Build a Wi-Fi Home Network

A Wi-Fi adapter has the radio and other components necessary to talk to a wireless gateway. Adapters vary depending on the kind of equipment you want to attach to your Wi-Fi network. Here's a quick primer on what to choose.

Wi-Fi comes in several flavors, the most important of which are called 802.11b, 802.11g, and 802.11a. The original 802.11b flavor of Wi-Fi operates at 11 megabits per second (Mbps). This is much faster than current residential broadband connections -- cable modem or DSL -- which typically offer speeds of 2 Mbps or less, so you might think it's all you need. However, while you can still buy 802.11b-only equipment, the next generation, 802.11g, is now the de facto standard. "Wi-Fi G" operates at a much faster 54 Mbps, and is backwardly compatible with 802.11b, so that computers with 802.11b adapters can connect to it.

At just a small price premium ($15-$30 per device), we recommend going with G for new installations, for several reasons. You'll be ready for faster broadband speeds in the future, and meanwhile can use the extra bandwidth to transfer files between computers or other devices at speeds closer to wired Ethernet. This makes applications like network backup and networked storage more practical. 802.11g's faster throughput also enables multimedia applications like wireless audio and game players, and DVDs played back over a network. Having more wireless bandwidth also makes it easier to support multiple wireless devices.

If you go with 802.11g, make sure all your equipment is G, and even from the same manufacturer (there are several different G chipsets, and some vendors have enabled proprietary features, such as 108 Mbps operation, that will only work with other devices in the same product line). While older 802.11b equipment works with 802.11g networks, it may slow down the overall speed of the networksignificantly, reducing the benefit of buying G in the first place.

If you purchase or have a new Intel Centrino laptop or similar model with built-in Wi-Fi, you already have what you need to connect to your new home network. If you are buying a new laptop, make sure to get the G flavor of Centrino (it comes in B, A/B and B/G options). Most laptop vendors offer either the Centrino or other built-in 802.11 choices, such as Dell's TrueMobile technology.

For older laptops you typically add a PC card, which fits into a slot and can be removed and replaced with other PC cards for special purposes. Here are some PC cards to consider:

For desktop computers we recommend wireless USB adapters. You can also buy internal PCI cards, but these require difficult installation, while USB adapters are plug-and-play.

While Apple PowerBook and Power Mac models can also accept PC cards and USB adapters, it's much easier to use Apple's own AirPort cards, which fit into special internal slots, and are specifically supported by the Mac OS. Apple's 802.11b AirPort Card fits Macintoshes released before 2003, while the 802.11g AirPort Extreme Card works with 2003/2004 iMac, eMac, and PowerBook models. Unfortunately, these proprietary card interfaces are different from each other, so an AirPort Extreme card will not work in older Macs and vice versa.

With AirPort 3.1 software and later, PowerBooks released before 2003 can be brought up to 802.11g's 54 Mbps speed when you insert a PC card from Linksys, Buffalo, or Belkin PC. These cards use the same chips that Apple uses in the AirPort Extreme Card, and are compatible without any additional software.

There's one more way to add Wi-Fi, even if you don't have any of the above ports. You can plug a special Wi-Fi adapter directly into a wired Ethernet jack, and make a connection. These are typically called wireless bridges, and come from most major Wi-Fi vendors, such as Linksys and D-Link. They are often marketed as ways to add printers and game machines with Ethernet ports to your wireless network. Wireless bridges can also be used to take several wired machines and add them to a Wi-Fi network; in this case, they double as wireless access points.