5. Copper cable

One of the key things that determines bandwidth is the physical nature of the cable being used.

A signal becomes weaker the longer it travels along a cable, eventually becoming so weak that it is no longer detectable above natural noise. Therefore the length of cable determines the bandwidth of the link.

For instance the bandwidth of broadband to the home is determined by the length of copper cable between the house and the nearest telephone exchange. This is the so called 'last-mile' bottleneck.

Coaxial cable

This consists of a solid copper core surrounded by insulation which is then surrounded by a copper shielding and finally covered with a plastic sheath. Coaxial cable is widely used for television wiring as it has enough bandwidth to handle a television signal over a typical run from antenna to television..

Early computer networks also used coaxial cable with a bandwidth of 10Mbps. But for high speed networks (100 Mbps and above) coax cable is no longer sufficient, twisted pair has become the norm.