Visible light communication
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The document discusses visible light communication (VLC) technology. VLC utilizes visible light sources like LEDs to transmit data through the air to photodiodes. It has a history dating back to the late 1990s and the Visible Light Communication Consortium was established in 2003 to promote standards. The VLC process involves LED or fluorescent light transmitters that can be modulated, and photodiode receivers. VLC offers advantages like high data rates, unlicensed spectrum, and security, but also has limitations like short range and limited transmission power. Potential applications include indoor positioning, retail environments, transportation systems, and wireless networking and audio.
Visible light communication
- 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.
- 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
- 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
- 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.
- 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.