High Performance Browser Networking

Chapter 6. WiFi

WiFi operates in the unlicensed ISM spectrum; it is trivial to deploy by anyone, anywhere; and the required hardware is simple and cheap. Not surprisingly, it has become one of the most widely deployed and popular wireless standards.

The name itself is a trademark of the WiFi Alliance, which is a trade association established to promote wireless LAN technologies, as well as to provide interoperability standards and testing. Technically, a device must be submitted to and certified by the WiFi Alliance to carry the WiFi name and logo, but in practice, the name is used to refer to any product based on the IEEE 802.11 standards.

The first 802.11 protocol was drafted in 1997, more or less as a direct adaptation of the Ethernet standard (IEEE 802.3) to the world of wireless communication. However, it wasn’t until 1999, when the 802.11b standard was introduced, that the market for WiFi devices took off. The relative simplicity of the technology, easy deployment, convenience, and the fact that it operated in the unlicensed 2.4 GHz ISM band allowed anyone to easily provide a “wireless extension” to their existing local area network. Today, most every new desktop, laptop, tablet, smartphone, and just about every other form-factor device is WiFi enabled.

From Ethernet to a Wireless LAN

The 802.11 wireless standards were primarily designed as an adaptation and an extension of the existing Ethernet (802.3) standard. Hence, while Ethernet is commonly referred to as the LAN ...