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Is FACCH used during call setup?

  • This topic has 8 replies, 1 voice, and was last updated 12 years ago by eorenmh.
Viewing 9 posts - 1 through 9 (of 9 total)
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  • #59414
    DangerousMinds
    Guest

    Hey All,

    My question is: Is FACCH channel used at any point during call setup? I understand that the BTS sends the ASSIGNMENT COMMAND (for tch assignment) on the SDCCH, but I read somewhere that the returning ASSIGNMENT COMPLETE message sent by the MS is on FACCH? Can anybody confirm?
    Thanks/

    #59415
    Pix
    Guest

    Hello,

    I’ve never thought about this… but yes, it’s probably sent on FACCH. I should check it out though… Anyone else can confirm ?

    #59416
    Michele
    Guest

    Dear All, Assignment Command (containing the information about the new TCH channel already opened) is sent on SDCCH. then MS sends SABM on the FACCH associated to the new channel and BTS answers with UA on FACCH. At receiption of UA, MS sends the Assignment Complete on FACCH.

    #59417
    DangerousMinds
    Guest

    Thanks!
    So from what I understand, FACCH is used during call setup, and this FACCH is different from the TCH that MS is going to camp on.

    #59418
    Michele
    Guest

    The FACCH is the one associated to the new channel on which the MS in going to camp on. It has been already opened by BSS.
    FACCH is the Fast Associated Control CHannel, the fast signaling channel, and is always related to a TCH.

    #59419
    Pix
    Guest

    Thank you Michele.

    DangerousMinds : FACCH is physically located on the same timeslot as the TCH (same TRX, same frequency, same timeslot…). The only difference is that the burst is actually carrying “signalling” rather than “speech”.

    #59420
    DangerousMinds
    Guest

    All right, Thank you all!

    #59421
    KRISH
    Guest

    HI,

    U CAN USE FACH CALL SET UP FOR REDUCING SD CONGESTION IFU HAVE IDLE TCH.

    #59422
    eorenmh
    Guest

    hi
    i wonder if we could use FACCH for signalling, in case SDCCH already occupied?

Viewing 9 posts - 1 through 9 (of 9 total)
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