Entities calling for the allocation of unused TV “white space” spectrum to unlicensed wireless devices were disappointed by the release of FCC test results that show inconsistencies in the ability of two prototype devices to detect broadcast TV or wireless microphone signals and the potential of one such device to interfere with incumbent TV and wireless microphone operations. The lab report, issued by the FCC’s Office of Engineering and Technology (OET), is associated with ongoing agency proceedings regarding the usage of unlicensed portable and personal devices within white space channels at the conclusion of the digital TV transition in 2009. The FCC, which has already approved the use of unlicensed fixed devices in the white space bands, is expected to rule on the matter in October. Two prototype devices—one submitted by Microsoft, the other manufactured by Phillips— were tested by the OET. According to the OET, the Microsoft device was “generally not able to detect DTV signals on any of the tested channels” at two signal thresholds established by the FCC. Although the Phillips device was “generally able to reliably detect DTV signals” at FCC mandated thresholds, the OET found that the device’s performance “declines very rapidly as the signal levels are reduced.” The OET further determined that the Microsoft device, which included a transmitter, was capable of causing interference to TV broadcast and wireless microphone signals. With respect to the vulnerability of cable TV signals to unlicensed wireless emissions, the OET concluded that its test results “provide an empirical demonstration for the potential for . . . interference at relatively lower power levels, and, as such, a useful input to the decision process.” The National Association of Broadcasters praised the OET’s findings as proof that “the portable, unlicensed devices proposed by high-tech firms can’t make the transition from theory to actuality without compromising interference-free television reception.”