zxur 9000 gsm (v6.50.00) system description

ZXUR 9000 GSMBase Station ControllerSystem Description

Version: V6.50.00

ZTE CORPORATIONNO. 55, Hi-tech Road South, ShenZhen, P.R.ChinaPostcode: 518057Tel: +86-755-26771900Fax: +86-755-26770801URL: http://ensupport.zte.com.cnE-mail: [email protected]

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Revision History

Revision No. Revision Date Revision Reason

R1.0 2011-08-04 First edition

Serial Number: SJ-20101019110320-022

Publishing Date: 2011-08-04(R1.0)

ContentsAbout This Manual ......................................................................................... I

Chapter 1 Overview.................................................................................... 1-11.1 ZXUR 9000 Overview......................................................................................... 1-1

1.2 Overview of the ZXUR 9000 GSM System ........................................................... 1-1

1.3 ZXUR 9000 GSM Application .............................................................................. 1-3

Chapter 2 System Functions..................................................................... 2-12.1 Basic Services ................................................................................................... 2-1

2.2 Mobility Management ......................................................................................... 2-7

2.3 Channel Management ........................................................................................ 2-8

2.4 External Interface ............................................................................................... 2-8

2.5 Radio Resource Management............................................................................. 2-9

2.6 Network Management Functionality ................................................................... 2-10

Chapter 3 Software and Hardware Architecture...................................... 3-13.1 Hardware Architecture of ZXUR 9000 GSM ........................................................ 3-1

3.2 Software Architecture of ZXUR 9000 GSM .......................................................... 3-3

Chapter 4 Networking ................................................................................ 4-14.1 Networking via the Abis Interface ........................................................................ 4-1

4.1.1 Star Networking ....................................................................................... 4-1

4.1.2 Chain Networking..................................................................................... 4-1

4.1.3 Ring Networking....................................................................................... 4-2

4.1.4 Star-Chain Hybrid Networking .................................................................. 4-2

4.2 Networking via the A/Gb Interface ....................................................................... 4-3

4.2.1 Networking via the Gb Interface ................................................................ 4-3

4.2.2 Networking via the A Interface................................................................... 4-4

Figures............................................................................................................. I

Tables ............................................................................................................ III

Glossary .........................................................................................................V

I

About This ManualPurpose

This manual provides a system description of ZXUR 9000 GSM, including the features,applications, functions and networking.

Intended Audience

l System engineersl Planning engineers

What Is in This Manual

Chapter Summary

Chapter 1, Overview Describes the features and applications of ZXUR 9000 GSM.

Chapter 2, System

Functions

Describes the service functions of ZXUR 9000 GSM.

Chapter 3, System

Architecture

Describes the software and hardware architecture of ZXUR 9000 GSM.

Chapter 4, Networking Describes the networking of ZXUR 9000 GSM.

I

Chapter 1OverviewTable of Contents

ZXUR 9000 Overview.................................................................................................1-1Overview of the ZXUR 9000 GSM System .................................................................1-1ZXUR 9000 GSM Application .....................................................................................1-3

1.1 ZXUR 9000 OverviewDuring the development of mobile telecommunication technology from 2G to 3G, multipleradio network systems coexist in the network. The operation and maintenance of differentsystems increases the cost for the telecom operators. The focus of future development forZTE is to provide equipment that both integrates radio networks of different systems andsupports more advanced technology in the future, helping the operators reduce costs.

ZXUR 9000 is a multimode controller solution provided by ZTE Corporation to integrateradio networks of different systems. With a multimode and IP-oriented modular design,ZXUR 9000 provides the functions of BSC and RNC in the GSM and UMTS systemsrespectively to adequately fulfill the requirements of multimode integration.

Depending on the network environment, ZXUR 9000 can be configured to three systems:ZXUR 9000 GSM, ZXUR 9000 UMTS, and ZXUR 9000 GU. ZXUR 9000 GSM and ZXUR9000 UMTS are independent network element modes. ZXUR 9000 ZXUR 9000 GU isintegrated network element mode.

If configured to a ZXUR 9000 GU system, ZXUR 9000 can, as an independent element,access a network where GSM and UMTS coexist. In this case, ZXUR 9000 GU providesfunctions of both GSM BSC and UMTS RNC. When ZXUR 9000 GU accesses a GSMnetwork, it complies with the 3GPP R7 protocol. When ZXUR 9000 GU accesses a UMTSnetwork, it complies with the 3GPP R8 protocol.

This document only describes the ZXUR 9000 in independent network element mode, thatis, ZXUR 9000 GSM.

1.2 Overview of the ZXUR 9000 GSM SystemZXUR 9000 GSM is a base station controller (BSC) developed by ZTE according to the3GPP R7 protocol. With all functions specified in 3GPP R7, ZXUR 9000 GSM providesa series of standard interfaces and supports connectivity with the CNs from differentmanufacturers. The system features high capacity, high reliability, and high scalability,and supports IP GERAN transmission.

The ZXUR 9000 GSM system has the following features:

1-1

SJ-20101019110320-022|2011-08-04(R1.0) ZTE Proprietary and Confidential

ZXUR 9000 GSM System Description

Advanced System Architecture

The ZXUR 9000 GSM system is based on the ATCA architecture, providing standardplatform architecture for carrier-class applications, with features like high reliability andmaintainability.

l The service control unit has a standard ATCA architecture.l The media access unit provides additional rear boards as compared with the standard

ATCA.Without sacrificing the capacity of front boards, the added rear interface boardscan improve the processing capacity with more interfaces for such NEs as BSC, whichneeds a relatively larger amount of low-speed interfaces.

More Scalable Software Platform

The software platform uses the multi-process architecture of Linux, which ensuresthe independence of individual processes, separating the errors occurring to differentprocesses.

Higher Service Processing Capability

ZXUR 9000 GSM is a highly integrated system with strong processing capabilities, whichkeeps operators in the lead in the mobile Internet era.

Carrier-Class Reliability

ZXUR 9000 GSM uses a modular design that facilitates the installation and maintenanceprocess and makes capacity expansion or adjustment flexible. With good strength,rigidity, electromagnetic compatibility (EMC), and interchangeability, the cabinet will notbecome loose, deformed, or damaged during normal loading, unloading, storage, andtransportation.

Environment-Friendly Design

ZXUR 9000 GSM uses advanced technologies to reduce power consumption. Forexample, the dynamic power consumption management strategies used in the systemcan turn off less used carriers or shut off less used boards to reduce power consumption.

More Competitive Evolution Potential

l ZXUR 9000 GSM provides various external interfaces that are compatible with bothall-IP networking and traditional E1 and TDM access.

l ZXUR 9000 GSM is compatible with IPV6.l ZXUR 9000 GSM is compatible with future network development. The media access

system gives consideration to both multimode applications and the evolution to the3G system to maximize operators’ benefits from investment.

1-2


Chapter 1 Overview

2G/3G Handover Compatibility

ZXUR 9000 GSM supports handovers between 2G and 3G networks in both CS and PSdomains. By providing 3G services via 2G-3G handover, the system can reserve theinvestment in 2G networks for 2G operators.

Easy Operation and Maintenance

ZXUR 9000 GSM uses a new hardware architecture that contains reduced types ofboards. ZXUR 9000 GSM only consists of operation and maintenance boards, dataswitching boards, interface boards, and service processing boards. This architectureallows telecom operators to maintain less spare parts and provides a unified operationand maintenance platform. In this way, ZXUR 9000 GSM effectively reduces maintenancecosts and makes operation and maintenance easier.

1.3 ZXUR 9000 GSM ApplicationZXUR 9000 GSM is part of the GSM/EDGERadio Access Network (GERAN). The GERANincludes one or more Base Station Subsystems (BSSs), each of which is made up of oneBSC and one or more BTSs. The BSC and the BTS are connected via the Abis interface,while the GERAN and the CN are connected via the A/Gb interface.

The network location of ZXUR 9000 GSM (BSC) and its relations with other networkelements are shown in Figure 1-1.

Figure 1-1 The Context of BSC

The external system and interfaces are illustrated in Table 1-1.

Table 1-1 The External System and Interfaces

External System Function Related Interface

BTS Establish the radio environment and

transport data under the control of BSC.

Abis

1-3



External System Function Related Interface

MSC/MGW Connect BSC with MS to establish radio

voice channel for voice switching.

A

SGSN Connect BSC with MS to establish PS

radio channel for data switching.

Gb

1-4


Chapter 2System FunctionsTable of Contents

Basic Services............................................................................................................2-1Mobility Management .................................................................................................2-7Channel Management ................................................................................................2-8External Interface .......................................................................................................2-8Radio Resource Management ....................................................................................2-9Network Management Functionality..........................................................................2-10

2.1 Basic ServicesZXUR 9000 GSM supports the service functions of the BSC specified in GSM Phase II+standards, while compatible with GSM Phase II standards. The major functions are listedas follows:

1. Supports GSM900, GSM850, GSM1800 and GSM1900 network.2. Connects with NetNumen M31 via the OMC interfaces for the management of BSS(s).3. Supports various types of services, including

a. Circuit-Switched Voice Servicesl Full Rate (FR) Speech Servicel Enhanced Full Rate Speech Servicel Half Rate (HR) Speech Servicel AMR Speech Service

Adaptive Multirate (AMR) technique is a kind of speech coding algorithm withvariable rates. It can automatically adjust speech coding rate based on C/Ivalue, thus ensuring the best speech quality for different C/I values.

According to relevant protocols, AMR-FR speech coder has 8 rate modes,which are all supported by ZXUR 9000 GSM. ZXUR 9000 GSM also supportsthe five rates for AMR-HR speech coding7.4 kbit/s, 6.7 kbit/s, 5.9 kbit/s, 5.15kbit/s, 4.75 kbit/s .

b. Circuit Switched Data Service at 9.6 kbit/s

c. Short Message Services (SMS) (supporting messages in Chinese)l MS terminated point-to-point short message servicel MS initiated point-to-point short message servicel Cell broadcast service originated from the SMC or the Operation and

Maintenance System

d. GPRS Service

2-1



Supports point-to-point interactive telecom service, such as database access,session service and tele-action service.

e. EDGE Service

4. Supports frequency hopping.5. Supports discontinuous transmission (DTX) and voice activation detection (VAD).6. Supports various handover modes.

Supports synchronous handover, non-synchronous handover andpseudo-synchronous handover.

Supports handover within frequency bands of 900 MHz, 1800 MHz, and between900 MHz and 1800 MHz; it can process handover measurement; supports handovermeasurement before handover; supports network initiated handover due to service orinterference management; supports handover between channels of different speechcoding rates; supports handover for DTX; supports handover caused by trafficreasons; supports cocentric circle handover based on the carrier-to-interference ratio.

7. Supports 6-level static and 15-level dynamic power control for the MS and the BTS,and supports fast power control based on the receiving quality.

8. Supports overload control and traffic control.

ZXUR 9000 GSM can locate and analyze system overload and report the cause to theOMC. When the traffic is heavy, it can control the traffic through the A interface, theAbis interface and the Gb interface by limiting some services, thus keeping the normalsystem running while ensuring maximum call traffic capacity.

9. Supports call re-establishment upon radio link faults.10. ZXUR 9000 GSM supports call queuing and forced call release in the provisioning and

handover programs.11. Supports Enhanced Multi-level Precedence and Preemption (EMLPP).

The EMLPP classifies mobile subscribers into different priority levels. The subscriberswith higher levels are prioritized over others in obtaining channel resources.

12. Supports Co-BCCH.

Co-BCCH is used in dual-band cells. A dual-band cell is a cell that supports twofrequency bands that share the same BCCH.

Co-BCCH has the following advantages:

l Saves a BCCH timeslot.l For the configuration of 1800M frequency in the 900M cell, it is unnecessary to

modify the existing adjacent cells and re-plan the network. The re-selection andhandover is also not required between dual-band cells that share the same site.

13. Supports dynamic HR channel conversion.

ZXUR 9000 GSM supports dynamic HR channel conversion. The system candynamically and automatically switch between HR and FR channels in real timeaccording to the call traffic.

14. Supports dynamic radio channel assignment.

2-2


Chapter 2 System Functions

ZXUR 9000 GSM supports the dynamic assignment of CS and PS channels.

Dynamic channel assignment means that the logic type of radio channels can bedynamically generated according to the current call type, instead of being configuredat the OMM (OMC client). The dynamic radio channel assignment makes it possibleto make the most of radio resources according to the service type.

ZXUR 9000 GSM performs channel allocation according to integrated analysis ofthe channel rate, carrier priority, interference band, channel allocation on intra-cellhandover, allocation of reserved channels, and sub-cell channel selection.

15. Supports voice version selection.

ZXUR 9000 GSM supports voice version selection, which enables the user to set apreferred voice version for FR and HR channels. The FR voice versions include FR,EFR and AMR. The HR voice versions include HR and AMR.

16. Supports three-digit network IDs.

ZXUR 9000 GSM supports three-digit network IDs. Two-digit or three-digit network IDscan be used according to the current network conditions. Based on the network ID,the MNC in the signaling messages received over the A interface and the Gb interfacecan be interpreted, thus determining the MNC format in the signaling messages to besent. The network ID is also the basis for determining the MNC format in broadcastmessages over the Um interface.

17. Supports handover between 2G and 3G systems.l Supports the 3G-to-2G incoming handover for CS services.l Supports the 2G-to-3G outgoing handover for CS services.

18. Supports full dynamic Abis.

Full dynamic Abis means the relation between radio channels and Abis channels isnot generated in the O&M system, but dynamically configured in the service process.Dynamic Abis provides wider bandwidths for data services when the transmissionbandwidth over Abis is fixed.

19. Supports coding control.

Compared with GPRS, EDGE has significantly improvedmeasurement reports. EDGEmeasurement could be performed by impulse, that is, by the granularity of BURST.

The feature of rapid EGPRSmeasurement enables the network side to respond timelyto changes in radio environment, that is, choosing the most proper coding mode andperforming power control.

In the downlink direction, BSC supports the determination of coding modes bytimeslots and by TBF.

In the uplink direction, BSC determines the uplink TFB coding mode based on theuplink channel measurement parameters reported by the BTS.

20. Supports retransmission.

In the packet services, retransmission is controlled by negative feedback. The TXside determines which packets are not correctly received by the RX side according

2-3



to the bitmaps sent from the RX side, thus deciding whether the network side shouldretransmit the corresponding packets.

In GPRS, packet data is retransmitted using the same coding mode as the firsttransmission. For example, if the packet data was originally transmitted using CS4coding, it will be retransmitted with CS4 code.

EDGE introduces two new retransmission methods: Segmentation and Assembly(SAR) and incremental redundancy.

21. Optimizes the algorithm for packet channel allocation.

ZXUR 9000 GSM supports the multi-timeslot function of MSs, and assigns GPRS TBFor EDGE TBF to MSs according to their capacity of supporting GPRS or EDGE.

ZXUR 9000 GSM chooses low-load carriers first when assigning PDTCHs to the MSs.After the carrier is selected, it chooses the most suitable PDTCH combination in thecarrier according to MS requirements.

22. Supports QoS.

When the GSM network evolves to GERAN, the high-speed transmission of packetdata brought by EDGE enables operators to provide subscribers with lots of colorfulnew services, such as session service, stream media service, and interaction service.ZXUR 9000 GSM supports different QoS requirements for these services.

23. Supports extended uplink Temporary Block Flow (TBF).

Before extended uplink dynamic allocation is introduced into the GPRS, the number ofuplink channels available for the uplink TBF is always less than or equal to the numberof downlink channels occupied by at the same time. However, ZXUR 9000 GSMsupports extended uplink TBF, which can realize more uplink channels than downlinkchannels, thus better meeting the actual service needs.

24. Supports intelligent power-off.

When the performance data reaches the power-on/power-off threshold, ZXUR 9000GSM notifies the BTS to perform power-on/power-off operations through a message.

ZXUR 9000 GSM can combine multiple scattered timeslots to allocate them to theminimum number of carriers possible, and then shut down the unused carriers toreduce power consumption. The scattered timeslots are preferentially combined ontoBCCH carriers.

ZXUR 9000 GSM supports the customization of intelligent shutdown by period toprevent the intelligent shutdown from influencing the network in busy hours.

25. Supports TFO.

Tandem Free Operation (TFO) is an in-band codec negotiation protocol that makescodec negotiation between two Transcoders (TC) after a call is set up. It eliminatesunnecessary voice code conversion at the sending and receiving ends of calls betweenmobile subscribers, thus increasing voice quality and reducing transmission delay.

26. Supports transparent channel.

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The transparent channel implements transparent transfer of data between a timeslotin the E1 line of an interface at one end and another timeslot in the E1 line of anotherinterface at the other end.

ZXUR 9000 GSM supports transparent channels from the Abis interface to the Ainterface, from the Abis interface to the Abis interface, and from the A interface tothe A interface. When remote TC is implemented, transparent channel from the Abisinterface to the Ater interface is supported.

27. Supports EGPRS and GPRS channel scheduling.

Take GPRS mobile phone as an example. First, GPRS preferential channels areassigned to the phone. When EGPRS channels are free andGPRS channels is heavilyloadded, EGPRS channels can be assigned to the phone. Contrarily, when EGPRSchannels have a heavy load and GPRS channels are free, GPRS phones can switchto GPRS channels.

28. Supports the Dual-Transmission Mode (DTM).

ZXUR 9000 GSM supports DTM. Under A/Gb mode, ZXUR 9000 GSM can processCS and PS services at the same time.

29. Supports subscriber signaling tracing.

ZXUR 9000 GSM implements subscriber signaling tracing based on IMSI, TMSI orTLLI.

30. Supports PS paging coordination.

ZXUR 9000 GSM supports PS paging coordination. In packet transmission mode,ZXUR 9000 GSM enables the MSs to intercept circuit paging messages.

31. Supports FLEX A.

When FLEX A is used, a BSC can connect to multiple MSCs, which constitute an MSCPOOL.

FLEX A provides flexible networking. Compared with the traditional single-MSCstructure, the MSC pool has the following advantages:

l Expands the service area of one MSC, and reduces the frequency and traffic ofinter-MSC handover, location area update, and HLR update.

l Improves the efficiency of network equipment. In one MSC Pool, the homingVLR/MSC can be fixed. In this way, the load of an MSC does not increase whenthe traffic in hot spot goes up in a short time.

l Improves the overall disaster recovery capability of the network. When a MSC inthe MSC Pool is faulty, its traffic can be taken over by another MSC in the MSCPool.

The networking method of FLEX A is transparent to the MS, which means that the MSis not involved when networking changes. This guarantees the compatibility of MS inthe network.

32. Supports FLEX Gb.

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FLEX Gb means one BSC can connect multiple SGSNs that form SGSN pools.

FLEX Gb provides flexible networking modes. Compared with the traditionalsingle-SGSN structure, the SGSN pool provides the following advantages:

l Expands the service area of one SGSN, and reduces the frequency and traffic ofinter-SGSN PS handover, routing area update and HLR update.

l Improves the efficiency of network equipment. In an SGSN POOL, the homingVLR/SGSN can be fixed. In this way, the load of an SGSN does not increasewhen the traffic of a hot spot goes up suddenly.

l Improves the overall disaster recovery capability of the network. When a SGSNin the SGSN Pool is faulty, its traffic can be taken over by another SGSN in theSGSN Pool.

For MS, the networking mode of FLEX Gb is transparent, that is, the MS is not involvedin the modification of networking mode. This guarantees the network compatibility withthe MS.

33. Supports preemption and queuing for packet services.

The preemption of packet services considers all dynamic and static packet channelsin assigning packet radio resources according to subscriber QoS requirements. If thefree radio resources on a channel cannot meet QoS requirements or the maximumnumber of subscribers is reached in the channel, and the current subscriber has theright of preemption, the BSC will attempt to forcibly release the radio resources of oneor more low-priority subscribers for the use of the current subscriber.

When the BSC cannot allocate sufficient packet radio resources according tosubscriber QoS requirements, the queuing of packet services allows the BSC to admitservices as many as possible, and then queue them up to wait for radio resourcesthat meet subscriber QoS requirements.

When the BSC supports both preemption and queuing, the preemption of packetservices precedes queuing in priority. Queuing is activated when preemption fails.

34. Supports re-selection of the external network assisted cell.

re-selection of assisted cell in external network accelerates the access speed of theMSduring re-selection of an external cell, shortens the cell re-selection time during datatransmission, increases data transmission rate, thus providing better user experience.

35. Supports network controlled cell re-selection.

Network controlled cell re-selection is a procedure in which the BSC receives themeasurement report from the MS, and then performs storage and weighted averageprocessing of the measured level values of the service cell and the adjacent cells. Thecalculation result is analyzed together with network service load conditions to makecell re-selection decisions.

By fully utilizing available information and making reasonable decisions, the networkcontrolled cell re-selection optimizes network services. The function also reducesMS autonomous re-selection of useless cells, thus increasing TBF data transmissionefficiency and providing the best service quality to end users.

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36. Supports uplink incremental redundancy.

Incremental redundancy is a method to control the link quality for EDGE. With thismethod, when the BTS successfully decodes the RLC head but fails to decode adata chunk, the BTS stores this data chunk and informs the MS. The MS then usesanother perforation method to encode and retransmit the data chunk so that the BTScan decode the resent data chunk. If decoding fails, the stored data chunk on BTS canbe used together to perform joint decoding. Data chunks using different perforationmethods have different redundant information. Therefore, joint decoding has a highersuccess rate because more redundancy information can be utilized.

37. Supports Multiple PLMN IDs.

ZXUR 9000 GSM supports the radio network sharing among different operators.Operators can configure their own cells on the same site to provide common accessfor subscribers with different operators.

38. Supports noise suppression (only for E1 A interface) and level control.

Noise suppression can increase the voice SNR, enhance voice quality, and provide amore comfortable communication environment.

Level control helps to optimize signal levels, thus improving communication quality.

TFO is exclusive with noise suppression and level control. If the TFO is established,noise suppression and level control are not necessary.

39. Supports higher-order multiple timeslots for PS services.

ZXUR 9000 GSM supports higher-order multiple timeslots for PS services. Thedownlink can have up to five timeslots at the same time, which increases the downlinkrate to 296 Kbps. The increased transmission rate can significantly improve userexperience for FTP transmission and email services.

40. Supports IP transmission for the A interface.

With the evolution of network technology, it is easier to get IP-based transmissionresources. Compared with the traditional circuit network, IP network has a higherutilization rate and more flexible networking modes.

ZXUR 9000 GSM supports IP-based bearing at the A interface, which helps thenetwork evolve to an all-IP network. With this feature, the GSM can be easilyintegrated with the transmission network in the future.

2.2 Mobility ManagementZXUR 9000 GSM provides the following mobility management functions:

l Cell Reselection

Supports inter-BSC and intra-BSC cell reselection.

l Cell Handover

Supports inter-BSC and intra-BSC cell handover.

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2.3 Channel ManagementZXUR 9000 GSM supports the following channel management functions:

1. Service channel managementl channel assignmentl link monitoringl channel releasel channel blocking/unblockingl channel conversionl function control

2. Supported Control Channelsl FCCHl SCHl BCCHl PCHl AGCHl RACHl SDCCHl SACCHl FACCHl PACCHl PAGCHl PBCCHl PCCCHl PPCHl PRACHl PTCCH

2.4 External InterfaceZXUR 9000 GSM supports the following external interfaces:

l Abis Interface

The interface connects the BSC with the BTS. To connect the BTS for configurationand management, the BSC provides the E1/T1 interface, CSTM-1 interface, EthernetFE(electrical port)/GE(optical or electrical port) interface.

l A Interface

The interface connects the BSC with the CN, that is, MSC/MGW. To connect theCN, the BSC provides the E1/T1 interface, CSTM-1 interface, Ethernet FE(electricalport)/GE(optical or electrical port) interface.

l Gb Interface

The interface connects the BSC with the SGSN. To connect to the SGSN, the BSCprovides the E1/T1 interface, CSTM-1 interface, Ethernet FE(electrical)/GE(optical orelectric) interface.

2-8



l OMC Interface

Operations can be performed on the OMC client to control and maintain the BSC andthe BTS.

2.5 Radio Resource ManagementThe BSC provides the following radio resource management functions:l System Access Control

System access of a subscriber is initiated at the subscriber side (e.g., mobile caller) orthe network side (e.g., mobile called party). The access of a subscriber is to acquireGSM services through GERAN. GERAN controls the access according to subscribercapability and resources utilization.

l Access Control

The system decides whether to accept user's access request based on such aspectsas current resource utilization, load level, general interference level of the cell, totaltransmission power, and the bandwidth resource of the Abis interface.

l Load Control

When multiple subscribers access to the system, the BSC monitors the system load,determine whether the system is overloaded and, if yes, the overload level. After that,the BSC takes measures according to preset rules to ensure system stability.

l Power Control

Given that the signal quality is ensured, the transmit power is kept at a low level toimprove system capacity.

In the uplink, open loop and closed loop power control are adopted. When theuplink is not established, the open loop power control regulates the transmit powerin the Physical Random Access Channel (PRACH). Closed loop power control isused after the link is established. Closed loop power control includes outer loop andinner loop power control. Outer loop power control adjusts the bit error rate (BER)or frame error rate (FER), while inner loop power control targets adjusts the targetsignal-to-interference rate (SIR).

In the downlink, only closed loop power control is used.

l System Message Broadcast

This function broadcasts the information of the access layer and non-access layer tothe MS for access to the GSM services.

l Radio Environment Measurement

This function measures the present public channels and dedicated channelsaccording to radio resource management requirements.

l Dynamic Channel Allocation

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Dynamic channel allocation includes low-speed channel allocation and high-speedchannel allocation. High-speed channel allocation conforms to the principles specifiedin access control. Low-speed channel allocation allocates radio resources to differentcells according to their service load.

2.6 Network Management Functionalityl Configuration Management

Configuration of BSC physical and logical resource, radio parameter configuration,data import/export.

l Security Management

Network security control and operation log management.

l Fault Management

Displays and saves alarm data that reflects equipment faults and threshold-crossingcases.

l Signaling Tracing

Tracing signaling according to specified BTSs, cells, and MSs for fault analysis.

l Performance Statistics

Performs statistics on services and data transmission.

l Diagnosis Testing

Diagnoses system faults.

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Chapter 3Software and HardwareArchitectureTable of Contents

Hardware Architecture of ZXUR 9000 GSM ...............................................................3-1Software Architecture of ZXUR 9000 GSM ................................................................3-3

3.1 Hardware Architecture of ZXUR 9000 GSMThe hardware of ZXUR 9000 GSM contains access unit, switching unit, processingunit, operation and maintenance unit, and the peripheral equipment monitoring unit, asillustrated in Figure 3-1.

Figure 3-1 Hardware Architecture

The functions of different hardware units of ZXUR 9000 GSM are described in Table 3-1.

Table 3-1 Description of ZXUR 9000 GSM Hardware Units

Hardware Unit Function Boards Included

Access Unit Provides STM-1, E1, T1,

CSTM-1 and IP access for the

Abis, A, Gb, Ater, and Iur-g

interfaces of ZXUR 9000 GSM.

EGPB, EDTI, ESDTI, EDTT,

ESDTT

3-1




Switching Unit Provides a large-capacity,

non-blocking switching platform

by implementing the Ethernet

protocols and IP protocols

for ZXUR 9000 GSM system

control and management,

communication among service

processing boards, and traffic

flow connection among multiple

access units.

EGBS, EGFS

Processing Unit Implements radio protocols in

the control plane and user plane,

including LAPD, No.7 signaling,

RTP and TC processing for the

CS services, and RLC/MAC,

BSSGP, and NSVC processing

for the PS services.

USP (implements the functions

of CMP and RUP logical

boards), ETCB

Operation and Maintenance

Unit

Performs global processes

and controls operation and

maintenance in the system,

including O&M agents. The unit

connects to the OMC-R via the

Ethernet, so that the external

and internal networks are

separated. As the core for BSC

operation and maintenance,

the unit directly or indirectly

monitors and manages all

boards in the BSC.

UMP (implements the functions

of OMP and OMM logical

boards)

Peripheral Equipment

Monitoring Unit

This unit is subordinate to the

operation and maintenance unit

and is responsible for collecting

information of environment

peripheral to the cabinet,

including the status of power

distributor and fan, and the

environment alarms, such as

those reflecting changes in

temperature, humidity, and

the alarms of smoke, moisture,

water and infrared rays. The unit

reports different levels of alarms

Power distribution subrack, fan

unit, and the alarm box.

3-2


Chapter 3 Software and Hardware Architecture


according to specific faults,

thus facilitating timely handling

by equipment management

personnel.

3.2 Software Architecture of ZXUR 9000 GSMThe software of ZXUR 9000 GSM includes the NE software and the network elementmanagement system (EMS). The NE software is running on a board of ZXUR 9000GSM. The EMS provides operation and maintenance functions for managing NEs inthe base station subsystem (BSS), including management of alarms, performance, andconfigurations.

The software of ZXUR 9000 GSM is designed with layers and modules. Modules of acertain layer perform specified functions, and provide services for modules of the upperlayer. The software architecture of ZXUR 9000 GSM is illustrated in Figure 3-2.

3-3



Figure 3-2 System Software Architecture

The functions of different software modules of ZXUR 9000 GSM are described in Table3-2.

Table 3-2 Description of ZXUR 9000 GSM Software Modules

Software Module Function

SODA Service Oriented Drive Architecture provides

such main functions as drive, BSP, and interfaces

for relevant devices.

LINUX Linux commercial operating system

VxWorks VxWorks commercial operating system

WINDOWS Windows commercial operating system

3-4




TULIP Telecom Unified Integrated Platform (Unified

Support) runs in a commercial operating

system. It shields the differences among

operating systems, and provides such supporting

services as scheduling, communication,

memory management, exception handling. It

also provides version management, system

monitoring and management functions.

DBS Database Subsystem provides a high-

performance distributed memory database

engine and database applications.

SCS System Control Subsystem provides system

description and such functions as availability

management, status management, and realtime

status checking.

OAM Operation and Maintenance Subsystem provides

access service for system management and the

operation and maintenance services. System

access services include SNMP, CLI, and custom

management interfaces. O&M services include

system configuration, performance statistics, and

alarm management.

SIG Signaling subsystem processes types of signaling

protocols, transmits signaling messages in

real time, and manages the signaling network.

The processed signaling includes No.7 and

SIGTRAN.

BRS Bearer subsystem provides complete IPV4/IPV6

protocol stacks, such as dynamic router protocol,

MPLS, and IPSEC.

MCS Multicore microcode media bearer subsystem

is the extension of the bearer subsystem. It

provides internal and external packet interfaces.

The MCS functions is limited at the forwarding

layer. The functions of the bearer and control

layer are provided by the BRS.

RAP Provides such functions as operation and

maintenance, application database, operation

support, version management, and transmission.

3-5




Common Component Base Provides a series of components for

encapsulating data structure, algorithms, and for

other functions.

OSSAPP Provides application functions, including main

control, system load control, and energy reducing.

DBSAPP Provides data access interfaces, data triggering

services, and resource management for

application subsystems.

OAMAPP Implements non-tracing O&M functions, such as

fault management, performance management,

diagnosis, and dynamic data monitor (DDM).

SIGAPP Provides bottom-layer bearer and access control

for the RNLC, and implements router-based load

sharing in IP transmission.

TraceLog Provides supplementary commissioning methods,

including debugging tools, tracing tools, exception

log tool, and network planning and optimization.

GSM Product Differentiation Code Provides differentiation function for RAP-based

GSM products that are not included in the unified

management of the RAP.

RMP Includes the microcode operating system (MOS)

and the Microcode subsystem (MCSAPP).

MOS Provides operation support for the media plane

and management and control functions for the

SLAVE subunit.

MCSAPP Distributes data inside or outside the network

element.

RANC Processes L3 control-plane protocols at the

interfaces of RRC, RR, RANAP, RNSAP.

The module functions include radio resource

management, mobility management, and

signaling connection management.

3-6




RANSS Provides support for control-plane and user-plane

subsystems. The main purpose of this module is

to ensure normal service functions. It provides

monitoring for various services and implements

BSC global processes. The functions include

signaling tracing, load and access control,

performance measurement, global processes,

and signaling coding.

RANU Implements data transmission between the

radio interfaces and the Gb or Iu interface, and

performs scheduling. The protocols included in

this module include MAC, RLC, PDCP, and IuUP.

OMC-R Operation and maintenance management

system.

ToolKit Maintenance toolkit.

3-7



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3-8


Chapter 4NetworkingTable of Contents

Networking via the Abis Interface ...............................................................................4-1Networking via the A/Gb Interface ..............................................................................4-3

4.1 Networking via the Abis InterfaceZXUR 9000 GSM supports several ways of networking.

According to the network topology, ZXUR 9000 GSM supports the star networking,chain networking, ring networking (requires supported transmission network), and hybridnetworking.

The Abis interface supports following transmission modes: CSTM-1, E1/T1, EthernetGE/FE (optical or electrical).

4.1.1 Star NetworkingThe star networking involving ZXUR 9000 GSM is shown in Figure 4-1.

Figure 4-1 Star Networking

In star networking, ZXUR 9000 GSM connects with BTS directly. This networking issimple, and the maintenance and engineering are very convenient too. Since the signalsare transmitted through fewer intermediate links, the reliability of transmission is higher.Generally, this networking is adopted in densely-populated urban areas.

4.1.2 Chain NetworkingThe chain networking involving ZXUR 9000 GSM is shown in Figure 4-2.

4-1



Figure 4-2 Chain Networking

Chain Networking has relatively more intermediate links, so that the reliability is poorer.Chain networking is usually applied in strip-shaped areas with sparse population, and alarge amount of transmission equipment can be saved.

The chain networking can also be applied in the case of one site having multiple BTSs.

In actual engineering networking, the transmission equipment is generally added betweenZXUR 9000 GSM and BTSs, different from the basic networking, because the sites areoften scattered. The common transmission media include: microwave, fiber cable, HDSLcable, and coaxial cable.

4.1.3 Ring NetworkingThe ring networking involving ZXUR 9000 GSM is shown in Figure 4-3.

Figure 4-3 Ring Networking

The ring networking involves two sets of links running in the active/standby relation. Everynode on the ring has two upper-level nodes, thus improving the link reliability. Therefore,if a site is damaged or a link fails, the subordinate nodes can select another link as theactive one.

4.1.4 Star-Chain Hybrid NetworkingThe star-chain hybrid networking involving ZXUR 9000 GSM is shown in Figure 4-4.

4-2


Chapter 4 Networking

Figure 4-4 Star-Chain Hybrid Networking

The advantages of hybrid networking are:

l Easily adaptable to the current transmission mode of the operator. In earlyestablishment of the network, hybrid networking makes the most of the establishedtransmission network, thus saving the network cost and speeding the networkestablishment for the operator.

l Easier networking on complex terrain. Hybrid networking supports multiple topology,thus making network establishment flexible and simple.

l Easy configuration of abundant transmission paths, thus enhancing the networkrobustness.

4.2 Networking via the A/Gb InterfaceThe A interface connects the BSC with the MSC/MGW.

The Gb interface connects the BSC with the SGSN.

4.2.1 Networking via the Gb InterfaceThe networking via the Gb interface is shown in Figure 4-5.

4-3



Figure 4-5 Networking via the Gb Interface

The Gb interface supports following transmission modes: CSTM-1, E1/T1, and EthernetGE/FE (optical or electrical ports).

4.2.2 Networking via the A InterfaceThe networking with the A interface is shown in Figure 4-6.

Figure 4-6 Networking via the A Interface

The A interface supports following transmission modes: CSTM-1, E1/T1, and EthernetGE/FE (optical or electrical ports).

4-4


FiguresFigure 1-1 The Context of BSC................................................................................. 1-3

Figure 3-1 Hardware Architecture ............................................................................. 3-1

Figure 3-2 System Software Architecture .................................................................. 3-4

Figure 4-1 Star Networking ....................................................................................... 4-1

Figure 4-2 Chain Networking .................................................................................... 4-2

Figure 4-3 Ring Networking ...................................................................................... 4-2

Figure 4-4 Star-Chain Hybrid Networking.................................................................. 4-3

Figure 4-5 Networking via the Gb Interface ............................................................... 4-4

Figure 4-6 Networking via the A Interface ................................................................. 4-4

I

Figures


TablesTable 1-1 The External System and Interfaces .......................................................... 1-3

Table 3-1 Description of ZXUR 9000 GSM Hardware Units ....................................... 3-1

Table 3-2 Description of ZXUR 9000 GSM Software Modules ................................... 3-4

III

Tables


Glossary3GPP- 3rd Generation Partnership Project

AMR- Adaptive Multiple Rate

ATCA- Advanced Telecommunications Computing Architecture

Abis- Abis Interface between BSC and BTS

BSC- Base Station Controller

BSSGP- Base Station System GPRS Protocol

CN- Core Network

CS- Circuit Switched

EDGE- Enhanced Data rates for GSM Evolution

EDTI- Enhanced Digital Trunk board IP version

EDTT- Enhanced Digital Trunk board TDM version

EFR- Enhanced Full Rate

EGBS- Enhanced GE Base Switch board

EGFS- Enhanced GE Fabric Switch board

EGPB- Enhanced GE Process Board

ESDTI- Enhanced SDH Digital Trunk board IP version

ESDTT- Enhanced SDH Digital Trunk board TDM version

V


ETCB- Enhanced TransCoder Board

FE- Fast Ethernet

FR- Full Rate

GE- Gigabit Ethernet

GERAN- GSM/EDGE Radio Access Network

GSM- Global System for Mobile Communication

HR- Half Rate

IMSI- International Mobile Subscriber Identity

IP- Internet Protocol

LAPD- Link Access Procedure for D-channel

MAC- Medium Access Control

MGW- Media GateWay

MS- Mobile Station

MSC- Mobile Switching Center

NSVC- Network Service Virtual Connection

PS- Packet Switched

QoS- Quality of Service

RLC- Radio Link Control

RNC- Radio Network Controller

VI

Glossary

RTP- Real-time Transport Protocol

SGSN- Service GPRS Supporting Node

TBF- Temporary Block Flow

TC- Trunk Circuit

TDM- Time Division Multiplexing

TFO- Tandem Free Operation

PRM- Partner Relationship Management

UMTS- Universal Mobile Telecommunication System

USP- Universal Service Processing Board

VII

zxur 9000 gsm (v6.50.00) system description

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