U.S. mobile operators are eyeing with interest a pair of upcoming radio spectrum auctions that will open up large swaths of frequencies to mobile data services.The auctions are the biggest developments in mobile communications coming over the next year or so, Federal Communications Commission Chairman Kevin Martin said during a keynote appearance Wednesday at the CTIA Wireless trade show.The FCC plans to auction AWS (Advanced Wireless Services) spectrum during summer in the U.S., generally considered June through August, and it also hopes to put rules in place within the next year or so to auction former TV frequencies around 700 MHz for mobile data, Martin said.Future high-speed services to support large data transfers for business and high-quality mobile entertainment offerings for consumers depend in part on having a wide enough band of frequencies. The auctions also come as Google shows interest in wireless Internet access and buys up fiber capacity that could provide the backbone for a high-speed national network. Some have speculated Google could buy spectrum licenses for such a network.The two auctions will roughly double the amount of spectrum available in the U.S. for mobile data services, Martin said in a conversation on stage with Steve Largent, president and CEO of the Cellular Telecommunications and Internet Association (CTIA), which sponsors this week's event in Las Vegas. Demand for spectrum is a major issue for the U.S. mobile data industry, Martin said.The 700-MHz spectrum is especially important because it can reach farther and penetrate walls better than can higher frequencies such as AWS, Martin said. The frequencies have been used for UHF (ultrahigh frequency) TV stations but are being phased out of that use. AWS includes bands around 1.7 GHz and 2.1 GHz.Verizon Wireless plans to compete for one of those types of spectrum, President and CEO Denny Strigl said in a press conference Wednesday. The company is currently examining which to bid for, Strigl said."Ideally, we would participate in the 700-MHz auction," Strigl said. However, the carrier's choice will depend on the expected price of the spectrum and participants in the auctions. Another big factor is how difficult the clearing of the 700-MHz band will be, he added. The transfer of that band, which will take away frequencies used by many local TV stations, has been the subject of a lengthy debate in Washington.Services based on the new spectrum probably would not be available for several years, Strigl said. Verizon believes it has adequate spectrum for its plans for the rest of this decade, he said.Sprint Nextel has a less urgent need for additional spectrum than other mobile operators because it has licenses in the 2.5-GHz band that cover much of the country, said Stephen Falk, vice president of global standards at Sprint Nextel.Cingular Wireless is comfortable with the amount of spectrum it has today but is evaluating the upcoming auctions,CTO Kris Rinne said at the show. The 700-MHz band is attractive because of its propagation characteristics, but questions remain about the process of clearing out current users and how much transmitting power the carrier could use, she said.CTIA continues through Friday.