86 research outputs found

    A routing protocol for multisink wireless sensor networks in underground coalmine tunnels

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    Traditional underground coalmine monitoring systems are mainly based on the use of wired transmission. However, when cables are damaged during an accident, it is difficult to obtain relevant data on environmental parameters and the emergency situation underground. To address this problem, the use of wireless sensor networks (WSNs) has been proposed. However, the shape of coalmine tunnels is not conducive to the deployment of WSNs as they are long and narrow. Therefore, issues with the network arise, such as extremely large energy consumption, very weak connectivity, long time delays, and a short lifetime. To solve these problems, in this study, a new routing protocol algorithm for multisink WSNs based on transmission power control is proposed. First, a transmission power control algorithm is used to negotiate the optimal communication radius and transmission power of each sink. Second, the non-uniform clustering idea is adopted to optimize the cluster head selection. Simulation results are subsequently compared to the Centroid of the Nodes in a Partition (CNP) strategy and show that the new algorithm delivers a good performance: Power efficiency is increased by approximately 70%, connectivity is increased by approximately 15%, the cluster interference is diminished by approximately 50%, the network lifetime is increased by approximately 6%, and the delay is reduced with an increase in the number of sinks

    Joint transceiver design and power optimization for wireless sensor networks in underground mines

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    Avec les grands dĂ©veloppements des technologies de communication sans fil, les rĂ©seaux de capteurs sans fil (WSN) ont attirĂ© beaucoup d’attention dans le monde entier au cours de la derniĂšre dĂ©cennie. Les rĂ©seaux de capteurs sans fil sont maintenant utilisĂ©s pour a surveillance sanitaire, la gestion des catastrophes, la dĂ©fense, les tĂ©lĂ©communications, etc. De tels rĂ©seaux sont utilisĂ©s dans de nombreuses applications industrielles et commerciales comme la surveillance des processus industriels et de l’environnement, etc. Un rĂ©seau WSN est une collection de transducteurs spĂ©cialisĂ©s connus sous le nom de noeuds de capteurs avec une liaison de communication distribuĂ©e de maniĂšre alĂ©atoire dans tous les emplacements pour surveiller les paramĂštres. Chaque noeud de capteur est Ă©quipĂ© d’un transducteur, d’un processeur de signal, d’une unitĂ© d’alimentation et d’un Ă©metteur-rĂ©cepteur. Les WSN sont maintenant largement utilisĂ©s dans l’industrie miniĂšre souterraine pour surveiller certains paramĂštres environnementaux, comme la quantitĂ© de gaz, d’eau, la tempĂ©rature, l’humiditĂ©, le niveau d’oxygĂšne, de poussiĂšre, etc. Dans le cas de la surveillance de l’environnement, un WSN peut ĂȘtre remplacĂ© de maniĂšre Ă©quivalente par un rĂ©seau Ă  relais Ă  entrĂ©es et sorties multiples (MIMO). Les rĂ©seaux de relais multisauts ont attirĂ© un intĂ©rĂȘt de recherche important ces derniers temps grĂące Ă  leur capacitĂ© Ă  augmenter la portĂ©e de la couverture. La liaison de communication rĂ©seau d’une source vers une destination est mise en oeuvre en utilisant un schĂ©ma d’amplification/transmission (AF) ou de dĂ©codage/transfert (DF). Le relais AF reçoit des informations du relais prĂ©cĂ©dent et amplifie simplement le signal reçu, puis il le transmet au relais suivant. D’autre part, le relais DF dĂ©code d’abord le signal reçu, puis il le transmet au relais suivant au deuxiĂšme Ă©tage s’il peut parfaitement dĂ©coder le signal entrant. En raison de la simplicitĂ© analytique, dans cette thĂšse, nous considĂ©rons le schĂ©ma de relais AF et les rĂ©sultats de ce travail peuvent Ă©galement ĂȘtre dĂ©veloppĂ©s pour le relais DF. La conception d’un Ă©metteur/rĂ©cepteur pour le relais MIMO multisauts est trĂšs difficile. Car Ă  l’étape de relais L, il y a 2L canaux possibles. Donc, pour un rĂ©seau Ă  grande Ă©chelle, il n’est pas Ă©conomique d’envoyer un signal par tous les liens possibles. Au lieu de cela, nous pouvons trouver le meilleur chemin de la source Ă  la destination qui donne le rapport signal sur bruit (SNR) de bout en bout le plus Ă©levĂ©. Nous pouvons minimiser la fonction objectif d’erreur quadratique moyenne (MSE) ou de taux d’erreur binaire (BER) en envoyant le signal utilisant le chemin sĂ©lectionnĂ©. L’ensemble de relais dans le chemin reste actif et le reste des relais s’éteint, ce qui permet d’économiser de l’énergie afin d’amĂ©liorer la durĂ©e de vie du rĂ©seau. Le meilleur chemin de transmission de signal a Ă©tĂ© Ă©tudiĂ© dans la littĂ©rature pour un relais MIMO Ă  deux bonds mais est plus complexe pour un ...With the great developments in wireless communication technologies, Wireless Sensor Networks (WSNs) have gained attention worldwide in the past decade and are now being used in health monitoring, disaster management, defense, telecommunications, etc. Such networks are used in many industrial and consumer applications such as industrial process and environment monitoring, among others. A WSN network is a collection of specialized transducers known as sensor nodes with a communication link distributed randomly in any locations to monitor environmental parameters such as water level, and temperature. Each sensor node is equipped with a transducer, a signal processor, a power unit, and a transceiver. WSNs are now being widely used in the underground mining industry to monitor environmental parameters, including the amount of gas, water, temperature, humidity, oxygen level, dust, etc. The WSN for environment monitoring can be equivalently replaced by a multiple-input multiple-output (MIMO) relay network. Multi-hop relay networks have attracted significant research interest in recent years for their capability in increasing the coverage range. The network communication link from a source to a destination is implemented using the amplify-and-forward (AF) or decode-and-forward (DF) schemes. The AF relay receives information from the previous relay and simply amplifies the received signal and then forwards it to the next relay. On the other hand, the DF relay first decodes the received signal and then forwards it to the next relay in the second stage if it can perfectly decode the incoming signal. For analytical simplicity, in this thesis, we consider the AF relaying scheme and the results of this work can also be developed for the DF relay. The transceiver design for multi-hop MIMO relay is very challenging. This is because at the L-th relay stage, there are 2L possible channels. So, for a large scale network, it is not economical to send the signal through all possible links. Instead, we can find the best path from source-to-destination that gives the highest end-to-end signal-to-noise ratio (SNR). We can minimize the mean square error (MSE) or bit error rate (BER) objective function by sending the signal using the selected path. The set of relay in the path remains active and the rest of the relays are turned off which can save power to enhance network life-time. The best path signal transmission has been carried out in the literature for 2-hop MIMO relay and for multiple relaying it becomes very complex. In the first part of this thesis, we propose an optimal best path finding algorithm at perfect channel state information (CSI). We consider a parallel multi-hop multiple-input multiple-output (MIMO) AF relay system where a linear minimum mean-squared error (MMSE) receiver is used at the destination. We simplify the parallel network into equivalent series multi-hop MIMO relay link using best relaying, where the best relay ..

    Feature Selection and Energy Management in Wireless Sensor Networks using Deep Learning

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    In wireless sensor networks, when the available energy sources and battery capacity are extremely constrained, energy efficiency is a major issue to be adressed. One of the main goals in the design of wireless sensor networks (WSNs) is to maximize longevity of battery life. Designers can benefit from the use of intelligent power utilization models to accomplish this goal. These models seek to decrease the number of chosen sensors used to record environmental measures in order to minimize power utilization while retaining the acceptable level of measurement accuracy. In order to simulate wireless sensor networks, we looked at real world datasets. Our simulation findings demonstrate that the suggested strategy can be used to accomplish significant goals by using the right number of sensors using deep learning, extend the lifespan of the wireless sensor networks

    Underground Mining Monitoring and Communication Systems based on ZigBee and GIS

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    ZigBee as a wireless sensor network (WSN) was developed for underground mine monitoring and communication systems. The radio wave attenuations between ZigBee nodes were investigated to measure underground communication distances. Various sensor node arrangements of ZigBee topologies were evaluated. A system integration of a WSN-assisted GIS for underground mining monitoring and communication from a surface office was proposed. The controllable and uncontrollable parameters of underground environments were assessed to establish a reliable ZigBee network

    CDAR : contour detection aggregation and routing in sensor networks

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    Wireless sensor networks offer the advantages of low cost, flexible measurement of phenomenon in a wide variety of applications, and easy deployment. Since sensor nodes are typically battery powered, energy efficiency is an important objective in designing sensor network algorithms. These algorithms are often application-specific, owing to the need to carefully optimize energy usage, and since deployments usually support a single or very few applications. This thesis concerns applications in which the sensors monitor a continuous scalar field, such as temperature, and addresses the problem of determining the location of a contour line in this scalar field, in response to a query, and communicating this information to a designated sink node. An energy-efficient solution to this problem is proposed and evaluated. This solution includes new contour detection and query propagation algorithms, in-network-processing algorithms, and routing algorithms. Only a small fraction of network nodes may be adjacent to the desired contour line, and the contour detection and query propagation algorithms attempt to minimize processing and communication by the other network nodes. The in-network processing algorithms reduce communication volume through suppression, compression and aggregation techniques. Finally, the routing algorithms attempt to route the contour information to the sink as efficiently as possible, while meshing with the other algorithms. Simulation results show that the proposed algorithms yield significant improvements in data and message volumes compared to baseline models, while maintaining the integrity of the contour representation

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    í•™ìœ„ë…ŒëŹž (ë°•ì‚Ź)-- 서욞대학ꔐ 대학원 : ì „êž°Â·ì»Ží“ší„°êł”í•™ë¶€, 2015. 8. 신현식.Simple wireless sensor networks (WSNs) usually have a flat topology and transmit data using a flooding scheme of which there are several variants. However, these can cause the broadcast storming problem, reducing the efficiency and reliability of the WSN. Due to these problems, most WSNs have a cluster or tree structurebut this causes an imbalance of residual energy between nodes, which gets worse over time as nodes become defunct and replacements are inserted. Moreover, a defunct cluster head leads to a sharp drop of network connectivity. Therefore, an efficient way to improve the energy imbalance and the network connectivity is needed. In this thesis, we propose a hierarchical topology control scheme, in which each node periodically selects its own layer accommodating itself with different levels of residual energy and the amount of data to transfer, in order to balance the energy level and to increase the network connectivity. Simulations show that this scheme can balance node energy levels, and thus extend network lifetime. We also introduce a hierarchical topology control scheme for WSNs, which contains both energy-harvesting nodes and battery-powered nodes, in order to extend the lifetime of battery-powered nodes and to increase the network connectivity. In such a WSN, the energy harvesting nodes are also arranged in layers like the battery-powered nodes depending on their expected level of residual energy. This scheme is shown to increase the lifetime of battery-powered nodes preferentially by locating energy-harvesting nodes on the higher layers.Abstract i Contents iii List of Figures vi List of Tables ix 1 Introduction 1 1.1 Motivation 1 1.2 Research Contributions 4 1.3 Organization of This Thesis 5 2 Background and Related Work 7 2.1 Wireless Sensor Networks 7 2.1.1 Characteristics of WSNs 8 2.1.2 WSN Applications 10 2.1.3 Topology Control for WSNs 18 2.1.4 WSN using multiple sink nodes 22 2.2 Energy-harvesting WSNs 22 2.2.1 Hierarchical Topology Control for WSNs with Energy-Harvesting Nodes 23 3 Multi-layer Topology Control for Long-term Wireless Sensor Networks 25 3.1 Layer-Based Topology Control 25 3.1.1 Proposed Scheme 25 3.1.2 The Layering Algorithm Design 26 3.2 Layer Determination 28 3.2.1 TCI message 30 3.2.2 How a node selects its layer 30 3.3 Experimental Results 32 3.3.1 Simulation Environment 33 3.3.2 Simulation Results 35 4 Energy-aware Hierarchical Topology Control for Wireless Sensor Networks with Energy-Harvesting Nodes 41 4.1 Layer-based Topology Control with Energy-harvesting Sensor Nodes 41 4.1.1 Review of Layer-based Topology Control for Long-term WSNs with Battery-powered Nodes 42 4.1.2 The Layer Determination Algorithm 43 4.1.3 Introducing Energy-Harvesting Nodes to a Layered Topology 56 4.2 Experimental Results 58 4.2.1 Simulation Environment 58 4.2.2 Simulation Results 59 5 Conclusion 73 5.1 Summary 73 5.2 Future Research Directions 75 요앜 92Docto

    A survey on gas leakage source detection and boundary tracking with wireless sensor networks

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    Gas leakage source detection and boundary tracking of continuous objects have received a significant research attention in the academic as well as the industries due to the loss and damage caused by toxic gas leakage in large-scale petrochemical plants. With the advance and rapid adoption of wireless sensor networks (WSNs) in the last decades, source localization and boundary estimation have became the priority of research works. In addition, an accurate boundary estimation is a critical issue due to the fast movement, changing shape, and invisibility of the gas leakage compared with the other single object detections. We present various gas diffusion models used in the literature that offer the effective computational approaches to measure the gas concentrations in the large area. In this paper, we compare the continuous object localization and boundary detection schemes with respect to complexity, energy consumption, and estimation accuracy. Moreover, this paper presents the research directions for existing and future gas leakage source localization and boundary estimation schemes with WSNs

    An Enhanced Backbone-Assisted Reliable Framework for Wireless Sensor Networks

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    An extremely reliable source to sink communication is required for most of the contemporary WSN applications especially pertaining to military, healthcare and disaster-recovery. However, due to their intrinsic energy, bandwidth and computational constraints, Wireless Sensor Networks (WSNs) encounter several challenges in reliable source to sink communication. In this paper, we present a novel reliable topology that uses reliable hotlines between sensor gateways to boost the reliability of end-to-end transmissions. This reliable and efficient routing alternative reduces the number of average hops from source to the sink. We prove, with the help of analytical evaluation, that communication using hotlines is considerably more reliable than traditional WSN routing. We use reliability theory to analyze the cost and benefit of adding gateway nodes to a backbone-assisted WSN. However, in hotline assisted routing some scenarios where source and the sink are just a couple of hops away might bring more latency, therefore, we present a Signature Based Routing (SBR) scheme. SBR enables the gateways to make intelligent routing decisions, based upon the derived signature, hence providing lesser end-to-end delay between source to the sink communication. Finally, we evaluate our proposed hotline based topology with the help of a simulation tool and show that the proposed topology provides manifold increase in end-to-end reliability

    Energy-Efficient Broadcasting Scheme for Smart Industrial Wireless Sensor Networks

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