The FCC gave the red light to a first-round prototype device being developed by Microsoft, Google and others, that they say will work to broadcast high-speed Internet over unused TV spectrum.

However, the FCC in its report, said the device couldn't reliably detect the unused airwaves and worried that the device could interfere with TV signals.

Tech companies have been looking for a way to take advantage of unused and unlicensed TV spectrum, called white spaces. Despite the FCC's initial rejection of the device, the commission said it would still like to find a way to use the unused airwaves.

The coalition working on the prototype devices, which includes Dell, HP, Intel, Earthlink and Philips Electronics North America, said it will work with the FCC to resolve issues of reliability and interference.