Point-controlled contention arbitration in multiple access wireless LANs

• US 20060092868A1
• Filed: 11/21/2005
• Published: 05/04/2006
• Est. Priority Date: 11/22/2000
• Status: Active Grant

• Current Assignee: Robert C. Meier
• Original Assignee: Robert C. Meier
• Inventors: Meier, Robert C.
• Granted Patent: US 8,159,977 B2
• Time in Patent Office: Days
• US Class Current: 370/312
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames

Abstract

A power management method that divorces multicast frames for power save stations from DTIM beacons. An access point associates power save stations with a multicast group. Each station has an associated power save interval, the station being in a power save state during the interval, otherwise in an active state. The access point maintains a timer for each station in order to determine whether the station is in an active or power save state. The timer can be reset whenever the station sends an inbound frame. When the access point receives a multicast frame for the group, it buffers the frame until the timer for each member of the group expires, thereby ensuring each member of the group is in an active state, and broadcasts the multicast frame.

Claims

1. A method of power management for a network, comprising:

buffering a frame for a multicast group;

associating a station with the multicast group, the station having an automatic power save interval and being in a power save mode during the power save interval and in an active mode otherwise;

monitoring to determine when the station is in an active mode;

waiting until every wireless station of the multicast group is in the active mode; and

,

broadcasting the frame.

2. The method of power management for a network as in claim 1, wherein the station is contention free pollable.

3. The method of power management for a wireless network as in claim 2, wherein the wireless station is in active mode when it is available for a contention free poll.

4. The method of power management for a network as in claim 1, wherein a GARP Multicasting Registration Protocol is used to associate the station with the multicast group.

5. The method of power management for a network as in claim 1, the monitoring further comprises initializing a timer for the station and determining the station is in the active mode after the timer expires.

6. The method of power management for a network as in claim 5, further comprising resetting the timer upon receiving an inbound frame from the station.

7. The method of power management for a network as in claim 5, the monitoring further comprising associating a separate timer for every station in the multicast group and determining every station in the multicast group is awake upon the expiration of every associated separate timer.

8. The method of power management for a network as in claim 7, further comprising resetting an associated timer for a station upon receiving an inbound frame from the station.

9. The method of power management for a network as in claim 1, wherein the broadcasting of the frame occurs during a contention period.

10. The method of power management for a network as in claim 6, further comprising waiting for an inbound packet from a wireless station immediately after sending the broadcast packet.

12. The method of power management of claim 8, wherein the predetermined time interval is an interframe space that is one of the group consisting of a short interframe space, a distributed interframe space and a point inteframe space.

11. A method of power management for a wireless station, comprising:

starting a timer;

entering a power save state;

exiting the power save state after the timer expires;

waiting for a transmission; and

sending a transmission immediately after waiting for a transmission without waiting a predetermined time interval and without sensing the media.

13. An access point, comprising:

the access point configured to associate a first wireless station and a second wireless station into a multicast group, wherein the first wireless station having a first power save interval corresponding to a time period that the first wireless station is in a power save state and the second wireless station having a second power save interval corresponding to a time period that the second wireless station is in a power save state;

the access point configured to set a first timer corresponding to the first power save interval and a second timer corresponding to the second power save interval;

the access point configured to buffer a frame for the multicast group;

the access point configured to broadcast the frame after the first timer and the second timer have expired.

14. The access point of claim 13, wherein a GARP Multicasting Registration Protocol is used to associate the first wireless station and the second wireless station with the multicast group.

15. The access point of claim 13, further comprising the access point configured for at least one of the group consisting of resetting the first timer upon receipt of an inbound frame from the first wireless station and resetting the second timer upon receipt of an inbound packet from the second wireless station.

16. The access point of claim 13, further comprising, reserving a wireless channel after the first timer expires;

sending a unicast frame with a poll to the first station after the first timer expires; and

waiting for a response for the poll.

17. A wireless station, comprising:

the wireless station configured to start a timer corresponding to a power save state;

the wireless station configured to entering a power save state;

the wireless station configured to exiting the power save state after the timer expires;

the wireless station configured to wait for a transmission; and

the wireless station configured to sending an inbound frame immediately after waiting for a transmission without waiting a predetermined time interval and without sensing the media.

18. The wireless station of claim 17, wherein the predetermined time interval is an interframe space that is one of the group consisting of a short interframe space, a distributed interframe space and a point inteframe space.

19. An access point, comprising:

means for associating a first wireless station and a second wireless station into a multicast group, wherein the first wireless station having a first power save interval corresponding to a time period that the first wireless station is in a power save state and the second wireless station having a second power save interval corresponding to a time period that the second wireless station is in a power save state;

means for setting a first timer corresponding to the first power save interval;

means for setting a second timer corresponding to the second power save interval;

means for buffering a frame for the multicast group; and

means for broadcasting the frame after the means for setting a first timer and the means for setting a second timer have expired.

20. An access point according to claim 19, further comprising:

means for resetting the first timer upon receipt of an inbound packet from the first wireless station; and

means for resetting the second timer upon receipt of an inbound packet from the second wireless station.