Light-fidelity by Aakash, Aravind raj, Malavan, Manimuthu

2. Light fidelity technology
li-fi
Under the
guidance of
Mr.Natarajan M.E
AP/CSE
Presented by
Aakash A
Aravindaraj K
Malavan P
Manimuthu M

3. Outline
 What is Li-Fi?
 Need for Li-Fi
 Present scenario
 Life and history of Li-Fi
 Overcoming Wi-Fi issues
 Electromagnetic spectrum and VLC
 Construction, working and Implementation
 Comparision
 Applications
 Advantages and disadvantages
 Conclusion

4. What is Li-Fi ?
 Light-Fidelity
 Sending data through LED
 Intensity is faster than human eye can follow
 Optical version of the Wi-Fi
 The fastest and cheapest wireless communication
.

5. Li-fi technology

6. NEED FOR LI-FI
 Radio spectrum is congested, but the demand for wireless data
doubles each year
 Issues regarding radio spectrum
 Speed of data transmission can be increased.

7. PRESENT SCENARIO
 Radio Spectrum is congested but the demand for wireless data
double each year .Every thing, it seems want to use wireless data
but the capacity is drying up.
 So what can carry this excess demand in the future.
 Drawbacks - Capacity, Availability, Security & Efficiency.

8. GENESIS OF Li-fi
 Harald Hass, a professor at the University of Edinburgh who began
his research in the field in 2004, gave a debut demonstration of what
he called a Li-Fi prototype at the TEDGlobal conference in
Edinburgh on 12th July 2011.
 The technology truly began during the 1990's in countries like
Germany, Korea, and Japan where they discovered LED's could be
retrofitted to send information. Harald Haas continues to wow the
world with the potential to use light for communication .

9. History of lifi
 The technology truly began during the 1990's
 Introduced by Professor Herald hass, at the
university of Edinburgh.
 Established in 2011 TED global talk
 In October 2011, few companies and industries
group formed

10. Life of lifi
 Established in 2011 TED global talk
 The promotion of idea through TED helped to start a company,
 Pure LiFi
 Pure LiFi, formerly pure VLC, is an original equipment
manufacture firm setup to commercialize Li-Fi products for
integration with existing LED lighting systems
 In October 2011, few companies and industries group formed
 Li-Fi consortium to promote the high speed optical wireless
systems

11. OVERCOMING WIFI ISSUES
 CAPACITY
Spectrum is 10,000 times greater than that of radio frequency
 EFFICIENCY
Highly efficient since LED consumes less energy
 AVAILABILITY
Light waves available everywhere.
 SECURITY
Cannot penetrate through walls. Hence data cannot be intercepted.

12. Why only in vlc?
Radio
Waves
Infrared
Rays
Visible
Rays
Ultraviolet
Rays
X- Rays
Gama
Rays
 Gama rays cant be used as they could be dangerous.
 X-rays have similar health issues.
 Ultraviolet light is good for place without people, but
other wise dangerous for the human body.
 Infrared, due to eye safety regulation, can only be used
with low power.
HENCE WE LEFT WITH THE ONLY THE
VISIBLE - LIGHT COMMUNICATION.

13. 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 kind of light
i.e., Light may be Invisible, Ultraviolet or Visible part of
spectrum.
 The speed of the internet is incredibly high and the user
everything in just a few minutes.

14. Who can replace radio waves for wireless
communication?
Li-Fi

15. CONSTRUCTION OF LI-FI
 Li-Fi product consists of 4 primary sub-assemblies:
 Bulb
 RF power amplifier circuit (PA)
 Printed Circuit Board (PCB)
 Enclosure

16. CONSTRUCTION OF LI-FI in detail
 The PCB controls the electric inputs and outputs of the lamp and
houses the microcontroller used to manage different lamp
functions.
 An RF (Radio-Frequency) signal is generated by the solid-state
PA and is guided into an electronic field about the bulb.
 The high concentration of energy in the electric field vaporizes
the contents of the bulb to a plasma state at the bulb’s center; this
controlled plasma generates an intense source of light.
 All of these sub-assemblies are contained in an aluminum
enclosure.

17. How Li-Fi works..
 Its working is much simply explained as follows:
 If the LED is on, the digital 1 is transmitted.
 And if it is off, the digital 0 is transmitted.
 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.
 Operational procedure is very simple.
 LEDs varies in intensity so fast that a human eye cannot detect it
 A controller connected at the back side of these LEDs is used to
code data.
 Also called as 5G optical communication.

18. Working process
 On one end all the data on the internet will be
streamed to a lamp driver when the led is
turned on the microchip converts the digital
data in form of light.
 A light sensitive device (photo detector)
receives the signal and converts it back into
original data. This method of using rapid
pulses of light to transmit information
wirelessly is technically referred as Visible
Light Communication .

19. LI-FI NETWORKS
 Li-Fi connector and router are the main components for a
network
 Room connector:
 Optical signals cannot penetrate through walls, in order to
provide an optical WLAN, rooms need to be connected with
each other
 Li-Fi room connector is a replicator, which sends the data
stream from one side of the wall to the other side via an
optical fiber.
 For smaller rooms, connector act as the only Li-Fi hotspot in
the room

20. LI-FI ROUTER
 SERVES AS A CONNECTOR TO
EXTERNAL LINK LIKE DSL.
 COVERS A RADIUS OF ABOUT 20
METERS
 THE TRANSMISSION SPEED IS
100 MBPS.
 SUITABLE FOR SMALL OFFICE
OR HOME USE

21. COMPARISION OF LI-FI VS WI-FI

22. Difference Between The Technologies
Technology Speed Data density
Wired
Fire wire 800 Mbps *****
USB 3.0 5 Gbps *****
Thunderbolt 2X 10 Gbps *****
Wireless (current)
Wi-Fi IEE(802.11N) 150 Mbps *
Bluetooth 3 Mbps *
IrDA 4 Mbps ***
Wireless (Future)
Wi-Gig 2 Gbps **
Giga-IR 1 Gbps ***
Li-Fi >10 Gbps *****

23. APPLICATIONS
 LIFI can be used in
 sensitive areas such as aircrafts for data transmission
without causing interference
 Places where it is difficult to lay optical fibers like
operation theaters
 Traffic scenarios, thereby reducing accidents
 Underwater applications where radio waves cannot
propagate.
 Industries like petrochemical plants, nuclear power
plants , petrol pumps etc

24. Traffic Lights :
Traffic lights can communicate
to the car and with each other.
Cars have LED-based
headlights, LED-based cack
lights, and cars can
communicate with each other
and prevent accidents in by
exchanging information.

25. Intrinsically Safe Environment
Visible Light is more safe than RF, hence it can be used in
places where RF can't be used such as petrochemical plants .

26. Hospitals(In Few Medical Equipment)

27. On Ocean Beds
Li-Fi can even work underwater were Wi-Fi fails completely,
thereby throwing open endless opportunities for
military/navigation operations.

28. Street Lamps
• There are millions of street lamps deployed around the world.
• Each of these street lamps could be a free access point.

29. TRAFFICSCENARIO
 IN TRAFFIC SCENARIO, LIFI CAN BE USED
TO COMMUNICATE WITH THE LED LIGHTS
OF CARS.
 CARS CAN HAVE LED-BASED HEADLIGHTS,
BACKLIGHTS AND CAN COMMUNICATE
WITH EACH OTHER.
 THIS MIGHT PREVENT ACCIDENTS, BY
EXCHANGING INFORMATION, WHEN THE
VEHICLES ARE TOO CLOSE

30. LECTURE / SEMINAR HALLS
 DOWNLOADING NOTES FROM BLOGS OF
TEACHERS.
 SHARING VIEWS AND QUERIES WITH THE
ENTIRE CLASS.

31. INDUSTRIES
USED IN RF RESTRICTED ENVIRONMENTS LIKE
CHEMICAL INDUSTRIES,
NUCLEAR POWER PLANTS, PETROL PUMPS

32. HOME ANDSMALL OFFICES
IN HOME AND SMALL OFFICES, LI-FI CAN BE USED TO
COMMUNICATE WITH DEVICES LIKE
Laptops
Internet access
HD video streaming
Printer

33. A PROVENTECHNOLOGY

34. VLC SMARTPHONES
 THE FIRST VLC SMARTPHONE WAS
PRESENTED BY CONSUMER
ELECTRONICS IN JANUARY, 2014
 THE PHONE USES WYSIPS CONNECT –
A CLEAR THIN LAYER OF CRYSTAL
GLASS IS ADDED TO THE SMALL
SCREENS
 SMARTPHONE MAKES THEM SOLAR
POWERED.
 SMARTPHONE COULD GET 15% MORE
BATTERY LIFE IN A DAY
 CAN COMMUNICATE USING LI-FI.

35. ADVANTAGES
 DATA RATE GREATER THAN 10 GBPS
 CAN BE USED ANYWHERE, EVEN IN RF RESTRICTED
AREAS
CONSUMES LESS ENERGY.
COST EFFICIENT
SECURED COMMUNICATION
IT IS QUICK AND RELIABLE.

36. Limitations
 Light can't pass through objects.
 Interferences from external light will cause interruption in the
communication.
 Li-Fi requires line of sight.
 High installation cost of the VLC systems.
 A major challenge facing Li-Fi is how the receiving device will
transmit back to transmitter.

37. Conclusion
 Thus, if Li-Fi technology can be put into practical use, every bulb can be
used as an alternative to Wi-Fi hotspots. It provides simple, faster and
efficient wireless data communication. Li-Fi will make us to proceed
towards the cleaner, greener, safer and brighter future.

39. Thank you

40. ANY QUESTIONS?