Sprint is using small cells provided by Alcatel-Lucent to supplement the capacity of its LTE network.

The operator said today it will deploy metrocells from Alcatel-Lucent's lightRadio portfolio to "augment coverage" in high-traffic indoor areas like stadiums and campuses.

The equipment is capable of supporting 2G, 3G, LTE and Wi-Fi, but "this particular contract is specific to the 4G LTE network," an Alcatel-Lucent spokesman said.

Sprint is the first U.S. carrier to use Alcatel-Lucent's lightRadio metrocells, described on the company's website as a miniature base station weighing about four pounds that can be mounted on walls or ceilings for indoor use. Specifications vary for outdoor models.

"We will be able to increase our coverage and capacity where it’s needed," Sprint top network executive Bob Azzi said.

Sprint is also using Alcatel-Lucent equipment and services for its wide-reaching network modernization project, which includes the installation of new base stations and the deployment of an LTE network. Ericsson and Samsung are also vendors for the project.

Alcatel-Lucent says it has 39 commercial agreements to deploy small cells. The contract with Sprint marks the first time an operator has gone public with its use of the vendor's lightRadio metrocells.

Financial terms of the deal were not announced, but the agreement is separate from the companies' existing work on Sprint's network modernization project.

Sprint did not say which markets would receive the new equipment. Its 2010 contract with Alcatel-Lucent for its LTE rollout and network upgrade includes cities in the Northeast, Mid-Atlantic and Southern California, including New York City, Philadelphia, Boston, Washington, D.C., Baltimore and Los Angeles.

Small cells have been widely touted as a solution to the capacity crunch; the infrastructure creates a more dense network architecture capable of better handling rising data traffic. There have so far been few public announcements about large-scale commercial deployments in the United States. Use of small cells is complicated by the need for backhaul and self-organizing network technology to minimize interference issues.