li-fi: the future of wireless...
TRANSCRIPT
ISSN No: 2309-4893
International Journal of Advanced Engineering and Global Technology I Vol-03, Issue-02, February 2015
Li-Fi: The Future of Wireless Technology
Golthi Tharunn, G Dixith Reddy, Virisha Timmaraju
Electronics and Communication Department, GITAM University Rudraram, Hyderabad, Telangana, India
[email protected], [email protected], [email protected]
Abstract: A breakthrough in modern day technology, Light fidelity (Li-Fi) the 5G visible light communication uses the visible light spectrum to transfer high amounts of data at high speeds. It surpasses the present day RF communication in terms of speed, capacity, security, accuracy, cost, electromagnetic interference and efficiency. This technology is still under research and further exploitation could lead to wide applications.
I. INTRODUCTION
The longest known form of energy to mankind has been 'Visible Light' and its features are innumerous and inexhaustible. Two novel attributes that Visible Light offers to Communication technology are its speed and range. Communication technology, is the theme of a major sector of technology as it shoulders the responsibility of transmitting and receiving data, in short, binding the world together.
Speed, Range and Reliability, being the fundamental requirements for data transmission necessitated the development of 'Visible Light Communication'(VLC) which literally means "Any form of information being sent using light signals and visible to humans". This paper describes the concept of Li-Fi which stems from VLC and is described as high speed VLC or the complementary of Wi-Fi, using visible light instead of radio waves.
II. COMPARING LI-FI AND WI-FI
Li-Fi and Wi-Fi differ in the spectrum of propagation. Li-Fi uses the Visible Light (VL) spectrum whereas Wi-Fi uses the Radio Frequency (RF) spectrum. Wi-Fi uses complex receivers, antennas and radio circuits for its operation whereas Li-Fi uses low cost LED's and other simple devices to establish communication. Another major advantage of Li-Fi over Wi-Fi is its range of transmission. Li-Fi's range is controlled by the intensity of light whereas Wi-Fi's range doesn't exceed 150 mts.
III. IMPLEMENTATION OF A LI-FI SYSTEM
The entire mechanism of sending data through light centers around varying the intensity of light either directly by varying the input current or by using an assembly of various colored LED bulbs with different frequencies. If the current is slowly varied, the output intensity toggles up and down. The LED being a semi-conductor device can achieve high speed intensity modulation which is undetectable by the human eye, therefore not annoying them by constant flickering. The on is encoded as logic 1 and off as logic 0. These modulated intensities can be detected by a photo detector, thus converting it back into electrical signals. This conversion is done by using a receiver dongle which detects the smallest of changes in amplitude thus sending back electrical information; this is again converted into a data stream and transmitted to the connected device. Thus, transmission and reception of data through an LED is achieved.
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ISSN No: 2309-4893
International Journal of Advanced Engineering and Global Technology I Vol-03, Issue-02, February 2015
IV. APPLICATIONS OF LI-FI
The dramatic growth of LEDs (light emitting diodes) for lighting provides the opportunity to incorporate Li-Fi technology into a plethora of LED environments.
Li-Fi has many applications in the internet such as video and audio downloads, live streaming etc. These applications place heavy demands on the downlink bandwidth, but require minimal uplink capacity; This results in reduction of internet traffic in the RF channel, thus the capacity of cellular and Wi-Fi are extended.
The many applications of Li-Fi include the following ;
1) RF Spectrum Relief: The use of wireless networks has drastically increased during the last two decades. As a consequence, the limited available RF spectrum is subjected to aggressive special reuse and co-channel interference has become a major capacity limiting factor. This results in “RF spectrum crisis” since the mobile data demands continue to increase while the network spectrum efficiency saturates despite newly-introduced standards and great technological advancements in the field. This problem can be solved with the help of VLC (visible light communication)
2)Smart lighting: We find lights everywhere around us, these lights can be used to provide Li-Fi hotspots and the devices can receive and transmit data with the help of sensor infrastructure. This sensor infrastructure can also be used to control the lighting and data.
We can use this concept in malls for advertising purposes, in offices for high data transfer and on streets for traffic updates etc., with the help of street lights.
3)Mobile Connectivity: Smart phones, Laptops, Tablets and other mobile devices can interconnect with the help of Li-Fi. The typical transmission range is between 3 and 5 meters with a transmission speed of 1 to 5 Gbps. This even has high security because access to this data communication is only possible within the laser beam. Reflections of the signal are so weak that they would not go far, for example outside the window.
4) Hazardous Environments: In the last 5 years with the advent of wireless devices, there has been a massive increase in radiofrequency (RF) exposure from wireless devices as well as reports of hypersensitivity and diseases related to electromagnetic field and RF exposure. Multiple studies correlate RF exposure with diseases such as cancer, neurological disease, reproductive disorders, immune dysfunction, and electromagnetic hypersensitivity. Thus Li-Fi provides a safe alternative to electromagnetic interference.
343 www.ijaegt.com
ISSN No: 2309-4893
International Journal of Advanced Engineering and Global Technology I Vol-03, Issue-02, February 2015
5) Hospital and Health care: Since Li-Fi emits no electromagnetic interference, it does not interfere with the medical instruments or any MRI scanners. 6) Aviation: Since RF operated gadgets are not allowed in aircrafts Li-Fi can be used. Li-Fi reduces weight and cabling and adds flexibility to seating layouts in the aircraft passenger cabins where LED lights are already deployed. In-flight entertainment (IFE) systems can also be supported and integrated with the passenger’s own mobile device. 7) Underwater Communications: Due to strong signal absorption in water, RF use is impractical. Acoustic waves have extremely low bandwidth and disturb marine life. Li-Fi provides a solution for short-range communications. 8) Vehicles and Transportation: Now a Days even vehicles are introduced with LED headlamps and tail-lights. Even Street lights, signage and traffic signals are being made of LEDs. These LEDs can be used for vehicle to vehicle and vehicle to roadside communication. Thus we can control traffic more efficiently and road safety is also improved.
9) Location Based Services (LBS): Highly accurate location specific information services such as advertising and navigation that enables the recipients to receive appropriate, pertinent information in a timely manner and location. 10) Toys: Many toys incorporate LED lights and are used to enable extremely low cost communication between interactive toys.
V. FUTURE SCOPE
Li-Fi provides a great platform to explore the grounds of transmission of wireless data at high rates. If this technology is put into practical use, each light bulb installed, is potential and can be used as a Wi-Fi hotspot to transmit data in a cleaner, greener and safer manner. The applications
of Li-Fi are beyond imagination at the moment. With this enhanced technology, people can access wireless data with the LED’s installed on the go at very high rates. It resolves the problem of shortage of radio frequency bandwidth. In various military applications, where RF based communications are not allowed, Li-Fi could be a viable alternative to securely pass data at high rates to other military vehicles. Also LEDs can be used effectively to carry out VLC in many hospital applications where RF based communications could be potentially dangerous. Since light cannot penetrate through walls, it could be a limitation to this technology. Nevertheless, given its high rates of data transmission and applications in multiple fields, Li-Fi is definitely the future in wireless communication.
VI. CONCLUSION Li-Fi is the most ideal solution for effective data transmission due to its basic building block : Light. Inexhaustible, accurate, fast, safe and cost effective, Li-Fi could potentially be the successor of Wi-Fi upon further development. Its working centers around the principle of varying the electrical signal based on the required output. Its applications range widely from toys to communication and can find uses in critical fields like military and medicine. Further research on Li-Fi is gaining pace in the recent times which will potentially resolve the many unsolved mysteries of the world.
VII. REFERENCES
1. http://visiblelightcomm.com/what-is-visible-light-communication-vlc/
2. http://visiblelightcomm.com/ 3. http://purelifi.com/what_is_li-fi/how-does-
vlc-work/ 4. http://purelifi.com/what_is_li-
fi/applications-of-li-fi/# 5. http://www.see.ed.ac.uk/~hxh/PRE_PRIN
TS/14_Haas_Photonics_West.pdf 6. http://www.lificonsortium.org/tech4.html 7. http://techyworld.in/lifi-enhanced-mode-fu
ture-wireless-communication-review/
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