Patent ID: 8855105

Claim:
An Access Gateway Node (MAGCF) adapted to handle a call in a packet-based multimedia system (IMS) domain for a circuit-switched controlled user's terminal (MS) located in circuit-switched controlled domain (CS) wherein said Access Gateway Node (MAGCF) comprises a microprocessor coupled to a memory storing instructions that, when executed by the microprocessor, cause the MAGCF to: receive an originating circuit-switched call at an originating circuit switched logic (Org CS) from the circuit-switch controlled user's terminal (MS); send an originating packet-based multimedia call from an originating packet-based multimedia logic (Org PS) via a proxy call control function (P-CSCF) being part of the Access Gateway Node (MAGCF) towards a Session Initiation Protocol (SIP) server Call Session Control Function (S-CSCF) of the packet-based multimedia domain (IMS), wherein the S-CSCF is adapted to serve the user in the IMS domain and is determined by the MAGCF during a registration procedure of the circuit-switched controlled user's terminal (MS) and wherein MAGCF knows an address of the S-CSCF based on the registration of the circuit-switched controlled user's terminal (MS); receive from the packet-based multimedia domain (IMS) at a terminating packet-based multimedia logic (Term PS) a terminating packet-based multimedia call being addressed to the proxy call control function (P-CSCF) being part of the Access Gateway Node (MAGCF), wherein the call is received from the S-CSCF determined during the registration procedure of the circuit-switched controlled user's terminal (MS) and wherein the S-CSCF knows an address of the MAGCF based on the registration procedure of the circuit-switched controlled user's terminal (MS); send a terminating circuit-switched call from a terminating circuit-switched logic (Term CS) towards the circuit-switch controlled user's terminal; and convert the originating circuit-switched call using a conversion function (Conv) into the originating packet-based multimedia call and the terminating packet-based multimedia call into the terminating circuit-switched call.