wireless LAN
(wireless Local Area Network) A communications network that provides connectivity to wireless devices within a limited geographic area. "Wi-Fi" is the universal standard for wireless networks and is the wireless Ethernet equivalent of wired Ethernet networks. In the office, Wi-Fi networks are adjuncts to the wired networks. At home, a Wi-Fi network can serve as the only network since all laptops and many printers come with Wi-Fi built in, and it can be added to desktop computers.
Wi-Fi LANs do not require line of sight between sender and receiver. Wireless base stations, called "access points," have antennas that transmit and receive a radio frequency within a range of 30 to 150 feet through walls and other non-metal barriers.
Laptops and Desktops Can Be Retrofitted
Old laptops can be upgraded with Wi-Fi adapters via a PC card slot or USB. Although desktop computers are typically wired to the network, they can be made wireless by plugging a wireless adapter into a USB port or internal PCI slot.
The Wireless Router - All In One
A wireless router is an all-in-one network device specialized for the home or small office that has cable or DSL Internet access. It contains an access point, switch and router. The access point provides the wireless antennas; the switch interconnects wireless and wired devices, and the router forwards Internet traffic to the modem. The modem is wired to the cable company's coaxial cable or the telephone company's DSL phone line. Since all wireless and wired computers are hooked up to the wireless router, they can exchange data with each other for backup and file sharing. For technical details of the wireless standards, see 802.11. See hotspot, router, LAN switch and WPAN.
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| Wireless LAN |
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| This shows both wired and wireless networks in a hypothetical company. To support numerous computers in a large office, the access points, switches and routers are stand-alone products. An access point is like a cellphone tower, but transmits and receives signals within an area measured in feet, not miles. In a large office, users can roam between access points without losing a connection similar to a cellular system. |
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| Wireless Router |
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| A wireless router combines access point, switch and router in one unit for setting up a small wireless and wired network from scratch. The antennas transmit Wi-Fi, while the four Ethernet ports are wired to computers and printers. The Internet/WAN connection goes to the cable or DSL modem. This Belkin router uses multiple antennas: two send and three receive (see MIMO). (Image courtesy of Belkin Corporation, www.belkin.com) |