Google, Microsoft and more than 500 rural US colleges, universities, and public interest groups have joined forces to finally solve the issue of rural internet connectivity — using Super Wi-Fi on the white space spectrum. This initiative, called AIR.U, hopes to bring between 20 and 100Mbps of wireless connectivity to rural educational institutions, which will then provide internet access to local communities.

Super Wi-Fi (a term coined by the FCC and strongly frowned upon by the official Wi-Fi Alliance because it isn’t Wi-Fi), or IEEE 802.22 as it’s technically known, uses the TV channel frequencies that were originally used by analog TV, but which were freed up by the digital switchover in 2009. These channels — 6MHz blocks in the VHF and UHF ranges (54-698MHz) — are capable of carrying up to 20Mbps over a distance of 18 miles (30km). Multiple channels can be banded together to create faster links.

The reason 802.22 white space connectivity is so desirable is because low-frequency signals (such as 54MHz VHF) can travel very long distances, bend around mountains, and pass through obstacles. These low-frequency signals are the reason that single, huge TV transmitters can broadcast a signal to millions of homes — and why higher-frequency services, such as cellular radio, require broadcast towers every few miles.

Actually implementing a wireless network in the white space spectrum has proven to be tricky, though. The main problem is that while a VHF channel might be available in City A, it might be used in City B. Much in the same way that FM radio frequencies are re-used multiple times throughout a country, there is no guaranteed spectrum for Super Wi-Fi to operate in; it isn’t like Verizon or AT&T, which both have blocks of spectrum that no one else is allowed to use. To get around this issue, Super Wi-Fi gear either has to geographically aware and pre-loaded with a list of channels that it can’t use, or it has to “sniff” the air to find out which channels are available. Fortunately, compared to urban areas, rural US has a lot of spare white space spectrum.

Moving forward, the AIR.U (it’s the world’s most banal acronym, by the way: Advanced Internet Regions) consortium plans to start rolling out some pilot Super Wi-Fi networks in 2013, as and when white space networking equipment becomes widely available. Once the wireless links have been made to universities and colleges, a wired network or normal WiFi can be used to provide internet access to the rest of the community.

As for Microsoft and Google’s involvement in the project, we can only really guess. Both companies have always pushed quite hard in the educational sector — so it could be a case of getting them rural types hooked while they’re still young. As we know, Google is currently rolling out a fiber network in Kansas City, and these Super Wi-Fi base stations will have to be connected to the internet, so perhaps Google is tasked with building the backhaul network.

The flip side to bringing broadband to the boonies, of course, is that rural communities will cancel their dial-up subscriptions in droves. With 40% of its income still stemming from its dial-up business, what will AOL do?!

Read more at Gig.U, or about how white space wireless (802.22) works