The proposed two-sided incentive auctions, in which TV stations would be paid a portion of an auction's proceeds for giving up their spectrum, will be complex, Cramton said. The incentive auction "requires a great deal of study by experts to get the details right," he said. "It would be a mistake for Congress to prevent the FCC from adopting the best auction design by mandating auction details and other restrictions."

The proposal would require prospective users of unlicensed spectrum to band together and outbid commercial bidders in the auctions, instead of allowing the FCC to reserve some spectrum for unlicensed uses, as it has done in the past. That provision would make it nearly impossible for new unlicensed spectrum to be allocated, said Michael Calabrese, director of the Wireless Future Project at the New America Foundation, a Washington, D.C., think tank.

The Republican plan would stop the FCC from allowing so-called super Wi-Fi in the TV spectrum's unused bands, called white spaces, Calabrese said. No one has come up with a good model to auction unlicensed spectrum, because it's free and available for anyone to use, he said.

"Had this provision been in place before the FCC designated the 2.4 GHz band for unlicensed [Wi-Fi] sharing, America's invention of today's multibillion-dollar Wi-Fi industry, with all its benefits, would never have occurred," he said. "It would ... undermine the nation's longer-term economic interest in ensuring opportunistic use of wireless broadband and the emergence of increasingly interconnected smart radio devices."

But Representative John Shimkus, an Illinois Republican, questioned why prospective users of unlicensed spectrum shouldn't pay for it. "Our national debt is really the threat," he said. "Isn't spectrum too valuable to give away for free, especially in this economy?"