I put a mobile phone on the plane, used wifi and flight control connection to transmit data, and then sent it to my own simple server, so I had a data link. Then installed the remote control software on the mobile phone. And added a USB camera. This results in the transfer of the image. Then you can fly wherever there is internet. After my many tests. The signal stability of mobile phones is the best. Compared with some other development boards or 4G modules. The phone is not easily disconnected. Other modules easily drop out and cannot continue to connect.
https://youtu.be/geC9FtZAJwo