T-Mobile's (NYSE:TMUS) LTE network expanded geographically by nearly 250 percent in 2015, company executives boasted, and now covers 304 POPs. CTO Neville Ray credited most of that expansion to T-Mobile's used of 700 MHz A block spectrum, which it has deployed to a population of 185 million POPs.

"A big part of [the overall LTE growth] was the low-band spectrum that we secured in '14, and we really got through clearance and deployment in a very meaningful way in '15," Ray said at an investor conference. "Originally we had 190 million licensed POPs of 700 coverage; by the end of '15 we rolled out 185 million. Nobody has ever rolled out that much LTE with new spectrum with broadcasters to clear, zoning and jurisdictional battles to go through."

Roughly half of T-Mobile's LTE customers use a handset that supports low-band spectrum, and 60 percent of the carrier's customer base access its LTE network.

"Forty percent of voice calls are on LTE," Ray continued. "Ask my competition where they are. I know one of them is at zero, and the other two are pretty close to zero. So their adoption of really moving into an IP era of communications -- voice, RCS, video, VoLTE, all those pieces -- we are the most advanced on that, hands-down."

That enables T-Mobile to refarm its spectrum and move away from legacy 2G and 3G services more quickly than its competitors can, Ray said. And T-Mobile plans to be aggressive in the upcoming incentive auction of 600 MHz spectrum, deploying services over those airwaves in 2017 and 2018 despite competitors' claims that leveraging that spectrum will take longer. Indeed, a top AT&T executive said this week that the carrier might not deploy its own 600 MHz spectrum -- if it wins it in the auction -- until 2021.

T-Mobile's network expansion coupled with its uncarrier marketing campaign have paid dividends in a very big way during the past two years. The operator reported this week that it added more than 2 million subscribers during the fourth quarter, extending a streak of 11 consecutive quarters with at least 1 million net adds. The news also marks the third consecutive quarter of more than 2 million net adds for T-Mobile.

Executives also didn't shy away from the recent controversy over T-Mobile's Binge On program. The Electronic Frontier Foundation recently said that T-Mobile is slowing the transmission speeds of all video regardless of whether the content provider is part of T-Mobile's Binge On program. T-Mobile initially denied it was throttling such transmissions, claiming it was only "degrading" the content, and T-Mobile representatives continue to decline to respond to the EFF's allegations directly.

But T-Mobile executives at the investor conference touted the network payload benefits of the program as well as the ability for consumers to turn the service on and off. And according the company, its customers like Binge On.

"Customers love it," said COO Mike Sievert. "We're dumbfounded that there are people out there that are critiquing it on a vague net neutrality basis; it's crazy to us. This is something that's a huge step forward for customers."

For more:

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