Wireless LAN data rate adaptation
A WLAN communication system and algorithm that adaptively changes the data transmission rate of a communication channel based on changing channel conditions. The WLAN communication system or algorithm has two modes being a searching mode and a transmission mode. Furthermore, the WLAN communication system or algorithm incorporates an additive increase, multiplicative decrease (AIMD) function into the rate adaptation algorithm.
1. A method for selecting a configurable data transmission rate for a wireless LAN (WLAN) device which operates to send WLAN communications and receive acknowledgments of said sent WLAN communications, comprising:
increasing the data transmission rate in response to receipt of a number of consecutive acknowledgments in excess of a success threshold;
responding to an acknowledgment received immediately after increasing the data transmission rate by increasing the success threshold;
responding to failure to receive the acknowledgment immediately after increasing the data transmission rate by increasing the success threshold and decreasing the data transmission rate;
responding to failure to receive the acknowledgment at instances other than immediately after increasing the data transmission rate by decreasing the success threshold and decreasing the data transmission rate.
2. The method of claim 1 , wherein increasing the success threshold comprises adding a predetermined constant amount (α) to the success threshold.
3. The method of claim 1 , wherein decreasing the success threshold comprises setting the success threshold to be equal to a prior success threshold value divided by a predetermined constant amount (β).
4. The method of claim 1 , wherein the data transmission rate has a plurality of settable integer value modes, and increasing the data transmission rate comprises increasing to a mode which is approximately midway between a current mode and a maximum mode.
5. A method for wireless LAN (WLAN) device communication, comprising:
sending WLAN communications;
receiving acknowledgments of said sent WLAN communications;
configuring a data transmission rate for the sent WLAN communications, the data transmission rate selected in accordance with an adaptive rate algorithm process, comprising:
increasing the data transmission rate in response to receipt of a number of consecutive acknowledgments in excess of a success threshold;
responding to an acknowledgment received immediately after increasing the data transmission rate by increasing the success threshold;
responding to failure to receive the acknowledgment immediately after increasing the data transmission rate by increasing the success threshold and decreasing the data transmission rate;
responding to failure to receive the acknowledgment at instances other than immediately after increasing the data transmission rate by decreasing the success threshold and decreasing the data transmission rate.
6. The method of claim 5 , wherein increasing the success threshold comprises adding a predetermined constant amount (α) to the success threshold.
7. The method of claim 5 , wherein decreasing the success threshold comprises setting the success threshold to be equal to a prior success threshold value divided by a predetermined constant amount (β).
8. The method of claim 5 , wherein the data transmission rate has a plurality of settable integer value modes, and increasing the data transmission rate comprises increasing to a mode which is approximately midway between a current mode and a maximum mode.
9. A method for selecting a setting of a configurable data transmission rate for a wireless LAN (WLAN) device which operates to send WLAN communications and receive acknowledgments of said sent WLAN communications, the data transmission rate having a plurality of settings, comprising:
increasing the setting of the data transmission rate in response to receipt of a number of acknowledgments in excess of a success threshold, and
decreasing the setting of the data transmission rate in response to failure to receive the acknowledgment, the success threshold being increased in response to each increasing of the data transmission rate setting, and the success threshold being set to a fraction of the success threshold in response to decreasing of the data transmission rate setting.
10. The method of claim 9 , wherein increasing the success threshold comprises increasing a value for the success threshold by a predetermined constant amount (α).
11. The method of claim 9 , wherein the success threshold being set to a fraction comprises setting a value for the success threshold to be equal to a prior success threshold value divided by a predetermined constant amount (β).
12. The method of claim 9 , wherein the plurality of setting of the data transmission rate comprise a plurality of settable integer value modes, and increasing the data transmission rate comprises increasing to a mode which is approximately midway between a current mode and a maximum mode.
13. A method for wireless LAN (WLAN) device communication, comprising:
sending WLAN communications;
receiving acknowledgments of said sent WLAN communications;
configuring a data transmission rate for the sent WLAN communications, the data transmission rate having a plurality of settings selected in accordance with an adaptive rate algorithm process, comprising:
increasing the setting of the data transmission rate in response to receipt of a number of acknowledgments in excess of a success threshold;
decreasing the setting of the data transmission rate in response to failure to receive the acknowledgment;
increasing the success threshold in response to each increasing of the data transmission rate setting by the adaptive rate algorithm; and
setting the success threshold to a fraction of the success threshold in response to decreasing of the data transmission rate setting by the adaptive rate algorithm.
14. The method of claim 13 , wherein increasing the success threshold comprises increasing a value for the success threshold by a predetermined constant amount (α).
15. The method of claim 13 , wherein setting the success threshold to a fraction comprises setting a value for the success threshold to be equal to a prior success threshold value divided by a predetermined constant amount (β).
16. The method of claim 13 , wherein the plurality of settings for the data transmission rate comprise a plurality of settable integer value modes, and increasing the data transmission rate comprises increasing to a mode which is approximately midway between a current mode and a maximum mode.
17. A method for selecting a configurable data transmission rate for sent wireless LAN (WLAN) communications by a WLAN device which operates to send WLAN communications and receive acknowledgments of said sent WLAN communications, the WLAN device operating in a searching phase and a transmission phase, the method comprising:
when in the searching phase to search for a preferred data transmission rate:
increasing the data transmission rate in response to receipt of a number of consecutive acknowledgments in excess of a success threshold;
responding to an acknowledgment received immediately after increasing the data transmission rate by increasing the success threshold;
exiting the searching phase to enter the transmission phase with the increased data transmission rate as the preferred data transmission rate;
responding to failure to receive the acknowledgment immediately after increasing the data transmission rate by increasing the success threshold and decreasing the data transmission rate;
responding to failure to receive the acknowledgment at instances other than immediately after increasing the data transmission rate by decreasing the data transmission rate; and
staying in the searching phase; and
when in the transmission phase to transmit WLAN communications at the preferred data transmission rate:
increasing the data transmission rate in response to receipt of a number of consecutive acknowledgments in excess of a success threshold;
responding to an acknowledgment received immediately after increasing the data transmission rate by increasing the success threshold;
responding to failure to receive the acknowledgment immediately after increasing the data transmission rate by increasing the success threshold, decreasing the data transmission rate and exiting the transmission phase to enter the searching phase; and
responding to failure to receive the acknowledgment at instances other than immediately after increasing the data transmission rate by decreasing the data transmission rate and exiting the transmission phase to enter the searching phase.
18. The method of claim 17 , wherein increasing the success threshold comprises adding a predetermined constant amount (α) to the success threshold.
19. The method of claim 17 , wherein decreasing the success threshold comprises setting the success threshold to be equal to a prior success threshold value divided by a predetermined constant amount (β).
20. A method for wireless LAN (WLAN) device communication, comprising:
sending WLAN communications;
receiving acknowledgments of said sent WLAN communications;
operating in a searching phase and a transmission phase;
configuring a data transmission rate for the sent WLAN communications, the data transmission rate selected in accordance with an adaptive rate algorithm process, comprising:
when operating in the searching phase to search for a preferred data transmission rate:
increasing the data transmission rate in response to receipt of a number of consecutive acknowledgments in excess of a success threshold;
responding to an acknowledgment received immediately after increasing the data transmission rate by increasing the success threshold;
exiting the searching phase to enter the transmission phase with the increased data transmission rate as the preferred data transmission rate;
responding to failure to receive the acknowledgment immediately after increasing the data transmission rate by increasing the success threshold and decreasing the data transmission rate;
responding to failure to receive the acknowledgment at instances other than immediately after increasing the data transmission rate by decreasing the data transmission rate; and
staying in the searching phase; and
when operating in the transmission phase to transmit WLAN communications at the preferred data transmission rate:
increasing the data transmission rate in response to receipt of a number of consecutive acknowledgments in excess of a success threshold;
responding to an acknowledgment received immediately after increasing the data transmission rate by increasing the success threshold;
responding to failure to receive the acknowledgment immediately after increasing the data transmission rate by increasing the success threshold, decreasing the data transmission rate and exiting the transmission phase to enter the searching phase; and
responding to failure to receive the acknowledgment at instances other than immediately after increasing the data transmission rate by decreasing the data transmission rate and exiting the transmission phase to enter the searching phase.
21. The method of claim 20 , wherein increasing the success threshold comprises adding a predetermined constant amount (α) to the success threshold.
22. The method of claim 20 , wherein decreasing the success threshold comprises setting the success threshold to be equal to a prior success threshold value divided by a predetermined constant amount (β).