The biggest factor in selecting a communications systems is understanding the amount of data you want to ship. Basic 360*540 10 fps video is a lot different from full 4kHD at 30 or 60fps. Is the received signal for just kick?, or for security or a HQ public broadcast? all have very different requirements for quality and stability, hence radio bandwidth and power.
All radio systems, even ultra high bandwidth point to point microwave systems as used by the TV ENG trucks suffer fade or dropouts, hence they tend to forward buffer like crazy. This problem is exponentially worse of either the transmitter or receiver is moving. The problem with using the 4G network is that the antennas are designed (polarised) to look down to the earth, and not up. Some signal is usable at elevation, but again what is your expected operating ceiling.
My feeling is a dedicated (and approved) narrow band digital radio link, probably with a omnidirectional antenna on the plane and a tracking directional yagi on the ground. Encoding and using one of the common digital video standards designed for unstable links.
This is how the racing cars, F1 and Red Bull Air races track their vehicles/planes.
Small light aircraft are also notorious for high levels of RFI due to engine ignition and low tech radio systems. Thorough screening, RFI design and yes FCC.CAA, UKCAS approval is essential. With the exception of a mobile phones (and thats unclear), its generally illegal to operate any form of radio transmitter on any aircraft, and even then within proximity to controlled airspace.
..the only thing worse than a stupid question is a question not asked.