Decrease RRC NoReply Failure in LTE

[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