Variable SDMA ACK timeout

• US 20050157734A1
• Filed: 01/15/2004
• Published: 07/21/2005
• Est. Priority Date: 08/08/2003
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Ho, Minnie, Stephens, Adrian P., Lin, Xintian E., Li, Qinghua
• Granted Patent: US 7,408,908 B2
• Time in Patent Office: Days
• US Class Current: 370/406
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 27/261 Details of reference signals
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 74/02 Hybrid access
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

In a spatial division multiple access system that employs acknowledgements to variable length transmissions within a timeout period, a station that has completed its transmission may delay beginning the timeout period until it determines that other stations on the same channel have completed their transmissions.

Claims

1. An apparatus, comprising

a device adapted to:

perform a transmission over a wireless channel;

monitor the wireless channel, subsequent to completion of the transmission, to determine if another device is transmitting over the wireless channel; and

begin a timeout period responsive to determining said another device is not transmitting over the wireless channel.

2. The apparatus of claim 1, wherein the device is further adapted to not begin the timeout period responsive to determining said another device is transmitting over the wireless channel.

3. The apparatus of claim 1, wherein the device is further adapted to monitor for an acknowledgement to the completed transmission during the timeout period.

4. The apparatus of claim 3, wherein the device is further adapted to cancel the timeout period responsive to receiving the acknowledgement prior to an end of the timeout period.

5. The apparatus of claim 3, wherein the device is further adapted to retransmit the transmission responsive to not receiving the acknowledgement prior to the end of the timeout period.

6. The apparatus of claim 1, wherein said monitoring comprises monitoring for a carrier wave.

7. The apparatus of claim 1, wherein said monitoring comprises monitoring for transmission of data.

8. A system, comprising:

an omnidirectional antenna;

a device coupled to the omnidirectional antenna and adapted to

perform a transmission from the omnidirectional antenna to a base station over a wireless channel;

monitor the wireless channel, subsequent to completion of the transmission, for a clear channel condition; and

begin a timeout period responsive to determining a presence of a clear channel condition.

9. The system of claim 8, wherein the device is further adapted to not begin the timeout period responsive to determining an absence of the clear channel condition.

10. The system of claim 8, wherein the device is further adapted to cancel the timeout period responsive to receiving an acknowledgement prior to an end of the timeout period.

11. The system of claim 10, wherein the device is further adapted to begin an error process responsive to not receiving the acknowledgement prior to the end of the timeout period.

12. The system of claim 11, wherein the error process comprises preparing to retransmit the transmission over the wireless channel.

13. The system of claim 8, wherein said monitoring comprises monitoring for a carrier wave.

14. A method, comprising:

transmitting a data transmission over a wireless communications channel;

monitoring the wireless communications channel, subsequent to said transmitting, until a clear channel condition is detected;

beginning a timeout period subsequent to said detecting a clear channel condition; and

determining if an acknowledgement to said data transmission is received during the timeout period.

15. The method of claim 14, further comprising aborting said timeout period responsive to receiving the acknowledgement during the timeout period.

16. The method of claim 14, further comprising beginning an error process responsive to not receiving the acknowledgement prior to an expiration of the timeout period.

17. A machine-readable medium that provides instructions, which when executed by a processing platform, cause said processing platform to perform operations comprising:

placing data into at least one transmit queue to perform a data transmission over a wireless communications channel;

monitoring the wireless communications channel subsequent to said performing;

beginning a timeout period responsive to said monitoring determining that said wireless communications channel is not busy; and

reading data from a receive queue to determine if an acknowledgement to said data transmission is received during the timeout period.

18. The medium of claim 17, wherein said operations further comprise aborting said timeout period responsive to said receiving the acknowledgement prior to an expiration of the timeout period.

19. The medium of claim 17, wherein said operations further comprise beginning an error process responsive to not receiving the acknowledgement prior to an expiration of the timeout period.

20. The medium of claim 17, said monitoring comprises monitoring for a clear channel condition.