Patent ID: 8542672

Claim:
A Mobile Access Gateway Function (MAGCF) node adapted to handle a call in a packet-based multimedia system domain for a circuit-switched controlled user's terminal located in circuit-switched controlled domain and being registered in the packet-based multimedia system wherein said MAGCF node, an anchor point for the handled call, comprises a microprocessor coupled to a persistent memory storing instructions that, when executed by the microprocessor enable the MAGCF to: receive an originating circuit switched call from a serving Mobile Switching Center (MSC) by using a routing number to route the originating circuit switched call from the serving MSC to the MAGCF node and, send an originating packet-based multimedia call via a proxy call control function (P-CSCF) being part of the MAGCF node towards the packet based multimedia domain, and receive from the packet-based multimedia domain a terminating packet-based multimedia call being addressed to the P-CSCF that is part of the MAGCF node, and send a terminating circuit-switched call towards the circuit-switched controlled user's terminal via the serving MSC, and convert the originating circuit-switched call into the originating packet-based multimedia call by starting a packet-based call setup procedure, and to convert the terminating packet-based multimedia call into the terminating circuit-switched call by initiating a circuit-switched call setup procedure, wherein said MAGCF node comprises a registration logic adapted to perform a registration procedure for registering the circuited-switched controlled user's terminal into the packet-based multimedia domain, wherein said registration procedure results in storing an address of a serving packet-based multimedia node in the MAGCF node and in providing an address of the P-CSCF that is part of the MAGCF node to the serving packet-based multimedia node, and wherein the serving MSC is located in a visited network into which the circuit-switched controlled user's terminal has roamed.