Apparatus and methods for delivery traffic indication message (DTIM) periods in a wireless network

• US 20060187864A1
• Filed: 01/21/2005
• Published: 08/24/2006
• Est. Priority Date: 01/21/2005
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Nagy, Tom, Wang, James
• Granted Patent: US 8,005,032 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

An access point is to transmit delivery traffic indication messages at different periods of beacon frames for different wireless client devices associated with the access point. A client device may store an indication of a preferred period of beacon frames at which to listen to delivery traffic indication messages when in power save mode. The client device may adjust its preferred period according to predefined considerations, for example a charge level of a battery to power the client device and/or an expected usage model for the client device. A client device may negotiate its preferred period with the access point.

Claims

1. An access point comprising:

a processor able to transmit delivery traffic indication messages at different periods of beacon frames for different wireless client devices associated with said access point.

2. The access point of claim 1, wherein in the event of having buffered data destined for two or more of said wireless client devices, said access point is to ensure that each of said two or more of said wireless client devices has had an opportunity to listen to a delivery traffic indication message indicating the presence of said buffered data.

3. The access point of claim 2, wherein said buffered data is broadcast data.

4. The access point of claim 2, wherein said buffered data is multicast data.

5. The access point of claim 1, wherein said access point is able to store one-to-one or one-to-many mappings of indications of said different periods with association identifiers of said wireless client devices.

6. The access point of claim 1, wherein said access point is able to receive a request from a particular one of said wireless client devices, and said request is a request to listen to delivery traffic indication messages from said access point at a preferred period of beacon frames when said particular one of said wireless client devices is in power-save mode.

7. The access point of claim 1, wherein said access point uses an IEEE 802.11 wireless local area network standard.

8. A wireless client device comprising:

a memory to store an indication of a preferred period of beacon frames at which to listen to delivery traffic indication messages from an access point when said wireless client device is in power-save mode.

9. The wireless client device of claim 8, further comprising:

a processor to generate a request to listen to delivery traffic indication messages from said access point at said preferred period of beacon frames when said wireless client device is in power-save mode; and

a radio to transmit said request to said access point.

10. The wireless client device of claim 8, wherein said indication is hard-coded.

11. The wireless client device of claim 8, wherein said indication is configurable by a user of said wireless client device.

12. The wireless client device of claim 8, further comprising:

a processor to adjust said preferred period according to predefined considerations.

13. The wireless client device of claim 12, wherein said predefined considerations include a charge level of a battery to power said wireless client device.

14. The wireless client device of claim 12, wherein said predefined considerations include an expected usage model for said wireless client device.

15. The wireless client device of claim 8, wherein said wireless client device uses an IEEE 802.11 wireless local area network standard.

16. A method in a wireless client device, the method comprising:

sending an access point a request to listen to delivery traffic indication messages according to a preferred period of beacon frames when in power-save mode.

17. The method of claim 16, comprising:

receiving from said access point a response that said request was accepted.

18. The method of claim 16, comprising:

receiving from said access point a response to said request that indicates a different period of beacon frames according to which to listen to delivery traffic indication messages when in power-save mode.

19. The method of claim 16, comprising:

adjusting said preferred period according to predefined considerations; and

transmitting a further request, where said further request is a request to listen to delivery traffic indication messages at said adjusted preferred period of beacon frames when in power-save mode.

20. The method of claim 19, wherein said predefined considerations include a charge level of a battery to power said wireless client device.

21. The method of claim 19, wherein said predefined considerations include an expected usage model for said wireless client device.

22. A method in an access point, the method comprising:

transmitting delivery traffic indication messages at different periods of beacon frames for different wireless client devices associated with said access point.

23. The method of claim 22, further comprising:

buffering data destined for two or more of said wireless client devices; and

ensuring that each of said two or more of said wireless client devices has had an opportunity to listen to a delivery traffic indication message indicating the presence of said buffered data.

24. The method of claim 22, further comprising:

negotiating said different periods with said different wireless client devices.