International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print),

ISSN 0976 - 6375(Online), Volume 5, Issue 12, December (2014), pp. 186-191© IAEME

186

Li Fi (LIGHT FIDELITY) – ILLUMINATING CIVIL

PLACES FOR COMMUNICATION

Adwait R. Pinglikar 1, Priyanka A. Shandilya

2

1, 2

Student, MCA, JNEC, Aurangabad, Maharashtra, India

ABSTRACT

Now a days everyone carries tablet, smart phone and laptop everywhere and everyone

searches for Wi-Fi in public places for connecting to internet but problem is Wi-Fi is not allowed in

public places like hospitals, power plant, chemical reactors, petrol pumps and airplanes due to radio

wave/ radiation disturbance, also number of increasing users hamper the network speed, range is

matter in case of Wi-Fi and Wi-Fi is not so secure and bandwidth is limited due to radio frequency so

it also matter, but Now we can solve this problem by applying Li-Fi technology in this public places.

A German physicist Harald Hass, professor at university of Edinburgh, UK enlighten this Li-Fi

technology in front of world in his TED Global speech on 12th

July 2011; he said “data through

illumination” by taking fibber out of fibber optic by sending data through a LED i.e. light emitting

diode light bulb that varies in intensity faster than the human eye can follow. If we use Li-Fi in

public places like hospitals, public transport stations, airplanes, petrol pumps that time LED will not

only illuminate that place but empower us for communication via illumination.

Key words: Li-Fi: Light Fidelity, Wi-Fi: Wireless Fidelity, VLC: Visible Light Communication,

IR: Infrared, UV: Ultraviolet, LOS: Line Of Sight.

I. INTRODUCTION

Today we uses Wi-Fi as wireless communication medium but Wi-Fi uses radio waves which

are not allowed everywhere due to radio waves effect or there radiations concern which create

disturbance in areas like hospital (in medical equipment like MRI scanner), power plant, chemical

reactors, petrol pumps and airlines, but now we can use wireless communication facility in this areas

or many other crowded public areas because of Li-Fi i.e. light fidelity. A German physicist Harald

Hass, professor at university of Edinburgh, UK enlighten this Li-Fi technology in front of world in

his TED Global speech on 12th

July 2011. Professor Harald Hass was working on Visible Light

Communication (VLC) from 2004 and in 2011 he achieved great success. We can use this

technology in areas where Wi-Fi is not allowed. This technology will not only improve

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ISSN 0976 – 6367(Print)

ISSN 0976 – 6375(Online)

Volume 5, Issue 12, December (2014), pp. 186-191

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International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print),

ISSN 0976 - 6375(Online), Volume 5, Issue 12, December (2014), pp. 186-191© IAEME

187

communication but also illuminate work place, and many public places like hospitals, chemical

plant, public transport stations keeps light ON for 24x7 so this will create nice opportunity to create

wireless communication using light. Li-Fi not only gives opportunity to create wireless

communication but it also help to save energy as technology uses LED lights which consume very

less electricity. Li-Fi technology uses frequency from 300GHz-30PHz and wavelength from 1mm-

10nm. This magnetic spectrum is 100 times more than radio wave spectrum. Li-Fi is not only

technology it is actually framework for all new capabilities to current and future services,

applications and end users.

II. HOW DOES LI-FI WORKS

Li-Fi technology uses wide electromagnetic spectrum range starting from middle of infrared

(IR) spectrum straight to visible light spectrum to ultraviolet (UV) spectrum. Li-Fi uses frequency

from 355GHz-30PHz [355GHz-405THz (IR) to 405THz-790THz (visible light) to 790THz-30PHz

(UV)] and wavelength used by Li-Fi is 1mm-10nm [1mm-750nm (IR) to 750nm-390nm (visible

light) to 390nm-10nm]. Li-Fi technology use two type’s first one Giga byte and second one is Sub-

Giga byte for data transmission speed for long, medium and short ranges. Li-Fi is unidirectional and

bidirectional for data transfer. Li-Fi works only when device is in Line of Sight (LOS) of light.When

LED light is ON it transmit digital data 1 and when light is OFF then it transmit digital data 0. The

LED light bulb can be switched ON and OFF very frequently. This flickering of ON and OFF light is

annoying to normal eyes but when they are made to flicker at very fast or high speed which human

eyes can’t detect they can be more useful. The principle behind this is the amplitude of the light is

varied at very high speed which create an impression that it is not actually blinking. LED light bulb

is connected with microchip which detect change in high flickering so it will help to convert light in

data in its digital form like when light is On digital data is 1 and when light is OFF then digital data

is 0. This is like using Morse code using torch but at very-very high speed. On LED side data from

server or from internet is streamed to lamp drivers when LED is turn ON microchip converts this

digital data in the light, on the other end this light is detected by photo sensitive device. Then this

light is amplified and processed then converted back to digital form so devices can recognise it.

International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print),

ISSN 0976 - 6375(Online), Volume 5, Issue 12, December (2014), pp. 186-191© IAEME

188

III. HOW TO BUILD LI-FI

LED light bulbs are basic need of Li-Fi technology, so here we use array of LEDs or

Combination of LED light bulbs. Then we need emitter, RF coax cable, RF driver, connector, Molex

connector jumper, AC/DC power supply, power switch, circuit board. Array of LED bulbs at

downlink transmitter connected to microchip, photo diode, emitter, power supply with RF cable

which is connected to Internet and central server. Same design with photo diode, transmitter,

converter and access device like laptop, smart phone, PDA, etc…

IV. AREA WHERE WE CAN IMPLEMENT LI-FI

There are some limitations of Li-Fi as presence of natural light, sun light, normal electric

light can affect Li-Fi structure and data transmission speed. Also Li-Fi need Line of Sight (LoS) for

perfect communication. So if we want to implement Li-Fi for wireless communication then which

are better areas to apply it are public sectors as Hospitals, Public Transport Station, Chemical Plants,

Power Plants, Underwater communication, Petrol Pumps, and Airlines. We can implement Li-Fi in

hospitals, petrol pumps, chemical plants, atomic reactors, power plant as at this places Wi-Fi is not

allowed due to its radiation or radio wave disturbance, also this all are in closed infrastructure places

so lights are commonly kept on for 24x7 hrs. Soif we apply Li-Fi here then it will help to reduce

electricity consumption also give nice opportunity for communication means LED will not only

illuminate work place but also Illuminating it for communication. It is very difficult to establish

communication underwater but using Li-Fi we can communicate with other underwater things like

International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print),

ISSN 0976 - 6375(Online), Volume 5, Issue 12, December (2014), pp. 186-191© IAEME

189

communication between two submarines. In airlines we have light above seat of every passenger for

reading if we replace them with Li-Fi then it is possible to have connectivity with internet using light

also it will not disturb aircraft working. We can also use Li-Fi at public transport stations like

airports, railway stations, metro stands, bus stations at this public stations many countries are

providing free Wi-Fi but as number of uses increases bandwidth will decrease but if we apply Li-Fi

firstly it will reduce electricity consumption second it will provide wireless communication facility

in LoS of each LED. Also we can use Li-Fi in Military Base Stations as light cannot penetrate from

walls so it is possible to achieve high level of security while sharing very secret information. It is

also hard to hack light medium.

V. LIMITATIONS OF LI-FI

1. Li-Fi will work only when there is direct line of sight i.e. LoS.

2. Data transmission can be affected by opaque obstacles.

3. As Li-Fi uses very high frequency so it is limited in range and only point to point

communication can be possible.

4. Outer light like sun light or day light can affect speed.

VI. ADVANTAGES OF LI-FI

1. Li-Fi can solve problem of insufficient bandwidth in Wi-Fi.

2. High data transmission rate are possible in Li-Fi until now scientist able to transfer up to

10Gbps practically and theoretically proven speed is 100Gbps.

3. As light cannot penetrate through walls it is highly secure and reliable.

4. Li-Fi need low maintenance cost.

5. Li-Fi is safe for human body, animals, and birds as there are no side effects of light.

6. Li-Fi is eco-friendly and it helps to achieve green effect with technology.

VII. MYTHS ABOUT LI-FI

1. Many of the peoples thinking that Li-Fi will replace Wi-Fi, but this is not true Li-Fi and Wi-Fi

are similar technologies but there working capacities are different.

2. Wi-Fi is cheaper than Li-Fi, here implementing Li-Fi is costly but it is long time investment

but Wi-Fi look like cheaper at cost but it need maintenance.

3. Once we setup Li-Fi we don’t need to pay internet bills, this is done only when we use Li-Fi

for only LAN purpose, if we want to use internet on this LAN then we need to pay minimum

charges to provider.

4. Li-Fi will increase electricity bill, this is also not thing we are suggesting that implement Li-Fi

where we need to use light 24x7, places like hospitals, chemical plants, public transport station.

Also LED light consume very low electricity so they save more electricity than normal light

bulbs.

VIII. SECURITY OF LI-FI

As all we know that light cannot penetrate through walls so data transmitted will remain

secure. And it is hard to hijack light medium from outside room. Still if we want more security we

can use combination of Red, Green and Blue i.e. RGB LED array for different encryption for each

color.

International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print),

ISSN 0976 - 6375(Online), Volume 5, Issue 12, December (2014), pp. 186-191© IAEME

190

IX. GREEN EFFECT OF LI-FI

Li-Fi is not only technology it is framework, it not only enable use for communication it also

help us to reduce electricity consumption. If we use less electricity then automatically we save extra

production of electricity which help to reduce pollution and extra man work. Li-Fi do not create any

radiations li Wi-Fi which disturbs the nature so here also it helps to green effect. This technology

reduces all type cost in terms of money, pollution, man power, nature resources, natural life hazard

like radiation disturb animal life and birds life also some scantiest say it also disturb human body. So

using this technology at public places will not only improve communication but it will help use to

save earth and keep it green.

X. PROPOSED WORK

The proposal plan behind this research paper is to force or make awareness in public and

government of each country to implement Li-Fi instead of Wi-Fi at public places like Hospitals,

Railway station, Bus Stand, Metro Stand, Airports, Airlines, Petrol Pumps, Cafes, Hotels, Streets,

Public Booths and Shopping Malls as in all this public areas we need Wi-Fi or wireless data access.

This will not only reduce radio wave interference and its side effects on nature and life but it will

reduce electricity consumption, secure and high bandwidth will be allocated to everyone and this will

achieve green effect as it is eco-friendly technology. This technology not limited to use in public

areas but we can use it in Underwater Research Labs as many times it is impossible to use radio

frequency for communication under water.In ChemicalPlants, Atomic Reactors here radio waves are

banned here we can use Li-Fi. Li-Fi not only save cost in terms of electricity but it will also reduce

maintenance cost extremely. This technology not only reducing cost in terms of money but it is

helping to achieve green effect for reducing global worming also. Here we are proposing to

implement Li-Fi at Hospitals, Chemical Plants, Atomic Reactors, Petrol Pumps, Underwater

Communication, Military Base Stations, Café, Hotels, Shopping Malls, all Public Transport Stations

and achieve high benefits from it.

XI. CONCLUSION

Definitely Li-Fi is not here to replace Wi-Fi but to reduce limitation of Wi-Fi and improve

communication using Visible Light. Li-Fi is not only technology but it is framework if we use Li-Fi

in public area/places/sector then this technology will achieve many breakthroughs of which we never

imagine. Li-Fi will not only help use to reduce cost in terms of money and electricity but it will help

us to achieve green effect, reduce electricity generation and man work on it, also it will reduce

pollution and radiation created by radio waves. This technology will empower us for high

bandwidth, number of maximum users and faster communication.If every nation will use this Li-Fi

on suggested places definitely this will help us in such way we never think before. Li-Fi (Light

Fidelity) not only Illuminating Civil Places for visible illumination but also for Communication.

REFERENCES

[1] http://www.ted.com/talks/harald_haas_wireless_data_from_every_light_bulb?language=en

[2] http://visiblelightcomm.com/tag/harald-haas/

[3] http://sloanreview.mit.edu/article/harald-haass-li-fi-vision-light-bulbs-that-transmit-data/

[4] http://www.lificonsortium.org/

[5] http://purelifi.com/

[6] http://en.wikipedia.org/wiki/Li-Fi

International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print),

ISSN 0976 - 6375(Online), Volume 5, Issue 12, December (2014), pp. 186-191© IAEME

191

[7] http://thenextweb.com/insider/2014/08/21/purelifi-li-fi-vlc-led/

[8] http://www.ripublication.com

Journal references

[1] http://www.iraj.in/journal/journal_file/journal_pdf/1-10-139036985861-63.pdf

[2] http://www.slideshare.net/shwrvppt/li-fi-tch

[3] http://gimt.edu.in/clientFiles/FILE_REPO/2012/NOV/23/1353645362045/69.pdf

[4] http://ijircce.com/upload/2013/april/52_New%20Epoch.pdf

[5] http://www.iraj.in/journal/journal_file/journal_pdf/1-10-139036985861-63.pdf

[6] http://www.ijarcsse.com/docs/papers/Volume_3/11_November2013/V3I11-0434.pdf

Diagrams References

[1] http://www.noypigeeks.com/tech-news/meet-li-fi-potential-light-bulbrouter/

[2] http://cdn.phys.org/newman/gfx/news/hires/2012/lifiedinburg.png

[3] http://www.ijarcsse.com/docs/papers/Volume_3/11_November2013/V3I11-0434.pdf