Patent ID: 8180338

Claim:
A method of selectively anchoring calls for a user element in a multimedia subsystem comprising: determining when the user element is in a multimedia subsystem (MS) anchoring zone associated with the multimedia subsystem, the multimedia subsystem comprising a home multimedia system of the user element and wherein the multimedia subsystem anchoring zone corresponds to a plurality of different cells supported by a circuit switched subsystem and a plurality of different Wireless Local Area Network (WLAN) zones supported by the MS for which call control should be anchored in the home multimedia subsystem; effecting establishment of a call with the user element such that the call is anchored in the home multimedia subsystem when the user element is in the multimedia subsystem anchoring zone, wherein anchoring the call includes passing all call signaling through a continuity control function (CCF) in the home multimedia subsystem, such that the same CCF terminates an access signaling leg with the user element and a signaling leg with a remote endpoint of the call; and effecting establishment of the call with the user element such that the call is not anchored in the multimedia subsystem when the user element is not in the multimedia subsystem anchoring zone, wherein when the user element is served by the circuit switched subsystem, effecting establishment of the call comprises instructing a node on the circuit-switched subsystem to route the call initiated by the user element toward a call continuity control function of the multimedia subsystem when the user is in the multimedia subsystem anchoring zone, such that the call is anchored at the continuity control function, and instructing the node on the circuit switched subsystem to route the call initiated by the user element toward a called party when the user is not in the multimedia subsystem anchoring zone.