+ 1 Votes Powerline adapters wjal1 1 year ago At 120 meters, you are just beyond the specification for ethernet cable. If you have power in each building, I would try a pair of powerline adapters. They should work even if the service is on 2 different meters, as long as they are serviced from the same pole transformer. If there is no power in the second building then perhaps you can run power out through the trench, and then use the powerline adapters. As for wi-fi, the higher frequencies like 2.4GHz and 5GHz are not effective without line of sight, but 900MHz equipment should work well enough at 120M.