AT&T has revealed a few of the US cities in which it expects to launch mobile 5G services, towards the end of 2018.

AT&T Inc. (NYSE: T) said late Tuesday night that it expects to launch commercial 5G in parts of Atlanta, Dallas and Waco, Texas, in late 2018 as part of a 12-market rollout. (See AT&T Joins 5G Marketing War, Promising 'Mobile' Launch in 2018.)

"We're working on an aggressive schedule to help ensure customers can enjoy mobile 5G when we launch the network this year," AT&T said in a statement.

The 5G network will launch with a "mobile puck" device that can route 5G connectivity to devices via WiFi. "We will add more 5G capable mobile devices and smartphones in early 2019 and beyond," the carrier stated. (See AT&T's 'Mobile' 5G: What the Puck?.)

AT&T's network will be based on the 3GPP 5G New Radio standard at launch. AT&T also says it will use high-band millimeter wave frequency spectrum for the initial markets, although it didn't specify whether it will utilize 28GHz or 39GHz spectrum. (See AT&T's Mobile 5G Plan Leaves as Many Questions as Answers.)

Millimeter wave services should allow carriers to offer gigabit-speed downloads but has its own set of propagation issues in urban and suburban environments. (See 5G: The Density Question .)

— Dan Jones, Mobile Editor, Light Reading