lifi
                     
PowerPoint Presentation



LIFI-LIGHT FIDELITY

Presentation By:
                         Jasleen Kaur

131200023
ECE 3rd Year

NATIONAL INSTITUTE OF TECHNOLOGY, DELHI


CONTENTS
• What is Li-Fi?
• Why is it required?
• LiFi over WiFi
• Working
• Disadvantages
• Applications
• Ideas for more applications of this technology


Li-Fi, as coined by Prof. Harald Haas during his TED Global 
talk, is bidirectional, high speed and fully networked wireless 
communications similar to Wi-Fi. Li-Fi is a subset of optical 
wireless communication (OWC) and can be a complement 
to RF communication (Wi-Fi or Cellular network), or a 
replacement in contexts of data broadcasting.

WHAT IS LI-FI?


Existing wireless technology - Why 
do we need an alternate 
technology?

• CAPACITY
• EFFICIENCY
• AVAILABILITY
• SECURITY


VISIBLE SPECTRUM


LIFI OVER WIFI


WORKING


DISADVANTAGES
Nothing in this world is perfect and so does LIFI.
• These signals cannot penetrate walls. So the person needs 

wired bulb in that room also. 
• Only works if there is direct line of sight between source 

and receiver.
• Used for broadcast and it is difficult to uplink.


APPLICATIONS
• Underwater communications: Since radio waves cannot be used under 

water because these waves are strongly absorbed by sea water within feet of 
their transmission and this renders it unusable underwater but LIFI is 
suitable for underwater communication 

• Health sector: Since WIFI is not safe to be used in hospitals and other 
various health care sectors because it penetrates human body. LIFI can be 
implemented and well suit in this sector.

• Internet anywhere: street lamps, light of vehicles can be used to access 
internet anywhere in footpaths, roads, malls, anywhere where light source is 
available.

• Safety and management: it can be used to update traffic information at 
almost every instant and it will be easy for traffic police to deal with traffic 
and catch the one who breaks the rule.


• Finding the location of a person : 
LiFi uses visible light and this property can be exploited 

in finding the location of people. Suppose if a child is 
misplaced and he/she is wearing an earing which is made of 
Led’s. this led can constantly communicate with the visible 
light available and reveal the location of the child.
• Navigation System : since visible light is present 

everywhere, we can create internal navigation systems 
for the bigger areas to create automated machinery/ 
automatic navigation for the visitors.

IDEAS FOR MORE APPLICATIONS : 


• Underwater Applications : the LEDs can be embedded in the 
water bed to reveal the various impurities underwater. The 
various leds will communicate with each other to give the 
overall amount of impurity in that particular area.

• Instant data transfer between the devices : the high speed 
transfer of the leds can be used to transfer the data between 
the devices. 

• The disadvantage of the Lifi is uplink is difficult.
• So we can have the photodiodes embedded near to the people on the 

pillars for eg.
• Or we can have the same led behaving as a photodiode as well as an 

led.

IDEAS FOR MORE APPLICATIONS : 


REFERENCES

• http://
www.ijstr.org/final-print/oct2014/Li-fi-A-New-Era-Of-W
ireless-Communication-Data-Sharing.pdf

• https://www.youtube.com/watch?v=NaoSp4NpkGg