An access point operating in a wireless communication network includes a smart antenna for generating directional antenna beams. A method for operating the access point includes communicating with a client station using a selected directional antenna beam, with the client station initially being in a stationary position. Signal to noise ratios of signals received from the client station within a time interval are measured. At least one variation metric of a mean of the measured signal to noise ratios within the time interval is determined. This at least one determined variation metric is compared to a threshold for determining if the client station is moving.