The introduction of wireless networks, whether inside corporate network infrastructure or common homes, introduces additional security exposures that are much more threatening than wired network attacks.
Since, the only boundary wireless networks know are their signals, it becomes easy for hackers to identify wireless networks simply by "driving" or walking around office buildings with their wireless network equipment- this technique is known as "war driving".
Once an open wireless access point is found, the war driver usually maps it, so at the end he would have a map of access points with their properties (SSID, WEP, MAC etc.).
The goal of wireless network testing is to identify security gaps or flaws in the design, implementation or operation of the organization's wireless network.