1.  What is VLC
 Visible light & Spectrum
 Indoor VLC scenario
 History
 VLC process
-Transmitter
-Receiver
-Modulation
 VLCC
 VLC characteristics
 Comparison with RF & IR
 Demerits of VLC
 Applications

2. What is VLC..???
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.

3. 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.

5. History of VLC

6.  First research can be traced to as early as 1998-
1999
 Contribution addressing broadband VLC
using WLED started appearing in 2001
 Visible Light Communication Consortium
(VLCC) was established in November 2003
 WWRF showed a few more contributions
between 2000 and 2006

7. VISIBLE LIGHT COMMUNICATION
PROCESS

8. Transmitters:-
•LED
•Fluorescent Light

9. LED Technical Evolution

10. LED Modulation
• Opto-electronic response
V 0
Vd White response
Rs L
Blue response
-5
I Cd
Relative response (dB)
SPICE Model
Cs -10
Rs = 0.9727
L = 33.342 nH -15
Cs = 2.8 nF
Cd = 2.567 nF
tt = 1.09 ns -20
Luxeon LED
-25
0 10 20 30 40 50
freq (MHz)
Measured LED small-signal bandwidth

11. Receiver:-
•Photodiode

12. MODULATION:-
•Pulse Position Modulation(PPM)
•Frequency Shift Keying(FSK)

14. The Visible Light Communications
Consortium (VLCC) which is mainly
comprised of Japanese technology companies
was founded in November 2003. It promotes
usage of visible light for data transmission
through public relations and tries to establish
consistent standards.

15.  Research Advancement and
Planning Committee
 Technical Committee
 Standardization Committee
 Popularization Committee

16. •Human Safety
•High Data Rate
•Bandwidth
•Security
•Visibility
•Unlicensed Spectrum

17. •Limited Transmission Power
•Regulated Spectrum:
•Banned in Sensitive Areas

18. Limited Data Rates:
In IR communications, data rates cannot be
increased beyond a prescribed level as it
poses serious threat to human eyes. This can
be attributed to the high energy density
created by IrDA due to invisibility.

19. •LOS Communication
•Short Range

20. • Position Detection
• Intelligent Super Mart
• Intelligent Transport System
• Image Sensor Communications
• Networking
• Audio Applications
• Aesthetics

21. •LED can be used not only for lighting the
homes but also as means for wireless in-
house communication.
• VLC can create a revolution in the area of
consumer networking because of efficiency
and affordability.