Just two months after activating Voice over LTE (VoLTE) in its first market (the Seattle area), T-Mobile announced the availability of VoLTE across its entire U.S. LTE network, which now covers 233 million Americans in 325 metro areas. The rollout uses Enhanced Single Radio Voice Call Continuity (eSRVCC), a new LTE Advanced function.
T-Mobile’s VoLTE is currently supported on LG G Flex, Samsung Galaxy S 5, Galaxy Light and Note 3 devices. The company said that more than 2.8 million VoLTE-capable devices are already on its network, and that customers have made more than 52 million VoLTE calls to date. For HD Voice, T-Mobile US uses a 23.85 Kbps voice codec rate.
In May, Neville Ray, Chief Technology Officer at T-Mobile, said VoLTE would reach nationwide status by the end of the year.
T-Mobile is also aggressively rolling out Wideband LTE, which the company defines as at least 15+15MHz. Wideband LTE is already in 17 metro areas. T-Mobile expects at least 26 total metro areas will be up with Wideband LTE by the end of the year. The carrier is also starting to roll out its new low-band 700 MHz A-Block spectrum. Wideband LTE enables peak network download speeds up to nearly 150 Mbps.
http://newsroom.t-mobile.com/issues-insights-blog/firing-on-all-cylinders-earnings-jdp.htm
In July, Mavenir Systems confirmed that T-Mobile US’ recent VoLTE launch was enabled using Mavenir’s converged IMS voice solution, which was first deployed to launch Wi-Fi Calling in 2011. T-Mobile leveraged those early investments in Wi-Fi Calling to accelerate network readiness and launch VoLTE service.
Mavenir provides the end-to-end IMS solution including key IMS components such as the CSCF (Call Session Control Function), Session Border Controller (SBC), Telephony Application Server (TAS), as well as professional services to perform verification and integration testing to ensure successful end-to-end service interworking.
