Fundamental Ideas

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Fundamental Ideas
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What is Communication ??
Exchange Of Information
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What is Communication??
Exchange Of Information
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THE MILLION DOLLAR 'Q' "WHAT IS
TELECOMMUNICATION"
Transfer of information from one place to another
I get it !!!!!!!!!!!! My Information.
Audio Video Data Signal
Transmission Medium
Source
Destination
Free Space Copper Fiber Optic
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How to transfer information??
Through Some Carrier
Some carrier is required to carry information
over long distances. Why???
Limitation Information cannot go beyond certain
distance without the aid of a carrier
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Carrier

• Should be capable of carrying information
• Can take it through long distance
• Should have good speed
• Which is the most suitable carrier??

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Electromagnetic Wave

• Highest Known speed 3x108m/s
• Can carry any information through modulation
• Energetic - Can go through long distance
• Supports multiple media Eg Free
  space/Copper/Fiber etc..

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Electromagnetic Wave

• In electromagnetic wave electrical and magnetic
  fields vary harmonically
• Harmonic oscillations at atomic level gives
  oscillating electric field
• Electromagnetic wave generation

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Relation between electric and magnetic field
Changing electric field gives rise to changing
magnetic field vise versa (Perpendicular) So
in electromagnetic wave electric and magnetic
fields oscillate perpendicular to each other and
electromagnetic energy transmits perpendicular
to both
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Figure of a
wave Wavelength distance travelled in one
cycle(l) Frequency Number of cycles per
second(n) Velocity(v) l x n
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Electro Magnetic Spectrum
Velocity of all the electromagnetic wave is same,
3 x 108m/s
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Block Diagram of a Telecommunication System
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Media..
What is the other thing required apart from
carrier for transmitting signals over longer
distances?? Some medium for carrying signals
from transmitter to the receiver
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Different types of media used for transmitting
signals.

• Wired Twisted Pair
• Co-axial cable
• Optical fiber
• Wireless(Free space/air)Microwave
• 
  Satellite

Rx
Tx
Carrier
MEDIA
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Twisted Pair

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Twisted Pair

• Twisted pair is made of two copper wires which
  are covered by plastics or materials that are
  similar
• The insulated wires are twisted to form the
  communication line,the purpose of twisting the
  wires is to avoid electrical interference
• Twisted pair can be combined into a cable that
  may consist of two,four,fifty or hundreds of
  pairs
• Twisted pair is the basis of transmission
  media(Telephone)

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Coaxial Cable
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Coaxial Cable

• Coaxial cable contains two conductors which are
  insulated from one another
• The inner conductor is covered by the dielectric
  and the outer conductor is covered by a shield
• Coaxial cable has many applications,for instance
  cable TV,local networks,short run computer system
  links and long distance telephone transmission
• In local network coaxial cable can support
  different type of traffic and data
• By using FDM,it can carry more than 10,000
  channels at a time

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Optic Fiber
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Optic Fiber(Physical Appearance)
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Optic Fiber

• Optic fiber is made up of 3 parts
• Core,Cladding and jacket
• The inner most part is the core which contains
  one or more thin fibers that are made up of
  plastic or glass
• Each of the fiber in the core is covered by a
  cladding which has different optical properties
  from the core
• The outer most part of the optical fiber is made
  up of plastic or other materials ,which is called
  the jacket

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Optic Fiber

• Because of greater performance and higher data
  rate,the application of optic fiber has
  dramatically increased in long distance
  communication and military applications

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Microwave
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Microwave

• In terrestrial microwave transmission a pair of
  towers mounted on top of the towers will transmit
  signals through air
• Microwave antennas are equipped in higher place
  in order to achieve better transmission effect
• Voice transmission,television transmission and
  the short point to point links will be the major
  application of microwave transmission

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Satellite Communication
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Satellite

• A satellite consists of several transponders
  which receive signal from one frequency
  band,this action is called uplink
• The satellite will amplify or repeat the signal
  to other frequency band,this action is called
  downlink
• A satellite link is called a microwave link
• The most application of satellite communication
  will be long distance telephone transmission
• Private business networks and television
  distribution

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Comparison of Twisted Pair,Coaxial Cable and
Optic fiber
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Comparison of Satellite and Optic Fiber