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TBF Establishment Failure Rate :

Viewing 15 posts - 1 through 15 (of 25 total)
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  • #67106 Reply
    alonewolves
    Guest

    TBF_ESTABLISMENT_FAILURE_RATE =
    ( DL_TBF_Establishment_Failed
    + DL_EGPRS_TBF_REL_DUE_NO_RESP
    + UL_TBF_Establishment_Failed
    + UL_EGPRS_TBF_REL_DUE_NO_RESP)/
    (Nbr_Of_DL_TBF + Nbr_Of_UL_TBF)

    here the definition of the Counters :

    DL_TBF_Establishment_Failed:
    Description: The number of downlink TBF establishments that have failed due to no response from MS
    When the TBF establishment is aborted due to no response from MS.

    UL_TBF_Establishment_Failed:
    Description: The number of uplink TBF establishments that have failed due to no response from MS.
    When the TBF establishment is aborted due to no response from MS.

    DL_EGPRS_TBF_REL_DUE_NO_RESP:
    Description: The number of downlink EGPRS TBF establishments that have failed due to no response from MS.
    When the EGPRS TBF establishment is aborted due to no response from MS.

    UL_EGPRS_TBF_REL_DUE_NO_RESP:
    Description: The number of uplink EGPRS TBF establishments that have failed due to no response from MS.
    When the EGPRS TBF establishment is aborted due to no response from MS.

    My question is simple : What is the reason or event that MS does not response in above cases,

    i have check the sectors that have high TBF_ESTABLISMENT_FAILURE_RATE don’t provide GPRS/EDGE services to MSs under its coverage,

    so i reviewed sector configuration and corrected configuration errors , then finally gprs/edge services started.

    Although Faulty thing was in sector, not in mobiles, so what does it mean “no response from MS.”

    i hope my question is clear,

    i will be greatful if you have opportunity to answer my question,

    Regards

    #67107 Reply
    pix
    Guest

    hi alonewolves,

    With which vendor are you working with?
    The info you need is the TRIGGER of those counters, not their literal definition (which is often misleading). In other words, to which message is pegged this counter? Or to which timer expiry?

    Once you know that, you will know your answer ๐Ÿ™‚ Sorry I cannot help more, but as I said, it is very vendor dependent (if it is ALU, then I will be able to help)

    Regards
    pix

    #67108 Reply
    alonewolves
    Guest

    Hi Pix, thanks for replay,

    Vendor is Nokia, 2G Network.
    i will look at the those triggers,

    Regards..

    #67109 Reply
    ouchfa
    Guest

    hi alonewolves hi pix,

    i’m working with Nokia, and I have the same problem, i’m looking for the reason but no thing for the moment, if there is one who can help us so thanks to enrich ๐Ÿ™‚

    #67110 Reply
    Agha
    Guest

    Hi All,
    For TBF Estab. failure, chk the below points::
    1)Failure due to Insufficient channel
    2)Failure due to MS no response
    3)Max PDCH on DSP is not exceeded, confirm for ur GTAC.
    4)Check the ports of Abis and DSP boards if it’s mismatch, it’ll also cause to failure.
    If all RF condition is correct, u check the above points and let me know.

    #67111 Reply
    Agha
    Guest

    Also check Transmission performance KPI’s(TRAU Error Rate).

    #67112 Reply
    ouchfa
    Guest

    hi Agha, thanks for your reply ๐Ÿ™‚
    I have already deactivate PC, and changed INIT_GMSK_MCS and INIT_8PSK_MCS to MCS1, but no improvment.
    I was thinking to increase T3168 to give more time for users in UL (What do you say?)
    ok I’ll check points listed in your coment.
    Thanks

    #67113 Reply
    pix
    Guest

    hi Ouchfa,

    Are you having failure due to No Response, or something else ?

    Could you give an exemple of the TBF failure %, hourly, over 24hours ? (the % , but also, the numerator + denominator of the formula)

    Please post the UL failure % and the DL failure % separately.

    Radio failures should normally be caused by interference :
    – try allocating your PDCH on another TRX than the one it is currently using. (the idea is to swap TCH and PDCH, so you can check TCH quality where there were previously the PDCH.)
    – ensure your UL GPRS Power Control is disabled. (look for gamma and alpha values) – (Edit : you said you did disable it already.)
    – ensure your rx access min is not set too low
    – ensure your path balance is … balanced ๐Ÿ™‚

    Regards
    pix

    #67114 Reply
    KP
    Guest

    Is the TBF failure ratio is increased after enabling the BB hopping?

    #67115 Reply
    ouchfa
    Guest

    Hi Pix, Thanks for reply;

    Number of Attempts:
    TBFEstAttUL = NUACATCL[1..3]
    TBFEstAttDL = NUACATCL[4..6]

    Number of estab_Failure:
    TBFEstFailNoReactUL = SUCPDASA [1..4] – SULACCEL[1..4]
    TBFEstFailNoReacDL = SUCPDASA [5..7] – SULACCEL[5..7]

    Number of estab_Success:
    TBFEstSuccUL = SULACCEL[1..4]
    TBFEstSuccDL = SULACCEL[5..7]

    UL_TBF_Succ_Rate=TBFEstSuccUL/TBFEstAttUL

    Problem: high difference between SUCPDASA & SULACCEL which increase Fail due to no reaction from MS.
    Where:
    SUCPDASA:Number of successful PDCH assignments
    (uplink/downlink) per cell
    SULACCEL:Number of successful PDCH seizures (uplink/downlink)per cell

    UL_Succ_Rate < 60% till 20% DL_Succ_Rate >=85%

    No interferance is detected and Fail due to no reaction remains all the time.

    Rx_Access_min = 6 -> -105 dB
    (Alpha,Gam) = (0,0)
    Init_MCS = MCS1

    I changed T3168 from 1s to 2s, (waiting for remark after 2 or 3 days)

    Thanks/ Best Regards

    #67116 Reply
    ouchfa
    Guest

    hi KP;

    No BB hopping, just one TRX is dedicated for EDGE (SW installed) so no BB hopping for the concerned EDGE users.

    Best Regards

    #67117 Reply
    ouchfa
    Guest

    no respnse from MS caused by:
    – Invalid assignment (no valid RLC/MAC block)
    – cell change or radio failure
    – timer expiry befor MS response

    And exist other reasans which i’m working to find it

    Best Regards

    #67118 Reply
    pix
    Guest

    – try allocating your PDCH on another TRX than the one it is currently using. (the idea is to swap TCH and PDCH, so you can check TCH quality where there were previously the PDCH.)

    #67119 Reply
    Agha
    Guest

    Hi ouchfa,
    Please share analysis/results..

    #67120 Reply
    KP
    Guest

    Hi,

    Please check the IMM ASS message and verify whether correct information was sent to the MS.

    Check the Radio condition

    Regards,
    KP

Viewing 15 posts - 1 through 15 (of 25 total)
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