- This topic has 6 replies, 1 voice, and was last updated 6 years ago by pix.
18th February 2014 at 12:41 #69505AtheerGuest
i working with NSN equipment’s flexi BTS. i have new BSC , so during the re homing from exit BSC to New BSC i suffer high SDCCH drop, so all the other events good.
please your supporting & advice how the reason.
Atheer24th February 2014 at 10:46 #69506PritamGuest
Is ciphering enabled or disable at BSC and MSC end for both the cases.11th March 2014 at 12:38 #69507AtheerGuest
hi pix & ALL;
PLEASE HOW I CAN IMPROVE THE SDCCH DROP.
WHAT ABOUT THE T3101,11th March 2014 at 13:37 #69508pixGuest
The T3101 is supervising the paging retransission. I can’t find a correlation between SDR and PSR, but please correct me if i’m wrong.
First thing to do is to find the cause of SDR. Timing Advance ? Bad Quality ? Bad Level ?
Activate the SDCCH HO. Doing so will give you precise counter regarding SDCCH HO CAUSE, which will help you diagnose the main issue.
Put 2 SDCCH on the TRX0 (bcch) only.
Then put 1 SDCCH on the TRX1, and 1 SDCCH on BCCH TS.
Then compare SDR between those two configuration.
If available, check the SDR per TRX.
Check the path imbalance.
Check the VSWR.
Also, the cells may be located at a MSC border ? I’m not familiar with this issue, but if you do a drivetest, you may be able to see things more clearly : call setup can’t go through when the MS has just changed MSC area. (to be verified)
Pix5th April 2014 at 07:39 #69509AhmadGuest
I think changing the value of “T200S” can help you.10th June 2014 at 23:07 #69510RexGuest
we had a case with high sdcch drop in a cell. The hoping type was BBH. We changed to Non Hoping in order to check which TRX is mostly interfered. According to KPIs there is no interference. But, with the Non Hoping activated sdcch drop was decreased and quality improved. Any idea, what could cause the increase of sdcch drop with BBH and improvement (decreasing) of sdcch drop with NH? Changing TRXs didn’t help, vendor is ALU.
Rex13th June 2014 at 05:08 #69511pixGuest
what kind of trx are you using ? The mc trx, or 1 trx per freq ?
with no hopping : check the kpi “tch assignment execution failure%” and the path balance.
could you please share some numerical values of kpis, with and without hopping ?