Light Fidelity

1. COLLEGE OF
ENGINEERING,POONJAR
Guided by
Chrisly Issac
Asst. Professsor
ECE Department
Presented by
Abhijith Uthaman
EC VII, Roll No: 1
ECE
LI-FI: INFORMATION
TRANSFERRING
THROUGH LEDS

2. WELCOME
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3. Li-Fi Slide no:3

4. TOPIC
WHAT IS LIFI
WHY LIFI
HISTORY
WORKING
LI-FI VS WI-FI
IMPLEMENTATION
MODULATION TECHNIQUES
ADVANTAGES
APPLICATIONS
LIMITATIONS
CONCLUSION
REFERENCES
CONTENTS
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5. LI-FI: INFORMATION
TRANSFERRING
THROUGH LEDS
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6. What is Li-Fi ?
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7. • Li-Fi is transmission of data through
illumination .
• i.e sending data through an LED light bulb
that varies in intensity faster than human eye
can follow.
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8. Why Li-Fi ?
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.
1.4 Million Base Stations 5 Billion Li-Fi Slide no:8

9. •He introduced the idea of ‘wireless data from every light’.
History
•In 2011, professor Harald Hass
introduced the term ‘Li-Fi’ , in the TED
global talk
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10. WI-FI LI-FI
Electromagnetic spectrum
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11. WORKING
•Works by switching the bulb on and off within
nanoseconds
•Too quick to be noticed by human eye
•On state implies 1
•Off state implies 0
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12. •High brightness LED acts as
transmitter
•Si photodiode shows good
response to visible light region;
acts as receiver
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13. Li-Fi Slide no:13

14. Fig. Working of Li-Fi
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15. Li-Fi Slide no:15

16. Why Li-Fi over Wi-Fi?
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17. CURRENT RADIO SPECTRUM-ISSUES
 Radio waves
 Cost and Expensive
 Less Bandwidth
compared to other
spectrums
 Insufficient spectrum
for increasing data
Millions of base
stations consume huge
amount of energy for
•Transmitting the
radio waves
•To cool the base
station cabins
•5% Efficiency
 Available within
the range of Base
stations
 Limited
availability
 Unavailable in
aircrafts
 Less
secure(passes
through the
walls)
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18. Table 1: Wi-Fi vs Li-Fi
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19. IMPLEMENTATION – LARGE SCALE
Internet
Data feed
PLC (Power line
comm.)
VLC Visible Light Comm.
ISP
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20. MODULATION TECHNIQUES
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21. ADVANTAGES
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22. APPLICATIONS
Vehicles and
Transportation
Location Based
Services
RF Spectrum relief
Underwater
communication
Hospitals and
Healthcare
Mobile connectivity
Aviation
Hazardous
environment
Smart lighting
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23. LIMITATIONS & CHALLENGES
•Light can't pass through objects.
•Interferences from external light sources like sun
light, normal bulbs, and opaque materials in the
path of transmission will cause interruption in the
communication.
•Li-Fi requires line of sight.
•A major challenge facing Li-Fi is how the
receiving device will transmit back to transmitter.
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24. CONCLUSION
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 Li-Fi hotspots to transmit wireless data.
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25. REFERENCES
[1]International Conference on Electrical, Electronics, and Optimization Techniques (ICEEOT)
– 2016;LI-FI: information transferring through led’s ;Anshu Adwani , Smita Nagtode
[2] IEEE Standard for Local and Metropolitan Area Networks--Part 15.7:
Short-Range Wireless Optical Communication Using Visible Light, pp. 1–
309, Sept.2011.
[3] http://beyondweblogs.com/what-is-li-fi-is-this-replacing- Wi-Fi/
[4] http://www.purelifi.com
[5] T. Komine and M. Nakagawa, “Integrated system of white LED visiblelight
communication and power-line communication,” IEEE Trans. Consum.
Electron, vol. 49, pp. 71–79, Feb. 2003
[6] http://www.lifi.eng.ed.ac.uk/
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