Sales of 802.11g-based hardware are on fire, but organizations could get burned by buying into "g" now.
The WRT54G wireless router from Linksys Group Inc. was released in late December and is already a bona fide success—enticing consumers and scaring competitors with a low, $130 retail price and promises of 54M-bps wireless performance.
Organizations, however, should show fortitude and avoid 802.11g-based products—at least for now. Available devices are based on a preratified version of 802.11g, making future interoperability questionable and current performance lethargic.
Performance tests run by Ziff Davis Media Inc.s ExtremeTech (www.extremetech.com) show that 802.11g products are significantly slower than 802.11a devices. Most likely, this has nothing to do with the standard and is the result of early firmware and drivers.
However, some major vendors, including Netgear Inc., have delayed release of their 802.11g products until performance can be improved.
In tests, 802.11b-based gear achieved top speeds of 6.12M bps, a fairly decent number.
The rule of thumb is that actual wireless throughput will be about half the rated specification (11M bps, in 802.11bs case). An 802.11a device reached a top speed of 22M bps, about 40 percent of its rated specification of 54M bps, but the 802.11g device achieved only 11M bps—about one-fifth of its rated specification (also 54M bps).
At distances of 100 feet, the 802.11a device achieved a maximum throughput of 12M bps and the 802.11b device hit 4.74M bps, but the 802.11g device reached only 3.29M bps.
802.11gs OFDM, or Orthogonal Frequency Division Multiplexing, technology is theoretically better than 802.11b (and far better than 802.11a) at handling bouncing radio waves. This should make access point placement extremely easy, especially when line-of-site placement from client to access point is impossible.
However, since early tests show that 802.11g products have problems at a distance, most customers will not see this benefit until the kinks are worked out.
If performance isnt enough to keep you away from these early g-based systems, interoperability—or lack thereof—should be.
Products that are based on the same chip set, such as the BCM4306 from Broadcom Corp., most likely will work together. However, they may not work well together in mixed-mode environments—one of the main reasons for moving to the 802.11g specification rather than to 802.11a.
For example, problems are likely when 802.11b and 802.11g clients are accessing the same 802.11g access point. And early tests show that 802.11g will face a 40 percent slowdown in performance whenever an 802.11b device becomes associated with an 802.11g access point.
Many vendors, including Broadcom, have attempted to future-proof their chip sets. However, its far safer for organizations to wait for the Wi-Fi Alliance to come out with its certification and interoperability test results some time after the 802.11g standard is ratified. (Ratification is expected by midyear.)
eWeek Labs Director John Taschek can be reached at firstname.lastname@example.org.
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