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9th January 2009 at 07:59 #55310BALKYGuest
Is there any body to know, how we can decrease the TBF_Estbl_Congestion rate in UL direction for Siemens_BR9 systems.
During last 5 month a high value of TBFEstCongRateUL and low value of TBFsuccessfulRate is monitored in some of BSC’s…
We were check all parameters related to the GPRS KPI’s, but we can’t find the problem…
In all cells there are configured one or two static PDCH and more than 4 dynamic PDCH.
In more of them there is no high voice and data traffic and this BSC has independent LAC and RAC/RACOL areas.
The Load of PCU is between 60% and 80% and BSC has 2 or 3 PCU’s.
There is cells with high value of TBF blocking rate and the successful rate also is high …
Please give us any idea about this problem.
Thank you in advance !10th January 2009 at 02:49 #55311AterGuest
Im not familiar with Siemens PCU but in other vendors a PCU load of 80% is rather high ( and should be investigated as a possible cause of your problem)
what kind of services do you deliver (wap, ptt, internet)?
For only wap services with that amount of PDCHs (2+4) dedicated to GPRS you shouldnt have problems of TBF establishment but if you deliver ptt services 2 PDCHs + high voice traffic can cause congestion issues ( but this would be an odd situation)
One test that you can make to discard BTS capacity issues is to increase the sharing of PDCHs for different TBFs? if you change this parameter and de blocking decreases you need to add more PDCHs ( this will tend reduce the throughput but works as a test)
Do you have EDGE or CS3 and CS4 in your system? how they perform?13th January 2009 at 08:48 #55312BALKYGuest
thank you for your help..
Yes, we have edge facilities in our systems.The strange is that the high value of TBF Blocking are from BTS’s with very low traffic.