International Journal of Sensors Wireless Communications and Control - Volume 11, Issue 3, 2021

Obstructive Sleep Apnea is a kind of sleep syndrome, which has an adverse effect on both the health, and quality of life of an individual. It results in severe health problems like hypertension, stroke and many cardiovascular issues. Only a very less percentage of persons with Obstructive Sleep Apnea are diagnosed and treated. This is due to the lack of available devices and technology. Detection of this sleep disorder is extremely important, as negligence can prove fatal. Hence, the critical need in healthcare is the instantaneous monitoring of this disorder. The current approaches for detecting this disorder are very expensive, bulky and intrusive which in turn will affect the sleep quality of patients. So there is a necessity to design less expensive, light-weight non-intrusive systems to diagnose these sleep-related issues. In this paper, the various noninvasive schemes using sensors and Internet-of-Things to detect Obstructive Sleep Apnea are reviewed. Further, the open research issues and challenges in detecting Obstructive Sleep Apnea are presented.

Sensors power the entire internet of things applications. Sensors are one of the major power consuming devices of IoT networks while transmitting and receiving data. Optimizing power is one of the approaches to solve this problem. This paper surveys various power modeling techniques of sensors that are applicable to the internet of things and sensor networks applications. Various techniques and strategies have been studied in this paper. Some of the techniques that are studied and surveyed are transmission power modeling, power modeling of the sensor for sensor subsystems and IoT systems, clustered approach, energy harvesting models and transmission distance modeling. Our survey proposes that there exists a valid and feasible model for a given application that satisfies the power constraints of the sensor devices.

Background: The Yagi-Uda antenna is a highly directive antenna used widely in many applications including pulsed Doppler radars to study the dynamics of the atmosphere. Yagi antennas configured in planar array configurations in phased array radars to achieve high peak powers to probe the atmosphere from troposphere. In this paper, a two-element Yagi-Uda antenna design is presented to investigate the ionospheric irregularities from the Gadanki Ionospheric Radar Interferometer. A new approach devised for the first time to design the two element, wide beam width tilted Yagi antenna, where folded dipole acts as active driver element and reflector as parasitic element. Methods: Several design techniques have been studied and new approach has been employed in designing the antenna and simulations have been carriedout and optimized the performance at 30 MHz with 14o tilt towards geometric north from vertical (zenith) direction for the maximum back scattered echo gain. Based on the design antenna has been fabricated and the system performance has been evaluated. Detailed validation methods have been listed to validate the parameters like reflection coefficient, gain, bandwidth and front-to-back ratio. Results: The antenna is designed and simulated results with 4NEC2 provided the optimized parameters before fabrication. The measured results indicate that the antenna has a gain of 5.65dBi and a reflection coefficient of -30 dB and these results are in close agreement with the simulation results. The band width obtained is about 2MHz is very good for the ionospheric remote sensing applications. The peak power handling capability upto 1kW shows the reliable system design for continuous and long term use of the system. Conclusion: Two element wide beam width 14o tilted Yagi-Uda antenna at 30MHz has been designed, simulated and optimized. Realized system performance validated to use for ionospheric radar remote sensing application. Details of the test methodologies are explained and the same have been executed to characterize the performance of the fabricated antenna with simulation results by measuring reflection coefficient, gain, radiation pattern. All the measured results have very close agreement with the simulation results and satisfy the design requirements to fit into 30 MHz radar antenna array for dedicated ionospheric probing. In future, we intended to carry out the radiation pattern simulation of the 20x8 phased array antennas to describe the overall radiation pattern.

Background: This paper presents S shaped frequency reconfigurable antenna which gives six operating bands. Objective: The size of proposed antenna is 26×12 mm2. The FR4 substrate having thickness of 1.6 mm is used for this antenna. Methods: The proposed antenna resonates at six different frequencies i.e. at 2.76 GHz, at 2.98 GHz, at 4 GHz, at 4.6 GHz, at 4.96 GHz and at 5.28 GHz depending upon the ON/OFF states of PIN diodes. The lumped RLC elements are used in HFSS simulation in order to reconfigure the frequency of antenna. Results: For switching, PIN diode are used in fabricated antenna for frequency reconfiguration to validate the simulated results. The compact size of proposed antenna is suitable for recent communication devices such as laptop, mobile phone and other electronics instruments. Conclusion: The proposed antenna shows good matching in the simulated and measured results.

Background: The advent of wireless sensor networks makes it possible to track the events even in the remotest areas that too without human intervention. But severe resource constraints, generally energy of sensor nodes push researchers worldwide to develop energy efficient protocols in order to accomplish the application objectives of these networks. Objective: However, till date there is no energy efficient routing protocol which provides uniformity with maximum resource utilization for WSNs. Methods: In this paper, a Uniform Clustering Algorithm for Energy Efficiency in Wireless Sensor Networks (UCAEE) has been proposed. UCAEE is a base station controlled algorithm where entire sensing area is partitioned into uniform clusters. The motive of the algorithm is to split the sensing area into uniform clusters and to select cluster heads and gate-way nodes within each cluster so that the network energy can be balanced in a best possible way. Results: Simulation results indicate that proposed UCAEE algorithm conserves more energy than its contemporary clustering algorithms like LEACH, PEGASIS and SECA and promises better network lifetime of wireless sensor networks. Conclusion: UCAEE achieves minimum energy consumption during data transmission and reception.

Aim: To deploy Cloud Components in a cloud integrated WOBAN in a cost-efficient manner. Background: Wireless-Optical Broadband Access Network (WOBAN) is a network which provides higher bandwidth and better stability at lower cost to the users. Integration of cloud services over traditional WOBAN called as CIW (cloud integrated WOBAN) increases existing load carrying capacity and available bandwidth. In CIW, Cloud Components (CCs) are integrated as storage components, servers etc. within WMN of WOBAN. These cloud components may follow distributed or centralized architectures. Availability of these low-cost and easy-to-deploy CCs make CIW technologically feasible and practically deployable architecture. Objective: The proposed algorithm eliminates redundant ONUs and optimizes number of CCs while ensuring network connectivity and cloud services to all users. Methods: Extensive simulation is carried out to implement proposed work. A simulation model and code is developed in MATLAB to get the results for existing and proposed algorithms for varying number of variables such as number of ONUs, wireless routers, grid sizes etc. Result: We compare the performance of proposed algorithm with existing algorithm for varying grid sizes as well as number of wireless routers. Simulation results show the worthiness of proposed work. Conclusion: Optimization of cloud components in CIW is one of the important issues as it affects overall network deployment cost. Considering this issue, we proposed a cluster based approach to optimize number of network components such as CCs and ONUs in the network. Simulation results show that cluster based approach is efficient as compared to existing approach for optimizing CCs. Hence proposed solution offers a suitable candidature for deploying a cost efficient CIW.

Background: Although research has been done in the areas of VANET routing protocol performance focusing on highway scenarios, no research has been observed for highway flyovers. This research paper is an effort in this direction to find out the solution for flyover scenario where line of sight is one of the major challenges. Objective: The main objectives of the proposed research paper is to analyze the feasibility of vehicular ad-hoc networks for highway flyover (NCR) Scenario. Further to Compare the performance of an on-demand routing protocols for vehicular ad-hoc networks using VanetMobiSim 2.0 and NS-2 .34 to find out the best one that may be used as the most reliable and efficient ondemand routing protocol. Method: The prime focus of this paper is to explore the feasibility of VANETs for Highway traffic management over flyovers (NCR) and to analyze & compare possibility of reactive routing protocols AODV, DSR and TORA for VANETs under study. The feasibility of vehicular ad-hoc networks based on live data for Rajiv Chowk on NH- 8 Scenario has been analyzed. The performance of On-demand routing protocols for vehicular Ad-hoc network is compared using VANETMobiSim 2.0 and NS -2.34. Result: The simulation is done for four performance matrices for mentioned reactive routing protocols using VanetMobisim 2.0and NS 2.34. The graphs are plotted for all three protocols to find out the most feasible protocol. Conclusion: It is observed that DSR is most feasible reactive protocols for proposed research on flyover.

Aim: Optimize position of ONUs using Whale Optimization Algorithm (WOA) to make cost-effective FiWi network. Background: Fiber-Wireless (FiWi) is a network which provides higher bandwidth and better stability at lower cost to the users. The placement of network components (such as ONU) in FiWi is of utmost importance since it comes under the network planning. ONU placement mainly focuses on this thing that how efficiently ONUs are placed so that with fewer number of ONUs all the routers get interconnected. Objective: Optimize position of ONUs using WOA algorithm such that, with minimum ONUs all routers can connects with satisfactory network performance. Methods: Extensive simulation is carried out to implement proposed work. A simulation model and code is developed in MATLAB to get the results for existing and proposed algorithms for varying number of variables such as number of ONUs, wireless routers, grid sizes etc. Result: We compare the performance of proposed algorithm with existing algorithm for varying grid sizes as well as number of wireless routers. Simulation results show the worthiness of proposed work. Conclusion: The present work optimizes the location of ONUs using encircling prey mechanism and spiral update mechanism of WOA. Results show that proposed work gives best result in terms of minimum number of ONUs in the network with almost comparable PDR and TTDPN with that of deterministic.

Aim: In this article, wideband Substrate Integrated Waveguide (SIW) and rectangular waveguide (RWG) transition operating in Ka-band is proposed. Objective: To design wideband Substrate Integrated Waveguide (SIW) and rectangular waveguide (RWG) transition operating in Ka-band. Method: The coupling patch was etched on the SIW cavity to couple the electromagnetic energy from SIW to RWG. Moreover, metasurface was introduced into the radiating patch to enhance bandwidth. To verify the functionality of the proposed structure back to back transition was designed and fabricated on a single layer substrate using standard Printed Circuit Board (PCB) fabrication technology. Results: Measured results match with the simulation results, measured insertion loss was less than 1.2 dB and return loss was better than 3 dB for the frequency range of 28.8 to 36.3 GHz. By fabricating transition with 35 SRRs, bandwidth of the proposed transition can be improved. Conclusion: The proposed transition has advantages like compact size, easy to fabricate, low cost and wide bandwidth. The proposed structure is a good candidate for millimeter-wave circuits and systems.

Objective: The main purpose of the proposed research work is to perform the segmentation of characters from the handwritten Kannada document. The reason behind segmentation is to support the implementation of handwriting recognition system for Kannada language. Methodology: To perform segmentation of characters, input document has to go through gray scale conversion, denoising, contrast normalization and binarization process. Results: Documents collected from ICDAR-2013 and ICDAR-2015 were considered for experiment and obtained 100% accuracy for line segmentation and 96% accuracy for character segmentation. Conclusion: To further improve the efficiency with respect to accuracy of character segmentation, other pre-processing steps like skew detection and correction shall be considered.

Background: In this paper, A definition of proposed enhancement approach to reduce the energy consumption, extend the network lifetime and improve the performance of protocol Fuzzy Low-Energy Adaptive Clustering Hierarchy Algorithm (Fuzzy LEACH). Objective: This improvement will augment the energy balancing in clusters among all sensor nodes and minimize the energy dissipation during network communications. Methods: The proposed method is based on a cluster head selection method. Moreover, an enhanced organization of this selection has been implemented. Results: Mathematical analysis and MATLAB 2013a simulation results show the effectiveness of the proposed approach. The new approach reduce the energy consumption of Wireless Sensor Network (WSN) about 0.99% to 5.64%, prolongs the network life cycle by 42% and increases the number of packets sent by 86% to 732%. Conclusion: The developed approach indicates a progress in terms of network lifetime, energy consumption and number of packets transferred to BS compared to Low-Energy Adaptive Clustering Hierarchy Algorithm (LEACH) and other related extended spaces protocols.