The document discusses visible light communication (VLC), which uses visible light as a means of data transmission. It describes the VLC process, opportunities of using the visible light spectrum for unlicensed communication, and integration of VLC with other technologies like powerline communication and Wi-Fi. Challenges in commercializing VLC are also presented. The conclusion is that VLC can improve wireless performance for short-range downlink access and device-to-device transfers, with smartphones being able to decode VLC signals without extra hardware. This first step shows promise for VLC commercialization.

1. Khulna University of Engineering & Technology
Visible Light Communication:
Opportunities, Challenges and
the path to market.
Written by:
Aleksandar Jovicic, Junyi Li, and
Tom Richardson
Presented by: Shuvo Raj Paul
Roll Number: 1003110
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2. Contents
 Introduction.
 Visible light & its spectrum.
 Motivation: Why visible light is used for communication
purpose?
 The VLC communication process based on intensity
modulation.
 LED modulation characteristics.
 VLC link capacity for typical office desk-level illumination.
 Integration with power line communication (PLC) for the VLC
downlink.
 Integration with the uplink technology such as Wi-Fi.
 Conclusion.
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3. What is
“Visible Light Communication” ?
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.
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4. Visible Light
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 Spectrum
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5. Why Visible light communication is needed ???
 The visible light spectrum is unlicensed & creates an
opportunity for low-cost broadband communication.
 VLC signals in adjacent rooms or apartment units would not
interfere with each other & data security is ensured.
 The front-end components of both transmitters and
receivers are relatively simple and cheap devices.
 The human eye cannot perceive the amplitude modulation
of light as long as the frequency of modulation is above the
so-called flicker fusion threshold.
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6. THE VLC COMMUNICATION PROCESS BASED ON
INTENSITY MODULATION
Fig-1: The VLC radio transmitter and receiver based on
intensity modulation/direct detection.
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7. LED MODULATION CHARACTERISTICS:
Fig-2: Frequency response of high-powered BRLUX-2670 LED &
BRLUX-560 LED.
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8. VLC link capacity for typical office desk-level illumination.
“Typical office desk-level
lighting is between 400 and
1000 lux. At 600 lux the
capacity of the link is around
150 Mb/s.”
Fig-3. VLC link capacity as a function of received illuminance
in lux. 600 lux is typical office desk-level illumination.
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9. INTEGRATION WITH POWER LINE
COMMUNICATION (plc) FOR THE VLC DOWNLINK.
“Since LEDs need a certain
DC voltage to turn on, they
can’t run directly off of the
60 Hz power cycle that’s
why bridge-rectifier or AC-to-
DC converter is used
inside their power supplies
that regulate the current
supplied to the LED.”
Fig-4: The modifications to the LED lamp or fixture that are required to
enable high data rate VLC signal transmission.
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10. INTEGRATION WITH THE UPLINK TECHNOLOGY
SUCH AS Wi-Fi.
Fig-5: The uplink can use an out-of-band technology such as
Wi-Fi. The Hy-Fi router manages the VLC downlink and Wi-Fi
uplink on a per user basis.
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11. CHALLENGES IN COMMERCIALIZATION
OF VLC.
Fig-6: Low Data Rate (LDR) Visible Light Communication that uses
simple, power-efficient ON-OFF signaling can be decoded by the
smartphone camera sensor.
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12. Conclusion
Visible light communication can supplement radio
frequency communication and improve wireless
network performance wherever short range links
are used such as in a home or office for downlink
Internet access or for device-to device file transfers
and video streaming. It requires no additional
hardware in mobile devices. this use case is the
most promising first step in the commercialization
of VLC.
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13. Thank you for
your
kind attention
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