RoV: receiving files from voice calls using dual-tone multi-frequency method

When data service is not available, it is almost impossible for smartphones to receive data files. In this paper, we propose a system, called RoV, which can send data files to a smartphone via voice calls instead of data service. In this system, data files are encoded into acoustic signals by the sender, transmitted to the receiver through the normal voice channel, and decoded by the receiver at the end. There are two main challenges for the...