scholarly journals Indoor Visible Light Applications for Communication, Positioning, and Security

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xiangyu Liu ◽  
Lei Guo ◽  
Xuetao Wei
Keyword(s):  
Visible Light ◽  
Electromagnetic Interference ◽  
High Speed ◽  
Smart Cities ◽  
Low Cost ◽  
Rapid Development ◽  
Light Emitting ◽  
Indoor Lighting ◽  
White Light Emitting Diodes ◽  
Communication Privacy

With the rapid development of smart cities, white light-emitting diodes (LEDs) are widely used in indoor lighting due to their characteristics of energy-saving, long lifetimes, and low cost. At the same time, the high-frequency modulated LEDs allow visible light to be used for indoor communications, positioning, and security. Visible light applications have many advantages, such as avoiding electromagnetic interference, high communication speed, great privacy, and high-precise positioning. In this paper, we will survey the application prospects and research results of visible light from scenarios such as high-speed communication, privacy security, and navigation localization and focus on analyzing and discussing the challenges and development trends encountered in visible light positioning.

scholarly journals Research on visible light indoor positioning algorithm based on fire safety

2020 ◽  
Vol 50 (2) ◽  
Author(s):  
Mao Li ◽  
Feng Jiang ◽  
Cong Pei
Keyword(s):  
Visible Light ◽  
Fire Safety ◽  
High Speed ◽  
Response Speed ◽  
Indoor Positioning ◽  
Light Emitting ◽  
Straight Line ◽  
White Light Emitting Diodes ◽  
Positioning Algorithm ◽  
Led Lights

From the perspective of ensuring life safety, combined with the advantages of high-speed time response and energy conservation of white light emitting diodes (LEDs), the visible light indoor positioning algorithm based on fire safety is proposed in the paper. First, the model is designed which needs three LED lights arranged in a straight line and positioned in the geographically north direction on the top of the model. Then, the proposed algorithm is discussed and analyzed when the camera is located at the center of the model and facing north, when the camera is located at the center of the model and the angle is rotated, and when the camera is located at any position of the model, respectively. It can accurately calculate the current position of the camera, its response speed is fast and the positioning accuracy is high. Furthermore, this paper also verifies the practicability and reliability of the algorithm by designing the visible light indoor positioning system based on fire safety rescue in natural environment and smoke environment. The experimental results show that the positioning error does not exceed 0.70 cm in smoke environment.

The Design and Implementation of ECC High-Speed Encryption Engine Based on FPGA

2012 ◽  
Vol 459 ◽  
pp. 544-548 ◽  
Author(s):  
Wei Liang ◽  
Jian Bo Xu ◽  
Wei Hong Huang ◽  
Li Peng
Keyword(s):  
Data Transmission ◽  
High Speed ◽  
Lower Cost ◽  
Low Cost ◽  
Rapid Development ◽  
Security Technology ◽  
Multiplication Algorithm ◽  
Secure Data Transmission ◽  
And Performance ◽  
Computation Speed

Network security technology ensures secure data transmission in network. Meanwhile, it brings extra overhead of security system in terms of cost and performance, which seriously affects the rapid development of existing high-speed encryption systems. The existing encryption technology cannot meet the demand of high security, low cost and high real-time. For solving above problems, an ECC encryption engine architecture based on scalable public key cipher and a high-speed configurable multiplication algorithm are designed. The algorithm was tested on FPGA platform and the experiment results show that the system has better computation speed and lower cost overhead. By comparing with other systems, our system has benefits in terms of hardware overhead and encryption time ratio

Detecting Malicious Switches for a Secure Software-defined Tactile Internet

2021 ◽  
Vol 21 (4) ◽  
pp. 1-23
Author(s):  
Bin Yuan ◽  
Chen Lin ◽  
Deqing Zou ◽  
Laurence Tianruo Yang ◽  
Hai Jin
Keyword(s):  
High Speed ◽  
Data Transfer ◽  
Low Cost ◽  
Rapid Development ◽  
Denial Of Service ◽  
Linear Structure ◽  
Network Layers ◽  
High Speed Data ◽  
Network Status ◽  
Sdn Controller

The rapid development of the Internet of Things has led to demand for high-speed data transformation. Serving this purpose is the Tactile Internet, which facilitates data transfer in extra-low latency. In particular, a Tactile Internet based on software-defined networking (SDN) has been broadly deployed because of the proven benefits of SDN in flexible and programmable network management. However, the vulnerabilities of SDN also threaten the security of the Tactile Internet. Specifically, an SDN controller relies on the network status (provided by the underlying switches) to make network decisions, e.g., calculating a routing path to deliver data in the Tactile Internet. Hence, the attackers can compromise the switches to jeopardize the SDN and further attack Tactile Internet systems. For example, an attacker can compromise switches to launch distributed denial-of-service attacks to overwhelm the SDN controller, which will disrupt all the applications in the Tactile Internet. In pursuit of a more secure Tactile Internet, the problem of abnormal SDN switches in the Tactile Internet is analyzed in this article, including the cause of abnormal switches and their influences on different network layers. Then we propose an approach that leverages the messages sent by all switches to identify abnormal switches, which adopts a linear structure to store historical messages at a relatively low cost. By mapping each flow message to the flow establishment model, our method can effectively identify malicious SDN switches in the Tactile Internet and thus enhance its security.

scholarly journals Electroluminescence and photo-response of inorganic halide perovskite bi-functional diodes

Nanophotonics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 1981-1988 ◽  
Author(s):  
Ning Li ◽  
Ying Suet Lau ◽  
Yanqin Miao ◽  
Furong Zhu
Keyword(s):  
Visible Light ◽  
High Speed ◽  
Light Emission ◽  
Forward Bias ◽  
Green Light ◽  
Visible Light Communication ◽  
Light Emitting ◽  
Response Characteristics ◽  
Photo Response ◽  
Halide Perovskite

AbstractIn this work, we report our efforts to develop a novel inorganic halide perovskite-based bi-functional light-emitting and photo-detecting diode. The bi-functional diode is capable of emitting a uniform green light, with a peak wavelength of 520 nm, at a forward bias of >2 V, achieving a high luminance of >103 cd/m2 at 7 V. It becomes an efficient photodetector when the bi-functional diode is operated at a reverse bias, exhibiting sensitivity over a broadband wavelength range from ultraviolet to visible light. The bi-functional diode possesses very fast transient electroluminescence (EL) and photo-response characteristics, e.g. with a short EL rising time of ~6 μS and a photo-response time of ~150 μS. In addition, the bi-functional diode also is sensitive to 520 nm, the wavelength of its peak EL emission. The ability of the bi-functional diodes for application in high speed visible light communication was analyzed and demonstrated using two identical bi-functional diodes, one performed as the signal generator and the other acted as a signal receiver. The dual functions of light emission and light detection capability, enabled by bi-functional diodes, are very attractive for different applications in under water communication and visible light telecommunications.

scholarly journals Experimental Demonstration of Special-Shaped 32-Quadrature Amplitude Modulation Constellations for Visible Light Communications

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Xinyue Guo ◽  
Shuangshuang Li ◽  
Yang Guo
Keyword(s):  
Visible Light ◽  
Amplitude Modulation ◽  
High Speed ◽  
Light Emitting Diode ◽  
Rapid Development ◽  
Average Power ◽  
Visible Light Communication ◽  
Quadrature Amplitude Modulation ◽  
Visible Light Communications ◽  
Transmission Distance

With the rapid development of light-emitting diode, visible light communication (VLC) has become a candidate technology for the next generation of high-speed indoor wireless communication. In this paper, we investigate the performance of the 32-quadrature amplitude modulation (32-QAM) constellation shaping schemes for the first time, where two special circular constellations, named Circular (4, 11, 17) and Circular (1, 5, 11, 15), and a triangular constellation are proposed based on the Shannon’s criterion. Theoretical analysis indicates that the triangular constellation scheme has the largest minimum Euclidian distance while the Circular (4, 11, 17) scheme achieves the lowest peak-to-average power ratio (PAPR). Experimental results show that the bit error rate performance is finally decided by the value of PAPR in the VLC system due to the serious nonlinearity of the LED, where the Circular (4, 11, 17) scheme always performs best under the 7% preforward error correction threshold of 3.8 × 10−3 with 62.5Mb/s transmission data rate and 1-meter transmission distance.

Synthesis and Characterization of CaMgSi2O6 Activated by Eu2+

2016 ◽  
Vol 881 ◽  
pp. 30-34
Author(s):  
Agatha Matos Misso ◽  
Hermi F. Brito ◽  
Lucas C.V. Rodrigues ◽  
Vinicius R. Morais ◽  
Chieko Yamagata
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Sol Gel ◽  
Solid State Reactions ◽  
Phase Identification ◽  
Molten Salt Method ◽  
Persistent Luminescence ◽  
Light Emitting ◽  
Fluorescent Lamps ◽  
White Light Emitting Diodes

Rare earth silicate based MnMgSi2O5+n (M = Ca, Sr or Ba and n=1-2) phosphors, have attracted interest of researchers due to their high efficiency as a host, excellent thermal and chemical stability and high brightness adding to their low cost. These phosphors showed great potential in various applications such as fluorescent lamps, white light emitting diodes, and display components. High temperature solid-state reactions are usually employed to synthesize those compounds. This paper proposes an alternative method of obtaining nanophosphor host based on Eu-doped CaMgSi2O6 (CMS:Eu), persistent luminescence phosphor. Sol gel technique combined to a modified molten salt method was used. The resulted powder was calcined for 3h under an atmosphere of 5% H2 and 95% Ar2. Phase identification by XRD and the measurements of photoluminescence (PL) and photoluminescence excitation (PLE) were performed. Single phased CMS:Eu with persistent luminescence characteristics was prepared.

Phase-Change Heat Transfer Measurements Using Temperature-Sensitive Paints

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Husain Al Hashimi ◽  
Caleb F. Hammer ◽  
Michel T. Lebon ◽  
Dan Zhang ◽  
Jungho Kim
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
Uv Light ◽  
Flow Boiling ◽  
Low Cost ◽  
Data Interpretation ◽  
Temperature Sensitive ◽  
Time Resolved ◽  
Light Emitting ◽  
Phase Change Heat Transfer

Techniques based on temperature-sensitive paints (TSP) to measure time-resolved temperature and heat transfer distributions at the interface between a wall and fluid during pool and flow boiling are described. The paints are excited using ultraviolet (UV) light emitting diodes (LEDs), and changes in fluorescence intensity are used to infer local temperature differences across a thin insulator from which heat flux distribution is obtained. Advantages over infrared (IR) thermometry include the ability to use substrates that are opaque to IR (e.g., glass, plexiglass and plastic films), use of low-cost optical cameras, no self-emission from substrates to complicate data interpretation, high speed, and high spatial resolution. TSP-based methods to measure wall heat transfer distributions are validated and then demonstrated for pool and flow boiling.

scholarly journals Design and Implementation of a Monitoring System using Optical Camera Communication for a Smart Factory

2019 ◽  
Vol 9 (23) ◽  
pp. 5103 ◽  
Author(s):  
Nguyen Cong Hoan ◽  
Nguyen Van Hoa ◽  
Vu Thanh Luan ◽  
Yeong Min Jang
Keyword(s):  
Visible Light ◽  
Monitoring System ◽  
Low Cost ◽  
Visible Light Communication ◽  
Modulation Scheme ◽  
Light Emitting ◽  
Hospital Patients ◽  
Effects On Children ◽  
The Time Domain ◽  
Optical Camera Communication

Wireless technologies that are based on radio frequencies are currently widely used, with numerous applications around the world. However, they pose some disadvantages to human health. High frequencies can have potentially harmful effects on children, hospital patients, and even healthy people if the signal power exceeds the permitted standard. Conversely, the use of visible light for data transmission is a trend that presents new options, including optical wireless communication, optical camera communication, and visible light communication. This paper proposes a modulation scheme based on on-off keying in the time domain, which is applied to a monitoring system using optical camera communication. This scheme has various compatible supports for the global-shutter camera and rolling-shutter camera, which are popular commercially available cameras. Furthermore, this scheme facilitates a low-cost monitoring system. By using small light-emitting diodes (LEDs) and controlling the exposure time in a single camera, the camera, as a receiver, can simultaneously detect signals from up to 10 sensor devices in different positions at a maximum distance of up to 50 m, with a low error rate.

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