Method and apparatus for media independent handover
A method and apparatus for performing a handover are disclosed. An Internet protocol (IP) multimedia subsystem (IMS) client registers with an IMS network and establishes an MIH session with an MIH application server using an SIP. The IMS client establishes a session for IP-based service, (e.g., VoIP), with a communication peer using SIP messaging. MIH messages are exchanged for handover with the MIH application server over IP using SIP messages by encapsulating the MIH messages in SIP instant messages. Alternatively, the MIH messages may be exchanged with the MIH application over IP by sending equivalent SIP messages in place of the MIH messages.
1. A method for use in a wireless transmit/receive unit (WTRU), the method comprising:
the WTRU registering with a Call Session Control Function (CSCF) in an Internet Protocol (IP) Multimedia Subsystem (IMS) via a first wireless network of a first network type;
the WTRU transmitting a first session initiation protocol (SIP) message to an application server in the IMS via the first wireless network, wherein the first SIP message includes a media independent handover (MIH) message; and
the WTRU establishing an application session with a second WTRU via the first wireless network;
the WTRU communicating with the second WTRU according to the application session via the first wireless network using a first Internet Protocol (IP) address;
the WTRU performing a handover from the first wireless network to a second wireless network of a second network type;
the WTRU obtaining a second IP address for communicating in the second wireless network;
the WTRU transmitting a second SIP message via the second wireless network for continuing the application session in the second wireless network, wherein the second SIP message indicates the second IP address; and
the WTRU communicating with the second WTRU according to the application session via the second wireless network using the second IP address.
2. The method of claim 1 wherein the first SIP message is a SIP instant message.
3. The method of claim 1 wherein the MIH message is a MIH_CAPABILITY_DISCOVERY.REQUEST message.
4. The method of claim 1 wherein the MIH message is a MIH_REGISTER.REQUEST message.
5. The method of claim 4 , further comprising:
receiving a third SIP message from the application server, wherein the third SIP message includes a MIH_REGISTER.CONFIRM message that is responsive to the MIH_REGISTER.REQUEST message.
6. The method of claim 1 wherein the MIH message is a MIH_EVENT_SUBSCRIBE.REQUEST message.
7. The method of claim 1 wherein the first SIP message is a SIP OPTIONS message.
8. A wireless transmit/receive unit (WTRU), the WTRU comprising:
at least one transceiver configured to transmit, via a first wireless network of a first network type, one or more messages to register the WTRU with a Call Session Control Function (CSCF) in an Internet Protocol (IP) Multimedia Subsystem (IMS); and
a processor, configured to generate a first session initiation protocol (SIP) message that includes a media independent handover (MIH) message;
wherein the at least one transceiver is further configured to:
transmit the SIP message to an application server in the IMS via the first wireless network;
establish an application session with a second WTRU via the first wireless network;
communicate with the second WTRU according to the application session via the first wireless network using a first Internet Protocol (IP address);
perform a handover from the first wireless network to a second wireless network of a second network type;
obtain a second IP address for communicating in the second wireless network;
transmit a second SIP message via the second wireless network for continuing the application session in the second wireless network, wherein the second SIP message indicates the second IP address; and
communicate with the second WTRU according to the application session via the second wireless network using the second IP address.
9. The WTRU of claim 8 wherein the first SIP message is a SIP instant message.
10. The WTRU of claim 8 wherein the MIH message is a MIH_CAPABILITY_DISCOVERY.REQUEST message.
11. The WTRU of claim 8 wherein the MIH message is a MIH_REGISTER.REQUEST MESSAGE.
12. The WTRU of claim 11 ,
wherein the at least one transceiver is configured to receive a third SIP message from the application server, wherein the third SIP message includes a MIH_REGISTER.CONFIRM message that is responsive to the MIH_REGISTER.REQUEST message.
13. The WTRU of claim 8 wherein the MIH message is a MIH_EVENT_SUBSCRIBE.REQUEST message.
14. The WTRU of claim 8 wherein the first SIP message is a SIP OPTIONS message.
15. The method of claim 1 , wherein the application session is a Voice over Internet Protocol (VoIP) session, an instant messaging session, or a video streaming session.
16. The method of claim 1 , wherein the first network type is wireless local area network (WLAN) and the second network type is cellular.
17. The method of claim 1 , wherein the first network type is cellular and wherein the second network type is wireless local area network (WLAN).
18. The method of claim 1 , wherein the second SIP message is a SIP REFER message and is transmitted to the application server.
19. The method of claim 1 , wherein the second SIP message is a SIP RE-INVITE message and is transmitted to the application server.
20. The method of claim 1 , wherein the second SIP message is a SIP RE-INVITE message and is transmitted to the second WTRU.
21. The WTRU of claim 8 , wherein the application session is a Voice over Internet Protocol (VoIP) session, an instant messaging session, or a video streaming session.
22. The WTRU of claim 8 , wherein the first network type is wireless local area network (WLAN) and the second network type is cellular.
23. The WTRU of claim 8 , wherein the first network type is cellular and the second network type is wireless local area network (WLAN).
24. The WTRU of claim 8 , wherein the second SIP message is a SIP REFER message and is transmitted to the application server.
25. The WTRU of claim 8 , wherein the second SIP message is a SIP RE-INVITE message and is transmitted to the application server.
26. The WTRU of claim 8 , wherein the second SIP message is a SIP RE-INVITE message and is transmitted to the second WTRU.