T-Mobile is officially the first Tier 1 US operator to go live with voice over LTE, having launched the 4G voice service near its home market of Seattle.
The carrier is beating AT&T Inc. (NYSE: T) by one day in announcing its service is live in Seattle and working on the LG Electronics Inc. (London: LGLD; Korea: 6657.KS) G Flex and the Samsung Corp. Galaxy Note 3 and Galaxy Light via a software update. AT&T plans to launch VoLTE in parts of four states tomorrow, and Verizon Wireless has said it will go live with its 4G voice service with HD voice and video calling sometime in the coming months. (See Verizon's Journey to VoLTE, in Videos and AT&T Confirms VoLTE Launch in 4 States.)
T-Mobile US Inc. -owned MetroPCS was actually the first to launch VoLTE in the US back in 2012, so the carrier might have had a leg up. It will offer VoLTE with HD voice, which it has been providing for 3G calls since January 2013. In a blog post on the launch, T-Mobile CTO Neville Ray wrote the carrier has "been working hard on a LTE Advanced version of VoLTE, which we plan to roll out to more T-Mobile customers throughout the coming year." (See MetroPCS Changes Course on 4G Voice.)
Ray also wrote that the carrier will be the first in the US to use enhanced single-radio voice call continuity (eSRVCC) to ensure calls aren't dropped when its customers move from an LTE pocket to an HSPA+ or 2G area. He called VoLTE a step toward offering a host of rich communications services and additional innovations around WiFi calling in the coming months, suggesting T-Mobile's launch will just include HD voice initially.
After months -- even years -- of delays, VoLTE is finally coming to the US. Sprint Corp. (NYSE: S) is the only operator that has yet to give a solid timeline for deploying its version of the 4G voice technology. (See VoLTE: So Close You Can Hear It and Sprint Taps BroadSoft for VoLTE Transition.)
— Sarah Reedy, Senior Editor, Light Reading