Television's Spectral Gold Mine

One of the best places to find inefficiently used spectrum is undoubtedly television stations. The rise of cable TV has undercut the need for broadcast stations. As of July, nearly 90% of US households paid for television either from cable, satellite or phone companies rather than getting it free from broadcast stations, according to Nielsen. Competition for viewers and ad dollars has eroded TV stations' business so badly that a number are struggling financially. And things will get worse if, as has been suggested, broadcast networks cut ties to stations and convert to cable-channel status as a way of generating more revenue. Shutting off stations unilaterally probably isn't practical given the public-interest arguments in favor of free broadcasting. But some argue that reconfiguring how broadcast TV's spectrum is used and allocated would free up as much as half the bandwidth TV currently occupies while allowing outlets to continue broadcasting. Broadcasters are allocated channels of spectrum that ranges across roughly 300 megahertz of bandwidth. Each station needs only six MHz, and few markets have more than 10 or 20 stations. Much of the spectrum is left unused, because signals interfere if they are too close together. But technology has moved on. One possibility now would be to use cellular technology used by wireless carriers to overcome the interference problem. Broadcast channels' frequencies could be grouped closer together, freeing up 130 to 180 MHz of bandwidth, or two to three times the amount that was auctioned off last year for $19 billion.