I have what may be a considered a silly question but as someone who often visit's people in bad service areas this is something I've always wondered. Why don't phones 'fall back' to a Wifi connection if no cellular service is available?
- Voice calls could go over a 'backup' VoIP service. - Digital service is digital service. It's all packets shuffling around and shouldn't matter whether is a cellular network or IP network.
- MMS is already basicly email that could in theory go over any data network not just the APN.
- SMS is even more basic than MMS, I'm guessing it would be trivial to move messages to an IP based network.
Whenever I plan on visiting someone who lives in a black hole (aka no service), I tell my friends to text my Google Voice number as it goes over Wifi. If they need to call me they can call my Google Voice number which forwards to my Skype In number that runs over VoIP on an Android app.
Is it just a money thing with the carriers? Why make your customers suffer through no or spotty service when you could just move everything OFF your network and on to something more reliable for them?