Optical fiber communication versus wireless communication

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Transcript of Optical fiber communication versus wireless communication

WIRELESS COMMUNICATION

Presented by:-Chanchal Class/sem :- (B.Tech/EEE/7th)Roll No. 1282728

Optical fiber verses wireless communication system

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Firstly of all we discuss, optical fiber communication

-Optical fiber which are long, thin, made with pure glass about the diameter of human hair and it is a dielectric waveguide or medium in which information (voice, data or video) is transmitted through a glass or plastic fiber, in a form of light.

-Optical fiber communication system consists of three basic elements:- 1) the optical transmitter 2) optical fiber cable 3) the optical receiver

Definition of optical fiber communication

Block diagram of optical fiber communication system

Jacques Babinet>< John Tyndallincluded a demonstration of it in his public lectures inLondon, 12 years later.Tyndall also wrote about the property oftotal internal reflectionin an introductory book about the nature of light in 1870.History of optical fiber< Daniel Colladon

Optical fiber Based on principle Total Internal Reflection

Basic structure of optical fiber

Modes of optical fiber1) Multimode fiber :-If the diameter of the core of the fiber is large enough so that there are many paths that light can take through the fiber, the fiber is called "multimode" fiber.2) Single mode fiber :-Single-mode fiber has a much smaller core that only allows light rays to travel along one mode inside the fiber, the fiber is called single mode fiber.

Advantages 1) Enormous bandwidth2) Low transmission loss3) Immunity to cross talk4) Electrical isolation5) Signal security6) Flexibility7) Reliability8) Ease of installation

1) High cost and most expensive2) Fragility3) Affected by chemicals4) Opaqueness (exposed to radiation)5) Scattering6) Absorption

Advantages and disadvantages of optical fiber communicationDisadvantages

Applications of optical fiber1) Tele-Communication2) Medical system3) Interconnect4) Networking5) Gigabit Ethernet6) Harsh environment7) Military8) Aerospace & avionics9) Data transfer tests10) Data storage equipments11) Simulation12) Semiconductor equipments

Secondly we discuss about.WIRELESS COMMUNICATION SYSTEM

Transmitting/receiving voice and data using electromagnetic waves in open space.

The information from sender to receiver is carried over a well defined frequency band(channel).

Each channel has a fixed frequency bandwidth & capacity(bit rate).

Different channels can be used to transmit information in parallel and independently.WHAT IS WIRELESS COMMUNICATION?

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How communication takes place?

Transmitting signalReceived signal satelliteTransmitting antenna Receivingantenna

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FM RADIO88 MHZTV BROADCAST200 MHZGSM PHONES900 MHZGPS1.2 GHZPCS PHONES1.8 GHZBLUETOOTH2.4 GHZWi-Fi2.4 GHZ TYPICAL FREQUENCIES

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Freedom from wires.No bunch of wires running from here and there.Auto Magical instantaneous communication without physical connection setup e.g.- Bluetooth, Wi-Fi.Global coverageCommunication can reach where wiring is infeasible or costly e.g.- rural areas,buildings,battlefield,outerspace.Stay connected,flexiblity to connect multiple devices.NEED OF WIRELESS COMMUNICATION

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RADIO TRANSMISSION:- easily generated, Omni-directional , travel long distance , easily penetrates buildings.

PROBLEMS:- frequency dependent , relatively low bandwidth for data communication , tightly licensed by government.

MICROWAVE TRANSMISSION:- widely used for long distance communication , give high S/N ratio , relatively inexpensive.

PROBLEMS:- dont pass through buildings , whether and frequency dependent.TYPES OF WIRELESS COMMUNICATION

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INFRARED AND MILIMETER WAVES:- widely used for short range communication , unable to pass through solid objects , used for indoor wireless LANs , not for outdoors.

LIGHT WAVE TRANSMISSION:- unguided optical signal such as laser , unidirectional , easy to install , no license required.

PROBLEMS:- unable to penetrate rain or thick fog , laser beam can be easily diverted by air. TYPES CONTINUED.

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CELLULAR SYSTEM

WIRELESS LANs

SATELLITE SYSTEM

PAGING SYSTEM

PANs(BLUETOOTH) CURRENT WIRELESS SYSTEMS

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DefinitionWirelesscommunication technology in which several smallexchanges(calledcells) equipped with low-power radio antennas (strategically located over a wide geographical area) are interconnected through a central exchange. As areceiver(cell phone) moves from one place to the next, itsidentity,location, and radiofrequencyis handed-over by one cell to another without interrupting a call.

What is cellular system?Practical

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By systematically spacing base stations and the channel groups may be reuse as many number of times as necessary.

Cellular system basic concept contd

MSC

CELLS

PSTN

SUBSCRIBER UNIT

BASE STATIONSCoverage area

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NSS = MSC + HLR + VLR + AUC + EIRTHE N/W SWITCHING SUBSYSTEM?

MANAGECOMMUNICATION B/W USERS

INCLUDE DATABASE TO STORE INFORMATION OF USER

CALL CONTROL

MOBILITYMGMT

SUBSCRIBERDATA HANDLING

CHECK IDENTITY OF USER

PERMANENT STORAGE OF USER INFORMATION

STORE A COPY OF HLR

CHECK ROAMING

PROVIDE AUTHENTICATION

SECURITY

CHECK IMEI NUMBER OF MOBILE

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PARAMETERSOPTICAL FIBER WIRELESS SYSTEM1) Basically defineIt is wired system and used light for comm.It is wireless system and used electromagnetic waves for comm.2) Main PrincipleTotal internal reflection.Modulation and demodulation techniques are used.3) Component For transmission- LED and LASERFor receiver-PHOTODIODE ANTENNA, MODULATOR and DEMODULATOR4) Frequency Approx 180 THz to 330 THzApprox 300 GHz to 3000GHz5) Loss0.002db/km (approximate), scattering and absorption problems.Low bandwidth, Weather problems, Interference problems.6) ApplicationsTelecommunication, Imaging optics , EndoscopeMobile phones, broadcasting, Wireless fidelity (Wi-Fi), Satellite communication.

Main comparison between optical and wireless system

A huge amount of development can be made by making further research and work on fiber optics .We need it for a faster and more sophisticated infrastructure which would be the prime demand of the ever growing population of tomorrow. At present there are many optical fibre communication links throughout the world without using optical solutions. When we introduce optical solutions as light pulses through the fibres, we can achieve high quality telecommunication at a lower cost. We can expect a great revolution in optical fibre communication within a few years by means of solutions.Conclusion

1) Eagles Prakashan (Regd.) optical fiber communication, Rajesh Kumar2) http://www.gatewayforindia.com/technology/opticalfiber.htm3) http://www.vigyanprasar.gov.in/wos/optical.htm4) http://en.wikipedia.org/wiki/Optical_fiber5) T Okoshi and K Kikuchi,Coherent optical fibre communication(Kluwer Academic, Boston)6) http://wsl.stanford.edu/~andrea/Wireless/SampleChapters.pdf7) http://www.authorstream.com/Presentation/amitsorot-1373854-wireless-communication/

REFRENCES