Symmetric transmit opportunity (TXOP) truncation

• US 20070115882A1
• Filed: 01/10/2007
• Published: 05/24/2007
• Est. Priority Date: 11/08/2005
• Status: Active Grant

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Conexant Systems Incorporated (Synaptics Incorporated)
• Inventors: Wentink, Menzo
• Granted Patent: US 8,031,661 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04N 21/4126 The peripheral being portable, e.g. PDAs or mobile phones
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 28/12 using signalling between network elements
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access
• CPC Class Codes: H04W 74/0891 for synchronized access
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 92/10 between terminal device and access point, i.e. wireless air interface

Abstract

Various embodiments of symmetric transmit opportunity (TXOP) truncation (STT) systems and methods are disclosed. One method embodiment, among others, comprises receiving a frame that truncates a TXOP around a first station, and responsive to receiving the frame, sending a second frame that truncates the TXOP around a second station. Others system and method embodiments are disclosed.

Claims

1. A symmetric transmit opportunity (TXOP) truncation method, comprising:

receiving a frame that truncates a TXOP around a first station; and

responsive to receiving the frame, sending a second frame that truncates the TXOP around a second station.

2. The method of claim 1, wherein receiving the frame comprises receiving a CF-end frame.

3. The method of claim 1, wherein receiving the frame comprises receiving a CF-end frame having an address of the second station.

4. The method of claim 3, wherein a destination for the CF-end resides in a basic service set identification (BSSID) field.

5. The method of claim 1, wherein receiving the frame comprises receiving at a client station or an access point.

6. The method of claim 1, wherein sending the second frame comprises sending a CF-end response frame to the first station, the second station, or a third station.

7. The method of claim 1, wherein sending the second frame comprises including an address of the first station, an address of the second station, or an address of a third station.

8. The method of claim 1, wherein sending the second frame comprises sending to a client station or an access point.

9. The method of claim 1, further comprising receiving the second frame at a third station.

10. The method of claim 9, further comprising, responsive to receiving the second frame at the third station, sending a third frame that truncates the TXOP around the third station.

11. The method of claim 10, wherein sending the third frame comprises sending the third frame with an address of the third station.

12. The method of claim 1, wherein sending comprises sending after a short interframe space (SIFS) interval or a PCF interframe space (PIFS) interval.

13. The method of claim 1, wherein receiving comprises receiving with a NAV duration value comprising a time after the second frame is expected to be sent.

14. The method of claim 1, wherein receiving comprises receiving the frame with a physical layer convergence protocol duration substantially equal to a duration of the frame plus a SIFS interval plus an expected duration of the second frame.

15. A symmetric transmit opportunity (TXOP) truncation method, comprising:

receiving a frame from an access point (AP) that includes an indicator of an end of a TXOP;

responsive to receiving the indicator, sending a first frame that truncates the TXOP around a first station;

receiving the first frame at the AP; and

responsive to receiving the first frame at the AP, sending a second frame that truncates the TXOP around the AP.

16. The method of claim 15, wherein receiving the frame comprises receiving a data frame.

17. The method of claim 15, further comprising receiving an acknowledgement (ACK) frame before receiving the first frame at the first station.

18. The method of claim 15, wherein sending the first frame and sending the second frame comprises sending the first frame and the second frame with an address of the AP.

19. The method of claim 18, wherein the address of the AP comprises an address in the BSSID field of the first or second frame.

20. A symmetric transmit opportunity (TXOP) truncation method, comprising:

sending at a first station a first frame;

sending at the first station an extended interframe space (EIFS) set frame after the first frame; and

sending at a second station a second frame having a completed transmission corresponding to time based on an interval of EIFS less DIFS, the interval commencing from an end of the short frame.

21. The method of claim 20, wherein sending the first frame and sending the second frame each comprise sending a CF-end frame.

22. The method of claim 20, wherein sending the first frame and sending the second frame comprise sending an end of transmission (EOT) frame and an acknowledgement frame, respectively.

23. The method of claim 20, wherein sending of the second frame is independent of the presence of the EIFS set frame.

24. The method of claim 20, wherein the EIFS set frame comprises a faulty frame check sequence (FCS).

25. The method of claim 20, wherein the EIFS set frame consists of a PHY header.

26. A symmetric transmit opportunity (TXOP) truncation system, comprising:

a processor configured with logic to receive a frame that truncates a TXOP around a first station and, responsive to receiving the frame, the processor further configured with the logic to send a second frame that truncates the TXOP around a second station.

27. The system of claim 26, wherein the frame comprises a CF-end frame.

28. The system of claim 26, wherein the frame comprises a CF-end frame having an address of the second station.

29. The system of claim 26, wherein the logic resides in a client station or an access point.

30. The system of claim 26, wherein the processor is further configured with the logic to send a CF-end response frame to the first station, a second station, or a third station.

31. The system of claim 26, wherein the second frame comprises an address of the first station, an address of the second station, or an address of a third station.

32. The system of claim 26, wherein the processor is further configured with the logic to send to a client station or an access point.

33. The system of claim 26, further comprising a third station, the third station comprising a second memory with second logic and a second processor configured with the second logic to receive the second frame.

34. The system of claim 33, wherein the second processor is configured with the second logic to, responsive to receiving the second frame, send a third frame that truncates the TXOP at the third station.

35. The system of claim 34, wherein the third frame comprises an address of the third station.

36. A symmetric transmit opportunity (TXOP) truncation system, comprising:

means for receiving a frame that truncates a TXOP around a first station; and

responsive to receiving the frame, means for sending a second frame that truncates the TXOP around a second station.

37. A symmetric transmit opportunity (TXOP) truncation method, comprising:

sending at a first station a first frame addressed at a second station; and

sending at the first and the second station an extended interframe space (EIFS) set frame after the first frame.

38. The method of claim 37, wherein sending the first frame comprises sending a CF-end frame.