Wifi

Wi-Fi pronounced wa fa is a trademark of the Wi-Fi Alliance that manufacturers may use to brand certified products that belong to a class of wireless local area network WLAN devices based on the IEEE 802.11 standards, which is by far the most widespread WLAN class today. Because of the close relationship with its underlying standards, the term Wi-Fi is often used as a synonym for IEEE 802.11 technology. 1

The Wi-Fi Alliance, a global association of companies, promotes WLAN technology and certifies products if they conform to certain standards of interoperability. Not every IEEE 802.11-compliant device is submitted for certification to the Wi-Fi Alliance, sometimes because of costs associated with the certification process. The lack of the Wi-Fi logo does not necessarily imply a device is incompatible with Wi-Fi devices.

IEEE 802.11 devices are installed in many personal computers, video game consoles, MP3 players, smartphones, printers, and other peripherals, and virtually all laptop computers.

Wi-Fi products use both single-carrier direct-sequence spread spectrum radio technology part of the larger family of spread spectrum systems and multi-carrier orthogonal frequency-division multiplexing OFDM radio technology. The deregulation of certain radio-frequencies by whom? for unlicensed spread spectrum deployment enabled the development of Wi-Fi products, Wi-Fi's onetime competitor HomeRF, Bluetooth, and many other products such as some types of cordless telephones.

Many other countries later adapted these FCC regulations, enabling use of this technology in all major countries. The FCC action was proposed by Michael Marcus of the FCC staff in 1980 and the subsequent regulatory action took 5 more years. It was part of a broader proposal to allow civil use of spread spectrum technology and was opposed at the time by mainstream equipment manufacturers and many radio system operators.