[Ali]

Hi every body,
I’m facing a big problem. my cell contain the Common BCCH. The Call Setup Success Rate (CSSR) is bad. when trying to see which composant is impacting the CSSR i find that there are a lot off TCH Fail in the 1800 band. does any one have an idea about what can be the cause. there is no problem on the SDCCH which is only in the 900 band.

[Suy]

Chek if yor 1800 TRX are note in faulty

[Ali]

I’ve checked alarms and trx quality for 1800 band it shows no problem, i think that there is a problem in the 1800 TCH activation. Please if you know any parameters that can influence or impact this I’ll be pleased to know it. Below some question that I couldn’t answer:
Could the AMR impact the TCH Fail on the 1800 Band, there exist any specific parameters to adjust when using AMR and 1800 (AMR is activated on the BSC)?

[Pix]

What is the cause of TCH assign unsuccess ? Radio or Congestion or BSS or BSS Preparation ?

Are you working with Alcatel system (it looks like it) ? In which release ?
Since B9, there is an improvement of the call setup in the concentric cells.

Also, are you sure your parameters are well defined ?
RXLEV UL & DL ZONE = ?
ZONE HYST UL & DL = ?

Do you suspect interference of inner zone ?

[Ali]

Hi Pix,
thx for replying. i’m not working on Alcatel system but Nokia ones. can you give me some details about the parameters you have mentioned on your last mail in order to see which are the parameters for Nokia equipment.
thx in advance.

[des]

U try to change “TRX priority” for that cell , TRX ( have BCCH ) level 0 , TRX traffic level 2 . If it exist , u change TRX (have BCCH) level 2 , and TRX traffic level 0 . Level “0” is highest level

[Author]

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