There appear to be at least 1 reasonably high-res (500+ px vertical res) live video stream being transmitted from both the SpaceX F9 first and upper stages all the way up into LEO throughout their launches.
What system of transmission is being used? Which band is used? Where is the transmitter? Is there an external antenna? Where is/are the receiver(s) located?
It seems to transmit mostly uninterrupted video from launch and halfway around the Earth. How do they do it?