Li-Fi is a new wireless communication technology proposed by German physicist Harald Haas that uses visible light communication (VLC) to transmit data using LED light bulbs. It can provide internet speeds over 1Gbps without any decrease in speed as more devices connect. Data is transmitted by switching an LED on and off very fast in a way imperceptible to the human eye. At the receiver, a photodiode converts light signals into electrical pulses representing data. Potential applications include smart lighting, vehicle-to-vehicle communication, underwater networks, and use in homes, hospitals, and industrial settings like petrochemical plants. Li-Fi offers advantages over Wi-Fi like higher speeds, more secure communication contained in light beams,

1. Li-Fi(Light Fidelity)
The future technology In Wireless communication
B131983, B131481, B131987 E1 - ECE
As per the growing demands of Wireless Communication there are enormous new technologies participating to make sophisticated environment for the users. To
serve this increasing number and size of users in Wireless Communication System, the German physicist, – Harald Haas proposed a “Li–Fi Technology”. It is very
difficult to procure to a reliable signal as more and more people and their many devices access Wireless Internet. What if we could use other waves to surf the Internet?
What if the Internet get available at great speed of 1Gbps? What happens, if the connective speed do not alter when any number of devices that connected to any broad
casting data services? How wonder it is, if your LED bulb in your room transmits this high speed data? An innovative idea called Li-Fi make this technology possible.
WORKING PRINCIPLE :
LED is the light emitting diode can be switched on and off faster since
operating speed of LED is less than 1 micro second causing the light source to appear
continously. This is invisible on-off keying(OOF) activity enables a kind of data
transmission using binary codes. Switching on the LED is a logical '1', switching it
off is a logical '0'. It is possible to encode data in the light by varying the rate at which
LED's flicker on and off .The LED can be switched off and on very quickly enabling
oppurtunity for transmiting data Modulation is so fast that human eye doesn't notice.
Such advancement promise a theoritical speed of 10 Gbps.
LI­FI Reciever­ Photodiode:
At the receiver side of the system photo
detector is used. This photo detector senses
light and converts into the respected pulses.
These pulses are then amplified and processed
to achieve the original data stream.
Uplink :
For a complete Li-Fi communication system,
full duplex communication is required. This can
be
achieved by using the infrared (IR) transmission,
where the devices terminals can send data using
infrared frequencies.
so as to surf the internet with LI-FI, steaming
Content must have a proper integration with server & internet network. Data can be
Spreadout Illuminating certain area with an LED light bulb.
As it's classifications and novelty approach in wireless technology is solely different
from WI-FI.The differences as follows:
Comparison b/w Li-Fi &Wi-Fi
INTRODUCTON :
WHY ONLY VLC?
APPLICATIONS AND ADVANTAGES :
The Various applications of Li-Fi system providing a reliable,
secure, cheaper and ultra-high-speed communication infrastructure
are as follows:
a) Smart Lighting: The Li-Fi transmitter is a great combination of
data source producing thousands of data streams as well
as light source producing a much brighter light.
b) In Vehicles Light:To develope an intelligent transport system
where cars can talk to each other and also to the
traffic lights provides statistics.
c) Undersea Water:RF can’t propagate undersea water as its salty,
high conductivity and due to a high attenuation but light
does.
d) In Home Appliances: Li-Fi system can be integrated in home
appliances like thermos, freeze, clocks, TV’s etc.
connecting to an Internet to reduce energy consumptions
for intelligent energy management.
e) In Health:To monitor your health issues more sophisticatedly
and providing any health concern changes to your
family doctors by connecting to the internet and updating
your information online.
f) In Hospitals:The Li-Fi transmitters can be enhanced in Hospitals
also where the RF wave does not. They can be used in
different machines to communicate with each other for fast
data interpretation.
g) In Petrochemical Industries:These industries do not allow
because various radioactive chemicals are used for
processing.
h) Security:As the visible light cannot penetrates the walls the
security can be achieved at higher levels.
LIMITATIONS :
a) light can't pass through the objects.
b) Vast majority of interference from external light source.
FUTURE SCOPE :
a) Li-Fi provides a great platform to explore wireless data transmission
at high rates.
b) Given the band width crunch being faced. LiFI gives great solution as
it uses optical spectrum instead of radio spectrum.
REFERENCES :
[1] http://www.digplanet.com/wiki/Li-Fi
[2] www.lificonsortium.org
[3] http://en.wikipedia.org/wiki/Li-Fi
[4] seminarprojects.com/s/seminar-report-on-lifi
[5] slideshare.com/lifi-technology
[6] http://www.slideshare.net/tapeshchalisgaonkar1/gi-fi-technology-finl-
ppts
CONCLUSIONS :
a) If this technology can be put into practical use, bulb can be used lifi
hotspots.
b) With its magic of light it will make our world greener, safer, moreover a
brighter place to live.
c) Report says that the growth will elevated to 83% by the year of 2018.
ABSTRACT :
S.No Parameters Light- fidelity Wireless-fidelity
1. Speed for data
transfer
Faster transfer
speed(>1Gbps)
Data transfer speed
(150Mbps)
2. Medium through
which data transfer
occurs
Use light as a carrier. Use radio spectrum.
3. Spectrum Range Visible light spectrum
has 10,000 times
broad spectrum in
comparison to radio
frequency.
Radio frequency
spectrum range is less
than visibe spectrum.
4. Cost Cheaper than Wi-Fi
because free band
doesnt need license
and it uses light.
Expensive in
comparison to Li-Fi
because its uses radio
spectrum.
5. Network topology Point to point Point to point
6. Operating freqency Hundreds of tera hz 2.4Ghz
Li-Fi is a fast & cheap techonology (which is based on VLC) that uses
visible light as optical carrier for data tranmission and illumination.
a) X-rays have some healthy issuse.
b) Gamma-rays can't be used as if they are dangerous.
c) UV-rays is good for place without people otherwise dangerous
for human body.
d) IR-rays due to eye safety regultions can be used with the low
power.
transmission of data through illumination. This
technology use a part of the electromagnetic
spectrum instead using of radio waves, to transmit
information.As we all know that Radio waves are
part of spectrum that can carry our data in the form
of WiFi.
Li-Fi is a VLC (visible light communication)
typically implemented using white LED bulbs and
retrieve information from photo detector.
Li-Fi stands for light fidelity, which
means
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