Wi-Fi: The next generation

• Tags:
• Wi-Fi,
• 802.11n

Andrew Donoghue ZDNet.co.uk

Published: 24 Aug 2007 16:59 BST

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...the use of MIMO techniques because they use multipath, an RF phenomenon where the same signal arrives at two different times due to reflections combining with a line-of-sight signal.

Ken Dulaney, a vice president at Gartner, in his July 2007 report Key Challenges Arise for 802.11n Deployments, describes multipath as "an unpredictable by-product of RF transmission" that is highly dependent on environmental factors such as the presence of walls.

Therefore, he indicates that "while 802.11n provides a great deal of flexibility and robustness", it also introduces complexity into the process of "predicting how each unit will perform". This means that layout will have to be considered carefully to optimise performance and reduce interference.

Another factor to bear in mind on the technical side is that, although the Wi-Fi Alliance is now certifying 802.11n products based on Draft 2.0 of the standard, there are no guarantees that another year or so's work on the standard will not lead to more alterations, which means that firmware in current purchases may need to be upgraded in the future.

There are also challenges on the business side of the equation, not least in terms of justifying the cost of upgrading. For example, says Craig Mathias, principle analyst at the Fairpoint Group, prices for enterprise access points will initially be about twice that of older kit, although he expects them to fall quite rapidly, while mobile devices such as PDAs are also likely to be more costly.

"If people want better performance from their 11n-based systems, they're almost certainly going to have to use products operating at 5GHz. But because devices will probably be dual-mode so that they can work at 2.4GHZ too, they're also likely to be more expensive because they've got more technology in there," explains Main.

This means organisations will need to consider the legacy and business case for swapping out existing equipment, which may lead some to choose to stay with b and g if it's adequate for their needs.

Despite all of this, however, Mathias is convinced that 802.11n is the way forward and that it will be the primary Wi-Fi technology within five years. "11n is the last barrier to broad enterprise adoption of wireless Lans," he says. "A lot of people said that wireless is great, but the technology is changing rapidly, which led to fears that whatever they bought would be obsolete too quickly. But with n, the last serious objection goes away."

Taking the plunge
Because he himself does not expect to see any major changes to the draft standard over the next 18 months, Mathias recommends that organisations jump right in and take advantage of improvements in reliability, capacity, throughput and rate versus range performance. This is not least because he believes that 11n-based equipment will become the dominant wireless technology for running all types of applications and, this means that by the first quarter of 2009 when the standard is released, "people won't buy anything else".

Dulaney is more cautious. In his report, he recommends that organisations feel free to install Draft 2.0 clients in new notebook computers now in order to improve their performance with existing wireless Lan infrastructure — although he points out that other types of device may not initially support the draft standard.

At the same time, Dulaney warns that enterprises with earlier versions of wireless Lan infrastructure equipment, such as access points, should not migrate those to 802.11n until the final specification is ratified and Wi-Fi certification is provided — and even then, they "should consider it a complete refresh of equipment rather than a gradual upgrade". The same does not apply to greenfield sites, however, which should evaluate whether to deploy Draft 2.0 equipment in lieu of existing alternatives.

Although Dulaney's colleague Phillip Redman, a research vice president at Gartner, indicates that "there isn't much demand in most industries" for 802.11n technology at the moment, over the next three to seven years, he expects to see it replacing existing wireless Lan technology, which will help boost market growth.

While the 2007 global forecast in this area anticipates that expenditure will hit $1,700m (£858m) by 2010, this figure is predicted to rise to $3,000m (£1,514m), with industries such as healthcare, warehousing and manufacturing experiencing the "deepest uses".

But Rob Bamforth, a service director at Quocirca, is not so sure. He points out that nothing can ever be certain in today's complex technological world, as was evidenced by the VHS/Betamax wars in the video space of the 1980s — and that Wi-Fi is no longer the only game in town.

"Technology always gets smaller, faster and cheaper, but the big question is whether people need it. So as they increasingly put 3G data cards into their laptops and have the option of putting pico and femtocells around their sites, the question is which technology will be best suited to their needs. It all comes down to the business case in the end," he concludes.

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