From: Xam R. Time (xam_at_chalupa.wi2600.org)
Date: 2002-09-26 14:18:40 UTC
On Thu, 26 Sep 2002, Joshua Wright wrote:
> If anyone has thoughts on detecting WLAN discovery applications, I'd
> love to hear them.
There is indeed very little (almost nothing) you can do on layer 2 to detect a station recieving. However, on layer 1 you would have a tiny bit more latitude. One way would be to emit a very energetic burst of energy centered at about 2440 Mhz. You could then wait for reflections from anything in your environment that's a) resonant at 2440 Mhz or b) reflective at 2440 Mhz.
Essentialy you could (with the correct equipment) detect antennas or things that have a conductive path at or near a critical distance (that is something that happens to be a 1/2 wave @ 2440, for example).
Alternatively, you could look for tell-tale leakage of the Rx stations IF section. I'm not sure the radiated energy is even above the noise floor, and I can't even remember what the IF stages might run at. I recal direct conversion is getting more and more popular..
--Tk