International Journal of Sensors Wireless Communications and Control - Volume 12, Issue 4, 2022

Background: Wireless technology has made a great impact on the whole world by providing us with 5G cellular to backscatter networking, from long-range wireless power to low-power wide-area networks. The ability to see through the walls via wireless signals has ushered in a new era. This technology has a wide range of applications, such as military, law enforcement, medicine, and games. Objective: This paper has concisely analyzed recent advances in the field of see-through-the-wall technology to improve a definitive knowledge of existing models and methodologies as well as provide recommendations for future directions. One of the most recent models is the Xaver ™ LR80, which is the first gadget that detects objects across a distance of more than 100 metres. Methods: The dry lab technique for the comparison of existing models for frequency, power, model, detection ability, accuracy, localization feature, and applications has been used. Further comparison is based on the multipath effect. Their applications, the challenges that they need to face, and eventually suggestions for future work have been elaborated. Conclusion: In general, the paper outlines the current level of knowledge in the field of see-through the wall technology. It establishes a foundation for comprehending the issue by examining the findings of contemporary research in the field.

Introduction: In this paper, a surface acoustic wave sensor (SAW) for dangerous gas sensing applications has been designed and validated. The glucose sensor applications have been simulated to show that the piezoelectric material has a high significance for use in detection. Background: Detection of gases is one of the major applications. SAW gas sensors extend their services into medical and even in power plants. A Surface Acoustic Wave (SAW) is an acoustic wave that propagates on the surface of an elastic material (usually a solid), with an amplitude that decreases with the depth of the substrate. Objectives: SAW devices typically use electrodes on a piezoelectric material to convert an electrical signal to a SAW. Methods: This paper aimed to review the significance of piezoelectric materials and focused on MEMS-based SAW. The resonance frequencies of a SAW gas sensor, consisting of an Interdigital Transducer (IDT) etched onto a piezoelectric substrate and covered with a thin Poly Isobutylene (PIB) film, were investigated. Results: The mass of the PIB film increases as PIB selectivity adsorbs CH2Cl2 (Dichloromethane, DCM) in the air. This causes a shift in resonance to a slightly lower frequency. Conclusion: Our characterization of the piezoelectric material has shown a high significance when a sensitive layer of gas is etched for detecting the dangerous gases; we used it in another application of glucose sensor to show the importance of our system. The sensor of the glucose sensor application has been designed and simulated by a finite element analysis, which was conducted on LiNbO3 pellets. This model was applied to verify the sensing properties of DCM and glucose. On the other hand, the glucose sensor and the toxic gas detection allowed us to measure the concentration, whether it is for the dangerous gases or glucose. The concentration of external glucose and the current density versus glucose concentration were measured by a finite element.

Background: Agriculture sector is one of the prime and widely spread sectors. So to make it autonomous and increase its yield, we require a major technological improvement. The only solution to make advancement is with the use of wireless sensor networks. Internet of Things in this field is used to provide connectivity to all real-time sensors and to collect that data in computer-based systems without human involvement. Objective: IoT based system is used to monitor physical and environmental conditions of the agriculture field through a network of wireless sensor. Here, a novel ultra-wideband Dielectric Resonator antenna is designed that is used in Wi-Fi for transmission of data received from sensors. The antenna designed should be easy to fabricate and compact in size and should provide high data rates. The complete designed system should be reliable and cost effective one. Methods: A proposed IoT based system monitors physical and environmental conditions using a wireless sensor network consisting of power supply, soil moisture sensor (FC-28), humidity sensor (LM-35), temperature sensor (HR-202), water level sensor, ARM 7 processor, Liquid Crystal Display (LCD), Relay, motor and Wi-Fi module that is installed at remote locations and connected to the main system comprises of a novel ultra-wideband Dielectric Resonator antenna. Results: The designed WSN based IoT system for agriculture application monitors temperature, humidity, soil moisture, and water level in the field. For Wi-Fi module implementation ultra-wideband inverted sigmoid shaped DRA is designed that provides an impedance bandwidth of 36.46 % at 6.226 GHz (5.51 - 7.78 GHz). The designed antenna provides a peak gain of 5.44 dB at a resonant frequency of 6.226 GHz. Conclusion: The proposed IoT based system is used to monitors physical and environmental conditions like soil moisture, humidity, temperature and water level and sends the data through Wi-Fi module comprising of an ultra-wideband Dielectric Resonator antenna. The designed antenna is compact and can be easily fabricated using printed circuit board technology. The complete system is cost-effective and can be easily implemented.

Background and Objective: Wireless sensor networks (WSN) consist of sensor nodes with a limited battery life and limited communication distance. The minimal energy expended by the sensor nodes and network can be achieved either by reducing the number of communications or by controlling the topology. Thus, energy consumption can be optimized by employing several techniques, such as clustering. Clustering allows the network to be divided into a set of clusters, each of which is managed by a cluster head. In a hierarchical cluster-based WSN, the cluster head receives the data from its sensor members, aggregates it and sends the result to the base station, which leads to an extra overload. So, the selection of appropriate cluster head plays a very important role in conserving the energy of the sensor nodes and extend the lifetime of the network. This paper introduces an energyefficient cluster head election and cluster formation algorithm for WSNs, called EECH/CF. To select cluster heads, our proposal election algorithm uses the initial and residual energy level of the sensor nodes, and efficiently creates the different clusters using an appropriate mechanism. Performance evaluation has shown a significant improvement in energy conservation and the network lifetime for EECH/CF in comparison to some existing clustering algorithms. Methods: Our proposal election algorithm uses the initial and residual energy level of the sensor nodes, and efficiently creates the different clusters using an appropriate mechanism. Results and Discussion: Performance evaluation has shown a significant improvement in energy conservation and the network lifetime for EECH/CF in comparison to some existing clustering algorithms. Conclusion: Results show that our clustering algorithms improve the lifetime of the network as we expected. Indeed, the delay before the death of the first node can be up to seven times longer with EECH/CF.

Background: Increasing demand for wireless devices leads to the efficient use of spectrum resources. Despite the limited availability of spectrum resources, all licensed users do not utilize their spectrum all the time. Objective: Cognitive Radio (CR) is used to detect free channels in the available spectrum resources and access them dynamically without interfering with licensed users. Various spectrum sensing (SS) techniques are available to sense the spectrum of licensed users. Methods: The spectrum sensing technique, energy detector (ED), is analysed under a Rayleigh fading channel. Further, Single Input Single Output (SISO) and Multiple Input Multiple Output (MIMO) channel models are developed in the consumer environment. The ED technique is further analysed with cooperative spectrum sensing (CSS) to overcome detection problems for a single CR user. Results: The ED achieves a probability of detection (PD) of 0.9 and a probability of false alarm (PFA) of 0.1 at the lowest SNR of −20 dB, which is the requirement for a standard IEEE 802.22 Wireless Regional Area Network (WRAN). Conclusion: Various receiver operating characteristics are determined by conducting practical simulations and theoretical calculations for each SISO and MIMO channel model with and without the CSS scenario to achieve the target PD and PFA .

Background: Trust and security are the biggest challenges facing the Cooperative Spectrum Sensing (CSS) process in Cognitive Radio Networks (CRNs). The Spectrum Sensing Data Falsification (SSDF) attack is considered the biggest threat menacing CSS. Methods: This paper investigates the performance of different soft data combining rules such as Maximal Ratio Combining (MRC), Square Law Selection (SLS), Square Law Combining (SLC), and Selection Combining (SC), in the presence of Always Yes and Always No Malicious User (AYMU and ANMU). Results: This comparative study aims to assess the impact of such malicious users on the reliability of various soft data fusion schemes in terms of miss detection and false alarm probabilities. Furthermore, computer simulations are performed to show that the soft data fusion scheme using MRC is the best in the field of soft data computing. Conclusion: ANMU has a slight impact on CSS. Yet, AYMU affects the cooperative detection performance.

Background: Vehicular ad hoc networks (VANETs) are built on the principles of mobile ad-hoc networks, and there are numerous approaches to achieving vehicular communication, like vehicle to infrastructure or vehicle to vehicle, with the advantage of ad-hoc networks. In VANETs, both vehicle-to-vehicle and vehicle-to-roadside architecture coexist to provide safety, services, and navigation; therefore, they are an integral element of the intelligent transportation system framework. The routing protocols in vehicle-to-vehicle communication are used to optimize the propagation of the messages. Objective: The purpose of this study is to analyze the traits of the routing protocols based on various performance metrics like end-to-end delay, packet drop ratio, and throughput. The routing protocols named ad-hoc on-demand distance vector (AODV), dynamic source routing (DSR), and destination sequenced distance vector (DSDV) have been compared considering a real-life scenario. Methods: It evaluates DSDV, DSR, and AODV protocols in the simulation of urban mobility (SUMO) through the open street map. SUMO mobility file was configured to the network simulator 3 to study the performance of AODV, DSDV, and DSR. Results: By examining the protocols, we concluded that AODV is better when evaluated on the parameters named end-to-end delay, packet drop ratio, and throughput. Conclusion: The practical application of our study can be found in collision alert, emergency response community, highway/rail collision avoidance, etc.

Background: Long-term evolution (LTE) is the fourth generation (4G) mobile communication technology developed by the 3rd Generation Partnership Project (3GPP). In comparison to previous generations of cellular systems, LTE incorporates several innovative technologies. These innovative technologies are used to increase spectrum efficiency and data speeds, as envisioned by designers. Methods: This study provides a comprehensive investigation of orthogonal frequency division multiple access and the single carrier frequency division multiple access transmission model and investigates the physical layer performance of the LTE system using a MATLAB-Simulink environment. Results: By providing spectrum flexibility, the SC-FDMA-OFDMA 16 QAM with the AWGN channel transmission model achieves a higher outcome and has a packet loss rate of 0%. The numerical evaluation is used to illustrate the trade-off between loss of capacity in the time and frequency domains. Conclusion: SC-FDMA has a lower multipath propagation rate and peak to average power ratio than OFDM; therefore, multipath must be eliminated to make it more efficient. The final section of this study contains a full description of the techniques required to simulate a simple communication model.