Transfer data from one place to another is one of the most important day-to-day activities. The current wireless networks that connect us to the internet are very slow when multiple devices are connected. As the number of devices that access the internet increases, the fixed bandwidth available makes it more and more difficult to enjoy high data rates and connect to a secure network.
Nowadays, everyone is interested in using his mobile phone, laptop to communicate with other people through WirelessFidelity (Wi-Fi) systems, and this technology, Wi-Fi, is widely used in all public areas like home, cafes, hotels and airports by people, also the time usage of wireless systems is increasing exponentially every year; but the capacity is going down, due to the limitation of Radio Frequency (RF) resources, so we are going to suffer from severe problem such as Capacity, Efficiency, Availability, and Security.
This new technology is known as Light–Fidelity (LI-FI). It is a short range wireless communication system based on light illumination from LED, and use the visible light as a signal carrier instead of traditional RF carrier as in Wi-Fi. Professor Harald Haas coined the term “Light-Fidelity” and set up a private company, called “Pure Visible Light Communication”, to exploit that technology. He envisions a future where data for laptops and smart phones are transmitted through the light in a room in a secure way.
Li-Fi basically outcome of twenty first century. Li-Fi is a Visible Light Communications (VLC) system running wireless communications travelling at very high speeds. Li-Fi uses common household LED (light emitting diodes) light bulbs to enable data transfer, boasting speeds of up to 224 gigabits per second. The basic ideology behind this technology is that the data can be transmitted through LED light whose intensity varies even faster than the human eye. As the transmission of the data takes place through the light emitting diodes (LED’s) the amount is comparatively small. In modern times, it is called as the optimized version of Wi-Fi. In simple terms, Li-Fi can be thought of as a light-based Wi-Fi
Architecture of Li-Fi Li-Fi architecture consist numbers of LED bulbs or lamps, many wireless devices such as PDA, Mobile Phones, and laptops. Important factors we should consider while designing Li –Fi as following:
- Presence of Light must be line-of-sight.
- Lamp driver where internet connection, switch and LED lamp connected.
- For better performance use LED bulbs.
- A photo detector received data.
APPLICATIONS OF LI-FI
Many areas where Li-Fi system provide a reliable, secure, cheaper and ultra-high-speed communication infrastructure have already been launched worldwide, so we can summarize some of them as follows:
1) Vehicle and traffic lights: LED devices can be installed as headlights and tail-lights developing an intelligent transport system. Traffic lights can also move to LED with the benefit of road safety and traffic control.
2) Underwater communication: Light propagate underwater where radio frequencies cannot be used because of salty, high conductivity and high attenuation environment. Since cables creates threads in communication undersea water, can be replaced with Li-Fi transmitters. Also, they can send data to submarines, to surface as well as to divers with their head lights.
3) Home and office appliances: Li-Fi system can be integrated in home appliances such as: secure systems, freeze, central heating systems, TV’s, clocks and so on to reduce energy consumptions for an intelligent energy management. Hotspots and monitoring lighting and data can be used to the same communications and sensor infrastructure
4) Airplanes: Since Wi-Fi during flights with most of airlines is forbidden, and therefore limited, Li-Fi can be a suitable replacement for wireless communication. The use of this technology within aircraft cabin has more advantages since significant amounts of cabling can be saved resulting in cost saving, reduced weights and flexible layout design.
5) Petrochemical industry: Since various radioactive chemicals are used for processing, the industry does not allow RF.
