System and method for providing an addressing and proxy scheme for facilitating mobility of wireless nodes between wired access points on a core network of a communications network

• US 20030091012A1
• Filed: 08/15/2001
• Published: 05/15/2003
• Est. Priority Date: 08/15/2001
• Status: Active Grant

• Current Assignee: Ruckus IP Holdings LLC
• Original Assignee: MeshNetworks, Inc. (Motorola Solutions, Inc.)
• Inventors: Barker, Charles R. Jr., Roberts, Robin U.
• Granted Patent: US 7,349,380 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/10 of different types
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

A communications network which is capable of effectively and efficiently handling mobility of wireless user terminals between access point nodes of a packet-switched network with minimal overhead and packet loss, and a method for using the same. The communications network employs a packet-switched core network and a plurality of access points coupled to the core network. Each access point is adapted to provide any user terminal with wireless communications access to the core network when that user terminal becomes affiliated with that access point. Each access point, as well as other nodes on the network such as a media server, DNS server and an IP gateway router, includes an address resolution cache which is adapted to store information representative of affiliation between the user terminals and the access points of the network. Each access point is adapted to deliver to the other access points a message indicating that a user terminal has changed its affiliation from another access point to that access point, to enable the other access points and core LAN nodes to update their respective address resolution cache based on the message. Preferably, an access point is adapted to issue the message over the core network as an address resolution request for an address, in particular, an IP protocol address, of the user terminal which has changed its affiliation to that access point.

Claims

1. A communications network, adapted for use with mobile wireless user terminals, said network comprising:

a packet-switched core network; and

a plurality of access points coupled to said core network, each said access point being adapted to provide any said user terminal with communications access to said core network when said any user terminal becomes affiliated with said access point, and including an address resolution cache which is adapted to store information representative of affiliation between said user terminals and said access points, and each said access point being adapted to deliver to the other said access points a message indicating that a said user terminal has changed its affiliation from another said access point to said access point, to enable said other access points to update their respective address resolution cache based on said message.

2. A communications network as claimed in claim 1, wherein:

said each access point is adapted to issue said message over said core network as an address resolution request for an address of said user terminal which has changed its affiliation thereto.

3. A communications network as claimed in claim 2, wherein:

said address resolution request includes an address resolution protocol request.

4. A communications network as claimed in claim 2, wherein:

said address of said user terminal includes an Internet protocol address assigned to said user terminal.

5. A communications network as claimed in claim 1, wherein:

said access point with which a said user terminal is affiliated is adapted to transmit a received data packet to said user terminal via a wireless communications link.

6. A communications network as claimed in claim 1, wherein:

each said access point includes a wireless transceiver, adapted to transmit and receive data packets to and from a said user terminal affiliated therewith via a wireless communications link.

7. A communications network as claimed in claim 1, wherein:

each said address resolution cache includes an address resolution protocol cache.

8. A communications network as claimed in claim 1, further comprising:

at least one of a media server, DNS server and an IP gateway router, each including a respective an address resolution cache which is adapted to store information representative of affiliation between said user terminals and said access points and is updateable based on said message.

9. A communications network as claimed in claim 8, wherein:

said address resolution cache includes an address resolution protocol cache.

10. A communications network as claimed in claim 1, wherein:

each said access point is adapted to provide any said user terminal with communications access to said core network when said user terminal is participating in an ad-hoc network.

11. An access point, coupled to a communications network and being adapted to provide mobile wireless user terminals with communications access said network, said access point comprising:

a wireless transceiver, adapted to transmit and receive data packets to and from a said wireless user terminal affiliated with said access point;

an address resolution cache, adapted to store information representative of affiliation between said user terminals and said access points; and

an affiliation indicator, adapted to deliver a message to other access points coupled to said communications network indicating that a said user terminal has changed its affiliation from another access point to said access point, to enable said other access points to update their respective address resolution cache based on said message.

12. An access point as claimed in claim 11, wherein:

said affiliation indicator is adapted to issue said message over said communications network as an address resolution request for an address of said user terminal which has changed its affiliation thereto.

13. An access point as claimed in claim 12, wherein:

said address of said user terminal includes an Internet protocol address assigned to said user terminal.

14. An access point as claimed in claim 12, wherein:

said address resolution request includes an address resolution protocol request.

15. An access point as claimed in claim 11, wherein:

each said address resolution cache includes an address resolution protocol cache.

16. An access point as claimed in claim 11, wherein:

said wireless transceiver is adapted to transmit and receive data packets to and from a said wireless user terminal affiliated with said access point when said user terminal is participating in an ad-hoc network.

17. A method of handling mobility of wireless user terminals adapted for use with a communications network including a packet-switched core network and a plurality of access points coupled to said core network, said method comprising:

provide a said user terminal with communications access to said core network via said access point when said user terminal becomes affiliated with said access point;

storing information representative of affiliation between said user terminals and said access points in a respective address resolution cache of each said access point;

controlling said access point to deliver to the other said access points a message indicating that a said user terminal has changed its affiliation from another said access point to said access point; and

updating respective said address resolution caches of the other said access points based on said message to indicate said change in affiliation of said user terminal.

18. A method as claimed in claim 17, wherein:

said controlling step controls said access point to issue said message over said core network as an address resolution request for an address of said user terminal which has changed its affiliation thereto.

19. A method as claimed in claim 18, wherein:

said address resolution request includes an address resolution protocol request.

20. A method as claimed in claim 18, wherein:

said address of s aid user terminal includes an Internet protocol address assigned to said user terminal.

21. A method as claimed in claim 17, further comprising:

controlling said access point with which a said user terminal is affiliated to transmit a received data packet to said user terminal via a wireless communications link.

22. A method as claimed in claim 17, wherein:

each of said address resolution caches includes an address resolution protocol cache.

23. A method as claimed in claim 17, further comprising:

updating respective address resolution caches of at least one of a media server, DNS server and an IP gateway router of said network based on said message.

24. A method as claimed in claim 23, wherein:

each of said respective address resolution caches includes an address resolution protocol cache.

25. A method as claimed in claim 17, wherein:

said providing step includes providing said user terminal with communications access to said core network when said user terminal is participating in an ad-hoc network.

26. A method for providing mobile wireless user terminals with communications access to a packet-switched network, said method comprising:

controlling an access point on said packet-switched network to transmit and receive data packets to and from a said wireless user terminal affiliated with said access point;

controlling said access point to store information representative of affiliation between said user terminals and access points on said packet-switched network in an address resolution cache of said access point;

controlling said access point to deliver a message to other said access points coupled to said packet-switched network indicating that a said user terminal has changed its affiliation from another access point to said access point; and

controlling said other access points to update their respective address resolution cache based on said message.

27. A method as claimed in claim 26, wherein:

said third controlling step controls said access point to issue said message over said packet-switched network as an address resolution request for an address of said user terminal which has changed its affiliation thereto.

28. A method as claimed in claim 27, wherein:

said address resolution request includes an address resolution protocol request.

29. A method as claimed in claim 27, wherein:

said address of said user terminal includes an Internet protocol address assigned to said user terminal.

30. A method as claimed in claim 26, wherein:

each said address resolution cache includes an address resolution protocol cache.

31. A method as claimed in claim 26, wherein:

said first controlling step controls said access point to transmit and receive data packets to and from a said wireless user terminal affiliated with said access point when said user terminal is participating in an ad-hoc network.

32. A computer-readable medium of instructions, adapted to control access points of a communications network including a packet-switched core network to handle mobility of wireless user terminals adapted for use with said communications network, said computer-readable medium of instructions comprising:

a first set of instructions, adapted to control a said access point to provide a said user terminal with communications access to said core network via said access point when said user terminal becomes affiliated with said access point;

a second set of instructions, adapted to control each of said access points to store information representative of affiliation between said user terminals and said access points in their respective address resolution cache;

a third set of instructions, adapted to control said access point to deliver to the other said access points a message indicating that a said user terminal has changed its affiliation from another said access point to said access point; and

a fourth set of instructions, adapted to update respective said address resolution caches of the other said access points based on said message to indicate said change in affiliation of said user terminal.

33. A computer-readable medium of instructions as claimed in claim 32, wherein:

said second set of instructions is adapted to control said access point to issue said message over said core network as an address resolution request for an address of said user terminal which has changed its affiliation thereto.

34. A computer-readable medium of instructions as claimed in claim 33, wherein:

said address resolution request includes an address resolution protocol request.

35. A computer-readable medium of instructions as claimed in claim 33, wherein:

said address of said user terminal includes an Internet protocol address assigned to said user terminal.

36. A computer-readable medium of instructions as claimed in claim 32, further comprising:

a fifth set of instructions, adapted to control said access point with which a said user terminal is affiliated to transmit a received data packet to said user terminal via a wireless communications link.

37. A computer-readable medium of instructions as claimed in claim 32, wherein:

each of said address resolution caches includes an address resolution protocol cache.

38. A computer-readable medium of instructions as claimed in claim 32, further comprising:

a sixth set of instructions, adapted to control at least one of a media server, DNS server and an IP gateway router of said network to update its respective address resolution cache of based on said message.

39. A computer-readable medium of instructions as claimed in claim 38, wherein:

each of said respective address resolution caches includes an address resolution protocol cache.

40. A computer-readable medium of instructions as claimed in claim 32, wherein:

said first set of instructions is adapted to control said access point to provide said user terminal with communications access to said core network when said user terminal is participating in an ad-hoc network.

41. A computer-readable medium of instructions for controlling an access point of a packet-switched network to providing mobile wireless user terminals with communications access to said packet-switched network, said computer-readable medium of instructions comprising:

a first set of instructions, adapted to control a said access point on said packet-switched network to transmit and receive data packets to and from a said wireless user terminal affiliated with said access point;

a second set of instructions, adapted to control said access point to store information representative of affiliation between said user terminals and access points on said packet-switched network in an address resolution cache of said access point;

a third set of instructions, adapted to control said access point to deliver a message to other said access points coupled to said packet-switched network indicating that a said user terminal has changed its affiliation from another access point to said access point; and

a fourth set of instructions, adapted to control said other access points to update their respective address resolution cache based on said message.

42. A computer-readable medium of instructions as claimed in claim 41, wherein:

said third set of instructions is adapted to control said access point to issue said message over said packet-switched network as an address resolution request for an address of said user terminal which has changed its affiliation thereto.

43. A computer-readable medium of instructions as claimed in claim 42, wherein:

said address resolution request includes an address resolution protocol request.

44. A computer-readable medium of instructions as claimed in claim 42, wherein:

said address of said user terminal includes an Internet protocol address assigned to said user terminal.

45. A computer-readable medium of instructions as claimed in claim 41, wherein:

each of said respective address resolution caches includes an address resolution protocol cache.

46. A computer-readable medium of instructions as claimed in claim 41, wherein:

said first set of instructions is adapted to control said access point to provide said user terminal with communications access to said core network when said user terminal is participating in an ad-hoc network.