Adaptive contention for wireless devices

• US 7,826,838 B1
• Filed: 11/02/2006
• Issued: 11/02/2010
• Est. Priority Date: 11/02/2006
• Status: Active Grant

• Current Assignee: NVIDIA Corporation
• Original Assignee: NVIDIA Corporation
• Inventors: Bhat, Naren, Nanda, Sameer, Maufer, Thomas A.
• Primary Examiner(s): Afshar; Kamran
• Assistant Examiner(s): Choo; Munsoon
• Application Number:
  US11/556,076
• Time in Patent Office: 1,461 Days
• Field of Search: 370/328, 370/465, 455/423, 455/425, 709/224
• US Class Current: 455/423
• CPC Class Codes: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 74/0841 with collision treatment

Abstract

A method and apparatus for reducing a contention window range of a client device located in a wireless network is described. In one embodiment, network conditions present in the wireless network are monitored. The network conditions are subsequently utilized to determine if the wireless network is small or if traffic in the wireless network is low. Afterwards, the contention window range of the client device is reduced if either of the wireless network is small or if the traffic in the wireless network is low.

Claims

1. A method for establishing a contention window range for a client device located in a wireless network, the method comprising:

operating the client device within a contention window (CW) range having a minimum standard size;

monitoring network conditions present in said wireless network;

estimating the number of client devices in said wireless network by determining a number of client devices that transmit signals to the client device;

determining that said wireless network is small based on the estimated number of client devices;

reducing the size of said contention window range of the client device to a first range that is smaller than the minimum standard size when traffic in said wireless network is low based on the network conditions, wherein said traffic in said wireless network is designated as low if a predefined threshold number of transmissions originating from said client device to an access point in said wireless network is performed without interference; and

thereafter, upon detecting a collision, increasing the size of said CW range of the client device to a second range that is above the minimum standard size.

2. The method of claim 1, wherein the step of determining that said wireless network is small comprises determining that a predefined threshold number of client devices on said wireless network is not exceeded.

3. The method of claim 1, wherein a maximum value of the second range is computed as one less than 2ⁱ, where i is an integer and 2ⁱ is greater than a maximum value of said contention window range.

4. The method of claim 3, further comprising decreasing the size of said CW range of the client device incrementally by one when a number of detected collisions is deemed to be acceptable.

5. The method of claim 1, further comprising:

determining that all of the client devices in the wireless network are capable of adjusting their respective CW ranges to the minimum standard size; and

increasing said CW range of the client device to the minimum standard size.

6. A non-transitory computer readable medium having stored thereon instructions that, when executed by a processor, causes the processor to perform a method for establishing a contention window range of a client device located in a wireless network, comprising:

operating the client device within a contention window (CW) range having a minimum standard size;

monitoring network conditions present in said wireless network;

estimating the number of client devices in said wireless network by determining a number of client devices that transmit signals to the client device;

determining that said wireless network is small based on the estimated number of client devices;

reducing the size of said contention window range of the client device to a first range that is smaller than the minimum standard size when traffic in said wireless network is low based on the network conditions, wherein said traffic in said wireless network is designated as low if a predefined threshold number of transmissions originating from said client device to an access point in said wireless network is performed without interference; and

thereafter, upon detecting a collision, increasing the size of said CW range of the client device to a second range that is above the minimum standard size.

7. The non-transitory computer readable medium of claim 6, wherein the step of determining that said wireless network is small comprises determining that a predefined threshold number of client devices on said wireless network is not exceeded.

8. The non-transitory computer readable medium of claim 6, wherein a maximum value of the second range is computed as one less than 2ⁱ, where i is an integer and 2ⁱ is greater than a maximum value of said contention window range.

9. The non-transitory computer readable medium of claim 8, further comprising decreasing the size of said CW range of the client device incrementally by one when a number of detected collisions is deemed to be acceptable.

10. The non-transitory computer readable medium of claim 6, further comprising:

determining that all of the client devices in the wireless network are capable of adjusting their respective CW ranges to the minimum standard size; and

increasing said CW range of the client device to the minimum standard size.

11. An apparatus for reducing a contention window range of a client device located in a wireless network, comprising:

a contention window adjustment module that is configured to;

operate the client device within a contention window (CW) range having a minimum standard size;

monitor network conditions present in said wireless network;

estimate the number of client devices in said wireless network by determining a number of client devices that transmit signals to the client device;

determine that said wireless network is small based on the estimated number of client devices;

reduce said contention window range of said client device to a first range that is smaller than the minimum standard size when traffic in said wireless network is low based on the network conditions, wherein said traffic in said wireless network is designated as low if a predefined threshold number of transmissions originating from said client device to an access point in said wireless network is performed without interference; and

thereafter, upon detecting a collision, increase the size of said CW range of the client device to a second range that is above the minimum standard size.

12. The apparatus of claim 11, wherein the contention window adjustment module is further configured to compute a maximum value of the second range as one less than 2ⁱ, where i is an integer and 2ⁱ is greater than a maximum value of said contention window range.

13. The apparatus of claim 12, wherein the contention window adjustment module is further configured to decrease the size of said CW range of the client device incrementally by one when a number of detected collisions is deemed to be acceptable.

14. The apparatus of claim 11, wherein the contention window adjustment module is further configured to:

determine that all of the client devices in the wireless network are capable of adjusting their respective CW ranges to the minimum standard size; and

increase said CW range of the client device to the minimum standard size.