Just what does Wi-Fi calling bring to the table? This happens to be a feature which will allow calls to be placed over a wireless connection whenever there is very little or extremely poor cellular connectivity, such as when you are in an elevator or in a basement, making it work pretty much in the same vein as that of an AT&T M-Cell. It also has similarities to Apple’s very own FaceTime Audio feature, where it will route calls over a Wi-Fi connection.
If you would like to activate Wi-Fi calling, just head to the Phone section of the Settings app, and hit the Wi-Fi calling feature toggle. Go through all the no-brainer steps listed there, and you should be able to enjoy Wi-Fi calling on the iPhone 6, 6s, 6 Plus, and 6s Plus which run on iOS 9 in double quick time. [Press Release]