supported on BSC6800 V100R002 and BSC6800 V100R005.


8.4.1 Method of Header Compression [RFC2507-3]

The IP protocol together with transport protocols like TCP or UDP and optional application protocols like RTP are described as a packet header. The information carried in the header helps the applications to communicate over large distances connected by multiple links or hops in the network. The information comprises of source and destination addresses, ports, protocol identifiers, sequence numbers, error checks etc. As long as the applications are communicating most of this information carried in packet headers remains the same or changes in specific patterns. For non-TCP packet streams almost all fields of the headers are constant. For TCP many fields are constant and others change with small and predictable values. By observing the fields that remain constant or change in specific patterns it is possible either not to send them in each packet or to represent them in a smaller number of bits than would have been required originally. This process is described as compression.

The process of header compression uses the concept of flow context, which is a collection of information about field values and change patterns of field values in the packet header. This context is formed on the compressor and the decompressor side for each packet flow. Once the context is established on both sides, the compressor compresses the packets as much as possible.

Figure 8-1 shows the header compression principle. To initiate compression of the headers of a packet stream, a full header carrying a context identifier, CID, is transmitted over the link. The compressor and decompressor store most fields of this full header as context. The context consists of the fields of the headers whose values are constant and thus need not be sent over the link at all, or change little between consecutive headers so that it uses fewer bits to send the difference from the previous value compared to sending the absolute value. Any change in fields that are expected to be constant in a packet stream will cause the compressor to send a full header again to update the context at the decompressor. As long as the context is the same at compressor and decompressor, headers can be decompressed to be exactly as they were before compression. However, if a full header or compressed header is lost during transmission, the context of the decompressor may become obsolete as it is not updated properly. Compressed headers will then be decompressed incorrectly. So a header compression scheme provides mechanisms to update the context at the decompressor and to detect or avoid incorrect decompression.


8-6

Figure 8-1 Header Compression Principle

8.4.2 Architecture

I. UMTS Structure for Packet Switch Domain

The network structure of packet switch domain is shown in Figure 8-2. The header compression function is located in RNC. Packet data is transferred from INTERNET or other external networks to RNC by GGSN and SGSN via GPRS Tunnel Protocol. RNC relay the packet data to UE and UE present data to the end user.

Uu lu

USIM

ME

Cu

Node B

Node BRNC

lub

VLR

SGSN GGSN

HLR

INTERNET

External NetworksCNUTRANUE

Figure 8-2 UMTS Structure for Packet Switch Domain

II. Protocol Stack in User Plan for Packet Switch Domain

As shown in Figure 8-3, the user plane consists of a layered protocol structure providing user information transfer, along with associated information transfer control procedures. The header compression is performed by PDCP.


8-7

L1

RLC

PDCP

MAC

E.g., IP,PPP

Application

L1

RLC

PDCP

MAC

ATM

UDP/IP

GTP-U

AAL5

Relay

L1

UDP/IP

L2

GTP-U

E.g., IP,PPP

3G-SGSNUTRANUEIu-PSUu Gn Gi

3G-GGSN

ATM

UDP/IP

GTP-U

AAL5

L1

UDP/IP

GTP-U

L2

Relay

Figure 8-3 Protocol Stack in User Plan for Packet Switch Domain (Rel99)

III. PDCP in the Radio Interface Protocol Architecture

PDCP in the Radio Interface Protocol Architecture is shown in Figure 8-4.

Every PS domain RAB is associated with one RB, which in turn is associated with one PDCP entity. Each PDCP entity is associated with one or two (one for each direction) RLC entities depending on the RB characteristic (namely uni-directional or bi-directional) and RLC mode. The PDCP entities are located in the PDCP sub-layer.

PDCP in RNC and UE perform the function of header compression and decompression of IP data streams (e.g., TCP/IP and RTP/UDP/IP headers for IPv4 and IPv6) at the transmitting and receiving entity, respectively. Every PDCP entity uses zero, one or several different header compression protocol types.


8-8

. . .

. . .

RLC

PDCP-SDU

PDCP- sublayer

RLC-SDU

Radio Bearers

UM-SAP AM-SAP

C-SAP

TM-SAP

PDCP entity

HC Protocol Type2

HC Protocol Type1

PDCP entity

PDCP entity

HC Protocol Type1

PDCP-SAPs

SDU numbering

HC Protocol Type1

HC Protocol Type2

Figure 8-4 PDCP Structure in the radio interface protocol architecture[2]

8.4.3 Algorithm

I. Overview of the Header Compression Algorism

Figure 8-5 shows the composition and procedure of header compression algorisms.


8-9

Compressor

Decompressor

Compressible chainof subheaders

Judge Algorithm

Packet Flow JudgeAlgorithm

Packet FlowType

NONTCP

Slow-StartAlgorithm

Periodic HeaderRefresh Algorithm

TCP

FEEDBACK

NO

OUTPUTINPUT

NO

Header RequestAlgorithm

Twice Algorithm

Decompressfail

YES

fail again

YES

Figure 8-5 Algorithms in an entire compress-decompress procedure

II. Compressible Chain of Subheaders Judge Algorithm[RFC2507-7]

Subheaders that may be compressed include IPv6 base and extension headers, TCP headers, UDP headers, and IPv4 headers. The compressible chain of subheaders extends from the beginning of the header

a) up to but not including the first header that is not an IPv4 header, an IPv6 base or extension header, a TCP header, or a UDP header, or

b) up to and including the first TCP header, UDP header, Fragment Header, Encapsulating Security Payload Header, or IPv4 header for a fragment,

Whichever gives the shorter chain. For example, rules a) and b) both fit a chain of subheaders that contain a Fragment Header and ends at a tunneled IPX packet. Since rule b) gives a shorter chain, the compressible chain of subheaders stops at the Fragment Header.


8-10

III. Packet Flow Judge Algorithm

Compressor uses criterion it finds appropriate to group packets into packet streams. To determine what packet stream a packet belongs to, a compressor :

a) examine the compressible chain of subheaders,

b) examine the contents of an upper layer protocol header such as TCP or UDP,

c)examine whether the defining fields of compressible chain of subheaders are changed

IV. The Twice Algorithm for TCP Packet Flow[RFC2507 10.1]

In this algorithm the decompressor computes a checksum to determine if its context information has been updated properly. All failed checksums are assumed to result from a lost header-compressed packet. Assuming that the lost packet’s delta is the same as the current packet’s delta, the context data is then adjusted by adding the delta of the current packet. The decompressor recomputes the checksum and, if successful, continues to deliver packets as if nothing had happened. If it is not successful, the delta is applied a second time, which means adding the delta and recomputing the checksum again.

Analysis of traces of various TCP bulk transfers show that applying the delta of the current segment one or two times will repair the context for between 83 and 99 per cent of all single-segment losses in the data stream. For the acknowledgment stream, the success rate is smaller due to the delayed ack mechanism of TCP. The "twice" mechanism repairs the context for 53 to 99 per cent of the losses in the acknowledgment stream.

V. Header Request Algorithm for TCP Packet Flow[RFC2507 10.2]

When TWICE fails, another recovery mechanism called Header Request is available for repairing the context at the decompressor. When the decompressor fails to repair the context after a loss, the decompressor will optionally request a complete header from the compressor. This is possible only when bi-directional links are used, since the decompressor must communicate with its compressor. The decompressor sends a context state message to the compressor when making a header request. The context state message can include all compressed packet streams that need a context update.

VI. Compression Slow-Start Algorithm for NONTCP Packet Flow[RFC2507 3.3.1]

To allow the decompressor to recover quickly from loss of a full header that would have changed the context, full headers are sent periodically with an exponentially increasing period after a change in the context as shown in Figure 8-6. This technique avoids an exchange of messages between compressor and decompressor. Such exchanges can be costly for wireless mobiles as more power is consumed by the transmitter and delay can be introduced by switching between sending and receiving.


8-11

| . | . ...| . . . . | . . . . . . . . |. . . . . . . . . . . . . . . . | ..............................

| : full header. : compressed header

Figure 8-6 Exponentially increasing period after a change

Figure 8-6 shows how packets are sent after change. The compressor keeps a variable for each non-TCP packet stream, F_PERIOD, which keeps track of how many compressed headers may be sent between full headers. When the headers of a non-TCP packet stream change so that its context changes, a full header is sent and F_PERIOD is set to one. After sending F_PERIOD compressed headers, a full header is sent. F_PERIOD is doubled each time a full header is sent during compression slow-start.

VII. Periodic Header Refresh Algorithm for NONTCP Packet Flow[RFC2507 3.3.2]

To avoid losing too many packets if a receiver has lost its context, there is an upper limit, F_MAX_PERIOD, on the number of non-TCP packets with compressed headers that may be sent between header refreshes. If a packet is to be sent and F_MAX_PERIOD compressed headers have been sent since the last full header for this packet stream was sent, a full header must be sent.

To avoid long periods of disconnection for low data rate packet streams, there is also an upper bound, F_MAX_TIME, on the time between full headers in a non-TCP packet stream. If a packet is to be sent and more than F_MAX_TIME seconds have passed since the last full header was sent for this packet stream, a full header must be sent.

8.5 Interaction

None

8.6 Implementation

8.6.1 Engineering guideline

None

8.6.2 Parameter [RFC2507 14]

Header compression parameters are negotiated between compressor and decompressor. RNC configures the header compression parameters according to RFC2507 and 25.306(UE Radio Access capabilities).

The following parameter is fixed for all implementations of this header compression scheme.


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MIN_WRAP - minimum time of generation value wrap around.

The following parameters can be negotiated between compressor and decompressor. If not negotiated, the values must be as specified by DEFAULT.

F_MAX_PERIOD: Largest number of compressed non-TCP headers that may be sent without sending a full header.

F_MAX_TIME: Compressed headers may not be sent more than F_MAX_TIME seconds after sending last full header.

MAX_HEADER: The largest header size in octets that may be compressed TCP_SPACE: Maximum CID value for TCP NON_TCP_SPACE: Maximum CID value for non-TCP EXPECT_REORDERING: Whether use the reordering mechanisms.

See Table 8-1 for more details about these parameters.

Table 8-1 Header compression parameter

Parameter Name Default Value

Recommended Value

Minimum Value

Maximum Value

Unit

MIN_WRAP 3 3 3 3 s

F_MAX_PERIOD 256 256 1 65535 -

F_MAX_TIME 5 3 1 255 -

MAX_HEADER 168 168 60 65535 byte

TCP_SPACE 15 15 3 255 -

NON_TCP_SPACE 15 15 3 65535 -

EXPECT_REORDERING No No - - -

8.6.3 Example

None


1) RFC2507

Some information is from RFC2507, as marked in the documents. The copyright statement of RFC2507 is as follows:

Full Copyright Statement(RFC2507)

Copyright (C) The Internet Society (1999). All Rights Reserved.


8-13

This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English.

The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

2) 3GPP TS 25.323 V5.2.0 (2002-09) "Packet Data Convergence Protocol (PDCP) Specification"

Feature Description HUAWEI UMTS Radio Access Network Chapter 9 LoCation Service

9-1

Chapter 9 LoCation Service

9.1 Introduction

Location based service is one of most exciting dimensions in UMTS. UE position knowledge can be used for example in support of Radio Resource Management functions, location-based services for operators, subscribers and third party service providers.

There are all together three mobile positioning methods standardized in WCDMA:

CELL-ID OTDOA A-GPS

This description gives a brief introduction of LCS services, methods by which location information is obtained, and parameters required to fulfill the UE positioning procedure.

This description is mainly confined to the UTRAN Access Stratum. Meanwhile, some CN related terms will be referred when needed.

9.2 Glossary

9.2.1 Terms

LCS: LoCation Services (LCS) is a service concept in system (e.g. GSM or UMTS) standardization. LCS specifies all the necessary network elements and entities, their functionalities, interfaces, as well as communication messages, to implement the location service functionality in a cellular network.

LCS Feature: the capability of a PLMN to support LCS Client/server interactions for locating Target UEs.

LCS Server: a software and/or hardware entity offering LCS capabilities. The LCS Server accepts services requests, and sends back responses to the received requests. The LCS server consists of LCS components, which are distributed to one or more PLMN and/or service provider.

LCS Client: a software and/or hardware entity that interacts with a LCS Server for the purpose of obtaining location information for one or more UEs. LCS Clients subscribe to LCS in order to obtain location information. LCS Clients may or may not interact with human users. The LCS Client is responsible for formatting and presenting data and managing the user interface (dialogue). The LCS Client may reside in the UE.


9-2

Location (Based) Application: a location application is an application software processing location information or utilizing it in some way. The location information can be input by a user or detected by UTRAN or UE. Navigation is one location application example.

LBS: Location Based Service (LBS) is a service provided either by telecom operator or a 3rd party service provider that utilizes the available location information of the terminal. Location Application offers the User Interface for the service. LBS is either a pull or a push type of service (see Location Dependent Services and Location Independent Services).

Position Estimate: the geographic position of a UE expressed in latitude and longitude data, and optionally altitude data. The Position Estimate shall be represented in a well-defined universal format. Translation from this universal format to another geographic positioning system may be supported, although the details are considered outside the scope of the primitive services.

Positioning: positioning is a functionality, which estimates a geographical position (of e.g. a UE).

Positioning method: a principle and/or algorithm that the estimation of geographical position is based on, e.g. AOA, TOA, TDOA. For example, GPS is based on TOA, and E-OTD (on GSM) or OTDOA (on UMTS) are based on TDOA. Currently, AOA is not standardized on 3GPP.

Global Positioning System: the Global Positioning System (GPS) consists of three functional elements: Space Segment (satellites), User Segment (receivers), and Control Segment (maintenance etc.). The GPS receiver estimates its own location based on the observed times of arrival of the satellite signals.


A-GPS network Assisted GPS

AOA Angular Of Arrival

CN Core Network


DGPS Differential Global Positioning Systems

DRNC Drift RNC

FCC Federal Communications Commission

GDP Geometric Dilution of Position

GMLC Gateway MLC

GPS Global Positioning System

IPDL Idle Period Downlink

LCS LoCation Services


9-3

LMU Location Measurement Unit

LMU-A LMU type A

LMU-B LMU type B

OTDOA Observed Time Difference Of Arrival


RAN Radio Access Network


RTD Real Time Difference

RTT Round Trip Time

SAI Service Area Identifier

SMLC Servicing Mobile Location Centre

SRNC Serving RNC

TOA Time Of Arrival

TOW Time Of Week

UE User Equipment


UTC Universal Time Coordinates



9.3 Application

9.3.1 Availability


9.3.2 Benefit

The LCS feature gives the service provider capability to supply location information to CN according to requested QoS.

By using hybrid method which combines individual UE positioning method, it can be expected that relatively high location accuracy could be achieved.

9.3.3 Limitations and Restrictions

These LCS methods are restricted by license. The RNC supports the three standard mobile positioning methods only when the “CELLID POSITION”, “OTDOA POSITION”, and “AGPS POSITION” licenses are purchased.


9-4

The number of simultaneous LCS users is confined to 24*176. 24 denotes max number of rack per RNC, and 176 denotes max LCS users allowed per rack, which is one tenth of max numbers of simultaneous calls allowed per rack (SPU).

The uncertainty of the position measurement is network implementation dependent and at the choice of the network operator. The uncertainty may vary between networks as well as areas within a network. The uncertainty may be hundreds of meters in some areas and only a few meters in others.

To make full use of mobile positioning methods, it is preferable that UE to be located should has ability to support kinds of UE positioning capability, for instance support for Network Assisted GPS, and Support for Rx-Tx time difference type2 measurement, as well as Support for IPDL which serves as an enhancement for OTDOA method.


There are all together three mobile positioning methods standardized in WCDMA:

CELL-ID OTDOA A-GPS

These methods are complementary with each other rather than competing, and suited for different purposes.

The above methods may be operated in two modes: UE-assisted and UE-based. The two modes differ in where the actual position calculation is carried out.

In the UE-assisted mode, the UE makes the measurements and direct the measures to RNC where the position calculation are carried out, taking into consideration the measures from NodeB, LMU as well as from UE.

In the UE-based mode, the UE makes the measurements and also carries out the position calculation, and thus requires additional information, such as the position of the measured NodeBs, or GPS navigation data that is required for the position calculation. It should be noted that currently only UE based AGPS method is supported in this mode.

Generally, positioning an UE involves two main steps:

1) Signal measurements; and 2) Position estimate computation based on the measurements.

The signal measurements may be made by the UE, the NodeB or an LMU. The basic signals measured are typically the UTRA radio transmissions; however, A-GPS method also makes use of GPS radio navigation signals in addition to UTRA radio transmissions.

The position estimate computation may be made by the UE or by the UTRAN.


9-5

9.4.1 QoS of LCS

The QoS of LCS service contains several aspects, for instance: horizontal accuracy, vertical accuracy, response time, positioning priority. Currently, only horizontal accuracy and response time are took into consideration in deciding positioning method to be used in a specific location request from CN.

I. Horizontal accuracy

The horizontal accuracy is subject to the method used, and the activity of network elements as well as the position of the UE within the coverage area.

Different positioning methods render various positioning accuracy under the same environment. Generally, AGPS method can give out best positioning performance with highest horizontal accuracy, whereas CELL ID method could only produce coarse result with lowest horizontal accuracy.

The accuracy of positioning related measurements also contributes significantly to the positioning accuracy. Typically, positioning related measurements are provided by NodeB, UE, or LMU. And their accuracy depends on the capability of corresponding network elements as well as the multi-path propagation delay environment where these measurements are carried out or where UE is in.

For example, A-GPS can give out highest accurate result if UE is under a clear sky, but it fails to function normally when UE is in an in-door condition.

There is no method which can always produce acceptable result on all kind of radio environments, Hence, hybrid method is proposed to combine various methods to get more attractive result.

Table 9-1 gives a general estimate of various methods with respect to horizontal accuracy. In this table, the figure under 67% denotes the worst horizontal deviation in meter within the best 67% performance of all attempts; 95% denotes the worst horizontal deviation in meter within the best 95% performance of all attempts. As shown in this table, only hybrid method can give out satisfying outcome to meet FCC requirement (67% is 50m, and 95% is 150m).

Table 9-1 Horizontal Accuracy (m)

Method 67% 95%

CELL ID 500 3000

OTDOA 76 281

AGPS 33 262

HYBRID 49 147


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II. Response time

The response time is dependent on the method used. Different method would require different measurements. And each measurement has it own specific measurement durations. Hence, different method would take different period to fulfill the positioning procedure.

Table 9-2 gives a general estimate of various methods with respect to response time. As shown in this table, AGPS or hybrid method consumes more time than OTDOA and CELL ID method do.

Table 9-2 Response Time (s)

Method Response Time (s)

CELL ID 0.5 ~ 1.5

OTDOA 1.5 ~ 4

AGPS 5 ~ 8

HYBRID 5 ~ 9

From the above, you can conclude that there is trade-off between two major aspects of QoS of LCS: horizontal time and response time.

9.4.2 Brief Descriptions of Possible Location Based Services [1]

I. Public Safety Services

Service providers offer these location-based services for the good of the public. They are made available without pre-subscription, for instance, the Emergency Services.

II. Location Based Charging

Location Based Charging allows a subscriber to be charged different rates depending on the subscriber's location or geographic zone, or changes in location or zone. The rates charged may be applicable to the entire duration of the call, or to only a part of call's duration. This service may be provided on an individual subscriber basis, or on a group basis.

For example, when provided on an individual basis this service could apply reduced rates to those areas most often frequented by the subscriber by taking into consideration the subscriber's daily route and life style.

III. Tracking Services

Tracking services allow the tracking of location and status of specific service group users. Examples may include supervisors of a delivery service who needs to know the


9-7

location and status of their employees, parents who need to know where their children are, animal tracking, and tracking of assets.

IV. Enhanced Call Routing

Enhanced Call Routing (ECR) allows subscriber or user calls to be routed to the closest service client based on the location of the originating and terminating calls of the user. The user may optionally dial a feature or service code to invoke the service (*GAS for closest gas station, etc).

V. Location Based Information Services

Location-Based Information services allow subscribers to access information for which the information is filtered and tailored based on the location of the requesting user. Service requests may be initiated on demand by subscribers, or automatically when triggering conditions are met, and may be a singular request or result in periodic responses.

The following subsections provide some examples of possible location based information services.

1) Navigation

The purpose of the navigation application is to guide the handset user to his/her destination. The destination can be input to the terminal, which gives guidance how to reach the destination. The guidance information can be e.g. plain text, symbols with text information (e.g. turn + distance) or symbols on the map display. The instructions may also be given verbally to the users by using a voice call.

2) City Sightseeing

City Sightseeing would enable the delivery of location specific information to a sightseer. Such information might consist of combinations of the services described throughout this document to describe historical sites, provide navigation directions between sites, facilitate finding the nearest restaurant, bank, airport, bus terminal, restroom facility, etc.

3) Location Dependent Content Broadcast

An example of such a service may be localized advertising. For example, merchants could broadcast advertisements to passersby based on location / demographic / psychographic information (for example "today only, 30% off on blue jeans").

VI. Network Enhancing Services

The Network Enhancing Services described in this section are for further study and privacy issues will require further consideration.

1) Applications for Network Planning

The network operator may be able to use location information to aid network planning. The operator may be able to locate calls in certain areas to estimate the distribution of


9-8

calls and user mobility for network planning purposes. These applications may be used for hot spot detection and user behavior modeling

2) Applications for Network QoS Improvements

The network operator may be able to use location services to improve the Quality of Service of the network. The location system may be used to track dropped calls to identify problematic areas. The system may also be used to identify poor quality areas.

3) Improved Radio Resource Management

The location of the handset may be used for more intelligent handovers and more efficient channel allocation techniques.

9.4.3 LCS Architecture

I. Overview of LCS Architecture

Figure 9-1 shows general arrangement of UE positioning in UTRAN. The General UE positioning procedure in UTRAN starts with a request over Iu from the CN. UTRAN then determines the UE position by selecting a suitable positioning method. UTRAN then responds to the request with the estimated position and possible an associated accuracy.

MSC

Uu Iub

NodeB(LMU-B)

LMU-A

Iu

UE

AGPS receiver

AGPS receiver

NodeB(LMU-B)

NodeB(LMU-B)

RNC(LMU-B)

LCS ClientGMLC

GPS satellite syst em

Figure 9-1 General arrangement of UE Positioning in UTRAN

Communication among the UTRAN UE Positioning entities makes use of the messaging and signaling capabilities of the UTRAN interfaces (Iub, Uu). Currently, Iur interface is not supported with respect to UE positioning function.

The functionality of each kind of UTRAN positioning entity is presented as following sections.


9-9

II. RNC

RNC manages the UTRAN resources (including NodeBs, LMUs), the UE and location calculation functions, to estimate the position of the UE and return the result to the CN.

The RNC provides the following functionality:

positioning method selection according to required QoS from CN, and method option configured in database as well as LCS license purchased by the network operator;

Request dedicated measurements for only one UE, typically from the UE itself and one or more related NodeB in which are supposed to be near the target UE; The RNC should provide UE positioning assistance data in the support of various positioning methods;

regularly request UE Positioning related common measurements for a number of UE, typically from several LMU and several NodeB under control of RNC;

Regularly request UE Positioning related AGPS reference information for a number of UE, typically from AGPS receiver resided either in NodeB or in RNC.

perform location calculating function and estimate the accuracy of the position estimate;

Controlling the IPDL mechanism for OTDOA measurements. This functionality is optional and depends highly on whether the target cell supports IPDL or not. It is not mandatory for NodeB to support IPDL mechanism;

perform any needed co-ordinate transformations between different geographic reference systems;

Send the results to the LCS entities in the CN.

As part of its operation, the UTRAN UE Positioning calculating function resided in RNC may require additional information, for instance, location information of NodeBs or LMUs. This is obtained by the function directly by communication with database in RNC.

III. NodeB

NodeB is a network element of UTRAN that may provide measurement results for position estimation and makes measurements of radio signals and reports these measurements to the RNC.

The NodeB provides the following functionality:

Performing RTT measurement and reporting it’s result to RNC on demand.

It should be noted that parts of functionality of NodeB are shifted to LMU entity which sometimes is a supplementary part of NodeB, for instance LMU type B (LMU-B).

IV. LMU

The main reason to introduce LMU in UMTS positioning architecture is that WCDMA is not a synchronous communication system. It is necessary to get the exact


9-10

asynchronous information before the UE position is determined. Hence, LMU is responsible to perform Radio Interface Timing measurements and report the exact timing difference between NodeBs or between NodeB and GPS radio signals to RNC.

The LMU provides the following functionality:

Performing UTRAN GPS timing of cell frames measurement. Performing SFN-SFN Observed Time Difference measurement. Currently, this

functionality is not supported.

LMU could report to RNC the measurement results in response to requests from the RNC, or it may be instructed by RNC to measure and report regularly or when there are significant changes in radio conditions (e.g. changes in the UTRAN GPS timing of cell frames or SFN-SFN Observed Time Difference).

The LMU has two types: type A (LMU-A in short) and type B (LMU-B in short).

LMU-A is also called stand alone LMU. It is indeed an independent element rather than an auxiliary one that interacts with controlling RNC via Uu interface. Currently, LMU-A is not supported mainly due to it’s drawback of difficulty to maintain.

LMU-B is logical resource rather than a real appliance that adheres to a NodeB and communicates with controlling RNC via Iub interface. Currently, LMU-B can only perform and report to RNC the UTRAN GPS timing of cell frames measurement.

There may be one or more LMUs associated with the UTRAN and an UE Positioning request may involve measurements by one or more LMU. The RNC will select the appropriate LMUs depending on the UE Positioning method being used and the location of the target UE.

V. UE

The UE may make measurements of downlink signals determined by the chosen positioning method.

The UE provides the following functionality:

Performing OTDOA type 2 measurements as in OTDOA method. Performing UE Rx-Tx type 2 measurements as in OTDOA method or enhanced

CELL ID method. Performing UE GPS timing of cell frames measurement as in AGPS method. Performing AGPS related measurement such as Doppler frequency and

pseudo-range measurement for the particular satellite as in AGPS method. Performing related measurements and calculation of UE position as in UE based

methods, for instance in UE based AGPS method. Reporting the measurement results to RNC.

It should be noted here that UE may also contain LCS applications, or access an LCS application, for example, for the purpose of self navigation.


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VI. AGPS receiver

To make UE easier to acquire the GPS satellite, it is recommended for the UTRAN to provide the GPS related assistance information to UE. Thus, AGPS receiver is introduced to gain original GPS satellite related data for UTRAN positioning purpose.

The AGPS receiver provides GPS related data in response of RNC and reporting to RNC periodically until RNC send an explicit command to stop requiring GPS related data.

There are two different ways to connect the AGPS receiver to UTRAN:

One way is to attach the AGPS receiver to NodeB so that original GPS satellite related data can be directed to RNC via Iub interface by Information Exchange Procedure. This solution has been standardized within 3GPP, but currently, this functionality is not supported due to difficulty to implement among various kind of NodeB.

Another way is to link the AGPS receiver directly to RNC. In this solution, the AGPS receiver provides the same kind of data to RNC just as what is interchanged via Iub interface by Information Exchange Procedure.

9.4.4 CELL ID + RTT

The principle of CELLID + RTT positioning method is shown in Figure 9-2.

UE1 NodeB NodeB

NodeB

TOA

UE2

Figure 9-2 CELLID + RTT positioning method

The position of an UE is estimated with the knowledge of its serving NodeB. The estimated position of the UE can be indicated as the Service Area Identity or as the geographical center of the serving cell coverage area.

The geographical position can also be obtained by combining information on the cell geographical center with some other available information, such as RTT measured by NodeB and UE Rx-Tx type 2 measured by UE itself.


9-12

In some circumstance, for instance, during soft handover, the RNC have to make decision to select which cell would be best suitable cell for final calculation of UE position. Or RNC can combine these cells to determine final UE position.

Figure 9-3 illustrates the operations for the CELL ID + RTT when the request for position information is initiated by a LCS application signaled from the Core Network.

2. Meas Ctrl

6. Loc Rprt

4. Dedi Meas Init Rsp

5. Meas Rprt

3. Dedi Meas Init Req

1. Loc Rprt Ctrl

CNRNCNode B

RNSAPRNSAP

UE

NBAPNBAP

RRCRRC

NBAP

RRC

NBAP

RRC

RNSAPRNSAP

Figure 9-3 General flow of CELL ID + RTT method

1) The operation begins with an authenticated request from CN via LOCATION REPORT CONTROL message in Iu interface to RNC. The RNC considers the location request, the UTRAN and UE capabilities, the SMLC license, as well as method configured in database. Supposing in this time, RNC select UE assisted CELL ID + RTT method.

2) The RNC requests from the UE the measurement of the UE Rx-Tx type 2 for the signals in the active sets via MEASUREMENT CONTROL message in Uu interface. These measurements are made while the UE is in connected mode CELL_DCH state, otherwise they will not be sent (skip to step 6 directly).

3) The RNC requests the RTT measure for the UE from cells in the active sets via DEDICATED MEASUREMENT INITIALIZATION REQUEST message in Iub interface.

4) The UE returns the UE Rx-Tx type 2 measures to the RNC via MEASUREMENT REPORT message in Uu interface.

5) Cells in active sets return the RTT measures to the RNC via DEDICATED MEASUREMENT INITIALIZATION REPONSE message in Iub interface.


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6) The RNC passes the position estimate to the CN via LOCATION REPORT message in Iu interface after it has finished a position calculation using above measures, if any.

The calculation may include a co-ordinate transformation to the geographic system or Service Area Identity requested by the application. The position estimate includes the position, the estimated accuracy of the results and the time of day of the estimate.

9.4.5 OTDOA-IPDL

I. Principle

The principle of OTDOA-IPDL positioning method is shown in Figure 9-4.

NodeB(LMU-B)

NodeB(LMU-B)

NodeB(LMU-B)

UE

OTDOA HyperbolaTOA

OTDOA Hyperbola

Figure 9-4 OTDOA positioning method

The primary standard OTDOA measurement is the "SFN-SFN observed time difference" observed at the UE. These measurements, together with other information concerning the surveyed geographic position of the transmitters and the RTD of the actual transmissions of the downlink signals may be used to calculate an estimate of the position of the UE.

Each OTDOA measurement for a pair of downlink transmissions describes a line of constant difference (a hyperbola) along which the UE may be located. The UE's position is determined by the intersection of these hyperbola lines for at least two pairs of NodeBs.

As an enhanced solution, according to its capability, the NodeB may provide idle periods in the downlink instructed by RNC, so that UE can detect signals more easier from neighboring NodeBs. The support of these idle periods in the UE is optional. The


9-14

simplest case of OTDOA-IPDL is without idle periods. In this case the method can be referred to as simply OTDOA.

The OTDOA-IPDL method involves measurements made by the UE (OTDOA type 2) and LMU (e.g. LMU-B) of the UTRAN frame timing (e.g. UTRAN GPS timing of cell frames). These measures are then sent to the RNC where the position of the UE is calculated.

In order to support the OTDOA method, the positions of the UTRAN transmitters needs to be accurately known by the calculation function in RNC. This can be done by a kind of conventional technique for instance a GPS receiver.

Furthermore, the RTD of the DL transmissions must also be known to perform the calculation. Since generally the UTRAN transmitters are unsynchronized, the RTD will change over time as the individual clocks drift. Thus, RTD estimations may need to be made regularly and the calculation function updated appropriately. Generally, RTD is calculated by RNC upon the know position of the UTRAN transmitters and the know position of the LMU as well as the measurement results observed by the LMU.

The accuracy of the position estimates made with this technique depends on the precision of the timing measurements, the relative position of the NodeBs involved (Geometric Dilution of Position, in short GDP), and is also subject to the effects of multi-path radio propagation. Thus it is preferable that UE would provide SFN-SFN observed time difference measurements for as many cells as it can receive so that some kind of deviation reduction technique could be used such as Least Mean Square method.

II. OTDOA-IPDL Operations Message Flow

Figure 9-5 illustrates the operations for the OTDOA-IPDL when the request for position information is initiated by a LCS application signaled from the Core Network.


9-15

2.3. Meas Ctrl

8. Loc Rprt

5. Dedi Meas Init Rsq

6.7. Meas Rprt

4. Dedi Meas Init Req

1. Loc Rqrt Ctrl

CNRNCNode B

RNSAPRNSAP

UE

NBAPNBAP

RRCRRC

NBAP

RRC

NBAP

RRC

RNSAPRNSAP

Figure 9-5 General flow of OTDOA-IPDL method

1) The operation begins with an authenticated request from CN via LOCATION REPORT CONTROL message in Iu interface to RNC. The RNC considers the location request, the UTRAN and UE capabilities, the SMLC license, as well as method configured in database. Supposing in this time, RNC select UE assisted OTDOA-IPDL method with CELL ID + RTT method as a supplement.

2) The RNC requests from the UE the measurement of the OTDOA for the signals in the active and neighborhood sets via MEASUREMENT CONTROL message in Uu interface.

3) If it is considered advantageous to do so, the RNC requests the UE Rx-Tx timing difference type 2 information of reference cell from the UE via MEASUREMENT CONTROL message in Uu interface. Note that a prerequisite in this step is that reference cell must be in active set, otherwise this measurement request will not be sent.

It should be noted that only one MEASUREMENT CONTROL message in Uu interface is actually sent which combines two measurement requirements in step 2, and step 3, if any.

4) If it is considered advantageous to do so, the RNC requests the RTT measure of reference cell for the UE from the serving NodeB via DEDICATED MEASUREMENT INITIALIZATION REQUEST message in Iub interface. Note that a prerequisite in this step is same as step 3.

5) The NodeB returns the RTT measure of reference cell to the RNC via DEDICATED MEASUREMENT INITIALIZATION RESPONSE message in Iub interface, if it was requested.


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6) The UE returns the UE Rx-Tx timing difference type 2 information of reference cell to the RNC, together with a time stamp of when the value was obtained via MEASUREMENT REPORT message in Uu interface, if it was requested.

7) The UE returns the OTDOA measures to the RNC via MEASUREMENT REPORT message in Uu interface.

It should be noted that only one MEASUREMENT REPORT message in Uu interface is actually sent which combines two measurement results in step 7, and step 6, if any.

8) The RNC passes the position estimate to the CN via LOCATION REPORT message in Iu interface after RNC has finished a position calculation using the OTDOA type 2 measures, RTD, the known position of NodeBs antenna and if necessary, RTT and UE Rx-Tx timing difference type 2 measure.

The calculation may include a co-ordinate transformation to the geographic system requested by the application. The position estimate includes the position, the estimated accuracy of the results and the time of day of the estimate.

To support above procedure, Information to be transferred from UTRAN to UE in air interface is listed as table 3. In this table, “No” means that the relative information is only needed in UE based OTDOA mode, which now is not supported. “Yes, if active” means that if IPDL is active in servicing NodeB, IPDL information is preferable to be sent to UE to assist it to observe more neighbor NodeBs.

Table 9-3 Information to be transferred from UTRAN to UE

Information needed

Intra frequency Cell Info (neighbour list) Yes

Ciphering information for UE Positioning No

Sectorisation of the neighbouring cells No

RTD values for Intra frequency Cell Info Yes

RTD accuracy No

Measured roundtrip delay for primary serving cell No

Geographical position of the primary serving cell No

Relative neighbour cell geographical position No

Accuracy range of the geographic position values No

IPDL parameters Yes, if active


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The data that may be signaled from UE to RNC in air interface is listed in table 4. In this table, “No” means that the relative information is only needed in UE based OTDOA mode, which now is not supported.

Table 9-4 Information to be transferred from UE to SRNC

Information needed

OTDOA measurement results Yes

OTDOA measurement accuracy Yes

UE geographical position No

Position accuracy indicator No

III. Common measurement message flow for obtaining RTD

In order to obtain RTD of pairs of DL transmissions which is indispensable for OTDOA-IPDL method, RNC must first get measures from LMU. Currently, only LMU-B and GPS frame timing measurement is supported to support RTD calculation.

The common measurement procedure in order to get GPS frame timing measures in Iub interface between LMU-B and RNC is illustrated in figure 6.

2. Comm Meas Init Rsp

1. Comm Meas Init Req

CNRNCNode BUE

NBAPNBAP

NBAPNBAP

3. Comm Meas RprtNBAPNBAP

4. Comm Meas Term NBAPNBAP

Figure 9-6 Common measurement procedure between LMU-B and RNC

1) RNC initialize the common measurement procedure via COMMOM MEASUREMENT INITIALIZATION REQUEST message in Iub interface to


9-18

instruct LMU-B to start UTRAN GPS timing of cell frames measurement with proper parameters, for instance, reporting mode.

2) LMU-B respond to RNC with COMMOM MEASUREMENT INITIALIZATION RESPONSE message in Iub interface to indicate that it now started to work.

3) LMU-B makes measurement and reports to RNC the UTRAN GPS timing of cell frames measures via COMMOM MEASUREMENT REPORT message in Iub interface, in a regular interval or in a condition when a significant change occurred among measurements according to threshold parameter set by RNC previously.

4) When explicitly instructed by RNC via COMMOM MEASUREMENT TERMINATION message in Iub interface, LMU-B stop reporting to RNC, and stop measuring, if necessary.

9.4.6 AGPS

I. Principle

The principle of AGPS positioning method is shown in Figure 9-7.

RNC(SMLC)

NodeB

UENodeB

GPS satellite system

AGPS receiver

AGPS receiver

Figure 9-7 AGPS positioning method

Assisted GPS (AGPS) methods make use of UE, which is equipped with radio receiver capable of receiving GPS signals.

The originality of introducing AGPS method is to provide higher positioning accuracy while decreasing the complexity of UE which is capable of observing GPS transmissions by supplying assistant GPS data from RNC to UE, thus quickening GPS related measure, reducing power consuming as well as improving the UE GPS receiver’s sensitivity.


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The AGPS methods rely on signaling between UE GPS receiver and a continuously operating GPS reference receiver network, which has clear sky visibility of the same GPS constellation as the assisted UE.

When the UE is unable to detect a sufficient number of satellites, the assisted GPS method can be combined with other information, for instance, TOA or altitude assistance which can compensate for one satellite measurement respectively, to make the position calculation possible.

II. UE search

Provided that timing assistance, data assistance, and/or frequency reference is available in the UE, they should be applied in the GPS signal search procedure. The UE search procedure involves a three-dimensional search for a satellite pseudo-random code, time of arrival of a signal and the associated carrier Doppler.

"Modulation wipe-off" is defined here to mean a removal of the GPS navigation data bit modulation to GPS signals received at the UE, through the application of UTRAN timing and data assistance provided from the UTRAN to the UE. This process allows the UE to coherently integrate received GPS signals beyond 1 data bit period (i.e., 20 milliseconds).

III. Position Determination

There are two types of AGPS methods, namely UE-based and UE-assisted, which differ according to where the actual position calculation is carried out.

The UE-based method maintains a full GPS receiver functionality in the UE, and the position calculation is carried out by the UE, thus allowing stand-alone position fixes.

In the UE-assisted method, the UE employs a reduced complexity GPS receiver functionality. This carries out the pseudo-range (code phase) measurements. These are signaled, using RRC signaling, to the RNC that estimates the position of the UE and carries out the remaining GPS operations. In this method, accurately timed code phase signaling is required on the downlink.

IV. Assistance GPS Data

The assistance GPS data signaled from RNC to the UE may include information listed below:

Data assisting the measurements; e.g. reference time, visible satellite list, satellite signal Doppler, code phase, Doppler and code phase search windows. This data can be valid for a few minutes (e.g., less than 5 minutes) or longer depending on the code phase and Doppler search window size that can be accommodated by the UE;

Data providing means for position calculation; e.g. reference time, reference position, satellite ephemeris, clock corrections. Satellite ephemeris and clock corrections data can be used for up to six hours.


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If DGPS is utilized, then differential corrections may also be transmitted. If Selective Availability is turned off, these corrections can be valid for a few minutes or more. The DGPS data is valid for a large geographical area, so one centrally located reference receiver can be used to service this large region.

Notes:

Certain types of GPS Assistance data may be derived, wholly or partially, from other types of GPS Assistance data.

V. AGPS Operations Message Flow

Figure 8 illustrates the operations for the AGPS when the request for position information is initiated by a LCS application signaled from the Core Network.

2. Meas Ctrl

3.4 Meas Rprt

5. Loc Rprt

1. Loc Rprt Ctrl

CNRNCNode B

RNSAPRNSAP

UE

RRCRRC

RRCRRC

RNSAPRNSAP

Figure 9-8 General flow of AGPS method

1) The operation begins with an authenticated request from CN via LOCATION REPORT CONTROL message in Iu interface to RNC. The RNC considers the location request, the UTRAN and UE capabilities, the SMLC license, as well as method configured in database. Supposing in this time, RNC select UE assisted or UE based AGPS method

2) Depending on the UE capabilities, the RNC may prepare certain GPS assistance data. This information may include: the reference time for GPS, the satellite IDs, the Doppler frequency, the pseudo-range search window and its center, the ephemeris and clock corrections, etc.

For UE-based method, the RNC may prepare additional information, such as: the almanac. Then jump to step 4.


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For UE-assisted method, the RNC may optionally request the following information: the time difference between the NodeB and the GPS (e.g. UTRAN GPS timing of cell frames) obtained from LMU-B and RTT measurement obtained from NodeB.

After AGPS assistance data got prepared, the RNC requests from the UE the measurement of GPS satellite pseudo-ranges and other information such as Doppler frequency via MEASUREMENT CONTROL message in Uu interface.

Additionally, the RNC may request Rx-Tx timing difference type 2 information from the UE via another MEASUREMENT CONTROL message in Uu interface as a supplement to AGPS measures.

3) In case of UE assisted method, the UE returns to the RNC the measurement of GPS satellite pseudo-ranges and other information via MEASUREMENT REPORT message in Uu interface. If requested, the UE may also return the Rx-Tx time difference type 2 information, together with a time stamp of when this value were obtained via another MEASUREMENT REPORT message in Uu interface.

4) In case of UE based method, UE returns the position estimate to the RNC. This estimate includes the position, the estimated accuracy of the results and the time of the estimate.

5) The RNC passes the position estimate to the CN via LOCATION REPORT message in Iu interface after The UE position is calculated in the RNC.

The calculation may include a co-ordinate transformation to the geographic system requested by the application. The position estimate includes the position, the estimated accuracy of the results and the time of day of the estimate.

Table 5 lists information that may be sent from RNC to UE according to the procedure specified above.

Table 9-5 Information that may be transferred from UTRAN to UE

Information UE-assisted UE-based

Number of satellites for which assistance is provided Yes Yes

reference time for GPS (TUTRAN-GPS) Yes Yes

3-d reference position No Yes

ionospheric corrections No Yes

satellite ID for identifying the satellites for which assistance data is provided

Yes Yes

Ephemeris & clock corrections Yes Yes

UTC offset No Yes


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DGPS corrections No Yes

almanac data No Yes

real-time integrity (e.g. a list of unusable satellites) No Yes

doppler (0th order term) Yes No

Doppler Search Window width Yes No

doppler (1st order term) Yes No

azimuth Yes No

elevation Yes No

code phase Yes No

code phase centre and search window width Yes No

The information that may be signaled from UE to RNC is listed in table 6.

Table 9-6 Information that may be transferred from UE to RNC


reference time for GPS (TUE-GPS) Yes Yes

serving cell information No Yes

Latitude/Longitude/Altitude/Error ellipse No Yes

velocity estimate in the UE No Yes

satellite ID for which measurement data is valid Yes No

Whole/Fractional chips for information about the code-phase measurement

Yes No

C/N0 of the received signal from the particular satellite used in the measurements

Yes No

Doppler frequency measured by the UE for the particular satellite

Yes No

pseudo-range RMS error Yes No

multipath indicator Yes No


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number of Pseudo-ranges Yes No

The specific AGPS assistant data will be brief described as following[3]

Almanac data

The almanac parameters specify the coarse, long-term model of the satellite positions and clocks. These parameters are a subset of the ephemeris and clock correction parameters in the Navigation Model, although with reduced resolution and accuracy. The almanac model is useful for receiver tasks that require coarse accuracy, such as determining satellite visibility. The model is valid for up to one year, typically.

Optionally, "SV Global Health" information may accompany this almanac information to indicate the health condition of specific satellite.

DGPS corrections

DGPS corrections can be used to adjust biases in the pseudo-range measurements by UE or RNC in a simpler and more accurate way. This kind of data typically contains biases and changing rates of biases of pseudo-range measurements.

Ionospheric corrections

The ionospheric Model contains information needed to model the propagation delays of the GPS signals through the ionosphere. Proper use of this information allows a single-frequency GPS receiver to remove approximately 50% of the ionospheric delay from the range measurements. The ionospheric Model is valid for the entire constellation and changes slowly relative to the Navigation Model.

Ephemeris data and clock correction

Ephemeris data and clock corrections provide an accurate model of the satellite positions to the UE.

Real Time integrity monitor function

An Integrity Monitor (IM) function in the network should detect unhealthy (i.e., failed/failing) satellites.

f) GPS reference time

GPS reference time may be used to provide a mapping between UTRAN and GPS time.

UTC

UTC parameters may be used to provide Coordinated Universal Time to the UE.

Reference Location


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The Reference Location contains a 3-D location (without uncertainty) of UE. The purpose of this field is to provide the UE with a priori knowledge of its position in order to improve GPS receiver performance.

VI. Information Exchange Procedure for AGPS Assist Data

In order to obtain AGPS assist data which is indispensable for AGPS method, RNC shall first initiate Information exchange procedure in Iub interface.

Information exchange procedure between RNC and NodeB is illustrated in figure 9.

2. Info Ex Init Rsp

1. Info Ex Init Req

CNRNCNode BUE

NBAPNBAP

NBAPNBAP

3. Info Ex Rprt

NBAPNBAP

4. Info Ex Term

NBAPNBAP

Figure 9-9 Information Exchange procedure between RNC and NodeB

1) RNC initialize the Information Report Control Exchange procedure via INFORMATION EXCHANGE INITIALIZATION REQUEST message in Iub interface, to instruct NodeB to start report AGPS assistant data with proper parameters, for instance, reporting mode.

2) NodeB respond to RNC with INFORMATION EXCHANGE INITIALIZATION RESPONSE message, to indicate that it now started to work.

3) NodeB makes measurement and reports to RNC AGPS assistant data via INFORMATION EXCHANGE REPORT message, in a regular interval or in a condition when a significant change occurred among measurements according to threshold parameter set by RNC previously.

4) When explicitly instructed by RNC via INFORMATION EXCHANGE TERMINATION message in Iub interface, NodeB stop reporting to RNC, and stop measuring, if necessary.

Currently, only RNC AGPS receiver is supported, thus there is indeed no Information Report Control Exchange procedure in Iub interface. The AGPS receiver resided in


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RNC totally takes place of AGPS receiver resided in NodeB and works just the same way as the Information Report Control Exchange procedure over Iub interface.

In order to get the AGPS assistant data, RNC shall first get the AGPS assistant data from AGPS receiver. Table 7 shows the information that may be transferred from AGPS receiver to its RNC.

Table 9-7 Information that may be transferred from AGPS receiver to RNC


GPS Navigation Model & Time Recovery Yes Yes

GPS Ionospheric Model Yes Yes

GPS UTC Model Yes Yes

GPS Almanac Yes Yes

GPS Real-Time Integrity Yes Yes

DGPS Corrections Yes Yes

GPS Recerver Position Yes Yes

In order to get higher timing accuracy, RNC may request the UTRAN GPS Timing of Cell Frame from NodeB (LMU-B). Information that may be transferred from LMU-B to RNC is illustrated in figure 8.

Table 9-8 Information that may be transferred from LMU-B to RNC


reference time for GPS (TUTRAN-GPS) Yes Yes

9.4.7 Assistance Data Delivery to UE

When requested by CN, RNC shall provide UE positioning related assistance data to target UE after it has successfully obtained the required assistance data.

Typically, there are two kind of UE positioning related assistance data:

UE based AGPS assistance data, this kind of assistance data is same as assistance data sent over air interface if the positioning method is UE based AGPS.

UE based OTDOA assistance data, this kind of assistance data is same as assistance data sent over air interface if the positioning method is UE based OTDOA.


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Figure 9-10 shows how the assistance data shall be sent to UE.

3. Loc Rel Data Rsp

1. Loc Rel Data Req

CNRNCNode B

RNSAPRNSAP

UE

RRCRRC

RNSAPRNSAP

2. Assist Data Deliv ery

Figure 9-10 Assistance Data Delivery to UE

1) When requested by CN via LOCATION RELATED DATA REQUEST message in Iu interface, RNC start to collect required assistance data form LMU, NodeB or AGPS receiver depend on which data CN instructs RNC to forward to UE.

2) RNC deliver to UE assistance data via ASSISTANCE DATA DELIVERY message in Uu interface after it has successfully obtained the required assistance data.

3) RNC reply to CN via LOCATION RELATED DATA RESPONSE message in Iu interface, indicating that requested assistance data has been successfully sent to target UE.

9.5 LCS Interaction with Soft Handover

In UE assisted enhanced CELL ID method, SMLC should decide which cells could be required from NodeBs (cells) and UE to get RTT and corresponding UE Rx-Tx type 2 measures.

Since those measures can only be performed in connection mode CELL_DCH state and RLs in active set is maintained in soft handover module. Thus, SMLC need to communicate with soft handover module to get the information about cells in active set.

9.6 Implementation


To activate LCS functionality within UTRAN, configure all or part of following parameters first.

SMLC algorithm parameters. This kind of data specifies the overall SMLC algorithm parameters, mainly concerned with timer length of individual procedure required to fulfill whole positioning procedure.

Cell positioning information. This kind of data specifies cell position information as well as cell coverage knowledge.


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SMLC neighboring cell. This kind of data specifies the neighboring cell set to be used especially in OTDOA method.

GPS Frame Timing measurement parameters. This kind of data specifies how GPS Frame Timing measurement shall be performed in Iub interface.

IPDL Information: This kind of data specifies IPDL parameters to be used especially in OTDOA method.

GPS Reference Receiver. This kind of data specifies GPS reference receiver position information and describes how GPS reference receiver works and reports to SMLC. Those data is used only in AGPS method.

Before part of parameters (in “Cell positioning information”) was configured, one should first carry out some kind of field test to get those parameters, including:

Delay Measurement of Cell TX Channel. Delay Measurement of Cell RX-TX Channel.

In the following section, more details information about above set of parameters will be described as well as the way how to configure them.

9.6.2 Parameter

I. set SMLC algorithm parameters

Table 9 shows parameters and their implications in order to set proper values for RNC SMLC algorithm.

Those parameters can be configured or modified by MML command:

SET SMLC

Table 9-9 location service algorithm parameters

ID Name Range

(Recommend)Comments

SMLCAUDITTIMERLEN

Resource audit timer 1~720 min

(720)

To insure conformity of LSC related internal resources within RNC

SHORTUPTIMERLEN

Short position procedure timer

1~60 s

(6)

Max allowed duration of one positioning procedure. It is used only if there applies no retransmission mechanism in case of failure of Uu measurement

LONGUPTIMERLEN

Long position procedure timer

1~60 s

(12)

Max allowed duration of one positioning procedure. It is used only if there applies retransmission mechanism in case of failure of Uu measurement


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ID Name Range

(Recommend)Comments

UESTATTRANTIMERLEN

UE status transition timer

1~60 s

(4)

Max allowed duration of UE RRC state transition when it is thought to be needed

UPMEASRESENDTIMERLEN

Measurement message resending timer

1~6 s

(1)

If there applies retransmission mechanism in case of failure of Uu measurement, this parameter specifies the period that must elaped before sending another request of measurement to UE

CELLINFOQUERYTIMERLEN

Cell information query timer

1~6 s

(1)

Max allowed duration to gather necessary assistance data.

DATARESPTIMERLEN

Assistance data delivery response timer

1~6 s

(3)

Max allowed duration for L2 to respond to SMLC of Assistance data delivery message to UE

WAITMEASRSLTCONS

Waiting measurement result timer offset

1~6 s

(1)

Offset added to timer length when sending request of measurement to UE

MAXRESENDNUM

Max times of resending measurement

0~8

(2)

If there applies retransmission mechanism in case of failure of Uu measurement, this parameter specifies max retransmission times

RTTMEASFILTERCOEFF

RTT measurement filtering coefficient

0 to 9, 11, 13, 15, 17, 19.

(0)

Default value mean no filtering applying on RTT measures mainly because a rapid reponse of RTT measures is preferred

NOIPDLTDOAMEASPERIOD

OTDOA measurement period without IPDL

NOTE1*

(500 ms)

Max allowed duration for UE to respond to SMLC of UE assisted OTDOA measure without IPDL

IPDLTDOAMEASSHORTPERIOD

Short OTDOA measurement period with IPDL

NOTE1*

(1000 ms)

Max allowed duration for UE to respond to SMLC of UE assisted OTDOA measure with IPDL, It is used only if there applies no retransmission mechanism in case of failure of Uu measurement

IPDLTDOAMEASLONGPERIOD

Long OTDOA measurement period with IPDL

NOTE1*

(2000 ms)

Max allowed duration for UE to respond to SMLC of UE assisted OTDOA measure with IPDL, It is used if there applies retransmission mechanism in case of failure of Uu measurement


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ID Name Range

(Recommend)Comments

CELLIDMEASPERIOD

Cell ID measurement period

NOTE1*

(500 ms)

Max allowed duration for UE to respond to SMLC of UE assisted CELL ID measure

GPSMEASSHORTPERIOD

Short GPS measurement period

NOTE1*

(2000 ms)

Max allowed duration for UE to respond to SMLC of UE assisted APGS measure, It is used only if there applies no retransmission mechanism in case of failure of Uu measurement

GPSMEASLONGPERIOD

Long GPS measurement period

NOTE1*

(4000 ms)

Max allowed duration for UE to respond to SMLC of UE assisted APGS measure, It is used if there applies retransmission mechanism in case of failure of Uu measurement

UEBASEDMEASPERIOD

UE based measurement period

NOTE1*

(4000 ms)

Max allowed duration for UE to respond to SMLC of UE based AGPS measure

EMPHERISSENDFLAG

GPS ephemeris sending flag

NODELIVERY, DELIVERY

(NODELIVERY)

Default value means GPS ephemeris data shall not be sent in air interface in order to reduce traffic flow

ALMANACSENDFLAG

GPS almanac sending flag

NODELIVERY, DELIVERY

(NODELIVERY)

Default value means GPS almanac data shall not be sent in air interface in order to reduce traffic flow

SMLCMETHOD SMLC method enum *{0 ~11 }

(11)

Default value means a UE assisted hybrid method incorporated with CELL ID, OTDOA, AGPS will be supported in RNC

Possible value of measurement period of Uu interface is listed as following: [250, 500, 1000, 2000, 3000, 4000, 6000, 8000, 12000, 16000, 20000, 24000, 28000, 32000, 64000] ms.


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Notes:

There implies some constraints on above parameters as following: The value of [Short position procedure timer] must be smaller than that of [Long position procedure

timer]. The value of [OTDOA measurement period without IPDL] must be smaller than that of [Short

OTDOA measurement period with IPDL]. The value of [Short OTDOA measurement period with IPDL] must be smaller than that of [Long

OTDOA measurement period with IPDL]. The value of [Short GPS measurement period] must be smaller than that of [Long GPS

measurement period].

Details of enumeration of SMLC method is listed and explained at table 10.

Table 9-10 SMLC method configuration

Enum ID Name Comments

0 NONE No method No method is supported

1 CID Basic CELLID The position of UE is known only at cell level

2 ASS_ECID Enhanced CELLID UE assisted CELL ID possiblely making use of RTT and UE Rx-Tx type 2 measures

3 ASS_OTDOA UE assisted OTDOA

UE assisted OTDOA only. It is not allowed to degrade SMLC method to carry out a coraser result if OTDOA has failed.

4 ASS_AGPS UE assisted AGPS UE assisted AGPS only. It is not allowed to degrade SMLC method to carry out a coraser result if AGPS has failed.

5 BAS_AGPS UE based AGPS UE based AGPS only. It is not allowed to degrade SMLC method to carry out a coraser result if AGPS has failed.

6 ASS_AGPS_CID

UE assisted AGPS and basic CELL ID

UE assisted AGPS plus basic CELL ID. It is allowed to degrade SMLC method to carry out a coraser result if AGPS has failed.

7 BAS_AGPS_CID

UE based AGPS and basic CELL ID

UE based AGPS plus basic CELL ID. It is allowed to degrade SMLC method to carry out a coraser result if AGPS has failed.

8 GEN_AGPS_CID

Generic AGPS and basic CELL ID

Generic (UE assisted or UE based) AGPS plus basic CELL ID. It is allowed to degrade SMLC method to carry out a coraser result if Generic AGPS has failed.


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Enum ID Name Comments

9 ASS_OTDOA_ECID

UE assisted OTDOA and enhanced CELL ID

UE assisted OTDOA plus enhanced CELL ID. It is allowed to degrade SMLC method to carry out a coraser result if OTDOA has failed.

10 ASS_AGPS_ECID

UE assisted AGPS and enhanced CELL ID

UE assisted AGPS plus enhanced CELL ID. It is allowed to degrade SMLC method to carry out a coraser result if AGPS has failed.

11 ASS_AGPS_OTDOA_ECID

UE assisted AGPS, OTDOA and enhanced CELL ID

Hybrid method incorporated with UE assisted AGPS, OTDOA and enhanced CELL ID. It is most promising method which is expected to be effective under all circumstances.

It should be emphasized here that SMLC is not bound to use the method configured form table 10. Other factors may be also taken into consideration in method selection, such as:

UE positioning capability, especially “Network Assisted GPS support” and “Support for Rx-Tx time difference type 2 measurement”.

License purchased by network operator. License of SMLC is divided into three parts: license of CELL ID, license of OTDOA, license of AGPS. If license of OTDOA or AGPS is purchased, then CELL ID functionality will automatically be taken into effect without any more purchase of license of CELL ID.

QoS of location request from CN, for instance, horizontal accuracy and response time.

II. Set cell positioning information

Table 11 shows parameters of cell positioning information.

Only when those parameters are properly configured, can LCS service be provided to network operator correctly. Those parameters can be configured, modified, or listed by following MML command:

ADD SMLCCELL MOD SMLCCELL RMV SMLCCELL LST SMLCCELL


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Table 9-11 parameters of cell positioning information

ID Name Range

(Recommend)Comments

CELLID Cell ID 0~65535 -

LATITUDEDEGREE

Cell antenna latitude -90~90 degree Degree of cell antenna latitude

LONGITUDEDEGREE

Cell antenna longitude

-180~180 degree

Degree of cell antenna longitude

ALTITUDEMETER

Cell antenna altitude -10000~10000m Cell antenna height

MAXANTENNARANGE

Cell antenna max coverage

1~100000 m Max cell antenna coverage distance

ANTENNAORIENTATION

Cell antenna orientation

0~360 degree Cell antenna main-lobe direction angle (the offset angle between the antenna main-lobe and the North).

ANTENNAOPENING

Cell antenna opening 0~360 degree Cell antenna coverage opening angle

CELLAVERAGEHEIGHT

Cell average altitude -10000~10000 m

Average height of cell coverage area

CELLHEIGHTSTD

Cell altitude standard deviation

0 ~10000 m Standard deviation of cell height

CELLENVIRONMENT

Cell environment case

NLOS, LOS, MIXED (MIXED)

Cell environment type is listed as following:

NLOS: Non-Line-of-sight transmission

LOS: Line-of-sight transmission.

MIXED: both of above exist in the cell.

This information is usful to determine achieved accuracy of OTDOA.

TXCHANDELAY

cell transmission channel delay

0~65535 ns

(0)

Cell TX channel delay. This parameter is introduced In order to compensate measurement deviation of GPS frame timing measurement reported by LMU-B

RXTXCHANDELAY

cell transceiver channel delay

0~65535 ns

(0)

Total delay of RX and TX channel of the cell. This parameter is introduced In order to compensate measurement deviation of RTT reported by NodeB


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ID Name Range

(Recommend)Comments

MASKREPEATEXIST

Repeater flag TRUE, FALSE

(FALSE)

This parameter reveals whether there exists repeaters or not in the cell. This information is usful to determine achieved accuracy of OTDOA.

Default value means there is no repeater in this cell.

OTDOAACTIVATEFLAG

OTDOA active flag TRUE, FALSE

(TRUE)

This parameter reveals whether OTDOA shall be supported or not in the cell. This is indeed an algorithm switch in cell level.

AGPSACTIVATEFLAG

AGPS active flag TRUE, FALSE

(TRUE)

This parameter reveals whether AGPS shall be supported or not in the cell. This is indeed an algorithm switch in cell level.

Notes:

There implies some constraints on above parameters as following: This cell must have been configured. The value of [cell transmission channel delay] must be less than or equal to that of [cell transceiver

channel delay].

III. Set SMLC Neighboring Cell

Table 12 shows parameters of SMLC Neighboring Cell to a reference cell.


ADD SMLCNCELL RMV SMLCNCELL LST SMLCNCELL

One could used above command several times to configure an adequate number of neighboring cells. Neighboring cells should be chosen in such way that UEs in any position within the reference cell could hear at least 2 neighboring cells.


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Table 9-12 SMLC Neighboring Cell parameters

ID Name Range Comments

REFCELLID Reference cell ID 0~65535 Uniquely identifying a location reference cell

NCELLID Neighboring cell ID for UE positioning

0~65535 Uniquely identifying a location neighboring cell. It is recommended to configure five to six netigbor cells per reference cell.

Notes:

There implies some constraints on above parameters as following: Both the reference cell and neighboring cell must have been configured with location configuration

information. The reference cell and neighboring cell cannot be located in the same NodeB. One cell can be configured with 6 location neighboring cells at most. It should be noted also that one

must configure more than 2 neighboring cell in order to take OTDOA method into effect.

IV. Set Cell GPS Frame Timing measurement parameters

Table 13 shows parameters of Cell GPS Frame Timing measurement configuration to a cell.


ADD CELLGPSFRMTIMING MOD CELLGPSFRMTIMING RMV CELLGPSFRMTIMING LST CELLGPSFRMTIMING

Table 9-13 Cell GPS Frame Timing measurement parameters

ID Name Range

(Recommend) Comments

CELLID Cell ID 0~65535 Uniquely identifying the reference cell which regularly reports to RNC the GPS frame timing measures

REPORT PERIOD

GPS frame timing meas report period

10ms~20000ms;

(100)

UTRAN GPS frame timing measurement reporting interval.


9-35

ID Name Range


MEASFILTERCOEFF

GPS frame timing meas filter coef

0 to 9, 11, 13, 15, 17, 19.

(0)

Physical layer measurement filtering coefficient value.

Default value means no L1 filtering is used on this measure

STARTFLAG GPS frame timing active flag

INACTIVE, ACTIVE

(ACTIVE)

Default value means UTRAN GPS frame timing measurement is to be activated.

Notes:

There implies some constraints on above parameters as following: Only after the cell has been configured with location information can UTRAN GPS frame timing measurement information be added.

V. Set or activate IPDL Information

Table 14 shows IPDL parameters of a cell.

Only when those parameters are properly configured, can enhanced OTDOA method (with IPDL mechanism) be provided to network operator correctly. Those parameters can be configured, modified, or listed by following MML command:

ADD IPDL MOD IPDL RMV IPDL LST IPDL ACT IPDL DEA IPDL LST IPDLCELL

Table 9-14 IPDL parameters

ID Name Range


NODEB NAME

NodeB name

1~31 characters.NodeB name which specify the NodeB to be configured with IPDL parameters

IPSPACING IP spacing

5, 7, 10, 15, 20, 30, 40, 50 frames

(10)

Number of radio frames between two idle periods.

The larger this number, the less compact to system capacity, but the longer for UE to complete OTDOA measures in case when it need aid from IPDL


9-36

ID Name Range


IPLENGTH IP length5, 10 symbols

(10)

Length of an idle period.

The larger this number, the more compact to system capacity, but more efficient to apply cohensive detection in case when it need aid from IPDL.

SEED Seed 0~63

(0)

Pseudo-random sequence generator seed to decide series of IP occurance.

It should be noted that no value of this set has advantage over others. It is recommended to attribute different value to cells nearby this NodeB in order to homogenize or randomize IP occurance.

Notes:

there implies some constraints on above parameters as following: IPDL information of the home NodeB of the cell must have been configured before attempting to activate IPDL.

It should be pointed out that currently, only IPDL mechanism in continuous mode is supported. The burst mode IPDL pattern is left for further consideration.

VI. set GPS Reference Receiver

Table 15 shows parameters of GPS Reference Receiver.

Only when those parameters are properly configured, can AGPS method be provided to network operator correctly. Those parameters can be configured, modified, or listed by following MML command:

ADD GPS MOD GPS RMV GPS LST GPS ACT GPS DEA GPS DSP RNCGPS RST RNCGPS


9-37

Table 9-15 Parameters of GPS Reference Receiver

ID Name Range


GPSID GPS ID 0~65535 Uniquely identifying a GPS receiver

CFGT GPS type RNC, NODEB Indicating whether the GPS receiver is configured on RNC or NodeB

CELLID Cell ID 0~65535 ID of the home cell of the GPS receiver, if it is installed in NodeB.

GPSPERIOD GPS data report period

1~60 min

(1)

GPS data reporting period. This parameter specify how often should the GPS data be reported to SMLC

DGPSPERIOD DGPS data report period

1~60 min

(1)

Differential GPS data reporting period. This parameter specify how often should the DGPS data be reported to SMLC

LATITUDE GPS antenna latitude -90~90 degree -

LONGITUDE GPS antenna longitude

-180 ~180.

degree -

ALTITUDE GPS antenna altitude -10000~10000 m -

Notes:

there implies some constraints on above parameters as following:

The GPS receiver can be configured on RNC or NodeB according to [GPS type]. The RNC can be configured with one GPS receiver at most while one NodeB can be configured with

five GPS receivers at most. If the GPS receiver is configured in the WRBS of the RNC, its control shelf is the RFN source shelf.

The physical connection between the GPS receiver and the WRBS must satisfy this relation. If the GPS receiver is configured on the NodeB, the ID of the home cell of the GPS receiver must be

specified. This cell must have been configured and be in active state.

It should be noted again that currently, only AGPS receiver resided in RNC is supported.


9-38

VII. Delay Measurement of Cell TX Channel

Table 16 shows Parameter of Delay Measurement of Cell TX Channel.

This functionality is introduced In order to compensate measurement deviation of GPS frame timing measurement reported by LMU-B. It could be fulfilled by following MML command:

TST CELLTXDELAY

Table 9-16 Parameter of Delay Measurement of Cell TX Channel


CELLID Cell ID 0~65535 Uniquely identifying a cell

IMSI IMSI ID digits 0~9 with length of 6~15

Uniquely identifying a UE

Notes:

Before using this functionality, one must check carefully to meet the following conditions and constraints: The cell to be tested must have been configured with cell location information. Where, [AGPS active

flag] must be configured as "ACTIVE". The specified UE must have the A-GPS measurement ability and UE GPS frame timing

measurement ability. The specified UE must be located in the coverage of the cell and must be in line-of-sight

transmission mode with the antenna of the cell. In addition, it can well receive GSP satellite signals within its air domain.

The specified UE must be accessed into the cell first and must be in CELL_DCH status before above MML command is activated.

The principle of delay measurement of cell TX channel will be briefly described as following:

1) NodeB (LMU-B) reports to RNC UTRAN GPS frame timing measures requested by RNC.

2) UE reports to RNC UE GPS frame timing measures requested by RNC. 3) UE’s position is determined by UE assisted AGPS method. Because UE is

located under clear sky, one can believe UE’s position could be very accuracy in this case.

4) Let’s denote “Delta-GPS-Timing” as the timing difference between UTRAN GPS frame timing measures and UE GPS frame timing measures; and denote


9-39

“Distance-Timing” as the timing difference between UE and NodeB derived from the known position of UE and NodeB (cell) and the velocity of light “c”.

5) Subtracts “Distance-Timing” form “Delta-GPS-Timing”, one can get cell TX channel delay, supposing that UE has given us an accurate UE GPS frame timing measures.

Typically, cell TX channel delay is in a scale about several micro seconds.

VIII. Delay Measurement of Cell RX-TX Channel

Table 17 shows Parameter of Delay Measurement of Cell RX-TX Channel.

This functionality is introduced In order to compensate measurement deviation of RTT reported by NodeB, and it could be fulfilled by following MML command:

TST CELLRXTXDELAY

Table 9-17 Parameter of Delay Measurement of Cell RX-TX Channel


CELLID Cell ID 0~65535 Uniquely identifying a cell

IMSI IMSI ID digits 0~9 with length of 6~15

Uniquely identifying a UE

Notes:

Before using this functionality, one must check carefully to meet the following conditions and constraints: The cell to be tested must have been configured with cell location information. Where, [AGPS active

flag] must be configured as "ACTIVE". The specified UE must have the A-GPS measurement ability and UE RX-TX Type 2 measurement

ability. The specified UE must be located in the coverage of the cell and must be in line-of-sight

transmission mode with the antenna of the cell. In addition, it can well receive GSP satellite signals within its air domain.

The specified UE must be accessed into the cell first and must be in CELL_DCH status before above MML command is activated.

The principle of delay measurement of cell RX-TX channel will be briefly described as following:

1) NodeB reports to RNC RTT measures requested by RNC. 2) UE reports to RNC UE Rx-Tx type 2 measures requested by RNC.


9-40

3) UE’s position is determined by UE assisted AGPS method. Because UE is located under clear sky, one can believe UE’s position could be very accuracy in this case.

4) Let’s denote “RTT-Timing” as timing difference which is subtraction of UE Rx-Tx type 2 measures from RTT measures; and denote “Round-Distance-Timing” as twice of the timing difference between UE and NodeB derived from the known position of UE and NodeB (cell) and the velocity of light “c”.

5) Subtracts “Round-Distance-Timing” form “RTT-Timing”, one can get cell RX-TX channel delay, supposing that UE has given us an accurate UE Rx-Tx type 2 measures.

Typically, cell RX-TX channel delay is in a scale about several micro seconds.

9.6.3 Example

I. Set SMLC Algorithm Parameters

SET SMLC: SMLCAUDITTIMERLEN=720, SHORTUPTIMERLEN=6, LONGUPTIMERLEN=12, UESTATTRANTIMERLEN=4, UPMEASRESENDTIMERLEN=1, CELLINFOQUERYTIMERLEN=1, DATARESPTIMERLEN=3, WAITMEASRSLTCONS=1, MAXRESENDNUM=2, RTTMEASFILTERCOEFF=D0, NOIPDLTDOAMEASPERIOD=D500, IPDLTDOAMEASSHORTPERIOD=D1000, IPDLTDOAMEASLONGPERIOD=D2000, CELLIDMEASPERIOD=D500, GPSMEASSHORTPERIOD=D2000, GPSMEASLONGPERIOD=D4000, UEBASEDMEASPERIOD=D4000, EMPHERISSENDFLAG=NODELIVERY, ALMANACSENDFLAG=NODELIVERY, BAMCONFIGSMLCMETHOD=ASS_AGPS_OTDOA_ECID;

Explanation: After the above operation, RNC is configured with default parameters as specified in previous section to run LCS service within UTRAN.

II. Set Cell Position Information

ADD SMLCCELL: CELLID=1, LATITUDEDEGREE=31232120, LONGITUDEDEGREE=121000000, ALTITUDEMETER=0, MAXANTENNARANGE=1000, ANTENNAORIENTATION=0, ANTENNAOPENING=120, CELLAVERAGEHEIGHT=0, CELLHEIGHTSTD=250, CELLENVIRONMENT=MIXED_ENVIRONMENT, TXCHANDELAY=0, RXTXCHANDELAY=0, MASKREPEATEXIST=NOREPEATER, OTDOAACTIVATEFLAG=ACTIVE, AGPSACTIVATEFLAG=ACTIVE;

Explanation: After the above operation, cell 1 has configured with its own position information.

III. Set SMLC Neighboring Cell

ADD SMLCNCELL: REFCELLID=1, NCELLID=2;


9-41

Explanation: After the above operation, Cell 2 is configured as a location neighboring cell of Cell 1.

IV. Set Cell GPS Frame Timing Measurement Parameters

ADD CELLGPSFRMTIMING: CELLID=1, REPORTPERIOD=100, MEASFILTERCOEFF=D0, STARTFLAG=ACTIVE;

Explanation: After the above operation, the UTRAN GPS frame timing measurement is started, the measurement period is 1 second, and the measurement filtering coefficient is 0.

V. Set or Activate IPDL Information

ADD IPDL: NODEBNAME="NODEB1", IPSPACING=D10, IPLENGTH=D10, SEED=1;

Explanation: Add IPDL information to NodeB 1. The IPDL interval is 10 radio frames; the IPDL length is 10 symbols; and the pseudo-random sequence generator seed is 1.

ACT IPDL: CELLID=1;

Explanation: Activate the IPDL function of Cell 1.

VI. Set GPS Reference Receiver

ADD GPS: GPSID=1, CFGT=RNC, LATITUDE=10000000, LONGITUDE=20000000, ALTITUDE=100;

Explanation: Add a GPS receiver to the RNC with the antenna latitude of 10 degrees, longitude of 20 degrees and height of 100 meters.

ACT GPS: ACTT=RNC_GPS, GPSID=1;

Explanation: Activate the RNC GPS of GPS1.

VII. Delay Measurement of Cell TX Channel

TST CELLTXDELAY: CELLID=1, IMSI="460071234567000";

Explanation: After the above operation, the TX channel delay of Cell 1 can be obtained. The unit is ns.

VIII. Delay Measurement of Cell RX-TX Channel

TST CELLRXTXDELAY: CELLID=1, IMSI="460071234567000";

Explanation: After the above operation, the RX/TX channel delay of Cell 1 can be obtained. The unit is ns.


1) 3GPP TS 22.071 "Location Services (LCS); Service description, Stage 1" 2) 3GPP TS 23.171 "Functional stage 2 description of location services in UMTS".


9-42

3) 3GPP TS 25.305 "Stage 2 functional specification of User Equipment (UE) positioning in UTRAN"

4) 3GPP TS 25.215 "Physical layer – Measurements (FDD)" 5) 3GPP TS 25.331 "Radio Resource Control (RRC)" 6) 3GPP TS 25.433 "UTRAN Iub interface NBAP signaling" 7) 3GPP TS 25.413 "UTRAN Iu interface RANAP signaling"

Feature Description HUAWEI UMTS Radio Access Network Chapter 10 Power Control

10-1

Chapter 10 Power Control

10.1 Introduction

The third-generation mobile communication systems are based on CDMA technique. In this radio network users share a common frequency. Therefore, interference control is crucial issue.

Power control is especially important for the uplink direction, since a mobile station that is close to the NodeB and transmitting with excessive power can easily overshout mobiles that are at the cell edge or even block the whole cell. This is referred to as the near-far effect. The control mechanism to the control the uplink power is referred as uplink power control.

In downlink the system capacity is directly determined by the required code power for each connection. Therefore it is essential to keep the transmission powers at a minimum level while ensuring adequate signal quality at the receiving end. The control mechanism to the control the downlink power is referred as downlink power control.

In the WCDMA system, power control includes the following types:

open-loop power control inner-loop power control (also called fast closed-loop power control) outer-loop power control in both uplink and downlink downlink power balancing and so on

These types of power control are employed in uplink power control and downlink power control. As an example, Figure 10-1 illustrates the uplink power control.

UE NodeB RNCBLERFER/BER

SIR

SIR target

TPC command

Outer Loop Power Control

Inner Loop Power Control

Figure 10-1 Uplink Power Control

By adjusting the powers, Power Control maintains the link quality in uplink and downlink, mitigates the near far effect by providing minimum required power level for each connection, provides protection against shadowing and fast fading, minimizes the interference in the network, and thus improves system capacity and quality.


10-2

10.2 Glossary

10.2.1 Terms

None


BER Bit error rate

BLER Block error rate

FER Frame error rate

RSCP Received Signal Code Power

SHO Soft HandOver

SIR Signal to interference ratio

SRNC Serving Radio Network Controller

UE User equipment

10.3 Application

10.3.1 Availability


10.3.2 Benefit

1) Maintain the link quality in uplink and downlink by adjusting the powers; 2) Mitigate the near far effect by providing minimum required power level for each

connection; 3) Provide protection against shadowing and fast fading; 4) Minimize the interference in the network, thus improve capacity and quality.


None


10.4.1 Open-Loop Power Control

I. Uplink Open-Loop Power Control

The uplink open-loop power control function is located both in the terminal and in the UTRAN.


10-3

The uplink open-loop power control function requires some control parameters being broadcast in the cell and the received signal code power (RSCP) being measured by the terminal on the active P-CPICH.

Based on the calculation for the open-loop power control, the terminal sets:

the initial powers for the first PRACH preamble the initial powers for the uplink DPCCH before starting the inner-loop power

control (See Figure 10-2) 1) During the random access procedure, the power of the first transmitted preamble

is set by the UE as: Preamble_Initial_Power = Primary CPICH DL TX power -CPICH_RSCP + UL

interference + Constant Value, where Primary CPICH DL TX power, UL interference and Constant Value are broadcasted in the System Information, and CPICH_RSCP is measured by UE.

2) When establishing the first DPCCH, the UE starts the uplink inner-loop PC at a power level according to:

DPCCH_Initial_power = DPCCH_Power_offset - CPICH_RSCP, where the DPCCH_Power_offset is calculated in the RNC, and the CPICH_RSCP is measured by the terminal.

BCH :•CPICH channel pow er• UL interference level

•Measure CPICH_RSCP•Determine the initial transmitted power

RACH

Figure 10-2 Uplink Open-Loop Power Control

II. Downlink Open-Loop Power Control

In the downlink, the open-loop power control is used to set the initial power of the downlink channels based on the downlink measurement reports from the UE. This function is located in both UTRAN and UE (See Figure 10-3). A possible algorithm for calculating the initial power of the DPDCH when the first bearer service is set up is


10-4

α−××= Total

CPICH

CPICHDLinitial P

)0N

Ec(

P)

0NEb(

WRP

Where R is the user bit rate, W is the chip rate, (Ec/N0)CPICH is reported by the UE, α is the downlink orthogonality factor, and PTotal is the carrier power measured at the NodeB and reported to the RNC.

Determine the downlink initial pow er control

RACH reports the measured value

Measure CPICH Ec/N0

DCH

Figure 10-3 Downlink Open-Loop Power Control

10.4.2 Inner-Loop Power Control

The inner-loop power control, also referred to as fast closed-loop power control, relies on the feedback information at Layer 1 from the opposite end of the radio link. This allows the UE/NodeB to adjust its transmitted power based on the received SIR level at the NodeB/UE for compensating the fading of the radio channel.

The inner-loop power control function in UMTS is used for the dedicated channels in both the uplink and downlink directions and for the CPCH in uplink.

In WCDMA fast power control with 1.5 kHz frequency is supported.

I. Uplink Inner-Loop Power Control

The uplink inner-loop power control is used to set the power of the uplink DPCH. The RNC sends the target SIR to NodeB. The NodeB compares the SIR target with the estimated SIR calculated on the pilot symbol of the uplink DPCCH once every slot. If the estimated SIR is greater than the target SIR, the NodeB transmits a TPC command ‘down’ to the UE on the downlink DPCCH. If the received SIR is below the target, a TPC command ‘up’ is sent. The benefits of fast power control are showed in Figure 10-4.


10-5

Figure 10-4 BLER vs. Eb/N0 for 12.2 kbps speech in multipath Case 1 channel

II. Downlink Inner-Loop Power Control

The downlink inner-loop power control sets the power of the downlink DPCH. The UE receives from higher layers the SIR target for the downlink outer-loop power control together with other control parameters. UE estimates the downlink SIR from the pilot symbols of the downlink DPCH. This SIR estimation is compared with a target SIR. If the estimation is greater than the target, the UE transmits the TPC command ‘down’ to the NodeB, otherwise the UE transmits the TPC command ‘up’.

III. Downlink Power Balancing

When the UE is in SHO only one single TPC command is sent on the uplink to all cells participating in the SHO. Since it would introduce too much delay to combine all the received TPC commands in the RNC and send one combined command back, each cell detects the TPC command independently. Due to, for example, signaling errors in the air interface it is possible that each cell is interpreting this TPC command differently. As a consequence one cell lowers its transmission power to that mobile while the other cell might increase it, and therefore the downlink powers are drifting apart.

Since power drifting degrades the performance in downlink, methods to combat this effect are need. The transmission code power levels of the connection from the cells in SHO are forwarded to the RNC after they have been averaged. From these measurements the RNC derives a reference power value, Pref, which is sent to the cells (See Figure 10-5). This is then used to periodically calculate a small power adjustment towards the reference value, which balances the link powers of the SHO connections and therefore reduces the power drifting.


10-6

SRNC can receive information from the NodeB about the transmission power levels of the soft handover connections, and start downlink power balancing to reduce the amount of power drifting if necessary.

UE

SRNC

NodeB NodeB

Figure 10-5 Downlink power balancing

10.4.3 Outer-Loop Power Control

The aim of the outer-loop power control algorithm is to maintain the quality of the communication at the level defined by the quality requirements of the bearer service in question. To achieve the quality, outer-loop power algorithm adjusts the target SIR for the inner-loop power control. This operation is done for each DCH belonging to the same RRC connection. The SIR target needs to be adjusted when the UE speed or the multipath propagation environment change. The higher the variation of the received power is, the more necessary it is to adjust the SIR target. If a fixed SIR target was selected, the resulting quality of the communication would be too low or too high, causing an unnecessary power rise in most situations.

The uplink quality is observed after macrodiversity selection combining in the RNC, and the target SIR is provided to all cells participating in the SHO. During SHO the Iub and Iur DCH data streams coming from the different cells are combined in the SRNC into one data stream in uplink. In downlink the DCH data stream is split between the NodeBs. This combining and splitting in the RNC is performed by the Macro Diversity Combiner (MDC). The MDC in the RNC is based on the information received from the NodeB in FP frames, namely transport block-specific CRC results and possibly estimated quality information. Reliable SHO is based on the CFN information included in the Iub/Iur data streams. At the UE the MRC of the received signals is performed at symbol level (data and pilots).

I. Uplink Outer-Loop Power Control

The uplink outer-loop power control operates within the SRNC and is responsible for setting a target SIR in the NodeB for each individual uplink inner-loop power control. This target SIR is then updated on an individual basis for each UE according to the


10-7

estimated uplink quality, e.g. BLER or BER, for that particular RRC connection. If the received BLER is greater than the BLER target, the SIR target is increased by a certain amount, otherwise it is lowered by a certain amount.

II. Downlink Outer-Loop Power Control

The downlink outer-loop power control function is implemented in the UE, and the target SIR for the downlink inner-loop PC is adjusted by the UE using a proprietary algorithm to approach the target quality (BLER) set by the RNC.

10.5 Interaction

None

10.6 Implementation


None

10.6.2 Parameter

Constant Value: This parameter is for the calculation of Preamble_Initial_Power. It is the required C/I in uplink. Greater Constant Value produces greater interference, while smaller Constant Value results in lower access probability. The default value is -20.

Initial SIR target: Initial SIR target is service dependent. Greater Initial SIR target produces greater interference, but if it is too small, a UE can not access. For example, the default value is 2dB for 12.2kbps speech.

10.6.3 Example


1) 3GPP, 25.214 "Physical layer procedures (FDD)" 2) 3GPP, 25.427 "UTRAN Iub/Iur interface user plane protocol for DCH data

streams" 3) Jaana Laiho, Achim Wacker and Tomas Novosad, Radio Network Planning and

Optimisation for UMTS, John Wiley & Sons, LTD, 2002 4) 3GPP, 25.331 "RRC Protocol Specification"

Feature Description HUAWEI UMTS Radio Access Network Chapter 11 DCCC

11-1

Chapter 11 DCCC

11.1 Introduction

The interactive or background service has its own particular characters. The traffic volume can vary rapidly, sometimes the volume is huge and sometimes the volume is little. So, during an interactive or background service connection, because of the above character, we should dynamic allocate the OVSF channel code resource according the current volume. If the volume is huge, the more channel code resource is allocated, while the volume is little, the less channel code is allocated. If there is no volume, the UE state can transit from CELL_DCH state to CELL_FACH state and CELL_PCH/URA_PCH state.

11.2 Glossary

11.2.1 Terms

Best Effort: The Best Effort services indicate the interactive or background services.

OVSF code: The OVSF code is an Orthogonal Variable Spreading Factor code, it is used as the downlink channel code.

DCCC: Adjust the DCH rate based on the source traffic requirement (DCH user).

RRC State Control: Control the RRC state transition, different amount of resource is consumed in different state.

Request Rate: The maximum rate limit threshold that the code resources can be allocated.

DCCC threshold Rate: If the request rate is below than or equal to this rate, the dynamic allocated algorithm don’t work.


BE Best Effort

DCCC Dynamic Channel Configuration Control

DL Downlink

OVSF Orthogonal Variable Spreading Factor

RAB Radio Access Bearer

RB Radio Bearer

RL Radio Link

RLC Radio Link Control


11-2



TFC Transport Format Combination

TFCS Transport Format Combination Set

TVM Traffic Volume Measurement

UE User Equipment

UL Uplink


11.3 Application

11.3.1 Availability


11.3.2 Benefit

Through the dynamic allocating channel resource, the system resources can be optimized. Because the OVSF code is limited, the Iub and Iur band resource is limited, if the resource can be allocated by the actual traffic volume, the channel code using rate can be enhanced, the more UE call can be admitted.

Through the state transition, the UE state can transmit from CELL_DCH to CELL_FACH and from CELL_FACH to CELL_PCH/URA_PCH, in the CELL_FACH or CELL_PCH/URA_PCH state, the code resource can be saved and the UE battery consumption can decrease.


The DCCC function is restricted by license. The RNC provides DCCCC function only when “DYNAMIC CHANNEL CONFIGURATION CONTROL” license is purchased.


11.4.1 Architecture

The DCCC and state transition algorithms are embedded in the SRNC as shown in Figure 11-1.


11-3

NodeB CRNC SRNC CN

Uu Iub Iur if needed Iu

DCCC algorithm

Figure 11-1 Network architecture

11.4.2 Procedure and Algorism

The DCCC algorithm performs rate re-allocation for UEs having best effort (BE) services, (that is interactive and background) which are in the CELL_DCH RRC state. The DCCC algorithm serves the following purposes:

In the uplink the data rate is modified according to the volume of traffic to be transmitted, this information is obtained from traffic volume measurements (TVM) that are made by the UE. A TVM is triggered if the RLC buffer payload rises above an upper threshold (event 4a) for a predefined time period. A TVM is also triggered if the RLC buffer payload drops below a lower threshold (event 4b) for a predefined time period.

In the downlink, the DCCC requests a CDMA channel code which is commensurate with the volume of traffic that is being transmitted. In this way, the DCCC algorithm makes efficient use of the code resource. In order to achieve this, the RNC makes traffic volume measurements for the DL. A TVM is triggered if the RLC buffer payload rises above an upper threshold (event 4a) for a predefined time period. A TVM is also triggered if the RLC buffer payload drops below a lower threshold (event 4b) for a predefined time period.

If a service request rate is below than or equal to a DCCC control threshold, the dynamic allocated channel code resource algorithm don’t work. The threshold can be configured.

DCCC algorithm can send the “MEASURMENT CONTROL” to configure the uplink TVM upper threshold and TVM lower threshold.

UE UTRAN

MEASUREMENT CONTROL

Figure 11-2 Measurement Control[1]


11-4

The UE can send the “MEASUREMENT REPORT” to report the Event 4a and Event 4b.

UE UTRAN

MEASUREMENT REPORT

Figure 11-3 Measurement Report[1]

The downlink measure report is the same to uplink, but it is a inter primitive in UTRAN.

11.4.3 Uplink DCCC

The same to the downlink DCCC, the down limit threshold and the up limit threshold can also be configured to UE. When the UE observes that the uplink Transport Channel Traffic Volume stays a certain time below the down limit threshold (event 4b) or above the up limit threshold (event 4a), it can report to UTRAN and the UTRAN can allocate the appropriate channel resource.

The example of triggered by an up limit threshold report (event 4a):

MAC-d

UTRAN

DCCH: Radio bearer Reconfiguration

DCCH: Radio bearer Reconfiguration Complete

UL Transport Channel Traffic Volume

Threshold for Report

DCCH: Measurement Report

Evaluation

Change of MAC MUX at Action Time

UE Configuration in L2

RLC

DCH1

RLC

TFC Select

DCH2

Channel Switching

Signalling bearer RB1

DCCH DTCH

DCH/DCH substate

Figure 11-4 Transport channel reconfiguration triggered by increased UL data[2]

11.4.4 Downlink DCCC

Since downlink channelisation codes are a scarce resource a UE with a too high, allocated gross bit rate (low spreading factor) must be reconfigured and use a more appropriate channelisation code (with higher spreading factor). While a UE with too low, allocated insufficient bit rate (higher spreading factor) must also be reconfigured and use a more appropriate channelisation code (with lower spreading factor).

This could be triggered by a down limit threshold or an up limit threshold for the Transport Channel Traffic Volume and some inactivity timer, i.e. that the Transport Channel Traffic Volume stays a certain time below the down limit threshold (event 4b)


11-5

or above the up limit threshold (event 4a). After the RB has been reconfigured, some of the transport formats and transport format combinations that require a new SF can be used.

The example of triggered by a down limit threshold (event 4b):

MAC-d

UTRAN



DL Transport Channel Traffic Volume

Threshold + Timer



RLC

DCH1

RLC

TFC Select

DCH2

Channel Switching

Signalling bearer RB1

DCCH DTCH

DCH/DCHsubstate

Figure 11-5 Physical channel reconfiguration triggered by decreased DL data[2]

The example of triggered by an up limit threshold (event 4a):

MAC-d

UTRAN



DL Transport Channel Traffic Volume

Threshold DCH/DCHsubstate



RLC

Signalling bearer

DCH1

RLC

RB1

TFC Select

DCH2

Channel Switching

DCCH DTCH

Figure 11-6 Physical channel reconfiguration triggered by increased DL data[2]

11.4.5 UE State Transition

The UE state transition algorithm perform the state transition, when the RRC is setup, the UE activity is observed, if the activity is lower, UE can transit from CELL_DCH state to CELL_FACH or from CELL_FACH to CELL_PCH/URA_PCH, while if the activity is higher, it can transit from CELL_PCH/URA_PCH to CELL_FACH or from CELL_FACH to CELL_DCH. Figure 11-7 shows the RRC states and state transitions.

If the UE have the BE service and CS domain service at the same time, the state transition algorithm don’t work.

When the current state is CELL_DCH, the RNC will monitor the UE activity. An RNC timer is started if a low activity report is received. The RNC then determines the maximum number of the low activity reports, if the number of the low activity reports exceed the maximum number, RNC will trigger the move to CELL_FACH from CELL_DCH.


11-6

The transition from CELL_FACH to CELL_PCH is the same as the transition from CELL_DCH to CELL_FACH.

In CELL_PCH state, an RNC timer is started to monitor the number of CELL UPDATE message (if the cell reselection occurs, the UE will report the CELL UPDATE message), if the number exceeds a threshold, the UE transits from CELL_PCH to URA_PCH. In CELL_PCH or URA_PCH state, the UE transits to the CELL_FACH state when there is date needed to transfer or the UE is paged by UTRAN. In CELL_FACH state, when the uplink or downlink TVM report (event 4a) is received by UTRAN, the UE transits to the CELL_DCH state.

The following is state transition figure from 25.331 protocol.

Establish RRCConnection

Release RRCConnection

UTRA RRC Connected ModeUTRA:Inter-RATHandover

GSM:Handover

Establish RRCConnection

Release RRCConnection

URA_PCH CELL_PCH GSMConnected

Mode

Establish RRConnection

Release RRConnection

Idle Mode

Camping on a UTRAN cell1 Camping on a GSM / GPRS cell1

GPRS Packet Idle Mode1

GPRSPacket

TransferMode

Initiation oftemporaryblock flow

Release oftemporaryblock flow

Cell reselection

CELL_DCH out of service

in service

CELL_FACH

out of service

in service

out of service

in service

Figure 11-7 RRC States and State Transitions Including GSM[1]

11.5 Interaction

None

11.6 Implementation


To Tune the DCCC functionality within UTRAN, configure all or parts of the parameters described in the following section.

11.6.2 Parameter

UlRateThresForDCCC: The DCCC algorithm capability may be very low for some Best Effort (BE) service with very low applied maximum rate. The UL DCCC algorithm


11-7

does not activate for the BE service whose applied uplink maximum rate is smaller than or equal to the threshold. Default value: 64k.

DlRateThresForDCCC: The DCCC algorithm capability may be very low for some Best Effort (BE) service with very low applied maximum rate. The DL DCCC algorithm does not activate for the BE service whose applied downlink maximum rate is smaller than or equal to the threshold. Default value: 32k.

Event4AThd: Event 4A trigger threshold. Default value: 1024bytes.

Event4BThd: Event 4B trigger threshold. Default value: 64bytes.

DtoFStateTransTimer: This parameter is used to detect the stability of a UE in low activity state in CELL_DCH state. Default value: 180s.

FtoDTVMthd: The parameter is used to define the traffic volume measurement threshold for event 4a when the state transition form FACH to DCH will be triggered. Default value: 1024bytes.

FtoPStateTransTimer: This parameter is used to detect the stability of a UE in low activity state in CELL_FACH state. Default value: 180s.

CellReselectTimer: This parameter is used to detect whether a UE is in the state of frequent cell reselection. Default value: 180s.

CellReselectCounter: For a UE in CELL_PCH, if the number of cell reselections exceeds this parameter within the [cell reselection timer], it can be considered that the UE is in the state of frequent cell reselection. Default value: 9 (this value is not reasonable).

11.6.3 Example

Through the below command the uplink DCCC control threshold is set 64k and the downlink DCCC threshold is set 32k.

SET DCCC: ULDCCCRATETHD=D64, DLDCCCRATETHD=D32;


1) 3GPP, TS 25.331 "Radio Resource Control (RRC)” 2) 3GPP, TR 25.922 "Radio Resource Management Strategies"

Feature Description HUAWEI UMTS Radio Access Network Chapter 12 AMRC

12-1

Chapter 12 AMRC

12.1 Introduction

The AMR speech codec consists of the multi-rate speech codec with eight source rates from 4.75 kbit/s to 12.2 kbit/s. The change between the AMR specified rates could occur in the WCDMA in downlink, when the link power exceeds an acceptable value. In uplink the corresponding change can be made when there is need to extend the uplink coverage area for speech by using several AMR modes.

12.2 Glossary

12.2.1 Terms

PCM sample 8-bit value representing the A_Law or µ_Law coded sample of a speech or audio signal; sometimes used to indicate the time interval between two PCM samples (125µs).


AMR Adaptive Multi-Rate

AMRC Adaptive Multi-Rate control algorithm

DSCS Distant Supported Codec Set

DL Downlink

GBR Guaranteed Bit Rate

ICM Initial Codec Mode

PCM Pulse Coded Modulation



RRM Radio Resource Management

SF Spreading Factor

SID Silence Insertion Descriptor

TRAU Transcoder and Rate Adaptor Unit

UL Uplink


12-2

12.3 Application

12.3.1 Availability


12.3.2 Benefit

Through the AMRC, the Cell capacity can be enhanced in Downlink, the coverage range can be expanded in Uplink.


This feature is restricted by license. The RNC provides the AMRC function only when “AMR SPEECH CODING RATE CONTROL” license is purchased.

12.4 Technical description

12.4.1 Architecture

The AMRC algorithm is embedded in SRNC as shown in Figure 12-1.

NodeB CRNC SRNC CN


AMR algorithm

Figure 12-1 Network architecture of AMRC

The AMRC algorithm controls uplink and downlink respectively according to link qualities. Uplink and downlink can adopt different AMR modes.

12.4.2 Uplink AMRC Algorithm

After establishing a service, the UTRAN sends the MEASUREMENT CONTROL signaling to the UE and the UE sends the Tx power measurement report through air interface to UTRAN. The UE can measure the Tx power through UE internal measurement.

The UE Tx power is the total Tx power over the carrier. The referential measurement point is the antenna connector. When the UE Tx power is higher or lower than the


12-3

threshold, the UE will report a corresponding measurement event to the network side. At present, the reported events include 6A1, 6B1, 6A2, and 6B2. Correspondingly, four thresholds need be set. When an event is triggered, the uplink AMRC algorithm makes a corresponding adjustment, as shown Figure 12-2.

Reporting ev ent 6A2

Reporting ev ent 6B2

Reporting ev ent 6A1

Reporting ev ent 6B1

Ti me

Tx power threshold 6B1

Tx power threshold 6A2

Tx power threshold 6B2

UE Tx power

Tx power threshold 6A1

Delta_6b1

Delta_6a2

Delta_6b2

Delta_6a1

Figure 12-2 UE Tx Power threshold and reporting event

The uplink AMRC algorithm adjusts the uplink rate as follows:

When receiving event 6A1, the uplink AMRC algorithm reduces the uplink rate by a level.

When receiving event 6B2, the uplink AMRC algorithm increases the uplink rate by a level.

When receiving events 6A2 or 6B1, the uplink AMRC algorithm does not make any adjustment for the current uplink AMR mode is appropriate.

AMRC algorithm can send the “MEASURMENT CONTROL” to configure the 6a1, 6b1, 6a2, 6b2 threshold as shown in Figure 12-3.

UE UTRAN

MEASUREMENT CONTROL

Figure 12-3 Measurement control[1]

The UE can send the “MEASUREMENT REPORT” to report the Event 6a1, 6b1, 6a2, 6b2, as shown in Figure 12-4.


12-4

UE UTRAN

MEASUREMENT REPORT

Figure 12-4 measurement report[1]

12.4.3 Downlink AMRC Algorithm

After establishing a service, the UTRAN sends a measurement request to the NodeB for measuring downlink code Tx power values periodically.

The RNC converts the reported downlink code Tx power values into an average, and compares this value with the E1, E2, F1, and F2 thresholds that are set in the RNC. When the average power is higher or lower than a threshold, the downlink AMRC algorithm makes a corresponding adjustment, as shown Figure 12-5.

Tx Power threshold E1

Tx Power threshold E2

Tx Power threshold F2

Tx Power threshold F1

DL DPDCH Tx Power

Maxi mum DL DPDCH Power

Time

Delta_E1 Delta_E2 Delta_F2 Delta_F1

Rate-Down Normal Rate-Up Normal

Figure 12-5 Downlink AMRC Algorithm

The downlink AMRC algorithm adjusts the downlink rate as follows:

When the average power is higher than the E1 threshold, the downlink AMRC algorithm reduces the downlink rate by a level.

When the average power is lower than the F1 threshold, the downlink AMRC algorithm increases the downlink rate by a level.


12-5

When the average power is lower the E2 threshold or lower than the F2 threshold, the downlink AMRC algorithm does not make any adjustment for the current downlink AMR mode is appropriate

AMRC algorithm can send the “DEDICATED MEASURMENT INITIATION REQUEST” to configure the period measurement report as shown in Figure 12-6.

NodeB CRNC

DEDICATED MEASUREMENT INITIATIONREQQUEST

DEDICATED MEASUREMENT INITIATIONRESPONE

Figure 12-6 Dedicated measurement procedure[2]

The NodeB can report the measurement result through the “DEDICATED MEASUREMENT REPORT” as shown in Figure 12-7.

NodeB CRNC

DEDICATED MEASUREMENT REPORT

Figure 12-7 Dedicated measurement report[2]

12.5 Interaction

None

12.6 Implementation

12.6.1 Engineering guideline

None

12.6.2 Parameter

I. UlThd6a1

Measurement report threshold at which the event 6a1 is triggered. For UL measurement, event report mode is used. The event 6a1 refers to the event triggered when the measured value is higher than the UL 6a1 event absolute threshold. When the event 6a1 is triggered, AMRC will decide to decrease the AMR speech rate by one


12-6

level. What defined via this parameter is a kind of relative threshold. The absolute threshold = [MaxUlTxPower] - [UlTh6a1]. The greater this parameter is valued, the lower the absolute threshold is. In this case, there are more possibilities of triggering the request for AMR speech rate decrease. Accordingly the ARM speech rate is more likely to be decreased.

II. UlThd6b1

Measurement report threshold at which the event 6b1 is triggered. For UL measurement, event report mode is used. The event 6b1 refers to the event triggered when the measured value is lower than the UL 6b1 event relative threshold. When the event 6b1 is triggered, AMRC will stop adjusting the UL AMR speech rate. What defined via this parameter is a kind of relative threshold. The absolute threshold = [MaxUlTxPower] - [UlTh6b1].The greater this parameter is valued, the lower the absolute threshold is. In this case, there are fewer possibilities of reaching the value at which the AMR speech rate decrease can stop. Accordingly the ARM speech rate is more likely to be decreased.

III. UlThd6b2

Measurement report threshold at which the event 6b2 is triggered. For UL measurement, event report mode is used. The event 6b2 refers to the event triggered when the measured value is lower than the UL 6b2 event relative threshold. When the event 6b2 is triggered, AMRC will decide to increase the AMR speech rate by one level. What defined via this parameter is a kind of relative threshold. The absolute threshold = [MaxUlTxPower] - [UlTh6b2]. The greater this parameter is valued, the lower the absolute threshold is. In this case, there are fewer possibilities of triggering the request for AMR speech rate increase. Accordingly the ARM speech rate is less likely to be increased.

UlThd6a2: Measurement report threshold at which the event 6a2 is triggered. For UL measurement, event report mode is used. The event 6a2 refers to the event triggered when the measured value is higher than the UL 6a2 event relative threshold. When the event 6a2 is triggered, AMRC will stop adjusting the UL AMR speech rate. What defined via this parameter is a kind of relative threshold. The absolute threshold = [MaxUlTxPower] - [UlTh6a2]. The greater this parameter is valued, the lower the absolute threshold is. In this case, there are more possibilities of reaching the value at which the AMR speech rate increase can stop. Accordingly the ARM speech rate is less likely to be increased.

IV. DlThDE1

Threshold E1 of DL AMR mode adjustment. For DL measurement, period report mode is used. When the measured value is higher than the upper threshold E1, AMRC will decide to decrease the DL AMR mode by one level. What defined via this parameter is a kind of relative threshold. The absolute threshold = [MaxDlTxPower] - [DlThE1]. The


12-7

greater this parameter is valued, the lower the absolute threshold is. In this case, there are more possibilities of satisfying the request for AMR mode decrease. Accordingly the ARM speech mode is more likely to be decreased.

V. DlThDE2

Threshold E2 of DL AMR mode adjustment. For DL measurement, period report mode is used. When the measured value is lower than the upper threshold E2, AMRC will stop adjusting the DL AMR mode. What defined via this parameter is a kind of relative threshold. The absolute threshold = [MaxDlTxPower] - [DlThE2]. The greater this parameter is valued, the lower the absolute threshold is. In this case, there are fewer possibilities of satisfying the request for AMR mode decrease stop. Accordingly the ARM speech rate is more likely to be decreased.

VI. DlThDF1

Threshold F1 of DL AMR mode adjustment. For DL measurement, period report mode is used. When the measured value is lower than the lower threshold F1, AMRC will decide to increase the DL AMR mode by one level. What defined via this parameter is a kind of relative threshold. The absolute threshold = [MaxDlTxPower] - [DlThF1]. The greater this parameter is valued, the lower the absolute threshold is. In this case, there are fewer possibilities of satisfying the request for AMR mode increase. Accordingly the ARM speech rate is less likely to be increased.

VII. DlThDF2

Threshold F2 of DL AMR mode adjustment. For DL measurement, period report mode is used. When the measured value is higher than the lower threshold F2, AMRC will stop adjusting the DL AMR mode. What defined via this parameter is a kind of relative threshold. The absolute threshold = [MaxDlTxPower] - [DlThF2]. The greater this parameter is valued, the lower the absolute threshold is. In this case, there are more possibilities of satisfying the request for AMR speech mode increase stop. Accordingly the ARM mode is less likely to be increased.

12.6.3 Example

Through the below command the UlThd6a1 is set as two.

SET AMRC: ULTHD6A1=2;

12.7 Reference information

1) 3GPP, TS 25.331 "Radio Resource Control (RRC)” 2) 3GPP TS 25.433 "UTRAN Iub interface NBAP signaling"

Feature Description HUAWEI UMTS Radio Access Network Chapter 13 Load Control

13-1

Chapter 13 Load Control

13.1 Introduction

Load control is a series of algorithms which can control the cell’s total load and keep it in a stable region. Figure 13-1 provides the relationship of noise rise and the user number per cell. Noise rise can be seen as an estimating metric of cell’s load.

Figure 13-1 Relationship between noise rise and load factor

Load control is comprised by 6 sub features:

Call Admission Control (CAC) Load Congestion Control (LCC) Inter-frequency load balancing (LDB) Cell Breathing Potential User Control (PUC) Directed Retry Decision and redirection (DRD)

The algorithms’ application realm and inter-action relationship can be expressed as follows.

I. Seeing from the Point of Individual Call

As shown in Figure 13-2:

1) For users in the idle status, PUC takes effect; 2) If a user initiates a new call, CAC does the checking and admission; 3) For rejected users, RNC use DRD mechanism to assign them another chance;


13-2

4) For the accepted users, they will be managed or impacted by LCC, cell breathing or inter-frequency load balancing algorithms.

4. Call admitted3. Call rejected2. Call Access1. Idle

PUC

time

CAC DRD •LCC, •Cell breathing,•Inter-freq load balancing

Figure 13-2 The algorithms’ application realm and Inter-action relationship (individual call)

II. Seeing from the Point of Neighboring Cells

As shown in Figure 13-3, PUC, DRD and inter-frequency load balancing will transfer some users from cell A (the serving cell) to the neighboring cell B in another carrier. Cell breathing algorithm will move some users between cell A and cell B (they are in the same carrier). CAC and LCC only manage the users just inside cell A.

Carrier I: Cell C

Carrier II: Cell B

Carrier I: Cell A(CAC, LCC)

PUC, DRD, Inter-frequency LDB

Ce ll Breathing

Figure 13-3 The algorithms’ application realm and Inter-action relationship (neighboring cells)

III. Seeing from the Point of Load Variety

Along with the increase of the cell load, different algorithm will become effective in order as shown in Figure 13-4.


13-3

NodeB TX Power (Noise)

Load (user no.)

need NO load control

Many users drop

PUC begins: Idle users can camp on light cells

Cell breathing and inter-freq load balancing begin:

Hot-spot load can be distributed to other cells

CAC begins: New calls will be rejected by the heavycell. DRD begins: Direct the rejected users to

neighboring cells or GSM cells.

LCC begins: BE services' rate will be reducedand some victims will be selected and dropped.

Figure 13-4 The algorithms’ application realm and Inter-action relationship (load variety)

The algorithms of load control will perform real-time monitoring on the load of the cell, indicate the idle users to camp on the light-loaded cells (PUC), accept or deny the new calls based their impact to the total load (CAC), expand or shrink the coverage of CPICH depending on the load (Cell breathing), select and then handover some users to an inter-frequency neighboring cell (Inter-frequency load balancing), direct the rejected users to retry in other cells (DRD), detect the cells’ congestion and relieve it (LCC). These can guarantee the cells’ coverage and capacity, make the network stay in a stable status and keep the customers’ QoS (Quality of Service).

13.2 Glossary

13.2.1 Terms

PN: Background noise of base station receiver. It is the sum of thermal noise and base station receiver noise.

UL: Uplink load factor. The uplink load factor is related to RTWP, it can be calculated

by formula RTWPPN

UL −=1η .


13-4

Eb/No: Bit energy divided by the noise spectral density. It means the required SNR for demodulating the transmitted signal. Uplink and downlink have different value.

Ec/No: The received energy per chip divided by the power density in the band. The CPICH Ec/No is identical to CPICH RSCP/UTRA Carrier RSSI. Measurement shall be performed on the Primary CPICH.

Quality of Service: The collective effect of service performances which determine the degree of satisfaction of a user of a service. It is characterized by the combined aspects of performance factors applicable to all services, such as:

service operability performance; service accessibility performance; service retainability performance; service integrity performance; and Other factors specific to each service.


BE Best Effort

CAC Call Admission Control

CN Core Network

CPICH Common Pilot Channel


CS Circuit Switch

DCCC Dynamic Channel Configuration Control


DRD Directed Retry Decision and Redirection

DRNC Drift RNC

HO Hand Over

LCC Load Congestion Control

LDB Load Balancing

PCPICH Physical Common Pilot Channel

PS Packet Switch

PUC Potential User Control




RTWP Received Total Wideband Power



13-5

SNR Signal Noise Rate

SRNC Serving RNC

TCP Transmitted Carrier Power

UE User Equipment




13.3 Application

13.3.1 Availability

These features are available on BSC6800 V100R002 and later generic releases of the BSC6800 system.

Intra-system DRD, Inter-system DRD, Inter-system Redirection, PUC, Intra-frequency cell LDB, Inter-frequency cell LDB are optional features for Huawei UMTS RAN.

13.3.2 Benefit

The load control feature can guarantee the cells’ coverage and capacity, make the network stay in a stable status, and keep the customers’ Quality of Service (QoS).


Intra-system DRD, Inter-system DRD, Inter-system Redirection, PUC, Intra-frequency cell LDB, Inter-frequency cell LDB are restricted by license. The RNC provides these functions only when the “INTRA-SYSTEM DRD, INTER-SYSTEM DRD, INTER-SYSTEM REDIRECTION, PUC, INTRA-FREQUENCY CELL LDB, INTER-FREQUENCY CELL LDB” licenses are purchased.

For PUC, only inter-frequency neighboring cell will become the camping target. There is no impact to intra-frequency neighboring cells. This function is done mainly by the cell selection and re-selection process in UE. So what the network can do is just adjusting some parameters. This function needs the supporting from UE.

Cell breathing adjusts the power of CPICH only depending on the TCP. But CPICH power is a sensitive metric, many parameters are set relative to this metric, so the adjustment of it will cause magnitude impact. This function should be used very carefully.

As inter-frequency LDB, the handover is blind handover which needs no measurement. Therefore the target cell’s coverage has to be larger than or the same as the source cell, this function is only applied to concentric cells.


13-6

The RAB Retry Procedure is only applied to CS speech (identified through the traffic class setting within the UEs RAB request) and encompasses redirection to GSM.


13.4.1 Architecture

The algorithms of Load Control are mainly embedded in the CRNC/SRNC, as shown in Figure 13-5.

NodeB CRNC SRNC CN


Load control algorithm

Figure 13-5 The location of Load Control feature

Measurements reported from NodeB will be looked as an input for these algorithms. They get the information about cell load from NodeB and act on RNC itself. As a ultimate result of these algorithms, UE will be the beneficiary.

13.4.2 Call Admission Control

Figure 13-6 shows the basic CAC flow chart.


13-7

Request Arrive

Uplink call admissioncontrol

admitted?

Downlink calladmission control

admitted?

request admitted request rejected

end

no

no

yes

yes

Figure 13-6 Basic CAC flow

Generally, a request is admitted only when uplink and downlink CAC are both admitted.

Figure 13-7 shows basic uplink call admission control.

Uplink admission control request

Get measured RTWP and calculatethe current uplink load factor.

Calculate the increment of theuplink load due to the request.

Get the predicted uplink loadfactor.

RTWPPN

UL −=1η

LUη∆

LUULpredictedUL ηηη ∆+=,

Compare the predicted value withadmission threshold

Figure 13-7 Basic uplink call admission control


13-8

1) Get the measured RTWP and then use formula RTWPPN

UL −=1η to calculate

the current uplink load factor ULη .

2) Calculate the increment of the uplink load LUη∆ based on the characteristic of

the request.

3) Calculate the predicted uplink load factor LUULpredictedUL ηηη ∆+=, .

4) Compare the predicted uplink load factor predictedUL,η with the corresponding

threshold to determine whether admit the request or not.

Basic downlink call admission control has a similar flow chart with uplink.

5) Get the measured TCP, and multiple with the maximum downlink transmit power to get the downlink load.

6) Calculate the increment of the downlink load based on the characteristic of the request and current load.

7) Calculate the predicted downlink load. 8) Compare the predicted downlink load with the corresponding threshold to

determine whether admit the request or not.

13.4.3 Potential User Control

Figure 13-8 shows the algorithm for potential user control.

Monitoring the serving cell's current load periodically

Are these

parameters changed?

Label the serving cell and its neighboring cells based on their load: HEAVY, NORMAL, LIGHT

Adjust the parameters for the cell selection and

reselection in UE.

YesNo

Update the system information of the serving cell and its neighboring cell, and

broadcast it.

Figure 13-8 Potential User Control


13-9

Potential User Control (PUC) is used by RNC to manage traffic load amongst overlaid cells with different carrier frequencies.

The cell load is labeled HEAVY, NORMAL or LIGHT by comparison of the load with some thresholds.

Load is managed by altering the cell selection and reselection parameters, which are broadcasted in system information. If the cell load is labeled as HEAVY, these parameters are adjusted to make users in serving cell easier to select neighboring cells; if the cell load is labeled as LIGHT, these parameters are modified to make users in neighboring cells easier to camp in the serving cell.

UEs in Idle mode or CELL_FACH state will be affected.

13.4.4 Cell Breathing

I. Principle of Cell Breathing

Figure 13-9 shows the principle of cell breathing.

Cell A Cell B

If Cell A’s load is heavy while Cell B is load is light, decrease PCPICH power of Cell A to let some UEs handover to Cell B or reselect to Cell B, and thus balance the load the two cells.

Figure 13-9 Cell breathing

II. Algorism of Cell Breathing

Figure 13-10 describes the cell breathing algorithm.


13-10

Yes

No

Monitoring the serving cell's current load periodically

If the load is greater than a certain threshold?

Yes

Decrease the power of PCPICH by a step.

No

If the load is less than a certain threshold?

No

If the power of PCPICH has reached its maximum value?

Increase the power of PCPICH by a step.

No

Yes

Yes

If the power of PCPICH has reached its minimum

value?

Figure 13-10 Cell breathing algorithm

1) Monitoring the current load of the serving cell periodically; 2) If the current load is greater than a certain threshold, go to Step 3. Otherwise, go

to Step 4; 3) If PCPICH power has already reached its minimum value, go to Step 1; otherwise

decrease the power of PCPICH by a step; 4) If the current load is less than a certain threshold, go to Step 5; otherwise go to

Step 1; 5) If PCPICH power has already reached its maximum value, go to Step 1;

otherwise increase the power of PCPICH by a step.

13.4.5 Inter-frequency Load Balancing

Inter-frequency load balancing focuses on the heaviest-loaded cell and distributes its load into the lightest-loaded cell by selecting some UEs and handover them, which can balance the load between cells in the same region.

The handover is blind handover which needs no measurement. Therefore the target cell’s coverage has to be larger than or the same as the source cell, this function is only applied to concentric cells. Figure 13-11 shows the Inter-frequency load balancing algorism.


13-11

Monitoring the serving cell's currentload periodically

Yes

Select some UEs from the heaviest-loadedcell and hand them over to the lightest-

loaded cell.

No

Within the cells covering the samearea, select the heaviest-loaded one

and the lightest-loaded one.

No

If the load difference of these twocells is greater than a certain threshold?

If the load of the heaviest-loaded

cell is greater than a certain threshold?

Yes

Figure 13-11 Inter-frequency load balancing

13.4.6 Directed Retry Decision and Redirection

This algorithm includes three key levels of functionality, namely:

RRC Retry Decision Algorithm Redirection Algorithm RAB Retry Decision Algorithm

Figure 13-12 illustrates the RRC and RAB establishment procedures incorporating the three components of the DRD algorithm.


13-12

UE RNC

1．RRC CONNECTION REQUEST(Containing RACH measurement report)

RRC CONNECTION SETUP(Containing (new) cell information)

RRC CONNECTION SETUP COMPLETE

CN

RRC DIRECT TRANSFER

RANAP DIRECT TRANSFER

RANAP RAB ASSIGNMENT REQUEST

RANAP RAB ASSIGNMENT RESPONSE

2. RRC Retry Decision Algorithm

4. RAB Retry Decision Algorithm

3. Redirection Algorithm

Figure 13-12 Directed Retry Decision and Redirection

1) When a UE wants to establish an RRC connection it must first send an RRC CONNECTION SETUP REQUEST message to the UTRAN (RNC) to establish an SRB on a DCH. To invoke the DRD algorithm, the UE should include a RACH measurement report (containing the CPICH Ec/No measurements of several neighboring/candidate cells). This list of candidate cells is then ranked in descending order, based on the Ec/No measurements;

2) If the UE cannot establish an RRC connection with its preferred cell, the candidate list is then sequentially examined in a top-down manner until a suitable cell is obtained. Then the selected cell information is sent to UE by RRC CONNECTION SETUP. This is so called RRC Retry Decision Algorithm;

3) If none of the cells in the list satisfy the criteria of the RRC Retry Decision Algorithm, the UE fails in its attempt to establish an RRC connection and the Redirection Algorithm is invoked. The latter algorithm will use the Redirection IE in RRC CONNECTION REJECT message to redirect UE to another frequency or other system (e.g. GSM);

4) If the UE is successful in its attempt to establish the requested RRC connection, the CN then initiates the RAB assignment procedure. If the assignment procedure is not successful, the RAB Retry Decision Algorithm is invoked to retry the procedure in an inter-frequency cell or a GSM cell.


13-13

13.4.7 Load Congestion Control

Congestion is an emergent status. Once RNC detects such a status, what it should do is to reduce the cell’s load as quickly as possible. Figure 13-13 shows the Load Congestion Control algorithm.

Monitoring the serving cell'scurrent load periodically.

Yes

The congestion status isdetected.

If the load is greaterthan a certain threshold?

If the congestion isrelieved?

No

Do some post-congestionactions. For example,recover the BE users'

bandwidth.

Yes

Choose some actions to resistthe congestion:

Reduce the BE users'bandwidth temporarily.Selective user dropping.

No

Figure 13-13 Load Congestion Control Algorithm

The candidate action includes the follows:

reducing the BE users’ bandwidth temporarily dropping some users

13.5 Interaction

Feature Interaction

DCCC

In the case that the DCCC desires to increase a user's transmission data rate on either up or downlink or both, a reconfiguration requests is sent to CAC for admission checking. If the admission is granted by the CAC, the reconfiguration may be successful. If the reconfiguration request is rejected by the CAC, the call will continue with its current data rate. When LCC wants to reduce the BE users’ bandwidth, it should have to ask DCCC to perform the actual operation.

HO If inter-frequency load balancing wants to handover some UEs, it should have to revoke HO to do the actual action.


13-14

13.6 Implementation


The algorithms of Load Control are mainly integrated and embedded in the CRNC/SRNC.

To Tune the Load Control functionality within UTRAN, configure all or parts of the parameters described in the following section.

13.6.2 Parameter

I. Potential User Control

SET CERRMTIMER

Parameter Parameter name Comments

LDCPUCPERIODTIMERLEN

PUC Period TimerA timer used for identifying Potential User Control (PUC) adjustment period.

ADD/MOD/RMV/LST CELLPUC


SPUCLIGHT Load level division threshold 2

One of the thresholds used to judging cell load level, it is used to decide whether the cell load level is "Light" or not.

SPUCHEAVY Load level division threshold 1

Another threshold used to judging cell load level, it is used to decide whether the cell load level is "Heavy" or not.

SPUCHYST Load level division hysteresis

The hysteresis used while judging cell load level, it is used to avoid the unnecessary ping-pong of a cell between two load levels due to tiny load change.

II. Cell Breathing

SET CERRMTIMER


LDCINTRAFREQLDBPERIODTIMERLEN

Intra-Frequency LDB Period Timer

A timer used for identifying intra-frequency LDB adjustment period.


13-15

ADD/MOD/RMV/LST CELLLDB


PCPICHPOWERPACE

Pilot power adjustment step

Pilot power adjustment step.

CELLOVERRUNTHD

Cell overload threshold

If the cell downlink load exceeds this threshold, the algorithm can decrease the pilot transmit power of the cell so as to increase the whole system's capacity.

CELLUNDERRUNTHD

Cell under load threshold

If the cell downlink load is lower than this threshold, the algorithm can increase the pilot transmit power of the cell so as to share the load of other cells.

III. Inter-frequency Load Balancing

SET CERRMTIMER


LDCINTERFREQLDBPERIODTIMERLEN

Inter-Frequency LDB Period Timer

A timer used for identifying inter-frequency Load Balance (LDB) adjustment period.

ADD/MOD/RMV/LST CELLLDB


INTERCARRIERLOADDIFFTHD

Inter-freq cell load difference threshold

The inter-frequency handover can be implemented when the load difference between the cell with the maximum load and the cell with the minimum load exceeds this threshold and the load of the former exceeds [Inter-frequency cell load adjustment threshold].

INTERCARRIERLOADADJUSTTHD

Inter-freq cell load adjustment threshold

The inter-frequency handover can be implemented when the load of the cell with the maximum load exceeds this threshold.

IV. Directed Retry Decision and Redirection

SET DRD ADD/MOD/RMV/LST CELLDRD



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SET DRD ADD/MOD/RMV/LST CELLDRD

DRMAXNUMBER Max number of direct reattempts

The maximum allowed number of reattempts initiated by the system after the first access failure.

REFCSMAXNUM Max number of reference cell set

Max number of RAB direct reattempts reference cell set.

RABDRMAXNUMBER

Max number of RAB direct reattempts

Max number of RAB direct reattempts.

CSTHRESHOLD Candidate set absolute threshold

When the cell signal quality exceeds the threshold, the cell will be put into the DRD candidate set. When the UE fails to access the cell, the DRD algorithm will automatically originate access to another cell in the candidate set.

MINSIGNALREQUIRED

Min Ec/No

The minimum requirement for the CPICH Ec/No received when the UE demodulates normally. In DRD algorithm, the cell will be taken into consideration only when the cell signal quality exceeds this parameter value. Otherwise, the cell with poor signal quality will be neglected.

V. Load Congestion Control

ADD/MOD/RMV/LST CELLLCC


LCCMRTHD1 Measurement threshold 1

This parameter represents the percentage of the total DL transmit power to the total BTS transmit power. It is used to decide whether the LCC is triggered or not.

LCCMRTHD2 Measurement threshold 2

This parameter represents the percentage of the total DL transmit power to the total BTS transmit power. It is used to decide whether the LCC is triggered or not.

VI. Call Admission Control

ADD/MOD/RMV/LST CELLCAC



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ULHOTHD UL handover admission threshold

Uplink admission control threshold for handover request. [UlHoThd] should be set higher than [UlConvThd] to give handover request higher priority than conversation request.

ULCONVTHD UL threshold of conversation service

Uplink admission control threshold for conversation request. [UlConvThd] should be set higher than [UlOtherThd] to give conversation request higher priority than other request.

ULOTHERTHD UL threshold of other services

Uplink admission control threshold for other request.

DLHOTHD DL handover admission threshold

Downlink admission control threshold for handover request. [DlHoThd] should be set higher than [DlConvThd] to give handover request higher priority than conversation request.

DLCONVTHD DL threshold of conversation service

Downlink admission control threshold for conversation request. [DlConvThd] should be set higher than [DlOtherThd] to give conversation request higher priority than other request.

DLOTHERTHD DL threshold of other services

Downlink admission control threshold for other request.

BACKGROUNDNOISE

Background noise

Background noise for uplink load factor calculation when auto-adaptive background noise update algorithm is switched off.

Initial background noise value when auto-adaptive background noise update algorithm is switched on.

BGNSWITCH Auto-Adaptive Background Noise Update Switch

When the parameter is '0', the auto-adaptive background noise update algorithm will be switched off, otherwise, the algorithm wiil be switched on.

BGNADJUSTTIMELEN

Background Noise Update Continuance Time

Only when the measured background noise's duration reaches this parameter, the ouput of the auto-adaptive background noise update filter could be regarded as effect background noise, and replace the current value, at the same time, the auto-adaptie status should be restarted; otherwise, the output could not be regarded as the effective background noise.


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BGNEQUSERNUMTHD

Equivalent User Number Threshold for Background Noise Update

When the Uplink equivelent user number is not larger than this parameter, the RTWP could be regarded as background noise, so the measured RTWP could be input to the auto-adaptive background noise update filter; otherwise, the RTWP could not be regarded as background noise, and should not be input to the filter, and at the same time, the auto-adaptive status should be reset.

13.6.3 Example

I. Modify PUC Algorithm Parameters of Cell 1.

MOD CELLPUC: CELLID=1, SPUCLIGHT=45, SPUCHEAVY=70, SPUCHYST=5;

After the above operation, the parameters are added as follows: the Load level division threshold 2 is 45%; the Load level division threshold 1 is 70%; the Load level division hysteresis is 5%.

II. Modify Cell Breathing Algorithm Parameters of Cell 1.

MOD CELLLDB: CELLID=1, PCPICHPOWERPACE=2, CELLOVERRUNTHD=55, CELLUNDERRUNTHD=45;

After the above operation, the parameters are set as follows: the pilot power adjustment step is 0.2dB; the cell overload threshold is 55%; the cell under load threshold is 45%.

3. Modify inter-frequency load balancing algorithm parameters of cell 1.

MOD CELLLDB: CELLID=1, INTERCARRIERLOADDIFFTHD=10, INTERCARRIERLOADADJUSTTHD=55;

After the above operation, the parameters are set as follows: the inter-frequency cell load difference threshold is 10%; the inter-frequency cell load adjustment threshold is 55%.

III. Modify the Cell Oriented DRD Algorithm Parameters to the Cell 1.

MOD CELLDRD: CELLID=1, DRMAXNUMBER= 2, REFCSMAXNUM=2, RABDRMAXNUMBER=2, CSTHRESHOLD=-18, MINSIGNALREQUIRED=-18;

After the above operations, the DRD algorithm parameters of the cell 1 are modified as follows: the Max number of RRC direct reattempts is 2; the Max number of reference cell set is 2; the Max number of RAB direct reattempts is 2; the Candidate set absolute threshold is -18; the minimum Ec/No when the UE works normally is -18 dB.


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IV. Modify LCC Algorithm Parameters of Cell 1.

MOD CELLLCC: CELLID=1, LCCMRTHD1=90, LCCMRTHD2=80;

After the above operation, the parameters are added as follows: the measurement threshold 1 is 90%; the measurement threshold 2 is 80%.

Suppose the maximum transmit power of this cell is 43dBm (20W), then the power threshold 1 is 42.5dBm (about 18W) and the power threshold 2 is 42dBm (about 16W).

V. Modify CAC Algorithm Parameters of Cell 1.

MOD CELLCAC: CELLID = 1, ULCONVTHD = 700, ULOTHERTHD = 650, DLCONVTHD = 75, DLOTHERTHD = 65, ULHOTHD = 750, DLHOTHD = 80, BGNSWITCH = ON, BGNADJUSTTIMELEN = 5, BGNEQUSERNUMTHD = 2;

After the above operation, we change the uplink admission threshold as flowing: handover threshold=0.75, conversation threshold=0.7, other threshold=0.65;

Change the downlink admission threshold as flowing: handover threshold=0.8, conversation threshold=0.75, other threshold=0.65;

Turn on the auto-adaptive background noise update function, and set the adjust time=5minutes, Equivalent user number for background noise update=2.


1) 3GPP, TS 25.133 "Requirements for Support of Radio Resource Management (FDD)"

2) 3GPP, TS 25.215 "Physical layer - Measurements (FDD)" 3) 3GPP, TS25.304 “UE Procedures in Idle Mode and Procedures for Cell

Reselection in Connected Mode” 4) 3GPP, TS 25.331 "Radio Resource Control (RRC)” 5) 3GPP TS 25.413 "UTRAN Iu Interface RANAP Signaling"

Feature Description HUAWEI UMTS Radio Access Network Chapter 14 Integrity Protection and Encrypt

14-1

Chapter 14 Integrity Protection and Encrypt

14.1 Introduction

In order to prevent user data from illegal intercepting or input to the network and keep safety of the network and user, ciphering and integrity protection functions are used in WCDMA system. Comparing to GSM, WCDMA enhances the integrity protection functionality, the property that the receiving entity (MS or SN) is able to verify that signalling data has not been modified in an unauthorized way since it was sent by the sending entity (SN or MS) and that the data origin of the signalling data received is indeed the one claimed. Ciphering key length has been increased in 3G, more robust ciphering algorithm and integrity algorithm are used to make sure safety of the network and user. If ciphering and integrity protection are set in the network, they will be executed in radio interface.

14.2 Glossary

14.2.1 Terms

Quintet, UMTS authentication vector: temporary authentication and key agreement data that enables a VLR/SGSN to engage in UMTS AKA with a particular user. A quintet consists of five elements: a) a network challenge RAND, b) an expected user response XRES, c) a cipher key CK, d) an integrity key IK and e) a network authentication token AUTN.

Triplet, GSM authentication vector: temporary authentication and key agreement data that enables a VLR/SGSN to engage in GSM AKA with a particular user. A triplet consists of three elements: a) a network challenge RAND, b) an expected user response SRES and c) a cipher key Kc.

Data integrity: The property that data has not been altered in an unauthorized manner. UMTS security context: a state that is established between a user and a serving network domain as a result of the execution of UMTS AKA. At both ends "UMTS security context data" is stored, that consists at least of the UMTS cipher/integrity keys CK and IK and the key set identifier KSI. One is still in a UMTS security context, if the keys CK/IK are converted into Kc to work with a GSM BSS.

GSM security context: a state that is established between a user and a serving network domain usually as a result of the execution of GSM AKA. At both ends "GSM security context data" is stored, that consists at least of the GSM cipher key Kc and the cipher key sequence number CKSN.


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Authentication vector: either a quintet or a triplet.

R98-: Refers to a network node or ME that conforms to R97 or R98 specifications.

R99+: Refers to a network node or ME that conforms to R99 or later specifications.

R99+ ME capable of UMTS AKA: either a R99+ UMTS only ME, a R99+ GSM/UMTS ME, or a R99+ GSM only ME that does support USIM-ME interface.

R99+ ME not capable of UMTS AKA: a R99+ GSM only ME that does not support USIM-ME interface.

14.2.2 Symbol

For the purposes of the present document, the following symbols apply:

f1 Message authentication function used to compute MAC

f8 encryption algorithm

f9 Integrity algorithm


AKA Authentication and key agreement

AUTN Authentication Token

BSS Base Station System

BTS Base Transceiver Station

CK Cipher Key

CKSN Cipher key sequence number

CS Circuit Switched

HE Home Environment

HLR Home Location Register

IK Integrity Key


KSI Key Set Identifier


MAC The message authentication code included in AUTN, computed using f1

ME Mobile Equipment

MS Mobile Station


14-3

MSC Mobile Services Switching Center

PS Packet Switched

RAND Random challenge


SGSN Serving GPRS Support Node

SQN Sequence number

SN Serving Network

UEA UMTS Encryption Algorithm

UIA UMTS Integrity Algorithm


USIM User Services Identity Module


Uu Radio interface between UTRAN and UE

VLR Visitor Location Register

XRES Expected Response

14.3 Application

I. Availability


II. Benefit

This feature enhances network and user data security, effectively keeps data between user and network from intercepted and illegal modified, effectively prevents imitation behavior.

III. Limitation and Restriction

Ciphering and integrity algorithm should be supported by both network and handsets.


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14.4.1 Architecture

UE RNCIntegrity Procedure

Signalling

Encrypt Procedure

Signalling and Data

Figure 14-1 Integrity and Encrypt Procedure

As shown in Figure 14-1, Ciphering and integrity protection procedure are completed on Uu interface. The object of integrity protection is signalling while ciphering is used in not only signalling but also data.

14.4.2 Integrity Protection and Ciphering Algorithm

I. Integrity Protection and Ciphering Algorithm Keys

Integrity Protection and Ciphering Algorithm include the following key parameters:

UIA: UMTS Integrity Algorithm, According to the protocol, the RNC supports only UIA1 currently, i.e., f9 integrity protection

UEA: UMTS Encryption Algorithm, According to the protocol, the RNC supports only two encryption algorithms currently, UEA0 and UEA1. UEA0: Not encrypted. UEA1: f8 encryption algorithm.

Integrity Key (IK): The integrity key IK is 128 bits long. There may be one IK for CS connections (IKCS), established between the CS service domain and the user and one IK for PS connections (IKPS) established between the PS service domain and the user. For UMTS subscribers IK is established during UMTS AKA,.IK is stored in the USIM and a copy is stored in the ME. IK is sent from the USIM to the ME upon request of the ME. IK is sent from the HLR/AuC to the VLR/SGSN and stored in the VLR/SGSN as part of a quintet. It is sent from the VLR/SGSN to the RNC in the (RANAP) security mode command.

Cipher Key (CK): The cipher key CK is 128 bits long. There may be one CK for CS connections (CKCS), established between the CS service domain and the user and one CK for PS connections (CKPS) established between the PS service domain and the user. For UMTS subscribers, CK is established during UMTS AKA. CK is stored in the USIM and a copy is stored in the ME. CK is sent from the USIM to the ME upon request of the ME. CK is sent from the HLR/AuC to the


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VLR/SGSN and stored in the VLR/SGSN as part of the quintet. It is sent from the VLR/SGSN to the RNC in the (RANAP) security mode command.

II. UTRAN Encryption

Once the user and the network have authenticated each other they may begin secure communication. A cipher key CK is shared between the core network and the terminal after a successful authentication event.

Before encryption can begin, the communicating parties have to agree on the encryption algorithm also. Fortunately, in UMTS implemented according to 3GPP R99, only one algorithm is defined.

The encryption/decryption takes place in the terminal and in the RNC on the network side. This means that the cipher key CK has to be transferred from CN to the radio access network. This is done in a specific RANAP message called security mode command. After the RNC has obtained CK it can switch on the encryption by sending an RRC security mode command to the terminal.

The UMTS encryption mechanism is based on a stream cipher concept as described in Figure 14-2.This means the plain text data is added bit-by-bit to random-looking mask data, which are generated based on the cipher key CK and a few other parameters. This type of encryption has the advantage that the mask data can be generated even before the actual plaintext is known. Then the final encryption is a very fast bit operation. The decryption on the receiving side is done in exactly the same way since adding the mask bits twice has the same result as adding zeros.

PLAINTEXT BLOCK

f8

COUNT-C/32 DIRECTION/1

BEARER/5 LENGTH

CK/128

KEYSTREAM BLOCK(MASK)

CIPHERTEXT BLOCK

f8

COUNT-C/32 DIRECTION/1

BEARER/5 LENGTH

CK/128

KEYSTREAM BLOCK(MASK)

PLAINTEXT BLOCK

Sender UE or RNC

Receiver RNC or UE

Figure 14-2 Ciphering of user and signalling data transmitted over the radio access link

As the mask data does not depend on the plaintext at all there has to be another input parameter, which changes every time a new mask is generated. Otherwise two different plaintexts, say P1 and P2, would be protected by the same mask. Then the following unwanted phenomenon would happen: if we add P1 to P2 bit-by-bit, and we do the same to their encrypted counterparts, then the result bit string is exactly the


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same in both cases. This is, again, due to the fact that two identical masks cancel each other in the bit-by-bit addition. Therefore, the bit-by-bit sum of P1 and P2 would become known to any attacker who eavesdrops on the corresponding encrypted messages on the radio interface. Typically, if two bit strings of meaningful data are added to each other bit-by-bit, both of them can be totally revealed from the result bit string. Hence, this would imply a break of the encryption for the two messages P1 and P2.

III. UMTS Intergrity Protection of RRC Signalling

The purpose of the integrity protection is to authenticate individual control messages. This is important since a separate authentication procedure gives assurance of the identities of the communicating parties only at the time of the authentication.

The integrity protection is implemented at the RRC layer, i.e. radio interface. Thus it is used between the terminal and RNC, just like encryption. The integrity key IK is generated during the authentication and key agreement procedure, again similar to the cipher key. Also, IK is transferred to the RNC together with CK in security mode command.

Figure 14-3 illustrates the use of the integrity algorithm f9 to authenticate the data integrity of a signalling message.

f 9

COUNT-I/32 DIRECTION/1

MESSAGE FRESH/32

IK/128

MAC –I/32

f 9

COUNT-I/32 DIRECTION/1

MESSAGE FRESH/32

IK/128

XMAC –I/32

Sender UE or RNC

ReceiverRNC or UE

Figure 14-3 Derivation of MAC-I (or XMAC-I) on a signalling message

The input parameters to the algorithm are the Integrity Key (IK), the integrity sequence number (COUNT-I), a random value generated by the network side (FRESH), the direction bit DIRECTION and the signalling data MESSAGE. Based on these input parameters the user computes message authentication code for data integrity MAC-I using the integrity algorithm f9. The MAC-I is then appended to the message when sent over the radio access link. The receiver computes XMAC-I on the message received in the same way as the sender computed MAC-I on the message sent and verifies the data integrity of the message by comparing it to the received MAC-I.


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IV. Summary of Access Security

AKA Algorithms

Encryption and IntegrityProtection Algorithms

AKA Algorithms

VLR

RES

CKcs, I Kcs CKps, IKps

Encryption and IntegrityProtection Algorithms

CKps,IKpsCKcs,IKcs

Secure communication

ME

RNC

SGSN

HLR/AUC

USIM

RAND, AUTN

K SQNAuC

Authentication Vectors

K SQNUSIM

Figure 14-4 UMTS access security summary

Figure 14-4 concludes this section by presenting a schematic overview of the most important access security mechanisms and their relationships to each other. For the sake of clarity, many parameters are not shown in this figure.

V. Ciphering and Integrity Mode Negotiation

When an MS wishes to establish a connection with the network, the MS shall indicate to the network in the MS/USIM Classmark which cipher and integrity algorithms the MS supports. This information itself must be integrity protected. As it is the case that the RNC does not have the integrity key IK when receiving the MS/USIM Classmark this information must be stored in the RNC. The data integrity of the Classmark is


14-8

performed, during the security mode set-up procedure by use of the most recently generated IK

The network shall compare its integrity protection capabilities and preferences, and any special requirements of the subscription of the MS, with those indicated by the MS and act according to the following rules:

1) If the MS and the network have no versions of the UIA algorithm in common, then the connection shall be released.

2) If the MS and the network have at least one version of the UIA algorithm in common, then the network shall select one of the mutually acceptable versions of the UIA algorithm for use on that connection.

The network shall compare its ciphering capabilities and preferences, and any special requirements of the subscription of the MS, with those indicated by the MS and act according to the following rules:

3) If the MS and the network have no versions of the UEA algorithm in common and the network is not prepared to use an unciphered connection, then the connection shall be released.

4) If the MS and the network have no versions of the UEA algorithm in common and the user (respectively the user's HE) and the network are willing to use an unciphered connection, then an unciphered connection shall be used.

5) If the MS and the network have at least one version of the UEA algorithm in common, then the network shall select one of the mutually acceptable versions of the UEA algorithm for use on that connection.

Because of the separate mobility management for CS and PS services, one CN domain may, independent of the other CN, establish a connection to one and the same MS. Change of ciphering and integrity mode (algorithms) at establishment of a second MS to CN connection shall not be permitted. The preferences and special requirements for the ciphering and integrity mode setting shall be common for both domains. (e.g. the order of preference of the algorithms).

In case of a UE with Radio Access Bearers towards both core networks, the user data towards CS shall always be ciphered with the ciphering key received from CS and the user data towards PS with the ciphering key received from PS. The signalling data shall always be ciphered with the last received ciphering key and integrity protected with the last received integrity protection key from any of the two CNs.

14.5 Interaction

14.5.1 Relation and Influence with Authentication Procedure

IK and CK used in integrity protection and ciphering are interacted in authentication procedure, which will be stored in USIM card after authentication successes.


14-9

14.5.2 Relation and Influence with Intersystem Handover Procedure

I. Intersystem Handover for CS Services – from UTRAN to GSM BSS

If ciphering has been started when an intersystem handover occurs from UTRAN to GSM BSS, the necessary information (e.g. Kc, supported/allowed GSM ciphering algorithms) is transmitted within the system infrastructure before the actual handover is executed to enable the communication to proceed from the old RNC to the new GSM BSS, and to continue the communication in ciphered mode. The RNC may request the MS to send the MS Classmarks 2 and 3 which include information on the GSM ciphering algorithm capabilities of the MS. This is necessary only if the MS Classmarks 2 and 3 were not transmitted from UE to UTRAN during the RRC Connection Establishment. The intersystem handover will imply a change of ciphering algorithm from a UEA to a GSM A5. The GSM BSS includes the selected GSM ciphering mode in the handover command message sent to the MS via the RNC.

The integrity protection of signalling messages is stopped at handover to GSM BSS.

1) UMTS security context

A UMTS security context in UTRAN is only established for a UMTS subscriber with a R99+ ME that is capable of UMTS AKA. At the network side, three cases are distinguished:

In case of a handover to a GSM BSS controlled by the same MSC/VLR, the MSC/VLR derives the GSM cipher key Kc from the stored UMTS cipher/integrity keys CK and IK (using the conversion function) and sends Kc to the target BSC (which forwards it to the BTS).

In case of a handover to a GSM BSS controlled by other R98- MSC/VLR, the initial MSC/VLR derives the GSM cipher key from the stored UMTS cipher/integrity keys (using the conversion function) and sends it to the target BSC via the new MSC/VLR controlling the BSC. The initial MSC/VLR remains the anchor point throughout the service.

In case of a handover to a GSM BSS controlled by another R99+ MSC/VLR, the initial MSC/VLR sends the stored UMTS cipher/integrity keys CK and IK to the new MSC/VLR. The initial MSC/VLR also derives Kc and sends it to the new MSC/VLR. The new MSC/VLR store the keys and sends the received GSM cipher key Kc to the target BSC (which forwards it to the BTS). The initial MSC/VLR remains the anchor point throughout the service.

At the user side, in either case, the ME applies the derived GSM cipher key Kc received from the USIM during the last UMTS AKA procedure.

2) GSM security context

A GSM security context in UTRAN is only established for a GSM subscriber with a R99+ ME. At the network side, two cases are distinguished:


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In case of a handover to a GSM BSS controlled by the same MSC/VLR, the MSC/VLR sends the stored GSM cipher key Kc to the target BSC (which forwards it to the BTS).

In case of a handover to a GSM BSS controlled by another MSC/VLR (R99+ or R98-), the initial MSC/VLR sends the stored GSM cipher key Kc to the BSC via the new MSC/VLR controlling the target BSC. The initial MSC/VLR remains the anchor point throughout the service.

If the non-anchor MSC/VLR is R99+, then the anchor MSC/VLR also derives and sends to the non-anchor MSC/VLR the UMTS cipher/integrity keys CK and IK. The non-anchor MSC/VLR stores all keys. This is done to allow subsequent handovers in a non-anchor R99+ MSC/VLR.

At the user side, in either case, the ME applies the stored GSM cipher key Kc.

II. Intersystem Change for PS Services – from UTRAN to GSM BSS


A UMTS security context in UTRAN is only established for UMTS subscribers. At the network side, three cases are distinguished:

In case of an intersystem change to a GSM BSS controlled by the same SGSN, the SGSN derives the GSM cipher key Kc from the stored UMTS cipher/integrity keys CK and IK (using the conversion function) and applies it.

In case of an intersystem change to a GSM BSS controlled by another R99+ SGSN, the initial SGSN sends the stored UMTS cipher/integrity keys CK and IK to the new SGSN. The new SGSN stores the keys, derives the GSM cipher key Kc and applies the latter. The new SGSN becomes the new anchor point for the service.

In case of an intersystem change to a GSM BSS controlled by a R98- SGSN, the initial SGSN derives the GSM cipher key Kc and sends the GSM cipher key Kc to the new SGSN. The new SGSN stores the GSM cipher key Kc and applies it. The new SGSN becomes the new anchor point for the service.

At the user side, in all cases, the ME applies the derived GSM cipher key Kc received from the USIM during the last UMTS AKA procedure.

2) GSM security context

A GSM security context in UTRAN is only established for GSM subscribers. At the network side, two cases are distinguished:

In case of an intersystem change to a GSM BSS controlled by the same SGSN, the SGSN starts to apply the stored GSM cipher key Kc.

In case of an intersystem change to a GSM BSS controlled by another SGSN, the initial SGSN sends the stored GSM cipher key Kc to the (new) SGSN controlling the BSC. The new SGSN stores the key and applies it. The new SGSN becomes the new anchor point for the service.


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At the user side, in both cases, the ME applies the GSM cipher key Kc that is stored.

III. Intersystem Change for PS Services – from GSM BSS to UTRAN


A UMTS security context in GSM BSS is only established for UMTS subscribers with R99+ ME that is capable of UMTS AKA and connected to a R99+ VLR/SGSN. At the network side, two cases are distinguished:

In case of an intersystem change to a UTRAN controlled by the same SGSN, the stored UMTS cipher/integrity keys CK and IK are sent to the target RNC.

In case of an intersystem change to a UTRAN controlled by another SGSN, the initial SGSN sends the stored UMTS cipher/integrity keys CK and IK to the (new) SGSN controlling the target RNC. The new SGSN becomes the new anchor point for the service. The new SGSN then stores the UMTS cipher/integrity keys CK and IK and sends them to the target RNC.

At the user side, in both cases, the ME applies the stored UMTS cipher/integrity keys CK and IK.

2) GSM security context- Established for a UMTS subscriber

A GSM security context for a UMTS subscriber is established in case the user has a R98- ME or R99+ ME not capable of UMTS AKA, where intersystem change to UTRAN is not possible or in case the user has a R99+ ME but the SGSN is R98-, where intersystem change to UTRAN implies a change to a R99+ SGSN.

As result, in case of intersystem change to a UTRAN controlled by another R99+ SGSN, the initial R98- SGSN sends the stored GSM cipher key Kc to the new SGSN controlling the target RNC.

Since the new R99+ SGSN has no indication of whether the subscriber is GSM or UMTS, a R99+ SGSN shall perform a new UMTS AKA when receiving Kc from a R98- SGSN. A UMTS security context using fresh quintets is then established between the R99+ SGSN and the USIM. The new SGSN becomes the new anchor point for the service.

At the user side, new keys shall be agreed during the new UMTS AKA initiated by the R99+ SGSN.

3) GSM security context-Established for a GSM subscriber

Handover from GSM BSS to UTRAN for GSM subscriber is only possible with R99+ ME. At the network side, three cases are distinguished:

In case of an intersystem change to a UTRAN controlled by the same SGSN, the SGSN derives UMTS cipher/integrity keys CK and IK from the stored GSM cipher key Kc (using the conversion functions) and sends them to the target RNC.

In case of an intersystem change from a R99+ SGSN to a UTRAN controlled by another SGSN, the initial SGSN sends the stored GSM cipher key Kc to the (new) SGSN controlling the target RNC. The new SGSN becomes the new anchor point


14-12

for the service. The new SGSN stores the GSM cipher key Kc and derives the UMTS cipher/integrity keys CK and IK which are then forwarded to the target RNC.

In case of an intersystem change from an R98-SGSN to a UTRAN controlled by another SGSN, the initial SGSN sends the stored GSM cipher key Kc to the (new) SGSN controlling the target RNC. The new SGSN becomes the new anchor point for the service. To ensure use of UMTS keys for a possible UMTS subscriber (superfluous in this case), a R99+ SGSN will perform a new AKA when a R99+ ME is coming from a R98-SGSN.

At the user side, in all cases, the ME derives the UMTS cipher/integrity keys CK and IK from the stored GSM cipher key Kc (using the conversion functions) and applies them. In case c) these keys will be over-written with a new CK, IK pair due to the new AKA.

14.6 Implementation


Huawei WCDMA network support integrity protection algorithm UIA0 and ciphering algorithm UEA0, UEA1. According to protocol specification, those algorithms shall be set same in both CS and PS Core network domain, RNC select at least one of integrity protection algorithm and one of ciphering algorithm, further more, intersection between CN and RNC should be existed.

Default Value:

Integrity algorithm: support UIA0 Encryption Algorithms: support UEA0 and UEA1

14.6.2 Parameters

If handsets support UIA1, UEA0 and UEA1 algorithm, the parameters in Table 14-1 must be kept consistency.

Table 14-1 Integrity protection and encrypt parameters

NE Command Name algorithm Description

SET UIA Integrity protection algorithm

UIA1 Set the UMTS Integrity Algorithm (UIA) supported by an RNC. According to the protocol, the RNC supports only UIA1 currently.

RNC

SET UEA Encryption algorithm

UEA0,

UEA1

Set the UMTS Encryption Algorithms (UEAs) supported by an RNC. According to the protocol, the RNC supports only two encryption algorithms currently, UEA0 and UEA1. UEA0: Not encrypted. UEA1.


14-13

NE Command Name algorithm Description

CIPHER YES Whether encrypt the transferred information

MSC MOD MAPACCFG CIPHER

ALGORITHM NOCIPH3G UEA1

This parameter is used to specify the ciphering algorithm to be used.

Cipher YES Indicates whether ciphering is required for the service.

SGSN SET PMM Cipher algorithm

NO_ENCRYPTION, UEA1

This parameter is used to specify the ciphering algorithm to be used.


1) 3GPP TS 33.102 "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; 3G Security; Security Architecture"

2) 3GPP TS 31.111 "USIM Application Toolkit (USAT)"

Feature Description HUAWEI UMTS Radio Access Network Chapter 15 Clock

15-1

Chapter 15 Clock

15.1 Introduction

The RAN clock features include clock features of both RNC and NodeB.

The stability of the 8.192 MHz RNC master clock should be enhanced clock on stratum 3, while that of the 10 MHz NodeB master clock should be kept at +/-0.05 ppm.

There are three optional external reference sources for RNC system clock:

Iu clock GPS clock BITS clock (2 MHz or 2 Mbit/s)

There are three optional external reference clocks for NodeB system clock:

Iub clock GPS clock BITS clock (2 MHz)

To organize RAN clock network, select any one of the three reference clocks for RNC and any one of the three reference clocks for NodeB.

15.2 Glossary

15.2.1 Terms

None

15.2.2 Acronyms and Abbreviation

AGPS Assistant GPS

BITS Building Integrated Timing Supply System

GLONASS GLObal Navigation Satellite System

DAC Digit-Analog Converter

GPS Global Position System

LCS Location Services

NMPT NodeB Main Processing & Timing Unit

OCXO Oven Controlled Crystal Oscillator

PFD Phase-Frequency Detector

OTDOA Observed Time Difference Of Arrival


15-2

WCLK RNC Clock Board

WLPU RNC Line Process Board

WNET RNC Network Switch Board

WRBS RNC Business Subrack

WRSS RNC Switch Subrack

15.3 Application

15.3.1 Availability

This is a basic feature for Huawei UMTS RAN.

15.3.2 Benefit

By using digital phase-locked loop and reliable phase locking technique controlled by software, the system clock can reliably trace signals of satellite clock, BITS clock, or upper-level clock.

The enhanced clock on stratum 3 precedes the international standards, and provides clock source for the RNC. The receiver tracing satellite signals meets the clock standards on stratum 1, and its frequency precision is better than 2.0 E-11.

The software is powerful with the functions of display, alarm reporting and maintenance for system clock. You may set the internal parameters of the clock through the local maintenance terminal.

RNC and NodeB provide several choices of clock reference sources. You may decide which reference source to use by comparing the performance and cost of the following clock reference sources. See Table 15-1 and Table 15-2 for detailed comparison.

Table 15-1 Comparison between RNC clock reference sources

Reference Source

Strong Point Weak Point

GPS clockIt operates with higher precision and works relatively independently. When AGPS is used or Iu clock stability is not good, GPS clock is preferred.

It operates with greater cost and makes engineering more complex.

Iu clock It operates with easy networking and without additional costs. It is in common use.

It operates with larger jitter affected by Iu transmission.

BITS clockIt is higher precision. When you have had BITS equipment, perhaps, it will be used.

It operates with the greatest cost and requires external cable.


15-3

Table 15-2 Comparison between NodeB clock reference sources

Reference Source

Strong Point Weak Point

GPS clockIt operates with higher precision and works relatively independently. When OTDOA is used or Iub clock stability is not good, GPS clock is preferred.

It operates with greater cost and makes engineering more complex.

Iub clock It operates with easy networking and without additional costs. It is in common use.

It operates with larger jitter affected by Iub transmission.

BITS clockIt operates with higher precision. When there are BITS equipment already, perhaps, it is used.

Generally it is seldom used because It operates with the greatest cost and requires external cables.


The stability of the 8.192 MHz RNC master clock should be enhanced clock on stratum 3. Otherwise, voice quality and network capacity will decrease.

The 10 MHz NodeB master clock should be kept at +/-0.05 ppm. Otherwise, the success rate of access and handover will decrease.


15.4.1 Architecture

As illustrated in Figure 15-1, the timing generation module in the WRSS subrack is the WCLK on the WNET.


15-4

WNET

WCLK

WMPU

WLPU

WHPU

WBIE

WSPU

WFMR

WMUX

WRBS

8 kHz 32 MHz

WBIE

WSPU

WFMR

WMUX

WRBS

BITS CLKGPS CLK

Iu CLK( 2 MHz)

Iu

Iu

WRSS

Iu CLK (8 kHz)

8 kHz 32 MHz

CN

CNIubNodeB

ClkSignalFunction signals

RNC

Figure 15-1 RNC system clock

The reference sources for the RNC system clock can be the satellite synchronization clock, BITS clock, 8 KHz Iu clock, and 2 MHz Iu clock.

The RNC master clock is obtained from the above clock sources, which are input and phase locked on the WCLK. Transmitted from the WRSS to the WLPU, this clock synchronizes the clocks at the optical interfaces. The 8 KHz and 32 MHz clocks in the WRBS subracks are obtained from the reference source, which is extracted from the optical interface of the WLPU and phase locked by the WMUX.


15-5

Baseband subrack

NMPT Iub boardOther baseband boards

ClK

Sof tware

ClK

hardware

RF subrack

Function signals

Iub ClK

RNC

Clk signals

BITS GPS

NodeB

Figure 15-2 NodeB system clock

As illustrated in Figure 15-2, the NodeB clock generation module is the NMPT in the baseband subrack. The reference sources for the NodeB system clock can be the satellite synchronization clock, BITS clock, and 8 KHz Iub clock. The 10 MHz NodeB master clock is obtained from the above clock reference sources, which are input and phase locked on the NMPT. This master clock performs frequency synthesis on the NMPT to provide the working clocks for the baseband subrack and RF subrack of the NodeB.

15.4.2 Procedure and Algorism

RNC supports handover between clock reference sources. The higher stratum the clock source is at, the higher priority the clock source has.

To make algorism easy, NodeB does not support the handover between reference sources. When the reference sources are lost or unavailable, the NodeB system clock works in free-run mode and can provide precise clock for a month. At the same time, NodeB will report the alarm.

15.5 Relationship and Interaction with Other Features

Clock interacts with other service is demonstrated in Table 15-3.

Table 15-3 Clock interacts with other service

Service Interaction

LCS The higher the clock precise is, the higher nicety the LCS is.


15-6

15.6 Implementation


To choose GPS as the reference source, install GPS feeders first.

If NodeB uses Iub clock as its clock reference source, the cascading of NodeBs must be not more than five levels. Otherwise, the NodeB clock will not meet the requirements.

15.6.2 Parameter

The clock parameters of RNC and NodeB can be set through MML commands as described in Table 15-4 and Table 15-5.

Table 15-4 NodeB clock parameter

Parameter MML Command Description

Clock Source Quality

STR CLKTST

This command can be used to start clock source quality test.

After successful command execution, the system will report "Clock Quality Test Report-Phase Discrimination Value" or "Clock Quality Test Report-DA Value". Phase Discrimination Value is the comparative value of system clock frequency and the standard 10MHz. It indicates the drift of the system clock.

Reference Clock Source

MOD CLKSRC

Use this command to modify the reference clock source.

When NodeB is in normal operation, it is necessary for it to trace an external clock to correct the master clock frequency. That clock is called clock source. The referenced clock source can be GPS clock source, external clock source and Iub clock source.

Central DA MOD CENTERDA

This command can be used to modify central DA of the MASTER cabinet clock.

When NodeB is in normal operation, the main clock frequency is about 10MHz, which is output from OCXO. Fine tuning can be realized for the main clock frequency by adjusting voltage on OCXO. When the main clock frequency is 10MHz, the voltage employed on OCXO is called central frequency.


15-7


Current DA MOD CURRDA

This command can be used to modify current DA of the MASTER cabinet clock.

When NodeB is in normal operation, the main clock frequency is about 10MHz, which is output from OCXO. Fine tuning can be realized for the main clock frequency by adjusting voltage on OCXO.

Clock work MOD CLKMODE This command can be used to modify clock work mode of the MASTER cabinet as LOCK or FREE.

Table 15-5 RNC clock parameter


Reference Clock Source

ADD CLKSRC

Add a system clock source. Clocks in the board are selected or traced according to handover strategy of the clock source.

1. The higher the clock source stratum is, the higher priority the clock source has.

2. The stratum 0 clock source is set as default local oscillator clock source.

3. A clock source can only correspond to one stratum, and a grade can only correspond to one clock source.

4. The SDH clock source is extracted from the WLPU. Only one clock input can be selected for one WLPU, and therefore, clock sources of different stratums can only correspond to different WLPUs.


15-8


Handover Strategy

SET CLKMODE

The clock sources are classified as current clock source and non-current clock source. According to a certain handover strategy, the system clock can be fixed to the current clock source or handed over between the current and the non-current clock sources. 1. [System clock working mode] has two types: (1) Manual handover: The user specifies a clock source and inhibits it from automatically be handed over to other sources. (2) Preemptive automatic handover: The user need not to specify a clock source and the system is able to select the clock source with the highest priority automatically.

2. If the system clock works in the preemptive automatic handover mode, the stratum of the currently used clock source need not be specified and the system shall choose the clock of the highest stratum automatically.

15.6.3 Example

If you need to set GPS as the clock reference source of the RNC and NodeB, and if you need to set handover strategy of the RNC clock reference source as the manual handover, you may use the MML commands below:

1) RNC MML commands:

ADD CLKSRC: SRCGRD=4, SRCT=GPS1;

SET CLKMODE: CLKWMODE= PREEMPTIVE_AUTO_HANDOVER_STRATEGY;

2) NodeB MML commands:

MOD CLKSRC:CLKSRC=GPS;

MOD CLKMODE: MODE=LOCK.

When you set GPS as the RNC highest clock source stratum, as RNC master clock, the 8.192 MHz OCXO on the WCLK traces the GPS signals. If GPS fails, RNC will choose to synchronize with the BITS clock or the Iu clock in the preset sequence.

When you set the NodeB clock mode as LOCK and clock source reference as GPS, as NodeB master clock, the 10 MHz OCXO on the NMPT traces the GPS signals. If GPS fails, the OCXO will not follow it. The 10 MHz OCXO on NMPT board will work in the free-run mode.


None

Feature Description HUAWEI UMTS Radio Access Network Chapter 16 STS

16-1

Chapter 16 STS

16.1 Introduction

Statistics and Traffic measurement subsystem (STS) is one of the important functions of BSC6800, which is also called performance management function. The BSC6800 Performance Management System measures the BSC6800 performance and manages the measurement result.

Many activities in the daily operation, UTRAN network planning and optimization require STS data for decision making. System behavior evaluation is based on the performance data collected and recorded by BSC6800.

One function of the performance management system is to collect data, which can be used to verify the physical and logical configuration of the network and to locate potential problems as early as possible.

Another function of the performance management system is to transfer the data to an external system, e.g. M2000, for further evaluation.

In M2000, the performance management is executed by setting performance management task, collecting the statistics data, exporting the statistics results.

16.2 Glossary

16.2.1 Terms

None



STS Statistics and Traffic measurement subsystem




16-2

16.3 Application

16.3.1 Availability


16.3.2 Benefit

The performance management covers the domains of traffic load, quality of service, resource availability etc. It monitors the performance data a RNC, a cell, a link etc, and is an important tool for routine maintenance, fault handling, network optimization and network management.


None


16.4.1 Architecture

Figure 16-1 System architecture of Performance Management

Figure 16-1 illustrates the architecture of the performance management. It contains M2000, BAM, and RNC.

The M2000 system includes the M2000 Server and the M2000 Client. It is used to implement centralized management of configurations, alarms and performances of various WCDMA Network Elements. BSC6800 connects the M2000 via BAM. M2000 handles performance measurement task management and performance measurement data query functions.

M2000 BAM RNC

Performance Measurement

Performance Measurement

Measurement item (counter)


16-3

The performance measurement task management is used to collect, manage and analyze measurement data. The measurement items are selected and the attribute of measurement period is set.

The performance Measurement Data Query function facilitates the retrieval of measurement data that defined in the measurement task.

The results of measurement data are created from the RNC running system. All the counters related to the measurement item are sent to the M2000 periodically.

16.4.2 Measurement Items

In order to collect the data, the BSC6800 defines the measurement items which comprise all the raw counters and adopts a tree structure for counter management.

The structure is as below:

Measurement object type

-> Measurement set

-> Measurement unit

-> Measurement item

The measurement items provided by the system are classified as original item and calculation item that is derived from the original items.

BSC6800 defines the following object types which covers all the functions of BSC6800:

RNC measurement Iu interface measurement GTPU measurement SCCP measurement CPU measurement Iur interface measurement Cell measurement SAAL link measurement MTP3B link measurement MTP3B link set measurement MTP3B destination signal point measurement QAAL2 adjacent node measurement Cell relation measurement

Notes:

For all the meaning description of each item and counter, refer to HUAWEI “UMTS Radio Access Network Performance Measurement Item Reference Manual”.


16-4

I. RNC Measurement

RNC measurement object contains all the performance measurement of RNC basic signaling procedure. Measurement units are defined according to different signaling procedure, which may be the paging procedure, RRC connection setup and release, RAB setup and release, RB setup and release, handover procedure, inter-RAT handover procedure, SRNC relocation procedure, CBS and LCS function measurement.

II. Iu Interface Measurement

Iu interface measurement object contains the measurement items relating to the Iu interface signaling procedure. It measures the inter-operation procedure between RAN and CN via Iu interface, including the Iu signaling setup, release procedure.

III. GTPU Measurement

Measure the number of messages and bytes transmitted/received by RNC GTPU. GTPU is the entity that handles the PS data plane.

IV. SCCP Measurement

Measure the SCCP error performance and SCCP utilization performance.

V. CPU Measurement

Measure the usage of the CPU in WSPU subsystem.

VI. Iur Interface Measurement

Iur interface measurement contains measurement items of signaling procedures through Iur interface.

VII. Cell Measurement

Cell measurement contains the counterparts of RNC measurements.

VIII. SAAL Link Measurement

Measure SAAL link performance.

IX. MTP3B Link Measurement

Measure the performance of MTP3B link.

X. MTP3B Link Set Measurement

Measure the performance of MTP3B link sets.

XI. MTP3B Destination Signal Point Measurement

Measure the performance of MTP3B destination signaling point (DSP).


16-5

XII. QAAL2 Adjacent Node Measurement

Measure the performance of QAAL2 adjacent nodes.

XIII. Cell Relation Measurement

Measure the handover performance between neighbor cells.

16.5 Interaction

None

16.6 Implementation


None

16.6.2 Parameter

None

16.6.3 Example

None


None

Feature Description HUAWEI UMTS Radio Access Network Chapter 17 Interface Tracing

17-1

Chapter 17 Interface Tracing

17.1 Introduction

Interface tracing function of BSC6800 can be grouped into following types:

Radio network layer standard interface tracing: including Iu interface tracing, Iur interface tracing, Iub interface tracing and Uu interface tracing;

Transport network layer tracing: including QAAL2 protocol tracing, SCCP protocol tracing, MTP3B protocol tracing and SAAL protocol tracing;

UE standard interface message tracing; Sample tracing.

17.2 Glossary

17.2.1 Terms

None


RNL Radio Network Layer

TNL Transport Network Layer


TMSI Temporary Mobile Subscriber Identity

P-TMSI Packet Temporary Mobile Subscriber Identity

IMEI International Mobile Equipment Identity

KPI Key Performance Indicator

DPC Destination Point Code

17.3 Application

17.3.1 Availability


17.3.2 Benefit

UE standard interface message tracing enables operator to monitor message of four standard interfaces (Iu, Iub, Iur, Uu) of one specific IMSI, TMSI, P-TMSI or IMEI.


17-2

Sample tracing enables operator to monitor message of four standard interface(Iu, Iub, Iur, Uu) of specific cell(s).


The interface tracing function is restricted by license. The RNC provides interface tracing function only when “INTERFACE TRACE” and “UE TRACE” licenses are purchased.


17.4.1 RNL Standard Interface Tracing

I. Iu Interface Tracing

This function is used to trace RANAP message between the RNC and specified DPC or all DPCs of CN.

II. Iur Interface Tracing

This function is used to trace RNSAP message between the RNC and specified DPC or all DPCs of DRNC.

III. Iub Interface Tracing

This function is used to trace NBAP message between the RNC and a specified port of a specified NodeB, or all NodeBs.

IV. Uu Interface Tracing

This function is used to trace RRC message of specified cell(s).

17.4.2 TNL Tracing

I. QAAL2 Protocol Tracing

This function is used to trace QAAL2 protocol messages, mainly used to locate the problems of AAL2 setup failure and AAL2 abnormal release.

II. SAAL Protocol Tracing

This function is used to trace SAAL protocol messages, mainly used to locate the problem of SAAL link unavailability.

III. SCCP Protocol Tracing

This function is used to trace SCCP protocol messages, including connection-oriented messages and connectionless messages.


17-3

IV. MTP3B Protocol Tracing

This function is used to trace MTP3B protocol messages, including MTP3B upper layer (QAAL2 and SCCP) messages, MTP3B signaling link test messages, and MTP3B signaling network management messages.

17.4.3 UE Standard Interface Message Tracing

This function is used to trace Iu, Iur, Iub and Uu interfaces signalling messages of a specified UE.

For the "Iu interface message" (RANAP protocol message) and "Iur interface message" (RANSAP protocol message) options, only the connection-oriented messages can be traced.

For the "Iub interface message" (NBAP protocol message) option, the task will trace only the dedicated NBAP messages.

17.4.4 Sample Tracing

This function traces four standard interfaces (Iu, Iub, Iur, Uu) of specific cell(s). It is mainly used in KPI analysis. If KPI of one or more cells is not acceptable, operator can start sample tracing of these cells and find reason of unacceptable KPI by means of signaling analysis.

17.5 Interaction

None

17.6 Implementation


None

17.6.2 Parameter

None

17.6.3 Example

None

17.7 Reference information

None

Feature Description HUAWEI UMTS Radio Access Network Index

i-1

Index

A acceptable cell, 2-1

AGPS

receiver, 9-11

AMRC, 12-1

implementation, 12-5

parameter, 12-5

technical description, 12-2

APGS, 9-18

available PLMN, 2-1

C CAC, 13-1

call admission control, 13-1

camped normally, 2-1

camped on a cell, 2-1

camped on any cell, 2-1

cell breathing, 13-1

cell measurement, 16-3

cell relation measurement, 16-3

cell reselection, 2-1

engineering guideline, 2-35

cell selection, 2-1


cell update, 4-1

implementation, 4-6

parameter, 4-6

procedure, 4-3

technical description, 3-2, 4-2

clock

BITS clock, 15-1

GPS clock, 15-1


Iu clock, 15-1

Iub clock, 15-1

parameter, 15-6


context identifier, 8-1

CPU measurement, 16-3

D DCCC, 11-1

differential coding, 8-1

directed retry decision and redirection, 13-1

downlink power balancing, 10-1

DRD, 13-1

E encrypt, 14-1

EPLMN, 2-1

F fast closed-loop power control, 10-1

feature list, 1-1

G GPS, 9-1

GTPU measurement, 16-3

H handover

inter-RAT handover, 7-1

soft handover, 5-1

softer handover, 5-1

HPLMN, 2-1

I idle mode behavior, 2-1


interaction, 2-34

parameter, 2-39

inner-loop power control, 10-1

integrity protection, 14-1

integrity protection and encrypt


i-2



interface tracing, 17-1

inter-frequency load balancing, 13-1

inter-RAT handover, 7-1


parameter, 7-17


Iu interface measurement, 16-3

Iu interface tracing, 17-2

Iub interface tracing, 17-2

Iur interface measurement, 16-3

Iur interface tracing, 17-2

L LBS, 9-6

LCC, 13-1

LCS

A-GPS, 9-1

cell ID + RTT, 9-11

cell-ID, 9-1

client, 9-1

enhanced call routing, 9-7

horizontal accuracy, 9-5


location based charging, 9-6

location based information service, 9-7

network enhancing service, 9-7

OTDOA, 9-1

OTDOA-IPDL, 9-13

parameter, 9-27

public safety service, 9-6

response time, 9-6

server, 9-1


tracking service, 9-6

LDB, 13-1

list

feature, 1-1

LMU, 9-9

load congestion control, 13-1

load control, 13-1


parameter, 13-14


location registration, 2-1

location service, 9-1

location update, 2-1

M measurement

cell, 16-3

cell relation, 16-3

CPU, 16-3

Iur interface, 16-3

MTP3B destination signal point, 16-3

MTP3B link, 16-3

QAAL2 adjacent node, 16-3

RNC, 16-3

SAAL link, 16-3

SCCP, 16-3

MTP3B destination signal point measurement, 16-3

MTP3B link measurement, 16-3

MTP3B protocol tracing, 17-2

O open-loop power control, 10-1

P paging, 2-1


PDCP header compression, 8-1


parameter, 8-11


PLMN selection, 2-1


position method, 9-1

potential user control, 13-1

power control, 10-1


parameter, 10-7


PUC, 13-1


i-3

Q QAAL2 adjacent node measurement, 16-3

QAAL2 protocol tracing, 17-2

R reserved cell, 2-1

restricted cell, 2-1

RNC measurement, 16-3

roaming


routing area updating, 2-1

S SAAL link measurement, 16-3

SAAL protocol tracing, 17-2

SCCP measurement, 16-3

SCCP protocol tracing, 17-2

security context

GSM, 14-1

UMTS, 14-1

soft handover, 5-1


parameter, 5-16


softer handover, 5-1

SRNS relocation, 6-1


parameter, 6-10


standby power consumption


state transition

in connected mode, 11-5

in idle mode, 2-8

statistics and traffic measurement subsystem, 16-1

STS, 16-1



suitable cell, 2-1

system information, 2-1

T tracing

Iu interface, 17-2

Iub interface, 17-2

Iur interface, 17-2

MTP3B protocol, 17-2

QAAL2 protocol, 17-2

SAAL protocol, 17-2

SCCP protocol, 17-2

Uu interface, 17-2

U UMTS authentication vector, 14-1

URA update, 3-1

implementation, 3-4

parameter, 3-4

procedure, 3-3

type, 3-2

Uu interface tracing, 17-2

i.

42812354 umts radio access network feature description 1

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