02-Fault Analysis and Location
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Maintenance ManualM900/M1800 BTS3X Series Base Transceiver Station Table of Contents
Huawei Technologies Proprietary
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Table of Contents
Chapter 3 Communication Fault.................................................................................................. 3-1
3.1 Introduction to MS's Search for the Network ..................................................................... 3-1
3.2 Call Failure......................................................................................................................... 3-2
3.2.1 Fault Description ..................................................................................................... 3-2
3.2.2 Fault Analysis and Location .................................................................................... 3-2
3.2.3 Troubleshooting Procedure..................................................................................... 3-3
3.3 No Voice Heard after the Call is Connected...................................................................... 3-5
3.3.1 Fault Description ..................................................................................................... 3-5
3.3.2 Fault Analysis and Location .................................................................................... 3-5 3.3.3 Troubleshooting Procedure..................................................................................... 3-6
3.4 Unidirectional Talk ............................................................................................................. 3-6
3.4.1 Fault Description ..................................................................................................... 3-6
3.4.2 Fault Analysis and Location .................................................................................... 3-6
3.4.3 Troubleshooting Procedure..................................................................................... 3-6
3.5 Poor Voice Quality ............................................................................................................. 3-7
3.5.1 Fault Description ..................................................................................................... 3-7
3.5.2 Fault Analysis and Location .................................................................................... 3-7
3.5.3 Troubleshooting Procedure..................................................................................... 3-7
3.6 Conversation Interruption .................................................................................................. 3-8
3.6.1 Fault Description ..................................................................................................... 3-8
3.6.2 Fault Analysis and Location .................................................................................... 3-8
3.6.3 Troubleshooting Procedure..................................................................................... 3-8
3.7 Cross Talk.......................................................................................................................... 3-9
3.7.1 Fault Description ..................................................................................................... 3-9
3.7.2 Fault Analysis and Location .................................................................................... 3-9
3.7.3 Troubleshooting Procedure..................................................................................... 3-9
3.8 Mobile Station Frequently Disconnected from the Network .............................................. 3-9
3.8.1 Fault Description ..................................................................................................... 3-9 3.8.2 Fault Analysis and Location .................................................................................... 3-9
3.8.3 Troubleshooting Procedure................................................................................... 3-10
3.9 Immediate Assignment Rejection .................................................................................... 3-10
3.9.1 Fault Description ................................................................................................... 3-10
3.9.2 Fault Analysis and Location .................................................................................. 3-10
3.9.3 Troubleshooting Procedure................................................................................... 3-10
Chapter 4 Network Fault ............................................................................................................... 4-1
4.1 Mobile Station Fails to Find a Network.............................................................................. 4-1
4.1.1 Fault Description ..................................................................................................... 4-1
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4.1.2 Fault Analysis and Location .................................................................................... 4-1
4.1.3 Troubleshooting Procedure..................................................................................... 4-2
4.1.4 Clearing Hardware Problem.................................................................................... 4-2
4.2 Mobile Station Fails to Access the Network ...................................................................... 4-3
4.2.1 Fault Description ..................................................................................................... 4-3
4.2.2 Fault Analysis and Location .................................................................................... 4-3
4.2.3 Troubleshooting Procedure..................................................................................... 4-3
4.3 MS Frequent Location Updating........................................................................................ 4-5
4.3.1 Fault Description ..................................................................................................... 4-5
4.3.2 Fault Analysis and Location .................................................................................... 4-5
4.3.3 Troubleshooting Procedure..................................................................................... 4-5
Chapter 5 Loading Fault ............................................................................................................... 5-1
5.1 Software Loading Failure................................................................................................... 5-1
5.1.1 Fault Description ..................................................................................................... 5-1
5.1.2 Introduction to Software Loading ............................................................................ 5-1
5.1.3 Fault Analysis and Location .................................................................................... 5-3
5.1.4 Troubleshooting Procedure..................................................................................... 5-4
5.2 Base Station Initialization Failure....................................................................................... 5-4
5.2.1 Fault Description ..................................................................................................... 5-4
5.2.2 Introduction to Base Station Initialization ................................................................ 5-4
5.2.3 Fault Analysis and Location .................................................................................... 5-4
5.2.4 Troubleshooting Procedure..................................................................................... 5-5
5.3 Signaling Fault ................................................................................................................... 5-5 5.3.1 Fault Description ..................................................................................................... 5-5
5.3.2 Introduction to OML................................................................................................. 5-5
5.3.3 Fault Analysis and Location .................................................................................... 5-5
5.3.4 Troubleshooting Procedure..................................................................................... 5-6
5.4 RSL Link Blocked............................................................................................................... 5-6
5.4.1 Fault Description ..................................................................................................... 5-6
5.4.2 Introduction to RSL Link.......................................................................................... 5-6
5.4.3 Fault Analysis and Location .................................................................................... 5-6
5.4.4 Troubleshooting Procedure..................................................................................... 5-7
Chapter 6 Antenna and Feeder System Fault............................................................................. 6-1
6.1 Fault Description................................................................................................................ 6-1
6.2 Introduction to the Antenna and Feeder System............................................................... 6-1
6.3 Fault Analysis and Location............................................................................................... 6-1
6.4 Troubleshooting Procedure ............................................................................................... 6-1
6.4.1 Poor downlink signal ............................................................................................... 6-1
6.4.2 Unstable downlink signal......................................................................................... 6-2
6.4.3 Poor uplink signal.................................................................................................... 6-2
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Chapter 7 Optical Channel Fault.................................................................................................. 7-1
7.1 Fault Description................................................................................................................ 7-1
7.2 Fault Analysis and Location............................................................................................... 7-1
7.3 Troubleshooting Procedure ............................................................................................... 7-1
Chapter 8 Board Fault................................................................................................................... 8-1
8.1 TMU ................................................................................................................................... 8-1
8.1.1 Sources of Fault Information................................................................................... 8-1
8.1.2 Related Functional Units ......................................................................................... 8-1
8.1.3 Fault Classification.................................................................................................. 8-1
8.1.4 Troubleshooting Procedure..................................................................................... 8-1
8.2 CDU ................................................................................................................................... 8-4
8.2.1 Sources of Fault Information................................................................................... 8-4
8.2.2 Fault Classification.................................................................................................. 8-4
8.2.3 Troubleshooting Procedure..................................................................................... 8-4
8.3 EDU ................................................................................................................................... 8-7
8.3.1 Sources of Fault Information................................................................................... 8-7
8.3.2 Fault Classification.................................................................................................. 8-7
8.3.3 Troubleshooting Procedure..................................................................................... 8-8
8.4 SCU ................................................................................................................................. 8-10
8.4.1 Sources of Fault Information................................................................................. 8-10
8.4.2 Fault Classification ................................................................................................ 8-10
8.4.3 Troubleshooting Procedure................................................................................... 8-11
8.5 TRX.................................................................................................................................. 8-12 8.5.1 Sources of Fault Information................................................................................. 8-12
8.5.2 Fault Classification ................................................................................................ 8-12
8.5.3 Troubleshooting Procedure................................................................................... 8-13
8.6 PBU.................................................................................................................................. 8-15
8.6.1 Sources of Fault Information................................................................................. 8-15
8.6.2 Fault Classification ................................................................................................ 8-15
8.6.3 Troubleshooting Procedure................................................................................... 8-16
8.7 PMU ................................................................................................................................. 8-17
8.7.1 Sources of Fault Information................................................................................. 8-17
8.7.2 Related Functional Units ....................................................................................... 8-17
8.7.3 Fault Classification ................................................................................................ 8-17
8.7.4 Troubleshooting Procedure................................................................................... 8-17
8.8 PSU.................................................................................................................................. 8-21
8.8.1 Sources of Fault Information................................................................................. 8-21
8.8.2 Fault Classification ................................................................................................ 8-21
8.8.3 Troubleshooting Procedure................................................................................... 8-21
8.9 TEU.................................................................................................................................. 8-23
8.9.1 Sources of Fault Information................................................................................. 8-23
8.9.2 Related Functional Units ....................................................................................... 8-23
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8.9.3 Fault Classification ................................................................................................ 8-23
8.9.4 Troubleshooting Procedure................................................................................... 8-23
8.10 TES ................................................................................................................................ 8-24
8.10.1 Sources of Fault Information ............................................................................... 8-24
8.10.2 Related Functional Units ..................................................................................... 8-25
8.10.3 Fault Classification.............................................................................................. 8-25
8.10.4 Troubleshooting Procedure................................................................................. 8-25
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Maintenance ManualM900/M1800 BTS3X Series Base Transceiver Station Chapter 3 Communication Fault
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Chapter 3 Communication Fault
3.1 Introduction to MS's Search for the Network
Mobile Station (MS) may operate either in the HPLMN (Home Public Land Mobile
Network), or in other PLMNs. There are two modes for a mobile station to select the
serving network:
Automatic network search
Manual network search
After a mobile station (with a SIM card or after a SIM card is inserted) is powered on,
the mobile station searches for the PLMN it logged in last time. If the PLMN does
exist, the mobile station attempts to log in.
If the login succeeds, the mobile station will be served by this PLMN.
If the login fails because no appropriate cell is available, the mobile station will
search at least thirty 900M channels or forty 1900M channels (The process of
searching the radio frequency channels actually includes the selection of PLMN).
If the login fails due to the failure of location updating, then it is unnecessary to
select the above mentioned frequency channels. However, the available PLMNs
must be displayed to the subscriber. Subscribers can then select network inautomatic or manual mode.
In automatic network search mode, the mobile station selects the network according
to the priority of PLMN list it has saved. While in manual mode, the mobile station
displays the available networks to the subscriber and tries to log in to the specified
PLMN according to the subscriber's selection.
Network search may be affected by the roaming process of the mobile station. This
process can be classified into two types: international roaming and domestic roaming.
International roaming: in which the mobile station logs in to other PLMNs in a differentcountry from where the HPLMN is located.
Domestic roaming: in which the mobile station logs in to other PLMNs in the same
country where the HPLMN is located in. When the mobile station is roaming across
the country, it will search for a HPLMN periodically. To prevent a mobile station from
logging in frequently to a prohibited Location Area (LA) during domestic roaming, the
mobile station saves this LA in a table named ‘‘Forbidden Las for domestic roaming’’
of the mobile station equipment. This table will be cleared when the mobile station is
powered off or when the SIM card is pulled out.
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In addition, the mobile station saves in its own SIM card some of the PLMNs where
services are prohibited. Only when these PLMNs are selected in the manual network
search mode and the location updating succeeds can these PLMNs be deleted from
the service-prohibited PLMN table.Failure of mobile station network search indicates the failure in selecting a PLMN or a
cell.
3.2 Call Failure
3.2.1 Fault Description
When the mobile station is powered on and detects a network, the following occur
after subscriber dial-up:
No ringing at the called MS after dialing though that MS is idle.
After dialing, the caller hears the ring-back tone, but the call is automatically
disconnected.
After dialing, the caller hears the ring-back tone, but the call is automatically
disconnected when the called answers.
3.2.2 Fault Analysis and Location
The failure of an MS in originating calls might be related to the fault of BTS, BSC,MSC or the PSTN.
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3.2.3 Troubleshooting Procedure
No
Yes
No
YesNo
Yes
No
Yes ANo
B
Yes
Start
Check Abis interface
Immediateassignment
Assignmentis over
Radio linkfails
Check the measurement
SDCCHavailable?
TCHFavailable?
Re-configure or increasethe cell capacity
Check the setting of paging parameter
Check Abis interfacedata mapping relationship
Re-configure or increasethe cell capacity
report
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Receiving qualityis too poor
B
Yes
Possible causes:1. Improper BTS connection
2. Poor TMU clock precision3. Too much air interference4. BSC clock is not accurate enough
5. Problems with antenna and feeder system
No route at network sideYes
Possible causes:
2. TC board abnormal3. A-interface blocked4. MSC unable to obtain the No. Of roaming subscribers
5. Some routes are blocked at MSC side
No
1. Wrong connection of BSC switching
No
Other causes
Possible causes:
End
TC board program abnormal
A
Figure 3-1 Troubleshooting procedures for call failure
To clear the faults in originating calls, follow the instructions below:
Trace and check Abis interface message via the interface in BSC maintenance
console.
1) If the immediate assignment fails, check if any assignment failed because
SDCCHs are insufficient.
Y The cell capacity is not large enough. In this case, re-configuyre or expand
the cell capacity. N The failure of immediate assignment may be caused by data configuration
errors. In this case, check the setting of paging parameters of the cell at the data
management console.
2) If instead of immediate assignment failure there is TCH assignment failure,
check whether the TCHs are insufficient.
Y Check Abis interface data mapping relationship at the data management
console.
N The cell capacity is not large enough. In this case, re-configure or expand
the cell capacity.
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3) If the radio link failure occurs after the TCH channel is established, observe the
measurement report on the channel before the failure.
Poor quality of BTS or MS signals may be the result of the following factors:
Improper BTS connection Low TMU clock precision
Too much air interference
BSC clock not accurate enough
Problems with the antenna and feeder system
Blind spots in network coverage
4) The causes for absence of route at network side that causes the disconnection
of links may be:
Connection error of BSC switching network
Abnormality of TC board
Blocking of A-interface
Failure of MSC in get roaming subscriber number
Blocking of some routes at MSC side
3.3 No Voice Heard after the Call is Connected
3.3.1 Fault Description
There is ringing at the called mobile station, but no voice is heard when the called
subscriber answers to the call.
3.3.2 Fault Analysis and Location
The ringing at the called mobile station indicates that the signaling flow is normal. The
voice generation failure may be related to multiple aspects (not sure):
The failure of corresponding timeslots of TC board, which is the only place where
the voice can be converted from voice signals of 16K into that of 64K.
Switching network failure, which disables proper switching of voice timeslots.
Activation failure of DTX voice transmission.
Call re-establishment failure, which causes the signaling course being switched
over before the time specified in data configuration, but the switching circuit did
not receive the indication of change properly, therefore, the circuit failed to react
to the change.
Abnormality of TMU board.
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3.3.3 Troubleshooting Procedure
1) Check the occupation of network board timeslots to see whether the network is
distributed correctly, i.e., check whether both TCHs have been switched over
correctly.
2) Switch off the DTX to see whether the phenomenon reappears.
3) Check signaling analyzer or Abis signaling interface tracing through BSC
maintenance console to see whether there are any messages about call
re-establishment failure.
4) Reset TMU board to see whether the phenomenon reappears.
5) If the phenomenon persists, there may be erroneous switching at the fixed
network side.
6) Plug in/pull out or replace TC board to see whether the phenomenon reappears.
7) If not, it is the board that fails.
3.4 Unidirectional Talk
3.4.1 Fault Description
Mobile station can make calls, but:
When both the two parties use an MS for conversation, one of them cannot hear
the other.
When one of the two parties uses an MS and the other a fixed phone forconversation, one of them cannot hear the other.
3.4.2 Fault Analysis and Location
Judging from that one of the two parties can hear the other, the signaling flow is
normal.
Then, this fault may be caused by:
Mobile phone transmitter fault.
Activation failure of DTX voice transmission. GNET board switching error, which disables the up-link of one party from being
switched properly to the down-link circuit of the other party.
Some links on TC Board are blocked.
3.4.3 Troubleshooting Procedure
1) Does this occur repeatedly to some MSs? If so, the transmitter function of the
mobile station may be faulty.
2) Switch off the DTX to see whether the fault still exists.
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3) View the occupation status of GNET board timeslots to see whether the circuits
are switched normally by querying GNET board status on BSC maintenance
console.
4) Trace and query the circuit status at MSC. If some circuit ports are alwaysdisconnected, block the port or replace TC board.
5) Check if there is any public network faults.
3.5 Poor Voice Quality
3.5.1 Fault Description
The mobile station can detect a network after it is powered on, and can make/receive
calls, but the voice quality is poor.
3.5.2 Fault Analysis and Location
If the mobile station can make calls, the signaling channels are normal.
Poor voice quality indicates that the voice BER (Bit Error Ratio) at the radio interface
is high. Generally, the high BER during decoding at the base station is caused by low
receiving level or degrading of clock precision.
3.5.3 Troubleshooting Procedure
1) Check the signal intensity at the mobile station. Low signal intensity indicates
that the receiving level is too low. Try to communicate in an open place.
2) Ask the peer party to check whether the battery of the mobile station is low.
3) Determine whether the fault is related to the TRX or any timeslots of it. If yes,
reset or replace the TRX.
4) Check the measurement reports by an MS with the signaling analyzer or by
tracing Abis interface at the BSC maintenance console to determine whether it is
up-link level or down-link level that is poor.
If the up-link level is poor, please check whether the power supply of the MS issufficient.
If the down-link level is poor, the fault may be caused by the coverage. In this
case, check whether the radio frequency is degrading or whether the subscriber
is at the edge of a cell.
5) If the receiving level is OK but BER is high, the fault may be caused by the
instability of the clock. In this case, try to relocate the network by measuring the
precision of BTS, BSC clocks.
6) If both the receiving level and BER are OK, check the interference on the
transmission links between BSC and BTS.
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7) Check antenna and feeder system.
3.6 Conversation Interruption
3.6.1 Fault Description
Conversation interruption during the normal process of a conversation of a mobile
station refers to the fact that there is no voice heard for a while, or the voice is
intermittent.
3.6.2 Fault Analysis and Location
Conversation interruption possibly results from the degrading of environment or
equipment performance, and may also be caused by faults of BTS, BSC, MSC or
PSTN.
3.6.3 Troubleshooting Procedure
The fact that the voice is intermittent during the conversation indicates that the
speech channel has been established and kept in service. But there may be some
break points in the link, which hinders the normal transmission of the voice to the
receiving end and causes conversation interruption. The following may be related to
the causes of break points in this link and suggested solutions are also provided ifpossible.
1) If the TC board is abnormal, reset it (or replace it if necessary). High BER at
network side and BTS side may be the result of low precision of BSC or BTS
clock, or the interference between transmission links.
2) TRX sensitivity is too low,.Handling suggestion: Replace TRX.
3) Co-frequency interference among cells. Handling suggestion: reconfigure cell
data.
4) The receiving antenna and feeder are abnormal. Handling suggestion: check
whether there are water-penetration, corrosion or short-circuit with the receivingantenna and feeder.
5) Check whether the mobile station is located too far away from the BTS, or in
blind area.
6) Fixed network equipment is abnormal.
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3.7 Cross Talk
3.7.1 Fault Description
The voice from another channel is heard in the course of normal conversation of the
mobile station.
3.7.2 Fault Analysis and Location
Cross talk is most possibly caused by switching error, i.e., the signals of another
speech channel are switched to the current conversation timeslot. As a result, the
subscriber affected may either hear the voice from the ongoing conversation among
some other subscribers, hear nothing at all, or cannot be heard by the other partyengaged in the conversation with him.
3.7.3 Troubleshooting Procedure
1) Check GNET board networking to see whether there is any missing or duplicated
networking.
2) Check the switching of timeslots at the switch side. Fault of this switching is
common in fixed network.
3.8 Mobile Station Frequently Disconnected from theNetwork
3.8.1 Fault Description
When the MS is idle, it happens frequently that the MS sometimes display the
network it accessed and sometimes not, indicating that the MS is frequently
disconnected from the network.
The MS is frequently disconnected from the network while in the course of
communication.
3.8.2 Fault Analysis and Location
When the MS receives system message and calculates the parameters such as C1, it
finds that the cell where it is located no longer meets the requirements of the
protocols. Besides, no other cells are detected appropriate. In this case, the mobile
station disconnects from the network.
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3.8.3 Troubleshooting Procedure
1) Check whether the system message is sent properly, whether the reselected
parameters of the cell and the parameters of random access control changes
frequently.
2) Check with the tester MS whether the value of C1 displayed on the MS is too
small. If yes, check whether the parameters that may affect the value of C1 are
set properly, such as MS RXLEV_ACCESS_MIN, MS maximum transmission
power allowable, etc. Check the up-link and down-link receiving levels to see
whether the MS is located in an area of poor coverage.
3) Check whether the BTS output is stable. If not, check whether the TRX output is
normal or whether the antenna is fixed in a stable manner.
3.9 Immediate Assignment Rejection
3.9.1 Fault Description
From Abis interface, it can be observed that immediate assignment rejection message
is sent on CCCH channel in the course of SDCCH channels assigning.
3.9.2 Fault Analysis and Location
No SDCCH channel is available for the assignment.
3.9.3 Troubleshooting Procedure
1) Check whether BSC data configuration is correct, such as radio channel
configuration table, and so on.
2) Observe at BTS maintenance console whether SDCCH channels are blocked or
whether they are available. Unblock them if they are in ‘BLOCKED’ state.
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Chapter 4 Network Fault
4.1 Mobile Station Fails to Find a Network
4.1.1 Fault Description
The message ‘No Network’ is displayed at the MS.
There is no display at the MS at all.
There is no home PLMN in the network list displayed at the MS.
4.1.2 Fault Analysis and Location
I. The cell is not in service
At the BTS maintenance console, select [Obtain Cell Attributes] to view the
information of the corresponding cell.
If it is prompted that ‘Cell is not initialized’, the cell then is not in service.
If the information on the corresponding cell is displayed, the cell then is already
in service.
II. Trace Abis interface message flow and observe whether there is anychannel request
If no channel request is detected to be directed to this cell, either the network or the
individual MS may be faulty.
1) The causes of network fault may be:
BS hardware problem
At the BTS maintenance console, check whether the operating status or the status
indicators of respective boards are normal. Check if the attributes of TRX and TMUboards are consistent with the data configuration of the data management console,
and whether the BSC clock is locked by the clock board. If all these items are normal,
test whether the power output of the antenna and feeder is normal.
Incorrect system message
Check whether the configurations of CI, LAI, BSIC and CCCH are consistent with
those in the radio channel configuration table.
2) The causes of individual MS is fault may be:
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The MS is not located in a suitable place and RXQUAL (signal quality) is poor or
RXLEV (signal level) is too low. Move the MS to an open place and try again.
The battery of the MS is low.
4.1.3 Troubleshooting Procedure
If the cell is not in service, reset the site hierarchically. Please note that this may affect
the other cells under this site. During the initialization, the progress of the initialization
will be displayed. Base station initialization is embodied by the initialization of site and
cell.
I. Site Initialization Procedure:
1) Set site logic object
2) Set site hardware object3) Set site extended attributes
4) Establish multi-point connection
5) Site activation
II. Cell Initialization Procedure:
1) Create TEI
2) Establish signaling channel connection
3) Establish traffic channel connection
4) Set cell attributes5) Set cell extended attributes
6) Set RC attributes
7) Set RC extended attributes
8) Set channel attributes
9) Set cell alarm threshold
10) Cell activation
11) Wait for cell status change report
The result of these two types of initialization will be displayed at the maintenance
console on a realtime basis.
If the operation succeeds, a solid star will be displayed.
If the operation fails, a hollow star together with the cause of failure will be
displayed.
4.1.4 Clearing Hardware Problem
If the system messages are wrong, correct them. Set the whole table and validate
them with the help of dynamic data configuration.
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4.2 Mobile Station Fails to Access the Network
4.2.1 Fault Description
The MS displays ‘No Services’ or ‘Only Emergence Call’, or does not display
anything at all.
One or more networks are detected when manual searching of networks is
performed.
From Abis interface, no message can be observed or ‘Location Updating
Rejection’ is observed.
The indicator of OML link of LAPD board flashes quickly or is off.
The indicator of RSL link of LAPD board flashes quickly or is off.
4.2.2 Fault Analysis and Location
No SIM card is installed. Please insert a SIM card.
The battery of the MS is low. Please recharge the battery.
The cell is not in service. For details, refer to ” 4.2.3 Troubleshooting
Procedure ”.
If RSL is disconnected, the indicator of RSL link on LAPD board flashes quickly
or is off. For details, refer to ‘4 Signaling Fault’ of this module.
If OML is disconnected, the indicator of OML link on LAPD board blinks quickly
or is off. For details, refer to ‘4 Signaling Fault’ of this module.
System message is incorrect.
If a dual-band MS is forcedly set as a single band 1800M (or 900M) MS, then it
can not access the 900M network (or 1800M network).
If some internal settings of the MS are improperly modified, the MS may fail to
access the network.
4.2.3 Troubleshooting Procedure
If the cell is not in service, then perform level-4 resetting to the site and check
whether the initialization flow is normal. 1) Is the cell activated?
Y Refer to step 3) below.
N Refer to step 2) below.
To judge whether the cell has been activated:
Select [Obtain Cell Attributes] to view for the information of the corresponding cell at
the base station maintenance console. If it is prompted ‘Cell is not initialized’, the cell
has not been activated. If attribute information about the cell is displayed, the cell has
already been in service.
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2) For the cell that has not been activated, reset the site that the cell belongs to.
Please note that this will affect the conversation of other cells under the site.
During the initialization, the progress indication of respective stages of the
initialization will be displayed.
Base station initialization is embodied by the initialization of site and cell.
Site initialization procedures:
Set site logic object
Set site hardware object
Set site extended attributes
Establish multi-point connection
Site activation
Cell initialization procedures:
Create TEI
Establish signaling channel connection
Create traffic channel connection
Set cell attributes
Set cell extended attributes
Set RC attributes
Set RC extended attributes
Set channel attributes
Set cell alarm threshold Cell activation
Wait for the cell status change report
The result of these two types of initialization will be displayed at the maintenance
console in real time. If the operation succeeds, a solid star will be displayed. If the
operation fails, a hollow star along with the causes of failure will be displayed.
If there is any data error in the initialization, check the corresponding data
configuration.
If the initialization can not be executed, there is a configuration error in the board
corresponding to the main control board of the base station. Check the boardand return to Step 1).
3) If the cell has already been in service, check whether the clock signal of the cell
and TRX board corresponding to BCCH are normal. If they are not, please take
corresponding measures.
How to check:
Select [Equipment Status Query] at the maintenance console to view the board
status.
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If the icon of the board is red, the board is abnormal. In this case, check whether
the hardware of the base station, the communication between TRX and TMU,
and whether each board is normally powered on.
4) If the MS is a dual band one, but forcedly set to single band mode, change backinto dual band mode.
5) If the MS is improperly set, restore the ex-factory default setting.
4.3 MS Frequent Location Updating
4.3.1 Fault Description
When powered on, the MS can locate the network and make/receive calls. But the
voice quality is poor because the MS updates its location frequently.
4.3.2 Fault Analysis and Location
Location update of an MS takes place when:
It is moved into a new location area.
It is time for a regular location update.
It is powered on.
Frequent location updating usually results from improper data configuration.
4.3.3 Troubleshooting Procedure
1) Check the interface signaling. If ‘Normal location updating’, then the MS may be
located on the edge of a boundary area where multiple location areas are
overlapped (which is a rare case). Please try to move the MS forward to any
direction.
2) If the interface message ‘IMSI ATTACH’ appears frequently, and the MS is not
powered on and off frequently, check whether the MS RXLEV is so low that the
MS fails to receive base station messages and is thus disconnected from the
network.3) If frequent MS location updating is periodical, then the system message may be
abnormal and the location updating period may be set too short. Please check
whether the MS receives system message (T3212) correctly. Modify the value of
T3212 in the system message.
4) Check if the location area codes in different system messages are consistent .
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Chapter 5 Loading Fault
5.1 Software Loading Failure
5.1.1 Fault Description
If software fails to be loaded to the base station, and the interface does not prompt on
the successful completion of software loading, it indicates that the software of the new
version is not loaded to the base station.
5.1.2 Introduction to Software Loading
In BTS software loading, the specified software is loaded to the base station through
a remote maintenance console or the local MMI to upgrade the software of the base
station.
Files that can be loaded and activated are the ones named in the format of *.bin. The
loading of TRX software is actually the loading of 7 files that are bundled together.
TMU uses OM software.
The interface of software loading is shown in Figure 5-1 .
Figure 5-1 [SW Download] interface
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In this interface, set all items of the software to be loaded, including file name,
sending window size, version, and file ID (file type), and then click <Begin> to start
the loading
Caution:
The software loaded will not take effect until it is activated.
Interface description:
1) File ID
File ID is the identifier of various types of board software of the base station. Software
No. varies with the types of boards. The file ID must match with the software.
TRX_MAIN is the running software for TRX, and TMU_MAIN that of TMU.
2) Version
Version is the Identifier the software of different versions for the same type of boards.
3) File Name
The path and file name of the file loaded.
4) Send Window Size
Send window size decide the number of frames of the messages sent by TMU
between two responses. Generally it can be set as 49.
After the software is successfully loaded, the interface of software loading will be as
shown in Figure 5-2 . The prompt ‘Load SW successfully’ will be displayed in the
message bar at the bottom of the interface [SW Download] .
If the loading does not proceed as described above, it is not successful.
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Figure 5-2 Load SW successfully
5.1.3 Fault Analysis and Location
1) Check the channel for the software loading.
If the software is loaded via a local MMI, check whether the serial port
connection is normal.
If the software is loaded via a remote maintenance console, check whether thenetwork connection is normal, and whether E1 line connection is correct.
2) Check whether the management authority is correct.
If it is loaded at a local end, the management authority should be obtained at the
local end.
If it is loaded remotely, the management authority should be released at the local
end.
3) Confirm whether the selection of software type is correct. For example, if the
loaded software is TRX software, but the selected software type is not
TRX_MAIN, then the loading will fail.
4) Check whether the data configuration meets the requirement of the version. Ifdoes not meet, the loading will fail.
5) Check whether every parameter is set correct, especially when use the remote
maintenance console, whether the software configuration description table is
correct (Please refer to “M900/M1800 Base Transceiver Station (BTS3X)
Software Installation”). If the software path in the “Software filename” is incorrect,
the loading will fail.
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5.1.4 Troubleshooting Procedure
1) Make sure that the line connection is normal.
2) Make sure that the management authority is correctly set.
3) Make sure that the loaded software matches the selected type.
4) Make sure that the version No. of the loaded software is correct.
5.2 Base Station Initialization Failure
5.2.1 Fault Description
Base station initialization cannot be normally completed.
5.2.2 Introduction to Base Station Initialization
Base station initialization is embodied by the initialization of site and cell.
Site initialization procedures
1) Set site logic object
2) Set site hardware object
3) Set site extended attributes
4) Establish multi-point connection
5) Site activation
Cell initialization procedures
1) Create TEI
2) Establish signaling channel connection
3) Establish traffic channel connection
4) Set cell attributes
5) Set cell extended attributes
6) Set RC attributes
7) Set RC extended attributes
8) Set channel attributes
9) Set cell alarm threshold
10) Cell activation
Corresponding commands or data configuration is sent to the base station during
different stages of the initialization.
5.2.3 Fault Analysis and Location
For site initialization error, check the corresponding data configuration, the TMU
board and the maintenance link.
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For cell initialization error, check the corresponding data configuration, the TMU board,
the maintenance link and the corresponding board.
Check if the bit error rate on the transmission cable is too high or if there is any
transmission fault.
5.2.4 Troubleshooting Procedure
1) Check the corresponding data configuration step by step according to the
erroneous initialization. Correct errors if there is any.
2) Check if the corresponding boards and the maintenance links are normal.
Listed below is an explanation of the prompts on initialization errors:
‘Data configuration error’ and ‘Message does not match the physical
configuration’: there are errors in the data configuration of BSC datamanagement console. Please check the corresponding data configuration.
‘Communication timeout’: BTS does not respond within the specified time. After
this prompt appears, BSC will re-send the message. If the fault repeats, the
transmission link between BSC and BTS is disconnected or a fatal error has
occurred to the TMU of BTS.
‘Message structure error’, ‘Message type error’, ‘Illegal object type’,
‘Unsupported object type’, ‘BTS No. error’, ‘TRX No. error’, ‘Illegal attribute ID’,
‘Unsupported attribute’, and ‘Parameter exceeds the boundary’: there are errors
with the commands sent by BSC, which may be caused by BSC fault. The
problem ‘Parameter exceeds the boundary’ may possibly be caused by incorrect
data configuration.
5.3 Signaling Fault
5.3.1 Fault Description
While querying the corresponding maintenance link from BSC maintenance console,
it is detected that the signaling link status corresponding to OML link is not in
multi-frame link-setup state.
5.3.2 Introduction to OML
OML link is the link for maintenance message between BSC and BTS.
5.3.3 Fault Analysis and Location
1) Check the status of the corresponding link.
2) Check whether the corresponding data configuration is correct.
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3) Check whether the corresponding LAPD board is in normal position.
4) Check whether the BIE board of BSC are in normal position, whether the
corresponding E1 line and HW line are well connected, whether the status of the
corresponding E1 port of BIE board is normal.
5) Check whether the status of TMU board of the base station is normal.
5.3.4 Troubleshooting Procedure
1) If the corresponding OML link is in ‘TEI unallocated’ status, first check whether
the corresponding data configuration is correct.
2) Check whether the corresponding data configuration is correct and consistent
with hardware configuration.
3) Check whether LAPD board is in normal position.
4) Check whether the corresponding BIE board status is correct, and whether HWline and E1 line of the board are connected properly. If the corresponding E1 port
status is abnormal, HW line or E1 line might be wrongly connected.
5) Check whether the status of BIE board of the base station is correct.
5.4 RSL Link Blocked
5.4.1 Fault Description
While querying the corresponding signaling link via the BSC maintenance console, it
is detected that the link is not in multi-frame link-setup state.
5.4.2 Introduction to RSL Link
RSL link is the channel for signaling message between TRX and BSC.
5.4.3 Fault Analysis and Location
1) Check the status of the corresponding signaling link. If it is not in multi-frame
link-setup state, specify what status it is in. 2) Check whether the corresponding data configuration of the link is correct.
3) Check the BIE board of BSC to see whether the corresponding E1 line and HW
line are well connected, and whether their status is normal.
4) Check whether the status of TMU board of BTS is normal.
5) Check whether the software of the cell is activated.
6) Check whether TRX board works normally.
7) Check whether the attributes of TRX are correct.
8) Check whether the DIP switch settings of the TMU, CMB, TRB and TDU are
correct.
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5.4.4 Troubleshooting Procedure
1) If links are in ‘TEI unallocated’ status, check whether the data of the
corresponding link are configured correctly.
2) If the link is in disconnected status, please check whether the data of the
corresponding link matches the configuration of the hardware. If not, adjust either
the data configuration or the hardware configuration to make them match.
3) Check the status of the BIE board of BSC. Check whether E1 line and HW line
are well connected. If not, please connect them properly, and then recheck
whether the corresponding status recovers normal.
4) Check whether the corresponding LAPD board is in right location, and whether
its status is normal, and whether other links have been established.
5) Check whether TMU board status to see if it is normal.
6) Check whether the software of the cell is activated, whether it is in normalrunning.
7) Make sure that TRX is inserted in a proper slot.
8) Check whether the connector on the BTS cabinet top is well inserted.
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Chapter 6 Antenna and Feeder System Fault
6.1 Fault Description
Small coverage
Reduced coverage
Signal fluctuation
Poor conversation quality
High ratio of dropped calls
6.2 Introduction to the Antenna and Feeder System
The antenna and feeder system is used to provide duplex radio channels between
MS and BTS.
A radio channel from BTS to MS is defined as a downlink channel, while one from MS
to BTS an uplink channel.
6.3 Fault Analysis and Location
Poor downlink signal
Unstable downlink signal
Poor uplink signal
Note that the distribution of interference band can be viewed at the traffic
measurement console using the menu command “TCH performance measurement”.
6.4 Troubleshooting Procedure
6.4.1 Poor downlink signal
1) Check whether the output of TRX OUT port on TRX module (including power
amplifier) is normal. If not, replace TRX module.
2) Check whether the output of TX/RX_ANT port on CDU module is normal. If not,
replace the CDU
Note:
Make sure that the transmission cable between TRX and CDU is normal.
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Caution:
The prerequisite to the above procedures is that the transmission cable from TRX to
CDU is not faulty.
3) Test the antenna VSWR (voltage standing wave ratio) from 1/4” jumper
connector connected with TX/RX_ANT port of CDU module. If it is normal, check
the pitch angle of the antenna and adjust it to an appropriate angle.
4) If the VSWR at testing antenna end, tested from 1/4’’ jumper connector, is
abnormal, check section by section the VSWRs of respective connection ports of
the connecting cable (including tower-top amplifier, lightning arrester) between
this port and the transmitting antenna till the causes that worsen the VSWR arefound. The causes may be poor connection of connectors:
water leakage due to poor waterproofing of connectors
high VSWR of the antenna and feeder lightning arrester
high VSWR and water penetration of the antenna etc
Then take corresponding measures to clear the fault according to the different
causes.
6.4.2 Unstable downlink signal
1) Check whether the output (PA OUT port) of TRX module (including power
amplifier) is stable. If not, replace the TRX module.
2) Check whether the outdoor antenna and feeder system is reliable, and make
sure that the antenna and feeder do not sway with wind too much.
6.4.3 Poor uplink signal
1) Check whether CDU has tower-top amplifier alarm (TTA). If so, replace the
tower-top amplifier. CDU tower-top amplifier alarm can be obtained by viewing
the panel indicator and the alarm report from the operation and maintenance
console.
2) Check whether CDU LNA gives alarm. If so, replace the CDU module.
3) Check whether the connecting cable from input port TX/RX_ANT of CDU
antenna to the top of cabinet is normal. If not, replace the cable.
4) Test the VSWR of antenna and feeder from the top of the cabinet, the procedure
is the same as that in step 4 in I (Poor downlink signal).
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Chapter 7 Optical Channel Fault
7.1 Fault Description
Optical channel alarm and transmission fault.
7.2 Fault Analysis and Location
This fault may be caused by:
Fault of the receiving and transmitting optical channel. Loss of 2M analog signals, 2M interface external clock or 2M line signals, or 2M
signal alarm.
Loss of 2M interface transmitting clock or 2M interface digital signals.
Fault of TEU-TES communication.
7.3 Troubleshooting Procedure
1) Check the optical channel between ASU and BSC.
2) Check the E1 wiring of ASU.
3) Check ASU board. 4) Check TES and TEU.
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Chapter 8 Board Fault
8.1 TMU
8.1.1 Sources of Fault Information
TMU fault can be detected from the information gathered from:
The alarm box
The alarm console
TMU indicators
Hardware configuration status panel of the maintenance console
8.1.2 Related Functional Units
TRX, CDU, PSU, PMU, E1 lines.
8.1.3 Fault Classification
TMU fault may be caused by: No power supply
System alarm
E1 link alarm
Clock is in holdover or free-run mode
13M output clock is found to be inaccurate when tested with a frequency meter
8.1.4 Troubleshooting Procedure
I. Board power-off
In this case, the PWR power indicator on TMU board is off, the board does not work
and remote treatment becomes impossible.
1) Check whether PSU is switched on and whether VOUT indicator is on. If the
indicator is off, it means there is no PSU voltage output.
2) Check whether the TMU power switch in the switch box on top of the cabinet is
on.
3) Check whether the TMU is properly inserted and whether the power cable of the
backplane is well connected.
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4) If the problem still exists, replace the TMU board.
II. System alarm
1) The remote maintenance console prompts on OML link faultFirst check whether CPU is normal, i.e., if the RUN indicator on TMU panel stops
flashing, CPU is abnormal.
If it is abnormal, replace the board and then check whether the E1 ports connected to
BSC are normal, i.e., if Indicators LI1, LI2, LI3 or LI4 on TMU panel are on or flashing,
it indicates that faults have occurred to the corresponding E1 ports.
If they are abnormal, refer to Section III 'E1 link alarm (including local alarm and
remote alarm)' to solve the problem and then check whether BSC data configuration
is correct.
If the problem still exists, replace the TMU.
2) The terminal maintenance console shows the fault of the boards or modules
other than TMU
First check whether the board reported to be faulty is really faulty.
Y Refer to relevant chapters or sections to solve the problem.
N There may be communication fault between TMU and this board. In this
case, solve the problem according to the following instructions:
Check BSC data configuration and the wiring of the backplane.
If the problem still exists, replace the TMU board or the board or module that is
reported to be faulty.
III. E1 link alarm (including local and remote alarm)
When some of the E1 ports are faulty, the line alarm indicators LI1, LI2, LI3 or LI4 on
the TMU board are on or flashing.
Fault of local E1 port is indicated with the above listed indicators on, while that of the
remote E1 ports, with these indicators flashing.
To clear this type of fault, first check whether data configuration and line connection
are correct.
For fault of local E1 port, check if the port reported to be faulty is configured and if the
E1 cables are connected.
For fault of E1 port that has been configured, connect the receiving and transmitting
terminals of the port with a 75 Ω coaxial cable to determine whether the board is faulty.
If alarm appears, it may be a TMU fault. Then replace the TMU board.
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If the site is configured as in cascading mode, check the data configuration relative to
the cascaded sites.
IV. Clock is in free-run mode
In this case, the PLL indicator on TMU panel is on.
The clock enters free-run mode due to poor stability or loss of upper level clock
reference signal.
Check whether the configured clock reference source is introduced by the E1 link or
form the external clock.
1) If the clock reference signal is introduced by the E1 link, check whether there is
E1 link alarm.
Y Refer to Section III, 'E1 link alarm (including local alarm and remote alarm)'. N Test T2M clock on the panel.
If this clock is not very stable, there is fault with the upper level clock. Clear the fault
of the upper level clock and TMU will automatically switch to the locked mode.
2) If external clock is configured, check:
whether the wiring is correct
whether there is any external clock
whether the external clock, if any, meets the requirements
Clear the fault of the upper level clock and TMU will switch to the locked mode
automatically.
V. 13M output clock is found to be inaccurate when tested with a frequencymeter
Possible causes include:
Upper level clock is not accurate enough
TMU is damaged.
To clear this fault, check whether T2M signals on the TMU panel are faulty. If yes,
there is fault with the upper level clock. In this case, clear the upper level clock fault.
Correct the time of the upper level clock, and then:
1) Set the 13M output clock in free-run mode.
2) Send user-defined command to the 13M output clock to adjust the time of it.
3) Check if the 13M output clock returns to normal.
4) If the 13M output clock fails to lock the right frequency within (about) 20 minutes,
replace the TMU board.
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8.2 CDU
8.2.1 Sources of Fault Information
TMU fault can be detected from the information gathered from:
The alarm box
The alarm console
CDU indicator status
Hardware configuration status panel of the maintenance console
8.2.2 Fault Classification
High VSWR 1 (VSWR1) alarm
High VSWR 2 (VSWR2) alarm
Tower-top amplifier (TTA) alarm
Low noise amplifier (LNA) alarm
8.2.3 Troubleshooting Procedure
I. High standing wave ratio alarm 1 (VSWR1)
Check sequence: antenna system → CDU antenna port → CDU alarm .
1) Use a test mobile station to check if the antenna feeder system of the basestation can receive and transmit signals properly.
Y Manually reset the CDU and see whether the reported alarm is false. If yes,
proceed with Step 3).
N There might be fault with the antenna and feeder system. In this case,
proceed with Step 2).
2) Test the voltage standing wave ratio of the outdoor antenna feeder system.
Check if it is faulty, and determine whether replacement is necessary on the
parts of antenna feeder.
Below are the instructions on the testing of the outdoor antenna and feeder system: Shake the 1/4-inch jumper and 1/2-inch jumper connected with TX/RX_ANT port
of CDU, and see if their VSWR is stable.
Test the SWR at the 1/4-inch jumper connector connected with TX/RX_ANT port
of CDU, and shake the 1/4-inch jumper and the 1/2-inch jumper on top of the
cabinet to see if the VSWR changes noticeably.
When the VSWR is less than 1.3:1, the VSWR of the antenna feeder system is
regarded as normal. When the VSWR is greater than 1.4:1 or the cable is not
correctly connected, it is very probable that the antenna feeder system is faulty.
Try to replace the antenna feeder system to further determine whether the
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system is faulty. If replacement does not help, go to Step 3). If this step shows
the antenna feeder system is faulty, please replace the antenna feeder system.
Caution:
If a tower top amplifier is installed on the feeder line, cut off its power feed and test if
the VSWR of CDU TX/RX_ANT port exceeds the standard by a large degree.
3) Check if CDU is faulty
Test if the VSWR of CDU TX/RX_ANT port is more than 1.5:1 which is seriously
in contravention of the standard. Check the VSWR alarm processing function of CDU: 1) Reset and re-power-on
CDU. In this case, the system should react like being restarted. Otherwise, CDU
is faulty. 2) Determine whether CDU is faulty by replacing it.
If CDU is found faulty, replace it.
4) If after Step 2) and Step 3) the cause of CDU VSWR alarm fault is not
determined, treat it as CDU VSWR alarm or as poor match between TX/RX_ANT
and the 1/4-inch jumper connector. In the former case, replace CDU. In the latter
case, replace CDU and the 1/4-inch jumper.
Note:
The cables from the 1/4-inch jumper to the antenna are connected in the following
manner:
The 1/4-inch jumper inside the cabinet 1) (N-type male connector to the 7/16 DIN
female connector on top of the cabinet)<===>1/2-inch jumper from the cabinet top to
the 2) (7/16 DIN male connector to 7/16 DIN female connector) <===>3) Lightning
arrestor (7/16 DIN female connector to 7/16 DIN male connector) <===> the feeder
line from the sealing window through wall to the triplex tower amplifier 4) (7/16 DIN
female connector to 7/16 DIN connector) <===> 1/2 jumper from the feeder line to thetriplex tower amplifier 5) (7/16 DIN male connector to 7/16 DIN male
connector)<===>triplex amplifier 6) (7/16 DIN female connector to 7/16 DIN female
connector) <===>1/2-inch jumper from triplex tower amplifier to the antenna 7) (7/16
DIN male connector to 7/16 DIN male connector)<===> antenna 8) (7/16 DIN female
connector).
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II. High standing wave ratio alarm 2 (VSWR2)
Check sequence: antenna feeder system → CDU antenna port → CDU alarm .
1) CDU reports alarm to the TMU when VSWR2 occurs to it, and reports criticalVSWR2 alarm to the TMU if the alarm lasts for more than one minute.
2) After the TMU is informed of the VSWR2 alarm, it sends a command to the TRX
to switch off transmitting excitation.
3) Test if the reporting CDU has transmitting power.
Y TMU has not switched off the transmitting excitation. In this case, In this
case, go back to the last section "I. High standing wave ratio alarm 1 (VSWR1)"
and repeat step 1)-3).
N TMU has disabled transmitting excitation. In this case, repeat steps 2) and 3)
in the last section "I. High standing wave ratio alarm 1 (VSWR1)".
If the fault is not yet located at this point, enable TRX transmitting excitation and
repeat Step 1) of the last section "I. High standing wave ratio alarm 1 (VSWR1)".
4) Replace the CDU.
III. Tower-top Amplifier (TTA) Alarm
Check sequence: CDU → antenna feeder system (including tower top amplifier)
1) Reset CDU. Is the TTA alarm cleared after the resetting?
Y Proceed with Step 2).
N The reported CDU alarm is false. In this case, replace the CDU.2) Switch on the power supply to CDU tower top amplifier module. Does tower top
amplification occur to the CDU?
Y CDU voltage output is normal, and the alarm is caused by the insufficient
current of the TTA, which shuts down the voltage. In this case, the TTA is normal.
3) Disconnect CDU antenna port with the 1/4-inch jumper. Use a multimeter to
check if any short circuiting has occurred to the antenna feeder system;
Y The antenna feeder system is faulty. In this case, check the feeder line, jumper
and tower amplifier to locate the short circuit (such as water inflow).
4) Connect a galvanometer in series between the antenna port of the CDU and the1/4-inch jumper.
Keep the external conductor of CDU antenna port and the external conductor of the
1/4-inch jumper in good contact.
Switch on the power supply to the TTA and measure whether the voltage is 12V and
whether the power supply to the selected TTA is within the specified normal range. If
the voltage is normal but the current is zero, it indicates the TTA is in a state of
bypass. In this case, the TTA is damaged. Please replace it.
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Note:
If Step 4) cannot be performed due to the limit of the actual conditions, replace this
CDU with one that does not comprise a TTA to check whether the antenna feeder
system is normal. Here are the procedures for the checking:
Power off this CDU, and disconnect the jumpers.
Connect the jumpers of the antenna feeder system to the antenna port of the CDU
that does not comprise a TTA.
Power on the new CDU and switch on the power supply to the TTA.
Is the new CDU reporting TTA alarm?
Y If any, it indicates that the tower amplifier is faulty.
5) Replace the TTA when it is confirmed to be faulty.
IV. Low noise amplifier (LNA) alarm
1) Test the gain from the testing coupling port to RX output port of this channel to
see whether it is normal. If not, replace the CDU.
2) Reset the CDU forcedly at the maintenance console. Does the CDU return to
normal after the resetting? Judge whether the software is faulty with the result of
the resetting.
3) After the CDU is confirmed to be faulty, replace it.
8.3 EDU
8.3.1 Sources of Fault Information
The fault of EDU can be detected with the information gathered from:
The alarm box
The alarm information at the alarm console
Status of EDU indicators
Hardware configuration status at the maintenance console panel
8.3.2 Fault Classification
VSWRA alarm
VSWRB alarm
TTA alarm
LNA alarm
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8.3.3 Troubleshooting Procedure
The faults are removed step by step. When one step fails to remove the fault, go to
the next step.
I. High standing wave ratio alarm A (VSWRA)
Check sequence: antenna feeder system fault, EDU antenna port fault or EDU false
alarm.
1) When VSWRA occurs to EDU, EDU will report the alarm to TMU. When this
alarm lasts one minute, CDU will report a critical SWR alarm to TMU; After the
TMU receives this report, it will automatically send a command to the TRX to
switch off transmitting excitation
2) Test to see if the said CDU has transmitting power. If not, go to Step 4); if so, (theTMU does not switch off transmitting excitation), got to Step 3).
3) Use a test mobile station to check if the antenna feeder system of the base
station can receive and transmit signals properly.
Y Check whether the reported alarm is false by manually resetting the CDU. If
the alarm is false, proceed with Step 5).
N There might be fault with the antenna feeder transmission system.
4) Test the standing wave ratio of the outdoor antenna feeder system to determine
whether it is faulty and whether parts of the antenna feeder system should be
replaced.
Below are the instructions:
Shake the 1/4-inch jumper and 1/2-inch jumper on top of the cabinet connected
with TX/RX_ANT port of EDU, and see if their VSWR is stable.
Test the VSWR at the 1/4-inch jumper connector connected with TX/RX_ANT
port of EDU, and shake the 1/4-inch jumper and the 1/2-inch jumper on top of the
cabinet to see if the VSWR changes noticeably.
When the VSWR is less than 1.3:1, the VSWR of the antenna feeder system is
regarded as normal. When the VSWR is greater than 1.4:1 or the cable is not
correctly connected, you may initially conclude that the antenna feeder system is
faulty. Adopt the method of antenna feeder system replacement to further make
sure if the system is faulty. When this method fails, go to Step 5). If this step
shows the antenna feeder system is faulty, please deal with fault in the way of
checking the fault of the antenna feeder system
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Caution:
If a tower top amplifier is installed on the feeder line, its power feed must be cut off
first. Then, test if the SWR of EDU TX/RX_ANT port exceeds the standard by a large
degree.
5) Check if the EDU is faulty
Test to see if the VSWR of EDU TX/RX_ANT port is more than 1.5:1 beyond the
standard seriously.
When it is confirmed that the VSWR alarm processing function of EDU is abnormal,
first reset EDU and power on again. Does the system return to normal? Y If the alarm occurs again, the EDU is normal. If not, the EDU is faulty
Secondly, use EDU replacement method to make sure if the EDU is faulty.
Y Replace the EDU.
If the fault is not yet cleared at this point, switch on the TRX transmitting excitation,
and repeat Step 3) to make sure if the alarm is false.
6) If the EDU is found faulty, replace it.
II. Standing wave ratio alarm B (VSWRB)
Its removal process is the same as with the voltage standing wave alarm A.
III. Top-tower amplifier alarm (TTA)
Check sequence: CDU → antenna feeder system (including tower amplifier)
1) Reset EDU to see if the TTA alarm disappears. If not, a false alarm occurs to
EDU and it is necessary to replace the EDU. If the alarm disappears, go to Step
2).
2) Disconnect EDU antenna port with the 1/4-inch jumper. Use a multimeter to
check if short circuit occurs to the antenna feeder system; if so, it indicates theantenna feeder system is at fault, and it is necessary to check the feeder line,
jumper and tower amplifier to locate the short circuit (such as water inflow).
3) Switch on EDU TTA feeding power, and see if TTA alarm occurs to the EDU. If so,
it indicates that EDU voltage output is normal (the alarm arises from the shortage
alarm of TTA current, which shuts down the voltage. This is normal).
4) Connect a galvanometer in series between the antenna port of the EDU and the
1/4-inch jumper. Please be sure to keep good electric contact between the
external conductor of EDU antenna port and the external conductor of the
1/4-inch jumper. Switch on the feeding power of tower amplifier and measure
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whether the feeding voltage is accurate (12V) and see if the current of the
feeding power of tower top amplifier stays within the normal work current range
of the tower amplifier selected. If the voltage is normal but the current is zero, it
indicates the tower top amplifier is in a state of bypass, the tower amplifier hasbeen damaged and thus requires replacing.
Note:
When the conditions for taking this step are not satisfied, an EDU without its tower top
amplifier working properly to check if the antenna feeder system that the EDU with
alarm fault corresponds to is normal: connect the jumper of this antenna feeder
system to the antenna port of the EDU that works properly (power off this EDU
beforehand, and disconnect the jumper as well), and power on EDU as well as the
tower top amplifier feeding (TCP), to see if the EDU tower top amplifier gives an
alarm. If any, it indicates that the tower amplifier is faulty.
5) Check each part of the antenna feeder system to locate the fault. If the tower top
amplifier is still faulty, replace it.
IV. Low noise amplifier alarm (LNA)
1) Test the gain from the testing coupling port to RX output port of this channel to
see whether it is normal. If not, replace the EDU.
2) Utilize the forced reset function of EDU alarm control unit.
3) Reset the EDU by force on the terminal maintenance console to check if EDU
indicator works properly. Thus, make sure if it is a software false alarm.
4) When EDU fault is located, replace the EDU.
8.4 SCU
8.4.1 Sources of Fault Information
Alarm box
View alarm console information
Hardware configuration status panel of the maintenance console
Downlink signals abnormal
8.4.2 Fault Classification
Downlink signals not good
Transmitting power very small or the transmitting power of various channels
rather unbalanced
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No transmitting power
8.4.3 Troubleshooting Procedure
The faults are removed step by step. When one step fails to remove the fault, go to
the next step.
Note:
SCU module is a passive component, whose mean time between failures (MTBF) is
lengthy, and has no panel indicator. Furthermore, SCU needs to be used together
with CDU(not solely used at the front of base station RF). So, when fault occurs, it is
not easy to be noticed, and thus it is necessary to check carefully.
I. Downlink signals not good
1) First remove the fault, if any, of the RF cable between the antenna feeder system,
CDU module, TRX module, including TRX, SCU and CDU modules.
Use the wireless testing function of a test mobile station (configured with the base
station) to check whether the antenna feeder system of the base station can receive
and transmit signals properly. If the transmitting signals are intermittent or obviously
low, various CW of the same antenna are not balanced or signals are not through, it
indicates there might be something wrong with TRX transmission and the RF front
end, including the antenna feeder system.
First remove the fault, if any, of the RF cable between the antenna feeder system,
CDU module, TRX module, including TRX, SCU and CDU modules (for example,
the antenna is not installed, and the feeder line/jumper is not connected well).
If there is no fault, check if TRX transmitting power is normal.
In the event of any fault with TRX, CDU or the antenna feeder system, go to the
flow of dealing with fault with TRX, CDU and the antenna feeder system;
otherwise, go to the next step.
2) Test the transmitting insertion loss of SCU module and the return loss (SWR) of
each interface, to make sure if they are normal. If the transmitting insertion loss
of SCU (including any channel of the four) exceeds 7.1 dB, it indicates it's faulty;
if the interface return loss is less than 14 dB, it indicates SCU module is faulty.
3) When the above steps have been completed, if SCU is found faulty, please
replace the SCU module
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II. Transmitting power very small or the transmitting power of variouschannels rather unbalanced
1) First check if the installation (connection) from TRX module to the outdoor
antenna feeder system is at fault, and if TRX module is abnormal. Check if the installation (collection) of the cable from TRX module to outdoor
antenna feeder system is faulty, so as to rule out the fault of cable damage or
installation fault
Check if TRX module has any alarm, and test to see if its transmitting power is
normal
2) Check CDU module and the parts of antenna feeder system such as feeder line,
lightning arrester, tower top amplifier and antenna. Refer to the process flow for
CDU fault and antenna feeder system fault for the processing.
3) When Step 2) fails to locate the fault, go to Step 2) in the section 'downlinksignals not good' for processing.
4) Replace SCU.
III. No transmitting power
1) First check if there is anything wrong with CDU module and TRX module.
When critical standing wave alarm occurs to CDU, BTS will switch off TRX
transmitting power
When standing wave alarm occurs to TRX, BTS will switch off TRX transmitting
power
2) Test to see if SCU combiner output port (TX-COM) is abnormal. If TRXtransmitting power is normal, use a spectrum analyzer (connected to high-power
attenuator of 60 dB) or power meter at the combiner output port (TX-COM) to
test if the output power of each TRX carrier wave connected with SCU is normal.
3) Replace SCU module.
8.5 TRX
8.5.1 Sources of Fault Information
Alarm box
Alarm console
TRX indicator status
Hardware configuration status panel of maintenance console
8.5.2 Fault Classification
Over standing-wave alarm
Power alarm
Temperature alarm
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Clock alarm
Phase-locked loop alarm
DSP alarm
Frequency hopping bus alarm
DBUS bus alarm
Power supply alarm
TRX no power output
8.5.3 Troubleshooting Procedure
The faults are cleared step by step. If one step alone can not clear the fault, go to the
next step.
I. High voltage standing wave ratio alarm1) Check the connecting cable between TRX and CDU. If there is poor contact or
any broken point, replace the cable.
2) Check whether the antenna is installed properly.
3) Replace the TRX if the fault still can not be removed.
II. Power alarm
Check whether there is power supply alarm.
Check whether there is any clock alarm and whether the clock line between
backplanes TRB and CMB is normal. Check whether TRX is firmly inserted.
Replace the TRX if the fault still can not be removed.
III. Temperature alarm
Check the cooling fan. Replace it if it stops running.
Check whether the ambient temperature is too high.
Replace the TRX if the fault still can not be removed.
IV. Clock alarm
Check whether TRX is in good contact with the backplane. Make sure that it is
firmly inserted.
Replace the TRX. If the problem still exists, replace the backplane.
If all TRXs of this cabinet give clock alarms, then go as follows:
Check whether the wiring is correct. If not, modify the wiring as required. Check
whether there is any broken line.
Check whether TDU module and the wire are properly connected and whether
there is any fault in TDU module. If there is, replace the TDU module.
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Check whether there is fault in TMU module. If there is, replace the TMU
module.
V. Phase-locked loop alarm
1) Check whether there is any clock alarm. If there is, refer to section IV, 'Clock
alarm', to solve the problem.
2) Check whether there is any power supply alarm. If there is, refer to section XI,
'Power supply alarm', to solve the problem.
3) Check whether the data configuration of this cell is consistent with the attributes
of this cell.
4) Replace the TRX if the fault still can not be removed.
VI. DSP alarm
1) Check whether there is any clock alarm. If there is, refer to section IV, 'Clockalarm', to solve the problem.
2) Check whether TRX is firmly inserted.
3) Check whether the indicators on TRX panel are flashing alternatively. If they stop
flashing or they are not on, reactivate TRX software or reset the TRX.
4) Replace TRX if the fault still can not be removed.
VII. FPGA alarm
1) Check clock alarm.
2) Reset TRX.3) Replace TRX if the fault still can not be removed.
VIII. FIFO alarm
1) Check whether there is any clock alarm. If there is, refer to section IV, 'Clock
alarm', to solve the problem.
2) Check whether TRX is firmly inserted.
3) Replace TRX.
IX. Frequency hopping bus alarm
1) Check whether there is any clock alarm. If there is, refer to section IV, 'Clockalarm', to solve the problem.
2) Check whether there is any DSP alarm. If there is, refer to section VI, 'DSP
alarm', to solve the problem.
3) Check whether there is any FPGA alarm. If there is, refer to section VII, 'FPGA
alarm', to solve the problem.
4) Replace TRX if the fault still can not be removed.
X. DBUS bus alarm
1) Check whether data configuration is correct and whether the cell is in service.
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2) Check whether the wiring is correct.
3) Check whether TMU module is in good contact with the backplane.
4) Check whether there is any fault in TMU module.
5) Check whether E1 line connection is proper.6) Check whether the TRX and the backplane are well connected.
7) Check whether TRX is inserted into the right slot.
8) Replace TRX if the fault still can not be removed.
XI. Power supply alarm
1) Check whether the power is switched off.
2) Check the backplane wiring.
3) Replace TRX.
XII. TRX no power output1) Check whether there is any clock alarm. If there is, refer to section IV, 'Clock
alarm', to solve the problem.
2) Check whether there is any phase lock loop alarm. If there is, refer to section V,
'Phase-locked loop alarm', to solve the problem.
3) Check whether there is any DSP alarm. If there is, refer to section VI, 'DSP
alarm', to solve the problem.
4) Check whether there is any power supply alarm. If there is, refer to section XI,
'Power supply alarm', to solve the problem.
5) Check whether TRX is firmly inserted.6) Replace TRX if the fault still can not be removed.
8.6 PBU
8.6.1 Sources of Fault Information
Alarm box
View alarm console information
Observe the status of PBU indicator
View hardware configuration status of maintenance console panel
8.6.2 Fault Classification
High voltage standing-wave ratio alarm
Overtemperature alarm
Underpower alarm
Board communication alarm
Flash memory alarm
EPLD load times alarm
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EPLD upgrade failure alarm
Master clock alarm
Slave clock alarm
Clock critical alarm
8.6.3 Troubleshooting Procedure
The faults are removed step by step. When one step fails to remove the fault, go to
the next step.
I. PBU high voltage standing wave ratio alarm
1) Check the connecting cable and connection input from PBU to CDU.
2) Reset PBU.
3) If the alarm continues, replace this PBU.
II. PBU over temperature alarm
1) Check the equipment temperature and environment control equipment.
2) Check the operation of rack fans.
3) If all the temperature control equipment works properly, replace this PBU
module.
III. PBU underpower alarm
1) Restart the equipment to see if it can be restored.2) If it cannot be restored, replace the said PBU module.
IV. PBU board communication alarm
1) Check if PBU is powered on.
2) Replace PBU.
V. PBU Flash memory alarm
1) Replace Flash memory.
2) Replace PBU.
VI. EPLD load times alarm
If EPLD is erased for times more than the threshold value (100 times), this alarm will
be generated.
VII. PBU EPLD upgrade failure alarm
If EPLD in Flash upgrade software fails to be loaded for three times consecutively,
this alarm will occur.
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VIII. PBU master clock alarm
1) Check TMU clock.
2) Check clock transmission line.
3) Check TDU.4) View if extended TMU is installed.
IX. PBU slave clock alarm
1) TMU clock.
2) Check the clock transmission line.
3) Check TDU.
4) View if extended TMU is installed.
X. PBU clock critical alarm
1) Check active and standby clock transmission line.
2) Check active and standby clock.
3) Replace PBU unit.
8.7 PMU
8.7.1 Sources of Fault Information
PMU indicator status
Hardware status display panel on the maintenance console
8.7.2 Related Functional Units
PMU, power frame backplane distribution line, power module PSU, sensor and its
circuitry, battery pack loop.
8.7.3 Fault Classification
Board power-off
Power supply system alarm
8.7.4 Troubleshooting Procedure
I. Board power-off
In this case, the indicator RUN on PMU board is off, the board does not work, and
remote treatment becomes impossible.
1) First check whether PSU is switched on, and whether VOUT indicator is on. If
the indicator is off, then there must be no PSU voltage output.
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2) If VOUT indicator is on, measure whether the output voltage is normal.
If it does not fall within the operating voltage range, then PSU power supply is
abnormal
If it is normal, check whether PMU is properly inserted.
3) If the problem still exists, replace the PMU board
II. Power supply system alarm
In this case, the ALM system alarm indicator on PMU panel is on. It indicates that
there are faults in the power supply system. These faults can be viewed via the base
station maintenance console and they may be power module alarm, power
distribution alarm, and environment alarm.
III. Power module alarm
1) Power module fault
First check whether the input voltage and output voltage of the power frame fall within
the operating range.
If they do not, check the input power supply and output load
If they are normal, pull out the faulty power module from the backplane according
to the alarm power module address prompted in the base station maintenance
console. Then re-insert when all indicators are off. View the base station
maintenance console for any module fault alarm. If there is no fault alarm, then
the power module has recovered and can be put into use again. If the alarmreoccurs, replace the faulty power module.
2) Power module protection
The cause is that the power module input voltage exceeds the operating range or the
operating temperature is too high. Check whether there is any over/under-voltage in
the input power supply.
If it is abnormal, repair the input power supply
If it is normal, check whether the operating temperature of the power module is
too high or whether the cooling fan is faulty
If all the above are normal, pull out the power protection module from thebackplane according to the alarm power module address prompted in the base
station maintenance console. Reinsert the module when all indicators are off.
View the base station maintenance console for any module protection alarm. If
there is no alarm, then the power module has recovered and can be put into use
again. If the alarm reoccurs, replace the power protection module.
3) Power module communication failure
Check whether PMU and PSU are well inserted. If they are properly installed and of
good contact, check via the base station maintenance console to see whether the
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power module quantity and the data configuration of each module address are
correct.
If correct, check whether all the inserted modules fail in communication.
If all fail in communication and yet it is not sure whether the PMU is normal,replace the PMU. If PMU is confirmed to be normal, replace power frame
backplane.
If communication failure only occurs to some modules, interchange the positions
of the power modules of successful communication with those of communication
failure. If the modules that previously failed in communication still fail in
communication, replace the power module PSU. If the power module of
successful communication fails in communication after the interchange, replace
the power frame backplane.
IV. Power distribution alarm
1) AC input power-off or AC input over/under-voltage
In DC/DC power supply system, check whether module communication is successful.
If all fail in communication, refer to Subsection c (Power Module Communication
Failure) in Section 1) for solutions. When no power module is installed, check via the
base station maintenance console to see whether module quantity is set as 0. Check
the AC input distribution in AC/DC power supply system. If the distribution wires are
normal and AC input voltage is normal as well, check whether the PMU is well
inserted. If it is properly installed and of good contact, first consider replacing the
PMU. If AC input power-off alarm still exists, replace the power supply backplane.
2) DC output over/under-voltage
View the busbar voltage via the base station maintenance console and compare it
with the actual voltage.
If the over/under-voltage is caused by measurement error, check whether the
PMU is well inserted.
If it is properly installed and of good contact, consider replacing the PMU. If the
measurement is made correctly, check when there is DC over-voltage alarm
whether the power module or power supply input or power load is abnormal.
When there is DC under-voltage alarm, check whether the AC input, power
module or power supply input, and power load are abnormal.
3) Battery powered off
If the conditions for batteries being powered off are met, the monitoring module
should stop working and no battery powered off alarm should be detected due to
single power supply mode. Check whether the power-off contactor is working.
Replace it if it is not working.
4) Battery fuse broken
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Check whether the battery loop fuse, contactor and wiring are normal. If no problem is
found with the wiring of the battery loop and devices, check whether the PMU is well
inserted. If it is properly installed and of good contact, replace the PMU.
5) System output voltage abnormal There is wide differences between the busbar voltage and the specified output
voltage. If it is a DC/DC system, the problem may come from the power module
or the load. Check whether the power module and the load are abnormal.
If it is an AC/DC system, the problem may come from battery pack temperature
compensation, power module fault or the load. Check via the base station
maintenance console to see whether the measured value of the battery pack
temperature is correct. If the value is correct, do calculation using the following
formula:
Temperature compensation voltage = floating charge voltage – (battery packtemperature - 25) % temperature compensation coefficient
If the battery pack compensation voltage and busbar output voltage calculated
deviate within the error range (0.3V), then it is normal. If the deviation is too big,
check whether the power module and the load are abnormal.
If the temperature sensor measurement value is incorrect and there is no battery
pack temperature sensor attached, check whether the PMU is well inserted. If it
is properly installed and of good contact, replace the PMU. When there is a
battery pack temperature sensor attached, remove the temperature sensor.
And if the measured temperature value is the default value 25 ° C, then thetemperature sensor must be defective. Replace the battery pack temperature
sensor.
If the measured temperature value of the battery pack is not the default value,
the PMU temperature measurement circuit may be faulty. Replace the PMU.
V. Environment alarm
1) Ultra high/low ambient temperature or humidity
When installing temperature/humidity sensor, check via the base station maintenance
console to see whether the measured value is consistent with the actual value. If it is, tackle the environment problem.
If the alarm is caused by incorrect measurement, check whether the PMU is well
inserted. If it is properly installed and of good contact, replace the sensor first. If
the measurement remains inaccurate, replace the PMU. If no
temperature/humidity sensor is installed, check whether the PMU is well inserted.
If it is properly installed and of good contact, replace the PMU.
2) Smoke alarm, infrared alarm and soaking alarm
Check whether the PMU is well inserted. If it is properly installed and of good contact,
check whether there is any environmental alarm on the site mentioned above.
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If there is any such alarm, tackle the on-site environment problem.
If no such alarm, check whether there is any fault in the sensor and its line. If the
sensor and its line are normal, replace the PMU.
3) Door control alarmCheck whether PMU is well inserted.
If it is properly installed and of good contact, and no door control sensor is
installed, check whether there is short-circuit jumper connector in the door
control sensor interface MC on the power supply backplane. If there is not, install
short circuit jumper connector. If there is, replace the PMU.
If door control sensor has been installed, check the site for any environmental
alarm mentioned above. If such alarm exists, solve the on-site environment
problem. If there is no such alarm, check whether the sensor and its line are
faulty. If they are normal, replace the PMU.4) Fan alarm
Check whether PMU is well inserted.
If it is well installed and of good contact, check whether the rack feature No.
configured in the base station maintenance console is correct.
If it is, check whether the fan fault signal input connector has been installed in
the fan port of the power supply backplane. Install the connector if it is not
installed. If there is a line fault, solve the problem of fan fault signal input line.
If everything is normal, replace the PMU.
8.8 PSU
8.8.1 Sources of Fault Information
Alarm box
Alarm console
PSU indicator status
Hardware configuration status panel of the maintenance console
8.8.2 Fault Classification
Power supply alarm
Proper power supply unavailable
8.8.3 Troubleshooting Procedure
The faults are cleared step by step. If one step does not work, go to the next step.
Under normal conditions, the two green indicators on the power module are on
simultaneously, and the red indicator is off.
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1) If the green input indicator (VIN) of the power module is on, while the green
output indicator (VO) is off or flashing, check by the following procedures.
Note:
When system output load is small, individual modules may not work (i.e., the VO
indicator is off) due to current equalization. Yet it should not be considered as a fault.
Check whether the faulty module is well installed, and whether the two fasteners
at the upper and lower sides of the panel are tightly screwed. If not, reinstall the
module following the specified module assembly procedure.
Check whether the system fan is running normally. If it is not running, turn on thefan.
When the fan is running normally, and the green output indicator (VO) remains
off, then it may be that the module has not yet received the PMU voltage
regulation signal. Please wait for half a minute and observe.
If the green output indicator (VO) remains off after the above steps, this module
must be faulty.
2) If none of the three indicators on the module are on, check by the following
procedures
Check the status of other power module indicators in the same system. If all of
them are off, check whether the power supply system input busbar (or connector
post) is live or whether the connection is loose. If any problem is found,
reconnect the input line.
If one or module indicators are on or it is sure the power system input busbar is
live, check whether the module is properly installed and whether the two
fasteners at the upper and lower sides of the panel are tightly screwed. If not,
reinstall the module following the specified module assembly procedure.
If the indicator remains off after the above steps, this module must be faulty.
If the green input indicator (VIN) and red indicator (ALM) on the module panel are off
while the green output indicator (VO) is on, it means that the module itself cannormally output power supply. Please make replacement if spares are available. If no
spares are available, this module can still work as before and normal power supply
function will not be affected.
3) If the red alarm indicator (ALM) on the module panel is on while the green output
indicator (VO) is off, check by the following procedures
Check the system monitoring for any input over/under-voltage alarms. If such
alarm is found, then it is normal that the red indicator (ALM) is on. When the
input voltage resumes normal, the module will also resume its normal operation.
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If the input voltage is normal, check whether the cooling fan of the system
cabinet has stopped running. When the fan has stopped for a long time, over
temperature protection will occur to the module. Pull out the alarm module
according to the power module replacement procedure. Detach the module fromthe power system and reinsert it into the power supply system frame a few
minutes later when it is cooled. Then the module should work normally,
otherwise it must be faulty and replacement is needed.
8.9 TEU
8.9.1 Sources of Fault Information
Alarm console
TEU indicator status
Hardware configuration status panel of the base station maintenance console
8.9.2 Related Functional Units
PSU, TES, TMU, Transmission line, E1 line.
8.9.3 Fault Classification
Board power-off
Transmission line alarm
E1 link alarm
Calls can not be put through
8.9.4 Troubleshooting Procedure
I. Board power-off
In this case, all indicators on TEU board are off and the board does not work.
1) First check whether PSU is switched on, and whether VOUT indicator is on. IfVOUT indicator is not on, it means that there is no PSU voltage output.
2) Then check whether the TES power switch of the switch box on top of the
cabinet is on,
3) Check whether the PWR indicator of the TES board is on.
4) If they are all normal, check whether TEU is properly inserted.
5) If the problem still exists, replace the TEU board.
When the TEU is used for the optical transmission system, it is a public resource of
the whole network. If the transmission is interrupted due to improper operation,
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serious consequences will arise. Therefore, TEU power-off operation must be done
with extreme caution.
II. Transmission line alarm
In this case, the RUN indicator on TEU panel will indicate fault. For details, refer to
the instructions of various interface boards.
Seen from the OMC, transmission line alarm breaks up into transmission line
receiving alarm and transmission line sending alarm. Transmission line receiving
alarm means that all receiving lines of the board are blocked. Please check the
receiving lines.
Transmission line sending alarm means that all sending lines of the board are blocked.
Please check the sending lines.
III. E1 link Alarm
1) Off-board E1 alarm
This alarm means that faults have occurred to the E1 line. Check whether the E1 line
connectors are in good contact. E1 line transmits in 75 Ω and 120 Ω resistance
respectively. Check whether the setting of board toggle switch is correct. The default
value of the board is 75 Ω . Directly connect the receiving end and sending end of the
port using a 75 Ω coaxial cable to determine whether the board is faulty. If any alarm
occurs, it can be determined that the TEU board is faulty. Please replace the board.2) In-board E1 alarm
This alarm means that a fault occurs within the board. Please replace the board.
IV. Orderwire blocked
Check whether the board has 48V or 24V power supply input, i.e., whether the jumper
setting is correct (Jumpers of ASU and PAT are all set to 48V). Replace TEU board. If
the problem still exists, replace CMB backplane.
8.10 TES
8.10.1 Sources of Fault Information
Alarm console
TES indicator status
Hardware configuration status panel of the maintenance console
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8.10.2 Related Functional Units
TMU, TEU, CDU
8.10.3 Fault Classification
Board powered off
Board communication alarm
8.10.4 Troubleshooting Procedure
I. Board powered off
In this case, the PWR power indicator on TES board is off. The board does not workand remote treatment becomes impossible.
First check whether PSU is switched on and whether VOUT indicator is on. If the
indicator is not on, it means that there is no PSU voltage output. Then check whether
the TES power switch of the switch box on top of the cabinet is shut on. If they are all
normal, check whether the TES is properly inserted and whether the power cable of
the backplane is well connected. If the problem still exists, replace the TES board.
II. Board communication alarm
In this case, the ALM indicator on TES panel is on, indicating that a communication
fault has occurred to the serial port between TES and TEU, and the serial port
between the two boards is blocked.
First replace the TES board. If the communication alarm does not disappear, replace
the TEU board. If the alarm still exists, replace the CMB backplane.