Method for propagating beacons in a multi-tier WLAN

• US 20060098606A1
• Filed: 10/22/2004
• Published: 05/11/2006
• Est. Priority Date: 10/22/2004
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: Pandey, Aparna, Ekl, Randy L., Ware, Christopher G.
• Granted Patent: US 8,068,467 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 56/00 Synchronisation arrangements

Abstract

A method for transmitting beacons by nodes in a multi-tier wireless local area network is disclosed. First, a first beacon by a tier 1 node in the multi-tier wireless local area network is transmitted. Then, a second beacon by a tier 2 node is transmitted where the second beacon is transmitted based upon the time that the first beacon is sent by the tier 1 node.

Claims

1. A method for transmitting beacons by nodes in a multi-tier wireless local area network comprising:

transmitting a first beacon by a tier 1 node in the multi-tier wireless local area network; and

transmitting a second beacon by a tier 2 node based upon the time that the first beacon is sent by the tier 1 node.

2. The method of claim 1 wherein the node is chosen from the list comprising a client and an access point.

3. The method of claim 1 further comprising the step of transmitting a third beacon by a tier 3 node based upon the time that the second beacon is sent by the tier 2 node.

4. The method of claim 3 wherein the tier 3 node is a coverage access point.

5. The method of claim 3 further comprising the step of transmitting a fourth beacon by a tier 4 node based upon the time that the third beacon is sent by the tier 3 node.

6. The method of claim 3 wherein the step of transmitting a third beacon takes into account a time that tier 2 node beacon interval and a number of tier 3 nodes.

7. The method of claim 6 wherein the step of transmitting further comprises waiting a time equal to TBTT_i,j+BCN_OFST_T2,Cov+(k−

1)*BCN_OFST_Cov,Cov, where, i=1, 2, . . . , a number of tier 1 nodes in the multi-tier WLAN, j=1,2, . . . , a number of tier 2 nodes in the multi-tier WLAN, and k=1,2, . . . , the number of tier 3 nodes in the multi-tier WLAN.

8. The method of claim 1 wherein the step of transmitting a second beacon takes into account a tier 1 node beacon interval and a number of tier 2 nodes.

9. The method of claim 8 wherein the step of transmitting further comprises waiting a time equal to TBTT_i+BCN_OFST_T1,T2+(j−

1)*BCN_OFST_T2,T2 where, i=1, 2, . . . , a number of tier 1 nodes in the multi-tier WLAN and j=1, 2, . . . , the number of tier 2 nodes in the multi-tier WLAN

10. The method of claim 1 wherein the first beacon further comprises an information field indicating a beacon propagation period for clients associated with the tier 1 node.

11. The method of claim 1 wherein the first beacon further comprises an information field indicating pending traffic for nodes associated with the tier 1 node.

12. The method of claim 10 wherein the second beacon is transmitted by a client during the beacon propagation period.

13. The method of claim 12 wherein the beacon propagation period is a protected time.

14. The method of claim 12 wherein the beacon propagation period is a pre-designated time corresponding to a controlled access period.

15. The method of claim 1 wherein the first beacon is transmitted at a rate which is variable wherein variable is based upon a number of hops to a serving coverage access point, a number of clients supported, and a rate of beacons sent by access points in the multi-tier wireless local area network.

16. The method of claim 1 wherein the multi-tier wireless local network comprises at least one tier of access points and at least one tier of clients.

17. The method of claim 16 wherein the at least one tier of access points further comprise coverage access points providing coverage to the at least one tier of clients of the multi-tier wireless local area network.

18. A method for transmitting beacons by access points in a multi-tier wireless local area network comprising:

transmitting a first beacon by a tier 1 access point in the multi-tier wireless local area network; and

transmitting a second beacon by a tier 2 access point based upon the time that the first beacon is sent by the tier 1 access point.

19. The method of claim 18 wherein the first beacon is transmitted on a first channel and the second beacon is transmitted on a second channel wherein the second channel is based upon the first channel.

20. A method for transmitting beacons by clients in a multi-tier wireless local area network comprising:

transmitting a first beacon by a tier 1 client in the multi-tier wireless local area network; and

transmitting a second beacon by a tier 2 client based upon the time that the first beacon is sent by the tier 1 client.

21. The method of claim 20 wherein the first beacon is transmitted on a first channel and the second beacon is transmitted on a second channel wherein the second channel is based upon the first channel.