T-Mobile's CEO and Sprint's executive chairman banged the drum for their 5G plans in a lengthy hearing before a Senate Committee Wednesday.

"We'll make sure that America wins the global 5G race," T-Mobile US Inc. CEO John Legere told the Subcommittee on Antitrust, Competition Policy and Consumer Rights.

The $26.5 billion merger is expected to close in the first half of 2019, if approved by regulators. (See T-Mobile to Buy Sprint for $26.5B to Create US 5G Powerhouse.)

Legere and Sprint Corp. (NYSE: S) executive chairman Marcelo Claure talked frequently about the 5G issue and especially the spectrum needed to deploy it. (See Can the 'New' T-Mobile Make America's Networks Great Again?)

In particular, the pair referred to the 600MHz and 2.5GHz bands that the operators will begin to use for 5G in 2019, if the merger is approved. "It's a starting point," Claure, although said they would look to add more millimeter wave high-band spectrum as it gets auctioned.

In fact, later in the session, Legere suggested that the "new" T-Mobile 5G strategy could even push AT&T and Verizon into deploying 5G on more bands in the US, noting that both are currently planning to deploy on millimeter wave in "dense urban areas."

That, he suggested wouldn't be practical for a nationwide deployment, as it would just be too costly. "[That's] a [cell]site every thousand square yards at a cost of $1.5 trillion [nationwide]." Legere told the senators, who had likely previously thought that millimeter waves referred to really calm beach weather.

The "new" T-Mobile has already promised a mobile 5G network with average speeds of 450 Mbit/s, higher than either company could offer alone, the executives noted. Legere also says the combined company would take on Comcast and Charter with "in-home broadband" CPE units. (See T-Mobile, Sprint Say 5G-Focused Merger Will Lead to 'Cord Cutting'.)

"We expect to sell 10 million of these," Legere claimed.

Nonetheless, despite three hours of questioning about price competition, rural coverage and low-income customers, the executives stuck to their well established talking points on why the merger -- making four operators into three -- will be good for the US. (See Is the Sprint & T-Mobile Merger Too Risky?)

— Dan Jones, Mobile Editor, Light Reading