AT&T said it has agreed to purchase licenses to high-speed cellular spectrum in 18 states, including California, from Verizon Wireless for $1.9 billion. The spectrum, in the 700 MHz B band, covers 42 million people, and would allow AT&T to expand 4G LTE services "to meet demand for mobile Internet services on a wide array of smartphones, tablets and other devices," the company said. Big carriers have been switching to 4G LTE technology to provide higher-speed data connections for mobile devices. As part of the deal, AT&T said it will also give Verizon licenses to 10 MHz Advanced Wireless Services spectrum in Los Angeles, Phoenix, Fresno and Portland. AWS is another type of wireless technology used for high-speed networks. AT&T, the nation's second-largest wireless carrier, has been acquiring airwaves in a bid to catch up with Verizon, which has a more extensive LTE network. The deal, which AT&T said could be completed by the second half of 2013, requires regulatory approval. But Public Knowledge, a public interest group, said it opposes the deal, saying the pact would increase consumer costs because it would further push the wireless industry into a duopoly between AT&T and Verizon. "This acquisition would add insult to injury for smaller providers that provide a competitive alternative to AT&T and Verizon," the group said in a statement. Google redesigns image search results for faster viewing