To the Nth Degree: 802.11n Supercharges Enterprise WLANs

doctors would like to download and have access to MRI images on the fly, or to stream lab results to the bedside. In the education sector, schools increase their competitive edge by offering latest and greatest broadband, while leveraging 802.11n in libraries or lecture halls to stream video.

“Some partners are actually creating innovative services,” said Roy. “If you go to a mall, for instance, instead of a Web page on plasma screens, you’ll have video downloaded to welcome you to the mall. This just allows you to think outside of the box, because bandwidth is not a constraint anymore.”

As for rollouts, some customers might question whether to deploy 802.11n now or wait for the final spec. “But because of UC and mobility, we say, go for it,” said Roy. “And UC and mobility together is what customers want. Channel partners can go in and sell the entire value proposition.”

The enterprise is very ready for 802.11n, “and we’ve seen quite a bit of interest, with lots of testing and piloting going on,” said Kelly Davis-Felner, senior marketing manager of the Wi-Fi Alliance. “Also, a lot of enterprise Wi-Fi users have aging networks, reaching their third, fourth, fifth birthdays. So, from a replacement-cycle standpoint, it's a good time for 802.11n.”

For many businesses, a phased rollout works well if they already have a WLAN in place. “A rip and replace is OK for some customers, but most want a phased migration,” said Mike Tennefoss, head of strategic marketing at Aruba Networks, which sells 802.11n products through its channel program. “It does require upgrades to the wired infrastructure, including moving to GigE, updating the wiring closet switches, etc. [But] it allows them to do it on their own budget and schedule.”

This potentially can lead to a situation where a business might have legacy WLANs from different vendors. “A network-management system becomes important for simplifying that migration,” said Tennefoss. “You can look at two, three, four -- as many systems that you have -- and have a diagnostic and reporting capability.”

Tennefoss does caution that selling 802.11n requires attention to technical specifics. For example, first-generation 802.11n chipsets consume more power than their a/b/g predecessors. “This is really important as you look at retrofitting enterprises, because 802.11a/b/g uses power over Ethernet. With some products, putting in new 802.11n APs also requires a refresh of the PoE infrastructure.” In fact, some 802.11n products don't support PoE at all, or don't if the AP uses more than one radio. Thus, channel partners should do their homework.

Also, despite the availability of 802.11n access points, 802.11n clients — in laptops and handhelds — are still a rarity, although that should change gradually as more and more notebooks ship with the upgraded technology. “Even though 802.11n allows for a farther distance between APs to give you the same density, most of the clients out there are b/g,” said Tennefoss. “For some period of time, we’ll be living with legacy voice clients on the handset, too. So when deploying .11n APs, you’ll need to maintain same spacing between them as you would a/b/g APs, to accommodate the lower range in the clients.”

It’s also a good idea to use shorter spacing in order to gain the capacity benefits that 802.11n promises. “If you lower number of APs, you may only increase your capacity by a fraction,” said Roy. “So as a good practice, we strongly recommend that you use the same approach as a/b/g even if the n APs are more expensive. That way you get four to six times the legacy performance.”

802.11n APs do provide benefits even to those legacy clients. “Even if you have an a/b/g client base, you’ll start seeing benefits right away,” said Davis-Flener.“The 802.11n signal is more consistent, plus it can fill in coverage gaps in stairwells, lobbies and other places not easily covered before. As we have increasing mobility in the business environment