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RXLEV

Viewing 6 posts - 1 through 6 (of 6 total)
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  • 27th October 2011 at 15:30 #67430
    N.Skumar
    Guest

    Dear Pix,

    Actually we checked performance of 2 MS on low RF region. In same area, Two MS having different RXLEV {First MS had RXLEV around -108 dbM to -101 dbM and second MS had RXLEV around -105 dbM to -93 dbM }. We tried to make consecutive MO call attempts from those MS at the same time. Most of the times, First MS couldnt able to get channel(Immediate Assignment). Success ratio of call maturing is very less. But at the same time all of the second MS attempts was successful because of good RXLEV.

    This is what my analysis on that Issue. As a RR engineer I could say MS cant get Immediate assignment. So it cant able to connect the call. What is the reason for first MS having low RXLEV. As my knowledge it is concern about L1 layer(RF). I want to get some knowledge about L1 side also. How could find the problem from the L1 traces(logs). What is the thing I need to know bcoz of this L1 problem, it couldn’t perform well.

    Please give me brief explanation on that. Waiting for your valuable Reply.

    Thanks..,

    27th October 2011 at 15:37 #67431
    N.Skumar
    Guest

    Because of poor RXLEV, first MS didn’t able get dedicated channel.

    Actually In those we made like “In low RXLEV (> -110 dbM), MS can try to attempt for call”. So In low RXLEV also, it sent RACH attempt.

    28th October 2011 at 14:33 #67432
    pix
    Guest

    hi skumar,

    the MS1 has poor FR sensitivity, while MS2 has a better one.

    There is nothing you can do except trying to increase coverage in those areas, so that both MS gets a RXLEV > -100dBm.

    Second thing you can try is ensure that there is NO other cell using the serving cell’s frequencies (BCCH and TCH) in the surrounding area. Even the smallest noise would greatly penalize Call success at such low rxlev. The conditions have to be the best possible –> No Noise At All.

    To increase the RF level at cell border, you have to work at physical level.
    1/ activate

    – antenna hopping (new feature?)

    – or at least frequency hopping (SFH) -> this will benefit only for the TCH channels, not the BCCH (basically the TRX1 is not hopping, so TCH on TRX1 won’t enjoy the SFH neither)

    2/ ensure the cell is transmitting at maximum power.

    3/ increase cell tx power by using
    – better antenna feeders (less loss)
    – more powerful antenna
    – then, check antenna orientation and downtilt (on the field!)
    – if available use special TRX to increase coverage : high power TRX, or TRX with TX antenna.

    I don’t have other ideas…

    regards
    pix

    2nd November 2011 at 02:45 #67433
    N.Skumar
    Guest

    Then from my side as a RR engineer, i have nothing to do on that except ensuring the TXPWR(max).

    I have two other questions

    -> And what will happen if we increase TXPWR beyond some level.

    -> Can you tell briefly about the TRP/TIP

    And Let me know if you know any website to know about telecomm(2G/3G/4G protocol stack) opening.

    7th November 2011 at 12:55 #67434
    amit
    Guest

    Pix will u send ur mail id

    10th November 2011 at 16:19 #67435
    N.Skumar
    Guest

    I really need answer for my other question that i have asked.. Thank you

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