Wireless networking has become increasingly popular these days. Wireless networks have adopted many security mechanisms from the wired world. But wireless networks face larger amount of inherent limitations than the wired world. Threats like intercepting and unauthorized access to wireless traffic are common. More mature solutions to the security problems demand the need of understanding the current technologies and the security flaws. This course covers the basics of wireless networks security from both modes of operation -- the infrastructure mode and the ad hoc mode.