September 07, 2010, 9:20 AM — The iPhone 4 is the first to support 802.11n, which offers the highest Wi-Fi data rates and throughput. But it runs only on the crowded 2.4GHz band, and at one university, which is deploying hundreds of the new devices, that poses some big Wi-Fi challenges for IT.
The iPhone deployment at Abilene Christian University, in Abilene, Texas, is unusual, possibly unique: there can be up to 500 or more iPhone 4 handsets in a big lecture hall, all trying to connect to the hall's collection of wireless access points. It's especially frustrating because ACU's IT group had successfully deployed hundreds of 11g iPhones, in the same lecture hall, on the same 2.4GHz band with minimal problems.
For now, in the areas with 802.11n access points, 11n has in effect been turned off, and the new iPhone 4s will run as 11g clients, at least for a few weeks until the kinks get worked out. The WLAN setup based on ACU's 11g experience includes the unique idea of using the student's as RF signal attenuators.
At this point, it's not clear if the WLAN instability is an issue of: configuring the access points; the mix of 11g and 11n clients, which triggers 802.11 protection mechanisms adding overhead; the limited channel assignments; a possible iPhone 4 Wi-Fi bug; or some combination of these.
Other colleges and universities so far are reporting no similar problems, though iPhones are popular on nearly all of them. University of Washington, in Seattle, has seen iOS devices soar from 1,400 in the fall of 2007 to 17,000 as of July 2010, according to statistics tracked by David Morton, mobile strategies director for the university, on his blog. So far, he says, they've had no issues, though he's not run any tests on iPhone 4 (UW is just starting its 11n upgrade).
A university in Georgia has upgraded its residence halls to 11n, with classrooms to follow. So far, about two-thirds of students on the "ResNet" use 11n, evenly split between 2.4 and 5GHz, with no problems; the remaining third are still using 11b/g, according to a university RF engineer, who asked not to be identified.
Yet few of these other schools have the kinds of classroom concentrations that ACU does, since ACU courses increasingly are designed to require the use of iPhones in actual class work.