What is a “ Wireless LAN”?

A wireless LAN (WLAN) is a flexible data communication system implemented as an extension to, or as an alternative for, a wired LAN within a building or campus.  Using electromagnetic waves, WLANs transmit and receive data over the air, minimizing the need for wired connections.  Thus, WLANs combine data connectivity with user mobility, and through simplified configuration, enable movable LANs.

In a typical WLAN configuration, a transmitter/receiver (transceiver) device, called an access point, connects to the wired network from a fixed location using standard Ethernet cable.  At a minimum, the access point receives, buffers, and transmits data between the WLAN and the wired network infrastructure. A single access point can support a small group of users and can function within a range of less than one hundred to several hundred feet.  The access point is usually mounted high but may be mounted essentially anywhere that is practical as long as the desired radio coverage is obtained.

End users access the WLAN through wireless LAN adapters, which are implemented as PC cards in notebook computers, or use ISA or PCI adapters in desktop computers, or fully integrated devices within handheld computers.  WLAN adapters provide an interface between the client network operating system (NOS) and the airwaves (via an antenna). Users need very little new information to take advantage of wireless LANs.  Because the wireless nature of a WLAN is transparent to a user’s NOC, applications work the same as they do on wired LANs.