A wireless access point is operable to execute background scans of alternate channels by tuning to the alternate channel for short periods of time, thereby generating sub-windows of data. The sub-windows are calculated to have timing and duration that avoid disruption of communications on the active channel. Multiple background scan sub-windows are used to assemble a virtual target window of the alternate channel, e.g., a 100 mSec window, during which any periodic beacon within range might be expected to be received. The data such as beacon information is employed to generate a table ranking the alternate channels in terms of viability for communications.