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2G to 3G cell reselection issue

Viewing 8 posts - 1 through 8 (of 8 total)
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  • #68732
    Bocoum
    Guest

    If the UE loses 3G network for 2G, it never comes back to 3G even with very good radio conditions. Mainly imapcted devices are : Blackberry, iphone4 and Huawei dongles. The reselection worked before with the same devices. Traces show that le UE does not measure the 3G frequency at all. the problem is not general on the network but affects some area. Please for ideas. (Alcatel BTS, BSC, NodeB and RNC)

    #68733
    Bocoum
    Guest

    Any idea from anyone ?

    #68734
    GUINDO
    Guest

    NO, sorry my friend !

    #68735
    pix
    Guest

    hi,

    Not much ideas on my side neither…

    “The reselection worked before…”

    Before what ?

    Regards,
    pix

    #68736
    Gurbinder
    Guest

    Pix

    I think he means earlier….
    Bocoum: Please have a trace of the impacted No.s and check at SGSN end. We faced similar problem in our network

    #68737
    pix
    Guest

    before = earlier, i got that… but if something has changed between “before” and “now”, it means there is a cause. Since the MS is the only one deciding to come back from 2G to 3G, based on 2G parameters provided by the 2G network, then:
    1- either your 2G parameters are wrong
    2- or, the 2G system is not sending those parameters properly
    3- or, the MS are not interpreting the parameters properly

    There is counter in the 3G network that is counting how many 2G to 3G reselections are done within a specific period of time. You could see how it evolved over time ?

    If you upgraded your 2G network, ensure that the way FDD and Scrambling codes to be measured are well defined after the upgrade.

    1/ Which ALU release are you using ?

    2/ Collect your 2G to 3G reselection attempts and successes counters (from 3G network, not 2G), and compare those amouns before vs after

    3/ Check this 2G3G reselection success rate (attempt / succes) between before and after.

    If succes rate degrades, then the core network might be involved (refusing to give access to some specific MS)

    Cheers

    #68738
    Bocoum
    Guest

    Hello Pix
    Thank you for your reply.
    About your questions, here are some answers:
    1/ Which ALU release are you using ?
    We have UA6 release

    2/ Collect your 2G to 3G reselection attempts and successes counters (from 3G network, not 2G), and compare those amouns before vs after
    By doing the comparaison, I can see that there is a decrease of both attempts and succes.

    3/ Check this 2G3G reselection success rate (attempt / succes) between before and after.
    The success rate is stable (no significative change).

    We did an upgrade of Huawei UMG from core network side and just after the reselection issue occurs.

    #68739
    e39
    Guest

    Hi,

    Can someone post what values are you using for cell re-selections between 2G/3G, so we can compare it with ours.

    thnx

Viewing 8 posts - 1 through 8 (of 8 total)
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