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Fibre Optic Cable
A cable that communicates through electrical impulses is referred to as a fibre optic cable. These cables contain the
optical fibres that are plastic-coated and utilised to transmit data via light pulses. The plastic coating shields the optical
fibres from the effects of other types of wiring’s electromagnetic interference, heat, and cold. Compared to copper
wires, fibre optic cables offer faster data transmission. There is no electromagnetic interference that affects them.
However, fibre optic cable installation and upkeep are expensive and challenging.
2 cm
High density polyethylene
insulation (17 mm)
Copper tubing (8.3 mm)
Steel wires Water-resistant jelly
1 cm casing 2.3 mm)
Optical
fibers
Do You Know?
• Alexander Graham Bell is credited with creating Twisted Pair cables.
• Coax is another name for coaxial cable.
• In addition to being used for telecommunications, fibre optic wire is also employed by lasers, hydrophones
for seismic waves, SONAR, imaging devices, and sensors for measuring temperature and pressure.
Unguided Media
The electromagnetic waves are transmitted without the need of any physical medium in an unguided transmission. As
a result, it’s also called wireless transmission. Features of unguided media are as follows:
Ð ÐThe signal travels over empty space (air).
Ð ÐSignals can travel through sky propagation, ground propagation, or line-of-sight propagation
Ð ÐThe electromagnetic spectrum used for wireless communication ranges from 3 kHz to 900 THz.
There are mainly three types of unguided media which are as follows:
Radio Waves
Radio waves are electromagnetic impulses that can move in any direction through empty
space. As radio waves are omnidirectional, messages can travel in any direction. Due to
the omnidirectional nature of radio waves, they can be interfered with if another receiving
antenna sends out a signal with the same frequency or bandwidth. The frequency range of
radio radiation is 3 kHz to 1 GHz. In case the transmitting and receiving antennas are not
aligned, so any receiving antenna can pick up the wave that the sending antenna sends.
Microwaves
The electromagnetic wave used in microwave communication has a frequency range of about (1–300GHz). With regard
to sight, electromagnetic waves only travel in one way, preventing any intrusion. Line of sight and communication
between the two endpoints are much simpler to create when the transmission medium is in alignment.
There are two types of microwave transmission which are as follow:
Ð ÐTerrestrial Type Microwave Transmission: Terrestrial Type Microwave Transmission with the propagation of the
microwave, which is primarily used for telecommunication over the air, both antennas are fixed for the signal
transfer on the transmitting and receiving sides.
Basics of Networking 121

