Authorized Learning Center (Code: - 1537)

College for Professional Studies

Opp. Maitidevi Temple, Kathmandu, Nepal

LIGHT-FIDELITY

By

Sikendra pandit

College Roll No: 1407151347

University Roll No: 1408021710

Course: B.Sc.IT

Semester: 4th Semester

Submitted To:

Dr. R. K. Singh

Date of submission:

Abstract

This technical report contains the information and application about the light fidelity. The report

begins with the basic introduction and its history. Describing about its Introduction and features

does a basic explaining of the light fidelity. The title is focused toward the application of the

light fidelity in the various fields, so the content is diverted toward the application of light

fidelity after its brief introduction and history in the main/body part of this report.

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Acknowledgements

First of all I would like to thank our respected Sir Dr. R.K.Singh who guided us throughout this project. I am also thankful to my friends who advised me suggestion about the report. I would also like to thank my classmates for their kind suggestion and references for the further improvements and advance in this report. Thanks to our parent, family members and friends for their continuous support and encouragement to strive for our goals.

-Sikendra Pandit

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Preface

This report presents the brief information to light fidelity and its application. This report has

three chapters. The first chapter deals with introduction and history to light fidelity. The second

chapter deals about features, which is the most important chapter in this report. This chapter

includes main contents, which are very important in this report. The content of second chapter is

application and its type, advantages and disadvantages. The third chapter is objective and

conclusion.

III

List of Figures

Figure 1: Introduction of light fidelity 1

Figure2.1: History 3

Figure2.3: Advantage 6

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Acronym &Abbreviation

Lifi-light fidelity

LED-light emitting diode

GBPS-gigabit per second

VLC-visible light communication

OEM-original equipment manufacturer

2G-second generation

3G-third generation

4G-fourth generation

TB-terabyte

RW-radio waves

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Table of ContentsAbstract I

Acknowledgements II

Preface III

List of figures IV

Acronyms and abbreviations v

1 Introduction:...............................................................................................................................11.1 What we have to do?...........................................................................................................21.2 Is it a Proven Technology?.................................................................................................2

2 Discussions:.............................................................................................................................32.1 History:...............................................................................................................................32.2 Present Scenario of light fidelity........................................................................................42.3 Four Issues with Radio Waves............................................................................................52.4 Overcoming the four issues with RW in Li-Fi...................................................................52.5 Application of light fidelity..............................................................................................62.6 Advantages:........................................................................................................................62.7 Disadvantages:....................................................................................................................7

3 Conclusion:..............................................................................................................................8

4 Recommendations:.................................................................................................................9

Bibliography.................................................................................................................................10

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1 Introduction:

Li-fi is transmission of data through illumination by taking the fiber out of fiber optics by send-ing data through a LED light bulb that varies in intensity faster than the human eye can follow. Li-Fi is a wireless optical networking technology that uses light-emitting diodes (LEDs) for data transmission.

Li-Fi is designed to use LED light bulbs similar to those currently in use in many energy-con-scious homes and offices. However, LiFi bulbs are outfitted with a chip that modulates the light imperceptibly for optical data transmission. LiFi data is transmitted by the LED bulbs and re-ceived by photoreceptors.

LiFi's early developmental models were capable of 150 megabits-per-second (Mbps). Some commercial kits enabling that speed have been released. In the lab, with stronger LEDs and dif-ferent technology, researchers have enabled 10 gigabits-per-second (Gbps), which is faster than 802.11ad.

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.

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Figure 1: Introduction of light fidelity

1.1 What we have to do?

We have to replace inefficient fluorescents with this new dignitary of LED lights. The LED will hold a micro-chip that will do the job of processing the data. Light intensity can be modulated at very high speeds to send data by tiny changes in am-

plitude.

1.2 Is it a Proven Technology?Yes, this is already proven. Harald Haas demonstrated his invention using an ordinary table lamp that successfully transmitted data at speeds exceeding 10Mbps using light waves from LED light bulbs to a computer located below the lamp.

To prove that the light bulb was the source of the data stream, he periodically blocked the beam of light, causing the connection to drop.

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2 Discussions:

1.3 History:

Harald Haas, who teaches at the University of Edinburgh in the UK, coined the term "Li-Fi" at his TED Global Talk where he introduced the idea of "Wireless data from every light". He is Chair of Mobile Communications at the University of Edinburgh and co-founder of pure Li-Fi.

The general term visible light communication (VLC), whose history dates back to the 1880s, in-cludes any use of the visible light portion of the electromagnetic spectrum to transmit informa-tion. The D-Light project at Edinburgh's Institute for Digital Communications was funded from January 2010 to January 2012. Haas promoted this technology in his 2011 TED Global talk and helped start a company to market it. Pure Li-Fi, formerly pure VLC, is an original equipment manufacturer (OEM) firm set up to commercialize Li-Fi products for integration with exist-ing LED-lighting systems.

In October 2011, companies and industry groups formed the Li-Fi Consortium, to promote high-speed optical wireless systems and to overcome the limited amount of radio-based wireless spec-trum available by exploiting a completely different part of the electromagnetic spectrum.

A number of companies offer uni-directional VLC products, which is not the same as Li-Fi - a term defined by the IEEE 802.15.7r1 standardization committee.

VLC technology was exhibited in 2012 using Li-Fi. By August 2013, data rates of over 1.6 Gbit/s were demonstrated over a single color LED. In September 2013, a press release said that Li-Fi, or VLC systems in general, do not require line-of-sight conditions. In October 2013, it was reported Chinese manufacturers were working on Li-Fi development kits.

In April 2014, the Russian company Stins Coman announced the development of a Li-Fi wireless local network called Beam Caster. Their current module transfers data at 1.25 gigabytes per sec-ond but they foresee boosting speeds up to 5 GB/second in the near future. In 2014 a new record was established by Sisoft (a Mexican company) that was able to transfer data at speeds of up to 10 Gbit/s across a light spectrum emitted by LED lamps.

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Figure 2.1: History of Li-fi

1.4 Present Scenario of light fidelity We have 1.4million cellular mast radio waves base stations deployed. We also have over 5 billions of mobile phones. Mobile phone transmits more than 600 Tb of data. Wireless communication has become a utility like electricity & water. We use it in our everyday life, in our private life, business life. Currently Wi-Fi uses Radio Waves for communication. It is important to look into this technology which has become fundamental to our life.

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1.5 Four Issues with Radio Waves1. Capacity:

Radio waves are limited. Radio waves are scarce and expensive. We only have a certain range of it. With the advent of the new generation technologies like 2.5G, 3G, 4G and so

on we are running out of spectrum.2. Efficiency:

There are 1.4 million cellular radio base stations. They consume massive amount of energy. Most of this energy is not used for transmission but for cooling down the base sta-

tions. Efficiency of such a base station is only 5%.

3. Availability: Availability of radio waves is another cause of concern. We have to switch off our mobiles in aero planes. It is not advisable to use mobiles at places like petrochemical plants and petrol

pumps.4. Security:

Radio waves penetrate through walls. They can be intercepted. If someone has knowledge and bad intentions then he may misuse it.

1.6 Overcoming the four issues with RW in Li-Fi

1. Capacity:

10000 times more spectrum than RW. LEDs are already present. So we have the infrastructure available and already installed.

2. Efficiency:

Data through illumination and thus data transmission comes for free.

LED light consumes less energy Highly efficient

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3. Availability: Light is present everywhere.

4. Security: Light waves don’t penetrate through walls. Can’t be intercepted & misused.

Data is present where there is light.

1.7 Application of light fidelity

At present its applications are beyond imagination but still if to think about few then they are:

Can be used in places where it is difficult to lay the optical fiber like hospitals. In opera-tion theatre Li-Fi can be used for modern medical instruments.

In traffic signals Li-Fi can be used which will communicate with LED lights of the cars and accident numbers can be decreased.

Thousand and millions of street lamps can be transferred to Li-Fi Lamps to transfer data. In aircraft Li-Fi can be used for data transmission. It can be used in petroleum or chemical plants where other transmission or frequencies

could be hazardous.

1.8 Advantages: This technology can yield a speed more than 10 Gbps, allowing a HD film to be

downloaded within 30 seconds.

Li-fi is ideal for high density coverage in a confined region.

Cheaper than Wi-Fi since visible light spectrum is a free spectrum brand

No license needed

Thousands and millions of street lamps can be converted to li-fi spots

Figure 2.3: Advantage

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1.9 Disadvantages: Presence of light is essential

Works better with fluorescent light and LED but very low efficiency with bulb

High installation cost

Light can pass through object

Short range

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3 ConclusionThe possibilities are numerous and can be explored further. If this technology can be put into practical use, every bulb can be used something like a Wi-Fi hotspot to transmit wireless data and we will proceed toward the cleaner, greener, safer and brighter future. 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 many 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.

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4 RecommendationsHence by making this report I recommend to have an experience of light fidelity. It is easy to use and its applications are various in our daily life. It is reliable and effective wireless network. The numerous application area of this wireless internet made us easy to know about its scope and area. However, there may be more or less updates and features available. Thus, light fidelity can be a better choice.

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Bibliography http://en.wikipedia.org/wiki/Li-Fi Harald Haas. "Harald Haas: Wireless data from every light bulb". ted.com. Tsonev, Dobroslav; Videv, Stefan; Haas, Harald (December 18, 2013). "Light fidelity

(Li-Fi): towards all-optical networking". Proc. SPIE (Broadband Access Communication Technologies VIII) 9007 (2).

http://teleinfobd.blogspot.in/2012/01/what-is-lifi.html www.lificonsortium.org/ http://www.digplanet.com/wiki/Li-Fi

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