Seamless Handoff Across Heterogeneous Access Networks Using a Handoff Controller in a Service Control Point

A method for using a handoff controller for handing off a communication session of a first communication device from a first network to a second network, wherein the first network is one of an Internet Protocol (IP) network and a cellular network and the second network is a different one of the IP network and the cellular network as compared to the first network, and wherein the first communication device is in communication with a second communication device, the method comprising:

• sending a Session Initiation Protocol (SIP) message from the handoff controller to the first communication device instructing the first communication device to monitor at least one predetermined characteristic of an interface between the first communication device and the first network;
• receiving at the handoff controller an SIP message from the first communication device when a value associated with the at least one predetermined characteristic has been met to provide a received SIP message;
• receiving at the handoff controller network information regarding available connection points in the second network;
• determining in the handoff controller, based on the received SIP message and the network information, one of the available connection points in the second network to which the first communication device shall be connected;
• sending a further SIP message from the handoff controller to the first communication device identifying the one of the available connection points in the second network;
• and
• effecting, by the handoff controller, a seamless handoff of the first communication device from the first network to the second network via the identified one of the available connection points so as to allow continued communication between the first communication device and the second communication device;
• wherein the SIP messages contain non-SIP service primitives pertaining to handover capabilities, with the handoff controller performing the steps as a function, at least in part, of the service primitives.

A method for using a first communication device in connection with a handoff of a communication session of the first communication device from a first network to a second network, wherein the first network is one of an Internet Protocol (IP) network and a cellular network and the second network is a different one of the IP network and the cellular network as compared to the first network, and wherein the first communication device is in communication with a second communication device, the method comprising:

• receiving at the first communication device a Session Initiation Protocol (SIP) message from a handoff controller instructing the first communication device to monitor at least one predetermined characteristic of an interface between the first communication device and the first network;
• sending an SIP message from the first communication device to the handoff controller when a value associated with the at least one predetermined characteristic has been met;
• receiving at the first communication device a further SIP message from the handoff controller identifying one available connection point in the second network, wherein the identified one available connection point is determined by the handoff controller based on the SIP message and additional network information the handoff controller receives which contain information regarding available connection points in the second network;
• and
• effecting, through the first communication device, a seamless handoff of the first communication device from the first network to the second network via the identified one of the available connection points so as to allow continued communication between the first communication device and the second communication device;
• and
• wherein the SIP messages contain non-SIP service primitives pertaining to handover capabilities, with the first communication device performing the steps as a function, at least in part, of the service primitives.

An apparatus comprising a handoff controller for handing off a communication session of a first communication device from a first network to a second network, wherein the first network is one of an Internet Protocol (IP) network and a cellular network and the second network is a different one of the IP network and the cellular network as compared to the first network, and wherein the first communication device is in communication with a second communication device, the handoff controller comprising:

• a Session Initiation Protocol (SIP) interface configured to send and receive SIP messages;
• a handover processing part configured to process non-SIP service primitives that pertain to handover capabilities;
• and
• a session handover manager configured to effect the handing off of the communication session of the first communication device from the first network to the second network by:
• sending an SIP message to the first communication device instructing the first communication device to monitor at least one predetermined characteristic of an interface between the first communication device and the first network;
• receiving an SIP message from the first communication device when a value associated with the at least one predetermined characteristic has been met to provide a received SIP message;
• receiving network information regarding available connection points in the second network;
• determining, based on the received SIP message and the network information, one of the available connection points in the second network to which the first communication device shall be connected;
• sending a further SIP message to the first communication device identifying the one of the available connection points in the second network;
• and
• effecting a seamless handoff of the first communication device from the first network to the second network via the identified one of the available connection points so as to allow continued communication between the first communication device and the second communication device;
• wherein the SIP messages contain non-SIP service primitives pertaining to handover capabilities, with the session handover manager performing, at least in part, as a function of the service primitives.

A tangible computer-readable medium having stored thereon computer-executable instructions that, if executed by a computing device, cause the computing device to perform a method for handing off a communication session of a first communication device from a first network to a second network, wherein the first network is one of an Internet Protocol (IP) network and a cellular network and the second network is a different one of the IP network and the cellular network as compared to the first network, and wherein the first communication device is in communication with a second communication device, the method comprising:

• sending a Session Initiation Protocol (SIP) message from the computing device to the first communication device instructing the first communication device to monitor at least one predetermined characteristic of an interface between the first communication device and the first network;
• receiving at the computing device an SIP message from the first communication device when a value associated with the at least one predetermined characteristic has been met to provide a received SIP message;
• receiving at the computing device network information regarding available connection points in the second network;
• determining in the computing device, based on the received SIP message and the network information, one of the available connection points in the second network to which the first communication device shall be connected;
• sending a further SIP message from the computing device to the first communication device identifying the one of the available connection points in the second network;
• and
• effecting, by the computing device, a seamless handoff of the first communication device from the first network to the second network via the identified one of the available connection points so as to allow continued communication between the first communication device and the second communication device;
• wherein the SIP messages contain non-SIP service primitives pertaining to handover capabilities, with the computing device performing the steps as a function, at least in part, of the service primitives.