Patent ID: 8331384

Claim:
A femto gateway comprising: an interface configured to establish a security association using encryption to provide a secure tunnel through a broadband network to at least one femtocell; an interface configured to establish circuit switched communications with a circuit switched network; an interface configured to establish communications with an IP Multimedia Subsystem (IMS) network; an interworking function that communicates with user equipment through the security association to provide connectivity to both IMS and circuit switched networks and interworks NAS signaling received from the user equipment over the security association into session initiation protocol (SIP) signaling to enable communication with the IMS network using SIP signaling; and a service domain selection function that is configured to determine if the interworking function provides connectivity to the IMS network or the circuit switched network; wherein the femto gateway is configured to couple to a plurality of femto cells and wherein the femto gateway is configured to provide a proxy functionality to hide the complexity of the plurality of femto cells.