He probably means Adaptive Multi-Rate Wideband (AMR-WB) [1], AKA G.722.2. There is a common misconception that it is VoLTE only, but actually it works pretty we

He probably means Adaptive Multi-Rate Wideband (AMR-WB) [1], AKA G.722.2. There is a common misconception that it is VoLTE only, but actually it works pretty well on 3G too. It is night and day compared to legacy codecs. 1. https://en.wikipedia.org/wiki/Adaptive_Multi-Rate_Wideband https://en.wikipedia.org/wiki/Adaptive_Multi-Rate_Wideband