Veteran broadcast engineering consultant Charlie Rhodes must be smiling today. No one has been more active in warning about interference to television broadcasters from proposed unlicensed devices using the same spectrum, and
yesterday Tuesday the FCC issued a report supporting this position.
Nate Anderson writes:
The FCC's Office of Engineering and Technology issued a report late yesterday that gave negative marks to current attempts at building a personal "white space" receiver and transmitter. Such a device could open up the empty spaces in the television spectrum for unlicensed wireless broadband, unleashing a surge of creativity and innovation that could make WiFi look as attractive as a 900MHz cordless phone. That is, so long as such a device actually works. ¶ On the day that the switch over to digital television broadcasts is finalized in early 2009, companies could be free to sell unlicensed devices that can send and receive information in whatever parts of the television spectrum are unused in a given location (well, except for channels 37 and 52-69), so long as they meet FCC engineering criteria. Because the low frequencies used by over-the-air television signals are able to cover great distances and penetrate walls with ease, they theoretically provide a perfect place to deploy wireless broadband technologies over great distances—without having to purchase a chunk of licensed spectrum at auction. ...
Link: Ars Technica.
From the FCC web site:
FCC Office of Engineering and Technology Announces the Release of Reports of Initial Measurements on TV White Space Devices.
Public Notice: Word | Acrobat
Prototype Devices Report: Acrobat
Appendices A & B: Acrobat
Direct Pickup Report: Word | Acrobat
Disclosure: I'm on the board of the Association of Public Television Stations, one of the organizations which has been expressing concerns about interference from these devices. Still, I hope that through finding alternative spectrum, improvements in the interference rejection characteristics of receivers, "smart" broadband devices or other means, we can encourage open spectrum usage by wireless broadband devices. We broadcasters need to embrace alternative platforms for content distribution.
Update 7 August 2007:
See also Robert Horvitz's, FCC announces test results for TV "white-space" prototypes. Link: Open Spectrum. --Dennis