The topic of this bachelor's thesis is to set compact view on the issues of the wireless networks, their settings and proper security in corporate environment. Wireless networks are supposed to simplify access to the internet and business data, but especially in this area, it is necessary to put forth above standard care to security policy, to protect network from external attacks. First part of this work is focused on theoretical background of the Wi-fi, basic functioning principles, history and step-by-step development of technology. Explains differences between particular standards, defines basic parameters of Wi-fi devices. Next part is focused on network security. It explains encryption methods and procedures and describes differences ...