Wi-Fi calling allows you to use a Wi-Fi network to make and receive phone calls, rather than using the traditional mobile network. This benefits those in poor signal areas, such as rural villages and underground stations, as you'll be able to harness the power of available Wi-Fi networks to stay connected. It's not just calls that are supported, you can also send and receive texts.
The most appealing service of Wi-Fi calling lies in its simple and convenient, since this service can be achieved without any requirements of application, additional phone Numbers, the contract or additional costs of operators. What we just need to do is to flick the switch on the Wi-Fi calling option in the settings menu of the phone app. A word of warning here, if you start a call on Wi-Fi and then venture outside of your network's range the call won't automatically transfer to your mobile network - you'll get cut off, and vice versa.
Wi-Fi Calling is a technology that allows cellular packets from your phone to be transferred to your carrier over the internet, and injected back into the cellular network as if they'd been beamed over the air. At present, there are many applications and services allow users to make calls via the Internet, although the principle seems to be the same, it still has essential difference. For instance, Skype users use a completely independent Internet number, which is unable to dial an emergency call. Unlike Skype, which let you talk to other people using call forwarding or an internet-based interface, Wi-Fi Calling can support almost any kind of calling way, such as telephone, voice and video. When users in the use of the service, it will not need to change the number, rely on mobile operator network and start any application. Wi-Fi Calling is also distinct from VoIP technology, which lets you use an internet-connected phone exactly as you would a landline. VoIP transfers your voice over the internet to the switched telephone network, whereas Wi-Fi Calling connects your voice to your mobile carrier's network using the internet instead of cell towers.
However, not all the smartphones can support Wi-Fi calling service. Operator EE said that his own Wi-Fi calling service will be compatible with the Samsung Galaxy S6, S6 Edge, and Lumia 640 of Microsoft. At the same time, the iPhone 6 and iPhone Plus, Galaxy S5, and other equipment can also support the services after the operatorí«s update.