BSC6900 GSM Technical Description

BSC6900 GSM V900R012C01

Technical Description Issue

03

Date

2010-09-20

HUAWEI TECHNOLOGIES CO., LTD.

Copyright © Huawei Technologies Co., Ltd. 2010. All rights reserved. No part of this document may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Technologies Co., Ltd.

Trademarks and Permissions and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd. All other trademarks and trade names mentioned in this document are the property of their respective holders.

Notice The purchased products, services and features are stipulated by the contract made between Huawei and the customer. All or part of the products, services and features described in this document may not be within the purchase scope or the usage scope. Unless otherwise specified in the contract, all statements, information, and recommendations in this document are provided "AS IS" without warranties, guarantees or representations of any kind, either express or implied. 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 all statements, information, and recommendations in this document do not constitute the warranty of any kind, express or implied.

Huawei Technologies Co., Ltd. Address:

Huawei Industrial Base Bantian, Longgang Shenzhen 518129 People's Republic of China

Website:

http://www.huawei.com

Email:

[email protected]

Issue 03 (2010-09-20)

Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

i

BSC6900 GSM Technical Description

About This Document

About This Document Purpose This document describes the structure, working principles, signal flows, and transmission and networking of the BSC6900. It helps the reader understand the implementation and working principles of the BSC6900.

Product Version The following table lists the product version related to the document. Product Name

Product Version

BSC6900

V900R012C01

Intended Audience This document is intended for: l

Network planners

l

System engineers

l

Field engineers

Organization 1 Changes in the BSC6900 GSM Technical Description This chapter describes the changes in the BSC6900 GSM Technical Description . 2 Hardware Configuration Modes The BSC6900 supports flexible hardware configuration modes. The hardware configuration mode varies according to the scenario. 3 Overall Structure This chapter describes the interactions between the modules in the BSC6900. Issue 03 (2010-09-20)


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About This Document

4 Working Principles This chapter describes the working principles of the BSC6900 in the following ways: power supply, environment monitoring, clock synchronization, and OM. 5 Signal Flow The BSC6900 signal flow consists of the user-plane signal flow, control-plane signal flow, and OM signal flow. 6 Transmission and Networking The transmission and networking between the BSC6900 and other NEs can be classified into the following types: transmission and networking on the A/Gb interface, on the Abis interface, on the Ater interface, and on the Pb interface. 7 Parts Reliability The BSC6900 guarantees its operation reliability by means of board redundancy and port redundancy.

Conventions Symbol Conventions The symbols that may be found in this document are defined as follows. Symbol

Description Indicates a hazard with a high level of risk, which if not avoided,will result in death or serious injury. Indicates a hazard with a medium or low level of risk, which if not avoided, could result in minor or moderate injury. Indicates a potentially hazardous situation, which if not avoided,could result in equipment damage, data loss, performance degradation, or unexpected results. Indicates a tip that may help you solve a problem or save time. Provides additional information to emphasize or supplement important points of the main text.

General Conventions The general conventions that may be found in this document are defined as follows.

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Convention

Description

Times New Roman

Normal paragraphs are in Times New Roman.


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About This Document

Convention

Description

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

Examples of information displayed on the screen are in Courier New.

Command Conventions The command conventions that may be found in this document are defined as follows. Convention

Description

Boldface

The keywords of a command line are in boldface.

Italic

Command arguments are in italics.

[]

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

{ x | y | ... }

Optional items are grouped in braces and separated by vertical bars. One item is selected.

[ x | y | ... ]

Optional items are grouped in brackets and separated by vertical bars. One item is selected or no item is selected.

{ x | y | ... }*

Optional items are grouped in braces and separated by vertical bars. A minimum of one item or a maximum of all items can be selected.

[ x | y | ... ]*

Optional items are grouped in brackets and separated by vertical bars. Several items or no item can be selected.

GUI Conventions The GUI conventions that may be found in this document are defined as follows. Convention

Description

Boldface

Buttons, menus, parameters, tabs, window, and dialog titles are in boldface. For example, click OK.

>

Multi-level menus are in boldface and separated by the ">" signs. For example, choose File > Create > Folder.

Keyboard Operations The keyboard operations that may be found in this document are defined as follows. Issue 03 (2010-09-20)


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About This Document

Format

Description

Key

Press the key. For example, press Enter and press Tab.

Key 1+Key 2

Press the keys concurrently. For example, pressing Ctrl+Alt +A means the three keys should be pressed concurrently.

Key 1, Key 2

Press the keys in turn. For example, pressing Alt, A means the two keys should be pressed in turn.

Mouse Operations The mouse operations that may be found in this document are defined as follows.

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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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Contents

Contents About This Document...................................................................................................................iii 1 Changes in the BSC6900 GSM Technical Description.......................................................1-1 2 Hardware Configuration Modes.............................................................................................2-1 3 Overall Structure........................................................................................................................3-1 3.1 Switching Subsystem......................................................................................................................................3-5 3.2 Service Processing Subsystem........................................................................................................................3-9 3.3 Interface Processing Subsystem....................................................................................................................3-10 3.4 Clock Synchronization Subsystem................................................................................................................3-12 3.5 OM Subsystem..............................................................................................................................................3-13

4 Working Principles....................................................................................................................4-1 4.1 Power Supply Principle...................................................................................................................................4-2 4.2 Environment Monitoring Principle.................................................................................................................4-3 4.3 Clock Synchronization Principle.....................................................................................................................4-6 4.3.1 Clock Sources.........................................................................................................................................4-6 4.3.2 Structure of the clock synchronization subsystem.................................................................................4-7 4.3.3 Clock Synchronization Process..............................................................................................................4-9 4.4 OM Principle.................................................................................................................................................4-11 4.4.1 Dual OM Plane.....................................................................................................................................4-12 4.4.2 OM Network........................................................................................................................................4-13 4.4.3 Active/Standby Workspaces................................................................................................................4-14 4.4.4 Data Configuration Management.........................................................................................................4-16 4.4.5 Security Management...........................................................................................................................4-20 4.4.6 Performance Management....................................................................................................................4-23 4.4.7 Alarm Management..............................................................................................................................4-25 4.4.8 Loading Management...........................................................................................................................4-26 4.4.9 Upgrade Management..........................................................................................................................4-30 4.4.10 BTS Loading Management................................................................................................................4-32 4.4.11 BTS Upgrade Management................................................................................................................4-33

5 Signal Flow..................................................................................................................................5-1 5.1 User-Plane Signal Flow...................................................................................................................................5-2 5.1.1 CBC Signal Flow...................................................................................................................................5-2 Issue 03 (2010-09-20)


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Contents

5.1.2 GSM CS Signal Flow.............................................................................................................................5-3 5.1.3 GSM PS Signal Flow.............................................................................................................................5-8 5.2 Control-Plane Signal Flow............................................................................................................................5-10 5.2.1 Signaling Flow on the A Interface.......................................................................................................5-10 5.2.2 Signaling Flow on the Abis Interface...................................................................................................5-12 5.2.3 Signaling Flow on the Gb Interface.....................................................................................................5-14 5.2.4 Signaling Flow on the Pb Interface......................................................................................................5-14 5.3 OM Signal Flow............................................................................................................................................5-15

6 Transmission and Networking................................................................................................6-1 6.1 Transmission and Networking on the A/Gb Interface.....................................................................................6-2 6.1.1 TDM-Based Networking on the A/Gb Interface....................................................................................6-2 6.1.2 IP-Based Networking on the A/Gb Interface.........................................................................................6-3 6.2 Transmission and Networking on the Abis Interface......................................................................................6-4 6.2.1 TDM-Based Networking on the Abis Interface.....................................................................................6-4 6.2.2 IP-Based Networking on the Abis Interface...........................................................................................6-5 6.3 Transmission and Networking on the Ater Interface......................................................................................6-7 6.3.1 TDM-Based Networking on the Ater Interface......................................................................................6-7 6.3.2 IP-Based Networking on the Ater Interface...........................................................................................6-8 6.4 Transmission and Networking on the Pb Interface.........................................................................................6-8

7 Parts Reliability..........................................................................................................................7-1 7.1 Concepts Related to Parts Reliability..............................................................................................................7-2 7.1.1 Backup....................................................................................................................................................7-2 7.1.2 Resource Pool.........................................................................................................................................7-3 7.1.3 Port Trunking.........................................................................................................................................7-3 7.1.4 Port Load Sharing...................................................................................................................................7-4 7.2 Board Redundancy..........................................................................................................................................7-4 7.2.1 Backup of EIUa Boards..........................................................................................................................7-5 7.2.2 Backup of OIUa Boards.........................................................................................................................7-5 7.2.3 Backup of PEUa Boards.........................................................................................................................7-6 7.2.4 Backup of POUc Boards........................................................................................................................7-7 7.2.5 Backup of SCUa Boards........................................................................................................................7-8 7.2.6 Backup of TNUa Boards........................................................................................................................7-8 7.2.7 Backup of FG2a/FG2c Boards...............................................................................................................7-9 7.2.8 Backup of GCUa/GCGa Boards..........................................................................................................7-10 7.2.9 Backup of GOUa/GOUc Boards..........................................................................................................7-11 7.2.10 Backup of OMUa/OMUb Boards......................................................................................................7-12 7.2.11 Backup of XPUa/XPUb Boards.........................................................................................................7-13 7.2.12 Resource Pool of DPUa/DPUc/DPUd Boards...................................................................................7-13 7.3 Port Redundancy...........................................................................................................................................7-14 7.3.1 Optical Port Backup.............................................................................................................................7-14 7.3.2 FE/GE Port Backup..............................................................................................................................7-15 7.3.3 Port Load Sharing.................................................................................................................................7-15 viii


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Contents

7.3.4 Port Trunking.......................................................................................................................................7-16

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Figures

Figures Figure 3-1 Structure of the host software.............................................................................................................3-2 Figure 3-2 Structure of the OMU software..........................................................................................................3-2 Figure 3-3 Logical structure of MPS/EPS............................................................................................................3-3 Figure 3-4 Logical structure of TCS.................................................................................................................... 3-3 Figure 3-5 Position of the switching subsystem in the MPS/EPS........................................................................3-5 Figure 3-6 Position of the switching subsystem in the TCS................................................................................ 3-6 Figure 3-7 Network topologies between subracks...............................................................................................3-7 Figure 3-8 Interconnections between subracks through the crossover cables between the SCUa boards (MPS/EPS) ...............................................................................................................................................................................3-7 Figure 3-9 Interconnections between subracks through the crossover cables between the SCUa boards (TCS) ...............................................................................................................................................................................3-8 Figure 3-10 Interconnections between subracks through the inter-TNUa cables (MPS/EPS).............................3-8 Figure 3-11 Interconnections between subracks through the inter-TNUa cables (TCS)..................................... 3-9 Figure 3-12 Service processing subsystem.......................................................................................................... 3-9 Figure 3-13 Position of the interface processing subsystem in the MPS/EPS...................................................3-11 Figure 3-14 Position of the interface processing subsystem in the TCS............................................................3-11 Figure 3-15 Position of the clock synchronization subsystem in the BSC6900 system....................................3-12 Figure 3-16 Position of the OM subsystem in the BSC6900 system.................................................................3-13 Figure 4-1 Power input part of the BSC6900.......................................................................................................4-2 Figure 4-2 Working principle of power monitoring.............................................................................................4-3 Figure 4-3 Working principle of fan monitoring..................................................................................................4-4 Figure 4-4 Working principle of environment monitoring...................................................................................4-5 Figure 4-5 Structure of the clock synchronization subsystem..............................................................................4-7 Figure 4-6 Structure of the clock synchronization subsystem..............................................................................4-8 Figure 4-7 Process of clock synchronization in the MPS/EPS (1).......................................................................4-9 Figure 4-8 Process of clock synchronization in the MPS/EPS (2).....................................................................4-10 Figure 4-9 Process of clock synchronization in the TCS...................................................................................4-10 Figure 4-10 Dual OM plane...............................................................................................................................4-12 Figure 4-11 Structure of the OM network..........................................................................................................4-13 Figure 4-12 Principle of effective mode configuration......................................................................................4-17 Figure 4-13 Principle of ineffective mode configuration...................................................................................4-17 Figure 4-14 Check of the data consistency between the OMU and the host boards..........................................4-19 Figure 4-15 Process of collecting performance measurement data periodically................................................4-24 Figure 4-16 Alarm management process............................................................................................................4-25 Issue 03 (2010-09-20)


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Figures

Figure 4-17 Working principle of the alarm box................................................................................................4-26 Figure 4-18 Loading process (1)........................................................................................................................4-27 Figure 4-19 Loading process (2)........................................................................................................................4-28 Figure 4-20 Loading process (3)........................................................................................................................4-30 Figure 4-21 Upgrade through the OM network..................................................................................................4-31 Figure 4-22 Upgrade process.............................................................................................................................4-31 Figure 5-1 Signal flow from CBC-BSC to Abis..................................................................................................5-2 Figure 5-2 GSM CS signal flow (1).....................................................................................................................5-3 Figure 5-3 GSM CS signal flow (2).....................................................................................................................5-4 Figure 5-4 GSM CS signal flow (3).....................................................................................................................5-4 Figure 5-5 GSM CS signal flow (4).....................................................................................................................5-5 Figure 5-6 GSM CS signal flow (5).....................................................................................................................5-6 Figure 5-7 GSM CS signal flow (6).....................................................................................................................5-6 Figure 5-8 GSM CS signal flow (7).....................................................................................................................5-7 Figure 5-9 GSM CS signal flow (8).....................................................................................................................5-8 Figure 5-10 GSM PS signal flow (1)....................................................................................................................5-9 Figure 5-11 GSM PS signal flow (2)....................................................................................................................5-9 Figure 5-12 Signaling flow on the A interface in A over TDM mode (BM/TC separated)...............................5-11 Figure 5-13 Signaling flow on the A interface in A over TDM mode (BM/TC combined)..............................5-11 Figure 5-14 Signaling flow on the A interface in A over IP mode....................................................................5-12 Figure 5-15 Signaling flow on the Abis interface in Abis over TDM mode......................................................5-13 Figure 5-16 Signaling flow on the Abis interface in Abis over IP mode...........................................................5-13 Figure 5-17 Signaling flow on the Gb interface.................................................................................................5-14 Figure 5-18 Signaling flow on the Pb interface.................................................................................................5-15 Figure 5-19 OM signal flow (BM/TC separated)...............................................................................................5-16 Figure 5-20 OM signal flow (BM/TC combined)..............................................................................................5-17 Figure 6-1 TDM-based networking on the A interface in local TCS mode.........................................................6-2 Figure 6-2 TDM-based networking on the A interface in remote TCS mode......................................................6-2 Figure 6-3 TDM-based networking on the Gb interface......................................................................................6-3 Figure 6-4 IP over E1 networking on the A interface..........................................................................................6-3 Figure 6-5 IP over Ethernet networking on the A/Gb interface...........................................................................6-4 Figure 6-6 TDM-based networking on the Abis interface...................................................................................6-5 Figure 6-7 IP over E1 Networking.......................................................................................................................6-5 Figure 6-8 IP over Ethernet networking (layer 2)................................................................................................6-6 Figure 6-9 IP over Ethernet networking (layer 3)................................................................................................6-6 Figure 6-10 TDM-based networking on the Ater interface..................................................................................6-7 Figure 6-11 IP-based networking on the Ater interface.......................................................................................6-8 Figure 6-12 TDM-based networking on the Pb interface.....................................................................................6-8

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Tables

Tables Table 3-1 Components of the BSC6900 cabinet..................................................................................................3-1 Table 4-1 Definitions of the user rights..............................................................................................................4-20 Table 4-2 Types of logs......................................................................................................................................4-22

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1

1 Changes in the BSC6900 GSM Technical Description

Changes in the BSC6900 GSM Technical Description This chapter describes the changes in the BSC6900 GSM Technical Description .

03 (2010-09-20) This is the third commercial release of V900R012C01. Compared with issue 02 (2010-06-21), this issue does not include any new topics. Compared with issue 02 (2010-06-21), this issue incorporates the following changes: Topic

Change Description

7.2.12 Resource Pool of DPUa/DPUc/ DPUd Boards

The description of the resource pool is modified.

Compared with issue 02 (2010-06-21), this issue does not exclude any topics.

02 (2010-06-21) This is the second commercial release of V900R012C01. Compared with issue 01 (2010-04-10), this issue includes the following new topics: l

7 Parts Reliability

Compared with issue 01 (2010-04-10), this issue incorporates the following changes: Content

Description

4.4.5 Security Management

The requirement for password setting is added.

Compared with issue 01 (2010-04-10), this issue does not exclude any topics. Issue 03 (2010-09-20)


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1 Changes in the BSC6900 GSM Technical Description


01 (2010-04-10) This is the first commercial release of V900R012C01. Compared with issue 04 (2010-01-30) of V900R011C00, this issue does not include any new topics. Compared with issue 04 (2010-01-30) of V900R011C00, this issue does not incorporate any changes. Compared with issue 04 (2010-01-30) of V900R011C00, this issue does not exclude any topics.

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2 Hardware Configuration Modes

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Hardware Configuration Modes

The BSC6900 supports flexible hardware configuration modes. The hardware configuration mode varies according to the scenario. Learn the following concepts for a better understanding of the BSC6900.

BM/TC The main processing subrack (MPS) and extended processing subrack (EPS) are collectively known as basic module (BM) subrack. The transcoder subrack (TCS) is known as TC subrack.

Main TCS The TCS that forwards the OM signals to other TCSs is called the main TCS. All other TCSs are called extension TCSs. The main TCS is determined by both the cable connections and the data configuration. For details of the cable connections, see switching subsystem.

Subrack Configuration Modes The BSC6900 subracks can be configured in three modes: l

BM/TC separated In BM/TC separated mode, the BSC6900 is configured with the MPS, EPS, and TCS (local or remote). Characteristics: In this mode, the installation location of the TCS is flexible. The TCS can be installed in the transcoder rack (TCR) and be placed on the CN side, thus saving the transmission resources between the BSC6900 and the CN. Alternatively, the TCS can be installed in the same cabinet as the MPS or EPS and be placed on the BSC6900 side.

l

BM/TC combined In BM/TC combined mode, the boards of the TCS are installed in the MPS or in the EPS, with the subrack names unchanged. Characteristics: The BSC6900 in this mode has higher hardware integration than in BM/ TC separated mode, When the capacity is the same, the BSC6900 in this mode has fewer cabinets and subracks.

l

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A over IP Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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2 Hardware Configuration Modes

In A over IP mode, layer 3 (network layer) of the protocol stack on the A interface adopts the IP protocol. In this case, the BSC6900 is configured with the MPS and EPS but not with the TCS. The TC function is performed by the Media Gateway (MGW). Characteristics: In this mode, the BSC6900 has fewer cabinets and subracks. The BSC6900 must be interconnected with a specific MGW. One BSC6900 uses only one configuration mode.

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3 Overall Structure

3

Overall Structure

About This Chapter This chapter describes the interactions between the modules in the BSC6900.

Physical Structure The BSC6900 cabinet consists of power distribution boxes and subracks, as listed in Table 3-1. Table 3-1 Components of the BSC6900 cabinet Component

Configuration

MPS

One MPS must be configured.

EPS

Zero to five EPSs can be configured.

TCS

Zero to four TCSs can be configured.

Independent fan subrack

Each cabinet must be configured with one independent fan subrack.

Power distribution box

Each cabinet must be configured with one power distribution box.

NOTE

If customers purchase also the Nastar product of Huawei, customers need to install the SAU board in the MPS or EPS of the BSC6900 cabinet (the SAU board occupies two slots that work in active/standby mode). For details on how to install the SAU board, how to install the software on the SAU board, and how to maintain the SAU board, see the SAU User Guide of Nastar documents.

Software Structure The software of the BSC6900 has a distributed architecture. It is classified into the host software and OMU software. Issue 03 (2010-09-20)


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3 Overall Structure l

Host software The host software is distributed on the service boards. It consists of the operating system, middleware, and application software. See Figure 3-1. Figure 3-1 Structure of the host software

–

Operating system The VxWorks real-time embedded operating system runs on each service board.

–

Middleware The Versatile Protocol Platform (VPP) and the Virtual Operating System (VOS) function as the middleware. The middleware enables the upper-layer application software to be independent from the lower-layer operating system so that software functions can be transplanted between different platforms.

–

Application software Boards of different types can be installed with different application software. The application software is classified into radio resource processing software, resource control-plane processing software, base station management software, and configuration maintenance management software.

l

OMU software The Operation and Maintenance Unit (OMU) software runs on the OMUa board, OMUb board, and GBAM. The OMU is responsible for the operation and maintenance of the BSC6900. The OMU software consists of the operating system and the OMU application software. See Figure 3-2. Figure 3-2 Structure of the OMU software

–

Operating system The Dopra Linux, Suse Linux, or Windows Server 2003 operating system is used.

–

OMU application software The OMU application software runs on the lower-level operating system and provides various service processes, including the LMT process, fault diagnosis process, and authentication process.

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Logical Structure Figure 3-3 and Figure 3-4 show the logical structure of the BSC6900. Figure 3-3 Logical structure of MPS/EPS

Figure 3-4 Logical structure of TCS

The TCS that forwards the OM signals to other TCSs is called the main TCS. Issue 03 (2010-09-20)


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3 Overall Structure

The channel for the TCS and the MPS to exchange information varies according to the location of the TCS: local or remote. l

In local TCS mode, the SCUa board in the main TCS is connected to the SCUa board in the MPS through the crossover cable.

l

In remote TCS mode, the TCS is located in the TCR, which is separate from the cabinet that houses the MPS/EPS. The main TCS and the MPS are connected through the cable between the Ater interface boards.

Subsystems Logically, the BSC6900 consists of the following five subsystems: 3.1 Switching Subsystem The switching subsystem performs switching of traffic data, signaling, and OM signals. 3.2 Service Processing Subsystem The BSC6900 service processing subsystem performs the control functions defined in the 3GPP protocols and processes services of the BSC6900. 3.3 Interface Processing Subsystem The interface processing subsystem provides transmission ports and resources, processes transport network messages, and enables interaction between the BSC6900 internal data and external data. 3.4 Clock Synchronization Subsystem The clock synchronization subsystem provides clock signals for the BSC6900 and provides reference clock signals for base stations. 3.5 OM Subsystem The OM subsystem enables the management and maintenance of the BSC6900 in the following scenarios: routine maintenance, emergency maintenance, upgrade, and capacity expansion.

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3.1 Switching Subsystem The switching subsystem performs switching of traffic data, signaling, and OM signals.

Position of the Switching Subsystem in the BSC6900 System The switching subsystem consists of logical modules of two types: MAC switching and TDM switching. Figure 3-5 and Figure 3-6 show the position of the switching subsystem in the MPS/ EPS and TCS respectively, with the modules highlighted in apricot. Figure 3-5 Position of the switching subsystem in the MPS/EPS

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3 Overall Structure

Figure 3-6 Position of the switching subsystem in the TCS

Functions l

Provides intra-subrack Medium Access Control (MAC) switching

l

Provides intra-subrack Time Division Multiplexing (TDM) switching

l

Provides inter-subrack MAC switching and TDM switching

l

Distributes clock signals to the service processing boards

Hardware Involved The switching subsystem consists of the SCUa boards, TNUa boards, high-speed backplane channels in each subrack, crossover cables between SCUa boards, and inter-TNUa cables.

Network Topologies Between Subracks The BSC6900 subracks can be connected in the star or mesh topology. In Figure 3-7, (1) and (2) represent the star and mesh topologies respectively, where the dots represent subracks. l

Star topology One node functions as the center node and it is connected to each of the other nodes. The communication between the other nodes must be switched by the center node.

l

Mesh topology There is a connection between every two nodes. When any node is out of service, the communication between other nodes is not affected.

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Figure 3-7 Network topologies between subracks

In the switching subsystem of the BSC6900, the star topology is established among the MAC switching logical modules, and the mesh topology is established among the TDM switching logical modules.

Inter-Subrack Connection The MAC switching logical modules switch the IP-based traffic data, OM signals, and signaling. The switching is performed by the SCUa boards and the Ethernet cables between the SCUa boards. The inter-subrack connections related to MAC switching can be classified into the following types: l

Interconnections between the MPS and the EPSs The MPS functions as the main subrack, and a maximum of three EPSs function as extension subracks. The star interconnections between the MPS and the EPSs are established through the Ethernet cables between the SCUa boards, as shown in Figure 3-8.

l

Interconnections between the TCSs One TCS functions as the main subrack, and a maximum of three TCSs function as extension subracks. The star interconnections between the TCSs are established through the Ethernet cables between the SCUa boards, as shown in Figure 3-9.

Figure 3-8 Interconnections between subracks through the crossover cables between the SCUa boards (MPS/EPS)

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3 Overall Structure

Figure 3-9 Interconnections between subracks through the crossover cables between the SCUa boards (TCS)

The TDM switching logical modules switch the TDM-based traffic data. The switching is performed by the TNUa boards and the inter-TNUa cables. The inter-subrack connections related to TDM switching can be classified into the following types: l

Interconnections between the MPS and the EPSs The mesh interconnections between the MPS and the EPSs are established through the inter-TNUa cables, as shown in Figure 3-10.

l

Interconnections between the TCSs The mesh interconnections between the TCSs are established through the inter-TNUa cables, as shown in Figure 3-11.

Figure 3-10 Interconnections between subracks through the inter-TNUa cables (MPS/EPS)

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Figure 3-11 Interconnections between subracks through the inter-TNUa cables (TCS)

3.2 Service Processing Subsystem The BSC6900 service processing subsystem performs the control functions defined in the 3GPP protocols and processes services of the BSC6900.

Position of the Service Processing Subsystem in the BSC6900 System The service processing subsystem mainly consists of two logical modules: BSC control plane (CP) and BSC user plane (UP). Figure 3-12 shows the position of the service processing subsystem in the BSC6900 system, with the modules highlighted in apricot. NOTE

For details about the definitions of CP and UP, see 5 Signal Flow.

Figure 3-12 Service processing subsystem

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Functions The service processing subsystem performs the following functions: l

User data transfer

l

System admission control

l

Radio channel ciphering and deciphering

l

Data integrity protection

l

Mobility management

l

Radio resource management and control

l

Cell broadcast service control

l

System information and user message tracing

l

Data volume reporting

l

Radio access management

l

CS service processing

l

PS service processing

Service processing subsystems communicate with each other through the switching subsystem to form a resource pool and perform tasks cooperatively. They can be increased as required, according to the linear superposition principle, thereby improving the service processing capability of the BSC6900.

Hardware Involved The service processing subsystem consists of the XPUa, XPUb, DPUc, and DPUd boards. The XPUa and XPUb boards process signaling. The DPUc and DPUd boards process services.

3.3 Interface Processing Subsystem The interface processing subsystem provides transmission ports and resources, processes transport network messages, and enables interaction between the BSC6900 internal data and external data.

Position of the Interface Processing Subsystem in the BSC6900 System The interface processing subsystem consists of two types of interfaces: IP interfaces and TDM interfaces. Figure 3-13 and Figure 3-14 show the position of the interface processing subsystem in the BSC6900 system, with the interfaces highlighted in apricot.

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Figure 3-13 Position of the interface processing subsystem in the MPS/EPS

Figure 3-14 Position of the interface processing subsystem in the TCS

Functions l

The interface processing subsystem provides the following types of IP and TDM interfaces. –

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E1/T1 electrical ports Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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3 Overall Structure –

STM-1 optical ports

–

FE/GE electrical ports

–

GE optical ports

l

The interface processing subsystem processes transport network messages and, also hides differences between them within the BSC6900.

l

On the uplink, the interface processing subsystem terminates transport network messages at the interface boards. It also transmits the user plane, control plane, and management plane datagrams to the corresponding service processing boards. The processing of the signal flow on the downlink is the reverse of the processing of the signal flow on the uplink.

Hardware Involved The interface processing subsystem consists of the Abis, A, Ater, Gb, and Pb interface boards.

3.4 Clock Synchronization Subsystem The clock synchronization subsystem provides clock signals for the BSC6900 and provides reference clock signals for base stations.

Position of the Clock Synchronization Subsystem in the BSC6900 System Figure 3-15 shows the position of the clock synchronization subsystem in the BSC6900 system, with the clock module highlighted in apricot. Figure 3-15 Position of the clock synchronization subsystem in the BSC6900 system

Functions The clock synchronization subsystem provides the following clock sources for the BSC6900 and ensures the reliability of the clock signals: 3-12


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3 Overall Structure

l

Building Integrated Timing Supply System (BITS) clock

l

Global Positioning System (GPS) clock

l

External 8 kHz clock

l

LINE clock

The BSC6900 provides reference clock sources for base stations. Clock signals are transmitted from the BSC6900 to base stations over the Abis interface.

Hardware Involved The clock synchronization subsystem consists of the GCUa/GCGa board.

3.5 OM Subsystem The OM subsystem enables the management and maintenance of the BSC6900 in the following scenarios: routine maintenance, emergency maintenance, upgrade, and capacity expansion.

Position of the OM Subsystem in the BSC6900 System Figure 3-16 shows the position of the OM subsystem in the BSC6900 system, with the OM module highlighted in apricot. Figure 3-16 Position of the OM subsystem in the BSC6900 system

Functions The OM subsystem provides: l

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4.4.4 Data Configuration Management Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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3 Overall Structure l

4.4.5 Security Management

l

4.4.6 Performance Management

l

4.4.7 Alarm Management

l

4.4.8 Loading Management

l

4.4.9 Upgrade Management

l

4.4.10 BTS Loading Management

l

4.4.11 BTS Upgrade Management

Hardware Involved The OM subsystem consists of the OMUa board, OMUb board, or GBAM.

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4 Working Principles

4

Working Principles

About This Chapter This chapter describes the working principles of the BSC6900 in the following ways: power supply, environment monitoring, clock synchronization, and OM. 4.1 Power Supply Principle The power supply subsystem of the BSC6900 adopts the dual-circuit design and point-by-point monitoring solution. It consists of the power input part and the power distribution part. 4.2 Environment Monitoring Principle The environment monitoring subsystem of the BSC6900 comprises the power distribution box and the environment monitoring parts in each subrack. This subsystem monitors and controls the power supply, fans, and operating environment. 4.3 Clock Synchronization Principle The clock synchronization subsystem of the BSC6900 consists of the GCUa/GCGa board and the clock processing units of each subrack. It provides clock signals for the BSC6900 and reference clocks for base stations. 4.4 OM Principle OM is performed in the following scenarios: routine maintenance, emergency maintenance, troubleshooting, device upgrade, and capacity expansion. In addition, OM can be performed to rapidly adjust device status.

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4.1 Power Supply Principle The power supply subsystem of the BSC6900 adopts the dual-circuit design and point-by-point monitoring solution. It consists of the power input part and the power distribution part. The power supply subsystem of the BSC6900 consists of the -48 V DC power system, DC power distribution frame (PDF), and DC power distribution box (PDB) at the top of the cabinet. If a site has heavy traffic or more than two switching systems, two or more independent power supply systems should be provided. In the case of a communication center, independent power supply systems should be configured on different floors to supply power to different equipment rooms.

Power Input Part The power input part leads the power from the DC PDF to the PDB in the cabinet. It consists of the DC PDF, PDB, and cables between them. Figure 4-1 shows the power input part of the BSC6900. Figure 4-1 Power input part of the BSC6900

NOTE

The DC PDF and the DC power distribution panel are not regarded as the components of the BSC6900.

The working principle of the power input part is as follows: l

The DC PDF provides each cabinet with dual two-route -48 V DC inputs and one route for PGND connection.

l

Typically, the two power inputs work concurrently. If one power input is faulty, the other power input continues to supply power to the system to ensure stable operation. You can rectify the faulty power input without interrupting the services, thereby ensuring the optimum reliability and availability of the power supply subsystem.

Power Distribution Part The power distribution part distributes power from the PDB to various components in the cabinet. It comprises the PDB, power distribution switches, and various components in the cabinet. 4-2


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The working principle of the power distribution part is as follows: l

The PDB performs lightning protection and overcurrent protection on the dual two-route -48 V DC inputs. Then, it supplies power to all the components in the cabinet.

l

The PDB monitors each input in real time. After the PDB detects abnormal power supply, it reports the relevant alarms to the OMU. The OMU, then, forwards the alarms to the LMT or M2000.

l

The power distribution varies according to the type of cabinet. For details, see Connections of Power Cables and PGND Cables in the Cabinet.

4.2 Environment Monitoring Principle The environment monitoring subsystem of the BSC6900 comprises the power distribution box and the environment monitoring parts in each subrack. This subsystem monitors and controls the power supply, fans, and operating environment. NOTE

The physical entity of the OMU can be the OMUa board, OMUb board, or GBAM. The following takes the OMUa board as an example to describe environment monitoring.

Power Monitoring Power monitoring involves monitoring the power subsystem in real time, reporting the operating status of the power supply, and generating alarms when faults occur. Figure 4-2 shows the working principle of power monitoring. Figure 4-2 Working principle of power monitoring

The power monitoring process is as follows: 1.

The PAMU in the power distribution box monitors the operating status of the power distribution box and sends the monitoring signals to the signal transfer board through the serial port.

2.

The signal transfer board transmits the power monitoring signals to the independent fan subrack at the bottom of the cabinet through the monitoring signal cable of the power

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distribution box. Then, the fan subrack forwards the power monitoring signals to the active SCUa board in the power monitoring subrack. 3.

The SCUa board processes the monitoring signals. If faults occur, the SCUa board generates alarms and reports the alarms to the OMUa board. The OMUa board then forwards the alarms to the LMT or M2000.

Fan Monitoring Fan monitoring involves monitoring the operating status of the fans in real time and adjusting the speed of the fans based on the temperature in the subrack. Each subrack is configured with a built-in fan box. The temperature sensor next to the air outlet can detect the temperature in the subrack. Besides the built-in fan box in the subrack, there is an independent fan subrack at the bottom of the cabinet. This improves the heat dissipation capability of the cabinet. Figure 4-3 shows the working principle of fan monitoring. Figure 4-3 Working principle of fan monitoring

The fan monitoring process is as follows: 1.

The built-in fan box in the subrack and the fan monitoring unit PFCU in the independent fan subrack monitor the operating status of the fans in real time and reports the monitoring signals to the signal transfer board through the serial port.

2.

The signal transfer board transmits the monitoring signals to the active SCUa board.

3.

4-4

l

In the case of built-in fan box in the subrack, the signal transfer board transmits the monitoring signals to the active SCUa board through the backplane of the subrack.

l

In the case of independent fan subrack, the signal transfer board transmits the monitoring signals to the active SCUa board in the fan monitoring subrack through the monitoring signal cable.

The SCUa board processes the monitoring signals. If faults occur, the SCUa board generates alarms and reports them to the OMUa board. The OMUa board then forwards the alarms to the LMT or M2000. Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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Environment Monitoring Environment monitoring involves monitoring the temperature, humidity, operating voltage, door status, water damage, smoke, and infrared. The environment monitoring function is performed by the Environment Monitor Units (EMUs). Figure 4-4 shows the working principle of environment monitoring. Figure 4-4 Working principle of environment monitoring

If the power distribution box can transfer signals, the environment monitoring process is as follows: 1.

The sensors monitor the environment in real time and send the monitoring signals to the EMU.

2.

The EMU sends the monitoring signals to the power distribution box through the serial cable.

3.

The signal transfer board in the power distribution box transmits the monitoring signals to the active SCUa board in the power monitoring subrack through the monitoring signal cable of the power distribution box.

4.

The active SCUa board in the power monitoring subrack transmits the monitoring signals to the SCUa board in the MPS through the Ethernet cables between the SCUa boards.

5.

The SCUa board in the MPS processes the monitoring signals. If faults occur, the SCUa board generates alarms and reports the alarms to the OMUa board. The OMUa board then forwards the alarms to the LMT or M2000.

If the power distribution box cannot transfer signals, the environment monitoring process is as follows: 1.

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The sensors monitor the environment in real time and send the monitoring signals to the EMU. Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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2.

The EMU sends the monitoring signals to the active SCUa board in the lowest subrack through the serial cable.

3.

The active SCUa board in the lowest subrack transmits the monitoring signals to the SCUa board in the MPS through the Ethernet cables between the SCUa boards.

4.

The SCUa board in the MPS processes the monitoring signals. If faults occur, the SCUa board generates alarms and reports the alarms to the OMUa board. The OMUa board then forwards the alarms to the LMT or M2000.

4.3 Clock Synchronization Principle The clock synchronization subsystem of the BSC6900 consists of the GCUa/GCGa board and the clock processing units of each subrack. It provides clock signals for the BSC6900 and reference clocks for base stations. 4.3.1 Clock Sources The BSC6900 can use the following clock sources: Building Integrated Timing Supply System (BITS) clock, external 8 kHz clock, LINE clock, and Global Positioning System (GPS) clock. 4.3.2 Structure of the clock synchronization subsystem The clock synchronization subsystem consists of the clock board, backplanes, clock cables between subracks, and clock module in each board. 4.3.3 Clock Synchronization Process The BSC6900 processes external clock signals before sending them to its boards. The clock synchronization process varies slightly from one subrack to another.

4.3.1 Clock Sources The BSC6900 can use the following clock sources: Building Integrated Timing Supply System (BITS) clock, external 8 kHz clock, LINE clock, and Global Positioning System (GPS) clock.

External Clocks The external clocks of the BSC6900 are of two types: l

l

BITS Clock –

The BITS clock signals are of three types: 2 MHz, 2 Mbit/s, and 1.5 Mbit/s. The 2 MHz and 2 Mbit/s clock signals are E1 clock signals, and the 1.5 Mbit/s clock signals are T1 clock signals.

–

The BITS clock has two input modes: BITS0 and BITS1. BITS0 and BITS1 correspond to the CLKIN0 and CLKIN1 ports on the GCUa/GCGa board respectively. The BSC6900 obtains the BITS clock signals through the CLKIN0 or CLKIN1 port.

External 8 kHz Clock Through the COM1 port on the GCUa/GCGa board, the BSC6900 obtains 8 kHz standard clock signals from an external device.

LINE Clock The LINE clock is an 8 kHz clock that is transmitted from an interface board in the MPS to the GCUa/GCGa board through the backplane channel. The LINE clock has two input modes: LINE0 and LINE1. 4-6


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4 Working Principles NOTE

LINE0 and LINE1 correspond to backplane channel 1 and backplane channel 2 respectively.

GPS Clock The GPS clock provides 1 Pulse Per Second (PPS) clock signals. The BSC6900 obtains the GPS clock signals from the GPS system. The GCGa board is configured with a GPS card, and the BSC6900 receives the GPS signals at the ANT port on the GCGa board. NOTE

The GCUa board is not configured with a GPS card. Therefore, when the BSC6900 is configured with the GCUa board instead of the GCGa board, the GPS clock is unavailable to the BSC6900.

Local Oscillator If the BSC6900 fails to obtain any external clock, the BSC6900 can obtain its working clock signals from the local oscillator.

4.3.2 Structure of the clock synchronization subsystem The clock synchronization subsystem consists of the clock board, backplanes, clock cables between subracks, and clock module in each board. Figure 4-5 shows the structure of the clock synchronization subsystem. Figure 4-5 Structure of the clock synchronization subsystem

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The structure of the BSC6900 clock synchronization subsystem is described as follows: l

The clock board of the BSC6900 can be the GCUa or GCGa board. The BSC6900 cannot be configured with both the GCUa and GCGa boards simultaneously. Depending on the clock type, it can have either the GCUa board or the GCGa board.

l

If the MPS extracts the clock signals, the clock signals enter the MPS in any of the following ways: –

The clock signals enter the port on the panel of the GCUa/GCGa board.

–

The clock signals enter the port on the panel of an interface board that can extract line clock signals. The clock signals are then switched to the GCUa/GCGa board through the backplane.

–

The GCUa/GCGa board generates oscillator clock signals.

l

If the EPS extracts the clock signals, the interface board that extracts clock signals must be the EIUa/OIUa/PEUa board.

l

If the BSC6900 is configured with the Gb interface board, the Gb interface board extracts clock signals either from the backplane or from the CN. The Gb interface board, however, cannot extract clock signals from them simultaneously. If the PS services and CS services use different clock sources and the clock signals are extracted from the CN, the Gb interface board serves only the Gb interface.

Figure 4-6 shows the connections of the clock cables between the clock boards in the MPS and the SCUa boards in the EPS when the BSC6900 is configured with active and standby clock boards and SCUa boards. Figure 4-6 Structure of the clock synchronization subsystem

The active and standby clock boards in the MPS are connected to the active and standby SCUa boards in the EPS through the Y-shaped clock signal cables. This connection mode ensures that 4-8


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the system clock of the BSC6900 works properly in the case of a single-point failure of the clock board, Y-shaped clock signal cable, or SCUa board. In addition, the Y-shaped clock signal cable ensures the proper working of the SCUa boards during the switchover of the active and standby clock boards. NOTE

In the MPS, the clock board sends clock signals to the SCUa board in the same subrack through the backplane channel. Therefore, a Y-shaped clock signal cable is not required.

4.3.3 Clock Synchronization Process The BSC6900 processes external clock signals before sending them to its boards. The clock synchronization process varies slightly from one subrack to another.

Process of Clock Synchronization in the MPS/EPS The clock signals of the MPS/EPS are provided by the clock board. The clock board can extract clock signals from an external device or extract LINE clock signals from the A interface. The GCGa board can extract clock signals from the GPS. l

Figure 4-7 shows the process of clock synchronization in the MPS/EPS when the clock board extracts clock signals from an external device or from the GPS.

l

Figure 4-8 shows the process of clock synchronization in the MPS/EPS when the clock board extracts LINE clock signals from the A interface.

Figure 4-7 Process of clock synchronization in the MPS/EPS (1)

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Figure 4-8 Process of clock synchronization in the MPS/EPS (2)

As shown in Figure 4-7 and Figure 4-8, the process of clock synchronization in the MPS/EPS is as follows: 1.

If an external clock is used, external clock signals travel to the clock board through the port on the panel of the clock board. If the GPS clock is used, clock signals travel to the clock board through the GPS antenna port. If the LINE clock is used, clock signals travel to the clock board through the backplane.

2.

The clock source is phase-locked in the clock board to generate clock signals. The clock signals, then, are sent to the SCUa board in the MPS through the backplane and to the SCUa board in each EPS through the clock signal output ports.

3.

The SCUa board in the MPS/EPS transmits the clock signals to the other boards in the same subrack through the backplane. NOTE

The Abis interface boards transmit the clock signals to the base stations.

Process of Clock Synchronization in the TCS Figure 4-9 shows the process of clock synchronization in the TCS when the TCS extracts LINE clock signals from the A interface. Figure 4-9 Process of clock synchronization in the TCS

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1.

The TCS extracts LINE clock signals from the A interface. Then, the LINE clock signals are processed by the A interface board to obtain the required clock signals.

2.

In the TCS, the A interface board transmits the clock signals to the SCUa board through the backplane. Then, the SCUa board transmits the clock signals to the other boards in the TCS. NOTE

l

In A over IP over Ethernet mode, the BSC6900 can extract only external clock signals.

l

In A over IP over E1/T1 mode, the BSC6900 can extract only LINE clock signals.

4.4 OM Principle OM is performed in the following scenarios: routine maintenance, emergency maintenance, troubleshooting, device upgrade, and capacity expansion. In addition, OM can be performed to rapidly adjust device status. 4.4.1 Dual OM Plane The BSC6900 has a dual OM plane to prevent single-point failure from affecting the normal operation and maintenance. 4.4.2 OM Network The OM network of the BSC6900 consists of the M2000, LMT, OMU, SCUa boards, and OM modules in other boards. 4.4.3 Active/Standby Workspaces This section describes the active/standby workspaces of the OMU and those of the host boards. 4.4.4 Data Configuration Management The data configuration management involves managing the data configuration process of the BSC6900 so that configuration data is properly sent to the related boards in a secure manner. 4.4.5 Security Management The security management ensures the security of user login and helps to identify equipment faults. It involves rights management, log management, and inventory management. 4.4.6 Performance Management The BSC6900 performance management involves collecting, analyzing, and querying performance data. 4.4.7 Alarm Management The alarm management helps you monitor the running status of the BSC6900 and informs you of faults in real time so that you can take proper measures in time. 4.4.8 Loading Management The BSC6900 loading management involves managing the process of loading program and data files onto boards after the boards (or subracks) are started or restarted. 4.4.9 Upgrade Management The upgrade management involves managing the procedures for upgrading the OMU software and patch. 4.4.10 BTS Loading Management The BTS loading management involves managing the process of loading software to the boards in the BTS. Issue 03 (2010-09-20)


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4.4.11 BTS Upgrade Management The BTS upgrade management refers to upgrading the BTS to a later version. You can locally or remotely upgrade multiple BTSs through the OM network.

4.4.1 Dual OM Plane The BSC6900 has a dual OM plane to prevent single-point failure from affecting the normal operation and maintenance. Figure 4-10 shows this dual OM plane design. Figure 4-10 Dual OM plane

NOTE

If the internal network and external network are on different network segments, ensure that the two networks are isolated. The physical entity of the OMU can be the OMUa board, OMUb board, or GBAM. Both the OMUa board and the OMUb board can work in active/standby mode. The following takes the OMUa board as example to describe the dual OM plane.

The dual OM plane design is implemented by the hardware that works in active/standby mode. When an active component is faulty but the standby component works properly, a switchover is automatically performed between the active and standby components, to ensure that the OM channel works properly. The active/standby OMUa boards use the same external virtual IP address to communicate with the LMT or M2000 and use the same internal virtual IP address to communicate with the SCUa board. l

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When the active OMUa board is faulty, an active/standby switchover is performed automatically, and the standby OMUa board takes over the OM task. In this case, the Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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internal and external virtual IP addresses remain unchanged. Thus, the proper communication between the internal and external networks of the BSC6900 is ensured. l

When a single-point failure occurs on the switching network, the active/standby SCUa boards in each subrack are switched over automatically to ensure that the OM channel works properly.

4.4.2 OM Network The OM network of the BSC6900 consists of the M2000, LMT, OMU, SCUa boards, and OM modules in other boards. NOTE

The physical entity of the OMU can be the OMUa board, OMUb board, or GBAM. The following takes the OMUa board as example to describe environment monitoring.

Figure 4-11 shows the structure of the BSC6900 OM network. Figure 4-11 Structure of the OM network

NOTE

Figure 4-11 shows some of the boards in the OM network. The SCUa boards in the EPS/TCS are connected to the SCUa boards in the MPS through crossover cables. The crossover cables transmit OM signals from the MPS to the EPS/TCS. In remote TCS mode, the SCUa boards in the TCS are connected to the SCUa boards in the MPS through the cables between the Ater interface boards. These cables transmit OM signals from the MPS to the TCS.

M2000 The M2000 is a centralized network management system. The M2000 is connected to the BSC6900 through Ethernet cables. One M2000 can remotely manage multiple BSC6900s. Issue 03 (2010-09-20)


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LMT The LMT is connected to the OMUa board of the BSC6900 and works on the Windows XP Professional or Windows Vista operating system. One or more LMTs can be connected to the OMUa board directly or through networks. The maintenance of the BSC6900 can be performed locally or remotely through the LMT. The LMT is connected to an alarm box through a serial cable.

OMUa Board The OMUa board is the back administration module of the BSC6900. It is connected to an external device through the Ethernet cable. The BSC6900 can be configured with one OMUa board in independent mode or with two OMUa boards in active/standby mode. The OMUa board functions as a bridge between the BSC6900 and the LMT/M2000. The OM network of the BSC6900 is classified into the following networks: l

Internal network: implements the communication between the OMUa board and the host boards of the BSC6900.

l

External network: implements the communication between the OMUa board and external devices, such as the LMT or M2000.

SCUa Board The SCUa board is the switching and control board of the BSC6900. It is responsible for the OM of the subrack where it is located. If a subrack is configured with two SCUa boards, then the two boards work in active/standby mode. The SCUa board performs OM on other boards in the same subrack through the backplane channels. The SCUa boards in different subracks are connected through crossover cables.

4.4.3 Active/Standby Workspaces This section describes the active/standby workspaces of the OMU and those of the host boards.

Active/Standby Workspaces of the OMU The active/standby workspaces of the OMU are used for the upgrade and rollback of the BSC6900 versions, thus enabling quick switching between versions.

Concept of the Active/Standby Workspaces of the OMU The active/standby workspaces of the OMU refer to the active/standby workspaces for storing the version files on the OMU. Each workspace is used to store files of different versions. The relation between the active/standby workspaces is relative. The active/standby relation depends on the storage location of the running version. The workspace that stores the running OMU version files is the active workspace, and the other is the standby workspace.

Working Principles of the Active/Standby Workspaces of the OMU The working principles of the OMU active/standby workspaces in the case of the OMU version upgrade are as follows: 4-14


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1.

The standby workspace of the active OMU is upgraded to a new version.

2.

The standby workspace of the standby OMU is upgraded to a new version.

3.

A switchover is performed between the active and standby workspaces of the active OMU. The standby workspace that stores the new version of files becomes active, and the other workspace becomes standby.

4.

The active OMU runs the upgraded version.

5.

A switchover is performed between the active and standby workspaces of the standby OMU to ensure that the versions of the workspaces are consistent with those of the active OMU.

6.

The OMU version upgrade is complete.

After the OMU version upgrade, the standby workspaces of the active and standby OMUs store the files of the old version. In this case, version rollback can be performed as required. The working principles of the OMU active/standby workspaces in the case of version rollback are as follows: 1.

A switchover is performed between the active and standby workspaces of the active OMU. The running version of the active OMU is rolled back to the pre-upgrade version.

2.

The active OMU runs the pre-upgrade version.

3.

A switchover is performed between the active and standby workspaces of the standby OMU to ensure that the versions of the workspaces are consistent with those of the active OMU.

4.

The OMU version rollback is complete.

Relation Between Intra-OMU Active and Standby Workspaces The active and standby workspaces of the OMU are independent of each other. The operation of the active workspace does not change any information in the standby workspace.

Relation Between Inter-OMU Active and Standby Workspaces The active and standby workspaces of the active OMU correspond to the active and standby workspaces of the standby OMU respectively. Between the active and standby OMUs, the files in the active workspaces are automatically synchronized in real time, but those in the standby workspaces need to be synchronized manually.

Relation Between the Active/Standby Workspaces of Host Boards and the Active/ Standby Workspaces of the OMU On the active workspaces of the host boards, files can be loaded only from the active workspace of the OMU. On the standby workspaces of the host boards, files can be loaded only from the standby workspace of the OMU.

Active/Standby Workspaces of Host Boards BSC6900 host boards refer to all the boards except the OMUa board. The active/standby workspaces of host boards are used for file loading, version upgrade, and version rollback.

Concept of the Active/Standby Workspaces of Host Boards The active/standby workspaces of host boards refer to the active/standby workspaces for storing different versions of programs, data, and patch files in the board flash memory. Issue 03 (2010-09-20)


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The relation between the active/standby workspaces is a relative concept. The active/standby relation depends on the running version. The workspace that stores the running version files of a board is the active workspace, and the other is the standby workspace.

Working Principles of the Active/Standby Workspaces of Host Boards Before loading programs and data files, host boards choose the loading mode according to the loading control parameter. For details, see 4.4.8 Loading Management.

Relation Between Intra-Board Active/Standby Workspaces The active and standby workspaces of a host board are independent of each other. The operation of the active workspace does not change any information in the standby workspace.

Relation Between Inter-Board Active/Standby Workspaces The active and standby workspaces of the active board are independent of the active and standby workspaces of another host board. The operation of the active board does not change any information in the standby board.

Relation Between the Active/Standby Workspaces of Host Boards and the Active/ Standby Workspaces of the OMU On the active workspaces of the host boards, files can be loaded only from the active workspace of the OMU. On the standby workspaces of the host boards, files can be loaded only from the standby workspace of the OMU.

4.4.4 Data Configuration Management The data configuration management involves managing the data configuration process of the BSC6900 so that configuration data is properly sent to the related boards in a secure manner.

Data Configuration Modes The BSC6900 supports two data configuration modes: effective mode and ineffective mode.

Effective Mode and ineffective Mode l

Effective mode If data configuration is performed on the BSC6900 in effective mode, then the relevant configuration data takes effect on the host boards in real time.

l

Ineffective mode If data configuration is performed on the BSC6900 in ineffective mode, then the relevant configuration data takes effect only after the BSC6900 is reset or is switched to the effective mode.

Principle of Effective Mode Configuration Effective mode configuration is applied to dynamic modification of the BSC6900 configuration data. Figure 4-12 shows the principle of effective mode configuration. 4-16


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Figure 4-12 Principle of effective mode configuration

The process of effective mode configuration is as follows: 1.

The BSC6900 is switched to effective mode.

2.

The configuration console (LMT or M2000) sends MML commands to the configuration management module of the OMU.

3.

The configuration management module of the OMU sends the configuration data to the database of the related host board and writes the data to the OMU database.

Principle of Ineffective Mode Configuration Ineffective mode configuration is applied to BSC6900 initial configuration. Figure 4-13 shows the principle of ineffective mode configuration. Figure 4-13 Principle of ineffective mode configuration

The process of ineffective mode configuration is as follows: 1.

The BSC6900 is switched to ineffective mode.

2.

The configuration console (LMT or M2000) sends MML commands to the configuration management module of the OMU.

3.

The configuration management module sends only the configuration data to the OMU database.

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4.

When a subrack or the BSC6900 is reset, the OMU formats the configuration data in the database into a .dat file, loads the file onto the related host boards, and then activates the configuration data.

Data Configuration Rollback Data configuration rollback is performed to recover configurations when errors occur. If the modified data configuration fails to reach the expected result or even causes equipment or network failure, you can perform rollback to recover the configurations and to ensure the proper operation of the BSC6900.

WARNING Data configuration rollback cannot be performed when the CM control enable switch is set to ON, when the fast configuration mode is selected, or when batch configuration is performed. Data configuration rollback consists of the following types of operation: l

Undoing a single configuration command After you undo the latest ten commands one by one, the system rolls back to the configuration before each command is executed.

l

Redoing a single configuration command After you redo the latest ten commands one by one, the system rolls back to the configuration after each command is executed.

l

Undoing configuration commands in batches This operation is performed to undo all the configuration commands that were executed after a specified rollback savepoint. After this operation, the system rolls back to the configuration at the specified rollback savepoint.

l

Redoing configuration commands in batches This operation is performed to redo the configurations that were rolled back in batches. After this operation, the system returns to the configuration at the specified rollback savepoint or the configuration after the commands were executed.

Data Configuration Rights Management The data configuration rights management controls the data configuration rights and the number of users that simultaneously perform data configuration on the BSC6900 through the LMT or M2000. This ensures the security of data configuration. The principles of data configuration rights management are as follows: l

The data configuration rights management enables only one user to perform data configuration on the BSC6900 through the LMT or M2000 at a time.

l

The user must have data configuration rights.

With the data configuration rights management, users cannot configure data for the BSC6900 at the same time. 4-18


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Data Configuration Check The data configuration check involves the data validity check and data consistency check. This ensures the normal operation of the BSC6900.

Data Validity Check The data validity check involves checking whether a configuration complies with the configuration rules and whether an MML script file complies with the syntactic rules. When a configuration is performed or an MML command is executed, the data validity check is performed. If there is an error in the configuration, the BSC6900 stops the configuration or the running of the command. At the same time, a warning message is displayed.

Data Consistency Check The data consistency check consists of two parts: l

Check of the data consistency between the active and standby OMUs If the BSC6900 is configured with the active and standby OMUs, the data on the active OMU must be the same as that on the standby OMU, thus ensuring the reliability of the BSC6900. If the active OMU is faulty, the standby OMU takes over the tasks after an active/ standby switchover.

l

Check of the data consistency between the OMU and the host boards The data on the host boards must be the same as that on the OMU. Otherwise, the system cannot run stably. In addition, some data modified by users cannot take effect. Figure 4-14 shows the procedure for the data consistency check. Figure 4-14 Check of the data consistency between the OMU and the host boards

The procedure for checking the data consistency between the OMU and the host boards is as follows: Issue 03 (2010-09-20)


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1.

On the LMT, a data consistency check command is sent to the OMU automatically on a regular basis or manually.

2.

The OMU analyzes the parameters of the command and checks whether the data in the board databases is the same as that in the OMU database.

3.

The OMU generates a result file and sends it to the LMT.

4.4.5 Security Management The security management ensures the security of user login and helps to identify equipment faults. It involves rights management, log management, and inventory management.

Rights Management The rights management is performed to identify a user and define the rights of the user. The BSC6900 supports multi-user operations. It performs hierarchical rights management for users to ensure security. The BSC6900 authorizes users at multiple levels and assigns certain rights to the users at each level. To log in to the LMT of the BSC6900, a user must enter the registered user name and password, through which the BSC6900 identifies the user. l

l

User types –

Local users: refer to the accounts (including the default local account admin) managed by only the BSC6900 LMT. This type of LMT users can log in to the LMT during the BSC6900 installation and during the disconnection from the M2000.

–

Domain users: refer to the accounts that are created, changed, authenticated, and authorized on the M2000. Domain users can manage the BSC6900 after logging in to the LMT or after logging in to the M2000 server through the M2000 client.

User rights Table 4-1 Definitions of the user rights

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Class

Rights

Com mand Grou p

Description

Guest

Guest can only browse data.

G_0

The objects in this command group are used to query system information, such as users, command groups, logs, NTP, EMS, and time zones.

G_2

The objects in this command group are used to query data configurations and consist of the MML commands of the LST type.

G_4

The objects in this command group are used to query alarm information.

G_6

The objects in this command group are used to query performance data, for example, a result file or a task file.


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Class

User

Operator

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Rights

In addition to the rights granted to the Guest, User can perform system OM.

In addition to the rights granted to the User, the Operator can perform data configuration on the equipment.

Com mand Grou p

Description

G_8

The objects in this command group are used to query device information such as device status and consist of the MML commands of the DSP type.

G_13

The objects in this command group are used to query the information about base stations, for example, the attributes and boards of base stations.

G_7

The objects in this command group are used to perform performance management, for example, to activate a performance task file or to upload a performance result file.

G_9

The objects in this command group are used to perform device management, for example, to reset, block, unblock, or switch over a board.

G_10

The objects in this command group are used to trace and monitor the signal flow on the control plane and on the user plane, for example, to query a tracing task or to create/delete/start a tracing task.

G_11

The objects in this command group are used to modify device panels.

G_12

The objects in this command group are used to perform software management, for example, patch management.

G_14

The objects in this command group are used to perform base station management, for example, to manage base station software or to reset a base station.

G_3

The objects in this command group are used to configure data, for example, the data for a new cell.

G_5

The objects in this command group are used to perform alarm management, for example, to clear an alarm or to set the alarm level.


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Class

Rights

Com mand Grou p

Description

Adminis trator

Administrator has the highest operation rights. It can manage all the other users.

G_1

The objects in this command group are used to manage system information, for example, to manage a user, to set the time zone, to set the daylight saving time, or to perform batch configuration.

Custom

The rights of this user are defined by the Administrator.

Log Management Log management records the operation history and saves the related logs about the BSC6900. Thus, it helps analyze and identify faults. Table 4-2 lists the types of logs that are recorded when the BSC6900 is running. Table 4-2 Types of logs Type

Description

Running log

Records the information on the operating status of the system. The information is used to analyze and locate faults.

Operation log

Records the information on operation and maintenance performed by users.

Security log

Records the information on the operations that may affect the system security, for example, the information on the change of user password.

The log management provides the following functions: l

Saving log files You can save the log information to the OMU by setting the log record parameters.

l

Uploading log files You can upload the log files in the OMU to a specified FTP server by setting the uploading parameters.

l

Querying log files You can view the specified log information in the OMU by setting the querying conditions.

l

Extracting the up-to-date logs from the buffer You can obtain the latest log information by saving the logs stored in the buffer to the log file.

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4 Working Principles NOTE

The OMU saves the log information in the buffer. When the log information reaches the specified limit or the current time reaches the log record period, the OMU records the log file.

Inventory Management The inventory management refers to the efficient and centralized management of the primary configuration information about the equipment in the network. By exporting and uploading the inventory information files on the M2000, you can learn the physical and logical configurations of NEs. The inventory management system is deployed on the M2000. It obtains the required inventory information from NEs through the related interfaces. NEs report inventory information to the M2000 in the form of files, which contain the information on the following aspects: l

Equipment

l

Connection

l

Modules

l

Configurations

l

Peer equipment

l

Host version

l

Cabinets

l

Subracks

l

Boards and the Flash electronic labels of the boards

l

Slots

l

Ports

l

Antennas

4.4.6 Performance Management The BSC6900 performance management involves collecting, analyzing, and querying performance data.

Performance Management Process The boards of the BSC6900 collect performance measurement data and periodically report the data to the performance measurement module of the OMU. According to the task file, the performance measurement module reports the measurement data to the M2000 periodically. The OMU stores a maximum of 25 GB performance measurement data generated within the last 14 days. If the data exceeds the time or size, the data on the earliest day is deleted. Figure 4-15 shows the process of collecting performance measurement data periodically by the BSC6900.

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Figure 4-15 Process of collecting performance measurement data periodically

The process of collecting performance measurement data periodically is as follows: 1.

The user registers a performance measurement task and specifies the object, time, and item attributes of the task on the M2000 client.

2.

Based on the performance measurement task, the M2000 server modifies the measurement task file, sends it to the OMU, and issues a command to activate the modified measurement task file.

3.

Based on the modified measurement task file, the OMU requests host boards to collect data according to the new requirements. The OMU receives the measurement results from the host boards and saves them as files.

4.

The OMU notifies the M2000 server of the measurement results and uploads the files into the M2000 server. The M2000 server processes the files and saves them into the database.

5.

Based on the performance measurement task registered by the M2000 client, the M2000 server obtains the relevant results from the database, performs certain calculation on them, and then sends the result to the M2000 client.

Measurement Types Performance measurement objects are of three types: default measurement objects, optional measurement objects, and real-time measurement objects. l

Default measurement objects The BSC6900 automatically measures all objects of this type. The default measurement task file supports three periods: –

Normal measurement period with a default duration of 30 minutes or 60 minutes. A proper measurement period can be selected on the M2000.

–

Short measurement period with a default duration of 5 minutes or 15 minutes. A proper measurement period can be selected on the M2000.

–

Long measurement period with a default duration of 24 hours.

You cannot add objects to or remove objects from the list of default measurement objects on the M2000. l

Optional measurement objects By default, the BSC6900 does not measure the optional measurement objects. The purpose of defining optional measurement objects is to avoid measuring these objects every time because they are of a large quantity. You can add objects to or remove objects from the list of optional measurement objects on the M2000.

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BSC6900 GSM Technical Description l


Real-time measurement objects The BSC6900 measures real-time measurement objects in a short measurement period of one minute. The purpose is to monitor the changes in target KPIs in real time. The M2000 can start or stop real-time measurement tasks. Real-time measurement data is reported to the M2000 through messages.

4.4.7 Alarm Management The alarm management helps you monitor the running status of the BSC6900 and informs you of faults in real time so that you can take proper measures in time.

Alarm Management Function l

Setting the storage capacity and time limit for alarm logs The BSC6900 can store the information of the alarms generated in the latest 90 days and a maximum of 100,000 alarm logs. You can set the storage capacity and time limit as required.

l

Alarm shielding You can shield an alarm by alarm ID. Alternatively, you can shield a specific alarm or all alarms of a BTS, cell, board, port, or DSP by setting alarm shielding conditions, thus reducing the number of reported derivative alarms.

l

Alarm alert When a fault alarm occurs, the BSC6900 can notify you by Email, icon flash, short message, terminal sound, and audible and visual indication of alarm box.

l

Alarm information processing You can browse alarm information in real time, query history alarm information, and handle alarms based on the handling suggestions available on the online help.

Alarm Management Process The alarm management process consists of alarm generation, alarm reporting, alarm handling, and alarm clearance. Figure 4-16 shows the process of alarm management. Figure 4-16 Alarm management process

Each board detects alarms and reports them to the OMU automatically. The OMU then classifies these alarms into different severity levels and sends them to the LMT or the M2000 server. You can view and manage alarm information on the LMT or M2000 client. Issue 03 (2010-09-20)


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The alarm management module of the OMU provides the following functions: l

Alarm storage The alarm management module stores the alarms in the database of the OMU.

l

Alarm processing The alarm management module processes the operation commands from the LMT or M2000 client and then returns the operation results to the LMT or M2000 client. These commands include querying active alarms, querying alarm logs, and modifying alarm configuration items.

l

Alarm triggering If the generation of an alarm triggers another alarm, the alarm management module reports the two alarms to the LMT or M2000 client.

l

Alarm recovery After an alarm is handled, the system automatically clears the alarm. At the same time, the alarm management module clears the alarm information from the LMT or M2000.

Alarm Box The alarm box generates audible and visual alarms. The red, orange, yellow, and green alarm indicators on the alarm box indicate the critical, major, minor, and warning alarms respectively. Different alarm severity levels have different alarm sounds. Figure 4-17 shows the working principle of the alarm box. Figure 4-17 Working principle of the alarm box

The alarm box is connected to the LMT through a serial cable. When an alarm is reported, the LMT forwards it to the alarm box. The alarm box then generates an audible and visual alarm. You can stop alarm sounds, turn off alarm indicators, and reset the alarm box through the LMT.

4.4.8 Loading Management The BSC6900 loading management involves managing the process of loading program and data files onto boards after the boards (or subracks) are started or restarted. NOTE


Principle of Loading The OMUa board and the active SCUa board in each subrack play important roles during the BSC6900 loading process. 4-26


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l

The OMUa board functions as the first-level center of the entire BSC6900 loading management process. The loading and power-on of the OMUa board are independent of other boards. The OMUa board processes the loading control requests of other boards.

l

The active SCUa board functions as the second-level center of the loading management process. If the OMUa board is not in position, the active SCUa board in a subrack processes the loading control requests from the other boards in the same subrack. If the SCUa boards in an extension subrack are not started, the active SCUa board in the main subrack processes the loading control requests from the boards in the extension subrack.

l

The SCUa board in the main TCS functions as the file transfer server during the TCS loading process. If a board in a TCS needs to load files from the OMUa board, the SCUa board in the main TCS downloads the files from the OMUa board and then processes the file download request from the board.

Loading Process The BSC6900 loading process varies according to the configuration mode of subracks and the location of TCS. l

Scenario 1: BM/TC separated and local TCS Figure 4-18 shows the loading process. Figure 4-18 Loading process (1)

–

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If the OMUa board is in effective mode, the loading process is as follows: 1.

After a board is started, it sends a BOOTP request.

2.

After receiving the BOOTP request message from the board, the OMUa board generates a BOOTP response message and sends it to the board. The response Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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–

message contains the loading control parameter, IP address, and version information. 3. After receiving the response message, the board loads the program files and data files according to the loading control parameter. 4. The loading is complete. If the OMUa board is not started or is in ineffective mode, the loading process is as follows: 1. 2.

l

After a board is started, the board sends a BOOTP request. If the board does not receive any response 30 seconds after the request is sent, the SCUa board loads the program files and data files from its flash memory. 3. After the SCUa board in the MPS loads the program files and data files, it processes the BOOTP requests from the other boards in the MPS and from the SCUa boards in the EPS and TCS. 4. After the SCUa board in the EPS or TCS loads the program files and data files, it processes the BOOTP requests from the other boards in the same subrack. 5. After receiving the response messages, the other boards in each subrack load program files and data files from their flash memories. 6. The loading is complete. Scenario 2: BM/TC separated and remote TCS In this scenario, the Ater interface functions as the loading path between the BM and the TC. Figure 4-19 shows the loading process. Figure 4-19 Loading process (2)

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–

–

l


After a board is started, the board sends a BOOTP request.

2.

After receiving the BOOTP request message from the board, the OMUa board generates a BOOTP response message and sends it to the board. The response message contains the loading control parameter, IP address, and version information.

3.

After receiving the BOOTP response message, the board in the MPS or EPS loads the program files and data files according to the loading control parameter.

4.

After the Ater interface board in the MPS loads the program files and data files, it functions as the loading proxy of the Ater interface board in the main TCS and forwards the BOOTP request and response messages.

5.

After the Ater interface board in the main TCS loads the program files and data files, it functions as the loading proxy of the other boards in the TCS and forwards the BOOTP request and response messages.

6.

After receiving the response messages, the other boards in the TCS load program files and data files according to the loading control parameter.

7.

The loading is complete.

If the OMUa board is not started or is in ineffective mode, the loading process is as follows: 1.


2.

If the board does not receive any response 30 seconds after the request is sent, the SCUa board loads the program files and data files from its flash memory.

3.

After the SCUa board in the MPS loads the program files and data files, it processes the BOOTP requests from the other boards in the MPS and from the SCUa board in the EPS.

4.

After the SCUa board in the EPS loads the program files and data files, it processes the BOOTP requests from the other boards in the same subrack.

5.

After receiving the response messages, the other boards in the EPS load program files and data files according to the loading control parameter.

6.

After the Ater interface board in the MPS loads the program files and data files, it functions as the loading proxy of the Ater interface board in the main TCS and forwards the BOOTP request and response messages.

7.

After the Ater interface board in the main TCS loads the program files and data files, it functions as the loading proxy of the other boards in the TCS and forwards the BOOTP request and response messages.

8.

After receiving the response messages, the other boards in the TCS load program files and data files from their flash memories.

9.


Scenario 3: BM/TC combined or A over IP Figure 4-20 shows the loading process.

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Figure 4-20 Loading process (3)

–

–


After a board is started, it broadcasts a BOOTP request.

2.

After receiving the BOOTP request message from the board, the OMUa board generates a BOOTP response message and sends it to the board. The response message contains the loading control parameter, IP address, and version information.

3.

After receiving the response message, the board loads the program files and data files according to the loading control parameter.

4.


If the OMUa board is not started or is in ineffective mode, the loading process is as follows: 1.


2.

If the board does not receive any response 30 seconds after the request is sent, the SCUa board loads the program files and data files from its flash memory.

3.

After the SCUa board in the MPS loads the program files and data files, it processes the BOOTP requests from the other boards in the MPS and from the SCUa board in the EPS.

4.

After the SCUa board in the EPS loads the program files and data files, it processes the BOOTP requests from the other boards in the same subrack.

5.

After receiving the response messages, the other boards in the MPS/EPS load program files and data files from their flash memories.

6.


4.4.9 Upgrade Management The upgrade management involves managing the procedures for upgrading the OMU software and patch.

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Upgrade Scenarios The BSC6900 needs to be upgraded to rectify the existing defects and to support new functions, higher specifications, and later protocol standards. The upgraded version can provide better QoS.

Upgrade Mode You can use the dedicated upgrade tool to upgrade the BSC6900 through the OM network of the BSC6900. See Figure 4-21. Figure 4-21 Upgrade through the OM network

NOTE

The upgrade tool supports the upgrade of multiple BSC6900s in batches.

Upgrade Process The BSC6900 is upgraded remotely by using the dedicated upgrade tool, which consists of the upgrade client and the upgrade server. Figure 4-22 shows the upgrade process. Figure 4-22 Upgrade process

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NOTE

Client PC refers to the PC on which the upgrade client software runs.

1.

The user sends the upgrade version files and the upgrade server program to the specified directories of the active OMU through the network.

2.

The user connects the client PC to the active OMU and then starts the upgrade client on the client PC and the upgrade server on the active OMU to set up the connection between the upgrade client and the upgrade server.

3.

The upgrade server synchronizes the version files of the standby OMU with those of the active OMU.

4.

The user starts the upgrade server on the standby OMU and sets up the connection between the upgrade server on the standby OMU and the upgrade server on the active OMU.

5.

The upgrade server on the active OMU performs health check on the data and files in the active workspace of the active OMU and then backs them up before the upgrade.

6.

The upgrade server of the active OMU upgrades the software in the standby workspace of the active OMU. At the same time, the upgrade server of the standby OMU upgrades the software in the standby workspace of the standby OMU.

7.

The upgrade server of the active OMU upgrades the data in the standby workspace of the active OMU.

8.

The upgrade server of the active OMU issues a command to load the host program, DSP, BOOTROM, and data files in the standby workspace of the active OMU onto the standby workspaces of the host boards so that the standby workspaces of the boards are synchronized with the standby workspace of the active OMU.

9.

The upgrade server of the active OMU issues a command to switch over the active and standby workspaces of the active OMU to upgrade the active OMU.

10. The upgrade server of the active OMU issues a command to reset all the standby boards of the BSC6900. 11. After the reset, all the standby boards of the BSC6900 automatically load the program files and data files from the standby workspaces of their flash memories to upgrade the boards. 12. After the upgrade server of the active OMU detects that all the standby boards are started, it issues a command to reset all the active boards of the BSC6900. 13. When the active boards are being reset, the original standby boards become active. Similarly, after the reset, all the original active boards automatically load the program files and data files from the standby workspaces of their flash memories to upgrade themselves. 14. After the service verification is successful, the upgrade server of the active OMU issues a command to switch over the active and standby workspaces of the standby OMU so as to upgrade the standby OMU. After the switchover, the standby OMU automatically synchronizes with the active OMU. The upgrade is complete.

4.4.10 BTS Loading Management The BTS loading management involves managing the process of loading software to the boards in the BTS. l

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For the BTS connected to an IP Abis interface board, the loading management process is as follows: Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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l


1.

After the BTS is started, it attempts to establish the OML and then broadcasts a DHCP request over the OML.

2.

After receiving the DHCP request, the SCUa board in the subrack, in which the Abis interface board connected to the BTS is located, processes the request and sends a DHCP response to the BTS. Through this response, the SCUa board notifies the BTS of the IP address of the BTS board and the IP address of the OMUa board.

3.

Based on the version number of the BTS, the BSC6900 reads the version configuration file from the corresponding BTS version directory on the hard disk of the OMUa board, obtains the information about the software version numbers of all the BTS boards, and then sends the information to the BTS.

4.

After obtaining the software version numbers, the BTS automatically checks whether the number of the version running on each board is the same as the obtained number. If there is any inconsistency, the BTS requests the BSC6900 to load and activate the version software.

5.

After running the version software, the BTS requests the BSC6900 for configuration data.

6.

The OMUa board obtains the BTS configuration data from its database and sends it to the BTS through messages. Then, the BTS is initialized.

For the BTS connected to a non-IP Abis interface board, the loading management process is as follows: 1.

After the BTS is started, it attempts to establish the OML.

2.

The BSC6900 sends a version check request to the BTS. Then, the BTS reports its version information to the BSC6900.

3.

The BSC6900 checks the BTS version number. If the BTS version does not match the BSC6900 version, the BSC6900 sends a version loading request to the BTS, instructing the BTS boards to obtain and load program files from the OMUa board.

4.

After receiving a loading completion indication message from the BTS, the BSC6900 sends a version activation request to the BTS, instructing the BTS boards to run the new version.

5.

After running the version software, the BTS requests the BSC6900 for configuration data.

6.

The OMUa board obtains the BTS configuration data from its database and sends it to the BTS through messages. Then, the BTS is initialized.

4.4.11 BTS Upgrade Management The BTS upgrade management refers to upgrading the BTS to a later version. You can locally or remotely upgrade multiple BTSs through the OM network. NOTE


The BTS upgrade process is as follows: 1.

Downloading BTS software (1) The LMT or M2000 sends a download request to the OMUa board. (2) The OMUa board responds to the request. The LMT or M2000 downloads the BTS software to the specified directory on the OMUa board through FTP.

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2.

Loading BTS software (1) The LMT or M2000 sends a loading command to the OMUa board. The OMUa board then sends the loading command to the BTS. (2) The BTS responds to the command. The OMUa board and the SCUa board perform the BTS loading management and load the software from the OMUa board to the BTS.

3.

Activating BTS software (1) The LMT or M2000 sends an activation command to the OMUa board. (2) The OMUa board checks the activation command and then forwards it to the BTS. (3) The BTS activates the software. Then, the BTS is reset.

4.

Verifying upgrade result

You should verify services to ensure that the BTS is successfully upgraded.

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5 Signal Flow

5

Signal Flow

About This Chapter The BSC6900 signal flow consists of the user-plane signal flow, control-plane signal flow, and OM signal flow.

Definitions l

User plane User plane refers to the set of logical functions of the BSC6900 that process the service data, including the speech data and packet data.

l

Control plane Control plane refers to the set of logical functions of the BSC6900 that process the control signaling, including the call control signaling and the connection control signaling.

5.1 User-Plane Signal Flow The user plane of the BSC6900 processes the user-plane messages on each interface. 5.2 Control-Plane Signal Flow The control plane of the BSC6900 processes the control-plane messages on each interface. 5.3 OM Signal Flow OM signal flow refers to the messages transmitted between the BSC6900 and the LMT/M2000. The LMT or M2000 maintains and monitors the BSC6900 in real time through the OM signal flow.

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5-1


5 Signal Flow

5.1 User-Plane Signal Flow The user plane of the BSC6900 processes the user-plane messages on each interface. 5.1.1 CBC Signal Flow The data from the CBC-BSC interface to the Abis interface refers to the Cell Broadcast Center (CBC) signal flow. 5.1.2 GSM CS Signal Flow After a CS call is established in the GSM network, the MS and the network communicate with each other through the CS signal flow. The method of processing the GSM CS signal flow varies according to the transmission mode adopted on the Abis and A interfaces and the configuration mode of the BSC6900 subracks. 5.1.3 GSM PS Signal Flow After a PS connection is established in the GSM network, the MS and the network communicate with each other through the PS signal flow. The GSM PS signal flow varies according to the transmission mode adopted on the Abis interface.

5.1.1 CBC Signal Flow The data from the CBC-BSC interface to the Abis interface refers to the Cell Broadcast Center (CBC) signal flow. Figure 5-1 shows the signal flow from the CBC-BSC interface to the Abis interface. Figure 5-1 Signal flow from CBC-BSC to Abis

NOTE

l

The INT in the figure stands for the interface board. You can use different interface boards as required.

l

The boards shown in Figure 5-1 are only examples.

The signal flow is as follows: 1.

5-2

The CBC sends the broadcast data to the XPUa board of the BSC6900 over the CBC-BSC interface. The XPUa board processes the data according to the related protocols and then sends it to the Abis interface board. Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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5 Signal Flow NOTE

If the XPUa board in a subrack cannot process the data, the data is switched by the MPS to the XPUa board in another subrack.

2.

The Abis interface board processes the data and then sends it to the BTS.

3.

The BTS broadcasts the data to the MSs in the cells served by the base station.

5.1.2 GSM CS Signal Flow After a CS call is established in the GSM network, the MS and the network communicate with each other through the CS signal flow. The method of processing the GSM CS signal flow varies according to the transmission mode adopted on the Abis and A interfaces and the configuration mode of the BSC6900 subracks.

Abis over TDM and A over TDM Figure 5-2 shows the CS signal flow in Abis over TDM, Ater over TDM, A over TDM, and BM/TC separated mode. NOTE

l

The Abis, Ater, and A interface boards can be the EIUa/OIUa/POUc board. The boards shown in Figure 5-2, Figure 5-3, and Figure 5-4 are only examples.

l


Figure 5-2 GSM CS signal flow (1)

As shown in Figure 5-2, the CS signal flow on the uplink is as follows: 1.

The uplink CS signals are sent from the BTS to the Abis interface board in the MPS/EPS.

2.

The CS signals are demultiplexed in the Abis interface board. Each CS signal uses a 64 kbit/s timeslot and is transmitted to the Ater interface board through the TNUa board.

3.

The CS signals are multiplexed in the Ater interface board. Each full-rate CS signal uses a 16 kbit/s sub-timeslot, and each half-rate CS signal uses an 8 kbit/s sub-timeslot. The CS signals are then transmitted to the Ater interface board in the TCS over the Ater interface.

4.

The CS signals are demultiplexed in the Ater interface board of the TCS. Each CS signal uses a 64 kbit/s timeslot and is transmitted to the DPUc board through the TNUa board.

5.

The DPUc board performs speech codec and rate adaptation on the CS signals, which are converted into 64 kbit/s PCM signals. The 64 kbit/s PCM signals are transmitted to the A interface board through the TNUa board and then to the MSC over the A interface.

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The downlink flow is the reverse of the uplink flow. Figure 5-3 shows the CS signal flow in Abis over TDM, Ater over IP, A over TDM, and BM/ TC separated mode. Figure 5-3 GSM CS signal flow (2)



2.

The CS signals are demultiplexed in the Abis interface board. Each CS signal uses a 64 kbit/s timeslot and is transmitted to the Ater interface board through the TNUa board, DPUc board, and SCUa board in sequence.

3.


4.


5.


The downlink flow is the reverse of the uplink flow. In the case of BM/TC combined mode, the Ater interface does not exist. Figure 5-4 shows the CS signal flow in Abis over TDM and A over TDM mode. Figure 5-4 GSM CS signal flow (3)

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2.

The CS signals are demultiplexed in the Abis interface board. Each CS signal uses a 64 kbit/s timeslot and is transmitted to the DPUc board through the TNUa board.

3.


The downlink flow is the reverse of the uplink flow.

Abis over IP and A over TDM Figure 5-5 shows the CS signal flow in Abis over IP, Ater over TDM, A over TDM, and BM/ TC separated mode. NOTE

l

The Abis interface board can be the PEUa/FG2a/GOUa/POUc/FG2c/GOUc board, and the Ater and A interface boards can be the EIUa/OIUa/POUc board. The boards shown in Figure 5-5, Figure 5-6, and Figure 5-7 are only examples.

l





2.

The CS signals are transmitted from the Abis interface board to the DPUc board through the SCUa board.

3.

The DPUc board reorders PTRAU frames, eliminates jitter, and converts PTRAU frames into TRAU frames. Then, the TRAU frames are transmitted to the Ater interface board through the TNUa board.

4.

The CS signals are multiplexed in the Ater interface board in the MPS/EPS, and then are transmitted to the Ater interface board in the TCS.

5.


6.


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The downlink flow is the reverse of the uplink flow. Figure 5-6 shows the CS signal flow in Abis over IP, Ater over IP, A over TDM, and BM/TC separated mode. Figure 5-6 GSM CS signal flow (5)



2.

The CS signals are demultiplexed in the Abis interface board. Each CS signal uses a 64 kbit/s timeslot and is transmitted to the Ater interface board through the SCUa board.

3.


4.


5.


The downlink flow is the reverse of the uplink flow. In the case of BM/TC combined mode, the Ater interface does not exist. Figure 5-7 shows the CS signal flow in Abis over IP and A over TDM mode. Figure 5-7 GSM CS signal flow (6)

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2.

The CS signals are transmitted to the DPUc board through the SCUa board.

3.

The DPUc board reorders PTRAU frames, eliminates jitter, and performs speech codec and rate adaptation on the PTRAU frames, which are converted into 64 kbit/s PCM frames.

4.

The PCM frames are transmitted to the A interface board through the TNUa board, and then are transmitted to the MSC over the A interface.


Abis over TDM and A over IP In the case of A over IP, the Ater interface does not exist. Figure 5-8 shows the CS signal flow in Abis over TDM and A over IP transmission mode. NOTE

l

The Abis interface board can be the EIUa/OIUa/POUc board, and the A interface board can be the FG2a/ GOUa/FG2c/GOUc/POUc board. The boards shown in Figure 5-8 are only examples.

l





2.

The CS signals are demultiplexed in the Abis interface board. Each CS signal uses a 64 kbit/s timeslot and is transmitted to the DPUc board through the TNUa board.

3.

The DPUc board converts PTRAU frames into RTP frames, reorders RTP frames, and eliminates jitter.

4.

The SCUa board transmits the CS signals to the A interface board, which then transmits the signals to the MGW over the A interface.


Abis over IP and A over IP In the case of A over IP, the Ater interface does not exist. Figure 5-9 shows the CS signal flow in Abis over IP and A over IP transmission mode. Issue 03 (2010-09-20)


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5 Signal Flow NOTE

l

The Abis interface board can be the PEUa/FG2a/GOUa/POUc/FG2c/GOUc board, and the A interface board can be the FG2a/GOUa/PEUa/FG2c/GOUc/POUc board. The boards shown in Figure 5-9 are only examples.

l





2.

The Abis interface board encapsulates the CS signals in PTRAU frames, which are then transmitted to the DPUc board through the SCUa board.

3.

The DPUc board converts PTRAU frames into RTP frames, reorders RTP frames, and eliminates jitter.

4.

The SCUa board transmits the CS signals to the A interface board, and then the A interface board transmits the signals to the MGW over the A interface.


5.1.3 GSM PS Signal Flow After a PS connection is established in the GSM network, the MS and the network communicate with each other through the PS signal flow. The GSM PS signal flow varies according to the transmission mode adopted on the Abis interface.

Abis over TDM Figure 5-10 shows the PS signal flow in Abis over TDM transmission mode. NOTE

5-8

l

The Abis interface board can be the EIUa/OIUa/POUc board, and the Gb interface board can be the PEUa/ FG2a/POUc/FG2c/GOUc board. The boards shown in Figure 5-10 are only examples.

l



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Figure 5-10 GSM PS signal flow (1)

As shown in Figure 5-10, the PS signal flow on the uplink is as follows: 1.

The packet data is sent from the BTS to the Abis interface board in the MPS/EPS. The data uses one to four 16 kbit/s sub-timeslots on the Abis interface, depending on the modulation and coding scheme, for example, CS1-CS4 or MCS1-MCS9.

2.

The Abis interface board transmits the packet data to the TNUa board, which then transmits the data to the DPUd board.

3.

The DPUd board converts the frame format and then transmits the data to the Gb interface board through the SCUa board.

4.

The Gb interface board processes the packet data according to the IP or FR protocol and then transmits it to the SGSN over the Gb interface.


Abis over IP Figure 5-11 shows the PS signal flow in Abis over IP transmission mode. NOTE

l

The Abis interface board can be the PEUa/FG2a/GOUa/POUc/FG2c/GOUc board, and the Gb interface board can be the PEUa/FG2a/POUc/FG2c/GOUc board. The boards shown in Figure 5-11 are only examples.

l


Figure 5-11 GSM PS signal flow (2)

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As shown in Figure 5-11, the PS signal flow on the uplink is as follows: 1.

The packet data is sent from the BTS to the Abis interface board in the MPS/EPS.

2.

The SCUa board transmits the packet data to the DPUd board.

3.

The DPUd board converts the frame format and then transmits the data to the Gb interface board through the SCUa board.

4.

The Gb interface board processes the packet data according to the IP or FR protocol and then transmits it to the SGSN over the Gb interface.


5.2 Control-Plane Signal Flow The control plane of the BSC6900 processes the control-plane messages on each interface. 5.2.1 Signaling Flow on the A Interface The signaling flow on the A interface refers to the signaling messages transmitted between the BSC6900 and the MGW/MSC. The signaling flow varies according to the transmission mode adopted on the A interface. 5.2.2 Signaling Flow on the Abis Interface The signaling flow on the Abis interface refers to the signaling messages transmitted between the BSC6900 and the base station. The signaling flow varies according to the transmission mode adopted on the Abis interface. 5.2.3 Signaling Flow on the Gb Interface The signaling flow on the Gb interface refers to the signaling messages transmitted between the BSC6900 and the SGSN. 5.2.4 Signaling Flow on the Pb Interface The signaling flow on the Pb interface refers to the signaling messages transmitted between the BSC6900 and the external PCU.

5.2.1 Signaling Flow on the A Interface The signaling flow on the A interface refers to the signaling messages transmitted between the BSC6900 and the MGW/MSC. The signaling flow varies according to the transmission mode adopted on the A interface.

A over TDM In A over TDM mode, the signaling flow on the A interface varies according to the configuration mode of BSC6900 subracks. l

Figure 5-12 shows the signaling flow on the A interface in BM/TC separated mode.

l

Figure 5-13 shows the signaling flow on the A interface in BM/TC combined mode. NOTE

5-10

l

The A interface board can be the EIUa/OIUa/POUc board, and the XPUa/XPUb board processes signaling. The boards shown in Figure 5-12 and Figure 5-13 are only examples.

l



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Figure 5-12 Signaling flow on the A interface in A over TDM mode (BM/TC separated)

As shown in Figure 5-12, the uplink signaling flow on the A interface is as follows: 1.

In the MPS/EPS, the XPUa board processes the signaling according to the MTP3, SCCP, and BSSAP protocols. Then, the signaling is transmitted to the Ater interface board through the SCUa board.

2.

The Ater interface board processes the signaling according to the MTP2 protocol. Then, the signaling is transmitted to the Ater interface board in the TCS.

3.

In the TCS, the Ater interface board transparently transmits the signaling to the TNUa board and then to the A interface board. Then, the signaling is transmitted to the MSC over the A interface.

The downlink flow is the reverse of the uplink flow. Figure 5-13 Signaling flow on the A interface in A over TDM mode (BM/TC combined)


In the MPS/EPS, the XPUa board processes the signaling according to the MTP3, SCCP, and BSSAP protocols. Then, the signaling is transmitted to the A interface board through the SCUa board.

2.

The A interface board processes the signaling according to the MTP2 protocol. Then, the signaling is transmitted to the MSC over the A interface.


A over IP Figure 5-14 shows the signaling flow on the A interface in A over IP mode. Issue 03 (2010-09-20)


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5 Signal Flow NOTE

l

The A interface board can be the FG2a/GOUa/FG2c/GOUc/POUc board, and the XPUa/XPUb board processes signaling. The boards shown in Figure 5-14 are only examples.

l


Figure 5-14 Signaling flow on the A interface in A over IP mode


In the MPS/EPS, the XPUa board processes the signaling according to the BSSAP, SCCP, SCTP, and M3UA protocols. Then, the signaling is transmitted to the A interface board through the SCUa board.

2.

The A interface board processes the signaling according to the IP protocol. Then, the signaling is transmitted to the MSC server through the MGW.


5.2.2 Signaling Flow on the Abis Interface The signaling flow on the Abis interface refers to the signaling messages transmitted between the BSC6900 and the base station. The signaling flow varies according to the transmission mode adopted on the Abis interface.

Abis over TDM Figure 5-16 shows the signaling flow on the Abis interface in Abis over TDM mode. NOTE

5-12

l

The Abis interface board can be the EIUa/OIUa/POUc board, and the XPUa/XPUb board performs signaling processing. The boards shown in Figure 5-15 are only examples.

l



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Figure 5-15 Signaling flow on the Abis interface in Abis over TDM mode

As shown in Figure 5-15, the uplink signaling flow on the Abis interface is as follows: 1.

The signaling from the BTS is transmitted to the Abis interface board in the MPS/EPS over the Abis interface and is then transmitted to the SCUa board.

2.

The SCUa board transmits the signaling to the signaling processing board.


Abis over IP Figure 5-16 shows the signaling flow on the Abis interface in Abis over IP mode. NOTE

l

The Abis interface board can be the FG2a/GOUa/PEUa/FG2c/GOUc/POUc board, and the XPUa/XPUb board performs signaling processing. The boards shown in Figure 5-16 are only examples.

l


Figure 5-16 Signaling flow on the Abis interface in Abis over IP mode

As shown in Figure 5-16, the uplink signaling flow on the Abis interface is as follows: 1.

The signaling from the BTS is transmitted to the Abis interface board in the MPS/EPS over the Abis interface.

2.

The Abis interface board processes the signaling according to the MAC, IP, and UDP protocols. Then, the signaling is transmitted to the signaling processing board through the SCUa board.

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5 Signal Flow

5.2.3 Signaling Flow on the Gb Interface The signaling flow on the Gb interface refers to the signaling messages transmitted between the BSC6900 and the SGSN. Figure 5-17 shows the signaling flow on the Gb interface. NOTE

l

The Gb interface board can be the PEUa/FG2a/POUc/FG2c board, and the XPUa/XPUb board performs signaling processing. The boards shown in Figure 5-17 are only examples.

l


Figure 5-17 Signaling flow on the Gb interface

As shown in Figure 5-17, the uplink signaling flow on the Gb interface is as follows: 1.

In the MPS/EPS, the signaling processing board processes the signaling according to the NS and BSSGP protocols. Then, the signaling is transmitted to the Gb interface board through the SCUa board.

2.

The Gb interface board processes the signaling according to the IP or FR protocol. Then, the signaling is transmitted to the SGSN over the Gb interface.


5.2.4 Signaling Flow on the Pb Interface The signaling flow on the Pb interface refers to the signaling messages transmitted between the BSC6900 and the external PCU. Figure 5-18 shows the signaling flow on the Pb interface. NOTE

5-14

l

The Pb interface board can be the EIUa/OIUa/POUc board, and the XPUa board performs signaling processing. The boards shown in Figure 5-18 are only examples.

l



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Figure 5-18 Signaling flow on the Pb interface

As shown in Figure 5-18, the uplink signaling flow on the Pb interface is as follows: 1.

In the MPS/EPS, the signaling processing board processes the signaling according to the IP and RR protocols. Then, the signaling is transmitted to the Pb interface board through the SCUa board.

2.

The Pb interface board processes the signaling according to the LAPD protocol. Then, the signaling is transmitted to the PCU over the Pb interface.


5.3 OM Signal Flow OM signal flow refers to the messages transmitted between the BSC6900 and the LMT/M2000. The LMT or M2000 maintains and monitors the BSC6900 in real time through the OM signal flow. NOTE


The OM signal flow varies according to the configuration mode of subracks.

Scenario 1: BM/TC Separated Figure 5-19 shows the OM signal flow in the BSC6900 in BM/TC separated mode.

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5 Signal Flow

Figure 5-19 OM signal flow (BM/TC separated)

As shown in Figure 5-19, the OM signal flow in the BSC6900 is as follows: l

l

l

5-16

OM signal flow in the MPS 1.

The OM signal is transmitted from the LMT or M2000 to the OMUa board in the MPS.

2.

After the OM signal is processed by the OMUa board, it is transmitted to the SCUa board through the backplane of the MPS.

3.

The SCUa board then transmits the OM signal to the service boards to be maintained.

OM signal flow in the EPS 1.


2.

After the OM signal is processed by the OMUa board, it is transmitted to the SCUa board through the backplane of the MPS.

3.

The SCUa board in the MPS transmits the OM signal to the SCUa board in the EPS through the Ethernet cable between the SCUa boards.

4.

In the EPS, the SCUa board transmits the OM signal to the service boards to be maintained.

OM signal flow in the TCS 1.


2.

After being processed by the OMUa board, the OM signal is transmitted to the SCUa and Ater interface boards through the backplane of the MPS.

3.

The OM signal is transmitted from the Ater interface board in the MPS to the Ater interface board in the main TCS through the E1/T1 or optical cable between the Ater interface boards. In the main TCS, the OM signal is transmitted from the Ater interface board to the SCUa board through the backplane. Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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4.

In the main TCS, the backplane switches the signal from the SCUa board to the service boards to be maintained. The OM signal is transmitted from the SCUa board in the main TCS to the SCUa board in the extension TCS through the Ethernet cable between the SCUa boards. In the extension TCS, the backplane switches the signal from the SCUa board to the service boards to be maintained.

Scenario 2: BM/TC Combined In BM/TC combined mode, no TCS is configured. Figure 5-20 shows the OM signal flow. Figure 5-20 OM signal flow (BM/TC combined)

As shown in Figure 5-20, the OM signal flow in the BSC6900 is as follows: l

l

OM signal flow in the MPS 1.


2.

After the OM signal is processed by the OMUa board, it is transmitted to the SCUa board in the MPS through the backplane of the MPS.

3.

The SCUa board then transmits the OM signal to the service boards to be maintained.

OM signal flow in the EPS 1.


2.

After the OM signal is processed by the OMUa board, it is transmitted to the SCUa board in the MPS through the backplane of the MPS.

3.

The SCUa board in the MPS transmits the OM signal to the SCUa board in the EPS through the Ethernet cable between the SCUa boards.

4.

In the EPS, the SCUa board transmits the OM signal to the service boards to be maintained.

Scenario 3: A over IP In BM/TC combined mode, no TCS is configured, and the TC function is performed by the media gateway (MGW). The OM signal flow in A over IP mode is the same as that in BM/TC combined mode. Issue 03 (2010-09-20)


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6 Transmission and Networking

6

Transmission and Networking

About This Chapter The transmission and networking between the BSC6900 and other NEs can be classified into the following types: transmission and networking on the A/Gb interface, on the Abis interface, on the Ater interface, and on the Pb interface. 6.1 Transmission and Networking on the A/Gb Interface Multiple transmission and networking modes, including TDM-based networking on the A/Gb interface and IP-based networking on the A/Gb interface, can be adopted between the BSC6900 and the core network (CN). 6.2 Transmission and Networking on the Abis Interface Multiple transmission and networking modes, including TDM-based networking on the Abis interface, and IP-based networking on the Abis interface, can be adopted between the BSC6900 and the base station. 6.3 Transmission and Networking on the Ater Interface When the BSC6900 adopts the BM/TC separated mode, the Ater interface exists. Multiple transmission and networking modes, including TDM-based networking on the Ater interface and IP-based networking on the Ater interface, can be adopted between the BM subrack and the TC subrack. 6.4 Transmission and Networking on the Pb Interface In external PCU configuration mode, TDM transmission can be applied to the Pb interface between the BSC6900 and the PCU.

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6.1 Transmission and Networking on the A/Gb Interface Multiple transmission and networking modes, including TDM-based networking on the A/Gb interface and IP-based networking on the A/Gb interface, can be adopted between the BSC6900 and the core network (CN). 6.1.1 TDM-Based Networking on the A/Gb Interface In TDM-based networking mode, the BSC6900 and the MSC/MGW/SGSN communicate with each other through the SDH/PDH network. 6.1.2 IP-Based Networking on the A/Gb Interface In IP-based networking mode, the BSC6900 and the MSC/MGW/SGSN communicate with each other through the IP network.

6.1.1 TDM-Based Networking on the A/Gb Interface In TDM-based networking mode, the BSC6900 and the MSC/MGW/SGSN communicate with each other through the SDH/PDH network.

Networking on the A Interface In this networking mode, the BSC6900 and the MSC/MGW communicate with each other through the SDH/PDH network. The EIUa/OIUa/POUc of the BSC6900 functions as the A interface board. The EIUa board provides E1/T1 ports, the OIUa board provides channelized STM-1 ports, and the POUc board provides channelized STM-1 ports and OC-3 ports. The following describes the networking modes on the A interface in different TCS configuration modes: l

Figure 6-1 shows the networking on the A interface in local TCS mode.

l

Figure 6-2 shows the networking on the A interface in remote TCS mode.

Figure 6-1 TDM-based networking on the A interface in local TCS mode

Figure 6-2 TDM-based networking on the A interface in remote TCS mode

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Networking on the Gb Interface In this networking mode, the BSC6900 and the SGSN communicate with each other through the FR network. The PEUa/POUc board of the BSC6900 functions as the Gb interface board. The PEUa board provides E1/T1 ports, and the POUc board provides channelized STM-1 ports and OC-3 ports. Figure 6-3 shows the networking on the Gb interface. Figure 6-3 TDM-based networking on the Gb interface

Features of Networking Modes Advantages: The networking is mature, QoS-assured, safe, and reliable. Telecom operators can make full use of the SDH/PDH transmission network resources. Disadvantages: The cost of the TDM networking mode is higher than that of the IP networking mode.

6.1.2 IP-Based Networking on the A/Gb Interface In IP-based networking mode, the BSC6900 and the MSC/MGW/SGSN communicate with each other through the IP network.

IP over E1 Networking In this networking mode, the PEUa/POUc board of the BSC6900 functions as the A interface board. The PEUa board provides E1/T1 ports, and the POUc board provides channelized STM-1 ports and OC-3 ports. Figure 6-4 shows the IP over E1 networking on the A interface. The Gb interface does not support the IP over E1 networking mode. Figure 6-4 IP over E1 networking on the A interface

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IP over Ethernet Networking In this networking mode, the BSC6900 and the CN communicate with each other through the IP network. The FG2a/FG2c board functions as the A/Gb interface board and provides FE/GE electrical ports. The GOUa/GOUc board functions as the A interface board and provides GE optical ports. The GOUc board functions as the Gb interface board and provides GE optical ports. See Figure 6-5. Figure 6-5 IP over Ethernet networking on the A/Gb interface

Features of Networking Modes These networking modes provide large-capacity bandwidth on the A/Gb interface, thus reducing the CAPEX and OPEX.

6.2 Transmission and Networking on the Abis Interface Multiple transmission and networking modes, including TDM-based networking on the Abis interface, and IP-based networking on the Abis interface, can be adopted between the BSC6900 and the base station. 6.2.1 TDM-Based Networking on the Abis Interface In TDM-based networking mode, the BSC6900 and the base station communicate with each other through the SDH/PDH network, and TDM transmission is applied to the Abis interface. 6.2.2 IP-Based Networking on the Abis Interface In IP-based networking mode, the BSC6900 and the base station communicate with each other through the IP/SDH/PDH network, and layer 3 of the protocol stack for the Abis interface uses the IP protocol.

6.2.1 TDM-Based Networking on the Abis Interface In TDM-based networking mode, the BSC6900 and the base station communicate with each other through the SDH/PDH network, and TDM transmission is applied to the Abis interface.

TDM-Based Networking In this networking mode, the EIUa/OIUa/POUc board of the BSC6900 functions as the Abis interface board. The EIUa board provides E1/T1 ports, the OIUa board provides channelized 6-4


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STM-1 ports, and the POUc board provides channelized STM-1 ports and OC-3 ports. Figure 6-6 shows the TDM-based networking on the Abis interface. Figure 6-6 TDM-based networking on the Abis interface


6.2.2 IP-Based Networking on the Abis Interface In IP-based networking mode, the BSC6900 and the base station communicate with each other through the IP/SDH/PDH network, and layer 3 of the protocol stack for the Abis interface uses the IP protocol.

IP over E1 Networking In this networking mode, the BSC6900 and the base station communicate with each other through the SDH/PDH network. The PEUa/POUc board functions as the Abis interface board. The PEUa board provides E1/T1 ports, and the POUc board provides STM-1 ports and OC-3 ports. See Figure 6-7. Figure 6-7 IP over E1 Networking

IP over Ethernet Networking (Layer 2) In this networking mode, the BSC6900 and the base station communicate with each other through the IP network, and the data transmitted between them is processed by the switch according to the data link layer protocol. The FG2a/GOUa/FG2c/GOUc board of the BSC6900 functions as the Abis interface board and provides FE/GE ports. Figure 6-8 shows the IP over Ethernet networking (layer 2). Issue 03 (2010-09-20)


6-5



Figure 6-8 IP over Ethernet networking (layer 2)

IP over Ethernet Networking (Layer 3) In this networking mode, the BSC6900 and the base station communicate with each other through the IP network, and the data transmitted between them is processed by the router according to the IP protocol. The FG2a/GOUa/FG2c/GOUc board of the BSC6900 functions as the Abis interface board and provides FE/GE ports. Figure 6-9 shows the IP over Ethernet networking (layer 3). Figure 6-9 IP over Ethernet networking (layer 3)

Features of Networking Modes Advantages: l

l

IP over E1 Networking –

Telecom operators can make full use of the SDH/PDH transmission network resources.

–

The networking is mature, QoS-assured, safe, and reliable.

IP over Ethernet Networking –

The base station provides large-capacity bandwidth through FE/GE ports, thus facilitating the upgrade and capacity expansion.

–

The transmission network supports the evolution from the GSM TDM network to the IP network.

Disadvantages: l

6-6

IP over E1 Networking Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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This networking mode does not meet the requirements of the evolution from the telecom network to the IP network. l

IP over Ethernet Networking The QoS of the network cannot be guaranteed easily. Therefore, the end-to-end QoS mechanism must be adopted.

6.3 Transmission and Networking on the Ater Interface When the BSC6900 adopts the BM/TC separated mode, the Ater interface exists. Multiple transmission and networking modes, including TDM-based networking on the Ater interface and IP-based networking on the Ater interface, can be adopted between the BM subrack and the TC subrack. 6.3.1 TDM-Based Networking on the Ater Interface In TDM-based networking mode, the BM subrack and the TC subrack communicate with each other through the SDH/PDH network, and TDM transmission is applied to the Ater interface. 6.3.2 IP-Based Networking on the Ater Interface In IP-based networking mode, the BM subrack and the TC subrack communicate with each other through the SDH/PDH network, and IP transmission is applied to the Ater interface.

6.3.1 TDM-Based Networking on the Ater Interface In TDM-based networking mode, the BM subrack and the TC subrack communicate with each other through the SDH/PDH network, and TDM transmission is applied to the Ater interface.

TDM-Based Networking In this networking mode, the EIUa/OIUa/POUc board of the BSC6900 functions as the Ater interface board. The EIUa board provides E1/T1 ports, the OIUa board provides channelized STM-1 ports, and the POUc board provides channelized STM-1 ports and OC-3 ports. Figure 6-10 shows the TDM-based networking on the Ater interface. Figure 6-10 TDM-based networking on the Ater interface

Features of Networking Modes Advantages: The networking is mature, QoS-assured, safe, and reliable. Telecom operators can make full use of the SDH/PDH transmission network resources. Disadvantages: The cost of the TDM networking mode is higher than that of the IP networking mode. Issue 03 (2010-09-20)


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6.3.2 IP-Based Networking on the Ater Interface In IP-based networking mode, the BM subrack and the TC subrack communicate with each other through the SDH/PDH network, and IP transmission is applied to the Ater interface.

IP-Based Networking In this networking mode, the POUc board of the BSC6900 functions as the Ater interface board and provides channelized STM-1 ports and OC-3 ports. Figure 6-11 shows the IP-based networking on the Ater interface. Figure 6-11 IP-based networking on the Ater interface

Features of Networking Modes This networking mode provides large-capacity bandwidth on the Ater interface, thus reducing the CAPEX and OPEX.

6.4 Transmission and Networking on the Pb Interface In external PCU configuration mode, TDM transmission can be applied to the Pb interface between the BSC6900 and the PCU.

TDM-Based Networking In this networking mode, the EIUa/OIUa/POUc board of the BSC6900 functions as the Pb interface board. The EIUa board provides E1/T1 ports, the OIUa board provides channelized STM-1 ports, and the POUc board provides channelized STM-1 ports and OC-3 ports. Figure 6-12 shows the TDM-based networking on the Pb interface. Figure 6-12 TDM-based networking on the Pb interface

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7 Parts Reliability

7

Parts Reliability

About This Chapter The BSC6900 guarantees its operation reliability by means of board redundancy and port redundancy. 7.1 Concepts Related to Parts Reliability The concepts related to parts reliability are board backup, port backup, resource pool, port trunking, and port load sharing. 7.2 Board Redundancy Board redundancy of the BSC6900 is of two types: board backup and resource pool. 7.3 Port Redundancy Port redundancy is of three types: optical port backup, FE/GE port backup, port load sharing, and port trunking.

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7.1 Concepts Related to Parts Reliability The concepts related to parts reliability are board backup, port backup, resource pool, port trunking, and port load sharing. 7.1.1 Backup Backup is a process of synchronization between the active and standby units. In backup mode, two units of the same type work in active/standby mode, with one working as the active unit and the other working as the standby unit. When the active unit is faulty, the active and standby units are switched over, and the standby unit takes over the tasks from the active unit. In this manner, the impact of unit failure on services is minimized. 7.1.2 Resource Pool A resource pool is an operating mode in which the resource nodes with the same characteristics function as a resource pool. The resources in this pool are allocated and managed according to the capabilities and status of each resource node. 7.1.3 Port Trunking Port trunking is a technique based on which multiple physical ports are aggregated into one logical port. This technique helps enhance the reliability of data transmission. 7.1.4 Port Load Sharing Port load sharing is an operating mode in which the data streams that have the same destination are distributed to different physical ports so that the load is shared by these ports.

7.1.1 Backup Backup is a process of synchronization between the active and standby units. In backup mode, two units of the same type work in active/standby mode, with one working as the active unit and the other working as the standby unit. When the active unit is faulty, the active and standby units are switched over, and the standby unit takes over the tasks from the active unit. In this manner, the impact of unit failure on services is minimized.

Backup Types l

Board Backup In board backup mode, two boards work in active/standby mode, with one working as the active board and the other working as the standby board. Services can be processed by either the active board only or both the active and standby boards. If the active board is faulty, the BSC6900 automatically switches over the active and standby boards.

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Port Backup In port backup mode, two ports work in active/standby mode, with one working as the active port and the other working as the standby port. Data is transmitted through either the active port only or both the active and standby ports. If the active port is faulty, the BSC6900 automatically switches over the active and standby ports.

Concepts Related to Backup l

1:1 Backup The active and standby units work simultaneously. The normal operation of the system is ensured as long as one unit works properly.

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1+1 Hot Backup The active and standby units work simultaneously and process the same services, but the standby unit does not output the processing result. When the active unit is faulty, the standby unit takes over the tasks from the active unit.

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1+1 Warm Backup The active and standby units work simultaneously, and the standby unit backs up the necessary signaling and service data of the active unit. When the active and standby units are switched over, services are slightly affected. When the active unit is faulty, the standby unit takes over the tasks from the active unit. NOTE

When the active and standby units working in 1+1 warm backup mode are switched over, the established services may or may not be disrupted. If the established services are not disrupted and the impact on the services is acceptable, the impact on the services in 1+1 warm backup mode is equivalent to that in hot backup mode. l

1+1 Cold Backup The active and standby units work simultaneously, but the standby unit does not back up the necessary signaling and service data of the active unit. When the active and standby units are switched over, the established services are disrupted. When the active unit is faulty, the standby unit takes over the tasks from the active unit.

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N+1 Warm Backup The active and standby N+1 units work simultaneously, with N units being active and one unit being standby. The standby unit backs up the necessary signaling and service data of the active N units. When the active and standby units are switched over, services may be slightly affected. When any active unit is faulty, the standby unit takes over the tasks from this active unit.

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N+1 Cold Backup The active and standby N+1 units work simultaneously, with N units being active and one unit being standby. The standby unit does not back up the signaling and service data of the active N units. When the active and standby units are switched over , the established services are disrupted. When any active unit is faulty, the standby unit takes over the tasks from this active unit. NOTE

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The active and standby XPUa/XPUb boards of the BSC6900 work in 1:1 backup or 1+1 warm backup mode.

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The DPUa/DPUc/DPUd boards of the BSC6900 work in resource pool mode.

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Other active and standby boards of the BSC6900 work in 1+1 warm backup mode.

7.1.2 Resource Pool A resource pool is an operating mode in which the resource nodes with the same characteristics function as a resource pool. The resources in this pool are allocated and managed according to the capabilities and status of each resource node. In resource pool mode, the system allocates resources nodes to the services that access the resource pool and provides proper service resources.

7.1.3 Port Trunking Port trunking is a technique based on which multiple physical ports are aggregated into one logical port. This technique helps enhance the reliability of data transmission. Issue 03 (2010-09-20)


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Port trunking works in trunk groups. Multiple physical links form a trunk group. If a physical link in the trunk group becomes faulty, the data carried on the faulty link is transferred to other links in the trunk group. Thus, the link failure does not disrupt the communication between both ends of the trunk group. The traffic of the trunk group at the most can reach the total traffic on all the physical links in the trunk group. Port trunking helps enhance transmission reliability and increase transmission bandwidth.

7.1.4 Port Load Sharing Port load sharing is an operating mode in which the data streams that have the same destination are distributed to different physical ports so that the load is shared by these ports. Port load sharing is mainly applicable to data transmission. Each of the ports working in load sharing mode has an independent IP address so that each port can receive and transmit data packets. If a port is faulty, the system stops distributing data to the faulty port and transfers the data to other ports.

7.2 Board Redundancy Board redundancy of the BSC6900 is of two types: board backup and resource pool. 7.2.1 Backup of EIUa Boards When two EIUa boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in backup mode. 7.2.2 Backup of OIUa Boards When two OIUa boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in backup mode. 7.2.3 Backup of PEUa Boards When two PEUa boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in backup mode. 7.2.4 Backup of POUc Boards When two POUc boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in board backup mode or port backup mode. 7.2.5 Backup of SCUa Boards The BSC6900 is configured with two SCUa boards in each subrack. The two boards work in backup mode. 7.2.6 Backup of TNUa Boards The BSC6900 is configured with two TNUa boards in some subracks. The two boards work in backup mode. 7.2.7 Backup of FG2a/FG2c Boards When two FG2a/FG2c boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in one of the following two modes: board backup with no port backup and board backup with port backup. 7.2.8 Backup of GCUa/GCGa Boards The BSC6900 is configured with two GCUa/GCGa boards in the MPS. The two boards work in backup mode. 7.2.9 Backup of GOUa/GOUc Boards 7-4


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When two GOUa/GOUc boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in one of the following two modes: board backup with no port backup and board backup with port backup. 7.2.10 Backup of OMUa/OMUb Boards When the BSC6900 is configured with two OMUa/OMUb boards in the MPS, the two boards work in backup mode. 7.2.11 Backup of XPUa/XPUb Boards When two XPUa/XPUb boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in backup mode. 7.2.12 Resource Pool of DPUa/DPUc/DPUd Boards The DPUa/DPUc/DPUd boards of the BSC6900 and the Digital Signal Processors (DSPs) in all the DPUa/DPUc/DPUd boards work in resource pool mode.

7.2.1 Backup of EIUa Boards When two EIUa boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in backup mode. When two EIUa boards are configured to work in backup mode, one EIUa board is active and the other is standby. The standby board synchronizes its data with that on the active board in real time. The backup mode of the EIUa board is configurable when the ADD BRD command is used to add an EIUa board.

Switchover Modes The SWP BRD command can be used to switch over the active and standby EIUa boards.

Prerequisites for Switchover The active and standby EIUa boards can be switched over only when one of the following conditions is fulfilled: l

The active EIUa board is reset, but the standby EIUa board works properly.

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The active EIUa board is faulty, but the standby EIUa board works properly.

Switchover Process When the active and standby EIUa boards are switched over, the active EIUa board becomes standby after being reset, and the other EIUa board becomes active.

Impact of Switchover on the System The switchover between the active and standby EIUa boards slightly affects the TDM transmission but does not disrupt ongoing services.

7.2.2 Backup of OIUa Boards When two OIUa boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in backup mode. Issue 03 (2010-09-20)


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When two OIUa boards are configured to work in backup mode, one OIUa board is active and the other is standby. The standby board synchronizes its data with that on the active board in real time. The backup mode of the OIUa board is configurable when the ADD BRD command is used to add an OIUa board.

Switchover Modes The SWP BRD command can be used to switch over the active and standby OIUa boards.

Prerequisites for Switchover The active and standby OIUa boards can be switched over only when one of the following conditions is fulfilled: l

The active OIUa board is reset, and the standby OIUa board works properly.

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The active OIUa board is faulty, but the standby OIUa board works properly.

Switchover Process When the active and standby OIUa boards are switched over, the active OIUa board becomes standby after being reset, and the other OIUa board becomes active.

Impact of Switchover on the System The switchover between the active and standby OIUa boards slightly affects the TDM transmission but does not disrupt ongoing services.

7.2.3 Backup of PEUa Boards When two PEUa boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in backup mode. When two PEUa boards are configured to work in backup mode, one PEUa board is active and the other is standby. The standby board synchronizes its data with that on the active board in real time. Y-shaped E1/T1 cables are used to connect the active and standby boards to the peer equipment. The E1/T1 ports on only the active board are used to transmit, receive, and process data. The backup mode of the PEUa board is configurable when the ADD BRD command is used to add a PEUa board.

Switchover Modes The SWP BRD command can be used to switch over the active and standby PEUa boards.

Prerequisites for Switchover The active and standby PEUa boards can be switched over only when one of the following conditions is fulfilled:

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The active PEUa board is reset, but the standby PEUa board works properly.

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The active PEUa board is faulty, but the standby PEUa board works properly. Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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Switchover Process When the active and standby PEUa boards are switched over, the active PEUa board becomes standby after being reset, and the other PEUa board becomes active.

Impact of Switchover on the System The switchover between the active and standby PEUa boards slightly affects the data transmission on PPP/MLPPP links but does not disrupt ongoing services.

7.2.4 Backup of POUc Boards When two POUc boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in board backup mode or port backup mode. When two POUc boards are configured to work in board backup mode, one POUc board is active and the other is standby. The standby board synchronizes its data with that on the active board in real time. Port backup adopts the MSP 1:1 or MSP 1+1 backup mode. Services are processed by the board where the active port is located. Active ports may be located on both the active and standby boards because the switchover between the optical ports on the active and standby boards does not affect the active/standby relation between the boards. In that case, both the active and standby boards can process services. For details about the backup of the POUc optical ports, see 7.3.1 Optical Port Backup. The backup mode of the POUc board is configurable when the ADD BRD command is used to add a POUc board. If Backup is set to YES, both the POUc boards and their optical ports work in backup mode. Therefore, the backup mode of the optical ports does not need to be configured again.

Switchover Modes l

Automatic switchover: The active and standby POUc boards perform a switchover automatically.

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Manual switchover: The SWP BRD command can be used to switch over the active and standby POUc boards.

Prerequisites for Switchover The active and standby POUc boards can be switched over only when one of the following conditions is fulfilled: l

The active POUc board is reset, but the standby POUc board works properly.

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The active POUc board is faulty, but the standby POUc board works properly.

Switchover Process When the active and standby POUc boards are switched over, the active POUc board becomes standby after being reset, and the other POUc board becomes active. NOTE

After an active/standby switchover, the BSC6900 determines the active and standby ports according to the MSP protocol strategy.

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Impact of Switchover on the System The switchover between the active and standby POUc boards slightly affects data transmission but does not disrupt ongoing services.

7.2.5 Backup of SCUa Boards The BSC6900 is configured with two SCUa boards in each subrack. The two boards work in backup mode. When two SCUa boards are configured to work in backup mode, one SCUa board is active and the other is standby. The standby board synchronizes its data with that on the active board in real time. The data switched by the SCUa boards consists of the user-plane data and the controlplane data. The user-plane data is processed by the active and standby SCUa boards. The controlplane data is processed by the active SCUa board.

Switchover Modes l

Automatic switchover: The active and standby SCUa boards perform a switchover automatically.

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Manual switchover: The SWP BRD command can be used to switch over the active and standby SCUa boards.

Prerequisites for Switchover The active and standby SCUa boards can be switched over only when one of the following conditions is fulfilled: l

The active SCUa board is reset, but the standby SCUa board works properly.

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The active SCUa board is faulty, but the standby SCUa board works properly.

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The clock source of the active SCUa board is faulty, but that of the standby SCUa board works properly.

Switchover Process When the active and standby SCUa boards are switched over, the active SCUa board becomes standby after being reset, and the other SCUa board becomes active.

Impact of Switchover on the System The switchover between the active and standby SCUa boards does not affect ongoing services.

7.2.6 Backup of TNUa Boards The BSC6900 is configured with two TNUa boards in some subracks. The two boards work in backup mode. When two TNUa boards are configured to work in backup mode, one TNUa board is active and the other is standby. The standby board synchronizes its data with that on the active board in real time.

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Switchover Modes l

Automatic switchover: The active and standby TNUa boards perform a switchover automatically.

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Manual switchover: The SWP BRD command can be used to switch over the active and standby TNUa boards.

Prerequisites for Switchover The active and standby TNUa boards can be switched over only when one of the following conditions is fulfilled: l

The active TNUa board is reset, but the standby TNUa board works properly.

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The active TNUa board is faulty, but the standby TNUa board works properly.

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The clock source of the active TNUa board is faulty, but that of the standby TNUa board works properly.

Switchover Process When the active and standby TNUa boards are switched over, the active TNUa board becomes standby after being reset, and the other TNUa board becomes active.

Impact of Switchover on the System The switchover between the active and standby TNUa boards does not affect ongoing services.

7.2.7 Backup of FG2a/FG2c Boards When two FG2a/FG2c boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in one of the following two modes: board backup with no port backup and board backup with port backup. When two FG2a/FG2c boards are configured to work in board backup mode, one FG2a/FG2c board is active and the other is standby. The standby board synchronizes its data with that on the active board in real time. The backup mode of the FG2a/FG2c board is configurable when the ADD BRD command is used to add an FG2a/FG2c board. If Backup is set to YES, the backup mode of the FG2a/FG2c board is board backup with no port backup. When the FG2a/FG2c boards are configured to work in board backup mode, you can run the ADD ETHREDPORT command to set the backup mode of FE/GE ports. For details about the backup mode of FE/GE ports, see 7.3.2 FE/GE Port Backup.

Switchover Modes l

Automatic switchover: The active and standby FG2a/FG2c boards perform a switchover automatically.

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Manual switchover: The SWP BRD command can be used to switch over the active and standby FG2a/FG2c boards.

Prerequisites for Switchover The active and standby FG2a/FG2c boards can be switched over only when one of the following conditions is fulfilled: Issue 03 (2010-09-20)


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The active FG2a/FG2c board is reset, but the standby FG2a/FG2c board works properly.

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The active FG2a/FG2c board is faulty, but the standby FG2a/FG2c board works properly.

Switchover Process When the active and standby FG2a/FG2c boards are switched over, the active FG2a/FG2c board becomes standby after being reset, and the other FG2a/FG2c board becomes active. NOTE

If the FG2a/FG2c boards work in board backup with port backup mode, after an active/standby switchover, the BSC6900 determines the active and standby ports and defines the port load sharing strategy.

Impact of Switchover on the System l

When the FG2a/FG2c boards work in board backup with no port backup mode, The switchover between the active and standby FG2a/FG2c boards does not affect ongoing services.

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When the FG2a/FG2c boards work in board backup with port backup mode, the switchover between the active and standby FG2a/FG2c boards slightly affects data transmission but does not disrupt ongoing services.

7.2.8 Backup of GCUa/GCGa Boards The BSC6900 is configured with two GCUa/GCGa boards in the MPS. The two boards work in backup mode. When two GCUa/GCGa boards are configured to work in backup mode, one GCUa/GCGa board is active and the other is standby. The active board processes services. The standby board synchronizes its data with the data on the active board in real time.

Switchover Modes l

Automatic switchover: The active and standby GCUa/GCGa boards perform a switchover automatically.

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Manual switchover: The SWP BRD command can be used to switch over the active and standby GCUa/GCGa boards.

Prerequisites for Switchover The active and standby GCUa/GCGa boards can be switched over only when one of the following conditions is fulfilled: l

The active GCUa/GCGa board is reset, but the standby GCUa/GCGa board works properly.

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The active GCUa/GCGa board is faulty, but the standby GCUa/GCGa board works properly.

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The clock source of the active GCUa/GCGa board is faulty, but that of the standby GCUa/ GCGa board works properly. NOTE

The GCGa board supports the GPS clock. If the satellite card in the active GCGa board is faulty but that in the standby GCGa board works properly, the active and standby GCGa boards are switched over.

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Switchover Process When the active and standby GCUa/GCGa boards are switched over, the active GCUa/GCGa board becomes standby after being reset, and the other GCUa/GCGa board becomes active.

Impact of Switchover on the System The switchover between the active and standby GCUa/GCGa boards does not affect ongoing services.

7.2.9 Backup of GOUa/GOUc Boards When two GOUa/GOUc boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in one of the following two modes: board backup with no port backup and board backup with port backup. When two GOUa/GOUc boards are configured to work in board backup mode, one board is active and the other is standby. The standby board synchronizes its data with the data on the active board in real time. The backup mode of the GOUa/GOUc board is configurable when the ADD BRD command is used to add a GOUa/GOUc board. If Backup is set to YES, the backup mode of the GOUa/ GOUc board is board backup with no port backup.

Switchover Modes l

Automatic switchover: The active and standby GOUa/GOUc boards perform a switchover automatically.

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Manual switchover: The SWP BRD command can be used to switch over the active and standby GOUa/GOUc boards.

Prerequisites for Switchover The active and standby GOUa/GOUc boards can be switched over only when one of the following conditions is fulfilled: l

The active GOUa/GOUc board is reset, but the standby GOUa/GOUc board works properly.

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The active GOUa/GOUc board is faulty, but the standby GOUa/GOUc board works properly.

Switchover Process When the active and standby GOUa/GOUc boards are switched over, the active GOUa/GOUc board becomes standby after being reset, and the other GOUa/GOUc board becomes active. NOTE

If the GOUa/GOUc boards work in board backup with port backup mode, the BSC6900 determines the active and standby ports and defines the port load sharing strategy after an active/standby switchover.

Impact of Switchover on the System l

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When the GOUa/GOUc boards work in board backup with no port backup mode, the switchover between the active and standby GOUa/GOUc boards does not affect ongoing services. Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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When the GOUa/GOUc boards work in board backup with port backup mode, the switchover between the active and standby GOUa/GOUc boards slightly affects data transmission but does not disrupt ongoing services.

7.2.10 Backup of OMUa/OMUb Boards When the BSC6900 is configured with two OMUa/OMUb boards in the MPS, the two boards work in backup mode. When the OMUa/OMUb boards are configured to work in backup mode, one OMUa/OMUb board is active and the other is standby. The active board processes services. The standby board synchronizes its data with the data on the active board in real time.

Switchover Modes l

Automatic switchover: The active and standby OMUa/OMUb boards perform a switchover automatically.

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Manual switchover: The SWP OMU command can be used to switch over the active and standby OMUa/OMUb boards.

Prerequisites for Switchover l

The active and standby OMUa/OMUb boards automatically perform a switchover only when one of the following conditions is fulfilled: –

The standby OMUa/OMUb board fails to detect the heartbeat information from the active OMUa/OMUb board for five consecutive minutes.

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The active OMUa/OMUb board fails to detect the virtual IP address for three consecutive minutes, but the standby OMUa/OMUb board works properly.

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Both the active and standby OMUa/OMUb boards work properly for one period, and no switchover occurs during the period. NOTE

By default, the period for automatic switchover between the active and standby OMUa/OMUb boards is 90 days. You can also use the SET ASWPARA command to set the period for automatic switchover. l

Manual switchover can be performed only when the standby OMUa/OMUb board works properly and the state of data synchronization between the active and standby OMUa/ OMUb boards is Data synchronization is successful. NOTE

You can use the DSP OMU command to query the state of data synchronization between the active and standby OMUa/OMUb boards.

Switchover Process When the active and standby OMUa/OMUb boards are switched over, the active OMUa/ OMUb board becomes standby, and the other OMUa/OMUb board becomes active.

Impact of Switchover on the System The switchover between the active and standby OMUa/OMUb boards takes about one minute. The data synchronization after the switchover takes about two minutes. During the switchover, the communication between the operation and maintenance terminal and the host boards is interrupted for about one or two minutes. At that time, you cannot perform operation and 7-12


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maintenance on the BSC6900. The switchover, however, does not affect ongoing services of the BSC6900.

7.2.11 Backup of XPUa/XPUb Boards When two XPUa/XPUb boards are configured in adjacent slots in a subrack of the BSC6900, the two boards can be configured to work in backup mode. When two XPUa/XPUb boards are configured to work in backup mode, one XPUa/XPUb board is active and the other is standby. The active board processes services. The standby board synchronizes its data with that on the active board in real time.

Switchover Modes l

Automatic switchover: The active and standby XPUa/XPUb boards perform a switchover automatically.

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Manual switchover: The SWP BRD command can be used to switch over the active and standby XPUa/XPUb boards.

Prerequisites for Switchover The active and standby XPUa/XPUb boards can be switched over only when one of the following conditions is fulfilled: l

The active XPUa/XPUb board is reset, but the standby XPUa/XPUb board works properly.

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The active XPUa/XPUb board is faulty, but the standby XPUa/XPUb board works properly.

Switchover Process When the active and standby XPUa/XPUb boards are switched over, the active XPUa/XPUb board becomes standby after being reset, and the other XPUa/XPUb board becomes active.

Impact of Switchover on the System The switchover between the active and standby XPUa/XPUb boards does not affect ongoing services.

7.2.12 Resource Pool of DPUa/DPUc/DPUd Boards The DPUa/DPUc/DPUd boards of the BSC6900 and the Digital Signal Processors (DSPs) in all the DPUa/DPUc/DPUd boards work in resource pool mode.

Board Resource Pool All the BSC6900DPUa/DPUc/DPUd boards of the BSC6900 work as a resource pool. The BSC6900 appropriately schedules and allocates resources for services between the boards. Services in a subrack are preferentially processed by DPU boards in the same subrack. If the DPU boards in the subrack are unavailable, the services are allocated to the DPU boards in another subrack.

DSP Resource Pool All the DSPs in the BSC6900DPUa/DPUc/DPUd boards of the BSC6900 work as a resource pool. The status of the DSPs is managed by the Main Processing Unit (MPU) subsystem in the Issue 03 (2010-09-20)


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main control DPUa/DPUc/DPUd board. The MPU subsystem properly schedules and allocates resources for services among the DSPs. The priorities of DSPs to be allocated in descending order are DSPs in the same board, DSPs in the same subrack, and DSPs in different subracks.

7.3 Port Redundancy Port redundancy is of three types: optical port backup, FE/GE port backup, port load sharing, and port trunking. 7.3.1 Optical Port Backup Optical port backup adopts the MSP 1:1 or MSP 1+1 backup mode. 7.3.2 FE/GE Port Backup When the FG2a/GOUa/FG2c/GOUc boards work in active/standby mode, the FE/GE ports on the active and standby boards can be configured to work in port backup mode. 7.3.3 Port Load Sharing The FE/GE ports on the FG2a/GOUa/FG2c/GOUc board of the BSC6900 support load sharing. 7.3.4 Port Trunking The GE ports on the SCUa boards support port trunking.

7.3.1 Optical Port Backup Optical port backup adopts the MSP 1:1 or MSP 1+1 backup mode. In MSP 1:1 backup mode, one optical port is active and the other is standby. Only the active optical port transmits and receives data. In MSP 1+1 backup mode, one optical port is active and the other is standby. Both the active and standby optical ports transmit data, but only the active optical port receives data. The SET MSP command is used to set the attributes of MSP backup.

Switchover Modes l

Automatic switchover: The active and standby optical ports perform a switchover automatically.

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Manual switchover: The SET MSPCMD command can be used to switch over the active and standby optical ports.

Prerequisites for Switchover The active and standby optical ports can be switched over only when one of the following conditions is fulfilled:

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A switchover at the peer end triggers a switchover at the local end.

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The board where the active optical port is located is reset.

l

The active optical port is faulty, but the standby optical port works properly.

l

The active board is faulty, but the standby board works properly.

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The optical transmission device connected to the active optical port is faulty, but the optical transmission device connected to the standby optical port works properly. Huawei Proprietary and Confidential Copyright © Huawei Technologies Co., Ltd.

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Switchover Process When the active and standby optical ports are switched over, the active optical port stops receiving data and becomes standby, and the original standby optical port starts to receive data and becomes active.

Impact of Switchover on the System If the service traffic on the optical ports is heavy, the switchover between the active and standby optical ports slightly affects data transmission but does not disrupt ongoing services.

7.3.2 FE/GE Port Backup When the FG2a/GOUa/FG2c/GOUc boards work in active/standby mode, the FE/GE ports on the active and standby boards can be configured to work in port backup mode. In FE/GE port backup mode, one port is active and the other is standby. The active port transmits and receives data. When the boards work in active/standby mode, you can use the ADD ETHREDPORT command to configure the FE/GE ports on the active and standby boards to work in port backup mode.

Switchover Modes l

Automatic switchover: The active and standby ports on the active and standby FG2a/GOUa/ FG2c/GOUc boards perform a switchover automatically.

l

Manual switchover: The SWP ETHPORT command can be used to switch over the active and standby ports on the FG2a/GOUa/FG2c/GOUc boards.

Prerequisites for Switchover The active and standby ports can be switched over only when one of the following conditions is fulfilled: l

The active port is faulty, but the standby port works properly.

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The active board is faulty, but the standby board works properly.

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The board where the active port is located is reset.

Switchover Process When the active and standby ports are switched over, the active port stops receiving and sending data and becomes standby, and the original standby port starts to receive and send data and becomes active.

Impact of Switchover on the System If the service traffic on the ports is heavy, the switchover between the active and standby ports slightly affects data transmission but does not disrupt ongoing services.

7.3.3 Port Load Sharing The FE/GE ports on the FG2a/GOUa/FG2c/GOUc board of the BSC6900 support load sharing. Issue 03 (2010-09-20)


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7 Parts Reliability

Prerequisites The BSC6900 supports load sharing between FE/GE ports that are located either on the same board or on active and standby boards. NOTE

l

The BSC6900 does not support load sharing between the FE/GE ports on non-active/standby boards.

l

The BSC6900 does not support load sharing between active and standby ports.

Working Principles Load sharing between FE/GE ports is based on the user type. That is the data of a type of user is carried on one FE/GE port, and that of another type of user is carried on another FE/GE port. NOTE

The data of one user is transmitted through only one FE/GE port.

Application Scenario When the FE/GE ports of the BSC6900 work in load sharing mode, the data towards the same IP address may be transmitted through different ports, and thus different IP routes must be configured. For example, load sharing between two FE/GE ports requires two IP routes. The IP routes must have the same destination IP address, subnet mask, and priority, but different nexthop IP addresses. NOTE

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The ADD IPRT command can be used to add an IP route.

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The BSC6900 supports load sharing between a maximum of three FE/GE ports.

Benefits l

Data traffic is shared by the ports to avoid the condition where some ports are busy whereas others are idle.

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Load sharing enhances the reliability of data transmission.

7.3.4 Port Trunking The GE ports on the SCUa boards support port trunking.

Application of Port Trunking in the BSC6900 Port trunking is applicable to the switching subsystem of the BSC6900. l

In the same subrack, the ports serving the communication between the SCUa and the other boards work as a trunk group to implement port trunking.

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The ports serving the communication between the SCUa boards in different subracks work as a trunk group to implement port trunking.

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In a trunk group, the bandwidth is evenly allocated to the GE ports, thus fulfilling load balancing.

Benefits

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l

If a GE link in a trunk group is faulty, the data stream on the link is automatically switched to other GE links.

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If an SCUa or another service board is faulty, no associated switchover occurs.

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BSC6900 GSM Technical Description

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