A modest experiment began in several public parks on Jan. 26 in Wilmington, N.C. The city rolled out a wireless network that linked security cameras and offered free public Internet access. Public wireless Internet access in a park is not spectacular (and free public video surveillance is a little creepy), but the experiment lies in not what was offered, but how it was offered: by taking advantage of unused television spectrum.
Look to Wilmington to understand a piece of what happened yesterday on Capitol Hill. As part of its payroll tax cut compromise, the House agreed on a slate of measures around spectrum. First, AT&T and Verizon got their long-coveted spectrum auctions, which will offer broadcasters the option to relinquish their licenses in return for a share of the proceeds when those licenses are then sold to AT&T or Verizon. In theory, other companies can buy this spectrum; in practice, AT&T and Verizon tend to. These two companies argue that, with even more licenses, they can keep up with demand and roll out wireless broadband in rural areas. One hopes on faith rather than experience that they will do so.
Back when TV broadcasters had power—that is, over members of Congress, and not in wattage at home—they had the best spectrum, in the frequency range that carries well and through walls. But television signals interfere with each other, and so the FCC has always had to guarantee gaps, adequate spaces between cities and signals to ensure that The Cosby Show in Washington was not compromised by Cheers on the same frequency in Baltimore. I am not dating myself with these references; I am dating the dominance of broadcast television. These gaps of unused spectrum, which get wider as population density thins and fewer stations broadcast, are called “white spaces.” This is the spectrum Wilmington now uses in its parks.
But the draft bill also protects the Federal Communications Commission’s intention to preserve white spaces for unlicensed use. Spectrum is dry and technical even to the people who work in it, and so they assign nicknames to different bands. Wi-Fi, for example, uses what is referred to as “junk band,” spectrum reserved for microwaves and baby monitors. Junk band doesn’t propagate well, and the devices licensed to use it are limited in power to prevent interference; this is why you can’t take your baby monitor downtown with you while you have dinner.
Television broadcasts, on the other hand, sit on “beachfront” spectrum. To see the implications of Wilmington and yesterday’s draft bill, think of how you use Wi-Fi on your mobile phone now: in the house or at work, while walking around in roughly the same distance your baby monitor reaches. Maybe to your neighbor’s house for a glass of wine. Already, in this limited capacity, mobile phones get about a fifth of their data through Wi-Fi, not through the mobile spectrum sold to you by your wireless carrier (again, which is probably AT&T or Verizon).
Now imagine if Wi-Fi, now on junk band, moves beachfront. Bloomberg Businessweek does not recommend you leave your baby home without a sitter. You will, however, be able to head out to dinner pulling data from the same source, which is neither AT&T nor Verizon. This has the largest implications for rural America, which is less attractive to television broadcasters and therefore has the largest white spaces. For the same reasons—low population density and long distances—rural America is unattractive to Internet service providers, and has proven intractably difficult to connect to the Internet. In addition to giving AT&T and Verizon what they want, the shuffling on Capitol Hill around the payroll tax cut may have given them what they need: competitors.