The topic of this final paper is to get informed with wireless network technology WiFi and RADIUS protocol. Wireless computer technology or Wi-Fi system is becoming an indispensable part of today's time, and offers a number of advantages such as flexibility, more users and high speed range. As Wi-Fi technology uses a free medium for data transmission - air, there are numerous interferences that affect the transmission of the signal as well as the security of the network itself. The thesis is guided by a theoretical explanation of Wi-Fi technology, the principle of operation, the emergence and development of Wi-Fi network and the specific characteristics needed to ensure effective Wi-Fi network coverage. In addition to the Wi-Fi network, the RADIUS protocol has been described, which enables increased control and security of the network and works on the principle of authentication, authorization and administration. Theoretical knowledge of Wi-Fi technology and RADIUS protocol was practically applied in the development of the Preliminary Design, which was realized using various software tools such as Ekahau Site Survery, Adobe Photoshp, web browser, and others.