Transmission monitoring can be used to determine the optimum data rate for a channel. The transmission monitoring can include sending data packets in the channel using various data rates. At least some data packets are sent using the current optimum data rate, a rate lower than the current optimum data rate, and a rate higher than the current optimum data rate. One of these data rates can be selected as the new optimum data rate. In one embodiment, if the current optimum data rate is less than a predetermined data rate, then the client is triggered to begin scanning for other available access points.