Patent ID: 7522921

Claim:
A system for maintaining multiple service registrations for a dual mode mobile subscriber station comprising: means, responsive to receipt of a registration request from said mobile subscriber station, for registering a serving Mobile Switching Center in a first memory location in a Home Location Register for said mobile subscriber station as the serving apparatus for access for said mobile subscriber station; and means, responsive to receipt of a registration request from said mobile subscriber station for IP access, for registering a serving IP-based Mobile Switching Center in a second memory location in a Home Location Register for said mobile subscriber station as the serving apparatus for IP access for said mobile subscriber station, comprising: means, responsive to receipt of a request for registration message from the dual mode mobile subscriber station at a serving IP-based Mobile Switching Center, for transmitting enhanced Mobile Switching Center identification information, including an indication that said identification information is for a dual mode mobile subscriber station, to said Home Location Register for said mobile subscriber station, and means, in said Home Location Register for said mobile subscriber station, for storing said identification information in said second memory location in said Home Location Register for said mobile subscriber station.