This TS 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.
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 TS 24.229
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