I just want to point out there is a distinction between allocating spectrum for certain purposes and selling it to private companies. I would never recommend not having a frequency band restricted to emergency communications, though I admit I'm not informed enough about astronomy to know what is optimal there, but I still feel outright saying "you cannot produce radio waves of <these> frequencies, ever" is a very blunt solution.
My larger point is that we have observed in the last twenty years that while signal congestion can be real, we can also now build radios sophisticated enough to deal with it much better than in the past. Things you cannot have interfered with like air traffic control and emergency broadcasts should absolutely be given their own channels, but technology has improved enough that we can certainly stymie their band allocations they are given today without compromising integrity assuming the use of more capable radios.
But even then, I'm not strongly arguing to do any of that - I think it is possible, but I also don't think its particularly necessary - we could simply de-privatize most of the sold off spectrum to private companies to be used for public communications and in the common interest. Think of the Internet bandwidth over air we could get if we had gigahertz of available channels between the 500 to 5000mhz bands.
My larger point is that we have observed in the last twenty years that while signal congestion can be real, we can also now build radios sophisticated enough to deal with it much better than in the past. Things you cannot have interfered with like air traffic control and emergency broadcasts should absolutely be given their own channels, but technology has improved enough that we can certainly stymie their band allocations they are given today without compromising integrity assuming the use of more capable radios.
But even then, I'm not strongly arguing to do any of that - I think it is possible, but I also don't think its particularly necessary - we could simply de-privatize most of the sold off spectrum to private companies to be used for public communications and in the common interest. Think of the Internet bandwidth over air we could get if we had gigahertz of available channels between the 500 to 5000mhz bands.