Briefly taking the stage at a Mobile World Congress dominated by 5G news, T-Mobile today announced that it will build out its upcoming 5G network in 30 cities during 2018, specifically including New York, Los Angeles, Dallas, and Las Vegas. The third-largest U.S. carrier also committed to enabling customers in these cities to experience 5G “when the first 5G smartphones launch early next year.”

Today’s announcement demonstrates the rapid pace at which carriers are attempting to establish 5G leadership in the United States. Only last month, T-Mobile publicly said that it might start offering some 5G services in 2019, rather than focusing on its previously scheduled 2020 national deployment of 5G. The new announcement never mentions 2020, though clearly T-Mobile deployments will continue after the first 30 cities in 2018 into both 2019 and 2020.

In standard T-Mobile fashion, the company’s executives knocked AT&T and Verizon for their previously announced plans to offer earlier 5G services in the forms of mobile hotspots and fixed broadband modems. Once again calling its larger rivals “Dumb and Dumber,” T-Mobile CEO John Legere said that they were “in a meaningless race to be first,” using “pucks” and “routers” that wouldn’t be “truly transformative” for customers, who care about “actual smartphones” and brand new experiences. Live at MWC, T-Mobile CTO Neville Ray noted that for 5G, “you have to have coverage. If you don’t have broad coverage, there’s no way you can deliver this arc of experiences.”

Beyond its expected deployment of 5G-ready equipment, including low-band 600MHz radios and licensed assisted access (LAA) small cells, T-Mobile also said that it plans to deploy high-band millimeter wave spectrum equipment this year. The carrier identified Ericsson and Nokia as partners “already delivering equipment to support our multi-spectrum strategy.” In a separate release, Ericsson said that it is supplying T-Mobile with 600MHz, 28GHz, and 39GHz radio hardware for its 5G network.

Like Sprint, which announced 5G-ready rollout plans earlier today, T-Mobile underscored that improvements to its existing 4G network are building a better backbone for its 5G network. Since early 5G smartphones will use 5G and LTE simultaneously, “all the LTE Advanced work we do is 5G work,” said Ray, “and we’re leading the industry with the most advanced LTE network in the country.”