Dual-mode device and method for handover of session from voip interface to cellular interface

A dual-mode device configured for IP-based communication over an IP network and cellular wireless communication over a public land mobile network (PLMN), the IP network including a communications server, the dual-mode device comprising:

• a cellular communications subsystem and a cellular interface for engaging in cellular wireless communications over the PLMN;
• an IP communication subsystem and a Voice-over-IP (VoIP) interface for engaging in IP-based voice communications over the IP network;
• a processor for controlling the communication subsystems;
• and
• a communications application executable by the processor and configured to manage the handover of an active VoIP call between the dual-mode device and a remote device from the VoIP interface and the cellular interface, the communications application including a handover module configured to
• place the active call on hold,
• establish a second call from the VoIP interface to the cellular interface of the dual-mode device via the communications server and the PLMN, wherein the second call includes a VoIP leg from the VoIP interface of the dual-mode device to the communications server,
• instruct the remote device to initiate a new call to the communications server referencing the second call and cause the communications server to replace the VoIP leg of the second call with the new call, thereby joining the remote party to the second call connected to the cellular interface of the dual-mode device, and
• terminate the active call.

A computer program product comprising a machine-readable medium having encoded thereon computer-executable instructions for handing over an active call between a dual-mode device and a remote device, wherein the dual-mode device includes a Voice-over-IP (VoIP) interface for wireless communications over an IP network and a cellular interface for wireless communications over a public land mobile network (PLMN), wherein the IP network includes a communications server, and wherein the active call is a VoIP call using the VoIP interface of the dual-mode device, the computer-executable instructions comprising:

• instructions for placing the active call on hold;
• instructions for establishing a second call from the VoIP interface to the cellular interface of the dual-mode device via the communications server and the PLMN, wherein the second call includes a VoIP leg from the VoIP interface of the dual-mode device to the communications server;
• instructions for instructing the remote device to initiate a new call to the communications server referencing the second call and causing the communications server to replace the VoIP leg of the second call with the new call, thereby joining the remote party to the second call connected to the cellular interface of the dual-mode device;
• and
• instructions for terminating the active call.