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Reply To: GSM Nortel SDCCH Failed Assigment Rate

#56762
m@u
Guest

Hi Pix,
Thanks for your answer, but today I found some other things.
I was wrong, the reasons of the SDCCH disconnections were only for the SDCCH drops, but I figure out that the drops didn’t increase, so as you said the SCCP and T200 are the reasons for the drops. (I’ll look on that after solving this problem)

On the other hand I noticed the SDCCH Failed Assigment Rate is calculed by SDCCH Seizures/SDCCH Attempts*100%

Also comparing the counters when the cell was having problems and when it was not, I realized that the counter that measures the Expiration of the T3101 (set at 3 seconds) increased from 1 when it was OK to 707 when it was with problems. For this comparison I only selected one hour (12:00) at mid day.

On the other hand checking the notifications of the Site I found that the following alarm appeared at the BTS (cell) level:

Fault number : (1266) BLOCKAGE OF RADIO CHANNEL(S) IN FREE STATE
radAnoChln : (
transceiverId : 0
channelId : 1
subChanId : 0)
(
transceiverId : 0
channelId : 1
subChanId : 1)
(
transceiverId : 0
channelId : 1
subChanId : 3)
(
transceiverId : 0
channelId : 1
subChanId : 4)

indicating the TRX0 where the BCCH (TS0) and SDCCH/8 (TS1) are defined.
and some subchannels of the SDCCH8.

Reading about this fault, says that the RadioResourseSupervision measures the channels on BUSY and FREE state but do not understand what is the reason yet. I’ll investigate.

If any of you guys have experienced this before please guide me.

BR.