Failures after admission

[tsiz]

Hi All,

I wanted to know if you all can share some experiences to lower or fix failures after admission.

Sites have good T1 capacity and aal2 and VC's are dimensioned correctly. No aal2 congestion is observed but still very high failures after admission.

This is with E/// equipment.

Let me know if you have any suggestions!

[mulham_kh]

Hi All,

I wanted to know if you all can share some experiences to lower or fix failures after admission.

Sites have good T1 capacity and aal2 and VC's are dimensioned correctly. No aal2 congestion is observed but still very high failures after admission.

This is with E/// equipment.

Let me know if you have any suggestions!

Hi
I got the same problem but it was due to lack in Transmission resource
Regards

[tsiz]

Hi
I got the same problem but it was due to lack in Transmission resource
Regards

Yeah Mulham...mine has good resources but still I see a lot of failures after admissions.

[mulham_kh]

Yeah Mulham...mine has good resources but still I see a lot of failures after admissions.

If this problem is common for all sites maybe you have a problem with the bandwidth which it is dedicated between the RNC and SGSN
Regards

[salamanda1969]

Hi,

You may want to describe what kind of failures you are seeing. For e.g. call setup failures (call ended without announcement), call going straight to voicemail, congestion (from performance stats) or RAB setup failures.

[tsiz]

Hi,

You may want to describe what kind of failures you are seeing. For e.g. call setup failures (call ended without announcement), call going straight to voicemail, congestion (from performance stats) or RAB setup failures.

The failures I have is pegged with the incrementation of pmnoFailedafterAdm. The voice access fails are very high. retainability is pretty decent.

[zhanglw268]

Hi Tsiz,

pmnoFailedafterAdm can be pegged for SRB and RAB establishment, you can check certain stats to see whether it is related to SRB or RAB only, or they are mixed.
(1) RAB setup success rate check:
pmNoRabEstablishSuccess/pmNoRabEstablishAttempt, if they are nearly 100%, you can exclude RAB issue, then focus on the SRB stage
(2) SRB setup success rate check
If the pmnoFailedafterAdm happened at the SRB stage, the RRC success rate will be low, you can compare pmnoFailedafterAdm with
[pmTotNoRrcConnectReq - pmTotNoRrcConnectReqSuc - pmTotUtranRejRrcConnReq], if they're almost equal, then it is SRB.
(3). If both stages are involved, then (1) and (2) will not be true

The main check points shall be AAL2 setup and the procedure for NBAP "Radio Link setup" and "Radio link Reconfig".

Hope the above helps.

Regards

David

[edy.djunaedi]

Hi All,

I wanted to know if you all can share some experiences to lower or fix failures after admission.

Sites have good T1 capacity and aal2 and VC's are dimensioned correctly. No aal2 congestion is observed but still very high failures after admission.

This is with E/// equipment.

Let me know if you have any suggestions!

HI,

admission control is related to resource reservation..
resource on 3G is :
1. CE
2. Transport.
3. Power

so if you you didn't find the problem on transport, also check the CE utilization, check the power allocation..
and capability node B or RNC to guarantee the service like ; min or max bitrate related to parameter setting and required service bit rate.

you can find it by counter measuremet..

on procedure after pass the admission control by rnc it should be check the availability transport and then Node B (CE)

if there congest due to CE then propose to Upgrade CE or decrease max bitrate UL PS
if there overload due to power then adjust Ptx target and ptx Offset, Prx target and prx Offset.

CMIIW

BR//

[tsiz]

Hi Tsiz,

pmnoFailedafterAdm can be pegged for SRB and RAB establishment, you can check certain stats to see whether it is related to SRB or RAB only, or they are mixed.
(1) RAB setup success rate check:
pmNoRabEstablishSuccess/pmNoRabEstablishAttempt, if they are nearly 100%, you can exclude RAB issue, then focus on the SRB stage
(2) SRB setup success rate check
If the pmnoFailedafterAdm happened at the SRB stage, the RRC success rate will be low, you can compare pmnoFailedafterAdm with
[pmTotNoRrcConnectReq - pmTotNoRrcConnectReqSuc - pmTotUtranRejRrcConnReq], if they're almost equal, then it is SRB.
(3). If both stages are involved, then (1) and (2) will not be true

The main check points shall be AAL2 setup and the procedure for NBAP "Radio Link setup" and "Radio link Reconfig".

Hope the above helps.

Regards

David

Thanks David. For one ROP, I had the following values
pmTotNoRrcConnectReq-1250
pmTotNoRrcConnectReqSuc-615
pmTotUtranRejRrcConnReq-0
pmnoFailedafterAdm-28

So there is a big difference here. My CSSR and the CS RRC% are very low and the RAB% is very good.

[tsiz]

HI,

admission control is related to resource reservation..
resource on 3G is :
1. CE
2. Transport.
3. Power

so if you you didn't find the problem on transport, also check the CE utilization, check the power allocation..
and capability node B or RNC to guarantee the service like ; min or max bitrate related to parameter setting and required service bit rate.

you can find it by counter measuremet..

on procedure after pass the admission control by rnc it should be check the availability transport and then Node B (CE)

if there congest due to CE then propose to Upgrade CE or decrease max bitrate UL PS
if there overload due to power then adjust Ptx target and ptx Offset, Prx target and prx Offset.

CMIIW

BR//

Thanks Edy,

How do I calculate the UL CE utilization for the site? I tried pmapomcofullinkcap_avg but its not giving me in rnc or node b level.

The UE CE usage is 4829 with 3 sector and 3 carriers sharing 7 RaxB. Also where do I find the parameters Ptx target and ptx Offset, Prx target and prx Offset?

Thanks.