bss system description(v900r008c01_01)

8/10/2019 BSS System Description(V900R008C01_01)

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HUAWEI BSC6000 Base Station Subsystem

V900R008

BSS System Description

Issue 01

Date 2008-06-10

INTERNAL

Huawei Proprietary and Confidential

Copyright Huawei Technologies Co., Ltd


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Huawei Technologies Co., Ltd. provides customers with comprehensive technical support and service. For any

assistance, please contact our local office or company headquarters.

Huawei Technologies Co., Ltd.

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Email: [email protected]

Copyright Huawei Technologies Co., Ltd. 2008. All rights reserved.

No part of this document may be reproduced or transmitted in any form or by any means without prior written

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and other Huawei trademarks are the property of Huawei Technologies Co., Ltd.

All other trademarks and trade names mentioned in this document are the property of their respective holders.

Notice

The information in this document is subject to change without notice. Every effort has been made in the

preparation of this document to ensure accuracy of the contents, but the statements, information, and

recommendations in this document do not constitute a warranty of any kind, express or implied.

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3.5 BSC Hardware Configuration.........................................................................................................................3-7

3.6 OM of the BSC................................................................................................................................................3-7

4 Introduction to the PCU............................................................................................................4-1

4.1 Introduction to the Built-in PCU.....................................................................................................................4-24.2 Introduction to the External PCU....................................................................................................................4-4

4.2.1 PCU Physical Structure..........................................................................................................................4-4

4.2.2 PCU Software Structure.........................................................................................................................4-6

4.2.3 PCU Logical Structure...........................................................................................................................4-8

4.2.4 PCU Physical Ports................................................................................................................................4-9

4.2.5 PCU Technical Specifications................................................................................................................4-9

4.2.6 PCU Operation and Maintenance.........................................................................................................4-12

5 Introduction to the BTS.............................................................................................................5-1

5.1 Introduction to the BTS3012...........................................................................................................................5-35.2 Introduction to the BTS3012AE.....................................................................................................................5-6

5.3 Introduction to the BTS3006C......................................................................................................................5-10

5.4 Introduction to the BTS3002E......................................................................................................................5-12

5.5 Introduction to the DBS3900 GSM...............................................................................................................5-14

5.6 Introduction to the BTS3900 GSM...............................................................................................................5-17

5.7 Introduction to the BTS3900A GSM............................................................................................................5-20

6 Introduction to the BSS OM Subsystem............................................................................... 6-1

6.1 Huawei Mobile Network OM System.............................................................................................................6-2

6.2 OM System of 2G RAN Devices....................................................................................................................6-3

Contents



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Figures

Figure 1-1Position of the BSS in the GSM.........................................................................................................1-2

Figure 1-2Structure of the BSS...........................................................................................................................1-3

Figure 1-3BSS external interfaces.......................................................................................................................1-4

Figure 1-4BSS internal interfaces.......................................................................................................................1-5

Figure 2-1Channel assignment procedure...........................................................................................................2-4

Figure 2-2Immediate assignment procedure.......................................................................................................2-5

Figure 2-3Authentication procedure....................................................................................................................2-6

Figure 2-4Encryption procedure.........................................................................................................................2-7

Figure 2-5Basic principles of power control.....................................................................................................2-10

Figure 2-6Power control decision procedure of Huawei II power control algorithm.......................................2-11

Figure 2-7Power control decision procedure of Huawei III power control algorithm......................................2-12

Figure 3-1Physical structure of the BSC.............................................................................................................3-3

Figure 3-2Structure of the host software.............................................................................................................3-4

Figure 3-3Structure of the OMU software..........................................................................................................3-5Figure 3-4LMT software structure......................................................................................................................3-5

Figure 3-5Logical structure of the BSC..............................................................................................................3-6

Figure 4-1Logical structure of the built-in PCU.................................................................................................4-3

Figure 4-2Physical structure of the PCU.............................................................................................................4-5

Figure 4-3Fully configured PCU processing subrack (front subrack)................................................................4-5

Figure 4-4Fully configured PCU processing subrack (rear subrack)..................................................................4-6

Figure 4-5Software structure of the PCU............................................................................................................4-7

Figure 4-6Logical structure of the PCU..............................................................................................................4-8

Figure 4-7OM network of the PCU...................................................................................................................4-13

Figure 5-1BTS3002E system architecture..........................................................................................................5-3

Figure 5-2Logical structure of the BTS3012 with the QTRU.............................................................................5-5

Figure 5-3Logical structure of the BTS3012 with the DTRU.............................................................................5-5

Figure 5-4BTS3012AE system architecture........................................................................................................5-6

Figure 5-5Logical structure of the BTS3012AE (DC)........................................................................................5-8

Figure 5-6Logical structure of the BTS3012AE with the QTRU (AC)..............................................................5-9

Figure 5-7Logical structure of the BTS3012AE with the DTRU (AC)..............................................................5-9

Figure 5-8BTS3006C system architecture........................................................................................................5-10

Figure 5-9Logical structure of the BTS3006C..................................................................................................5-12

Figure 5-10BTS3002E system architecture......................................................................................................5-13


BSS System Description Figures

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Figure 5-11Logical structure of the BTS3002E................................................................................................5-14

Figure 5-12DBS3900 GSM system architecture...............................................................................................5-15

Figure 5-13Logical structure of the BBU3900 GSM........................................................................................5-16

Figure 5-14Logical structure of the RRU3004..................................................................................................5-17

Figure 5-15BTS3900 GSM system architecture...............................................................................................5-18

Figure 5-16Logical structure of the BTS3900 GSM.........................................................................................5-20

Figure 5-17BTS3900A GSM system architecture............................................................................................5-21

Figure 5-18Logical structure of the BTS3900A GSM......................................................................................5-22

Figure 6-1Huawei mobile network OM system..................................................................................................6-2

Figures



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Tables

Table 2-1handover type and the corresponding decision mode..........................................................................2-9

Table 3-1Components of the BSC.......................................................................................................................3-3

Table 4-1PCU physical ports...............................................................................................................................4-9

Table 4-2Working environment specifications of the PCU..............................................................................4-10

Table 4-3Noise and safety specifications of the PCU.......................................................................................4-11

Table 4-4Power supply and power consumption of the PCU...........................................................................4-11

Table 4-5Maximum capacity of a PCU processing subrack.............................................................................4-12

Table 4-6Minimum capacity of a PCU processing subrack..............................................................................4-12


BSS System Description Tables



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About This Document

Purpose

This document describes the Huawei BSS system. It covers the introductions to the BSS, BSC,

built-in PCU, external PCU, BTS, and BSS OM system. In addition, it introduces the functions

of the BSS.

Product Versions

The following table lists the product versions related to the document.

Product Name Model Product Version

BSC BSC6000 V900R008C01

BTS BTS3012 V300R004&V300R005&V300R006

BTS3012AE V300R005&V300R006

BTS3006C V300R005&V300R006

BTS3002E V300R005

BTS3036/BTS3900

GSM

V300R008

BTS3036A/BTS3900A

GSM

V300R008

DBS3036/DBS3900

GSM

V300R008

PCU PCU6000 V300R008

Intended Audience

This document is intended for:

l Network planners

l Field engineers

l System engineers

l Shift operators


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l Network operators

l Network administrators

Change HistoryFor changes in the document, refer to Changes in BSS System Description.

Organization

1 Introduction to the BSS

This describes the base station subsystem (BSS), which is controlled by an MSC. The BSS serves

as a communication bridge between the MSs and the MSC. The BSS transmits and receives

radio signals and manages radio resources.

2 BSS Functions

The BSS functions include radio resource management, connection management, BTS

management, and BSS OM.

3 Introduction to the BSC

This introduces the BSC. Physically, the BSC system is composed of the BSC hardware system

and the BSC software system. Logically, it consists of eights subsystems.

4 Introduction to the PCU

This introduces the PCU. The PCU provides packet data services. The main functions of the

PCU include packet radio resource management, packet calls control, and packet datatransmission. Huawei BSS supports built-in PCU and external PCU.

5 Introduction to the BTS

This topic describes the BTS. The BTS is an NE in the GSM network. It sends RF signals to the

MS and receives RF signals from the MS to achieve radio coverage. The BTS is connected to

the BSC through the Abis interface.

6 Introduction to the BSS OM Subsystem

This introduces the BSS OM subsystem. Huawei BSS system provides comprehensive operation

and maintenance tools, such as the M2000, a core operation and maintenance tool for Huawei

mobile networks, and the complete operation and maintenance tools for 2G radio access network.

Conventions

1. Symbol Conventions

The following symbols may be found in this document. They are defined as follows

Symbol Description

DANGER

Indicates a hazard with a high level of risk that, if not avoided,

will result in death or serious injury.

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Symbol Description

WARNING

Indicates a hazard with a medium or low level of risk which, if

not avoided, could result in minor or moderate injury.

CAUTION

Indicates a potentially hazardous situation that, if not avoided,

could cause equipment damage, data loss, and performance

degradation, or unexpected results.

TIP Indicates a tip that may help you solve a problem or save your

time.

NOTE Provides additional information to emphasize or supplement

important points of the main text.

2. General Conventions

Convention Description

Times New Roman Normal paragraphs are in Times New Roman.

Boldface Names of files,directories,folders,and users are in boldface. For

example,log in as user root.

Italic Book titles are in italics.

Courier New Terminal display is in Courier New.

3. Command Conventions


Boldface The keywords of a command line are in boldface.

Italic Command arguments are in italic.

[ ] Items (keywords or arguments) in square brackets [ ] are optional.

{x | y | ...} Alternative items are grouped in braces and separated by vertical

bars.One is selected.

[ x | y | ... ] Optional alternative items are grouped in square brackets and

separated by vertical bars.One or none is selected.

{ x | y | ... } * Alternative items are grouped in braces and separated by vertical

bars.A minimum of one or a maximum of all can be selected.

[ x | y | ... ] * Alternative items are grouped in braces and separated by vertical

bars.A minimum of zero or a maximum of all can be selected.

4. GUI Conventions


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Boldface Buttons,menus,parameters,tabs,window,and dialog titles are in

boldface. For example,click OK.

> Multi-level menus are in boldfaceand separated by the ">" signs.

For example,choose File > Create > Folder .

5. Keyboard Operation


Key Press the key.For example,press Enterand press Tab.

Key1+Key2 Press the keys concurrently.For example,pressing Ctrl+Alt+A

means the three keys should be pressed concurrently.

Key1,Key2 Press the keys in turn.For example,pressing Alt,A means the two

keys should be pressed in turn.

6. Mouse Operation

Action Description

Click Select and release the primary mouse button without moving the

pointer.

Double-click Press the primary mouse button twice continuously and quickly

without moving the pointer.

Drag Press and hold the primary mouse button and move the pointer

to a certain position.

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1Introduction to the BSSAbout This Chapter

This describes the base station subsystem (BSS), which is controlled by an MSC. The BSS serves

as a communication bridge between the MSs and the MSC. The BSS transmits and receives

radio signals and manages radio resources.

1.1 BSS in the GSM System Architecture

This describes the BSS in the GSM system architecture. The global system for mobile

communications (GSM) is the second generation mobile telephone system. The BSS functions

as the radio access network for the GSM.

1.2 BSS Structure

This describes the structure of the BSS. The BSS comprises the BSC, PCU, and BTS.

1.3 BSS External Interfaces

This describes the BSS external interfaces. The BSS provides 3GPP-compliant standard

interfaces and private interfaces. The standard interfaces are the Um interface, the A interface,

the BSC-CBC interface, and the Gb interface. These standard interfaces enable the

interconnection and interworking of different vendors' equipment. One example of the private

interface is the Itf-N interface.

1.4 BSS Internal Interfaces

This describes the BSS internal interfaces. These interfaces are the Abis interface, the Pb

interface, and the Itf-S interface. The BSS provides private interfaces to the internal devices.


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1.1 BSS in the GSM System Architecture

This describes the BSS in the GSM system architecture. The global system for mobile

communications (GSM) is the second generation mobile telephone system. The BSS functions

as the radio access network for the GSM.

Figure 1-1shows the position of the BSS in the GSM.

Figure 1-1Position of the BSS in the GSM

BTS

BTS

BTS

BSC

PCU

MSC

SGSN

HLR

GGSN

MS

MS

MS

BSS NSS

PDN

The GSM consists of the following three parts:

l Mobile station (MS): provides main-machine interfaces and various services to subscribers.

l Base station subsystem (BSS): performs functions such as the transmission and reception

of radio signals and the management of radio resources.

NOTE

Huawei BSS supports built-in PCU and external PCU.

l Network subsystem (NSS): performs functions such as circuit switching, packet switching,

and network interconnection.

1.2 BSS StructureThis describes the structure of the BSS. The BSS comprises the BSC, PCU, and BTS.

The BSC and BTS are network elements. The PCU can be configured either in the BSC (called

built-in PCU) or outside the BSC (called external PCU).

Figure 1-2shows the structure of the BSS.




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Figure 1-2Structure of the BSS

BSS BSS

BTSBTS

BSC PCU BSC PCU

M2000

The PCU can be configured

inside or outside the BSC.

MSMS

PS CoreCS Core

The components of the BSS are described as follows:

Each BSS system consists of one BSC, one or more PCUs, and one or more BTSs.

l The BSC plays a control role in the BSS.

l The PCU provides packet data services. When the PCU is configured in the BSC, the PCU

is an integral part of the BSC. When the PCU is configured outside the BSC, the PCU isan independent network element.

l The BTS is an NE in the GSM network. It sends RF signals to the MS and receives RF

signals from the MS to achieve radio coverage. The operation and maintenance of the BTS

is performed through the BSC.

The M2000 is an element management system (EMS) of the BSS. You can use the M2000 to

maintain the BSC, built-in PCU, and external PCU. You can also use the M2000 to maintain the

BTS through the BSC.

1.3 BSS External Interfaces

This describes the BSS external interfaces. The BSS provides 3GPP-compliant standard

interfaces and private interfaces. The standard interfaces are the Um interface, the A interface,

the BSC-CBC interface, and the Gb interface. These standard interfaces enable the

interconnection and interworking of different vendors' equipment. One example of the private

interface is the Itf-N interface.

Figure 1-3shows the BSS external interfaces.





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Figure 1-3BSS external interfaces

BSS

Um

A GbBSC-CBC

Itf-N

BTS

BSC PCU

M2000 NMS

The PCU can be configuredinside or outside the BSC.

SGSNCBCMSC

MS

l Um interface: between the MS and the BSS

l A interface: between the BSS and the MSC

l

Gb interface: between the BSS and the SGSNl BSC-CBC interface: between the BSS and the CBC

l Itf-N interface: between the BSS and the NMS

1.4 BSS Internal Interfaces

This describes the BSS internal interfaces. These interfaces are the Abis interface, the Pb

interface, and the Itf-S interface. The BSS provides private interfaces to the internal devices.

Figure 1-4shows the BSS internal interfaces.






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Figure 1-4BSS internal interfaces

BTS

BSC PCU

M2000Itf-S

Pb

Abis

The PCU can be configured

inside or outside the BSC.

l Abis interface: between the BTS and the BSC. The BSC controls and manages the BTS on

the Abis interface.

l Pb interface: between the BSC and the external PCU.

l Itf-S interface: between the M2000 and the BSC or external PCU. This interface serves

maintenance of the NEs.





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2BSS FunctionsAbout This Chapter

The BSS functions include radio resource management, connection management, BTS

management, and BSS OM.

2.1 Radio Resource Management

This describes the radio resource management (RRM) functions of the BSS. RRM is the

procedure through which a stable connection is established between the MS and the MSC for a

call. This procedure is also used to release the radio resources when a call is disconnected.

2.2 Connection Management

This describes the connection management of the BSS. Connection management is a function

for the control, assignment, and management of the services provided by the network. The

services are short message services (SMSs), teleservices, and location-based services.

2.3 BTS Management

This describes the BTS management function. BTS management is a function where procedures

and messages related to the BTS are performed. The procedures and messages such as the BTS

software downloading, BTS data configuration, BTS status management, and BTS alarms

management should be performed by the peer-layer entities of the BSC and BTS.

2.4 BSS Operation and Maintenance

This describes the OM functions of the BSS. The BSS provides OM functions, such as,

performance management, BTS OM, BSC OM, clock control setting, BSC alarms, BTS alarms,BTS commissioning, dynamic data configuration, GUI, and integrated network management

interfaces.


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2.1 Radio Resource ManagementThis describes the radio resource management (RRM) functions of the BSS. RRM is the

procedure through which a stable connection is established between the MS and the MSC for a

call. This procedure is also used to release the radio resources when a call is disconnected.

The limited radio resources must be dynamically allocated to maintain the stable connection

between the MS and the MSC. The RRM is mainly performed by the MS and the BSC. In

addition, the RRM maintains the channel connection when an MS is handed over to a neighbor

cell.

2.1.1 Paging

This describes the paging procedure. Paging is a broadcast procedure used by the network to

search for an MS. On receiving a call, the GSM/GPRS network initiates broadcasting in the

location area or routing area of the paged MS. For a PS service, paging can be performed on the

basis of the location area but is mainly performed on the basis of the routing area. Which areathe paging is based on is determined by the SGSN.

2.1.2 Assignment

This describes the assignment procedure. Through the assignment procedure, the BSS assigns

a TCH to an MS.

2.1.3 Initial Access and Immediate Assignment

This describes the initial access and immediate assignment procedures. The purpose of initial

access is to set up a radio resource (RR) connection on the Um interface between an MS and the

network. The purpose of immediate assignment is to assign a signaling channel for setting up

the RR connection.

2.1.4 Authentication and EncryptionThis describes the authentication and encryption procedures. Authentication and encryption are

two security mechanisms used by the GSM network to enhance network security and data

privacy.

2.1.5 System Information

This describes system information (SI). The SI contains the main radio network parameters on

the Um interface. These parameters include network identification parameters, cell selection

parameters, system control parameters, and network function parameters.

2.1.6 Handover

Handover is a procedure in which a conversation can be sustained when an MS moves from one

cell to another in order to meet the requirement of network management.

2.1.7 Radio Channel Management

This describes the radio channel management procedure. Radio channel management is

performed by the BSC. It consists of long-term channel configuration management and short-

term dedicated channel assignment management. The long-term management function is used

to select the channel sequence number and to configure relevant devices. The short-term

management function is used to assign and release various channels during communication.

2.1.8 Power Control

This describes power control. Power control aims to reduce the transmit power of the MS or the

BTS under the condition that the radio link quality is maintained and the power level of the MS

and the BSS is met. Through power control, the system interference is reduced, the frequency

spectrum efficiency is improved, and the standby time of the MS is extended.

2.1.9 Circuit Management

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This describes the circuit management procedure. The BSC can manage the circuits on the A

interface. For example, it performs circuit assignment, circuit blocking, circuit unblocking,

circuit group blocking, and circuit group unblocking. It also operates and maintains a single

circuit or the PCM group circuits of the GEIUA/GOIUA.

2.1.10 TRX ManagementThis describes the TRX management procedure. TRX management refers to TRX status

management.

2.1.11 Media Access Control

This describes Media Access Control (MAC).

2.1.12 Radio Link Control

This describes Radio Link Control (RLC).

2.1.1 Paging

This describes the paging procedure. Paging is a broadcast procedure used by the network to

search for an MS. On receiving a call, the GSM/GPRS network initiates broadcasting in the

location area or routing area of the paged MS. For a PS service, paging can be performed on the

basis of the location area but is mainly performed on the basis of the routing area. Which area

the paging is based on is determined by the SGSN.

Paging can be classified into the following types:

l CS service paging

l PS service paging

2.1.2 Assignment

This describes the assignment procedure. Through the assignment procedure, the BSS assigns

a TCH to an MS.

After an MS initiates the service request, the BSC assigns a TCH to the MS through the

assignment procedure. If there are idle TCHs in the cell where the MS initiates the call, the BSC

assigns a TCH to the MS. Huawei BSC uses Huawei Channel Algorithm II, which ensures that

an optimal channel is assigned to the MS. Figure 2-1shows the assignment procedure. For

detailed assignment procedure, refer to Speech Channel Assignment Procedure.





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Figure 2-1Channel assignment procedure

Channel Activation

Channel Activation

Acknowledge

MS BTS MSC

Assignment Command

BSC

Assignment

Request

Assignment

Complete

UA

SABM

Establishment Indication

Assignment

Complete

If there is no idle TCH in the cell where the MS initiates a call, you can set related parameters

to enable the BSC to perform directed retry. Then, the BSC assigns an idle TCH in another cell

to the MS. The Huawei BSC can determine which neighbor cell is optimal based on measurementresults. Then, the cell is used as the optimal target cell during directed retry.

Upon receiving an assignment failure message on the Um interface, the BSC reassigns a channel

on another carrier frequency in the same cell to the MS. If there is no other carrier frequency in

the same cell, the BSC selects the original carrier frequency to assign a channel.

NOTE

If the BSC has assigned a TCH to the MS during the immediate assignment, the BSC does not assign a new

TCH to the MS during the assignment procedure. Instead, the BSC modifies the mode of the assigned TCH for

service transmission.

2.1.3 Initial Access and Immediate AssignmentThis describes the initial access and immediate assignment procedures. The purpose of initial

access is to set up a radio resource (RR) connection on the Um interface between an MS and the

network. The purpose of immediate assignment is to assign a signaling channel for setting up

the RR connection.

The initial access is a procedure of random access, as shown in Figure 2-2. For detailed

procedure, refer to Immediate Assignment Procedure.

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Figure 2-2Immediate assignment procedure

Channel Request

MS BTS BSC

SABM

UA

Establish Indication

Channel Activation

Channel Required

Channel Activation Acknowledge

Immediate Assignment Command

2.1.4 Authentication and Encryption

This describes the authentication and encryption procedures. Authentication and encryption are

two security mechanisms used by the GSM network to enhance network security and data

privacy.

Authentication

Authentication is the procedure through which the network checks the validity of the IMSI or

TMSI transmitted on the Um interface to verify the identity of an MS.

The purpose of authentication is to prevent unauthorized subscribers from accessing the network

and to protect the private information of authorized subscribers. The authentication and

encryption procedures are performed by the Authentication Triplet, namely RAND, Kc, and

SRES. They are generated by the GSM authentication center. Figure 2-3shows the

authentication procedure. For detailed authentication procedure, refer to Authentication

Procedure.





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Figure 2-3Authentication procedure

Ki RAND

A3

SRES

AUC

Equal

Authentication

success

KiRAND

A3

SRES

MS Network

Authentication provides protection through the following measures:

l Checking the validity of a subscriber through the authentication center (AuC) when the

subscriber tries to access the network

l Encrypting the messages on the radio channels

l Using the information stored in the EIR to identify an MS

l Using the TMSI instead of the IMSI during communications

l Using the PIN to protect the SIM

Encryption

Encryption is an important function of the GSM network. It ensures the security of the messages

exchanged between an MS and the BTS. The signaling, speech, and data transmitted on the Um

interface are encrypted to achieve data privacy.

GSM protocols define eight encryption algorithms: A5/0 to A5/7. A5/0 indicates Not ciphered.

At present, A5/2 encryption algorithm is deciphered. The GSM association allows all countries

to apply for A5/1 encryption algorithm or A5/3 encryption algorithm. A5/3 encryption algorithm

is preferentially used because it achieves the best security.

The BSC and the MS need to be configured to support the encryption function. In addition, theencryption capabilities of the BTS and the MS determine the encryption algorithm to be used.

The RRM entity determines whether an encryption mode is used. If the encryption is initiated

by the network, the BTS encrypts the messages that are sent to the MS. Figure 2-4shows the

encryption procedure. For detailed encryption procedure, refer to Ciphering Procedure.

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Figure 2-4Encryption procedure

Ki RAND

A8

Kc

AUC

KiRAND

MS BSS

TDMA

frame No.

A5

Kc

A8

A5

TDMA

frame No.

NSS

Unencrypted

messages

Unencrypted

messages

2.1.5 System Information

This describes system information (SI). The SI contains the main radio network parameters on

the Um interface. These parameters include network identification parameters, cell selection

parameters, system control parameters, and network function parameters.

Depending on the received system information, the MS chooses the network for access and

makes full use of various services provided by the network.

Based on the functions, the system information is categorized into:

l Basic system information, including SI1, SI2, SI2bis, SI2ter, SI3, SI4, SI5, SI5bis, SI5ter,

and SI6.

l GPRS-supportive system information, including SI7, SI8, and SI13.

l 2G-3G handover and reselection-supportive system information, including SI2QUATER.

l Packet system information (PSI), including PSI1, PSI2, PSI3, PSI3bis, PSI4, PSI5, and

PSI13.

Based on the transmission channel of system information, the system information can be

classified into broadcast messages and associated messages.

l Broadcast messages

When an MS is in idle mode, it communicates with the network through system information

broadcast. Through system information broadcast, the MS obtains information on currentlocation, service types, and cell reselection parameters.





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Broadcast messages include SI1, SI2, SI2BIS, SI2TER, SI3, SI4, SI7, SI8, SI2QUATER,

and SI13.

If the cell is configured with a PBCCH, the types of PSI that can be broadcast on the PBCCH

are PSI1, PSI2, PSI3, PSI3bis, PSI4, and PSI5.

l Associated messages

When an MS is not in idle mode, it communicates with the network through associated

system information. The network uses the associated system information to control the

transmission, power, and handover of an MS.

The related system information is System Information Types 5, 5bis, 5ter, and 6.

If the cell is configured with a PACCH, the packet system information is periodically

broadcast to the MSs in transmission state on the PACCH.

If the cell is configured with a PBCCH, PSI1 is broadcast to the MSs in transmission

state periodically on the PACCH.

If the cell is not configured with the PBCCH, the PSI13 is broadcast to the MSs in

transmission state periodically on the PACCH.

NOTE

System information type 9 contains the allocation information on the BCCH. If a system information type

9 is sent, the reception location of system information type 9 is specified in system information type 3.

System information type 9 is rarely used.

2.1.6 Handover

Handover is a procedure in which a conversation can be sustained when an MS moves from one

cell to another in order to meet the requirement of network management.

Handover procedure is quite complex. It consists of handover initiation, handover preparation,handover decision based on the handover algorithm, and handover execution. Handover helps

to adjust the traffic in the cell to avoid call drops. In addition, handover helps to minimize the

cross interference, thus optimizing the overall performance of the network.

Handover is controlled by the network. Based on home NEs of systems of cells, handover is

categorized into:

l Intra-cell handover

l Intra-BSC handover

l Inter-BSC handover

l Inter-MSC handover

l 2G-3G handover

During the handover procedure, the MS and the BTS measure the current radio links, combine

the measurement results of uplinks and downlinks into one measurement report, and then send

the measurement report to the BSC for analysis.

l For intra-cell handover and intra-BSC handover, the BSC performs the handover decision

based on the handover algorithm and notifies the MSC of the handover after the handover

is complete.

l For inter-BSC handover, inter-MSC handover, and 2G-3G handover, the BSS initiates the

handover request and the MSC performs the handover decision based on the measurementreports of the BSS.

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Based on the emergency degree of the network, the handover algorithm decides the handover

in the sequence of emergency handover, load handover, and general handover.

Table 2-1lists the handover type and the corresponding decision mode.

Table 2-1handover type and the corresponding decision mode

Handover Type Decision Mode

Emergency handover l Timing advance (TA) handover

l Bad quality (BQ) handover

l Quick drop handover

l Interference handover

General handover l Edge handover

l

Power Budget (PBGT) handoverl Concentric cell handover

l AMR handover

l Better 3G cell handover

l Fast movement handover from a micro cell to a

macro cell

Load handover l Load handover

l Inter-layer (better cell) handover

2.1.7 Radio Channel Management

This describes the radio channel management procedure. Radio channel management is

performed by the BSC. It consists of long-term channel configuration management and short-

term dedicated channel assignment management. The long-term management function is used

to select the channel sequence number and to configure relevant devices. The short-term

management function is used to assign and release various channels during communication.

Radio channel management is performed during the establishment, maintenance, modification,

and release of a connection. The radio channel management can be classified as follows:

l Common channel management, that is, common control channel management. Huawei

BSS supports the management of six common channels, namely, PCH, RACH, AGCH,

PPCH, PRACH, and PAGCH.

l Dedicated channel management, that is, the assignment, activation, release, management,

and reporting of various dedicated channels such as SDCCH, SACCH, TCH, and PDCH.

2.1.8 Power Control

This describes power control. Power control aims to reduce the transmit power of the MS or the

BTS under the condition that the radio link quality is maintained and the power level of the MS

and the BSS is met. Through power control, the system interference is reduced, the frequencyspectrum efficiency is improved, and the standby time of the MS is extended.





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Power control is an important measure of radio link control. Based on the radio links, power

control is categorized into:

l Uplink power control

The BSS measures the receive level and receive quality of the uplink signals and calculates

the required transmit power of the MS. The BSS decides to increase or reduce the transmit

power of the MS according to the power control algorithm.

l Downlink power control

The MS measures the receive level and receive quality of the downlink signals and reports

the measurement reports to the BSS. Based on the measurement reports, the BSS decides

to increase or reduce the transmit power of the BTS according to the power control

algorithm.

Figure 2-5shows the basic principles of power control.

Figure 2-5Basic principles of power control

Receivelevel

Receive

quality

Uplink/downlink

signal quality

threshold

Uplink/downlink

signal quality

lower threshold

Uplink/downlink

signal strength

upper threshold

Uplink/downlink

signal strength

upper threshold

0

7

0 63

MAX(AdjStep_Lev,

AdjStep_Qul)

AdjStep_QulNo Action

AdjStep_LevNo Action

MAX(AdjStep_Lev,

AdjStep_Qul)

AdjStep_Lev

AdjStep_Qul

AdjStep_Lev

l If the receive level or signal quality is greater than the expected value, the transmit power

should be reduced to an appropriate value.

l If the receive level or signal quality is smaller than the expected value, the transmit power

should be increased to an appropriate value.

The performance of the power control algorithm has a great effect on system performance.

Huawei uses Huawei II power control algorithm and Huawei III power control algorithm toimprove the accuracy and effectiveness of the power control.

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l Huawei II power control algorithm

Figure 2-6shows the power control decision procedure of Huawei II power control

algorithm.

Figure 2-6Power control decision procedure of Huawei II power control algorithm

Calculate power adjustmentstep based on both receive

level and receive quality

Start

Calculate power adjustment

step based on receive

quality

End

Perform power control

Compensate MRs

(Compensate level)

MR prediction filtering

Calculate power adjustment

step based on receive level

Huawei II power control algorithm has the following characteristics:

Measurement report compensation

Prediction filtering

Dual-threshold power control algorithm

Variable step power control

Adaptive power control

Bad quality signal strength upper threshold adjustment and detachment of uplink and

downlink power control

l Huawei III Power Control Algorithm





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l Blocking or unblocking terrestrial group circuits in case of equipment failure or through

configurations on the BSC6000 Local Maintenance Terminal.

l Retransmitting circuit management messages (circuit block/unlock/reset) if no

acknowledge is received from the MSC before expiration.

l Supporting the uninstalled circuit function.

l Under the following conditions, the uninstalled circuit function enables the BSC to send

an uninstalled circuit message to the MSC if the specified circuit does not exist:

Circuit block, circuit unblock, or circuit reset

Channel assignment

Incoming BSC handover

BSC reset

NOTE

If IP transmission is used on the A interface, the circuit management function is not implemented by the

BSS.

2.1.10 TRX Management

This describes the TRX management procedure. TRX management refers to TRX status

management.

TRX management consists of the following procedures:

l SACCH filling information modification procedure

The BSC informs the BTS of the new system information transmitted on all DL SACCHs.

The BTS then informs the MS of the system information update.

l Radio resource indication procedure

The BTS informs the BSC of the interference level on the idle dedicated channels of each

TRX. Thus, the BSC is completely informed of the interference level of the current idle

channels to facilitate subsequent channel assignment.

l Flow control procedure

The frame unit controller (FUC) informs the BSC of the overload of a TRX. The possible

causes of overload are CCCH overload, AGCH overload, and processor overload.

l Error reporting procedure

The BTS reports to the BSC the detected DL message errors that cannot be reported by

other procedures.

2.1.11 Media Access Control

This describes Media Access Control (MAC).

The BSC supports the MAC on the Abis interface. MAC defines the process in which multiple

MSs share the transmission media. MAC provides data transmission services to the upper Radio

Link Control through logical channels. It maps the logical channels onto the transport channels.

MAC performs the following functions:

l Multiplexes the uplink and downlink of the MS on Packet Data Channel (PDCH).

l

Schedules the Uplink State Flag (USF) for PDCH to control the transmission of uplinksignaling of the MS.





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l Based on the priority of each downlink Temporary Block Flow (TBF), sends the downlink

data block and control block in polling period.

2.1.12 Radio Link Control

This describes Radio Link Control (RLC).

The BSC supports the RLC on the Abis interface. TLC ensures the reliability of the data

transmitted on the Um interface. The involved operations of the RLC include selecting the coding

scheme, processing data retransmission, and segmenting and reassembling the data.

RLC performs the following functions:

l Segmentation and reassembling of RLC data blocks

l TBF establishment and release procedures of RLC data blocks.

2.2 Connection ManagementThis describes the connection management of the BSS. Connection management is a function

for the control, assignment, and management of the services provided by the network. The

services are short message services (SMSs), teleservices, and location-based services.

2.2.1 Voice Calls

This describes the voice call function. The voice calls supported by the BSS consist of MS-

originated calls, MS-terminated calls, emergency calls, and call re-establishment.

2.2.2 Short Message Services

This describes the short message services (SMSs) function. SMSs consist of the point-to-pointSMS and cell broadcast SMS.

2.2.3 Voice Coding/Decoding and Transcoding

This describes the voice coding/decoding and transcoding functions. The transcoding and rate

adaptation is a function through which voice coding and decoding algorithms are used to convert

the 16 kbit/s or 8 kbit/s signals on the Abis interface to 64 kbit/s signals on the A interface. The

reverse procedure is also supported.

2.2.4 Packet Data Transfer

The BSC supports the functions of Relay (RL) layer.

2.2.1 Voice CallsThis describes the voice call function. The voice calls supported by the BSS consist of MS-

originated calls, MS-terminated calls, emergency calls, and call re-establishment.

The BSS uses resource management algorithms and service control procedures to establish an

RR connection. This provides a transmission channel for exchanging call control signaling

between the MS and the core network.

The BSS supports the following voice call procedures:

l MS-originated call establishment procedure

l MS-terminated call establishment procedure

l Emergency call establishment procedure

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l MS-originated call release procedure

l Network-originated call release procedure

2.2.2 Short Message Services

This describes the short message services (SMSs) function. SMSs consist of the point-to-point

SMS and cell broadcast SMS.

Point-to-Point Short Message Service

The point-to-point SMS is a type of basic services provided by the GSM network. The MS sends

or receives a message of limited length, which is displayed on the screen of the MS.

The short message center (SMC) stores and forwards short messages. SMC is completely

separated from the GSM system in terms of functions. The SMC can provide services for the

GSM and PSTN subscribers who can receive short messages.

The MS can send or receive point-to-point messages when it is in idle mode or when it is making

a call.

Cell Broadcast Short Message Service

The cell broadcast SMS-CB is a special service provided by the GSM network. The network

can send short messages on the CBCH to a specified network area in unacknowledged mode.

All the MSs in the specified area can receive and display the messages.

If the cell broadcast SMS is enabled, a message can be broadcast repeatedly. Thus, even the MSs

that just enter the broadcast area can receive the message and the MSs that have received the

message earlier do not receive it again. Mobile network operators can use cell broadcast SMS

to provide special services for their subscribers. Compared with the point-to-point SMS, the cell

broadcast SMS is an effective and economical measure to send messages to a large number of

subscribers in a specified area.

2.2.3 Voice Coding/Decoding and Transcoding

This describes the voice coding/decoding and transcoding functions. The transcoding and rate

adaptation is a function through which voice coding and decoding algorithms are used to convert

the 16 kbit/s or 8 kbit/s signals on the Abis interface to 64 kbit/s signals on the A interface. The

reverse procedure is also supported.

The voice coding and decoding algorithms supported by the BSC consist of full rate, half rate,

enhance full rate, and adaptive multirate (AMR).

NOTE

If IP transmission is used on the A interface, the voice coding/decoding and transcoding functions are not

implemented by the BSS.

2.2.4 Packet Data Transfer

The BSC supports the functions of Relay (RL) layer.

The RL layer adapts the data on the Um interface and Gb interface. It reassembles the uplink

data on the Um interface into Packet Data Units (PDUs) and chooses the appropriate link for

transmission. In addition, the RL layer segments the Gb PDUs into downlink data on the Uminterface and chooses the appropriate PDCH for transmission.





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2.3 BTS Management

This describes the BTS management function. BTS management is a function where procedures

and messages related to the BTS are performed. The procedures and messages such as the BTS

software downloading, BTS data configuration, BTS status management, and BTS alarms

management should be performed by the peer-layer entities of the BSC and BTS.

2.4 BSS Operation and Maintenance

This describes the OM functions of the BSS. The BSS provides OM functions, such as,

performance management, BTS OM, BSC OM, clock control setting, BSC alarms, BTS alarms,

BTS commissioning, dynamic data configuration, GUI, and integrated network management

interfaces.

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3Introduction to the BSCAbout This Chapter

This introduces the BSC. Physically, the BSC system is composed of the BSC hardware system

and the BSC software system. Logically, it consists of eights subsystems.

The BSC hardware system consists of the GBCR cabinet, GBSR cabinet, LMT, and alarm box.

In addition to the interfaces for the power supply input and clock signal input, the BSC hardware

provides communication interfaces for equipment such as the BTS, external PCU, MSC, SGSN,

and M2000.

The BSC software has a distributed structure. It consists of the board software and OM software.

The board software and the OM software can communicate with each other.

Logically, the BSC system consists of the TDM switching subsystem, GE switching subsystem,

service processing subsystem, service control subsystem, interface processing subsystem, clock

subsystem, power subsystem, and environment monitoring subsystem.

3.1 BSC Physical Structure

This describes the physical structure of the BSC, including the cabinet, cables, LMT computers,

and alarm box.

3.2 BSC Software Structure

The software of the BSC has a distributed architecture. It is classified into the host software,

OMU software, and LMT software.

3.3 BSC Logical Structure




3.4 BSC Technical Specifications

The BSC technical specifications consist of the capacity specifications, engineering

specifications, physical port specifications, reliability specifications, clock precision

specifications, noise and safety compliance, and environment specifications.

3.5 BSC Hardware Configuration

The GBAM and GOMU are the operation and maintenance entities of the BSC. There are two

types of BSC hardware configuration: configuration type A and configuration type B. In


BSS System Description 3 Introduction to the BSC



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configuration type A, the BSC is configured with the GBAM. In configuration type B, the BSC

is configured with the GOMU. One BSC can use only one configuration type.

3.6 OM of the BSC

You can maintain the BSC in different OM modes.






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3.1 BSC Physical Structure

This describes the physical structure of the BSC, including the cabinet, cables, LMT computers,

and alarm box.

Figure 3-1shows the physical structure of the BSC.

Figure 3-1Physical structure of the BSC

OM equipment room

LMT

LMT

Alarm box

Serial portcable

Ethernet

cable

Ethernet

cable

GBCR GBSR GBSR

Equipment room

Optical cable to other NEs

Trunk cable to other NEs

PGND cable to the PDF

Ethernet cable to other NEs

Power cable to the PDF

LMT: Local Maintenance Terminal PDF: Power Distribution Frame

Table 3-1lists the components of the BSC.

Table 3-1Components of the BSC

Component Introduction Description

GSM BSC control

processing rack (GBCR)

The GBCR provides

switching and processes

services for the BSC. One

GBCR is configured in a

BSC.

For details, refer to GBCR

(Configuration Type A)and

GBCR (Configuration Type B).

GSM BSC service

processing rack (GBCR)

The GBSR processes

various services for the

BSC. The number of

GBSRs to be configured

depends on the traffic

volume. Zero to three

GBSRs can be

configured.

For details, refer to GBSR

Cabinet.





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Component Introduction Description

BSC Cables BSC cables are classified

into the Ethernet cable,

optical cable, and trunk

cable. The number of

BSC cables to be

configured depends on

actual requirements.

For details, refer to BSC Cables.

BSC LMT The LMT is a computer

that is installed with the

LMT software package

and is connected to the

OM network of the NEs.

It is optional for the BSC.

For details, refer to LMT-Related

Definitions.

Alarm box The alarm box cangenerate audible and

visual alarms. It is

mandatory for the BSC.

User manual delivered with thealarm box

3.2 BSC Software Structure

The software of the BSC has a distributed architecture. It is classified into the host software,

OMU software, and LMT software.

Host Software

The host software runs on various service boards. It consists of the operating system, middleware,

and application software. Figure 3-2shows the structure of the host software.

Figure 3-2Structure of the host software

Operating system

Middleware

Application software

l Operating system

The operating system adopted in the BSC is VxWorks, which is an embedded real-time

operating system.

l Middleware

The Distributed Object-oriented Programmable Realtime Architecture (DOPRA) and

Platform of Advanced Radio Controller (PARC) middleware ensures that the upper-level

application software is independent of the lower-level operating system. The middlewareenables software functions to be transplanted between different platforms.






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l Application software

Different boards are configured with different types of application software. The

application software is classified into radio resource processing software, resource control

plane processing software, BTS management software, and configuration management and

maintenance software.

OMU Software

The operation maintenance unit (OMU) software runs on the GBAM server or on the GOMU

to perform the operation and maintenance of the BSC. Figure 3-3shows the structure of the

OMU software.

Figure 3-3Structure of the OMU software

OMU software

Middleware

Operating system

l Operating system

The OMU software runs on the Linux operating system.l Middleware

The DOPRA middleware ensures that the upper-level application software is independent

of the lower-level operating system. Thus, the middleware enables software functions to

be transplanted between different platforms.


The application software performs the functions of different logical entities in the GBAM/

GOMU.

LMT Software

The LMT software, which consists of the operating system and application software, runs on

the LMT computer. Figure 3-4shows the structure of the LMT software.

Figure 3-4LMT software structure

Operating system

Application software

l Operating system





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The LMT runs on the Windows 2000 Professional, Windows XP Professional, or Microsoft

Windows Vista Professional operating system.


The application software provides access to operation and maintenance of the BSC. The

application software consists of the BSC6000 Local Maintenance Terminal, BSC6000Online Help, Site Maintenance Terminal System, LMT Service Manager, Local

Maintenance Terminal, Performance Browser tool, and Convert Management System.

NOTE

The BSC6000 Local Maintenance Terminal provides a graphic user interface (GUI) for performing

operation and maintenance. The Local Maintenance Terminal is also called the MML client, which

provides MML commands for the users. Both of them support the maintenance and data configuration

of the BSC and the BTSs connected to the BSC.

3.3 BSC Logical Structure




Figure 3-5shows the logical structure of the BSC.

Figure 3-5Logical structure of the BSC

Service

processing

subsystem

Service

controlsubsystem

Interface

processingsubsystem

Environment

monitoring

subsystem

GBAM/GOMU

LMT/M2000

To BTS

To PCU/SGSN

To MSC/MGW

TDMswitching

subsystem

GE

switching

subsystem

Clocksubsystem

Powersubsystem

The interface processing subsystem of the BSC provides the Pb or Gb interface, depending on

the types of PCU.

l When the built-in PCU is used, the interface processing subsystem provides the Gb interface

to enable the communication between the BSC and the SGSN.

l

When the external PCU is used, the interface processing subsystem provides the Pbinterface to enable the communication between the BSC and the PCU.






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The interface processing subsystem of the BSC cannot provide the Gb interface and Pb interface

simultaneously.

The interface processing subsystem supports different transmission modes over the A interface:

l When the IP transmission is used, the A interface enables the communication between the

BSC and the MGW.

l When the TDM transmission is used, the A interface enables the communication between

the BSC and the MSC/MGW.

The interface processing subsystem of the BSC cannot support the two transmission modes

simultaneously.

3.4 BSC Technical Specifications

The BSC technical specifications consist of the capacity specifications, engineering

specifications, physical port specifications, reliability specifications, clock precision

specifications, noise and safety compliance, and environment specifications.

3.5 BSC Hardware Configuration

The GBAM and GOMU are the operation and maintenance entities of the BSC. There are two

types of BSC hardware configuration: configuration type A and configuration type B. In

configuration type A, the BSC is configured with the GBAM. In configuration type B, the BSC

is configured with the GOMU. One BSC can use only one configuration type.

3.6 OM of the BSC

You can maintain the BSC in different OM modes.





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4Introduction to the PCUAbout This Chapter

This introduces the PCU. The PCU provides packet data services. The main functions of the

PCU include packet radio resource management, packet calls control, and packet data

transmission. Huawei BSS supports built-in PCU and external PCU.

4.1 Introduction to the Built-in PCU

This introduces the built-in PCU. The BSC processes the packet services through the

configuration of the corresponding boards.

4.2 Introduction to the External PCU

Huawei BSS supports the external PCU. Physically, the external PCU consists of the hardware

system and the software system. Logically, the external PCU consists of the OM unit and the

radio packet processing unit.


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4.1 Introduction to the Built-in PCU

This introduces the built-in PCU. The BSC processes the packet services through the

configuration of the corresponding boards.

Physical Structure

The functions of the built-in PCU are implemented by the following BSC boards:

l GDPUP: processes the user plane of the packet services. For details on the GDPUP, refer

to Functions of the GDPUP.

l GXPUM: processes the control plane of the packet services. For details on the GXPUM,

refer to Functions of the GXPUM.

l GFGUG: the interface processing board that provides the Gb interface based on IP

transmission. For details on the GFGUG, refer to Functions of the GFGUG.l GEPUG: the interface processing board that provides the Gb interface based on FR

transmission. For details on the GEPUG, refer to Functions of the GEPUG.

The GDPUP and the GFGUG/GEPUG are configured in the GMPS/GEPS subrack.

l For details on the typical configurations of the GMPS in different scenarios, refer to

Configuration of the GMPS (Configuration Type A)and Configuration of the GMPS

(Configuration Type B).

l For details on the typical configurations of the GEPS in different scenarios, refer to

Configuration of the GEPS.

Logical Structure

The BSC processes the packet data services through the service processing subsystem, service

control subsystem, and Gb interface processing unit. Figure 4-1shows the logical structure of

the built-in PCU.






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Figure 4-1Logical structure of the built-in PCU

BSC

Built-in PCU

Gb

UNITDATA SIGNAL

Abis

Service

processingsubsystem

Service

controlsubsystem

Gb interface

processing unit

BTS

SGSN

Abis interface

processing unit

l

Service processing subsystemProcesses the PS user plane data. The function implemented by the GDPUP.

l Service control subsystem

Processes the PS signaling plane data. Performs the virtual connection management,

resource management, and network management layer of the network services. The

function is implemented by the GXPUM/GXPUT.

l Gb interface processing unit

Performs the data transmission and routing. The function is implemented by the GFGUG/

GEPUG.

Physical Ports

The GFGUG/GEPUG provides the Gb interface to the SGSN.

l Each GFGUG supports eight FE ports and two GE ports. For details on physical ports, refer

to Ports on the GFGUA/GFGUB/GFGUG Panel.

l Each GEPUG supports 32 E1/T1 ports. For details on physical ports, refer to Ports on the

GEHUB/GEPUG Panel.

Operation and Maintenance

The operation and maintenance of Huawei built-in PCU is implemented by the OM subsystemof the BSC.





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4.2 Introduction to the External PCU

Huawei BSS supports the external PCU. Physically, the external PCU consists of the hardware

system and the software system. Logically, the external PCU consists of the OM unit and the

radio packet processing unit.

4.2.1 PCU Physical Structure

This describes the physical structure of the PCU. Physically, the PCU consists of the power

distribution box, LAN switch subrack, LAN switch cable trough, filler panel, PCU processing

subrack, and air defense subrack.

4.2.2 PCU Software Structure

This describes the software structure of the PCU. The PCU software consists of the PCU

operating system (OS), POMU software, RPPU software, and L2PU software.

4.2.3 PCU Logical StructureThis describes the logical structure of the PCU. The PCU has a simple logical architecture. It

consists of the packet operation maintenance unit (POMU) and radio packet process unit

(RPPU).

4.2.4 PCU Physical Ports

This describes the PCU physical ports. The PCU physical ports consist of the transmission ports,

commissioning serial ports, and internal communication ports.

4.2.5 PCU Technical Specifications

This describes the technical specifications of the PCU. The technical specifications of the PCU

involves physical protection, data backup and security, working environment, ElectroMagnetic

Compatibility (EMC), noise, storage, transportation, power supply, power consumption, andcapacity.

4.2.6 PCU Operation and Maintenance

This describes the operation and maintenance (OM) of the PCU. The OM module of the PCU

provides operation and maintenance functions, such as OM management, data configuration

management, fault management, performance measurement management, and security

management. You can use these functions to remotely monitor the PCU running status, maintain

PCU devices, locate faults, and evaluate the network performance.

4.2.1 PCU Physical Structure

This describes the physical structure of the PCU. Physically, the PCU consists of the power

distribution box, LAN switch subrack, LAN switch cable trough, filler panel, PCU processing

subrack, and air defense subrack.

Figure 4-2shows the physical structure of the PCU.






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Figure 4-2Physical structure of the PCU

Powerdistribution box (2 U)

LAN switch

cable trough (1 U)

PCU processing

subrack (9 U)

LAN switch (1 U)

Filler panel (3 U)

Air defencesubrack (2 U)

Filler panel (3 U)

Filler panel (2 U)

PCU processing

subrack (9 U)

PCU processing

subrack (9 U)

Air defencesubrack (2 U)

NOTE

1 U = 44.45 mm

A PCU cabinet can hold up to three processing subracks. The three subracks are independent

from each other and are interconnected through the LAN switch and the OMC for centralized

monitoring.

The PCU processing subrack can be configured with the POMU, HSC, RPPU, L2PU sub-board,

E1TMb, BSU, and UPWRb. Figure 4-3and Figure 4-4show fully configured PCU processing

subracks.

Figure 4-3Fully configured PCU processing subrack (front subrack)

R

P

P

U

R

P

P

U

R

P

P

U

R

P

P

U

R

P

P

U

R

P

P

U

P

O

M

U

P

O

M

U

R

P

P

U

R

P

P

U

R

P

P

U

R

P

P

U

R

P

P

U

R

P

P

U

P

W

R

P

W

R

b b

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

U U





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Figure 4-4Fully configured PCU processing subrack (rear subrack)

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

B

SU

H

SC

B

SU

H

SC

1T

M

b

E

1T

M

b

E

1T

M

b

E

1T

M

b

E

1T

M

b

E

1T

M

b

E

1T

M

b

E

1T

M

b

E

1T

M

b

E

1T

M

b

E

1T

M

b

E

1T

M

b

E

PW

R

PW

R

b b

U U

4.2.2 PCU Software Structure

This describes the software structure of the PCU. The PCU software consists of the PCU

operating system (OS), POMU software, RPPU software, and L2PU software.

Figure 4-5shows the software structure of the PCU.






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Figure 4-5Software structure of the PCU

Performance

measurement

PCU software

RPPU

software

L2PU

software

POMU

software

Database

management

Software

management

Fault

management

status

monitoring and

management

OS

core module

I/O

processing

System

initialization

State

monitoring &

management

Fault

management

Software

management

Database

management

Performance

measurement

RLC/MAC

protocol

processing

Gb interface

processing

Pb interface

processing

G-Abis

interface

processing

link layer

protocol

processing

PCU operating

system

PCU Operating System

The PCU OS consists of the OS core module, input and output processing module, and system

initialization module.

POMU Software

The POMU software consists of the state monitoring and management module, fault

management module, software management module, database management module, and

performance measurement module.

RPPU Software

Each module of the POMU software has a corresponding module in the RPPU software. The

corresponding two modules communicate with each other to perform the OM function.

A database update procedure is initiated by the database management module in the POMUsoftware. If the procedure affects the database view stored in the RPPU, the procedure can be





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implemented only when the corresponding database management module in the RPPU software

is activated.

In addition to the previously mentioned modules, the RPPU software includes the RLC/MAC

protocol processing module, Gb interface processing module, G-Abis interface processing

module, and Pb interface processing module.

L2PU Software

The L2PU software performs link layer protocol processing. It consists of the LAPD processing

module, frame relay protocol processing module, and TRAU protocol processing module.

4.2.3 PCU Logical Structure

This describes the logical structure of the PCU. The PCU has a simple logical architecture. It

consists of the packet operation maintenance unit (POMU) and radio packet process unit

(RPPU).

Figure 4-6shows the logical structure of the PCU.

Figure 4-6Logical structure of the PCU

Signaling and data bus

RPPU RPPURPPU

BSC SGSN

RPPU

RPPUPOMU

N+1

1+1 LAN

Harddisk

RPPURPPU

POMU Module

The POMU module provides interfaces for users, processes the interface protocol between the

PCU and the OMC, and performs OM.

RPPU Module

The RPPU module implements the base station subsystem (BSS) part of the RLC/MAC protocol

and of the Gb interface protocols and performs Pb interface processing and G-Abis interfaceprocessing.






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4.2.4 PCU Physical Ports

This describes the PCU physical ports. The PCU physical ports consist of the transmission ports,

commissioning serial ports, and internal communication ports.

Table 4-1lists the PCU physical ports.

Table 4-1PCU physical ports

Connector Board Description

Ethernet port (10/100

BaseT)

POMU

RPPU

E1TMb

BSU

The Ethernet ports on the

POMU and on the RPPU are

invalid.

You can use Ethernet port 1 on

the BSU instead of that on the

POMU and Ethernet port 1 on

the E1TMb instead of that on

the RPPU. The Ethernet port

LED on the POMU indicates

the status of Ethernet port 1 on

the BSU. The Ethernet port

LED on the RPPU indicates

bss system description(v900r008c01_01)

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