Taking 1 BSC – SDCCH Drops are 1800 approx in Busy Hour for all the days, Traffic for this BSC in Busy Hr is 1400 Erl approx.
1.Yes the Problem is not related to all the cells, But 20-40 % of cells of all the BSC have this Problem, Though if compare with ZTE the problem is there with only 2-3% cells.
2.Drops are Increasing when Traffic is Increasing, Highest in the Busy Hour i.e 19th Hour.
Drops Start getting Double from 300 Drops to 600 & Increase so on from 7:00 AM till 22:00 Hrs in night.
3.Mean Holding Time i.e(SDCCH_occy_total / SDCCH_allocated) from NPO is 4.1 to 4.2 every day in Busy Hour.
4.Also, SDCCH Is mainly Configured on BCCH TRX, But will check for few cases & if configured on TCH, will shift & check the case.
5.Checked with many cells, SD Assignment & TCH Assignment are good for these Poor SD Drop cases, Even TCH Cong is not there.
6.We are Using Adhoc Freq Plan, Based on Optimized Frequency Plan generated from Measurements.. No degradation Observed because of this.
7.I am not able to get the SDCCH Drops due to Location Update failures, Can you help me with counters/indicators.(Also I learned somewhere that LOC Updates does not happen on SDCCH in Dedicated Mode) so how it will Impact in SDCCH Drops.
8.These are the drops, Happening due to radio Link Timeout or Lapdm timer expiry, So as Immediate remedy , Are there any Timer or parameter which can be increased to resolve this slightly.