Patent ID: 6940843

Claim:
An apparatus for inclusion in a station of a wireless network, the apparatus comprising: a radio receiver to wirelessly receive data from at least one remote station, said data transmitted by the remote station as at least one packet of data, the receiver including an analog-to-digital converter producing samples of signals received at the station from the remote station; a demodulator coupled to the radio receiver to demodulate samples of the signals received at the receiver from each station to produce, demodulated signals from each of the remote stations; and a signal quality calculator coupled to the receiver to determine for each remote station from which data is received a signal quality measure of the-received signal based on the samples of the received data from the remote station, such that, the receiving station selects one of the remote stations for communication according to a set of at least one criterion, said set including the respective received signal quality measure determined by the signal quality calculator for data from each of the respective remote stations, wherein the signal quality calculator is an error vector magnitude calculator to determine for each remote station from which data is received a measure of the error vector magnitude of the received data from the remote station, the error vector magnitude based on samples approximately at decision points of the demodulator, wherein at least some of the stations from which data is received are access points, and wherein the data received from remote stations that are access points are beacons or probe responses, such that one of the criteria for the station to select a remote access point for association is a measure of the error vector magnitude of a beacon or probe response received from the access point, and wherein the error vector magnitude of a beacon or a probe response received from the access point is used to determine the maximum transmission rate that the link between the station and the remote access points can support, and wherein the determined maximum supported transmission rate is one of the criteria for the station to select a remote access point for association.