Enhanced Voice Services:

Brilliant listening experience via the O2 LTE network

Telefónica Deutschland has successfully implemented the voice standard Enhanced Voice Services (EVS) within its national LTE network. Technically speaking, the new voice standard is a further development of AMR-WB (Adaptive Multi-Rate Wideband): O2 customers in the LTE network can now make calls in excellent Full HD voice quality. With EVS, telephone calls are transmitted much more clearly and naturally than before – EVS transmits the audible frequency range at up to 16,000 Hertz instead of up to 7,000 Hertz as used to be the case. As a result, EVS means conversations are perceived as clearer, more understandable and therefore more natural. Another advantage is that the new codec allows background noise to be suppressed better than before. EVS significantly improves the sound image compared to previous mobile calls.
“With the introduction of Enhanced Voice Services, we will offer customers in our O2 mobile network a unique and crystal-clear Full HD voice quality,” says Cayetano Carbajo Martín, Chief Technology Officer (CTO) of Telefónica Deutschland. “By continuously improving our voice services, we are once again significantly increasing the user experience in our network and taking a further step towards becoming Mobile Customer & Digital Champion.”

EVS depends on smartphone firmware

All O2 customers need for calls in excellent Full HD voice quality is access to the LTE network and a mobile device that supports Voice over LTE (VoLTE) or Voice over WiFi (VoWiFi). In addition, the device manufacturers must have activated EVS in the O2 network via a current firmware update. For example, Samsung already offers a firmware update for the Galaxy models S8 and S8+ in the Open Market version, and Sony offers a firmware update for the models Xperia XZ1 and XZ1 Compact, Xperia XZ Premium, Xperia XZ2 and XZ2 Compact. Other device manufacturers and phone models will follow in the coming weeks and months, so that more and more customers will in the future benefit from the improved voice quality for mobile calls. In general, EVS is available to all Telefónica Deutschland customers. In addition, Full HD voice telephony is also possible across networks to the mobile networks of Vodafone and Deutsche Telekom.

HD Voice for UMTS since 2014

O2 customers are already familiar with improved voice quality from the UMTS network, where “HD Voice” has ensured a noticeably higher transmission quality since 2014 (E-Plus) and 2015 (O2) – with “HD Voice” for UMTS, the frequency spectrum in the audio range reaches from 50 Hertz to 7,000 Hertz. In contrast, classic, older telephone connections only covered the range from 300 to 3,400 hertz.