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Hi Every one,
can you please tell me what is the main cause of call Drop on SD channel.
There is No congestion, No BSIC & BCCH Clash, No path Imbalance and HW issue.
Where this drop lie in SD Drop or TCH Drop.
How we can rectifies this drop.
Vendor Huawei.Hi Johny,
1. Are there both SD drop and TCH drop in the same time?
2. Are TCH drops occurring in the same TRX where SDCCH is declared or SDCCH drops in one TRX and TCH drops in another? If in the same TRX then the issue is that TRX.
3. Now, what is the cause? Radio, BSS, TC drops?
4. What is interference on Idle timeslots, what is percentage of UpLink quality HO (this is to ensure you might have interference in uplink)?Regards,
RexThaks rex,
we are using this formula for TCR
is that we including Call Drop on SD Channel in this formulaTCR Formulae :
100-ZTR304A: CELL_RATE_TCH_CALL_DROP_EXCLUDE_HO
ZTR304A = CM33/(K3013A+CH323+CH343-CH313-CH333)rex
only SD drop due to poor level & Quality in uplink.I think for TCR,
SD channel should not comes in picture but durring immediate assignment it may comes.
please share yours view.Problem indication:drop due to bad quality
. Interference-co-or adjacent interference
solution:
downtilt interferer cell or cellsProblem indication-Drop due to other reason
since there is no urgent conations but the call is dropped its hard to find the reason
. Generally drops due to other reason indicate a non RF problemsolution
.transmission problems
.dTRU or dRU hardware problem
.wrong definition of call in MSC BSC
.Wrong LAC definition in MSCthks Josue
I am getting immediate assignment failure in network also on SDCH and TCH both. but for different cells and different Trx.
The counters are
1. R4400A:Attempted Immediate Assignments (SDCCH)(times)2.R4400B:Successful Immediate Assignments (SDCCH)(times)
3.R4409A:Attempted Immediate Assignments (TCH)(times)
4.R4409B:Attempted Immediate Assignment Prodedures (TCH)(times)
can any bobyI am getting immediate assignment failure also on SDCH and TCH both. but for different cells and different Trx.
Can any body tell which KPI leads to stepped UP or Down for Immediate assignment failure
Hi Johny,
Try to make Drive Test measurement in the areas covering from those cells in order to be sure about interference. Check RxQual, FER etc. In layer 3 messages check for reasons of call drop.
Regards,thaks rex
But Which KPI effected if we are getting immediate assignment failure?whats the couter for?
Any one!!!
Help Mehardware problem can be, congestion might, interference is also possible, if site is covering large area change rxlevaccessmin or tilt milt…
Hi Johny,
KPI affected by immediate assignment failure is SDCCH success rate. Check threads regarding immediate assignment failure, for example thread=4091 or do search by topics you are interested.
Regards,
RexHigh utilization (above 60%) increased the call drop possibilities. AMR/FR tuned to 55%?
