AT&T is going to start testing small cells "later this year and into next year" to improve its network coverage and capacity, the company reiterated at CTIA. The miniature, short-range cell sites can be deployed at a fraction of the cost of a traditional tower. AT&T announced it was planning tests this year, and Cisco announced it was working with AT&T on developing small cells, at MWC in February. However, AT&T hasn't made clear the particular type of hardware (3G, 4G, etc.) it's planning to test. Small cells can be deployed in a wide variety of settings, like the sides of lamp posts, allowing telecoms to increase network coverage by filling in holes between their bigger, "macro" cell towers.
On the topic of small cells, FCC Chairman Julius Genachowski stated yesterday at CTIA that the organization plans to free up spectrum in the 3.5GHz band for small cell use. Due to its poor range and indoor penetration, the band lies outside of what is ordinarily considered prime wireless spectrum, but small cells would allow carriers to exploit it for outdoor reception in dense urban areas.