International Journal of Sensors Wireless Communications and Control - Volume 7, Issue 2, 2017

Background and Objective: Wireless Sensor Networks (WSNs) has become one of the most widely research areas; it proves to be a very supportive technology for various applications such as environmentalbased, military-based, health-based, home-based, office, and multimedia applications. Security is the major area of concern among many challenges in routing in theWSN. To solve the security challenge of any routing protocol, it must be confirmed that every new node entering the network is legitimate, efficient and energy aware counter measures have to be designed to prevent intrusion into the network. This paper presents a survey on some of the proposed schemes for securing routing protocols of WSNs, design challenges which include data delivery models, energy efficiency, quality of service and overheads. We also discussed some of the attacks peculiar to WSN routing protocols and an overview of some proposed solutions for thwarting these attacks. Conclusion: Our work is concluded by exposing the possible research areas in the WSN.

Background: Devices connected to the internet are increasing day by day, and the era of Internet of Things (IoT) is anticipated. However, handling big data generated by the IoT networks will present considerable challenge for the decision makers.Wireless sensor networks (WSNs) is one of the big data sources in IoT. In such networks, a wide range of areas is monitored by thousands of sensors where gathered data are sent to the sink node. Unfortunately, WSNs impose many challenges compared to other types of networks. Data management is mainly a challenging task for WSNs due to the huge amount of data collected in such networks. To the best of our knowledge, this paper represents the first formal overview about big data management in WSNs. We highlight and categorize, based on some performance measures, different algorithms designed for data collection, aggregation, correlation, compression and prediction in such networks. Furthermore, we give a review about most importantWSN applications. Conclusion: Finally, open research issues of WSNs are also suggested and put forward in this paper.

Background: Most existing works on Wireless Sensor Networks (WSNs) assume node deployment in regular terrain. Most of the works have considered the fact that in most real-life applications, nodes are actually in irregular terrain but are analyzed in two-dimensional plane. This paper attempts to analyze a sensor network in three-dimensional plane. The energy conservation and network lifetime prolongation problem along with secondary constraints of the sensor network are rigorously examined. Method: Through the investigation of existing works, it is found that a more practical way to analyze monitoring of real-life applications of WSNs is deployment of sensor network in irregular terrains e.g. mountainous regions. This paper designs a random node deployment scheme with the use of two ray radio propagation model for transmitting information through the channel. The communication coverage of the sensor nodes is defined by a probabilistic sensing model as deterministic sensing models are more effective with regular terrains than the irregular terrains. Results: Aimed at making progress on the constraints like energy conservation and lifetime prolongation, ML-MAC scheme is used for the analysis of a randomly deployed network. Results indicate an improvement of 21.98% in network lifetime and 1.25% in received throughput in irregular terrains when compared with regular terrains. Conclusion: This paper compares two scenarios with same parameters but different architecture i.e. regular and irregular. The impact of various performance parameters like network lifetime, number of packets dropped, average jitter and average throughput on performance of regular and irregular terrain networks is evaluated. Although a sensor network is considered as a regular terrain network ideally, but a lot of real life scenarios actually are irregular terrains. The use of ML-MAC protocol improved the performance of both regular and irregular networks.

Background and Objective: This paper considers the model in which the digital feedback equalizer (DFE) together with oblique projection (OB) has been used to minimize the effect of Inter symbol Interference and Inter carrier Interference in multiple input multiple output orthogonal frequency division multiplexing system. The conventional MIMO-OFDM system uses cyclic prefix (CP) to remove ISI in received signals & this cyclic prefix is just an overhead on the transmitted data. In the proposed model CP has been removed and placed with Oblique Projection for saving the bandwidth. Usually by eliminating the CP in the system, the effect of ISI and ICI is not sufficiently removed. The frequency- domain block based decision feedback equalizer with oblique projection technique is proposing to dealing with this problem. This will also improve the spectral efficiency of the system. The proposed system has been able to give improvement of 12dB SNR at BER of 26dB in MMSE equalization and 27dB in zero forcing (ZF) decoding as compared to CP based conventional MIMO-OFDM system. Result and Conclusion: Further the proposed system has been able to increase the achievable rate at 0dB SNR the rate is 1.8 bits/sec/Hz.

Background & Objective: The Internet of things (IoT) refers to the connection of smart electronics devices to the Internet which enables these devices to collect and exchange data. Wireless sensor networks (WSNs) are effectively connected in an ad-hoc manner which consists of collaborative sensing devices that have limited resources capabilities. The sensor nodes can work together to organize real-time monitoring, sensing, and collecting information about the various environments within the event area. Method: Connecting WSNs to the internet will allow new generations of WSN applications to appear. One of the main standards of Internet of Things (IoT) over WSN is IPv6 over Low-power Wireless Personal Area Network (6LoWPAN) which has been designed to enable low-power wireless personal area network devices to integrate with IPv6 networks. This paper presents a 6LoWPAN test bed which has been conducted using MICAZ and TELOSB platforms. It implements TCP/IPv6 layers using Berkeley IP (BLIP) in TELOSB and MICAZ platforms. Conclusion: The finding in this paper opens up new Internet applications over WSNs.

Background & Objective: This paper presents an optimized thinning process (based on density tapering) applied to different circular arrays (CAs) such as circular ring array (CRA), circular concentric array (CCA), circular planar array (CPA) and God's sunflower array (GSFLA). Here, all possible circular arrays are simulated in one platform for better comparison amongst themselves. Methods: The optimization process we have adopted here are particle swarm optimization (PSO) and cuckoo search (CS) optimization techniques. The performance parameters such as maximum sidelobe level (MSLL) and first null beam width (FNBW) of uniformly excited CAs are compared with optimized non-uniformly excited CAs and optimized thinned CAs. Here, the optimized density tapering thinning process provides much reduced MSLL and improved FNBW. Results and Conclusion: The simulation results of different thinned CAs exhibit array taper efficiency in the range of 46% - 61%. This further helps in increasing the overall system capacity keeping gain constant for both thinned and non-thinned CAs. The proposed optimized thinned GSFLA outperforms the other arrays in terms of FNBW and MSLL (~ -35 dB).

Background and Objective: Wireless sensors networks (WSNs) consist of a large number of devices called sensors. These sensors have the ability to collect physical quantities depending on the study area, then performing processing on the collected data before cooperating with each other in order to route these quantities to a center called a base station. The main requirements of wireless sensors networks are to prolong the lifetime of network and the energy efficiency while keeping the quality of information sent to the network. Methods: In this paper, a routing approach is proposed in order to transfer the data in the wireless sensors networks structured into clusters, each cluster has a cluster-head which routes the data to the appropriate gateway node, then the gateway nodes aggregate data, send it to the base station. The gateway node serves as an access point which forwards the data to the base station. To validate the proposed approach, an evaluation step has been performed by comparing the proposed multi-hop protocol with one of the existing systems in the related work. Result and Conclusion: The obtained results from the simulation show that the proposed algorithm achieves longer lifetime. In addition, it is efficient in managing the energy constraints of the network.

Background: The networked control systems are becoming progressively more significant and have many outstanding advantages compared to traditional point-to-point control systems. T-S fuzzy systems are nonlinear systems described by a set of If-Then rules. Especially, the combination communication networks with feedback control loops for fuzzy systems are worthy of being investigated, such as network-induced time delays, and control. Methods: Owing to existing network-induced random delays of the forward and feedback communication links in a direct-drive linear control system, we use two homogeneous Markov chains to express the delays. For the stability analysis, the new Lyapunov function and the free-weighting matrix inequality technique are used. Results: A new stability criterion is obtained, and the controller can be computed in terms of linear matrix inequalities (LMIs). The new criterion is less conservative for a new non finite-sum term is introduced in the Lyapunov-krasovskii functional, which brings some adjustable slack variables into the criterion, and can be efficient use of the networked delay information. Conclusion: The new stability criterion is shown to be effective and efficient by the numerical examples. It improves the stability theory of networked control systems and T-S fuzzy systems.