Take them from the Government first!
There is a BUNCH of nice white space between 300MHz and 400MHz. Of course it is used by governments (and their army/navies). What do governments need with radios, don't they all use cell phones or some such. All that nice unused spectrum gone to waste, and they can't use it. Let the FCC/OFCOM sell it off and make money. Surely the military can pay for it.
Yes, all this white space junk is terrible. You need to be in control of ALL aspects of the link to really know if it is compatible. Looking at just one side won't cut it, and never will!!