T-Mobile US (NYSE:TMUS) is seeing strong adoption of its Wi-Fi calling feature, according to a T-Mobile executive who said the operator now counts 7 million users of Wi-Fi calling.

"Wi-Fi calling is used by customers that see benefit from it, and we have over 7 million customers using it, and they are quite happy with it, but we never expect all our customers to use it," Grant Castle, T-Mobile's vice president of engineering services and QA, told Light Reading. "But for the people who use it, it's very successful. It's something that's a good part of our solution. It isn't one of these things where we have to push everyone to it for capacity. It's for the customer, not us."

Last fall T-Mobile made a big push for Wi-Fi calling by letting customers upgrade to a new Wi-Fi capable smartphone if they didn't already have one. In addition, the carrier began offering Simple Choice postpaid customers a free proprietary "Cellspot" Wi-Fi router for their home to enhance their in-home coverage.

Castle added that the solution supports Wi-Fi-to-cellular handoff.

Some critics of T-Mobile claimed the carrier was pushing Wi-Fi calling because of coverage gaps in its wireless network. The carrier currently covers 265 million POPs with LTE and plans to expand that to 280 million by mid-year and 300 million by the end fo the eyar. T-Mobile's 2G GSM footprint covers 285 million people, so to get to 300 million T-Mobile is going to rely on buildout out its 700 MHz spectrum.

T-Mobile currently covers around 190 million POPs with its 700 MHz spectrum and last year it deployed the spectrum in Cleveland; Colorado Springs, Colo.; Minneapolis and Washington, D.C. So far this year T-Mobile has launched the spectrum in Dallas and Houston and plans to keep expanding its 700 MHz coverage this year.

"Outside of cities, we see the low-band solution as really the key to end the map wars and get out there and show people we have coverage everywhere," Castle said. "Verizon always puts up maps to show they cover North Dakota, South Dakota, Montana, which are beautiful states, of course, but not a lot of people are there. It looks great on TV, but it doesn't make a huge difference to people. That said, we are going to close that gap with 700 MHz and expect to have a competitive map towards the end of the year, because we can with our low-band."

Castle said around 10-plus percent of T-Mobile's calls run on its new Voice over LTE technology. "It's slowly growing and it will accelerate quickly," he said. "It's mostly about handset adoption--getting them all enabled. Our launch with the iPhone was a big help. Our work with Samsung on the Galaxy line up is also helpful."

For more:

- see this Light Reading article



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