MEDIUM

LEARNING OUTCOMES

3.2.2 Medium • Identify various types of cables such as

Unshielded Twisted Pair (UTP), Shielded Twisted Pair (STP), Coaxial and Fibre Optic Cable.

• Identify various types of wireless transmission media such as infrared, radio wave and satellite.

PHYSICAL TRANSMISSION MEDIA

CABLES AS A PHYSICAL TRANSMISSION MEDIUM

• Cables are used as a physical transmission medium. There are three types of cables used in transmitting electrical messages. They are:

• Twisted-Pair Cable - Two insulated copper wires that are twisted around each other. Each connection on twisted-pair requires both wires.

• Coaxial Cable - A cable consisting of a conducting outer metal tube that encloses and is insulated from a central conducting core, used primarily for the transmission of high-frequency signals.

• Fibre Optic Cable - Glass fibre used for laser transmission of video, audio and/or data.

Various types of cables

• Unshielded Twisted Pair (UTP),

• Shielded Twisted Pair (STP),

• Coaxial

• Fibre Optic Cable.

UTP and STP

Twisted-Pair Cable

• - Two insulated copper wires that are twisted around each other. Each connection on twisted-pair requires both wires.

• Two types of twisted-pair cable

1. STP

2. UTP

COAXIAL

Coaxial Cable

• - A cable consisting of a conducting outer metal tube that encloses and is insulated from a central conducting core, used primarily for the transmission of high-frequency signals.

FIBRE OPTIC

Fibre Optic Cable

• - Glass fibre used for laser transmission of video, audio and/or data.

TRANSMISSION MEDIA

TWO BROAD CATEGORIES

1. Physical transmission media

2. Wireless transmission media

Physical Transmission media

• Refers to material substances that can propagate waves and energy.

• waves are guided along a solid transmission medium.

• Example1. connect PC to printer using parallel port or USB port.

2. connect PC to the same phone line for internet.

3. connect PC to PC using untwisted-pair cable

Wireless Transmission media

• Means data communication between network devices without using cables or cord, but by using radio frequency or infrared waves.

• Method of communication that uses electromagnetic waves rather than wire conductors to transmit data between devices.

• Waves are unguided and the transmission and reception are by means of antennas.

Cont… Wireless Transmission media

• Wireless data transmission is categorised into short, medium, and long range data transmission.

• Example:

short range – bluetooth, infra red

medium range – WiFi or Wireless LAN

long range– 3G