Generic selectors
Exact matches only
Search in title
Search in content
Search in posts
Search in pages

SDCCH congestion

Viewing 4 posts - 1 through 4 (of 4 total)
  • Author
    Posts
  • #68297 Reply
    slim omrane
    Guest

    Hi,

    Please to clarify that point :

    In case on SDCCH congestion , Is there a repetition of channel request?Only in case of location update and call reestablishment allowed?
    The KPI SDCCH_congestion rate is thus wrong because it contains redunduncy?

    Please the link for 3GPP clarification

    #68298 Reply
    pix
    Guest

    hi slim,

    if the sdcch is congested, the BSS will behave accordingly to your setting “Enable Immediate Assignment Reject”.
    If “ImmAssRej” = DISABLE then the MS will repeat the Channel Request almost immediately
    If “ImmAssRej” = ENABLE then the MS will repeat the Channel Request only “WI_xx” ms later, which provides more chance for a SDCCH channel to be available.

    The MS can send up to MAX_RETRANS+1 channel requests.

    Yes, the SDCCH Congestion is artificially increased by retransmission. However, if you activate the “ImmAssRej”, you can apply the formula:
    SDCCH_Cong – Imm_Ass_Rej / Channel_Request

    As a result, you are counting only the last congestion failure. If the SDCCH is setup at the 3rd attempt :
    SDCCH Cong = 3
    Imm Ass Rej = 3
    –> sdcch cong rate = 0%

    I hope it makes sense… please test the formula carefully because I don’t remember having tried it.
    (i didn’t care much about artificial SDCCH congestion.. it should always be zero IMO… really and artificially !)

    Cheers
    pix

    #68299 Reply
    SDCCH congestion
    Guest

    Thanks Pix,
    Further clarifications please:
    The SDCCH requests are repeated till max retrans+1 whatever is the type of the service needed (LU,SMS,call establishment)?

    In case of LU,it will stop retransmissions by max retrans+1 or it will do another cycle?

    Please the link of 3GPP doc for repetition of SDCCH requets in case of SDCCH cong

    #68300 Reply
    pix
    Guest

    yes, retransmission works for any kind of request.

    Location update will indeed start a new cycle, because the MS has to do the LU anyway.

    44.018 -> the channel request procedure

    23.122 -> the location update process (i’m not sure whether they say how long to launch a new cycle in this doc).

    cheers
    pix

Viewing 4 posts - 1 through 4 (of 4 total)
Reply To: Reply #68300 in SDCCH congestion
Your information:




<a href="" title="" rel="" target=""> <blockquote cite=""> <code> <pre class=""> <em> <strong> <del datetime="" cite=""> <ins datetime="" cite=""> <ul> <ol start=""> <li> <img src="" border="" alt="" height="" width="">