T-Mobile Turns Up VoLTE-to-WiFi Handoff

T-Mobile used its Un-carrier 7.0 event to remind the world of a technology it first announced back in 2007: WiFi calling.

Apple Inc. (Nasdaq: AAPL) has a way of making old technologies seem exciting and new, so T-Mobile US Inc. is hoping to coast off that by announcing its voice-over-WiFi calling service with a few upgrades. Most notably, the service, which now works on iPhones in addition to Android, now supports seamless handoff between voice-over-LTE and VoWiFi, although it's not compatible with T-Mobile's 3G network. (See Apple's New iPhones Have 20 LTE Bands, VoLTE.)

"Apple is only working with T-Mobile in the US," CTO Neville Ray said at Wednesday's event. "They've embraced this stuff, and we're going to move forward together. This doesn't come easy so I have no clue if our competition will replicate it."

The carrier also said that all of its new smartphones will support WiFi calling and texting. It's letting those customers that want to upgrade to a supported phone do so now through its JUMP device trade-in program. And it's offering a new, $25 router for the home that will prioritize voice calls over WiFi in the home and that can replace or work alongside a consumer's existing home router.

Finally, T-Mobile also announced a partnership with in-flight WiFi provider Gogo to enable customers to send texts and picture messages and check their visual voicemail in flight, a service T-Mobile is offering free of charge.

Read up on carrier's WiFi strategies on our dedicated carrier WiFi content channel here on Light Reading.

Why this matters
This announcement is interesting for a number of reasons. For one thing, it's a fine line to walk for T-Mobile, because, by promoting WiFi as a way to extend coverage, it's essentially admitting its LTE network doesn't reach everywhere -- a common complaint, especially in rural areas. (See T-Mobile: Going Bananas for Low-Band.)

CEO John Legere said he's been asked (by a "moron") if T-Mobile is only doing this because its network has problems, and, he says, "I only find one answer, why not? Why wouldn't you do this? Why wouldn't you want the ability to have five bars of connectivity anywhere you are?"

But, as CTO Ray said during the presentation, enabling seamless handover was no easy task. It required a new packet gateway and working with each handset OEM. Interestingly, however, Kineto, which was just recently acquired by Taqua LLC , has been powering T-Mobile's VoWiFi for years now, and Frederick Reynolds, vice president of marketing at Taqua, says that seamless handoff has always been available to wireless operators, they just chose not to do it. (See Taqua Acquires Kineto for VoWiFi Push.)

"We enabled seamless cellular-to-WiFi handover for a number of years with T-Mobile and other mobile operators," he says. "However, with handover comes some tradeoffs, and for the last few years all operators supporting VoWiFi had ceased handover support."

Reynolds said that fewer than 1% of wireless customers really need handoff as most are stationary in their homes or office, but T-Mobile is clearly banking on it being a value add to customers in rural areas, in homes or offices with poor coverage, in the air and internationally.

"Remember, uncarrier moves are permanent," CEO John Legere said today. "They are part of what we believe the industry should do."

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— Sarah Reedy, Senior Editor, Light Reading