Call Handoff Between Different Networks

Abstract

Disclosed are techniques for hosting a communication session in a call server between communication devices. The call server functions as a bridge service between the communication devices 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. The first communication device includes at least two RF transceivers each capable of communicating with the call server over a separate network. The call server receives a signal from the first communication device indicative of the need to handoff the original communication link to an alternate communication link on an alternate network. The call server establishes the alternate communication link with the first communication device on the alternate network and joins it with the second communication link to maintain the communication session between the communication devices.

1 . A method comprising:
 hosting a communication session in a call server between a first communication device and a second communication device, the call server operable in an Internet Protocol (IP) based packet data network in which:
 (i) the call server functions as a bridge service 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; 
   receiving, in the call server, an out of band signal from the first communication device, the out of band signal indicative of the need to handoff the original communication link to an alternate communication link between the first communication device and the call server on an alternate network;   establishing the alternate communication link between the first communication device and the call server on the alternate network; 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.   
     
     
         2 . The method of  claim 1 , wherein the out of band signal is sent over a Message Queue Telemetry Transport (MQTT) data channel. 
     
     
         3 . The method of  claim 1 , wherein the original network is one of a VoIP IP data network, a mobile carrier network, a WiMax network, and a whitespace network. 
     
     
         4 . The method of  claim 1 , wherein the alternate network is one of a VoIP IP data network, a mobile carrier network, a WiMax network, and a whitespace network. 
     
     
         5 . The method of  claim 1 , further comprising severing the original communication link between the first communication device and the call server. 
     
     
         6 . A method comprising:
 hosting a communication session in a call server between a first communication device and a second communication device, the call server operable in an Internet Protocol (IP) based packet data network in which:
 (i) the call server functions as a bridge service 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; 
   receiving, in the call server, an out of network signal over a network that is not the original network from the first communication device, the out of network signal indicative of the need to handoff the original communication link to an alternate communication link between the first communication device and the call server on the alternate network;   establishing the alternate communication link between the first communication device and the call server on the alternate network; 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.   
     
     
         7 . The method of  claim 6 , wherein the original network is one of a VoIP IP data network, a mobile carrier network, a WiMax network, and a whitespace network. 
     
     
         8 . The method of  claim 6 , wherein the alternate network is one of a VoIP IP data network, a mobile carrier network, a WiMax network, and a whitespace network. 
     
     
         9 . The method of  claim 6 , further comprising severing the original communication link between the first communication device and the call server. 
     
     
         10 . 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 service 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; 
 
   receive an out of band signal from the first communication device, the out of band signal indicative of the need to handoff the original communication link to an alternate communication link between the first communication device and the call server on an alternate network;   establish the alternate communication link between the first communication device and the call server on the alternate network; 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.   
     
     
         11 . The call server of  claim 10 , wherein the out of band signal is sent over a Message Queue Telemetry Transport (MQTT) data channel. 
     
     
         12 . The call server of  claim 10 , wherein the original network is one of a VoIP IP data network, a mobile carrier network, a WiMax network, and a whitespace network. 
     
     
         13 . The call server of  claim 10 , wherein the alternate network is one of a VoIP IP data network, a mobile carrier network, a WiMax network, and a whitespace network. 
     
     
         14 . The call server of  claim 10 , further comprising severing the original communication link between the first communication device and the call server. 
     
     
         15 . 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 service 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; 
 
   receive an out of network signal over a network that is not the original network from the first communication device, the out of network signal indicative of the need to handoff the original communication link to an alternate communication link between the first communication device and the call server on the alternate network;   establish the alternate communication link between the first communication device and the call server on the alternate network; 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.   
     
     
         16 . The call server of  claim 15 , wherein the original network is one of a VoIP IP data network, a mobile carrier network, a WiMax network, and a whitespace network. 
     
     
         17 . The call server of  claim 15 , wherein the alternate network is one of a VoIP IP data network, a mobile carrier network, a WiMax network, and a whitespace network. 
     
     
         18 . The call server of  claim 15 , further comprising severing the original communication link between the first communication device and the call server.