Wireless protocols define the standards that allow networking devices to exchange information through the airwaves, literally without wires. There are three main classes of wireless protocols: long-, medium- and short-range. Long-range is measured in miles, medium-range is measured in tens or hundreds of feet, while short-range is generally less than 10 feet. Each class has different protocols, with varying attributes, that make the selection dependent on the situation.
Long-range wireless protocols generally will sacrifice throughput, or speed, to transmit data over longer distances. They may be used as a "back-haul" between two sites, or to deliver data services to individual devices, such as smart phones and laptop computers. "Worldwide Interoperability for Microwave Access," or WiMAX, was primarily designed to allow mobile devices to access the Internet. "Global System for Mobile Communications," or GSM, is the most widespread long-range wireless protocol in the world, as it enables data communication to the majority of the world's cellular telephones.
Also referred to as "Wireless Local Area Network," or WLAN, medium-range wireless protocols are generally used for communications between computers to replace or enhance traditional wired LANs. There are four main protocols, all of which are part of the Institute of Electrical & Electronics Engineers, or IEEE, 802.11 standard. 802.11a can achieve a throughput, or speed, of 54 megabits per second, or Mbps, but generally over a shorter range than its counterparts. 802.11b has a longer range than 802.11a, but sacrifices speed with a lower maximum of 11 Mbps. 802.11g combines the best of 802.11a and 802.11b by offering 54 Mbps at longer ranges. 802.11n is the latest standard to gain widespread adoption, as of 2010. It offers speeds of 150 Mbps or more, at longer ranges.
Also referred to as "Wireless Personal Area Networks," or WPAN, short-range wireless protocols operate at lower frequencies between devices that are usually only a few feet apart. Bluetooth is a popular short-range protocol. One of the current common usages is to allow a wireless headset to communicate with a portable phone. Infrared Data Association, or IrDA, is an older, very-short range protocol that is used for close-range communication between devices, such a computer to a printer.