The ingenuity of wireless LAN vendors has paid off. Once relegated to niche industrial applications, WLANs have gained a foothold in corporate offices and taken the consumer market by storm. With huge markets for Wi-Fi in voice and home entertainment applications looming, the biggest growth still could lie ahead.

Apparently, that makes some vendors nervous. In a recent press release, the Wi-Fi Alliance issued a warning: Products that jump the gun on the future IEEE 802.11n standard will not be Wi-Fi-certified. Furthermore, any product incorporating so-called "pre-n" enhancements could be decertified "if that product is proven to adversely impact the interoperability of other Wi-Fi-certified products."

At issue is a momentous advance, central to every 802.11n proposal, known as Multiple Input/Multiple Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM). Using multiple transmitters, receivers and antennas, MIMO-OFDM exploits the "multipath" signals that normally plague wireless systems. When used at both ends of a link, MIMO-OFDM delivers profound throughput and range improvements (Read our explanation of MIMO). Added to today's Wi-Fi networks, products incorporating MIMO-OFDM can fall back to a smart antenna mode that enhances performance of existing 802.11a/b/g products.

The Wi-Fi Alliance insinuates that some vendors are misrepresenting products as conforming to a standard that probably won't be finalised until 2006. That's a red herring. The real problem is that products conforming to the 802.11n standard won't appear until 2007, but products offering the advantages of MIMO - the basic 802.11n technology - are available now.

Pre-N products don't interfere - they help
The Wi-Fi Alliance also warns against pre-n enhancements that interfere with existing certified products. That's another red herring. The market is brimming with products that offer proprietary but well-behaved enhancements to the 802.11a/b/g standards. Far from disrupting current Wi-Fi products, MIMO-OFDM products offered by vendors such as Belkin Corp. and SOHOware Inc. are Wi-Fi-certified and boost performance when used with 802.11a/b/g products.

[This is confirmed by our review of Belkin's Pre-N products, which showed that 802.11g clients actually get better range and throughput when talking to a Pre-N access point - Editor]

Learning from the 802.11g experience
A few years ago, the WLAN industry had a similar experience with the IEEE 802.11g standard. Vendors that introduced pre-G products wrested market share away from the market leaders. Customers with an urgent need for enhancements destined for the 802.11g standard were willing to buy pre-standard products to take immediate advantage of those enhancements.

Some leading vendors are worried the pre-n products spilling onto the market could reshuffle the market share deck. Their fears are well founded. But it would be unfair to make users wait three years just so slower-footed vendors can catch up.

Until now, the Wi-Fi Alliance has served both the industry and end users well by promoting and protecting interoperability. But the alliance must be careful not to confuse special interests with common interests. It's just as important to protect vendors' right to innovate. Standards help grow the market to the next level, but innovations like MIMO-OFDM get the ball rolling.

Brodsky is president of Datacomm Research in St. Louis. This article was written for Network World.

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