Silence for 4-5 seconds (NSN equipment)

[Ryurikovich]

Hi dear members!

Could you explain what is the possible reasons if sometimes my colleagues and me also discover silence for 4-5 seconds during 3G call? I think that is during HO but I can not prove that. After 4-5 seconds silence disappear and I can hear again.

We observe that problem on different places of our network.

Many thanks in advance!

[ChristopherAlbertini]

Hi dear members!

Could you explain what is the possible reasons if sometimes my colleagues and me also discover silence for 4-5 seconds during 3G call? I think that is during HO but I can not prove that. After 4-5 seconds silence disappear and I can hear again.

We observe that problem on different places of our network.

Many thanks in advance!


We are currently facing the same issue with NSN too but specialy on the sites where second carrier is activated.
A ticket is opened with NSN Care to address the same.
I will keep you updated.

br
CA

[pmperik]

Possible call re-establishment or mid call codec negotiation Panagiotis

[dtvt2]

Some reasons can cause silent call: lack of Neighbor, high Ul load, External Interference , cant do HO between 2 cells
dtvt2

[khurrambilal01]

Normally it's because of high RTWP and bad RSCP, if RTWP is -90/-85 and RSCP is weaker than -95dBm then silent call will happen.

[Ryurikovich]

Many thanks. I will waiting for news about the opened ticket.

In our case most likely reason is the lack of the proper neighbor on the second carier.

[ChristopherAlbertini]

Many thanks. I will waiting for news about the opened ticket.

In our case most likely reason is the lack of the proper neighbor on the second carier.

Can you please share the second carrier implementation done in your network?

[ranflinho]

What is the value of T313 in the problematic cells?

[fenixchoo]

Any news from the CARE? I have the similar problem with NSN too.


We are currently facing the same issue with NSN too but specialy on the sites where second carrier is activated.
A ticket is opened with NSN Care to address the same.
I will keep you updated.

br
CA

[diman]

In some case silent call caused by unstable transport.
Check TWAMP measurement (need license) to check transport performance.

[tanz]

Some time a pause could be due to loss of L1 Synch (check N313 and T313). For 4-5 silence, check the values for T314 (default 2sec) and T314 Offset Parameter (PR File : 4 sec). During T314+T314_Offset (2+4=6sec), UEs try to do Cell Update with cause of RL Sync Failure or other causes. From user perspective, this is mute and no sound could be heard from 6 sec.
If RL cannot be restored and Cell Update is unsuccessful, UE move to FACH and call drop counters are updated.

[eritelecom]

sure it is from T314 where synchronisation is lost but the RL still exist, however i didn't undestand from "Tanz" why we need PR File parameter (T314 offset) sinc we can increase the timer T314 (not hard coded) !!!??

[tanz]

I believe RL is teared down when T314 is started. L1 Sync is lost as soon as T313 + N313*Reporting Period timer expires.
T314 PR File (NSN Solution) is RNC side parameter setting. I, myself, not sure about why NSN implemented this as T314 + PR File Offset. But that is the case. Both values can be changed in NSN

[g.kashi@yahoo.com]

Many thanks. I will waiting for news about the opened ticket.

In our case most likely reason is the lack of the proper neighbor on the second carier.

[Ryurikovich]

We have added neighbors on the second carriers. Now we faced silence very seldom. How to find problem cells from statistics? May be reestablishment statistic? Wich KPI can show the problem?

[yassanino]

a faultu ystem module , we faced it replace a new one and problem was solved , other wise can be a bad definition of neighboring interference a trancature in neighbor ( SIB11 bis) or could be also a bad ISHO between 2G and 3G if you are separating the services
BR

[william.dg08]

Hi , check the timers for RRC Re-establishment for RT (T314) y for NRT (T315). Besides identify in Layer 3 with some DT tool like TEMS/NEMO which is the error (Radio Link Failure or Cell update Error) and the scenery (Multirab or Single RAB call). And with these inputs try to reduce the timers and see the impact, Besides the T313 should be 2 or 3 sec.

W/

If this is useful for you Please dont forget ADD REPUTATION..... !!!!! Thanksss!!!

[emgrande]

Hi,

Default value for timmers is:

T314 - 4 Sec.
T315 - 10 Sec.

BR,
Pires

[nunotechno2903]

Please check bw of transport, and statistic of twamp...

[BENRHOUMASALEM]

You find a solution for this problem ?
BR,