Method and system for providing transparent mobility support

• US 20030097484A1
• Filed: 11/16/2001
• Published: 05/22/2003
• Est. Priority Date: 11/16/2001
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Bahl, Pradeep
• Granted Patent: US 7,146,418 B2
• Time in Patent Office: Days
• US Class Current: 719/313
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• 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 69/162 involving adaptations of sockets based mechanisms secure socket layer H04L63/168
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 80/10 adapted for application session management, e.g. SIP [Session Initiation Protocol] connection management H04W76/00; arrangements for session management H04L67/14

Abstract

A system and method for providing transparent mobility support employs a mobile service in an API layer of an operating system to leverage the capability of a session establishment service that implements the Session Initiation Protocol or the like for locating a remote node for session setup and detecting address change of the remote node. When an application on a correspondent host (CH) wants to communicate with a second application on a mobile host (MH), the mobility service of the CH uses the session establishment service to locate the mobile host and set up a session with it, and then sets up a transport data channel for the session. When the MH changes its network address, the session establishment service of the CH finds out the new address through the operation of the session establishment protocol and reestablishes the session with the MH. The new address of the MH is then communicated to the CH'"'"'s mobility service, which resets the data channel to connect to the new address, thereby allowing communication data from the first application to continue to flow to the MH.

Claims

1. A computer-readable medium having computer-executable instructions for performing steps for a correspondent host to provide mobility support for communications with a mobile host, the steps comprising:

receiving, by a mobility service of the correspondent host, a request from a first application on the correspondent host to set up a communication connection with a second application on the mobile host, the mobility service being implemented in an application programming interface (API) layer of an operating system of the correspondent host;

calling, by the mobility service, a session establishment service of the correspondent host implementing a session establishment protocol to establish a session with the mobile host;

establishing, by the session establishment service, a session with the mobile host;

setting up, by the mobility service, a communication connection under a transport protocol for communications between the first and second applications;

obtaining, by the session establishment service, a notice through operation of the session establishment protocol that the mobile host has moved to a new address;

reestablishing, by the session establishment service, a session with the mobile host for the new address of the mobile host; and

resetting, by the mobility service, a communication connection for the new address of the mobile host.

2. A computer-readable medium as in claim 1, comprising further computer-executable instructions for the correspondent host to performs the steps of:

retrieving buffered communication data for the communication connection between the first and second applications prior to resetting the communication connection; and

sending the retrieved buffered communication data over the reset communication channel for the new address of the mobile host.

3. A computer-readable medium as in claim 1, comprising further computer-executable instructions for the correspondent host to performs the step of tunneling communication data to the mobile host using the new address of the mobile host before completing the step of resetting.

4. A computer-readable medium as in claim 1, wherein the session establishment protocol is the Session Initiation Protocol.

5. A computer-readable medium as in claim 1, wherein the transport protocol is the TCP.

6. A computer-readable medium as in claim 5, wherein the transport protocol is the UDP.

7. A computer-readable medium as in claim 1, wherein the first application identifies the second application by a name in the request to form a communication connection.

8. A computer-readable medium having computer-executable instructions for performing steps for a correspondent host to provide mobility support for communications between a first application on the correspondent host with a second application on a mobile host over an existing session and an existing communication connection, the steps comprising:

receiving, by a session establishment service of the correspondent host implementing a session establishment protocol, a notice through operation of the session establishment protocol that the mobile host has moved to a new address;

reestablishing, by the session establishment service, a session with the mobile host for the new address of the mobile host; and

resetting, by a mobility service, a communication connection for the new address of the mobile host for communications between the first and second applications, the mobility service being implemented in an application programming interface (API) layer of an operating system of the correspondent host.

9. A computer-readable medium as in claim 8, comprising further computer-executable instructions for the correspondent host to performs the steps of:

retrieving buffered communication data for the communication connection between the first and second applications prior to resetting the communication connection; and

sending the retrieved buffered communication data over the reset communication channel for the new address of the mobile host.

10. A computer-readable medium as in claim 8, comprising further computer-executable instructions for the correspondent host to performs the step of tunneling communication data to the mobile host using the new address of the mobile host after receiving the notice of the new address of the mobile host and before completing the step of resetting.

11. A computer-readable medium as in claim 8, wherein the session establishment protocol is the Session Initiation Protocol.

12. A computer-readable medium as in claim 8, wherein the transport protocol is the TCP.

13. A computer-readable medium as in claim 8, wherein the transport protocol is the UDP.

14. A method for a correspondent host to provide mobility support for communications with a mobile host, comprising the steps of:

receiving, by a mobility service of the correspondent host, a request from a first application on the correspondent host to set up a communication connection with a second application on the mobile host, the mobility service being implemented in an application programming interface (API) layer of an operating system of the correspondent host;

calling, by the mobility service, a session establishment service of the correspondent host implementing a session establishment protocol to establish a session with the mobile host;

establishing, by the session establishment service, a session with the mobile host;

setting up, by the mobility service, a communication connection under a transport protocol for communications between the first and second applications;

obtaining, by the session establishment service, a notice through operation of the session establishment protocol that the mobile host has moved to a new address;

reestablishing, by the session establishment service, a session with the mobile host for the new address of the mobile host; and

resetting, by the mobility service, a communication connection for the new address of the mobile host.

15. A method as in claim 14, comprising further the steps of:

retrieving buffered communication data for the communication connection between the first and second applications prior to resetting the communication connection; and

sending the retrieved buffered communication data over the reset communication channel for the new address of the mobile host.

16. A method as in claim 14, comprising further the step of tunneling communication data to the mobile host using the new address of the mobile host before completing the step of resetting.

17. A method as in claim 14, wherein the session establishment protocol is the Session Initiation Protocol.

18. A computer-readable medium as in claim 14, wherein the transport protocol is the TCP.

19. A method as in claim 14, wherein the transport protocol is the UDP.

20. A method as in claim 14, wherein the first application identifies the second application by a name in the request to form a communication connection.