Some form of Ubiquiti Nanostation. They are good for miles on line of sight, and far simpler, cheaper and quicker than trenching. How many trees are in the way? While they run on wifi frequency ranges (2.4/5 GHz), they can handle the traffic of numerous cameras. While they have IP addresses, they are basically like an Ethernet cable to the cameras. You install a POE switch to feed the cameras and connect it back to the Nanostation. I have a pair and they work great. And, if you have more than one location you are running to, I THINK you can have one station at the house talking to several remote stations.