I just stumbled on a great white paper, Reclaiming the Vast Wasteland, Why Unlicensed Use of the White Space in the TV Bands Will Not Cause Interference to DTV Viewers, by Michael J. Marcus, Paul Kolodzy and Andrew Lippman, published October 2005 by the New America Foundation.
I’ve long been an advocate of license-exempt access to wireless spectrum because of the enormous economic benefits we’ve realized from the few slivers of spectrum where license-exempt operation is currently permitted. Here rampant competition has emerged and usage has soared as WiFi, Bluetooth, pre-WiMAX and dozens of proprietary systems have taken off. And, it’s in these bands that we see new modulation schemes, smart antennas, and mass-market products.
Unfortunately, only a few slivers of spectrum are allocated for license-exempt use, even though most licensed spectrum is unused. In particular, large swathes of TV spectrum are unused — even in a major city, most broadcast TV channels are empty.
Our waste of spectrum is not a technical problem. Wireless performance (in bps per Hz per sq. mile, for example) has been improving exponentially for over a century. But as the result of government regulation, wireless spectrum utilization is frozen on a band-by-band basis at the state-of-the-art as it stood when the band was defined 20, 40, or 60 years ago. (In the US, broadcast TV was first authorized in 1941 and slightly updated for color broadcasting in 1953).
In the US in 2004, the FCC proposed allowing a new generation of wireless devices to make use of vacant TV channels. These are prime frequencies, as they more readily penetrate buildings, trees and other obstructions. Unfortunately, the National Association of Broadcasters and other broadcast TV industry lobbyists have strenuously objected to any use of any part of “their” bands and have raised a variety of objections. Marcus, Kolodzy & Lippman thoroughly debunk each and every one of their points.
We have the potential to open up prime wireless spectrum for broadband access and unlimited other purposes. It would be a pity if vested interests continued to block access to otherwise unused spectrum.