Wireless computing: all about Wi-Fi:.(Home computing: the new realities)

Wireless has become the new byword for computing, at home and on the road. One in 10 of the people we've surveyed who have linked their computers in a home network did it wirelessly so they can move laptops from room to room yet remain connected.

In addition, a million people in North America handle their e-mall and surf the Web wirelessly at more than 28,000 public "hotspots" at airports, hotels, Starbucks coffee shops, and even in parks and near phone booths. The Gartner research firm in Stamford, Conn., predicts that five million users, mainly toting laptops, will be using wireless in a year or two.

Still, many computer users may not have tried wireless, known as Wi-Fi. Although promising, Wi-Fi is freighted with concerns about security and privacy, plus questions about how it works and what it costs. Here are some answers:

What is Wi-Fi? Wi-Fi (the term is short for wireless fidelity) is basically a technical standard for short-range data transmissions. Various editions of the standard have been approved by industry: The terms 802.11b, 802.11a, and 802.11g, used in hardware ads, denote versions of the standard.

Wi-Fi carries two-way radio signals between a fixed base station and one or more laptop computers or some other device, such as a personal digital assistant. The Wi-Fi Alliance, a nonprofit research and education group, claims that transmissions have a range of some 350 feet outside and 80 feet indoors at full speed, and longer ranges at reduced speeds. Wi-Fi can be used at home to create a wireless home computer network, or away from home through a hotspot.

Wi-Fi works much like a cordless phone with its base station, but is typically connected to the Internet rather than the phone system. Wi-Fi signals usually use the 2.4-gigahertz band on which many cordless phones operate, and the systems can interfere with each other. Microwave ovens can also cause interference.

What hardware does Wi-Fi need? Some computers, desktops as well as laptops, come equipped for wireless. The newest laptops, powered by Intel's Centrino, are tailor-made for Wi-Fi. Other computers can be adapted with a plug-in card (about $50). A home network with a wireless router as its hub also requires the base-station hardware, which costs about $100. Windows and Macintosh computers work equally well with Wi-Fi.