Abstract: An access node anchoring a connection to, e.g., a PDSN in a core network establishes a session with a mobile station and assigns the mobile station an identifier such as a UATI. The anchor node sends the UATI to the PDSN, such as in a GRE key where the data link is a GRE tunnel. If the anchor node fails and data addressed to the mobile station comes to the PDSN, it may initiate a page for the mobile using the UATI. The anchor node may additionally send the PDSN the session seed and optionally the mobile station's network location. A registration zone may be defined to include access nodes within a predetermined distance of the anchor node, and the mobile station forced to re-register when moving outside of the registration zone. In this case, the PDSN may initiate a page for the mobile station only within the registration zone.

Abstract: A Handoff (HO) Function facilitates the handoff of a hybrid AT/MT from a packet data wireless network to a circuit switched wireless network. The HO Function translates a handoff indication from the packet data network to an emulated circuit switched handoff request for the circuit switched network. The HO Function also passes handoff radio parameters from the circuit switched network to the packet data network. The handoff parameters are transmitted to the hybrid AT/MT, allowing it to tune to the frequency band of the circuit switched network. Additionally, the HO Function initiates the IMS network signaling necessary to route voice signals from the other party of the existing call, through the IMS network, and to the hybrid AT/MT on the circuit switched network. The HO Function controls a Media Gateway that translates call media between the packet data networks and the circuit switched network formats and protocols.

Abstract: The hybrid mobile terminal is engaged in an existing call through a serving one of a circuit switched or packet data wireless networks. The mobile terminal places a new call through the target one of the wireless networks, the new call having a predetermined called party identifier. In response to the called party identifier, the call is converted to a loop-back call directed to the mobile terminal through the serving wireless network, establishing a call path through the target wireless network. The mobile terminal accepts the loop-back call, and directs the existing call to connect to the call path through the target wireless network. The existing call through the original network is then dropped, effecting an inter-system handoff from the serving to the target wireless network.