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SDCCH Mean Holding Time

Viewing 14 posts - 16 through 29 (of 29 total)
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  • #50317
    Pix
    Guest

    you should check your BSC’s

    (all the cells of the network, or just one or few BSC’s ?)
    if ALL the network, then it might be the MSC. Either a MSC board, or a timer that has been modified. The SDCCH is used for exchanging messages between MS and MSC. If it takes longer for the MSC to answer these messages, it might impact the whole network.

    You could investigate the VLR as well. The VLR is taking part during the authentication. If the VLR is slower, it will increazse the length of the SDCCH, etc.

    That’s a very interesting problem, please let me know how it ends !!

    Thanks,
    pix

    #50318
    rala
    Guest

    Thank you Pix, I got it. 😉

    #50319
    Promod
    Guest

    Hi Pix,

    I would like to know,
    1.Max MSC Capacity
    2.How it is calculated to the from Transcoder capacity to till MSC end.

    Regards,
    Promod

    #50320
    pix
    Guest

    i don’t know the MSC, sorry… not my field at all 🙂

    #50321
    Water
    Guest

    Hi Pix!
    The sdcch problem has affected most cells, in different BSCs, and different MSCs!
    If you talk of the VLR then i will try ask the core engineers to check that for me!
    I have been suspecting the LAPD signalling, but now i wonder what could have triggered such a problem in so many cells in different BSCs!

    Thanks for the other response!

    Thanks Guys!

    #50322
    Promod
    Guest

    Hi Pix,

    Some cells which are facing towards railway line are having high call drops and SDCCH drops.So will you suggest me what could be the reason?

    Regards,
    Promod

    #50323
    PAN
    Guest

    to Water
    There are some things, that may cause sdcch traffic increasing:
    – enabling Check Imei feature in MSC/VLR or increasing it’s frequency per radio event (for example, performing this procedure not only in Location Update cases, but in MOC, MTC, etc. and/or more frequently).
    – enabling TMSI reallocation feature in MSC/VLR or increasing it’s frequency per radio event in (see example above)
    – enabling authentication feature in MSC/VLR or increasing it’s frequency per radio event (see example above)

    #50324
    Pix
    Guest

    Promod,

    do you suspect the cell is catching railway traffic ? if yes :

    – do you want this cell to catch the fast moving traffic ?

    –YES : reduce the HO MARGIN, the DL EMERGENCY LEVEL THRESHOLD, disable DL power control, and strongly reuce the averaging windows (to 2, for instance). Drawback : you will impact the slow moving traffic in this cell as well.

    — NO : harden the incoming HO from the cells covering the fast moving traffic (higher HO MARGIN(n,s)) and direct this traffic from one “railway” cell to another “railway” cell. You can do this with LINK FACTOR and HO MARGIN (adjacency parameters)

    #50325
    Promod
    Guest

    Hi Pix,

    1.My Power margin handover is 6db,Level margin handover is 6db and quality margin handover is 0 db.As i guess that is we can change Power margin to 3db so that fast moving mobiles will get immediately handovers
    and what is the link factor parameter? In nokia what is the parameter name?

    Please suggest me which will be the better way?

    Regards,
    Promod

    #50326
    pix
    Guest

    the power margin is an adjacency parameter, isn’t it ?

    in this case you could set :

    power margin (railway cell, standard cell) = 12db
    power margin (railway cell, railway cell) = 3db
    power margin (standard cell, railway cell) = 12db

    That will certainly help. You see the idea behind these values ? Maybe you can use other parameters to achieve the same effects, as I’m not sure what are the nokia’s HO ALGORITHMS.

    Regards,
    Pix
    I don’t know the nokia parameters, sorry.

    #50327
    Muddassir
    Guest

    CAN someone brief me what is Mean holding time?

    #50328
    Nora
    Guest

    Dears From some weeks ago we faced with SDCCH MHT incremnet while radio team check and confirm that SDCCH traffic is decreased , there wasn’t any change on core side.

    would you pleas help me what could be the reason ?

    #50329
    Pix
    Guest

    Hello,

    If the SDCCH MHT has increased, then the SDCCH traffic must have increased as well !
    Traffic = MHT * SDCCH_Attempts

    So unless the overall number of SDCCH_Attempts have decreased, it doesn’t make sense to me.

    If attempts have decreased, then something must have occurred ! (for example : less IRAT HO 4G-2G or 3G-2G, or fast reselection to UTRAN/LTE)

    You may consider checking the cause of SDCCH establishments (MOC, MTC, LAU, SMS, IRAT reselection, etc) thanks to RAN counters. This may point you to the right direction.

    BR / Pix

    #50330
    Jammie
    Guest

    MHT Mean Holding Time is the average amount of time in seconds on KPI usually that the call was connected before the UE hung up the call, you’d be surprised how short the Mean time is when you see high traffic cells, I see 50 seconds 20 seconds, most people these days call people up and say, ‘hi, be there in 5 minutes’ and hang up so this is why it’s so low these days, but if it’s usually 50 seconds and drops to 10 seconds then you may have a silent call issue or poor call quality issues

Viewing 14 posts - 16 through 29 (of 29 total)
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