How does Handover to EUTRA procedure works?

Question

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

Answer 1

Following steps are followed to do handover :
1. eNodeB configures UE for measurements and reports.
2. UE sends measurement report and eNodeB takes decision to initiate handover based on report sent by UE.
3. Handover preparation phase is executed for that UE. Either X2 or S1 handover preparation phase.
4. Handover execution (RRC connection reconfiguration with "mobility control info" ) sent to UE.
5. RRC connection reconfiguration complete is sent by UE to target eNodeB as completion of handover.

Measurement configuration and reporting both are used for handover as well as for ANR (a SON feature).