Patent ID: 8478886

Claim:
A user equipment configured to support multiple session initiation protocol registrations, comprising: means for registering a first public user identity of the user equipment with a first internet protocol address of the user equipment in connection with a first session initiation protocol session that is established with a first access network, wherein registering the first public user identity with the first internet protocol address comprises using a first emulated private identity calculated from a private identity of the user equipment; and means for registering the first public user identity of the user equipment with a second internet protocol address of the user equipment in connection with a second session initiation protocol session that is established with a second access network, wherein registering the first public user identity with the second internet protocol address comprises using a second emulated private identity calculated from the private identity of the user equipment; wherein the first public user identity is registered with the second internet protocol address while the first public user identity is registered with the first internet protocol address.