Call handoff between different networks for hybrid mobile device

A call server operable in an Internet Protocol (IP) based packet data network, the call server comprising:

• a processor operable to execute one or more software modules, the software modules including instructions that when executed:
• host a communication session between a first communication device and a second communication device wherein:
• (i) the call server functions as a bridge between the first communication device and the second communication device joining an original communication link between the first communication device and the call server with a second communication link between the second communication device and the call server to create a communication session between the first and second communication devices, and
• (ii) the first communication device includes at least two RF transceivers each capable of communicating with the call server over a separate network, wherein the original communication link between the first communication device and the call server is initially established over an original network and the IP based packet data network using a first telephone number associated with the first communication device;
• receive an out of band signal from the first communication device, the out of band signal separate from the communication session and sent over an open data channel between the first communication device and the call server, the out of band signal comprising an instruction to handoff the original communication link to an alternate communication link between the first communication device and the call server;
• establish the alternate communication link between the first communication device and the call server on an alternate network and the IP based packet data network using a second telephone number associated with the first communication device;
• and
• join the alternate communication link between the first communication device and the call server on the alternate network with the second communication link between the second communication device and the call server to maintain the communication session between the first and second communication devices.

A method comprising:

• establishing an original communication link between a first communication device and a call server operable in an Internet Protocol (IP) based packet data network, the original communication link established over an original network and the IP based packet data network using a first telephone number associated with the first communication device;
• joining the original communication link between the first communication device and the call server on the original network with a second communication link between a second communication device and the call server to establish a communication session between the first and second communication devices;
• receiving an out of band signal from the first communication device, the out of band signal separate from the communication session and sent over an open data channel between the first communication device and the call server, the out of band signal comprising an instruction to handoff the original communication link to an alternate communication link between the first communication device and the call server;
• establishing the alternate communication link between the first communication device and the call server on an alternate network and the IP based packet data network using a second telephone number associated with the first communication device;
• and
• joining the alternate communication link between the first communication device and the call server on the alternate network with the second communication link between the second communication device and the call server to maintain the communication session between the first and second communication devices.