Tools to help the overworked Security Manager identify wireless networks in their premises range from free to $thousands. At the bottom end are Wi-Fi snooping tools such as NetStumbler and kismet, and the cheap-n-nasty wLAN detectors given away as merchandising at computer shows. In the mid range is commercial software that uses standard wireless LAN cards to scan the normal Wi-Fi frequency bands, and wide range UHF/SHF scanners. High end tools use very expensive software to get more information from the wLAN cards, or use dedicated spectrum analyzer hardware to get even more gen, provided the user has the technical skills to control the machine and interpret the output. Read about (some of) the range on Informit's review of Wi-Fi audit tools.
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