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SD question

Viewing 6 posts - 1 through 6 (of 6 total)
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  • #68531

    Hello friends,

    After i disabled power control just on uplink, sd drop rate and sd establishment rate are improved. Any idea or any logical answer on that issue?

    Thanks in advance


    what about TCH establishment/Drop rate before disabling UL PC?its on one or more cells and cell morphology? ur N/W frequency plan?and is it define on overlaid?


    There is no change for TCH establisment and TCH drop rate.

    UL PC disabled in BSC. Adhoc frequency plan. BCCH and TCH frequency layers are seperated.

    P.S. We have no SD channel on hopping TRxs.(Just on BCCH TRx) As you know BCCH TRx is using full power anyway.

    Also i checked that there is any worst cell improved on same time so i see an improvement on SD part but there is no such case.


    hi gsm,

    the DL PC on BCCH timeslots is never active, but UL PC is active (if enabled).
    Power Control is not active during the SDCCH estab phase, and usually not active during the SDCCH phase neither.
    So disabling the UL PC cannot improve the SDCCH establishment (it just can’t), and it may slightly affect the SD Drop (but i doubt it). What you are seeing is very strange…

    If you see an improvement, then it has to come from something else. Please share the SD Estab% and SD Drop% values here, try to roll back, and let us see the changes. I need to see it with my very own eyes 😀



    Hello Pix,

    On BCCH Trx we have no active UL and DL PC even if PC enabled, maybe is it vendor dependent?

    Anyway i am totally agree power control is not active during SD establishment, but after established SDCCH, can UL PC affect SD drop? how? am i missing something?
    I will rollback in week.
    Date SD Estab% SD Drop%
    17.08.2012 99.14 0.63
    18.08.2012 98.87 0.74
    19.08.2012 99 0.81
    20.08.2012 98.55 0.83
    21.08.2012 98.98 0.76
    22.08.2012 98.60 0.66
    23.08.2012 98.77 0.72
    UL PC Disabled (evening)
    24.08.2012 98.83 0.9 many sites down related transmission
    25.08.2012 99.06 0.65weekend
    26.08.2012 98.93 0.7 weekend
    27.08.2012 99.17 0.59
    28.08.2012 99.20 0.58
    29.08.2012 98.91 0.62
    30.08.2012 99.07 0.61


    i can see a good effect on SD Drop, but that may be due to the thing you did to fix the transmission problem. You may have reset the BSC, which may enhance the processing of the SDCCH signalling ?

    The enhancement on SDCCH estab succ % is much subtler. Maybe you ought to wait a longer period for this one.

    Anyway, back to the SD Drop.
    During the SDCCH phase, depending on your vendor, the UL PC may kick in especially if the SD phase is long (especially during SMS transmission, which uses SDCCH for a longer time). Indeed, the PC might be deactivated for few seconds, (ALU default : 3 sec.) and then will be started, even if you are still on SDCCH phase.

    Which vendor are you using ?

    On BCCH TRX, there is no reason (that i know of) that the vendor desides to deactivate the UL PC automatically. If you can share some documents about this, that’d be interesting.


Viewing 6 posts - 1 through 6 (of 6 total)
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