2. We are the students of Asansol Engineering
College very grateful to the teachers of Asansol
Engineering College for their continuous support in
completing our presentation. We are especially
very thankful to all faculty without whose help we
could not have finished this presentation. We
express our sincere gratitude to Mr. Sambhit
Sunder Mandal who gave us the opportunity to
participate on this project, and for guiding us and
pursue us to finish this presentation.
3. Introduction
What is transmission media?
Classification of transmission media.
Guided media
• Twisted Pair Cable
• Coaxial Cable
• Optical Fibre Cable
Unguided Media
• Microwave
• Infrared
• Radio wave
4. Computers and other telecommunication devices
use signals to represent data. These signals are
transmitted from one device to another in the form
of electromagnetic energy, which is propagated
through transmission media.
Transmission media is a path through which data
is transformed from one place to another. It is
broadly divided into guided and unguided media.
Guided includes twisted pair cable, coaxial cable,
optic fibre cable. Unguided media includes
microwave ,infrared, radio wave communication.
5. • The means through which data is transformed from one
place to another is called transmission or communication
media.
6. Guided media
Guided media provide a physical path along which the signals
are propagated .It is also called wired media or bounded
media.
Twisted Pair Cable
Coaxial Cable
Optical Fibre Cable
Unguided media
Unguided media employ an antenna for transmitting through air,
vacuum, or water. It is also called wireless media or unbounded
media.
Microwave.
Infrared
Radio waves
7. Twisted Pair Cable
• A twisted pair consists of two conductors(normally copper),each with
its own plastic insulation ,twisted together.
• One of the wire is used to carry signals to the receiver ,and other is
used only as a ground reference. The receiver uses the difference
between the two levels.
• The number of twists per unit length determines the quality of the
cable ,more the twists better is the quality.
Types of twisted pair
cable:
• Shielded Twisted Pair
Cable(STP)
• Unshielded Twisted Pair
Cable(UTP)
8. Shielded Twisted Pair Cable:
STP, a type of copper wiring in which each of the two copper wires that are
twisted together are coated with an insulating coating that functions as a
ground for the wires. The extra covering in shielded twisted pair wiring
protects the transmission line from electromagnetic interference leaking into
or out of the cable.
Unshielded Twisted Pair Cable:
Short for unshielded twisted pair, a popular type of cable that consists of two
unshielded wires twisted around each other. Due to its low cost, UTP cabling
is used extensively for local area network.
9. Coxial Cable:
Instead of having two wires ,coax has a central core conductor of solid or
stranded wire (usually copper) enclosed in an insulating sheath,which is in
turn cascaded in an outer conductor of metal or braid or combintion of two.
Applications:
• The use of coxial cable
started in anolog
telephone networks later
it was used in digital
telephone networks.
• Cable TV networks .
• Ethernet LANs.
10. Optical fiber cable :-
An optical fiber is a hair thin cylindrical fiber
of glass or any transparent dielectric medium
which is used as a wave guide for optical
communication
11. Working principle :
It is based on the principle of total internal reflection. When
light traveling in an optically dense medium hits a boundary
at a steep angle (larger than the critical angle for the
boundary), the light is completely reflected back.
12. Microwave:
Microwaves are a form of electromagnetic radiation with wavelengths ranging from
one meter to one millimeter; with frequencies between 300 MHz (100 cm) and
300 GHz (0.1 cm).
Used in WLAN, Cellular Phones, Satellite Networks.
Infrared:
Infrared signals with frequencies from 300 GHz to 400 THz(i.e. wavelength
from 1mm to 770 nm) can be used for short range communication. Infrared
signals ,having high frequencies, cannot penetrate walls . It can be used to
transmit digital data with a very high data rate.
Radio Waves:
An EM waves ranging in frequencies in between 3KHz and 1 GHz are
normally called radio waves . Radio waves ,particularly those waves that
propagate in sky mode, can travel long distances . It can be used for long
distance broadcasting such as AM radio.
13. Transmission media lie below the physical layer. A guided
media provides a physical conduit from one device to
another. Twisted Pair cable , coaxial cable ,and optical fibre
cable are the most popular types of guided media.
Unguided media (usually air) transport EM waves without
the use of physical conductor. Wireless data are
transmitted through ground propagation, sky propagation
and line of sight propagation.
