3900 Series GSM Base Station Technical Description(V100R013_03)(PDF)-En

8/10/2019 3900 Series GSM Base Station Technical Description(V100R013_03)(PDF)-En

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3900 Series GSM Base Station

V100R013

Technical Description

Issue 03

Date 2011-08-30

HUAWEI TECHNOLOGIES CO., LTD.


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Copyright Huawei Technologies Co., Ltd. 2011. All rights reserved.

No part of this document may be reproduced or transmitted in any form or by any means without prior writtenconsent 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 thecustomer. 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 representationsof any kind, either express or implied.

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

Huawei Technologies Co., Ltd. Address: Huawei Industrial Base

Bantian, LonggangShenzhen 518129People's Republic of China

Website: http://www.huawei.com

Email: [email protected]

Issue 03 (2011-08-30) Huawei Proprietary and ConfidentialCopyright Huawei Technologies Co., Ltd.

i
http://www.huawei.com/


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About This Document

OverviewThis document provides information about 3900 series GSM base stations such as system

principles, operation and maintenance, clock synchronization schemes, and surge protectionspecifications, aiming to enable operators to comprehensively understand functions of the 3900series GSM base stations.

Product VersionThe following table lists product versions involved in this document.

Product Name Product Version

BTS3900 GSM (BTS3900 for short) V100R013

BTS3900A GSM (BTS3900A for short) V100R013

BTS3900L GSM (BTS3900L for short) V100R013

DBS3900 GSM (DBS3900 for short) V100R013

Intended AudienceThis document is intended for:

l Network plannersl Field engineersl System engineers

Organization1 Changes in the 3900 Series GSM Base Station Technical Description

3900 Series GSM Base StationTechnical Description About This Document


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This section describes changes in the 3900 Series GSM Base Station Technical Description of each version.

2 Overview

3900 series base stations adopt the cutting-edge modular design for different modes and aremanaged by various systems. With simple components, they can be installed and deployed easilyand fast. With comprehensive functions and remarkable performance, they can meetrequirements in various scenarios. In addition, they are diversified by flexibly combiningfunctional modules and auxiliary devices.

3 BTS System Principle

The BTS consists of the BBU3900 (BBU for short), RF modules, and the antenna system. Itsfunctional subsystem includes the control system, transport system, monitoring system, RFsystem, antenna system, and power supply system.

4 Control and Transport Systems

The functions of the control and transport systems are provided by the BBU. The control systemmanages the entire BTS system in a centralized manner, including signaling processing,operation and maintenance, and system clock. The transport system provides physical portsconnecting the BTS and the transport network.

5 RF System

The functions of the RF system are provided by RF modules including the radio frequency units(RFUs) that are used in macro base stations and remote radio units (RRUs) that are used indistributed base stations. The RF system performs modulation, demodulation, data processing,and combinat ion and division of RF and base band signals.

6 Antenna System

The antenna system consists of antennas, feeders, jumpers, the Tower Mounted Amplifier (TMA), the Bias Tee (BT), and the GSM Antenna and TMA Control Module (GATM). Ittransmits and receives RF signal s.

7 Operation and Maintenance

Operation and Maintenance (OM) covers management, monitoring, and maintenance of thesoftware, hardware, and configuration of the BTSs. In addition, diversified OM modes are

provided in various scenarios.

8 External Reference Clock Sources

The BTS supports multiple external reference clock sources, including the IP reference clock,E1/T1 reference clock, synchronous Ethernet reference clock, BITS reference clock, and GPS/RGPS reference clock. If a BTS fails to obtain clock signals, it works in free-run mode for acertain period of time.

9 Surge Protection Specifications

This section provides surge protection specifications for the BBU, RF modules, and each typeof base stations.

ConventionsSymbol Conventions

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



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Symbol Description

Indicates a hazard with a high level of risk, which if notavoided, will result in death or serious injury.

Indicates a hazard with a medium or low level of risk, whichif not avoided, could result in minor or moderate injury.

Indicates a potentially hazardous situation, which if notavoided, could result in equipment damage, data loss,

performance degradation, or unexpected results.

Indicates a tip that may help you solve a problem or savetime.

Provides additional information to emphasize or supplementimportant points of the main text.

General Conventions

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

Convention Description

Times New Roman Normal paragraphs are in Times New Roman.

Boldface Names of files, directories, folders, and users are inboldface . For example, log in as user root .

Italic Book titles are in italics .

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

Command Conventions

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


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 byvertical bars. One item is selected.

[ x | y | ... ] Optional items are grouped in brackets and separated byvertical bars. One item is selected or no item is selected.



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{ x | y | ... } * Optional items are grouped in braces and separated byvertical bars. A minimum of one item or a maximum of allitems can be selected.

[ x | y | ... ] * Optional items are grouped in brackets and separated byvertical 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.


Boldface Buttons, menus, parameters, tabs, window, and dialog titlesare 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.

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 meansthe two keys should be pressed in turn.

Mouse Operations

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

Action Description

Click Select and release the primary mouse button without movingthe pointer.

Double-click Press the primary mouse button twice continuously andquickly 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

About This Document.....................................................................................................................ii

1 Changes in the 3900 Series GSM Base Station Technical Description...............................1

2 Overview.........................................................................................................................................4

3 BTS System Principle...................................................................................................................8

4 Control and Transport Systems................................................................................................104.1 Logical St ructure of the BBU...........................................................................................................................11

4.2 BB U Transmission Ports..................................................................................................................................12

4.3 Transport Network Topologies.........................................................................................................................13

5 RF Syste m......................................................................................................................................185.1 Logical St ructure of the RRU...........................................................................................................................19

5.2 Logical St ructure of the RFU...........................................................................................................................22

5.3 CPRI-Bas ed Topologies...................................................................................................................................245.4 RRU3004 Configuration...................................................................................................................................28

5.5 Configura tions of RRU3008, RRU3908, RRU3928, and the MRFUd............................................................33

5.6 DRFU Co nfiguration........................................................................................................................................40

5.7 Configura tions of the GRFU/MRFU/MRFUe..................................................................................................49

6 Antenna System...........................................................................................................................56

7 Operation and Maintenance......................................................................................................587.1 OM Modes of the BTS.....................................................................................................................................59

7.2 OM Functions of the BTS................................................................................................................................59

8 External Reference Clock Sources............................................................................................62

9 Surge Protection Specifications................................................................................................64

3900 Series GSM Base StationTechnical Description Contents


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1 Changes in the 3900 Series GSM Base StationTechnical Description

This section describes changes in the 3900 Series GSM Base Station Technical Description of each version.

03 (2011-08-30)

This is issue 03.

Compared wit h issue 02 (2011-06-25), this i ssue does not include any new topics.

Compared wit h issue 0 2 (2011-06-25), this issue incorporates the following changes:

Topic Description

5.7 Configurations of the GRFU/MRFU/MRFUe

Information about the MRFU V3 is added.

5.3 CPRI-Based Topologies Information about the MRFU V3 is added.

9 Surge Protection Specifications Information about the MRFU V3 is added.

VER.B of the cabinet is added.

Compared with issue 02 (2011-06-25), this issue does not exclude any topics.

02 (2011-06-25)

This is issue 02.

Compared with issue 01 (2011-04-30), this issue includes the following new topic:

l Configurations of RRU3008, RRU3908, RRU3928, RRU3929, and the MRFUdl 5.7 Configurations of the GRFU/MRFU/MRFUe

Compared with issue 01 (2011-04-30), this issue incorporates the following changes:

3900 Series GSM Base StationTechnical Description

1 Changes in the 3900 Series GSM Base Station TechnicalDescription


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Topic Description

5.1 Logical Structure of the RRU Information about the RRU3929 is added.

5.2 Logical Structure of the RFU Information about the MRFUe is added.

5.3 CPRI-Based Topologies Information about the RRU3929, MRFUe isadded.

9 Surge Protection Specifications Surge protection specifications for the portson the RRU3929, MRFUe are added.

Compared with issue 01 (2011-04-30), this issue excludes the following topic:

l Configura tions of RRU3008, RRU3908, RR U3928, GRFU, MRFU, and the MRFUd

01 (2011-04-30)This is issue 01.

Compared with issue 07 (2011-03-30) of V100R012, this issue includes the following newtopics:

l 2 Overviewl 3 BTS System Principlel 4.2 BBU Transmission Portsl 5.2 Logical S tructure of the RF Ul 5.5 Configur ations of RRU3008, RRU3908, RRU3928, and th e MRFUdl 5.7 Configurations of the GRFU/MRFU/MRFUel 6 Antenna S ysteml 7 Operation and Maintenance

Compared with iss ue 07 (2011-03-30) of V 100R012, this issue incorporates the followingchanges:

Topic Description

5.1 Logical Structure of the RRU Information about the RRU3908 and

RRU3928 is added.5.3 CPRI-Based Topologies Information about the MRFU, MRFUd,

RRU3908, and RRU3928 is added.

9 Surge Protection Specifications Surge protection specifications for the portson the BTS3900 (Ver.C), BTS3900L(Ver.C), BTS3900A (Ver.C), MRFU,MRFUd, RRU3908, and RRU3928 areadded.

Compared with issue 07 (2011-03-30) of V100R012, this issue excludes the following topics:




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l DBS3900 Product Familyl System Architecture of the BTS3900l System Architecture of the BTS3900Al System Architecture of the BTS3900Ll Software Structure of the BTSl Logical Structure of the BTS3900l Logical Structure of the BTS3900Ll Logical Structure of the BTS3900Al DBS3900 Monitoring Schemesl BTS3900 Monitoring Systeml BTS3900A Monitoring Systeml BTS3900L Monitoring Systeml Signal Flow of the BTS3900/BTS3900Al Signal Flow of the BTS3900Ll Configuration of the BTS3900/BTS3900Al Configuration of the BTS3900Ll CPRI Cable Connections of the RRUsl RRU3008 Configurationl Typical Scenarios of the DBS3900 (with the DC RRU)l Typical Scenarios of the DBS3900 (with the AC RRU)




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Figure 2-1 BSS architecture

BTS Types

There are four types of BTSs, that is, BTS3900, BTS3900A, BTS3900L, and DBS3900, meetingrequirements in various scenarios, as shown in Table 2-1 .

Table 2-1 BTS types

Nam

e

Type Usage Scenario Input

Power

Cabinet

Combination

Reference

BTS3900

Indoor macro

basestation

Indoor installationscenarios wheretraffic load isheavy, lease cost of equipment room ishigh, or equipmentroom is space-limited.

l -48 VDC

l +24 VDC

l 220 VAC

l 110 VAC

l Single cabinetl Double

cabinets: Twocabinets areinstalled side

by side or twocabinets arestacked.

For informationabout usagescenarios andconfigurations of cabinets, see

BTS3900(Ver.B) Hardware Description and BTS3900(Ver.C) Hardware

Description .

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Name

Type Usage Scenario InputPower

CabinetCombination

Reference

BTS3900A

Outdoor macro

basestation

Outdoor installationscenarios wherewide coverage isrequired such ascities, suburbs, or rural areas.

l -48 VDC

l 220 VAC

l 110 VAC

l TMC11H +RFC

l APM30H +RFC (+IBBS+ TMC11H)

APM30H is a power cabinet,the RFC is a radiofrequencycabinet,TMC11H is atransmissioncabinet, and theIBBS is a batterycabinet. For informationabout usagescenarios and

configurations of cabinets, see BTS3900A(Ver.B)

Hardware Description and BTS3900A(Ver.C)

Hardware Description .

BTS

3900L

Indoo

r macro basestation

Indoor installation

scenarios withlarge capacitywhere traffic loadis heavy, lease costof equipment roomis high, or equipment room isspace-limited.

-48 V DC Single cabinet For information

about usagescenarios andconfigurations of cabinets, see

BTS3900(Ver.B) Hardware Description and BTS3900(Ver.C) Hardware Description .



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Name

Type Usage Scenario InputPower

CabinetCombination

Reference

DBS3900

Distri buted basestation

Outdoor installationscenarios wheresite deployment isdifficult and widecoverage isrequired.

l -48 VDC

l +24 VDC

l 220 VAC

l BBU +APM30H +RRU

l BBU +TMC11H +RRU

l BBU + 19-inch rack +RRU

l Indoor wall-mounted BBU+ RRU

l BBU + OMB+ RRU

l BBU + ICR +RRU

l BBU + IMB03+ RRU

APM30H is a power cabinet,TMC11H is atransmissioncabinet, theOMB is anoutdoor mini

box, the ICR is anindoor centralized rack,and IMB03 is anindoor mini box.For information

about usagescenarios andconfigurations of cabinets, see

DBS3900(Ver.B) InstallationGuide , DBS3900(Ver.C)

InstallationGuide and

DBS3900 (ICR) Installation

Guide .



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3 BTS System PrincipleThe BTS consists of the BBU3900 (BBU for short), RF modules, and the antenna system. Itsfunctional subsystem includes the control system, transport system, monitoring system, RFsystem, antenna system, and power supply system.

Figure 3-1 shows the BTS system principle.

Figure 3-1 BTS system principle

Functions of each system are as follows:

l Control system: Managing the entire BTS system in a centralized manner, includingoperation and maintenance, signaling processing, and system clock. For details, see section4 Control and Transport Systems .

l

Transport system: Providing physical ports connecting the BTS and the transport network and also provides maintenance channels connecting the BTS and the Operation and

3900 Series GSM Base StationTechnical Description 3 BTS System Principle


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Maintenance Center (OMC) to enable information exchange between the BTS and thetransport network or OMC. For details, see section 4 Control and Transport Systems .

l Monitoring system: Collecting external alarm information and reporting the informationto the control system. For details, see chapter Monitoring System in the Hardware

Description of the corresponding base station type.l RF system: Processing RF and baseband signals. For details, see section 5 RF System .l Antenna system: Receiving uplink signals and transmitting downlink signals. For details,

see section 6 Antenna System .l Power supply system: Obtaining power from external power supply devices and providing

power for other subsystems of the BTS. For details, see chapter Power System in the Hardware Description of the corresponding base station type.

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4 Control and Transport SystemsAbout This Chapter

The functions of the control and transport systems are provided by the BBU. The control systemmanages the entire BTS system in a centralized manner, including signaling processing,operation and maintenance, and system clock. The transport system provides physical portsconnecting the BTS and the transport network.

4.1 Logical S tructure of the BBUThe BBU con sists of the main processing unit, BTS interface unit, high-speed interface unit,clock unit, an d monitoring unit.

4.2 BBU Tra nsmission PortsThe GTMU o r UTRP board provides transmission ports to enable information exchange betweenthe BTS and the transport network.

4.3 Transport Network TopologiesTransport net work topologies include TDM, IP, and High level Data Link Control (HDLC)network topo logies. In reality, these topologies are combined to save transmission device costswithout deter iorating service quality.

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4.1 Logical Structure of the BBUThe BBU consists of the main processing unit, BTS interface unit, high-speed interface unit,clock unit, and monitoring unit.

Figure 4-1 shows the logical structure of the BBU.

Figure 4-1 Logical structure of the BBU

The control system consists of the main processing unit while the transport system consists of the BTS interface unit and high-speed interface unit.

Main Processing Unit

The main processing unit manages the entire BTS system in a centralized manner, includingoperation and maintenance, signaling processing, and system clock. It provides the followingfunctions:

l Supports such protocols as UART, HDLC, and IP over FE.l Controls the BTS interface unit to enable communication between the BBU and the BSC.l Controls the High-speed interface unit to enable communication between the BBU and RF

modules.l Provides system clock for the BTS and obtains external clock signals.

BTS Interface Unit

The BTS interface unit enables information exchange between the BTS and the transport network by providing the following functions:

l Connects the BTS with the BSC.l Exchang es data bet ween the E1 link and the DBUS.



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l Synchronizes an upper-level clock with a lower-level clock.

High-Speed Interface Unit

The high-speed interface unit enables information exchange between the BBU and RF modules by providing the following functions:

l Receives the uplink baseband data from RF modules.l Transmits the downlink baseband data to RF modules.

Clock Unit

The clock unit provides the following functions:

l Provides system clock stemmed from high-precision clock sources for the BTS.

l Checks the phase-locked status, provides phase lock for the software, adjusts DA, andgenerates frame numbers.

Monitoring Unit

The monitoring unit collects external alarms and reports the alarms to the central processingunit.

4.2 BBU Transmission PortsThe GTMU or UTRP board provides transmission ports to enable information exchange betweenthe BTS and the transpo rt network.

Table 4-1 provides the specifications of transmission ports on the GTMU and UTRP boards.

Table 4-1 Specifications of transmission ports on the GTMU and UTRP boards

TransmissionMode

Board Port Capacity

TDM over E1/T1 GTMU/GTMUb 1 4 ports

UTRPb4 1 4 ports

IP over E1/T1 GTMU/GTMUb 1 4 ports

Transmission over FE optical ports

GTMU/GTMUb 1 10 Mbit/s or 100Mbit/s

Transmission over FE electrical ports

GTMU/GTMUb 1 10 Mbit/s or 100Mbit/s

NOTE

The GTMU or GTMUb board is a mandatory board while the UTRPb4 board must be configured only whenmore than four E1s/T1s are required.



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4.3 Transport Network TopologiesTransport network topologies include TDM, IP, and High level Data Link Control (HDLC)network topologies. In reality, these topologies are combined to save transmission device costswithout deteriorating service quality.

TDM Network Topology

E1/T1 transmission is adopted for communication between the BTS and the BSC while TDMtransmission is adopted on the Abis interface. TDM network topology includes such network topologies as chain, star, tree, and ring, as shown in Figure 4-2 .



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Figure 4-2 TDM network topology

Table 4-2 describes usage scenarios and advantages of the preceding four topologies.



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Table 4-2 Usage scenarios and advantages of the four topologies

Topology Usage Scenario Advantage

Star A wild range of areas,

especially densely populatedareas

l Networking is simple.

l Engineering is easy.l Maintenance is easy.l Network capacity expansion is easy.l Transmission reliability is high.

Chain Strip areas that are sparsely populated such as areas alonghighways and railways

This topology helps reduce expenditureon transmission device, engineering,and leased transmission cables.

Tree Areas where network architecture, site distribution,

and subscriber distributionare complicated such as anarea where large-scalecoverage overlaps with hotspot areas or small-scalecoverage.

Compared with the star topology, thistopology requires fewer transmission

cables.

Ring A wild range of areas.Because of its self-healingcapability, this topology isrecommended when a route isavailable.

A ring topology can automatically splitinto two chains if transmission isdisrupted at a breakpoint and basestations before and after the breakpointcan still function properly. This

improves the system robustness. Asshown in Figure 4-3 , transmission isdisrupted at B. Before disruption, BTSs0, 1, and 2 are connected in a clockwisedirection, forming a ring topology. After disruption, transmission is normal atBTS 0 and BTSs 1 and 2 form a chaintopology with BTS 2 being the upper-level base station.

Figure 4-3 Re-established topology after transmission is disrupted on a ring topology



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IP Network TopologyFE transmission is adopted for communication between the BTS and the BSC while IPtransmission is adopted on the Abis interface. IP network topology includes layer 2 and layer 3network topologies, as shown in Figure 4-4 .

Figure 4-4 IP network topology

HDLC Network TopologyE1/T1 transmission is adopted for communication between the BTS and the BSC while HDLCtransmission is adopted on the Abis interface. HDLC network topology includes such network topologies as chain, star, and ring, as shown in Figure 4-5 .



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Figure 4-5 HDLC network topology



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5 RF SystemAbout This Chap ter

The functions of the RF system are provided by RF modules including the radio frequency units(RFUs) that a re used in macro base stations and remote radio units (RRUs) that are used indistributed ba se stations. The RF system performs modulation, demodulation, data pro cessing,and combination and division of RF and baseband signals.

5.1 Logical S tructure of the RRURRUs include RRU3004, RRU3008, RRU3908, RRU3928, and RRU3929.

5.2 Logical S tructure of the RFUThe RFU incl udes the DRFU, GRFU, MR FU V1, MRFU V2, MRFUd, MRFUe and MRFU V3.

5.3 CPRI-Ba sed TopologiesMultiple CPR I-based topologies such as chain, star, and ring are supported for communication

between BBUs and radio frequency (RF) modules.

5.4 RRU3004 ConfigurationRRU3004 is a double-transceiver remote radio unit and supports two carriers. Differentconfigurations must be chosen in different topologies.

5.5 Configurations of RRU3008, RRU3908, RRU3928, and the MRFUdRRU3008, RRU3908, and RRU3928 are multi-carrier remote radio units. Each of them supportseight carriers. The MRFUd is a multi-carrier radio frequency (RF) module and supports eightcarriers. Different configurations must be chosen in different topologies.

5.6 DRFU ConfigurationThe DRFU is a double-transceiver module and supports two carriers. Different configurationsmust be chosen in different topologies.

5.7 Configurations of the GRFU/MRFU/MRFUeThe GRFU, MRFU V1, MRFU V2, MRFUe, and MRFU V3 are multi-carrier radio frequency(RF) modules. A GRFU or MRFU V1 or MRFU V2 or MRFU V3 supports six carriers, and anMRFUe supports eight carriers. Different configurations must be chosen in different topologies.

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5.1 Logical Structure of the RRURRUs include RRU3004, RRU3008, RRU3908, RRU3928, and RRU3929.

RRU3004 consists of a high-speed interface unit, signal processing unit, power amplifier (PA),low noise amplifier (LNA), and dual duplexer. Figure 5-1 shows the logic structure of RRU3004.

Figure 5-1 Logical structure of RRU3004

RXM_OUT: It is a main receive output port and is usedfor RRU interconnecting.

RXD_IN: It is a receive diversity input port and is usedfor RRU interconnecting.

RRU3008 consists of a main control and high-speed interface unit, signal processing unit, PA,LNA, RX, and dual duplexer. Figure 5-2 shows the logic structure of RRU3008.



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Figure 5-2 Logical structure of RRU3008

RXM_OUT: It is a main receive output port and is usedfor RRU interconnecting.

RXD_IN: It is a receive diversity input port and is usedfor RRU interconnecting.

RRU3908, RRU3928, or RRU3929 consists of a high-speed interface unit, signal processingunit, PA, LNA, and duplexer. Figure 5-3 shows the logic structures of RRU3908, RRU3928,and RRU3929.

Figure 5-3 Logical structures of RRU3908, RRU3928, and RRU3929

High-Speed Interface Unit

The high-speed interface unit mainly provides the following functions:



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l Receives data from an upper-level device, such as the BBU.l Sends data to an upper-level device, such as the BBU.l Transfers data transmitted from cascaded RRUs by using CPRI ports.

Main Control and High-Speed Interface Unit

The main control and high-speed interface unit mainly provides the following functions:

l Receives data from an upper-level device, such as the BBU.l Sends data to an upper-level device, such as the BBU.l Transfers data transmitted from cascaded RRUs by using CPRI ports.l Initializes RRU configurations and loads RRU software.l Collects alarms and reports board status.l Executes configuration commands sent from the BBU and manages configurations of an

RRU's other units.l Operates and maintains RRUs.

Signal Processing Unit

The signal processing unit consists of an uplink receive channel, a downlink transmit channel,and a control module. Moreover, it mainly processes radio frequency (RF) and GSM basebandsignals.

An uplink receive channel mainly provides the following functions:l Converts received signals into intermediate frequency analog signals by performing down-

conversion.l Converts intermediate frequency analog signals into digital signals by using an Analog

Digit Converter (ADC).l Processes intermediate frequency digital signals.l Matches filtering.l Provides the Digital Automatic Gain Control (DAGC) function.l Packs data.

A downlink transmit channel mainly provides the following functions:l Separates packed signals that are transmitted from the BBU including clock signals, control

signals, and data signals. Then, transmits them to specified units.l Combines and filters multiple routes of downlink signals.l Converts digital signals into analog signals by using a Digit Analog Converter (DAC).

Then, performs the Inphase and Quadrature (IQ) modulation.l Converts RF signals into signals that can be transmitted in transmit frequency bands by

performing up-conversion.

A control module mainly provides the following functions:

l Initializes RRU configurations and loads RRU software.l Collects alarms and reports board status.l

Executes configuration commands sent from the BBU and manages configurations of anRRU's other units.



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l Operates and maintains RRUs.

PA

A PA's major function is to amplify power of multi-carrier and low-power radio frequency (RF)signals that are sent from the signal processing unit.

LNA

The LNA performs low noise amplification on signals received by antennas.

RX

The RX's major function is to convert signals sent from the LNA into intermediate frequencyanalog signals by performing down-conversion. Then, it amplifies the intermediate frequencyanalog signals. Finally, it sends the signals to the ADC.

Duplexer

The duplexer and the dual duplexer mainly provide the following functions:

l Filters transmitted or received signals.l Multiplexes transmitted and received signals on RF channels. By doing this, signals are

transmitted or received using the same antenna channel.

5.2 Logical Structure of the RFUThe RFU includes the DRFU, GRFU, MRFU V1, MRFU V2, MRFUd, MRFUe and MRFU V3.

The RFU consists of a high-speed interface unit, signaling processing unit, power amplifier (PA),low noise amplifier (LNA), and duplexer. Figure 5-4 shows the logical structure of the DRFU.Figure 5-5 shows the logical structure of the MRFUd. Figure 5-6 shows the logical structuresof the GRFU, MRFU V1, MRFU V2, MRFUe and MRFU V3.

Figure 5-4 Logical structure of the DRFU



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Figure 5-5 Logical structure of the MRFUd

Figure 5-6 Logical structures of the GRFU, MRFU, MRFUe and MRFU V3

High-Speed Interface UnitThe high-speed interface unit mainly provides the following functions:l Adapts signals sent from the BBU for the signaling processing unit.l Adapts signals sent from the signaling processing unit for the BBU.



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Signal Processing UnitThe signaling processing unit consists of two uplink receive channels and one downlink transmitchannel.

An uplink receive channel mainly provides the following functions:l Converts received high frequency analog signals into intermediate frequency analog signals

by performing down-conversion.l Amplifies intermediate frequency analog signals and performs the Inphase and Quadrature

(IQ) modulation.l Converts analog signals into digital signals by using an Analog Digit Converter (ADC).l Samples digital signals.l Matches filtering.l Provides the Digital Automatic Gain Control (DAGC) function.l Seals frames.

A downlink transmit channel mainly provides the following functions:l Processes signals that are transmitted from the BBU including clock signals, control signals,

and data signals. Then, transmit them to specified units.l Shapes and filters the downlink signals.l Converts digital signals into analog signals by using a Digit Analog Converter (DAC).

Then, performs the Inphase and Quadrature (IQ) modulation.l Converts radio frequency (RF) signals into signals that can be transmitted in transmit

frequency bands by performing up-conversion.

PAThe PA amplifies low-power RF signals that are sent from the signaling processing unit.

LNAThe LNA's major function is to perform low noise amplification on signals received by antennas.

DuplexerThe duplexer mainly provides the following functions:

l Multiplexes transmitted and received signals on RF channels.l Enables signals to be transmitted or received using the same antenna channel.l Filters transmitted or received signals.

5.3 CPRI-Based TopologiesMultiple CPRI-based topologies such as chain, star, and ring are supported for communication

between BBUs and radio frequency (RF) modules.

Topologies

Figure 5-7 shows CPRI-based topologies supported for communication between BBUs and RFmodules. The DRFU, GRFU support the chain and star topologies. The RRU3004 and RRU3008



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support the chain, star, and ring topologies. The MRFU V1, MRFU V2, MRFUd, MRFUe,MRFU V3, RRU3908, RRU3928, and RRU3929 support the star topology.

Figure 5-7 CPRI-based topologies

NOTE

RXU in the preceding figure indicates an RFU or RRU.

Table 5-1 describes characteristics of the three topologies in the preceding figure.



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Table 5-1 Characteristics of the three topologies

Topology

Advantage Disadvantage Remarks

Chain The transmissionequipment cost is low.

l The number of cascading levels in achain and the cascadingdistance are restricted.

l Faults in an upper-levelRF module may affectlower-level RFmodules.

l This topology isapplicable toscenarios wherecapacity is large.

l RFUs and RRUscannot be cascaded.

Star l Installation andmaintenance are easy.

l Transmissionreliability is high.When an RF module or optical cable is faulty,only one sector isaffected.

Compared with other topologies, this topologyrequires large numbers of

optical cables.

This topology isapplicable to scenarioswhere capacity is small.

Ring Transmission reliability isguaranteed.

l The number of cascading levels in achain and the cascadingdistance are restricted.

l Faults in an upper-level

RRU may affect lower-level RRUs.

l Only RRUs can beused in the ringtopology.

l The ring topology isimplemented by

adding a redundantchain to a chaintopology.

Based on the distance between a BBU and an RRU, CPRI networking is classified into short-distance remote networking and long-distance remote networking.

l For the short-distance remote networking, the longest distance between an RRU and a BBUon a CPRI chain does not exceed 100 m.

l For the long-distance remote networking, the longest distance between an RRU and a BBU

on a CPRI chain ranges from 100 m to 40,000 m.

Different CPRI optical cables are used in the two types of networking. For details, see chapter CPRI Optical Cable in the BBU3900 Hardware Description .

CPRI SpecificationsTable 5-2 lists the specifications of CPRI ports on the GSM Transmission, Timing, andManagement Unit for BBU (GTMU).



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Table 5-2 Specifications of CPRI ports on the GTMU board

Board Numberof CPRIPorts

Data Rate Topology Number ofSupported TRXs

GTMU 6 1.25 Gbit/s Star, chain, or ring 36

GTMUb 6 1.25/2.5Gbit/s

Star, chain, or ring 36

Table 5-3 lists the specifications of CPRI ports on different RF modules.

Table 5-3 Specifications of CPRI ports on different RF modules

RFModules

Number ofCPRIPorts

Data Rate Topology Number ofSupportedCarriers

Cascading Levels

MaximumDistancefromtheBBU

DRFU 2 1.25 Gbit/s Star or chain 2 3 levels N/A

GRFU 2 1.25 Gbit/s Star or chain 6 2 levels N/A

RRU3004

2 1.25 Gbit/s Star, chain, or ring

2 6 levels 40

RRU3008

2 1.25 Gbit/s Star, chain, or ring

8 6 levels 40

MRFUV1

2 1.25 Gbit/s Star 6 N/A N/A

MRFUV2

2 1.25/2.5Gbit/s

Star 6 N/A N/A

MRFUV3

2 1.25/2.5Gbit/s

Star 6 N/A N/A

MRFUd 2 1.25/2.5Gbit/s

Star 8 N/A N/A

MRFUe 2 1.25/2.5Gbit/s

Star 8 N/A N/A

RRU3908 V1

2 1.25 Gbit/s Star 6 N/A 40

RRU3908 V2

2 1.25/2.5Gbit/s

Star 8 N/A 40



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RFModules

Number ofCPRIPorts

Data Rate Topology Number ofSupportedCarriers

Cascading Levels

MaximumDistance

fromtheBBU

RRU3928

2 1.25/2.5Gbit/s

Star 8 N/A 40

RRU3929

2 1.25/2.5Gbit/s

Star 8 N/A 40

5.4 RRU3004 ConfigurationRRU3004 is a double-transceiver remote radio unit and supports two carriers. Differentconfigurations must be chosen in different topologies.

Port

Table 5-4 describes major ports on RRU3004.

Table 5-4 Major ports on RRU3004

Type Silkscreen DescriptionPort for transceiving RFsignals

ANT_TX/RXA andANT_TX/RXB

The two ports, each of which is usedto transmit and receive RF signals,connect to the antenna systemthrough antenna channel 1 andantenna channel 2 respectively.

CPRI port TX RX CPRI_W The port is a westbound optical/electrical port and it is used to connectto the BBU or an upper-level RRU.

TX RX CPRI_E The port is an eastbound optical/

electrical port and it is used to connectto a lower-level RRU.

Interconnection port for receiving RF signals

RX_IN/OUT The port is used to transmit andreceive the diversity signals receivedthrough an antenna channel.

Basic Configurations

Table 5-5 lists the basic configurations of an RRU3004 serving only one sector.

The format of the description of the basic configuration is RF[F][TX][RX]_[C][TYPE]. Where,



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l F indicates the number of antenna channels for an RF module.l TX indicates the number of transmit channels for an RF module.l RX indicates the number of receive channels for an RF module.l C indicates the number of CPRI links connecting RF modules with the GTMU board.l TYPE indicates the CPRI network topologies applied to connect RF modules with the BBU.

If the value of TYPE is A, the star topology is applied. If the value of TYPE is B, the chaintopology is applied.

Table 5-5 Basic configurations

BasicConfiguration

Number ofModules

Sending Receiving Mode

HardwareConfiguration

RF111_1A 1 Single feeder [1TX 1RX]

Figure 5-8

RF211_1A 1 Double feeder [1TX 1RX]

Figure 5-9


Figure 5-10


Figure 5-11

RF112_2B 2 Single feeder [1TX 2RX]

Figure 5-12

RF111_1A

An RRU3004 connects to the antenna system through ANT_TX/RXA. Antenna channel 1transmits and receives signals. The star topology is applied to connect the BBU with theRRU3004.



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Figure 5-8 RF111_1A

RF211_1A

An RRU3004 connects to the antenna system through ANT_TX/RXA and ANT_TX/RXB.Antenna channel 1 transmits signals while antenna channel 2 receives signals. The star topologyis applied to connect the BBU with the RRU3004.

Figure 5-9 RF211_1A



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RF212_1AAn RRU3004 connects to the antenna system through ANT_TX/RXA and ANT_TX/RXB.Antenna channel 1 transmits and receives signals while antenna channel 2 receives signals only.The star topology is applied to connect the BBU with the RRU3004.

Figure 5-10 RF212_1A

RF222_1A

An RRU3004 connects to the antenna system through ANT_TX/RXA and ANT_TX/RXB. Bothantenna channel 1 and antenna channel 2 transmit and receive signals. The star topology isapplied to connect the BBU with the RRU3004.



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RF112_2B

Two RRU3004 connect to the antenna system through ANT_TX/RXA. Antenna channel 1transmits and receives signals. RX_IN/OUT on the two RRU3004 interconnect to transfer diversity signals. The chain topology is applied to connect the BBU with one RRU3004.

Figure 5-12 RF112_2B



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Typical Configurations

Table 5-6 describes the typical configurations of RRU3004 in different scenarios.

Table 5-6 Typical configurations

Scenario

Number ofModules

Send Mode Typical Configuration

S1 1 Transmit diversity RF222_1A

Independent transmit l RF111_1Al RF212_1Al RF222_1A

S2 1 Independent transmit or combination

l RF111_1Al RF212_1Al RF222_1A

2 PBT RF112_2B


RF112_2B


l RF112_2Bl RF111_1A + RF111_1A

5.5 Configurations of RRU3008, RRU3908, RRU3928, and theMRFUd

RRU3008, RRU3908, and RRU3928 are multi-carrier remote radio units. E ach of them supportseight carriers. The MRFUd is a multi-carrier radio frequency (RF) module and suppo rts eightcarriers. Different configurations must be chosen in different topologies.

Port

Table 5-7 describes major ports on RRU3008 V1.

Table 5-7 Major ports on RRU3008 V1

Type Silkscreen Description

RF port ANT_TX/RXA andANT_TX/RXB




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CPRI port TX RX CPRI_W The port is a westbound optical/electrical port and it is used to connectto the BBU or an upper-level RRU.

TX RX CPRI_E The port is an eastbound optical/electrical port and it is used to connectto a lower-level RRU.



Table 5-8 describes major ports on RRU3008 V2 and RRU3908 V2.

Table 5-8 Major ports on RRU3008 V2 and RRU3908 V2




CPRI port RX TX CPRI0 The port is used to connect to the

BBU or an upper-level RRU.

TX RX CPRI1 The port is used to connect to theBBU or a lower-level RRU.



Table 5-9 describes major ports on RRU3908 V1.

Table 5-9 Major ports on RRU3908 V1


RF port ANT-A and ANT-B The two ports, each of which is usedto transmit and receive RF signals,connect to the antenna systemthrough antenna channel 1 andantenna channel 2 respectively.

CPRI port TX RX CPRI_W The port is a westbound optical/electrical port and it is used to connectto the BBU.



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TX RX CPRI_E The port is an eastbound optical/electrical port and it is used to connectto the BBU.



Table 5-10 describes major ports on RRU3928.

Table 5-10 Major ports on RRU3928

Type Silkscreen DescriptionRF port ANT_TX/RXA and

ANT_TX/RXBThe two ports, each of which is usedto transmit and receive RF signals,connect to the antenna systemthrough antenna channel 1 andantenna channel 2 respectively.

CPRI port CPRI0 The port is optical/electrical port 0and it is used to connect to the BBU.

CPRI1 The port is optical/electrical port 1and it is used to connect to the BBU.



Table 5-11 describes major ports on the MRFUd.

Table 5-11 Major ports on the MRFUd




CPRI port CPRI0 The port is used to connect to theBBU.

CPRI1 The port is used to connect to theBBU.



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RX_INB The port is used to receive diversitysignals from an antenna channel.

RX_OUTA The port is used to transmit diversitysignals to an antenna channel.


The basic configurations of RRU3008, RRU3908, RRU3928, and the MRFUd are the same. Thefollowing description takes RRU3008 V2 as an example. Table 5-12 lists the basicconfigurations of a single sector.

The basic configurations are described in the "RF[F][TX][RX]_[C][TYPE]" fo rmat. Where ,


If the value of TYPE is A, the star topology is applied. If the value of TYP E is B, the ch aintopology is applied.

Table 5-12 Basic configurationsBasicConfiguration

Number ofModules




Figure 5-13

RF112_2B 2 Single feeder [1TX 2RX]

Figure 5-14


Figure 5-15


Figure 5-16


Figure 5-17

RF111_1A

An RRU3008 connects to the antenna system through ANT_TX/RXA. Antenna channel 1

transmits and receives signals. The star topology is applied to connect the BBU with theRRU3008.



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RF112_2B

Two RRU3008 connect to the antenna system through ANT_TX/RXA. Each antenna channel1 transmits and receives signals. RX_IN/OUT on the two RRU3008 interconnect to transfer diversity signals. The chain topology is applied to connect the BBU with one RRU3008.

Figure 5-14 RF112_2B



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RF211_1AAn RRU3008 connects to the antenna system through ANT_TX/RXA and ANT_TX/RXB.Antenna channel 1 transmits signals while antenna channel 2 receives signals. The star topologyis applied to connect the BBU with the RRU3008.


RF212_1A

An RRU3008 connects to the antenna system through ANT_TX/RXA and ANT_TX/RXB.Antenna channel 1 transmits and receives signals while antenna channel 2 receives signals only.The star topology is applied to connect the BBU with the RRU3008.



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RF222_1A

An RRU3008 connects to the antenna system through ANT_TX/RXA and ANT_TX/RXB. Eachantenna channel transmits and receives signals. The star topology is applied to connect the BBUwith the RRU3008.




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Table 5-13 describes the typical configurations of RRU3008 in different scenarios.


Scenario Number ofModules


S3-S8 1 Independent transmit RF212_1A

Transmit diversity RF222_1A

S8-S12 2 Combined transmit RF112_2B

Independent transmit RF222_1A + RF222_1A

5.6 DRFU ConfigurationThe DRFU is a double-transceiver module and supports two carriers. Different configurationsmust be chosen in different topologies.

Port

Table 5-14 describes major ports on the DRFU.

Table 5-14 Major ports on the DRFU


Port for transceiving RFsignals

ANT1 and ANT2 The two ports, each of which is usedto transmit and receive RF signals,connect to the antenna systemthrough antenna channel 1 andantenna channel 2 respectively.

CPRI port CPRI0 The port is used to connect to a lower-

level DRFU.

CPRI1 The port is used to connect to theBBU or an upper-level DRFU.


RX1/IN and RX1/OUT RX1/IN is the diversity receive portfor antenna channel 1 while RX1/OUT is the diversity transmit port for antenna channel 1.

RX2/IN and RX2/OUT RX2/IN is the diversity receive portfor antenna channel 2 while RX2/OUT is the diversity transmit port for antenna channel 2.



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Table 5-15 lists the basic configurations of a DRFU serving only one sector.

The format of the description of the basic configuration is RF[F][TX][RX]_[C][TYPE]. Where,




BasicConfiguration

Number ofModules




Figure 5-18


Figure 5-19

RF212_1A 1 Double feeder

[1TX 2RX]

Figure 5-20


Figure 5-21


Figure 5-22


Figure 5-23

RF111_1A

A DRFU connects to the antenna system through ANT1. Antenna channel 1 transmits andreceives signals.



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RF211_1AA DRFU connects to the antenna system through ANT1 and ANT2. Antenna channel 1 transmitssignals while antenna channel 2 receives signals.



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RF212_1AA DRFU connects to the antenna system through ANT1 and ANT2. Antenna channel 1 transmitsand receives signals while antenna channel 2 receives signals only.



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RF222_1AA DRFU connects to the antenna system through ANT1 and ANT2. Both antenna channel 1 andantenna channel 2 transmit and receive signals.



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RF112_2A

Two DRFUs connect to the antenna system through ANT1. Antenna channel 1 transmits andreceives signals. RX1/IN on one DRFU interconnects with RX1/OUT on the other DRFU totransfer the diversity signals received through antenna channel 1.



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RF224_2ATwo DRFUs connect to the antenna system through their own ports ANT1 and ANT2. Bothantenna channel 1 and antenna channel 2 transmit and receive signals. RX1/IN on one DRFUinterconnects with RX1/OUT on the other DRFU to transfer the diversity signals receivedthrough antenna channel 1. RX2/IN on one DRFU interconnects with RX2/OUT on the other DRFU to transfer the diversity signals received through antenna channel 2.



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Typical ConfigurationsTable 5-16 describes the typical configurations of the DRFU in different scenarios.




S1 1 Transmit diversity RF222_1A

Independent transmit or combination




2 PBT RF112_2A



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Transmit diversity l RF222_1A + RF222_1A

l RF224_2A (the receive modeis four-way receive diversity)


RF112_2A


l RF112_2Al RF111_1A + RF111_1Al RF224_2A (the receive mode

is four-way receive diversity)

Two carriers of a DRFU can be shared by two cells. That is, a DRFU can serve two cells.Therefore, three DRFUs are used to achieve the configuration S3/3. Figure 5-24 shows thehardware configuration in the scenario where the configuration S3/3 is applied and Table5-17 shows the corresponding data configuration.

Figure 5-24 Hardware configurations in the configuration S3/3



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Table 5-17 Data configurations in the configuration S3/3

DRFU Send Mode Sending Receiving Mode

DRFU0 Independent transmit or

combination

Single feeder [1TX 2RX]

DRFU1 Double feeder [2TX 4RX]

DRFU2 Single feeder [1TX 2RX]

5.7 Configurations of the GRFU/MRFU/MRFUeThe GRFU, MRFU V1, MRFU V2, MRFUe, and MRFU V3 are multi-carrier radio frequency(RF) modules. A GRFU or MRFU V1 or MRFU V2 or MRFU V3 supports six carriers, and anMRFUe supports eight carriers. Different configurations must be chosen in different topologies.

Port

Table 5-18 describes major ports on the GRFU, MRFU V1, MRFU V2, MRFUe, and MRFUV3.

Table 5-18 Major ports on the GRFU, MRFU V1, MRFU V2, MRFUe, and MRFU V3


RF port ANT_TX/RXA The port, used to transmit and receiveRF signals, connects to the antennasystem through antenna channel 1.

ANT_RXB The port, used to receive RF signals,connects to the antenna systemthrough antenna channel 2.

CPRI port CPRI0 The port is used to connect to theBBU or an upper-level RFU.

CPRI1 The port is used to connect to theBBU or a lower-level RFU.


RX_INB and RX_OUTA RX_INB is the diversity receive portfor an antenna channel whileRX_OUTA is the diversity transmit

port for the antenna channel.


The basic configurations of the GRFU, MRFU V1, MRFU V2, MRFUe, and MRFU V3 are thesame. The following description takes the GRFU as an example. Table 5-19 lists the basicconfigurations of the GRFU serving a single sector.

The basic configurations are described in the "RF[F][TX][RX]_[C][TYPE]" format. Where,



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BasicConfigurations

Number ofModules

Send andReceive Mode



Figure 5-25


Figure 5-26


Figure 5-27


Figure 5-28

RF111_1AA GRFU connects to the antenna system through ANT_TX/RXA. Antenna channel 1 transmitsand receives signals.



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RF112_2A

Two GRFUs connect to the antenna system through ANT_TX/RXA. Each antenna channel 1transmits and receives signals. RX_INB on one GRFU interconnects with RX_OUTA on theother GRFU to transfer the diversity signals received through an antenna channel.



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RF211_1A

A GRFU connects to the antenna system through ANT_TX/RXA and ANT_RXB. Antennachannel 1 transmits signals while antenna channel 2 receives signals.



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RF212_1AA GRFU connects to the antenna system through ANT_TX/RXA and ANT_RXB. Antennachannel 1 transmits and receives signals while antenna channel 2 receives signals only.



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Table 5-20 lists the typical configurations of the GRFU and MRFU in various scenarios. Table5-21 lists the typical configurations of the MRFUe in various scenarios.

Table 5-20 Typical configurations of the GRFU and MRFU



S3-S6 1 RF212_1A

S7-S12 2 RF112_2A

S13-S18 3 RF112_2A + RF212_1A

S19-S24 4 RF112_2A + RF112_2A



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Table 5-21 Typical configurations of the MRFUe



S3-S8 1 RF212_1AS9-S16 2 RF112_2A

NOTE

The configurations of the GRFU, MRFU, or MRFUe serving multiple sectors are the combination of theconfigurations of several GRFUs, MRFUs, or MRFUes serving a single sector.



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6 Antenna SystemThe antenna system consists of antennas, feeders, jumpers, the Tower Mounted Amplifier (TMA), the Bias Tee (BT), and the GSM Antenna and TMA Control Module (GATM). Ittransmits and receives RF signals.

Antenna

Antennas are used to radiate and receive radio waves. The working principle of antennas is asfollows: RF signals output from a radio transmitter are transmitted to antennas over feeders.After receiving the signals, the antennas transmit them to a destination in the form of electromagnetic waves. At the destination, antennas receive the electromagnetic waves, convertthem into RF signals, and transmit the signals to a radio transmitter over feeders. A remotecontrol (RC) can control the downtilt of the remote electric tilt (RET) antennas remotely.

Feeders and Jumpers

Feeders and jumpers are used to transmit RF signals between antennas and radio transmitters atminimum loss.

TMA

The TMA is a low noise amplifier that is installed close to antennas. One end of the TMA isconnected to an antenna port on an RF module while the other end is connected to antennas. Byamplifying weak signals received by antennas, the TMA helps improve receive sensitivity of the BTS, expand the uplink coverage, and lower transmit power of MSs.

BT

The BT couples the On-Off-Keying (OOK) signals or RF signals into the passive componentsof feeders.

GATM

The GATM must be configured if the DRFU, RET antennas, and TMA are configured. Functionsof the GATM are as follows:

l Controlling RET antennas.l Feeding power to the TMA.

3900 Series GSM Base StationTechnical Description 6 Antenna System


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l Reporting RET control alarms.l Monitoring the current designated for the TMA.

3900 Series GSM Base StationTechnical Description 6 Antenna System


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7 Operation and MaintenanceAbout This Chapter

Operation and Maintenance (OM) covers management, monitoring, and maintenance of thesoftware, hardware, and configuration of the BTSs. In addition, diversified OM modes are

provided in various scenarios.

7.1 OM Modes of the BTSThe OM modes of the BTS consist of the Site Maintenance Terminal mode, Local MaintenanceTerminal mode, and centralized network management mode.

7.2 OM Functions of the BTSThe OM func tions of the BTS consist of equipment management, software management,configuration management, service management, performance management, securitymanagement, alarm management, and environment monitoring.

3900 Series GSM Base StationTechnical Description 7 Operation and Maintenance


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7.1 OM Modes of the BTS

The OM modes of the BTS consist of the Site Maintenance Terminal mode, Local MaintenanceTerminal mode, and centralized network management mode.

Figure 7-1 shows the components of the BTS OM system.

Figure 7-1 Network structure of the OM system

You can maintain the BTS in the following modes:

l Site Maintenance Terminal mode: The Site Maintenance Terminal is locally connected tothe BTS through the Ethernet. You can use the Site Maintenance Terminal to operate andmaintain the site, cell, Radio Carrier (RC), Baseband Transceiver (BT), channel, and board.In this mode, only one BTS can be maintained at a time.

l LMT mode: The LMT is used to maintain the BTS through the OM links on the Abisinterface, which is an interface between the BSC and the BTS. The LMT communicates

with the BSC through a LAN. You can use the LMT to operate and maintain the site, cell,RC, channel, and board. This mode is used in configuring and modifying the data of theBSC and BTS.

l Centralized network management mode: The Huawei iManager M2000 is used to maintainthe BTS through the BSC. The M2000 can operate and maintain the site, cell, channel, and

board. In this mode, multiple BTSs can be maintained at a time.

7.2 OM Functions of the BTSThe OM functions of the BTS consist of equipment management, software management,configuration management, service management, performance management, securitymanagement, alarm man agement, and environment monitoring.



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Equipment Management

Provides the query function for the status of all the components (boards/modules) and all theexternal devices (power supply/environment monitoring/RET). You can also perform dataconfiguration and status management for some devices.

Software Management

Provides various functions, such as downloading and activating the BTS software, upgrading patches, and loading and downloading files. The associated tasks involve consistency check onthe software and hardware releases, release management, and software upgrade.

Configuration Managementl Checks whether the added, deleted, or changed BTS data is consistent with the actual

situation.

l Supports automatic data backup.l Supports dynamic and static data configuration. In dynamic data configuration, the data

immediately takes effect after modification; in static data configuration, the modified datatakes effect after the BTS is reset.

Service Managementl Supports parameter setting and alarm query for the baseband boards and environment

monitoring devices.l Supports complete self-test on hardware installation. The BTS software can be upgraded

through the software package saved in the USB disk; thus, shortening the upgrade period.

In addition, the local commissioning is not required.

Performance Managementl Monitors the performance of the internal and external telecommunications networks and

generates alarms when the performance deteriorates.l Monitors the operating status of the BTS, such as monitors the traffic volume on the ports

and measures the technical data of the BTS.l Monitors the usage of key components in the board, such as the CPU and DSP.

Security Management

Provides security management functions, such as connection management, user authentication,encryption, and forward and backward resolution of the interface messages between the BTSsoftware and the OMC.

Alarm Managementl Supports query of real-time alarms and history alarmsl Collects internal and external alarms, such as the environment monitoring device inputs

and Boolean inputsl Processes alarm correlation to ensure precision and accuracy in locating alarmsl

Provides functions of saving, interpreting, prompting, shielding, filtering, confirming,clearing, post processing, and reporting of alarms



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l Provides functions of detecting and reporting alarms, and processing alarm correlation inthe system

Environment Monitoring l Provides a perfect environment monitoring system.l Provides monitoring solutions regarding, for example, door control, infrared, smoke, water

immersion, and temperature, according to users' requirements.



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8 External Reference Clock SourcesThe BTS supports multiple external reference clock sources, including the IP reference clock,E1/T1 reference clock, synchronous Ethernet reference clock, BITS reference clock, and GPS/RGPS reference clock. If a BTS fails to obtain clock signals, it works in free-run mode for acertain period of time.

IP Reference Clock

When a BTS works in IP over FE mode, it obtains clock signals from an IP reference clock. Inthis case, an IP clock server must be configured. The server sends the User Datagram Protocol(UDP) packets carrying reference clock information to the BTS. After receiving the packets, theBTS interprets clock signals from the packets and then synchronizes its clock system.

E1/T1 Reference Clock

The BBU obtains clock signals from an E1/T1 port. Then, the BBU performs frequency division, phase locking, and phase adjustment on the clock module to export 2 MHz and 8 kHz clock signals for bit synchronization and frame synchronization. An E1/T1 reference clock obtainsclock signals from the BSC or transport network. The BTS can obtain clock signals from theBSC using an E1/T1 port. If the BTS adopts IP transmission mode but an IP reference clock isunavailable, the BTS uses an E1/T1 port to obtain clock signals from the transport network.

Synchronous Ethernet Reference Clock

When the BTS works in IP over FE mode and the transport network supports the synchronousEthernet reference clock, the BTS obtains Ethernet clock signals from the transport network.

BITS Reference Clock

When the BBU is configured with the USCU board, the GTMU board obtains external BITSclock signals from the USCU board.

GPS/RGPS Reference Clock

When the BBU is configured with the USCU board, the GTMU board obtains external GPS/RGPS clock signals from the USCU board.

3900 Series GSM Base StationTechnical Description 8 External Reference Clock Sources


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Free-Run Clock

In the absence of external clocks, the internal free-run clock ensures that the BTS keeps working properly for at least ninety days.

3900 Series GSM Base StationTechnical Description 8 External Reference Clock Sources


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9 Surge Protection SpecificationsThis section provides surge protection specifications for the BBU, RF modules, and each typeof base stations.

NOTE

l Unless otherwise specified, the surge protection specifications depend on the surge waveform of 8/20 s.l All the surge current items, unless otherwise specified as Maximum discharge current , refer to Nominal

discharge current .

Surge Protection Specifications of the Ports on BTS3900 (Ver.B)

Table 9-1 lists the surge protection specifications of the ports on BTS3900 (Ver.B).

Table 9-1 Surge protection specifications of the ports on BTS3900 (Ver.B)

Port Surge Protection Mode Specification

DC power supply port

Surge Differentialmode

2 kV (1.2/50 s)

Commonmode

4 kV (1.2/50 s)

AC power supply port

Surge Differentialmode

2 kV (1.2/50 s)

Commonmode

Documents

3900 Series GSM Base Station Technical Description(V100R013_03)(PDF)-En