In the end, it's not about which spectrum they are using, but whether it can support the services that customers are demanding, he added. "If T-Mobile can show that type of performance on a fully loaded commercial network, it can call the service whatever it wants."
Another analyst, Charles King of Pund-IT, said that while the company's 5G plans are still several years away from being delivered, "it would be a mistake to underestimate T-Mobile which has under CEO John Legere consistently gained share and flummoxed competitors by embracing unconventional strategies and initiatives."
With that in mind, "it's hard to tell whether T-Mobile's 5G effort is premature or prescient, but the company has turned similar past efforts into market and mind share gains," said King.
Rob Enderle, principal analyst at Enderle Group, agreed.
"T-Mobile is the nightmare that never ends for AT&T and Verizon," said Enderle. "If they pull this off, instead of T-Mobile chasing Verizon and AT&T it could be both those vendors being talked about in past tense. This is a race for who becomes the next AT&T and given how fast T-Mobile is moving, if they get ahead AT&T and Verizon will never catch up."
Another analyst, Jan Dawson with Jackdaw Research, has a different view, however.
While T-Mobile's technical plans for 5G and the use of low-band spectrum are novel, the carrier still lacks a huge asset that is held by both AT&T and Verizon—the company doesn't offer its own home broadband and TV services.
Calling it a "big strategic weakness," T-Mobile will be under increasing pressure to pair up with a provider that can offer those services so it can continue to appeal to new customers who want bundled services, said Dawson. "Other carriers are pursuing 5G in a form which could replace home broadband services where deployed, but T-Mobile won't be going down that route at least in the beginning, which means it will likely still need a merger with a cable or landline telecoms provider somewhere down the line to be competitive in bundled services."
5G is expected to offer as much as 50 times the throughput of current 4G LTE and latency that will drop into the single milliseconds. It's also expected to play a significant role in the rapidly growing internet of things (IoT) as the number of connected devices creating traffic over the world's wireless networks continues to grow.
AT&T began its own 5G field trials in the summer of 2016, along with partners Ericsson and Intel, after conducting its own lab development and testing.
International standards for 5G networks are still being developed by 3GPP (3rd Generation Partner Project), which gave the go-ahead to the 4G LTE standard. In March 2015, the 3GPP rolled out a tentative timeline for 5G that doesn't show a standard for the technology being approved until 2020, though that hasn't stopped networking technology vendors and component makers from making moves to embrace 5G.