Temporary priority promotion for network communications in which access to a shared medium depends on a priority level

• US 7,660,327 B2
• Filed: 02/03/2004
• Issued: 02/09/2010
• Est. Priority Date: 02/03/2004
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Atheros Communications Incorporated (Qualcomm, Inc.)
• Inventors: Yonge, Lawrence W. III, Katar, Srinivas
• Primary Examiner(s): Yao; Kwang B
• Assistant Examiner(s): Tran; Tung Q
• Application Number:
  US10/771,136
• Publication Number:
  US 20050169296A1
• Time in Patent Office: 2,198 Days
• Field of Search: 370442-444, 370/447, 370/458, 370461-462
• US Class Current: 370/461
• CPC Class Codes: H04L 12/40156 by using dedicated slots associated with a priority level
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04W 74/0875 with assigned priorities based access

Abstract

A method of operating in a network in which a plurality of stations communicate over a shared medium (e.g., using a carrier sense multiple access (CSMA) service). The stations contend for access to the shared medium using a contention procedure that relies on a priority level, wherein transmissions with a lower priority level have a reduced chance of gaining access to the shared medium during a contention process. Selected stations are given the capability of temporarily promoting the priority level of transmissions they are attempting to make. The priority level is increased during an interval to reduce the chance that other stations gain access to the shared medium during that interval, and the priority level is restored to its normal level following the interval.

Claims

1. A method of operating in a network in which a plurality of stations communicate over a shared medium, the method comprising

having the stations contend for access to the shared medium using a contention procedure that relies on a priority level, wherein transmissions with a lower priority level have a reduced chance of gaining access to the shared medium during a contention process;

at each of a plurality of selected stations, temporarily promoting the priority level of transmissions that at least some of the selected stations are attempting to make to effect access to the shared medium without waiting for indication that the at least some of the selected stations have access to the shared medium, wherein the priority level is increased during an interval used by the selected stations for transmission of traffic not suited for the contention procedure, to reduce a chance that other stations gain access to the shared medium during that interval, and the priority level is restored to a normal level following the interval; and

at each of the at least some of the selected stations, transmitting traffic over the shared medium.

2. The method of claim 1 wherein the promoted priority level is used to interrupt a series of frames having a priority level such that the series of frames cannot be interrupted by transmissions of a same or lower priority level.

3. The method of claim 2 wherein the priority level is restored to the normal level for contention following the interrupted burst.

4. The method of claim 1 wherein the promoted priority level is used not to interrupt burst traffic but to reduce the chance that some stations gain access to the shared medium.

5. The method of claim 1 wherein priority may be promoted by a station under predefined circumstances.

6. The method of claim 5 wherein the predefined circumstances include detection that another station is using a robust transmission protocol indicative of a low transmission rate.

7. The method of claim 5 wherein the predefined circumstances include that the burst transmission has continued uninterrupted for more than a defined number of frames.

8. The method of claim 1 wherein the selected stations use the same communication protocol as the other stations.

9. The method of claim 1 wherein the selected stations employ a QoS guarantee protocol and the other stations are legacy stations lacking a QoS guarantee protocol.

10. The method of claim 2 wherein a station transmitting the burst follows a protocol that requires the station to interrupt a burst transmission if a higher priority level is asserted in priority resolution slots between frames, and at the selected stations, increasing the priority that the selected stations assert in the priority resolution slots to interrupt the burst transmission.

11. The method of claim 1 wherein a selected station asserting a temporarily promoted priority has data to transmit.

12. The method of claim 1 wherein a selected station asserting a temporarily promoted priority does not have data to transmit.

13. The method of claim 4 or 12 wherein a selected station asserts the promoted priority to assist other stations by:

increasing a likelihood that stations will see the promoted priority, and

on seeing the promoted priority, the stations refrain from transmission.

14. The method of claim 13 wherein the selected station employs a QoS guarantee protocol that transmits QoS traffic during regularly repeated contention free intervals, and by asserting the promoted priority the station increases a likelihood that other stations do not attempt to transmit during the regularly repeated contention free intervals.

15. A method of operating in a network in which a plurality of stations communicate over a shared medium, the method comprising:

having the stations contend for access to the shared medium using a contention procedure that relies on a priority level, wherein transmissions with a lower priority level have a reduced chance of gaining access to the shared medium during a contention process;

at each of a plurality of selected stations using a first protocol having QoS guarantees, temporarily promoting the priority level of transmissions that at least some of the selected stations are attempting to make to effect access to the shared medium without waiting for indication that the at least some of the selected stations have access to the shared medium, wherein the priority level is increased during an interval to reduce a chance that stations using a legacy protocol gain access to the shared medium during that interval, and the priority level is restored to its normal level following the interval; and

at each of the at least some of the selected stations, transmitting traffic over the shared medium.

16. The method of claim 15 wherein the selected stations using a first protocol having QoS guarantees transmit QoS traffic during contention free intervals, and

in response to temporarily promoting the priority level of transmissions, the selected stations block stations using the legacy protocol from transmitting during the intervals.

17. The method of claim 15 wherein the first protocol supports time division multiple access based channel access for QoS traffic, and the legacy protocol supports carrier sense multiple access based channel access.

18. The method of claim 15 wherein the selected stations temporarily promote the priority level of transmissions they are attempting to make by transmitting priority signals during allocations for priority resolution slots in the transmissions by the selected stations.

19. A method of operating in a network in which a plurality of stations communicate over a shared medium, the method comprising

having the stations contend for access to the shared medium using a contention procedure that relies on a priority level, wherein transmissions with a lower priority level have a reduced chance of gaining access to the shared medium during a contention process;

at each of a plurality of selected stations, temporarily promoting the priority level of transmissions that at least some of the selected stations are attempting to make, wherein the priority level is increased during an interval used by the selected stations for transmission of traffic not suited for the contention procedure, to reduce a chance that other stations gain access to the shared medium during that interval, and the priority level is restored to a normal level following the interval; and

at each of the at least some of the selected stations, transmitting traffic over the shared medium;

wherein a first selected station asserting a temporarily promoted priority has data to transmit, and a second selected station asserting the temporarily promoted priority does not have data to transmit and asserts the temporarily promoted priority to assist in the transmission of data by the first selected station.

20. The method of claim 19 wherein the promoted priority level is used to interrupt a series of frames having a priority level such that the series of frames cannot be interrupted by transmissions of a same or lower priority level.

21. The method of claim 20 wherein the priority level is restored to the normal level for contention following the interrupted burst.

22. The method of claim 20 wherein a station transmitting the burst follows a protocol that requires the station to interrupt a burst transmission if a higher priority level is asserted in priority resolution slots between frames, and at the selected stations, increasing the priority that the selected stations assert in the priority resolution slots to interrupt the burst transmission.

23. The method of claim 19 wherein the promoted priority level is used not to interrupt burst traffic but to reduce the chance that some stations gain access to the shared medium.

24. The method of claim 23 wherein a selected station asserts the promoted priority to assist other stations by:

increasing a likelihood that stations will see the promoted priority, and

on seeing the promoted priority, the stations refrain from transmission.

25. The method of claim 24 wherein the selected station employs a QoS guarantee protocol that transmits QoS traffic during regularly repeated contention free intervals, and by asserting the promoted priority the station increases a likelihood that other stations do not attempt to transmit during the regularly repeated contention free intervals.

26. The method of claim 19 wherein priority may be promoted by a station under predefined circumstances.

27. The method of claim 26 wherein the predefined circumstances include detection that another station is using a robust transmission protocol indicative of a low transmission rate.

28. The method of claim 26 wherein the predefined circumstances include that the burst transmission has continued uninterrupted for more than a defined number of frames.

29. The method of claim 19 wherein the selected stations use the same communication protocol as the other stations.

30. The method of claim 19 wherein the selected stations employ a QoS guarantee protocol and the other stations are legacy stations lacking a QoS guarantee protocol.

31. A method of operating in a network in which a plurality of stations communicate over a shared medium, the method comprising:

having the stations contend for access to the shared medium using a contention procedure that relies on a priority level, wherein transmissions with a lower priority level have a reduced chance of gaining access to the shared medium during a contention process;

at each of a plurality of selected stations using a first protocol having QoS guarantees, temporarily promoting the priority level of transmissions that at least some of the selected stations are attempting to make, wherein the priority level is increased during an interval to reduce a chance that stations using a legacy protocol gain access to the shared medium during that interval, and the priority level is restored to its normal level following the interval; and

at each of the at least some of the selected stations, transmitting traffic over the shared medium;

wherein a first selected station asserting a temporarily promoted priority has data to transmit, and a second selected station asserting the temporarily promoted priority does not have data to transmit and asserts the temporarily promoted priority to assist in the transmission of data by the first selected station.

32. The method of claim 31 wherein the selected stations using a first protocol having QoS guarantees transmit QoS traffic during contention free intervals, and

in response to temporarily promoting the priority level of transmissions, the selected stations block stations using the legacy protocol from transmitting during the intervals.

33. The method of claim 31 wherein the first protocol supports time division multiple access based channel access for QoS traffic, and the legacy protocol supports carrier sense multiple access based channel access.

34. The method of claim 31 wherein the selected stations temporarily promote the priority level of transmissions they are attempting to make by transmitting priority signals during allocations for priority resolution slots in the transmissions by the selected stations.