Abstract: A method and apparatus are provided for automatic data rate control in wireless communication systems, such as wireless LANs. A data rate controller adapts a transmission rate of said data based on a signal quality and a transmit power level. The data rate controller can also adapt the transmission rate based on one or more of amplifier non-linearities, anticipated signal quality for a next frame transmission, regulatory emission limits and data rate advice. The data rate advice will decrease a data rate if a current signal quality is below a minimum required signal quality for a given data rate and increase a data rate if a current signal quality is above a minimum required signal quality for a given data rate. A probation mechanism allows a higher rate to be evaluated before switching to the higher rate permanently. A retry balance mechanism forces a rate fallback when a number of failed transmission exceeds a predefined threshold.

Abstract: A method and apparatus are disclosed for automatic transmit power variation in a wireless communication system. A wireless communication device according to the present invention includes a dynamic transmit power controller that adapts a transmit power level based on a transmission rate of the data. One aspect of the dynamic transmit power controller selects a maximum allowable power level that is based on limits specified for a given region and frequency band, or a maximum directional gain of an antenna (or both). Another aspect of the dynamic transmit power controller selects a maximum capable power level that is based on the transmission rate, frequency band, or characteristics of a transmitter output amplifier (or a combination of the foregoing). Generally, the transmit power level is selected based on a minimum of the maximum allowable power level and the maximum capable power level.

Abstract: A method and apparatus are disclosed for reducing a transmission rate for retransmission of a current frame in a wireless communication system. The reduced transmission rate increases the probability that the current frame is correctly transmitted and acknowledged. The transmission rate is progressively reduced for the current frame to avoid the expiration of the frame's retry count, while not affecting the transmission rate of subsequent frames. The next frame should be transmitted at the highest rate permitted, by the signal quality. A disclosed retry count expiry avoidance algorithm increases the reliability of a retransmission by lowering the transmission rate for the current frame when an acknowledgement is not received. When an acknowledgement is not received, the transmitting station proceeds to a retransmitting state where the transmitting station first attempts to retransmit the frame at the same rate.