Josh Miller/CNET

T-Mobile CEO John Legere is stumping for his company's merger with Sprint again, arguing that the combined entity would be the only carrier to bring 5G nationwide, because rivals AT&T and Verizon are "locked in a meaningless race just to claim they're first." In a blog post Thursday, Legere said the new T-Mobile would "fix the broken, arrogant wireless industry."

5G, already launched in the US by Verizon, AT&T and Sprint, is the next-generation network being used by smartphones to provide faster speeds and more capacity.

With 5G currently available only in select areas of some cities, building it in rural areas was one of the conditions that Federal Communications Commission (FCC) Chairman Ajit Pai placed on T-Mobile and Sprint when he OK'd the $26.5 billion merger in May. The deal still needs to get the thumbs-up from the US Department of Justice.

"It's so important to deliver 5G across the entire country," Legere said in the post. "There are brilliant people in every corner of the US, from small towns to big cities, and we'll only benefit from their ideas if they have access to the right tools."

Nationwide 5G will come only via the merger, he said, because T-Mobile has high-band spectrum and low-band spectrum, while Sprint has midband spectrum. He said that by combining this spectrum -- the radio airwaves that make the wireless system work -- the combined company would have full coverage unlike its rivals.

"The New T-Mobile ... will ensure that 5G reaches people across the entire country," the chief executive said.

This spectrum argument isn't bulletproof though. The FCC's Pai said earlier this week that he's now pushing to auction off midband spectrum for 5G to all carriers, and the Justice Department is reportedly considering requiring T-Mobile and Sprint to divest their wireless spectrum as well as other parts of their businesses.

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Rumors earlier this week said T-Mobile and Sprint are nearing a $6 billion payday for their assets, including wireless spectrum and the Boost Mobile prepaid wireless service, in a move to gain regulatory approval for the merger, with satellite TV provider Dish Network reportedly the buyer.

T-Mobile and Sprint are the third- and fourth-largest carriers behind Verizon and AT&T. Should they merge, Legere would remain in his role.

Legere also hinted Thursday that a new T-Mobile would have lower-price offerings so consumers of all economic backgrounds could afford it.

T-Mobile's 5G made an early appearance in New York in May after being delayed in February to the second half of 2019.