Battling Wi-Fi Specs Come Together Wichita KS

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Originally published at Internet.com

While several wireless chip manufacturers are following up on implementations that are based on a single 802.11 specification, analysts and industry insiders say the future of Wi-Fi can be summed up in one word: multi-mode.

Tri-mode, actually, would be more specific, since most experts envision the eventual delivery of client and access products that are capable of being conversant with networks based on 802.11a, 802.11b or 802.11g, a pending standard that is expected to be completed near the middle of next year.

The idea behind the multi-mode movement, of course, is to create a sort of master key for wireless networking.

"With a universal line card it just won't matter," says John Allen, senior manager of marketing communications at Intersil Corp. "You can run your laptop at an airport based on 11b, a corporate office with an 11a system or a home system based on 11g."

While the endgame is the same for wireless chip and product manufacturers, it is likely that the many players involved will take several different paths to reach the same destination.

Some manufacturers are already working on products that will blend the three specifications. At the same time, however, many are working on single implementations of 11a or 11b or some combination of the two.

Different strategies, say analysts, are also emerging based on whether they are building an access point or a client device. For its access point product, the Aironet 1200, Cisco is ensuring compatibility by supporting multiple types of radios, which can be swapped out in a similar fashion to the way a laptop user would change a battery. The primary reason Cisco is going with a dual-radio approach rather than incorporating a chipset that supports two or more wireless specifications is the fact that the early implementations of dual-band chipsets work at both the 2.4 and 5 gigahertz frequencies, just not at the same time.

"Until they [chip makers] overcome the problem of dual-band simultaneous technology," says Andy Winston, product manager for Cisco's wireless networking business unit, "Cisco will have two radios that can talk to either band."

Winston added that Cisco will eventually add an 802.11g-compliant radio as well.

Cisco's approach to a dual-mode access point makes sense, says Chris Kozup, an analyst with the Meta Group research firm. While equipping client devices with essentially separate systems would prove cost prohibited to most enterprises, updating access points to support multiple technologies would help some businesses get a step closer to the idea of universal access. Theoretically, says Kozup, if all access points supported all flavors of the specification, all clients would be able to access the wireline network at their respective speeds.

"Think of the scenario where all the access points become dual mode," he says. "Therefore, you don't need a universal access card."

At the same time, however, Kozup says that that type of scenario would be plausible only if wireless network users never roamed outside the corporate network. Only a universal client can ensure that a wireless user will be able to link up with a network regardless of his or her location.

"The end point is the scenario where the end user doesn't care what type of network they're on," says Kozup, "as long as they get connectivity."

In a sense, it is the future completion of the 802.11g specification that has driven the industry down the multi-mode path. Because 802.11g, which uses the same frequency modulation scheme as 802.11a but operates on the same frequency as 802.11b, is a sort of an amalgam of its predecessors, it is now cost effective for chip and product manufactures to support all three flavors of the technology.

For makers of 802.11a products, for example, supporting 802.11g is a no-brainer because they are already well versed in the Orthogonal Frequency Division Multiplexing (OFDM) modullation scheme. For the same reason, manufacturers of pending 802.11g products, which are naturally backward compatible with 802.11b, are logically including support for 802.11a.

In fact, Kozup predicts that an 802.11g-only market will fail to get started.

"I don't expect to see standalone g products to gain traction whatsoever," says Kozup, explaining that the growing penetration of 802.11a will demand that equipment makers support all the different types of wireless technology. "Once all that happens, the software becomes the important thing and the name of the game will be seamless roaming between networks."

Kozup's comments also reflect the fact that talk of 802.11g superseding the need for 802.11a, which also operates at a speed of 54 megabits per second, has all but vanished.

Winson says that in the past six to nine months industry players have come to recognize that the advantages 802.11a derives from operating in the higher frequency range justify its place in the network alongside 802.11b and, eventually, 802.11g. The biggest advantage over 802.11g, says Winson is the scalability of 802.11a, which is able to spread users across 8 channels of communications rather than the three that are available at the 2.4 gigahertz range.

"Those eight clear channels are a real plus," says Winson. "I have to say that some of the excitement over 802.11g has faded as people have become more comfortable with 802.11a."

Winson adds that while the range of 802.11a is shorter than 802.11g, the difference is not as substantial as originally believed. In addition, 802.11a has a slight advantage in terms of performance, says Winson. While both technologies purportedly operate at 54 mbps, the transmission overhead required for 802.11g and 802.11a systems to speak with each other eats up some of the available bandwidth.

In the end, Winson, echoing the thoughts of most industry experts, says the endgame is to build products that offer maximum flexibility by supporting all the different types of Wi-Fi technologies.

"From an infrastructure perspective," he says, "the best way of looking at is that instead of thinking of 802.11a supporting eight channels and 802.11b or g supporting three channels, the better way to think of it is having one network with 11 channels. It just doesn't matter which frequency you use."

Joe McGarvey is a freelance writer based in New York. He can be reached at mmcgarvey@optonline.net. Got a comment or question? Discuss it in the 802.11 Planet Forums