Now suppose you enter such a WiFi jungle with your portable computer,
seeking wireless Internet access and a blueberry muffin. Suppose there are five
APs in the WiFi jungle. To gain Internet access, your wireless station needs to join
exactly one of the subnets and hence needs to associate with exactly one of the
APs. Associating means the wireless station creates a virtual wire between itself
and the AP. Specifically, only the associated AP will send data frames (that is,
frames containing data, such as a datagram) to your wireless station, and your
wireless station will send data frames into the Internet only through the associated
AP. But how does your wireless station associate with a particular AP? And more
fundamentally, how does your wireless station know which APs, if any, are out
there in the jungle?