Lifi final
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Transcript of Lifi final
LIFI
(LIGHT FEDILITY)
CONTENTS
• INTRODUCTION• WORKING• COMPARISION• ADVANTAGES• DISADVANTAGES• APPLICATIONS
INTRODUCTION
WHAT IS LI-FI?• LI-FI is transmission of data through illumination ,sending data
through a LED light bulb.• LI-FI comes under VLC(VISIBLE LIGHT COMMUNICATION)
INTRODUCTION
HISTORY 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.
WORKINGHow LI-FI works?• operational procedure is very simple, if the led is on, you
transmit a digital 1, if its off you transmit a digital 0. The LEDs can be switched on and off very quickly, which gives
nice opportunities for transmitting data.
WORKING PRINCIPLE
LAN Server
Router
Display Signal processing
Photo detector
Led Lamp
TRANSMISSION ELEMENT
• Signals from the data input is modulated to intensity of light.
• Transmission side simply contains an led lamp which transmits the modulated light signals.
• This led lamp contains a series of LED’s which proto fits according to the input given.
RECEIVING ELEMENT
• Receiving elements are “AVALANCHE PHOTO DIODE” .• Avalanche photo diode is responsible for converting the light
signal into electrical signal and further the procedure is carried out by image sensor.
ILLUSTRATION
COMPARISIONWHY VLC??
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 rays, due to eye safety regulation, can only
be used with low power.
ISSUES REGARDING RADIO SPECTRUM
Cont…
CAPACITY• Radio waves• Cost and expensive• Less bandwidth compared to other spectrums• Insufficient spectrum for increasing data
EFFICIENCY• Millions of base stations consume huge amount of energy for
1. Transmitting the radio waves
2. To cool the base station cabins• 5 % efficiency
Cont…
AVAILABILITY• Availability within the range of base stations• Limited availability• Unavailability in aircrafts
SECURITY• Less secure(passes through the walls
PRESENT SCENARIO
1.4 million 5million
• Radio Spectrum is congested but the demand for wire-less data double each year .Everything, it seems wants to use wireless data but the capacity is drying up
DIFFERENCE B/W TECHNOLOGIES
TECHNOLOGY SPEED
Fire wire 800 Mbps
USB 3.0 5 Gbps
Thunder bolt 20 Gbps
Wi-Fi 150 Mbps
Bluetooth 3 Mbps
IrDA 4 Mbps
Wi-Gig 2 Gbps
Giga-IR 1Gbps
Li-Fi >10 Gbps
APPLICATIONS
• Used in traffic lights which can communicate with cars to avoid accidents.
• Used in airlines: Generally in airlines mobile phones can’t be used as they can effect the radars which are main way of communication.
• Used in power plants for faster data exchange.• Underwater communications. (rare)
ADVANTAGES
• Availability • Efficiency • High security• Easy to use• Fast data transfer• Harmless• Low-cost
DISADVANTAGE
• However, everything comes with a disadvantage. The major disadvantage here is the fact that these signals cannot penetrate walls. So if you want to move from one room to another, you will need to have a wired bulb present in that room as well!
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 hotspot to transmit wireless data and we will proceed toward the cleaner, greener, safer and brighter future.
REFERENCES
• http://timesofindia.indiatimes.com/home/science/Now-just-light-a-bulb-to-switch-on-your-broadband/articleshow/9713554.cms
• http://oledcomm.com/lifi.html• http://en.wikipedia.org/wiki/Li-Fi• http://slideshare.com/li-fitech.html