Presence service using the IP Multimedia (IM) Core Network (CN) subsystem; Stage 3
The present document provides the protocol details for the presence service within the IP Multimedia (IM) Core Network (CN) subsystem based on the Session Initiation Protocol (SIP) and SIP Events as defined in 3GPP TS 24.229 [9].
Where possible the present document specifies the requirements for this protocol by reference to specifications produced by the IETF within the scope of SIP and SIP Events, either directly, or as modified by 3GPP TS 24.229 [9].
Requirements for manipulation of presence data are defined by use of a protocol at the Ut reference point based on XML Configuration Access Protocol (XCAP) (RFC 4825 [33]).
The present document is applicable to Application Servers (ASs) and User Equipment (UE) providing presence functionality.