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High TCH drop after SFH

Viewing 10 posts - 1 through 10 (of 10 total)
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  • #52884 Reply
    madani
    Guest

    Dears,
    We did fixed oreintation for all cells in the city then we applied SFH 1/1 but TCH drop is increased double.

    The most of drop due to intercell HO.

    How we do overcome for these problems??

    #52885 Reply
    pix
    Guest

    Hello,

    you need to ensure that there is not too much overlap between cells whan appliyng SFH 1/1.
    What is the average number of TRX / cells ?
    What is the number of frequencies you put in your MA list ?
    Did you ensure the HSN was the same within cells of same BTS, and different between cells of different BTS ?
    Did you check your MAIO planning ?

    What is the cause of intercell HO ?

    What do you see during drivetests ?

    Regards,
    Pix

    #52886 Reply
    Madani
    Guest

    Thanks Pix

    we’ve 2 TRX’s per Cell
    MA List= 12
    We’ve the same HSN within the same site
    We’ve Checked the MAIO

    In the drivetests we saw delay in the HO and alot of IntraCell HO

    And in the Stat the major causes for HO due to the uplink and Downlink Quality

    #52887 Reply
    pix
    Guest

    2 TRX / cell ?? the first TRX is BCCH, so it is not hopping. So only the second trx is hopping ?

    strange strategy. BBH would be more useful here.

    could you write down the HSN and MAIO configuration for one BTS ?
    In this BTS, what is the CSSR ?
    what is the CDR ?
    how many HO/call ?
    what percentage of HO Quality ?

    What is the threshold for HO Quality ? It is 4 without hopping, and 5 with hopping, by default.

    #52888 Reply
    Madani
    Guest

    Dear Pix,
    I meant 2TRX hopping so, 3TRX/Cell

    We use Siemens equipment
    Example:
    BTS01A MAIO:0& MAAIO:6, HSN:5
    BTSO1B MAIO:2& MAAIO:8, HSN:5
    BTS01C MAIO:4& MAAIO:10,HSN:5

    CSSR=90%
    CDR=1.5%
    HO/Call= 1.2
    threshold for HO Quality =5
    percentage of HO Quality=15%

    These values are the average

    #52889 Reply
    pix
    Guest

    hi madani,

    thanks for the values.. mmm.

    2 hopping TRX on 12 frequencies, it gives a radio load of 16.6%. This is the theoretical limit of 1×1. At this amount of load, you must expect a poor radio quality.

    On-the-field threshold of radio load is about 12%. At 12% radio load, you can expect same CDR as the one you’ll get with an average BBH frequency planning. At 16.6%, it’ll be quite worse.

    Could you try to unload TRX 2 and TRX 3 by favoring TCH allocation on TRX 1 ? Or lock some TRX’s that are not used.

    Or perhaps just allocate more frequencies in the MA list ? If you can’t, then i strongly recommend you roll back to BBH solution. Or if you want to stick to SFH, you have to make a really aggressive cell design (too time-consuming imo)

    Regards,
    PIx

    #52890 Reply
    GM
    Guest

    Did you try to switch of Intracell handover? What happend than?

    #52891 Reply
    Madani
    Guest

    Dear Pix,

    Thannks for ur attention

    We reverted back to the previous plan.

    and we decided to:
    1- Do aggressive tilt.
    2- MA=18
    And then we’ll applay SFH.

    I’ve another Question

    We alawys receive MCN although we’ve a full coverage!

    Do u know why??

    #52892 Reply
    ORO
    Guest

    how many BCCH, TCH and SDCCH would i require or configure for an s222.thanks

    #52893 Reply
    xxx
    Guest

    confirm whether the call has been dragged without handover even resource available in target cell.
    check out values of hop count and timer.

Viewing 10 posts - 1 through 10 (of 10 total)
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