A Beam Scanning-Based Indoor Localization System using Light Emitting Diodes

In this paper, an indoor localization system using light emitting diodes (LEDs) is presented. Location of an object is determined by scanning two LEDs at pre-defined angles which are modulated at different frequencies. During scanning process, for each LED, two maximum values of received signal strength (RSS) are logged and this information is used to compute the position of an object. Time division multiplexing (TDM) is used to incorporate angle information at the receiver. A bicubic spline interpolation is applied to estimate the position of an object. Simulations are executed for a typical indoor environment with dimensions of (3 × 3 × 2 m3) and results are validated using experiments. The experimental results confirm that proposed beam scanning approach can be used to determine the location of an object precisely

A Reduced Complexity of Vahedi's Tag Estimation Method for DFSA

In order to calculate the number of tags in a radio frequency identification (RFID) system, several tag estimation methods have been investigated in literature and most of the available estimation methods need the overall knowledge of idle, success and collision slots of the previous frame to carry out the tag estimation process. In this article, we present three techniques to reduce the complexity of Vahedi’s tag estimation for tag collision resolution in RFID systems using dynamic frame slotted ALOHA. Our modified and useful approach considers the information about only the number of empty, successful or colliding slots in the previous frame for the tag estimation. Three decision rules were obtained by maximizing the likelihood of success, idle and collision which helps in the reduction of complexity substantially. However, the accuracy of estimation decreases for success-only and idle-only methods while the collision-only method gives a consistent and lower estimate error when the frame sizes and the number of tags increase

Digital Twin for Metasurface Reflector Management in 6G Terahertz Communications

The performance demands from data-intensive applications, such as multimedia streaming, as well as the growing number of devices connecting to the Internet, will increase the need for higher capacity wireless communication links. The research community has recently explored regions of the spectrum, including the Terahertz band (0.1 THz to 10 THz), that are underutilised for communications. THz frequencies come with a plethora of special challenges, one of which is the very narrow effective beam, thereby requiring a Line of Sight (LoS) between sender and receiver. Researchers have explored the use of reflectors that can redirect beams around blockages. In this paper, we propose a THz signal guidance system where a Digital Twin is used to model, predict and control the signal propagation characteristics of an indoor space. Our approach finds the best THz signal path from the base station to the mobile target via the tunable metamaterial walls, avoiding obstacles as needed, using geometric (ray tracing), path loss and Terahertz Potential Field (THzPF) models. With this knowledge, the digital twin guides the selection of antenna strips at a base station and the reflectors along the signal path. A top-view camera, with advanced image processing, provides context updates (obstacle and mobile target locations) to the digital twin. The image processing system also senses factors like water vapour concentration, and the material composition and surface roughness of obstacles. Such factors affect propagation strength, and the digital twin modifies the beam paths to adapt. Simulation results have shown the efficiency of our control system to maintain a reliable signal connection while minimising the use of antenna and reflector strips. Our system is the first proposal that maximises THz signal-to-noise ratio (SNR) through such a dynamic and robust control system, which integrates image processing of a room with base station configuration

Hardware Software Co-Design of a Farming Robot

Food means life and no one can think about living without food. This is the most fundamental human necessity and food security is one of the major global concern of this century. With the revolution and recent advancements in the field of electronics and communication, there has been a paradigm shift from conventional farming ways to the modern one. This paper talks about the development of hardware software co-design of agricultural farming robot. Our developed farming robot has two parts namely hardware part which further consists of mechanical, electrical, control and tools segments and the software part which allows user to interact with the farming robot via cloud service. Our proposed hardware architecture is compatible with commercial Farmbot product and the developed web-based software can be extended for more features and applications. Furthermore, the developed robot has been tested and it works well

A Comparative Study of Customer Preferences for Telecommunication Technologies in Pakistan

The telecommunication industry is a huge and ever-growing industry and it is contributing dominantly to the economy in terms of revenue generation and being one of the biggest taxpayers to the government. Telecommunication is now considered to be a basic necessity. In this paper, a study has been conducted to know the customer preferences of telecommunication technologies in Lahore, Pakistan, and also to compare different customer preferences for telecommunication technologies. From the results of our study, we have concluded that there is a great variation among people in terms of their usage of mobile phones and internet services. Furthermore, results regarding the relationship between the socio-demographic characteristics and the preference towards specific telephony and internet service providers have also been analyzed. This work is unique when the scenario of Pakistan is considered. No such study has been conducted in Pakistan to know the customer preferences in Pakistan. Some recommendations for the telecommunication operators have also been discussed which can help to know their customer needs in a better fashion

Frame Size Analysis of Optimum Dynamic Tree in RFID Systems

In RFID (Radio Frequency Identification) system, an anti-collision algorithm plays a prominent role in the tag identification process in order to reduce the tag identification delay and enhance the RFID system efficiency. In this work, we present a theoretical analysis of optimal frame size assignment for maximizing the system efficiency of a tree-based anti-collision algorithm, called optimum dynamic tree (ODT) algorithm, for RFID tag identification process. Our analysis indicates that the appropriate frame size for a given number of competing tags should not be set to the same value as the number of tags, which is commonly adopted in the literature. Instead, the frame size should be smaller roughly by a factor of 0.871 to maximize system efficiency. The closed-form for calculating system efficiency is derived and the derived simulation results are in a good agreement with the theoretical one. The exact appropriate frame sizes for the number of tags ranging from 2 to 100 are tabulated and compare the tag-identification time of conventional binary tree and ODT algorithms by using the international standard ISO 18000-6B

Digital-Twins towards Cyber-Physical Systems: A Brief Survey

Cyber-Physical Systems (CPS) are integrations of computation and physical processes. Physical processes are monitored and controlled by embedded computers and networks, which frequently have feedback loops where physical processes affect computations and vice versa. To ease the analysis of a system, the costly physical plants can be replaced by the high-fidelity virtual models that provide a framework for Digital-Twins (DT). This paper aims to briefly review the state-of-the-art and recent developments in DT and CPS. Three main components in CPS, including communication, control, and computation, are reviewed. Besides, the main tools and methodologies required for implementing practical DT are discussed by following the main applications of DT in the fourth industrial revolution through aspects of smart manufacturing, sixth wireless generation (6G), health, production, energy, and so on. Finally, the main limitations and ideas for future remarks are talked about followed by a short guideline for real-world application of DT towards CPS

Robust optimal design of FOPID controller for five bar linkage robot in a cyber-physical system: a new simulation-optimization approach

This paper aims to further increase the reliability of optimal results by setting the simulation conditions to be as close as possible to the real or actual operation to create a Cyber-Physical System (CPS) view for the installation of the Fractional-Order PID (FOPID) controller. For this purpose, we consider two different sources of variability in such a CPS control model. The first source refers to the changeability of a target of the control model (multiple setpoints) because of environmental noise factors and the second source refers to an anomaly in sensors that is raised in a feedback loop. We develop a new approach to optimize two objective functions under uncertainty including signal energy control and response error control while obtaining the robustness among the source of variability with the lowest computational cost. A new hybrid surrogate-metaheuristic approach is developed using Particle Swarm Optimization (PSO) to update the Gaussian Process (GP) surrogate for a sequential improvement of the robust optimal result. The application of efficient global optimization is extended to estimate surrogate prediction error with less computational cost using a jackknife leave-one-out estimator. This paper examines the challenges of such a robust multi-objective optimization for FOPID control of a five-bar linkage robot manipulator. The results show the applicability and effectiveness of our proposed method in obtaining robustness and reliability in a CPS control system by tackling required computational efforts

A data driven approach in less expensive robust transmitting coverage and power optimization

This paper aims the development of a new reduced-cost algorithm for a multi-objective robust transmitter placement under uncertainty. Toward this end, we propose a new hybrid Kriging/Grey Wolf Optimizer (GWO) approach combined with robust design optimization to estimate the set of Pareto frontier by searching robustness as well as accuracy (lower objective function) in a design space. We consider minimization of the energy power consumption for transmitting as well as maximization of signal coverage in a multi-objective robust optimization model. The reliability of the model to control signal overlap for multiple transmitting antennas is also provided. To smooth computational cost, the proposed method instead of evaluating all receiver test points in each optimization iteration approximates signal coverages using Kriging interpolation to obtain optimal transmitter positions. The results demonstrate the utility and the efficiency of the proposed method in rendering the robust optimal design and analyzing the sensitivity of the transmitter placement problem under practically less-expensive computational efforts (350% and 320% less than computational time elapsed using standalone GWO and NSGAII respectively)