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 InfoWorld.com. Read more of Galen Gruman's Mobile Edge blog and follow the latest developments in mobile technology at InfoWorld.com. Follow Galen's mobile musings on Twitter at MobileGalen. For the latest business technology news, follow InfoWorld.com on Twitter.