Mute call on 3G

[djordjebeg]

Hmm it seams that is related to multirab .
we have disabled PS sessions for few Ues where mute call occurred frequently for 2 days and mute call did not happens.
Anyway I still expect Root cause analysis from NSN as i have opened ticket to them.

thank you for you suggestions , I think that we are on the right direction to solve this.
i will keep you informed!

regards,

[djordjebeg]

hello , here is the nsns expert analysis of the problem:
seams reasonable...

In this failure case RLC reset happens to PS bearer and UE is transferred to PCH. But also CS Iub is removed. UE does cell update after 13 seconds and also the CS is setup again but user has disconnected the call already.

For RLC resets following findings:
HSUPA seems to be using low bit rate power offsets and used SIR target looks too high. No byte is coming from EDCH.
RNC SW TN 159: 6.1.26 HSUPA Initial SIR target offset enhancements has not been implemented. Please check and do the changes according to the TN:
- 0x4240H for 1703 RN50_MAINT_27
- 0xA864H for 1704 RN50_MAINT_28.

Also these parameters maybe reasonable to be modified:
RNCHSPA- CPICHRSCPThreEDCH2MS 130 ->125
RNHSPA- CPICHEcNoThreEDCH2MS -10dB to -6dB.

[ChristopherAlbertini]

hello , here is the nsns expert analysis of the problem:seams reasonable...In this failure case RLC reset happens to PS bearer and UE is transferred to PCH. But also CS Iub is removed. UE does cell update after 13 seconds and also the CS is setup again but user has disconnected the call already. For RLC resets following findings:HSUPA seems to be using low bit rate power offsets and used SIR target looks too high. No byte is coming from EDCH.RNC SW TN 159: 6.1.26 HSUPA Initial SIR target offset enhancements has not been implemented. Please check and do the changes according to the TN: - 0x4240H for 1703 RN50_MAINT_27 - 0xA864H for 1704 RN50_MAINT_28. Also these parameters maybe reasonable to be modified:RNCHSPA- CPICHRSCPThreEDCH2MS 130 ->125RNHSPA- CPICHEcNoThreEDCH2MS -10dB to -6dB.

Did you manage to perform the changes?Is the problems fixed now?

[paboya]

Same ISSUE...even with NSN Core (ATCA) and ERIC Core
One our suspect is multiRAB, but still trial to disable MultiRAB
Coz in 2G Network no issue ?

We are exactly facing the same issue.
Our RAN is NSN and the core Ericsonn.

Can anyone help to locate where the issue is?

[ash_or]

Like Paboya said,

sometimes if parameter setting in multirab is not correct mute call will happen.
you should take look deeper in drivetest, and trace call using signalling trace analyzer, than you will find exactly signalling message before mute call happen.

[djordjebeg]

Hello,

we have changed parameter for lowbitrate HSUPA initial SIR target offset :
- 0x4240H for 1703 RN50_MAINT_27
- 0xA864H for 1704 RN50_MAINT_28
and problem did not disabpeard but mute periods are now much shorter ( before 8-12 sec) now ( 2-5 sec), and user perceprion is a bit improved , but far from that it is solved.

I guess that core has nothing to do with this.
Next step would be do disable multirab with hsupa, meaning that amr+HSDPA/DCH is only allowed.- planned for next Monday. Keep you informed people!
regards,

[gprastomo]

Hi,

I got this issue also on RNC Siemens, the problem was due to call reestablishment on CS Call, during this reestablishment, the cell update procedure was happened then produce mute call.
Then whem it swapped to NSN RNC it was solved, it was due to the minimum and max DL DPDCH power per connection for Siemens RNC was too low, the min was 3.4 dBm and max was 28.4 dBm, while for NSN 17 - 33 dBm, so it produced unnecessary out of sync which impact on call re establishment.

[plannerguy]

Hi

facing similar issue...NSN RAN and NSN Core.

Regards
Plannerguy

[ChristopherAlbertini]

Hello,

we have changed parameter for lowbitrate HSUPA initial SIR target offset :
- 0x4240H for 1703 RN50_MAINT_27
- 0xA864H for 1704 RN50_MAINT_28
and problem did not disabpeard but mute periods are now much shorter ( before 8-12 sec) now ( 2-5 sec), and user perceprion is a bit improved , but far from that it is solved.

I guess that core has nothing to do with this.
Next step would be do disable multirab with hsupa, meaning that amr+HSDPA/DCH is only allowed.- planned for next Monday. Keep you informed people!
regards,

Thanks for the feedback.

[kyokuman]

Hello,

we have changed parameter for lowbitrate HSUPA initial SIR target offset :
- 0x4240H for 1703 RN50_MAINT_27
- 0xA864H for 1704 RN50_MAINT_28
and problem did not disabpeard but mute periods are now much shorter ( before 8-12 sec) now ( 2-5 sec), and user perceprion is a bit improved , but far from that it is solved.

I guess that core has nothing to do with this.
Next step would be do disable multirab with hsupa, meaning that amr+HSDPA/DCH is only allowed.- planned for next Monday. Keep you informed people!
regards,

I am also having 3G mute calls. Investigations were done on L1 Reestablishment timers.. But problem still exists. I believe it has nothing to do with it..

My question to you is how the modification of those PRfile parameters could affect mute calls in a positive way? By Improving UL load by reducing Init SIR target for HSUPA?