AT&T Inc. is planning to combine 3G, 4G LTE and Wi-Fi access in its radio access small cells and aims to deploy 40,000 or more of the tiny base stations through 2015.That plan was unveiled by Bill Smith, president of network operations at AT&T, on Thursday morning at the Jefferies 2013 Global Technology Media and Telecom Conference in New York City as he provided some insight into what was characterized as AT&T's "lead" in U.S. small-cell deployments. Small cells are tiny, standalone base stations that, in theory at least, help add voice capacity and enhanced data access in high usage areas such as urban centers. "The early small cells that we're deploying today are single-technology ... our plan is to go to units that can support UMTS [3G], LTE and Wi-Fi," Smith said. AT&T has previously said it plans to deploy 3G HSPA+ "metrocells" that are currently being installed across a significant portion of the U.S."Yesterday morning I was in St Louis looking at one of early trials," said Smith of the operator's small-cell efforts so far. He explains that AT&T has been covering a residential neighborhood using cells attached to every third or fourth street light pole and connected back to the metro network via a VDSL connection.This will be one of the uses for small cells for the operator -- working around the "not-in-my-backyard" mentality that greets macro cellular deployments by using much smaller and more discreet radio access units. "As beautiful as I think a new cell site might be, you know, not everybody does," Smith quipped.Initially, however, AT&T will be using early small cells to bolster in-building coverage. "Most of what we do this year ... will be indoors," says Smith. "Shopping malls are a problem for us," he added.All of this involves a lot more work than just bolting down a small cell and connecting it to the network. The network head says AT&T has learnt a lot from its deployment of 3G femtocells during the past few years. They work well in a rural area where macro cellular coverage is unavailable, Smith explained."The real challenge," Smith said, is when the small cell battles the macro network for a device that is attempting to connect to the network. Dealing with this, he said, involves having more intelligence and visibility at the network control. For instance, if a user is in their car connected to the macro network, AT&T does not want that user roaming onto a small cell located in a restaurant on the street as they pull up at a stop light and then losing the connection as they drive away.AT&T has been working on its own and with others to deal with some of these issues for several years, Smith said. "I think we ultimately will get to point where we characterize each connection at the control plane and define where they go," he said.This is part of the reason why AT&T's planned combo LTE/3G/Wi-Fi Multi-Standard Metrocell (MSM) small cells are still in the lab right now and not expected to arrive on the network until some time in 2014 or 2015. Putting in the smarts to decide the right connection for the right application while not fighting the larger macro network gets exponentially more difficult when layering together and managing 3G, 4G and Wi-Fi connections.Smith says that AT&T is working with technologies such as "Hotspot 2.0" in a bid to fix some of these issues for Wi-Fi. All this will lead to an eventual goal that every cellular small cell deployed by AT&T will also have Wi-Fi onboard.The CEO of AT&T's major rival, Verizon Wireless, said Wednesday at the conference that it will be deploying its first small cells sometime in 2013. (See Verizon CEO: Small Cells Coming in 2013.)— Dan Jones, Site Editor, Light Reading Mobile