This figure uses two illustrations to depict active and passive scanning. The image on the left depicts passive scanning. In this illustration we see two basic service sets, labeled "BSS 1" and "BSS 2," that overlap to form a common area in between them. BSS 1 includes a cell tower labeled AP1, and BSS2 includes a cell tower labeled "BSS 2." In the center common area is a laptop computer labeled H1. A blue arrow points from AP1 to H1 and a second arrow points from AP 2 to H1. Both arrows are labeled 1 and correspond to a numbered sequence below the figure. 1 = "Beacon frames sent from APs." An arrow labeled 2 points from H1 back to AP 2. 2 = "Association Request frame sent: H1 to selected AP." A blue arrow labeled 3 points from AP2 to H1. 3 = "Association Response frame sent: Selected AP to H1."

The second figure, depicting active scanning, is the same as the first. In this figure, however, a blue line labeled 1 rises from H1 and extends in either direction towards AP1 and AP2. 1 = "Probe Request frame broadcast from H1." Blue arrows labeled 2 point from AP1 to H1 and from AP2 to H1. 2 = "Probes Response frame sent from APs." A blue arrow labeled 3 points from H1 to AP2. 3 = "Association Request frame sent: H1 to selected AP." A blue arrow labeled 4 points from AP2 to H1. 4 = Association Response frame sent: Selected AP to H1."