top button
Flag Notify
    Connect to us
      Facebook Login
      Site Registration Why to Join

Facebook Login
Site Registration

Whether UE will do Tracking Area Update after successfully handover to Target ENB?

+2 votes

After UE handover to target ENB it sent RRC Connection Reconfiguration complete.why UE doing suddenly Tracking Area Update request? Even it is in RRC-Connected State.

posted Aug 24, 2015 by Manohar

Share this question
Facebook Share Button Twitter Share Button LinkedIn Share Button

2 Answers

+1 vote

If UE is performing HO to target eNodeB which have different TAC from the tai_list in which UE is registered then UE will perform the TAU after HO.

answer Aug 24, 2015 by Veer Pal Singh Yadav
+1 vote

First let me tell you a bit about the TAU procedure.
As part of Attach, MME sends a TAI list (list of Tracking areas) to the UE - For eg.- TA1, TA2, TA3 and TA4.

In lay man's term - MME says to the UE that you can move around in TA1 to TA4 and I can provide you
the required services. Now if the UE moves to a new Tracking area, for eg.- TA5 which is not in that TAI
list, it is the UE's responsibility to inform the same to the MME to continue receiving the service.

The UE does so by the Tracking Area Update Procedure. Now coming to your question which has already been answered by Veer.
The target enodeB may have a TA5 or any TAC which is not in the list of TAI that MME shared with UE during the attach. So the moment UE realizes that it has entered a new TA which is not present in the TAI list, it notifies the MME by the TAU procedure.
If the MME is capable of serving this new TAC ,i.e, TA5, it shall accept the UE's request.

You can refer the link below for complete call flow along with the explanation -

answer Aug 25, 2015 by Ankush Surelia
Similar Questions
+1 vote

On what basis UE decides whether it should trigger TAU procedure or not ?

+2 votes

ENB will include only UTRA objects or both EUTRA and UTRA objects in meas config for UE to send measurement reports during IRAT HO ???

Contact Us
+91 9880187415
#280, 3rd floor, 5th Main
6th Sector, HSR Layout
Karnataka INDIA.