US operators went head-to-head on mobile 5G, with Verizon claiming a data transmission first involving a smartphone and AT&T quietly announcing the lighting of its second compatible mobile site.

Verizon’s news focused on its mobile launch, which it is planning for 2019 to supplement the launch of a fixed wireless access service last month. In a statement, the operator said it completed a data transmission call on a 3GPP-compliant 5G New Radio network using a Moto Z3 smartphone and Moto Mod 5G clip-on.

Samsung and Qualcomm also participated in the tests, which involved web browsing and a video call on Verizon’s 28GHz spectrum.

In an apparent potshot at AT&T’s mobile 5G plans, Verizon’s VP of technology development and planning Bill Stone said: “This successful test, using an actual smartphone, widens our lead. We will be the first to offer a 5G upgradeable smartphone on our network in 2019.”

Verizon’s announcement came shortly after AT&T announced Dallas, Texas, had become the second location where it had turned on a mobile 5G site following a similar move in Waco, Texas, last month. A company representative challenged Verizon’s data transmission claim, stating AT&T had completed such work using a Netgear hotspot dubbed the Puck, which the operator plans to use while it waits for the arrival of compatible smartphones in 2019.

Waco and Dallas are the first of a dozen US cities AT&T previously announced would lead its mobile 5G charge.