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Dynamic Clustering with Relay Nodes (DCRN): A Clustering Technique to Maximize Stability in Wireless Sensor Networks with Relay Nodes  [PDF]
A. B. M. Alim Al Islam, Mohammad Sajjad Hossain, Vijay Raghunathan
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2012, DOI: 10.4236/ijcns.2012.56047
Abstract: With the growing popularity of wireless sensor networks, network stability has become a key area of current research. Different applications of wireless sensor networks demand stable sensing, coverage, and connectivity throughout their operational periods. In some cases, the death of just a single sensor node might disrupt the stability of the entire network. Therefore, a number of techniques have been proposed to improve the network stability. Clustering is one of the most commonly used techniques in this regard. Most clustering techniques assume the presence of high power sensor nodes called relay nodes and implicitly assume that these relay nodes serve as cluster heads in the network. This assumption may lead to faulty network behavior when any of the relay nodes becomes unavailable to its followers. Moreover, relay node based clustering techniques do not address the heterogeneity of sensor nodes in terms of their residual energies, which frequently occur during the operation of a network. To address these two issues, we present a novel clustering technique, Dynamic Clustering with Relay Nodes (DCRN), by considering the heterogeneity in residual battery capacity and by removing the assumption that relay nodes always serve as cluster-heads. We use an essence of the underlying mechanism of LEACH (Low-Energy Adaptive Clustering Hierarchy), which is one of the most popular clustering solutions for wireless sensor networks. In our work, we present four heuristics to increase network stability periods in terms of the time elapsed before the death of the first node in the network. Based on the proposed heuristics, we devise an algorithm for DCRN and formulate a mathematical model for its long-term rate of energy consumption. Further, we calculate the optimal percentage of relay nodes from our mathematical model. Finally, we verify the efficiency of DCRN and correctness of the mathematical model by exhaustive simulation results. Our simulation results reveal that DCRN enhances the network stability period by a significant margin in comparison to LEACH and its best-known variant.
Reprogramming wireless sensor nodes
Helen C. Leligou, Christos Massouros, Eleftherios Tsampasis, Theodore Zahariadis, Dimitrios Bargiotas, Konstantinos Papadopoulos, Stamatis Vo
International Journal of Computer Trends and Technology , 2011,
Abstract: As the applications of Wireless Sensor Networks increase rapidly, the number of deployed sensor devices proliferates, which prompts the research community to work towards their integration in the so-called “Internet of Things” to gather real time information and make the maximum out of their use towards enhancing the user experience. The capability to reconfigure/reprogram them remotely not only enables easy maintenance and code updates, which is mandatory in large sensor network deployments, but also provides an unprecedented flexibility regarding the use of all available resources of different types. However, the design of a reliable dissemination protocol is a real challenge and the reason is threefold: the desired eprogramming requirements differ from use case to use case (e.g. tolerated reprogramming time, affordable overhead), the wireless medium is characterized by low reliability, and the devices are severely resource constrained. For this reason, in this paper we first explore the reprogramming requirements and the intricacies of WSNs and then review the already proposed network protocols for reprogramming wireless sensor networks placing emphasis on the their features to guide both prospect users and designers efforts
Underwater Sensor Nodes and Networks  [PDF]
Jaime Lloret
Sensors , 2013, DOI: 10.3390/s130911782
Abstract: Sensor technology has matured enough to be used in any type of environment. The appearance of new physical sensors has increased the range of environmental parameters for gathering data. Because of the huge amount of unexploited resources in the ocean environment, there is a need of new research in the field of sensors and sensor networks. This special issue is focused on collecting recent advances on underwater sensors and underwater sensor networks in order to measure, monitor, surveillance of and control of underwater environments. On the one hand, from the sensor node perspective, we will see works related with the deployment of physical sensors, development of sensor nodes and transceivers for sensor nodes, sensor measurement analysis and several issues such as layer 1 and 2 protocols for underwater communication and sensor localization and positioning systems. On the other hand, from the sensor network perspective, we will see several architectures and protocols for underwater environments and analysis concerning sensor network measurements. Both sides will provide us a complete view of last scientific advances in this research field.
Energy Options for Wireless Sensor Nodes  [PDF]
Chris Knight,Joshua Davidson,Sam Behrens
Sensors , 2008, DOI: 10.3390/s8128037
Abstract: Reduction in size and power consumption of consumer electronics has opened up many opportunities for low power wireless sensor networks. One of the major challenges is in supporting battery operated devices as the number of nodes in a network grows. The two main alternatives are to utilize higher energy density sources of stored energy, or to generate power at the node from local forms of energy. This paper reviews the state-of-the art technology in the field of both energy storage and energy harvesting for sensor nodes. The options discussed for energy storage include batteries, capacitors, fuel cells, heat engines and betavoltaic systems. The field of energy harvesting is discussed with reference to photovoltaics, temperature gradients, fluid flow, pressure variations and vibration harvesting.
Energy Management for Wireless Sensor Network Nodes
Amit Sharma,Kshitij Shinghal,Neelam Srivastava,Raghuvir Singh
International Journal of Advances in Engineering and Technology , 2011,
Abstract: Wireless sensor networks consist of small, autonomous devices with wireless networking capabilities. In order to further increase the applicability in real world applications, minimizing energy consumption is one of the most critical issues. Therefore, accurate energy model is required for the evaluation of wireless sensor networks. In this paper, the energy consumption for wireless sensor network (WSN) node is analyzed. To estimate the lifetime of sensor node, the energy characteristics of sensor node are measured. Research in this area has been growing in the past few years given the wide range of applications that can benefit from such a technology. In this paper, analysis of energy consumption of a WSN node is analyzed with a proposed node. Based on the proposed model, the estimated lifetime of a battery powered sensor node can be increased significantly.
Adaptively Directional Wireless Power Transfer for Large-scale Sensor Networks  [PDF]
Zhe Wang,Lingjie Duan,Rui Zhang
Mathematics , 2015,
Abstract: Wireless power transfer (WPT) prolongs the lifetime of wireless sensor network by providing sustainable power supply to the distributed sensor nodes (SNs) via electromagnetic waves. To improve the energy transfer efficiency in a large WPT system, this paper proposes an adaptively directional WPT (AD-WPT) scheme, where the power beacons (PBs) adapt the energy beamforming strategy to SNs' locations by concentrating the transmit power on the nearby SNs within the efficient charging radius. With the aid of stochastic geometry, we derive the closed-form expressions of the distribution metrics of the aggregate received power at a typical SN and further approximate the complementary cumulative distribution function using Gamma distribution with second-order moment matching. To design the charging radius for the optimal AD-WPT operation, we exploit the tradeoff between the power intensity of the energy beams and the number of SNs to be charged. Depending on different SN task requirements, the optimal AD-WPT can maximize the average received power or the active probability of the SNs, respectively. It is shown that both the maximized average received power and the maximized sensor active probability increase with the increased deployment density and transmit power of the PBs, and decrease with the increased density of the SNs and the energy beamwidth. Finally, we show that the optimal AD-WPT can significantly improve the energy transfer efficiency compared with the traditional omnidirectional WPT.
Gaussian Sensor Networks with Adversarial Nodes  [PDF]
Emrah Akyol,Kenneth Rose,Tamer Basar
Mathematics , 2013,
Abstract: This paper studies a particular sensor network model which involves one single Gaussian source observed by many sensors, subject to additive independent Gaussian observation noise. Sensors communicate with the receiver over an additive Gaussian multiple access channel. The aim of the receiver is to reconstruct the underlying source with minimum mean squared error. The scenario of interest here is one where some of the sensors act as adversary (jammer): they strive to maximize distortion. We show that the ability of transmitter sensors to secretly agree on a random event, that is "coordination", plays a key role in the analysis. Depending on the coordination capability of sensors and the receiver, we consider two problem settings. The first setting involves transmitters with coordination capabilities in the sense that all transmitters can use identical realization of randomized encoding for each transmission. In this case, the optimal strategy for the adversary sensors also requires coordination, where they all generate the same realization of independent and identically distributed Gaussian noise. In the second setting, the transmitter sensors are restricted to use fixed, deterministic encoders and this setting, which corresponds to a Stackelberg game, does not admit a saddle-point solution. We show that the the optimal strategy for all sensors is uncoded communications where encoding functions of adversaries and transmitters are in opposite directions. For both settings, digital compression and communication is strictly suboptimal.
Mobile Base Station and Clustering to Maximize Network Lifetime in Wireless Sensor Networks  [PDF]
Oday Jerew,Kim Blackmore,Weifa Liang
Journal of Electrical and Computer Engineering , 2012, DOI: 10.1155/2012/902862
Abstract: Using a mobile base station (BS) in a wireless sensor network can alleviate nonuniform energy consumption among sensor nodes and accommodate partitioned networks. In the work of Jerew and Liang (2009) we have proposed a novel clustering-based heuristic algorithm for finding a trajectory of the mobile BS that strikes a nontrivial tradeoff between the traffic load among sensor nodes and the tour time constraint of the mobile BS. In this paper, we first show how to choose the number of clusters to ensure there is no packet loss as the BS moves between clusters. We then provide an analytical solution to the problem in terms of the speed of the mobile BS. We also provide analytical estimates of the unavoidable packet loss as the network size increases. We finally conduct experiments by simulation to evaluate the performance of the proposed algorithm. The results show that the use of clustering in conjunction with a mobile BS for data gathering can significantly prolong network lifetime and balance energy consumption of sensor nodes.
An Energy Supply System for Wireless Sensor Network Nodes
Guoqiang Zheng,Liwei Zhang,Jishun Li
International Journal of Distributed Sensor Networks , 2012, DOI: 10.1155/2012/603709
Abstract: The power source is a critical obstacle for wireless sensor network nodes. In order to prolong the lifetime of wireless sensor networks, this paper presents an energy supply system that uses a specially designed broadband piezoelectric energy harvesting technology for sustaining the operation of wireless sensor network nodes. The proposed energy supply circuit can apply an optimal control voltage to the piezoelectric element to ensure impedance matching between the vibration source and the energy supply system in nonresonance frequencies. As compared to the conventional piezoelectric energy harvesting circuit, it is shown that the efficiency has been increased 4 times. In this work, the overall system structure, the function modules design, and the performance testing analysis are illuminated in detail. Experimental results reveal that this energy supply system can significantly improve power within the wide bands by the active piezoelectric energy harvesting technology and enable wireless sensor network nodes to operate normally.
Detection of Mobile Replica Nodes in Wireless Sensor Networks  [PDF]
International Journal of Computer Science and Mobile Computing , 2013,
Abstract: In wireless sensor networks (WSN), there are many nodes and they are unattended so anadversary can easily capture and compromise the sensor nodes and take secret key from the nodes then makemany replicas (duplicate) of them. After getting the secret key from the sensor node the sensitive data whichis present in the nodes get leaked so an adversary can quickly degrades the network communication. To avoidthis node compromised attack we use sequential probability ratio testing (SPRT). In literature severalcompromised node detection works well in static sensor networks and they do not work well in mobile sensornetworks. Using SPRT we detect the compromised node in mobile sensor networks. This paper showanalytically and through ns2 simulation experiments that the scheme detects duplicate node in an efficientand robust manner.
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