Light fidelity orLight fidelity or Li-Fi - is a Visible Light Communications system, which makes use of light waves instead of radio technology to deliver data. - is a Visible Light Communications system, which makes use of light waves instead of radio technology to deliver data.

1. LI-FI TECHNOLOGYPREPARED BY SYMBAT UTEPOVA
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2. WHAT IS LI-FI?
Light fidelity or Li-Fi
- is a Visible Light
Communications
system, which
makes use of light
waves instead of
radio technology
to deliver data.

3. WHERE IT CAME FROM?
• IN 2011, THE BRITISH PROFESSOR HARALD HAAS
INTRODUCED THE CONCEPT OF A COMPLETELY
NEW TECHNOLOGY FOR WIRELESS DATA
TRANSMISSION USING LIGHT-EMITTING DIODES
TO THE WORLD. JUST THEN THERE WAS A TERM LI-
FI, ACCORDANT TO OUR USUAL WI-FI.
• WHILE MANY PEOPLE FOUND THE IDEA OF THE
PROFESSOR JUST "COOL CONCEPT" THAT NEVER
FINDS PRACTICAL APPLICATION IN OUR LIVES.
HOWEVER, FOUR YEARS LATER, HARALD HAAS
CREATED THE FIRST WORKING PROTOTYPE OF LI-
FI-ROUTER.

4. PRINCIPLE OF OPERATION
• The functioning of new Li-Fi technology is just simple. You will
have a light source at one end like a LED and a photo
detector (Light Sensor) on the other end.
• As soon as, LED starts glowing, photo detector or light
sensor on other end will detect light and get a binary 1
otherwise binary 0.
• How can data be transmit via this new Li-F- technology?
• Flashing a LED certain times will build up a message to
transmit. Flashing of light is detected by the photo detector
or light sensor and it will receive a message.
• Now, think of several LEDs with some different colors, flashing
together and building a huge information to transmit. It is
observed that green laser with the red laser can transmit
data at 1 GBPS.

5. HOW LI-FI WORKS?
• Short video

6. STANDARDS
LI-FI AS WI-FI USES PROTOCOLS SIMILAR IEEE 802.11, BUT IT USES ELECTROMAGNETIC WAVES OF THE
VISIBLE LIGHT RANGE WHICH HAS A MUCH WIDER BANDWIDTH, COMPARED TO THE RADIO WAVES, SIMILAR
TO IEEE 802.3, BUT WITHOUT THE USE OF OPTICAL FIBER. IEEE 802.15.7 STANDARD DEFINES A PHYSICAL
LAYER (PHY) AND MEDIUM ACCESS CONTROL (MAC). THE STANDARD DEFINES THREE PHYSICAL (PHY)
LEVELS WITH DIFFERENT BANDWIDTHS: PHY I WAS CREATED FOR OUTDOOR APPLICATIONS AND
OPERATES AT SPEEDS OF 11.67 KBIT / S UP TO 267.6 KBIT / S. PHY II CAN ACHIEVE DATA RATES OF 1.25
MBPS / S UP TO 96 MBIT / SEC. PHY III IS DESIGNED FOR MULTIPLE SOURCES WITH A SPECIFIC MODULATION
METHOD: COLOR SHIFT KEYRING (CSK), WHICH CAN BE TRANSLATED AS "MANIPULATION OF THE
WAVELENGTH SHIFT." PHY III CAN REACH A SPEED OF 12 MBIT / S UP TO 96 MBIT / SEC.

7. BENEFITS OF USING LI-FI
• HIGH DATA TRANSFER RATE OF 500 MB / S, OR 30 GB / MIN.
• THE USE OF LIGHT, RATHER THAN RADIO FREQUENCY SIGNALS.
• SAFE USE IN AIRPLANES.
• USAGE IN HOSPITALS AND MEDICAL DEVICES IN GENERAL, AS THIS TECHNOLOGY DOES NOT DEAL WITH
RADIO WAVES, SO IT CAN BE USED IN PLACES WHERE BLUETOOTH, INFRARED DATA ASSOCIATION, WI-FI AND
THE INTERNET ARE PROHIBITED.
• UNDER THE WATER IN THE SEA WI-FI DOES NOT WORK, BUT LI-FI CAN PROVIDE DATA TRANSMISSION AT A
DISTANCE.
• THERE ARE APPROXIMATELY 19 BILLION LIGHT BULBS ALL OVER THE WORLD, THEY JUST HAVE TO BE
REPLACED BY LED, WHICH TRANSMIT DATA.
• INFORMATION SECURITY - ANOTHER MAJOR ADVANTAGE, SINCE NO LIGHT GOES THROUGH THE WALL.

8. BENEFITS OF USING LI-FI
• ON THE STREETS FOR TRAFFIC CONTROL. CARS ARE FITTED WITH LED HEADLIGHTS, LED-BASED LIGHTING WILL
HELP CARS EVEN TO "COMMUNICATE" WITH EACH OTHER, TO PREVENT ROAD ACCIDENTS. TRAFFIC LIGHTS
CAN ALSO "COMMUNICATE" WITH THE MACHINES, ETC.
• BY IMPLEMENTATION OF LI-FI TECHNOLOGY WORLDWIDE, EVERY STREET LIGHT WILL BE A FREE INTERNET
POINT.
• LI-FI WILL SOLVE THE PROBLEM WITH THE LACK OF CAPACITY OF THE RADIO FREQUENCY POWER.
• LED USES 85% LESS POWER THAN USUAL ELECTRIC BULBS AND OPERATES 20 TIMES LONGER.
• FOR LI-FI USER CAN CHOOSE WHETHER TO RECEIVE THE DATA, LEAVING SMARTPHONE IN THE SCOPE OF THE
LEDS ACTIONS OR SIMPLY PUT THE PHONE TO HIS POCKET, TO AVOID THIS. IT LIMITS THE APPLICATION
SCOPE OF THIS TECHNOLOGY, FOR EXAMPLE, FOR RETAILERS.

9. DISADVANTAGES OF NEW TECHNOLOGY
• THE DATA TRANSFER CAN TAKE PLACE ONLY WITHIN THE LINE OF
SIGHT. THE ROOM LIGHT IS NOT ABLE TO PASS THROUGH WALLS.
• THE SIGNAL QUALITY OUTSIDE DEPENDS ON THE WEATHER
CONDITIONS. WHILE LI-FI IS MORE SUITABLE FOR INDOOR USE:
SERVICE CENTERS, MUSEUMS AND SCHOOLS. OUTDOOR
SUNLIGHT, FOG OR SMOG CAN CAUSE INTERFERENCE,
ALTHOUGH MANUFACTURERS CLAIM THAT IN THE FUTURE, LI-FI
WILL BE ADAPTED FOR OPEN SPACES.
• THE NEED FOR ON LIGHT TO MAKE THE CONNECTION ALWAYS.
WHILE IT IS NOT A PROBLEM IN INDUSTRIAL SECTORS, IT IS
PROBLEMATIC AT HOMES FROM A PRACTICAL AND
ENVIRONMENTAL POINTS OF VIEW. YOU HAVE TO KEEP THE
LIGHTS ON FOR LI-FI, REGARDLESS OF THE TIME OF A DAY.

11. LI-FI PROTOTYPE SIMULATION
• First presentation of Li-Fi prototype out from the lab was made in December , 2015
• (Video)

12. • LI FI LIMITATIONS
• "ITS MAIN PHYSICAL LIMITATION IS THAT VISIBLE LIGHT IS USED, SO REQUIRES
PHOTONS TO BE EMITTED AND DETECTED, THUS A MOBILE THAT IS IN A SHADOW
MAY NOT WORK," SAYS ANDREW FERGUSON, EDITOR OF
THINKBROADBAND.COM. LI-FI SIGNALS CAN ALSO BE INTERRUPTED BY BRIGHT
SUNLIGHT, WHICH AGAIN MAKES IT LESS THAN RELIABLE OUTDOORS. "IT CAN'T BE
USED IN DIRECT SUNLIGHT, OR IN OTHER CONDITIONS WITH HARSH LIGHTING, AS
THE PHOTODETECTORS WILL NOT BE ABLE TO DETECT THE MODULATING LIGHT
WAVES," ADDS ATTIAS, WHO THINKS THAT LI-FI WOULD REQUIRE MUCH
INVESTMENT IN LIGHTING AND WIRING INFRASTRUCTURE.
• LI FI COST
• "MANY OF THE MATHEMATICAL TECHNIQUES ARE SIMILAR TO THOSE USED IN
EXISTING WI-FI SYSTEMS, BUT COST WILL ULTIMATELY DEPEND ON THE VOLUME
OF SALES," SAYS FERGUSON, WHO POINTS OUT THAT WHEN IT FIRST APPEARED,
WI-FI WAS VERY EXPENSIVE. "TO KEEP COSTS REASONABLE, IT'S POSSIBLE THAT
THE FIRST COMMERCIAL VERSIONS OF LI-FI MAY BE A LOT SLOWER THAN THE LAB
DEMONSTRATIONS SEEN SO FAR," ADDS FERGUSON.
COULD LI-FI REPLACE WI-FI?

13. • LI-FI TECHNOLOGY OFFERS DATA TRANSFER RATES UP TO 1
GB / S, WHICH IS 100 TIMES FASTER THAN TODAY'S WI-FI
NETWORKS.
• TESTS WERE CARRIED OUT BY THE ESTONIAN COMPANY
VELMENNI IN TALLINN IN NOVEMBER 2015.
• ANY LIGHT SOURCE IS REQUIRED TO SEND A SIGNAL, FOR
EXAMPLE, CONVENTIONAL LED LAMP, INTERNET CONNECTION
AND A PHOTOSENSOR.
• DURING THE TEST, THE DATA RATE ACHIEVED 1 GB / S.
LABORATORY TESTS HAVE SHOWN THAT THEORETICALLY
POSSIBLE SPEEDS ARE UP TO 224 GB / S.
• TESTS WERE CONDUCTED IN OFFICES AND IN INDUSTRIAL
SHOP.
• CEO DEEPAK SOLANKI SAID THAT THE NEW METHOD OF DATA
TRANSFER CAN REACH THE MARKET WITHIN THREE TO FOUR
YEARS.
SPEED TESTS

14. LATEST NEWS!
• INTEGRATION OF NEW EQUIPMENT NEEDED FOR LI-FI HAS ALREADY SOME
RESULTS!
• ON 23RD OF DECEMBER, 2016 VLNCOMM INTRODUCED LUMINETᵀᴹ DESKTOP:
STREAMING DATA THROUGH LIGHTING.
• GET WIRELESS INTERNET ACCESS THROUGH YOUR DESK LAMP.
• (VIDEO)

15. ANY QUESTIONS OR COMMENTS?

16. THANK YOU
FOR
YOUR ATTENTION