Clustering Objectives in Wireless Sensor Networks: A Survey and Research Direction Analysis

Wireless sensor networks (WSNs) have demonstrated research and developmental interests in numerous fields, like communication, agriculture, industry, smart health, monitoring, and surveillance. In the area of agriculture production, IoT-based WSN has been used to observe the yields condition and automate agriculture precision using various sensors. These sensors are deployed in the agricultural environment to improve production yields through intelligent farming decisions and obtain information regarding crops, plants, temperature measurement, humidity, and irrigation systems. However, sensors have limited resources concerning processing, energy, transmitting, and memory capabilities that can negatively impact agriculture production. Besides efficiency, the protection and security of these IoT-based agricultural sensors are also important from malicious adversaries. In this article, we proposed an IoT-based WSN framework as an application to smart agriculture comprising different design levels. Firstly, agricultural sensors capture relevant data and determine a set of cluster heads based on multi-criteria decision function. Additionally, the strength of the signals on the transmission links is measured while using signal to noise ratio (SNR) to achieve consistent and efficient data transmissions. Secondly, security is provided for data transmission from agricultural sensors towards base stations (BS) while using the recurrence of the linear congruential generator. The simulated results proved that the proposed framework significantly enhanced the communication performance as an average of 13.5% in the network throughput, 38.5% in the packets drop ratio, 13.5% in the network latency, 16% in the energy consumption, and 26% in the routing overheads for smart agriculture, as compared to other solutions.

https://www.mdpi.com/1424-8220/20/7/2081/pdf

An Energy Efficient and Secure IoT-Based WSN Framework: An Application to Smart Agriculture

Internet of Things (IoT) applications have been growing significantly in recent years, however, the security issue has not been well studied in the literature for the IoT ecosystem. The sinkhole attack is one of serious destructive attacks for IoT as it is easy to launch the attack and difficult to defend it. In this paper, a Probe Route based Defense Sinkhole Attack (PRDSA) scheme is proposed to resist Sinkhole attack and guarantee security for IoT, which is the first work that can detect, bypass and locate the sinkhole at the same time. The PRDSA scheme proposes a routing mechanism combining the far-sink reverse routing, equal-hop routing, and minimum hop routing, which can effectively circumvent the sinkhole attacks and find a safe route to the real sink, so that the scheme can achieve better sinkhole detection. More importantly, the PRDSA scheme overcomes the limitation of previous schemes that they cannot locate the sinkhole. During the detection of the sinkhole attack, the PRDSA scheme requires the nodes and the sink node to return the signature of the information (e.g., IDs, etc.), so that the location of the sinkhole can be determined. Furthermore, the PRDAS scheme mainly utilizes the characteristics of network energy consumption. The probe route of sinkhole attack mainly occurs in the region where the remaining energy exists. Thus, the PRDSA scheme has little impact on the network lifetime. Theory and experiments show that this scheme can achieve better performance than existing schemes in term of network security and lifetime.

Design and Analysis of Probing Route to Defense Sink-Hole Attacks for Internet of Things Security

Wireless Sensor Networks (WSNs) are among the most emerging technologies, thanks to their great capabilities and their ever growing range of applications. However, the lifetime of WSNs is extremely restricted due to the delimited energy capacity of their sensor nodes. This is why energy conservation is considered as the most important research concern for WSNs. Radio communication is the utmost energy consuming function in a WSN. Thus, energy efficient routing is necessitated to save energy and thus prolong the lifetime of WSNs. For this reason, numerous protocols for energy efficient routing in WSNs have been proposed. This article offers an analytical and up to date survey on the protocols of this kind. The classic and modern protocols presented are categorized, depending on i) how the network is structured, ii) how data are exchanged, iii) whether location information is or not used, and iv) whether Quality of Service (QoS) or multiple paths are or not supported. In each distinct category, protocols are both described and compared in terms of specific performance metrics, while their advantages and disadvantages are discussed. Finally, the study findings are discussed, concluding remarks are drawn, and open research issues are indicated.

https://www.mdpi.com/1999-4893/13/3/72/pdf

Energy Efficient Routing in Wireless Sensor Networks: A Comprehensive Survey

Data fusion based coverage optimization in heterogeneous sensor networks: A survey

Wireless Sensor Networks (WSNs) consist of several battery powered sensor nodes. The sensing coverage of the Field of Interest (FoI) is an important function of the sensor nodes in connected WSNs. A FoI is said to be covered if each point in the FoI is monitored by at least one sensor node. Due to small size, battery power supply, simple architecture, and light weight Operating System of the sensor nodes, maintaining the desired coverage of the FoI consists various issues and challenges in a connected WSN. This paper surveys the existing work done to address various issues and challenges for solving the coverage and connectivity problems in WSNs. Our discussion emphasis on sensing models, classification of coverage, research issues in WSNs and practical challenges in deployment of WSNs. We review a brief but complete overview of the various solutions of coverage problems in connected WSNs and describing insights into issues and challenges for research in this area.

Coverage and Connectivity in WSNs: A Survey, Research Issues and Challenges

A compact high step up dc–dc converter with continuous input current and lower device voltage stress is a prime requirement for renewable application. In this article, a high gain dc–dc converter is proposed, which combines the concept of switched inductor and switched capacitor along with a unique interconnection of input–output. This arrangement reduces capacitor voltage stress. The proposed converter has reduced conduction losses, reduced components count, and low voltage stress across the devices. Besides, the proposed converter has lower inductor current ripple, which is suitable for renewable integration. The operation and steady-state analysis of the converter are done in continuous current mode. For the proposed converter, voltage and current stress and the losses are calculated analytically. A comparative analysis is presented to prove the potential of the proposed converter. The dynamic analysis of the proposed converter is performed to regulate the output voltage. Finally, an experimental set up is designed to test the converter under both distinct power ratings and closed loop.

Switched-LC Based High Gain Converter With Lower Component Count

Some monitoring applications in wireless sensor networks (WSNs) may require that the target is tracked by at least $k$ directional nodes in $m$ -connected WSNs, where $k \geq 1$ and $m \geq 1$ . In this paper, we address the target tracking problem in term of the number and orientation of tracking region of directional nodes required to achieve $k$ -target tracking in $m$ -connected WSNs. We consider the different values of $k$ , $m$ , target range, tracking angle, communication range of nodes, and shape of the field of interest (FoI) for solving the problem. The FoI is divided into an equilateral triangle, square, and hexagon patterns to estimate the optimal side length of a polygon and tracking direction of the nodes for $k$ -target tracking and $m$ -connectivity of the network. Next, the optimal side length in a polygon is used to estimate the node locations required for the desired level of target tracking and connectivity. Finally, we select a regular deployment pattern, which requires the least number of nodes for the designed level of tracking and connectivity. We also propose a target tracking system using the proposed analysis for tracking the moving targets in the FoI.

A Target Tracking System Using Directional Nodes in Wireless Sensor Networks

Effect of A-site Fe substitution on the magnetic behavior of Dy2Ti2O7 spin ice

Free space optic (FSO) communication offers a supplement to optical fibre for satisfying the demand of next-generation wireless networks. This paper signifies photonic generation of a double sideband-suppressed carrier (DSB-SC)-based 60 GHz mm-wave by operating a dual-drive Mach–Zehnder modulator (DD-MZM) in the null point region. The radiofrequency (RF) carrying signal is investigated for dual-hop FSO/RF links of 500 m/50 m by taking optical links in the turbulent atmosphere.At the data rates of 1.25, 2.5, and 5 Gb/s, overall operation is evaluated in terms of bit error rate (BER) as a function of the received optical power. In our analysis, system performance under the Gamma-Gamma (ΓΓ) matches with the Lognormal (LN) model in moderate fluctuation using aperture averaging effect. The results are obtained with a maximum difference in the receiver sensitivity of ∼1 dB at BER = 10−6 between ΓΓ and LN models.

Abhishek Tripathi

Papers

Coverage and Connectivity in WSNs: A Survey, Research Issues and Challenges

Switched-LC Based High Gain Converter With Lower Component Count

A Target Tracking System Using Directional Nodes in Wireless Sensor Networks

Effect of A-site Fe substitution on the magnetic behavior of Dy2Ti2O7 spin ice

Optically assisted mm-wave-based multi-Gbps RoFSO transmission link under channel fading models