kpi's for umts

Introduction to KPI’s for UMTS

•For more detailed information see T035 course.

•W-CDMA

•MM/SM

•SSCF-UNI

•AAL2

•SSCOP

•RRC

•RLC

•MAC

•AAL5

•SSCOP

•RANAP

•SCCP

•SSCF-NNI

•GTP-C

•AAL5

•IP

•ATM

•SSCF-UNI

•AAL2

•SSCOP

•NBAP•RRC

•RLC

•MAC •SSCF-NNI

•AAL5

•SSCOP

•SCCP

•RANAP

•MTP3-b

•UDP

•GTP-C•NBAP

•Physical

•Channels

•MM/SM

•UE •Node B •RNC •SGSN

•Relay •Relay

•Physical

•Channels

•Relay

•W-CDMA •ATM •ATM

•MTP3-b

Revision of protocol stack

KPI’s for UMTSRRC Connection

Number of RRC connection requests

Number of RRC connection set up

Number of successful RRC connection establishments

Number of RRC failures

Number of release requests on Iu per cause

Just some of many counters

•UE

•RRC Connection Set up-UM

•RNC

•RRC Connection Set up Complete-AM

•RRC Connection request-TM

•UE

•RRC Connection request •RNC

•UE identity

•Cause

•CHOICE

•IMSI

•TMSI + LAI

•PTMSI + RAI

•RRC establishment Cause

•Originating Conversational Call

•Originating Streaming

•Originating Interactive

•Originating Background

•Terminating Conversational Call

•Terminating Streaming

•Terminating Interactive

•Terminating Background

•Emergency Call

•Inter-RAT Cell reselection

•Registration

•Detach

•Originating High Priority Signalling

•Originating Low PrioritySignalling

•Terminating High Priority Signalling

•Terminating Low PrioritySignalling

•Protocol error

•This message can indicate whether a protocol error occurred.

message rrcConnectionRequest :

initialUE-Identity tmsi-and-LAI : {

tmsi '10000111011100001001000101101011'B,

lai {

plmn-Identity {

mcc {

2 3 4

mnc {

20

lac '0000010010110000'B

establishmentCause originatingHighPrioritySignalling,

protocolErrorIndicator noError

1.RRC Connection Set up message

•Uplink

•Power control

•Information

•Power Control

•Algorithm

•1 OR 2

•TPC step size

•Power offsets from pilot

•Up Link Scrambling Code

•Long

•0……16,777,215

•Number DPDCH

•1….max 6

•Spreading Factor•4, 8, 16, 32, 64, 128, 256

•Size of CRC

•Beta Parameters •Information the UE requires from the Network (NOT A COMPLETE LIST)

•Transport /Logical channel/ Physical Number

•RNC

KPI’s for UMTSNBAP Radio – Link Management

Successful NBAP radio link setups

Number of failed NBAP radio-link setups

Number of successful NBAP radio link deletions

Number of failed NBAP radio link deletions

Just some of many NBAP counters

The Node B Application Part (NBAP)The Node B Application Part (NBAP)

Dedicated functions of NBAP include:

• Dedicated transport channel establishment, reconfiguration and removal.

• Downlink power control.

• Measurement handling of dedicated radio channels.

• Some control of compressed mode operations

AAL2

ALCAPNBAP

AAL5AAL5

FPs

ATM ATM ATM

AAL2

ALCAP NBAP

AAL5 AAL5

FPs

ATMATMATM

PVC

PVC

SVC

Node B RNC

•The NBAP protocol is transmitted over the Iub interface on its own PVC

AAL5 on ATM.

•The NBAP procedures can be split into two types, common and

dedicated. The common procedures are not related to a particular UE,

where the dedicated procedures are related to a specific UE context.

•Common Functions of NBAP include:

•Common transport channel establishment, reconfiguration and

removal.

•Logical Operation and Maintenance resource control.

•Measurement handling of Common Channels.

•RNC

•NBAP:UL initiating Message Id: audit required

• For each cell

•NBAP DL initiating message id audit ‘start’

•NBAP UL successful outcome id audit ‘ end of audit’(local cell id)

•NBAP DL initiating Id –cell set up

•Cell id = a Primary SC, Common Channels

•NBAP UL successful Outcome

•NBAP:DL initiating Message

id SIB update

•NBAP UL successful Outcome SIB update

•With the Cell update message, the RNC assigns:

•Primary SC

•Common channels

•Primary Synchronization Channel

•Secondary synchronization channel

•Common Pilot channel

•Common Control Physical channel (CCPCH) that carriers

the broadcast channel

•NEW NODE B-must have SC etc

•R

•N

•C

•Minimum and Maximum DL power

•Power offsets PO1, PO2, PO3

•TPC Step Sizes: 0.5,1,1.5, 2dB

•UE •Node B

•RNC

•RRC Connection Request

•NBAP •NBAP•Radio link setup request

•Step size

•Power adjustment is contained in the RADIO LINK SETUP REQUEST

(NBAP). It cannot be reconfigured during

connection.

•Values are: O.5, 1, 1.5 and 2 dB

•Downlink DPCCH power offsets

•With the DL DPCCH are the TFCI, Pilot and TPC. These can be transmitted at different power levels.

•PO1: TFCI

•PO2: TPC

•PO3: Pilot bits

KPI-Number of failed NBAP radio-link setups- Major problem

•UE •Node B •RNC

•RRC•1. RACH: CCCH: RRC CONNECTION REQUEST <TM>

•2. RADIO LINK SETUP REQUEST

•3. RADIO LINK SETUP RESPONSE

•6. DOWNLINK SYNCHRONISATION

•7. UPLINK SYNCHRONISATION

•11. DCCH: RRC CONNECTION SETUP COMPLETE <AM>

•8. FACH: CCCH: RRC CONNECTION SETUP <UM>

•4. ESTABLISH REQUEST (AAL2)

•5. ESTABLISH CONFIRM (AAL2)

•Start RX

•RRC

•NBAP•NBAP

•NBAP•NBAP

•ALCAP

•ALCAP

•ALCAP

•ALCAP

•DCH-FP•DCH-FP

•DCH-FP •DCH-FP

•RRC

•RRC

•RRC

•RRC

•Start TX

•10. RADIO LINK RESTORE INDICATION•NBAP•NBAP

•9. INSYNCH IND•L1 •L1

•ALL KPI’s

KPI’s for UMTSNode B – Radio

Wideband received power

Transmitted carrier power


•R

•N

•C

•CCCH/RACH Connection Request

•NBAP - Received Total Wideband Power

•If RTWP(dBM) < Max UP Interference level

•RRC is accepted

•Max Up Inter= -112 to -50 step 0.1

Received Total Wideband Power (RTWP)

UL RTWP

Received total wideband power, including nose generated in the receiver. This measurement is used to filter RRC CONNECTION REQUESTS. If the RNC is going to accept message or not.

The overall UL interference received in a cell is evaluated with the UL RTWP with is measured by the node B and reported to the RNC through NBAP common measurement.

On the RACH reception, before allocating SRB, the RNC compares the RTWP with the maximum UL interference level parameter to decide whether to accept the RRC connection OR not.

Parameter Range default

Max UPLINK Interference

-112 …..50 (Step 0.1) -50

KPI’s for UMTSRNSAP– Radio Link Management

Number of successful RNSAP radio link set up

Number of failed RNSAP radio link setups

Just some of many RNAP counters

•The Radio Network Subsystem Application Part (RNSAP)

•The RNSAP protocol is mainly used for:

•Basic mobility procedures used in soft handover and relocation.

•Carrying RRC messages, bridging the gap between SRNC and CRNC.

•Establishment and release of dedicated channels between RNCs, as well as reconfiguration of existing channels.

Node B

Node B

Node B

Node B

Node B

Node B

RNC

RNC

MSC/VLR

SGSN

HLR

GGSN

Gs

Iu-CS

Gn

Iu-PS

Iub

Iur

Gr

D

UE

Uu

KPI’s for UMTSRRC Radio Link management

Number of successful RRC active set updates per cell

Number of successful RRC active set updates per RNC

Number of failed RRC active set updates per cell

Number of failed RRC active set updates per RNC

Active set size

Number of RRC state transitions from Cell_FACH to cell_DCH

Number of RRC state transitions from Cell_DCH to cell_FACH

Number of calls in cell_FACH state


KPI’s for UMTSRAB Management

Number of successful radio bearer establishments per cell

Number of successful radio bearer establishments per RNC

Number of refused radio bearer establishments per cell

Number of refused radio bearer establishments per RNC

Number of successful RAB releases

Number of failed RAB releases

Number of RAB failures due to UE capabilites


KPI’s for UMTSQuality of service

Number of successful downsizing per cell

Number of successful downsizing per RNC

Number of successful up sizing per cell

Number of successful up sizing per RNC


DedicatedChannels

Common Channels Shared Channels

DCH FACH RACH CPCH DSCH USCH

UplinkDownlink

Both DL UL UL DL UP TDD only

FastPower Control

Yes No No Yes Yes Yes

SoftHandover

Yes No No No No No

Suitedfor

Medium or LargeData amounts

Small Small Small or Medium

Medium or large

Medium or large

Suited for bursty

data

No Yes Yes Yes Yes Yes

CELL_FACH stateCELL_FACH state

•Downsizing timer

•Upsizing

•UL or DL traffic

Threshold

Cell_DCH

Cell_FACH

CELL_FACH stateCELL_FACH state

•Idle mode

•CELL_DCH

•CELL_FACH

•AO upsize

•AO downsize

•Add token•Remove token

•Establish shared connection

•Release Shared Connection


Number of free downlink channelization codes

Percentage of time a cell is congested

Percentage of time a cell is congested due to OVSF codes

Percentage of time a cell is congested due to power

Number of RAB assignments rejected for high priority users


KPI’s for UMTSHard Handover

Number of 3G to 2G handover requests per cell

Number of 3G to 2G handover requests per RNC

Number of failures


Intra-Frequency: UMTS to UMTS- Same Carrier

Inter-Frequency: UMTS to UMTS- Between Carriers

Inter-Mode: UMTS to UMTS- Between FDD and TDD Modes

IRAT: UMTS to GSM

IRAT: GSM to UMTS

UMTS FDD Neighbour typesUMTS FDD Neighbour types

Hard HandoverHard Handover

During an HHO the used radio frequency of UE changes

Break before make handoverNot seamless

UE stops transmission on one frequency before it moves to another frequency

CAN Make it more seamless

Use of compressed mode if:Both frequencies use overlapping compressed mode

gaps and switch is done during gap-seamless

Eb/No Cell 1

Eb/No Cell 2

Eb/No

Threshold

Threshold

Counter

Decision to HO to GSM

-20dB

Decision to HO to GSM

RNC

3GMSC

2GMSC

BSC

Iub

Iu-CS

A-bis

Node B

BTS

Intersystem reporting events:

3A – the estimated quality of the current used UTRAN frequency is below a certain threshold and and the estimated quality of the other system is above a certain threshold

3B - The estimated quality of the other system is below a certain threshold

3C – The estimated quality of the other system is above a certain threshold

3D – Change to best cell in other system

SS7 Network

HLR

MAP

•Normal Frame •Normal Frame

•Extra Power needed for compressed mode

•10ms •10ms •10ms

Gap

Compressed Frame

•Same amount of data is transmitted in a shorter time.

•10log10(15 slot/7 slot gap) = 2.7dB

•With 7 slot gap in 15 slot frame

KPI’s for UMTSPower Management

Cell power used for speech calls

Cell power used for data calls

Cell power used for signalling

Cell power used for miscellaneous

TX power


•Power for SHO

•Power for Overhead

•Call Admission

•Power

•Common Channel Power

•Power For signalling

•Power for speech

•Power for

•Data•Maximum

•Power

Initial DL traffic channel power

When a traffic channel is setup it is done at a certain DL power.

Power = DL CPICH power + Ec/No target – UE received CPICH pilot

Example

= 33 + ( -13) – (- 10)

= +30dB

= 33 + ( -13) - (-15)

= +35dB

KPI’sKPI’s

• If one speech circuit is configured for 3dbm of power. How much power in dBm will 100 connections take in dBm?


Number of successful IRM scheduling downgrades per cell

Number of failed IRM scheduling downgrades per cell


KPI’s for UMTSIRM scheduling

The principle of IRM scheduling is that when experiencing power shortage:

When the UE leaves the centre of the cell and reaches the cell edge it is a way to AVOID a DROP CALL.

•Reducing power by reducing user bit rate and increasing process gain.

•Process gain = 10 log 384000/User bit rate


The bearer downgrade maybe triggered by observing the BLER. When this exceeds a threshold, bad radio conditions are detected. If these radio conditions remain bad during a period of time, bearer fallback is triggered.

RNC

Checks BLER


Is based on detection of bad radio conditions due to layer 1. BLER increase for a period of time.

The RNC reduces the Transport Format Combination set so limits the user bit rate.

•BLER Target

Good radio conditions

•384kbps •384kbps

SHO

•User rate reduction

KPI’s for UMTSRadio Measurements

Uplink RSSI

CPICH Ec/No measurements

Compressed mode configuration success

Compressed mode configuration failure


KPI’s for UMTSNode B –ATM

Number of received cells (AAL2)

Number of lost packets(AAL2)

Number of error AAL2 packets

Number of invalid CID(AAL2)

Number of received cells (AAL5)



Loss of cell delineation


Node B – PCM

Loss of incoming signal

Alarm indication signal

•Question?

•If you are receiving an AIS alarm. What is the problem?

•What other KPI’s will show?

•If you had a loss of signal in one direction. What KPI will be set in the

other?



Number of invalid CID(AAL2)



•If you had the following KPI’s. Give a list of problems?


Loss of cell delineation – Major problem – Cannot decode the HEC field- Result cannot find any ATM cell

RNC

Iub

Iu-CS

Node B

Iu-PS

•5 Octet Header

•48 Octet

•Payload

•5 Octet Header

•48 Octet

•Payload

•5 Octet Header

•48 Octet

•Payload

•5 Octet Header

•48 Octet

•Payload

•LCD – loss all data

•LCD- loss of data and speech

•LCD- loss of speech

•RNC

•Iub (E1)•STM-1/4/16

•PLMN may not own this network

•NODE B

•ATM

•ROUTER

•IMA Group

•KPI’s for UMTS

•There are a number of KPI’s regarding Node B IMA:

•IMA group unavailable seconds

•IMA group near end failures

•IMA link violations

•etc

•You require a good understanding of ATM and SDH to understand these. Covered on

the T035 course.

AAL 2AAL 2

•5 Octet Header

•48 Octet Payload•SDU

•HEC •UUI •LI •CID

•5 •5 •6 •8

•Mini Cell Header

•SDU •Why do we use AAL2 connections?

•Packet Fill Delay

•If the size of the mini packets is set to 12 bytes what will be the PFD for:

•12kbps service

•4.7kbps•What the function of

HEC

KPI’s for UMTSNode B – RACH

RACH negative acknowledgements

Number of accepted RACH


BCH PCHCPCHRACH FACH DSCH DCH

DPDCH

DPCCH

PDSCH

S-CCPCH

P-CCPCH

PCPCH

PRACH

S-SCH

CPICH

AICH

PICH

AP-AICH

CD/CA-ICH

P-SCH

Physical Channels

Transport ChannelsSpreading/Modulation

•Access preambles are sent using increasing power levels until a matching response is received or the max number of preambles have been sent

BCH PCHCPCHRACH FACH DSCH DCH

DPDCH

DPCCH

PDSCH

S-CCPCH

P-CCPCH

PCPCH

PRACH

S-SCH

CPICH

AICH

PICH

AP-AICH

CD/CA-ICH

P-SCH

Physical Channels

Spreading/Modulation

SIB5 –

accessServiceClass-FDD availableSignatureEndIndex 15 assignedSubChannelNumber '1111'B

primaryCPICH-TX-Power 33,

prach-PowerOffset {

powerRampStep 2,

preambleRetransMax 64

•rachSubChannels – Defines the set of access slots on which the mobiles are authorised to transmit their access on the PRACH.

•preambleSignature –Defines a set of allowed signatures of the PRACH preamble part.

KPI’s for UMTSMobility Management

Number of cell updates

Number of cell update failures

Number of failed RRC security mode command procedures

Number of failed RANAP security mode command procedures


Without the GsWithout the Gs

HLRSGSN

1. GPRS ATTACH REQUEST (PTMSI/IMSI, Classmark, old RAI)

AUTHENTICATION AUTHENTICATION

MSC

1. GMS ATTACH REQUEST (PTMSI/IMSI, Classmark, old RAI)


HLR

With the GsWith the Gs

HLRSGSN

1. GPRS ATTACH REQUEST (PTMSI/IMSI, Classmark, old RAI)


MSC HLR

•GS Interface

Network Operation Modes

NetworkOperation

Mode

GSM/GPRSAttach

RA/LAUpdating

MS Paging

1

Combined functionsGSM (IMSI) Attach performed via GPRSAttach

Combined functionsGSM (LA) update performed via the RA Update

Co-ordinatedPaging for GSM andGPRS on CCCH (PCH)or PPCH

2

Not Combined GSM (IMSI) Attach performed.GPRS Attach alsoperformed

Not CombinedGSM (LA) update via A-InterfaceGPRS (RA) updatevia Gb-Interface

Not Co-ordinatedPaging for GSM on CCCH (PCH)Paging for GPRS onCCCH (PCH)

3

Not Combined GSM (IMSI) Attach performed.GPRS Attach alsoperformed

Not CombinedGSM (LA) update via A-InterfaceGPRS (RA) updatevia Gb-Interface

Not Co-ordinatedPaging for GSM on CCCH (PCH)Paging for GPRS onPPCH

Authentication

Authentication Key (Ki) (128 bits) stored in HLR/SIM

AUC/HLR

KiKi RANDRAND

A3A3

A8A8

SGSN

SRES(Signed response)

Kc(Cipher Key)

RAND

MS

SRES valueReturned to The SGSN

SRES=SRESAccess Allowed

SRES=SRESAccess Barred

THE END

kpi's for umts

Documents

nbap procedures

common functions of

radio link setup request

countersrrc connection

umrncrrc connection

common procedures

dedicated procedures

downlink power control