Do you have issue with reception of mobile signal when you want to call your friend or someone else? Some people also have this kind of issues in their homes. However there is the solution called WiFi calling 🙂
How does it work? This technology is similar to VoLTE (VoIP over LTE), however it uses WiFi instead of LTE as the access technology. You can say that you have something like that already, because you have used Skype. Unfortunately, you are wrong, because Skype is the third part application and both callers have to use the same program. In case of WiFi calling this is transparent and you can call everyone (even stationary phones).
It look very interesting, does not it? What are requirements? The most important aspect of this technology is the security. Therefore the mobile phone has to establish encrypted connection (tunnel to be precisely) with the IMS (IP Multimedia Subsystem) – it is something like VoIP gateway/server in the carrier core network. The encryption is provided by IPSec technique, because WiFi access point is entrusted element of the network. And here is the catch…
As you might have guessed, not all mobile phones support this technique. Currently WiFi calling is supported by the HTC One M9, Samsung Galaxy S6, Galaxy S6 Edge, Galaxy S5, iPhone 6, 6 Plus, 5S, 5C and Microsoft Lumia 640. Also this technique is currently under tests in many European mobile networks.