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why 2 steal bits are used in TCH burst ?

Viewing 11 posts - 1 through 11 (of 11 total)
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  • #48505
    giri
    Guest

    in TCH burst packet:
    3 tail Bits
    57 data bits
    1 steal bit
    26 training squence bits
    1 steal bit
    57 data bits
    3 tail Bits
    8.25 gaurd band

    wht do we need 2 steal bits here, we ca do it with one steal bit only to identify a data or a control signal(FACCH)

    #48506
    NarChai
    Guest

    2 stealing bits in TCH use for FACCH (Fast Associated Control Channel)is used when a handover is requied
    good lock

    #48507
    giri
    Guest

    than u can use only one bit for FACCH and TCH identifying

    why u need two bits

    #48508
    giri
    Guest

    u can identify TCH or FACCH from 1 bit only
    why 2 bits are used??

    #48509
    pix
    Guest

    i’ve no idea…

    #48510
    naveen
    Guest

    Probably the second stealing bit might be used for future use! 🙂

    #48511
    giri
    Guest

    for Pix
    in spec 05.03 it is mention that two stealing bits r for two halfs of the message part

    in the spec it is mentioned that voice data and FACCH goes at the same burst.

    #48512
    pix
    Guest

    so maybe it has something to do with half rate ? 1 FACCH bit per channel…

    that was my first assumption, but since HR are sent once every 2 TS (and not each time on half of the timeslot), it didn’t seem very logical… but i don’t know, really.

    #48513
    giri
    Guest

    pix–

    it nothing to do with half rate
    FACCH is used when mobile is trying for handover

    so u may not know when it can try for handover

    one possiblity is send FACCH in the whole burst and TCH in the next burst

    but in the spec it is not the case(reason i dont know)

    #48514
    Bhanu
    Guest

    2 steal bits r used to indiacte if the upper or lower segment have been stolen.

    #48515
    giri
    Guest

    thks bhanu

Viewing 11 posts - 1 through 11 (of 11 total)
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