I would have thought you would have laser comms and radio transmitters aplenty. I envisage you have a mini -Parkes setup at home
Cat cabling is easy just make sure you wire correctly before crimping, the connectors are usually the weak point with all cables. I could lend you my kit if you like to test/repair what you have. (message me, I have bag with crimping tool, cable tester and male ends). Too fiddly for me one handed now. My cables have never failed, and I agree with Martin on good luck with Chinese cables made with lowest grade recycled copper etc. You really should put in a permanent length shielded (electrically) and insulated (thermally) to a switch at each end where you can run lengths as needed and replace easier. Its worth sourcing better quality components to have a lasting reliable run. Running on a fence I would be wary of with fences getting induced currents and lightning discharges on their lengths. Plus many people use fences as earths too from their mains so personally I would find shielded cabling for my paranoia. I've forgotten so much about electrician stuff I dont know if baluns or similar at intervals along tthe run would provide protection from interference. There are likely optic fiber options for this sort of thing: a long run with a terminal at each end to wire in LANs.