
The technology is based on so-called Enhanced Voice Services (EVS) Codecs, which expand the voice service to the entire frequency range heard by humans of 20 kHz, instead of 7 kHz. The new technology offers better voice quality than HD Voice, according to the "Behind the VoLTE Curtain" study by Spirent Communications and Signal Research Group cited by Vodafone.
Free firmware updates will be made available to customers with supporting smartphones.