IMS - RCS

Presence Model

A presence allows users to subscribe to each other and be notified of changes in state.

Following is the summary of the model based on RFC 2788. Try to get familiar with each entities shown here and their roles because you will see each of these entities very often in various SIP message in RCS.

The communication between these entities are done by specific SIP messages and the main contents of those message is expressed in a format as follows.