Mobility States

MS TURNED OFF

In this case the MS cannot be reached by the network. This could be due to the MS being out
of coverage for an extended period or in powered down or the SIM has been removed. In all
cases, the MS fails to respond to paging messages and does not provide periodic location
updates. In such circumstances, the network assumed the MS is IMSI detached (see below).

MS Mobility States

A Mobile Station (MS) can be in one of three
mobility states:
• MS turned off
• MS turned on in idle mode
• MS turned on in dedicated mode

MS TURNED ON IN IDLE MODE

In idle mode the MS is ‘camped-on’, synchronised to the network and is ready to place or
receive a call. The MS is said to be ‘IMSI-attached’. It can also receive paging messages and
provide periodic location updates (e.g. on change of Location Area). In addition it carries out
cell reselection procedures as it moves around the network.

 MS TURNED ON IN DEDICATED MODE

In dedicated mode, the MS is participating in user information transfer, either through a voice
or data call.