The various aspects of the WLAN domain are based on public standards from various bodies?the IEEE, the European Telecommunications Standards Institute (ETSI), and the Internet Engineering Task Force (IETF). The fundamental standard is the IEEE 802.11, which specifies the WLAN protocols, data frames, various layers, and frequencies. The IETF standards are in the security protocols and methods domain, whereas ETSI specifies the frequencies and other radio regulatory matters. Chapter 3, "WLAN Standards," describes the various standards in detail.