While some of the spectrum held by the military would be useful, most of it wouldn&#x27;t be, same goes for whats currently used for police too. The issue with lower frequency spectrum (say, sub 550 mhz) is it starts to interact with the atmosphere and can result in some off propagation patterns (like tropospheric ducting).<p>I also suspect that the users of that spectrum (save for the military which has a huge amount of lightly used spectrum) might disagree with you as to how useless their technology is, I mean would you take the spectrum currently held for ham radio operators and sell it off?<p>Navigation (GPS) is pretty spectrum efficient, so I&#x27;m not really sure what you&#x27;re getting at there.