vISIBLE LIGHT COMM

1. By:
Suhail More
ME-E&TC
Rollno-E1109
Under Guidance of:
Prof C.V Kulkarni
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Visible Light Communication

2.  Introduction
 Why VLC
 Technology
 Modulation
 VLC Consortium
 Applications
 Difficulties
 Conclusion and Outlook
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Visible Light Communication

3.  New communication technology using Visible
light.
 Visible light is only a small portion of the
electromagnetic spectrum.
 Wavelength between 380nm(750 THz) to
750nm(428 THz).
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Visible Light Communication

4.  It does not cause any health problems.
 No EM-interference.
 It is free.
 Fast switching.
 Ever-increasing market share of LEDs makes
VLC ubiquitously available.
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Visible Light Communication

5.  Transmitters
◦ Theoretically every kind of light source can be used
as transmitting device.
◦ More promising alternatives are fluorescent lights
and LEDs.
◦ LEDs are the predominant choice for transmitters.
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Visible Light Communication

6.  Receivers
◦ Photodiode receivers.
◦ CCD and CMOS sensors.
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8.  Phosphorus LEDs can achieve up to 40 Mbps.
 By using RGB LEDs data rates can go up to
100 Mbps.
 RCLEDs (Resonant Cavity LEDs) can achieve
data rates up to 500 Mbps.
• RCLEDS use Bragg reflectors to enhance the
emitted light.
• Increased spectral purity when compared to
conventional LEDs.
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Visible Light Communication

9. 9
Transmitter unit Receiver unit
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Visible Light Communication

10.  Modulation is used to transform the data(given
as a sequence of 0s and 1s) into a series of
light pulses.
 Two main alternative modulation schemes:
• Pulse Position Modulation(PPM):
- Amplitude & width of pulse is constant.
• Frequency Shift Keying (FSK):
- Digital information is transmitted through
frequency changes of carrier wave.
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Visible Light Communication

11. Property VL Comm. RF Comm.
EMI NO YES
Line of Sight YES NO
Standard Beginning Matured
Power Consumption Relatively low Medium
Visibility Security YES NO
Infrastructure LED illumination Access point
Mobility Limited YES
Coverage, Distance Narrow, Short Wide, Medium
Bandwidth More Less
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Visible Light Communication

12.  The Visible Light Communication Consortium
was established in 2003 by Japanese tech-
companies.
 Four Committees:
• Research & Planning
• Technical
• Standardization
• Popularization
 Two standards are proposed:
• JEITA CP-1221
• JEITA CP-1222
 Standardization efforts for physical and media
access layer are also done by IEEE 802.15, Task
Group 7.
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Visible Light Communication

13.  Smart Home Network
 Commercial Aviation
 Hazardous Environments
 Hospital and Healthcare
 Defense and Military Applications
 Underwater Communications
 Indoor location estimation
 Vehicle to vehicle communication
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Visible Light Communication

14. 14
 Many cars have LED lamps. Traffic signage,
traffic lights, and street lamps are adopting
the LED technology so there are massive
applications opportunities here.
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Visible Light Communication

15. 15
 There are advantages for using VLC in
hospitals and in healthcare. Mobile phones
and Wi-Fi's are undesirable in certain parts of
hospitals, especially around MRI scanners and
in operating theatres.
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Visible Light Communication

16.  Smart buildings require smart lighting. Smart
lighting with VLC provides the infrastructure
for illumination, control and communications
and will greatly reduce wiring and energy
consumption within a building.
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Visible Light Communication

17. 17
 Radio waves do not propagate for a long
distance under water.
 It was demonstrated that the flashlight visible
light transmitter was able to transmit signals
for 7 meters distance.
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Visible Light Communication

18.  Line of sight.
 Very high light intensity of other source can
cause the sensor to misjudge the light from
the original source.
 Short range.(max 15 meters)
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19.  VLC is a promising technology even if it is
still in a very early stage.
 Transmission rates are high as compared to
other technology.
 Using arrays of LED’s more data transmission
can be obtained.
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20. THANK YOU
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