What is LiFi? Full Information

LIFI-LIGHT FIDELITY

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

WHAT IS LI-FI?

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.

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

• CAPACITY
• EFFICIENCY
• AVAILABILITY
• SECURITY

VISIBLE SPECTRUM

LIFI OVER WIFI

WORKING

LiFi is high speed bidirectional networked and mobile communication of data using light. LiFi comprises of multiple light bulbs that form a wireless network.

When an electrical current is applied to a LED light bulb a stream of light (photons) is emitted from the bulb. LED bulbs are semiconductor devices, which means that the brightness of the light flowing through them can be changed at extremely high speeds. This allows us to send a signal by modulating the light at different rates. The signal can then be received by a detector which interprets the changes in light intensity (the signal) as data.

The intensity modulation cannot be seen by the human eye, and thus communication is just as seamless as other radio systems, allowing the users to be connected where there is LiFi enabled light. Using this technique, data can be transmitted from a LED light bulb at high speeds.

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.

IDEAS FOR MORE APPLICATIONS : 

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.