8/10/2019 Light Fedility

1/26

LIGHT FIDELITYThe artery of future technology

SANJIV KUMAR

206113020M Tech 1st yr, CSE ,

National Institute of Technology,

Tiruchirappalli

8/10/2019 Light Fedility

2/26

VLC introduction

VLC history

VLC frequency band

What motivate for visible light communication

Li-Fi Basic Idea

Working Principle of Li-Fi

Li-Fi technological aspects

Standards

Issues and challenges

Conclusion

Key Points

8/10/2019 Light Fedility

3/26

VLC (Visible Light Communication)

New communication technology using Visible Light.

Visible Light

Wavelength between ~400nm to ~700nm.

General Characteristic

Visibility : Aesthetically pleasing.

Security : What You See Is What You Send.

Health : Harmless for human body.

Unregulated : no regulation in optical frequency.

Using in the restricted area : aircraft, spaceship, hospital.

Eye safety.

VLC Introduction

8/10/2019 Light Fedility

4/26

VLC History

8/10/2019 Light Fedility

5/26

Frequency Band for VLC

8/10/2019 Light Fedility

6/26

VLC Motivation

Communication community trend

Ubiquitous (Connected anywhere, anytime)

Security

LEDtrend

LED technical evolution (efficiency, brightness)

LED availability and cost effectiveness.

Environmental trend

Energy saving.

No E-smog.

8/10/2019 Light Fedility

7/26

Intrinsic characteristics of VLCVisibility.

No interference / No regulation.

Limitations of other technology

The spectrum crunch.

Increasing demand in cloud and in media server.

VLC Motivation

8/10/2019 Light Fedility

8/26

Light Fidelity (Basic Idea)

Li-Fi, or light fidelity, is visible light communication systems

using light from light-emitting diodes (LEDs) as a medium to

deliver networked, mobile, high-speed communication in a

similar manner as Wi-Fi and Optical fiber.

Off means 0and Onmeans 1

Use fast modulation (OFDM).

Based on persistent of vision.

8/10/2019 Light Fedility

9/26

Senderside using special LED bulb capable of

modulating the signal.

Receiverside a receiver capable of demodulating

the incoming signal.

Working Principle

8/10/2019 Light Fedility

10/26

Working Principle

8/10/2019 Light Fedility

11/26

Salient features of technology

8/10/2019 Light Fedility

12/26

Capacity

Almost infinite bandwidth

Visible light spectrum is 10000 times larger then Radio spectrum.

Ready to fulfill growing demands of cloud and media server .

No government regulation act on visible light spectrum.

Efficiency

Instant start time ,parallel transmission of data

Low power consumption

Dynamic dark brightness modulation of lamp to enhance

video contrast

Li-Fi Technological aspects

8/10/2019 Light Fedility

13/26

Security

Signals cannot pass through walls so more secure.

All the security mechanism above DLL are compatible.

Availability

No health issue.

During Night time lamp can be set to modulate dim light.

Environmental friendly.

No interference with other electromagnetic wave.

Li-Fi Technological aspects

8/10/2019 Light Fedility

14/26

8/10/2019 Light Fedility

15/26

Li-Fi Technology demonstration

Data transmission using Li-Fi RGB

8/10/2019 Light Fedility

16/26

Li-Fi Technology demonstration

Live demonstration in TED GLOBAL

8/10/2019 Light Fedility

17/26

JEITA CP-1221

Inter frequency accuracy range of 1nm.

3 major frequency range.

15 KHz to 40 KHz

40 KHz to 1 MHz

Above 1 MHz

IEEE 802.15.7

Data modulation schemes

On-off keying (OOK)

Variable pulse position modulation (VPPM)

The physical layer division

PHY I,PHY II and PHY III

Standards and protocols

8/10/2019 Light Fedility

18/26

VLC / RF

8/10/2019 Light Fedility

19/26

Potential applications of Li-Fi

Traditional use.

8/10/2019 Light Fedility

20/26

Potential applications of Li-Fi

Traffic light

8/10/2019 Light Fedility

21/26

Potential applications of Li-Fi

Visible light ID system

Use in underwater.

8/10/2019 Light Fedility

22/26

8/10/2019 Light Fedility

23/26

Issues and challenges

Backward Compatibility

Integration with Wireless infrastructure.

RF is dominating in digital communication

Providing an uplink.

The light source can be co-located with a VLC receiver

A retro reflector can be used to return incident light back.

Regulatory challenges

regulation by a non-communications standard.

IEEE 802.15.7

8/10/2019 Light Fedility

24/26

Conclusion

Visible Light Communications is the best system for an

ecology and human health, and can use the established

retro-system including the lighting facility as well as power

line system. This system is also free from the current radio

regulation.

VLC cant replace Wi-Fi completely .But it can act as

complementary technology to Wi-Fi .

A wide range of VLC is yet to be explored and Wi-Fi is

fairly mature technology.

8/10/2019 Light Fedility

25/26

References

.

1.www.ieee802.org/15/pub/TG7.htm

2.http://www.ted.com/talks/harald_haas_wireless_data_

from_every_light_bulb.html

3. http://en.wikipedia.org/wiki/Visible_light_communication4. http://ijarcsse.com/docs/papers/Volume_3/11_November

2013/V3I11-0434.pdf

5. http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=4699964

8/10/2019 Light Fedility

26/26

Questions?

Thank you.