Li Fi

1

light-fidelity

SUBMITTED BY : NAZIA ISHRAT

ROLL NO: 1005231025

Submitted to the Department of ELECTRONICS AND COMMUNICATION

In partial fulfillment of the requirements

For the degree of

Bachelor of Technology

In

ELECTRONICS & COMMUNICATION

INSTITUTE OF ENGINEERING AND TECHNOLOGY

G.B. Technical University

[2012-2013]

Student Name:NAZIA ISHRAT Seminar Guide Name: ER. DIVYA TRIPATHI

Student Signature: Seminar Guide signature:

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CERTIFICATE

This to certify that Miss NAZIA ISHRAT prepared this B.Tech seminar report titled LIGHT

FIDELITY(LI-FI) under the esteemed guidance of Er. Divya Tripathi .This seminar report is

submitted to the department of Electronics Engineering in partial fulfilment of the requirements

for the degree of Bachelor of Technology in Electronics and Communication Engineering.

Seminar Guide Name Head of Department

ER.DIVYA TRIPATHI Dr. NEELAM SRIVASTAVA

Seminar Guide Signature H.O.D Signature

3

ACKNOWLEDGEMENT

It gives me a great sense of pleasure to present the B.Tech Seminar report undertaken during B.

Tech. Third Year. I owe special debt of gratitude to respected H.O.D Neelam Srivastava for

her guidance. I would like to take this opportunity to thank my seminar guide Er.Divya

Tripathi for her constant support and guidance throughout the course of my work. Her

sincerity, thoroughness and perseverance have been a constant source of inspiration for me. It is

only her cognizant efforts that mine endeavor have seen light of the day.

I also do not like to miss the opportunity to acknowledge the contribution of all dignitary

Staff-members of I.E.T. Lucknow for their kind assistance and cooperation during the

development of my Seminar report. Last but not the least, I acknowledge my friends for their

contribution in the completion of the seminar report.

Apart from the efforts of me, the success of this project depends largely on the encouragement

and guidelines of many others. I take this opportunity to express my gratitude to the people

who have been instrumental in the successful completion of this report.

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ABSTRACT

Whether you‘re using wireless internet in a coffee shop, stealing it from the guy next door, or

competing for bandwidth at a conference, you’ve probably gotten frustrated at the slow speeds

you face when more than one device is tapped into the network. As more and more people and

their many devices access wireless internet, clogged airwaves are going to make it increasingly

difficult to latch onto a reliable signal. But radio waves are just one part of the spectrum that can

carry our data. What if we could use other waves to surf the internet?

One German physicist,DR. Harald Haas, has come up with a solution he calls“Data Through

Illumination”—taking the fiber out of fiber optics by sending data through an LED light bulb

that varies in intensity faster than the human eye can follow. It’s the same idea behind infrared

remote controls, but far more powerful. Haas says his invention, which he calls D-Light, can

produce data rates faster than 10 megabits per second, which is speedier than your average

broadband connection. He envisions a future where data for laptops,smartphones, and tablets is

transmitted through the light in a room. And security would be a snap—if you can’t see the

light,you can’t access the data.

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INDEX

SERIAL NO.

PAGE NO.

CHAPTER 1 07-08

1.1 INTRODUCTION 07

CHAPTER 2 09-10

2.1 VISIBLE LIGHT COMMUNICATION 09

CHAPTER 3 11-14

3.1 LIGHT FIDELITY (LI-FI) 11

CHAPTER 4 15-17

4.1 SYSTEM DESIGN 15

4.2 METHODS OF VLC 15

CHAPTER 5 18-21

5.1 WORKING TECHNOLOGY 18

CHAPTER 6 22-24

6.1 COMPARISION BETWEEN LI-FI&WI-FI 22

6.2 ISSUES WITH RADIO WAVES 23

6.3 HOW IS LI-FI DIFFERENT 24

CHAPTER 7 25-31

7.1 FUTURE PROSPECTS 25

7.2 APPLICATIONS 26

CHAPTER 8 32-32

8.1 CONCLUSION 32

CHAPTER 9 33-33

9.1 BIBLIOGRAPHY 33

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List of figures

Figure no.

Figure name Page no.

Fig 1.1 2.4 GHz Wireless Router 08

Fig 2.1 Electromagnetic spectrum 09

Fig 3.1 Coinage of LI-FI 11

Fig 3.2 Transfer of data through light 13

Fig 4.1 Communication system 16

Fig 5.1 Working of Li-fi 19

Fig 5.2 Block diagram 20

Fig 5.3 Transfer of data from internet to user 21

Fig 6.1 Four aspects of WI-FI 23

Fig 7.1 Anticipated uses of LI-FI 25

Fig 7.2 Use in medical field 27

Fig 7.3 Use in airlines 28

Fig 7.4 Use in power plants 29

Fig 7.5 Under sea awsomeness 30

Fig 7.6 Use of LI-FI in traffic control 31

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CHAPTER 1

1.1 INTRODUCTION

Li-Fi is transmission of data through illumination by taking the fiber out of fiber optics by

sending data through a LED light bulb that varies in intensity faster than the human eye can

follow. Li-Fi is the term some have used to label the fast and cheap wireless-communication

system, which is the optical version of Wi-Fi. The term was first used in this context by Harald

Haas in his TED Global talk on Visible Light Communication. ―At the heart of this technology

is a new generation of high brightness light-emitting diodes‖, says Harald Haas from the

University of Edinburgh, UK.Very simply, if the LED is on, you transmit a digital 1, if it‘s off

you transmit a 0.Haas says,―They can be switched on and off very quickly, which gives nice

opportunities for transmitted data.‖It is possible to encode data in the light by varying the rate at

which the LEDs flicker on and off to give different strings of 1s and 0s.The LED intensity is

modulated so rapidly that human eye cannot notice, so the output appears constant. More

sophisticated techniques could dramatically increase VLC data rate. Terms at the University of

Oxford and the University of Edingburgh are focusing on parallel data transmission using array

of LEDs, where each LED transmits a different data stream. Other group are using mixtures of

red, green and blue LEDs to alter the light frequency encoding a different data channel.Li-Fi, as

it has been dubbed, has already achieved blisteringly high speed in the lab. Researchers at the

Heinrich Hertz Institute in Berlin, Germany have reached data rates of over 500 megabytes per

second using a standard white-light LED. The technology was demonstrated at the 2012

Consumer Electronics Show in Las Vegas using a pair of Casio smart phones to exchange data

using light of varying intensity given off from their screens, detectable at a distance of up to ten

metres In October 2011 a number of companies and industry groups formed the Li-F

Consortium, to promote high-speed optical wireless systems and to overcome the limited amount

of radio based wireless spectrum available by exploiting a completely different part of the

electromagnetic spectrum. The consortium believes it is possible to achieve more than 10Gbps,

theoretically allowing a high-definition film to be downloaded in 30 seconds.

Most of us are familiar with Wi-Fi (Wireless Fidelity), which uses 2.4-5GHz RF to deliver

wireless Internet access around our homes, schools, offices and in public places. We have

become quite dependent upon this nearly ubiquitous service. But like most technologies, it has its

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limitations.

While Wi-Fi can cover an entire house, its bandwidth is typically limited to 50-100 megabits per

second (Mbps) today using the IEEE802.11n standard. This is a good match to the speed of most

current Internet services, but insufficient for moving large data files like HDTV movies, music

libraries and video games

Figure 1.1 . Linksys 2.4 Ghz Wireless Router

The more we become dependent upon ‗the cloud‘ or our own ‗media servers‘ to store all of our

files, including movies, music, pictures and games, the more we will want bandwidth and speed.

Therefore RF-based technologies such as today‘s Wi-Fi are not the optimal way.

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CHAPTER 2

2.1 VISIBLE LIGHT COMMUNICATION

Many people‘s first exposure to optical wireless technology was VLC. This emerging technology

offers optical wireless communications by using visible light. Today, it is seen as an alternative

to different RF-based communication services in wireless personal-area networks. An additional

opportunity is arising by using current state-of-the-art LED lighting solutions for illumination

and communication at the same time and with the same module. This can be done due to the

ability to modulate LEDs at speeds far faster than the human eye can detect while still providing

artificial lighting.

Thus while LEDs will be used for illumination, their secondary duty could be to ‗piggyback‘

data communication onto lighting systems. This will be particularly relevant in indoor ‗smart‘

lighting systems, where the light is always ‗on.‘

In contrast to infrared, the so-called ―what you see is what you send‖ feature can be used to

improve the usability of transmitting data at shorter point-to-point distances between different

portable or fixed devices. There, illumination can be used for beamguiding, discovery or

generating an alarm for misalignment.

Fig 2.1 Electromagnetic spectrum

The premise behind VLC is that because lighting is nearly everywhere, communications can ride

along for nearly free. Think of a TV remote in every LED light bulb and you‘ll soon realise the

possibilities of this technology.

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One of the biggest attractions of VLC is the energy saving of LED technology. Nineteen per cent

of the worldwide electricity is used for lighting. Thirty billion light bulbs are in use worldwide.

Assuming that all the light bulbs are exchanged with LEDs, one billion barrels of oil could be

saved every year, which again translates into energy production of 250 nuclear power plants.

Driven by the progress of LED technology, visible light communication is gaining attention in

research and development. The VLC Consortium (VLCC) in Japan was one of the first to

introduce this technology.

After establishing a VLC interest group within the IEEE 802.15 wireless personal-area networks

working group, the IEEE 802.15.7 task group was established by the industry, research institutes

and universities in 2008. The final standard was approved in 2011. It specifies VLC comprising

mobile-to-mobile (M2M), fixed-to-mobile (F2M) and infrastructure-to-mobile (I2M)

communications. There, the focus is on low-speed, medium-range communications for

intelligent traffic systems and on high-speed, shortrange M2M and F2M communications to

exchange, for example, multimedia data. Data rates are supported from some 100 kbps up to 100

Mbps using different modulation schemes.

Other standardisation groups are working on standardised optical wireless communication

(OWC) solutions using visible and infrared light. The most important groups are IrDA with its

new 10 Giga-IR working group, ISO and ICSA.

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CHAPTER 3

3.1 LIGHT FIDELITY(Li-Fi)

VLC represents only a fraction of what appears to be a much larger movement towards optical

wireless technologies in general. This larger word has been dubbed ‗Li-Fi‘ (Light Fidelity) by Dr

Harald Haas of Edinburgh University and organisations such as the Li-Fi Consortium.

Figure 3.1“Li Fi”- The Term Coined By Dr Harald Haas

Li-Fi is a VLC, visible light communication, technology developed by a team of scientists

including Dr Gordon Povey, Prof. Harald Haas and Dr Mostafa Afgani at the University of

Edinburgh. The term Li-Fi was coined by Prof. Haas when he amazed people by streaming high-

definition video from a standard LED lamp,at TED Global in July 2011. Li-Fi is now part of the

Visible Light Communications (VLC) PAN IEEE 802.15.7 standard.

Li-Fi is typically implemented using white LED light bulbs. These devices are normally used for

illumination by applying a constant current through the LED. However, by fast and subtle

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variations of the current, the optical output can be made to vary at extremely high speeds.Unseen

by the human eye, this variation is used to carry high-speed data, says Dr Povey, , Product

Manager of the University of Edinburgh's Li-Fi Program‘D-Light Project’.

Li-Fi is a short term of light fidelity. Just like the more commonly known wireless fidelity,it

aims to transfer data through light. It is a technology based on LED‘s for the exchange of data.

Data will be sent via light, all kinds of light, regardless the part of the spectrum where they

belong. Li-Fi has been developed by Haas whose expertise is on the mobile communications

at Edinburgh University, known as the head over heels in LED from his teenage years.

In that connection, Li-Fi comprises several optical wireless technologies such as optical wireless

communication, navigation and gesture recognition applied for natural user interfaces .Thus it

provides a completely new set of optical technologies and techniques to offer users add-on as

well as complementary functionalities compared to well-known and established RF services.

This could reach from a new user experience regarding communication speeds in the gigabitclass

to bridge the well-known spectrum crunch, over to precise indoor positioning or controlling

video games, machines or robots with entirely new natural user interfaces. Finally, these and

many more could be merged to a full-featured Li-Fi cloud providing wireless services for other

future applications as well.

Li-Fi comprises a wide range of frequencies and wavelengths, from the infrared through visible

and down to the ultraviolet spectrum. It includes sub-gigabit and gigabit-class communication

speeds for short, medium and long ranges, and unidirectional and bidirectional data transfer

using line-of-sight or diffuse links, reflections and much more. It is not limited to LED or laser

technologies or to a particular receiving technique. Li-Fi is a framework for all of these

providing new capabilities to current and future services, applications and end users.

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Fig 3.2 Transfer of data through light

Within a local Li-Fi cloud several databased services are supported through a heterogeneous

communication system. In an initial approach, the Li-Fi Consortium defined different types of

technologies to provide secure, reliable and ultra-high-speed wireless communication interfaces.

These technologies included giga-speed technologies, optical mobility technologies, and

navigation, precision location and gesture recognition technologies.

For giga-speed technologies, the Li-Fi Consortium defined GigaDock, GigaBeam, GigaShower,

GigaSpot and GigaMIMO models to address different user scenarios for wireless indoor and

indoor-like data transfers. While GigaDock is a

wireless docking solution including wireless charging for smartphones, tablets or notebooks,

with speeds up to 10 Gbps, the GigaBeam model is a point-to-point data link for kiosk

applications or portable-to-portable data exchanges. Thus a two-hour full HDTV movie (5 GB)

can be transferred from one device to another within four seconds.

GigaShower, GigaSpot and Giga- MIMO are the other models for in-house communication.

There a transmitter or receiver is mounted into the ceiling connected to, for example, a media

server. On the other side are portable or fixed devices on a desk in an office, in an operating

room, in a production hall or at an airport. GigaShower provides unidirectional data services via

several channels to multiple users with gigabit-class communication speed over several metres.

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This is like watching TV channels or listening to different radio stations where no uplink channel

is needed. In case GigaShower is used to sell books, music or movies, the connected media

server can be accessed via Wi-Fi to process payment via a mobile device. GigaSpot and

GigaMIMO are optical wireless single- and multi-channel HotSpot solutions offering

bidirectional gigabit-class communication in a room, hall or shopping mall for example.

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CHAPTER 4

4.1 SYSTEM DESIGN

Li-Fi is typically implemented using white LED light bulbs at the downlink transmitter. These

devices are normally used for illumination only by applying a constant current. However, by fast

and subtle variations of the current, the optical output can be made to vary at extremely high

speeds. This very property of optical current is used in Li- Fi setup. The operational procedure is

very simple-,data from the internet and local network is used to modulate the intensity of the

LED light source if any undetectable to the human eye. The photo detector picks up signal,

which is converted back into a data stream and sent to the client. The client can communicate

through its own LED output or over the existing network. An overhead lamp fitted with an LED

with signal-processing technology streams data embedded in its beam at ultra-high speeds to the

photo-detector. A receiver dongle then converts the tiny changes in amplitude into an electrical

signal, which is then converted back into a data stream and transmitted to a computer or mobile

device.

4.2 Methods of Visible Light Communication

Devices used for Visible Light Communication

Communication using Image Sensors

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Devices used for Visible Light Communication

TRANSMITTER RECEIVER

Fig 4.1 Communication system

Transmitter devices of visible light communication

1.>Visible Light LED

LED light intensity is modulated by controlling its current.

Data rate: low speed to very high speed (up to several hundred Mbps)

2.> Fluorescent Lamp

FSK modulation of high frequency fluorescent light.

Data rate: up to several kilo bps.

Receiver devices of visible light communication

1.>PIN diode

A PIN diode is a diode with a wide, lightly doped 'near' intrinsic semiconductor region between a

p-type semiconductor and an n-type semiconductor region. The p-type and n-type regions are

typically heavily doped because they are used for Ohmic contacts.

Visible light

17

The wide intrinsic region is in contrast to an ordinary PN diode. The wide intrinsic region makes

the PIN diode an inferior rectifier (one typical function of a diode), but it makes the PIN diode

suitable for attenuators, fast switches, photo detectors, and high voltage power electronics

applications.

2.>Avalanche photodiode

An avalanche photodiode (APD) is a highly sensitive semiconductor electronic device that

exploits the photoelectric effect to convert light to electricity. APDs can be thought of as photo

detectors that provide a built-in first stage of gain through avalanche multiplication. From a

functional standpoint, they can be regarded as the semiconductor analog to photo multipliers .By

applying a high reverse bias voltage (typically 100-200 V in silicon), APDs show an internal

current gain effect (around 100) due to impact ionization (avalanche effect). However, some

silicon APDs employ alternative doping and beveling techniques compared to traditional APDs

that allow greater voltage to be applied (> 1500 V) before breakdown is reached and hence a

greater operating gain (>1000).In general, the higher the reverse voltage the higher the gain.

Communication through image sensors

An image sensor is a device that converts an optical image into an electronic signal. It is used

mostly in digital cameras, camera modules and other imaging devices. Early analog sensors were

video camera tubes; most currently used are digital charge-coupled device (CCD) or

complementary metal–oxide–semiconductor (CMOS) active pixel sensors.

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CHAPTER 5

5.1 WORKING TECHNOLOGY

VLC uses visible light between 400 THz (780 nm) and 800 THz (375 nm) as optical carrier for

data transmission and illumination. It uses fast pulses of light to transmit information wirelessly.

The main components of this communication system are

1) a high brightness white LED, Which acts as a communication source and

2) a silicon photodiode which shows good response to visible wavelength region serving as the

receiving element.

LED can be switched on and off to generate digital strings of 1s and 0s. Data can be encoded in

the light to generate a new data stream by varying the flickering rate of the LED. To be clearer,

by modulating the LED light with the data signal, the LED illumination can be used as a

communication source. As the flickering rate is so fast, the LED output appears constant to the

human eye. A data rate of greater than 100 Mbps is possible by using high speed LEDs with

appropriate multiplexing techniques. VLC data rate can be increased by parallel data

transmission using LED arrays where each LED transmits a different data stream. There are

reasons to prefer LED as the light source in VLC while a lot of other illumination devices like

fluorescent lamp, incandescent bulb etc. are available.

Very simply, if the LED is on, you transmit a digital 1, if it‘s off you transmit a 0,‖Haas says,

―They can be switched on and off very quickly, which gives nice opportunities for transmitted

data.‖It is possible to encode data in the light by varying the rate at which the LEDs flicker on

and off to give different strings of 1s and 0s.The LED intensity is modulated so rapidly that

human eye cannot notice, so the output appears constant. More sophisticated techniques could

dramatically increase VLC data rate. Terms at the University of Oxford and the University of

Edingburgh are focusing on parallel data transmission using array of LEDs, where each LED

transmits a different data stream. Other group are using mixtures of red, green and blue LEDs to

alter the light frequency encoding a different data channel.Li-Fi, as it has been dubbed, has

already achieved blisteringly high speed in the lab. Researchers at the Heinrich Hertz Institute in

Berlin Germany, have reached data rates of over 500 megabytes per second using a standard

19

white-light LED. The technology was demonstrated at the 2012 Consumer Electronics Show in

Las Vegas using a pair of Casio smart phones to exchange data using light of varying intensity

given off from their screens, detectable at a distance of up to ten metres.

Figure 5.1 Working of LI-FI

So what you require at all are some LEDs and a controller that code data into those LEDs. We

have to just vary the rate at which the LED‘s flicker depending upon the data we want to encode.

Further enhancements can be made in this method, like using an array of LEDs for parallel data

transmission, or using mixtures of red, green and blue LEDs to alter the light‘s frequency with

International Journal of Applied Engineering Research, ISSN 0973-4562 Vol.7 No.11 (2012)©

Research India Publications; http://www.ripublication.com/ijaer.htm each frequency encoding is

a different data channel. Such advancements promise a theoretical speed of 10 Gbps –meaning

20

you can download a full high-definition film in just 30 seconds. Simply awesome! But blazingly

fast data rates and depleting bandwidths worldwide are not the only reasons that give this

technology an upper hand. Since Li-Fi uses just the light, it can be used safely in aircrafts and

hospitals that are prone to interference from radio waves. This can even work underwater where

Wi-Fi fails completely, thereby throwing open endless opportunities for military operations.

Imagine only needing to hover under a street lamp to get public internet access, or downloading

a movie from the lamp on your desk. There's a new technology on the block which could, quite

literally as well as metaphorically, 'throw light on' how to meet the ever-increasing demand for

high-speed wireless connectivity. Radio waves are replaced by light waves in a new method of

data transmission which is being called Li-Fi Light-emitting diodes can be switched on and off

faster than the human eye can detect, causing the light source to appear to be on continuously.

Figure 5.2 Block Diagram

A flickering light can be incredibly annoying, but has turned out to have its upside, being

precisely what makes it possible to use light for wireless data transmission. Light-emitting diodes

can be switched on and off faster than the human eye can detect, causing the light source to

appear to be on continuously, even though it is in fact 'flickering'. This invisible on-off activity

21

enables a kind of data transmission using binary codes. Information can therefore be encoded in

the light by varying the rate at which the LEDs flicker on and off to give different strings of 1s

and 0s. This method of using rapid pulses of light to transmit information wirelessly is

technically referred to as Visible Light Communication (VLC), though it‘s potential to compete

with conventional Wi-Fi has inspired the popular characterisation Li-Fi.

Fig 5.3 Data from internet to user through light

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CHAPTER 6

6.1 COMPARISION BETWEEN LI-FI&WI-FI

LI-FI is a term of one used to describe visible light communication technology applied to high

speed wireless communication. It acquired this name due to the similarity to WI-FI, only using

light instead of radio WI-FI is great for general wireless coverage within buildings, and li-fi is

ideal for high density wireless data coverage in confined area and for relieving radio interference

issues, so the two technologies can be considered complimentary.

Table 6.1Comparison between current and future wireless technologies

The table also contains the current wireless technologies that can be used for transferring data

between devices today, i.e. Wi-Fi, Bluetooth and IrDA. Only Wi-Fi currently offers very high

data rates. The IEEE 802.11.n in most implementations provides up to 150Mbit/s (in theory the

23

standard can go to 600Mbit/s) although in practice you receive considerably less than this. Note

that one out of three of these is an optical technology.

6.2 ISSUES WITH WI-FI USING RADIO WAVES

There are four issues with the current wi-fi scenario , which are :-

Fig 6.1 Four aspects of WI-FI

1.>CAPACITY:

We transmit wireless data is by using electromagnetic waves -- inparticular, radio waves.

Radio waves are scarce, expensive and we only have a certain range of it.

Due to this limitation one can’t forever hope to cope with the demand of wireless data

transmissions and the number of bytes and data which are transmitted every month.

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2.>EFFICIENCY

There are 1.4 million cellular radio masts deployed worldwide.

Most of the energy consumed, is not used to transmit the radio waves,but is used to cool

the base stations.

The efficiency of such a base station is only at about five percent.

3.>AVAILABILITY

Availability of radio waves or RW signals causes another concern

We have to switch off our mobile devices in aero planes

It is not advisable to use mobiles at places like petrochemical plants and petrol pumps

4.>SECURITY

The radio waves penetrate through walls.

They can be intercepted, and somebody can make use of one‘s network.

6.3 How LI-FI is different?

Li-Fi technology is based on LEDs for the transfer of data. The transfer of the data can be with

the help of all kinds of light, no matter the part of the spectrum that they belong. That is, the light

can belong to the invisible, ultraviolet or the visible part of the spectrum. Also, the speed of the

internet is incredibly high and you can download movies, games, music etc in just a few minutes

with the help of this technology. Also, the technology removes limitations that have been put on

the user by the Wi-Fi. You no more need to be in a region that is Wi-Fi enabled to have access to

the internet. You can simply stand under any form of light and surf the internet as the connection

is made in case of any light presence. There cannot be anything better than this technology.

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CHAPTER 7

7.1 FUTURE PROSPECTS

First applications of Li-Fi have been put to use already, for example,in hospitals where RF signal

are a threat due to interference problems with medical equipment such as blood pumps and other

life supporting instruments. Axiomtek Europe presented such a product at the Embedded World

exhibition in Nurnberg, Germany. The prototype of a mobile phone with an incorporated VLC

system was presented by Casio at the Consumer Electronics Show in Las Vegas in January this

year. In the coming years, we will see more Li-Fi products entering the market, both in the

industrial as well as consumer markets.

Fig 7.1 Anticipated uses of VLC Technology

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7.2 APLICATIONS

7.2.1 Enhanced & Exclusive Shopping Experience

Imagine yourself walking into a mall where GPS signals are unavailable but the mall is equipped

with ceiling bulbs that create their own ‗constellation‘ of navigation beacons. As the camera of

your cellphone automatically receives these signals, it switches your navigation software to use

this information to guide you to the ATM machine you‘re

looking for.

You conclude your ATM transaction and notice the GigaSpot sign for instant digital movie

downloads. You pick out that new Tom Cruise movie using your phone‘s payment facility, and

then download within a few seconds the high-definition movie into the GigaLink flash drive

plugged into the USB port of your smartphone.

As you walk away, your phone notifies you that the leather jacket Tom featured in the movie is

on sale nearby. You walk over towards the show window and your image comes up on the

screen, wearing that coveted jacket. You turn and pose while the image matches your orientation

and body gestures for a ‗digital fitting.‘ When you walk into the store, the clerk hands you the

actual jacket in exactly your size.

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7.2.2 You Might Just Live Longer

For a long time, medical technology has lagged behind the rest of the wireless world. Operating

rooms do not allow Wi-Fi over radiation concerns, and there is also that whole lack of dedicated

spectrum. While Wi-Fi is in place in many hospitals, interference from cell phones and

computers can block signals from monitoring equipment. Li-Fi solves both problems: lights are

not only allowed in operating rooms, but tend to be the most glaring (pun intended) fixtures in

the room. And, as Haas mentions in his TED Talk, Li-Fi has 10,000 times the spectrum of Wi-Fi,

so maybe we can delegate red light to priority medical data. Code Red!

Figure 7.2 Use In Medical Field

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7.2.3 Airlines ( Data on the go!)

Nothing says captive audience like having to pay for the "service" of dial-up speed Wi-Fi on the

plane. And don‘t get me started on the pricing. The best I‘ve heard so far is that passengers will

"soon" be offered a "high-speed like" connection on some airlines. United is planning on speeds

as high as 9.8 Mbps per plane. Uh, I have twice that capacity in my living room. And at the same

price as checking a bag, I expect it. Li-Fi could easily introduce that sort of speed to each seat's

reading light. I‘ll be the guy WoWing next to you. Its better than listening to you tell me about

your wildly successful son, ma‘am.

Figure 7.3 Use in airlines

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7.2.3 Smarter Power Plants

Wi-Fi and many other radiation types are bad for sensitive areas. Like those surrounding power

plants. But power plants need fast, inter-connected data systems to monitor things like demand,

grid integrity and (in nuclear plants) core temperature. The savings from proper monitoring at a

single power plant can add up to hundreds of thousands of dollars. Li-Fi could offer safe,

abundant connectivity for all areas of these sensitive locations. Not only would this save money

related to currently implemented solutions, but the draw on a power plant‘s own reserves could

be lessened if they haven‘t yet converted to LED lighting.

Figure 7.4 Use in power plants

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7.2.4 Undersea Awesomeness

Underwater ROVs, those favourite toys of treasure seekers and James Cameron, operate from

large cables that supply their power and allow them to receive signals from their pilots above.

ROVs work great, except when the tether isn‘t long enough to explore an area, or when it gets

stuck on something. If their wires were cut and replaced with light — say from a submerged,

high-powered lamp — then they would be much freer to explore. They could also use their

headlamps to communicate with each other, processing data autonomously and referring findings

periodically back to the surface, all the while obtaining their next batch of orders.

Figure 7.5 Under sea awesomeness

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7.2.5 It Could Keep You Informed and Save Lives

Say there‘s an earthquake in New Delhi,or a hurricane. Take your pick — it‘s a wacky city. The

average Delhiite may not know what the protocols are for those kinds of disasters. Until they

pass under a street light, that is. Remember, with Li-Fi, if there‘s light, you‘re online. Metro

stations and tunnels, common dead zones for most emergency communications, pose no

obstruction. Plus, in times less stressing cities could opt to provide cheap high-speed Web access

to every street corner.

Figure 7.6 Use of li fi in traffic control

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CHAPTER 8

8.1 CONCLUSION

The concept of Li-Fi is currently attracting a great deal of interest, not least because it may offer

a genuine and very efficient alternative to radio-based wireless. As a growing number of people

and their any devices access wireless internet, the airwaves are becoming increasingly clogged,

making it more and more difficult to get a reliable, high-speed signal. This may solve issues such

as the shortage of radio-frequency bandwidth and also allow internet where traditional radio

based wireless isn‘t allowed such as aircraft or hospitals. One of the shortcomings however is

that it only work in direct line of sight.

33

CHAPTER 9

9.1 Bibliography

1. http://ted.com

2 http://visiblelightcomm.com/

3 http://teleinfobd.blogspot.in/2012/01/what-is-lifi.html

4 technopits.blogspot.comtechnology.cgap.org/2012/01/11/a-lifi-world/

5 www.lificonsortium.org/