Voice over wireless LAN is the use of a wireless broadband network according to the IEEE 802.11 standards for the purpose of vocal conversation. In essence, it is voice over IP over a Wi-Fi network. In most cases, the Wi-Fi network and voice components supporting the voice system are privately owned.
Samsung supported Devices for VoWifi:
For Now VoWifi Works only in supported Region (Hyderabad) with Supported ISP only (Act fibrenet).