Wi-Fi Calling is a technology that enables a smartphone user to make and receive calls over a wireless internet connection as opposed to the typical cellular connection. In addition to facilitating voice calls, Wi-Fi Calling also supports wirelessly sending and receiving text messages and utilizing higher data speeds than most cellular connections.
The Wi-Fi Calling technology transfers the cellular packets of a phone call or text message from a smartphone so that they are sent over the internet wirelessly, and then sends the packets back to the cellular network prior to being delivered to the recipient party.
Only the sender of a call needs a smartphone that supports Wi-Fi Calling; the receiver can be on a wireless, cellular, or landline connection.
The State of Wi-Fi Calling Support from Cellular Providers
Wi-Fi Calling has gained mainstream attention recently, particularly following the release of Apple’s iPhone 6 and iPhone 6 Plus smartphones, which are the first Wi-Fi Calling-compatible smartphones from Apple.
While not all cellular carriers currently support Wi-Fi Calling, a few have supported it for a number of years, including T-Mobile, which added Wi-Fi Calling support in 2007. Sprint added initial support for Wi-Fi Calling in 2014, and AT&T and Verizon expect to add Wi-Fi Calling capabilities in 2015.
There is concern that Wi-Fi Calling connections can be disconnected when the sender moves between a Wi-Fi and cellular network, and as a result, some cellular providers are looking to complement Wi-Fi Calling with another technology called Voice over LTE (VoLTE) that facilitates seamless handoffs between Wi-Fi and cellular networks.