The LTE network also carries VoWiFi (Voice Over Wi-Fi). This technology is often mistaken for VoIP (Voice Over IP), which enables calls over the Internet. VoWiFi connects to the radio part of the network via your home Wi-Fi coverage, so it looks like you are simply calling via a standard GSM network. It is mainly used in areas with poor coverage. Just like VoIP, this function must be supported both by your operator and your phone in order to work.