Li-Fi is a technology for wireless communication between devices that use the lights to transmit data. In the current situation only LED lamps can be used for the spread of visible light. This term was first introduced by Harald Hass during 2011’s Ted Global Talk in Edinburgh. Technically, Li-Fu is a visible light communication system capable of transmitting data at high speed on visible light spectroscopy, ultraviolet and infrared radiation.
The use of technology in the context of its end is much like Wi-Fi. The key technical difference is that Wi-Fi uses radio frequency to transmit data. Using lights to transmit data, Li-Fi offers many advantages such as working in high bandwidth, working in sensitive areas for electromagnetic interference, and offering higher transmission speeds. This technology is being actively developed by many organizations around the world.
The O.W.C. Technology uses light-emitting diodes as a medium to deliver network, mobile, high-speed communication in Wi-Fi equally. Li-Fi market is estimated to have an annual growth rate of 82% by 2018 and an annual estimate from 2013 to 2018.
Visible light communication works by switching the LED up and running at a very high rate and switching quickly as seen by the human eye. Li-Fi leds will be kept to broadcast the data, even though it may fall down to human visibility, while still throwing enough light to carry information. Light waves can not penetrate the walls, making short ranges, though more secure than hacking, compared to Wi-Fine. A direct line of sight is not required for a signal transmission to the Li-Fi; The reflective light of the walls can achieve 70 Mbit / s
Without electromagnetic interference, Li-Fi is useful in electromagnetic sensitive areas such as aircraft cabins, hospitals, and atomic energy plants. Wi-Fi and Li-Fay broadcast data on electromagnetic spectrum, but when Wi-Fi uses radio waves, Li-Fi uses visible light, ultraviolet, and infrared. When the US The Federal Communications Commission has warned of the potential spectrum crisis, as Wi-Fi is near full capacity, there is no limit on the capacity of the Li-Fee. The visible spectrum is 10,000 times larger than the entire radio frequency spectrum. Researchers have reached data rates of 224 Gbit / s, which was faster than the typical fast broadband in 2013. Li-Fi is expected to be ten times cheaper than Wi-Fi. Short sequences, low reliability and high installation costs are potential downside.
Shurelli introduced the first commercially available Li-Fi system, Li-1 at the 2014 Mobile World Congress in Barcelona.
BGFI There is a one-fee system in which there is a simple consumer product, color sensor, microcontroller and embedded software such as mobile device applications, and Iot devices. The light device from the mobile device display interacts with color sensors on the consumer product, which converts light into digital data. Light emitting diodes enable consumer product to communicate with synchronized mobile devices.
Research About Li fi
Professor Herald Haas used the term “Li-Fi” in the 2011 Ted Global Talk, in which he presented the idea of ”Wireless Data of Every Light”. He is a Professor of Mobile Communications at Edinburgh University and a co-founder of PureLife.
The common word “visible light communication”, whose history dates back to the 1880s, is used in any of the visible light parts of the electromagnetic spectrum to transmit information. D-Lite project was funded from January 2010 to January 2012 in Edinburgh Institute for Dedicated Communications. Yes, this technology was promoted in TED Global Talk in 2011 and helped to start the company to bring it to market. PureLieFi, formerly pureVLC, is an original equipment manufacturer for the commercialization of Li-Fiia products for integration with existing LED-lighting systems. French company founded by Pro Suite Topps from Oledcom, Paris-Secell University
In October 2011, companies and industry groups created the Li-Fine Consortium to promote the high-speed wireless wireless systems and promote the available radio-based wireless spectrum by promoting high-speed optical wireless systems and absorbing a completely different part of the electromagnetic spectrum.
Many companies offer VLC products in one direction, not like Li-Fee – the term, defined by the IEEE 802.15.7 ray 1 Standards Committee.
VLC technology was used by Li-Fi in 2012. By August 2013, data rates of 1.6 Gbit / s were shown on one color LED. In September 2013, the press release said that generally Li-Fi, or VLC systems, do not require line-of-sight terms. In October 2013, it was reported that Chinese manufacturers were working on Li-Fi development kits.
In April 2014, Russian company Stin Coman announced the development of Beamster’s Li-Fi Wireless Local Network. Their current module transfers data to 1.25 gigabytes per second (GB / s), but in the near future they predict speed increases up to 5 GB / sec. In 2014, a new record was established by Sysoft, which could transmit data at LED speeds of up to 10 GB / s within the emitted light spectrum by LED lamp.
Currently integrated CIMOS optical receivers are applied with avalanche photodiodes (APD) for le-fi systems that have lower sensitivity. In July 2015, IEEE has operated an APD in a jogger-mode such as the single-font avalanche diode (SPAD) to increase the efficiency of the energy usage and the receiver becomes more susceptible. This action can also be done as a quantum-limited sensitivity, which enables the receivers to find weak signals from a distant distance.
Li Fi Standards
Like Wi-Finei, Li-Fai is wireless and uses the same 802.11 protocols, but it uses ultraviolet, infrared and visible light communication, which has a very large bandwidth.
Part of VLC is created after the Communication Protocols established by the IEEE 802 workgroup. However, the IEEE 802.15.7 standards are advanced: Optical Wireless Communications fails to keep in mind the latest technological developments, especially optical orthogonal frequency-division multiplexing (O-ODDM) modulation methods for data rates, multiplex access and energy efficiency. Has been optimized. The introduction of O-OFDM means that a new drive is required for standardization of optical wireless communications.
However, the IEEE 802.15.7 standard defines physical layer (PHY) and media access control (MAC) levels. Standard audio, video and multimedia services are able to deliver enough data rates to broadcast. It takes into account optical transmission dynamics, its consistency with artificial lighting in infrastructure, and interference caused by ambient lighting. The Mac level allows TCP / IP protocols with the use of links with other layers.
Defines three PHY layers with a standard different rate:
- PHY 1 was installed for outdoor application and 11.67kb. 267.6kb from second / second
- PHY2 level data rates reach 1.25 Mbit / s to 96 Mbit / s.
- PHY 3 is used for many emission sources with a specific modulation system called colored shift king (CSK). PHY III can deliver from 12 Mbit / s to 96 Mbit / s.
Unlike a radio frequency wave used by Wi-Fi, lights can not be destroyed through the walls and doors. This makes it more secure and it’s easy to control who can connect to the network. As long as the transparent contents like Windows are covered, the Li-Fi channel access is limited to the devices inside the room.
Most remote-powered water vehicles (ROVs) use cables to broadcast the command, but after cable length the area can detect RV. However, a light wave can pass through the water, and can be applied to the Li-FA vehicles to get back the signal.
It is theoretically possible to use Li-Fi under water, while its utility water span is limited by light. Significant light is not more than 200 meters. The last 1000 meters, there is no light entry.
Many treatments now include multiple individuals, the Li-Fi system can be a better way to transmit information about patients. In addition to providing high speed, there is little effect on light waves medical equipment and human body too.
Vehicles can communicate with each other through front and back lights to increase road safety. Street lights and traffic signals can also provide information about current road conditions.
Industrial Automation :
Anywhere information in the industrial areas should be transmitted, Li-Fine is capable of shortening, sliding and changing cloth rings, industrial ethernet. Due to Li-Fine real-time capability, which is often required for automation processes, it is also an alternative to the general industrial wireless standards.