FCC Part 15 allows for intentional radiators and is the basis for WiFi. With directional antennas, one can make a P2P link that reliably exceeds 10km. A world r

FCC Part 15 allows for intentional radiators and is the basis for WiFi. With directional antennas, one can make a P2P link that reliably exceeds 10km. A world record has been set at 381km [https://www.wired.com/2007/06/w-wifi-record-2 https://www.wired.com/2007/06/w-wifi-record-2] but I don't know if the power level into the antenna was low enough to be Part 15 compliant. In college, I set up a 40km link with compliant power and antenna gains (using offset feed Primestar satellite dishes), and we use Part 15 compliant P2P wifi in St. Louis for our ham radio repeater control and data network with links between 2 and 5km.