CENTRALIZED CONTENTION AND RESERVATION REQUEST FOR QOS-DRIVEN WIRELESS LANS

• US 20100080188A1
• Filed: 12/08/2009
• Published: 04/01/2010
• Est. Priority Date: 07/14/2000
• Status: Active Grant

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Ho, Jin-Meng, Lin, Wei
• Granted Patent: US 8,855,060 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A method and a system is disclosed for providing quality of service (QoS)-driven channel access within a basic service set (BSS) in a wireless local area network (WLAN). A contention control (CC) frame is sent from a point coordinator (PC) of the BSS during a contention-free period (CFP) of a superframe that includes the contention-free period (CFP) and a contention period (CP). The CC frame contains information relating to at least one of a priority limit for a next centralized contention interval (CCI), a length of the next CCI, a permission probability associated with the next CCI and information relating to a reservation request (RR) frame successfully received by the PC in a previous CCI. A non-colliding RR frame is then received at the PC in the CCI following the CC frame. The received RR frame is sent from a non-PC station in the BSS when at least one centralized contention opportunity (CCO) is available during the CCI after the CC frame. The RR frame indicates that the non-PC station sending the RR frame has at least one buffered data frame for transmission.

Claims

1. A method for providing a quality of service (QoS)-driven channel access within a basic service set (BSS) in a wireless network, comprising:

sending a contention control (CC) frame from a point coordinator (PC) of the BSS only during a contention-free period (CFP) of a time period, and

in a centralized contention interval (CCI) following the CC frame in the CFP, receiving at the PC a non-colliding reservation request (RR) frame from a non-PC station in the BSS when at least one centralized contention opportunity (CCO) is available during the CCI, the received RR frame indicating that the non-PC station sending the RR frame has at least one buffered data frame for transmission.

2. The method of claim 1, wherein the CC frame comprises a priority limit for a next CCI.

3. The method of claim 2, wherein the priority limit contained in the CC frame for the next CCI specifies a lowest priority level a data frame buffered at the non-PC station in the BSS must have for qualifying the non-PC station to send the RR frame for requesting transmission of the data frame.

4. The method of claim 1, wherein the CC frame comprises a length of a next CCI.

5. The method of claim 4, wherein the length of the next CCI is expressed in a number of CCOs contained in the next CCI.

6. The method of claim 1, wherein the CC frame comprises a permission probability (PP) associated with the next CCI.

7. The method of claim 6, wherein the PP specifies a probability number for statistically permitting a qualified non-PC station to send the RR frame.

8. The method of claim 6, further comprising:

receiving the CC frame at the non-PC station in the BSS; and

determining whether to send the RR frame in the next CCI based on the permission probability associated with the next CCI.

9. The method of claim 1, wherein the CC frame comprises information relating to a reservation request (RR) frame successfully received by the PC in a previous CCI.

10. The method of claim 9, wherein the information relating to a reservation request (RR) frame successfully received by the PC station in the previous CCI includes information relating to at least one of:

a virtual stream identifier (VSID) or an association identifier (AID) associating with the data frame for which the RR frame was sent.

11. A system for providing a quality of service (QoS)-driven channel access within a basic service set (BSS) in a wireless network, comprising:

a point coordinator (PC) of the BSS, configured to send a contention control (CC) frame only during a contention-free period (CFP) in a time period; and

a non-PC station in the BSS, configured to send a non-colliding reservation request (RR) frame to the PC when at least one centralized contention opportunity (CCO) is available during a centralized contention interval (CCI) following the CC frame in the CFP, the received RR frame indicating that the non-PC station has at least one buffered data frame for transmission.

12. The system of claim 11, wherein the CC frame comprises a priority limit for a next CCI.

13. The system of claim 11, wherein the priority limit contained in the CC frame for the next CCI specifies a lowest priority level a data frame buffered at the non-PC station in the BSS must have for qualifying the non-PC station to send the RR frame for requesting transmission of the data frame.

14. The system of claim 11, wherein the CC frame comprises a length of a next CCI.

15. The system of claim 14, wherein the length of the next CCI is expressed in a number of CCOs contained in the next CCI.

16. The system of claim 11, wherein the CC frame comprises a permission probability (PP) associated with a next CCI.

17. The system of claim 16, wherein the PP specifies a probability number for statistically permitting a qualified non-PC station to send the RR frame.

18. The system of claim 16, wherein:

the non-PC station in the BSS is further configured to receive the CC frame, and to determine whether to send the RR frame in the next CCI based on the permission probability associated with the next CCI.

19. The system of claim 11, wherein the CC frame comprises information relating to a reservation request (RR) frame successfully received by the PC in a previous CCI.

20. The system of claim 19, wherein the information relating to a reservation request (RR) frame successfully received by the PC station in the previous CCI includes information relating to at least one of:

a virtual stream identifier (VSID) or an association identifier (AID) associating with the data frame for which the RR frame was sent.