Coaxial Cable
Coaxial cable carries signals of higher frequency ranges than those in twisted pair cable. In part because the two media are constructed quite differently. Instead of having two in wires. Coaxial cable has a central core conductor of solid or standard wire ( usually copper) enclosed in an insulating sheath which is in turn encased in an outer conductor of metal foil braid or a combination of the two. The outer metallic wrapping servers both as a shield against noise and as the second conductor which completes the circuit. The outer conductor is also enclosed in an insulating sheath and the whole cable is protected by a plastic cover with this construction and a special insulation and shielding coaxial cable can have high bit rate.
figure Coaxial Cable
In past coaxial cable was widely used in analog telephone networks where a single coaxial network could carry 10,000 voice signals. Latte it was used in digital telephone networks. Where a single coaxial cable could carry digital data up to 600Mbps. However coaxial cable in telephone networks has largely been replaced today with fiber optic cable.
Coaxial cables are categorized by their radio government (RG) rating. Each cable defined by RG rating is adapted for a specialized functions as shown in table below.