an-introduction-to-optical-fiber-communication

1. EngrAuyon:
engrauyon@
Fundamental Ideas

2. EngrAuyon:
engrauyon@
What is Communication ??What is Communication ??
Exchange Of Information

3. EngrAuyon:
engrauyon@
What is Communication??
Exchange Of Information

4. EngrAuyon:
engrauyon@
I get it !!!!!!!!!!!!
My Information.
Audio Video
Data Signal
Free Space
Copper
Fiber Optic
Source
Destination
Transfer of information from one place to another
Transmission Medium

5. EngrAuyon:
engrauyon@
How to transfer information??How to transfer information??
Some carrier is required to carry information
over long distances….
Why???
Through Some Carrier
Limitation: Information cannot go beyond
certain distance without the aid of a carrier

6. EngrAuyon:
engrauyon@
CarrierCarrier
• Should be capable of carrying information
• Can take it through long distance
• Should have good speed
• Which is the most suitable carrier??

7. EngrAuyon:
engrauyon@
Electromagnetic WaveElectromagnetic Wave
• Highest Known speed 3x108
m/s
• Can carry any information through modulation
• Energetic - Can go through long distance
• Supports multiple media Eg: Free space/Copper/Fiber etc..

8. EngrAuyon:
engrauyon@
Electromagnetic WaveElectromagnetic Wave
 In electromagnetic wave electrical and magnetic fields vary
harmonically
 Harmonic oscillations at atomic level gives oscillating
electric field
 Electromagnetic wave generation

9. EngrAuyon:
engrauyon@
Relation betweenRelation between
electric and magnetic fieldelectric 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

10. EngrAuyon:
engrauyon@
Figure of a wave
Wavelength = distance travelled in one cycle(λ)
Frequency = Number of cycles per second(ν)
Velocity(v) = λ x ν
λ

11. EngrAuyon:
engrauyon@
Velocity of all the electromagnetic wave is same, 3 x 108
m/s
Electro Magnetic Spectrum

12. EngrAuyon:
engrauyon@
Block Diagram of a
Telecommunication System

13. EngrAuyon:
engrauyon@
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
Media…..

14. EngrAuyon:
engrauyon@
Different types of media used for transmittingDifferent types of media used for transmitting
signals….signals….
•Wired : Twisted Pair
Co-axial cable
Optical fiber
•Wireless(Free space/air):Microwave
Satellite
Rx
MEDIA
Tx
Carrier

15. EngrAuyon:
engrauyon@
Twisted Pair

16. EngrAuyon:
engrauyon@
 Twisted pair is made of two copper wires which areTwisted pair is made of two copper wires which are
covered by plastics or materials that are similarcovered by plastics or materials that are similar
 The insulated wires are twisted to form theThe insulated wires are twisted to form the
communication line,the purpose of twisting the wirescommunication line,the purpose of twisting the wires
is to avoid electrical interferenceis to avoid electrical interference
 Twisted pair can be combined into a cable that mayTwisted pair can be combined into a cable that may
consist of two,four,fifty or hundreds of pairsconsist of two,four,fifty or hundreds of pairs
 Twisted pair is the basis of transmissionTwisted pair is the basis of transmission
media(Telephone)media(Telephone)
Twisted PairTwisted Pair

17. EngrAuyon:
engrauyon@
Coaxial CableCoaxial Cable

18. EngrAuyon:
engrauyon@
 Coaxial cable contains two conductors which areCoaxial cable contains two conductors which are
insulated from one anotherinsulated from one another
 The inner conductor is covered by the dielectric andThe inner conductor is covered by the dielectric and
the outer conductor is covered by a shieldthe outer conductor is covered by a shield
 Coaxial cable has many applications,for instanceCoaxial cable has many applications,for instance
cable TV,local networks,short run computer systemcable TV,local networks,short run computer system
links and long distance telephone transmissionlinks and long distance telephone transmission
 In local network coaxial cable can support differentIn local network coaxial cable can support different
type of traffic and datatype of traffic and data
 By using FDM,it can carry more than 10,000By using FDM,it can carry more than 10,000
channels at a timechannels at a time
Coaxial CableCoaxial Cable

19. EngrAuyon:
engrauyon@
Optic FiberOptic Fiber

20. EngrAuyon:
engrauyon@
Optic Fiber(Physical Appearance)Optic Fiber(Physical Appearance)

21. EngrAuyon:
engrauyon@
Optic fiber is made up of 3 parts :Optic fiber is made up of 3 parts :
Core,Cladding and jacketCore,Cladding and jacket
 The inner most part is the core which contains oneThe inner most part is the core which contains one
or more thin fibers that are made up of plastic oror more thin fibers that are made up of plastic or
glassglass
 Each of the fiber in the core is covered by a claddingEach of the fiber in the core is covered by a cladding
which has different optical properties from the corewhich has different optical properties from the core
 The outer most part of the optical fiber is made up ofThe outer most part of the optical fiber is made up of
plastic or other materials ,which is called the jacketplastic or other materials ,which is called the jacket
Optic Fiber

22. EngrAuyon:
engrauyon@
 Because of greater performance and higher data rate,theBecause of greater performance and higher data rate,the
application of optic fiber has dramatically increased inapplication of optic fiber has dramatically increased in
long distance communication and military applicationslong distance communication and military applications
Optic Fiber

23. EngrAuyon:
engrauyon@
MicrowaveMicrowave

24. EngrAuyon:
engrauyon@
MicrowaveMicrowave
 In terrestrial microwave transmission a pair of towersIn terrestrial microwave transmission a pair of towers
mounted on top of the towers will transmit signalsmounted on top of the towers will transmit signals
through airthrough air
 Microwave antennas are equipped in higher place inMicrowave antennas are equipped in higher place in
order to achieve better transmission effectorder to achieve better transmission effect
 Voice transmission,television transmission and theVoice transmission,television transmission and the
short point to point links will be the major applicationshort point to point links will be the major application
of microwave transmissionof microwave transmission

25. EngrAuyon:
engrauyon@
Satellite CommunicationSatellite Communication

26. EngrAuyon:
engrauyon@
SatelliteSatellite
 A satellite consists of several transponders whichA satellite consists of several transponders which
receive signal from one frequency band,this action isreceive signal from one frequency band,this action is
calledcalled uplinkuplink
 The satellite will amplify or repeat the signal to otherThe satellite will amplify or repeat the signal to other
frequency band,this action is calledfrequency band,this action is called downlinkdownlink
 A satellite link is called a microwave linkA satellite link is called a microwave link
 The most application of satellite communication willThe most application of satellite communication will
be long distance telephone transmissionbe long distance telephone transmission
 Private business networks and television distributionPrivate business networks and television distribution

27. EngrAuyon:
engrauyon@
Comparison of Twisted Pair,CoaxialComparison of Twisted Pair,Coaxial
Cable and Optic fiberCable and Optic fiber
Twisted Pair Coaxial Cable Optic Fiber
Data Rate/
Bandwidth
4Mbps 500Mbps Upto
100Gbps
Repeater Spacing 1-10Km 1-10Km 10-100Km
Electromagnetism Affected Affected Not affected

28. EngrAuyon:
engrauyon@
Comparison of Satellite and Optic FiberComparison of Satellite and Optic Fiber
Optic Fiber Satellite
Reconfiguration Not possible Possible
Bandwidth Practicallyupto
10 GHz
36-72MHz
Weather Condition Affected by storm Not affected by
storm
Electromagnetic
Interference
Not affected Affected