SYMMETRIC TRANSMIT OPPORTUNITY (TXOP) TRUNCATION

• US 20140029433A1
• Filed: 07/15/2013
• Published: 01/30/2014
• Est. Priority Date: 11/08/2005
• Status: Active Grant

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Inventors: Wentink, Menzo
• Granted Patent: US 9,125,104 B2
• Time in Patent Office: Days
• US Class Current: 370/236
• 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. (canceled)

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

receiving a first frame at a first station that truncates a TXOP around a second station that transmitted the first frame;

determining an estimated distance between the first station and the second station based on one or more characteristics of the received first frame; and

responsive to a determination that the coverage areas for both the first station and the second station do not substantially overlap, sending a second frame from the first station that truncates the TXOP around the first station.

3. The method of claim 2, further comprising sending an acknowledgement (ACK) frame before sending the second frame.

4. The method of claim 2, wherein the first frame is sent at a non-basic rate, and the second frame is sent at a basic rate.

5. The method of claim 2, wherein sending the second frame comprises sending the first frame with an address of an access point (AP).

6. The method of claim 5, wherein the address of the AP comprises an address in a BSSID field of the first frame.

7. The method of claim 2, wherein the first frame is a CF-end frame.

8. The method of claim 2, further comprising sending a frame that includes an indicator of an end of a TXOP.

9. The method of claim 9, wherein the indicator is a trigger to truncate the TXOP.

10. A symmetric transmit opportunity (TXOP) truncation station comprising a processor configured to:

receive a frame that truncates a TXOP around a first station that transmitted the frame;

determine an estimated distance between the second station and the first station based on one or more characteristics of the received frame; and

responsive to a determination that the coverage areas for both the first station and second station do not substantially overlap, send a second frame from the second station that truncates the TXOP around the second station.

11. The station of claim 10, wherein the processor is further configured to send an acknowledgement (ACK) frame before sending the second frame.

12. The station of claim 10, wherein the first frame is sent at a non-basic rate, and the second frame is sent at a basic rate.

13. The station of claim 10, wherein the processor is further configured to send the second frame by sending the first frame with an address of an access point (AP).

14. The station of claim 13, wherein the address of the AP comprises an address in a BSSID field of the first frame.

15. The station of claim 10, wherein the first frame is a CF-end frame.

16. A non-transitory, computer-readable medium having instructions stored there-on for performing a symmetric transmit opportunity (TXOP) truncation between a first station and a second station, the instructions comprising:

instructions for receiving a first frame at a first station that truncates a TXOP around a second station that transmitted the first frame;

instructions for determining an estimated distance between the first station and the second station based on one or more characteristics of the received first frame; and

instructions for sending a second frame from the first station that truncates the TXOP around the first station responsive to a determination that the coverage areas for both the first station and the second station do not substantially overlap.

17. The computer-readable medium of claim 16, further comprising instructions for sending an acknowledgement (ACK) frame before sending the second frame.

18. The computer-readable medium of claim 16, wherein the first frame is sent at a non-basic rate, and the second frame is sent at a basic rate.

19. The computer-readable medium of claim 16, wherein sending the second frame comprises sending the first frame with an address of an access point (AP).

20. The computer-readable medium of claim 19, wherein the address of the AP comprises an address in a BSSID field of the first frame.

21. The computer-readable medium of claim 16, wherein the first frame is a CF-end frame.