This document discusses three main types of physical transmission media used in computer networks: twisted-pair cable which consists of two insulated copper wires twisted together and can transmit data via electrical signals; coaxial cable which has a single copper wire surrounded by insulating material and braided wires to transmit data electrically; and fibre optic cable which uses thin glass strands to transmit data pulses of light.

1. CHAPTER 3: COMPUTER
NETWORKS AND
COMMUNICATIONS
Physical Transmission Media

2. At the end of the lesson, student should
be able to:
Identify the various types of cables:
 Twisted-Pair Cable
 Coaxial
 Fibre Optic

3. Twisted Pair Cable
Description:
 Consists of two strands of
insulated copper wire,
twisted around each other.
 Multiple twisted can be
combined into a single cable.
 Can reduces interference from
electrical field.
How signal pass through:
 Transmit data by means
electrical signal

4. Coaxial Cable
Description:
 Consists of a single
copper wire surrounded
by at least three layer
an insulating material,
braided wired, plastic
coating.
How signal pass through:
 Transmit data by means
electrical signal

5. Fibre Optic
Description:
 Consists of dozens or
hundreds of thin strands
of glass that use light to
transmit signal.
 Each strand, call optical
fibre, is as thin as a human
hair.
How signal pass through:
 Transmit data as pulses of
light through tiny tubes of
glass.