https://ka7oei.blogspot.com/search/label/helium%20neon I've contemplated upon using narrow light beams, even modulated lasers, as an STL. However, you'd still have to deal with rain, fog, snow, falling debris, dust clouds, etc. Lines-of-sight is just that. So, a really neat experiment, but not practical for 24/7 data and COMM's delivery, except through Fibre Optic Cables.