Like many natural resources, radio frequency (RF) is a fixed resource: there's only so much of it to go around, and quite a lot of it is already used up. Imagine: every wireless device you can think of, and several that escape you, operates on its own slice of RF. Not only AM and FM radio, but UHF and VHF analog television, cellular and cordless phones, Wi-Fi networks, air traffic control, radio-controlled toy vehicles, garage door openers, emergency services radio, shortwave radios, etc. All of these things and more are assigned specific slices of RF in which to operate. Most users of RF either have to operate in the "unlicensed" common areas (e.g., common consumer wireless devices) and be low-powered so as not to spread their influence too far, or else purchase their own piece of the sky in which they may execute complete control. Your cell phone company is eager to purchase and acquire such frequency space so they can operate their voice and data networks. The FCC auctions off this spectrum to the highest bidder, and no one else gets to use it.
Television broadcasters, however, got their piece of the radio spectrum for free. First, they were given a slice of spectrum to operate local television broadcasts in the analog space. This is why each TV station operates on one "channel" to which you tune in order to watch. Later, they were given a second channel in order to build and operate digital broadcasts.
A digital broadcast means that the broadcast consists of efficient radio waves that represent a 1 or a 0, which is the language of computers and digital devices. This binary code is the same as that which stores music on a CD or a movie on a DVD. There are several advantages of a digital broadcast over a traditional analog broadcast.
1. A digital broadcast is more efficient, and the same amount of content can be sent in a fraction of the bandwidth an equivalent analog broadcast would require. A TV station with analog and digital channels of equal size could in fact "multiplex" their digital broadcasts to transmit two, three, or even more shows at the same time in the same channel, and the viewer just picks the one they'd like to watch. Because of this increased efficiency, less bandwidth is wasted than is the case with analog transmissions.
2. A digital broadcast does not deteriorate with distance. Most broadcast TV watchers are familiar with the "snow" or static that pollutes a TV signal that is weak or hitting an incorrectly positioned antenna. A digital broadcast is not subject to this deterioration, and can be only in one of two states: perfect or completely gone. Unlike analog, digital has no "in-between": you either get the signal and it looks perfect, or you don't get the signal and have a black screen, so even weak signals look as good as strong signals. This provides a better viewing experience for the consumer and a savings for the broadcasters, since they won't need to broadcast such a high-powered signal to reach their entire market.
3. Most people would agree that digital broadcasts are of higher visual and audio quality than their analog equivalents. More efficient bandwidth use also makes possible the broadcast of additional features, such as more subtitles and alternate language tracks. Digital broadcasting in general improves the capability of a broadcaster to introduce a richer entertainment experience for the viewer.
To hasten the adoption of digital broadcasting, the FCC gave new channel space to TV broadcasters to use for new digital broadcasts. The idea was that the industry would hurry towards implementing digital television, phase out analog, and give the old analog channels back to the FCC (which were also given out for free, back in the day, in order to hasten the rollout of television itself), which could then sell the bandwidth at auction and make money for the government.
The unintended consequence is that the TV broadcasters weren't in any hurry to replace their analog broadcasts with digital ones, manufacturers weren't in any hurry to produce TVs with digital tuners, and consumers weren't in any hurry to retire the old rabbit ears on the top of their set. For a while, the FCC was willing to let the market tend towards digital on its own, setting a benchmark at 85% penetration: until 85% of Americans had digital television, they would allow analog broadcasts to continue. The sluggish pace of adoption meant the TV broadcasters were "squatting" on their extra bandwidth, and the FCC recognized this as lost revenue. To compensate for this inertia, the FCC implemented the deadline with which we are now familiar: on February 19, 2009, analog broadcasts must cease and the analog channels returned to the FCC, which auctioned the rights to the spectrum in January 2008. The FCC set a minimum reserve price for the spectrum at $10 billion; not bad for air that the TV stations were using for free.
While some people will likely find their television sets dark on February 19, 2009, most people will hopefully have made the switch to digital, made easier by the availability of digital converter boxes that allow older non-digital televisions to continue receiving signals.
Ultimately, the switch to digital is good for everyone, broadcasters and viewers alike. Money changes hands, as it always does, and the growing pains hurt, as they always do. We can only hope that the winners of the FCC auction put the newly available analog spectrum to good use and bring us innovative and exciting new products and services. It certainly can't be any worse than analog television.
