AT&T promised mobile 5G before the end of 2018 and is set to deliver, though cutting it close to the self-imposed deadline.

AT&T lit up the first mobile 5G network in the U.S. today, with service launching in select parts of 12 cities on Friday.

This is not a full-blown launch, and AT&T acknowledged initial reach will be limited to dense urban areas. Still, Dec. 21 will be the first day certain consumers can get their hands on a commercial 5G mobile device  – the Netgear Nighthawk 5G Mobile Hotpot― and connect to a live standards-based 5G network.

“This is the first taste of the mobile 5G era,” said Andre Fuetsch, president, AT&T Labs and chief technology officer, in a statement. “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 noted that initially it will offer “select” businesses and consumers the Netgear Mobile Hotspot, plus 5G data at no cost for a 90 day trial period. In spring 2019, AT&T will start offering the hotspot for $499 and 15 GB of data for $70 per month.

AT&T and Verizon have both announced plans to offer 5G smartphones from Samsung in early 2019.

The 12 cities included in AT&T’s initial launch are Atlanta, Charlotte, N.C., Dallas, Houston, Indianapolis, Jacksonville, Fla., Louisville, Ky., Oklahoma City, New Orleans, Raleigh, N.C., San Antonio and Waco, Texas.

AT&T’s mobile 5G service will expand to parts of these seven additional cities in the first half of 2019: Las Vegas, Los Angeles, Nashville, Orlando, San Diego, San Francisco and San Jose, Calif.

As for speed, AT&T said it is just beginning to gather actual speed data as the hotspot starts rolling out. The carrier expects 5G to ultimately enable the promised multi-gigabit speeds in 2019, as the ecosystem evolves.

AT&T’s initial 5G rollout uses millimeter wave spectrum and the network launched based on the June 2018 version of the 5G NR specification. The carrier has upgrade plans in place to evolve with further drops of the standard as it becomes available.

“As the ecosystem evolves, this technology will ultimately change the way we live and conduct business,” said Mo Katibeh, chief marketing officer, AT&T Business, in a statement. “We expect that our initial adopters will be innovative, growing businesses. They’re the starting point for what we think will be a technology revolution like we’ve never seen before.”

Verizon already launched its fixed wireless 5G home broadband service earlier this year, with plans to deploy mobile service in early 2019.  T-Mobile and Sprint also have plans to roll out mobile 5G later in 2019.