Fog is a bigger problem, it says here. (Also heavy snow, per the RONJA link in the other comment.) https://en.wikipedia.org/wiki/Long-range_optical_wireless_co

Fog is a bigger problem, it says here. (Also heavy snow, per the RONJA link in the other comment.) https://en.wikipedia.org/wiki/Long-range_optical_wireless_communication#Extending_the_useful_distance https://en.wikipedia.org/wiki/Long-range_optical_wireless_co... This problem was possibly solved in the ten years since it defeated those four or five startups? Or not solved, who can say.