pmNoSystemRabReleaseSpeech

[KoJaa]

Hi Experts,

What other counters do I need to check for the cause of the sudden increase of this counter pmNoSystemRabReleaseSpeech (dropcall) and how to resolve this? No Alarms, no interference (rssi), no Co-SC, and not a RNC border.

Also, how will I know if the site is already lacking of DL power that will result to drop calls or maxTxPowerUl is configured too low?

[wolverine]

If it is a particular site that is causing the problem then the best approach will be to enable a GPEH trace (if you have purchased this feature) for the event that corresponds to the abnormal release (you can see which one in ALEX) and then analyse that. The GPEH trace will show you for every abnormal release what radio bearer was used, the cause code, Ec/No and RSCP etc.

[tsiz]

Hi Experts,

What other counters do I need to check for the cause of the sudden increase of this counter pmNoSystemRabReleaseSpeech (dropcall) and how to resolve this? No Alarms, no interference (rssi), no Co-SC, and not a RNC border.

Also, how will I know if the site is already lacking of DL power that will result to drop calls or maxTxPowerUl is configured too low?

When you have a sudden increase in drops on a cell, there are a few things that you can check.

In E******* Moshell--type CAB which gives cabinet configuration. Check your RAXb and the RU/FU boards.

If you type lhsh 00xx00 te log read where xx corresponds to your port number from the cab command, this would give you the errors on the RAXb. If you find Bold letters in red on the errors, go ahead and restart the RAXb. This would usually resolve the issue. Also restart the RU/FU boards.

Check the type of drops. Are drops because of missing neighbors, UL synch drops, drops due to others or SHO drops..you have counters for those.

SOHO %
(pmNoSysRelSpeechSoHo - pmNoSysRelSpeechNeighbr) / pmNoSystemRabReleaseSpeech * 100

Missing Neigh %
pmNoSysRelSpeechNeighbr / pmNoSystemRabReleaseSpeech* 100

UL SYNC %
pmNoSysRelSpeechUlSynch / pmNoSystemRabReleaseSpeech * 100

IRAT %
(pmnoattoutirathospeech - pmnofohospeechuerej - pmnosuccoutirathospeech - pmnofohosperetoldchphchfail -
pmnofohosperetochnophchfail ) / pmnosystemrabreleasespeech

Other %
( pmnosystemrabreleasespeech - pmnooftermspeechcong - pmnosysrelspeechsoho - pmnosysrelspeechulsynch -
(pmnoattoutirathospeech - pmnofohospeechuerej - pmnosuccoutirathospeech - pmnofohosperetoldchphchfail -
pmnofohosperetochnophchfail)) / pmnosystemrabreleasespeech

Check and see if a new site was brought on air close to this site that may not be added as a neighbor causing event 1d.

[probeat]

If it is a particular site that is causing the problem then the best approach will be to enable a GPEH trace (if you have purchased this feature) for the event that corresponds to the abnormal release (you can see which one in ALEX) and then analyse that. The GPEH trace will show you for every abnormal release what radio bearer was used, the cause code, Ec/No and RSCP etc.

Looking to GPEH trace , there is a lot
1-4 Radio link failure indication leading to a release with cause other than transport.
and
1-1 Radio Link Control (RLC) unrecoverable error in UTRAN (maximum number of RLC retransmissions is reached).

What is reason for this two!?

[KoJaa]

Thanks Tsiz that was very informative,

I've type the CAB command and here is the output
=====================================================================================================
SMN APN BOARD GREEN YELLOW RED PRODUCT NR REV DATE SERIAL NR TEMP COREMGR
=====================================================================================================
0 1 CBU1 ON 16HZ OFF ROJ 119 2209/1 R5G 20090925 BB9M047240 +50C Active*
0 2 ET-MFX ON OFF OFF ROJ 119 2315/1 R7A 20090812 TM15227264
0 6 RAX ON 16HZ OFF ROJ 119 2187/14 R1C 20090811 TM15226812
0 8 TX6HS-04 ON 16HZ OFF ROJ 119 2254/8 R1D 20090911 TM15229727
0 9 OBIF ON 16HZ OFF ROJ 119 2238/23 R1F 20090914 TB3C993243
-----------------------------------------------------------------------------------------------------
so by referring to this table i should input lhsh 000600 right? no bold nor red letters so it means that my RAXb is not at fault here, how can i see my FU/RU boards.

By using the formula, it seems that my problem is in IRAT and ULSync, How do I resolve UL Sync problem? Does it mean that i'm uplink limited already since my maximumUeTxPower is only 24? or I have to play with minPwrRL and minPwrMax?

[tsiz]

Thanks Tsiz that was very informative,

I've type the CAB command and here is the output
=====================================================================================================
SMN APN BOARD GREEN YELLOW RED PRODUCT NR REV DATE SERIAL NR TEMP COREMGR
=====================================================================================================
0 1 CBU1 ON 16HZ OFF ROJ 119 2209/1 R5G 20090925 BB9M047240 +50C Active*
0 2 ET-MFX ON OFF OFF ROJ 119 2315/1 R7A 20090812 TM15227264
0 6 RAX ON 16HZ OFF ROJ 119 2187/14 R1C 20090811 TM15226812
0 8 TX6HS-04 ON 16HZ OFF ROJ 119 2254/8 R1D 20090911 TM15229727
0 9 OBIF ON 16HZ OFF ROJ 119 2238/23 R1F 20090914 TB3C993243
-----------------------------------------------------------------------------------------------------
so by referring to this table i should input lhsh 000600 right? no bold nor red letters so it means that my RAXb is not at fault here, how can i see my FU/RU boards.

By using the formula, it seems that my problem is in IRAT and ULSync, How do I resolve UL Sync problem? Does it mean that i'm uplink limited already since my maximumUeTxPower is only 24? or I have to play with minPwrRL and minPwrMax?

Yes.. lhsh 000600 te log read will give you errors. RU/FU resets in the past have helped but if you are having IRAT drops, check and see if the proper 2G neighbors are defined and the selection priority is correct.

For uplink sync drops there is not much you can do. maybe its due to poor coverage / ecno. Try limiting your parameters qqualmin/qrxlevmin/usedfreqthresh2drscp/ecno.

[KoJaa]

Yes.. lhsh 000600 te log read will give you errors. RU/FU resets in the past have helped but if you are having IRAT drops, check and see if the proper 2G neighbors are defined and the selection priority is correct.

For uplink sync drops there is not much you can do. maybe its due to poor coverage / ecno. Try limiting your parameters qqualmin/qrxlevmin/usedfreqthresh2drscp/ecno.

usedfreqthreshold2drscp/ecno are already on -89 and -9 respectively (its their default one here) ill try the qqualmin/qrxlev

is there any counter that would tell me that i'm lacking in DL power or UE is lacking UL power that would cause drops?

i'm also getting a lot of Radio Link Control (RLC) unrecoverable error in UTRAN (maximum number of RLC retransmissions is reached). in GPEH messages, what does this mean?

[tsiz]

usedfreqthreshold2drscp/ecno are already on -89 and -9 respectively (its their default one here) ill try the qqualmin/qrxlev

is there any counter that would tell me that i'm lacking in DL power or UE is lacking UL power that would cause drops?

i'm also getting a lot of Radio Link Control (RLC) unrecoverable error in UTRAN (maximum number of RLC retransmissions is reached). in GPEH messages, what does this mean?

For lack of DL power, check pmnofailrabestattlackdlpwr counter.

Is the cell overshooting? Check propagation delay and see if you need to downtilt the sector. I am not sure about the max RLC retransmissions. Is this causing drops or accessibility failures..because I am thinking max RLC retransmissions reached may be due to the fact that the ue is not able to send the rrc request message back to the rnc.

[KoJaa]

For lack of DL power, check pmnofailrabestattlackdlpwr counter.

Is the cell overshooting? Check propagation delay and see if you need to downtilt the sector. I am not sure about the max RLC retransmissions. Is this causing drops or accessibility failures..because I am thinking max RLC retransmissions reached may be due to the fact that the ue is not able to send the rrc request message back to the rnc.

wow that was a fast reply.

This is really helpful, one last thing just incase if my drop cause is "Others" does this pertain to transmission drops, HW faults? or rather what is the usual cause for drops due to others?

[tsiz]

wow that was a fast reply.

This is really helpful, one last thing just incase if my drop cause is "Others" does this pertain to transmission drops, HW faults? or rather what is the usual cause for drops due to others?

Yes...transmisson, hw, drops because of bad ue all fall under other drops.