I just got a new gallexy S4 through AT&T, new contract. I had T mobil before and on my t mobil I had Wifi Calling which was great. The app when using the phone, if picking up Wifi would connect your calls through wifi when you have a weak 4G signal so you don't drop calls. I am having trouble finding this app to work with the S4. Does anyone know of this app for the S4 & or AT&T. The only one I have found so far wants you to use their software for dialing your calls. The app I had before just works with your wifi but you still use all he phones software. I can't find this. Help!! I'm in a basement appartment and really need this app.
T-Mobile's Wi-Fi Calling uses a technolgy called UMA (Unlicensed Mobile Access)/GAN (Generic Access Networks) which allows seamless transitions from carrier WANs (Wireless Area Networks: GSM/HSPA/etc) and LANs (Local Area Networks: Wi-Fi/Bluetooth/etc). T-Mobile's Wi-Fi Calling works by connecting and registering your device on T-Mobile's core network. Upon authentication, T-Mobile routes carrier data (calls, text messages, etc) over Wi-Fi to T-Mobile's core network, and routes it via their wireless network outside of Wi-Fi. In order for your device to determine which route to take, it requires specialized hardware and software, which is why only certain T-Mobile branded phones are capable of Wi-Fi Calling. Due to AT&T's lack of UMA/GAN support, their phones don't have the necessary hardware/firmware.
You could consider investing in an AT&T MicroCell, if it's available in your area. The MicroCell, rather than your phone, is connects to your home-internet connection and registers on AT&T's core network. Similarly to T-Mobile's Wi-Fi calling, it routes all data over your home internet connection, but unlike T-Mobile's Wi-Fi calling, it emits a cellular signal to increase in-home coverage.