- This topic has 24 replies, 1 voice, and was last updated 11 years, 10 months ago by Pd.
21st November 2006 at 06:11 #46187josebGuest
could somebody pls. tell me why we have T3126 expired?
joseb22nd November 2006 at 07:53 #46188yogesh_rfGuest
An MS requests resources from a cell by transmitting an “access burst(RACH) containing the
channel request message. The access burst has to be scheduled so that it is
transmitted during a frame that has been configured as a RACH. This scheduling Channel requests will only be repeated upto M+1 times where M is equal to max_retran,
broadcast on BCCH system information. After the last channel request T3126 is started
in the MS, on expiry the channel request procedure will be aborted.
yogesh_rf5th December 2006 at 17:27 #46189VanderleyGuest
do you know what is the value of T3126?
Vanderley6th December 2006 at 07:07 #46190yogesh_rfGuest
Its value is counted like suppose you are using max RACH retransmission as 4 ,then the value of this timer will be counted as 4+1=5.
Yogesh4th September 2007 at 16:57 #46191BomberGuest
T3126 timeout will occur if the BSS is not properly connected to the core. The cell will still transmit details of the cell (in particular the LAC). When the MS camps on a cell with a different LAC it will try to update the HLR with the new LA. This can only occur once the MS has an active channel, and this can only occur if there is a route to the core. Once the core connection is broken, the MS will keep trying to make a connection and keep failing resulting in contineous T3126 timeouts.5th September 2007 at 08:34 #46192asoGuest
this timer is work when you channel request and then you receive AGCH it will count the duration between this signaling and will stop when confirm ed6th September 2007 at 10:17 #46193Vivek KhajuriaGuest
At expiry of timer T3126, the immediate assignment procedure is aborted. A mobile station can now do a cell reselection or indicate “network busy” on the display of the mobile station.14th September 2007 at 13:52 #46194VanderleyGuest
Hi Vivek Khajuria,
What do you mean as “or”
Isn’t it after this MaxNumber of retransmisions + T3126 expires the MS should perform forced cell reselection?
When exactly this message “Network Busy” appears?18th February 2008 at 18:23 #46195AntonioGuest
Could any one please inform where I could find any document related to the timers T3120, T3122 and T3126?
Antonio19th February 2008 at 06:44 #46196vivek khajuriaGuest
If your times expires in a restricted area i.e your MS is not allowed to make a call then it is not able to do cell reselection.
So in this case it will display a network busy message.
More over it can also be set by the operator.
Thnx & bye.29th February 2008 at 19:19 #46197AterGuest
I cant see in all this posts why the timer expires.
Is because lack of resourses on air interface, interference..?1st March 2008 at 12:26 #46198RehmanGuest
what is the unit of T3126, and what its default value in different operators?1st March 2008 at 12:34 #46199PixGuest
All the answers are in 3GPP documents. I believe you’ll find them in the serie 45.xxx …
The timer expires because it waits for an immediate assignment from the BTS, but actually there is no reply. It can be due to poor radio conditions or SDCCH congestion (and the “immediate assignment reject” message is disabled)
Well, all the above is correct if vanderley’s definition of T3106 is correct 🙂 (i’m sure it is)
I’ve no idea..
Pix1st March 2008 at 14:22 #46200paraHOGuest
T3126 – This timer is started either after sending the maximum allowed number of CHANNEL REQUEST messages during an immediate assignment procedure. Or on receipt of an IMMEDIATE ASSIGNMENT REJECT message, whichever occurs first. It is stopped at receipt of an IMMEDIATE ASSIGNMENT message, or an IMMEDIATE ASSIGNMENT EXTENDED message. At its expiry, the immediate assignment procedure is aborted. The minimum value of this timer is equal to the time taken by T+2S slots of the mobile station’s RACH. S and T are defined in section 184.108.40.206. The maximum value of this timer is 5 seconds. See 3GPP TS0408 v7.0.1 2000-11 Clause 11.1.11st March 2008 at 15:07 #46201paraHOGuest
I put wrong version number of 3GPP TS0408 and hit the ‘0’ key instead of the ‘9’. The version number should read v7.9.1 – sorry.
– Antonio Clause 11.1.1 onwards provides an overview of all the timers including T3120, T3122 and T3126