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LITERATURE SURVEY PRESENTATION

DEPARTMENT OF ELECTRONICS

M.E.S. COLLEGE, MARAMPALLY

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Presented by

Abhilash K.M

Haseen M.H

Visible light communication and

LI-FI

3Contents What is communication

Access network

Visible light communication

-Spectrum analysis

-Features

LI-FI

-History

-working Process

Advantages and disadvantages

Application

Conclusion

Reference

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FROM LATIN COMMUNICARE, MEANING TO SHARE.

CONVEYING INFORMATION.

What is communication….?

5Electronic communication

•Transmitter: is an electronic device which, with the aid of an antenna , produces radio waves

•Channel : refers either to a physical transmission medium such as a wire ,or to a logical connection over a multiplexed medium such as radio channel

•Receiver: is an electronic device that receives radio wave and converts the information carried by them to a usable form

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AN ACCESS NETWORK IS THE PART OF A TELECOMMUNICATIONS NETWORK WHICH CONNECTS SUBSCRIBERS TO THEIR IMMEDIATE SERVICE PROVIDER

1.Wired access2.Wireless access

ACCESS NETWORK

7Wired access

Copper wire -ISDN(Integrated Services Digital Network)

*speed- 2x64kbps

- DSL(Digital Subscriber Line)

- *speed- 8Mbps

Optical fiber

-GPON(Gigabyte Passive Optical Network)*speed- 10Gbps

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• Transfer of information between two or more points that are not connected by an electric conducter

Example : wi-fi, radio

Wireless access

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Radio Spectrum is congested but the demand for wireless data double each year .Every thing, it seems want to use wireless data but the capacity is drying up.

So what can carry this excess demand in the future .

1.4 Million5 Billion

PRESENT SCENARIO

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WHO CAN REPLACERADIO WAVES FOR WIRELESS

COMMUNICATION ???

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The visible light communication (VLC) refers to the communication technology which utilizes the visible light source as a signal transmitter, the air as a transmission medium, and the appropriate photodiode as a signal receiving component. 

Visible Light Communication

12WHY ONLY VLC ?

Radio Waves

Infrared Rays

Visible Rays

Ultraviolet Rays X- Rays

Gama Rays

Gama rays cant be used as they could be dangerous.X-rays have similar health issues.Ultraviolet light is good for place without people, but other wise dangerous for the human body.Infrared, due to eye safety regulation, can only be used with low power.

HENCE WE LEFT WITH THE ONLY THE VISIBLE - LIGHT SPECTRUM.

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Visible light is the form in which electromagnetic radiation with wavelengths in a particular range is interpreted by the human brain. Visible light is thus by definition comprised of visually-perceivable electromagnetic waves. The visible spectrum covers wave lengths from 380 nm to 750 nm.

Visible Light

14Frequency spectrum

15VISIBLE LIGHT COMMUNICATION

PROCESS

16Transmitters:-

• LED

• Fluorescent Light

Receiver:-

• Photodiode

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A. Bandwidth: The visible light spectrum is plentiful(10,000 more than RF spectrum), unlicensed.

B. High speed: Very high data rates can be achieved due to low interference, high device bandwidths and

high intensity optical output.

C. Planning: Capacity planning is simple since there tends to be illumination infrastructure where people wish to

communicate, and good signal strength can literally be seen.

D. Low cost: Requires fewer components than radio technology.

FEATURES OF VLC

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E. Energy: LED illumination is already efficient and the data transmission requires negligible additional power.

F. Environment: RF transmission and propagation in water is extremely difficult but Li-Fi works well in this environment.

G. Safe: Life on earth has evolved through exposure to visible light. There are no known safety or health concerns for this technology.

H. Non-hazardous: The transmission of light avoids the use of radio frequencies which can dangerously interfere with electronic circuitry in certain environments.

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21LI – FI

LI-FI is transmission of data through illumination, sending data through a LED light bulb that varies in intensity faster than human eye can follow

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The technology truly began during the 1990's in countries like Germany, Korea, and Japan where they discovered LED's could be retrofitted to send information.  Harald Haas continues to wow the world with the potential to use light for communication

HISTROY

23INTRODUCTION OF LI-FI

•Li-Fi stands for ‘Light Fidelity’.

•Li Fi is now part of Visible Light Communication(VLC) PAN IEEE 802.15.7 Standard.”Li-Fi is typically implemented using white LED light bulbs”.

•These device are normally used for illumination by Appling a constant current through the LED

•Li-Fi is the term have been used to label the fast and cheap wireless communication system, which is the optical version of Wi –Fi .

•Li-Fi is light based Wi-Fi that is, it uses light instead of radio waves to transmit information

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Working process

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• He explained ,”very simple, if the LED is on, you transmit a 1 and when LED off transmit a 0.The LED can be switched on and off very quickly, which gives nice opportunities for transmitting data.”

• Further enhancements can be made in this method, like using an array of LEDs for parallel data transmission, or using mixtures of red, green and blue LEDs to alter the light’s frequency encoding a different data channel.

Working of Li- Fi

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Advantages

Larger bandwidth (10,000 times the radio bandwidth)

High efficiency

More availability

Highly secure

ADVANTAGES AND DISADVANTAGES

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Disadvantages

Presence of Light is essential

There will be interference from

sunlight

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Applications

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1. In Offi ces and Home as smart LED Lightings

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In Aircraft cabins

Whenever we travel through airways we face the problem in communication media ,because the whole airways communication are performed on the basis of radio waves. To overcomes this drawback on radio ways , li-fi is introduced.

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In Traffic lighting

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In RF restricted Environments

Visible Light is more safe than RF, hence it can be used in

places where RF can't be used such as petrochemical plants .

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There are millions of street lamps deployed around the world.

Each of these street lamps could be a free access point.

STREET LAMPS ( AS FREE ACCESS POINTS )

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The possibilities are numerous

and can be explored further. If

this technology can be put into

practical use , every bulb can be

used something like a Wi-Fi

hotspots to transmit wireless

data.

CONCLUSION

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REFRENCES

[1] S. Haruyama, “Advances in Visible Light Communication Technologies,” 38th Euro. Conf. and Exhibition on Optical Commun., 2012, paper We.3.B.5.[2] IEEE Communications Magazine • December 2013 0163-6804/13/$25.00 © 2013 IEEE[3] J. A. J. Roufs and F. J. J. Blommaizt, “Temporal Impulse and Step Responses of the Human Eye Obtained Psychophysically by Means of a Drift-Correction Perturbation Technique,” Vision Research, vol. 21, no. 8, 1981, pp. 1203–21.[4] “Solid-State Lighting Research and Development: Multi Year Program Plan,” http://apps1.eere.energy.gov/buildings/ publications/pdfs/ssl/ssl_mypp2013_web.pdf, Apr. 2013.

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[5] Lighting the Way: Perspectives on the Global Lighting Market, 2nd ed., McKinsey & Company, 2012, http://www.mckinsey.com. [6] International Journal of Applied Engineering Research, ISSN 0973-4562 Vol.7 No.11 (2012)[7] T. Komine and M. Nakagawa, ”Fundamental Analysis for Visible- Light Communication System using LED Lights”, IEEE Transactions on Consumer Electronics, vol. 50, no. 1, Feb. 2004[8] T. Komine and M. Nakagawa, “Fundamental analysis for visible-light communication system using LED lights,” IEEE Trans. Consumer Electron., vol. 50, no. 1, pp. 100–107, Feb. 2004.[9] H. Elgala, R. Mesleh, and H. Haas, “Indoor broadcasting via white LEDs and OFDM,” IEEE Trans. Consumer Electron., vol. 55, no. 3, pp. 1127–1134, Aug. 2009.[10] J. Rufo, F. Delgado, C. Quintana, A. Perera, J. Rabadan, and R. Perez- Jimenez, “Visible light communications for optical video transmission,” Microw. Opt. Technol. Lett., vol. 52, no. 7, pp. 1572–1576, Jul. 2010.

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Any Quarries…?

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