Guardians and Glitches: Navigating the Duality of Gen AI in AppSec
LiFi technology (visible light communication )
1. by
BRIJESH BHARTI
(CIT-06/16)
Under the supervision of
Dr. Gausia Qazi
Department of Electronics & Communication Engineering
National Institute of Technology,
Srinagar
(Visible Light Communication)
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LiFi Technology
2. Outline
Introduction
How it’s Works
The History of Li-Fi
Implementation of Li-Fi.
Comparison between Li-Fi / Wi-Fi
Currently Research progress 2017
Further research in the field can look into issue in LiFi
Present Standardization activities in LiFi
Features Advancement
Application of Li-Fi
Limitations of Li-Fi
Conclusion
References
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3. Introduction
Li-Fi basically known as Light fidelity is an outcome of twenty first century
Li-Fi technology is a wireless communication system based on the use of
visible light between 400 to 800 THz .[1}
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4. How it’s Works
Li-Fi is a Visible Light Communications (VLC) system
for data transmission
The working procedure is very simple,
if the light is on then transmit a digital “1”.if it’s off
transmit a ‘’0’’. [2]
The LEDs can be switched on and off very quickly
which gives nice opportunities for transmitting data.
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6. The History of Li-Fi
Alexander Graham Bell is most famous for inventing the telephone, but he also
demonstrated the first VLC system in 1880. [3]
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7. The History of Li-Fi
in 2003,
a team at the Nakagawa Laboratory located at Keio University in Japan used LEDs to transmit
data via visible light [12]. This is the first account of transmitting digital information via LEDs.
In 2010,
Heinrich Hertz Institute in Berlin .were able to transmit at a speed of 500 Mbit/s over a distance of
5 meters and transfer at 100 Mbit/s over an even longer distance with 5 white LEDs.[13]
In 2011,
at TED Global, there was a demonstration of the D-light project, a VLC project led by Harald Haas,
a professor at the University of Edinburgh [14]. The demonstration showed a HD video being
transmitted from a standard LED lamp. The data rate of the VLC system was approximately 10
Mbps
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8. Li-Fi is typically implemented using white LED
light bulbs at the downlink transmitter. These
devices are normally used for illumination only by
applying a constant current
by fast variations of the current, the optical output
can be made to vary at extremely high speeds. This
very property of optical current is used in Li - Fi
setup
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Implementation of Li-Fi.
10. Comparison between Li-Fi / Wi-Fi
Parameters Light Fidelity Wireless Fidelity
Speed for data transfer Faster transfer speed
(>1Gbps)
Data transfer speed (150Mbps)
Medium through which
data transfer occurs
Spectrum Range
Use Light as carrier
Visible light spectrum has
10,000 times broad
spectrum in comparison to
radio frequency
Use Radio spectrum
Radio frequency spectrum range is less than visible light
spectrum
Cost Cheaper than Wi-Fi
because free band doesn’t
need license and it uses
light
Expensive in comparison to Li-Fi because it uses radio spectrum
Network topology Point to point Point to point
Operating frequency Hundreds of Tera Hz 2.4GHz
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Currently, the University of Edinburgh UK is
immersed in researching Li-Fi to solve many of the
problems,[4]
The university has achieved 10 Gbps speed and also
demonstrated that line of sight may not be a necessity
for Li-Fi transmission. Research is underway on
wireless system concepts based on Li-Fi. The
university website lists the following projects currently
in progress:[5]
Currently Research progress 2017
12. Currently Research progress 2017
Optical Multiuser MIMO
Interference Management in Cellular
The Internet of Things
Li-Fi Spatial Modulation
Digital Modulation OFDM
Self-Powered Li-Fi
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13. Further research in the field can look into issue in LiFi
Further research in the field can look into the following issues[6]
1) Driving illumination grade LEDs at high speed
2) Increasing data rate with parallelism/arrays
3) Achieving low complexity/low cost modulation
4) Overcoming the line of sight constraint
5) Achieving seamless interoperability with other networks
6) Making Li-Fi work in environments with little or no light
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14. Present Standardization activities in LiFi
JEITA (Japan Electronics and Information Technology Industries Association)
accepted these standards as JEITA CP-1221 and JEITA CP-1222 [21]
Standardization efforts for physical and media access layer are also done by
IEEE 802.15, Task Group 7
In IEEE, 802.15 in IEEE 802 LMSC (LAN/MAN Standards Committee) has
organized the study group on VLC and the group is now the task group 7
(TG7) (TGVLC website). In South Korea, the telecommunications
technology association (TTA) (TTA website)
In Europe, the working group 5 of the wireless world research forum
(WWRF) deals with VLC technology as one of next-generation wireless
access technology.
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15. Li-Fi offers a number of key benefits over Wi-Fi but is inherently a
complementary technology
Capacity
Bandwidth:
The visible light spectrum is plentiful (10,000 more than RF spectrum),
unlicensed and free to use. [42]
Data density:
Li-Fi can achieve about 1000 times the data density of Wi-Fi because
visible light can be well contained in a tight illumination area whereas RF
tends to spread out and cause interference. [43]
High speed:
Very high data rates can be achieved due to low interference, high device
bandwidths and high intensity optical output
FPGA
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Features of Li Fi technology
16. Features of Li Fi technology
Efficiency
Energy:
LED illumination is already efficient and the data transmission requires
negligible additional power.
Environment:
RF transmission and propagation in water is extremely difficult but Li-
Fi works well in this environment. Safety:
There are no known safety or health concerns for this technology.
Non-hazardous:
The transmission of light avoids the use of radio frequencies which can
dangerously interfere with electronic circuitry in certain environments.
Security
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17. • Spectrum Relief:
• Mobile Connectivity:
• Hazardous Environments;
• Underwater Communications:
• traffic management:
• super fast internet
• Aircraft
• Helth and technology
• Application in sensitive areas
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Application of Li-Fi
18. Limitations of Li-Fi
The main problem is that light can’t pass through objects,
so if the receiver is inadvertently blocked in any way, then
the signal will immediately cut out[7]
Reliability and network coverage are the major issues to be
considered by the companies while providing VLC services.
Interference from external light sources like sun light,
normal bulbs; and opaque materials in the path of
transmission will cause interruption in the communication
We can’t have a light bulb that provides data to a high-
speed moving object or to provide data in a remote area
where there are trees and walls and obstacles behind[8]
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19. Conclusion
“ The possibilities are numerous and can be
explored further. If this technology can be put
into practical use , every bulb can be used
something like a Wi-Fi hotspots to transmit
wireless data”
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