If there were a band of legitimately useful long range spectrum that was a free for all, wouldn't there be a strong economic incentive for people to invent modulation techniques capable of functioning effectively in such a noisy environment?
Alternatively, wouldn't it be conceivable for transmitting nodes to cooperate with one another to send transmissions. For example, if N nodes all transmit encrypted content on the same band to M receivers, then the signals of all but one of those N transmitters look like noise to each of the M receivers, thus limiting the transmission rate achievable over any given channel. If instead of that approach, what if a transmitter instead used a second frequency solely for the purpose of coordinating transmissions with the other nodes so as to minimize interference which each other. In addition to coordinating when they are or are not transmitting, couldn't they selective choose different modulation techniques that are easily distinguishable from one another, and thus transmittable simultaneously.
Feel free to educate or correct me here. I know very little about this domain.