But you could go even further and use a voice call for telemetry and 3G Data link for video.
Your ground control station would need an internet connection as your data would be coming from your cellular provider over the internet rather then from the phone itself.
I am working on this and I am surprised that more drone builders are not.
Cellular modems are perfect for drones. They have wide coverage worldwide, have high data rates, and are tested and reliable.
I don't like the additional layer of getting the internet into the loop.
Suppose 2 people had a video call, the image and video for sure doesn't get routed through the internet. I attach a gsm module to the laptop and another gsm module to the drone.
So what i am looking at is basically point to point communication of video and data. I would prefer not to have internet access at either end as it seems to be an unnecessary luxury.
When you say "the internet into the loop", do you mean TCP/IP, or the public routed Internet?
Public routed internet is bad. TCP/IP layer should be fine.
The idea of dialing numbers directly without having to figure out IP-Addresses is much more convenient
Even if you use TCP/IP the data is still going to pass through the internet.
Its going to go like this Drone GSM <-> Cell Tower closest to drone <-> Cell Company Server (Internet) <-> Cell Tower closest to ground station <-> Ground Station GSM
So technically you will be connecting through the publically routed internet. But that is a good thing because it gives you options for your ground control station. For example you wouldn't need a GSM module for your ground control station, you could use the regular internet to control your drone too.