Probably also coming soon, very high PGs wherein the codes, bandwidth and frequencies quickly hop according to a shared secret between the drone and its controller. This combination is being explored for possible Next Generation military comms.
It is said that this is already in public knowledge and operation within SDR community. Though instead of the conventional "bandwidth and frequencies", all the observer sees on their spectrum is random noise, let's say across entire spectral ranges... from start freq to end freq of entire frequency range of ATSC / WiFi / Cellular / FM / Etc allocation space... more generally, across entire start to end of whatever capability range of the tx / rx hardware in use. And where a pre shared or negotiated key is used to impart or mask data into, and out of, the noise. It's not even that these may have, or be, waveform carriers, as the noise may be spark gaps driven, impulse / transform function generators, etc. And the difficulty in triangulating such noise, ie: how exactly does one lock onto random energy, the galactic radiation problem, from everywhere and nowhere. Post links to your favorite papers on these topics.