White Spaces prototypes fail initial FCC testing

As reported on this blog some months ago, the Federal Communications Commission has been testing a prototype device developed by the White Spaces Coalition that uses different transmission technology to beam ultra-fast wireless broadband via unused "white spaces" in the TV broadcast spectrum between 44 MHz and 885 MHz. The coalition is comprised of Dell, EarthLink, Google, HP, Intel, Microsoft, and Philips Electronics.

A major objective of the testing is to determine if the prototype would interfere with TV signals and wireless microphones. Two prototypes tested apparently do enough of the time that the FCC told the coalition to go back to the drawing board:

This report determined that the sample prototype White Space Devices submitted to the Commission for initial evaluation do not consistently sense or detect TV broadcast or wireless microphone signals. Our tests also found that the transmitter in the prototype device is capable of causing interference to TV broadcasting and wireless microphones. However, several features that are contemplated as possible options to minimize the interference potential of WSDs, such as dynamic power control and adjustment of power levels based on signal levels in adjacent bands, are not implemented in the prototype devices that were provided. Given these results, further testing of these devices was not deemed appropriate at this time.