All the wifi stuff like that is in the public spectrum in the us. Only regulatory requirements are for towers and things of that nature.

You can also setup repeaters in a similar fashion to make it work. An old radio tower from ebay or a telephone pole in a field with a couple units, a battery, and a solar panel creates the link just as easy. The WISP I worked for around 2010 did this to bounce a signal about 15 miles over some rough terrain and a military base. They provided free internet for the land owner to do it.