Decrease RRC NoReply Failure in LTE

[mounir34]

Dears
could you please share some Parameters to decrease RRC NoRply failure in Huawei Equipement based in your experience


Thanks

[sak2e]

Also faced the same issue,
I'm pretty sure there are no problem at coverage / interference / site to site distance is OK but somehow the NoReply failure come and leave without permission :D

[electron]

Also faced the same issue,
I'm pretty sure there are no problem at coverage / interference / site to site distance is OK but somehow the NoReply failure come and leave without permission :D

Hi,


RRC reconig time expiration could be the cause .


Cheers

[mounir34]

do you mean T300 ?


Hi,


RRC reconig time expiration could be the cause .


Cheers

[mounir34]

for your case to come and leave without permission,i think is related to 1 user ,did you check the trace or CHR to confirm if 1 or more user caused your problem ,


Also faced the same issue,
I'm pretty sure there are no problem at coverage / interference / site to site distance is OK but somehow the NoReply failure come and leave without permission :D

[babak1349]

do you mean T300 ?

Hello
T300 is good recommendation to be checked but it is UE timer which during UE waits for RRC connection setup message also there might be enodeB timer which during enodeB waits for RRC connection setup complete So you need to check this parameter too (it could be hidden or hard coded)
Anyway "no Reply" happens when EnodeB doesn't receive te RRC connection setup complete
it can happen due to poor quality or UE moved out of LTE coverage (it means reselects other RAT)
Different UE may have different firmware and some firmware allows reselect to another RAT during RRC establishment procedure so even the issue could be for specific UE type you can disable reselection to other RAT or making it very hard by setting the parameters appropriately for test purposes..
there are other points can help too:
1) does it happen in all cells ( if it does it mean a common issue like as timers ...)
2) what is the main RRC connection request cause of failed ones ? (registration ? might mean ping pong RAT reselection)
3) doing DT for worst cell and checking what happens on the field


cheers

cheers

[mounir34]

thanks freind,do you know some parameter for Power control can solve our issue ,
before for 3G we solved this problem by increase Constant value for Initial RACH Power (power control)


Hello
T300 is good recommendation to be checked but it is UE timer which during UE waits for RRC connection setup message also there might be enodeB timer which during enodeB waits for RRC connection setup complete So you need to check this parameter too (it could be hidden or hard coded)
Anyway "no Reply" happens when EnodeB doesn't receive te RRC connection setup complete
it can happen due to poor quality or UE moved out of LTE coverage (it means reselects other RAT)
Different UE may have different firmware and some firmware allows reselect to another RAT during RRC establishment procedure so even the issue could be for specific UE type you can disable reselection to other RAT or making it very hard by setting the parameters appropriately for test purposes..
there are other points can help too:
1) does it happen in all cells ( if it does it mean a common issue like as timers ...)
2) what is the main RRC connection request cause of failed ones ? (registration ? might mean ping pong RAT reselection)
3) doing DT for worst cell and checking what happens on the field


cheers

cheers

[oucht79]

Hi

Check contention resolution timer
change PDCCH CCE aggregation level
change PDCCH DCI1A power

Thx

[mounir34]

did you tried before,could you please share the report if you have ,thx

Hi

Check contention resolution timer
change PDCCH CCE aggregation level
change PDCCH DCI1A power

Thx

[sak2e]

From CHR i couldn't identify IMSI or MSISDN, can you help me how to figure out IMSI from CHR?
Only TMSI can be found there.


for your case to come and leave without permission,i think is related to 1 user ,did you check the trace or CHR to confirm if 1 or more user caused your problem ,

[babak1349]

thanks freind,do you know some parameter for Power control can solve our issue ,
before for 3G we solved this problem by increase Constant value for Initial RACH Power (power control)
Hello,
I think the equal (almost) parameter in LTE is preambleInitialReceivedTargetPower
Besides you can think of slightly increasing PZeronominal power as well

I had same issue in 3G but what I have done was playing with Sratsearch and I made it harder to reselect from 3G to 2G and it caused remark improvement on RRC establishment success rate. So I suggest to think of that as well
besides how is the reselection priority ? do you have problem on the RAT/Frequency with highest priority ? ( you can have 2 LTE carriers in different band)
I think the issue is due to UEs which moved out of LTE and they can't answer to RRC connection Setup... to make sure about it choose the worst cell and disable reselection to other RAT

BR

[khurrambilal01]

do you mean T300 ?

T300 and T302 Audit, Secondly try reducing Initial UL PRBs.

[khurrambilal01]

Hi

Check contention resolution timer
change PDCCH CCE aggregation level
change PDCCH DCI1A power


Thx

All of the above parameters will take care of DL part only, But remember the issue might be in UL where a UE is on cell Edge and it successfully sent Msg1 which involves lesser information like 7Bytes approx while Msg 3 involves more information especially for MO-Sig (Approx 7-100Bytes) so UE might not have that power to send per PRB and hence the message will not be decoded at eNB end, So whatever you do here will not improve situation for such UEs, Better to first optimize coverage for these UEs in case the issue isn't network level. Thanks

[mounir34]

thanks dear,what do uou think about UL Power control paramters ,
for exapmle P0nominal for PUCCH from -115 to -125 is a good idea or no



All of the above parameters will take care of DL part only, But remember the issue might be in UL where a UE is on cell Edge and it successfully sent Msg1 which involves lesser information like 7Bytes approx while Msg 3 involves more information especially for MO-Sig (Approx 7-100Bytes) so UE might not have that power to send per PRB and hence the message will not be decoded at eNB end, So whatever you do here will not improve situation for such UEs, Better to first optimize coverage for these UEs in case the issue isn't network level. Thanks

[babak1349]

thanks dear,what do uou think about UL Power control paramters ,
for exapmle P0nominal for PUCCH from -115 to -125 is a good idea or no
hi
you should increase it from -115 to for example -105 dBm.. it is the target of receiving signal level in enodeB and also increase Pzeronominal for PUSCH
just be careful too much increase of those parameters will increase the UL RSSI

cheers

[mounir34]

thanks feind for the help ,i will try to change Pzeronominal and i will share with you the result ,thx


hi
you should increase it from -115 to for example -105 dBm.. it is the target of receiving signal level in enodeB and also increase Pzeronominal for PUSCH
just be careful too much increase of those parameters will increase the UL RSSI

cheers

[electron]

thanks feind for the help ,i will try to change Pzeronominal and i will share with you the result ,thx

Hi,

As an alternate you may check PUSCH SINR trend after the change too . There is risk of degradation by increasing PzeronominalPusch as well. Anyway it is a trade off.


B
R