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Piscean21
2015-04-26, 11:37 PM
Dear Experts,

Can we have SDCCH drops due to HW issue on OL TRXs?

We have a case where SDCCH drops is high due to other reasons. All SDCCHs are defined on UL and UL is the prioirty layer for assignment.

Utilization is normal. Once we block 1800 TRXs SDCCH drops become normal. Technically speaking what can be reason for this as OL doesn't carry any SDCCH?

Ghost78
2015-04-27, 02:47 AM
Hi;

I think it's either faulty 1800 HW or syncronisation problem between UL and OL. check the syncronisation between the two subcells, and if UL is defined as a master and OL as a slave.

Best Regards.

Piscean21
2015-04-27, 06:27 AM
Dear Ghost78,
Thanks for your valuable input. Can you please shed more light on it as I am confused that SDCCH can only be dropped before assignment so how come OL(with no SDCCH) is related to immediate assignment parrt?

Mr.David
2015-04-28, 02:01 PM
Otherwise you can check the priority of CS in LAST(Tch) or FIRST (Bcch)

Ghost78
2015-04-28, 04:56 PM
Dear Piscean21 (http://www.finetopix.com/member.php?20760-Piscean21);

there is no problem if you have SDCCH only in UL, TCH assignment is done accroding to many strategies, you can prioritize to assginge on UL or OL and for signalling you use SDCCH channel configured in UL TRXs, this is not an issue, but if you have a drop in SDCCH due to OL, it means, either that OL ressources can not handle the call "congestion or faulty HW" or there is no synch between UL and OL, this is what I think, If there is something else, we can wait for an expert to explain more.

Best Regards.

khurrambilal01
2015-04-28, 10:32 PM
Dear Mudi,
When you are going for a handover from SDCCH to TCH (any layer), if the call drops during this phase then it is pegged in SDCCH drops.
For your specific case, OL has some hardware issues due to which it drops the incoming handover call from UL SDCCH, thus increasing your SDCCH drops.