Method and apparatus for effecting a seamless handoff between IP connections

• US 20040028009A1
• Filed: 08/06/2002
• Published: 02/12/2004
• Est. Priority Date: 08/06/2002
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Dorenbosch, Jheroen P., Bennett, Richard L., Raymer, David L.
• Granted Patent: US 6,768,726 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/169 Special adaptations of TCP, UDP or IP for interworking of IP based networks with other networks protocols for interworking, protocol conversion H04L69/08
• CPC Class Codes: H04W 36/0019 adapted for mobile IP [MIP]
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 80/06 Transport layer protocols, e.g. TCP [Transport Control Protocol] over wireless transmission control protocol/Internet protocol [TCP/IP] or user datagram protocol [UDP] H04L69/16
• CPC Class Codes: H04W 88/16 Gateway arrangements

Abstract

A method 900 of and apparatus for effecting a handoff from a first Internet Protocol (IP) connection 221 to a second IP connection 331 is disclosed. The method includes: communicating a packet data communication between a first station and a gateway (either acting as an application level gateway or as and endpoint for an SCTP tunnel) using the first IP connection and a first IP address for the first station, the gateway relaying the packet data communication with a second station; setting up the second IP connection with a second IP address for the first station, the first IP connection being a primary connection and the second IP connection being a secondary connection between the first station and the gateway, the first and the second IP connection existing concurrently; determining that the second IP connection should be the primary connection between the first station and the gateway; and changing the second IP connection to the primary connection by informing the gateway that the second IP address is the primary address using stream control transmission protocol (SCTP) messages, wherein the packet data communication is immediately switched over to the second IP connection.

Claims

1. A method of effecting a seamless handoff from a first Internet Protocol (IP) connection to a second IP connection, the method comprising:

communicating a packet data communication between a first station and a gateway using the first IP connection and a first IP address for said first station, said gateway relaying said packet data communication with a second station;

setting up the second IP connection with a second IP address for said first station, the first IP connection being a primary connection and the second IP connection being a secondary connection between said first station and said gateway, said first and said second IP connection existing concurrently;

determining that the second IP connection should be said primary connection between said first station and said gateway; and

changing the second IP connection to said primary connection by informing said gateway that the second IP address is the primary address using stream control transmission protocol (SCTP) messages,

wherein said packet data communication is immediately switched over to the second IP connection.

2. The method of claim 1 further including, initiating the first IP connection by informing said gateway of said first IP address using SCTP messages before starting said communicating.

3. The method of claim 1 wherein said communicating between said first station and said gateway uses SCTP over the first IP connection and the second IP connection and said gateway uses one of Transport Communication Protocol (TCP) and Universal Datagram Protocol (UDP) to relay said packet data communication with said second station.

4. The method of claim 1 wherein said setting up the second IP connection further includes searching for an appropriate IP connection, associating with an IP access point, and establishing connectivity with the gateway by informing said gateway of said second IP address using SCTP.

5. The method of claim 4 wherein said searching, said associating, and said establishing are undertaken independent of an application supporting said communicating.

6. The method of claim 4 wherein said searching for said appropriate IP connection further includes one of determining that an available connection includes an access point and suitable services, that said first station is able to successfully authenticate with said access point, and that connectivity to said gateway is available.

7. The method of claim 4 wherein said informing said gateway of said second IP address using SCTP uses said second IP connection thereby initializing said second IP connection.

8. The method of claim 1 wherein said determining that the second IP connection should be said primary connection further includes one of determining that the first IP connection quality of service is degrading, that tariffs for the second IP connection are favorable, and that services are desired that are available via the second IP connection.

9. The method of claim 1 further including, when the second IP connection becomes said primary connection, discontinuing the first IP connection by instructing, using SCTP messages, said gateway to delete said first IP address and terminating any association using said first IP address.

10. The method of claim 1 wherein said gateway in said relaying said packet data communications further performs a translation between an external IP address corresponding to said first station and one of said first IP address and said second IP address for said first station.

11. The method of claim 10 wherein said gateway further translates between SCTP on one of the first and the second IP connections with said first station and one of Transport Communication Protocol (TCP) and Universal Datagram Protocol (UDP) to relay said packet data communication with said second station.

12. The method of claim 1 wherein the first IP connection uses SCTP tunneling facilitated by said gateway for said communicating said packet data communication with said first station wherein said first station can interact with said second station when each are running one of a Transport Communication Protocol (TCP) and Universal Datagram Protocol (UDP) based application.

13. The method of claim 12 wherein said second IP connection uses SCTP tunneling facilitated by said gateway.

14. The method of claim 1 wherein one of the first and the second IP connection is a wireless IP connection.

15. The method of claim 14 wherein the wireless IP connection includes one of an 802.11 access point, a Bluetooth access point, a HiperLan access point, a wireless local area network (LAN) access point, a cellular station, a Code Division Multiple Access station and a Universal Mobile Telecommunication Service station.

16. A wireless communications unit arranged and constructed to effect a handoff from a first Internet Protocol (IP) connection to a second IP connection, the wireless communications unit comprising:

a wireless transceiver and a controller cooperatively arranged for communicating a packet data communication with a gateway using the first IP connection and a first IP address for the wireless communications unit, said gateway for relaying said packet data communication to a second station;

said controller further for;

setting up the second IP connection with a second IP address for the wireless communications unit, the first IP connection being a primary connection and the second IP connection being a secondary connection between the wireless communications unit and the gateway, the first and the second IP connection existing concurrently;

determining that the second IP connection should be said primary connection; and

changing the second IP connection to said primary connection by informing said gateway that said second IP address is said primary address using stream control transmission protocol (SCTP) messages,

wherein said packet data communication is immediately switched over to the second IP connection.

17. The wireless communications unit of claim 16 wherein said wireless transceiver and said controller initiate the first IP connection by informing said gateway of said first IP address using SCTP messages before starting said communicating.

18. The wireless communications unit of claim 16 wherein said communicating with said gateway uses SCTP over the first IP connection and the second IP connection whereas said gateway uses one of SCTP, Transport Communication Protocol (TCP), and Universal Datagram Protocol (UDP) to relay said packet data communication with said second station.

19. The wireless communications unit of claim 16 wherein said transceiver is further cooperatively operating with said controller for said setting up the second IP connection and further for searching for an appropriate wireless IP connection, associating with a wireless IP access point, and establishing connectivity with said gateway by informing said gateway of the second IP address using SCTP.

20. The wireless communications unit of claim 19 wherein said searching, said associating, and said establishing are undertaken independent of an application supporting said communicating.

21. The wireless communications unit of claim 19 wherein said searching for said appropriate wireless IP connection further includes one of determining that an available connection includes an access point and suitable services, that said wireless communications unit is able to successfully authenticate with said access point, and that connectivity to said gateway is available.

22. The wireless communications unit of claim 19 wherein said informing said gateway of said second IP address using SCTP uses said second IP connection thereby initializing said second IP connection.

23. The wireless communications unit of claim 16 wherein said determining that the second IP connection should be said primary connection further includes one of determining that the first IP connection quality of service is degrading, that tariffs for the second IP connection are favorable, and that services are desired that are available via the second IP connection.

24. The wireless communications unit of claim 16 further including, when the second IP connection becomes said primary connection, discontinuing the first IP connection by instructing, using SCTP messages, said gateway to delete said first IP address and terminating any association using said first IP address.

25. The wireless communications unit of claim 16 wherein said gateway in said relaying said packet data communications further performs translation between an external IP address corresponding to said wireless communications unit and one of said first IP address and said second IP address for said wireless communications unit.

26. The wireless communications unit of claim 25 wherein said gateway further translates between SCTP on one of the first and the second IP connections with said wireless communications unit and one of Transport Communication Protocol (TCP) and Universal Datagram Protocol (UDP) to relay said packet data communication with said second station.

27. The wireless communications unit of claim 16 wherein the first IP connection uses SCTP tunneling facilitated by said gateway for said communicating said packet data communication with said wireless communications unit wherein said wireless communications unit interacts with said second station when each are running one of a Transport Communication Protocol (TCP) and Universal Datagram Protocol (UDP) based application.

28. The wireless communications unit of claim 27 wherein the second IP connection uses SCTP tunneling facilitated by said gateway.

29. The wireless communications unit of claim 16 further including a port for coupling to an external device, wherein the first IP connection uses SCTP tunneling facilitated by said gateway for said communicating said packet data communication with said wireless communications unit, said port for exchanging one of a Transport Communication Protocol (TCP) and Universal Datagram Protocol (UDP) with said external device, thereby providing TCP/UDP communications between the external device and said second station when each are running a TCP/UDP based application.

30. The wireless communications unit of claim 16 wherein the first and the second IP connection are each one of an 802.11 access point, a Bluetooth access point, a HiperLan access point, a wireless local area network (LAN) access point, a cellular station, a Code Division Multiple Access station and a Universal Mobile Telecommunication Service station.

31. A gateway arranged and configured to facilitate a seamless handoff from a first Internet Protocol (IP) connection to a second IP connection, the gateway operable for:

communicating a packet data communication with a first station using the first IP connection and a first IP address for said first station and for relaying said packet data communication with a second station;

setting up the second IP connection with a second IP address for said first station, the first IP connection being a primary connection and the second EP connection being a secondary connection with said first station, said first and said second IP connection existing concurrently;

receiving a stream control transmission protocol (SCTP) message indicating that the second IP connection should be said primary connection with said first station; and

changing the second IP connection to said primary connection by using the second IP address as the primary address for said packet data communications, wherein said packet data communication is immediately switched over to the second IP connection.

32. The gateway of claim 31 further including, initiating the first IP connection by receiving an SCTP message indicating that said first IP address corresponds to said first station before starting said communicating.

33. The gateway of claim 31 wherein said communicating with said first station uses SCTP over the first IP connection and the second IP connection and said relaying said packet data communication with a second station uses one of Transport Communication Protocol (TCP) and Universal Datagram Protocol (UDP).

34. The gateway of claim 31 wherein said setting up the second IP connection further includes receiving an SCTP message including said second IP address for said first station.

35. The gateway of claim 34 wherein said receiving said SCTP message including said second IP address uses said second IP connection thereby initializing said second IP connection.

36. The gateway of claim 31 further including, when the second IP connection becomes said primary connection, discontinuing the first IP connection by receiving an SCTP message indicating to said gateway to delete said first IP address and terminate any association using said first IP address.

37. The gateway of claim 31 wherein said relaying said packet data communications further includes translating between an external IP address corresponding to said first station and one of said first IP address and said second IP address for said first station.

38. The gateway of claim 37 wherein said translating further includes translating between SCTP on one of the first and the second IP connections with said first station and one of Transport Communication Protocol (TCP) and Universal Datagram Protocol (UDP) when said relaying said packet data communication with said second station.

39. The gateway of claim 31 further using SCTP tunneling to support the first IP connection for said communicating said packet data communication with said first station wherein said first station can interact with said second station when each are running one of a Transport Communication Protocol (TCP) and Universal Datagram Protocol (UDP) based application.

40. The gateway of claim 39 wherein said gateway uses SCTP tunneling to support said second IP connection.