We have spent the past six years working with the New Zealand Red Cross to create a solution. We call it the Serval Mesh, and it is free software that allows smart-phones to communicate, even in the face of catastrophic failure of cellular networks.
It works by using your phone's Wi-Fi & bluetooth to communicate with other phones in your vicinity. Or even by forming impromptu networks consisting only of mobile phones. Mesh communications is an appropriate technology for complementing cellular networks. Think of it like two-way radio or CB radio that has been propelled into the 21st century. For long-range communications you will still need to make use of cellular or fixed telephone networks
or the internet.
This software allows you to easily make private phone calls, send secure text messages and share files in caves, in subways, in the Outback, in Australia or Africa, in Europe or the United States -- even when cellular networks fail or are unavailable.
You can also keep using your existing phone number on the mesh, which is really important in a disaster when people are trying to get back in contact with each other.
* Is completely open and open-source; free for all
* Can be carried and activated in seconds by those who need it when it is needed
* Is carrier independent
* Can be installed during an emergency from only one phone
* Is distributed in nature making the network resilient
* Can use your existing phone number
* Encrypts mesh phone calls and mesh text messages by default
* Can distribute pictures, videos and any other files