4 Things to Know About 802.11n

Courtesy of VARBusiness As wireless protocols go, 802.11n is everything an IT admin could want. The newest flavor in the alphabet soup that is Wi-Fi, "n" carries data faster and farther than its predecessors and is perfectly suited to multimedia transmission. There's just one tiny problem: 802.11n doesn't really exist yet. It's a familiar headache : A standards body proposes a protocol such as 802.11n that promises breathtaking advances. Vendors hype the technology for all it's worth, but politics stall the standard for years. Meanwhile, caught up in all the hype, customers start to demand products from their solution providers. With that in mind, here are four things to know about 802.11n even before it becomes available. 1. Just What Is 802.11n? 802.11n is a work in progress at the Institute of Electrical and Electronics Engineers (IEEE). A typical 802.11n connection will transmit data or voice packets at up to 200 Mbps, with theoretical rates of up to 540 Mbps. In other words, it's up to 10 times faster than the standard 802.11g and 802.11a wireless LAN technology on the market today. Furthermore, 802.11n promises a range of up to 50 meters between an access point and a client. 2. How Does 802.11n Work? 802.11n will run in both the 2.4-GHz and 5-GHz frequency bands--currently the homes of 802.11b/g and 802.11a, respectively. The standard will achieve its high speeds by using multiple data streams and multiple antennas in a single channel. The multiple antenna feature is often called MIMO, which stands for multiple-input/multiple output. MIMO patents have been around since the late 1980s--before the advent of wireless LANs--but the term has received a great deal of attention ever since the IEEE proposed the 802.11n standard. The standard will work in both 20-MHz and 40-MHz channels. But it will be backward-compatible with legacy 802.11b and 802.11a wireless LANs--adjusting its performance accordingly by using just the 20-MHz channels. 3. What Is the Status of 802.11n? According to the IEEE, which oversees 802.11 standards, 802.11n isn't due for final standards-board approval until September 2007. The industry has been looking forward to the promise of wire-speed wireless since September 2003, when the IEEE first approved a project-authorization request for the standard. Back then, the 802.11n task group hoped for ratification in late 2005, and customers expected products shortly thereafter. But warring factions within the task group have slowed things down. The task group kept running into a stalemate as it tried to vote on proposals from three special-interest parties, which shared little in common except that their names sounded like pubescent rock bands: TGnSync, Wwise and MitMot. "There were an awful lot of people who had a vested interest in this standard," says Winston Sun, technical marketing director at Atheros Communications, which makes radio chipsets for wireless LAN hardware. (The company's CTO, Sheung Li, is the vice chair of the 802.11n task group.) "Traditional Wi-Fi has been dominated by the PC industry, but with 802.11n, instead of having just one industry driving the standard, you've had three competing industries vying for their share of the pie," Sun says. "Some of these industries had conflicting wish lists. The consumer-electronics industry that was interested in putting Wi-Fi into a flat-panel HDTV set didn't care if a chip burned 15 milliwatts or 15 watts, but the handset [cellphone] vendors cared about battery life. And the PC guys were in the middle. There was a lot of politicking." In October of last year, a splinter group called the Enhanced Wireless Consortium (EWC), which included IT industry heavyweights such as Atheros, Broadcom and Cisco Systems, presented its own proposal for wireless. The purported goal of that recommendation? Putting a fire under the fanny of the standard. Its plan worked in that the other competing factions adopted the proposal in January 2006, jump-starting the standards effort again. Still, ratification is at least a year away, so it's too soon for vendors to promise true 802.11n products. By the same token, it's too soon for the Wi-Fi Alliance certification body to plan its interoperability tests for upcoming 802.11n equipment. "There's still so much to do in terms of the IEEE getting this sorted out," says Frank Hanzlik, managing director of the Wi-Fi Alliance in Austin, Texas. "We hope to be in a position to bring out a certification program next year." Such interoperability tests will require both access points and clients. On the client side, Intel earlier this year announced plans to include an 802.11n Wi-Fi adapter as part of the next generation of its Centrino notebook-computer chipset, code-named Santa Rosa, which is due out next year. But again, the release of that product will depend on the ratification of the standard. 4. What's the Deal With So-Called 'Pre-n' Solutions? To the chagrin of the IEEE, some companies already have released products based on early drafts of the 802.11n standard. In April, for example, both Linksys (the consumer-brand arm of Cisco) and Netgear introduced pre-n gear that uses "True MIMO" chipsets from Airgo Networks. Linksys launched its Wireless-N router and companion adapter, while Netgear came out with its RangeMax Next device. Belkin, the maker of the N-1, and D-Link, with its RangeBooster N, also offers pre-n access points, routers and client cards. In addition, Atheros, Broadcom, Airgo and Marvel all offer chipsets based on a draft version of the 802.11n standard. Initial tests have garnered various results, but it's safe to say these products should run significantly faster than legacy 802.11b, 802.11g and 802.11a products. While prestandard gear might make for good interim solutions for home-office customers and consumers, analysts generally warn against using it for large enterprises. Technology consultancy Gartner in May 2006 released a paper warning that "vendors that market draft compliance are misleading prospects, even if they articulate what such compliance means in other documentation." Among customers, "there was much confusion about what would be required or what would be possible with existing access points to upgrade them [to 802.11n]," says Mark Melvin, director of professional services and presales engineering at ePlus Technology, a solution provider based in Herndon, Va. Some companies offering pre-n solutions acknowledge that there's no guarantee of a smooth migration path from prestandard gear to the official standard. "We anticipate that any change will be minor enough that it will be upgradable by changing the firmware," Atheros' Sun says. "But because the standardization won't be final for another year, we're not guaranteeing that it will be firmware-upgradable." To that end, most of the market-leading enterprise WLAN hardware providers don't plan to offer products that are directly based on draft versions of the 802.11n standard. "If you don't have an impending crisis, the risk of blowing past the standard just isn't worth it," says Alan Cohen, senior director of mobility solutions at Cisco.

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