On Dec. 21, AT&T will start offering the first mobile 5G device over a commercial, standards-based mobile 5G network.

While the initial launch starts small and will be limited, as the 5G ecosystem evolves AT&T promises that the company's customers will see enhancements in coverage, speeds and devices.

"This is the first taste of the mobile 5G era," said Andre Fuetsch, president, AT&T Labs and chief technology officer. "Being first, you can expect us to evolve very quickly. It's early on the 5G journey and we're ready to learn fast and continually iterate in the months ahead."

AT&T's standards-based mobile 5G network is live today in parts of 12 cities: Atlanta, Charlotte, N.C., Dallas, Houston, Indianapolis, Jacksonville, Fla., Louisville, Ky., Oklahoma City, New Orleans, Raleigh, N.C., San Antonio and Waco, Texas.

In the first half of 2019, the company plans to deploy mobile 5G in parts of these 7 additional cities: Las Vegas, Los Angeles, Nashville, Orlando, San Diego, San Francisco and San Jose, Calif.

Early adopters will be the first to experience the NETGEAR Nighthawk 5G Mobile Hotspot on AT&T's mobile 5G+ network. 5G+ is built to provide a mobile 5G experience over mmWave spectrum, offering users a faster mobile experience than standard LTE. 5G+ will start out in dense urban areas, but if you're outside of 5G+ network coverage you'll be able to access AT&T's 5G in 385 markets on the NETGEAR Nighthawk 5G Mobile Hotspot.

Through an initial offer, AT&T will deliver select businesses and consumers its first mobile 5G device plus 5G data usage at no cost for at least 90 days. Next spring, AT&T's customers will be able to get the Nighthawk for $499 upfront and 15GB of data for $70 a month on a compatible plan and no annual commitment.

For actual 5G phones, you'll have to wait until 2019. Samsung and Verizon have said they'll launch a 5G smartphone in the first half of next year. AT&T and Sprint too.

Two months back, Verizon launched a variant of 5G as a home internet service, and in early 2019 it plans to begin a standards-based mobile service.