Huawei BTS3606AE Troubleshooting Guide(V400R006_03)

Airbridge BTS3606AE CDMA Base Station

V400R006

Troubleshooting Guide

Issue 03

Date 2009-09-09

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mailto:[email protected]

Contents

About This Document.....................................................................................................................1

1 Safety Information.....................................................................................................................1-11.1 Safety Precautions...........................................................................................................................................1-11.2 Electricity Safety.............................................................................................................................................1-31.3 Inflammable Environment...............................................................................................................................1-51.4 Battery.............................................................................................................................................................1-51.5 Radiation.........................................................................................................................................................1-71.6 Working at Heights.........................................................................................................................................1-91.7 Mechanical Safety.........................................................................................................................................1-111.8 Others............................................................................................................................................................1-13

2 BTS Troubleshooting Process..................................................................................................2-1

3 Common Troubleshooting Methods for the BTS................................................................3-1

4 Clearing BTS Startup Faults.....................................................................................................4-14.1 Process of BTS Startup...................................................................................................................................4-2

4.1.1 Initialization of the BTS Boards.............................................................................................................4-34.1.2 Process of OML Setup...........................................................................................................................4-34.1.3 Process of Searching Satellites...............................................................................................................4-44.1.4 Loading of Software of BTS Boards......................................................................................................4-44.1.5 Process of Establishing the BTS Signaling Link...................................................................................4-54.1.6 Process of Establishing the BTS Service Link.......................................................................................4-54.1.7 Process for the Setup of BTS Cells........................................................................................................4-5

4.2 Troubleshooting the BTS Startup Failures......................................................................................................4-54.3 Case: BTS Startup Failures Caused by the Failure of the Load Process in the BAM..................................4-154.4 Case: BTS Startup Failures Caused by Signaling IP Configuration Inconsistency......................................4-16

5 Troubleshooting BTS Power Supply Failures......................................................................5-15.1 Overview of the BBU3900 Power Supply......................................................................................................5-2

5.1.1 Functional Structure of the UPEU.........................................................................................................5-25.1.2 UPEU Panel............................................................................................................................................5-25.1.3 Technical Specifications of the UPEU...................................................................................................5-4

5.2 Power Supply in the BTS3606AE Cabinets....................................................................................................5-45.2.1 Principles of Power Distribution in Cabinets.........................................................................................5-5

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5.2.2 PSUAC/DC Panel......................................................................................................................................5-5

5.2.3 Technical Specifications of the PSUAC/DC.............................................................................................5-6

5.3 Troubleshooting the BBU3900 Power Module Failures.................................................................................5-75.4 Troubleshooting the Power Module Failures................................................................................................5-105.5 Case: Frequent Restart of the BTS Due to Power Module Failures..............................................................5-14

6 Troubleshooting the BTS Environment Monitoring Failures...........................................6-16.1 Overview of BTS Environment Monitoring...................................................................................................6-2

6.1.1 Functional Structure of the Environment Monitoring Subsystem.........................................................6-26.1.2 Meanings of Terminologies Related to the BTS Environment Monitoring Instrument.........................6-36.1.3 Environment Monitoring Instrument.....................................................................................................6-46.1.4 BTS Environment Monitoring Specifications........................................................................................6-9

6.2 Troubleshooting the BTS Environment Monitoring Failures.........................................................................6-96.3 Case: False Alarms Caused by Incorrect Configuration of the EMUA........................................................6-14

7 Troubleshooting the BTS Clock Failures..............................................................................7-17.1 Overview of the BTS Clock............................................................................................................................7-2

7.1.1 Functional Structure of the Satellite Synchronization Antenna Subsystem...........................................7-27.1.2 BTS Clock Source and Local Time........................................................................................................7-37.1.3 BTS Clock Failure Alarms.....................................................................................................................7-4

7.2 Troubleshooting the Open-Circuit or Short-Circuit Failures in the BTS Antenna System............................7-57.3 Troubleshooting the Failure of Insufficient Satellites.....................................................................................7-97.4 Troubleshooting the BTS Phase-Locked Loop Failures...............................................................................7-147.5 Case: HCPM Startup Failures Caused by GPS Clock Failures.....................................................................7-177.6 Case: Interference in Voice Calls Caused by the Damaged GPS Feeder Connector....................................7-18

8 Troubleshooting the BTS Transmission Failures................................................................8-18.1 Overview of the BTS Transmission................................................................................................................8-3

8.1.1 IP-Based BTS Physical Links and Logical Links..................................................................................8-38.1.2 Abis Traffic Signal Flow in the BTS.....................................................................................................8-48.1.3 Abis Signaling Signal Flow in the BTS.................................................................................................8-58.1.4 CMPT Panel...........................................................................................................................................8-68.1.5 BTS Transmission Failure Alarms.........................................................................................................8-88.1.6 Principles of Locating the BTS Transmission Failures........................................................................8-11

8.2 Troubleshooting the Abis Transmission Link Failures.................................................................................8-158.3 Troubleshooting the Abis Signaling or Traffic Link Failures.......................................................................8-208.4 Clearing Abis Link Overload Faults.............................................................................................................8-238.5 Case: Unstable Service Quality Caused by Incorrect Link Configuration....................................................8-258.6 Case: BTS Transmission Link Intermittent Failure Caused by Poor Grounding..........................................8-26

9 Troubleshooting the BTS RF Failures....................................................................................9-19.1 Overview of the BTS RF.................................................................................................................................9-2

9.1.1 Configuration of the BTS RF Subsystem...............................................................................................9-29.1.2 OMTR Panel..........................................................................................................................................9-49.1.3 OMPA Panel..........................................................................................................................................9-7

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9.1.4 Performance Specifications of the BTS.................................................................................................9-99.1.5 BTS RF Fault Alarms...........................................................................................................................9-139.1.6 Working Principles of the BTS RF Modules and Data Point Tracking...............................................9-149.1.7 Test and Analysis of BTS Reverse RSSI.............................................................................................9-17

9.2 Troubleshooting the BTS Power Failures.....................................................................................................9-209.3 Troubleshooting the BTS Standing Wave Failures.......................................................................................9-239.4 Troubleshooting the BTS Predistortion Failures...........................................................................................9-279.5 Troubleshooting the BTS Reverse RSSI Failures.........................................................................................9-299.6 Case: Clearing BTS Standing Wave Alarms.................................................................................................9-32

10 Clearing BTS Service Failures.............................................................................................10-110.1 Overview of BTS Services..........................................................................................................................10-3

10.1.1 Basic Knowledge About BTS Access................................................................................................10-310.1.2 Basic Knowledge About BTS Voice Service.....................................................................................10-510.1.3 Basic Knowledge About BTS Call Drop...........................................................................................10-610.1.4 Basic Knowledge About BTS Data Service.......................................................................................10-710.1.5 Basic Knowledge About BTS Handoff..............................................................................................10-8

10.2 Troubleshooting the BTS Access Failures................................................................................................10-1010.3 Clearing BTS Voice Service Failures.......................................................................................................10-1310.4 Troubleshooting the BTS Data Service Failures.......................................................................................10-1810.5 Troubleshooting the BTS Handoff Failures..............................................................................................10-2110.6 Case: Failure of Random Access to the Carriers Caused by HCPM Failures...........................................10-2310.7 Case: Voice Service Failures Caused by Cell Radius Too Small.............................................................10-2410.8 Case: Slow Call Access in the Coverage Caused by Antenna System Failures........................................10-25

11 Clearing BTS OM Failures...................................................................................................11-111.1 Overview of the BTS OM Channels...........................................................................................................11-311.2 Troubleshooting the Remote OM Failures..................................................................................................11-311.3 Clearing Faults in Local OM.......................................................................................................................11-711.4 Case: BTS Data Upload Failures Caused by Incorrect FTP Properties......................................................11-911.5 Case: BTS Board Software Loading Failure Caused by Incorrect FTP Virtual Directory Setting...........11-1011.6 Case: Red or Grey Cross Indicating Connection Failures Displayed on the Service Maintenance System...........................................................................................................................................................................11-11

12 List of BTS Troubleshooting Tools....................................................................................12-1

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Figures

Figure 1-1 Wearing an ESD wrist strap...............................................................................................................1-5Figure 1-2 Lifting a weight................................................................................................................................1-10Figure 1-3 Slant angle........................................................................................................................................1-11Figure 1-4 One meter higher than the eave........................................................................................................1-11Figure 2-1 BTS troubleshooting process..............................................................................................................2-2Figure 2-2 Procedure for determining the level of a fault....................................................................................2-6Figure 4-1 BTS startup flow.................................................................................................................................4-2Figure 4-2 Procedure for troubleshooting the BTS startup failures...................................................................4-10Figure 5-1 Functional structure of the UPEB.......................................................................................................5-2Figure 5-2 UPEU panel........................................................................................................................................5-3Figure 5-3 Power distribution in a cabinet...........................................................................................................5-5Figure 5-4 Appearance of the PSUAC/DC Panel....................................................................................................5-6

Figure 5-5 Procedure for troubleshooting the BBU3900 power module failures................................................5-9Figure 5-6 Procedure for troubleshooting the power module failures...............................................................5-12Figure 5-7 Installation of the power wiring posts..............................................................................................5-13Figure 6-1 Functional structure of the environment monitoring subsystem of the AC cabinet...........................6-3Figure 6-2 Principle of the extended port alarm...................................................................................................6-4Figure 6-3 Front view of the PMU Panel.............................................................................................................6-6Figure 6-4 DIP switches of the PMU...................................................................................................................6-8Figure 6-5 Procedure for troubleshooting the faults in the communication between the environment monitoringinstrument and the BTS.......................................................................................................................................6-12Figure 7-1 Functional structure of the satellite synchronization antenna subsystem...........................................7-2Figure 7-2 Procedure for troubleshooting the open-circuit or short-circuit failures in the BTS antenna system...............................................................................................................................................................................7-7Figure 7-3 Procedure for troubleshooting the fault of insufficient satellites received by the BTS....................7-11Figure 7-4 Visual angle of the vertical antenna..................................................................................................7-12Figure 7-5 Installation position of the GPS antenna in a complicated electromagnetic environment...............7-13Figure 7-6 Procedure for troubleshooting the PLL failure.................................................................................7-16Figure 8-1 CMPT panel........................................................................................................................................8-6Figure 8-2 Normal connection and crossed pair connection..............................................................................8-11Figure 8-3 Section-by-section loopback test......................................................................................................8-12Figure 8-4 Procedure for troubleshooting the Abis transmission link failures..................................................8-17Figure 8-5 E1/T1 Transmission Environment for the BTS................................................................................8-19Figure 8-6 Procedure for troubleshooting the Abis transmission link failures..................................................8-22

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Figure 8-7 Procedure for clearing Abis link overload faults..............................................................................8-24Figure 9-1 Configuration of the RFC...................................................................................................................9-3Figure 9-2 Appearance of the OMTR panel.........................................................................................................9-4Figure 9-3 Panel of the OMPA.............................................................................................................................9-8Figure 9-4 Forward channel structure of the RF modules..................................................................................9-15Figure 9-5 Cable connection for the local reverse RSSI test..............................................................................9-18Figure 9-6 Procedure for troubleshooting the BTS power failures....................................................................9-22Figure 9-7 Procedure for troubleshooting the BTS standing wave failures.......................................................9-25Figure 9-8 Procedure for troubleshooting the BTS predistortion failures..........................................................9-28Figure 9-9 Procedure for troubleshooting the BTS reverse RSSI failures.........................................................9-30Figure 10-1 Procedure of signaling exchange over the air interface for the calling MS to access the network.............................................................................................................................................................................10-4Figure 10-2 Procedure for troubleshooting the access failures........................................................................10-12Figure 10-3 Signal flow of the voice services..................................................................................................10-14Figure 10-4 Procedure for handling voice service failures..............................................................................10-17Figure 10-5 Procedure for troubleshooting the data service failures...............................................................10-20Figure 10-6 Procedure for troubleshooting the handoff failures......................................................................10-22Figure 11-1 OM signal flow...............................................................................................................................11-3Figure 11-2 Procedure for troubleshooting the remote OM failures..................................................................11-5Figure 11-3 Procedure for handling the faults in local OM...............................................................................11-8Figure 11-4 Adding WSs....................................................................................................................................11-9

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Tables

Table 2-1 BTS data backup..................................................................................................................................2-3Table 2-2 Fault information..................................................................................................................................2-3Table 2-3 Common faults in the BTS...................................................................................................................2-4Table 2-4 Levels of BTS faults.............................................................................................................................2-5Table 2-5 Faults and associated troubleshooting procedures...............................................................................2-7Table 4-1 Symptoms of the initialization of boards.............................................................................................4-3Table 4-2 Phenomenon when a BTS downloads the configuration files.............................................................4-4Table 4-3 Symptoms of the BTS startup failures.................................................................................................4-5Table 4-4 Possible causes and analysis of the BTS startup failures.....................................................................4-6Table 5-1 Description of the UPEU ports............................................................................................................5-3Table 5-2 Description of the indicators................................................................................................................5-4Table 5-3 Description of the PSU indicators........................................................................................................5-6Table 5-4 Symptoms of the BBU3900 power module failures............................................................................5-7Table 5-5 Possible causes and analysis of the BBU3900 power module failures................................................5-7Table 5-6 Symptoms of the power module failures...........................................................................................5-10Table 5-7 Possible causes and analysis of the power module failures...............................................................5-11Table 6-1 Functions of the PMU and EMUA.......................................................................................................6-4Table 6-2 Description of PMU Ports....................................................................................................................6-6Table 6-3 Indicators on the PMU panel................................................................................................................6-7Table 6-4 DIP switches of the PMU.....................................................................................................................6-8Table 6-5 Symptoms of the environment monitoring failures.............................................................................6-9Table 6-6 Possible causes and analysis of the environment monitoring failures...............................................6-10Table 7-1 Clock failure alarms.............................................................................................................................7-4Table 7-2 Symptoms of the open-circuit or short-circuit failures in the BTS antenna system............................7-5Table 7-3 Possible causes and analysis of the open-circuit or short-circuit failures in the BTS antenna system...............................................................................................................................................................................7-6Table 7-4 Symptoms of the insufficient satellites received by the BTS..............................................................7-9Table 7-5 Possible causes and analysis of the insufficient satellites received by the BTS................................7-10Table 7-6 Symptoms of the BTS PLL failures...................................................................................................7-14Table 7-7 Possible causes and analysis of the BTS PLL failures.......................................................................7-15Table 8-1 Features of physical links.....................................................................................................................8-4Table 8-2 Description of the CMPT ports............................................................................................................8-6Table 8-3 Description of the indicators................................................................................................................8-7Table 8-4 Alarms related to the E1/T1 link..........................................................................................................8-8

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Table 8-5 Description of the FE link alarm..........................................................................................................8-9Table 8-6 Description of the IMA/UNI/FRAC/PPP link alarms........................................................................8-10Table 8-7 Symptoms of the Abis transmission link failures..............................................................................8-15Table 8-8 Possible causes and analysis of the Abis transmission link failures..................................................8-16Table 8-9 Symptoms of the Abis signaling or traffic link failures.....................................................................8-21Table 8-10 Possible causes and analysis of the Abis signaling or traffic link failures.......................................8-21Table 8-11 Symptoms of Abis link overload faults............................................................................................8-23Table 8-12 Possible causes and analysis of Abis link overload faults...............................................................8-24Table 9-1 Major modules in the RFC...................................................................................................................9-3Table 9-2 Description of the OMTR ports...........................................................................................................9-5Table 9-3 Description of the OMTR indicators....................................................................................................9-5Table 9-4 Description of the OMPA ports...........................................................................................................9-9Table 9-5 Transmit specifications in band class 0 (800 MHz).............................................................................9-9Table 9-6 Receive specifications in band class 0 (800 MHz)............................................................................9-10Table 9-7 Transmit specifications in band class 1 (1900 MHz).........................................................................9-10Table 9-8 Receive specifications in band class 1 (1900 MHz)..........................................................................9-10Table 9-9 Transmit specifications in band class 5 (450 MHz)...........................................................................9-10Table 9-10 Receive specifications in band class 5 (450 MHz)..........................................................................9-11Table 9-11 Transmit specifications in band class 6 (2100 MHz).......................................................................9-11Table 9-12 Receive specifications in band class 6 (2100 MHz)........................................................................9-11Table 9-13 Transmit specifications in band class 15..........................................................................................9-12Table 9-14 Receive specifications in band class 15...........................................................................................9-12Table 9-15 ODU cascading specifications of the BTS3606AE.........................................................................9-12Table 9-16 BER threshold specifications of the BTS on the transmission links................................................9-13Table 9-17 Alarms related to RF subsystem faults.............................................................................................9-13Table 9-18 Data Point Tracking Parameters.......................................................................................................9-15Table 9-19 Symptoms of the BTS power failures..............................................................................................9-20Table 9-20 Possible causes and analysis of the BTS power failures..................................................................9-20Table 9-21 Symptoms of the BTS standing wave failures.................................................................................9-24Table 9-22 Possible causes and analysis of the BTS standing wave failures.....................................................9-24Table 9-23 Possible causes and analysis of the BTS predistortion failures.......................................................9-27Table 9-24 Symptoms of the BTS reverse RSSI failures...................................................................................9-29Table 9-25 Possible causes and analysis of the BTS reverse RSSI failures.......................................................9-30Table 10-1 Possible causes and analysis of the access failures........................................................................10-11Table 10-2 Possible causes of MOC failures....................................................................................................10-15Table 10-3 Possible causes of MTC failures....................................................................................................10-15Table 10-4 Symptoms and possible causes of voice quality problems............................................................10-16Table 10-5 Possible causes of the data service failures....................................................................................10-19Table 10-6 Possible causes and analysis of the handoff failures......................................................................10-21Table 11-1 Possible causes of the remote OM failures......................................................................................11-4Table 11-2 Possible causes of the faults in local OM.........................................................................................11-7Table 12-1 Troubleshooting tools.......................................................................................................................12-1

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About This Document

PurposeThis document describes the fault symptoms, troubleshooting methods, and troubleshootingprocedures of the BTS3606AE.

Related VersionThe following table lists the product version related to this document.

Product Name Product Version

BTS3606AE V400R006

Intended AudienceThis document is intended for:

l Site maintainers

l Field engineers

l System engineers

l Network shifts

Change HistoryVersion Change History

03(2009-09-09) The modifications in this version are asfollows:l Upgrade the BBU3606 to the BBU3900.

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Version Change History

02(2009-04-14) The value of RSSI is modified and Modifiedsome bugs.

01(2007-10-30) Initial release.

Organization1 Safety Information

2 BTS Troubleshooting Process

This describes the general BTS troubleshooting process. You must handle the faults in the BTSby following this process.

3 Common Troubleshooting Methods for the BTS

Troubleshooting methods vary according to the fault types of the BTS. This topic describescommon troubleshooting methods such as alarm analysis, subscriber tracing, interface tracing,traffic statistics, service test, instruments and meters, performance measurement, andcomparison/replacement/switchover.

4 Clearing BTS Startup Faults

BTS startup faults may involve one or more types of faults such as hardware faults and softwarefaults. When an alarm is generated during BTS startup, boards do not work, or the BTS isrepeatedly reset, you must clear the faults by following the procedure for clearing BTS startupfaults.

5 Troubleshooting BTS Power Supply Failures

The power subsystem of the BTS consists of the BBU3900 power module, the cabinet powermodule PSU, the power distribution module, the lightning protection module, and the monitoringmodule. If the BTS fails to be powered on, or if the BTS restarts frequently and the logged failurecause for each startup is different, then the failure might be a power supply failure.

6 Troubleshooting the BTS Environment Monitoring Failures

The BTS environment monitoring subsystem monitors the DC and switching power supplies ofthe BTS, voltage of the storage battery, temperature and humidity of equipment rooms, smokeconditions, and unauthorized entry into the equipment room. If an environment alarm isgenerated on the BTS Alarm Management System or the ALM indicator on the monitoringinstrument is on, a BTS environment monitoring failure might occur.

7 Troubleshooting the BTS Clock Failures

When the BTS reports the GPS antenna open-circuit alarm, GPS antenna short circuit alarm, orphase-locked loop alarm, the switchover of the active and standby CMPTs may be triggered andthe ongoing BTS services may be interrupted. Therefore, you need to locate and troubleshootthe BTS clock failures. The causes of BTS clock failures include GPS antenna open-circuit orshort-circuit failure, phase-locked loop failure, and insufficient satellites received by the BTS.

8 Troubleshooting the BTS Transmission Failures

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If the BTS generates link-related alarms and the LMT cannot send OM commands to the BTS(whose NE status is offline), you can troubleshoot the faults by following the procedure describedin this topic.

9 Troubleshooting the BTS RF Failures

The symptoms of BTS RF failures include generation of RF system alarms, weak signals, calldrops, or a low access rate of MSs.

10 Clearing BTS Service Failures

When MSs fail to access the network, voice discontinuity occurs, call drops occur duringhandoff, or data services fail, you must clear BTS service failures. BTS service failures are accessfailures, voice service failures, data service failures, and handoff failures.

11 Clearing BTS OM Failures

The BTS OM channels can be divided into the local OM channel and the remote OM channel.When the BTS data uploading or downloading fails, board software loading fails, starting theLMT fails or login fails, or the reverse OM fails, you must clear the failures by following theprocedure for clearing BTS OM failures.

12 List of BTS Troubleshooting Tools

This topic describes the tools that you may use during BTS troubleshooting.

ConventionsSymbol 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 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.

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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.

{ 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.

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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 thepointer to a certain position.

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1 Safety Information

1.1 Safety PrecautionsThis section describes certain safety precautions and helps to choose the measurement deviceand testing device. Read and follow these safety precautions before installing, operating, andmaintaining Huawei devices.

Following All Safety Precautions

Before any operation, read the instructions and precautions in this document carefully tominimize the possibility of accidents.

The Danger, Caution, and Note items in the package of documents do not cover all the safetyprecautions that must be followed. They only provide the generic safety precautions foroperations.

Symbols

DANGERThis symbol indicates that casualty or serious accident may occur if you ignore the safetyinstruction.

CAUTIONThis symbol indicates that serious or major injury may occur if you ignore the safety instruction.

NOTE

This symbol indicates that the operation may be easier if you pay attention to the safety instruction.

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Complying with the Local Safety Regulations

When operating the device, comply with the local safety regulations. The safety precautionsprovided in the documents are supplementary. You must comply with the local safetyregulations.

General Installation Requirements

The personnel in charge of installation and maintenance must be trained and master the correctoperating methods and safety precautions before beginning work.

The rules for installing and maintaining the device are as follows:

l Only the trained and qualified personnel can install, operate and maintain the device.

l Only the qualified specialists are allowed to remove the safety facilities, and repair thedevice.

l Any replacement of the device or part of the device (including the software) or any changemade to the device must be performed by qualified or authorized personnel of Huawei.

l Any fault or error that might cause safety problems must be reported immediately to thepersonnel in charge.

Grounding Requirements

The following requirements are applicable to the device to be grounded:

l Ground the device before installation and remove the ground cable after uninstall.

l Do not operate the device in the absence of a ground conductor. Do not damage the groundconductor.

l The unit (or system) must be permanently connected to the protection ground beforeoperation. Check the electrical connection of the device before operation and ensure thatthe device is reliably grounded.

Safety of Personnel

Ensure the following:

l When lightning strikes, do not operate the device and cables.

l When lightning strikes, unplug the AC power connector. Do not use the fixed terminal ortouch the terminal or antenna connector.

NOTE

The previous two requirements are suitable for the wireless fixed terminal.

l To prevent electric shock, do not connect safety extra-low voltage (SELV) circuits totelecommunication network voltage (TNV) circuits.

l To prevent laser radiation from injuring your eyes, never look into the optical fiber withouteye protection.

l To prevent electric shock and burns, wear the electrostatic discharge (ESD) clothing, glovesand wrist strap, and remove conductors such as jewelry and watch before operation.

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Device Safetyl Before operation, the device must be secured on the floor or other fixed objects, such as

the walls and the mounting racks.l Do not block ventilation openings while the system is running.

l When installing the panel, tighten the screw with the tool.

1.2 Electricity Safety

High Voltage

DANGERl The high voltage power supply provides power for running the system. Direct contact with

the high voltage power supply or contact through damp objects may result in fatal danger.l Non-standard and improper high voltage operations may result in fire and electric shock.

l The personnel who install the AC facility must be qualified to perform operations on highvoltage and AC power supply facilities.

l When installing the AC power supply facility, follow the local safety regulations.

l When operating the AC power supply facility, follow the local safety regulations.

l When operating the high voltage and AC power supply facilities, use the specific toolsinstead of common tools.

l When the operation is performed in a damp environment, ensure that water is kept off thedevice. If the cabinet is damp or wet, shut down the power supply immediately.

ThunderstormThe following requirements are suitable only for the wireless base station or the device with anantenna or GPS antenna.

DANGERIn a thunderstorm, do not perform operations on high voltage and AC power supply facilities oron a steel tower and mast.

High Electrical Leakage

CAUTIONGround the device before powering on the device. Otherwise, the personnel and device are indanger.



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If the "high electrical leakage" flag is stuck to the power terminal of the device, you must groundthe device before powering it on.

Power Cable

CAUTIONDo not install and remove the power cable with a live line. Transient contact between the coreof the power cable and the conductor may generate electric arc or spark, which may cause fireor eye injury.

l Before installing or removing the power cable, turn off the power switch.

l Before connecting the power cable, ensure that the power cable and label comply with therequirements of the actual installation.

Fuse

CAUTIONTo ensure that the system runs safely, when a fuse blows, replace it with a fuse of the same typeand specifications.

Electrostatic Discharge

CAUTIONThe static electricity generated by the human body may damage the electrostatic sensitivecomponents on the circuit board, such as the large-scale integrated circuit (LIC).

In the following situations, the human body generates a static electromagnetic field:

l Movement of body parts

l Clothes friction

l Friction between shoes and the ground

l Holding plastic in hand

The static electromagnetic field will remain within the human body for a long time.

Before contacting the device, plug boards, circuit boards, and application specific integratedcircuits (ASICs), wear a grounded ESD wrist strap. It can prevent the sensitive components frombeing damaged by the static electricity in the human body.

Figure 1-1shows how to wear an ESD wrist strap.




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Figure 1-1 Wearing an ESD wrist strap

1.3 Inflammable Environment

DANGERDo not place the device in the environment that has inflammable and explosive air or fog. Donot perform any operation in this environment.

Any operation of the electrical device in the inflammable environment causes danger.

1.4 Battery

Storage Battery

DANGERBefore handling the storage battery, read the safety precautions for the handling and connectionof the storage battery.

Incorrect operation of storage batteries may cause danger. During operation, ensure thefollowing:

l Prevent any short-circuit.

l Prevent the electrolyte from overflowing and leakage.

Electrolyte overflow may damage the device. It will corrode the metal parts and the circuitboards, and ultimately damage the device and cause short-circuit of the circuit boards.



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General Operations

Before installing and maintaining the storage battery, ensure the following:

l Use special insulation tools.

l Use eye protection devices and operate with care.

l Wear rubber gloves and an apron in case of an electrolyte overflow.

l Always keep the battery upright when moving. Do not place the battery upside down or tiltit.

Short-Circuit

DANGERShort-circuit of the battery may cause injury. Although the voltage of a battery is low, hightransient current generated by short-circuit will release a surge of power.

Keep metal objects away from the battery to prevent short circuit. If they have to be used,disconnect the battery in use before performing any other operation.

Harmful Gas

CAUTIONl Do not use unsealed lead-acid storage batteries, because the gas emitted from it may result

in fire or device corrosion.

l Lay the storage battery horizontally and fix it properly.

The lead-acid storage battery in use will emit flammable gas. Therefore, store it in a place withgood ventilation and take precautions against fire.

High Temperature

CAUTIONHigh temperature may result in distortion, damage, and electrolyte overflow of the battery.

When the temperature of the battery exceeds 60oC, check whether there is acid overflow. If acidoverflow occurs, handle the acid immediately.




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Acid

CAUTIONIf the acid overflows, it should be absorbed and neutralized immediately.

When handling a leaky battery, protect against the possible damage caused by the acid. Use thefollowing materials to absorb and neutralize acid spills:

l Sodium bicarbonate (baking soda): NaHCO3

l Sodium carbonate (soda): Na2CO3

Antacids must be used according to the instructions provided by the battery manufacturer.

Lithium Battery

CAUTIONThere is danger of explosion if the battery is incorrectly replaced.

l Replace the lithium battery with the same or equivalent type recommended by themanufacturer.

l Dispose of the used battery according to the instructions provided by the manufacturer.

l Do not dispose of the lithium battery in fire.

1.5 Radiation

Electromagnetic Field Exposure

CAUTIONHigh power radio-frequency signals are harmful to human body.

Before installing or maintaining an antenna on a steel tower or mast with a large number oftransmitter antennas, the operator should coordinate with all parties to ensure that the transmitterantennas are shut down.

The base transceiver station (BTS) has RF radiation (radiation hazard). Suggestions for theinstallation and operation of BTSs are given in the following section. Operators are also requiredto comply with the related local regulations on erecting BTSs.

l The antenna should be located in an area that is inaccessible to the public where the RFradiation exceeds the stipulated value.



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l If the areas where RF radiation exceeds the stipulated value are accessible to workers,ensure that workers know where these areas are. They can shut down the transmitters beforeentering these areas. Such areas may not exist; but if they exist, the areas must be within arange of less than 10 m around the antennas.

l Each forbidden zone should be indicated by a physical barrier and striking sign to warn thepublic or workers.

Laser

CAUTIONWhen handling optical fibers, do not stand close to, or look into the optical fiber outlet withouteye protection.

Laser transceivers or transmitters are used in the optical transmission system and associated testtools. Because the laser that is transmitted through the optical fiber produces a small beam oflight, it has a very high power density and is invisible to human eyes. If a beam of light entersthe eye, the retina may be damaged.

Normally, staring into the end of an unterminated optical fiber or broken optical fiber withouteye protection from a distance of more than 150 mm [5.91 in.] will not cause eye injury. Eyesmay, however, be damaged if an optical tool such as a microscope, magnifying glass or eyeloupe is used to stare into the bare optical fiber end.

Read the following guidelines to prevent laser radiation:

l Only the trained and authorized personnel can perform the operation.

l Wear a pair of eye-protective glasses when you are handling lasers or optical fibers.

l Ensure that the optical source is switched off before disconnecting optical fiber connectors.

l Never look into the end of an exposed optical fiber or an open connector if you cannotensure that the optical source is switched off.

l To ensure that the optical source is switched off, use an optical power meter.

l Before opening the front door of an optical transmission system, ensure that you are notexposed to laser radiation.

l Never use an optical tool such as a microscope, a magnifying glass, or an eye loupe to lookinto the optical fiber connector or end.

Read the following instructions before handling optical fibers:

l Only the trained personnel can cut and splice optical fibers.

l Before cutting or splicing an optical fiber, ensure that the optical fiber is disconnected fromthe optical source. After disconnecting the optical fiber, use protecting caps to protect allthe optical connectors.




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1.6 Working at Heights

CAUTIONWhen working at heights, ensure that the objects do not fall.

When working at heights, ensure that the following requirements must be met:

l The personnel who work at heights must be trained.

l The operating machines and tools should be carried and handled safely to prevent themfrom falling.

l Safety measures, such as wearing a helmet and a safety belt, should be taken.

l In cold regions, warm clothes should be worn before working at heights.

l Ensure that the lifting appliances are well prepared for working at heights.

Lifting Weights

CAUTIONDo not access the areas under the arm of the crane and the goods in suspension when liftingweights.

l Ensure that the operators have been trained and qualified.

l Check the weight lifting tools and ensure that they are intact.

l Lift the weight only when the weight lifting tools are firmly mounted onto the weight-bearing object or the wall.

l Use a concise instruction to prevent incorrect operation.

l The angle between the two cables should be less than or equal to 90o in the lifting of weights(See Figure 1-2).



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Figure 1-2 Lifting a weight

Safety Guide on Ladder Use

Checking the Ladder

l Check the ladder before using it. Check the maximum weight that the ladder can support.

l Never overload the ladder.

Placing the Ladder

l The slant angle is preferred to be 75o. The slant can be measured with the angle square orwith arms, as shown in Figure 1-3. When using a ladder, place the wider end of the ladderon the ground and take protective measures on the base of the ladder against slippage. Placethe ladder on a stable ground.

When climbing the ladder, ensure the following:

l The gravity of the body does not shift from the edge of the ladder.

l Keep balance on the ladder before performing any operation.

l Do not climb higher than the fourth highest step of the ladder.

If you tend to climb to the roof, the length of the ladder should be at least one meter higher thanthe eave, as shown in Figure 1-4.




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Figure 1-3 Slant angle

Figure 1-4 One meter higher than the eave

1.7 Mechanical Safety

Drilling

CAUTIONDo not drill on the cabinet without permission. Inappropriate drilling on the cabinet may damagethe electromagnetic shielding and internal cables. Metal shavings from the drilling may resultin a short-circuit of the circuit board if they get into the cabinet.



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l Before drilling a hole on the cabinet, remove the cables from the cabinet.

l During the drilling, wear blinkers to protect your eyes.

l During the drilling, wear the protective gloves.

l Prevent the metal shavings from getting into the cabinet. After drilling, clean the metalshavings in time.

Handling Sharp Objects

CAUTIONWhen carrying the device by hand, wear the protective gloves to prevent injury by sharp objects.

Handling Fansl When replacing a component, place the component, screw, and tool at a safe place to prevent

them from falling into the running fan.l When replacing the ambient equipment around the fan, do not place the finger or board

into the running fan until the fan is switched off and stops running.

Moving Heavy ObjectsWear the protective gloves when moving heavy objects.

CAUTIONl Be careful when moving heavy objects.

l When moving the chassis outwards, be aware about the unfixed or heavy objects on thechassis to prevent injury.

l Two persons should be available to move a chassis; one person must not move a heavychassis. When moving a chassis, keep your back straight and move stably to prevent asprain.

l When moving or lifting a chassis, hold the handle or bottom of the chassis. Do not hold thehandle of the installed modules in the chassis, such as the power module, fan module, orboard.




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1.8 Others

Inserting and Removing a Board

CAUTIONWhen inserting a board, wear the ESD wrist strap or gloves. Insert the board gently to preventany bent pins on the backplane.

l Insert the board along the guide rail.

l Avoid contact of one board with another to prevent short-circuit or damage.

l Do not remove the active board before powering off.

l When holding a board in hand, do not touch the board circuit, components, connectors, orconnection slots.

Bundling Signal Cables

CAUTIONBundle the signal cables separately from the strong current cables or high voltage cables.

Cabling RequirementsAt a very low temperature, movement of the cable may damage the plastic skin of the cable. Toensure the construction safety, comply with the following requirements:

l When installing cables, ensure that the environment temperature is above 0oC.

l If cables are stored in the place below 0oC, move the cables into a place at a roomtemperature and store the cables for more than 24 hours before installation.

l Move the cables with care, especially at a low temperature. Do not drop the cables directlyfrom the vehicle.



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2 BTS Troubleshooting Process

This describes the general BTS troubleshooting process. You must handle the faults in the BTSby following this process.

Figure 2-1 shows the general troubleshooting process for the BTS.

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Figure 2-1 BTS troubleshooting process

NOTE

Currently, the BTS3606AE supports the IP over E1/T1 mode only.

Backing Up BTS DataBefore troubleshooting, you must back up BTS configuration data, running logs, alarminformation, and command logs, as described in Table 2-1.

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Table 2-1 BTS data backup

Number

Data to BeBacked Up

Instruction

1 Configurationdata

Refer to Setting Automatic Backup for BTS Configuration Data.

2 Running logs Refer to Manually Backing Up BTS System Running Logs.

3 Alarminformation

Refer to Manually Backing Up BTS Alarm Logs.

4 Commandlogs

Refer to Manually Backing Up BTS Operation Logs.

Collecting Fault InformationAfter a fault occur, collect and back up information of the fault in time. If you need technicalsupport from Huawei, send the fault information to Huawei for analysis.

Collecting fault information is the first step in troubleshooting a fault. Therefore, themaintenance personnel must collect sufficient fault information for analysis. Table 2-2 lists thefault information to be collected.

Table 2-2 Fault information

Number

Fault Information Content

1 Detailed symptoms Consult equipment maintenance personneland the person who reports the fault.

2 When, where, and how often thefault occurs

3 Scope and impact of the fault Perform service tests, performancemeasurement, and interface tracking.

4 Running status of the system beforethe fault occurs

Observe the board indicators, the ServiceMaintenance System, and the AlarmManagement System.

5 Operations performed before thefault occurs

Consult equipment maintenance personnel.

6 Measures taken after the faultoccurs and effectiveness of thesemeasures

7 Information of alarms associatedwith the fault

Query alarm information, command logs, andBTS logs.

8 Status of the board associated withthe fault

Observe board indicators.



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Determining the Scope, Type, and Level of the FaultAfter collecting symptoms of a fault, determine the scope and type of the fault. In the BSS, thescope of the fault covers the areas affected by the fault, thus providing the basis for determiningthe level of the fault.

Based on the fault information, determine the type of the fault. Table 2-3 describes the symptomsof the different types of faults.

Table 2-3 Common faults in the BTS

Fault Description

BTS startupfailure

During BTS startup, an alarm is generated, boards do not work, or theBTS resets repeatedly.

Power supplyfailure

The power module alarm is generated on the Alarm ManagementSystem. The ALM indicator on the panel of the PSU is on. The BTS mayreset repeatedly.

Environmentmonitoring failure

The alarm related to the environmental indicators is generated on theAlarm Management System. The indictor on the environmentmonitoring board is abnormal.

Clock systemfailure

The BTS reports the GPS antenna open circuit or short circuit alarm andthe phase-locked loop alarm. The switchover of the active and standbyCMPTs may be triggered. The BTS services may be interrupted.

Transmissionfailure

l The BTS reports alarms such as the E1/T1 link far-end alarm and E1/T1 link signal loss alarm, and alarms which indicate that the trafficlink is not configured, the Abis signaling link is overloaded, the trafficlink is overloaded, and the Abis signaling link is interrupted.

l The BTS repeatedly reports the alarms "BER of E1/T1 Link TooHigh" and "E1/T1 Link Lost of Frame."

l The LMT cannot send OM commands to the BTS and the status ofthe BTS is offline.

RF system failure l An alarm related to the RF system is generated.

l Call drop occurs because the network signals received by MSs areweak.

l The BTS coverage area decreases.

l The MS detects good signals, but the access success rate is low, andthe call drop rate is high.

Service failure l The MS fails to access the network or the network access is slow.

l Mobile-originated calls or mobile-terminated calls fail. Failures suchas one-way audio, no audio, noise, crosstalk, and echo occur, thusaffecting voice quality.

l Data services are unpleasant or unavailable.

l Handoffs cannot be triggered or call drop occurs during a handoff.




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Fault Description

Operation andmaintenancefailure

l The Abis link is functional, but the BTS cannot be pinged.

l The BTS cannot upload files.

l You cannot log in to the BTS through the LMT or the Telnet.

l The reverse maintenance fails.

Based on their scope and severity, faults in the CDMA BSS are classified into three levels,namely emergency, severe, and common. Table 2-4 describes the fault levels.

Table 2-4 Levels of BTS faults

Level Description

Emergency All the services of a BTS (or several BTSs) are interrupted, and all the MSs ofthe BTS (or BTSs) cannot access the network when the external power supplyor the transmission is interrupted.

Severe Some services of a BTS (or several BTSs) are affected, and some MSs of theBTS (or BTSs) cannot access the network or receives services with poor qualityafter the access when some carriers are abnormally blocked or insufficientsatellites are detected.

Common Alarms are generated, but services are not affected. If faults related to thesealarms are not rectified in time, they may become emergency or severe faults.Some examples of these alarms are abnormality in the operation temperatureand stall of fans.

Faults of different levels are handled in different ways:

l In the case of a severe or common fault, follow the general troubleshooting processdescribed in this document.

l In the case of an emergency fault, follow the troubleshooting methods given in the BTSemergency maintenance guide.

Figure 2-2 shows the procedure for determining the level of a fault.



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Figure 2-2 Procedure for determining the level of a fault

The steps shown in Figure 2-2 are described as follows:

1. Collect information about the fault and determine the scope of the fault.2. Check whether services of the BTS are normal. Services of the BTS may be interrupted

when:l The external power supply fails.

l The trunking transmission is faulty.




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l The hardware of the BTS is faulty.

l The modification of BSC data fails.

l The BSC interface board is faulty.

l The BTS is damaged.

If services of the BTS are interrupted due to the preceding factors, you can infer that thefault is an emergency fault.

3. Check whether all or only a part of the services are interrupted. Partial service interruptionoccurs when:l The quality of voice calls decreases due to a high interface level.

l The success rate of handoffs decreases.

l Carriers are abnormally blocked.

l The transmission rate of data services is low.

If partial service interruption occurs due to the preceding factors, you can infer that thefault is a severe fault.

4. Check whether services are normal although a fault occurs.All the services of the BTS and the served MSs are normal, but alarms are generated andthe associated faults may become severe or emergency faults. For example, when theoperation temperature alarm is generated, configuration data may fail to be saved and logsmay fail to be reported. If alarms are generated but services are not affected, you candetermine that the fault is a common fault.

Troubleshooting FaultsTable 2-5 shows the types of faults and the procedures of troubleshooting the faults.

Table 2-5 Faults and associated troubleshooting procedures

Fault Refer to ...

BTS startup failure 4 Clearing BTS Startup Faults

Power supplyfailure


Environmentmonitoring failure

6 Troubleshooting the BTS Environment Monitoring Failures

Clock systemfailure


Transmissionfailure

8 Troubleshooting the BTS Transmission Failures

RF system failure 9 Troubleshooting the BTS RF Failures

Service failure Case: RSSI Peak Too Low and BTS Coverage Shrinking Caused byAntenna System Failures



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Fault Refer to ...

Operation andmaintenancefailure


CAUTIONIf you have to change the position for installing cables, the DIP switch status, the position forinstalling boards during hardware installation, first record the current conditions.

Contacting Huawei for Technical SupportContact Huawei by the following methods:l Customer service phone: +86-755-28560000

l Customer service fax: +86-755-28560111

l E-mail: [email protected]

l Technical support web site: http://support.huawei.com

NOTE

Visit http://www.huawei.com to view the contact methods of the local Huawei offices.

To make troubleshooting easier, prepare fault information before you contact Huawei fortechnical support.

The general information of a fault consists of:

l The full name of the site

l The name and phone number of the contact person

l Time of the fault

l Symptoms of the fault

l The version of the host software

l Measures taken after the fault occurs and effectiveness of these measures

l The severity level of the fault, and the expected time taken to rectify the fault

The basic information of a fault consists of:

l Alarm information

l Subscriber-tracked information

l Interface-tracked information

l Traffic statistics information

l Service test analysis information

l Instrument analysis information

l Performance measurement analysis information




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l Comparison and interchange information

Checking the Troubleshooting ResultAfter troubleshooting the fault, check the troubleshooting result.

1. Check the equipment status, board indicators, and the Alarm Management System to ensurethat the system is running normally.

2. Make test calls to ensure that all services are functioning normally.3. Assign a staff on duty during peak hours to ensure that the problems (if any) can be resolved

in time.

Recording the Troubleshooting ProcessAfter rectifying the fault, review the entire process, record the key points, and propose measuresto prevent faults of the same type.



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3 Common Troubleshooting Methods for theBTS

Troubleshooting methods vary according to the fault types of the BTS. This topic describescommon troubleshooting methods such as alarm analysis, subscriber tracing, interface tracing,traffic statistics, service test, instruments and meters, performance measurement, andcomparison/replacement/switchover.

Alarm AnalysisThe BSS alarm system offers alarm information in the form of sound, light, light emitting diode(LED)or screen output. The alarm information offered by the alarm management system containsdetails about the fault, possible causes, and suggestions. The alarm information may beassociated with the equipment, links, disconnection, and CPU load. The alarm information is animportant basis for fault analysis and location. Alarm analysis is performed to locate faults andfind out causes. If an alarm is generated, the alarm and the method of handling the alarm aredisplayed in the alarm management system. Each alarm provides a detailed procedure forhandling the fault. Follow the procedure to clear the fault.

Alarm analysis is applicable to the following scenarios:

l Clearing faults in equipment

l Clearing faults in services

For operation instructions on the use of the Alarm Management System, refer to the online help.

Subscriber TracingThrough subscriber numbers, this function traces and displays on the Service MaintenanceSystem the standard interfaces, internal interface messages, internal status messages ofsubscribers in the sequence of the occurrence time.

Subscriber tracing has the following features:

l Displaying tracing results in real time

l Tracing all the standard interfaces

l Applying to heavy traffic

l Applying to the analysis of call procedures and the tracing of VIP subscribers.

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Subscriber tracing is performed for locating call failures.

For instructions on subscriber tracing, refer to the online help of the Service MaintenanceSystem.

Interface TracingThrough a standard or internal interface, this function traces and displays on the ServiceMaintenance System all the messages over the interface.

Interface tracing has the following features:

l Displaying tracing information in real time

l Having complete interface messages

Interface tracing is performed for locating call problems that are difficult to categorize, forexample, the access success rate is low in a particular office direction.

For instructions on interface tracing, refer to the online help of the Service Maintenance System.

Traffic StatisticsTraffic statistics record events during calls, such as call drops and handoffs. Compared withother locating methods, traffic statistics can reflect the overall situation of all the calls. Forexample, the call completion rate can be calculated according to traffic statistics.

Traffic statistics are applicable to the following scenarios:

l KPI analysis

l Performance analysis

For instructions on traffic statistics, refer to the online help of the Service Maintenance System.

Service TestThrough service tests (for example, tests on voice services, data services, and short messageservices), you can determine the scope and type of a fault and whether the fault is cleared.

Service tests are applicable to the following scenarios:

l Clearing faults in equipment

l Clearing faults in services

l Deployment commissioning

Instruments and MetersUsing instruments and meters is a common technical means in fault analysis and location. Thismethod is straightforward and quantitative, and it reflects the nature of the fault.

The following instruments and meters are required for analyzing and locating faults:

l Power meter

l Spectrum analyzer

l Error bit tester

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l SiteMaster

l Multimeter

Instruments and meters are applicable to the following scenarios:

l Power supply testing

l Signaling analysis

l Bit error detection

For details about the use of instruments and meters, refer to their instructions.

Performance Measurement

Through the performance management system, you can create performance measurement tasks.The operation results of these tasks help you analyze the possible cause and scope of the fault.

Performance measurement is applicable to the following scenarios:

l Transmission alarms are generated.

l Transmission bit errors are gauged with the bit error tester on site.

l Alarms about the RF subsystem are generated.

l The standing wave ratio or transmit power of the antenna is measured at the near end.

For details about the use of the performance management system, refer to the online help of theperformance measurement items.

Comparison/Replacement/Switchover

You can compare the symptoms of a faulty part with those of a normal part to find out the cause.This method applies to simple faults.

If the fault persists after you replace the faulty part with a spare part, replace the spare part withanother one (such as a board or an optical fiber) that is operational, and then observe the changesto locate the fault. This method applies to complicated faults.

Through an active/standby switchover, you can shift all the services in the active device to thestandby device. By comparing the status of the system before and after the switchover, you cancheck whether the previous active device is faulty or whether the active/standby configurationis proper.

These methods are applicable to the following scenarios:

l Alarms about boards are generated, and boards need to be replaced.

l Alarms indicate that some boards are faulty and need to be interchanged.

l The transmission link is disconnected.

l The output power of the BTS is 0, thus causing call failures.

When using these methods to locate faults, pay attention to the following points:

l Replacement is a risky operation. For example, after a short-circuited board is moved tothe subrack in normal condition, the subrack may be damaged. Therefore, be cautious toperform the operation and ensure that no other faults are brought about.

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l Before switching over the active and standby boards, back up all the data to avoid systemdata loss.

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4 Clearing BTS Startup Faults

About This Chapter

BTS startup faults may involve one or more types of faults such as hardware faults and softwarefaults. When an alarm is generated during BTS startup, boards do not work, or the BTS isrepeatedly reset, you must clear the faults by following the procedure for clearing BTS startupfaults.

4.1 Process of BTS StartupThis describes the process of BTS startup.

4.2 Troubleshooting the BTS Startup FailuresAny failure in the BTS startup process may cause a BTS startup failure. The BTS startup failuresinvolve failures such as power supply failures and clock system failures. This describes thesymptoms of the faults and the procedure for troubleshooting the faults.

4.3 Case: BTS Startup Failures Caused by the Failure of the Load Process in the BAMThe failure of the Load process in the BAM may cause a BTS startup failure. This topic describeshow to clear the BTS startup failures caused by the failure of the Load process in the BAM.

4.4 Case: BTS Startup Failures Caused by Signaling IP Configuration InconsistencyIn IPOA mode, the BTS may fail to start and MSs may fail to access the network if the IPaddresses of the BTS and BSC signaling links are inconsistent. This describes the symptoms ofthe faults and the procedure for troubleshooting the faults.

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4.1 Process of BTS StartupThis describes the process of BTS startup.

Figure 4-1 shows the BTS startup flow.

Figure 4-1 BTS startup flow

4.1.1 Initialization of the BTS BoardsAfter the BTS is powered on, the BOOT software in each board loads the software of the boardfrom the flash memory to the RAM, performs self-check and initialization, and establishes inter-board communication links. If the initialization fails, the corresponding board resets.

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4.1.2 Process of OML SetupYou must set up an Operation and Maintenance Link (OML) between the BTS and the BAMbefore you start to remotely configure a BTS. The physical transmission bearer between the BTSand the BSC can be E1/T1 or FE. The transmission mode over the physical bearer can be ATMor IP. The E1/T1 link can bear ATM or IP transmission. The FE link can bear IP transmissiononly.The BTS3606AE supports only the IP over E1/T1 transmission.

4.1.3 Process of Searching SatellitesAfter initialization, the CMPT searches for satellites to obtain stable and reliable clock signals.

4.1.4 Loading of Software of BTS BoardsThe software of BTS boards can be loaded from the configuration files on the BAM or from theflash memory.

4.1.5 Process of Establishing the BTS Signaling LinkThis describes the process of establishing the Abis signaling link.

4.1.6 Process of Establishing the BTS Service LinkThis describes the process of establishing the Abis service link.

4.1.7 Process for the Setup of BTS CellsThis describes the process for the setup of BTS cells.

4.1.1 Initialization of the BTS BoardsAfter the BTS is powered on, the BOOT software in each board loads the software of the boardfrom the flash memory to the RAM, performs self-check and initialization, and establishes inter-board communication links. If the initialization fails, the corresponding board resets.

Table 4-1 describes the symptoms of initialization of boards.

Table 4-1 Symptoms of the initialization of boards

ObservationMode Phenomenon Description

BTS After the CMPT is powered on and initialized, the RUN indicators blink at4 Hz.The ALM indicators blink at different frequencies according to differentseverities of alarms.

ServiceMaintenanceSystem

If the CMPT is initialized, the BTS is in a link-disconnected state.

4.1.2 Process of OML SetupYou must set up an Operation and Maintenance Link (OML) between the BTS and the BAMbefore you start to remotely configure a BTS. The physical transmission bearer between the BTSand the BSC can be E1/T1 or FE. The transmission mode over the physical bearer can be ATMor IP. The E1/T1 link can bear ATM or IP transmission. The FE link can bear IP transmissiononly.The BTS3606AE supports only the IP over E1/T1 transmission.



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IP over E1/T1If the BSC is a Huawei BSC6680, the information about the OML is configured on the BSC,and you do not need to add such information to the configuration of the BTS.

If the BSC is a Huawei BSC6600, the BTS uses two BOOTP requests to obtain the IP addressof the CMPT, the route information, and the OM IP address of the BTS.

1. During the startup of the BTS, the CMPT sends the BOOTP request to the CBPE in theBSC.

2. With the BOOTP request, the CBPE obtains the IP address of the CMPT and the routeinformation according to the information about the BOOTP transmission channel.

3. The CBPE adds the IP address of the CMPT and other information to the BOOTP responseframe and sends it to the CMPT.

4. The CMPT sends the BOOTP request to the BSC again to obtain the OM IP address of theBTS.

5. When the BTS obtains the OM IP address, it sends the TCP link setup request to the BAM.6. The BAM accepts this request, and the BTS sets up the OML to the BAM.

4.1.3 Process of Searching SatellitesAfter initialization, the CMPT searches for satellites to obtain stable and reliable clock signals.

l If the BTS fails to find any satellite, the ACT indicator on the CMPT blinks at 0.25 Hz,and the channel processing board restarts repeatedly.

l If a standby CMPT is configured and the standby CMPT finds suitable satellites, the BTSswaps the active and standby CMPTs.

4.1.4 Loading of Software of BTS BoardsThe software of BTS boards can be loaded from the configuration files on the BAM or from theflash memory.

The BTS first attempts to load the software of boards from the configuration files on the BAM.Table 4-2 shows the phenomenon when a BTS downloads the configuration files from the BAM.

Table 4-2 Phenomenon when a BTS downloads the configuration files

ObservationMode Phenomenon Description

BTS Boards are reset. The ACT indicators on the boards are on.

ServiceMaintenanceSystem

After the configuration is complete, the states of all boards are indicatedon the equipment panel.

Associatedalarms

The link interruption alarm is generated.

In the case that the software in a board is inconsistent with the configuration files on the BAMand the automatic loading is enabled, the BTS downloads the configuration files from the BAM.




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In the case that the establishment of the OML link to the BAM fails and the configuration filesare available in the flash memory of the CMPT, the BTS downloads the configuration files fromthe flash memory.

4.1.5 Process of Establishing the BTS Signaling LinkThis describes the process of establishing the Abis signaling link.

After the CMPT is configured, the CMPT establishes the Abis signaling link by using theconfiguration parameters to implement signaling exchange between the BTS and the BSC.

If the Abis signaling link is interrupted, the BTS automatically resets 10 minutes later.

4.1.6 Process of Establishing the BTS Service LinkThis describes the process of establishing the Abis service link.

After the BTS obtains a stable clock source, the HCPM/HECM establishes an Abis traffic linkby using the CMPT to implement service data interchange between the BTS and the BSC.

4.1.7 Process for the Setup of BTS CellsThis describes the process for the setup of BTS cells.

After the Abis signaling link is set up, the baseband boards report the BTS resource configurationstate to the BSC and request logical configuration. After the BSC sends the cell configurationdata to the baseband boards, the BTS configures the carrier properties, sets up the commonchannel, and updates the overhead message. After that, the MS is allowed to access the networkand make a call.

4.2 Troubleshooting the BTS Startup FailuresAny failure in the BTS startup process may cause a BTS startup failure. The BTS startup failuresinvolve failures such as power supply failures and clock system failures. This describes thesymptoms of the faults and the procedure for troubleshooting the faults.

Symptoms

Table 4-3 describes the symptoms of the BTS startup failures.

Table 4-3 Symptoms of the BTS startup failures

Item Symptom

Services l The BTS fails to start.

l The BTS resets repeatedly.

l A carrier restarts repeatedly.

Board status l The RUN or ALM indicator of BTS boards blinks fast or BTS boards arein offline state.

l The CMPT resets repeatedly.



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Item Symptom

Alarms The following alarms may be generated on the BTS:l Physical link alarms

Physical link alarms are generated when signals on the E1 link are lost,received signals on the FE link are lost, frames on the E1/T1 link are out ofsynchronization or when there is an error on the FE link transmission.

l OML alarmsOML alarms are generated when the OML is disconnected or when theOMLs between the CMPT and other boards are disconnected.

l Signaling/traffic link alarmsSignaling/traffic link alarms are generated when the active links in the linkgroup are insufficient or when the Abis signaling link is faulty.

l GPS clock alarmsGPS clock alarms are generated when the satellites locked by the satellitereceiver of the CMPT are not sufficient or when the CMPT and the satelliteantenna are short circuited.

l Carrier resource alarmsCarrier resource alarms are generated when the sector carrier is incorrectlyconfigured or when the channel number on the sector carrier is incorrect.

l Configuration file loading alarmsConfiguration file loading alarms are generated when there are errors in theconfiguration files.

Fault LocationTable 4-4 lists the possible causes and analysis of BTS startup failures.

Table 4-4 Possible causes and analysis of the BTS startup failures

Cause Analysis

The hardware ofboards or the Abistransmissionsystem is faulty.The cabinet is notproperlygrounded.

The slot of the CMPT isfaulty. The settings of theDIP switch are incorrect.

The E1/T1 or FE transmission-relatedalarms are generated.

The GPS clock signalcable is disconnected fromthe CMPT.

l If the OML is faulty, the ACT indicatorblinks at 4 Hz.

l If the satellite lockon fails, the ACTindicator blinks at 0.25 Hz.

The slot of the HCPM/HECM is faulty.

The equipment panel on the ServiceMaintenance System shows that the RFmodule is unavailable. When the CSMchip is faulty, the ALM indicator is on andthe ACT indicator blinks at 0.25 Hz.




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Cause Analysis

The Abis transmissionsystem is faulty.

In the loopback test from the transmissionequipment room to the BSC or to the BTS,the bit error rate is very high.

The cabinet is not properlygrounded.

The BTS transmission link is intermittent.

Faulty powermodule

The PSUAC/DC has no orabnormal power input.

l If the power indicator (green) on thepanel of the PSU is on, you can infer thatthere is power input.

l If the monitoring indicator (yellow) onthe panel of the PSU is on, you can inferthat the DC input voltage or theenvironment temperature is not withinthe proper range.

l If the ALM indicator (red) on the panelof the PSU is on, you can infer that anundervoltage alarm or a module failurealarm is generated.

The PSUAC/DC hasinsufficient or abnormalpower output.

If the ALM indicator (red) on the panel ofthe PSU is on, you can infer that the poweroutput is abnormal.

The PSUAC/DC isdisconnected from otherparts.

If the PSU has normal power output but theindicators of other parts are off, you caninfer that the cables that connect the PSUto other parts are faulty or the circuit on thebackplane is faulty.

The power module of theBBU3900 is faulty.

If the power module UPEU of theBBU3900 is faulty, services may beinterrupted.



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Cause Analysis

The GPS clocksystem is faulty.

The satellite receiver orthe CMPT is faulty.

Run the DSP CBTSBRDSPECSTATcommand to view the type of the satellitereceiver.l The satellite receiver is faulty.

The number of locked satellites is 0when the GPS antenna is installed in aproper position.– The query result is UNKNOWN.

– The type of the satellite receiver isdisplayed, but the alarm "The antennaof the CMPT satellite receiver isshort-circuited" is generated.

– The type of the satellite receiver isdisplayed, but the alarm "Thesatellites locked by the CMPTsatellite receiver is not enough" isgenerated.

l Faults of the CMPTThe type of the satellite receiver isdisplayed, but the alarm "the antenna ofthe CMPT satellite receiver is opencircuited" is generated and the voltageof the GPS port in the panel of theCMPT is 0 V or less than 4.5 V.

The GPS antenna systemis faulty.

Run the SET CBTSCLK command tochange the clock to Internal ClockSource. If the BTS is operational, you caninfer that the GPS antenna system is faulty.

The installation positionof the GPS antenna isimproper.

l There are tall buildings around theinstallation position.

l The antenna is located under amicrowave antenna, a high-voltagecable, or a TV tower.

l The installation position is susceptibleto a lightning strike. The antenna isbeyond the protection range of thelightning arrester.

The dataconfiguration isincorrect or isinconsistent withthe dataconfiguration ofthe BSC.

The configuration of thesector carrier resource orthe local cell ID isincorrect or missing.

The indicator on the panel of each boardindicates no exceptions, but the carrierresource cannot be established.




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Cause Analysis

The configuration of themask or the IP address ofthe OML or the signalinglink is incorrect ormissing.

l If the OML is not connected, the BTScannot upload software.

l If the signaling link is not connected, theBTS restarts automatically every 10minutes.

The configuration of thetransmission resource isincorrect or missing.

The transmission link number or the linkgroup number is incorrect or beyond thevalue range.

The configuration of thebands is incorrect ormissing.

After the BTS starts up, the OML isestablished but does not start.

The BAM server isfaulty.

The BAM server fails to start or the Load process on the BAM server isabnormal. Therefore, the OML fails to be established and the BTS failsto start.

The temperatureof the BTS isbeyond the properrange.

The operating temperature for the BTS ranges from -40oC to +52oC.The temperature is measured 1.5 m [59.06 in.] above the floor and 0.4m [15.75 in.] in front of the equipment, without protective panels in frontof or behind the cabinet.

The softwareversion of the BTSdoes not match thesoftware versionof the BAM.

In the deployment or upgrade of a BTS, the software version of boardsin the BTS may not match the software version of the BAM.If the software version of the BTS does not match the software versionof the BAM, the BTS may fail to start or be upgraded.

Fault HandlingFigure 4-2 shows the procedure for troubleshooting the BTS startup failures.



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Figure 4-2 Procedure for troubleshooting the BTS startup failures




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Procedure

Step 1 Check the hardware of boards.Check whether the failure is caused by faults in the hardware of boards.

1. Check the status of the CMPT port.

The commands vary according to the transmission types, as described in the followingtable.

Type Commands and Query Results

E1/T1 Run the DSP CBTSMLTDRPBRDSTAT command to query the status ofthe CMPT port. The query result for E1 transmission shows that the status ofthe CMPT port is 75 ohms or 120 ohms. The query result for T1 transmissionshows that the status of the CMPT port is 100 ohms.



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Type Commands and Query Results

FE Run the DSP CBTSFEPORTINFO command. The query result involves thelink status and the loopback status.

2. Check the DIP switches of the CMPT and the CESP.

For details on the DIP switches, refer to the BTS hardware description manual.3. Check the indicators on the panel of the CMPT.

If the RUN indicator blinks at 4 Hz, you can infer that the CMPT is faulty. Replace theCMPT. If the ACT indicator blinks at 0.25 Hz, you can infer that the satellite receiver isfaulty. Replace the satellite receiver.

4. Check the connection of the GPS clock signal cable with the GPS port in the panel of theCMPT.l The GPS clock signal cable that connects to the GPS port in the panel of the CMPT

loosens easily, thus resulting in unlocking of satellites. To check whether the CMPT orthe slot is faulty, run the SET CBTSCLK command to set the clock to internal clock.If the fault is rectified, you can infer that the CMPT or the slot functions properly. Inthis case, you need to locate the fault in the GPS antenna system.

l Disconnect the GPS clock signal cable from the GPS port in the panel of the CMPT.Use a multimeter to the measure the output voltage of the CMPT (connect the positivepole of the multimeter to the internal hole of the GPS port and the negative pole to theouter sheath). Check whether the output voltage is about 5 V. If the output voltage isnot within the range, you can infer that the CMPT or the slot is faulty. Replace theCMPT.

5. Check the indicators on the panel of the HCMP/HCEM.l If the RUN indicator blinks at 4 Hz, you can infer that the HCMP/HCEM is faulty.

Replace the HCMP/HCEM.l If the ACT indicator blinks at 0.25 Hz and the ALM indicator is on, you can infer that

the CSM chip is faulty. Replace the CSM chip.6. Check the RF module.

The RF module obtains the synchronization clock from the HCMP/HCEM. Therefore, theRF module fails if the HCMP/HCEM is faulty.

7. Check the transmission links.For details, refer to 8 Troubleshooting the BTS Transmission Failures.

If the result shows that the transmission system is faulty, ask the transmission systemengineers to rectify the fault.

8. Check the grounding of the digital distribution frame (DDF).Use a multimeter to measure the resistance of the PGND port on the top of the cabinet orthe resistance from the PE grounding bar to the grounding bar in the equipment room. Ifthe measured resistance is less than 10 ohms, you can infer that the DDF is properlygrounded.

Step 2 Check the power supply voltage.Check whether the fault is caused by faults in the power supply.1. Check the power supply system.

If the power supply system is faulty, ask the power supply engineers to rectify the fault.




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2. Check the PSU.Check whether the SET CBTSPOWEROFF command is run to switch off the additionalpower supply. If the software configuration is correct, switch to the standby power supplyor replace the PSU.

3. Check the cables between the PSU and other parts and the backplane.Reconnect the cables or replace the backplane. Check the power cables from the powerdistribution box to the OMTR/OMPA.

Step 3 Check the GPS clock system.Check whether the fault is caused by problems with the GPS clock system.1. Check the satellite receiver and the CMPT.

Check whether the satellite receiver or the CMPT is faulty. If the satellite receiver or theCMPT is faulty, replace the satellite receiver or the CMPT.

2. Bypass the lightning arrester.Remove the lightning arrester, and then directly connect the cables that are originallyconnected to the two ends of the lightning arrester. If the GPS antenna system is operational,you can infer that the lightning arrester is faulty or cables are loose or inversely connected.In this case, replace the lightning arrester or reconnect the cables.

3. Check the resistance between the shielding layer of the feeder and the core wire.

Disconnect the clock signal cable from the CMPT and disconnect the GPS antenna. Use amultimeter to measure the resistance between the shielding layer of the feeder and the corewire. Ensure that the resistance is more than 1 megaohm.

Connect the shielding layer at one end of the feeder and the core wire. Check the resistanceat the other end of the feeder. Ensure that the resistance is less than 10 ohms.

4. Check all the outdoor connectors.Ensure that the outdoor connectors are not penetrated by water and are properly connected.

5. Check the resistance of the GPS antenna.Use a multimeter to measure the resistance of the GPS antenna.l If the resistance is less than 10 ohms, you can infer that the GPS antenna is faulty and

you need to replace it.l If the resistance ranges from 150 ohms to 200 ohms, test the working current of the GPS

antenna.6. Check the current of the GPS antenna.

Reconnect the antenna system. Disconnect the cable from the GPS port in the panel of theCMPT. Connect the outer sheath of the cable with the outer layer of the GPS port, and thenuse a multimeter to measure the voltage between the cable and the core wire of the GPSport.

If the voltage ranges from 20 mA to 30 mA, you can infer that the GPS antenna isoperational. If the GPS antenna is faulty, replace it.

7. Check the position of the GPS antenna and check whether there are interference sourcesand obstacles.

Tall buildings or trees and high-power microwave devices or the radio broadcast stationmay affect the normal operation of the GPS antenna.

For details, refer to Installing the Satellite Antenna System.



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Step 4 Check the data configuration.After the fault location and analysis, check whether the fault is caused by the incorrect dataconfiguration.1. Check the configurations of the sector carrier resource or the local cell ID at the BSC and

BTS sides.On the BAM, run the LST CELL command to check whether the cell resource is configuredand whether the cell information configured at the BSC side is consistent with thatconfigured at the BTS side. Run the RMV CBTSCELL or ADD CBTSCELL commandto modify the cell resource configuration.

NOTE

The difference between CELLID and LOCALLCELLID is as follows:

l The CELLID configured on the MSC should be consistent with that configured on the BSC. TheLOCALLCELLID configured on the BSC should be consistent with that configured on theBTS.

l If the LOCALLCELLID is not added when the CELLID is added on the BSC, theLOCALLCELLID is equal to the CELLID by default.

2. Check the mask or the OM IP address or the signaling link IP address at the BSC and BTSsides.Run the LST BSCBTSINF command and the LST BTS command to check whether theOM IP address configured at the BSC side is consistent with that configured at the BTSside.

On the BAM, run the DSP SIGLNKSTAT command to check the signaling link status. Ifthe signaling link is not connected, run the LST BTSLNK command and the DSPCBTSCFG command to check whether the data configurations such as the mask or thesignaling link IP address at the BTS and BSC sides are consistent.

3. Check the transmission resources at the BSC and BTS sides.Run the DSP CBTSCFG command to query the information of the transmission link. AnE1 link cannot be configured to two CMPTs that have no backups.

Ensure that the chip parameter settings of the HCMP/HCEM in the SETCBTSCDMA1XCHIPPARA or SET CBTSCDMADOCHIPPARA command areconsistent with the actual situation.

4. Check the band information at the BSC side.Run the LST CDMACH command to check whether the band configuration is correct. Ifthe band configuration is incorrect, run the RMV CDMACH or ADD CDMACHcommand to modify it.

Step 5 Check the BAM server.Check whether the fault is caused by problems with the BAM server.

Check whether the BAM server starts up and the Load process is operational.

Step 6 Check the ambient temperature for the BTS.Check whether the ambient temperature for the BTS is within the proper range.

Run the DSP CBTSENVPARA command to check whether the ambient temperature for theBTS is within the proper range.

Before you run the DSP CBTSENVPARA command, ensure that the BTS is equipped with theenvironment monitoring equipment EMUA and the power management unit PMU. Adjust thetemperature for the BTS if it exceeds the specified range.




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Step 7 Check the software version.Check whether the fault is caused by the inconsistency of software versions.

Run the CHK CBTSSWVER command to check whether the board software version isconsistent with the BAM software version.

The CHK CBTSSWVER command cannot be used to check the consistency between theconfiguration file and the INI file. To check whether the configuration file is consistent with theINI file, open the files and compare the version information at the head of the files.

----End

PostrequisiteIf the faults persist, contact Huawei for technical support.

4.3 Case: BTS Startup Failures Caused by the Failure of theLoad Process in the BAM

The failure of the Load process in the BAM may cause a BTS startup failure. This topic describeshow to clear the BTS startup failures caused by the failure of the Load process in the BAM.

Symptomsl After the BTS transmission link failure is rectified, restart the BTS. But the BTS cannot

start working.l The OM IP address cannot be pinged on the BAM. The OML to the BTS cannot be

established.l Only the clear alarms corresponding to the alarms such as E1/T1 link signal loss and

insufficient active links in the far-end IMA group exist. The clear alarms corresponding tothe OML disconnection alarms do not exist.

Fault LocationThe possible causes of the BTS BOOTP failure are as follows:

l The BTS transmission is disrupted or intermittent link failures occur. Therefore, the biterror rate is too high, the E1 link is unavailable, or the IMA link cannot be activated.

l The BTS information or the BOOTP information at the BAM side and at the BTS side iswrong or missed or the configurations at both sides are inconsistent.

l The BAM fails or the Load process is exceptional. During the BTS BOOTP process, theBTS requests an IP address from the BAM through the Load process. If the Load processis exceptional, the BTS BOOTP process fails.

If only the clear alarms corresponding to the E1/T1 link signal loss alarms exist, and the clearalarms corresponding to the OML disconnection alarms do not exist, you can infer that thephysical transmission layer is in normal condition and that the BTS BOOTP process fails.

Fault HandlingTo rectify the fault, proceed as follows:



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1. On the Service Maintenance System, run the DSP E1T1STAT command to check whetherthe E1 link status is Available. Run the DSP IMALNKSTAT command to check whetherthe IMA link status is Effective. If the transmission link does not perform loopback, youcan infer that the transmission links are functional.

2. Run the LST BSCBTSINF command to query the BTS information on the BAM. Run theLST BTSBTPINFO command to query the BOOTP information configured on the BTS.If the BTS information and the BOOTP information are configured are correct, you caninfer that the fault is not caused by data errors.

3. Start the Load process on the BAM and find that the Load process status is Exceptional.When the Load process is exceptional, the BOOTP information reported by the BTS cannotreach the BAM and then the BTS does not obtain the OM IP address. Therefore, the OMLsetup fails. Restart the Load process. Ensure that the BTS restarts and works without errors.

4.4 Case: BTS Startup Failures Caused by Signaling IPConfiguration Inconsistency

In IPOA mode, the BTS may fail to start and MSs may fail to access the network if the IPaddresses of the BTS and BSC signaling links are inconsistent. This describes the symptoms ofthe faults and the procedure for troubleshooting the faults.

Symptomsl All the boards are functional and the data configuration script file can be loaded properly.

But the BTS does not work and the MS cannot access the network.

l After the board software is loaded, the version information of all the boards can be reportedand the clock for the BTS is functional.

l The Abis signaling link interrupted alarm is generated.

Fault Location

The prerequisites for the normal operation of the BTS are as follows:

l The OML is correctly configured at the BAM and BTS sides.

l The PVC and routing information is correctly configured on the BSC. In a DOSenvironment, you can run the route print command to query the routing information onthe BSC.

l The signaling data and traffic data are correctly configured at the BSC and BTS sides, andthey are kept consistent.

Because the board software is loaded properly and the OML link of the BTS is normal, you caninfer that the possible cause of the fault is the data configuration error of the signaling link orthe traffic link.

To locate the data configuration problem of the signaling link, check whether the signaling IPaddresses configured at the BSC and BTS sides are consistent.

Fault Handling

To rectify the fault, proceed as follows:




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1. Run the LST IPOAPVC command to query the IPoA PVC information at the BSC side.Ensure that the IPoA PVC information is correct.

2. Run the route print command to query the routing information on the BAM. Ensure thatthe routing information on the BAM is correct.

3. Run the CHK CBTSIFCFG command to check whether the data on the BSC and BTS isconsistent. SIGIP=80.17.130.216 is inconsistent with BTSIP=80.17.130.116.Modify the IP addresses to ensure the consistency. After the software is reloaded, the BTSis functional and the MS can access the network.



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About This Chapter

The power subsystem of the BTS consists of the BBU3900 power module, the cabinet powermodule PSU, the power distribution module, the lightning protection module, and the monitoringmodule. If the BTS fails to be powered on, or if the BTS restarts frequently and the logged failurecause for each startup is different, then the failure might be a power supply failure.

5.1 Overview of the BBU3900 Power SupplyThe BBU3900 is powered by the PSU AC/DC in the cabinet. The PSU AC/DC provides +24 V DCto the BBU3900. The BBU3900 has a built-in power module, UPEU, to convert +24 V DC to+12 V DC.

5.2 Power Supply in the BTS3606AE CabinetsThe BTS3606AE cabinets support 110 V AC or 220 V AC mains supply. The cabinet powermodule PSU AC/DC converts 110 V AC or 220 V AC power to +24 V DC power.

5.3 Troubleshooting the BBU3900 Power Module FailuresBBU3900 power module failures may interrupt ongoing services and damage chips. Thisdescribes the symptoms of the faults and the procedure for troubleshooting the faults.

5.4 Troubleshooting the Power Module FailuresWhen the BTS power module is faulty, the BTS may fail to be powered on or may restartrepeatedly. This describes the symptoms of the faults and the procedure for troubleshooting thefaults.

5.5 Case: Frequent Restart of the BTS Due to Power Module FailuresThis describes the procedure for troubleshooting the problem that the BTS restarts frequentlyafter an upgrade.

Airbridge BTS3606AE CDMA Base StationTroubleshooting Guide 5 Troubleshooting BTS Power Supply Failures


5-1

5.1 Overview of the BBU3900 Power SupplyThe BBU3900 is powered by the PSU AC/DC in the cabinet. The PSU AC/DC provides +24 V DCto the BBU3900. The BBU3900 has a built-in power module, UPEU, to convert +24 V DC to+12 V DC.

5.1.1 Functional Structure of the UPEUThis describes the functional structures of the UPEB and the UEIC in the UPEU and the functionsof each module.

5.1.2 UPEU PanelThis describes the appearance and the ports of the UPEU panel.

5.1.3 Technical Specifications of the UPEUThis describes the dimensions, input voltage range, input current, input voltage, output voltage,and rated power of the UPEU.

5.1.1 Functional Structure of the UPEUThis describes the functional structures of the UPEB and the UEIC in the UPEU and the functionsof each module.

l Functional Structure of the UPEB

The UPEB consists of the protection circuit, delay startup/blind mating, EMI filter circuit,and power module. It converts the +24 V DC power into +12 V DC power, reports detectedfaults and undervoltage input alarms through I2C. Figure 5-1 shows the functional structureof the UPEB.

Figure 5-1 Functional structure of the UPEB

l Functional Structure of the UEIC

The UEIC collects the external alarm information about water damage, smoke, door status,and temperature and humidity, and reports the alarm information to the main controltransmission board in the BBU3900 through the UPEB and the backplane.

5.1.2 UPEU PanelThis describes the appearance and the ports of the UPEU panel.

Appearance

Figure 5-2 shows the UPEU panel.

5 Troubleshooting BTS Power Supply FailuresAirbridge BTS3606AE CDMA Base Station



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Figure 5-2 UPEU panel

(1) EXT_ALM1 port (2) EXT_ALM0 port (3) MON1 port

(4) MON0 port (5) PWR port

PortsTable 5-1 lists the ports on the UPEU panel.

Table 5-1 Description of the UPEU ports

Port Input/Output

Function Description

MON0 port Input/Output Input and output ofRS485 signal

X1: Rx+ of RS485 outputX2: Rx- of RS485 outputX4: Tx+ of RS485 inputX5: Tx- of RS485 inputX6 and X8: GND

MON1 port Input/Output Input and output ofRS485 signal

X9: X9: Rx+ of RS485 inputX10: Rx- of RS485 inputX12: Tx+ of RS485 outputX13: Tx- of RS485 outputX14 and X16: GND

EXT_ALM0 port

Output dry node output X17: dry node 0X19: dry node 1X21: dry node 2X23: dry node 3X18, X20, X22, and X24: GND



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Port Input/Output

Function Description

EXT_ALM1 port

Output dry node output X25: dry node 4X27: dry node 5X29: dry node 6X31: dry node 7X26, X28, X30, and X32: GND

PWR port Input 24 V power input -

NOTEThe pins in the port are numbered from right to left, that is, they are numbered X1 to X32.

Indicators on the Front PanelTable 5-2 lists the indicators on the UPEU panel.

Table 5-2 Description of the indicators

Name Remarks Normal State

Power supplyindicator

On: The board functions properly. Green

5.1.3 Technical Specifications of the UPEUThis describes the dimensions, input voltage range, input current, input voltage, output voltage,and rated power of the UPEU.

The technical specifications of the UPEU are as follows:

l Dimensions (length x width x depth): 292.39 mm [11.51 in.] x 85 mm [3.35 in.] x 40.14mm [1.58 in.]

l Input voltage: 19 V to 29 V

l Input current: ≤ 18 A

l Output voltage: 20 V to 36 V

l Output voltage: 12 V

l Rated power: 300 W

5.2 Power Supply in the BTS3606AE CabinetsThe BTS3606AE cabinets support 110 V AC or 220 V AC mains supply. The cabinet powermodule PSU AC/DC converts 110 V AC or 220 V AC power to +24 V DC power.

5.2.1 Principles of Power Distribution in Cabinets




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The BTS3606AE uses AC power supply and uses PSU AC/DC to convert 110 V AC or 220 VAC to +24 V DC.

5.2.2 PSUAC/DC PanelThis topic describes the appearance of and the indicators on the PSUAC/DC panel.

5.2.3 Technical Specifications of the PSUAC/DCThis describes the technical specifications of the PSUAC/DC.

5.2.1 Principles of Power Distribution in CabinetsThe BTS3606AE uses AC power supply and uses PSU AC/DC to convert 110 V AC or 220 VAC to +24 V DC.

Figure 5-3 shows the power distribution in a cabinet.

Figure 5-3 Power distribution in a cabinet

The AC power passes through the AC power distribution unit to the power input busbar on themotherboard of the power frame. Then, the PSU AC/DC on the motherboard converts the ACpower to +24 V DC power and outputs the +24 V DC power to the +24 V DC busbar.

Then, the +24 V DC total line bank distributes the +24 V DC power to power consumption unitssuch as the BBU3900, EMUA, batteries, transmission power modules, RF subracks, and heatexchangers.

5.2.2 PSUAC/DC PanelThis topic describes the appearance of and the indicators on the PSUAC/DC panel.

Appearance of the PSUAC/DC Panel

Figure 5-4 shows the appearance of the PSUAC/DC panel.



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Figure 5-4 Appearance of the PSUAC/DC Panel

Indicators on the PSU PanelTable 5-3 lists the indicators on the PSU panel.

Table 5-3 Description of the PSU indicators

NameColor Meaning Description

NormalStatus

Powersupplyindicator

Green

Indicatesthe statusof powersupply.

ON: normalOFF: No AC power is inputted or theinput fuse is damaged.

ON

Monitoringindicator

Yellow

Indicatesthemonitoringstatus.

ON: The AC power input voltage orambient temperature exceeds thethreshold. The current limiting andtemperature protection are started.OFF: normal

OFF

Alarmindicator

Red Indicatesalarms.

ON: The overvoltage/undervoltagealarm, module fault alarm, or fan faultalarm is generated.OFF: normal

OFF

5.2.3 Technical Specifications of the PSUAC/DC

This describes the technical specifications of the PSUAC/DC.

The specifications of the PSUAC/DC are as follows:

l Input voltage: 90 V DC to 300 V DC




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l Working frequency: 44 Hz to 66 Hz

l Output voltage: 22 V to 29 V (can be adjusted through the PMU)

l Undervoltage protection point: 85 V

l Overvoltage protection point: 305 V

l Output power: 680 W (90 V AC to 150 V AC) or 1400 W (150 V AC to 300 V AC)

l Dimensions (length x width x depth): 89 mm [6.97 in.] x 107 mm [1.57 in.] x 249 mm[11.02 in.]

5.3 Troubleshooting the BBU3900 Power Module FailuresBBU3900 power module failures may interrupt ongoing services and damage chips. Thisdescribes the symptoms of the faults and the procedure for troubleshooting the faults.

Symptoms

The BBU3900 uses the power module UPEU, which supports the 1+1 redundancy mode. Table5-4 describes the symptoms of the BBU3900 power module failures.

Table 5-4 Symptoms of the BBU3900 power module failures

Item Symptom

Services Services are interrupted.

Boardstatus

No abnormal status is displayed.

Alarms The BTS may report the following alarms:l Power module failure alarm

l The DC undervoltage alarm is generated.

Fault Location

Table 5-5 lists the possible causes and analysis of BBU3900 power module failures.

Table 5-5 Possible causes and analysis of the BBU3900 power module failures

Cause Analysis

Powermodulefailure alarm

The BBU3900 powermodule is not properlyinstalled.

The UPEU is in poor contact with the slot.

The parameterconfiguration of theBBU3900 power module isincorrect.

The configured number and position of theUPEU do not comply with the actualconditions.



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Cause Analysis

The BBU3900 powermodule is faulty.

The hardware of the UPEU is faulty and needsto be replaced.

The DCundervoltagealarm isgenerated.

The power supply system isfaulty.

The input voltage of the UPEU is lower than+24 V.

Fault HandlingFigure 5-5 shows the procedure for troubleshooting the BBU3900 power module failures.




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Figure 5-5 Procedure for troubleshooting the BBU3900 power module failures

Procedure

Step 1 Check the installation of the BBU3900 power module.Check whether the UPEU is properly installed. If the UPEU is not properly installed, "The powermodule is faulty" alarm is generated after you run the LST ALMFE command.



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1. Check whether the connector at the PWR joint on the UPEU is tightened. If the connectoris loose, tighten it.

2. Check whether the other end of the connector is connected to the DC power distributionbox of the cabinet.

Step 2 Check the parameter configuration of the BBU3900 power module.Check whether the parameter configuration of the power module is correct.1. Run the DSP CBTSBBUPWRINFO command to check whether the configured number

and position of the BBU3900 power module are correct.The UPEU supports the 1+1 redundancy mode.

2. If the configured number and position of the BBU3900 power modules are incorrect, runthe RMV CBTSUPEU command to delete the incorrect configuration, and then run theADD CBTSUPEU command to correct the configuration.

Step 3 Check the BBU3900 power module.If the fault is rectified after you replace the UPEU with a new one, you can infer that the UPEUis faulty.

Step 4 Check the DC power supply.Check whether the DC power supply is faulty.1. Measure the input voltage of the UPEU and check whether the voltage is lower than +24

V.

The UPEU is powered by PSU AC/DC. If the PSU AC/DC becomes faulty or the DC powerdistribution fails, the UPEU is adversely affected.

2. To troubleshoot failures of the PSU AC/DC or the DC power distribution, refer to relatedsections in this document.

----End


5.4 Troubleshooting the Power Module FailuresWhen the BTS power module is faulty, the BTS may fail to be powered on or may restartrepeatedly. This describes the symptoms of the faults and the procedure for troubleshooting thefaults.

SymptomsThe BTSBTS3606AE cabinets support AC power supply and use the AC power module PSUAC/DC. Table 5-6 describes the symptoms of the power module failures.

Table 5-6 Symptoms of the power module failures

Item Symptom

Services The BTS may fail to be powered on or may restart repeatedly. The cause ofeach restart of the BTS recorded in the log is different.




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Item Symptom

Boardstatus

If the AC power supply is used, the green power indicator on the panel of thePSU AC/DC is on, and the red ALM indicator is off.

Alarms The BTS may report the following alarms:l The PSU AC/DC is faulty.

l AC overvoltage occurs.

l AC undervoltage occurs.

Fault Location

Table 5-7 lists the possible causes and analysis of power module failures.

Table 5-7 Possible causes and analysis of the power module failures

Cause Analysis

The power module isfaulty.

The connection from thepower distribution cabinetto the BTS cabinet fails.

The MCB or the fuse from the powerdistribution cabinet to the BTScabinet is disconnected or isexcessively used. The excessive useof the MCB may lead to currentinstability.

The EMI filter or the powermodule is faulty.

If the PSU AC/DC is faulty, the redALM indicator on the panel of thePSU AC/DC is on or is displayed greyon the panel of the ServiceMaintenance System.

The circuit is faulty. The wiring terminals are oxidized,thus reducing the power supplycapability. This causes the powersupply failure or the RF modulefailure.

The parameters of thepower module areincorrectly configured.

l The number and position of the configured power modules donot comply with the actual conditions.

l The parameters of the PMU are incorrectly configured or are notconfigured after the PMU is replaced.

The power supplysystem is faulty.

l If the 220 V or 110 V AC power supply is used, use a multimeter(set to the AC range) to measure the voltage between the Lterminal and the N terminal. Check whether the voltage is withinthe proper range.

l The voltage ranges from 90 V to 150 V (for 110 V AC input) orfrom 150 V to 300 V (for 220 V AC input).



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Fault HandlingFigure 5-6 shows the procedure for troubleshooting the power module failures.

Figure 5-6 Procedure for troubleshooting the power module failures

Context

CAUTIONIn the case that the BTS is powered on, do not perform any operations on the power cables.




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Procedure

Step 1 Check the installation of the power module.Check whether the power module is properly installed. If the power module is not properlyinstalled, an alarm indicating "the power module is faulty or not in position" is generated afteryou run the LST ALMFE command.1. Check whether the bolts that connect to the power wiring posts on the top of the cabinet

are tightened. Figure 5-7 shows the installation of the power wiring posts on the top of thecabinet using the -48 V DC power supply.If the cabinet is not properly grounded, the bit error rate may be excessively high, therebycausing the BTS to restart repeatedly.

Figure 5-7 Installation of the power wiring posts

2. Check whether the power cables are properly and securely connected to the power

distribution cabinet.Check whether cable lugs are overlapping and whether the overlapping cable lugs areproperly installed.



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3. Check whether the PSU AC/DC is properly installed.

If the PSUAC/DC functions properly, the green power indicator is on, and the red ALMindicator is off. If the power indicator does not function properly, reinstall or replace thePSU AC/DC.

Step 2 Check the parameter configuration of the power module.Check whether the parameter configuration of the power module is correct.

1. Run the DSP CBTSPMUPSU command to check whether the number and position of theconfigured power modules are correct.The PSU AC/DC supports the N+1 redundancy mode. The number of the power modules isdependent on the number of the sector carriers.

2. If the number and position of the power modules are incorrectly configured, run the SETCBTSPMUPSU command to reconfigure them.

Step 3 Check the power supply system.Check whether the power supply system is faulty.

1. Check whether the power supply voltage of the cabinet is proper and stable.

If the AC power input is used, set the multimeter to the AC voltage range, and then connectthe positive pole to the L wire and the negative pole to the N wire. Check whether thevoltage of the single-phase, two-phase, or three-phase power supply is in the specifiedrange.

2. If the power supply voltage is beyond the proper range or unstable, contact the power supplysystem engineers for assistance in rectifying the fault.The causes of the fault may be that the cables from the power distribution cabinet to thetop of the cabinet are loose or excessively used and that the fuse or the MCB is disconnected.

----End

Postrequisite

If the faults persist, contact Huawei for technical support.

5.5 Case: Frequent Restart of the BTS Due to Power ModuleFailures

This describes the procedure for troubleshooting the problem that the BTS restarts frequentlyafter an upgrade.

Symptomsl The BTS restarts frequently after the upgrade. The restart time is uncertain and the BTS

may restart several times a day or once in several days.

l The following alarms are generated (you can query the alarms through Telnet):

– E1/T1 link disconnection

– Network disconnection of the BAM

– Abis signaling link disconnection




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Fault LocationThe possible causes of restart of the BTS include:

l Incomplete upgradeIn normal cases, this fault is logged.

l Intermittent blinking of transmission linksThis fault can be detected by a loopback at the BTS side. The troubleshooting of this faultis omitted in the procedure for troubleshooting the frequent restart of the BTS.

l Faulty power moduleIf the power supply system has failures such as unstable output voltage or insufficientcapacity, the BTS restarts. The restart time is uncertain and the reported restart time is notthe actual time.

l Faulty CMPTYou can determine whether the CMPT is faulty by observing the indicators on the panelof the CMPT. If the CMPT is faulty, the BSC data cannot be delivered to the BTS andcauses a restart of the BTS.

Fault Handling1. Run the RPT CBTSLOG command to obtain the BTS logs.

Check the BTS logs. You can find that the cause of each BTS restart is different and thetime of each BTS restart is 2000-01-01 (because the original GPS time is lost after the BTSrestarts). Each software reset is recorded in the BTS log. This indicates that repeated restartsof the BTS is not caused by the software failure.Therefore, the hardware reset maybe caused by failures in the power module or the CMPT.Failures in the power module are most likely to cause a hardware reset.

2. Run the DSP CBTSPOWERPARA command to check whether the output voltage of thepower module is normal.

3. Run the SET CBTSPOWEROFF command to reset the BTS. You can find that the faultoccurs again.

4. Check the power supply system. You can find that the input voltage of the power supplysystem is beyond the proper range. Ask site maintenance engineers to repair the powersupply system.

TIP

l Each software reset is recorded in the BTS log.

l The causes of hardware reset in the BTS log are uncertain. The report time is 2000-01-01.



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6 Troubleshooting the BTS EnvironmentMonitoring Failures

About This Chapter

The BTS environment monitoring subsystem monitors the DC and switching power supplies ofthe BTS, voltage of the storage battery, temperature and humidity of equipment rooms, smokeconditions, and unauthorized entry into the equipment room. If an environment alarm isgenerated on the BTS Alarm Management System or the ALM indicator on the monitoringinstrument is on, a BTS environment monitoring failure might occur.

6.1 Overview of BTS Environment MonitoringThe BTS environment monitoring subsystem consists of alarm ports, EMUA, and PMU. Thisdescribes the functions of the BTS environment monitoring subsystem and introduces theenvironment monitoring instruments and environment indices.

6.2 Troubleshooting the BTS Environment Monitoring FailuresThe BTS environment monitoring subsystem monitors the equipment operation and providesthe operation information on a real-time basis. This describes the symptoms of the faults andthe procedure for troubleshooting the faults.

6.3 Case: False Alarms Caused by Incorrect Configuration of the EMUAIf an error occurs during the installation of the EMUA, an alarm may be reported on the AlarmManagement System. This describes the symptoms of the faults and the procedure fortroubleshooting the faults.

Airbridge BTS3606AE CDMA Base StationTroubleshooting Guide 6 Troubleshooting the BTS Environment Monitoring Failures


6-1

6.1 Overview of BTS Environment MonitoringThe BTS environment monitoring subsystem consists of alarm ports, EMUA, and PMU. Thisdescribes the functions of the BTS environment monitoring subsystem and introduces theenvironment monitoring instruments and environment indices.

6.1.1 Functional Structure of the Environment Monitoring SubsystemThis describes the functional structure of the environment monitoring subsystem. Theenvironment monitoring function of the BTS3606AE are implemented through sensors andmonitoring devices. The monitoring devices of the AC cabinet are the PMU and EMUA. TheEMUA is optional.

6.1.2 Meanings of Terminologies Related to the BTS Environment Monitoring InstrumentThe EAC monitors the equipment operation on a real-time basis. You can acquire relatedenvironment information in real time through the EAC. This topic introduces the terminologiesrelated to the EAC of the BTS.

6.1.3 Environment Monitoring InstrumentThe environment monitoring instruments for the BTS3606AE cabinets that use AC powerinclude PMU and EMUA (optional).

6.1.4 BTS Environment Monitoring SpecificationsEnvironmental requirements for the BTS include the requirements for the storage, transportation,and operation of the equipment. This describes the requirements for the ambient temperatureand humidity.

6.1.1 Functional Structure of the Environment MonitoringSubsystem

This describes the functional structure of the environment monitoring subsystem. Theenvironment monitoring function of the BTS3606AE are implemented through sensors andmonitoring devices. The monitoring devices of the AC cabinet are the PMU and EMUA. TheEMUA is optional.

Functional Structure of the Environment Monitoring Subsystem of the AC CabinetFigure 6-1 shows the functional structure of the environment monitoring subsystem of the ACcabinet.

6 Troubleshooting the BTS Environment Monitoring FailuresAirbridge BTS3606AE CDMA Base Station



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Figure 6-1 Functional structure of the environment monitoring subsystem of the AC cabinet

6.1.2 Meanings of Terminologies Related to the BTS EnvironmentMonitoring Instrument

The EAC monitors the equipment operation on a real-time basis. You can acquire relatedenvironment information in real time through the EAC. This topic introduces the terminologiesrelated to the EAC of the BTS.

l BooleanA variable that determines the ON or OFF state

l AnalogA consecutive value in the reported information such as temperature and humidity

l Dry contactA Boolean interface that reports the status of equipment

l Active contactA contact in which the output signal contains the output voltage

l Basic interfaceA default monitoring interface of the monitoring device, which used for monitoring waterdamage, infrared ray, door control, temperature and humidity, and smoke

l High level or low levelWhen you run the SET CBTSENVSWTEXTPORT command to set the Boolean extendedport parameters, set the Alarm Boolean to high level or low level.As shown in Figure 6-2, the meaning of the high-level alarm is that the voltage detectorstarts the alarm reporting mechanism when the switch of the sensor or dry contact is on andthe level of the voltage detector is high level.



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Figure 6-2 Principle of the extended port alarm

The meaning of the low-level alarm is opposite to the meaning of the high-level alarm.

6.1.3 Environment Monitoring InstrumentThe environment monitoring instruments for the BTS3606AE cabinets that use AC powerinclude PMU and EMUA (optional).

Monitoring Functions of PMU and EMUAThe PMU and EMUA monitor the control variable signal, Boolean variable signal, current andvoltage analog signal, and environment variable analog signal on a real-time basis.

Table 6-1 lists the functions of the PMU and EMUA.

Table 6-1 Functions of the PMU and EMUA

MonitoringDevice Function Set Function Description

PMU Control variable signal Average voltage floating charge and currentcontrol for batteriesOverload protection for batteries

Boolean variable signal Alarming of AC lightning protection devicesAlarming of lightning arresters for ports ofbatteriesSmoke alarming and door status alarming

Current and voltageanalog signal

Current (A) of battery groupTotal load current (A)Input voltage (V)

Environment variablesignal

Temperature in cabinets (with sensors) (oC)Humidity in cabinets (with sensors) (RH%)




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MonitoringDevice Function Set Function Description

Management of thepower supplysubsystem

PSU failure or protection alarmingPSU-PMU communication failure alarmingFuse status alarmingMains supply availability alarmingMains supply overvoltage and undervoltagealarming

EMUA Boolean variable signal Smoke, door status, and water alarming

Environment variablesignal

Temperature in cabinets (with sensors) (oC)Humidity in cabinets (with sensors) (RH%)

PMU PanelThis topic describes the appearance, ports, indicators, and DIP switches of the PMU.

Appearance of the PMU PanelFigure 6-3 shows the front view of the PMU panel.



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Figure 6-3 Front view of the PMU Panel

1) RS232/RS422 port 2) Indicator 3) Power supply test port

4) TEST port 5) Battery control switch 6) COM port

Ports of the PMUTable 6-2 lists the ports of the PMU.

Table 6-2 Description of PMU Ports

Port Name Description

RS232/RS422 port An independent serial port used for the communication with theupstream equipment.

TEST port A port used for tests

Battery controlswitch

A switch with ON and OFF for connecting and disconnecting thepower supply to the batteries.Press ON for 5s to 10s to connect the PMU to the batteries.Press OFF for 5s to 10s to disconnect the PMU with the batteries.




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Port Name Description

Power supply testport

The two power supply test ports "-48V/+24V" and "0V" can beconnected with ordinary multimeter for measuring voltage of powersupply.l For the -48 V DC system, connect the red terminal to the "OV"

port, and connect the black terminal to the "-48V/+24V" port.l For the -48 V DC system, connect the red terminal to the "-48V/

+24V" port, and connect the black terminal to the "OV" port.

COM port A DB50 connector connected to the external signal forwarding boardthrough the PMU montoring cable.

Indicators on the PMU PanelTable 6-3 lists the indicators on the PMU panel.

Table 6-3 Indicators on the PMU panel

Name Color

Meaning Description Normal Status

Run Green Operationindicator

Blinking at 1 Hz: The communicationis normal.Blinking fast: The communication isabnormal.Others: The monitoring unit isabnormal.

Blinking at 1 Hz

Alm Red Alarmindicator

ON: alarmOFF: normal

OFF

DIP Switches of the PMUFigure 6-4 shows the DIP switches of the PMU.



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Figure 6-4 DIP switches of the PMU

Table 6-4 describes the DIP switches of the PMU.

Table 6-4 DIP switches of the PMU

No. Function Indication

Bits 0-3 Indicates the PMUcommunicationaddress.

ON: 1; OFF: 0.For example, if the PMU communication address is 8,bits 0-2 are set to OFF and bit 4 is set to ON.

Bit 7 Indicates the systemtype.

For the CDMA system, bit 7 is set to OFF.

Bits 4-6 Not defined None.

Technical Specifications of the PMUThis topic describes the technical specifications of the PMU.

The technical specifications of the PMU are as follows:

l Power consumption: ≤ 30 W

l Dimensions (length x width x depth): 249 mm [9.80 in.] x 107 mm [4.21 in.] x 89 mm [3.50in.]




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Overview of the EMUAThe EMUA is an environment monitoring unit. It collects environment variables such astemperature, humidity, smoke, water, and door control from each sensor, and then reports theenvironment variables to the BTS. The EMUA is used in the AC cabinets of the BTS3606AE.

The EMUA is classified into three types. For details, refer to the instructions shipped with theEMUA.

6.1.4 BTS Environment Monitoring SpecificationsEnvironmental requirements for the BTS include the requirements for the storage, transportation,and operation of the equipment. This describes the requirements for the ambient temperatureand humidity.

The requirements for operating temperature and humidity for a BTS with cabinets of hotexchanger type are as follows:l Operation temperature

– Temperature for operation in the short term: -40oC to +52oC

– Temperature for operation in the long term: -40oC to +49oC

l Relative humidity: 5% to 100%

6.2 Troubleshooting the BTS Environment MonitoringFailures

The BTS environment monitoring subsystem monitors the equipment operation and providesthe operation information on a real-time basis. This describes the symptoms of the faults andthe procedure for troubleshooting the faults.

SymptomsTable 6-5 describes the symptoms of environment monitoring failures.

Table 6-5 Symptoms of the environment monitoring failures

Item Symptom

Boardstatus

The Run indicator and the ALM indicator of the EMUA blink at 0.5 Hz.



6-9

Item Symptom

Alarms If environmental indices such as temperature and humidity do not meet thespecified ranges, the environment monitoring instrument generates alarms andreports them to the BTS, and then to the BSC. Such alarms include:l Equipment room or board temperature too high/low alarm

l Equipment room humidity too high/low alarm

l Equipment room or cabinet smoke alarm

l Equipment room or cabinet water damage alarm

l DC overvoltage or undervoltage alarm

l Malfunction of the temperature sensor

l Equipment room or cabinet door control alarm

If the environment monitoring instrument is not properly installed, thecommunication between the environment monitoring instrument and the BTSfails. Therefore, failures might exist in the operating environment of the BTSbut no alarms are generated. Alarms, however, might be generated when the dataconfiguration does not comply with the actual conditions.l If the communication between the BTS and the environment monitoring

instrument fails, or if the environment monitoring instrument is not installedbut the data configuration commands are run, the system displays "Thecommunication link between the environment monitoring instrument and theCMPT is disconnected." when you run the DSP CBTSEMUAINFOcommand.

l If the environment monitoring instrument configured (by running the ADDCBTSEMUA command) on the BTS does not match the actual environmentmonitoring instrument type and BTS type, the system generates the alarm"The data configuration does not match the actual environment monitoringinstrument type."

Fault LocationTable 6-6 lists the possible causes and analysis of environment monitoring failures.

Table 6-6 Possible causes and analysis of the environment monitoring failures

Cause Analysis

The environmentalindices of theequipment room donot meet thespecified ranges.

Board temperature andhumidity alarm

The temperature and humidity of theenvironment is excessively high or low ora fire occurs in the equipment room due tostall of the BTS fans.

Cabinet smoke alarm Smoke is generated due to burncomponents in the cabinet or a fire occursin the cabinet.




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Cause Analysis

Cabinet water alarm Accumulated water exists in the equipmentroom.

DC overvoltage orundervoltage alarm

The DC voltage is unstable or the DC alarmthreshold is improper.

Malfunction of thetemperature sensor

The temperature sensor is faulty or the I2Cbus connector is faulty.

Cabinet door controlalarm

The door of the cabinet is open. Ask themaintenance personnel to keep the doorclosed.

The environmentmonitoringinstrument is notproperly installed.

If the environment monitoring instrument is not properly installed orthe data cable connected with the BTS is faulty, the communicationbetween the environment monitoring instrument and the BTS fails.Therefore, faults might exist in the operating environment of the BTSbut no alarms are generated.

The dataconfiguration of theenvironmentmonitoringinstrument isimproper.

The data configuration of the environment monitoring instrument doesnot comply with the actual conditions.

The ranges of environmental indicators are improper.

Failure in theCMPT, PMU,EMUA, orbackplane

If the operating environment for the BTS does not meet therequirements, but alarms are not generated, check the status of theCMPT, PMU, EMUA, and backplane. If required, replace or switchover the boards and conduct a test.

Fault HandlingFigure 6-5 shows the procedure for troubleshooting the faults in the communication betweenthe environment monitoring instrument and the BTS.



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Figure 6-5 Procedure for troubleshooting the faults in the communication between theenvironment monitoring instrument and the BTS




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Procedure

Step 1 Check the environmental indices of the equipment room.Check whether the environmental indices of the equipment room meet the specified ranges.Clear the environmental index alarms by using the alarm help. For detailed on parts replacement,refer to the BTS site maintenance guide.

Step 2 Check the installation and cabling of the environment monitoring instrument.Check whether the environment monitoring instrument is properly installed or whether the cablesof the environment monitoring instrument are securely connected.

For details on the installation of the EMUA and cables, refer to Installation of the EMUA andSensors in the EMUA user guide.

1. Check whether the EMUA is powered on.

If the RUN indicator blinks at 0.5 Hz and the ALM indicator is off, you can infer that theEMUA is powered on. For details on indicators, refer to LED Indicators on the EMUA inthe EMUA user guide.

If the RUN indicator is off, the power cables might be inversely connected.2. Check whether the EMUA is inserted in position and whether the data cable between the

EMUA and the CMPT is properly connected.

If the EMUA is installed, but the system displays "The communication link between theEMUA and the CMPT is disconnected." after the DSP CBTSEACINFO command is run,you can infer that the EMUA is not properly installed or that the data cable is not properlyconnected.

3. Check whether the cables between the EMUA and the sensors are properly connected.For details on interfaces between the EMUA and various sensors, refer to Panel of theEMUA.

4. Check whether the DIP switches on the EMUA are correctly set.l The use of sensors is dependent on the settings of the corresponding DIP switches on

the EMUA. For example, if you want to use a water sensor, you need to set the DIPswitch of the water sensor to ON. For details on the DIP switches on the EMUA, referto Board Structure of the EMUA in the EMUA user guide.

l In addition, to enable serial port communication between the EMUA and the BTS, youneed to set a communication protocol by setting the corresponding DIP switch on theEMUA. For example, the type of the protocol used by a CDMA BTS is CDMA.Therefore, you need to set the four bits of the SW_ADDR DIP switch to ON, that is,set the four bits to 0000. For details on the SW_ADDR DIP switch, refer to SW_ADDRDIP Switch on the EMUA in the EMUA user guide.

Step 3 Check the data configuration of the environment monitoring instrument.Check whether the data configuration of the environment monitoring instrument is correct.1. Run the ADD CBTSEMUA command and check whether the EMUA is added.

If an environment monitoring instrument is not configured, an alarm is generated after thiscommand is run.

2. Run the DSP CBTSCFG command to check whether parameters such as analog extendedport, Boolean extended port, temperature and humidity range, and smoke and anti-burglaryalarm clearing are added.



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Read the instructions of the environment monitoring instrument and check whether theenvironment monitoring instrument supports the analog extended port or the Booleanextended port.

Read the instructions of the environment monitoring instrument and check whether thesettings of the parameters comply with the specifications.

NOTE

Temperature and humidity are analog values, which must meet the actual conditions and complywith the software configuration rules. For example, the difference between the analog upper alarmthreshold and the lower alarm threshold must exceed 2% of the analog value range.

Step 4 Check the CMPT, EMUA, and PMU.After you locate the faults, check whether the faults are caused by an faulty CMPT or EMUA.

Replace the CMPT, EMUA, PMU, or backplane and check whether they are faulty. If the BTSis configured with a standby CMPT, you can swap the active and standby CMPTs to checkwhether the original active CMPT is faulty.

For details on how to replace the CMPT, EMUA, PMU, and backplane, refer to the BTS sitemaintenance guide.

----End


6.3 Case: False Alarms Caused by Incorrect Configurationof the EMUA

If an error occurs during the installation of the EMUA, an alarm may be reported on the AlarmManagement System. This describes the symptoms of the faults and the procedure fortroubleshooting the faults.

SymptomsThe Alarm Management System of a BTS generates a large number of "The communicationlink between the EMUA and the CMPT is disconnected" alarms.

Fault LocationThe possible causes of the fault are as follows:l The EMUA is not properly installed or the connection cables are faulty.

l The data configuration is incorrect.

l The CMPT, alarm equipment, or backplane is faulty.

Fault Handling1. Check the installation of the EMUA.

On the site, only some of the BTSs are equipped with the EMUAs and the information ofthese EMUAs, such as BTS ID and EMUA type, is unknown.




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Therefore, "The communication link between the EMUA and the CMPT is disconnected"alarms may be caused by the fact that the data of an EMUA is configured by using theADD CBTSEMUA command but the actual EMUA is not installed.

2. Run the DSP CBTSEMUAINFO command to query the information of the EMUA.If Failure Cause = "EMUA absent" is returned, you can infer that the EMUA is notconfigured. If the information of an EMUA is configured but the actual EMUA is notinstalled, you need to delete the information of the EMUA.

3. Run the RMV CBTSEMUA command to delete the EMUA, and then run the DSPCBTSEMUAINFO command to query the information of the EMUA. If Failure Cause= "EMUA unconfiged" is returned, you can infer that the EMUA is not configured. On theAlarm Management System, "The communication link between the EMUA and the CMPTis disconnected" alarm related to this EMUA is cleared.

Repeat step 3 to clear all the alarms.

NOTE

Such alarms are caused by the fact that the information of an EMUA is configured but the actual EMUAis not installed. When such alarms are generated, check the configured EMUA information of the BTSfirst. If necessary, refer to instructions for using an EMUA.



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About This Chapter

When the BTS reports the GPS antenna open-circuit alarm, GPS antenna short circuit alarm, orphase-locked loop alarm, the switchover of the active and standby CMPTs may be triggered andthe ongoing BTS services may be interrupted. Therefore, you need to locate and troubleshootthe BTS clock failures. The causes of BTS clock failures include GPS antenna open-circuit orshort-circuit failure, phase-locked loop failure, and insufficient satellites received by the BTS.

7.1 Overview of the BTS ClockThe BTS synchronizes its clock with the GPS system or the GLONASS system through a satellitesynchronization antenna.

7.2 Troubleshooting the Open-Circuit or Short-Circuit Failures in the BTS Antenna SystemOpen-circuit or short-circuit failures in the BTS antenna system can be caused by a broken ordisconnected antenna feeder, a faulty lightning arrester, or the condition of water entry into theconnectors. This describes the symptoms of the faults and the procedure for troubleshooting thefaults.

7.3 Troubleshooting the Failure of Insufficient SatellitesThe incorrect configuration of clock parameters or the improper installation of the GPS antennamay cause an insufficient quantity of satellites received by the BTS. This describes the symptomsof the faults and the procedure for troubleshooting the faults.

7.4 Troubleshooting the BTS Phase-Locked Loop FailuresBTS phase-locked loop (PLL) failures are a part of BTS clock failures. This describes thesymptoms of the faults and the procedure for troubleshooting the faults.

7.5 Case: HCPM Startup Failures Caused by GPS Clock FailuresThe BTS uses the satellite synchronization clock signals as the clock source. The satellitesynchronization clock signals are received by the satellite receiver of the CMPT. The HCPMfails to start when a clock failure occurs. This describes the symptoms of the faults and theprocedure for troubleshooting the faults.

7.6 Case: Interference in Voice Calls Caused by the Damaged GPS Feeder ConnectorThe BTS satellite synchronization antenna system consists of the antenna, feeder, and lightningarrester. When the GPS feeder becomes faulty, there may be interference in voice calls. Thisdescribes the symptoms of the faults and the procedure for troubleshooting the faults.

Airbridge BTS3606AE CDMA Base StationTroubleshooting Guide 7 Troubleshooting the BTS Clock Failures


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7.1 Overview of the BTS ClockThe BTS synchronizes its clock with the GPS system or the GLONASS system through a satellitesynchronization antenna.

7.1.1 Functional Structure of the Satellite Synchronization Antenna SubsystemThis section describes the functional structure of the satellite synchronization antennasubsystem. For system security and reliability, the BTS receives signals from the GPS orGLONASS through a satellite synchronization antenna to implement radio synchronization.

7.1.2 BTS Clock Source and Local TimeThe BTS and the BSC both have their own satellite receivers. This enables the synchronizationbetween the BTS and the BSC.

7.1.3 BTS Clock Failure AlarmsThis describes BTS clock failure alarms.

7.1.1 Functional Structure of the Satellite Synchronization AntennaSubsystem

This section describes the functional structure of the satellite synchronization antennasubsystem. For system security and reliability, the BTS receives signals from the GPS orGLONASS through a satellite synchronization antenna to implement radio synchronization.

The satellite synchronization antenna subsystem consists of an antenna, two feeders, and a surgeprotector, as shown in Figure 7-1.

Figure 7-1 Functional structure of the satellite synchronization antenna subsystem

(1) GPS antenna (2) Feeder (3) Surge protector

7 Troubleshooting the BTS Clock FailuresAirbridge BTS3606AE CDMA Base Station



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NOTE

The 1/2 in. feeder and the RG8 feeder are used.

Figure 7-1 shows only the basic composition of the satellite antenna subsystem. For details on the installationposition and method, see the /BTS3606AE GPS Antenna System Installation Guide.

7.1.2 BTS Clock Source and Local TimeThe BTS and the BSC both have their own satellite receivers. This enables the synchronizationbetween the BTS and the BSC.

Clock SourceIn a CDMA system, the system time of all BTSs must be synchronous.

The following is a list of synchronization sources supported by the BTS in descending order ofpriority:

l Board synchronization source: the synchronization clock output by the satellite receiver onthe CMPT

l External clock: a synchronization clock from a source other than the CMPT

l Internal clock: also called synchronizationless clock, the crystal oscillator in the CMPT isin free-run or holdover state

l Line clock: also called the 2 MHz line recovery clock, a synchronization clock providedby the transmission system

Generally, the board synchronization source is allocated with the top priority.

NOTE

l If you add multiple synchronization sources, the BTS searches for the available one with the highestpriority.

l If you want to set the synchronization source to external clock, you must configure the HPCM.

l The internal clock synchronization source does not have a synchronization clock. Therefore, it is notconsidered as an available synchronization source.

Local Time of the BTSThe BTS can obtain the universal time coordinated (UTC) from the satellite synchronizationsystem. To determine the local time based on the UTC, you need to set the local time zone andadjustment minute (time offset).

If the local time uses DST, you need to set the DST for the BTS so that the BTS can output thelocal time during the specified period.

The command for configuring DST is SET CBTSDAYLT.

Synchronization Between the BTS and the BSCThe CDMA2000 mobile communication system is a synchronization system. It needs precisesynchronization source. The BTS and the BSC both have their own satellite receivers. Thisenables the synchronization between the BTS and the BSC.

On the LMT, the time of the service maintenance system is based on the time of the BAM:l The time of command execution is based on the time of the BAM.



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l The time of alarm report on the alarm console is based on the time of the BAM.

l The time of log record is based on the time of the BAM.

7.1.3 BTS Clock Failure AlarmsThis describes BTS clock failure alarms.

Table 7-1 lists the clock failure alarms.

Table 7-1 Clock failure alarms

ID Alarm Priority

ALM-18348 The 50Fc PLL is unlocked. 1


ALM-18386 The 10 MHz signal is lost. 1

ALM-18524 The 10 MHz PLL is unlocked. 1


ALM-17583 The power supply of the 10 MHz crystaloscillator is faulty.

1

ALM-17581 The 10 MHz crystal oscillator has nooutput.

1

ALM-17585 The frequency offset of the 10 MHz crystaloscillator is excessive.

1

ALM-17582 No 16Fc clock signal is output. 1

ALM-17584 The 32Fc hardware PLL is unlocked. 1

ALM-17589 The satellite receiver of the CMPT does notoutput second signals.

2

ALM-17590 The communication link between theCMPT and the satellite receiver of theCMPT is interrupted.

2

ALM-17586 The quantity of satellites locked by thesatellite receiver of the CMPT isinsufficient.

3

ALM-17587 The antenna of the CMPT satellite receiveris open-circuited.

3

ALM-17588 The antenna of the CMPT satellite receiveris short-circuited.

3

ALM-17591 The reference source is the internal clock. 3




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The alarms have three priorities: 1, 2, and 3. Priority 1 is the highest priority. When you handlesclock failures, clear the alarm with a higher priority first.

7.2 Troubleshooting the Open-Circuit or Short-CircuitFailures in the BTS Antenna System

Open-circuit or short-circuit failures in the BTS antenna system can be caused by a broken ordisconnected antenna feeder, a faulty lightning arrester, or the condition of water entry into theconnectors. This describes the symptoms of the faults and the procedure for troubleshooting thefaults.

SymptomsTable 7-2 describes the symptoms of the open-circuit or short-circuit failures in the BTS antennasystem.

Table 7-2 Symptoms of the open-circuit or short-circuit failures in the BTS antenna system

Item Symptom

Services The BTS fails to work. If you change the clock to Internal Clock Source, theBTS works again.

Boardstatus

The CMPT is operational. The ALM indicators on the panels of the CMPT andthe HCPM/HECM are on. Alarms are generated. If the BTS is started for thefirst time, run the DSP CBTSBRDSTAT command to check whether the statusof the HCPM/HECM and the TRM is Unavailable.

Alarms l The antenna of the CMPT satellite receiver is open-circuited.

l The antenna of the CMPT satellite receiver is short-circuited.

l Other associated alarms, such a switchover of CMPTs due to insufficientsatellites tracked by the satellite receiver of the CMPT, are generated.

Fault LocationTable 7-3 lists the possible causes and analysis of the open-circuit or short-circuit failures in theBTS antenna system.



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Table 7-3 Possible causes and analysis of the open-circuit or short-circuit failures in the BTSantenna system

Cause Analysis

Thelightningarrester isfaulty.

The symptoms of faults in the lightning arrester are as follows:l An open-circuit or short-circuit occurs in the lightning arrester after a

lightning strike.l An open-circuit or short-circuit occurs due to the rusty conditions in the

lightning arrester.l An open-circuit occurs due to disconnection of cables.

The GPScables arefaulty.

The GPS signal cablesare incorrectlyconnected.

l The GPS signal cable that connects to the GPS portof the CMPT is open-circuited.

l The GPS signal cable that connects to the lightningarrester is open-circuited.

l The GPS signal cable is broken or short-circuited.

The feeders, jumpers,or grounding cablesbetween the GPSantenna and the GPSport are faulty.

l A short-circuit occurs because the cables arebroken or are excessively used, the lightningarrester is damaged, or the connectors are loose.

l A short-circuit occurs because the waterproofingmeasures are inadequate or the cables areexcessively used.

The GPS antenna isfaulty.

The failures in the GPS antenna are classified intoopen-circuit and short-circuit failures. The GPSantenna may be struck by lightning because the GPSantenna is beyond the protection range of thelightning arrester.

Thesatellitereceiver orthe CMPTis faulty.

Run the DSP CBTSBRDSPECSTAT command to view the type of the satellitereceiver.l If the type is UNKNOWN, or the type is displayed but alarms such as "The

antenna of the CMPT satellite receiver is short-circuited" and "The satelliteslocked by the CMPT satellite receiver is not enough" are generated, you caninfer that the satellite receiver is faulty.

l If the type is displayed, but "The antenna of the CMPT satellite receiver isopen-circuited" alarm is generated or the voltage of the ANT port in the panelof the CMPT is 0 V or less than 4.5 V, you can infer that the CMPT is faulty.

Fault HandlingFigure 7-2 shows the procedure for troubleshooting the open-circuit or short-circuit failures inthe BTS antenna system.




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Figure 7-2 Procedure for troubleshooting the open-circuit or short-circuit failures in the BTSantenna system

Procedure

Step 1 Check the lightning arrester and the cables.Check whether the lightning arrester is faulty or whether the cables that connect to the lightningarrester are faulty.1. Bypass the lightning arrester.

Remove the cables at the two sides of the lightning arrester, and then connect the ends ofthe two cables directly."If the fault is rectified after the bypass, you can infer that thelightning arrester is faulty."



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2. Check the cables that connect to the two sides of the lightning arrester.

l If the cables are disconnected, reconnect them.

l If the cables are incorrectly connected, reconnect them.

NOTEThe lightning arrester is installed in factory. When you replace the lightning arrester, follow theinstructions for replacing the lightning arrester.

Step 2 Check whether the cables of the GPS antenna are faulty.Check whether the fault is caused by the cables of the GPS antenna. The GPS antenna isconnected to the feeder through the RF conversion port. The feeder is led into the cabinet fromthe bottom of the cabinet. At the bottom of the cabinet, the feeder is connected to the clock signalcable through a conversion port.

1. Check whether the connection between the GPS antenna and the feeder and that betweenthe feeder and the cabinet fail.Disable the connection between the GPS antenna and the feeder and the connection betweenthe feeder and the cabinet. Connect the shielding layer and the core layer of the feeder atone end, and then measure the resistance between the shielding layer and the core layer atthe other end. The resistance should be less than 10 ohms.

2. Check whether the cable between the GPS antenna and the feeder and the cable betweenthe feeder and the cabinet are short-circuited.Disconnect the feeder from the GPS antenna and the cabinet. Measure the resistancebetween the shielding layer and the core layer of the feeder. If the measured resistanceranges from 200 ohms to 20 megaohms, you can infer that a short circuit may occurs in thefeeder.

3. Check whether water enters the connectors.If water enters a connector, dry the connector and use waterproof tape to wrap it again.There are two types of waterproof tape: PVC tape and insulating tape. For details on howto wrap a connector using waterproof tape, refer to Sealing Outdoor Connectors.

4. Check the resistance of the GPS antenna.Use a multimeter to measure the resistance of the GPS antenna.

l If the resistance is less than 10 ohms, you can infer that the GPS antenna is faulty andyou need to replace it.

l If the resistance is more than 150 ohms, you need to test the working current of the GPSantenna.

5. Check the current of the GPS antenna.Reinstall the cables in the antenna system. Disconnect the cables at the two sides of thelightning arrester. Connect the outer sheath of the cable to the outer layer of the lightningarrester, and then use a multimeter to measure the current between the cable and the corewire of the lightning arrester.

If the current ranges from 20 mA to 30 mA, you can infer that the GPS antenna isoperational. If the GPS antenna is faulty, replace it.

Step 3 Check the installation of the CMPT (and the satellite receiver).Check whether the fault is caused by improper installation of the CMPT.

1. Check whether the clock signal cable between the lightning arrester and the CMPT doesnot function properly due to deformation.




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Before you replace the faulty clock signal cable, remove the SMA male connector first. Donot pull the cable directly.

2. Check whether the satellite receiver is faulty.Run the DSP CBTSBRDSPECSTAT command to check the status of the satellite receiver.If the type of the satellite receiver type is UNKNOWN, you can infer that the satellitereceiver is faulty and you need to replace it. If the satellite receiver is built in the CMPT,you need to replace the CMPT.

3. Check whether the CMPT is faulty.Run the DSP CBTSBRDSTAT command to check the status of the CMPT. If the statusof the CMPT is Not Installed or Faulty, you can infer that the CMPT is faulty and youneed to replace it.

----End

Postrequisite


7.3 Troubleshooting the Failure of Insufficient SatellitesThe incorrect configuration of clock parameters or the improper installation of the GPS antennamay cause an insufficient quantity of satellites received by the BTS. This describes the symptomsof the faults and the procedure for troubleshooting the faults.

Symptoms

Table 7-4 describes the symptoms of the insufficient satellites received by the BTS.

Table 7-4 Symptoms of the insufficient satellites received by the BTS

Item Symptom

Services The BTS fails to work. If you change the clock to Internal Clock Source,the BTS works again.

Board status The CMPT is operational. The ALM indicator of the HCPM/HECM is on.An alarm is generated. If the BTS is started for the first time, run the DSPCBTSBRDSTAT command to check whether the status of the HCPM/HECM and the TRM is Unavailable.

Alarms The satellites received by the satellite receiver of the CMPT are insufficient.

Fault Location

Before you locate the fault, check whether:

l The BTS is powered on for the first and the power-on time is less than 10 minutes. If thisis the case, you can infer that the process of tracking satellites by the satellite receiver isslow. Check the quantity of received satellites10 minutes after the BTS is powered on.



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l There are higher-priority GPS clock system alarms. Table 7-1 lists the clock failure alarms.If there are alarms of higher priority, clear these alarms first.

Table 7-5 lists the possible causes and analysis of insufficient satellites received by the BTS.

Table 7-5 Possible causes and analysis of the insufficient satellites received by the BTS

Cause Analysis

The quantity oftracked satellites isinsufficient.

No satellites aretracked.

l Check whether the clock source is set toInternal Clock Source.

l Check whether the mode of the satellitereceiver is correctly configured andwhether the mode of the GPS or GPS/GLONASS satellite receiver conforms tothe actual conditions.

If the clock source, mode of the satellitereceiver, and mode of the GPS or GPS/GLONASS satellite receiver are correctlyconfigured, the fault is most likely caused bythe hardware system. To troubleshoot thefault, refer to Troubleshooting the OpenCircuit or Short Circuit Failures in the BTSAntenna System.

The quantity oftracked satellites ismore than 1.

If the type of the satellite receiver is known,you can infer that the GPS antenna is notproperly installed. Check the installationposition of the GPS antenna.

The positioninformation of thesatellite receiver isincorrectlyconfigured.

If the 3D information (longitude, latitude, and altitude) stored in thesatellite receiver does not conform to the actual 3D information of theBTS, it may take a long time for the satellite receiver to determine theposition of itself by using the iteration algorithm.In this case, you can infer that the fault is caused by incorrectconfiguration of the position information rather than failures in the GPSantenna system (provided that the hardware of the GPS antenna systemfunctions properly). You can rectify the fault by correcting the positioninformation of the satellite receiver.

The satellitereceiver is faulty.

To check whether the satellite is faulty, refer to Troubleshooting theOpen Circuit or Short Circuit Failures in the BTS Antenna System.




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Cause Analysis

The installationposition of the GPSantenna isimproper.

The requirements for installation of the GPS antenna are as follows:l The antenna is installed away from tall buildings. If the antenna is

installed on the rooftop, it should be situated away from ancillarybuildings.

l The visual angle of the vertical antenna is greater than 90°, as shownin Figure 7-4.

l The antenna is not located under a microwave antenna, a high-voltage cable, or a TV tower.

l The antenna is placed within the protection range of the lightningarrester.

For details, refer to Installing the Satellite Antenna System.

Fault HandlingFigure 7-3 shows the procedure for troubleshooting the fault of insufficient satellites receivedby the BTS.

Figure 7-3 Procedure for troubleshooting the fault of insufficient satellites received by the BTS



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Procedure

Step 1 Check the special status of the CMPT.Check whether the satellite receiver is faulty or whether the installation position of the satellitereceiver is improper.1. Run the DSP CBTSBRDSPECSTAT command to query the special status of the CMPT.

l If the satellite receiver type is UNKNOWN, you can infer that the satellite receiver isfaulty. Refer to Step 3 to rectify the fault.

l If the satellite receiver type is returned and the number of the tracked satellites is 0, youcan infer that the hardware of the GPS antenna system does not function properly. Referto Step 2 to rectify the fault.

l If the type of the satellite receiver is returned and the number of tracked satellites ismore than 1, you can infer that the hardware of the GPS antenna system functionsproperly. Check the installation position of the GPS antenna. For details, refer to Step2.

2. Check whether the satellite receiver is faulty. For details on how to rectify the fault, referto Step 3.

3. Run the DSP CBTSBRDSPECSTAT command to check whether the working mode ofthe satellite receiver is incorrectly set. For example, the working mode of the GPS satellitereceiver is incorrectly set to the GPSGLNS mode. Run the SET CBTSCLKSRCMODEcommand to correct the working mode of the satellite receiver. Check whether the alarmis cleared.

Step 2 Check the installation position of the GPS antenna.Check whether the GPS antenna is installed at a proper place.1. Check whether the GPS antenna is installed around tall buildings or near ancillary buildings.2. Check whether the visual angle of the vertical GPS antenna is smaller than 90°. The visual

angle of the vertical antenna is greater than 90°, as shown in Figure 7-4.

Figure 7-4 Visual angle of the vertical antenna

(1) Surrounding buildings or other obstacles (2) GPS/GLONASS antenna

3. Check whether strong interference sources such as a microwave antenna, a high-voltage

cable, or a TV tower exist around the GPS antenna. If strong interference sources exist




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around the GPS antenna, install the GPS antenna at another place, as shown in Figure7-5.

l If any round satellite antenna exists nearby, position the GPS antenna away from thetransmit direction of the satellite antenna, as shown in (1).

l If any microwave antenna exists nearby, position the GPS antenna above the transmitlobe of the microwave antenna, as shown in (2). If the GPS antenna cannot be installedabove the transmit lobe of the microwave antenna, the distance between the GPS antennaand the microwave antenna should be longer than 10 times of the wavelength of transmitsignals, as shown in (3).

l If any other receiving antennas exist nearby, the distance between the GPS antenna andthe other receiving antennas should be longer than a wavelength of the received signal,for example, 0.5 m, as shown in (4).

l Do not install the GPS antenna under the main lobe of a microwave antenna or a high-voltage cable, or expose the GPS antenna to the strong radiation of a TV tower, as shownin (5), (6), and (7).

Figure 7-5 Installation position of the GPS antenna in a complicated electromagneticenvironment

4. Check whether the GPS antenna is located within the protection range of the lightningarrester. Though the failure of insufficient satellites received by the BTS is unrelated to theprotection range of the lightning arrester, you need to check whether the GPS antenna is



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located within the protection range of the lightning arrester to rule out any possibilities thatcause the fault.

----End


7.4 Troubleshooting the BTS Phase-Locked Loop FailuresBTS phase-locked loop (PLL) failures are a part of BTS clock failures. This describes thesymptoms of the faults and the procedure for troubleshooting the faults.

SymptomsTable 7-6 describes the symptoms of the BTS PLL failures.

Table 7-6 Symptoms of the BTS PLL failures

Item Symptom

Boardstatus

l If the active and standby CMPTs are configured, the active/standbyswitchover is automatically triggered. If the active and standby CMPTs arenot configured, the BTS does not work and the voice and data services andthe service switching between BTSs are affected.

l The faulty HCPM/HECM cannot process baseband services.

l Services carried carriers of the faulty TRM are interrupted.

Alarms l The 32Fc hardware PLL is unlocked, the 10 MHz crystal oscillator has nooutput, or the frequency offset of the 10 MHz crystal oscillator is excessive.

l The 50Fc hardware PLL is unlocked or the 100Fc hardware PLL is unlocked.

l The 10 MHz signal is lost, the 10 MHz PLL is unlocked, the 64Fc PLL isunlocked or the 100Fc PLL is unlocked.

l The RF PLL is unlocked, the RF reverse PLL is unlocked or the RF feedbackPLL is unlocked.

Fault LocationTo locate the fault, analyze the alarms on the Alarm Management System first. Before you handlethe fault, check whether there are GPS clock system-related alarms of high priority. Table 7-1lists the clock fault alarms. If there are alarms of higher priority, clear these alarms first.

Table 7-7 lists the possible causes and analysis of the BTS PLL failures.




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Table 7-7 Possible causes and analysis of the BTS PLL failures

Cause Analysis

Faults of theCMPT

l If "The 10 MHz crystal oscillator has no output" or "The frequency offsetof the 10 MHz crystal oscillator is excessive" alarm is generated, you caninfer that the CMPT hardware is faulty.

l If "The 32Fc hardware PLL is unlocked" alarm is generated, you can inferthat the CMPT hardware is faulty.

NOTE

l The software PLL reduces the clock offset locked by the PLL by comparing thefrequency of signals before and after phase locking.

l The hardware PLL reduces the clock offset locked by the PLL by comparing thephase of signals before and after phase locking.

l Only the CMPT has the software PLL.

The CMPT generates 2s, 16Fc, and 10 MHz signals after phase locking.Therefore, the boards using these clock signals fail to lock the clock if thePLL in the CMPT becomes faulty. When the lower-level boards report thePLL failure, check whether the CMPT generates "The PLL is unlocked"alarm.

The HCPM/HECM isfaulty.

The HCPM/HECM has 50Fc or 100Fc hardware PLL.l If "The 50Fc hardware PLL is unlocked" or "The 100Fc hardware PLL is

unlocked" alarm is generated, and "The 10 MHz crystal oscillator has nooutput" alarm is not generated, you can infer that the HCPM, the HECM,the slot, or the backplane is faulty.

l If "The 10 MHz crystal oscillator has no output" alarm is generated, youmust handle the CMPT failure first.

The OMTR isfaulty.

The OMTR has the 10 MHz, 64Fc, 100Fc, RF, RF reverse, and RF feedbackPLLs.l If only one of the PLLs is unlocked, you can infer that the OMTR

hardware is faulty.l If the 10M/64Fc/100Fc PLL unlocking alarm and the RF/RF reverse/RF

feedback PLL unlocking alarm are generated, you can infer that no clockinput passes through the HCPM/HECM to the OMTR. If the 100Fchardware PLL unlocking alarm is not generated, the fault may lies in theconnection ports between boards.

Fault HandlingFigure 7-6 shows the procedure for troubleshooting the PLL failure.



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Figure 7-6 Procedure for troubleshooting the PLL failure

Procedure

Step 1 Check the CMPT.Check whether the PLL in the CMPT is faulty. Run the LST ALMFE command to query alarmsgenerated on the Alarm Management System.

l If "The 10 MHz crystal oscillator has no output" or "The frequency offset of the 10 MHzcrystal oscillator is excessive" alarm is generated, install the CMPT in another slot. If thefault persists, replace the CMPT.

l If both "The 10 MHz crystal oscillator has no output" and "The frequency offset of the 10MHz crystal oscillator is excessive" alarms are generated, check whether GPS clock systemalarms of higher priority are generated. If higher-priority alarms are generated, clear themfirst. If no higher-priority alarms are generated, install the CMPT in another slot. If the faultpersists, replace the CMPT.




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Step 2 Check the HCPM/HECM.Check whether the PLL in the HCPM/HECM is faulty. Run the LST ALMFE command toquery alarms generated on the Alarm Management System.l If only the 50Fc or 100Fc hardware PLL alarm is generated, install the HCPM/HECM in

another slot. If the fault persists, replace the HCPM/HECM.l If the 50Fc and 100Fc hardware PLL alarms are generated, check whether "The 10 MHz

crystal oscillator has no output" alarm is generated. If "The 10 MHz crystal oscillator has nooutput" alarm is generated, refer to Step 1 to clear the alarm. If the fault persists after thealarm is cleared, replace the backplane.

Step 3 Check the OMTR.

Check whether the PLL in the OMTR is faulty. Run the LST ALMFE command to query alarmsgenerated on the Alarm Management System.

l If only one of the 10M/64Fc/100Fc PLLs or the RF/RF reverse/RF feedback PLLs isunlocked, replace the OMTR.

l If both the 10M/64Fc/100Fc PLLs and the RF/RF reverse/RF feedback PLLs are unlocked,check whether "The 100Fc hardware PLL is unlocked" alarm is generated.

l If "The 100Fc hardware PLL is unlocked" alarm is generated, refer to Step 2 to clear thealarm. If the fault persists after the alarm is cleared, replace the OMTR.

----End

Postrequisite


7.5 Case: HCPM Startup Failures Caused by GPS ClockFailures

The BTS uses the satellite synchronization clock signals as the clock source. The satellitesynchronization clock signals are received by the satellite receiver of the CMPT. The HCPMfails to start when a clock failure occurs. This describes the symptoms of the faults and theprocedure for troubleshooting the faults.

Symptoms

The symptoms of the faults are as follows:

l The OM link of the BTS is functional.

l On the Service Maintenance System, the ALM indicators of the two HCPMs are red andthe OMTR is unavailable.

l Run the LST ALMFE command to query alarms. The "Main Processing Module SatelliteCard No Second Signal Output" alarm is displayed.

Fault Location

According to alarm information, the unavailability of the OMTR is caused by faults in theHCPM. The possible causes are as follows:



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l The board clock is abnormal.

Fault Handling1. Run the DSP CBTSCFG command to check the configuration of the BTS resource pool

and the HCPM. The configuration of the BTS resource pool and the HCPM is correct.

2. Exchange the positions of the two HCPMs. The fault persists after the exchange.

3. Run the DSP CBTSBRDSPECSTAT command to query the special status of the CMPT.The number of received satellites is zero.

4. Run the SET CBTSCLK command to change the BTS clock source to INCLK (InternalClock Source). The boards are operational. Therefore, you can infer that the GPS antennahas open-circuit or short-circuit failures.

5. Bypass the lightning arrester and check the connectors that connect to the lightning arrester.The fault persists.

6. Check the GPS cables. The connection between the antenna and the feeder fails. Reconnectthe GPS cables and set the BTS clock source to INBRDREF (Board Clock Source). TheBTS is operational.

7.6 Case: Interference in Voice Calls Caused by theDamaged GPS Feeder Connector

The BTS satellite synchronization antenna system consists of the antenna, feeder, and lightningarrester. When the GPS feeder becomes faulty, there may be interference in voice calls. Thisdescribes the symptoms of the faults and the procedure for troubleshooting the faults.

Symptoms

The symptoms of the faults are as follows:

l Customers provide a feedback that there is interference in calls in an area covered by theBTS.

l The BTS generates alarms that indicate "The satellite antenna is open-circuit" and "Thenumber of traced satellites is insufficient."

Fault Location

The possible causes of the fault are as follows:

l The CMPT (or the satellite receiver) is faulty.

l The GPS antenna is faulty.

l The installation position of the GPS antenna is improper.

According to the priority of the alarms, first clear the alarm that indicates "The satellite antennais open-circuit."




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Fault Handling1. Measure the output voltage of the lightning arrester port. The output voltage is 5 V and is

in normal range.2. Bypass the lightning arrester. The voltage is in normal range but the fault persists.3. Disconnect the cable from the lightning arrester port and measure the resistance between

the core and the shielding layer. The resistance is 260 ohms and is in normal range.4. Connect the shielding layer of the signal cable with the sheath of the lightning arrester port

and measure the current of the signal cable and the core of the ANT port. The current is 25mA and is in the normal range.

5. Check the GPS cable segment by segment. On removing the connector between the GPSfeeder and the antenna, you find that the core of the feeder is split into four pieces. Thevoltage and resistance of the feeder are in normal range when you reinstall the connector.

6. Replace the feeder and reinstall the lightning arrester. When you set the BTS clock sourceto INBRDREF (Board Clock Reference Source), the alarm is cleared and the faults arerectified.

NOTE

Generally, you must clear a high-priority alarm first. If a low-priority alarm is located first, it may takemore time to troubleshoot the faults.



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8 Troubleshooting the BTS TransmissionFailures

About This Chapter

If the BTS generates link-related alarms and the LMT cannot send OM commands to the BTS(whose NE status is offline), you can troubleshoot the faults by following the procedure describedin this topic.

ContextNOTE

Currently, the BTS3606AE supports IP over E1 or T1 mode only. This document describes IP over thetwo modes. You can select a specific mode for reference.

8.1 Overview of the BTS TransmissionThis describes the transmission link type, Abis traffic signal flow, Abis signaling signal flow,indicators on the panel of the CMPT, BTS transmission fault alarms, and methods of locatingBTS transmission failure alarms.

8.2 Troubleshooting the Abis Transmission Link FailuresThe BTS and the BSC exchange information through the Abis transmission link. When the Abistransmission link fails, the BTS services are interrupted. This describes the symptoms of thefaults and the procedure for troubleshooting the faults.

8.3 Troubleshooting the Abis Signaling or Traffic Link FailuresIf the Abis signaling or traffic link fails, signals on the BTS may be poor, and the quality ofservices may degrade. This describes the symptoms of the faults and the procedure fortroubleshooting the faults.

8.4 Clearing Abis Link Overload FaultsIf the Abis link is overloaded, calling MSs or called MSs may fail to access the network. Thistopic describes the symptoms of Abis link overload faults and how to clear the faults.

8.5 Case: Unstable Service Quality Caused by Incorrect Link ConfigurationIncorrect configuration of link parameters may cause unstable service quality. This describesthe symptoms of the faults and the procedure for troubleshooting the faults.

8.6 Case: BTS Transmission Link Intermittent Failure Caused by Poor Grounding

Airbridge BTS3606AE CDMA Base StationTroubleshooting Guide 8 Troubleshooting the BTS Transmission Failures


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Poor grounding may cause intermittent failure of the BTS transmission link. This describes thesymptoms of the faults and the procedure for troubleshooting the faults.

8 Troubleshooting the BTS Transmission FailuresAirbridge BTS3606AE CDMA Base Station



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8.1 Overview of the BTS TransmissionThis describes the transmission link type, Abis traffic signal flow, Abis signaling signal flow,indicators on the panel of the CMPT, BTS transmission fault alarms, and methods of locatingBTS transmission failure alarms.

NOTE

Currently, the BTS3606AE supports only transmission over IP.

8.1.1 IP-Based BTS Physical Links and Logical LinksAn Abis link consists of two parts: physical link and logical link. Physical link is the bottomlayer of logical link.

8.1.2 Abis Traffic Signal Flow in the BTSThis describes the Abis traffic signal flow in the BTS. The Abis traffic signals are voice servicetraffic signals, inband signaling signals, and data service traffic signals.

8.1.3 Abis Signaling Signal Flow in the BTSThis describes the Abis signaling signal flow in the BTS. Two types of signals, namely, BTScontrol signaling signals and outband signaling signals, are transmitted on the Abis commonsignaling channel.

8.1.4 CMPT PanelThis describes the appearance, ports, and indicators of the CMPT panel.

8.1.5 BTS Transmission Failure AlarmsThis describes common BTS transmission failure alarms and their causes.

8.1.6 Principles of Locating the BTS Transmission FailuresThis describes the principles of locating BTS transmission failures, that is, locating the faultbased on different layers, looping back the transmission link segment by segment, checking theDIP switches, checking the configuration, and rectifying the connection.

8.1.1 IP-Based BTS Physical Links and Logical LinksAn Abis link consists of two parts: physical link and logical link. Physical link is the bottomlayer of logical link.

Physical Link (IP Transmission)The physical link (IP transmission) is the actual link that carries various logical links. Thenetworking of physical links depends on the BTS networking.

Physical links can be classified as follows:

l PPP

l MLPPP

Table 8-1 lists the features of physical links.



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Table 8-1 Features of physical links

Link Group Configuration Object

PPP One E1/T1 linkSome timeslots in one E1/T1 link

MLPPP One or more E1/T1 linksSome timeslots in one or more E1/T1 link

Logical Link (IP Transmission)

The logical link (IP transmission) is a virtual link. It carries control messages, service data, andOM data between the BSC and the BTS. From the perspective of logical links, the BSS is a starnetwork with the BSC as the center.

The logical links can be divided into the following types:

l OMLThe OM link between the CMPT and the BAM. If the link bearer is an E1/T1 link (PPP/MLPPP), the OML is set up by the system automatically.

l Signaling linkThe TCP link between the BTS main control and transmission board and the BSC.

l Traffic linkThe AAL2 Path between the BTS channel board and the BSC.

8.1.2 Abis Traffic Signal Flow in the BTSThis describes the Abis traffic signal flow in the BTS. The Abis traffic signals are voice servicetraffic signals, inband signaling signals, and data service traffic signals.

Forward Traffic Signal Flow

The forward traffic signal flow is as follows:

1. The ATM cells or IP packets from the BSC are sent to the CMPT through E1/T1 links, andthe CMPT processes the ATM cells or IP packets and then sends them to the HCPM orHECM through the backplane.

2. The HCPM or HECM encodes, interleaves, spreads, modulates, and multiplexes thebaseband signals that are sent from the CMPT and carry traffic. Then, the HCPM or HECMsends the processed baseband signals to the OMTR.

3. The OMTR performs demultiplexing, up-conversion, and filtering for the receivedbaseband signals, and then sends the signals to the OMPA.

4. The OMPA amplifies the signals and then sends them to the ODFU, which transmits thesignals through the antenna subsystem.

Reverse Traffic Signal Flow

The reverse traffic signal flow is as follows:




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1. Using the main and diversity antennas, the ODFU receives two CDMA signals and thensends the signals to the OMTR.

2. The OMTR performs filtering, down-conversion, and multiplexing for the main anddiversity signals, and then sends them to the HCPM or HECM through the optical port.

3. The HCPM or HECM demultiplexes, demodulates, de-interleaves, and decodes thebaseband signals, which carry traffic. Then, the HCPM or HECM sends the signals to theCMPT through the backplane.

4. The CMPT converts the received signals into IP packets that are adapted to the Abis linktypes, and then sends the ATM cells or IP packets to the BSC through E1/T1 links.

8.1.3 Abis Signaling Signal Flow in the BTSThis describes the Abis signaling signal flow in the BTS. Two types of signals, namely, BTScontrol signaling signals and outband signaling signals, are transmitted on the Abis commonsignaling channel.

BTS Control Signaling

The BTS control signaling signals contain parameters or control messages sent from the BSCto the BTS for processing. The BTS control signaling signals are not transmitted as RF signals.For example, the BSC sends PN codes to the BTS so that the channel processing boards canprocess them.

Forward Outband Signaling Signal Flow

The forward outband signaling signal flow is as follows:

1. Through E1/T1 links, the ATM cells or IP packets from the BSC are sent to the CMPT,which reassembles the ATM cells or IP packets, uses its SIG unit to process the reassembledATM cells or IP packets, and then sends the ATM cells or IP packets to the HCPM orHECM through the backplane.

2. The HCPM or HECM encodes, interleaves, spreads, modulates, and multiplexes thebaseband signals that are sent from the CMPT and carry Abis signaling. Then, the HCPMor HECM sends the processed baseband signals to the OMTR.

3. The OMTR performs demultiplexing, up-conversion, and filtering for the receivedbaseband signals, and then sends the signals to the OMPA.

4. The OMPA amplifies the signals and then sends them to the ODFU, which transmits thesignals through the antenna subsystem.

Reverse Outband Signaling Signal Flow

The reverse outband signaling signal flow is as follows:

1. Using the main and diversity antennas, the ODFU receives two CDMA signals and thensends the signals to the OMTR.

2. The OMTR performs filtering, down-conversion, and multiplexing for the main anddiversity signals, and then sends them to the HCPM or HECM.

3. The HCPM or HECM demultiplexes, demodulates, de-interleaves, and decodes thebaseband signals, which carry Abis signaling. Then, the HCPM or HECM sends the signalsto the CMPT.



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4. The CMPT converts the received signals into ATM cells or IP packets that are adapted tothe Abis link types, and then sends the ATM cells or IP packets to the BSC through E1/T1links.

8.1.4 CMPT PanelThis describes the appearance, ports, and indicators of the CMPT panel.

Appearance

Figure 8-1 shows the CMPT panel.

Figure 8-1 CMPT panel

(1) ETH port (2) FE0 port (3) FE1 port (4) USB port

(5) TEST port (6) E1/T1 port (7) GPS port

Ports

Table 8-2 lists the ports on the CMPT panel.

Table 8-2 Description of the CMPT ports

Port Description

ETH port Commissioning port

TEST port Clock test port

USB port Reserved port

E1/T1 port Used to transmit data between the BTS andthe BSC

FE0 port Used to connect the transmission equipment

FE1 port Used to connect the optical modules

GPS port Used to connect the GPS antenna

Indicators on the Front Panel

Table 8-3 lists the indicators on the CMPT panel.




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Table 8-3 Description of the indicators

Name Color Meaning Remarks NormalState

RUN Green Operationindicator

l On: There is power input but theboard is faulty.

l Off: There is no power input or theboard is faulty.

l Blinking at 4 Hz: The board is in theloading state.

l Blinking at 0.5 Hz: The board isoperational.

l Blinking at 0.25 Hz: The board isbeing tested.

l Other: The board is faulty.

Blinking at0.5 Hz

ALM Red Alarmindicator

l On: The board must be replaced.

l Blinking at 4 Hz: critical alarm

l Blinking at 0.5 Hz: major alarm

l Blinking at 0.25 Hz: minor alarm

l Off: no alarm

Off

ACT Green Active/standbyindicator

l On: active

l Off: standby

On

TX Green Portindicator

Optical port:l On: Optical transmission is normal.

l Off: Optical transmission is faulty.

Electrical port:l On: The SFP cable is normal.

l Off: The SFP cable is faulty.

On

RX Green Portindicator

Optical port:l On: Optical transmission is normal.


Electrical port:l On: Data receiving is normal, and the

data is correct.l Off: No data received or the data is

incorrect.

On

ACT(Ethernetport)

Yellow Ethernetportindicator

l Blinking: The data is exchanged.

l Off: No data is exchanged.

Blinking oroff



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Name Color Meaning Remarks NormalState

LINK(Ethernetport)

Green Ethernetportindicator

l On: The FE physical link functionsproperly.

l Off: The FE physical link is faulty.

On

8.1.5 BTS Transmission Failure AlarmsThis describes common BTS transmission failure alarms and their causes.

Local Alarms and Remote AlarmsTo fully understand and analyze the transmission alarms, you need to understand the conceptsof the local end and the remote end.

l The local end is a concept used in comparison with the remote end.– For the Alarm Management System on the BSC side, the remote end is the BTS side

and the local end is the BSC side.– For the Alarm Management System on the BTS side, the remote end is the BSC side

and the local end is the BTS side.l The local alarm is a concept used in comparison with the remote alarm. The transmission

alarms are detected at the RX end instead of the TX end.– The alarms detected by the local end are local alarms.

– The alarms detected by the remote end, and then sent to the local end through theprotocol are remote alarms.

A good understanding of the concepts of the local alarm and the remote alarm helps to locatefaults quickly. The following are some examples of locating a fault based on analysis of the typeof alarms:

l The E1/T1 signal loss alarm is a local alarm. You need to check the RX link. For the BTS,you need to check whether faults exist in cables or connectors (marked RX) between theBTS and the transmission equipment.

l The E1/T1 alarm indication signal alarm is a remote alarm. Particular attention should bepaid to the upper-level RX link or TX link. For the BTS, particular attention should be paidto cables or connectors between the BSC and the transmission equipment.

E1/T1 Link AlarmTable 8-4 lists the alarms of the E1/T1 link.

Table 8-4 Alarms related to the E1/T1 link

Alarm Possible Fault and Cause

Loss of the E1/T1 linksignal

The RX link is faulty. There is no signal on the RX link.Usually, the cables marked RX or the connectors between the BTSand the transmission equipment are disconnected.




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Loss of frames of theE1/T1 link

The RX link is faulty. The signal quality is poor.Usually, the cables marked RX or the connectors between the BSCand the transmission equipment are not in good contact, or the BERexceeds 10-3.

Alarm indicationsignal of the E1/T1link

The upper-level RX link or TX link is faulty.Usually, the cables or the connectors between the BSC and thetransmission equipment are faulty, or the RX or TX link of the BSCis faulty.

Far-end alarm of theE1/T1 link

The link on the transmission side is faulty.Usually, this alarm occurs because the cables marked TX or theconnectors between the BSC and the transmission equipment aredisconnected.

Slip frames of the E1/T1 link

Usually, this alarm occurs due to incorrect clock configuration. Thepossible cause is that the clocks of the far end and the near end arenot synchronized.

Excessively high BERof the E1/T1 link

This alarm is generated when the BER of the E1/T1 link exceeds-5. Usually, this alarm occurs due to incorrect settings of the DIPswitches or improper grounding.To locate the fault, first check whether the configuration oftransmission parameters is correct, and then loopback the E1/T1 linksection by section.

FE Link AlarmTable 8-5 lists the alarms of the FE link.

Table 8-5 Description of the FE link alarm


Loss of receiving signals of theFE link

Usually, the Ethernet transmission fails or the FE port isfaulty.

l Transmission error of theFE link

l Reception error of the FElink

Usually, the FE port is faulty.

Loopback of the FE link Usually, the command to loopback the FE link is run.

Conflicting IP address of theCMPT

Usually, the configured IP address of the FE port conflictswith an existing IP address.



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IMA/UNI/FRAC/PPP Link Alarms

Table 8-6 lists the alarms of the IMA/UNI/FRAC/PPP link.

Table 8-6 Description of the IMA/UNI/FRAC/PPP link alarms


l The IMA/FRACIMA link islost of cell delineation.

l The UNI/FRAC link is lostof cell delineation.

The physical transmission of the E1/T1 link is faulty or thehardware of the board is faulty.

The synchronization of framesof the IMA/FRACIMA link isunavailable.

The frames transmitted on the IMA/FRACIMA links are notsynchronized because the links are incorrectly connected orthe BER of the links is excessively high.

The synchronization of delayin the IMA/FRACIMA link isunavailable.

The IMA links in the same link group are on different trunkcables. The delay difference between links in the same linkgroup is considerable.

l The far end of the IMA/FRACIMA link is faulty.

l The far-end reception of theIMA/FRACIMA link isunavailable.

The far-end link that is connected to the IMA link generatesthe data link layer alarm.

l The IMA transmission isconnected incorrectly.

l The IMA reception isconnected incorrectly.

The E1/T1 is faulty, the delay difference between links inthe same link group is considerable, or the remote link is notconfigured.

l The PPP link is interrupted.

l A loopback occurs in thePPP link.

The E1/T1 link is faulty or the data is incorrectly configured.

Link Alarms After The IMA Group is Transferred

When the IMA group is transferred to another BTS, all the IMA links generate alarms. To rectifythe fault, run the RST IMAGRP command to set new parameters for the IMA link group.

If the alarm related to the IMA link group is not cleared after you reset the IMA group, refer toIMA/UNI/FRAC/PPP Link Alarms to clear the alarm.

E1/T1 Link Intermittent Blinking

When intermittent blinking occurs in the E1/T1 link, the Alarm Management System displaysalarms related to the E1/T1 link. The intermittent blinking in the E1/T1 link is rectified whenthe alarms are cleared.

Refer to E1/T1 Link Alarm to clear the E1/T1 link alarm.




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Crossed Pair Connection

The E1/T1 alarm or the IMA/UNI alarm is not generated if a crossed pair connection exists.Therefore, ensure that that the cable connections are correct.

Figure 8-2 shows the normal connection and crossed pair connection of E1 cables.

Figure 8-2 Normal connection and crossed pair connection

Innate Restriction

When you locate and handle the transmission failures, pay attention to the following restrictions:

l Bit error test and loopback test influence the services. The causes are as follows:

– The principle of the bit error test is to send the pseudo-random bits on the E1/T1, andthen check the number of bit errors at the RX end. The Bit Error Rate (BER) is calculatedbased on the number of bit errors in unit time.

– The principle of the loopback test is to send the specific data on a timeslot of the E1/T1link, and then check the data at the RX end. If the data is received, the loopback test issuccessful.

l The absolute delay of the link and the link group might be considerably great when theFRAC IMA link is configured. The causes are as follows:

– FRAC IMA link uses timeslot fragments, and the link needs at least 14 buffer cells. Therelationship between cell number, timeslot number, and maximum capacity is: C = M/((53*8)/(64*S)). Where, C denotes cell number, and S denotes timeslot number.

– When the timeslot number S is 1, the maximum capacity M is 92.75 ms because theminimum value of C is 14. The relative impact is small only when S is larger than orequal to 15.

8.1.6 Principles of Locating the BTS Transmission FailuresThis describes the principles of locating BTS transmission failures, that is, locating the faultbased on different layers, looping back the transmission link segment by segment, checking theDIP switches, checking the configuration, and rectifying the connection.

Locating the Failures Based on Different Layers

E1/T1, FE, IMA/UNI, PPP/MLPPP, and IP are located on different layers.



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Before you start to locate the Abis transmission link fault, check whether the current alarmscontain alarms on the data link layer and the physical transmission layer, or alarms on the datalink layer alone.

l If only alarms related to the data link layer are generated, such as alarms related to the IMA,UNI, FRAC, or PPP links, you need not consider a fault in the physical transmission layer.Rectify the fault on a basis of checking data configuration.

l If alarms related to the physical transmission layer and the data link layer are generated,such as alarms related to the E1/T1 link and the FE link, you need not consider a fault inthe data link layer. Rectify the fault on a basis of loopback by segments, checking DIPsettings, and checking data configuration.

Looping Back the Transmission Link Section by SectionLoop back the transmission link section by section to locate the fault. Then, check whether thealarm is cleared.

l If the alarm is cleared, this section of the link is functional.

l If the alarm persists, the link is faulty.

Repeat this procedure for each physical link to locate the fault accurately.

If the E1/T1 link alarm or the FE link alarm exists, the section-by-section loopback test is themost direct and effective method. Figure 8-3 shows the section-by-section loopback test.

Figure 8-3 Section-by-section loopback test

The section-by-section loopback test is described as follows:

l Perform loopback from the DDF box at the BTS side to the BTS.

1. On the DDF box at the BTS side, perform the loopback test of E1/T1 cables to theBTS (RX and TX connected). Manually configure the transmission link groups andtransmission links.

2. Run the STR CBTSLNKDATALP command on a computer that uses Telnet and isdirectly connected to the BTS to initiate a data loopback. Check the displayed resultsin four seconds. If the number of transmitted frames equals the number of receivedframes, the loopback session under test is connected.

l Perform loopback from the DDF box at the BTS side to the BSC. Perform the test on theDDF frame at the BTS side.

1. On the DDF box at the BTS side, perform the loopback of E1/T1 cables to the BSC.2. Run the LOP E1T1 command on remote LMT to initiate the E1/T1 loopback test.

Wait for four seconds, and then check the displayed results. If the number of




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transmitted frames equals the number of received frames, the loopback session undertest is connected.

3. On the DDF frame at the BTS side, perform the test on the link bit error for four hours.If the BER of voice services is lower than 10-4, and the BER of packet services islower than 10-6, you can infer that the links between the DDF frame at the BTS sideand the DDF box at the BTS side are functional.

l Perform a loopback from the DDF box at the BTS side to the BSC. Perform the test on theDDF box at the BSC side.

1. On the DDF box at the BTS side, perform a loopback of E1/T1 cables to the BSC.2. Run the LOP E1T1 command on remote LMT to initiate the E1/T1 loopback test.

Wait for four seconds, and then check the displayed results. If the number oftransmitted frames equals the number of received frames, the loopback session undertest is connected.

3. On the DDF box at the BSC side, perform the test on the link bit error for two hours.If the BER of voice services is lower than 10-4, and the BER of packet services islower than 10-6, you can infer that the links between the DDF box at the BSC side andthe DDF box at the BTS side are functional.

l Perform loopback from the DDF box at the BSC side to the BSC.

1. On the DDF box at the BSC side, perform the loopback of E1/T1 cables to the BSC.Manually configure the transmission link groups and transmission links.

2. Run the LOP E1T1 command on the remote LMT to initiate the E1/T1 loopback test.Run the DSP LPBACKE1T1 command to check the displayed results in four seconds.If the number of transmitted frames equals the number of received frames, theloopback session under test is connected.

3. Cancel the loopback after the test is complete.

NOTE

The method of troubleshooting the FE link fault is similar to the method of troubleshooting the E1/T1 linkfault.

Checking the DIP SwitchesWhen you check the DIP switches, pay attention to the following points:l Before you configure the grounding, check the grounding of all the transmission equipment.

l Check the switches for impedance selection (120 ohms and 75 ohms).

l Note that the 120-ohm twisted pair cable might be used for connection of the transmissionequipment and the 75-ohm coaxial cable might be used for inter-subrack connection.

The rules for generation of the BER of E1/T1 Link Too High alarm are:

l If the number of frame errors or CRC errors within one hour exceeds the alarm threshold,the BER of E1/T1 Link Too High alarm is generated, indicating that the BER of the E1/T1cable exceeds 10-5.

l If an E1/T1 signal loss alarm, E1/T1 frame out of synchronization alarm, or E1/T1 alarmindication signal alarm is generated within one hour, the system does not report the BERof E1/T1 Link Too High alarm.

Therefore, if the BER of E1/T1 Link Too High alarm is generated, no other alarms concerningthe E1/T1 transmission links are generated within a hour.



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The common cause of this kind of alarms is that the setting of the DIP switches is incorrect.

Checking the Configuration

The data of the physical transmission layer or the data link layer may be incorrectly configured.First check the link-related configuration of the physical transmission layer, and then that of thedata link layer.

l If there is an E1/T1 link alarm, check whether the configurations of the E1/T1 links on theBTS and the BSC are consistent.

– Transmission mode: E1 or T1.

– Frame format: Usually, E1 is in CRC_4 multiframe mode, and T1 is in Extended SuperFrame (ESF) mode.

– Link code: Usually, E1 uses HDB3, and T1 uses B8ZS.

– Impedance: 75 ohms or 120 ohms for E1, and 120 ohms (100 ohms by protocol) for T1.

At the BTS, the frame format is set and cannot be modified whereas other configurationsare determined by DIP switches.

l If there is an FE link alarm, check whether the IP addresses of the FE links on the BTS andthe BSC are consistent.

l After the physical transmission layer failures are rectified, follow the following principlesto locate the fault if the data link layer (IMA/UNI/FRAC/PPP/MLPPP) alarms persist:

– Based on the alarms, check whether the types of link groups configured on the BTS andthe BSC are consistent. You can run the ADD CBTSLNKGRP command to add a linkgroup to the BTS.

– If there is an IMA link alarm, the IMA link might not be properly connected. Theprocedure for rectifying the improper connection, which is described in the principlesof fault location, helps in troubleshooting the alarms of this type.

In addition, when you configure the data, adhere to the following two principles:

l If the quality of the transmission link is poor, for example, transmission through a satellite,Huawei recommends that you use the UNI link group instead of the IMA link group. TheIMA link group is more sensitive to the BER. If the IMA link group is used, a large numberof alarms may be generated. If only one transmission link is required, Huawei recommendsthat you use the UNI link group.

l If a logical link is carried on two or more physical links, the IMA link must be used. If theFractional IMA links are configured, the number of timeslots in each Fractional IMA linkin the same group must be the same.

Rectifying the Improper Connection

When the IMA link group is used, ensure that the following improper connections are rectified:

l The links in the same group are connected to different remote BTSs.

l In a group, some links are looped back and other links are correctly connected.

l All the links in the same group are connected to different BTSs.

l Rectifying the improper connection is the most effective method to locate an IMA linkfault.




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8.2 Troubleshooting the Abis Transmission Link FailuresThe BTS and the BSC exchange information through the Abis transmission link. When the Abistransmission link fails, the BTS services are interrupted. This describes the symptoms of thefaults and the procedure for troubleshooting the faults.

SymptomsTable 8-7 shows the symptoms of the Abis transmission link failures.

Table 8-7 Symptoms of the Abis transmission link failures

Item Symptom

Services l Services of the BTS are interrupted.

l The BTS is repeatedly loaded.

l The OML between the BTS and the BSC cannot be set up.

l All the services of the BTS are interrupted.

Board status The ALM indicator on the panel of the CMPT is on, indicating the alarmexits.

Alarms l The E1/T1 link signal is lost.

l The E1/T1 link is lost of frame.

l Alarm indication signal of E1/T1 link

l Far-end alarm of E1/T1 link

l The slip frames of the E1/T1 link in one hour are over limit.

l The bit error rate of the E1/T1 link is too high.

If the FE transmission mode is used, the BTS might report the followingphysical transmission alarms:l The FE link signal is lost.

l The transmission of the FE link fails.

l The reception of the FE link fails.

l A loopback occurs in the FE link.

l The IP address of the CMPT conflicts with an existing IP address.



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Item Symptom

If the E1/T1 transmission mode is used, the BTS might report the followingalarms related to the data link layer:l The IMA/FRACIMA link is lost of cell delineation.

l The UNI/FRAC link is lost of cell delineation.

l The IMA/FRACIMA link is lost of frame.

l The IMA/FRACIMA link is lost of delay.

l The far end of the IMA/FRACIMA link is faulty.

l The far-end reception of the IMA/FRACIMA link is unavailable.

l The IMA transmission is connected incorrectly.

l The IMA reception is connected incorrectly.

l The PPP link is interrupted.

l A loopback occurs in the PPP link.

Fault LocationTable 8-8 describes the causes and analysis of the Abis transmission link failures.

Table 8-8 Possible causes and analysis of the Abis transmission link failures

Cause Analysis

The E1/T1transmissionlink is faulty.

When the E1/T1 transmission link is faulty, the following alarms may begenerated:l Loss of the E1/T1 link signal

l Loss of frames of the E1/T1 link

l Alarm indication signal of the E1/T1 link

l Far-end alarm of the E1/T1 link

l Slip frames of the E1/T1 link

l Excessively high BER of the E1/T1 link

To locate failures in the E1/T1 link, conduct a section-by-section loopbacktest. For details, refer to 8.2 Troubleshooting the Abis TransmissionLink Failures.

The DIPswitches of theCMPT areincorrectly set.

To locate the fault of excessively high E1/T1 BER, check the settings ofthe DIP switches. For details, refer to 8.2 Troubleshooting the AbisTransmission Link Failures.

The dataconfiguration isincorrect.

The data of the physical transmission layer or the data link layer may beincorrectly configured. First check the link-related configuration of thephysical transmission layer, and then that of the data link layer. For details,refer to 8.2 Troubleshooting the Abis Transmission Link Failures.




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Fault Handling

Figure 8-4 shows the procedure for troubleshooting the Abis transmission link failures.

Figure 8-4 Procedure for troubleshooting the Abis transmission link failures

Procedure

Step 1 Check the transmission links.Check whether the failures are caused by a faulty transmission link.1. Run the DSP CBTSTSTTSK command to query whether the E1/T1 port at the BTS is in

the loopback or link test state. Run the STP CBTSTSTTSK command to stop the test.If the OML is disconnected, the BTS resets within five minutes.

2. Run the DSP E1T1STAT command to query whether the E1/T1 port at the BSC is in theloopback state. Run the SET LPBACKE1T1 command to stop the loopback.

3. Conduct a section-by-section loopback test to check whether the section is faulty.



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For details on the loopback test, refer to 8.2 Troubleshooting the Abis Transmission LinkFailures.

Before you conduct a loopback test, familiarize yourself with the concepts of local alarmand remote alarm described in 8.1.5 BTS Transmission Failure Alarms, and focus onchecking the transmission section in which faults are most likely to occur.

l The E1/T1 signal loss alarm and E1/T1 frame out of synchronization alarms are localalarms. The reception links between the BTS and the transmission equipment may befaulty.

l The E1/T1 alarm indication signal alarm and E1/T1 far-end alarms are remote alarms.The transmission links between the BSC and the transmission equipment may be faulty.

l For the E1/T1 slip frame alarm and the excessively high BER of E1/T1it error rate ofthe E1/T1 link is too high alarm, check whether the data configuration (clockconfiguration and E1/T1 attribute configuration) on both ends are consistent. Then,check the DIP switches and grouping segment by segment.

If the fault persists after the configuration of the E1/T1 link is corrected, replace the CMPTto check whether the CMPT is faulty. For details on how to replace the CMPT, refer to theBTS site maintenance guide.

If the fault occurs in the transmission equipment, contact the transmission engineers forhelp. If the fault occurs at the BSC, contact the BSC maintenance engineers for help.

4. Check whether the distance between the local end and the relay (or the peer end) exceedsthe maximum transmission distance of the transmission cable.

For example, the maximum transmission distance of a 75-ohm coaxial cable is 500 m[1640.42 ft], and the maximum number of sections is 100.

If the distance between the local end and the relay exceeds the maximum length of thecable, the E1/T1 frame out of synchronization alarm is generated. In such a case, adjust theposition, quantity, and specifications of the relay again.

5. Check whether the power system and cables function properly.Insufficient power supply may cause intermittent blinking in the BTS. Leaking of high-voltage power and poor grounding may result in a high BER. For details on how to locateand troubleshoot a power system fault, refer to 5 Troubleshooting BTS Power SupplyFailures.

For the coaxial cable, adhere to the following requirements:

l If the coaxial cable connects equipment A to equipment B, ground the TX wires of boththe equipment.

l If equipment B cannot be grounded, ground both RX and TX wires of equipment A.

If the transmission equipment room and the BTS equipment room do not share the sameground, an electric potential difference may exist between the two rooms. If the E1/T1shielding layer is grounded in both rooms, the shielding layer and the ground form a loopand cause interference. Therefore, ground either the transmitting end or the receiving end,but not both.




Issue 03 (2009-09-09)

Figure 8-5 E1/T1 Transmission Environment for the BTS

When you ground E1/T1 cables that connect to the transmission equipment, check thegrounding of E1/T1 cables on the DDF. If the transmission equipment is not required to begrounded, do not ground E1/T1 cables on the DDF at the transmission equipment side.

Step 2 Check the settings of the DIP switches on the CMPT.Check whether the faults are caused by incorrect settings of the DIP switches of the CMPT.

1. Check whether the type of the interface board and the number of the link interface arecorrect.

2. Check whether the transmission mode is correctly configured. The transmission mode mustbe consistent with the planning.

3. Check whether the transmission impedance matches the transmission cable.

4. Check whether the grounding status of the sheath of the transmission cable is consistentwith the settings of the DIP switches.For details on the settings of the DIP switches of the CMPT, refer to the BTS hardwaredescription manual.

If the DIP switches are correctly set, replace the CMPT to check whether the CMPT isfaulty. For details on how to replace the CMPT, refer to the BTS site maintenance guide.

Step 3 Check the data configuration.

Check whether the faults are caused by the incorrect data configuration.

1. Check whether the type of the interface board and the number of the link interface arecorrect.

2. For E1/T1 transmission, run the LST ALMFE command to query whether there is an E1/T1 alarm.

If the E1/T1 alarm exists, run the LST E1T1 command on the LMT at the BSC to querythe frame format, link code, and code type of the E1/T1 link. Run the DSPE1T1IMPEDANCE command to query the impedance of the E1/T1 interface board. Atthe BTS, run the DSP CBTSBCIMDIPSTAT command to query the link code, and thenrun the DSP CBTSMLTDRPBRDSTAT command to query the transmission mode andthe impedance. You can also check the settings of the DIP switches by observing the panelof the DIP switches.

3. For the FE transmission, check whether the IP addresses of the FE links on the BTS andthe BSC are consistent.

4. If there is an IMA link alarm, the IMA link might not be connected properly. Ensure thatthe following incorrect connections are not present in the IMA link:

l Different links in the same group are connected to different BSCs.



8-19

After the IMA group is activated, the IMA group receives links and randomly selectsone link for parameter configuration. In this case, some links in the IMA group cannotbe activated or the links to the peer end are disconnected.

l In the same group, some links are looped back and other links are correctly connected.You can run the LOP E1T1 command to check whether the links are looped back. Ifthe test is successful, you can infer that the transmission links are looped back.Disconnect the links section by section, and then run the LOP E1T1 command to cancelthe loopback.

l Different links in the same group are connected to different BSCs due to swapping ofthe BTS, reconfiguration of the transmission link, or network deployment.

Correct the incorrect connections, and then run the RST IMAGRP command to reset theIMA group.

5. For the UNI link group type, ensure that the configured link group types at both ends areconsistent.

6. For the FRAC IMA link group type, ensure that the number of links for each timeslot inthe group is consistent.

7. For the PPP/MLPPP link group type, ensure that the IP addresses at both ends meet therequirements of network planning and are in the same network segment.

8. If the E1/T1 has a crossed pair connection, a transmission link alarm is not reported on theAlarm Management System.

Run the SET TRTEST command to initiate the E1/T1 crossed pair connection test. Then,run the DSP TRTEST command to view the test results.

The common and crossed connections of the E1 cables are shown in Figure 8-2 in 8.1.5BTS Transmission Failure Alarms.

----End


8.3 Troubleshooting the Abis Signaling or Traffic LinkFailures

If the Abis signaling or traffic link fails, signals on the BTS may be poor, and the quality ofservices may degrade. This describes the symptoms of the faults and the procedure fortroubleshooting the faults.

SymptomsTable 8-9 describes the symptoms of the Abis signaling or traffic link failures.




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Table 8-9 Symptoms of the Abis signaling or traffic link failures

Item Symptom

Services l The BTS signals are poor and there is intermittent interruption during a call.

l Some carriers of the BTS cannot be accessed.

l The quality of the service degrade.

l The host cannot make or receive a call.

Board status The ALM indicator on the panel of the CMPT is on, indicating the alarm exits.

Alarms l Abis Signaling Link Interrupted alarm

l No Traffic LinkNo Traffic Link alarm

Fault LocationTable 8-10 describes the cause and analysis of Abis signaling or traffic link failures.

Table 8-10 Possible causes and analysis of the Abis signaling or traffic link failures

Cause Analysis

The Abistransmissionlink is faulty.

Before troubleshooting the Abis signaling or traffic link failures, checkwhether the Abis transmission link is faulty. For details, refer to 8.2Troubleshooting the Abis Transmission Link Failures.

The Abissignaling/trafficlinkconfiguration isincorrect.

It is usually caused by physical layer transmission link fault or data linklayer fault. When this alarm is reported, check whether there is lower-leveltransmission alarm.

The BTS boardsare faulty.

Check the CMPT and the HCPM/HECM.

The BSC boardsare faulty.

For details, refer to the troubleshooting guide on the BSC side.

Fault HandlingFigure 8-6 shows the procedure for troubleshooting the Abis transmission link failures.



8-21

Figure 8-6 Procedure for troubleshooting the Abis transmission link failures

Procedure

Step 1 Check the Abis transmission link.

Check whether the faults are caused by the faulty Abis transmission link.

If the transmission link failures are caused by transmission system failures, ask maintenancepersonnel of the power supply system or the transmission system to rectify the faults. For detailson the location of transmission system failures, refer to 8.2 Troubleshooting the AbisTransmission Link Failures.

Step 2 Check the configuration of the signaling/traffic link.




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Check whether the faults are caused by the incorrect configuration of the signaling/traffic link.

1. Run the CHK CBTSIFCFG command to check whether the signaling IP address orinterface configuration data of the BTS is consistent with that of the BSC.

2. Run the RMV CBTSTERSIGLNK/RMV CBTSTERTRFLNK/RMVCBTSIPTERTRFLNK command to remove the incorrect terrestrial signaling or trafficlink.

3. Run the ADD CBTSTERSIGLNK/ADD CBTSTERTRFLNK/ADDCBTSIPTERTRFLNK command to add a correct terrestrial signaling or traffic link.

4. Contact BSC maintenance engineers to modify the configuration of the signaling or trafficlink of the BSC.

Step 3 Check the BTS boards.

Check whether the faults are caused by the hardware problem of the BTS.

1. You can switch over or replace the CMPT or the HCPM/HECM to check whether they arefunctional.

2. Replace the baseband backplane to check whether it is functional.

Step 4 Rectify the fault in the BSC boards.

Contact the BSC side engineers to ensure that the BSC boards are functional.

----End


8.4 Clearing Abis Link Overload FaultsIf the Abis link is overloaded, calling MSs or called MSs may fail to access the network. Thistopic describes the symptoms of Abis link overload faults and how to clear the faults.

SymptomsTable 8-11 shows the symptoms of Abis link overload faults

Table 8-11 Symptoms of Abis link overload faults

Item Symptom

Services The new calling or called party cannot access the network. The existing callsare not affected.

Alarms l Abis signaling link is overloaded.

l The traffic link is overloaded.

Fault LocationTable 8-12 describes the cause and analysis of Abis link overload faults.



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Table 8-12 Possible causes and analysis of Abis link overload faults

Cause Analysis

The bandwidthsetting of the linkis too small.

The link bandwidth configuration principles are as follows:l The configured bandwidth of the traffic link approximates reverse CEs

x 20 kbit/s.l The configured bandwidth of the signaling link approximates carriers

x 33 kbit/s.l The total logical bandwidth of the traffic link, signaling link, and

operation and maintenance link should be as close as possible to theactual physical bandwidth. Usually, the total logical bandwidth doesnot exceed one and a half times of the physical bandwidth.

l The bandwidth of one E1 link is calculated by 1.9 Mbit/s, then, 1.9 x1.5 = 2.85 Mbit/s, that is, the total bandwidth of the link is usually lessthan 2.85 Mbit/s.

The settings ofthe networkparameters areunreasonable.

The alarm is caused by unreasonable settings of the traffic control or loadcontrol.

Fault Handling

Figure 8-7 shows the procedure for clearing Abis link overload faults.

Figure 8-7 Procedure for clearing Abis link overload faults




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Procedure

Step 1 Check the setting of the link bandwidth.

After locating the fault, check whether the fault is caused by the improper setting of the linkbandwidth.

1. Run the LST BTSLNK command to check the bandwidth of the BTS link.l For UNI or IMA transmission mode, the total logical bandwidth of the BTS traffic link,

BTS signaling link, and the BTS OML must meet the following requirements: Be closeto the actual physical bandwidth (1.9 Mbit/s per E1); cannot exceed one and a half timesof the actual physical bandwidth. When the total logical bandwidth is less than one anda half times of the actual physical bandwidth, adjust the bandwidth.

l For timeslot-based transmission mode, the calculation of the total bandwidth does notfollow the previous requirements. When the signaling load or the operation andmaintenance load is light, the bandwidth of the signaling link and OML is minimal(though it can be configured as 64 kbit/s), allocate all bandwidth to the traffic link.

2. If the setting of the link bandwidth is improper, run the MOD BTSLNKBW command tochange the bandwidth of the OM link, signaling link, and traffic link for the BTS.

Step 2 Adjust the network parameters.

After locating the fault, check whether the fault is caused by the improper setting of the networkparameter.

Contact the network planning engineers to adjust the network parameters. Enable the functions,such as Abis flow control and access load control, to reduce the load of the link.

----End

Postrequisite


8.5 Case: Unstable Service Quality Caused by Incorrect LinkConfiguration

Incorrect configuration of link parameters may cause unstable service quality. This describesthe symptoms of the faults and the procedure for troubleshooting the faults.

Symptomsl The quality of voice services is poor.

l The data services can be connected, but the downlink data does not exist. This causesabnormal transaction of the data services.

Fault Locationl The mapping between service frames and service frame numbers fails due to the fault in

the GPS clock. The BTS cannot identify the service frames and discards the packets.l The poor quality of the air interface causes forward packet loss.



8-25

l The data packets are not sent to the BTS, that is, the packet loss occurs on the Abis servicelinks because of the incorrect data configuration.

Fault Handling1. In the debugging system, initiate the data traffic monitor. On the network side, data packets

are sent to the CMFR in the BSC, but the BTS does not receive any data packet and requestsfor a release.

2. Check the GPS clock and track the clocks of the BSC and the BTS. On the BTS side, runthe DSP CBTSBRDSPECSTAT command to query the number of satellites locked by thesatellite receiver of the CMPT. The results show that seven satellites are locked, and youcan infer that the GPS clock is not faulty.

3. On examining the data returned from the field, you find that the data returned from the fieldinconsistent with that provided by the data center.

The bandwidth of physical configuration provided by an E1 link exceeds the maximumbandwidth of a single physical link, therefore, the CXIE fails to adjust the data rate.Bandwidth congestion occurs during data transmission, causing loss of packets and data.

4. Modify the data configuration, and then reload the data. The fault is rectified, the voicequality is good, and the data services are stable.

CAUTIONThe field engineers are not allowed to modify the data configuration. If required, apply to therelated personnel for approval, and record all the modified data.

8.6 Case: BTS Transmission Link Intermittent FailureCaused by Poor Grounding

Poor grounding may cause intermittent failure of the BTS transmission link. This describes thesymptoms of the faults and the procedure for troubleshooting the faults.

Symptomsl The links between the BSC and a BTS are intermittent. The BTS sometimes functions

properly and sometimes load data repeatedly.

l On the BSC side, the E1/T1 link far-end alarm and E1/T1 alarm indication alarm aregenerated repeatedly.

l On the BTS side, the OML fault, Abis link alarm, and E1 link far-end alarm are generated.

Fault Locationl The transmission link is faulty.

l The BER of the transmission link is excessively high.

l Faults of the CMPT




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Fault Handling1. Perform the loopback test from the DDF 2 Mbit/s cable in the BTS equipment room to the

BSC. The result shows that the link status is available. On the DDF of the transmissionroom, perform the test on the link bit error for four hours. The result shows that the BERis 0. This indicates that the links between the DDF of the transmission room and the DDFof the BTS equipment room are normal.

2. Perform the loopback test from the DDF 2 Mbit/s cable in the BTS equipment room to theBSC. The result shows that the link status is available. On the DDF of the BSC equipmentroom, perform the test on the link bit error for two hours. The result shows that the BER is0. This indicates that the links between the DDF of the BSC equipment room and the DDFof the BTS equipment room are normal.

3. Perform the loopback test from the DDF 2 Mbit/s cable in the BTS equipment room to theBTS. On the BTS, manually configure the transmission link groups and transmission links.Perform the BTS E1 connection test. The result shows that the TX and RX of the link arefunctional. This indicates that the links between the BTS and the DDF of the BTStransmission room are normal.

4. Based on these results, you can infer that the transmission link from the BSC to the BTSis functional. The CMPT may be faulty. On replacing the CMPT, you find that the faultpersists.

5. According to site investigation and test, all subracks are loaded with 110 V power and theBER might increase when the BTS is powered on. The 110 V power used by the subracksmight be the cause of the fault.

6. On checking the surrounding power equipment, you find a high-voltage power leakage.The leakage leads the 110 V power into the BTS equipment room and loads all theequipment with 110 V power. The fault in the BTS is rectified after the power leakageproblem is solved.



8-27

9 Troubleshooting the BTS RF Failures

About This Chapter

The symptoms of BTS RF failures include generation of RF system alarms, weak signals, calldrops, or a low access rate of MSs.

9.1 Overview of the BTS RFThis provides an overview of the BTS RF subsystem and describes the BTS RF failures.

9.2 Troubleshooting the BTS Power FailuresA BTS power failure may decrease the coverage range of the BTS or may degrade the qualityof signals. This describes the symptoms of the faults and the procedure for troubleshooting thefaults.

9.3 Troubleshooting the BTS Standing Wave FailuresWhen the antenna impedance does not match the feeder impedance, the antenna cannot receiveall high frequency energy transmitted by the feeder. Some energy forms reflected wave. If thereflected wave is excessively strong, namely, the VSWR is too high, the transmit powerfluctuates and the coverage range diminishes. This describes the symptoms of the faults and theprocedure for troubleshooting the faults.

9.4 Troubleshooting the BTS Predistortion FailuresThe RF module predistortion processing is performed to compensate for the signal distortion ofthe power amplifier in non-linear workspace. This function compares the feedback power of thepower amplifier and the output power of the RF module so that there is no signal distortion ofthe power amplifier. BTS predistortion failures may degrade the performance of RF modules.This describes the symptoms of the faults and the procedure for troubleshooting the faults.

9.5 Troubleshooting the BTS Reverse RSSI FailuresIf there is a reverse RSSI failure in the BTS, the reverse sensitivity and reverse capacity of theBTS is reduced, therefore affecting the access of the MS to the network. This describes thesymptoms of the faults and the procedure for troubleshooting the faults.

9.6 Case: Clearing BTS Standing Wave AlarmsBTS standing wave faults may deteriorate the antenna performance and diminish the coveragerange. This topic describes the fault symptoms and how to clear the BTS standing wave alarms.

Airbridge BTS3606AE CDMA Base StationTroubleshooting Guide 9 Troubleshooting the BTS RF Failures


9-1

9.1 Overview of the BTS RFThis provides an overview of the BTS RF subsystem and describes the BTS RF failures.

9.1.1 Configuration of the BTS RF SubsystemThe functions of the BTS RF subsystem are provided by the RFC. The configuration of the RFmodule is mandatory for the initial configuration of the BTS. Before configuring the RFC, youmust know the specifications and functions of the boards in the RFC.

9.1.2 OMTR PanelThis describes the appearance, ports, and indicators of the OMTR panel.

9.1.3 OMPA PanelThis describes the appearance and ports of the OMPA panel.

9.1.4 Performance Specifications of the BTSThis describes the technical specifications of the BTS, namely, the receive specifications,transmit specifications, and bit error rate (BER) threshold specifications on the transmissionlinks. The transmit and receive specifications refer to the technical parameters of the transceiverof the BTS.

9.1.5 BTS RF Fault AlarmsThis topic describes the RF subsystem faults and associated fault alarms.

9.1.6 Working Principles of the BTS RF Modules and Data Point TrackingThis describes the working principles of the BTS RF modules and data point tracking.

9.1.7 Test and Analysis of BTS Reverse RSSIYou need to test the RSSI value before locating the RSSI fault. This topic describes how to testand analyze the BTS reverse RSSI.

9.1.1 Configuration of the BTS RF SubsystemThe functions of the BTS RF subsystem are provided by the RFC. The configuration of the RFmodule is mandatory for the initial configuration of the BTS. Before configuring the RFC, youmust know the specifications and functions of the boards in the RFC.

Figure 9-1 shows the configuration of the RFC.

9 Troubleshooting the BTS RF FailuresAirbridge BTS3606AE CDMA Base Station



Issue 03 (2009-09-09)

Figure 9-1 Configuration of the RFC

Table 9-1 lists the boards of the RF subsystem.

Table 9-1 Major modules in the RFC

Equipment Description

ODFU The ODFU is a single channel duplex unit. It consists of an RF duplexisolator and a low pass filter. It provides coupling tests for the transmittedand received signals.

OMTR The OMTR is an outdoor multi-carrier transceiver module. It modulatesand demodulates IQ signals and up-converts and down-converts thefrequency in multi-carrier mode.

OMPA The OMPA is an outdoor multi-carrier high power amplification module.It is used to amplify the modulated RF signal and to monitor poweramplification alarm.



9-3

9.1.2 OMTR PanelThis describes the appearance, ports, and indicators of the OMTR panel.

Appearance

Figure 9-2 shows the OMTR panel.

Figure 9-2 Appearance of the OMTR panel




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PortsTable 9-2 describes the ports of the OMTR.

Table 9-2 Description of the OMTR ports

Port Description

TX The output port for RF transmission. It is used to send the RF transmit signalsto the OMTR for power amplification.

TXF The input port for RF transmission. It is used to receive the RF transmitsignals sent from the OMTR.

RXM out The RF main receive output port. It used to send the RF main receive signals.

RXM The RF main receive input port. It used to receive the RF main receive signalsreceived from the ODFU.

RXD The RF diversity receive input port. It used to receive the RF diversity receivesignals received from the ODFU.

TRX PWR The input port for OMTR power supply and alarm signals. It is used toreceive power supply and alarm signals from the OMPA.

DBG The port for DEBUG aging.

GDD The GDD commissioning port.

A The SFP port. It is used to connect the baseband module or the upper-levelOMTR.

B The SFP port. It is used to connect the lower-level OMTR.

Indicators on the Front PanelTable 9-3 lists the indicators on the OMTR panel.

Table 9-3 Description of the OMTR indicators

NameColor Meaning Remarks

NormalState

RUN Green

Board statusindicator

Blinking at 4 Hz: The OMTR is beingpowered on and initialized or software isbeing loaded.Blinking at 0.5 Hz: The OMTR is running.Other: The OMTR is faulty.

Blinking at0.5 Hz



9-5


NormalState

ALM Red Alarmindicator

On: The board must be replaced.Blinking at 4 Hz: critical alarmBlinking at 0.5 Hz: major alarmBlinking at 0.25 Hz: minor alarmOff: no alarm

Off

ACT Green

Operationindicator

On: The OMTR is running, and the clock islocked.Blinking at 0.5 Hz: The clock is not lockedor it cannot be locked.Blinking at 0.25 Hz: The monitoring link isfaulty.

On

A_TX Green

Port indicator Optical port:l On: Optical transmission is normal.

l Off: Optical transmission faulty.


l Off: The SFP cable is abnormal.

On

A_RX Green

Port indicator Optical port:l On: Optical receiving is normal.

l Off: Optical receiving is faulty.



incorrect.

On

B_TX Green

Port indicator Optical port:l On: Optical transmission is normal.



l Off: The SFP cable is abnormal.

On




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NormalState

B_RX Green

Port indicator Optical port:l On: Optical receiving is normal.

l Off: Optical receiving is faulty.



incorrect.

On

9.1.3 OMPA PanelThis describes the appearance and ports of the OMPA panel.

AppearanceFigure 9-3 shows the OMPA panel.



9-7

Figure 9-3 Panel of the OMPA

PortsTable 9-4 describes the ports of the OMPA.




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Table 9-4 Description of the OMPA ports

Port Description

TX An RF input port connected to the RF output port of the OMPA

TX out An RF output port connected to the RF input port of the ODFU

PA PWR The power supply input port and the power alarm and dry node alarm portof the power amplifier

TRX PWR The power input port and the alarm port of the transceiver

FAN The fan power and communication port

9.1.4 Performance Specifications of the BTSThis describes the technical specifications of the BTS, namely, the receive specifications,transmit specifications, and bit error rate (BER) threshold specifications on the transmissionlinks. The transmit and receive specifications refer to the technical parameters of the transceiverof the BTS.

NOTE

l The transmit power is the maximum value measured at the RF port of the cabinet.

l The multi-carrier transmit power refers to the total power.

l The signal receive sensitivity is the main and diversity receive sensitivity at RC3.

Receive and Transmit Specifications of the BTS

The transmit and receive specifications refer to the technical parameters of the transceiver ofthe BTS3606AE. The receive and transmit specifications of the BTS in different band classesare as follows:

l Receive and transmit specifications in band class 0:Table 9-5 and Table 9-6 list the performance specifications in band class 0 (800 MHz).

Table 9-5 Transmit specifications in band class 0 (800 MHz)

Item Specification

Working band 869 MHz-894 MHz

Channel bandwidth 1.2288 MHz

Channel precision 30 kHz

Frequency tolerance ≤ ±0.05 ppm

Transmit power 80 W (the maximum value measured at the RF port of thecabinet when the BTS works in the four-carrier mode and atan altitude lower than 3500 m [11,482.94 ft])



9-9

Table 9-6 Receive specifications in band class 0 (800 MHz)

Item Specification




Signal receivesensitivity

Better than -128 dBm (RC3, main and diversity receiving)

l Receive and transmit specifications in band class 1:

Table 9-7 and Table 9-8 list the performance specifications in band class 1 (1900MHz).


Item Specification

Working band 1930 MHz - 1990 MHz




Transmit power 60 W (the maximum value measured at the RF port of thecabinet when the BTS works in the three-carrier mode and atan altitude lower than 3500 m [11,482.94 ft])


Item Specification







Table 9-9 and Table 9-10 list the performance specifications in band class 5 (450MHz).


Item Specification

Working band 460 MHz-470 MHz, 489 MHz-493.48 MHz




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Item Specification


Channel precision 25 kHz, 20 kHz




Item Specification

Working band 450 MHz to 460 MHz, 479 MHz to 483.48 MHz


Channel precision 25 kHz, 20 kHz




Table 9-11 and Table 9-12 list the performance specifications in band class 6 (2100 MHz).


Item Specification







Item Specification





9-11

Item Specification





Table 9-13 and Table 9-14 list the performance specifications at band class 15.

Table 9-13 Transmit specifications in band class 15

Item Specification






Table 9-14 Receive specifications in band class 15

Item Specification






ODU Cascading Specifications

Table 9-15 lists the ODU cascading specifications of the BTS3606AE.

Table 9-15 ODU cascading specifications of the BTS3606AE

Item Specification

ODU3601C Maximum distance ofsingle-level cascading

20 km [12.43 mi.]




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Item Specification

Maximum number ofcascading levels

Three

Maximum total distance ofcascading

60 km [37.28 mi.]

ODU3601CE Maximum distance ofsingle-level cascading

20 km [12.43 mi.]

Maximum number ofcascading levels

Three

Maximum total distance ofcascading

60 km [37.28 mi.]

BER Threshold Specifications of the BTS on the Transmission Links

The bit error rates (BERs) on the transmission links have roughly the same impact on the UNIand IMA modes. Table 9-16 lists the BER threshold specifications of the BTS on thetransmission links.

Table 9-16 BER threshold specifications of the BTS on the transmission links

Type Maximum BER Threshold

CDMA2000 1X voice services 2 x 10e-4

Packet services 2 x 10e-6

Maintenance function 5 x 10e-5

9.1.5 BTS RF Fault AlarmsThis topic describes the RF subsystem faults and associated fault alarms.

Table 9-17 lists the alarms related to RF subsystem faults.

Table 9-17 Alarms related to RF subsystem faults

Fault Related Alarm

Power Faults The power amplifier is overloaded.

The transmit power is abnormal.

The power amplifier is out of position.

VSWR fault The DSP Start firmware loading of CMTR digital pre-distortion fails.



9-13

Fault Related Alarm

Pre-distortionfaults

The DSP Start firmware loading of CMTR digital pre-distortion fails.

The DSP self-test of CMTR digital pre-distortion fails.

The modular self-test of CMTR digital pre-distortion fails.

The firmware loading of CMTR digital pre-distortion fails.

An error occurs in loop delay of CMTR digital pre-distortion.

The digital pre-distortion module of the multi-carrier TRM is abnormal.

The digital pre-distortion module of the multi-carrier TRM leads insignals abnormally.

The self-adaptation of the pre-distortion module is hindered.

RSSI fault The RSSI contrast between the main and diversity receiving channels isabnormal.

9.1.6 Working Principles of the BTS RF Modules and Data PointTracking

This describes the working principles of the BTS RF modules and data point tracking.

Working Principles of RF Modules

The working status of the RF subsystem is controlled by one open-loop level control unit andthree closed-loop level control units.l The aim of level control is to limit the power input and to guarantee the power output.

– Limiting the power input is a self-protection mechanism of the system that preventsexcessive power input from damaging the hardware.

– Guaranteeing power output is to implement the predistortion and automatic gainadjustment functions so that the system has a normal output.

l Through the open-loop level control, the TRM limits the power input through the ALC. Ifthe power amplifier monitoring board detects excessive power input, the power amplifieris switched off for protection and, at the same time, "The power amplifier is overloaded"and "The power amplifier is closed" alarms are generated on the system.

l The first closed-loop level control is the closed-loop automatic gain control inside the poweramplifier. To keep the output of a power amplifier normal is to ensure the stability of thegain. The gain of the power amplifier relates to the frequency, VSWR, and input signalstrength. A relatively stable gain depends on the voltage control attenuator of the poweramplifier. A voltage control attenuator is used to adjust the gain.

l The second closed-loop level control is used when the first closed loop is not functional.In this case, the external RF automatic gain control is used to adjust the input signals of thepower amplifier.

l The third closed-loop level control is performed to compensate for the signal distortion ofthe power amplifier in non-linear workspace. This function compares the feedback power




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of the power amplifier and the output power of the RF module so that there is no signaldistortion of the power amplifier.

The normal and stable operation of the RF module is guaranteed by the open-loop level controland the three closed-loop level control, and the monitoring function of the power amplifiermonitor board. The hardware system often fails to work due to excessively used or faultycomponents, or incorrect cable connections. When a system does not function properly, alarmsare generated and the tracked data has errors.

Data Point Tracking

The BTS resource tracking function of the Service Maintenance System is often used to handlethe faults in power amplification and digital pre-distortion. Figure 9-4 shows the forwardchannel structure of the RF modules.

Figure 9-4 Forward channel structure of the RF modules

Table 9-18 describes the reported tracking information.

Table 9-18 Data Point Tracking Parameters

Number Parameter Name Description

1 Base Band Power This parameter indicates the input power that thebaseband module provides for the TRM.

2 Digital Power The baseband power is converted into the digital powerafter the automatic level control. In normal cases, thedigital power is the same as the baseband power. If thebaseband power amplification is higher than the normalpower (25 W or 44 dBm), the digital power can reach44.1 dBm after the automatic level control.

3 IF Gain Adjust This parameter is adjusted through the parameteradjustpower in the command SET CBTSRFPARAcommand. The value of this parameter affects themaximum output power of the TRM. If IF GainAdjust is set to -1, the maximum output power percarrier is: 44 dBm (rated power) - 1 dBm = 43 dBm.



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Number Parameter Name Description

4 Digital Power Sum Normally, this value is equal to the sum of the digitalpower.

5 RF Gain Adjust The value of the RF forward voltage control attenuatoris internally set and cannot be adjusted. When the closed-loop power control function is performed, the TRMautomatically adjusts this value to ensure that the RFoutput power reaches the predefined value.

6 RF Output Power This parameter indicates the output power of the STRM.(It can be obtained through Telnet from a computerdirectly connected to the BTS, not from an LMT).

7 Hpactrlcurval This parameter indicates the control voltage of poweramplifier. It is used to control the power amplificationgain. (It can be obtained through Telnet from a computerdirectly connected to the BTS, not from an LMT).

8 Hpaoutpwr(Mv/Dbm)

Normally, this value is equal to the sum of digital power.

9 SDFU Input Power Normally, this value is equal to the sum of digital power.

10 Hpa(Antenna)Power

Normally, this value is equal to the sum of digital power.

11 Observe ChanPower

Normally, the difference between this value and theHPA (antenna) power is 56±3 dB.

Based on the previously described working principle of the system, you can locate the faults intracking data.

For example, set up a Telnet connection to the BTS, and then run the str infotrace command toinitiate system data tracking.

For example, run the following command:str infotrace:brdtp=trm,brdid=0,item="power"The output is as follows:TRM0 :Base Band Power: Carrier0 = 38.5, Carrier1 = N/A, Carrier2 = 38.5, Carrier3 = N/A, Carrier4 = N/A, Carrier5 = N/ADigital Power : Carrier0 = 38.5, Carrier1 = N/A, Carrier2 = 38.5, Carrier3 = N/A, Carrier4 = N/A, Carrier5 = N/AAttenuation : Carrier0 = 0.0, Carrier1 = 0.0, Carrier2 = 0.0, Carrier3 = 0.0, Carrier4 = 0.0, Carrier5 = 0.0Sector : 0Digital Power Sum = 38.6, SDFU Input Power = 7.8, SDFU Echo Power = -3.3OBS Channel Power = N/A, OBS Gain Adjust = 0.0, OBS Gain Identical = 0.0IF Gain Adjust = -1.0, RF Gain Adjust = 0.0, DDU Gain Adjust = 0.0PD RMS Error = N/A, DAC Input Power = 38.5, RF Forward Power = 39.4HPA Output Power = N/A

The procedure for troubleshooting the fault is described as follows:l The normal output power (Digital Power) of a carrier is 43 dBm ± 1 dB (that is, 20 W ±

1 dB).




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l If the test result displayed on the power meter is not within the normal range, compare itwith the result of the interface tracking (HPA Output Power) to locate the fault.

l If the test result displayed on the power meter is out of normal range, initiate the interfacetracking. Check the values of the parameters Base Band Power, Digital Power, and HPAOutput Power.

l If the value of Base Band Power is incorrect, the values of Digital Power and HPA OutputPower are also incorrect. In such a case, check whether the BTS gain is correct. If the BTSgain is correct, check the HCPM or the HECM by querying the BTS configuration andverifying the chip.

l If the value of Base Band Power is correct but the value of Digital Power is incorrect, thevalue of the HPA Output Power is also incorrect. In such a case, check the OMTR tolocate the fault. For example, you can remove the OMTR and insert it again, or replace theOMTR.

l If only the value of HPA Output Power is incorrect, check the installation of the OMPAand its connection with the OMTR.

l If parameter values reported in the interface tracking are correct, check whether the cablingbetween the OMPA and the ODFU is normal and whether the antenna system and the topof the cabinet function properly.

9.1.7 Test and Analysis of BTS Reverse RSSIYou need to test the RSSI value before locating the RSSI fault. This topic describes how to testand analyze the BTS reverse RSSI.

Testing the Reverse RSSI

This describes how to test the reverse RSSI. You can test the reverse RSSI in remote mode orlocal mode. This document focuses on the local mode.

Remote Test and Local Testl To perform a remote RSSI test, choose Resource Monitoring > RSSI Monitoring on the

LMT or log in to the BTS in Telnet mode.

l To perform a local RSSI test, connect the workstation to the CMPT using a crossover cableand then log in to the BTS in Telnet mode.

Precautionsl You can choose not to install RF fans. In this case, however, you have to use the antenna

so that zero transmit power is ensured.

l The unit for the average and peak values of the RSSI is 0.1 dBm.

l Ensure that the coupling ports without connection cables are properly loaded to avoidinternal interference and external radiation.

Procedure

Step 1 Connect the cables, as shown in Figure 9-5.



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Figure 9-5 Cable connection for the local reverse RSSI test

Step 2 Choose Start > Run, type Telnet xxx.xxx.xxx.xxx in the Run dialog box, and then pressEnter to start the Telnet program.

Step 3 Check the BTS configuration and ensure that the data configuration is consistent with the actualcable connection of the RF subrack.

Step 4 Start the reverse RSSI test. The output information is as follows:HW CBTS>str infotrace<(brdtp=?bckm_omu/bckm_sig/bckm_clk/bcim/crdm/pmu/cpm/ecm/trm/CMPT_omu/CMPT_sig/CMPT_clk/CMPT_trs/htrp),mandatory>trm<(brdid=?),mandatory>0<(item=?),optional>"rssi"Ok

Step 5 Record the test data.

Step 6 Stop the reverse RSSI test. The output information is as follows:HW CBTS>stp infotrace<(brdtp=?bckm_omu/bckm_sig/bckm_clk/bcim/crdm/pmu/cpm/ecm/trm/CMPT_omu/CMPT_sig/CMPT_clk/CMPT_trs/htrp),mandatory>trm<(brdid=?),mandatory>0<(item=?),optional>"rssi"Ok

NOTE

You can also stop the RSSI test by restarting the Telnet program.

----End

ResultThis example shows the RSSI value of the ODFU of the BTS3606AE in the CDMA2000 1X &1xEV-DO S (6/6/6) configuration.

HW CBTS>str infotrace:brdtp=trm,brdid=0,item="rssi"okHW CBTS>TRM0:Carrier0 RSSI: Main Avg = -105.0, Main Peak = -104.1, Main Ratio = 0%Carrier0 RSSI: Divs Avg = -108.0, Divs Peak = -107.7, Divs Ratio = 0%Carrier1 RSSI: Main Avg = -103.0, Main Peak = -100.1, Main Ratio = 1%Carrier1 RSSI: Divs Avg = -106.8, Divs Peak = -104.2, Divs Ratio = 0%Carrier2 RSSI: Main Avg = -106.2, Main Peak = -104.8, Main Ratio = 0%Carrier2 RSSI: Divs Avg = -108.8, Divs Peak = -108.1, Divs Ratio = 0%Carrier3 RSSI: Main Avg = -106.2, Main Peak = -104.7, Main Ratio = 0%Carrier3 RSSI: Divs Avg = -109.0, Divs Peak = -108.6, Divs Ratio = 0%Revs pwr: Main = -89.7, Divs = -85.5; RF AGC gain: Main= 0.0, Divs = 0.0




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Analyzing the Results of the Reverse RSSI Test

Analyze the results of the reverse RSSI test to locate and handle exceptions.

Description

Parameter Name Description

Main Avg Average value of a main RSSI

Main Peak Peak value of a main RSSI

Main Ratio Ratio of main RSSIs that have a value exceeding the average value

Divs Avg Average value of a diversity RSSI

Divs Peak Peak value of a diversity RSSI

Divs Ratio Ratio of diversity RSSIs that have a value exceeding the averagevalue

Revs pwr Total reverse power

RF AGC gain AGC gain of RF

Operation Procedure

1. According to the parameter description, analyze the test results.

NOTE

The performance of air interfaces at different fields may vary. The following standards are forreference only:

l If the average value of a main RSSI is within the range of -116.0 dBm to -93.0 dBm,you can infer that the received main RSSI is functional.

l If the average value of a diversity RSSI is within the range of -116.0 dBm to -93.0 dBm,you can infer that the received diversity RSSI is functional.

l Under the idle loading condition, the average value of a main RSSI should be withinthe range of -116.0 dBm to -93.0 dBm.

l If the ODFU is not connected to the antenna, the difference between the average valueof a main RSSI and the average value of a diversity RSSI should be within the range of2 dB to 3 dB.

2. Handle exceptions.

l If the RSSI value is excessively low, perform the following steps:

– Check whether the antenna functions properly.

– Check whether the cabinet top is functional.

– Check whether the ODFU is functional.

– Check whether the cable connections between RF subracks are correct.

l If the RSSI value is excessively high, check whether there are interference sources.



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9.2 Troubleshooting the BTS Power FailuresA BTS power failure may decrease the coverage range of the BTS or may degrade the qualityof signals. This describes the symptoms of the faults and the procedure for troubleshooting thefaults.

Symptoms

Table 9-19 describes the symptoms of the BTS power failures.

Table 9-19 Symptoms of the BTS power failures

Item Symptom

Services The MS receives weak signals or no signals. The BTS coverage area decreases.

Boardstatus

The ALM indicator on the panel of the OMTR is on.

Alarms The power amplifier is overloaded. The transmit power is abnormal. The poweramplifier is not in position. The power amplification gain is abnormal.

Fault Location

When the input or output power of the power amplifier is higher than the rated value, overloadingalarms may be generated. Owing to overload, the power amplifier may be switched off and thusthe BTS has no power output.

Table 9-20 describes the possible causes and analysis of BTS power failures.

Table 9-20 Possible causes and analysis of the BTS power failures

Cause Analysis

The OMTR isfaulty.

If the OMTR is faulty, replace the OMTR and check whether the faultis rectified.

The OMPA isfaulty.

l Abnormity in power amplifier

l Overtemperature condition of power amplifier

l Stalled fan

l Monitoring failure of power amplifier

RF cableconnection failure

The RF cables to be checked consist of SMA RF cables and N-type RFcables.l The SMA RF cable connects the OMTR to the OMPA in the way of

TX-OUT corresponding to PA-IN.l The N-type RF cable connects the OMTR to the OMPA in the way of

TX-IN corresponding to PA-OUT.




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Cause Analysis


l If the configured RF data is not saved, the RF data is lost after theBTS resets, thus causing no power output from the BTS.

l If the power level of the power amplifier is inconsistent with the actualdata configuration, the power overload alarms may be reported. Forexample, the power amplifier provides 60 W power in effect, but indata configuration one sector is configured with four carriers and sothe power amplifier has to be used as an 80 W one. At this time, theoverload alarms may be reported.

l If the parameter ADJPOWER is improperly or incorrectly setthrough the SET CBTSRFPARA command, the power output maybe improper. The recommended value of ADJPOWER is -2 and it isadjustable within the range -20 to 10.

l If the maximum cell radius MAXCELLR set through the SETCBTSSECTORPARA command does not meet the requirement, theMS may receive poor signals or no signals. The recommended valueof MAXCELLR (km) is 40 km and it ranges from 0 km to 125 kmfor normal-sized cells, from 125 km to 184 km or from 217 km to 250km for large-sized cells.

Fault HandlingFigure 9-6 shows the Procedure for troubleshooting the BTS power failures.



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Figure 9-6 Procedure for troubleshooting the BTS power failures

Procedure

Step 1 Check the status of the OMTR/OMPA.

Check whether the faults are caused by the OMTR/OMPA.

1. Track the forward power by referring to 9.1.6 Working Principles of the BTS RF Modulesand Data Point Tracking. The difference between the baseband power (BaseBandPwr)and the forward power (FwdPwr) should be less than ±3 dB. If the difference between thesetwo parameters exceeds ±3 dB, the OMTR/OMPA is functional.

NOTEFor details on forward power tracking, refer to Checking the Forward Power in the BTScommissioning guide.

2. If the ALM indicator on the panel of the OMTR/OMPA indicates generation of alarms,replace the OMTR/OMPA. If the fault is rectified after the replacement, you can refer that




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OMTR/OMPA is faulty. For details on how to replace the OMTR/OMPA, refer toReplacing the BTS Boards in the BTS site maintenance guide.

Step 2 Check the connection of RF cables.Check whether the faults are caused by problems with the connection of RF cables.1. Check whether the SMA RF cables are correctly connected or cross-connected.

Unscrew the SMA male connector from the cable to check whether a 2 mm to 3 mm wireof the cable is exposed. If the cable does not meet this requirement, replace the SMA RFcable.

2. Check whether the N-type RF cables are correctly connected or cross-connected.Check the cable connections by replacing the N-type cables.

Step 3 Check the data configuration.After the fault location and analysis, check whether the fault is caused by the incorrect dataconfiguration.1. Run the DSP CBTSCFG command to check whether the RF module is correctly configured

or whether the data is already configured.If the configuration data is incorrect or the configuration is not saved, the power amplifiermay have no power output after the BTS is started.

2. Run the DSP CBTSHPAINFO command to check whether the power level of the poweramplifier is consistent with the number of carriers in data configuration.If the power level is inconsistent, replace the faulty power amplifier with a correct one. Ifthe data configuration is incorrect, modify the number of carriers in data configuration.

3. If the network parameters related to the forward power are not properly set, the forwardpower may be faulty. To enhance the coverage in important areas, you can change thenetwork parameters such as the antenna azimuth.

----End


9.3 Troubleshooting the BTS Standing Wave FailuresWhen the antenna impedance does not match the feeder impedance, the antenna cannot receiveall high frequency energy transmitted by the feeder. Some energy forms reflected wave. If thereflected wave is excessively strong, namely, the VSWR is too high, the transmit powerfluctuates and the coverage range diminishes. This describes the symptoms of the faults and theprocedure for troubleshooting the faults.

SymptomsTable 9-21 describes the symptoms of the BTS standing wave failures.



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Table 9-21 Symptoms of the BTS standing wave failures

Item Symptom

Services MSs cannot receive signals or receives only weak signals, which may result incall drop. The coverage of the BTS or the corresponding sector carrierdiminishes.

Boardstatus

The ALM indicator on the panel of the OMTR is on.

Alarms l A large number of standing wave alarms are generated.

l Alarms related to the RF system are generated.

Fault LocationTable 9-22 describes the possible causes and analysis of BTS standing wave failures.

Table 9-22 Possible causes and analysis of the BTS standing wave failures

Cause Analysis

The antenna system isfaulty.

Constructionquality

For example, the joint between the antennaand the feeder is not well connected, thejoint between the jumper and the feeder isnot well connected, or the jumper connectoris not properly made.

Antenna quality The antenna is damaged or is not protectedagainst water leakage.

Article problem For example, the jumper connector andjumper are mismatched.

The OMTR or OMPAis faulty.

The standing wave alarms are generated if the frequency bandassigned by using the ADD CELL command is inconsistent withthe frequency band supported by the OMTR or OMPA.The standing wave alarms are seldom generated due to faults in theOMTR or OMPA. Thus, replacing the OMTR or OMPA is anoption only when other methods fail to locate the fault.

Fault HandlingFigure 9-7 shows the procedure for troubleshooting the BTS standing wave failures.




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Figure 9-7 Procedure for troubleshooting the BTS standing wave failures

Procedure

Step 1 Check the antenna system.

Check whether the faults are caused by the antenna system. When checking the antenna system,adhering to the following rules:

l If damaged, the antenna system is an open circuit. If water leaks into the antenna system, theantenna system is a short circuit. In either of the preceding two situations, the VSWR isgreater than 4:1. If the BTS is functional, the VSWR should be smaller than 1.5:1. Thethresholds of the standing wave alarms are as follows:– If the VWSR is smaller than 1.5:1, the standing wave alarm is not generated.

– If the VWSR is greater than 4:1, the standing wave alarm is generated.

– If the VSWR ranges from 1.5 to 2.0, the standing wave alarm should not be generated.

– If the VSWR ranges from 2.0 to 4.0, the standing wave alarm should be generated.

l When the BTS is put into service, test the BTS coverage and record details of the test location.

l After standing wave alarms are generated, perform the coverage level test for the BTS andcompare the result with the information recorded when the BTS is put into service. If coverageis not affected, the alarms are false. If the coverage is affected and the TX level of the poweramplifier is normal, the fault may lie in the antenna system.

1. To measure the VSWR of the antenna system, connect the RF jumper connector at the topof the cabinet to the input port of the SiteMaster.



9-25

Typically, the VSWR is less than 1.5:1. The VSWR measured at the N-type connector ofthe 1/4" jumper that connects to the output port of the SDFU should be less than 1.3:1. Thereturn loss is 18 dB.

If the VSWR is equal to or greater than 1.5:1, check the antenna system. Use a SiteMasterto locate the position with the greatest echo loss. Then, examine the construction.

2. Check the connections of the feeders.

During the installation of the antenna system, the feeders may be connected to a wrong RFoutput port and the feeders may be crossed. Such mistakes generally happen in a BTS thathas multiple sectors.

3. Check the installation of feeders and jumpers.

Focus on the assemblies of feeder connections and the waterproof treatment of feederconnectors. Check whether the cable is damaged and whether there is any trace of waterleakage on the connector and cable.

Ensure that the connectors are well prepared, effective waterproof measures are taken, nowater leaks into the connectors and cables, and the cables are intact. The sites that havesignificant temperature difference are prone to water penetration. If the installation of thefeeder or the jumper is faulty, replace it with the same type of feeder or jumper.

4. Check the antenna.

Check whether the antenna is damaged and whether any trace of water leakage can be foundon the connectors of the antenna and jumpers. Ensure that the antenna is intact and no traceof water damage is on the connectors of the antenna and jumpers. If the antenna is faulty,contact Huawei for technical support.

Step 2 Check the OMTR or OMPA.

Check whether the faults are caused by the OMTR or OMPA.

1. Run the LST CELL command to check whether the frequency band of the cell isinconsistent with that supported by the OMTR or OMPA.l If the band configuration is incorrect, modify the data configuration.

l If the OMTR or OMPA does not support the required band, replace the OMTR orOMPA.

CAUTIONBefore you operate the RF cable or replace the RF parts, power off the RF module.

2. If the fault persists after the antenna is proved to be functional, replace the OMTR or OMPAto check whether the boards are operational.For details on how to replace the OMTR or OMPA, refer to Replacing the BTS Boards inthe BTS site maintenance guide.

----End





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9.4 Troubleshooting the BTS Predistortion FailuresThe RF module predistortion processing is performed to compensate for the signal distortion ofthe power amplifier in non-linear workspace. This function compares the feedback power of thepower amplifier and the output power of the RF module so that there is no signal distortion ofthe power amplifier. BTS predistortion failures may degrade the performance of RF modules.This describes the symptoms of the faults and the procedure for troubleshooting the faults.

Symptoms

When there are faults in predistortion, the BTS generates the following alarms:

l The DSP start firmware loading of CMTR digital predistortion fails.

l The DSP self-test of CMTR digital predistortion fails.

l The modular self-test of CMTR digital predistortion fails.

l The firmware loading of CMTR digital predistortion fails.

l An error occurs in loop delay of CMTR digital predistortion.

l The digital predistortion module of the multi-carrier TRM is abnormal.

l The digital predistortion module of the multi-carrier TRM leads in signals abnormally.

l The self-adaptation of the predistortion module is hindered.

Fault Location

Table 9-23 describes the possible causes and analysis of BTS predistortion failures.

Table 9-23 Possible causes and analysis of the BTS predistortion failures

Cause Analysis

The externalrequirements are notfulfilled, or theconnectionsbetween devices arenot functional.

Check the related alarms. Check whether the HCPM/HECM isoperational by querying the special status of the board. Check theconnections by replacing the cables between the baseband subrack andthe RF subrack.

The OMTR/OMPAis faulty.

Analyze the operation and tracking data. If the device is faulty, replacethe device and return the faulty device for repair. If the externalconditions and the operation data of the device are normal, you caninfer that no fault exists. In this case, wait until the alarm isautomatically cleared.If you need to locate the specific fault, familiarize yourself with thesystem rationale, and then analyze the tracked data to locate the fault.For the method of tracking and analyzing system data, refer to 9.1.6Working Principles of the BTS RF Modules and Data PointTracking.



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Fault Handling

Figure 9-8 shows the procedure for troubleshooting the BTS predistortion failures.

Figure 9-8 Procedure for troubleshooting the BTS predistortion failures

Procedure

Step 1 Check the external factors.

Check whether the faults are caused by the external factors.

1. Check whether the HCPM/HECM is functional. If alarms related to the HCPM/HECM aregenerated, replace the board and check whether the alarms are cleared.

2. Check the cables between the baseband subrack and the RF subrack. Replace the faultycables.

For details on parts replacement, refer to Replacing the BTS Parts in the BTS sitemaintenance guide.

Step 2 Check the OMTR/OMPA.Check whether the faults are caused by the OMTR/OMPA module.

1. Log in to the BTS through the Telnet and run the str infotrace command. Initiate the BTSresource tracking function and check whether the device is faulty by tracking the systemdata.




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For example, run the str infotrace:brdtp=trm,brdid=0,item="power" command. Forthe methods of tracking and analyzing system data, refer to 9.1.6 Working Principles ofthe BTS RF Modules and Data Point Tracking.

2. If the board is faulty, replace the board.For details on parts replacement, refer to Replacing the BTS Parts in the BTS sitemaintenance guide.

----End


9.5 Troubleshooting the BTS Reverse RSSI FailuresIf there is a reverse RSSI failure in the BTS, the reverse sensitivity and reverse capacity of theBTS is reduced, therefore affecting the access of the MS to the network. This describes thesymptoms of the faults and the procedure for troubleshooting the faults.

SymptomsTable 9-24 describes the symptoms of the BTS reverse RSSI failures.

Table 9-24 Symptoms of the BTS reverse RSSI failures

Item Symptom

Services The reverse sensitivity and reverse capacity of the BTS are reduced. Severefaults may lead to service interruption. MSs, except MSs that are near to theBTS, can detect signals but cannot access the network.

Alarms l The tower mounted amplifier (TMA) is faulty.

l The main/diversity LNA is unavailable.

l The main/diversity TMA is unavailable.

l The RSSI contrast between the main and diversity receiving channels isabnormal.

l The input signal on the receiving channel is too big.

l The TRM main/diversity reverse channel is abnormal.

l The connection of the TRM main/diversity cable is faulty.

Fault LocationTable 9-25 describes the possible causes and analysis of the BTS reverse RSSI failures.



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Table 9-25 Possible causes and analysis of the BTS reverse RSSI failures

Cause Analysis

Hardwareproblem

The connections between the TRM, the RF cables, and the antenna systemare not functional.

Settingparameters

The parameters related to the BTS RF, access channels, and load controlof access channels are not properly set. The network parameters are listedas follows:l BTS RF parameter, configured by running the SET CBTSRFPARA

commandl Access channel parameter, configured by running the MOD ACH

commandl Access channel load control parameter, configured by running the

MOD ALDCTRL command

Fault HandlingFigure 9-9 shows the procedure for troubleshooting the BTS reverse RSSI failures.

Figure 9-9 Procedure for troubleshooting the BTS reverse RSSI failures




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Procedure

Step 1 Check the RSSI.

Check whether the faults are caused by the hardware problem.

1. Connect to the BTS locally or remotely, and initiate the RSSI test. For details on how toconduct the test and how to make decisions, refer to Test and Analysis of BTS ReverseRSSI.

2. If the TRX module is faulty, replace the board and perform the check again.

3. If the connection between RF cables is faulty, check whether the connectors of RF cablesbetween OMTR and OMPA are properly fixed.

4. If the antenna system is faulty, follow the procedures given below:

l Check whether the installation of the antenna, such as the azimuth and isolation of theantenna, satisfies the engineering requirements.

l If the main and diversity RSSI values differ greatly, you can infer that a self excitationoccurs in the antenna system that has a large RSSI, or the cable connection of the antennasystem that has a small RSSI is faulty.

l Check whether the diversity bypass switch is correctly configured. If the diversitybypass configuration is incorrect, a false alarm "Abnormal Difference Between the Mainand Diversity" is generated.

l If the antenna system is equipped with a lightning arrester, ensure that the DCbreakdown voltage of the lightning arrester meets the requirements.

5. If the RSSI value is excessively large, you can infer that external interference exists. Usea spectrometer to track the spectrum of the interference source, or use the Nastar to initiatethe reverse spectrum scanning.For the description of the BTS features, refer to BTS Reverse Spectrum Scanning.

Step 2 Check the settings of the network parameters.

If no fault is found in the hardware, check the settings of the network parameters.

CAUTIONl When checking the network parameters, do not modify their settings. Modifying the BTS

RF parameters may result in service interruption.

l The network parameters can be modified only if the customer permits to do so.

l For the value range of each parameter, ask Huawei network optimization department forhelp.

1. Run the DSP CBTSCFG command to query the current settings of network parameters.

2. Run the SET CBTSRFPARA command to set the BTS RF parameter.

3. Run the MOD ACH command to modify the access channel parameter.

4. Run the MOD ALDCTRL command to modify the access channel load control parameter.

----End



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Postrequisite


9.6 Case: Clearing BTS Standing Wave AlarmsBTS standing wave faults may deteriorate the antenna performance and diminish the coveragerange. This topic describes the fault symptoms and how to clear the BTS standing wave alarms.

Symptoms

The accuracy of detecting standing wave faults is unsatisfying at many sites, for example:

l The BTS reports standing wave alarms, yet tests prove that the coverage and output powerare normal.

l The performance of the BTS antenna system deteriorates, which leads to a smaller coverage.Yet the system does not report any standing wave alarm.

Fault Location

The factors that influence the accuracy of VSWR tests are as follows:

l Accuracy of the output amplitude of the highly stable amplitude signal unit

l High directional accuracy and amplitude frequency characteristics accuracy of thedirectional coupling unit

l Accuracy of the calibration equipment for open and short circuits, especially the accuracyof the open circuit load

l Accuracy of the matching loads

l Processing accuracy of the network signal analyzing unit

These factors are described as follows:

l To achieve high accuracy of the output amplitude of the highly stable amplitude signal unit,the signal source should have an effective amplitude fixing system and heat stability. Thus,high accuracy of the amplitude fixing unit, which consists of the directional coupler,detector, and temperature compensation processing unit, is required.It is difficult to implement a highly stable amplitude signal unit, especially inside the BTSwhere strict requirements are set for the size and dissipation of the equipment. Typically,the BTS uses existing signal sources for VSWR tests. The accuracy of these signal sourcesare not high enough to be used for VSWR tests, which gives rise to the possibility of falsealarms.

l The directionality and amplitude frequency characteristics of the directional coupling unitare the keys to VSWR tests. The directional coupling unit is responsible for the clearseparation between signals of incident waves and reflected waves of the device under test.It is often used in measuring apparatus that provides standards for tests and that requireshigh accuracy. Yet it is difficult to implement a directional coupling unit inside the BTS.

l The highly accurate calibration equipment is used as a standard against which VSWR testsare performed. The accuracy of the calibration equipment directly decides the accuracy ofthe tests. It is more difficult to use calibration equipment for open circuits than for shortcircuits.




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l The VSWR is the ratio of reflected waves to incident waves. The antenna connectors arefixed to feeders, and the reflected signals are attenuated by the feeders depending on thefeeder length. Thus, the test result becomes inaccurate if the feeder length is close to orexceeds the threshold, which leads to false faults.

l As the test data is closely related to the location of the equipment, the threshold valuesshould be properly adjusted as required at each site. Otherwise, false fault are generated.The problem can be resolved through improvement in algorithm software.

Fault HandlingDetect standing wave alarms of Huawei BTS by adhering to the following rules:

l If the antenna system is damaged, an open circuit fault occurs.

l If water enters the antenna system, a short circuit fault occurs.

In these two cases, the VSWR is greater than 4:1. In normal condition, the VSWR should besmaller than 1.5:1.

Detecting standing wave alarms is not sufficiently accurate. Therefore, perform the followingoperations in practice:

1. Perform forward and reverse calibration tests for all BTSs to ensure reliable connectionsbetween modules. Ensure that the accuracy of the forward output power and the reversesensitivity reach the optimal levels.

2. Use dedicated tools to perform VSWR tests for all components in the antenna system toensure that the antenna system is properly installed.

3. After the BTS enters service, perform dialing tests and drive tests to ensure that the BTSis functional and the performance counters such as the coverage meet the designrequirements.



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10 Clearing BTS Service Failures

About This Chapter

When MSs fail to access the network, voice discontinuity occurs, call drops occur duringhandoff, or data services fail, you must clear BTS service failures. BTS service failures are accessfailures, voice service failures, data service failures, and handoff failures.

10.1 Overview of BTS ServicesBTS services are classified into voice services and data services. To ensure the normal operationof voice services and data services, mobility management such as access management, handoffmanagement, and congestion control must be performed in the BTS.

10.2 Troubleshooting the BTS Access FailuresBTS access failures include MS registration failure or rejection, network detection failure, anddisconnection from the network. This describes the symptoms of the faults and the procedurefor troubleshooting the faults.

10.3 Clearing BTS Voice Service FailuresBTS voice service failures include MOC failures, MTC failures, one-way audio, no audio, audiodiscontinuity, noise, crosstalk, and echo. This topic describes the fault symptoms and how toclear BTS voice service failures.

10.4 Troubleshooting the BTS Data Service FailuresThe data service failures of the BTS consist of the MS access failures, low call completion rate,low transmission speed, and poor transmission quality. This describes the symptoms of the faultsand the procedure for troubleshooting the faults.

10.5 Troubleshooting the BTS Handoff FailuresMSs cannot initiate a handoff or call drop occurs during a handoff. This describes the symptomsof the faults and the procedure for troubleshooting the faults.

10.6 Case: Failure of Random Access to the Carriers Caused by HCPM FailuresDuring BTS data configuration, the HCPMs are added into the resource pool. If one or moreHCPMs in the resource pool are faulty, a random access failure may occur on the carrier. Thisdescribes the symptoms of the faults and the procedure for troubleshooting the faults.

10.7 Case: Voice Service Failures Caused by Cell Radius Too SmallWrong data configuration is the common cause of BTS faults. If the maximum radius of the cellis set to a small value, the coverage of the cell diminishes. As a result, MSs at the cell border

Airbridge BTS3606AE CDMA Base StationTroubleshooting Guide 10 Clearing BTS Service Failures


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fail to access the network. This topic describes how to clear voice service failures caused by atoo small cell radius.

10.8 Case: Slow Call Access in the Coverage Caused by Antenna System FailuresIf the main or diversity antenna feeders in a sector are loose or faulty, the demodulation qualitybecomes poor in reverse reception and the demodulation takes more time. As a result, the averagetime of call access in the coverage area becomes long. This topic describes the fault symptomsand how to clear the fault.

10 Clearing BTS Service FailuresAirbridge BTS3606AE CDMA Base Station



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10.1 Overview of BTS ServicesBTS services are classified into voice services and data services. To ensure the normal operationof voice services and data services, mobility management such as access management, handoffmanagement, and congestion control must be performed in the BTS.

10.1.1 Basic Knowledge About BTS AccessBTS access refers to the process in which an MS accesses the BTS. This topic describes the MSaccess state and the access procedure.

10.1.2 Basic Knowledge About BTS Voice ServiceBTS voice service is the CDMA2000 1X service. This topic defines the terminologies relatedto BTS voice service faults and also describes the BTS voice service faults.

10.1.3 Basic Knowledge About BTS Call DropBTS call drop refers to the process in which the communication between the MS and the BTSis interrupted. This topic describes the causes of BTS call drops.

10.1.4 Basic Knowledge About BTS Data ServiceBTS data services consist of the CDMA2000 1X service and the CDMA2000 1xEV-DO service.This topic describes the common problems of data services and the possible causes.

10.1.5 Basic Knowledge About BTS HandoffBTS handoff refers to the process in which the MS performs a handoff between cells or sectors.This topic describes different types of handoff failures and the troubleshooting procedure.

10.1.1 Basic Knowledge About BTS AccessBTS access refers to the process in which an MS accesses the BTS. This topic describes the MSaccess state and the access procedure.

MS Access State

The MS access state consists of the following substates:

l Update Overhead Information Substate: In this substate, the MS monitors the PagingChannel until it has a current set of overhead messages.

l Mobile Station Origination Attempt Substate: In this substate, the MS sends an OriginationMessage to the BTS.

l Page Response Substate: In this substate, the MS sends a Page Response Message to theBTS.

l Mobile Station Order/Message Response Substate: In this substate, the MS sends a responseto a message received from the BTS.

l Registration Access Substate: In this substate, the MS sends a Registration Message to theBTS.

l Mobile Station Message Transmission Substate: In this substate, the MS sends a Data BurstMessage or a Peer-to-Peer Resource Control Message to the BTS.

l PACA Cancel Substate: In this substate, the MS sends a PACA Cancel Message to theBTS.



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MS Access Attempt

The MS accesses the network from the access channel in a random way. The access attemptrefers to the entire process of sending a message and receiving a response from the BTS. TheMS accesses the network by sending access probes. Several access probes compose an accessprobe sequence. Several access probe sequences form an access attempt.

MS Access Procedure

Figure 10-1 shows the procedure of signaling exchange over the air interface in the case thatthe calling MS accesses the network.

Figure 10-1 Procedure of signaling exchange over the air interface for the calling MS to accessthe network

The signaling procedure is described as follows:

1. The MS sends an Origination message to the BS through the access channel to request aservice. The message carries the request for acknowledgement by Layer 2.

2. The BS acknowledges the receipt of the Origination message by sending a Base Ack Ordermessage.

3. If a traffic channel (TCH) is available for the call and the MS is not on any TCH, the BSsends a channel assignment message through the PCH over the air interface to initiate thesetup of a radio TCH and sends Null Traffic Data through the TCH to the MS to help theMS obtain the forward channel.

4. The BS sends an assignment message to the MS.




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5. The MS sends a Traffic Channel Preamble message through the designated reverse TCHto help the BS obtain the reverse TCH.

6. Once the BS obtains the reverse TCH, it sends a Base Ack Order message which isacknowledged by Layer 2 to the MS through the forward TCH.

7. The MS acknowledges the receipt of the Base Ack Order message by transmitting an MSAck Order message through the reverse TCH.

8. The BS sends a Service Connect message or a Service Option Response Order message tothe MS, specifying the service configuration for the call. Upon receiving the ServiceConnect message or Service Option Response Order message, the MS starts processingtraffic in accordance with the specified service configuration.

9. The MS responds with a Service Connect Complete message. After the radio TCH and theterrestrial circuit are set up and fully interconnected, the BS sends an Assignment Completemessage to the MSC and regards that the call enters the conversation state.Failure of any step in the above described procedure causes access failure or slow access.

10.1.2 Basic Knowledge About BTS Voice ServiceBTS voice service is the CDMA2000 1X service. This topic defines the terminologies relatedto BTS voice service faults and also describes the BTS voice service faults.

Terminologies Related to BTS Voice Service FaultsThe terminologies related to BTS voice service faults are defined as follows:

l One-way audio: During a conversation between A and B, A can hear B but B cannot hearA.

l No audio: After a call is set up between A and B, they cannot hear each other.

l Discontinuity: There are pauses during the conversation, that is, the called party hears aspeech with words skipped.

l Noise: Strange sound occurs in the conversation, such as sound of bubbles, clatters, andknocking of metals. In serious cases, conversations are totally covered by noise.

l Cross talk: During the conversation, both the called party and a third party can be heard,or only a third party is heard.

l Echo: During the conversation, not only the called party but also echo of the calling partycan be heard.In serious cases, the echo may interrupt the conversation. The echo is classified into thefollowing types:– Acoustic echo: the echo that occurs when an MS calls another MS

The cause of the acoustic echo is that some MSs fail to meet the requirement for acousticseparation specified in protocols. As a result, the sound of the earpiece can be easilysent to the microphone and then be coded and sent to the BTS which sends the soundto the called MS.The acoustic echo is related only to the MSs. It has no relationship with the frequencytimeslot of the BTS or the data reloading.

– Electrical echo: the echo that occurs when an MS calls a PSTN userThe electrical echo is caused by the unmatched impedance of the PSTN hybridconverter. As a result of the unmatched impedance, the signals sent out are coupled intothe receiver line and causes the echo.



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– When an MS calls another MS or a PTSN user, one party can hear only his/her ownvoice and the other party hears nothing.

Description of the Voice Service Faults

The faults in voice services are described as follows:

l Noise

– Amplitude: For example, the amplitude of the noise is 1/3 of the amplitude of the normalvoice.

– Time: The noise happens when a phone is connected or disconnected, or happensrandomly or every X minutes during the conversation.

– Duration: short, X seconds (after that, voice is recovered), long.

– Impact on the conversation: The calling party cannot hear the called party, can hear thecalled party but can hardly tell what is said, or can hear what is said but the conversationquality is unsatisfactory.

– Symptoms: sound of bubbles, short and crisp clatters, knocking of metals with theamplitude larger than that of normal voice.

– Occurrence probability: for example, the noise occurs in 5% of all the calls.

l One-way audio, no audio, and discontinuity

– Type: Only one party cannot be heard, or neither the calling party nor the called partycan be heard.

– Time: continuously happening after the call is connected, happening during aconversation, happening during a conversation and the conversation is resumed after Xseconds.

– Occurrence probability: for example, the noise occurs in 5% of all the calls.

l Echo

– Amplitude: For example, the amplitude of the echo is 1/5 of the amplitude of the normalvoice.

– Occurrence probability: The noise occurs in 5% of all the calls.

– Terminals: the models of the terminals at the calling and called parties who hear theecho.

– Relation with voice volume: When the echo happens, adjust the voice volume of thepeer party to see if the amplitude of the echo heard at the local party changes.

10.1.3 Basic Knowledge About BTS Call DropBTS call drop refers to the process in which the communication between the MS and the BTSis interrupted. This topic describes the causes of BTS call drops.

The causes of BTS call drops are described as follows:

l Coverage

– Discontinuous coverage (blind areas). For example, lone offices or hilly areas wherethe radio propagation environment is complicated and signals are weak easily causediscontinuous coverage which results in call drops.




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– Indoor coverage. For example, some areas are crowded with the buildings, which resultsin large decay of signal transmission, and thick walls of the buildings also cause heavyloss when signals penetrate the walls. When the indoor level is low, call drops happen.

– Too small coverage. If the coverage is too small, the equipment is probably faulty.

l Handoff

– Improper setting of parameters. For example, the handoff threshold is set too small. Asa result, when signals in cell B are just a little stronger than the serving cell A, thehandoff is initiated. But if signals in cell B weaken after the handoff and there is noproper cell for handoff, call drops happen.

– Incomplete neighboring cells. Some neighboring cells may be missed to be configured.In that case, when the MS moves out of the coverage of the serving cell and cannot handoff to a cell with better signals, call drops happen.

– Traffic congestion. Imbalance traffic causes the unavailability of the handoff channelin the destination BTS, which results in the failure of handoff. If the re-establishmentfails, the call drops happen.

– The lost synchronization of the BTS clock causes handoff failure and then call dropshappen.

– When a timer expires, call drops happen.

l Interference

The interference mainly refers to the intra-frequency, side-frequency, and intermodulationinterference. If the MS receives strong intra-frequency or side-frequency interfering signalsin the serving cell, the bit error rate worsens and conversation in the network is interfered,which results in poor conversation quality and call drops.

l Antenna system

– If the feeder is connected reversely, call drops, one-way audio, and difficulty in callconnection happen in the area a little far away from the BTS.

– If a directional cell has both the main and the diversity antennas and the two antennashave different pitch angles or azimuths, the coverage of the two antennas is differentand call drops happen.

– Any damage of the feeder, water leakage, breaking, or poor contact of connectorsdecreases the TX power and the receiver sensitivity, which results in serious call drops.You can locate this type of problem by conducting VSWR tests.

l Transmission

The poor quality of data transmission over the Abis interface or the A interface causes theinstability of the transmission links, which results in call drops.

l Setting of radio parameters

– The settings of access channel parameters are incorrect.

– The settings of BTS RF parameters are incorrect.

l Other causes

For example, the board software version does not match the BAM software version.

10.1.4 Basic Knowledge About BTS Data ServiceBTS data services consist of the CDMA2000 1X service and the CDMA2000 1xEV-DO service.This topic describes the common problems of data services and the possible causes.



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Common Problems of Data Services

The following are common problems of data services:

l Low service completion rate

l Poor transport quality

l Slow transport speed

l Data service unavailability

Possible Causes

The possible causes of the problems of data services are described as follows:

l Loss of clock synchronizationData services have critical requirements for system clock synchronization. The clocks ofthe MS, BTS, BSC, and PDSN must be synchronized.

l Poor radio environmentA poor radio environment may cause large amounts of bit errors during the transmissionof data services, which results in the failure of the services. If the test report of the signalingover the Abis interface shows that the downlink or uplink bit error rate exceeds 3.2%, biterrors happen in data services.

l Frequent handoffsHandoffs cause loss of frames in data services. Frequent handoffs affect the stability ofdata services.

l Incorrect MS subscriptionThe MS must be correctly defined in the HLR for the bearing of services.

l Connection problemFor most of the data services, mobile phones shall be connected with computers throughserial ports or by infrared ray. If the connection breaks, data services fail. Mobile phonesof some manufacturers require dedicated drivers for the connection through infrared ray.Otherwise, the broadcast connection rate and the transmission quality of the data serviceswill be affected or the function may even fail to be performed.

l Wrong setting of the transmission mode supported by the MSDifferent MSs support different transmission modes, such as, transparent, non-transparent,synchronous, and asynchronous. Transmission rates of different MSs are different too.Parameters should be set correctly.

10.1.5 Basic Knowledge About BTS HandoffBTS handoff refers to the process in which the MS performs a handoff between cells or sectors.This topic describes different types of handoff failures and the troubleshooting procedure.

Types of Handoff Failures

According to the symptoms, handoff failures can be categorized as follows:

l Handoff is not initiated.

l MS incoming handoff fails.




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l MS outgoing handoff fails.

According to the causes, handoff failures can be categorized as follows:

l The hardware is faulty.

l The data configuration is wrong.

l Congestion occurs during the transmission.

Troubleshooting Procedure1. Check whether the faults happen in individual cells or all cells. Analyze the characteristics

of the cells where the faults happen, for example, whether the cells are all the neighboringcells of a cell, or whether the cells are controlled by the same BSC or MSC.l If faults happen in the two cells where the handoff is performed, check the data

configuration of the two cells and the hardware.l If faults happen in all the neighboring cells of a cell, check the data configuration of the

cell and the hardware used for the cell.l If faults happen in all the cells controlled by the same BSC, check the data configurations

between the BSC and the MSC.l If faults happen in all the cells controlled by the same MSC, the cause may be the

improper cooperation between the local office and the peer office, such as, theincompatibility of signaling and the improper setting of timers.

2. Check whether data is modified before faults occur in the handoff.l If faults happen in individual cells, check whether data in the cells is modified.

l If faults happen in all the cells controlled by the same BSC, check whether data of theBSC and the peer MSC is modified.

l If faults happen in all the cells controlled by the same MSC, check whether data of thepeer MSC is modified.

3. Check whether the handoff problem is caused by hardware failure. If no data in the cellswhere the faults happen and no data in the neighboring cells is modified recently, checkfirst whether the failure of the BTS hardware causes the faults.l If faults happen in all the cells controlled by the same BTS, check whether the failure

of the hardware that is shared by the cells causes the faults.l If faults happen in only one cell controlled by the BTS, the cause may be the failure of

the hardware used for the cell, for example, the damage of a carrier causes the failureof the handoff to the faulty carrier.This problem can be confirmed by blocking part of the carriers. If handoff succeedsafter a carrier is blocked, check whether the carrier is faulty or the CDU/antennaassociated with the carrier is faulty.

l Use the tracing on the Abis interface to check whether the signaling in the cell is normaland check the test report to see whether the receive quality in the UL and DL is good.If the test report shows that the receiver quality is poor, the hardware in the cell is faultyor serious interference exists, which interrupts the exchange of signaling and causeshandoff problems.

4. Record useful traffic statistics, such as handoff performance measurement and TCHperformance measurement.l Check whether the TCH occupancy of the cell whether the faults happen is normal, for

example, whether call drop rate is increasing.



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l Check whether the success rate of connecting or disconnecting cells is normal and checkthe categorization of the causes of the handoff failure.

l Check whether the success rate of the wireless handoff is normal.

5. Perform drive tests for the cells where faults happen and analyze the signaling of the drivetests.

l Check whether the UL level and DL level of the cell where faults happen are balanced.The imbalance probably causes handoff problems. Usually, the imbalance between theUL level and the DL level is caused by the faults of the BTS.

l Check the test report of the cell where faults happen to see whether the report containsthe correct list of neighboring cells.

l Check whether the MS can hand off from the cell where faults happen to the neighboringcell and whether the MS can hand off from the neighboring cell to the cell where faultshappen.

l Check whether the signaling procedure of the handoff is correct.

10.2 Troubleshooting the BTS Access FailuresBTS access failures include MS registration failure or rejection, network detection failure, anddisconnection from the network. This describes the symptoms of the faults and the procedurefor troubleshooting the faults.

Symptoms

The symptoms of BTS access failures are described as follows:

l The MS fails to initiate the registration procedure or the MSC rejects the registration.

l The MS frequently originates location updates or does not initiate the location update whenthe MS hands off from one network to another.

l The network access is slow or the call setup fails.

l The MS fails to detect or access the network, or is frequently disconnected from thenetwork.

Fault Location

According to the symptoms, check the hardware and data configuration to locate the faults innetwork access.

l The possible causes of the faults that the MS cannot initiate the registration procedure orthat the MSC rejects the registration are:

– The cell is not working and the cell configuration in the BTS is inconsistent with thatin the BSC.

– The BTS is faulty or not started, or the cell is not working.

– The system information is not properly configured.

– The MS is not correctly defined.

l The frequent location updates or the lack of location updates for network handoff is causedby the improper data configuration in the BSC and in the MSC.




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l The slow access of the network or the call setup failure is related to the BSC, BTS and theMSC. You can locate the faults by tracking messages over the Abis interface.

l The possible causes of the faults that the MS cannot detect or access the network, or isfrequently disconnected from the network are:– Improper configuration of the BSC system information

– Large jitter of the BTS output power

– Unstable installation of antennas

– Intra-frequency interference with other cells

Table 10-1 describes the possible causes and analysis of access failures.

Table 10-1 Possible causes and analysis of the access failures

Cause Analysis

The BTS is notworking.

The MSs served by the BTS cannot detect or access the network.

The HCPM orHECM is faulty.

The HCPM or HECM boards form a resource pool. If any board in theresource pool is faulty, the MSs served by carriers of the faulty board failto access the network.

The OMTR orOMPA is faulty.

If the RF module is faulty, there is no power output. The MS cannot obtainany signal and cannot access the network.

The antennasystem is faulty.

If the antenna system is faulty, the BTS cannot properly transmit or receivesignals and no service can be performed properly.

Externalinterferencesource exists.

In this case, though the BTS hardware is functional, adjust the BTShardware installation, for example, adjust the pitch angles or azimuths.


The causes of incorrect data configuration on the BTS side are describedas follows:l The information of the local cell and sectors added through the ADD

CBTSCELL command is inconsistent with the related parametersconfigured on the BSC.

l The cell radius added through the SET CBTSSECTORPARAcommand is too small and some of the MSs cannot access the cell.

l The RF parameters added through the SET CBTSRFPARA commandare incorrect.

Fault HandlingFigure 10-2 shows the procedure for troubleshooting the access failures.



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Figure 10-2 Procedure for troubleshooting the access failures

Procedure

Step 1 Check the hardware of the BTS/BSC/MSC.Check whether the faults are caused by a hardware failure in the BTS/BSC/MSC. To rectify thehardware failure in the BSC/MSC, contact engineers of the BSC/MSC for assistance.1. Check whether the BTS is working.

To troubleshoot the BTS startup failures, refer to 4.4 Case: BTS Startup Failures Causedby Signaling IP Configuration Inconsistency.

2. Check whether the HCPM or HECM is faulty.Check the panel of the HCPM or HECM for alarms. Replace the board and check whetherthe alarms are cleared.

3. Check whether the OMTR or OMPA is faulty.Check the panel of the OMTR or OMPA for alarms. Replace the board and check whetherthe alarms are cleared.

4. Check whether the RF antenna system is faulty.To troubleshoot the BTS startup failures, refer to 9 Troubleshooting the BTS RFFailures.

5. Check whether external interference source exists.Check whether there are other BTSs nearby, whether there is an intra-frequencyinterference between cells, and whether there is any strong electromagnetic interference.

Step 2 Check the data configuration of the BTS/BSC/MSC.




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Check whether the faults are caused by the improper data configuration of the BTS/BSC/MSC.Log in to the BTS through the Telnet, and then run the DSP CBTSCFG command to check thecell resource configuration and the radio parameters in the BTS.

l The Local Cell ID and the Local Sector ID are planned by the BSC. The associatedconfiguration in the BTS must be consistent with the planned values in the BSC. Theconfigurations can be queried on the BSC side by running the LST CELL command.

l If the radius of the cell is set too small, the coverage of the cell becomes small too. As aresult, the MSs out of the coverage fail to access the network. To modify the maximum radiusof the cell, contact the network planning personnel and ask for opinions of customers inadvance. The modification of the cell radius cause a reset of the channel board and causesthe interruption of the existing services.

l For the correct setting of the RF parameters, refer to the MML online help. The modificationof the RF parameters may cause the interruption of the existing services. Therefore, performthe modification with caution.

----End


10.3 Clearing BTS Voice Service FailuresBTS voice service failures include MOC failures, MTC failures, one-way audio, no audio, audiodiscontinuity, noise, crosstalk, and echo. This topic describes the fault symptoms and how toclear BTS voice service failures.

SymptomsThe symptoms of the voice service failures are as follows:

l MOC failures– The cause value of the Assignment Failure message is "no radio resource available."

– The cause value of the Assignment Failure message is "requested terrestrial resourceunavail."

– The cause value of the Clear Command message is "protocol error between BSC andMSC."

– The cause value of the Clear Command message is "Authentication Failure."

– The BSC receives an N_DISCONNECT_IND message and disconnects the MS. Thecall setup fails.

l MTC failures– The BSC fails to receive the Paging Request message.

– The BSC fails to receive the Page Response message.

– The cause value of the Assignment Failure message is "no radio resource available."

l Voice quality problems– One-way audio

– No audio



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– Audio discontinuity

– Noise

– Cross talk

– Echo

For details about the symptoms, refer to Basic Knowledge About BTS Voice Service.

Fault LocationThe faults in the voice services are located mainly by tracing the messages over interfaces. Beforethe fault location, start the A1 interface signaling tracing to obtain the procedure for signalingtracing.

Check whether the faults happen in the same MSC to decide the scope of the faults. Only thecall between two mobile phones that are controlled by the same MSC and are not pre-paid mobilephones can ensure that the signal flow circulates within the MSC. For the faults that happen outof the coverage of one MSC, check the associated equipment and data. If no fault happens inthe equipment and data, you can infer that faults happen in the equipment out of the office.Figure 10-3 shows the signal flow of the voice services.

Figure 10-3 Signal flow of the voice services

For the faults in the MSC, you need to check whether the faults happen in only one office or inmore than one office.

l If faults happen in only one office, make call tests on all the carriers of the office to furtherdetermine whether the faults happen only on a specific timeslot, a specific frequency, orhappen universally in the office.– If it is the frequency problem, the cause may be the interference, carrier problem, or the

problem of a specific timeslot.– If it is the problem of the whole office, check the transport path that connects the office

to the BSC, including the boards, the cable connection, and the trunk transportequipment of the BTS.

l If faults happen in more than one office, check the distribution of the offices based on thedata configuration to see whether the offices share the same transport system, the sameCBIE, the same CRPS, the same CSWS, or the same MSC.– If the specific transport path is faulty, check the associated transport equipment, cable

connection, and optical cables.– If a specific CBIE is faulty, check the CBIE and the cable connection between the CBIE

and the CNET.




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– If a specific CRPS is faulty, check the boards that connect the CRPS to the MSC andthe cable connections.

– If it is the problem of more than one CRPS and the CRPSs correspond to the sameCSWS, check all the boards that connect the CSWS to the MSC.

The faults in services are much more complicated than the faults in equipment. Therefore, it ishard to describe the fault handling starting with analyzing the causes. In another way, this manualdescribes the fault handling starting with introducing the symptoms.

Table 10-2 describes the possible causes of MOC failures.

Table 10-2 Possible causes of MOC failures

Symptom Cause

The cause value of the AssignmentFailure message is "no radio resourceavailable."

The AAL2 link that connects the BTS to the BSCis set improperly.

The cause value of the AssignmentFailure message is "requested terrestrialresource unavail."

The EVC resource is insufficient or the terrestrialcircuit is unavailable.

The cause value of the Clear Commandmessage is "protocol error between BSCand MSC."

The protocol versions on the two sides of the Ainterface are inconsistent.

The cause value of the Clear Commandmessage is "Authentication Failure."

The BSC global challenge is disabled or theauthentication parameters of the MS/R_UIM andthe HLR/AC are incorrect.

Table 10-3 describes the possible causes of MTC failures.

Table 10-3 Possible causes of MTC failures

Symptom Cause

The BSC does not receive thePaging Request message.

The subscription of the MS is not correctly defined, theBSC Power-up Registration Flag is not enabled, or dataconfiguration is not correct.

The BSC does not receive thePage Response message.

The data configuration between the BSC and the MSC isincorrect or the HLR subscription is not correctly defined.

The cause value of theAssignment Failure message is"no radio resource available."

The BTS is faulty, the access threshold set in the BSC isimproper, or the network between the BTS and the BSC iscongested.

Table 10-4 describes the symptoms and possible causes of voice quality problems.



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Table 10-4 Symptoms and possible causes of voice quality problems

Symptom Cause

One-way audioor no audio

l About the MS: The MS is faulty.

l About the radio environment: The radio environment is poor orinterference exists.

l About the BTS: The BTS hardware is faulty. The number of timeslotsor the trunk mode is set wrong.

l About the Abis interface: The trunk equipment is faulty, the connectorsare in poor contact, or the transport bit error rate is high.

l About the BSC: Boards are faulty, timeslots of the CBIE are set wrong,or the CRPS and the CSWS are connected improperly.

l About the A interface: Associated hardware is faulty, the DIP switchesare set wrong, or the CIC is configured wrong.

l About the MSC: The associated hardware is faulty, the associatedconnection is damaged or loose, the connection of the output opticalcables is incorrect, or the data configuration is wrong.

Echo Acoustic echo To determine whether the acoustic echo is caused by thepeer MS, adjust the voice volume of the peer MS tocheck whether the volume of the echo heard at the localMS changes.

Electrical echo The electrical echo is caused by the unmatchedimpedance of the PSTN hybrid converter. As a result ofthe unmatched impedance, the signals sent out arecoupled into the receiver line and causes the echo.

Soundloopback

l If the sound loopback happens in an intra-office call,usually the cause is the trunk loopback over the Ainterface.

l If the sound loopback happens in an inter-office call,usually the cause is the inter-office trunk loopback.

Voicediscontinuity

Frequenthandoff

For confirmation, use a test MS to check whether thechannel occupied by the voice service changescontinuously.

Interference ofradio links

For confirmation, use a test MS to perform drive testsand use the network optimization software to analyzeand see whether interference of radio links exists.

Poor BTStransmission

Connectors are in poor contact, the cabinet is not wellgrounded, the transmission bit error rate is high, or thetransport impedances are unmatched.For confirmation, check whether the bit error rate ishigh.

Faulty carrierboards

For confirmation, use a test MS to check whether thechannel occupied by the voice service changescontinuously and whether the frequencies and timeslotsare fixed for each other when no sound is heard.




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Symptom Cause

Noise The noise is usually caused by bit errors. The bit errors have the followingcauses:l The boards, connectors, and cable connections on which the voice

signals are transported are faulty.l The grounding is wrong.

l Interference exists.

l The clock is faulty. The loss of clock synchronization causes slip framesor loss of frames.

l The DIP switches are set wrong. The incorrect setting of DIP switchesfor the 75-ohm and the 120-ohm transport modes causes bit errors.

Cross talk Cross talk usually happens when voice signals are output from the MSC.If the cross talk is caused by the wrong data configuration (for example,CIC) or wrong cable connections (for example, the connection of the E1cable for the A interface), usually one-way audio or no audio happens too.For how to handle the fault, refer to the troubleshooting of the one-wayaudio or the no audio.

Fault HandlingFigure 10-4 shows the procedure for handling voice service failures.

Figure 10-4 Procedure for handling voice service failures



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Procedure

Step 1 Determine the scope and type of the fault.Start the signaling tracing over the A1 interface as described in the fault location of the voiceservices, and determine the scope and the type of the fault after obtaining the signaling over theinterface.l Check whether the faults happen in the offices that share the same transport system, the same

CBIE, the same CRPS, the same CSWS, or the same MSC.l Check whether the problem is the calling failure, called failure, or poor voice quality.

Step 2 Solve the problem of calling failure.Refer to the associated BSC troubleshooting guide for details.

Step 3 Solve the problem of called failure.Refer to the associated BSC troubleshooting guide for details.

Step 4 Solve the problem of poor voice quality.Refer to the associated BSC troubleshooting guide for details.

----End


10.4 Troubleshooting the BTS Data Service FailuresThe data service failures of the BTS consist of the MS access failures, low call completion rate,low transmission speed, and poor transmission quality. This describes the symptoms of the faultsand the procedure for troubleshooting the faults.

SymptomsThe symptoms of the data service failures are as follows:

l Low service completion rate

l Poor transport quality

l Slow transport speed

l Data service unavailability

Fault LocationThe method of locating data service failures is similar to that of locating voice service failures.Before you locate and troubleshoot a data service failure, you must analyze the causes of thedata service failure. For details, refer to 10.1.4 Basic Knowledge About BTS Data Service.

Initiate the signaling tracking over the A interface, and determine the scope of the fault accordingto the tracking result. This manual describes the procedure for troubleshooting the fault on theBTS side. For the troubleshooting on the BSC or PDSN side, refer to the associatedtroubleshooting guides.

Table 10-5 describes the possible causes of the data service failures.




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Table 10-5 Possible causes of the data service failures

Cause Analysis

Theconfiguration ofthe MS or thewireless modemis incorrect.

l About the MS: The port rate of the MS is inconsistent with that of thecomputer. The port ID is incorrect. The setting of dial-up attributes isincorrect. The transport mode (transparent/non-transparent,synchronous/asynchronous) is improperly set.

l About the wireless modem: The wireless modem has an indicator toshow its operational state. If the wireless modem operates properly, theindicator blinks at 2 Hz. If the wireless modem does not operateproperly, the indicator blinks fast. Observe the indicator and checkwhether the wireless modem operates properly.

The radioenvironment ispoor orinterferenceexists.

The poor radio environment or interference causes bit errors. A high biterror rate causes loss of frames, discontinuity, and illegible characters.During the test, the antenna of the MS must point towards the BTS.

The BTS isfaulty.

The possible causes of the faults in the BTS are:l The GPS antenna system is faulty. For details, refer to 7

Troubleshooting the BTS Clock Failures.l Transport data configuration is incorrect. For details, refer to 8

Troubleshooting the BTS Transmission Failures.l The RF antenna system is faulty. For details, refer to 9 Troubleshooting

the BTS RF Failures.

The BSC or thePDSN is faulty.

l To locate the faults in the BSC, refer to the BSC troubleshooting guide.

l To locate the faults in the PDSN, refer to the PDSN troubleshootingguide.

Fault HandlingFigure 10-5 shows the procedure for troubleshooting the data service failures.



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Figure 10-5 Procedure for troubleshooting the data service failures

Procedure

Step 1 Check the MS or the wireless modem.Check whether the data service failures are caused by the incorrect configuration of the MS orthe wireless modem.

Step 2 Check the radio environment.Check whether the data service failures are caused by the poor radio environment.

The radio environment is poor if any of the following cases exists:

l Interference such as the intra-frequency and side-frequency interference exists. Interferingfrequencies of any other BTS within a radius of ten kilometers exist.

l Intense magnetic fields such as a television station and TV transmission tower exist. In thiscase, adjust the azimuth or the position of the antenna by referring to Requirements for theInstallation Position of the Satellite Antenna.

l Obstacles that affect the radio environment exist.

l The MS is located at an area where the signals are weak.

Step 3 Check the BTS.Check whether the data service failures are caused by faults in the BTS.1. The GPS antenna system is faulty. For details, refer to 7 Troubleshooting the BTS Clock

Failures.




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2. Transport data configuration is incorrect. For details, refer to 8 Troubleshooting the BTSTransmission Failures.

3. The RF antenna system is faulty. For details, refer to 9 Troubleshooting the BTS RFFailures.

Step 4 Check the BSC/PDSN.

l To locate the faults in the BSC, refer to the BSC troubleshooting guide.

l To locate the faults in the PDSN, contact PDSN maintenance engineers.

----End

PostrequisiteIf the data service failures persist, contact Huawei for technical support.

10.5 Troubleshooting the BTS Handoff FailuresMSs cannot initiate a handoff or call drop occurs during a handoff. This describes the symptomsof the faults and the procedure for troubleshooting the faults.

Symptoms

The symptoms of the BTS handoff failures are as follows:

l MSs cannot initiate a handoff.

l The success rate of handoffs initiated by MSs is low.

l Call drop occurs during a handoff.

Fault Location

Before you troubleshoot the faults, familiarize yourself with the handoff failure types,troubleshooting method, and handoff procedure. For details, refer to 10.1.5 Basic KnowledgeAbout BTS Handoff.

Before you locate the faults, use the common handling method to determine the scope of thefaults.

Incorrect configuration is the most possible cause of handoff failures. When handoff failuresoccur, check whether any data is modified.

Table 10-6 describes the possible causes and analysis of handoff failures.

Table 10-6 Possible causes and analysis of the handoff failures

Cause Analysis

The dataconfigurationis incorrect.

Connecting the MSCor disconnecting theMSC fails.

Check the signaling configuration on the two sidesof the MSC and check whether any data on theMSC is modified recently.



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Cause Analysis

Handoffs betweenBSCs of differentmanufacturers fail.

Check the signaling configuration on the two sidesof the MSC and check whether any data on theBSC is modified recently.

Handoffs in a specificcell fail.

l If faults occur in the handoff between a cell andthe neighboring cells, check the dataconfiguration of the cell.

l If faults occur in the handoff between a cell andjust one neighboring cell, check the dataconfiguration of the neighboring cell.

The hardwareis faulty.

Handoffs in cells thatare controlled by thesame BTS fail.

Check the BTS hardware that is shared by thecells, for example, the OMTR/OMPA or theODFU.

Handoffs in only onecell fail.

Check the hardware used for the carrier of the cell.You can locate the fault by blocking certaincarriers.

Fault HandlingFigure 10-6 shows the procedure for troubleshooting the handoff failures.

Figure 10-6 Procedure for troubleshooting the handoff failures




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ProcedureStep 1 Check the hardware and the data configuration of the BSC/MSC.

l To locate the hardware or data configuration failures in the MSC, contact the MSC engineers.

l To locate the hardware or data configuration failures in the BSC, refer to the BSCtroubleshooting guide.

Step 2 Check the hardware and data configuration of the BTS.Check whether the faults are caused by the hardware or data configuration failures in the BTS.1. Check the ODFU. If the ODFU is faulty, replace it and check whether the alarms are cleared.2. Check whether the GPS clock system of the BTS is faulty. For details, refer to 7

Troubleshooting the BTS Clock Failures.3. Check whether the antenna system and the OMTR/OMPA of the BTS are faulty. For details,

refer to 9 Troubleshooting the BTS RF Failures.4. Check the installation position, azimuth, and tilt of the antenna.

The planning of the azimuth should not only satisfy the coverage of main targets but alsoconform to the distribution rules of handoffs. A serious overlap of cells or blind areas inthe coverage may affect handoffs. Adjusting the antenna direction, however, does notcontribute to a decrease in traffic. The decrease in traffic is dependent on the number ofcarriers.

----End


10.6 Case: Failure of Random Access to the Carriers Causedby HCPM Failures

During BTS data configuration, the HCPMs are added into the resource pool. If one or moreHCPMs in the resource pool are faulty, a random access failure may occur on the carrier. Thisdescribes the symptoms of the faults and the procedure for troubleshooting the faults.

SymptomsThe symptoms of the faults are as follows:

l The trial office consists of one MSC, one BSC, and six BTSs. Among the six BTSs, twoBTSs use the S(2/2/2) configuration and four BTSs use the S(1/1/1) configuration.

l After the network is put into service, calls can be set up successfully in all the sectors.

l After a period of time, an access failure occurs in one BTS that uses the S(2/2/2)configuration. When the MS fails to access the cell, the MS continuously sends accessprobes, but the system does not respond. Some MSs frequently hand off from one frequencyto another.

Fault LocationThe system does not respond, therefore there may be faults in the BTS. The possible causes ofthe faults are as follows:



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l The carrier boards are faulty.


l The HCPM is faulty. If one HCPM in a resource pool is faulty, some MSs may fail to accessthe cell when the resource is allocated randomly. Therefore, when there is a random accessfailure, check the HCPM.

Fault Handling1. Check the carriers of the sectors of the BTS. No fault is found.2. Check the forward channel load and reverse RSSI of the carriers of all sectors. No fault is

found.3. Check the data related with the sectors. No fault is found.4. Reset the BTS. The MS can access the cell.5. The access failure happens sometimes.6. Check the HCPMs. One of the HCPMs is faulty. Replace the faulty HCPM. The access

failure is rectified.

10.7 Case: Voice Service Failures Caused by Cell Radius TooSmall

Wrong data configuration is the common cause of BTS faults. If the maximum radius of the cellis set to a small value, the coverage of the cell diminishes. As a result, MSs at the cell borderfail to access the network. This topic describes how to clear voice service failures caused by atoo small cell radius.

Symptoms

The call is automatically cut after the phone rings three or four times.

Fault Location

The possible causes of the fault are as follows:

l The MS is faulty.

l The data configuration is faulty.

l The BTS is faulty.

Fault Handling

Perform the following steps to handle this type of fault:

l Check the alarms on the Service Maintenance System. No alarm is reported.

l Check the data configuration. No obvious mistake is found.

l Use another MS for the call. If the problem persists, you can infer that the MS is not faulty.

l Check the data configuration one by one. MAXCELLR=20 is found in the ADDCBTSCELL command. The call failure is cleared after the setting is modified.




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10.8 Case: Slow Call Access in the Coverage Caused byAntenna System Failures

If the main or diversity antenna feeders in a sector are loose or faulty, the demodulation qualitybecomes poor in reverse reception and the demodulation takes more time. As a result, the averagetime of call access in the coverage area becomes long. This topic describes the fault symptomsand how to clear the fault.

SymptomsWhen the MS initiates a call in a specific sector, the access takes 9-10 seconds, that is, 4-5seconds slower than in other cells.

Fault LocationThe possible causes of the fault are:

l The power control parameters are improperly set.

l The BTS antenna system is faulty.

Fault HandlingPerform the following steps to handle this type of fault:

1. Use the MS to make call tests and start the tracing over the MS. The test results show thatthe problem stays in the reverse link from the MS to the BTS.

2. Check the data configuration of the sector and mainly check the consistency between thepower control parameters and the access parameters. No obvious mistake is found.

3. Replace the antenna systems for several sectors. Slow access always happens in one of thesectors. Check the antenna system. The connector of the feeder is loose. Tighten theconnector and the slow access problem is solved.



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About This Chapter

The BTS OM channels can be divided into the local OM channel and the remote OM channel.When the BTS data uploading or downloading fails, board software loading fails, starting theLMT fails or login fails, or the reverse OM fails, you must clear the failures by following theprocedure for clearing BTS OM failures.

11.1 Overview of the BTS OM ChannelsThe BTS OM channels enable you to operate and maintain the BTS. The BTS OM channels aredivided into the local OM channel and the remote OM channel.

11.2 Troubleshooting the Remote OM FailuresThe remote OM failures include failure to ping the BTS by the remote LMT, failure to uploadand download data of the BTS, failure to load the board software. This describes the symptomsof the faults and the procedure for troubleshooting the faults.

11.3 Clearing Faults in Local OMFaults in local OM are the failure to start the local LMT, login failure, failure to log in to theBTS through the Telnet, and failure of reverse OM. This describes the symptoms of the faultsand the procedure for troubleshooting the faults.

11.4 Case: BTS Data Upload Failures Caused by Incorrect FTP PropertiesThe FTP properties setting includes the omu account setting, user properties setting, virtualdirectory setting, and read/write rights setting. This topic describes the fault symptoms and howto clear the fault.

11.5 Case: BTS Board Software Loading Failure Caused by Incorrect FTP Virtual DirectorySettingIncorrect virtual directory setting may cause BTS data uploading failure and board softwareloading failure. This topic describes the fault symptoms and how to clear the fault.

11.6 Case: Red or Grey Cross Indicating Connection Failures Displayed on the ServiceMaintenance SystemWhen the OML is properly connected, you can view the site information and the front panelinformation on the Service Maintenance System. When the connection between the ServiceMaintenance System and the BTS is broken, the site name is marked with a red cross on theService Maintenance System. When the OMC version of the BAM does not match the software

Airbridge BTS3606AE CDMA Base StationTroubleshooting Guide 11 Clearing BTS OM Failures


11-1

version of the BTS, the site name is marked with a red cross on the Service Maintenance System.This topic describes the fault symptoms and how to clear the fault.

11 Clearing BTS OM FailuresAirbridge BTS3606AE CDMA Base Station



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11.1 Overview of the BTS OM ChannelsThe BTS OM channels enable you to operate and maintain the BTS. The BTS OM channels aredivided into the local OM channel and the remote OM channel.

OM signal flow

The operation and maintenance of the BTS is accessible either from the remote BAM or fromthe local maintenance terminal and is implemented by the operation and maintenance unit(OMU) in the CMPT. Figure 11-1 shows the OM signal flow.

Figure 11-1 OM signal flow

Remote OM Channel

As shown in Figure 11-1, the remote LMT is connected to the BAM on the BSC side. The BAMtransfers the OM signals to the boards in the BTS. The channel formed is called the remote OMchannel.

Local OM Channel

As shown in Figure 11-1, the local LMT or the Telnet is connected to the CMPT on the BTSside to transmit the OM signals to the boards in the BTS. The channel formed is called the localOM channel.

In addition, if the local LMT or the Telnet is connected to the CMPT, and the OM signals aretransferred to the boards in the BTS by the BAM on the BSC side, the channel formed is calledthe reverse OM channel.

11.2 Troubleshooting the Remote OM FailuresThe remote OM failures include failure to ping the BTS by the remote LMT, failure to uploadand download data of the BTS, failure to load the board software. This describes the symptomsof the faults and the procedure for troubleshooting the faults.

Symptoms

The symptoms of the remote OM failures are as follows:



11-3

l The BTS cannot be logged into although the Abis link is functional.

l The BTS cannot upload or load data.

l The remote service maintenance system does not show the status of the BTS.

l The software cannot be loaded to boards.

Fault LocationTable 11-1 describes the possible causes of the remote OM failures.

Table 11-1 Possible causes of the remote OM failures

Cause Analysis

The BOOTPinformation isincorrectlyconfigured.

You need to configure the BOOTP information when the base stationcontroller uses Huawei BSC6600 and the transmission link is E1/T1. Runthe LST BTSBTPINFO command to check whether the BOOTPinformation, such as the OM IP address and the VPI/VCI, is correct. Afterthe basic information of the BTS and the BOOTP information is added, youneed to choose Start > Run on the BAM server and run theping***.***.***.*** command to check the setting of the BTS OM link.The ***.***.***.*** represents the IP address of the BTS OM channel.You do not need to configure the BOOTP information when the base stationcontroller uses Huawei BSC6680.

The advancedattributes of theFTP isincorrectlyconfigured.

The incorrect configuration of attributes of the FTP may cause faults inloading and uploading data.

The version ofthe BAMsoftware doesnot match theversion of theboard software.

If the version of the BAM software does not match the version of the boardsoftware, the BAM may fail to identify the board, which results in the failureof software loading.

The Abistransmissionlink is faulty.

If the OM failures are caused by the faulty Abis transmission link, theservices of the BTS are affected. Therefore, if faults occur only in the OM(not in the services), you can infer that the Abis transmission link is notfaulty. For details, refer to 8 Troubleshooting the BTS TransmissionFailures.

Faults of theCMPT

If the OMU of the CMPT is faulty, the OM fails. You can switch over orreplace the CMPT to check whether the CMPT is faulty.

The OML datais incorrectlyconfigured.

The incorrect BSC data configuration usually occurs when:l Adding OM links

l Adding routers

For details on the OM link configuration of the BTS, refer to the BTSconfiguration guide.




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Fault Handling

Figure 11-2 shows the procedure for troubleshooting the remote OM failures.

Figure 11-2 Procedure for troubleshooting the remote OM failures

Procedure

Step 1 If the base station controller uses Huawei BSC6600 and the transmission link is E1/T1, you needto check whether the failures are caused by incorrect configuration of the BOOTP information.Check whether the faults are caused by incorrect configuration of the BOOTP information.1. Run the Ping command on the BSC side to connect the BTS. If the BTS cannot be pinged,

the BOOTP setting may be incorrect.2. Run the LST BTSBTPINFO command to check whether the BOOTP information is

incorrectly configured. Check the following parameters:l BTS ID

l IP address of the BTS OM



11-5

l Slot number, subslot number, and optical port number of the CLPC corresponding tothe active/standby CMUX that connects to the OML or the subrack number of the CIPSthat connects the BSC to the BTS

l IP address of the BTS gateway

l VCI/VPI

3. If the BOOTP information is incorrectly configured, run the MOD BTSBTPINFOcommand to modify the parameters.

Step 2 Check the FTP parameters.Check whether the faults are caused by incorrect FTP configuration.

If the BTS cannot upload or load data, username, password, the configuration of the FTP maybe incorrect.

l On the BAM server, check whether the omu account exists and whether the password of theomu user is correct. The Username and Password are both omu in the lower case. In theaccount properties, "Users cannot change the password" and "The password is permanentlyvalid" are selected.

l On the BAM server, check whether the FTP service is started from the Internet servicemanager and whether the authority is correct. Ensure that the virtual directory is correctlyconfigured and started. The virtual directory must be the same as the root directory ofthe loading directory. For example, if the loading directory is D:/btsload, the virtualdirectory should be D:.

Step 3 Check the consistency between the software versions of the BAM and the boards.Check whether the faults are caused by version mismatch between the BAM and the boards.

When the software versions of the BAM and the boards do not match, the BTS fails to identifythe board numbers while running the software. The following faults may occur:

l Activation fails when the software of the FPGA or the CPU is upgraded.

l After the upgrade, all BTS boards displayed on the remote service maintenance system aremarked with a grey cross.

Check the software versions of the BAM and the boards and use consistent versions for theupgrade.

Step 4 Check the Abis transmission link.Check whether the faults are caused by the faulty Abis transmission link.

If the BTS cannot be pinged from the BSC although the BOOTP information is correct, the Abistransmission link may be faulty. For details, refer to 8 Troubleshooting the BTS TransmissionFailures.

Step 5 Check the CMPT.Check whether the faults are caused by the faulty CMPT.

The core module of the OM channel, that is, the OMU, is integrated on the CMPT. If the CMPTis faulty, the OM channel is disconnected.

If the BOOTP is set correctly and the Abis transmission link is functional, the faulty CMPT maycause the faults in OM. You can switch over or replace the CMPT to check whether the CMPTis faulty.

Step 6 Check the BTS/BSC data configuration.




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Check whether the faults are caused by incorrect BTS/BSC data configuration.

1. Check the settings of the BTS model. The BTS types set in the ADD BTS: BTSTP=BTSType and SET CBTSINFO: BTSCLASS=BTS Type commands should be identical.

2. Check the route information on the BAM. If the BAM can log in to the BTS through theLMT or the BTS can load data from the BAM, but the BAM cannot log in to the BTSthrough the Telnet, the route information configured for the BAM may be incorrect. Thereason is that when the BAM logs in to the BTS through the Telnet, the signal flow istransferred to the BTS in IP packets.

3. Check the configuration of the Abis transmission. For details, refer to 8 Troubleshootingthe BTS Transmission Failures.

----End

Postrequisite


11.3 Clearing Faults in Local OMFaults in local OM are the failure to start the local LMT, login failure, failure to log in to theBTS through the Telnet, and failure of reverse OM. This describes the symptoms of the faultsand the procedure for troubleshooting the faults.

Symptoms

The symptoms of the BTS handoff failures are as follows:

l No interface is displayed on the local LMT.

l The local LMT or the Telnet cannot log in to the BTS.

l The reverse maintenance fails.

Fault Location

Faults hardly happen in local OM. Table 11-2 describes the possible causes of the faults in localOM.

Table 11-2 Possible causes of the faults in local OM

Symptom Cause

No interface isdisplayed on the localLMT.

The BTS model set by running the ADD BTS command isinconsistent with the BTS model set by running the SETCBTSINFO command.

The local LMT cannotlog in to the BTS.

The IP address for the local OM is modified on the Telnet.

The reverse OM fails. The channel for the reverse OM is set wrong.



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Fault Handling

Figure 11-3 shows the procedure for handling the faults in local OM.

Figure 11-3 Procedure for handling the faults in local OM

Procedure

Step 1 Check the setting of the BTS model.Run the DSP CBTSCFG command and the LST BTS command to check whether the BTSmodels are consistent. If the BTS models are inconsistent, modify the setting.

Step 2 Check the IP address for the local OM.You can log in to the BTS through the Telnet and modify the IP address for the local OM. If theIP address is modified, other maintenance engineers may fail to log in to the BTS by using thedefault OM IP address 172.16.16.16. If there is no special requirement, do not modify the OMIP address.




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Step 3 Check the setting of the reverse OM.The correct configuration of the channel for reverse OM is described as follows.1. Log in to the BAM server on the remote LMT and run the STR CBTSRVSMNT command

to enable the reverse maintenance function.2. On the BAM server, choose Authority Management > Add a WS to add a workstation

for the BTS and set the command authority, as shown in Figure 11-4.

When adding a WS, you must set the IP Address to the OM IP address of the BTS insteadof the real IP address of the workstation.

Figure 11-4 Adding WSs

3. At the WS on the BCKM side, use the local Telnet or the local LMT to log in to the BAM

server. The Office IP Address that you set when logging in to the BAM must be the IPaddress of the BCKM Ethernet port instead of the real IP address of the BAM.

----End


11.4 Case: BTS Data Upload Failures Caused by IncorrectFTP Properties

The FTP properties setting includes the omu account setting, user properties setting, virtualdirectory setting, and read/write rights setting. This topic describes the fault symptoms and howto clear the fault.

SymptomsOn the Service Maintenance System, run the ULD CBTSSW command to upload BTS data tothe BAM. The system displays The uploading command is executed. or The FTPinitialization failed. or The BTS data uploading failed.



11-9

Fault Location

If the system prompts The FTP initialization failed., you can infer that the loginthrough the FTP fails authentication. The data is uploaded through the FTP.

During the upload, the BAM works as the server and the BTS works as the client. The UserName and Password are omu.

The possible causes of the failure in the login through the FTP are:

l The omu account is not registered or is set wrong.

l In the properties of the omu account, "Users cannot change the password" and "Thepassword is permanently valid" are not selected.

l No virtual directory is set for the FTP directory.

l The FTP directory cannot be written into.

Fault Handling


1. Enter the domain user manager to find that the omu account exists. Select "Users cannotchange the password" and "The password is permanently invalid." Note that the UserName and the Password are omu in lower case. The registration information of the omuaccount is correct.

2. Enter the internet service manager to find that the FTP service is enabled.3. Enter the Directory to find that Read only and Read and Write are selected, but no virtual

directory is set.4. Select and set the virtual directory, and then click OK to save the setting.5. Run the ULD CBTSSW command to upload data.

11.5 Case: BTS Board Software Loading Failure Caused byIncorrect FTP Virtual Directory Setting

Incorrect virtual directory setting may cause BTS data uploading failure and board softwareloading failure. This topic describes the fault symptoms and how to clear the fault.

Symptoms

On the Service Maintenance System, run the DLD CBTSALLSW command to upload boardsoftware, but the upload fails.

Run the SAV CBTSCFG command to save the BTS data configuration, but the scripts fail tobe uploaded to the BAM.

Fault Location

The failures of board software loading and script uploading may be caused by the wrong settingof the BTS FTP. Check whether:

l The FTP service is enabled.




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l The FTP authority is set correctly.

l The FTP account is set correctly.

l The FTP configuration is correct.

Fault Handling


1. Check the FTP service of the BAM. The FTP service is enabled. Stop the FTP service andthen restart the FTP service. The faults persist.

2. Check the FTP configuration and find that the FTP virtual directory is set to btsload whenthe FTP virtual directory is created, but the loading directory is D:/. Change the virtualdirectory to D:. The faults are cleared.

11.6 Case: Red or Grey Cross Indicating Connection FailuresDisplayed on the Service Maintenance System

When the OML is properly connected, you can view the site information and the front panelinformation on the Service Maintenance System. When the connection between the ServiceMaintenance System and the BTS is broken, the site name is marked with a red cross on theService Maintenance System. When the OMC version of the BAM does not match the softwareversion of the BTS, the site name is marked with a red cross on the Service Maintenance System.This topic describes the fault symptoms and how to clear the fault.

Symptoms

The connection between the BTS and the Service Maintenance System is marked with a red orgrey cross.

Fault Location

If the connection between the BTS and the Service Maintenance System is marked with a redcross, the BTS is configured with links, but links are broken. The possible causes are as follows:

l The physical transmission link over the Abis interface is unavailable.

l The VPI or the VCI in the BOOTP information is inconsistent with the parameter of theOML link.

l The number of the optical port indicated in the BOOTP information is inconsistent withthe real one.

l The IP address set through the ADD BTS command on the BTS side is inconsistent withthe IP address set through the ADD BTSBSCINF command on the BSC side.

l The router connecting to the BTS is not added in the BAM.

If the connection between the BTS and the Service Maintenance System is marked with a greycross, you can infer that the OMC version of the BAM does not match the software version ofthe BTS.



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Fault HandlingIf the connection between the BTS and the Service Maintenance System is marked with a redcross, perform the following steps to clear the fault:

1. Run the DSP E1T1STAT command to check whether the E1 link is available.2. Check whether the Abis link is faulty. For details, refer to Clearing BTS Transmission

Failures.3. Run the LST BTSBTPINFO command to check whether the BOOTP information added

through the ADD BTSBTPINFO command is consistent with the OM link informationadded through the ADD BTSOMLNK command.

4. Run the LST BTS command and the LST BTSBSCINF command to check whether theconfigured IP address is correct.

5. Check whether the correct router which connects the BTS is added in the BAM.

If the connection between the BTS and the Service Maintenance System is marked with a greycross, the OMC version of the BAM does not match the software version of the BTS. Therefore,upgrade the software version of the BTS.




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12 List of BTS Troubleshooting Tools

This topic describes the tools that you may use during BTS troubleshooting.

Table 12-1 Troubleshooting tools

Type Tool Function Instructions

Universaltool

LMT If the M2000 detects any fault in a BTS, you canuse the LMT to log in to this BTS and to locate,analyze and clear the fault.

See the onlinehelp of theServiceMaintenanceSystem.

M2000 client The M2000 client provides centralizedmanagement for the performance, configuration,and faults of NEs.

See theM2000 help.

Instrument

Power meter The power test equipment is used to measure andanalyze the BTS output power. The output powerdetermines the effect of forward coverage.

See themanuals of thetool orinstrument.

Spectrumanalyzer

The spectrum analyzer is used for trace spectruminformation.

Error bit tester The bit error tester is used for measuring the E1/T1 transmission bit error rate so that faults in thetransmission link are easy to locate.

SiteMaster The SiteMaster is used to check the standingwave ratio/return loss and locates the fault in theantenna.

Multimeter The multimeter is used to test the AC powerequipment, DC power equipment, and cabinetgrounding.

Airbridge BTS3606AE CDMA Base StationTroubleshooting Guide 12 List of BTS Troubleshooting Tools


12-1

Huawei BTS3606AE Troubleshooting Guide(V400R006_03)

Documents

uld cbtssw

lst bscbtsinf

lop e1t1 command

rst imagrp

chk cbtsswver

lst btslnk

chk cbtsifcfg

lst btsbtpinfo