What Is Li-Fi? How Does It Work? – Li-Fi vs Wi-Fi.

Pre Release Jul 15, 2016 No Comments

Wi-Fi could be a thing of the past in the coming years, if a high-speed and fully-networked wireless technology under development becomes a success. The new wireless technology is Light Fidelity which is abbreviated as Li-Fi. The visible light communications (VLC) system is claimed to be 100 times faster than Wi-Fi. Most wireless technology enthusiasts are calling it a super-fast alternative to Wi-Fi.

So What Exactly Is Li-Fi?

Li-Fi is a bidirectional communication system that uses regular LED light bulbs to enable data transfer. Started by Professor Harald Haas, the system uses the light bulbs as wireless routers and can boast speeds of up to 224 Gbps. The term Li-Fi was also coined by the professor who teaches at the University of Edinburgh and owns the pureLiFi company.

Li-Fi, which is also a subset of optical wireless communication technology, is being implemented by Velmenni. The Estonian startup showcased the technology at the Slush 100 startup competition held in Helsinki where it emerged as a finalist. The company is doing pilot projects within different industrial environments and offices in Tallinn.

In addition to using visible light, Li-Fi can work with infrared or near-ultraviolet light. Since light cannot pass through walls, the wireless network will allow for greater security and eliminate the problem of interference between devices. The technology is also expected to do away with the bandwidth limitations of Wi-Fi and cellular networks.

How It Works


source= extremetech.com

As mentioned earlier, Li-Fi uses visible light to transmit data. For it to work, there must be a light source fitted with a processing unit/microchip and a device equipped with a photodiode that can receive light signals. The processing unit is for converting data into a content that can be streamed.

A semiconductor light source like LED gives out extremely high rates of light output which is converted into electrical signal by a photo-detector.

The conversion process is aided by changes of light intensity and modulation of thousands of light signals. The changes of light intensity include dipping and dimming of the light. The modulation of light signal cannot be noticed by the human eye, but it involves up and down movement of the signals.

The electrical signal is then converted into a stream of binary data consisting of web, audio, video and application information. This data can be accessed with the help of an internet-enabled device.

Li-Fi Vs Wi-Fi

Starting with the operational difference, Li-Fi transmits data using light supplied by LED bulbs. On the other hand, Wi-Fi transmits data using radio waves emitted by a Wi-Fi router.

Similar to radio frequency waves, Li-Fi does not have any interference issues. Wi-Fi always has interference issues. The signal is usually interrupted by nearby access points or routers.

Li-Fi is IrDA compliant while Wi-Fi is WLAN 802 compliant. The IrDA deals with wireless infrared communications. It provides specifications for a set of protocols that guide these forms of communications. The WLAN 802 offers media access controls and physical layer specifications that guide implementation of wireless local area network.

Li-Fi is more secure than Wi-Fi. The VL signal is blocked by walls which means that the network is contained inside a room. This provides a more secure data transfer. On the other side, the RF signal cannot be blocked by walls which means that unauthorized people can access the network creating an insecure data transfer. Some techniques are needed to secure these types of networks.

The data transfer speed is higher in Li-Fi compared with Wi-Fi. The speed can go up to 224 Gbps for the VLC network. Wi-Fi operates at 150 Mbps, but some sophisticated systems can offer a maximum speed of 2 Mbps.

The frequency of operation is higher in Li-Fi. This system can operate at a frequency 10 thousand times that of the radio (higher values of the range). Wi-Fi operates between 2.4GHz and 5.0GHz.

The coverage distance is larger in Wi-Fi. This network can cover an area of diameter 32 meters. The coverage is determined by the antenna type and transmit power. Li-Fi covers an area of about 10 meter diameter.

Li-Fi has system components such as an LED bulb, a lamp driver and a photo detector device. On the side of Wi-Fi, components such as router and user devices are needed for a complete system.

Wi-Fi is the better choice when it comes to public networks. This is because only a router is needed to provide a network. In order for Li-Fi to be used as a public network, light bulbs need to be switched on and need to be in view of lifi receiver…


The future of Li-Fi.

Some better Li-Fi-enabled products will be introduced in the near future. PureLiFi is partnering with Lucibel- a French lighting company- to make these products. There are already Li-Fi-enabled products, such as Li-Flame Ceiling Unit and Li-Flame Desktop Unit, but more sophisticated products are needed. The ceiling unit is used to connect to an LED light while the desktop unit is used to connect to a device via USB. The two units provide light and connectivity.

Apple is also likely to build Li-Fi-enabled devices in the near future. According to some reports, the tech giant may include Li-Fi capabilities in their iPhones. There is evidence that the iOS 9.1 code has a reference to the VLC system.

The use of infrared light could tremendously improve the communication system. Some researchers believe that if an infrared light is used in a photo detector that has a mobile device connected on to it, the device can send data back to the light source creating an uplink. Other researchers are working to see if a multicolored RGB light could be used in the system to create a wider range of signals.

If the technology gets absorbed well, businesses will definitely benefit a lot from it. Information will be acquired and shared in a very short period of time, improving the efficiency of running businesses. Due to the secure nature of the network, more businesses will be willing to use it.

In conclusion, Li-Fi will not necessarily come to replace Wi-Fi, but to complement it. The VLC technology will be adopted by those who need higher data transfer speeds and securer networks. The technology consumes less power, so those who need to save on energy will also go for it.


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