This TR is a temporary container for the functional models, flows and 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 this TR specifies the requirements for this protocol by reference to specifications produced by the IETF within the scope of SIP and SIP Events. Where this is not possible, extensions to SIP are defined within this TR. This TR has therefore been structured in order to allow both forms of specification.
This TR includes information applicable to network operators, service providers and manufacturers.