CTIA, a trade group for mobile carriers, said recently its members need up to 800MHz of spectrum to meet growing wireless broadband demands. But the trade group also praised the FCC proposal to free up 500MHz of spectrum when the agency first released some details last month.

"Based on the executive summary [of the FCC plan], it is clear the broadband team recognized the importance of the mobile Internet to the economy and to meeting many national priorities," CTIA said in a statement. "We applaud their commitment to providing everyone equal access to the most advanced wireless communications."

The FCC's national broadband plan has several specific recommendations about how to free up new wireless spectrum. With the goal of freeing up 300MHz within five years, the FCC would count on broadcasters for 120MHz.

The FCC would also auction 10MHz of spectrum that was unsold in the 700MHz spectrum auctions that ended in March 2008. The so-called D block was designated for a shared commercial/public safety network, but the block failed to generate the minimum bid required by the FCC. Several public safety agencies have called on the FCC to give them the D block so they could move ahead with a nationwide, interoperable network, but the FCC broadband plan advocates that Congress pay $12 billion to $16 billion to build a nationwide network.

In addition, the FCC plan would make new spectrum available in the 2.3GHz wireless communications service band, in the advanced wireless services bands and in the mobile satellite spectrum to get to 300MHz in five years.