In a little-noticed meeting on May 9, 1985, the Federal Communications Commission adopted a rule that changed the tech world forever. Until that point, the FCC’s main role had been to define specific uses for the public radio waves. If you picture all of the country’s available radio spectrum as a pie, the FCC was the waiter who sliced it up and handed it out to the nation’s most well-connected institutions: the radio and TV networks, telecom companies, and the military. The 1985 rule changed that. At the prodding of Michael Marcus, an engineer who joined the FCC under the Carter administration and stayed on during the Reagan era, the agency set aside a few distinct radio bands for “unlicensed” use. The rule allowed tech companies and customers to run devices on these bands for free, for any purpose, and without seeking government permission. In other words, the FCC was reserving a slice of the pie for the rest of us.

It wasn’t a very pretty slice. The frequencies that the FCC gave away—the 900 MHz, 2.4 GHz and 5.8 GHz bands—were known as “garbage bands,” because they were generally considered too prone to interference to be of much use (microwave ovens, for instance, emit radiation on the 2.4 GHz band). But as a result of a clever broadcasting technique known as “spread spectrum“—in which a device can communicate along a range of radio frequencies, making it less susceptible to interference—tech companies managed to make good use of the garbage bands. Thanks to the 1985 rule, the public has enjoyed a bonanza of wireless technologies—today, nearly every wireless device you use, from your cordless home phone to your Wi-Fi router to your Bluetooth headset, operates on the unlicensed band. None of these technologies would have been possible under any other regulatory regime.

Still, there is a downside to the unlicensed radio spectrum. Because the frequencies reserved for public use were never envisioned for widespread communication, they’re prone to failure—they don’t easily penetrate through walls or cover vast distances. That’s why your Wi-Fi router doesn’t reach your basement, and why your Internet connection conks out every time you microwave a burrito.

In a long-anticipated ruling last week, the FCC adopted a regulation (PDF) that could dramatically improve our wireless devices. The rule offered a brand new and much-improved slice of the radio space for unlicensed use. The new frequencies are known as “white spaces“—the waves that were freed up when TV channels switched from analog to digital transmission last year—and unlike the garbage band, they’re considered prime real estate. Radio waves on white-space frequencies can travel for miles, they’re much better at penetrating walls and buildings, and they’re capable of carrying lots of data.

Tech observers say the new rules will lead to a new class of wireless devices known as “Super Wi-Fi.” These new routers will be able to broadcast over very large areas—you could use a single device to bring Internet connections to an entire university campus, apartment building, or hospital. Anyone who’s ever fiddled with a balky router will welcome these new devices. But Super Wi-Fi isn’t the most interesting thing about this rule. The best part about the new spectrum is … well, we don’t know what the best part will be. When the FCC first opened up unlicensed spectrum in 1985, few people expected amazing things like Wi-Fi and Bluetooth. “It took about three years after that ruling before people started developing Wi-Fi,” says Julius Genachowski, the FCC chairman. The same thing is likely to happen on the new spectrum—the most interesting uses of the new airwaves will be some new technology that we can’t anticipate. “Super Wi-Fi will be the first application of this spectrum, but I don’t think it will be the last,” Genachowski says. “This is a new, significant platform for innovators to innovate without permission—and, God bless ‘em, who knows what they’ll come up with.”

The new rule comes after years of lobbying from large tech firms, including Microsoft and Google, who’ve argued that freeing up white spaces would prompt wireless innovation. Tech firms have also suggested that white spaces could spur renewed interest in free, community-wide public Internet connections. Your city could blanket large parks or community centers—or perhaps entire ZIP codes—in these new Super Wi-Fi connections. In Wilmington, N.C., where the FCC has been running a test of Super Wi-Fi, the city has been using the service to broadcast live video traffic feeds to the Web, and to monitor sensors at a remote watershed that had previously only been accessible by boat. Several companies are working on “smart grid” systems that could communicate over these new Wi-Fi signals, with sensors mounted in faraway places transmitting information back to headquarters. Finally, there’s the possibility that white spaces could lead to more competition in the market for broadband. Genachowski says that ISPs could offer new home or mobile Internet plans over Super Wi-Fi—creating competition for the cable and phone companies that give you the Internet today.

As promising as these devices have been, white space rules were held up for years by complaints from broadcasters and other entertainment companies. The main issue was interference—TV stations and companies putting on live entertainment argued that the new devices would harm their signals. (Sports leagues and concert promoters feared the new rule would interfere with their wireless microphones.) If these concerns sound a bit trivial to you—what’s more important, the Jonas Brothers’ mics or better wireless Internet for everyone?—that’s because they are. Still, entertainment companies have a lot of clout, and the commission was forced to spend time working out a way for white space devices to play nice with old technology. Under the new rules, white-space devices will be required to check in with a centralized database to determine which channels are available for use in a certain geographical area. Theoretically, this will prevent Super Wi-Fi routers from interfering with TV or microphone signals. But some observers have complained the rules go too far—in particular, it’s not at all clear how well the new devices will work in big cities, where the airwaves are clogged with TV signals.

It will take many months—and probably longer—for technology companies to manufacture and market devices that use the new radio space. Genachowski anticipates the first devices hitting shelves within a year’s time, while tech companies I spoke to say we’ll probably see Super Wi-Fi devices around the 2011 holiday season. It will probably take even longer than that for new standards to be devised, and then for the technology to be perfected—you can bet that the first white-space devices will be too expensive, and won’t offer much in return, sort of like the way the first cell phones were as big as a house.

But things will change fast. Some of the most wide-eyed visions include the white spaces replacing cell carriers—if we can get everything over Super Wi-Fi, why would we need voice and data contracts? That may sound ambitious, but it’s not every day that the public gets a new swath of radio waves to use for anything we want. The last time that happened, we saw amazing things. It’s likely to happen again.

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