PS NETWORK WITH CS SERVICE ENABLING FUCTIONALITY

Method and system for optimization of a handoff of a user equipment between packet switched and circuit switched networks in response to a request for circuit switched network services on the user equipment while the user equipment is resident on a packet switched only network. The system includes a mobile device, a first network, and a second network. The first network includes a third network and an interworking unit. The second network communicates with the first network. The mobile device sends registration information to the first network. The third network sends the registration information to the interworking unit. The interworking unit sends the registration information to the second network to provide a communication link between the mobile device and the second network.