A communication device adjusts its power level based on a desired quality of service and based on a data rate being used to transmit data. The communication device may comprise a processor, a transceiver, and a power source that provides a power level to the transceiver for transmitting data at a variable rate. The processor obtains a first value indicative of a number of transmission errors, computes a second value using the first value and based on the data rate, and determines whether the second value is below a threshold. Based on a comparison of the second value to said threshold, the processor initiates a change in the power level. Additionally or alternatively, the processor may adjust the power level based on whether a current frame contains an error, but not permitting the power level to be decreased to a level at which a signal-to-interference ratio falls below a threshold.