How to Enable Wi-Fi Calling on iPhone
Most major cellular carrier networks support a feature known as Wi-Fi Calling, and now you can enable wi-fi calling on the iPhone as well.
For the unfamiliar, Wi-Fi calling essentially uses an available wireless network for phone calls to improve the connection quality, rather than relying entirely on the cellular network. The result is generally cleaner and crisper sounding call quality, similar to the difference audibly observed through other Voice Over IP services like Skype and FaceTime Audio.
Read more »