This should not be a huge problem
In the US at least, the 5GHz band in only legal indoors.
The FCC has approved the first crop of LTE-U base stations for sale in the US, a move aimed at opening unlicensed spectrum space to boost broadband speeds. The US comms watchdog said that Ericsson and Nokia have been cleared to begin offering base stations that use a portion of the 5GHz band to move LTE wireless broadband data …
So all the WISPs using Cambium, Ubiquiti, Mimosa and Mikrotik 5ghz gear are doing so illegally? I don't think so. This is a sad decision for these small innovative businesses as the LTE-U will undoubtedly cause issues. End customers will just end up having less choice and paying more to the usual big telcos
It's legal for Wi-Fi use indoors only - this is usually buried in the small print - of course the signals can/do leak outside the building but most walls have a decent attenuation at 5GHz. I've just returned from a convention at San Antonio - the convention center Wi-Fi was all 5Ghz, nothing in the 2.4GHz band at all.