[vardump]

Interference is pretty much the only the limiting factor locally for information capacity for any given frequency band. What Artemis is doing is "spacetime" coding signal in such a way constructive interference forms at desired locations.

Part of the "magic" apparently comes from return channel analysis, nothing at all like noise cancelling earphones. This doesn't try to cancel existing interference in any way.

This is a superset of beamforming, a more generic solution with arbitrary positioning. Nothing is ever completely new.

I'm not sure what you mean by wide area systems, but I don't see any reason why the range can't be even hundreds of kilometers, limited just by line of sight and signal attenuation. Roundtrip delay might affect doppler compensation at greater distances.