How does RescueMe Phone send messages through the earth and rubble without cellular radio?
The basic idea is really simple. The text message is encoded into the timing between hammered pulses sent through the rubble. The message sender enters the message in the same way they enter a text message. The app adds error correction to the message and then beeps and flashes each time the sender needs to hammer another percussive pulse. The rescue professional receiving the message listens for the hammered pulses with either a seismic detector or a sensitive microphone. As each pulse of the message is detected, the receiver of the message taps a button on the application to store the pulse timing.
