While T-Mobile’s President of Technology Neville Ray threw water on Verizon’s dynamic spectrum sharing (DSS) plans on Thursday, Verizon said it’s sticking by its prior public commitments.

DSS is an important technology especially for Verizon. It allows operators to use 4G spectrum and reallocate it for 5G. AT&T also has shown interest in DSS, and T-Mobile to a lesser degree. T-Mobile is using 600 MHz as the basis for its 5G “layer cake” of spectrum, so to speak, and already covers much of the country with it.

Verizon is using millimeter wave spectrum to offer super high speeds and capacity in concentrated urban areas—some call them hot spots—to differentiate 5G from 4G. DSS will enable it to offer a nationwide flavor of 5G when it’s available; Verizon has promised to cover half the U.S. population with 5G by the end of this year.

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“We’re confident in our 5G strategy that we have, although it sounds like maybe T-Mobile is not confident in their 5G strategy anymore,” Kevin King, director of communications at Verizon, told FierceWireless on Friday. “They must really be panicking about the fact that this ‘nationwide’ 5G network that they’ve rolled out doesn’t perform as well as 4G networks,” including in some cases against T-Mobile’s own 4G network.

RELATED: Verizon gears up for DSS launch next year

Verizon Chairman and CEO Hans Vestberg told investors at a UBS conference in December that the operator believed it would have DSS in the first half of 2020, but when asked about timing during the company’s earnings call last week, things got a bit more ambiguous.

“We have already gotten this to work from the software point of view. And the majority of our baseband is ready for taking DSS. So what we have said, I'm not going to give you an exact date, but I'm going to tell you, we're going to be ready when we feel the market is ready and our customers need to have that coverage,” Vestberg said during the fourth-quarter earnings call.

That left observers to wonder if by “market ready” he meant when the handsets are ready to support DSS, or if there was something on the infrastructure side that needs to happen. Ericsson has been leading the charge on DSS, while Nokia late last year announced it will introduce DSS as a software upgrade in line with commercial 5G FDD mass market device availability in 2020.

Samsung Networks provided the following statement to FierceWireless earlier this week: “Samsung Networks expects that our DSS commercial readiness will meet the needs of our operator customers in 2020.”

The plot thickens

On T-Mobile’s earnings call on Thursday, Ray said it’s going to be a “tough year” on DSS, adding that one of the major network equipment vendors is “very late” on delivering the capability.

Ray said T-Mobile has been an early proponent on the development of DSS, but “it’s late.” T-Mobile doesn’t need to wait for DSS to mature as Verizon does; it is “stuck” in that it needs DSS, he said.

RELATED: T-Mobile’s Ray says ‘tough year’ ahead for DSS

“We’re seeing as we learn more, that as you deploy DSS it kind of eats away on the net capacity of the shared radio,” Ray said. “If you rush into that now, some of the early rollouts and work-arounds … that we’ve seen are pretty corrosive and would suck up capacity just by rolling out the feature.

“I’m just saying it’s got challenges,” he said. “For Verizon, it’s a big challenge.”

RELATED: Vodafone tests DSS using 700 MHz, 800 MHz spectrum

Meanwhile, Verizon has been running commercials, including around the Super Bowl, highlighting speed tests that show its own 4G LTE network is faster than T-Mobile’s 5G network.

King declined to talk about specific DSS vendors and trials. “We’re confident in the 5G strategy that we have and the rollout plans that we have and we’ll meet the commitments that we have already publicly identified,” he said.