Patent ID: 8630220
Filing Date: 2014-01-14
Classification: H04W

Abstract:
1. An access point scan method by which a station, connectable to a plurality of access points, actively scans among a plurality of radio channels for an access point with which to connect, comprising: a first step setting an order of scanning the radio channels; a second step transmitting a probe request for an access point scan over a specified radio channel according to the order of scanning; a third step generating a connection candidate access point (AP) list when a probe response to the probe request is received, the connection candidate AP list including information indicating an access point which transmits the probe response and a received signal strength indication; a fourth step referring to the connection candidate AP list and selecting one access point from access points whose corresponding received signal strength indications exceed a predetermined threshold; a fifth step performing connection processing on one access point selected in the fourth step on the specified radio channel; a sixth step specifying a radio channel which is second in the order and going back to the second step until scanning performed on all radio channels for which the order of scanning is set in the first step is completed when the probe response is not received in the third step or the connection candidate AP list includes no received signal strength indication which exceeds the threshold in the fourth step; a tenth step storing the specified radio channel and the connection candidate AP list when the connection candidate AP list includes no received signal strength indication which exceeds the threshold in the fourth step and entering the sixth step; and an eleventh step selecting an access point and a radio channel with a maximum received signal strength indication in received signal strength indications of the connection candidate AP list stored in the tenth step and performing processing for connection with the access point on the radio channel when scanning performed on all the radio channels is completed in the sixth step; before the fifth step, a seventh step transmitting a dummy packet to the access point selected in the fourth step over the specified radio channel, calculating a packet error rate from number of received acknowledgement frames relative to number of transmitted dummy packets, proceeding to the fifth step when the packet error rate is equal to or less than a predetermined threshold, and proceeding to the sixth step when the packet error rate exceeds the predetermined threshold.