The industry has been talking about small cells as a solution to the capacity crunch for a while now, but news about actual real-life deployments has been scarce.

That changed on Monday when Sprint announced it would incorporate Alcatel-Lucent metrocells in its LTE network, becoming the first U.S. operator to name a small cell vendor. From what Alcatel-Lucent is seeing, Sprint is not the only company preparing its small cell strategy.

"This is a really important public milestone for all of the carriers, Sprint included, that says the small cell solutions are no longer just a vision. They are a concrete part of the strategy going forward," said Michael Schabel, vice president of Alcatel-Lucent's lightRadio portfolio, in an interview with Wireless Week.

Sprint is using metrocells from Alcatel-Lucent's lightRadio portfolio to increase the capacity of its LTE network in high-traffic indoor areas like sports arenas and college campuses.

Operators are getting to a point where techniques like cell splitting, building new macro sites and using more efficient network technologies like LTE are no longer enough to add the capacity they need to meet soaring demand for mobile data, Schabel said.

"Now it's at the point where...it [small cell technology] is fundamental, it's required to meet the capacity demands," he said. "We have to do it. There's no choice, really."

The shift to denser network architecture will require the wireless industry to reexamine long-standing approaches to infrastructure deployments, Schabel said.

"The reality is, they've been building macro-based networks for 20 to 30 years. There's this institutional knowledge about how to build a network," he said.

While traditional network architectures rely on strategically located macrosites for the broadest possible coverage, small cell deployments focus on high-traffic areas where they can be installed cost effectively. With the potential for hundreds of small cells in a single network, keeping siting and backhaul expenses low is a top priority.

"You are potentially relooking at some of the RF design rules - where you would potentially build and locate small cells where you could get the lowest cost site and the lowest cost backhaul, versus what we do today, which build based on optimal RF location," Schabel said.

"That, to a classically trained RF engineer, is almost heresy," he said. "People will have to get used to it over time."

With that in mind, Alcatel-Lucent came out with its Metro Cell Express service in June. Under the program, Alcatel-Lucent assumes responsibility for installing and integrating its lightRadio small cells with an operator’s existing network. Once the equipment is performing as required, the operation of the network is transferred to the network provider. The managed service aims to help operators overcome daunting challenges with network design, site placement and backhaul for small cells.