The old light tower that’s been turned into a bed and breakfast off the coast of NC uses a small satellite dish to pull and internet signal from a tower on the mainland over 40 miles away.
Frying Pan Tower. The guy who owns it has the instructions set-up somewhere online.
I doubt that is possible without a booster. The home use routers are in mw. Most less than 500mw.
Now this is a current good choice:
EnGenius 11n 2.4GHz Wireless Ethernet Bridge/Access Point (ENH202)
https://www.amazon.com/EnGenius-2-4GHz-Wireless-Ethernet-ENH202/dp/B006M1PKWY/
That is complete unit with built in long range antenna and weather proof enclosure. Far cry from my home brew that is 10 years old.
Here are the FCC standards now:
https://www.air802.com/fcc-rules-and-regulations.html