I'm sure this must be answered somewhere or another, but I looked around and couidn't find it.
Do 802.11 cards in, say, a laptop, transmit periodic signals when not actively in use on a wi-fi network?
In other words can such laptops be detected by someone using (some magic or another)?
And similarly, when a laptop comes in range of a network and displays the choices on its screen, has it already pinged out various "here I am" responses to those bases (that is, before you tell it to join up)?
Thanks