The new Wi-Fi: What you need to know about 802.11ac

Access points have already appeared, and devices will soon. Here's how to strategize the next leap in Wi-Fi

The first consumer-grade access points running the new 802.11ac Wi-Fi protocol began hopping last summer, and IT-grade 802.11ac wireless gear is now appearing. Apple appears poised to include 802.11ac in Macs expected to be released this summer, if clues in beta versions of OS X are to be believed. PC, tablet, and smartphone makers will follow soon.

What's the story about 802.11ac? It brings several advantages that should promote fast consumer adoption: lower battery use when Wi-Fi is engaged in computers and mobile devices, faster throughput, extended signal range (I can personally attest to this), and less bandwidth contention than with other Wi-Fi gear. Those advances will help businesses, too, but IT will gain another reason to want to adopt 802.11ac, says Lisa Phifer, a network consultant at Core Competence: greater density, meaning more simultaneous connections per access point.

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Still, both Phifer and Bob Egan, principal at the Seraphim Group consultancy and one of the original 802.11 standard's designers, say enterprise adoption of 802.11ac will likely take five years, even as home users and small businesses move faster.

Why the lag in larger businesses? One reason is that because 802.11ac can carry four times the traffic, IT will need to do much more than just replace access points. The backhaul needs to be bulked up as well, Egan says, both the internal backbone network and the connections to the Internet. That affects routers, switches, and more.

In the meantime, it's fine to replace individual access points with 802.11ac models. But at some point, you'll want to redo the site survey because the radio reach is different in 802.11ac than in 802.11a, 11b, 11g, and 11n. Plus, 802.11ac runs on the 5GHz band, which interacts with building materials differently than the 2.4GHz band used by 11b, 11g, and 11n.

Phifer notes that one advantage of 802.11ac is that its greater bandwidth per channel and higher throughout mean it can also be used for some internal backhaul. IT may not need to replace or upgrade all its physical network backhaul within buildings.

She also suggests that you avoid access points with plug-in modules for 802.11ac upgrades. Such access points may sound convenient, letting you upgrade ahead of a formal 802.11ac rollout, but the radios in 802.11ac routers are different than in earlier-generation routers; you likely won't get an optimal 802.11ac result when you do plug in the 802.11ac modules.

It's better to use 802.11ac access points today as you do your normal upgrades and in any new facilities, Phifer says. You might disable the 802.11ac radios to keep an all-802.11b/g/n network in the meantime. But it's usually safe to just leave 802.11ac on where you happen to replace or install new access points -- if access points end up so close they cause contention, you can deal with it first through channel-changing and, if that doesn't work, by disabling 802.11ac on some of those access points.

When you do an 802.11ac site survey in preparation for a major Wi-Fi redeployment, consider leaving your existing 2.4GHz Wi-Fi 802.11b/g/n network at least partially in place. Using it for machine-to-machine wireless networking would create a clean separation of traffic that lowers the possibility of contention with computers, mobile devices, and printers; such separation also lets you achieve better security. You might also use that older wireless LAN for guest traffic, again creating a stronger separation for increased security and traffic control. Plus, putting guests on the slower network will discourage use of high-bandwidth services like video, which could see greater engagement due to 802.11ac's speed.

When all is said and done., it's a pretty straightforward transition for real benefits -- once all the pieces are in place, from client to wireless LAN to backhaul.

Then there's 802.11ad, aka WiGig, which is another Wi-Fi variation due in a few more years. It uses all-new spectrum (60GHz) and has greater speed but less range than 802.11ac. That means an all-new site survey. My guess is that early 802.11ad deployments will be more backbone-style uses or for a separate high-speed LAN segment meant for internal devices, not iPads and Androids. In other words, it's much too soon to worry about or to wait for 802.11ad.

But start your transition to 802.11ac -- or at least your planning for it.

This article, "The new Wi-Fi: What you need to know about 802.11ac," was originally published at Read more of Galen Gruman's Mobile Edge blog and follow the latest developments in mobile technology at Follow Galen's mobile musings on Twitter at MobileGalen. For the latest business technology news, follow on Twitter.