How-To's of Wi-Fi

Thinking of taking the plunge? BW's Steve Wildstrom has some tips for newbies to the world of the wireless Internet

So the Wi-Fi hype has gotten your attention, and you're considering taking the leap into the new world of (nearly) anytime, anywhere access to the Net. What should you know before you start? BusinessWeek Technology & You columnist Steve Wildstrom offers some sound advice:

Why should I even consider a wireless network for my home?

The first question is really why you would want any sort of network. The most common reason is to allow more than one computer to share a broadband Internet connection. Increasingly, though, the home network is moving beyond PCs to include consumer-electronics devices (for example, to obtain electronic TV program guides), game consoles (for online multiplayer gaming), and home-security and heating-and-cooling systems (for control and monitoring).

Once you decide you need a network, the choice of Wi-Fi wireless is obvious. Very few homes are built with network drops in every room, and while you can get around this by transmitting the data over existing phone lines or power lines, wireless is simpler, more convenient, and cheaper. And of course, Wi-Fi allows you to move your laptop freely around the house.

How hard is it to install a wireless network?

No special skills are required, just an ability to follow directions and a willingness to plunge into some slightly arcane concepts, such as network addresses. By far the most difficult part is the initial configuration of the wireless base station, or access point. Once you've done that, software built into recent versions of the Windows and Macintosh operating systems does most of the rest.

What do I need to set up a network?

The key component is the access point. In most setups, you'll want a combined access point/router, often called a wireless router. This device connects directly to your cable or DSL modem, and the rest of the network connects to it. Access points are available from a large number of companies, including Linksys (CSCO ), NetGear (NTGR ), D-Link, Buffalo, Microsoft (MSFT ), and Apple Computer (AAPL ). Most units also include four or so standard Ethernet ports, so you can hook up nearby equipment using cables. A basic access point/router costs less than $65.

Each computer that connects to the Wi-Fi network needs its own wireless adapter. Most notebooks made in the last year or so have one built in. If your laptop lacks Wi-Fi, you can add a PC Card radio for under $50. For desktops, you can use either an internal add-in card or an adapter that plugs into a USB port. Other adapters will let you connect printers and game consoles to a wireless network, but you have to check the manufacturer's specifications for compatibility.

What are all these different standards and speeds for wireless? What do I really need?

Wi-Fi started off as as that rarest of things in the high-tech business, a single standard that guaranteed compatibility when using equipment from different manufacturers. Of course, it was too good to last. The standard has now fragmented into three official variants and an assortment of proprietary "enhancements," offering varying degrees of compatibility.

The original version of Wi-Fi, also known as 802.11b, transmits data at 11 megabits per second, though, as is true for all forms of wireless, your actual speed is likely to be about half of the posted rate. Even that's much faster than most people's Internet connections, and reliable, compatible 802.11b remains the best bet for most home networks.

A newer version, 802.11g, runs at up to 54 mb/sec and works interchangeably with 802.11b gear. Buying "g" instead of "b" has no real downside now that early compatibility bugs seem to have been worked out, though the equipment tends to be bit more expensive.

Another variant, 802.11a, also runs at 54 mb/sec but operates at a different radio frequency, so it's not compatible with "b" or "g." The higher frequency is immune to interference from microwave ovens and cordless phones, but provides shorter range. It isn't used much in home equipment.

What kind of range can I expect from Wi-Fi?

In theory, you should get good reception at up to 100 feet, but that assumes no obstacles, like walls. In practice, range is wildly variable depending on the construction of the building and the design of radios and antennas. Most houses, unless they're very large or have interior walls or floors of wet plaster, masonry, or concrete, will get adequate coverage from a single, centrally located access point.

If necessary, you can use multiple access points, but your network then becomes much more complicated, likely requiring professional help for setup. You'll need a wired connection of some sort to link your access points together, and secondary access points have to be set up as what is known as "transparent bridges" rather than routers.

Are wireless networks secure?

Wireless networks are inherently less secure than wired connections, since anything transmitted over the air can be intercepted. But some relatively simple precautions can make the network safe for home or small-business use. The first generation of Wi-Fi gear used a badly flawed security system called Wired Equivalent Privacy. Most equipment being sold today uses a much improved system called Wi-Fi Protected Access (WPA) that provides reasonably strong encryption of the data transmitted over the air.

Still, no security system works unless you turn it on. From a laptop at home, I can see four wireless networks, three of them presumably in neighbors' houses. All three are unencrypted, and two are named "linksys" and "WLAN," indicating that their owners didn't change their default names. If you don't bother giving your network a name, anyone can use your Internet connection for free (which you may or may not regard as a problem). But it's also relatively simple for the 15-year-old next door to monitor and read all your traffic. Follow the instructions that come with your gear for enabling WPA.

If you communicate with your corporate system from your home wireless (or wired) network, you'll probably have to use virtual private network software in addition to Wi-Fi security. This adds an additional layer of encryption to protect the data.

By Stephen H. Wildstrom in Washington

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