li fi documentation

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Technical Seminar Report
On
LI-FI (LIGHT-FIDELITY)
Submitted in partial fulfillment of the requirement for the award of the Degree of
Bachelor of Technology
In
Electronics and Communication Engineering
By
B.Prabhu kiran (11621A0407)
Under the guidance of
Mr.A.Sai Prasad Goud (M.Tech)
Asst.prof
Department of Electronics and Communication Engineering
Aurora's Engineering College
Bhuvanagiri, Nalgonda District – 508 116
(Affiliated to JNTUH and Accredited by NBA, New Delhi)
(2014-15)

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Aurora's Engineering College
Bhuvanagiri, Nalgonda District – 508 116
(Affiliated to JNTUH and Accredited by NBA, New Delhi)
CERTIFICATE
This is to certify that the Technical Seminar report entitled “LI-FI (LIGHT-FIDELITY)” has been
submitted by Mr.B.Prabhu kiran bearing Roll No 11621A0407 under my guidance in partial
fulfillmentof the degree of Bachelorof TechnologyinElectronicsand Communication Engineering
to the Jawaharlal Nehru Technological University Hyderabad during the academic year 2014-15.
Date: 12-01-2015
Name of the Supervisor SeminarCoordinator
Mr. Vinod chavan Mr. A.Sai Prasad Goud
Head of Department Principal
Mr. V. Kumara Swamy Mr. J. Srikanth

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Acknowledgement
An Endeavour of a long period can be successful only with the advice of many well wishers.
We take this opportunity to express our deep gratitude and appreciation to all those who
encouraged us for successfully completion of the technical seminar.
We wish to express our sincere gratitude to Mr.SRIKANTH JATLA, principal of
AURORA’S ENGINEERING COLLEGE, BHONGIR. For his consistent help and
encouragement to complete the technical seminar.
Our special thanks to Mr.V.KUMAR SWAMY, Head of electronics and communication
engineering department. For valuable suggestions and help during the progress of technical
seminar in spite of his busy schedule.
We are thankful to our guide Mr.VINOD CHAVAN & Mr. A. SAI PRASAD GOUD,
Associate professor & Assistant professor in E.C.E Department, AURORA’S
ENGINEERING COLLEGE, and BHONGIR. For this valuable guidance and suggestions in
analyzing and testing throughout the period, till the end of the technical seminar completion.
Finally, we would like to express our sincere thanks to faculty members of E.C.E
Department, friends, lab-technicians, one and all who has helped us to complete the work
successfully.
 B.PRABHU KIRAN(11621A0407)

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DECLARATION
We here by solely declare that the technical seminar titled “LI-FI (LIGHT FIDELITY)”
submitted by us is a genuine and bonafide work done by us and is not submitted to any of
other university (or) published at any time before.
This technical seminar is for partial fulfillment for the task of mini project assigned in the
Course curriculum bachelor of technology under specialization of electronics and
communication engineering by JNTU-Hyderabad.
 B.PRABHU KIRAN(11621A0401)

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CONTENTS
1. INTRODUCTION………………………………………………………………....1
2. HISTORY OF LI-FI……………………………………………………………….4
2.1 The need for Visible Light Communication (VLC)…………………………...4
2.2 Genesis of Li-Fi………………………………………………………………..5
3. WORKING PRINCIPLES………………………………………………………...8
3.1 Visible Light Communication (VLC)………………………………………….9
3.1.1 Multiple access using VLC………………………………………………11
3.2 Technology in Brief……………………………………………………………14
3.2.1 LI-FI construction………………………………………………………..14
3.2.2 Uplink…………………………………………………………………….15
3.3.3 Summary………………………………………………………………….16
3.3 Working Models………………………………………………………………...16
4. COMPARISON BETWEEN LI-FI & WI-FI……………………………………..19
4.1 How is it different? ……………………………………………………………...21
5. APPLICATION AREAS OF LI-FI TECHNOLOGY……………………………22
5.1 Air Ways………………………………………………………………………...22
5.2 Medical Applications……………………………………………………………22
5.3 In Traffic Lights…………………………………………………………………23
5.4 Multi User Communication……………………………………………………..24
5.5 Secure Communication………………………………………………………….24
5.6 Lights Points Used as Hotspot…………………………………………………..24
5.7 Smart Power Plants……………………………………………………………...25
5.8 Undersea Awesomeness…………………………………………………………25
5.9 It Could Keep People Informed And Save Lives…..............................................26
6. ADVANTAGE OVER RADIO WAVES…………………………………………...27

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7. CHALLENGES OF LI-FI…………………………………………………………….29
8. CONCLUSION………………………………………………………………………...30
9. REFERENCES…………………………………………………………………………31

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LIST OF FIGURES
Fig. No Name Of The Figure Page No
1.1 Li-Fi Environment 3
2.1 issues regarding Radio spectrum 5
2.2 Prof. Harald Hass 7
3.1 Block Diagram of LI-FI 8
3.2(a) Unbiased bipolar OFDM signal 10
3.2(b) Biased unipolar OFDM signal 10
3.3 TDMA vs. OFDMA vs. CDMA (with optical orthogonal
code) in a six-user scenario)
12
3.4(a) Typical spectrum of a white-phosphor LED 13
3.4(b) Typical responsively of photo detector. 13
3.5 Li-Fi bulb with PCB 14
3.6 Giga-Speed usage models (Images courtesy: TriLumina
Corp.)
18
5.1 Use of Li-Fi in Aero plane 22
5.2 Use of LI-FI in Medical Field 23
5.3 Use of Li-Fi in traffic lights 23
5.4 Every light emitting device acting as a Li-Fi Hotspot 24
5.5 Use of LI-FI in Smart Power Plant 25
5.6 Use of VLC under water 26
6.1(a&b) Electromagnetic Spectrum 28

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LIST OF TABLES
S.No Name Of The Table Page NO
1 Comparison between Li-Fi and Wi-Fi 19
2 Comparison between current and future wireless
technology
20

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ABSTRACT
Whether you’re using wireless internet in a coffee shop, stealing it from the guy next
door, or competing for bandwidth at a conference, you have probably gotten frustrated at the
slow speeds you face when more than one device is tapped into the network. As more and
more people and their many devices access wireless internet, clogged airwaves are going to
make it.
One German physicist, Harald Haas has come up with absolution he calls “data
through illumination” –taking the fibber out of fiber optic by sending data through an LED
light bulb that varies in intensity faster than the human eye can follow. It’s the same idea
band behind infrared remote controls but far more powerful.
Haas says his invention, which he calls D-Light, can produce data rates faster than
10 megabits per second, which is speedier than your average broadband connection. He
envisions a future where data for laptops, smart phones, and tablets is transmitted through
the light in a room. And security would be snap – if you can’t see the light, you can’t access
the data.