It wasn't the lure of new technology that persuaded Montreal's Concordia University to adopt 802.11n, but the simple fact that the existing network, put in four years ago, couldn't cope with a rapidly expanding user base.

"Wireless networking is a baseline service you have to provide in education," says Andrew McAusland, associate vice president of instructional and information technology services at the university. "We've experienced a 200 percent growth in the use of wireless every semester since we put it in."

The university has a pretty-much all-Cisco network, and set up a couple of hundred managed "fat" Aironet Wi-Fi access points (APs), which use the 802.11g standard to cover the campus indoors and out, and serve up to 40,000 students. It built that wireless LAN in 2001, and adopted voice over IP in 2003.

Now the Wi-Fi network is well loaded, and the demand pattern was such that it wasn't enough to add new APs. "We have 90-95 percent coverage of the campus," says McAusland. "We've covered all the floor space. But students don't disperse to all of the floor space. They congregate."

Sixty percent of the WLAN traffic comes from eight to ten locations, he says: "With 802.11g, if we put in more and more APs, they would have conflicted with each other. With 802.11n, we have to put in more APs but we get more simultaneous connectivity."

802.11n didn't need a network change

So Concordia is putting in Cisco's Aironet 1250 access points. The integrator, Bell Canada has carried out a new radio survey and so far installed 24 new APs, which replace some of the older ones, in popular indoor locations. "802.11n hasn't caused us to change our network in any huge way," he says. "The old access points will continue in use, but we will upgrade across the board. In at the most 24 months, 80 percent of the wireless network will be converted to 802.11n."

The university is running 802.11n in both the 2.4GHz and 5GHz bands, to support a rapidly-growing number of 802.11n laptops, says McAusland. "With our client base, we don't have the luxury of ageing with the client base, like an enterprise can. Every year, we get new students in, with new equipment. More and more of our users have 802.11n, so we have to have a network that will accommodate it."