Presented by:-Chanchal

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

Optical fiber verses wireless communication

system

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 Tyndall included a demonstration of it in his public lectures in London, 12 years later. Tyndall also wrote about the property of total internal reflection in 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 expensive

2) Fragility3) Affected by

chemicals4) Opaqueness

(exposed to radiation)

5) Scattering6) Absorption

Advantages and disadvantages of optical fiber communication

Disadvantages

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?

How communication takes place?

Transmitting signal Received signal

satellite

Transmitting antenna

Receivingantenna

FM RADIO 88 MHZTV BROADCAST 200 MHZGSM PHONES 900 MHZGPS 1.2 GHZPCS PHONES 1.8 GHZBLUETOOTH 2.4 GHZWi-Fi 2.4 GHZ

TYPICAL FREQUENCIES

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

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:- don’t pass through buildings , whether and frequency dependent.

TYPES OF WIRELESS COMMUNICATION

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….

CELLULAR SYSTEM

WIRELESS LANs

SATELLITE SYSTEM

PAGING SYSTEM

PANs(BLUETOOTH)

CURRENT WIRELESS SYSTEMS

Definition Wireless communication

technology in which several small exchanges (called cells) equipped with low-power radio antennas (strategically located over a wide geographical area) are interconnected through a central exchange. As a receiver (cell phone) moves from one place to the next, its identity, location, and radio frequency is handed-over by one cell to another without interrupting a call.

What is cellular system?Practical

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

Cellular system basic concept contd…

MSCCELLS

PSTN

SUBSCRIBER UNIT

BASE STATIONS

Coverage area

NSS = MSC + HLR + VLR + AUC + EIR

THE N/W SWITCHING SUBSYSTEM?

MANAGECOMMUNICATI

ON 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

PARAMETERS

OPTICAL FIBER WIRELESS SYSTEM

1) Basically define

It is wired system and used light for comm.

It is wireless system and used electromagnetic waves for comm.

2) Main Principle

Total internal reflection.

Modulation and demodulation techniques are used.

3) Component For transmission- LED and LASERFor receiver-PHOTODIODE

ANTENNA, MODULATOR and DEMODULATOR

4) Frequency Approx 180 THz to 330 THz

Approx 300 GHz to 3000GHz

5) Loss 0.002db/km (approximate), scattering and absorption problems.

Low bandwidth, Weather problems, Interference problems.

6) Applications Telecommunication, Imaging optics , Endoscope

Mobile 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) Eagle’s Prakashan (Regd.) optical fiber communication, Rajesh Kumar

2) http://www.gatewayforindia.com/technology/opticalfiber.htm

3) 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.pdf

7) http://www.authorstream.com/Presentation/amitsorot-1373854-wireless-communication/

REFRENCES