Wireless network infrastructure including wireless discovery and communication mechanism

• US 7,340,247 B1
• Filed: 05/29/2003
• Issued: 03/04/2008
• Est. Priority Date: 05/29/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Airespace, Inc. (Cisco Systems, Inc.)
• Inventors: Calhoun, Patrice R., Friday, Robert J., O'Hara, Robert B. Jr., Dietrich, Paul F.
• Primary Examiner(s): Kincaid; Lester G.
• Assistant Examiner(s): SHEDRICK, CHARLES TERRELL
• Application Number:
  US10/447,735
• Time in Patent Office: 1,741 Days
• Field of Search: 455/418, 370/338, 370/349
• US Class Current: 455/418
• CPC Class Codes: H04W 40/246 Connectivity information discovery
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A wireless discovery and communication mechanism to facilitate configuration, management and performance tasks associated with wireless network environments. In certain embodiments, access elements transmit and receive neighbor messages on a periodic basis to neighboring access elements. The neighbor messages can include configuration and/or protocol information to allow the access elements or associated devices to discover each other over the air. The present invention can be applied to a variety of wireless network architectures, such as a plurality of distributed, substantially autonomous access points, or to a hierarchical wireless network system comprising central control elements, each supervising and controlling one or more access elements as described more fully below.

Claims

1. A wireless network system, comprising a plurality of access elements for communication with at least one remote client element and for communication with a central control element;

a first central control element supervising at least one of said access elements, wherein the first central control element manages and controls the wireless connections between the access elements and corresponding remote client elements; and

a second central control element supervising at least one other of said access elements;

wherein each access element is configured to;

transmit wireless neighbor messages, wherein the wireless neighbor messages identify a network address of a central control element supervising the access element;

receive wireless neighbor messages from neighboring access elements, wherein the received wireless neighbor messages identify network addresses of respective central control elements supervising the neighboring access elements;

provide received wireless neighbor messages to a supervising central control element associated with the access element; and

wherein the first and second central control elements are each configured to establish respective tunnels over a computer network with access elements for transmission of wireless traffic, associated with corresponding remote client elements with encapsulation headers;

bridge network traffic between the computer network and a remote client element through a tunnel with a corresponding access element;

perform data link layer management functions on wireless traffic corresponding to the remote client elements; and

discover each other'"'"'s respective network address by processing the wireless neighbor messages received from associated access elements.

2. The system of claim 1 wherein the wireless neighbor messages each include information associated with transmitting access elements.

3. The system of claim 1 wherein the wireless neighbor messages each include configuration information associated with transmitting access elements.

4. The system of claim 1 wherein the first and second central control elements are each operative to discover each other over a wired network using the network addresses received in wireless neighbor messages.

5. The system of claim 1 wherein the access elements are operative to encapsulate wireless neighbor messages with headers and transmit the encapsulated neighbor messages to corresponding central control elements.

6. The system of claim 5 wherein the access elements are further operative to

detect the strength of the signals associated with wireless neighbor messages;

include indicators of the detected signal strengths in the headers encapsulating the wireless neighbor messages.

7. The system of claim 1 wherein the wireless neighbor messages are each single data link layer frames.

8. The system of claim 7 wherein the wireless neighbor messages include a wireless distribution system mode header.

9. The system of claim 1 wherein the access elements are each operative to

coordinate transmission of wireless neighbor messages with wireless data link layer functionality associated with the access elements.

10. The system of claim 9 wherein the access elements are each operative to

coordinate transmission of wireless neighbor messages with the transmission of beacon frames.

11. The system of claim 1 wherein the access elements are each operative to

transmit wireless neighbor messages on one to a plurality of operating channels.

12. The system of claim 1 wherein the access elements are operative to encapsulate and transmit using a tunnel detected wireless neighbor messages to corresponding central control elements.

13. The system of claim 1 wherein the access elements are each connected to the central control element via a direct access line.

14. The system of claim 1 wherein the access elements are each operably coupled to the computer network.

15. The system of claim 13 wherein the computer network is a local area computer network.

16. The system of claim 13 wherein the computer network is a virtual local area computer network.

17. The system of claim 1 wherein the tunnel is a data link layer tunnel.

18. The system of claim 1 wherein the tunnel is a network layer tunnel.

19. The system of claim 1 wherein the computer network is a local area network.

20. The system of claim 1 wherein the computer network is a virtual local area computer network.

21. The system of claim 1 wherein the computer network is a wide area computer network.

22. The system of claim 19 wherein the central control element is coupled to a second local area network, and the access elements and the central control element communicate over a global network operative to route data between the first and second local area networks.

23. An apparatus for use in a wireless network environment,

Comprising

A transmit/receive unit communicating wireless communication with at least one remote client element, a network interface for communicating with a central control element,

Wherein the apparatus is configured to:

Establish and maintain;

in an access point mode, wireless connections with remote client elements to bridge wireless traffic between the remote client elements and the computer network;

Acknowledge wireless frames transmitted by the remote client elements;

transmit the received wireless frames with encapsulating headers to the central control element for processing;

Transmit beacon frames at regular intervals;

switch to a neighbor message mode at periodic intervals to transmit wireless neighbor messages, wherein the wireless neighbor messages, wherein the wireless neighbor messages are scheduled for transmission after respective beacon frames, wherein the wireless neighbor messages each identify a network address of the central control element, receive wireless neighbor messages from neighboring wireless access devices, process received wireless neighbor messages; and

encapsulate the received wireless neighbor messages with tunnel headers and transmit the encapsulated wireless neighbor messages to a central control element.

24. The apparatus of claim 23 wherein the apparatus is operative to transmit the wireless neighbor messages on all available operating channels.

25. The apparatus of claim 24 wherein a single wireless neighbor message is transmitted over a given available operating channel at each of said periodic intervals.

26. The apparatus of claim 25 wherein the apparatus comprises a daemon, invoked at the periodic intervals, operative to:

monitor operation of the transmit/receive unit to coordinate transmission of neighbor wireless messages with operation of the transmit/receive unit.

27. The apparatus of claim 26 wherein the daemon is operative to coordinate transmission of neighbor messages so as to not interfere with transmission of the beacon frames.

28. The apparatus of claim 23 wherein the beacon frames announce contention free periods, during which respective wireless neighbor messages are transmitted.

29. The apparatus of claim 23 wherein the wireless neighbor messages each include information associated with the transmitting apparatus.

30. The apparatus of claim 23 wherein the wireless neighbor messages each include configuration information associated with the transmitting apparatus.

31. The apparatus of claim 29 wherein the apparatus is further operative to discover other transmitting apparatuses over a wired network using the configuration information received in wireless neighbor messages.

32. The apparatus of claim 23 wherein the apparatus is further operative to

detect the strength of the signals associated with wireless neighbor messages;

and

include indicators of the detected signal strengths in the headers encapsulating the wireless neighbor messages.

33. The apparatus of claim 23 wherein the wireless neighbor messages are each single data link layer frames.

34. The apparatus of claim 33 wherein the wireless neighbor messages include a wireless distribution system mode header.