Genachowski: We need airwaves from government and broadcasters

Asked if broadcasters' new mobile TV offerings changed his mind about taking some spectrum from the broadcast industry, he said no.

And he said it is likely that government agencies will need to give up some spectrum or at least share it with private companies. Some departments, like the Defense Department, have large amounts of spectrum but only use it 1 percent of the time, leading the FCC to think it can be used more efficiently.

Still, it is difficult to take airwaves away from military and agencies that could need all of that spectrum in the case of a national disaster. If a spectrum sharing arrangeent is worked out, agencies would need to have priority in certain situations.

"It's hard to see a path where we don't reclaim spectrum from both opportunities," he said.

"From everything we've seen so far, the amount of spectrum that will be needed to meet the country's demands suggests we'll have to find spectrum from government and commercial uses."