Spectrum can be freed up for other uses, and people continuously make better modulation techniques to make better use of the spectrum. And there's already a lo

Spectrum can be freed up for other uses, and people continuously make better modulation techniques to make better use of the spectrum. And there's already a lot of ISPs that provide point to point wireless links. You get an antenna, hook it up outside your office building, point it at the radio tower of the ISP.