AT&T Inc. aims to be the first U.S. carrier to provide fifth-generation, or 5G mobile service to phone customers this year, pitting the wireless giant against Verizon Communications Inc. and T-Mobile US Inc. in a costly network upgrade race to spur revenue growth.

Unlike current trials using 5G technology to beam signals between stationary antennas, AT&T said in a statement it will introduce a commercial mobile service in more than a dozen U.S. cities later this year. The company didn’t offer specifics.

The faster connections will help carriers sell advanced services like virtual reality, 4K video and enable self-driving cars.

Verizon, T-Mobile and Sprint Corp. are also planning to offer mobile 5G services but haven’t elaborated on their plans.

While 5G technology offers a path for a slowing industry to revive growth, challenges abound. Mobile-phone companies, chipmakers, device manufacturers and software developers will need to spend about $200 billion a year in research and capital expenses to get there.

And engineers will have to find ways to get the technology to work around interference from trees and rain and provide a strong enough signal to handle the anticipated demand.

AT&T says it has laid the groundwork for 5G through network upgrades in 23 cities and fixed wireless trials in Kalamazoo, Michigan; South Bend, Indiana; Waco and Austin Texas.

The company has not disclosed where it plans to launch mobile 5G initially or what airwaves or network equipment it plans to use.