By Danielle Dunne

(IDG) -- A wireless LAN lets users roam around a building with a laptop (equipped with a wireless LAN card) and stay connected to their network without being connected to a wire.

What is a Wireless LAN?

A wireless LAN (WLAN) is a local area network (LAN) without wires. WLANs have been around for more than a decade, but are just beginning to gain momentum because of falling costs and improved standards. WLANs transfer data through the air using radio frequencies instead of cables. They can reach a radius of 500 feet indoors and 1000 feet outdoors, but antennas, transmitters and other access devices can be used to widen that area. WLANs require a wired access point that plugs all the wireless devices into the wired network.

A new standard put out by the Institute of Electrical and Electronics Engineers (IEEE) called 802.11b or Wi-Fi is making WLAN use faster and easier, and the market is growing quickly. The Cahners In-Stat Group predicts that revenue for total enterprise WLAN end-use will reach almost $4.6 billion by 2005.

Where are WLANs typically used?

WLANs are used on college campuses and in office buildings. They can be set up in houses allowing multiple users to access one Internet connection. Resorts, apartment buildings and airports plan to offer WLAN access (some already do). Often the best use for WLANs are in places where LANs arent installed yet, like schools or public institutions that are slow to adopt new technologies.

Starbucks and Microsoft are also getting into the WLAN game. They are teaming up to equip their coffee shops with WLANs, which allow laptop users to surf the Net while sipping lattes.

Are there different kinds of WLANs?

Bluetooth and HomeRF are also WLAN technologies, but Bluetooth works in a smaller area than 802.11b does and HomeRF hasnt become as popular as 802.11b.

What is 802.11b?

It sounds like something from Star Wars, but it is the standard that is behind WLANs current popularity. 802.11b transfers data at speeds of up to 11Mbps (million bits per second) in the 2.4 gigahertz radio band (a license is not required for this band).

The next version, 802.11a, is supposed to transfer data at even higher speeds of up to 54Mbps in the 5 gigahertz band.

Are Wireless LANs secure?

A small research group at the University of California at Berkeley recently put out a report stating that they found flaws in the 802.11 standard (and 802.11b standard). Their report says that they were able to intercept transmissions over the wireless network. These transmissions were encrypted, but the encryption was broken.

Are there other problems?

If too many people or businesses in the same area have WLANs, then the band of air that they transmit signals on can become overcrowded. Problems with signal interference are already occurring and there are fears that the airwaves will become overloaded.