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20th July 2007 at 09:06 #45815DirtyGuest
Hi, is there any recommended value for T3212 timer in the network (the timer used for location updating). what are the effects of increasing or decreasing the T3212 timre on the paging performance for a LAC.23rd July 2007 at 07:54 #45816PixGuest
T3212 = 4 hours (default)
every 4 hours, a mobile will send a location update message to its BSS, using a SDCCH subchannel for 3 seconds 🙂
increase T3212 : instead of every 4 hours, maybe do every 6 hours.
It reduces the amount of location updates in your network, reducing the SDCCH load (and TCU load as well)
drawback : there is a timer in the NSS that can expire. If the NSS receives a LU before the expiry, then the timer is restarted. Otherwise, the mobile becomes “IMSI DETACH”-ed. So ensure that your NSS timer is well defined.
There must be another drawback, but I can’t remember…
Decrease T3212 : instead of 4 hours, do 2 hours. That will double the amount of periodic LU in your network, overloading TCUs and SDCCHs.
Regards,24th July 2007 at 10:04 #45817Da ArchitectGuest
You said that there is a timer in the NSS that can expire. If the NSS receives a LU before the expiry, then the timer is restarted. Otherwise, the mobile becomes “IMSI DETACH”-ed. So ensure that your NSS timer is well defined.
Please, I urge to know more details about this timer. I have a problem of Paging Failure, and it might be due to this NSS timer!24th July 2007 at 13:48 #45818PixGuest
Hello Da Architect,
If you urge so badly, I’d rather tell you now then 🙂
Ok, i’ve been looking for the name of the parameter for 30 minutes now. And I just can’t find it ! NSS is so obscure, it is scary.
However the 3GPP doc confirms what I said earlier :
“2.4.2 Implicit IMSI detach
Implicit IMSI detach operation is the action taken by the VLR to mark an MS as detached when there has been no successful contact between the MS and the network for a time determined by the implicit detach timer. The value of the implicit detach timer is derived from the periodic location updating timer. During an established radio contact, the implicit detach timer shall be prevented from triggering implicit detach. At the release of the radio connection, the implicit detach timer shall be reset and restarted. Implicit IMSI detach shall also be performed in the case of a negative response to an IMEI check.”
(ref : Location registration procedures
(GSM 03.12 version 7.0.0 Release 1998)
I’m sorry, I really can’t find its name. But if you find it, PLEASE share it with me 🙂
Regards,25th July 2007 at 09:17 #45819TomarGuest
May be one note to increase T3212: instead of every 4 hours, maybe do every 8 hours.
It reduces the amount of location updates in your network, reducing the SDCCH load. Yes it is true, but only during the night – nobody send/receive SMS nobody makes MTS/MOC call.
During the day/BH, is the saving of resources nearly zero. Because every make a call or SMS – The timer is restarted in the mobile, but also in NSS. If the NSS receives a LU before the expiry, then the timer is restarted.
If the timer in the NSS expired, than NSS will try to page this MS. Than the mobile becomes “IMSI DETACH”-ed.
But it depends on behaviors of your customers.
Tomar3rd February 2009 at 18:19 #45820nitinGuest
Plz tell me the reason for high sdcch blocking in showcase even if traffic is less?14th March 2009 at 09:33 #45821vikas kanwarGuest
wrong t3212 timer settings for few cells in BSC ( timer value is lower than other cells so more periodic location updates by MSs resulting high signalling load resulting HIGH SDCCH LOAD19th March 2009 at 10:33 #45822GeraldGuest
I am having problems with our network on SDCCH. Two sites are having low SDCCH accessiblity and the company has a threshold of 97%.
please can you tell me what are the possible cause for this drop20th March 2009 at 14:42 #45823GeraldGuest
please can somebody help me. i am really waiting for your utmost attention……….
Please help20th March 2009 at 16:16 #45824bobGuest
Gerald can you post the formula you using23rd March 2009 at 13:57 #45825GeraldGuest
SDCCH accessibility =
Assigned successful SDCCH/(Assigned attained SDCCH – Assigned number of SDCCH seized)9th April 2009 at 06:28 #45826nitinGuest
plz tell me if utilization is high will it lead to SD blocking.some of my cells have utilization above 200% but no SD Blocking n few with 150% have SD blocking up to 25% even if SD available is same for both case.24th May 2009 at 10:29 #45827rama narayan nandaGuest
can anyone plz tell me what is the reason for sdcch block24th May 2009 at 11:27 #45828PixGuest
The answer is in this post, keep looking. It’s a bit in the past.17th June 2009 at 06:08 #45829AnitGuest
Can anyone help me to tackle the problem of High RACH Collision counts.Please give me the reasons and suggestions for the same.