Communication Media : Coaxial Cable

Coaxial Cables are a group of specially wrapped and insulated wires capable of transmiting data at a very high rate. They consist of a central copper wire (inner conductor) surrounded by a PVC (polyvinyl chloride) insulation over which a sleeve of copper mesh (second conductor) is covered.

The metal sleeve is again shielded by an outer shield of thick PVC material. The signal is transmitted by the inner copper wire and is electrically shielded by the outer metal sleeve. Coaxial cables are extensively used in long-distance telephone lines and in closed-circuit TV.




Advantages
  • They are capable of transmitting digital signals at a very high rate of approximately 10 mega bits per second.
  • They have a higher noise immunity.
Disadvantages
  • These are compariively costly.
  • Such cables can easily be tapped, posing security problems.