With Ericsson’s support, T-Mobile U.S. has implemented the Enhanced Voice Service (EVS) next-generation audio codec, which was standardized in 3GPP for VoLTE/LTE networks.
The companies confirmed that T-Mobile provides nationwide EVS support for VoLTE and Wi-Fi calling users, delivering even greater audio quality than current HD voice services, and better call reliability and quality across both T-Mobile’s LTE network and Wi-Fi access.
“With Ericsson’s partnership, we’ve been able to bring better voice reliability and higher fidelity calls to T-Mobile customers in more times and places than HD voice alone could provide. We already have three EVS-capable devices in the market and will have seven by the end of the year,” stated Mark McDiarmid, Vice President Radio Network Engineering and Development at T-Mobile.
https://www.ericsson.com/news/160614-evolved-hd0-voice-for-volte_244039855_c
