The TED system has been great for us. Transmitting USB would be a new twist. Ethernet should not be too much of a problem using an ethernet to serial adapter or serial server. There are some very good ones out there and we have used serial adapters and serial servers from B&B Electronics. As far as some other devices, as John suggests, I am not familiar with any devices that would accomplish what you are trying to do. The problem with most devices is that they operate in the 900MHz, 2.4GHz or 5.8GHZ range. The 900MHZ might get through the trees but hills would be another problem. From what you describe, I would not even try 2.4GHz or 5.8GHz as they tend to be more 'line of sight' or short distance through obstacles. One major advantage of the TED's is that they operate in the 433MHZ range where trees and hills are less of a problem. The TED 400 units have an antenna connector on the top of the unit so you could put a directional antenna on the unit to increase the range or help overcome the obstacles. I would recommend just trying a pair of units between your locations to see if the units will work. If the units work then I would look at interfacing your USB or ethernet to them.