ECE Li Fi Technology Report

8/15/2019 ECE Li Fi Technology Report

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Prefa ce

I have made this report file on the topic Li-Fi Technology; I have tried my best to collect all

the relevant detail to the topic to be included in the report. While in the beginning I have tried to

give a general view about this topic.

My efforts and wholehearted co-corporation of each and every one has ended on a successful

note. I express my sincere gratitude to who assisting me throughout the preparation of this

topic. I thank him for providing me the reinforcement, confidence and most importantly the

track


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Acknowledgement

I would like to thank respected !r. Manvendra and !r. "rinu #. "hillip for giving me such a

wonderful opportunity to expand my knowledge for my own branch and giving me guidelines

to present a seminar report. It helped me a lot to reali$e of what we study for.

%econdly, I would like to thank my parents who patiently helped me as i went through my work

and helped to modify and eliminate some of the irrelevant or un-necessary stuffs.

&hirdly, I would like to thank my friends who helped me to make my work more organi$ed and

well-stacked till the end.

'ext, I would thank Microsoft for developing such a wonderful tool like M% Word. It helped

my work a lot to remain error-free.

(ast but clearly not the least; I would thank &he )lmighty for giving me strength to complete

my report on time.

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Abstract of Li-Fi Technology

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. )s 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.

ut radio waves are ust one part of the spectrum that can carry our data. What if we could use

other waves to surf the internet /ne 0erman physicist, 12. 3arald 3aas, has come up with a

solution he calls 41ata &hrough Illumination56taking the fiber out of fiber optics by sending

data through an (!1 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.

3aas says his invention, which he calls 1-(ight, can produce data rates faster than 7

megabits per second, which is speedier than your average broadband connection. 3e envisions

a future where data for laptops, smart phones, and tablets is transmitted through the light in a

room. )nd security would be a snap6if you can+t see the light, you can+t access the data.

(i-8i is a 9(#, visible light communication, technology developed by a team of scientists

including 1r 0ordon "ovey, "rof. 3arald 3aas and 1r Mostafa )fghani at the :niversity of

!dinburgh. &he term (i-8i was coined by "rof. 3aas when he ama$ed people by streaming high-

definition video from a standard (!1 lamp, at &!1 0lobal in uly *7. (i-8i is now part of the

9isible (ight #ommunications


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Introduction

In simple terms, (i-8i can be thought of as a light-based Wi-8i. &hat is, it uses light instead of

radio waves to transmit information. )nd instead of Wi-8i modems, (i-8i would use transceiver-

fitted (!1 lamps that can light a room as well as transmit and receive information. %ince simple

light bulbs are used, there can technically be any number of access points.

&his technology uses a part of the electromagnetic spectrum that is still not greatly utili$ed- &he

9isible %pectrum. (ight is in fact very much part of our lives for millions and millions of years

and does not have any maor ill effect. Moreover there is 7,777 times more space available in

this spectrum and ust counting on the bulbs in use, it also multiplies to 7,777 times more

availability as an infrastructure, globally.

It is possible to encode data in the light by varying the rate at which the (!1s flicker on and off to give different strings of s and 7s. &he (!1 intensity is modulated so rapidly that human eyes

cannot notice, so the output appears constant.

More sophisticated techniDues could dramatically increase 9(# data rates. &eams at the

:niversity of /xford and the :niversity of !dinburgh are focusing on parallel data transmission

using arrays of (!1s, where each (!1 transmits a different data stream. /ther groups are using

mixtures of red, green and blue (!1s to alter the lightAs freDuency, with each freDuency

encoding a different data channel.

(i-8i, as it has been dubbed, has already achieved blisteringly high speeds in the lab. 2esearchers

at the 3einrich 3ert$ Institute in erlin, 0ermany, have reached data rates of over ?77

megabytes per second using a standard white-light (!1. 3aas has set up a spin-off firm to sell a

consumer 9(# transmitter that is due for launch next year. It is capable of transmitting data at

77 MEs - faster than most :F broadband connections.

&his /W# technology uses light from light-emitting diodes *G from *7C to *7> and to be worth over

H billion per year by *7>.

9isible light communications


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(i-8i has the advantage of being useful in electromagnetic sensitive areas such as in aircraft

cabins, hospitals and nuclear power plants without causing electromagnetic interference. oth Wi-

8i and (i-8i transmit data over the electromagnetic spectrum, but whereas Wi-8i utili$es radio

waves, (i-8i uses visible light.

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History

3arald 3aas, who teaches at the :niversity of !dinburgh in the :F, coined the term K(i-8iK at his

&!1 0lobal &alk where he introduced the idea of KWireless data from every lightK. 3e is #hair of

Mobile #ommunications at the :niversity of !dinburgh and co-founder of pure (i-8i.

&he general term visible light communication >7s,

includes any use of the visible light portion of the electromagnetic spectrum to transmit information.

&he 1-(ight proect at !dinburghAs Institute for 1igital #ommunications was funded from anuary

*77 to anuary *7*. 3aas promoted this technology in his *7 &!1 0lobal talk and helped start

a company to market it. "ure (i-8i, formerly pure 9(#, is an original eDuipment manufacturer

7*.?.@r standardi$ation committee.

9(# technology was exhibited in *7* using (i-8i. 0ust *7C, data rates of over . 0bitEs were

demonstrated over a single color (!1. In %eptember *7C, a press release said that (i-8i, or 9(#

systems in general, do not reDuire line-of-sight conditions. In /ctober *7C, it was reported #hinese

manufacturers were working on (i-8i development kits.

In )pril *7J, the 2ussian company %tins #oman announced the development of a (i-8i wireless

local network called eam #aster. &heir current module transfers data at .*? gigabytes per second

but they foresee boosting speeds up to ? 0Esecond in the near future. In *7J a new record was

established by %isoft


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Genesis of LI-FI

3arald 3aas, a professor at the :niversity of !dinburgh who began his research in the field in

*77J, gave a debut demonstration of what he called a (i-8i prototype at the &!1 0lobal

conference in !dinburgh on *th uly *7. 3e used a table lamp with an (!1 bulb to transmit a

video of blooming flowers that was then proected onto a screen behind him.

1uring the event he periodically blocked the light from lamp to prove that the lamp was indeed

the source of incoming data. )t &!1 0lobal, 3aas demonstrated a data rate of transmission of

around 7Mbps -- comparable to a fairly good :F broadband connection. &wo months later he

achieved *CMbps.

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Standards

(ike Wi-8i, (i-8i is wireless and uses similar >7*. protocols; but it uses visible light

communication 7*

workgroup. 3owever, the I!!! >7*.?.@ standard is out-of-date, it fails to consider the latest

technological developments in the field of optical wireless communications, specifically with the

introduction of optical orthogonal freDuency-division multiplexing


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"hilips lighting company has developed a 9(# system for shoppers at stores. &hey have to

download an app on their smartphone and then their smartphone works with the (!1s in the store.

&he (!1s can pinpoint where they are located in the store and give them corresponding coupons

and information based on which aisle they are on and what they are looking at.

How Li-Fi orks!

(i-8i is typically implemented using white (!1 light bulbs at the downlink transmitter. &hese

devices are normally used for illumination only by applying a constant current. 3owever, by fast

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

speeds.

&his very property of optical current is used in (i-8i setup. &he operational procedure is very

simple-, if the (!1 is on, you transmit a digital , if it+s off you transmit a 7. &he (!1s can be

switched on and off very Duickly, which gives nice opportunities for transmitting data. 3ence all

that is reDuired is some (!1s and a controller that code data into those (!1s. )ll one has to do

is to vary the rate at which the (!1+s flicker depending upon the data we want to encode.

8urther enhancements can be made in this method, like using an array of (!1s for parallel data

transmission, or using mixtures of red, green and blue (!1s to alter the light+s freDuency with

each freDuency encoding a different data channel. %uch advancements promise a theoreticalspeed of 7 0bps O meaning one can download a full high-definition film in ust C7 seconds.

(i-8i and Wi-8i are Duite similar as both transmit data electromagnetically. 3owever, Wi-8i uses

radio waves while (i-8i runs on visible light.

)s we now know, (i-8i is a 9isible (ight #ommunications


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&he signal is then converted back into a binary data stream that we would recognise as web, video

and audio applications that run on internet enables devices.

The future internet

(i-8i technology will in future enable faster, more reliable internet connections, even when the

demand for data usage has outgrown the available supply from existing technologies such as J0,

(&! and Wi-8i. It will not replace these technologies, but will work seamlessly alongside them.

:sing light to deliver wireless internet will also allow connectivity in environments that do not

currently readily support Wi-8i, such as aircraft cabins, hospitals and ha$ardous environments.

(ight is already used for data transmission in fibre-optic cables and for point to point links, but (i-8i

is a special and novel combination of technologies that allow it to be universally adopted for mobile

ultra-high speed internet communications.

A dual use for L"# lighting

&he wide use of solid state lighting offers an opportunity for efficient dual use lighting and

communication systems. Innovation in (!1 and photon receiver technology has ensured the

availability of suitable light transmitters and detectors, while advances in the modulation of

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communication signals for these types of components has been advanced through signal processing

techniDues, such as multiple-input-multiple-output


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&o further get a grasp of (i-8i consider an I2 remote. It sends a single data stream of bits at the

rate of 7,777-*7,777 bps. 'ow replace the I2 (!1 with a (ight ox containing a large (!1

array. &his system, fig C.J, is capable of sending thousands of such streams at very fast rate.

(ight is inherently safe and can be used in places where radio freDuency communication isoften deemed problematic, such as in aircraft cabins or hospitals. %o visible light

communication not only has the potential to solve the problem of lack of spectrum space, but can

also enable novel application. &he visible light spectrum is unused, itAs not regulated, and can be

used for communication.

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Li-fi $s i-Fi

While some may think that (i-8i with its **J gigabits per second leaves Wi-8i in the dust, (i-8iAs

exclusive use of visible light could halt a mass uptake.

(i-8i signals cannot pass through walls, so in order to enoy full connectivity, capable (!1 bulbs

will need to be placed throughout the home. 'ot to mention, (i-8i reDuires the light bulb is on at all

times to provide connectivity, meaning that the lights will need to be on during the day.

WhatAs more, where there is a lack of light bulbs, there is a lack of (i-8i internet so (i-8i does take a

hit when it comes to public Wi-8i networks.

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In an announcement yesterday, an extension of standard Wi-8i is coming and itAs called Wi-8i

3a(ow.

&his new proect claims to double the range of connectivity while using less power. 1ue to this, Wi-

8i 3a(ow is reportedly perfect for battery powered devices such as smart watches, smartphones and

lends itself to Internet of &hings devices such as sensors and smart applications.

ut itAs not all doom and gloomP 1ue to its impressive speeds, (i-8i could make a huge impact on

the internet of things too, with data transferred at much higher levels with even more devices able to

connect to one another.

WhatAs more, due to its shorter range, (i-8i is more secure than Wi-8i and itAs reported that

embedded light beams reflected off a surface could still achieve @7 megabits per second.

A%%lication of Li-Fi Technology

&ou 'ight (ust Li$e Longer

Lou Might ust (ive (onger 8or a long time, medical technology has lagged behind the rest of

the wireless world. /perating rooms do not allow Wi-8i over radiation concerns, and there is

also that whole lack of dedicated spectrum. While Wi-8i is in place in many hospitals,

interference from cell phones and computers can block signals from monitoring eDuipment.

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(i-8i solves both problems lights are not only allowed in operating rooms, but tend to be the

most glaring


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with each other, processing data autonomously and referring findings periodically back to the

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

It *ould +ee% &ou Informed and Sa$e Li$es

%ay there+s an earthDuake in 'ew Lork. /r a hurricane. &ake your pick 6it+s a wacky city. &he

average 'ew Lorker may not know what the protocols are for those kinds of disasters. :ntil they pass under a street light, that is.

2emember, with (i-8i, if there+s light, you+re online. %ubway stations and tunnels, common dead

$ones for most emergency communications, pose no obstruction. "lus, in times less stressing

cities could opt to provide cheap high speed Web access to every street corner.


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The future of Li-Fi

In 'ovember last year, (i-8i pioneers pure (i-8i oined forces with 8rench lighting company

(ucibel aiming to bring out (i-8i enables products, later this year.

"ure (i-8i already have two products on the market (i-8lame #eiling :nit to connect to an (!1light fixture and (i-8lame 1esktop :nit which connects to a device via :%, both aiming to provide

light and connectivity in one device.

"lus, with faster connectivity and data transmission it+s an interesting space for businesses. &he

integration of internet of things devices and (i-8i will provide a wealth of opportunities for retailers

and other businesses alike. 8or example, shop owners could transmit data to multiple customersA

phones Duickly, securely and remotely.

WhatAs more, reports suggest that )pple may build future i"hones with (i-8i capabilities. ) &witter

user found that within its i/% N. code there were references to (i-8i written as A(i-8i #apabilityAhinting that )pple may integrate (i-fi with i"hones in the future.

Whether or not (i-8i will live up to its hype is yet to be decided.

How it is different!

(i-8i technology is based on (!1s for the transfer of data. &he transfer of the data can be with the

help of all kinds of light, no matter the part of the spectrum that they belong. &hat is, the light can@


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belong to the invisible, ultraviolet or the visible part of the spectrum. )lso, the speed of the

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

with the help of this technology.

)lso, the technology removes limitations that have been put on the user by the Wi-8i. Lou no

more need to be in a region that is Wi-8i enabled to have access to the internet. Lou can simply

stand under any form of light and surf the internet as the connection is made in case of any light presence. &here cannot be anything better than this technology.

)ses in ,arious Areas

#an be used in the places where it is difficult to lay the optical fiber like hospitals. In operation

theatre (i-8i can be used for modern medical instruments. In traffic signals (i--8i can be used

which will communicate with the (!1 lights of the cars and accident numbers can be decreased.

&housand and millions of street lamps can be transferred to (i-8i lamps to transfer data. In

aircraft (i-8i can be used for data transmission. It can be used in petroleum or chemical plants

where other transmission or freDuencies could be ha$ardous.

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An integrated communication solution

Li-Fi technology is being developed into a ubiquitous systems technology, consisting of

application specific combinations of light transmitters, light receivers including solar cells,efficient computational algorithms and networking capabilities that can be deployed in a

wide range of communication scenarios and in a variety of device platforms

(i-fi ?g

"icture this-you wake up and tap your smartphone to switch on your coffee machine. )s you make

breakfast, your refrigerator sends you a text that you+re out of orange uice. #lued in with this

message, your car+s 0"% routes you to the grocery shop on your way back from work, as you use

your phone to switch on your home heating system, so things are toasty warm when you get back.

)t the forefront of this connectivity phenomenon popularly known as the AInternet of &hingsA, is anoptical communication technology that+s taking the world by storm. (ight 8idelity or (i-8i, is an

exciting breakthrough in ?0 visual light communication systems and the future of wireless Internet

access.

With (i-8i, information hitches a ride along a spectrum of visible light. (ight-emitting diode


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Ad$antages of LI-FI

• (i-8i can solve problems related to the insufficiency of radio freDuency bandwidth because this

technology uses 9isible light spectrum that has still not been greatly utili$ed.

• 3igh data transmission rates of up to 70bps can be achieved.

• since light cannot penetrate walls, it provides privacy and security that Wi-8i cannot.

• (i-8i has low implementation and maintenance costs.

• It is safe for humans since light, unlike radio freDuencies, cannot penetrate human body.

3ence, concerns of cell mutation are mitigated.

#isad$antage of LI-FI

• (ight canAt pass through obects.

• ) maor challenge facing (i-8i is how the receiving device will transmit back to

transmitter

• 3igh installation cost of the 9(# systems.

• Interferences from external light sources like sun, light, normal bulbs, opaDue materials.

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*onclusion

&he possibilities are numerous and can be explored further. If his technology can be put into

practical use, every bulb can be used something like a Wi-8i hotspot to transmit wireless data

and we will proceed toward the cleaner, greener, safer and brighter future.

&he concept of (i-8i is currently attracting a great deal of interest, not least because it may offer a

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

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

making it more and more difficult to get a reliable, high-speed signal.

&his may solve issues such as the shortage of radio-freDuency bandwidth and also allow internet

where traditional radio based wireless isn+t allowed such as aircraft or hospitals. /ne of the

shortcomings however is that it only work in direct line of sight.

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ECE Li Fi Technology Report

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