IEEE 802.11 Technology for Wireless LANs
IEEE 802.11 technology is being deployed widely for WLAN applications. WLANs permit a degree of mobility, and enhance convenience by eliminating the wires used to connect computers to networks. WLANs are increasingly being installed in businesses, shops, airport lounges, homes, and other venues; in nearly all of these cases, IEEE 802.11 is the technology of choice.
IEEE 802.11 is a popular WLAN technology because it was designed just for this purpose. As indicated above, WLANs usually replace or augment existing wired LANs; hence, the devices typically used with WLANs are the same ones used on wired LANs: servers, desktop computers, and notebook computers. For the same reasons, WLAN applications are usually identical to those of their wired counterparts: e-mail, Web browsing and others that rely on standard Internet-based protocols and technologies.
Earlier, we noted that typical WLAN applications consume a fair amount of electrical power for their relatively high-data-rate, medium-range transmissions. Portable devices such as notebook computers can supply this energy and still maintain reasonable battery life. But smaller portable devices such as handheld computers, pagers, mobile phones, and digital cameras typically can't sustain the necessary power draw for long periods of time without the auxiliary power supplies that make the devices less mobile and convenient. This is where WPAN technologies come into play.