1. Presentation Of Communication
System
Topic:-
Transmission media
Submitted to :-
Sir Mohsin bhatti
Submitted by :-
Muhammad Uzair Rasheed
2009-CPE-03
UCE&T BZU MULTAN

2. Transmission Media
The means through which data is transformed from
one place to another is called transmission or
communication media.
Types
Guided Media
Twisted Pair
Coaxial Cable
Optical Fiber
Unguided Media
Radio waves Transmission
Microwave Transmission
Infrared Transmission
Laser Transmission

3. Guided Media
Guided Media is that contain some conducting material
to carry data or signal. Many types of cable and wires
fall under this category. Each of them has its own
characteristics like transmission speed, effects of noise.
Guided media is also known as wired media. In this we
will use wires to send our data from one place to other
place.
Unguided Media
It does not contain the signal in some physical conductor
or metal. Rather, it transport electromagnetic signal
through air. It is also known as wireless media. Because
in this we are not using any kind of cable.

4. Guided Transmission Media
 Twisted Pair
 Coaxial cable
 Optical fiber
Twisted Coax
Fiber
Pair Optics
1Khz 1Mhz 1Ghz 1Thz 1000Thz
Frequency

5. Twisted Pair
Pair of copper wires constitutes a single communication
link . Twists minimize the effects of electromagnetic
interference
- emit less energy
- less susceptible to energy

6. Unshielded and Shielded TP
Unshielded Twisted Pair (UTP)
 Ordinary telephone wire
 Cheapest
 Easiest to install
 Suffers from external EM interference
 Shielded Twisted Pair (STP)
 Metal braid or sheathing that reduces
interference
 More expensive
 Harder to handle (thick, heavy)

7. Coaxial Cable
Shielded, less susceptible to noise and attenuation
than Twisted Pair.

8. Coaxial Cable Applications
 Most versatile medium
 Television distribution
 Cable TV
 Long distance telephone transmission
 Can carry 10,000 voice calls simultaneously
 Being replaced by fiber optic
 Short distance computer systems links
 Local area networks
 More expensive than twisted pair, not as
popular for LANs

9. Optical Fiber
Core: Thin strands of glass
Cladding :Glass with different optical properties than
core.
Jacket: Plastic/Insulation

10. Unguided Media
Radio waves Transmission
•The Radio waves have frequencies between 3khz
and1Ghz
•Radio waves can penetrate buildings easily, so that are
widely use for communication both indoors outdoors.
•They also absorbed by rains
•At high frequency, radio wave
tends to travel in straight line
and bounces off the obstacles.

11. Micro waves Transmission
•Micro waves electromagnetic waves having frequency
between 1 GHZ and 300 GHZ.
•There are two types of micro waves data
communication system :
• terrestrial and satellite
•Micro waves are widely
used for one to one
communication between
sender and receiver,
cellular phone,
satellite networks and
in wireless LANs.

12. Infrared Waves
•Electromagnetic waves having frequencies from 300
GHz to 400 THz are called IR waves or Infrared waves.
•IR waves are used for short range communication and
use line of sight propagation.
•Infrared waves cannot pass through solid objects, like
walls and be easily contained in a room.
•They are cheap, easy to build and do not require any
government license to use them.

13. Laser Transmission
•This type of transmission use thin laser to transfer data
up to few kilometers.
•Laser beams are unidirectional, therefore this type of
transmission system use line of sight propagation.
•In such a transmission system, a photo detector and
laser is set on both sender and receiver side.
•Such a system offer very high band width at a very low
cost.
•The major problem in
this transmission
system is that laser
beams cannot
Penetrate rain or
thick fog.