Light Fidelity Research Articles

Implementation of Navigation System using Li Fi Technology

In This Paper, an Indoor navigation system is proposed for persons with visually disability that utilize VLC (Visible Light Communication) Technology. Using VLC we can provide precise locational coordinates or directions regarding their journey. Light Fidelity (Li-Fi) refers to the VLC technology. VLC is based on the concept that uses visible light as a means of communication enabling faster flow of information [1]. The principle of VLC is that it uses light as a medium to deliver high speed communication. The main idea is to create internal navigation system for the area to create automatic navigation for the visitor who are visually challenged. The Li-Fi is preferred over Wi-Fi because Wi-Fi is nothing but radio-telecommunication which effective within premises, while Li-Fi is effective for faster communication in restricted places without any hurdles. The concept of Li-Fi is used to give the navigation path for visually challenged person and particularly voice guidance of the walk way. Headphone is used to give the voice message to such people. The data is transmitted through the LED light which emits the visible light and an embedded system accepts from receiver. The received data is converted into audio format for the blind people. The suitability of system has been confirmed by means of useful prototype through a trail with blind person.

Effective Visible Light Communication System for Underground Mining Industry

Adequate lightening and efficient communication technology have prime importance for safe underground mining communication system operations. Existing conventional light and communication systems used in underground mines are not very efficient solutions due to heavy power and maintenance requirements. Also, efficient communication technology is required for instantaneous reporting of any potential disaster event under hazardous underground environment. In this paper, we propose light fidelity (Li-Fi) as an efficient way of incident reporting as well as source of illumination for mines. Visible light communication (VLC) system is being used in mines operations, to support communication-blind areas. It exhibits superior performance over traditional radio frequency (RF) communication systems, in terms of low energy consumption, higher data rates achieved, and wide frequency band (430 − 790) T Hz. In this paper, we present VLC system for safe and reliable mining operations and analyze and discuss corresponding channel impulse response (CIR). We consider effect of shadowing and dust on our optical channel model. We compare the performance of our system with available methods in terms of bit error rate (BER), CIR, and prove the superiority of our proposed system.

Effective Visible Light Communication System for Underground Mining Industry

Adequate lightening and efficient communication technology have prime importance for safe underground mining communication system operations. Existing conventional light and communication systems used in underground mines are not very efficient solutions due to heavy power and maintenance requirements. Also, efficient communication technology is required for instantaneous reporting of any potential disaster event under hazardous underground environment. In this paper, we propose light fidelity (Li-Fi) as an efficient way of incident reporting as well as source of illumination for mines. Visible light communication (VLC) system is being used in mines operations, to support communication-blind areas. It exhibits superior performance over traditional radio frequency (RF) communication systems, in terms of low energy consumption, higher data rates achieved, and wide frequency band (430 − 790) T Hz. In this paper, we present VLC system for safe and reliable mining operations and analyze and discuss corresponding channel impulse response (CIR). We consider effect of shadowing and dust on our optical channel model. We compare the performance of our system with available methods in terms of bit error rate (BER), CIR, and prove the superiority of our proposed system.

Optimized joint LiFi coordinated multipoint joint transmission clustering and load balancing for hybrid LiFi and WiFi networks

Hybrid light fidelity (LiFi) and wireless fidelity (WiFi) networks provide a promising solution for future indoor wireless communication. Hybrid networks face the challenge of imbalanced cell load due to the uneven distribution of user equipment (UE), and they need to suppress inter-cell interference induced by the dense deployment of LiFi access points (APs). In this paper, with the aim to efficiently establish UE-AP associations and allocate resources, we propose a potential game (PG) aided design of joint user-centric LiFi coordinated multipoint (CoMP) joint transmission (JT) clustering and load balancing (LB). In our design, we formulate the joint design problem as a mixed-integer nonlinear programming (MINLP) problem, which integrates the requirement for the minimum data rate of each UE. With the aim to maximize the system throughput under proportional fairness constraints, we propose to build a PG model to solve the MINLP problem. Then we derive the Nash equilibrium based on the best-response dynamics, and thus a suboptimal solution is attained. Thanks to the space diversity gain brought by our joint LiFi CoMP-JT clustering and LB design, the signal-to-interference-plus-noise ratio can be improved. Thus, when the physical layer configurations remain the same, hybrid networks can achieve larger capacity and better reliability performances. Simulation results validate that hybrid networks using our presented design would achieve better throughput and satisfaction performances than benchmarks.

Parallel Transmission LiFi

Light fidelity (LiFi) is a relatively new wireless communication technology that exploits the optical spectrum. Compared to wireless fidelity (WiFi), LiFi is densely deployed with each access point (AP) covering an area only a few meters in diameter. Also, LiFi users are susceptible to intermittent light-path blockages. Meanwhile, the user is served by a single AP in conventional LiFi systems. This would cause frequent handovers for LiFi users, resulting in a degradation in quality of service. In this paper, parallel transmission is investigated for LiFi, which is named PT-LiFi. With a delicate design of the transmitter and the receiver, PT-LiFi enables multiple LiFi APs to serve the user simultaneously. Particularly, data transmission continues without interruption when the user is losing connectivity to some of the connected APs. Resource allocation is studied for the PT-LiFi system, and a novel load balancing method is proposed to jointly allocate resource across the APs. Results show PT-LiFi can make efficient use of the densely deployed LiFi APs and provide a flexible way of load balancing. Compared with a conventional LiFi system, the proposed method can increase user throughput by up to 150% and improve user fairness by up to 15%.

Transmission of data, audio and text signal using Li-fi technology

The light fidelity technology refers to visible light communication that uses light as a medium to deliver high speed data which is much greater than that of WiFi. LiFi data is transmitted in several bit streams and the receiver side consisting an IR detector decodes the message. The transmission happens in the form of binary data where 0 means LED in ‘OFF’ state and 1 means that the LED is in the ‘ON’ state. Transmitter and receiver sections contain Arduino which is programmed using Arduino IDE. High power intensity led’s are used in the LiFi transmitter. In receiver section photodiode module is used to detect the light signal generated by the LiFi transmitter. In this we are transmitting the 2 different data using light they are Audio signal and Text signal. Hence the study of various topologies to understand the characteristics a LiFi system.

Vehicle to Vehicle Communication using LI-FI Technology

Wireless communication has become a basic utility in our day to day life such that it becomes a fundamental of our lives and this communication uses the radio spectrum for data transfer. There are issues in using the radio spectrum they are capacity, efficiency, availability and security. The usage of Wi-Fi also causes damage to the ecosystem such as flora and fauna.The defects of the Wi-Fi technology has given birth to the concept of Li-Fi (Light Fidelity) technology. Li-Fi is an advanced technology. This project is concise to vehicle to vehicle communication for avoiding road accidents. We use the ultrasonic sensor, gas sensor, vibration sensor, LCD display, Li-Fi transmitter and receiver. In case of an abnormal condition in the front vehicle, the vehicle at the back will be intimated and will stop on the second. For future enhancement, Li-Fi can be implemented in class rooms where data stored in the server is transmitted through LED lights attached in the ceilings of the classroom and the data can be received through Li-Fi receiver(dongle) which is present with each student in the classroom.

Concept of Li-Fi on Smart Communication between Vehicles and Traffic Signals

Communication is an essential thing for any work to be done on desired condition. There are several ways are there to communicate between a person to a machine. Switches are made as primary communication medium to do a specific task by a machine. The advancement of technologies introduced a remote switch for operation. The advancement is still continuing with voice recognition, hand gesture movement and mind reading models. Recently machine to machine communication was introduced to communicate their status between another machine or a system for implementing smart work on its own intelligence. The paper introduces a smart communication between vehicles to traffic signals and vehicle to vehicle using Li-Fi (Light Fidelity) technology for sharing necessary information to the nearby vehicle. The paper also describes the limitations and challenges in the Li-Fi technology for further communication improvement.

Multi-Hop Wireless Optical Backhauling for LiFi Attocell Networks: Bandwidth Scheduling and Power Control

The backhaul of hundreds of light fidelity (LiFi) base stations (BSs) constitutes a major challenge. Building on an indoor wireless optical backhauling approach, this paper presents the top-down design of a multi-hop wireless backhaul configuration for multi-tier optical attocell networks by proposing super cells. Such cells incorporate multiple clusters of attocells that are connected to the core network via a single gateway. Consequently, new challenges arise for managing the bandwidth and power of the bottleneck backhaul. By putting forward user-based bandwidth scheduling (UBS) and cell-based bandwidth scheduling (CBS) policies, the system-level modeling and analysis of the end-to-end multi-user sum rate is elaborated. In addition, optimal bandwidth scheduling under both UBS and CBS policies are formulated as constrained convex optimization problems, and solved by using the projected subgradient method. Furthermore, the transmission power of the backhaul system is opportunistically reduced using a fixed power control (FPC) strategy. The notion of backhaul bottleneck occurrence (BBO) is introduced. An accurate approximate expression of the probability of BBO is derived, and verified using Monte Carlo simulations. Several insights are provided by studying different aspects of the performance of super cells including the average sum rate, the BBO probability and the backhaul power efficiency (PE).

Ultra-High Capacity FSK Transmission Using Silicon Microring Embedded Gold Grating Circuits

The Frequency Shift Keying (FSK) dual-transmission mode for short-range communication using the silicon microring resonator arrangement is proposed. FSK generated by an optical modified add-drop multiplexer embedded gold grating connected to three other microring resonators. The proposed system consists of a transmitted microring with two nano-ring phase modulators, which connected through a 10 km fiber channel to a receiver. The user end consists of three similar microring systems. A gold grating embedded on two side ring center (sensor probe) to introduce the plasmonic polariton, from which each of sensor probe identified by the Bragg wavelength. The frequency of n photonic oscillator is in the range of plasmonic frequencies, where the Whispering Gallery Mode (WGM) due to the light propagations can be obtained by controlling the used two sides smaller ring resonator in the proposed ring structures. The WGM beam can be used as another mode of transmission called light fidelity (LiFi) transmission. In manipulation, the FSK light source wavelength of 1.55 μm fed into the system. The transmission bit rates of 200 Tbits−1is achieved. The Bit Error Rate (BER) obtained at the user ends increases with increasing input power. Each sensor node identified the Bragg wavelength, while the change in Bragg wavelength on each sensor obtained and shown the linear trend, which is useful for sensing application. In applications, the proposed system is capable of dual mode of transmission either cable or wireless and in this case, the cable transmission of data using LiFi is more reliable than WiFi in terms of security, efficiency, availability, and safety.

Graphdiyne Nanosheets for Multicolor Random Lasers

By breaking the restriction of mirrors, random lasers from a disordered medium have found unique applications spanning from displays to spectroscopy to biomedical treatments to light fidelity. Gain...

Li-Net: towards a smart Li-Fi vehicle network

Background/Objectives: Light Fidelity is popularly known as Li-Fi. This is a most recent technology that was driven by German physicist Harald Haas(1) in 2011. The technology was proposed during a global talk on Technology Entertainment Design on VLC communications. Visible light communications are optical ways of communication that network the LED for data transmission. The term Li-Fi uses VLC communication for the high-end communication that can be an alternative to Wi-Fi. The proposal of Harald Haas is comparable with IEEE 802.15.7 that is the fully dual directional and networked standard built for 802.11. Li-Fi applications are featured for their comparison with other technologies like Wireless fidelity and their general use for LAN. Materials and methods: However, the optimality of the proposed Li-Fi is within highly dense areas where Wi-Fi faces interfaces and radio interferences are no good for complimentary performance goals of the communication standard. Li-Fi proves to be better in bandwidth, connectivity and secure when the higher speeds above 1Gbps are achieved. Finding/novelty : This study outlines the characteristics of Li-Fi and describes its potential use in a smart traffic net. The smart traffic net is the future of the transport system that is based on Li-Fi. Therefore, this is called Li-Net in this article. Li-Net is a modified VaNet that uses Li-Fi for V2V and V2I communication. The leveraging of Low cost LEDs and other lighting units have lots of opportunities that can help the Li-Fi to get over Wi-Fi. Keywords: Li-Fi; Li-Net; VaNet; communication technology; network; smart network

Light Fidelity: The Future of Data Communication

Light Fidelity: The Future of Data Communication

Realistic Indoor Hybrid WiFi and OFDMA-Based LiFi Networks

The increasing number of mobile devices challenges the current radio frequency (RF) networks, e.g. wireless fidelity (WiFi) networks. Light Fidelity (LiFi) is considered as a promising complementary technology, which operates within the visible light spectrum and infrared spectrum. In an indoor scenario, a hybrid LiFi/WiFi network (HLWN) provides a potential solution to future wireless communications where LiFi augments WiFi in providing ultra-high speed and low latency wireless connectivity. In this paper, dynamic load balancing (LB) with handover in HLWNs is studied. The orientation-based random waypoint (ORWP) mobility model is considered to provide a more realistic framework to evaluate the performance of HLWNs. Based on the low-pass filtering effect of the LiFi channel, we firstly propose an orthogonal frequency division multiplexing access (OFDMA)-based resource allocation (RA) method in LiFi systems. Also, an enhanced evolutionary game theory (EGT)-based LB scheme with handover in HLWNs is proposed. In the EGT scheme, each user adapts their strategy to improve the payoff until LB is achieved across LiFi and WiFi. Then, the LiFi system uses the proposed OFDMA-based RA method while the WiFi system applies the carrier sense multiple access with collision detection (CSMA/CA). Simulation results show that in the LiFi system the OFDMA-based RA scheme outperforms the time division multiple access (TDMA) scheme in terms of both user data rate and fairness. Regarding LB in HLWNs, the proposed EGT scheme can achieve a remarkable enhancement in throughput compared to benchmark schemes, such as hard threshold (HT) scheme and random access point assignment (RAA) scheme.

Design and Implementation of the MIMO-COOK Scheme Using an Image Sensor for Long-Range Communication.

Radio-frequency technologies are widely applied in many fields such as mobile systems, healthcare systems, television and radio broadcasting, and satellite communications. However, one major problem in wireless communication based on radio frequencies is its impact on human health. High frequencies adversely impact human health more than low frequencies if the signal power transgresses the permissible threshold. Therefore, researchers are investigating the use of visible light waves (instead of the radio-frequency band) for data transmission in three major areas: visible light communication, light fidelity, and optical camera communication. In this paper, we propose a scheme that upgrades the camera on–off keying (COOK) scheme by using it with the multiple-input multiple-output (MIMO) scheme; COOK has been recommended by the IEEE 802.15.7-2018 standard. By applying technologies, such as matched filter, region of interest, and MIMO, our proposed scheme promises to improve the performance of the conventional scheme by improving the data rate, communication distance, and bit error rate. By controlling the exposure time, the focal length in a single camera and using channel coding, our proposed scheme can achieve the communication distance of up to 20 m, with a low error rate.

High-Density Wavelength Multiplexing Model for THz-EMI Transmission

We propose the use of the specific form of the integrated device known as the boxcar filters for big data transmission, where the advantage of such device is the number of roll-off (bandwidth) can be increased to meet the large demand of the future bandwidth requirements. A boxcar filter system is formed by the serial Panda-ring resonators, where the initial and end rings are used to form the whispering gallery mode beams for the light fidelity (LiFi) up-down-link conversion. There are 5 boxcar circuits within the system. Each of boxcar devices has the electro-optic connection that can be used to perform the external signal processing applications, where all electronic signals are changed to be the light signals and connected to the network via the free-space up-down link nodes. In a simulation, the selected light source is fed into the boxcar filters via the input port, in which the single roll-off bandwidth of 300 THz is obtained. The frequency guard band is given by each boxcar separation. In applications, the electromagnetic immunity interference (EMI) signals can be obtained by the electro-optic conversion circuit, which is the medical instrument specification requirement. The low EMI signals can be connected to the network and transmission using the LiFi network to the remote area. In addition, the medical information to home using the big data via the ad hoc LiFi network and the internet of thing platform arrangements are also proposed.

Cyber security vulnerabilities for outdoor vehicular visible light communication in secure platoon network: Review, power distribution, and signal to noise ratio analysis

Light Fidelity (LiFi), a 5th Generation visible light communication (VLC) technology, is anticipated to be utilized in various locations where radio frequency (RF) cannot be deployed, due to RF health limitations and congestion. VLC offers a robust communication link for Vehicular Ad Hoc Networks (VANETs), where cars interact wirelessly to enhance the traffic flow and road safety. Thus VLC has been considered as a complementary approach to RF in Vehicle-to-vehicle (V2V) communication, for its potential to mitigate security vulnerabilities caused in RF V2V communication by using light directivity and impermeability. V2V VLC privacy and security are fields that have been hardly examined. In this study, we work on multiple VLC challenges and motivation especially for the security performance of the physical layer of a V2V VLC-based protocol. We introduce an improved V2V VLC proposed model and define a security protocol to enhance received power distribution and secrecy performance. We followed a two-step process to achieve this aim, first decrease the LED semi-angle then apply the protected zone between the legitimate vehicles where adversaries are banned. The simulation results, measuring the received optical power, SNR and BER, show that V2V VLC received power and secrecy performance are improved by using the proposed model.

A SECURITY REVIEW OVER WI-FI AND LI-FI

Wi-Fi and Li-Fi are two modern era technologies that are used for data communication. Wi-Fi stands for Wireless Fidelity and Li-Fi stands for Light Fidelity. Wi-Fi uses radio frequency (RF) waves to for transmission of data, on the other hand Li-Fi uses light signals or visible light for data communication. Li-Fi provides transmission of data through illumination by sending data through an LED light bulb. Wi-Fi and Li-Fi technology is used in the various applications of daily life. Both the technologies differ in their properties, architecture, and working. Li-Fi is based on the IEEE 802.11ad standard and uses VLC for data communication while Wi-Fi uses the IEEE standard 802.11 on different devices like routers to transmit data. The objective of this research work is to highlight security prospective of these both technologies; various attacks which can occur and their counter measure as well as misconceptions related to both Wi-Fi vs. Li-Fi is presented in this research paper. Wi-Fi is widely implemented in many major and minor fields of life and the capacity it is providing is accessed. Li-fi, on the end hand, is a means of an opportunity to further develop the efficiency and use of data and to provide resources that are required for the future needs.

Transferring patient’s biomedical information using illumination and communication technology under dim lighting in hospitals

Over the last 60 years, there have been incorrigible thought towards the development and design of hospital facilities in lighting. In specialty hospitals, new standards in lighting for patient rooms and design of healthy environments have been the subject of architectural thinking. Dimmed light emitting diode (LED) luminaries will provide visual comfort with appropriate optics during patient’s monitoring. Not only the ambience in the patient room but also the task of transferring patient’s health care information can be accomplished via illumination and communication technology which includes LED lighting together with light fidelity technology. In this paper we propose a hybrid digital dimming modulation which combines variable delta sigma modulation dimming modulation technique with reverse polarity optical OFDM data modulation technique to dim the LEDs installed in the patient’s room and to transfer the patient’s health care details.

Home Automation System using Li-Fi Technology

Light fidelity is a upcoming technology for high speed data transmission and controlling home appliances. Visible light communication is the technology used in Li-Fi that uses Light emitting diodes. The evolution of Li-fi is to overcome the rate of speed and security in Wi-Fi. The photo diode in this will convert the flashes into electrical signal and it is amplified to provide output. The optical carrier for data transmission is between 400 THZ and 800THZ.The main advantage of Li-Fi is high density, high speed and high accuracy.