What, technically speaking, is 802.11b and how does it relate to IEEE 802.11? This chapter covers the technology of transmitting data over the airwaves, the process of that transmission, and the topologies and components of wireless networks. Thousands of enterprises worldwide are cutting the wires to their local area networks (LANs) to enjoy greater productivity from their unwired work force. 802.11b also has the potential to save money on infrastructure (wiring buildings for networks) and telecommunications services.

How Does Wireless Fidelity (Wi-Fi) Work?

A networked desktop computer is connected to a larger network (a LAN, wide area network [WAN], or the Internet) via a network cable to a hub, router, or switch. The computer's network interface card (NIC) sends zeros and ones down the cable by changing the voltage on the wires from +5 volts to -5 volts in a prearranged cadence. Wi-Fi simply replaces these cables with small, low-powered two-way radios. Instead of changing the voltage on a wire, it encodes the zeros and ones by laying an alternating radio signal over a constant existing signal in a prearranged cadence. The alternating signal encodes zeros and ones on the radio waves. The 802.11b specification allows for the wireless transmission of approximately 11 Mbps of raw data at distances up to a few hundred feet over the 2.4 GHz unlicensed band. The distance depends on impediments, materials, and line of sight.

Many people might ask, "So what?" It means a PC user can install a $70 PC...