Mobile Computing: The Next High-Speed Wireless LAN

FAQ: What's Up With 802.11g?

Recently, Apple Computer announced new PowerBooks that feature built-in wireless networking. While wireless-enabled notebooks aren't exactly newsworthy anymore, the PowerBooks earned some ink for their support of the new 802.11g wireless specification rather than the 802.11b standard commonly called Wi-Fi.

Meanwhile, networking giants Netgear and D-Link have announced plans to launch 802.11g network adapters, followed by network access points and routers. Other companies such as Linksys and SMC Networks have unveiled or begun shipping 802.11g-based products, too.

But what exactly is 802.11g? How does it differ from 802.11b and 802.11a? And most importantly, should you upgrade or stick with Wi-Fi? This week's newsletter gives you the 411 on the 802.11 situation. For more information on Wi-Fi, and a comparison with Bluetooth, see "Mobile Computing Tips: Bluetooth vs. Wi-Fi FAQ."

The Specs

802.11g is the name given by the Institute of Electrical and Electronics Engineers to a new high-speed wireless local-area networking specification. 802.11g is an extension of 802.11b, which is the basis of many WLANs today such as the T-Mobile Hot Spots found in Starbucks locations.

While 802.11b delivers data transfer rates of up to 11 megabits per second, 802.11g promises speeds up to 54 mbps. Both specifications operate on the 2.4-GHz radio frequency band.

And then there's 802.11a, also known as Wi-Fi5. This wireless standard is also designed to deliver speeds of up to 54 mbps. But 802.11a uses the 5-GHZ radio frequency band and isn't compatible with 802.11b- or 802.11g-enabled devices.

The Good News

Because 802.11g is an extension of 802.11b, equipment based on these technologies is compatible. That means an 802.11g-equipped notebook (such as one of the new PowerBooks) or other device can still access the Internet via a Wi-Fi hot spot--although at the older standard's 11 mbps speed. Conversely, a 802.11b-equipped notebook can connect to an 802.11g hot spot, but only at the lower speed.

In theory, then, purchasing 802.11g equipment seems a good idea because you'll get fast speeds (when interfacing with 802.11g access points) as well as compatibility with the ubiquitous Wi-Fi standard.

The Bad News

Alas, it's not quite that simple. At the moment, 802.11g is a specification--not an accepted, industry-wide standard like 802.11a and 802.11b. In fact, 802.11g isn't even expected to be certified as a standard until later this year, according to C. Brian Grimm, communications director for the Wi-Fi Alliance, a nonprofit wireless industry association in Mountain View, California.

Standardization will come when consensus is reached among networking industry players regarding 802.11g's technology specifications, Grimm says. While 802.11g as it exists today is unlikely to change, he points out, it's possible that it could. If it does change, however, equipment purchased today could most likely be upgraded.

Nonetheless, there are risks in buying prestandard products, Grimm points out. You shouldn't have problems if you go to one company for all your 802.11g products, for example a 802.11g home networking setup from D-Link that includes a router and a PC Card adapter. But prestandard devices from one vendor may not be compatible with those from another, Grimm warns.

And there are potential downsides to 802.11g. While Wi-Fi devices can talk to one another within about 300 feet, 802.11g's range is about 10 percent less, Grimm says. "Generally speaking," he adds, "the faster you go, the lower the range." The result: To compensate for the shorter range, a company seeking to upgrade may have to buy more 802.11g network access points than the Wi-Fi points it is replacing.

As with Wi-Fi, 802.11g devices share the same radio spectrum as 2.4-GHz portable phones, so home users may experience some interference, Grimm says. If you're wirelessly transmitting multimedia, such as MP3 files, from your computer to your stereo set, you could notice some dropped notes here and there. But if you're transferring data--by surfing the Web wirelessly, for instance--you're less likely to notice interference from portable phones.

The Bottom Line

"Ultimately, I'd stick with Wi-Fi for now," Grimm concludes. "It will work anywhere there's a wireless hot spot." Once the 802.11g specification is standardized, consider buying a network card for your notebook or PDA that supports both the "g" and "a" standards. Because 802.11g and 802.11b are compatible, dual-band cards will give you access to all three wireless standards.

"Dual-band cards may be expensive at first," Grimm says, "but like everything else, their prices will soon drop."

For more information on 802.11g, check out the following PCWorld.com articles:

• "Faster, Cheaper Wireless Home Nets Emerge"
  
  
• "Wi-Fi Looks to Simplify Network Switching"
  
  
• "New Products Offer a Peek Into the Wireless Future"
  
  
• "Wi-Fi Boosts Security"