Hi, I'm a student of Prof. Anne-Laure. In fact, I've been researching about how to collect SMS data when there is no internet connection. To do that, I learned that we can use Twilio or Asterisk as a SMS gateway. But I'm not sure about how to transfer voice information. Since I'm searching for these kind of technologies, I'll post it later if I find out any information :)
This is so interesting idea! I'm attaching the link about 'a robot that flies like a bird', one of TED talks. It's quite difficult technology but we can get some idea from it. I'm sure there are many DIY drones which are easier to make.