This is used ever-increasingly in long distance lines. Fibre Optics is the transmission of light along a reflective glass or plastic fibre. This medium allows a large amount of data to be passed when compared to copper wire. One additional advantage is that fibre optics are far less affected by electromagnetic interference. The glass fibres need more protection than copper.
Installation is extremely labour intensive.
In order to limit crosstalk or electromagnetic induction between pairs of wires, two insulated copper wires are twisted around each other. Each signal on twisted pair necessitates both wires. The Unshielded Twisted Pair is by far the most frequently used form of copper telephone wiring. Twisted Pair is the typical copper wire that connects both home and business computers to the telephone company. Despite the fact that Twisted Pair is normally linked with home use, a higher grade of Twisted Pair is often used for horizontal wiring in LAN installations mainly due to it being cheaper than coaxial cable.