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Hi
could somebody pls. tell me why we have T3126 expired?Thanx
josebHi joseb,
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.BR//
yogesh_rfHi Yogesh_rf
do you know what is the value of T3126?
Regards,
Vanderleyhi vanderley,
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.
Rgds
YogeshT3126 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.
dear
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 edAt 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.
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?Could any one please inform where I could find any document related to the timers T3120, T3122 and T3126?
BR,
AntonioHi Vanderley,
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.
Hi
I cant see in all this posts why the timer expires.
Is because lack of resourses on air interface, interference..?Hi,
what is the unit of T3126, and what its default value in different operators?Antonio,
All the answers are in 3GPP documents. I believe you’ll find them in the serie 45.xxx …
Ater,
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)Rehman,
I’ve no idea..Regards,
PixT3126 – 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 3.3.1.2. The maximum value of this timer is 5 seconds. See 3GPP TS0408 v7.0.1 2000-11 Clause 11.1.1
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
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