While some of the spectrum held by the military would be useful, most of it wouldn'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).

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?

Navigation (GPS) is pretty spectrum efficient, so I'm not really sure what you're getting at there.

I wasn't referring to GPS, but to things like 4.3GHz +/- 100MHz for radio altimetry.

I think theres plenty of useful spectrum to go around between 2.4GHz and 5.8

All the legacy nonsense needs to be ruthlessly eliminated. People claim frequency auctions are efficient but that's clearly not the case if you are only auctioning .1% of whats useful and allocate the remainder to waste on a free cost basis.

I think perhaps for home broadband (read wifi) use sure, we could free up another 200 mhz easy - as replacement for mobile broadband.. you wanna look between 600-1900 mhz there, anything much above 2.5 is too high (read expensive) to build a mobile network with because of site spacing.

Much of what's in that band is allocated for point to point microwave and satellite, I'd also caution you, one mans 'wasted spectrum' is another 'vital important service' both of which can be technically correct at the same time.

What bands are you talking about? The spectrum map doesn't seem to show the wholesale wasting of spectrum you seem to imply, especially in the GHz range which is most useful for cell phones et al.

As you mention police, I'll also point out public service frequencies (Part 90) recently went to 12.5kHz bandwidth (half what hams use) and there is discussion of going even further.

The really legacy allocations like broadcast TV, AM radio, and radionavigation are in spectra that Johnny Startup probably isn't interested in. Data rates are pretty slow at 30kHz.

> The bandwidth-specific value we're getting from the ISM bands dwarf nearly all other uses.

This is totally true! And it was a "junk" band to begin with. What if they allocated another unlicensed band that had room for 3-4x as many exclusive 802.11 channels as the current one?

Or better yet add them to the unlicensed pool.