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SUDDEN SDCCH CONGESTION

Viewing 14 posts - 1 through 14 (of 14 total)
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  • 15th February 2010 at 10:05 #61070
    SHELDON
    Guest

    Hi All,

    I have a situation in my network.

    Sometimes, some cells record a sudden increase in SDCCH attempts and hence congestion.Eg, a cell which does an average of 1500 SDCCH attempts at busy hour suddenly does about 56000( yes, not a typo) attempts in one hour, resulting in extremely high congestion.

    My vendor is ericsson and there is no hardware fault, availability is ok, freqs are ok, neighbouring sites did not go out of service, etc.

    I would appreciate your suggestions if you have any ideas or if you have experienced similar situations.

    Best regards.

    SHELDON

    15th February 2010 at 12:24 #61071
    pix
    Guest

    i experienced this when the BTS from the other operator went down during the night (due to maintenance, swap, etc…).
    All MS from the other operator reselects my operator at the same time, resulting in extreme high congestion.

    Are your cells located at country border ?
    Check if those SDCCH requests are trying to perform location update, or IMSI detach, or MO call, SMS ?…?

    4th March 2010 at 08:51 #61072
    Frenchkiss
    Guest

    Hi SHELDON!
    Nokia vendor also happens like that. I have checked the corverage of and the boder of these cells, but I cannot find out that error. Please help us to check it!
    Thanks alot

    4th March 2010 at 13:48 #61073
    SHELDON
    Guest

    Hi Pix,

    No, the cells are not located at the country border. Sometimes it happens in the middle of the city.

    Unfortunately, ericsson say it’s impossible to determine the reason for the requests unless we upgrade our BSC software.

    We have raised a CSR (Customer Service Request) with ericsson on this issue, but so far, nothing has come out of it. It’s really difficult to track down, as we never know when the next episode is going to happen.

    We are still investigating, and I’ll let you in on whatever we find.

    Regards,

    Sheldon

    4th March 2010 at 14:30 #61074
    krish
    Guest

    hi sheldom,

    Can u tell me which counters are for sd attempts and which counter shows failed attempts out of total attemts?

    5th March 2010 at 11:43 #61075
    SHELDON
    Guest

    Hi Krish,

    The total number of SDCCH seizure attempts in ERICSSON is given by: CCALLS+CCALLSSUB.

    The number of successful SDCCH seizures is: CMSESTAB+CMSESTABSUB.

    From these, you can calculate the number of failed attempts.

    Regards,

    SHELDON

    7th March 2010 at 13:53 #61076
    KRISH
    Guest

    Hi Sheldom,

    thanks.The counter CCALLS will consider all type of SDCCH attmepts i mean for call set up,location update,sms or only for location update?

    and can i check sd attemtpts for location update from the total ? i mean is there any counter?

    7th March 2010 at 19:50 #61077
    Pix
    Guest

    Sheldon,

    I’m sure there are counters that gives you what are the cause of SDCCH establishment : Loc Upd, SMS, call attempts, etc. Check all your counters and that will definitely give you a good tip about what’s going on.

    Cheers
    pix

    9th March 2010 at 14:11 #61078
    krish
    Guest

    Hi sheldom,

    Hi Sheldom,

    thanks.The counter CCALLS will consider all type of SDCCH attmepts i mean for call set up,location update,sms or only for location update?

    and can i check sd attemtpts for location update from the total ? i mean is there any counter?

    9th March 2010 at 15:38 #61079
    SHELDON
    Guest

    Hi Krish

    Yes, CCALLS gives you the total number of SDCCH attempts for all transactions( call setup, location update, SMS, etc).

    The total number of SDCCH attempts for SMS is: CSMSDWN+CSMSUP.

    SDCCHs for Location updates are counted by CLUMSESTAB. However, you will only get this counter if your BSC software version is 08 or after.

    PIX,
    With the BSC SW version in my network (06A), there are NO counters that show the purpose for which an SDCCH was seized( loc. update, call establisment, SMS, etc). I raised a CSR with ericsson about this, but they said it’s only possible if we upgrade our BSC software. Thnx anyways.

    Regards,

    Matthew

    9th March 2010 at 17:33 #61080
    Pix
    Guest

    Sheldon, ok, sorry i misread your previous answer 😉

    10th March 2010 at 11:32 #61081
    ATTO
    Guest

    Hi SHELDON,

    I am experiencing the same problem of SDCCH congestion ( Ericsson vendor). Cells gets congested (high congeston) randomly in my network without any problem on Abis , BTS HW/SW.
    Let me know if you came across this issue.

    Regards

    12th May 2010 at 05:13 #61082
    JOJO
    Guest

    Hell all;

    My network vendor is Ericsson and the BSC SW we have is 06B, i have the same problem only difference is the congestion does not match the SDCCH UL/OL traffic carried and it random.

    12th May 2010 at 05:18 #61083
    JOJO
    Guest

    Oh we one time had sleeping SD TS, however this was cleared by upload of some patch provided by the vendor ericsson. However at the momemnt the problem is now big. such as UL/OL traffic=1.06, SD_congestion=89% with 3SDCCH (23 subchannels)

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