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PDCH allocation in Alcatel

Viewing 15 posts - 1 through 15 (of 21 total)
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  • #61556 Reply
    Van_Guen
    Guest

    Hi all,
    please tell me, who is responsible in Alcatel BSS system for timeslot allocation for MS for GPRS/EDGE service?
    The problem is that I have divice which use just two timeslots in the time when there are more free timeslots for data service.Is there any parmeters(BSS) that check MS and give him just two timeslots.
    Thank you in advance…

    #61557 Reply
    Pix
    Guest

    Van Guen,

    The MFS is in charge of the PDCH allocation.
    However, it is the BSC that provides “useable” TCH to the MFS, so that the MFS can use them as PDCH.

    Anyway, here are the parameters you should check:

    MAX_PDCH_PER_TBF = 4 or 5
    GPRS_MULTISLOT_CLASS_DEF_VALUE = 8

    Also check out the following :
    MAX_PDCH = “number of TCH in the cell * 80%”
    MAX_PDCH_HIGH_LOAD “number of TCH in the cell * 20%”
    MIN_PDCH = 0 or 1

    But the limitation might be due to congestion on TCH : Check your NPO indicators…
    Is your cell with high TCH load ?

    Cheers,
    pix

    #61558 Reply
    Van_Guen
    Guest

    Hi Pix,
    I check my parameters and the values are:

    MAX_PDCH_PER_TBF =5
    GPRS_MULTISLOT_CLASS_DEF_VALUE = 8
    MAX_PDCH = 6
    MAX_PDCH_HIGH_LOAD=1
    MIN_PDCH = 1

    The cell is not overloaded because when i tested there is no other connected users.just my divice..

    #61559 Reply
    pix
    Guest

    just to try : can you increase the max pdch high load ?

    what kind of transfers are you doing ? DL FTP download ? you must ensure that the transfer you are doing is DL-biased (with much more DL volume than UL volume)

    what is the multislot class of your MS ?

    cheers
    pix

    #61560 Reply
    Van_Guen
    Guest

    Hi Pix, I tried to FTP DL and the troughput in EDGE is 20-50kbps…

    #61561 Reply
    pix
    Guest

    which coding scheme is the MS using ?

    are you certain there are only 2 PDCH allocated ? where did you see that info ?

    multislot class of your MS ?

    #61562 Reply
    Van_Guen
    Guest

    Hi Pix, sorry for my mistake in previous posts …
    The MS use just ONE timeslot when the EDGE is activated(OMC_USD). When there is only GPRS the used timeslots are 4 ???
    The parameter values are :
    TBF_Init_MCS_UL/DL=6; TBF_Init_MCS_UL/DL=3;
    Max_TBF_MCS=9;
    Max_TBF_CS=4;
    I think that the multislot class of the device is 10.

    #61563 Reply
    pix
    Guest

    van guen,

    valuable info, thank you !

    there are no difference between PDCH allocated for GPRS or for EGPRS. It is the same principle, same algorithm. Therefore the problem comes from somewhere ele.
    Your parameters are fine, as far i can see.

    Regards
    pix

    #61564 Reply
    SHELDON
    Guest

    Hi Guen,

    How many EDGE time slots have you activated in the cell? If you’ve defined only one EDGE TS, then don’t expect the MS to use more than one.

    With the GPRS, the system can allocate more TSs if required, but with EDGE, it’s kind of fixed (‘cos you configure a fixed no. of EDGE TSs). Anyway, I use Ericsson, and I’m not sure if it’s the same as ALCATEL, so just check to see how many EDGE TSs you’ve defined in the cell.

    Hope this helps.

    Regards,

    #61565 Reply
    pix
    Guest

    in ALU, we don’t set a fixed number of TS for EDGE, it’s automatic.

    All TS which are GPRS capable are also EGPRS capable (if the “TRX version” supports it)

    no, really, i don’t see what could be the problem, so i’m sure it comes from the MS… or from the tester 🙂

    pix

    #61566 Reply
    AliAsgher
    Guest

    Dear Pix,

    For EDGE you will need 64K slot, so you should have enough resources at transmission for EDGE? Hence number of GPRS and EGPRS TS can be different. Please correct me if I am wrong.

    Regards,

    #61567 Reply
    Prabeen
    Guest

    Hi,

    My doubts are:

    By automatic u mean that it is dynamic? Say, the number of TS changes according to the data utilization? Or, the total number of TS is automatically dedicated at the begining?

    If first case is right, how can u say that u have got vacant EDGE time slot even after ur ms uses only 2 TS?

    #61568 Reply
    Van_Guen
    Guest

    Hi Pix,
    you are right:))May be there is problem in Tester :)))
    The strange is that the MS required just one timeslot in EDGE, and when use GPRS the used timeslots are 4 ???

    #61569 Reply
    pix
    Guest

    van guen,

    i know it is weird 🙂

    just to be sure, can you add some extra timeslots on your Abis ?
    can you increase your min pdch to 4 ?

    cheers,
    pix

    #61570 Reply
    Van_Guen
    Guest

    Hi Pix,
    all tested cell has more then 8 Extra Abis timeslots…

Viewing 15 posts - 1 through 15 (of 21 total)
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