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high call setup time

Viewing 7 posts - 1 through 7 (of 7 total)
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  • #45651
    harry
    Guest

    Hi all
    we have nokia DX200 and nokia BSS . We are observing high callset up time , can anybody tell us from where we have to start investigating.

    Regards
    harry

    #45652
    Pavel
    Guest

    Due to my expirience- call set up time is very dependent of NSS part, but not from BSS.

    Last time, when I had this problem – there was a problem on core signalling(c7) network.

    So, pay your attention to signalling links between BSC and MSC (A-int). Due to vendors recommendation- it shouln’t be more than 40% per link.

    #45653
    harry
    Guest

    Hi pavel

    I have checked the link utilization .. which is much below than 40%.

    #45654
    Pavel
    Guest

    And what about stablity and quality of links. Du you have stable transport nwetwork(SDH/PDH)?

    By the way, which speech codec been used between TCSM and BSC? Try to play with codecs- may be it is related with any AMR parameters, if you use it.

    #45655
    Vanderley
    Guest

    Check also if you have compression somewhere on the link (usualy between MSC’s).

    #45656
    DJ
    Guest

    AMR in GSM ?

    Guys can u explain me this ?

    Rgds

    #45657
    Vanderley
    Guest

    Hi,

    AMR stands for Adaptive Multi Rate speech codec. This actually is a set of speech codec modes at different bit rates.
    Bitrates are 12.2-FR1; 10.2-FR2; 7.95-FR3/HR1; 7.4-FR4/HR2; 6.7-FR5/HR3; 5.9-FR6/HR4; 5.15-FR7/HR5, and 4.75-FR8/HR6.
    AMR FR are 22.8kbps and AMR HR are 11.4kbps. The rest is the channel coding. I meen for example for FR8: speech coding 4.75 and 22.8-4.75=18.05 channel coding. This increases the robustness to channel errors due to bad radio conditions pretty much. In fact they say that the same quality as EFR at 10dB C/I could be achieved with AMR-FR at 4dB C/I.

    I hope this helps

Viewing 7 posts - 1 through 7 (of 7 total)
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