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 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-conscious 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 received by photoreceptors.

1. 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:

2. I
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.

3. II
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

4. III
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.

5. IV
List of Figures
Figure 1: Introduction of light fidelity 1
Figure2.1: History 3
Figure2.3: Advantage 6

6. V
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

7. VI
Table of Contents
Abstract I
Acknowledgements II
Preface III
List of figures IV
Acronyms and abbreviations v
1 Introduction: .............................................................................................................................. 1
1.1 What we have to do? .......................................................................................................... 2
1.2 Is it a Proven Technology?................................................................................................. 2
2 Discussions: ............................................................................................................................ 3
2.1 History:............................................................................................................................... 3
2.2 Present Scenario of light fidelity........................................................................................ 4
2.3 Four Issues with Radio Waves........................................................................................... 5
2.4 Overcoming the four issues with RW in Li-Fi................................................................... 5
2.5 Application of light fidelity.............................................................................................. 6
2.6 Advantages:........................................................................................................................ 6
2.7 Disadvantages: ................................................................................................................... 7
3 Conclusion:.................................................................................Error! Bookmark not defined.
4 Recommendations: ....................................................................Error! Bookmark not defined.
Bibliography ................................................................................................................................ 10

8. 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 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-
conscious 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
received 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
different 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.
Figure 1: Introduction of light fidelity

9. 2
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
amplitude.
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.

10. 3
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,
includes any use of the visible light portion of the electromagnetic spectrum to transmit
information. 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 existing 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
spectrum 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
second 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.

11. 4
Figure 2.1: History of Li-fi
1.4 PresentScenario oflight 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.

12. 5
1.5 Four Issues with Radio Waves
1. 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
stations.
 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

13. 6
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
operation 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

14. 7
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

15. 8
3 Conclusion
The 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.

16. 9
4 Recommendations
Hence by makingthisreportI recommendtohave anexperienceof lightfidelity.Itiseasytouse and its
applicationsare variousin ourdailylife.Itisreliable andeffectivewirelessnetwork.The numerous
applicationareaof this wirelessinternetmade useasytoknow aboutits scope and area.However,
there maybe more or lessupdatesandfeatures available.Thus,lightfidelitycan be a betterchoice.

17. 10
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

18. vi