LiFi Technology

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Light Fidelity, otherwise known as Li-Fi is a new evolutionary technology which was first proposed by Harald Haas, a German physicist in a TED Global Talk on Visible Light Communication. Li-Fi, similar to our current Wi-Fi, is a wireless optical networking technology that uses light emitting diodes also know as LEDs for transmitting the data. Li-Fi uses the light as a medium for the transmission of high-speed data/communication which is very much similar to Wi-Fi and also falls within the IEEE 802.15.7 standard of Institute of Electrical and Electronics Engineers (IEEE). The IEEE 802.15.7 is similar to the IEEE 802.11 in which the Wi-Fi operates. li fi is the best for high-density wireless data coverage in confined places. This technology is more useful in areas where radio interference issues are high. So basically li-fi send the data through LED light by taking the fiber out of the fiber optics.

How It Work’s ?

  • LiFi essentially uses light instead of radio waves like Wi-Fi. Transceivers fitted in the LED bulb transmits and receives information is the basic concept of li fi technology. Compared to a Radio Frequency (RF) communication, the li-fi can provide a band of the order 400 THz whereas the RF can provide up to 300 GHz. Li fi also uses visible spectrum which helps to terminate the health issues that could be caused by electromagnetic waves which come from the Wi-Fi.

Li-fi is potential can be the future of data transmission which is fast and affordable. The visible light electromagnetic spectrum is used for data transmission and illumination. The rays of light transmit information in a wireless medium which is also fast. The main parts of a li-fi system are:

  • Transmission source (White LED light)
  • Silicon Photodiode (for receiving visible light element)

Communication rate of 100 Mbps or more can be attained with a few other techniques. We can get up to 10gbps if the lights are arranged in an array transmitting different streams of data which is also known as parallel data transmission.

 There are four subassemblies:

  • Light Source (bulb)
  • PA Circuit (Radio Frequency Power Amplifier)
  • Printed Circuit Board (PCB)
  • Enclosure

There is a LED transmitter and a light sensor on the object receiving the data. The transmitter is inputted with the data which is then encoded to VLC (visible light communication) or light by stretching the flickering rate at which the LEDs get turned on and off into binary format in different strings. In other simple words, when you switch on the light, the binary code generated as a logical 1 and when it is turned of it’ll be a logical 0 which means the transmitter identifies if it’s on or off.

The LED is connected to the internet through a modem and at the receiver’s end, the data gets decoded which then displays if it is connected or not. The receiver is coded to recognize 1s as when LED is on and 0s when it is off. So each light beam received will eventually provide a range of 100s of Mbps of data.

 What is the major difference between Wi-Fi and Li-Fi?

The key difference is that the li-fi uses VLC radio technology which is useful to receive high-speed wireless communication. This is done by using light waves. Whereas the Wi-Fi uses radio waves. This enables the possibility of the li-fi to reach places of high density that Wi-Fi is not able to.

 Advantages:

  • Efficiency: It is very efficient in terms of energy consumption and performance. LEDs consume very less energy and are already available for lighting purpose. So the data transmission will only require a very slight amount of additional power.
  • Cheap: Li fi doesn’t require a lot of components or much of energy for transmission of data.
  • Security: The key advantage is that the Li-fi is highly secured because the light can’t go through the walls of the building which means it only will be used by the people in that confined space which makes it not possible for any interception from outside.
  • Speed: The li-fi will be able to provide a high data rate of 1 Gbps or more because of the combination of the high bandwidths, high-intensity output, and low interference.
  • Availability: As long as light bulbs (LEDs) are present at any place, Li fi can be applied, installed and made available as it only requires a light source to transmit the data. So essentially, it can be made available everywhere.

 Limitations:

  • No internet access without the light source and it could limit the situations and other locations where li-fi could be used
  • It requires a direct line of sight with the source to transmit the data
  • It can’t pass through concrete obstacles which make the range short
  • Other light source involved at that place can affect the transmission of data and its speed
  • Opaque items can affect the transmission of data