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3G Fast Reselection ALU feature

Viewing 8 posts - 1 through 8 (of 8 total)
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  • #69294 Reply
    Vitalie
    Guest

    Hi all,

    After activating 3G fast reselection 2G Location Update traffic have increased.
    Location Update traffic must decrease because the phone selects 3G network without LAU / RAU when the call ends in 2G.
    Also, the RRC establishment number of attempts (IRAT and registration) increased for the area where the feature was activated
    2G ALU
    3G Huawei

    Wait for your feedback
    Vitalie

    #69295 Reply
    pix
    Guest

    Hi Vitalie,

    Looks like your network is not behaving like you’d expect ! The kpi indicates that something is wrong. Doing a rollback brought you back the pre-trial performances?

    I don’t know what is the status of this feature today, but in the past some phones were having issues.
    Could you do a drivetest and check :
    1/ fast reselection info are correct
    2/ the phone connects to the right 3G LAC at the end of the call.

    Regards
    pix

    #69296 Reply
    Vitalie
    Guest

    Hi Pix,

    In the trial area, 2G and 3G is covered by different MSCs.
    I’ve checked the performance on core side for 2G LAC and I saw the LAU increase with the cause inter-VLR.
    Before activation of 3G Fast Reselection, we did the drive tests and the phone was camping to 3G LAC as it should.
    The channel release message received from BSC contains the FDD_ARFCN list that UE have to camp. Could be a issue for some Phones the quantity of
    FDD_ARFCNs that contains channel release message from BSC?
    What will happen at the end of the call if there is no 3G coverage ?

    Regards
    Vitalie

    #69297 Reply
    pix
    Guest

    hi,

    – “The channel release message received from BSC contains the FDD_ARFCN list that UE have to camp. Could be a issue for some Phones the quantity of
    FDD_ARFCNs that contains channel release message from BSC?”

    The Channel Release should contain more info than only the FDD ARFCN, such as the LAC, doesn’t it ?
    What is strange is that WITHOUT fast reslection, the MS will do the location update in 2G, and then it will do another in 3G, after doing a 2G to 3G reselection.
    The FAST reselection pushes the MS back to the 3G right after the call is released, and before it could do the 2G LAU. If the Fast reselection doesn’t work, it makes no sense that you should see MORE 2G LAU than before. You should only see the SAME amount. How weird !

    By the way, you are saying that you provide several FDD ARFCN to the MS. Usually one FDD ARFCN is enough : just send the MS to the “first” FDD in 3G. No need to provide several options.

    “What will happen at the end of the call if there is no 3G coverage ?

    The MS should do a normal reselection.

    which vendor are you using ? Could you share some info about the way this Fast Reselection is implemented ?
    There might be some constraints such as :
    1/ Ensure that your 2G cells have 3G neighbours defined
    2/ Ensure the Ms performs 3G measurements during the call
    etc.

    Regards
    pix

    #69298 Reply
    Vitalie
    Guest

    Hi Pix,

    Our 2G vendor is ALU and currently we are in B11.
    We implemented the fast reselection without any defined 3G neighbor and thus it doesn’t perform 3G measurement.
    I will repeat the drive test with 3G neighbor defined to see the differences in phone behavior and the contents of IEs in Channel Release.

    Regards
    Vitalie

    #69299 Reply
    pix
    Guest

    Ok, that sounds like a plan.
    Since it is ALU, i have several documents available, i’ll have a look soon.

    It is true that some phones (mainly : iphone 3 and earlier, I believe, maybe 4) do not support fast reselection because they cannot decode the 3G info in the Call Release properly .

    #69300 Reply
    Vitalie
    Guest

    Hi Pix,

    Problem almost has disappeared after removing 2 UARFCN from BSC FDD_UARFCN list. It seems thas some mobile devices support only one frequency.

    #69301 Reply
    pix
    Guest

    hi vitalie,

    ok, that’s good to know 🙂
    btw i did put my finger on it, didn’t i ?

    regards

    pix

Viewing 8 posts - 1 through 8 (of 8 total)
Reply To: 3G Fast Reselection ALU feature
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