The document discusses the history and development of wireless networks and introduces LiFi technology as an alternative to WiFi. LiFi transmits data through visible light communication by varying the intensity of LED bulbs and lamps. It has benefits over WiFi like higher speeds, more available spectrum, better security since light does not pass through walls easily. LiFi is expected to become widely available in the next decade and transform how people access and transmit data through ubiquitous light sources.

1. The future is here!!!

2. History of Networks
 In the olden days, people formed a network in order
to transmit a piece of data from one place to another.
 With the advances in technology a new mode of
networking was developed by using the wires as a
medium (wired networking).
 As time passed the technology increased and we
launched satellites into space and thus were in a
position to transmit enormous amounts of data
across various geographical locations.
 wireless networking gained a wide recognition and
became the most popular type of all networks .

3. General network scenario
 Whether you are using a wireless internet
in a coffee shop or mall, competing for
bandwidth at a conference or probably
stealing it from the guy next door, you
often get frustrated because of the low
speeds you face.
 Also as more and more devices get
connected to the network, clogged
airwaves are going to make it.

4.  A German physicist,Harald Haas, has
started working on transmission of data
using visible light back in 2004.
 In the year 2011 he first introduced to
the world this new technology,LI FI in
the TED talk show.
 He envisions a future where data for
laptops and other mobile devices is
transmitted through a light in a room.

5. Introduction to LI FI
 LI FI (light fidelity) is data through
illumination-taking he fiber out of fiber
optics by sending data through an LED
light bulb that varies in intensity faster than
the human eye can notice.
 At the heart of this technology is anew
generation of high brightness LEDs.
 If the LED is on a digital 1 is transmitted, if
the LED is off then a digital 0 is
transmitted.They can be switched on and
off in order to transmit data continuously.

6. How does LI FI work?
 Light has been around for millions of
years now and is a very cheap resource
unlike radio waves.
 LI FI is light fidelity technology.
 Generally flickering lights are annoying
but when they are made to flicker at a
very fast speed which our human eye
cannot detect they can be very useful.
 This fundamental principle is used in this
technology.

7.  The amplitude of the light is varied at
very high speed which creates an
impression that it is not actually blinking.
 Any LED light set if used along with a
microchip inside it can used to detect
the changes in the light flickering thus
helping in converting light into data in its
digital form.

8.  This is like sending a Morse code signal
using a torch but at a very fast speed.
 This very high speed blinking of the light
enables the source to transmit data in a
rapid stream of binary code that,
although invisible to the naked eye, can
be detected by a light sensitive device.
 Thus every light emitting source can be
used as a hub for data transmission.

9.  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 this digital data in the
form of light.
 On the other end this light is detected by
photo sensitive devices.
 Next this light is amplified and
processed and then fed to the device.

10. Architecture of LI FI

11. Present scenario
 At present we have as many as 1.5
million radio wave base stations across
the globe.
 We also have close to 5 billion mobile
connections which transmit a data over
600TB.
 This penetration of mobile devices into
our lives has led to a wide recognition
of WIFI technology.

12.  At present the data transmission across
the globe is being done using radio
wave range of the electromagnetic
spectrum.
 This results in some drawbacks in the
current system.

13. Issues with radio waves
 CAPACITY:
 The current system makes use of
radio waves.
 With the increasing number of mobile
connections the availability of the
spectrum is getting congested.
 Radio waves forms only a small
fraction of the entire EM spectrum
thus making the problem even worse.

14.  EFFICIENCY:
 The current system is high on energy
consumption.
 For every unit of energy consumed the
data transmitted is relatively less.
 The data speeds in the current system
can only reach up to a few hundreds of
megabits per second.

15.  AVAILABILITY:
 The availability of the radio waves is yet
another major issue now a days.
 These waves are not much available
during the flight travel.
 It is not advisable to use these devices I
places like petrol bunks.

16.  SECURITY:
 These radio waves can easily penetrate
through the walls, thus letting
anonymous users to use the network.
 This can pose threat if the people with
bad intentions start using it.

17.  ECONOMIC:
 Due the limited availability of the radio
waves the tariff rates are relatively
costlier.
 There can be many transparency issues
during the spectrum allocations paving
way for many scams like in the case of
2G.

18. Benefits of light waves
 Capacity:
 Light is a readily available form of
energy and it covers the major portion of
the EM spectrum.
 Visible light spectrum is 10000 times
more compared to radio wave spectrum.

19.  EFFICIENCY:
 The data transmission for a unit energy
consumption is high in the case of light
waves.
 The data transmission can reach upto
thousands of gigabits per second thus
providing very rich data streaming.
 Here in LI FI data bits can be
transmitted parallelly thus increasing
the efficiency.

20.  Availability:
 Light is readily available in every part of
the world.
 This makes it easy for people in
airplanes to work on the internet.
 There are an estimated 14 billion light
sources on earth and each can be easily
converted into a LI FI hotspot.

21.  SECURITY:
 Unlike radio waves light waves cannot
penetrate through opaque objects thus
providing plenty of network privacy.
 No other person can share a network
unless the owner has permitted them to
use it.
 The sources can be used as normal
lights when there is no use for a hotspot.

22.  ECONOMIC:
 The tariff rates can be very cheap as
light waves are a cheap resource.
 There can be transparency in spectrum
allocations due to its cheapness.

23. The Future is very bright
 In the next decade this technology can
be made available everywhere.
 Places where optical fibers are difficult
to reach can be reached using this
technology.
 Every light source on earth can be a
hotspot making technology very much
available to every person on earth.

24.  Traffic signals vehicles and many other
devices can communicate each other
making the world an easy place to live.
 Thousands of chemical plants can
transmit data without fear as light waves
are not hazardous to them.

25. A car in the near future

26. Conclusion
 LI FI will make are lives more
technology driven in the near future.
 With its magic of light it can make our
world a greener,safer,cleaner and
moreover a brighter place to live.
Anil kumar .k
CSE-4/4