Alarm & Hardware Investigation

7/27/2019 Alarm & Hardware Investigation

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Company Confidential

1 2005 Nokia V1-Filename.ppt / yyyy-mm-dd / Initials

Alarm & Hardware

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Nokia Systems


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7767 BCCH MISSING

Meaning The base station system has become faulty and the BSC recovery has not been

able re-configure a working BCCH to the BTS. The system also sets this alarm if

the BTS in question is in the normal working state but no BCCH-TRX has been

configured to the BTS or if the BCCH-TRX of the BTS is locked by the user. The

base station cannot transmit traffic without a working BCCH.Instructions

This alarm is usually a result of a fault situation in the BTS detected by the

BTS or the BSC. Use the MML command EOL to list other alarms affecting

the BTS and act according to their instructions. Check that the system

cancels the alarms (including this alarm) affecting the faulty unit. This

returns the BCCH-TRX to the WO state. If the system does not cancel thisalarm, lock and unlock the faulty object (BCF/BTS/TRX) with the

EFS/EQS/ERS MML command. This causes the object to restart. The

system then cancels all alarms affecting the unit, and if necessary, sets

them again. In such a case, correct the fault according to the instructions in

the active alarms affecting the unit.


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7725 TRAFFIC CHANNEL ACTIVATION FAILURE

Meaning

The system has blocked the radio time slot because the call control has failed anumber of times in the activation of a traffic channel.

Supplementary information fields

1 Type of the channel whose TCH activation failed The channel type can be

"TCH" , "SDCCH" or "Packet Data TCH". The number value "0" indicates "TCH",

"1" indicates "SDCCH" and "2" indicates "PDTCH" (Packet Data Traffic TCH). Instructions

if the failure type is "PDTCH", the alarm is cancelled automatically by the system,

when no more failure indications are observed if the channel type is "TCH" or

"SDCCH", cancel the alarm with the MML command EOR. Deblock the radio time

slot by first aligning the TRX in question with the command ERS and thenremoving the alignment of the TRX


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7743 MEAN HOLDING TIME BELOW DEFINED

THRESHOLD

Meaning

Mean holding time on a channel is below the operator-defined minimum during the measurement period. The alarmis used to supervise the functioning of traffic channels and to detect the possible faulty channels.


1 indicates if the mean holding time is below the defined threshold in time slot 0 00: above threshold (no alarm) 01:below threshold (alarm) 2 indicates if the mean holding time is below the defined threshold in time slot 1 00: abovethreshold (no alarm) 01: below threshold (alarm) 3 indicates if the mean holding time is below the defined thresholdin time slot 2 00: above threshold (no alarm) 01: below threshold (alarm) 4 indicates if the mean holding time isbelow the defined threshold in time slot 3 00: above threshold (no alarm) 01: below threshold (alarm) 5 indicates ifthe mean holding time is below the defined threshold in time slot 4 00: above threshold (no alarm) 01: belowthreshold (alarm) 6 indicates if the mean holding time is below the defined threshold in time slot 5 00: abovethreshold (no alarm) 01: below threshold (alarm) 7 indicates if the mean holding time is below the defined thresholdin time slot 6 00: above threshold (no alarm) 01: below threshold (alarm) 8 indicates if the mean holding time isbelow the defined threshold in time slot 7 00: above threshold (no alarm) 01: below threshold (alarm) 9 identifies thetime slot where the mean holding time is shortest 10 identifies the subchannel in the time slot with the shortest meanholding time 00: TCH/H subchannel 0 01: TCH/H subchannel 1 02: TCH/F subchannel 11 shortest mean holdingtime in seconds during the measurement period (TCH)

Instructions

Find out the reason for the fault by examining the release causes in channel release messages. Restore the channelby first locking it out of use and then unlocking it with the MML command ERS. ZERS:,,:L; lock

ZERS:,,:U; unlock Check that the parameters affecting the alarm are reasonable. The MMLcommand EEO outputs the radio network supervision parameter values and the EEN command modifies theparameter values. Parameters, with their default values, affecting the alarm: ZEEN:MINHTT = minimum meanholding time for a TCH (10 s) PRDMHT = length of TCH supervision measurement (120 min) CS = channel seizurethreshold value (10)


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7734 BCCH IS NOT AT PREFERRED BCCH TRX

Meaning

The BTS has at least one TRX defined as the preferred BCCH TRX but theBCCH channel is not on such a TRX so the BCCH coverage may have

decreased. This alarm is not set if the BCCH MISSING alarm is active.


Instructions

This alarm usually results from a fault affecting the BTS's preferred BCCH TRX.Check the radio network configuration with the MML command EEI or the

transceiver parameters with the MML command ERO. Check active alarms with

the MML command EOL and find out the reason for the preferred BCCH TRX

fault based on other alarms affecting the BTS in question. Act according to the

instructions of the other active alarms. Check that the system moves the BCCH to

the preferred BCCH TRX and cancels this alarm.


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7735 TRX TEST FAILED

Meaning

The TRX test has failed. The test outcome is concluded by comparing the test results to the threshold

values. The traffic capacity is likely to be decreased.


1 number of the radio time slot used for the test 0...7 2 transmitted power range 0...50 dBm 3standing wave ratio range 10...100. The actual SWR is 0.1 * the given value. Value 255 (hex 0xFF)indicates that SWR is not measured 4 bit error rate value of the diversity branch 1 The value is BCDcoded and the decimal point is after the fourth byte: XXXX.XXXX 00000 ... 1000000 5 measured RXsensitivity value of the diversity branch 1 Indicates the absolute value of the signal level. range (-

)85...(-)118 dBm 0 (the receiver sensitivity is less than can be measured) 254 (could not bemeasured) 255 (sensitivity is better than minumum TXLEV) 6 bit error rate value of the diversitybranch 2 The value is BCD coded and the decimal point is after the fourth byte: XXXX.XXXX 00000 ...1000000 7 measured RX sensitivity value of the diversity branch 2 Indicates the absolute value of thesignal level. range (-)85...(-)118 dBm 0 (the receiver sensitivity is less than can be measured) 254(could not be measured) 255 (sensitivity is better than minimum TXLEV)

Instructions

1. Use the MML command UCV to check that the threshold values of result parameters arereasonable ZUCV:TRP,CURRENT; Change THE threshold values if they are not reasonable. 2. If theprevious action fails to remove the fault, contact your local Nokia Customer Service Center.


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7753 TRX LOOP TEST FAILED

Meaning

A scheduled or a single TRX loop test failed. The test fails when an error rate value of theresult parameter is exceeded. The TRX's traffic capacity has probably decreased.


1 number of the diversity branch tested 1 = diversity branch 1 2 = diversity branch 2 2

identifier of radio time slot tested 0 .. 7 3 bit error ratio. The value is BCD coded and a

decimal point is after the fourth digit: XXXX.XXXX 00000000 .. 01000000 4 bit error ratio

for 2nd class bits. The value is BCD coded and a decimal point is after the fourth digit:XXXX.XXXX 00000000 .. 01000000 5 frame error ratio. The value is BCD coded and a

decimal point is after the fourth digit: XXXX.XXXX 00000000 .. 01000000 6 RX quality

parameter. The value is BCD coded 0 .. 7.

Instructions

1. Check that the threshold values of result parameters are reasonable. 2. Check if the

base station to be tested has frequency hopping on. If it does, set it off. See instructionson Base Transceiver Station Handling in BSC. After that, execute the TRX test to all the

TRXs in the BTS. 3. Execute a single TRX test to the alarming TRX.

7717 WORKING HALF RATE TCH RATIO BELOW


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7717 WORKING HALF RATE TCH RATIO BELOWTHRESHOLD

Meaning

The radio network configuration and failure management has detected that the ratio

between the number of half rate traffic channels in the cell in normal working state(UNLOCKED-WORKING) and the number of unlocked half rate traffic channels in the cellis below the defined threshold. Only one alarm per cell is possible. Object of the alarm isthe BTS which has the BCCH timeslot.


1 N = normal TRX E = extended range TRX

Instructions

Check why half rate traffic channels in the cell in normal working state (UNLOCKED-WORKING) or unlocked half rate traffic channels in the cell are out of use. If the reason isa faulty TRX, correct the fault. This increases the number of channels in normal workingstate, and the alarm is removed automatically. The BSC-specific threshold value of thealarm can be changed with the MMI command EEQ. The new threshold value takes effectas soon as the ratio of the channels changes, for example, when the administrative stateof the TRX is changed, or the TRX's operative state changes. The following formula is

used in calculating the ratio: ( number of WO and BL-SHD half rate and dual rate trafficchannels in the cell/ number of all half rate and dual rate traffic channels in the cellexcluding those in BL-USR state ) * 100


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7604 BTS OPERATION DEGRADED

Meaning

Major fault (or faults) has occurred in a unit (or units) that belong to the sector indicated in the alarm.

The fault reason can be read from the supplementary text field of the alarm. Supplementary information fields

1-6 XX XX XX XX XX XX 1 2 3 4 5 6 1) rack (cabinet) number 4) type of unit 2) shelf number 5) unitnumber 3) slot 6) subunit number For more information, see Alarm Structure

Instructions

METROSITE: Other fault reasons Instructions: 1. Check whether either of the following alarms isactive: 7606 TRX FAULTY 7607 TRX OPERATION DEGRADED and follow the instructions given forthe active alarm(s). ULTRASITE: Fault reason: Remote tune combiner temperature is dangerouslyhigh. Instructions: 1. Ensure that the ambient temperature of the base station is within specified limits.2. Check the cabinet fans. 3. Replace the RTxx. Note: An alarm is activated when the RTxx unitinternal temperature exceeds +70C. Fault reason: Remote tune combiner temperature is low.Instructions: 1. Ensure that the ambient temperature of the base station is within specified limits. 2.Check that the heater is working properly if equipped. 3. Replace the RTxx. Note: An alarm isactivated when the RTxx unit internal temperature is below -10C. Fault reason: Rx levels differ toomuch between main and diversity antennas. Instructions: 1. Check the RSSI measurements by BTSManager. 2. Check and measure the antenna lines. 3. Check the BTS RF cables and connections. 4.Replace the combiner unit. Check that the RXDL parameter at the BSC is set to a reasonable value,taking into account the site conditions in order to prevent unnecessary alarms. 5. Replace the TSxxunit. Other fault reasons Instructions: 1. Check whether either of the following alarms is active: 7606TRX FAULTY 7607 TRX OPERATION DEGRADED and follow the instructions given for the activealarm(s).

7741 MEAN HOLDING TIME ABOVE DEFINED


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7741 MEAN HOLDING TIME ABOVE DEFINEDTHRESHOLD

Meaning

The mean holding time on the channel specified exceeds the operator-defined threshold during the measurementperiod. The alarm is used to supervise the functioning of the traffic and signalling channels. It reveals unreleasedcalls.


1 subchannel identification 00 - 01: TCH/H subchannel F0 : TCH/F subchannel C0 - C7: SDCCH subchannel 2 meanholding time on the channel in minutes 3 number of seizures on the channel during the measurement period 4shortest seizure on the channel during the measurement period in seconds

Instructions

Find out whether the channel seizure that caused the alarm is a real call or an unreleased channel. Use the serviceterminal command S:,, B,

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