Subject: Mobile Computing

Difficulty: Medium

Marks: 4 Marks

Updating on entering a new location Area: The Location Area Identity (LAI) is broadcast in system information message and stored in mobile station memory. When a newreceived location area identity does not match with the previously stored location area identity, then MS does a location update.

Periodic update: Whenever MS performs location update if reset timer T. A time has timeout value. As and when the timer expires, the MS does the location update.

Updating on deactivation and activation: Mobile equipment do this update and send IMSI DETACH message when it is deactivated.

The network marks that MS as a deactivated and does not send paging message to for MS until it is activated again. A MS send IMSI DETACH message does a location update when it is activated again.