Wireless LANs (WLANs) have hit the mainstream, and like other fast-moving technologies, have done so without much explanation of what they are, how they work or what they can do. These networks rely on radio waves -- not wires -- to connect PC users to other computers, and more importantly, to the Internet.
WLAN's garnered a lot of attention when used to create a Wi-Fi hot spot -- a public access point where anyone with a laptop or other wireless device and wireless adapter can log onto the Internet. Some are in city parks; others are located in cafes and airports. WLANs are also gaining popularity in offices where workers need to roam, yet stay connected to a company's server or to a Web site.
The public sector is also adopting WLANs for both public access and office networking. The applications range widely according to need. In terms of public access, many local governments use the technology to provide connectivity to citizens away from the home or office PC. In public housing projects, officials look to WLANs to bring affordable Internet connectivity to aging housing projects where the cost of running broadband wires can be prohibitive.
WLANs are springing up in historic government buildings where LAN wiring would be intrusive and damaging to the architecture, not to mention expensive to install. The wireless networks are also showing up in government health facilities, particularly where health professionals roam from building to building.
Sharing data and resources across a wireless network delivers a number of crucial benefits, according to the Wireless LAN Alliance (WLANA). They include:
-Improvements in productivity and service from increased mobility of workers and customers with access to real-time information.
-Speed and simplicity of installation because WLANs eliminate the need to pull cable through walls and ceilings.
-Reduced cost of ownership. Though wireless LAN hardware costs can be higher than those of wired LAN hardware, overall installation expenses and life-costs can be significantly lower.
-Scalability. WLANs can be configured to meet the needs of specific applications and installations, and can be easily changed from independent networks for a handful of workers to enterprise LANs involving hundreds of people.
In terms of cost, WLANA reports that a wireless LAN involves both infrastructure costs for the access points ($800 to $2,000) and user costs for the wireless adapters that attach to PCs and laptops ($200 to $700), which vary by computer platform. Cisco Systems estimates that for $200 to $300 per person -- which includes equipment, installation, training and annual support -- an organization can extend their existing wired network to mobile workers.
WLANA notes that the cost of installing and maintaining a wireless LAN generally is lower than the cost of a wired LAN for two reasons: It eliminates the direct wiring and labor costs associated with installing, and it reduces indirect costs of downtime and administrative overhead because it is simpler to move, add or change.
WLANA also notes numerous factors that improve with wireless networking --productivity, user expectations and price-performance improvements -- as the technology spreads.
How the WLAN Works
The best way to picture a WLAN is to think of a cell phone network because their functions are similar. Access points send and receive data over radio waves in the 2.4 GHz bandwidth to PCs, laptops and mobile devices with LAN adapters, which provide an interface between the network's operating system and the airwaves that carry the signal. The access points are connected to the network backbone, transmit a radio frequency over an area of several hundred feet, and can penetrate walls and other nonmetal barriers. In offices or environments with numerous access points, roaming users can be handed from one point to another, much like a