Specific Sites only and they are not boundary cells
Lex - 29th June 2014 (04:33 GMT)
Hi zico are sdcch drop happening on specific sites or at the boundary cells of the plmn.
zico - 26th June 2014 (06:25 GMT)
reason: Number of error indications due to T200 expired on SDCCH(Num)
Also we get trace and we observe ; several times sdcch drop happens when location update happens, while signal level and quality is good. So we also increase resel hsty and even we delete 3g cell re-selection parameter.
There is only one kpi change while sdcch drop problem happens. Meanholding time increases due to comunication(t200)drops creates waiting time until period finishes.
Also there is no sdcch traffic type change.
Also problem not happens 9am-4pm period.
Lex - 25th June 2014 (15:46 GMT)
Hi zico can you elaborate the sdcch drop due to other reason counter.What are included in that counter?
zico - 25th June 2014 (13:07 GMT)
I have sdcch drop reason other problem at ZTE.
accmin, t200 values are ok. Sdcch drop problem started sharply however all other kpis are normal. There is no ta or traffic change at the site.
What can be reason?
sdcch ts change
frequency & bcch & bsic change
resel hysteresis change
re-create NR for 2g-3g
removing 3g cell re-selection
RACH Min.Access Level(dBm) set 10(NW value 6)
site reload from cdd while creating omcb
also below possibilities are checked:
Hardware failure >> no change at other kpis / rsu changed- general hw check done
Transmission >> there is no site level problem
Version upgrade >> no upgrade
Parameter setting >> there is no change and values are default
Intra-network and inter-network interference >> quality & icm values are ok
Poor Coverage >> there is no change at ta & traffic
Imbalance between uplink and downlink >> no change at site