He spoke on Friday at the CES conference in Las Vegas.

Genachowski urged Congress to pass bills that will allow the auctions to happen. Legislation in front of both houses of Congress supports incentive auctions, which would allow current spectrum users such as mobile satellite operators and TV broadcasters to give back their spectrum and, in return, receive a portion of the proceeds from the auction.

Some TV broadcasters, who use spectrum that would be prime for mobile broadband services, have excess spectrum since the transition to digital TV. The change to digital broadcasting allowed them to more efficiently use spectrum. Some have opted to broadcast additional channels, but others are letting the excess spectrum go unused.

Critics of the plan, including Gary Shapiro, head of the Consumer Electronics Association, wonder why the broadcasters should be compensated for giving up spectrum that they didn't have to pay for in the first place.

"What we worked to do was to put together an actionable plan that could move quickly and get to the result that we need, which is freeing up a substantial amount of spectrum for mobile broadband," Genachowski said. Rather than propose an unpopular idea that would require years of debate, the agency decided to start with a plan that was likely to be approved quickly, he said.