We have 12 (or 14 in some areas) channels in the 2.4Ghz band, so a full scan would take 102,400μs x 2 x 12 = 2,457,600μs or about 2.5 seconds.ĭuring this time, the receiver is in a high power usage mode - so battery life is negatively impacted and power usage for a wifi adapter sky-rockets. To have some hope of hearing most Access Points, you'll need to wait for 2 beacon intervals - say 102,400μs x 2 per channel. The beacon (by default) is only transmitted every 100 TU (102,400μs). The scan is completely passive and nothing is transmitted from your wifi adapter. There are two methods of scanning for active WiFi access points.ġ) Turn the receiver on and listen on each channel for the beacon orĢ) Broadcast a 'Who is there?' packet on each channel. Wifi is an interesting protocol when you get into the gritty details.
