- This topic has 8 replies, 1 voice, and was last updated 10 years, 1 month ago by halen_nguyen.
8th October 2009 at 07:29 #59107MKTGuest
What could be the reason for low SDCCH SUCCESS RATE in a cell when the SDCCH DROP & SDCCH BLOCKING are normal.
The cell is of ericsson and the immediate neighbour is Nokia cell.
Inter MSC/BSC handover are checked and are defined.
Where to check?
MKT8th October 2009 at 07:35 #59108MKTGuest
ERICSSON CELL STATS
TCH Availability Rate
TCH Traffic (Erlang)
TCH Drop (%)
TCH Blocking (%)
No. of SDCCHs
SDCCH Call Success Rate
SDCCH Drop (%)
Outgoing HO Success Rate
Incoming HO Success Rate
Call Success Rate
0.018th October 2009 at 07:40 #59109MKTGuest
The problem started to appear one month back when the Ericsson carried out an activity to redefine the LACs in their network.8th October 2009 at 11:12 #59110PixGuest
SDCCH DRop is around 9% !! That’s not what I’d call normal 🙂
What I see is:
High TCH drop
High SDCCH drop
Then, Call success % is excellent and HO success are good too. That proves that the way Ericsson are computing their indicators is very obscure ! (for me, at least)
Could you please state also the average duration of the SDCCH and TCH in the cells ? If it is very short, then that confirms my suspicion…
With such bad QoS I must suspect a hardware failure, or most probably a wrong configuration of the equipments or interfaces. I would investigate if the drops happen on some TRX only, or even on some TS only. I would check also what is the cause of the drops (with indicators, or with drivetest)
If there is a random pattern, then the failure is probably located further up in the core network (Ater ? TC ? A interface ? MSC ???). My instinct is leaning towards A and Ater misconfiguration, or a board failure somewhere.15th October 2009 at 07:59 #59111TukaiGuest
Can you please provide values for the following counters ccalls,cmsestab,ccongs,tassall,tcassall,cndrop,thndrop,tfndrop.
im not convinced with the kpi figures below16th October 2009 at 13:57 #59112Has UKGuest
Its the RACH sent from the mobile, two cells with the same BCCH anser the request. Awaitng response from handset which completes access on closer cell not responding to the futher cell (normally higher ground height). This does not affect KPI’s so can be ignored. Otherwise find the clashing BCCH and perform retune.19th October 2009 at 08:11 #59113MKTGuest
THE L3 MESSAGE DETAIL FOR CALL END
Transaction identifier : 0
Protocol discriminator : (3) Call control; call related SS messages
Message type : 45
Message dump (Hex):
NW initiated release
Call duration: 109094 ms19th October 2009 at 08:12 #59114MKTGuest
NW initiated release
Call duration: 109094 ms18th March 2011 at 01:00 #59115halen_nguyenGuest
how to make a statistic of times number seize SDCCH channel by nemo analyze, expect people to help