Method and apparatus for restricting channel access to a wireless station operating in accordance with a power saving scheme

• US 9,220,114 B2
• Filed: 06/06/2013
• Issued: 12/22/2015
• Est. Priority Date: 06/08/2012
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Liu, Yong
• Primary Examiner(s): Russell, Wanda Z
• Assistant Examiner(s): Banthrongsack, Jeff
• Application Number:
  US13/911,267
• Publication Number:
  US 20130329658A1
• Time in Patent Office: 929 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04W 74/02 Hybrid access
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A wireless station includes a transceiver configured to wirelessly receive networking frames over a wireless medium, and a channel access counter configured to track a time period and signal that the time period has expired. The time period begins in response to a first networking frame of the networking frames. The first networking frame is addressed to a receiver other than the wireless station. A length of the time period is based on a first length in response to a type of the first networking frame being an acknowledgment frame type. The length of the time period is based on a second length in response to the type of the first networking frame being a data frame type. The transceiver is configured to wait to access the wireless medium until after the channel access counter signals that the time period has expired.

Claims

1. A wireless device comprising:

a transceiver configured to wirelessly receive networking frames over a wireless medium; and

a channel access counter configured to (i) track a time period and (ii) signal that the time period has expired, wherein

the transceiver is configured to wait to access the wireless medium until after the channel access counter signals that the time period has expired,

the channel access counter is configured to begin the time period in response to a first networking frame of the networking frames being received by the transceiver,

the first networking frame is addressed to a receiver,

the channel access counter is configured to set a length of the time period based on a first length value in response to a type of the first networking frame being an acknowledgment frame type,

the first length value is a predetermined value that is equal to a sum of a short interframe space (SIFS) and a transmission time of a maximum length physical layer convergence procedure protocol data unit frame,

the channel access counter is configured to set the length of the time period based on a second length value in response to the type of the first networking frame being a data frame type,

the second length value is a predetermined value that is equal to a sum of the SIFS and a predetermined transmission time for an acknowledgement frame, and

the channel access counter is configured to selectively signal that the time period has expired in response to the transceiver receiving, during the time period, a second networking frame of the networking frames.

2. The wireless device of claim 1, wherein the first length value is longer than the second length value.

3. The wireless device of claim 1, wherein the channel access counter comprises a counter configured to count down to zero.

4. The wireless device of claim 3, wherein the channel access counter is configured to signal that the time period has expired when the counter reaches zero.

5. The wireless device of claim 1, wherein the channel access counter is configured to signal that the time period has expired in response to (i) the type of the first networking frame being the data frame type in combination with (ii) a type of the second networking frame being the acknowledgement frame type.

6. The wireless device of claim 1, wherein the channel access counter is configured to signal that the time period has expired in response to (i) the type of the first networking frame being the acknowledgement frame type in combination with (ii) a type of the second networking frame being the data frame type.

7. The wireless device of claim 1, wherein the channel access counter is configured to omit tracking the time period in response to the type of the first networking frame being the acknowledgement frame type and a more data indication within the first networking frame indicating that more data is not expected.

8. The wireless device of claim 1, further comprising a network allocation vector counter configured to count down to zero, wherein the network allocation vector counter is set to a value based on a duration field in the first networking frame, and wherein the transceiver is configured to wait to access the wireless medium until after the network allocation vector counter reaches zero.

9. The wireless device of claim 8, wherein the network allocation vector counter is configured to change directly to zero in response to the transceiver receiving a contention-free end (CF-END) frame.

19. The wireless device of claim 1, wherein:

the channel access counter is configured to set the length of the time period equal to the first length value in response to the type of the first networking frame being the acknowledgment frame type; and

the channel access counter is configured to set the length of the time period equal to the second length value in response to the type of the first networking frame being the data frame type.

10. A method of operating a wireless device, the method comprising:

wirelessly receiving networking frames over a wireless medium;

tracking a time period, including

beginning the time period in response to a first networking frame of the networking frames being received, wherein the first networking frame is addressed to a receiver;

setting a length of the time period based on a first length value in response to a type of the first networking frame being an acknowledgment frame type, wherein the first length value is a predetermined value that is equal to a sum of a short interframe space (SIFS) and a transmission time of a maximum length physical layer convergence procedure protocol data unit frame; and

setting the length of the time period based on a second length value in response to the type of the first networking frame being a data frame type, wherein the second length value is a predetermined value that is equal to a sum of the SIFS and a predetermined transmission time for an acknowledgement frame;

generating an expiration signal in response to the time period expiring;

selectively generating the expiration signal in response to receiving, during the time period, a second networking frame; and

waiting to access the wireless medium until the expiration signal has been generated.

11. The method of claim 10, wherein the first length value is longer than the second length value.

12. The method of claim 10, wherein the tracking the time period includes decrementing a counter to zero starting from a value based on the time period.

13. The method of claim 12, wherein the generating the expiration signal is performed in response to the counter reaching zero.

14. The method of claim 10, wherein the selectively generating the expiration signal comprises generating the expiration signal in response to (i) the type of the first networking frame being the data frame type in combination with (ii) a type of the second networking frame being the acknowledgement frame type.

15. The method of claim 10, wherein the selectively generating the expiration signal comprises generating the expiration signal in response to (i) the type of the first networking frame being the acknowledgement frame type in combination with (ii) a type of the second networking frame being the data frame type.

16. The method of claim 10, further comprising, in response to the type of the first networking frame being the acknowledgement frame type and a more data indication within the first networking frame indicating that more data is not expected, omitting tracking the time period.

17. The method of claim 10, further comprising:

decrementing a network allocation vector counter to zero from a value based on a duration field in the first networking frame; and

waiting to access the wireless medium until after the network allocation vector counter reaches zero.

18. The method of claim 17, further comprising decreasing the network allocation vector counter directly to zero in response to receiving a contention-free end (CF-END) frame.

20. The method of claim 10, wherein:

the setting the length of the time period based on the first length value comprises setting the length of the time period equal to the first length value; and

the setting the length of the time period based on the second length value comprises setting the length of the time period equal to the second length value.