TYPES OF CABLES

1.TWISTED PAIR CABLES
2.CO-AXIAL CABLES
3.OPTICAL CABLES


TWISTED PAIR CABLES

Cables having twisted pairs of wires are called twisted paired cables.
These cables are of two types:

UTP (unshielded twisted pair) cable
-this cable is not shielded and hence it is sensitive to external electrical interference
or EMI (electro-magnetic interfernce

-it is cheap and widely used in local area networks.

-UTPs are available in different categories-cat5,cat5e,cat6 and cat7
(cat=category,e=enhanced)

STP (shielded twisted pair)
-this cable is shielded and hence it is less sensitive to external electrical interference or EMI.
-this cable is expensive and not widely used.

WHY WIRES ARE TWISTED IN TWISTED PAIR CABLES ?

Twisting help in stopping electrical interference from the wires to each other. In other words,twisting help in
stopping cross-talk.



CO-AXIAL CABLE

Cable used in cable TV is co-axial cable. It has two conductors.One conductor is in straight copper wire and
the other conductor is in wire mesh.Both the conductors share the same axes.

Co-axial cables are rarely used now-a-days in networking.
Co-axial cables are available in different ratings

RG-8      (THICK CO-AXIAL CABLE)
RG-58     (thin co-axial cable)

RG-59      (used in cable TV)

(RG = Radio Grade)

OPTICAL CABLE

Optical cable contains optic fibres. A optic fibre is very thin and it can carry light to transmit information from one
PC to another.It is mainly used in Metropolitan area networks.
Optical cable only use light to transmit data and hence they are not sensitive to external electrical interfernce or EMI.
They are used in long distances.

Media converters(MC) are used to install optical cable. A media converter converts light into electricity and vice-versa.