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Visible Light Communications:
Recent Activities in Japan
Shinichiro Haruyama, Professor
The Graduate School of System Design and Management,
Keio University, Yokohama, Japan
Smart Spaces: A Smart Lighting ERC Industry - Academia Day
at BU Photonics Center, Boston University
February 8, 2011

Shinichiro Haruyama

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Contents
1. Visible light communication
2. Methods of visible light communication
3. Areas to which visible light
communication may be applied
4. Conclusion

Shinichiro Haruyama

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1. Visible light communication

Shinichiro Haruyama

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1. Visible light communication
Visible Light communication is a wireless communication
technology that uses light that is visible to humans.
Typical example of visible light communication: the use of LED illumination as a transmitter

LED Lights

Receiver

Why do we want to use visible light for communication?
Shinichiro Haruyama

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Reason 1: Visible light communication is not regulated.
Radio Wave and Light Wave
Frequency (Hz)

13
10
3THz 12
1THz 10
11
10
1010

Visible light
Infrared light

9
1GHz 10
108

Wireless LAN
Cellular phone
TV
FM radio

7
10
1MHz 106

Light Wave

Ultraviolet light

Radio Wave

16
10
15
10
1014

Visible light communication

Frequency above 3THz is NOT
regulated by the Radio Regulation
Law .

The use of radio frequency below 3THz
is regulated by the Radio Regulation
Law .

AM radio

Visible light communication is not regulated, so it is fairly easy to introduce new products , though safety regulation of high-power LED light has been already discussed. Shinichiro Haruyama

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Reason 2: Visible light LED will be used everywhere.
Infrared light is already used for communication, such as wireless remote control , IrDA, Infrared wireless LAN, and infrared interbuilding communication. However, visible light LEDs are beginning to be used in every home and office, which makes visible light LEDs...