Patent ID: 8856880

Claim:
A method for providing a subscription to an IP Internet-Protocol based Multimedia Subsystem (IMS) for a first client of a packet-switched network, the method comprising: a) identifying the first client by a Mobile Subscriber Integrated Services Digital Network (MSISDN) number, and identifying a second, mobile client of a circuit-switched network by a MSISDN number that is identical to the MSISDN number identifying the first client; b) sending, by the first client, a register request to an IMS Server via the packet-switched network; c) sending, by the IMS server, a location query request to a Home Subscriber Server (HSS) register; d) requesting, by the HSS register, user subscription information of the circuit-switched network from a Home Location Register (HLR) of the circuit switched network; e) sending, by the HLR of the circuit-switched network, to the HSS register, the user subscription information of the second client; and f) creating, by the HSS register, a user IMS subscription information based on the user subscription information received in step e).