Point-controlled contention arbitration in multiple access wireless LANs

• US 7,251,232 B1
• Filed: 09/12/2001
• Issued: 07/31/2007
• Est. Priority Date: 11/22/2000
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Meier, Robert C.
• Primary Examiner(s): Chan; Wing
• Assistant Examiner(s): LEE, ANDREW CHUNG CHEUNG
• Application Number:
  US09/953,820
• Time in Patent Office: 2,148 Days
• Field of Search: 370/338, 370/352, 370/331, 370/337, 370/348, 370/465, 370/468, 370/355
• US Class Current: 370/338
• 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 method providing quality of service during a contention period. A tiered access protocol enables an Access Point to act as a channel arbitrator and gain control a channel during a contention period. The Enhanced Access Point waits a specified amount of time after before taking control of a channel for either transmitting an outbound frame or initiating Polled-Contention Free Bursts. In addition, a method for increasing the time span between Delivery Traffic Indication Message beacons by tracking when Wireless Stations are able to receive messages and instantly delivering messages to those Wireless Stations.

Claims

1. A method for providing quality of service during a contention period, comprising:

determining whether a channel load exceeds a predetermined level;

reserving the channel using high priority access responsive to determining the channel exceeds the predetermined level;

polling to initiate a point controlled contention free burst responsive to determining the channel exceeds the predetermined level during the contention period;

receiving the contention free burst during the contention period responsive to the poll; and

sending an acknowledgement to the contention free burst;

wherein sending the acknowledgement to the contention free burst cancels the channel reservation.

2. The method for providing quality of service during a contention period as in claim 1, the reserving a channel further comprising sensing the channel for a sensing time period.

3. The method for providing quality of service during a contention period as in claim 2, the reserving a channel further comprising sensing the that the channel is idle for one of the group consisting of a point coordination interframe space and a short interframe space.

4. The method providing quality of service during a contention period as in claim 3, wherein the sensing time period is a short interframe space after receiving an inbound transmission.

5. The method for providing quality of service during a contention period as in claim 4, wherein the sensing time period is a short interframe space after a station to station transmission that originates within a basic service set.

6. The method for providing quality of service during a contention period as in claim 1, further comprising:

determining a predetermined interval corresponding to a service rate for an associated wireless client; and

waiting for the predetermined interval to expire;

wherein polling to initiate a point controlled contention free burst is responsive to the predetermined interval expiring.

7. The method for providing quality of service during a contention period as in claim 6, further comprising:

receiving an inbound frame from the associated wireless client; and

re-starting waiting for the predetermined interval to expire responsive to receiving the inbound frame.

8. The apparatus as in claim 1, wherein the access point reserves the channel by sensing the channel for a predetermined time period.

9. The apparatus as in claim 8, wherein the access point senses the channel is idle for one of the group consisting of a point coordination interframe space and a short interframe space.

10. The apparatus as in claim 8, wherein the predetermined time period is a short interframe space after receiving an inbound transmission.

11. An apparatus, comprising

an access point for providing quality of service during a contention period;

wherein the access point is configured to determine whether a channel load exceeds a predetermined level;

wherein the access point is configured to reserve the channel using high priority access responsive to determining the channel exceeds the predetermined level;

wherein the access point is configured to implement polling to initiate a point controlled contention free burst responsive to determining the channel exceeds the predetermined level during the contention period;

wherein the access point is configured to receive the contention free burst during the contention period responsive to the poll;

wherein the access point is responsive to send an acknowledgement to the contention free burst; and

wherein sending the acknowledgement to the contention free burst cancels the channel reservation.

12. The apparatus as in claim 11, further comprising:

the access point is configured to wait for the predetermined interval corresponding to a service rate for an associated wireless client; and

the access point is wait for the predetermined interval to expire;

wherein polling to initiate a point controlled contention free burst is responsive to the predetermined interval expiring.

13. The apparatus as in claim 11, further comprising:

the access point is responsive to receiving an inbound frame from the associated wireless client to re-start waiting for the predetermined interval to expire responsive to receiving the inbound frame.

14. An apparatus for providing quality of service during a contention period, comprising:

means for determining whether a channel load exceeds a predetermined level;

means for reserving the channel using high priority access responsive to determining the channel exceeds the predetermined level;

means for polling to initiate a point controlled contention free burst responsive to the determining the channel exceeds the predetermined level during the contention period;

means for receiving the contention free burst during the contention period responsive to the poll; and

means for sending an acknowledgement to the contention free burst;

wherein sending the acknowledgement to the contention free burst cancels the channel reservation.

15. The apparatus as in claim 14, further comprising:

means for determining a predetermined interval corresponding to a service rate for an associated wireless client; and

means for waiting for the predetermined interval to expire;

wherein the means for polling to initiate a point controlled contention free burst is responsive to the predetermined interval expiring.

16. The apparatus as in claim 14, further comprising:

means for receiving an inbound frame from the associated wireless client; and

means for re-initializing the means for waiting for the predetermined interval to expire responsive to the means for receiving the inbound frame.