Adaptive beacon interval in WLAN

• US 7,333,460 B2
• Filed: 03/25/2003
• Issued: 02/19/2008
• Est. Priority Date: 03/25/2003
• Status: Expired due to Fees

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Orava, Pekka, Vaisanen, Ari, Haverinen, Henry
• Primary Examiner(s): Nguyen; Quynh H.
• Application Number:
  US10/400,233
• Publication Number:
  US 20040192284A1
• Time in Patent Office: 1,792 Days
• Field of Search: 370/338, 370/230, 455/343.3, 709/225, 709/229, 709/230, 709/236
• US Class Current: 370/338
• CPC Class Codes: H04W 48/12 using downlink control channel

Abstract

The present invention relates to Wireless Local Area Networks and Access Points in such networks, in particular it relates to the control and use of varying beacon intervals in such networks. According to the present invention, the beacon frames in the Wireless Local Area Network are provided with an adaptive beacon interval. The interval is adapted in dependence on a current network load such that the length of the beacon interval is decreased when the network load is decreased and increased when network load is increased. The invention is applicable in existing as well as future IEEE 802.11 standards.

Claims

1. A method for controlling transmission of beacon frames from an access point in a wireless local area network, comprising:

adding additional beacons at subintervals between beacons with a fixed beacon interval in order to provide an overall beacon interval that forms an adaptive beacon interval, wherein said fixed beacon interval is fixed prior to operation of the access point,

transmitting the beacon frames from the access point with said adaptive beacon interval in dependence on a current network load during operation of the network by

decreasing an adaptive beacon interval length when the network load is decreased, and

increasing said adaptive beacon interval length when the network load is increased.

2. The method as claimed in claim 1, including:

measuring the network load as the load of the access point.

3. The method as claimed in claim 1, including:

measuring the network load as the occupancy level of a channel used by the access point on the wireless medium.

4. The method as claimed in claim 1, including:

measuring the network load as the combination of the load of the access point and the occupancy level of a wireless medium for a channel used by the access point for transmitting the beacon frames.

5. The method as claimed in claim 1, wherein the subinterval is chosen such that the fixed beacon interval divided with the subinterval forms an integer value.

6. The method as claimed in claim 5, including:

measuring the network load as the load of the access point.

7. The method as claimed in claim 5, including:

measuring the network load as the occupancy level of a channel used by the access point on the wireless medium.

8. The method as claimed in claim 5, including:

measuring the network load as the combination of the load of the access point and the occupancy level of a wireless medium for a channel used by the access point for transmitting the beacon frames.

9. An access point providing beacon frames in a wireless local area network, the access point comprising:

a signal processor for adding additional beacons at subintervals between beacons with a fixed beacon interval in order to provide an overall beacon interval that forms an adaptive beacon interval, wherein said fixed beacon interval is configured prior to operation of the access point; and

a transmitter for transmitting the beacon frames in the wireless local area network with the adaptive beacon interval in dependence on a current network load during operation of the network,

wherein the signal processor is configured for decreasing a length of the adaptive beacon interval when the network load is decreased and increasing the length of the adaptive beacon interval when network load is increased.

10. The access point as claimed in claim 9, further comprising:

measuring device for measuring the network load as the load of the access point.

11. The access point as claimed in claim 9, including:

measuring device for measuring the network load as the occupancy level of a channel used by the access point on the wireless medium.

12. The access point as claimed in claim 9, further comprising:

measuring device for measuring the network load as the combination of the load of the access point and the occupancy level of a wireless medium for a channel used by the access point for transmitting the beacon frames.

13. The access point as claimed in claim 9, wherein the subinterval is chosen such that the fixed beacon interval divided with the subinterval forms an integer value.

14. The access point as claimed in claim 13, including:

measuring device for measuring the network load as the load of the access point.

15. The access point as claimed in claim 13, further comprising:

measuring device for measuring the network load as the occupancy level of a channel used by the access point on the wireless medium.

16. The access point as claimed in claim 13, further comprising:

measuring device for measuring the network load as the combination of the load of the access point and the occupancy level of a wireless medium for a channel used by the access point for transmitting the beacon frames.

17. A wireless local area network including an access point providing beacon frames and a wireless station for receiving said beacon frames, the access point having a fixed beacon interval configured prior to its operation, the access point comprising:

a signal processor for adding additional beacons at subintervals between the beacons with the fixed beacon interval in order to provide an overall beacon interval that forms an adaptive beacon interval; and

a transmitter for transmitting the beacon frames from the access point with the adaptive beacon interval in dependence on a current network load during operation of the network,

wherein the signal processor is configured for decreasing a length of the adaptive beacon interval when the network load is decreased and increasing the length of the adaptive beacon interval when network load is increased.

18. The wireless local area network as claimed in claim 17, wherein the subinterval is chosen such that the fixed beacon interval divided with the subinterval forms an integer value.

19. The wireless local area network as claimed in claim 18, wherein said access point includes:

measuring device for measuring the network load as the load of the access point.

20. The wireless local area network as claimed in claim 18, wherein said access point comprises:

measuring device for measuring the network load as the occupancy level of a channel used by the access point on the wireless medium.

21. The wireless local area network as claimed in claim 18, wherein said access point comprises:

measuring device for measuring the network load as the combination of the load of the access point and the occupancy level of a wireless medium for a channel used by the access point for transmitting the beacon frames.

22. The wireless local area network as claimed in claim 17, wherein the included wireless station is a mobile phone with wireless local area network capabilities or a portable computer with a plug-in card having wireless local area network capabilities.