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Viewing 11 posts - 1 through 11 (of 11 total)
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  • #36450

    Hi all,

    I have a big problem of SDCCH drop, what is the solution to reduce these drops?




    I understand its an irritating thing that can happen in a network !.

    We have to analyse the problem in three angles.

    1. Hardware, where a specific cell is involved.
    2. Software, did you find any process being overloaded in your BSC whenever this problem happens ?
    3. RF, Did RF guys do any changes recently.

    Give me some more background so that I can help you.


    I know you must be irritated much by this as SDCCH Drop do affect the Call Success.
    1) You must check the performance of your TREs. Most SDCCH Drop in the Network could be experienced on particulr TREs and especially when there is low Traffic i.e during the night. A work-arround is to Prioritise your TREs so that when there is Low Traffic, the TRE with the BCCH is opted for call handling.
    2) If this fails, then you can delete and recreate the TREs of the cells affected

    Belal Khosravi

    i have two question PLZ
    1- what is the reason off high SDCCH drop in the network and special cells
    2- reason of high TCH assign fail.
    3- diffrence between SDCCH drop & SDCCH BLK & SDCCH Cong.


    To find out if SD drop is on a particular TRX, check the average time for SD transactions for all the TRX of the cell. Is is ususally higher for TRX having hardware problesm that generate SD drops.

    Shakeeb Azazi

    I have a big problem of CHO_DL_quality_rate > 50%, what is the solution to reduce these indecators?


    I am experiencing SD drops in one cell.Can anybody tell me how to rectify this.
    Huawei equipemnt used.

    Ali NSN

    Hi Every Body,

    SD drop are cosed either by:
    1)hardware problems
    2)coverage & interference problems
    for the first case try to resolve your HW problem, check your alarm and try to restart your TRX. check quality of each TRX and try to have SD TS over the best ones. also we should have one SD TS over your BCCH at least.
    2) for the second case try analyze your HO causes & TA & TRX Qual if interference is found try change frequenceies. otherwise check your parameter try reduce your cell edge (RxLevAccessMin high value), increase your BS Transmission power and finaly try increase your T200 timer to give your cell sufficient time to wait for the ack before retransmission check.


    no combination on SDCCH TS.
    one trx that has 2 SDCCH is better than one SDCCH for every trx.
    Also check 2 sdcch feeder and bcch feeder are seperated.nice network…


    If vendor is Huawei just change timer T200(SDCCH 5ms) from 60 (default value) to 120. It will help. You can also put more value, e.g. 180.


    Set “TRP=0″(TRX priority in TCH allocation=NO priority)

Viewing 11 posts - 1 through 11 (of 11 total)
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