That's an unfair comparison to cellular though as cellular has its own licenced spectrum with nobody else able to interfere, high transmit power limits and pote

That's an unfair comparison to cellular though as cellular has its own licenced spectrum with nobody else able to interfere, high transmit power limits and potentially a friendlier frequency for the sort of waveguiding you're talking about. That's why I find the smartsky comparison so interesting - because it's a completely level playing field.