Method for optimized layer 2 roaming and policy enforcement in a wireless environment

• US 7,602,746 B2
• Filed: 12/21/2005
• Issued: 10/13/2009
• Est. Priority Date: 11/04/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Calhoun, Patrice R., Cam-Winget, Nancy, O'Hara, Robert B. Jr.
• Primary Examiner(s): Bhattacharya; Sam
• Application Number:
  US11/315,861
• Publication Number:
  US 20070104126A1
• Time in Patent Office: 1,392 Days
• Field of Search: 455/414.1, 455/41.2, 455/410, 455/411, 455/461, 455/550.1, 455/551, 455/561, 455/450, 370/338, 370/328
• US Class Current: 370/328
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Methods, apparatuses, and systems directed to facilitating the application of pre-allocation policies in a wireless network environment. According to one implementation of the present invention, a central controller, or other control point in a wireless network infrastructure, applies one or more policies that limit the number of resource pre-allocations a given wireless client may establish with one or more wireless access points. In one implementation, the central controller provides a pre-allocation list to a wireless client that is requesting pre-allocation. By limiting a wireless client'"'"'s ability to pre-allocate resources, the central controller optimally manages the resources of the wireless network. In alternative embodiments, the central controller can terminate pre-allocations between a wireless client and one or more wireless access points to enforce pre-allocation policy on the wireless network infrastructure.

Claims

1. In a wireless network comprising a plurality of wireless access points operative to pre-allocate resources to one or more requesting wireless clients, a method comprising:

monitoring pre-allocation activity corresponding to a wireless client as the wireless client roams within a wireless network environment comprising a plurality of wireless access points, wherein the pre-allocation activity comprises the attempted pre-allocation of wireless resources of one or more of the plurality of wireless access points by the one or more wireless clients; and

applying a pre-allocation policy operative to limit a total number of pre-allocations between the wireless client and one or more of the plurality of wireless access points.

2. An apparatus operative in a wireless network comprising a plurality of wireless access points operative to pre-allocate resources to one or more requesting wireless clients, the apparatus comprising:

one or more processors;

a memory;

a network interface;

computer program code, physically stored in the memory, comprising computer-readable instructions operable to cause the one or more processors and the apparatus to

monitor pre-allocation activity corresponding to a wireless client as the wireless client roams within a wireless network environment comprising a plurality of wireless access points, wherein the pre-allocation activity comprises the attempted pre-allocation of wireless resources of one or more of the plurality of wireless access points by the one or more wireless clients; and

apply a pre-allocation policy operative to limit a total number of pre-allocations between the wireless client and one or more of the plurality of wireless access points.

3. An apparatus operative in a wireless network comprising a plurality of wireless access points operative to pre-allocate resources to one or more requesting wireless clients, the wireless network comprising:

means for monitoring pre-allocation activity corresponding to a wireless client as the wireless client roams within a wireless network environment comprising a plurality of wireless access points, wherein the pre-allocation activity comprises the attempted pre-allocation of wireless resources of one or more of the plurality of wireless access points by the one or more wireless clients; and

means for applying a pre-allocation policy operative to limit a total number of pre-allocations between the wireless client and one or more of the plurality of wireless access points.

4. In a wireless access node of a wireless network comprising one or more wireless access points operative to conditionally pre-allocate resources to one or more wireless clients, a method comprising:

receiving a wireless client identifier corresponding to a wireless client accessing the wireless network through a first wireless access point, the wireless network including the first wireless access point and a plurality of additional wireless access points;

generating a pre-allocation policy for the wireless client, wherein the pre-allocation policy establishes a limit on a total number of pre-allocations between the wireless client and one or more of the plurality of additional wireless access points; and

transmitting the pre-allocation policy to the wireless client.

5. The method of claim 4 further comprising

configuring one or more wireless access points to enforce the pre-allocation policy.

6. The method of claim 4 wherein the generating a pre-allocation policy comprises

obtaining a list of neighboring wireless access points corresponding to the first wireless access point;

and

selecting one or more neighboring wireless access points from the list of neighboring wireless access points to create a pre-allocation list.

7. The method of claim 4 further comprising

providing pre-allocation data to the neighboring wireless access points selected for the pre-allocation list.

8. The method of claim 6 wherein the pre-allocation list is transmitted to the wireless client.

9. A wireless access node of a wireless network comprising one or more wireless access points operative to conditionally pre-allocate resources to one or more wireless clients, the wireless access node comprising:

one or more processors;

a memory;

a network interface;

a wireless access point application, physically stored in the memory, comprising instructions operable to cause the one or more processors and the wireless access point to

receive a wireless client identifier corresponding to a wireless client accessing the wireless network through a first wireless access point, the wireless network including the first wireless access point and a plurality of additional wireless access points;

generate a pre-allocation policy for the wireless client, wherein the pre-allocation policy establishes a limit on a total number of pre-allocations between the wireless client and one or more of the plurality of additional wireless access points; and

transmit the pre-allocation policy to the wireless client.

10. A wireless access node of a wireless network comprising one or more wireless access points operative to conditionally pre-allocate resources to one or more wireless clients, the wireless access node comprising:

means for receiving a wireless client identifier corresponding to a wireless client accessing the wireless network through a first wireless access point, the wireless network including the first wireless access point and a plurality of additional wireless access points;

means for generating a pre-allocation policy for the wireless client, wherein the pre-allocation policy establishes a limit on a total number of pre-allocations between the wireless client and one or more of the plurality of additional wireless access points; and

means for transmitting the pre-allocation policy to the wireless client.

11. In a wireless management node of a wireless network comprising one or more wireless access points operative to pre-allocate resources to one or more wireless clients, a method comprising

receiving a pre-allocation event message from a first wireless access point, wherein the pre-allocation event message includes a wireless client identifier corresponding to a wireless client and the first wireless access point, wherein the wireless client is associated with a second wireless access point, and wherein the pre-allocation event message corresponds to a pre-allocation of wireless resources of the first wireless access point by the wireless client;

tracking the total number of pre-allocations between the wireless client and one or more wireless access points in a wireless network; and

causing a selected wireless access point to terminate a pre-allocation between the wireless client and the selected wireless access point if the total number of pre-allocations exceeds a pre-allocation limit.

12. The method of claim 11 wherein tracking the number of pre-allocations comprises

storing the wireless client identifier in association with the wireless access point in a pre-allocation data structure.

13. The method of claim 12 wherein the wireless client identifier and the wireless client are stored with a corresponding time stamp.

14. The method of claim 13 wherein the selected wireless access point is selected based on the wireless client identifier and the time stamp stored in the pre-allocation data structure.

15. The method of claim 14 further comprising:

if the wireless client is not a permitted wireless client, transmitting a failure response to the wireless client; and

transmitting a report to a central wireless network management node.

16. A wireless management node of a wireless network comprising one or more wireless access points operative to pre-allocate resources to one or more wireless clients, the wireless network server comprising:

one or more processors;

a memory;

a network interface;

a management application, physically stored in the memory, comprising instructions operable to cause the one or more processors and the wireless network server to

receive a pre-allocation event message from a first wireless access point, wherein the pre-allocation event message includes a wireless client identifier corresponding to a wireless client and the first wireless access point, wherein the wireless client is associated with a second wireless access point, and wherein the pre-allocation event message corresponds to a pre-allocation of wireless resources of the first wireless access point by the wireless client;

track the total number of pre-allocations between the wireless client and one or more wireless access points in a wireless network; and

cause a selected wireless access point to terminate a pre-allocation between the wireless client and the selected wireless access point if the total number of pre-allocations exceeds a pre-allocation limit.

17. The wireless management node of claim 16 wherein the management application further comprises instructions operable to cause the one or more processors and the wireless network server to

obtain a list of neighboring wireless access points corresponding to the first wireless access point;

and

select one or more neighboring wireless access points from the list of neighboring wireless access points to create a pre-allocation list.

18. The wireless management node of claim 16 wherein the management application further comprises instructions operable to cause the one or more processors and the wireless network server to

providing pre-allocation data to the neighboring wireless access points selected for the pre-allocation list.

19. The wireless management node of claim 16 wherein the pre-allocation list is transmitted to the wireless client.

20. A wireless management node of a wireless network comprising one or more wireless access points operative to pre-allocate resources to one or more wireless clients, the wireless network server comprising:

means for receiving a pre-allocation event message from a first wireless access point, wherein the pre-allocation event message includes a wireless client identifier corresponding to a wireless client and the first wireless access point, wherein the wireless client is associated with a second wireless access point, and wherein the pre-allocation event message corresponds to a pre-allocation of wireless resources of the first wireless access point by the wireless client;

means for tracking the total number of pre-allocations between the wireless client and one or more wireless access points in a wireless network; and

means for causing a selected wireless access point to terminate a pre-allocation between the wireless client and the selected wireless access point if the total number of pre-allocations exceeds a pre-allocation limit.

21. In a wireless access point operative to associate with one or more wireless clients in a wireless network and operative to conditionally allocate resources for one or more wireless clients, a method comprising:

receiving, at a first wireless access point, information from a remote node indicating permission for identified wireless clients to establish pre-allocations of wireless resources of the first wireless access point;

receiving, at the first wireless access point, a pre-allocation request from a wireless client currently associated with a second wireless access point;

accessing the information to determine if the wireless client is a permitted wireless client;

establishing a pre-allocation with the wireless client to reserve wireless resources for use if the wireless client roams away from the second wireless access point and establishes an association with the first wireless access point, if the wireless client is a permitted wireless client; and

transmitting a response to the wireless client.

22. The method of claim 21 further comprising

reporting the pre-allocation to a central wireless network management node.

23. A wireless access point operative to associate with one or more wireless clients in a wireless network and operative to conditionally allocate resources for one or more wireless clients, the wireless access point comprising:

one or more processors;

a memory;

a wireless network interface;

a wireless access point application, physically stored in the memory, comprising instructions operable to cause the one or more processors and the wireless access point to

receive information from a remote node indicating permission for identified wireless clients to establish pre-allocations of wireless resources of the first wireless access point;

receive a pre-allocation request from a wireless client currently associated with a second wireless access point;

access the information to determine if the wireless client is a permitted wireless client;

establish a pre-allocation with the wireless client to reserve wireless resources for use if the wireless client roams away from the second wireless access point and establishes an association, if the wireless client is a permitted wireless client; and

transmit a response to the wireless client.

24. The wireless access point of claim 23 wherein the wireless access point application further comprises instructions operable to cause the one or more processors and the wireless access point to

report the pre-allocation to a central wireless network management node.

25. A wireless access point operative to associate with one or more wireless clients in a wireless network and operative to conditionally allocate resources for one or more wireless clients, the wireless access point comprising:

means for receiving, at a first wireless access point, information from a remote node indicating permission for identified wireless clients to establish pre-allocations of wireless resources of the first wireless access point;

means for receiving a pre-allocation request from a wireless client currently associated with a second wireless access point;

means for access the information to determine if the wireless client is a permitted wireless client;

means for establishing a pre-allocation with the wireless client to reserve wireless resources for use if the wireless client roams away from the second wireless access point and establishes an association, if the wireless client is a permitted wireless client; and

means for transmitting a response to the wireless client.

26. In a wireless client operative to associate with a wireless access point in a wireless network and operative to reserve resources with at least one other wireless access point, a method comprising:

associating with a first wireless access point;

storing a pre-allocation policy if the pre-allocation policy is received from the first wireless access point; and

applying the pre-allocation policy by limiting, in a manner consistent with the pre-allocation policy, transmission of pre-allocation requests to one or more wireless access points that neighbor the first wireless access point, wherein the pre-allocation requests request pre-allocation of wireless resources for use if the wireless client roams away from the first wireless access point.

27. The method of claim 26 wherein the pre-allocation policy is a pre-allocation list identifying one or more wireless access points.

28. The method of claim 26 further comprising:

scanning for neighboring wireless access points;

determining if a pre-allocation list is stored; and

limiting the transmission of pre-allocation requests to the neighboring access points that are identified in the pre-allocation list.

29. A wireless client operative to associate with a wireless access point in a wireless network and operative to reserve resources with at least one other wireless access point, the wireless client comprising:

one or more processors;

a memory;

a network interface;

a wireless network driver application, physically stored in the memory, comprising instructions operable to cause the one or more processors and the apparatus to

associate with a first wireless access point;

store a pre-allocation policy if the pre-allocation policy is received from the first wireless access point; and

apply the pre-allocation policy by limiting, in a manner consistent with the pre-allocation policy, transmission of pre-allocation requests to one or more wireless access points that neighbor the first wireless access point, wherein the pre-allocation requests request pre-allocation of wireless resources for use if the wireless client roams away from the first wireless access point.

30. The wireless client of claim 29 wherein the pre-allocation policy is a pre-allocation list identifying one or more wireless access points.

31. The wireless client of claim 29 wherein the wireless network driver application further comprises instructions operable to cause the one or more processors and the wireless access point to

scan for neighboring wireless access points;

determine if a pre-allocation list is stored; and

limit the transmission of pre-allocation requests to the neighboring access points that are identified in the pre-allocation list.

32. A wireless client operative to associate with a wireless access point in a wireless network and operative to reserve resources with at least one other wireless access point, the wireless client comprising:

means for associating with a first wireless access point;

means for storing a pre-allocation policy if the pre-allocation policy is received from the first wireless access point; and

means for applying the pre-allocation policy by limiting, in a manner consistent with the pre-allocation policy, transmission of pre-allocation requests to one or more wireless access points that neighbor the first wireless access point, wherein the pre-allocation requests request pre-allocation of wireless resources for use if the wireless client roams away from the first wireless access point.