Dissertations / Theses on the topic 'Wireless sensor networks'
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1
Yazar, Dogan. "RESTful Wireless Sensor Networks." Thesis, Uppsala University, Department of Information Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-110353.
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Sensor networks have diverse structures and generally employ proprietary protocols to gather useful information about the physical world. This diversity generates problems to interact with these sensors since custom APIs are needed which are tedious, error prone and have steep learning curve. In this thesis, I present RESThing, a lightweight REST framework for wireless sensor networks to ease the process of interacting with these sensors by making them accessible over the Web. I evaluate the system and show that it is feasible to support widely used and standard Web protocols in wireless sensor networks. Being able to integrate these tiny devices seamlessly into the global information medium, we can achieve the Web of Things.
2
Tan, Hailun Computer Science & Engineering Faculty of Engineering UNSW. "Secure network programming in wireless sensor networks." Awarded By:University of New South Wales. Computer Science & Engineering, 2010. http://handle.unsw.edu.au/1959.4/44835.
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Network programming is one of the most important applications in Wireless Sensor Networks as It provides an efficient way to update program Images running on sensor nodes without physical access to them. Securing these updates, however, remains a challenging and important issue, given the open deployment environment of sensor nodes. Though several security schemes have been proposed to impose the authenticity and Integrity protection on network programming applications, they are either energy Inefficient as they tend to use digital signature or lacks the data confidentiality. In addition, due to the absence of secure memory management in the current sensor hardware, the attacker could inject malicious code into the program flash by exploiting buffer overflow In the memory despite the secure code dissemination. The contribution of this thesis Is to provide two software-based security protocols and one hardware-based remote attestation protocol for network programming application. Our first protocol deploys multiple one-way key chains for a multi-hop sensor network. The scheme Is shown to be lower In computational, power consumption and communication costs yet still able to secure multi??hop propagation of program images. Our second protocol utilizes an Iterative hash structure to the data packets in network programming application, ensuring the data confidentiality and authenticity. In addition, we Integrated confidentiality and DoS-attack-resistance in a multi??hop code dissemination protocol. Our final solution is a hardware-based remote attestation protocol for verification of running codes on sensor nodes. An additional piece of tamper-proof hardware, Trusted Platform Module (TPM), is imposed into the sensor nodes. It secures the sensitive information (e.g., the session key) from attackers and monitors any platform environment changes with the Internal registers. With these features of TPM, the code Injection attack could be detected and removed when the contaminated nodes are challenged in our remote attestation protocol. We implement the first two software-based protocols with Deluge as the reference network programming protocol in TinyOS, evaluate them with the extensive simulation using TOSSIM and validate the simulation results with experiments using Tmote. We implement the remote attestation protocol on Fleck, a sensor platform developed by CSIRO that Integrates an Atmel TPM chip.
3
Lim, Tiong Hoo. "Dependable network protocols in wireless sensor networks." Thesis, University of York, 2013. http://etheses.whiterose.ac.uk/4903/.
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This thesis is concerned with the dependability of Wireless Sensor Networks (WSNs). We propose an approach, inspired by the immune system, that allows individual nodes to detect, diagnose and recover from different failures by switching between different protocols using a multi-modal switching mechanism. A causal link between different failures in WSN is identified. Existing fault tolerance in WSNs approaches are examined. From the survey, it is identified that various attempts have been made to improve the fault tolerance of the communication protocol especially in the routing protocols. Although tests have been performed to evaluate the communication protocols prior to deployment, failures in WSNs are still being reported when deployed in real environments. A Systematic Protocol Evaluation Technique (SPET) is proposed and applied to evaluate the dependability of the proposed multi-modal protocol and reduce the uncertainties in the experiment and to demonstrate the confidence in the measurements taken from experiments.
4
Chaves, Andrea, Bruno Mayoral, Hyun-Jin Park, Mark Tsang, and Sean Tunell. "Wireless Sensor Networks: A Grocery Store Application." International Foundation for Telemetering, 2008. http://hdl.handle.net/10150/606223.
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ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, CaliforniaThis paper explains the development of a wireless network system implemented to streamline grocery store checkout procedures. The design employs a wireless telemetry network consisting of a base station and wireless motes (Micaz MPR2400) that will be located on certain aisles, and attached to shopping carts. This system allows customers to scan items while they shop and uses cashiers for payment purposes only. The objective is to minimize the amount of processing performed by cashiers in order to reduce waiting times in line. The system was tested in a simulation environment and waiting times were reduced by 65%.
5
Dogru, Sedat. "Sycophant Wireless Sensor Networks Tracked By Sparsemobile Wireless Sensor Networks While Cooperativelymapping An Area." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12615139/index.pdf.
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In this thesis the novel concept of Sycophant Wireless Sensors (SWS) is introduced. A SWS network is a static ectoparasitic clandestine sensor network mounted incognito on a mobile agent using only the agent&rsquos mobility without intervention. SWS networks not only communicate with each other through mobileWireless Sensor Networks (WSN) but also cooperate with them to form a global hybrid Wireless Sensor Network. Such a hybrid network has its own problems and opportunities, some of which have been studied in this thesis work. Assuming that direct position measurements are not always feasible tracking performance of the sycophant using range only measurements for various communication intervals is studied. Then this framework was used to create a hybrid 2D map of the environment utilizing the capabilities of the mobile network the sycophant. In order to show possible applications of a sycophant deployment, the sycophant sensor node was equipped with a laser ranger as its sensor, and it was let to create a 2D map of its environment. This 2D map, which corresponds to a height dierent than the follower network, was merged with the 2D map of the mobile network forming a novel rough 3D map. Then by giving up from the need to properly localize the sycophant even when it is disconnected to the rest of the network, a full 3D map of the environment is obtained by fusing 2D map and tracking capabilities of the mobile network with the 2D vertical scans of the environment by the sycophant. And finally connectivity problems that arise from the hybrid sensor/actuator network were solved. For this 2 new connectivity maintenance algorithms, one based on the helix structures of the proteins, and the other based on the acute triangulation of the space forming a Gabriel Graph, were introduced. In this new algorithms emphasis has been given to sparseness in order to increase fault tolerance to regional problems. To better asses sparseness a new measure, called Resistance was introduced, as well as another called updistance.
6
Sevgi, Cuneyt. "Network Dimensioning In Randomly Deployed Wireless Sensor Networks." Phd thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12611213/index.pdf.
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In this study, we considered a heterogeneous, clustered WSN, which consists of two
types of nodes (clusterheads and sensor nodes) deployed randomly over a sensing field.
We investigated two cases based on how clusterheads can reach the sink: direct and
multi-hop communication cases. Network dimensioning problems in randomly deployed
WSNs are among the most challenging ones as the attributes of these networks are
mostly non-deterministic. We focused on a number of network dimensioning problems
based on the connected coverage concept, which is the degree of coverage achieved by
only the connected devices. To evaluate connected coverage, we introduced the term
cluster size, which is the expected value of the area covered by a clusterhead together
with sensor nodes connected to it. We derived formulas for the cluster size and validated
them by computer simulations. By using the cluster size formulas, we proposed
a method to dimension a WSN for given targeted connected coverage.
Furthermore, we formulated cost optimization problems for direct and multi-hop
communication cases. These formulations utilize not only cluster size formulas but also
the well-connectivity concept. We suggested some search heuristics to solve these optimization
problems. Additionally, we justified that, in practical cases, node heterogeneity
can provide lower cost solutions. We also investigated the lifetime of WSNs and for
mulated a cost optimization problem with connected coverage and lifetime constraints.
By solving this optimization problem, one can determine the number of nodes of each
type and the initial energies of each type of node that leads to lowest cost solution while
satisfying the minimum connected coverage and minimum lifetime requirements.
7
Yuan, Fenghua. "Lightweight network management design for wireless sensor networks." Online access for everyone, 2007. http://www.dissertations.wsu.edu/Thesis/Fall2007/F_Yuan_081307.pdf.
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8
Karaaslan, Ibrahim. "Anti-sensor Network: Distortion-based Distributed Attack In Wireless Sensor Networks." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609276/index.pdf.
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In this thesis, a novel anti-sensor network paradigm is introduced against wireless sensor networks (WSN). Anti-sensor network (ASN) aims to destroy application reliability by adaptively and anonymously introducing adequate level of artificial distortion into the communication of the event features transported from the sensor nodes (SN) to the sink. ASN is composed of anti-sensor nodes (aSN) randomly distributed
over the sensor network field. aSNs pretend to be SNs tomaintain anonymity and so improve resiliency against attack detection and prevention mechanisms. Performance
evaluations via mathematical analysis and simulation experiments show that ASN can effectively reduce the application reliability of WSN.
9
Chraibi, Youssef. "Localization in Wireless Sensor Networks." Thesis, KTH, Reglerteknik, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-107528.
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Similar to many technological developments, wireless sensor networks have emerged from military needs and found its way into civil applications. Today, wireless sensor networks has become a key technology for different types of ”smart environments”, and an intense research effort is currently underway to enable the application of wireless sensor networks for a wide rangeof industrial problems. Wireless networks are of particular importance whena large number of sensor nodes have to be deployed, and/or in hazardous situations. Localization is important when there is an uncertainty of the exact location of some fixed or mobile devices. One example has been in the supervision of humidity and temperature in forests and/or fields, where thousands of sensors are deployed by a plane, giving the operator little or no possibility to influence the precise location of each node. An effective localization algorithm can then use all the available information from the wireless sensor nodes to infer the position of the individual devices. Another application is the positioning of a mobile robot based on received signal strength from a set of radio beacons placed at known locations on the factory floor. This thesis work is carried out on the wireless automation testbed at the S3. Focusing on localization processes, we will first give an overview of the state of the art in this area. From the various techniques, one idea was found to have significant bearing for the development of a new algorithm. We present analysis and simulations of the algorithms, demonstrating improved accuracy compared to other schemes although the accuracy is probably not good enough for some high-end applications. A third aspect of the work concerns the feasibility of approaches based on received signal strength indication (RSSI). Multiple measurement series have been collected in the lab with the MoteIV wireless sensor node platform. The measurement campaign indicates significant fluctuations in the RSSI values due to interference and limited repeatability of experiments, which may limit the reliability of many localization schemes, especially in an indoor environment.
10
Cao, Hui. "Stabilization in wireless sensor networks." Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1211079872.
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11
Tseng, Kuan-Chieh Robert. "Resilience of wireless sensor networks." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/33713.
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The coverage of a wireless sensor network is a measure of the quality of service. One type of coverage is k-barrier coverage. Given a starting region S and an ending region T , we say that a sensor network has k-barrier coverage with respect to S and T if any S−T path in the surveillance domain must intersect the coverage regions of at least k sensors.
In this thesis, we focus on determining the resilience of a wireless sensor network. The resilience is defined to be the minimum number of sensors that need to be removed in order to ensure the existence of a S−T path that does not cross any sensor coverage region. A sensor network with resilience k constitutes a k-barrier coverage.
We demonstrate that determining resilience of a wireless sensor network with 2D surveillance domain is NP-hard for the case when the sensor coverage regions are unit line segments. Furthermore, it is possible to extend the reduction to show that the problem remains NP-hard for other types of sensor coverage regions. In general, if the shape of the coverage region is non-symmetric, then determining resilience is NP-hard.
We also investigate the problem of determining resilience of a wireless sensor network with 3D surveillance domain. In this case, we show that if the coverage regions of the sensors are unit spheres, then the problem is NP-hard.
12
Saif, Waleed Abdulwahed. "Localization in wireless sensor networks." Thesis, University of Leeds, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.555845.
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In this thesis we examine localization in wireless sensor networks starting with a brief overview of the basics of radiolocation techniques and then look at some of the most well-known commercial positioning techniques and localization algorithms. We then concentrate on the application of the Fastmap (FM) algorithm in the field of wireless sensor localization. Our first contribution in this thesis is the mathematical analysis of the FM algorithm in terms of the mean squared error (MSE) of the coordinate estimate under a multiplicative noise model followed by the optimum placement of anchor nodes. The algorithm is compared to Linear Least Squares (LLS) algorithm, which is well known and has a similar complexity to that of FM. Another contribution is proposing the angle-projected FM algorithm for wireless sensor nodes localization in order to enhance the connectivity of the network and the overall performance. A comprehensive study and mathematical analysis in terms of the MSE for this algorithm is presented and it is also compared with the original FM algorithm. We also propose a weighted Fastmap (WFM) algorithm in which more than one pair of anchor nodes is used to evaluate the first coordinate (i.e., x-coordinate) of the unknown nodes in order to reduce the effect of error dependency in the y-coordinate estimation. (In the original FM algorithm only one pair of anchor nodes was employed.) The optimal WFM weights are determined via (constrained) minimization of the MSE of the estimated node coordinates. A simplification of the WFM is also introduced, called the averaged FM (AFM), where complexity is reduced at the expense of degradation in the overall WFM performance. Both the WFM and AFM exhibit improved performance over the original FM algorithm. Finally, an unbiased version of the WFM, AFM and FM is presented in which an estimate of the bias term is removed to improve the overall MSE performance. The effect of this modification on the algorithms' performance is then analysed and discussed.
13
Li, Wei. "Cooperation arrayed wireless sensor networks." Thesis, Imperial College London, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.536033.
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14
Peng, Wei. "Optimisation of wireless sensor networks." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543734.
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15
Cheng, King-yip, and 鄭勁業. "Localization in wireless sensor networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B38700189.
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16
Goh, Hock Guan. "Cognitive wireless sensor networks (CogWSNs)." Thesis, University of Strathclyde, 2014. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=24216.
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Cognitive Wireless Sensor Networks (CogWSNs) are an adaptive learning based wireless sensor network relying on cognitive computational processes to provide a dynamic capability in configuring the network. The network is formed by sensor nodes equipped with cognitive modules with awareness of their operating environment. If the performance of the sensor network does not meet requirements during operation, a corrective action is derived from stored network knowledge to improve performance. After the action is implemented, feedback on the action taken is evaluated to determine the level of improvement. Example functions within CogWSNs can be as simple as to provide robust connectivity or as complex as to negotiate additional resources from neighbouring network groups with the goal of forwarding application-critical data. In this work, the concept of CogWSNs is defined and its decision processes and supporting architecture proposed. The decision role combines the Problem Solving cognitive process from A Layered Reference Model of the Brain and Polya Concept, consisting of Observe, Plan, Implement, and Evaluate phases. The architecture comprises a Transceiver, Transducer, and Power Supply virtual modules coordinated by the CogWSN's decision process together with intervention, if necessary, by a user. Three types of CogWSN modules are designed based on different implementation considerations: Rule-based CogWSN, Supervised CogWSN, and Reinforcement CogWSN. Verification and comparison for these modules are executed through case studies with focus on power transmission and communication slot allocation. Results show that all three modules are able to achieve targeted connectivity and maintain utilisation of slots at acceptable data rates.
17
Krol, Michal. "Routin in wireless sensor networks." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAM004/document.
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Le paradigme d’Internet des objets (IoT) envisage d’élargir Internet actuelle avec un grand nombre de dispositifs intelligents. Réseaux de Capteurs sans Fil (WSN) déploie les dispositifs fonctionnant sur des approvisionnements énergétiques maigres et mesurant de phénomènes environnementaux (comme la température, la radioactivité, ou CO 2). Des applications populaires de WSN comprennent la surveillance, le télémétrie, et la prévention des catastrophes naturelles. Des défis majeurs de WSN sont comment permettre à l’efficacité énergétique, surmonter les déficiences de support sans fil, et d’opérer dans à la manière auto-organisée. L’intégration de WSN dans IoT se posera sur des standards ouvertes efforçant d’offrir évolutivité et de fiabilité dans une variété de scénarios et conditions de fonctionnement. Néanmoins, l’état actuel des standards a les problèmes d’interopérabilité et peuvent bénéficier de certaines améliorations. Les contributions de la thèse sont :Nous avons effectué une étude approfondie des filtres de Bloom et de leur utilisation dans le stockage de caractéristiques de nœud dans l’adresse IP. Différentes techniques de compression et de variantes de filtres nous ont permisde développer un système efficace qui comble l’écart entre le routage de caractéristiques et l’approche classique compatible avec les réseaux IPv6.Nous proposons Featurecast, un protocole de routage / service de nommage pourWSN. Il permet d’interroger les réseaux de capteurs en utilisant un ensemble de caractéristiques tout raccord en entête de paquet IPv6. Nous intégrons notre protocole dans RPL et introduisons une nouvelle mesure, qui augmentent l’efficacité de routage. Nous vérifions sa performance contre dans des simulations approfondies et des test sur des capteurs réels dans un bancd’essai à grande échelle. Simulations approfondies démontrent les avantagesde notre protocole en termes d’utilisation de la mémoire, le surcharge de con-trôle, le taux de livraison de paquets et la consommation d’énergie.Nous introduisons WEAVE - un protocole de routage pour les réseaux avec géolo-calisation. Notre solution n’utilise pas de message de contrôle et apprend sesvoies seulement en observant le trafic. Plusieurs mécanismes sont introduitspour garder un en-tête de taille fixe, contourner à la fois les petits commeles grands obstacles et fournir une communication efficace entre les nœuds.Nous avons effectué des simulations à grande échelle impliquant plus de 19000noeuds et des expériences avec des capteurs réels sur banc d’essai IoT-lab.Nos résultats montrent que nous atteignons bien meilleures performances enparticulier dans les réseaux grands et dynamiques sans introduire de surchargeInternet of Things (IoT) paradigm envisages to expand the current Internet witha huge number of intelligent communicating devices. Wireless Sensor Networks(WSN) deploy the devices running on meagre energy supplies and measuring environmental phenomena (like temperature, radioactivity, or CO 2 ). WSN popularapplications include monitoring, telemetry, and natural disaster prevention. Major WSN challenges are energy efficiency, overcome impairments of wireless medium, and operate in the self-organisation. The WSN integrating IoT will rely on a set of the open standards striving to offer scalability and reliability in a variety of the operating scenarios and conditions. Nevertheless, the current state of the standards have interoperability issues and can benefit from further improvements. The contributions of the thesis work are:We performed an extensive study of Bloom Filters and their use in storing nodetext-based elements in IP address. Different techniques of compression andvariants of filters allowed us to develop an efficient system closing the gapbetween feature-routing and classic approach compatible with IPv6 networks.We propose Featurecast, a routing protocol/naming service for WSN. It allowsto query sensor networks using a set of characteristics while fitting in anIPv6 packet header. We integrate our protocol in RPL and introduce a newmetric, which increase the routing efficiency. We check its performance inboth extensive simulations and experimentations on real sensors in a large-scale Senslab testbed. Large-scale simulations demonstrate the advantagesof our protocol in terms of memory usage, control overhead, packet deliveryrate and energy consumption.We introduce WEAVE - a routing protocol for networks with geolocation. Our so-lution does not use any control message and learn its paths only by observingthe traffic. Several mechanisms are introduce to keep a fixed-size header andbypass both small as well as large obstacles and provide an efficient communication between nodes. We performed simulations on large scale involvingmore than 19000 nodes and real-sensor experimentations on IoT-lab testbed. Our results show that we achieve much better performance especially in large and dynamic networks without introducing any control overhead
18
Maalel, Nourhene. "Reliability in wireless sensor networks." Thesis, Compiègne, 2014. http://www.theses.fr/2014COMP1944/document.
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Vu les perspectives qu'ils offrent, les réseaux de capteur sans fil (RCSF) ont perçu un grand engouement de la part de la communauté de recherche ces dernières années. Les RCSF couvrent une large gamme d'applications variant du contrôle d'environnement, le pistage de cible aux applications de santé. Les RCSFs sont souvent déployés aléatoirement. Ce dispersement des capteurs nécessite que les protocoles de transmission utilisés soient résistants aux conditions environnementales (fortes chaleurs ou pluies par exemple) et aux limitations de ressources des nœuds capteurs. En effet, la perte de plusieurs nœuds capteurs peut engendrer la perte de communication entre les différentes entités. Ces limitations peuvent causer la perte des paquets transmis ce qui entrave l'activité du réseau. Par conséquent, il est important d'assurer la fiabilité des transmissions de données dans les RCSF d'autant plus pour les applications critiques comme la détection d'incendies. Dans cette thèse, nous proposons une solution complète de transmission de données dans les RCSF répondant aux exigences et contraintes de ce type de réseau. Dans un premier temps, nous étudions les contraintes et les challenges liés à la fiabilisation des transmissions dans les RCSFs et nous examinons les travaux proposés dans la littérature. Suite à cette étude nous proposons COMN2, une approche distribuée et scalable permettant de faire face à la défaillance des nœuds. Ensuite, nous proposons un mécanisme de contrôle d'erreur minimisant la perte de paquets et proposant un routage adaptatif en fonction de la qualité du lien. Cette solution est basée sur des acquittements implicites (overhearing) pour la détection des pertes des paquets. Nous proposons ensuite ARRP une variante de AJIA combinant les avantages des retransmissions, de la collaboration des nœuds et des FEC. Enfin, nous simulons ces différentes solutions et vérifions leurs performances par rapport à leurs concurrents de l'état de l'artOver the past decades, we have witnessed a proliferation of potential application domainsfor wireless sensor networks (WSN). A comprehensive number of new services such asenvironment monitoring, target tracking, military surveillance and healthcare applicationshave arisen. These networked sensors are usually deployed randomly and left unattendedto perform their mission properly and efficiently. Meanwhile, sensors have to operate ina constrained environment with functional and operational challenges mainly related toresource limitations (energy supply, scarce computational abilities...) and to the noisyreal world of deployment. This harsh environment can cause packet loss or node failurewhich hamper the network activity. Thus, continuous delivery of data requires reliabledata transmission and adaptability to the dynamic environment. Ensuring network reliabilityis consequently a key concern in WSNs and it is even more important in emergencyapplication such disaster management application where reliable data delivery is the keysuccess factor. The main objective of this thesis is to design a reliable end to end solution for data transmission fulfilling the requirements of the constrained WSNs. We tackle two design issues namely recovery from node failure and packet losses and propose solutions to enhance the network reliability. We start by studying WSNs features with a focus on technical challenges and techniques of reliability in order to identify the open issues. Based on this study, we propose a scalable and distributed approach for network recovery from nodefailures in WSNs called CoMN2. Then, we present a lightweight mechanism for packetloss recovery and route quality awareness in WSNs called AJIA. This protocol exploitsthe overhearing feature characterizing the wireless channels as an implicit acknowledgment(ACK) mechanism. In addition, the protocol allows for an adaptive selection of therouting path by achieving required retransmissions on the most reliable link. We provethat AJIA outperforms its competitor AODV in term of delivery ratio in different channelconditions. Thereafter, we present ARRP, a variant of AJIA, combining the strengthsof retransmissions, node collaboration and Forward Error Correction (FEC) in order toprovide a reliable packet loss recovery scheme. We verify the efficiency of ARRP throughextensive simulations which proved its high reliability in comparison to its competitor
19
Kordari, Kamiar. "Self organizing wireless sensor networks." College Park, Md.: University of Maryland, 2007. http://hdl.handle.net/1903/7625.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Dept. of Electrical and Computer Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
20
Meier, Andreas. "Safety critical wireless sensor networks." Aachen Shaker, 2009. http://d-nb.info/997314435/04.
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Fairbairn, M. L. "Dependability of wireless sensor networks." Thesis, University of York, 2014. http://etheses.whiterose.ac.uk/8205/.
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As wireless sensor networks (WSNs) are becoming ever more prevalent, the runtime characteristics of these networks are becoming an increasing issue. Commonly, external sources of interference make WSNs behave in a different manner to that expected from within simplistic simulations, resulting in the need to use additional systems which monitor the state of the network. Despite dependability of WSNs being an increasingly important issue, there are still only a limited number of works within this specific field, with the majority of works focusing on ensuring that specific devices are operational, not the application as a whole. This work instead aims to look at the dependability of WSNs from an application-centric view, taking into account the possible ways in which the application may fail and using the application's requirements to focus on assuring dependability.
22
Al-Khateeb, Shadi A. "Fire Detection Using Wireless Sensor Networks." Youngstown State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1411471850.
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Spinden, David, Jeffrey Jasper, and Kurt Kosbar. "Comparison of Wireless Ad-Hoc Sensor Networks." International Foundation for Telemetering, 2004. http://hdl.handle.net/10150/605786.
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International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, CaliforniaThere are a number of telemetry applications where it would be helpful to have networks of sensors that could autonomously discover their connectivity, and dynamically reconfigure themselves during use. A number of research groups have developed wireless ad-hoc sensor network systems. This paper reviews the state-of-the-art in wireless ad-hoc networks, examining the features, assumptions, limitations and unique attributes of some of the more popular solutions to this problem.
24
Ogunlu, Bilal. "Lifetime Analysis For Wireless Sensor Networks." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605226/index.pdf.
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Sensor technologies are vital today in gathering information about certain environments and wireless sensor networks are getting more widespread use everyday. These networks are characterized by a number of sensor nodes deployed in the field for the observation of some phenomena. Due to the limited battery capacity in sensor nodes, energy efficiency is a major and challenging problem in such power-constrained networks. Some of the network design parameters have a direct impact on the network&rsquos lifetime. These parameters have to be chosen in such a way that the network use its energy resources efficiently. This thesis studies these parameters that should be selected according to certain trade offs with respect to the network&rsquo
s lifetime. In this work, these trade offs have been investigated and illustrated in detail in various combinations. To achieve this goal, a special simulation tool has been designed and implemented in this work that helps in analyzing the effects of the selected parameters on sensor network&rsquo
s lifetime. OMNeT++, a discrete event simulator, provides the framework for the sensor network simulator&rsquo
s development. Ultimately, results of extensive computational tests are presented, which may be helpful in guiding the sensor network designers in optimally selecting the network parameters for prolonged lifetime.
25
Sriporamanont, Thammakit, and Gu Liming. "Wireless Sensor Network Simulator." Thesis, Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-290.
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In the recent past, wireless sensor networks have been introduced to use in many applications. To
design the networks, the factors needed to be considered are the coverage area, mobility, power
consumption, communication capabilities etc. The challenging goal of our project is to create a
simulator to support the wireless sensor network simulation. The network simulator (NS-2) which
supports both wire and wireless networks is implemented to be used with the wireless sensor
network. This implementation adds the sensor network classes which are environment, sensor
agent and sensor application classes and modifies the existing classes of wireless network in NS-
2. This NS-2 based simulator is used to test routing protocols – Destination-Sequenced Distance
Vector (DSDV), and Ad-Hoc On-Demand Distance Vector (AODV) as one part of simulations.
Finally, the sensor network application models and the extension methods of this NS-2 based
simulator for simulations in specific wireless sensor network applications are proposed.
26
Ould-Ahmed-Vall, ElMoustapha. "Algorithms for Self-Organizing Wireless Sensor Networks." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14473.
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The unique characteristics of sensor networks pose numerous challenges that have to be overcome to enable their efficient use. In particular, sensor networks are energy constrained because of their reliance on battery power. They can be composed of a large number of unreliable nodes. These characteristics render node collaboration essential to the accomplishment of the network task and justify the development of new algorithms to provide services such as routing, fault tolerance and naming.
This work increases the knowledge on the growing field of sensor network algorithms by contributing a new evaluation tool and two new algorithms.
A new sensor network simulator that can be used to evaluate sensor network algorithms is discussed. It incorporates models for the different functional units composing a sensor node and characterizes the energy consumption of each. It is designed in a modular and efficient way favoring the ease of use and extension. It allows the user to choose from different implementations of energy models, accuracy models and types of sensors.
The second contribution of this thesis is a distributed algorithm to solve the unique ID assignment problem in sensor networks. Our solution starts by assigning long unique IDs and organizing nodes in a tree structure. This tree structure is used to compute the size of the network. Then, unique IDs are assigned using the minimum length. Globally unique IDs are useful in providing many network functions, e.g. node maintenance and security. Theoretical and simulation analysis of the ID assignment algorithm demonstrate that a high percentage of nodes are assigned unique IDs at the termination of the algorithm when the algorithm parameters are set properly. Furthermore, the algorithm terminates in a short time that scales well with the network size.
The third contribution of this thesis is a general fault-tolerant event detection scheme that allows nodes to detect erroneous local decisions based on the local decisions reported by their neighbors. It can handle cases where nodes have different and dynamic accuracy levels. We prove analytically that the derived fault-tolerant estimator is optimal under the maximum a posteriori criterion. An equivalent weighted voting scheme is derived.
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Murukesvan, Abhinash. "Distributed Overlays in Wireless Sensor Networks." Thesis, KTH, Kommunikationssystem, CoS, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-92202.
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This thesis investigates two architectures and compares their suitability for selective application and user differentiation in sensor networks. A hierarchical architecture consisting of more capable cluster heads surrounded by weaker nodes is compared to a flat architecture of equally powerful nodes. In both architectures there exists a logical overlay network that connects the nodes, depending on the application and user. Furthermore, a broadcast encryption scheme is proposed to aid in distributing keys to nodes for secure communication and to maintain these restricted groups.applikation och användar differentiering i trådlösa sensor nätverk. En hierarkisk arkitekturbestående av kraftfullare sensor noder omgiven av mindre kraftfulla sensor noder jämförsmed en platt arkitektur bestående av lika kraftfulla sensor noder. I båda arkitekturer existerarett logiskt lager ovanpå stacken som kopplar noder beroende på applikation och användare,helt oberoende av geografisk placering. Utöver det, bör en nyckel management schema användas till att distribuera nycklar tillnoderna för säker kommunikation och att bibehålla dessa slutna grupper.
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KHAN, SARMAD ULLAH. "Key Management in Wireless Sensor Networks, IP-Based Sensor Networks, Content Centric Networks." Doctoral thesis, Politecnico di Torino, 2013. http://hdl.handle.net/11583/2506342.
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Cryptographic keys and their management in network communication is considered the main building block of security over which other security primitives are based. These cryptographic keys ensure the privacy, authentication, integrity and non-repudiation of messages. However, the use of these cryptographic keys and their management in dealing with the resource constrained devices (i.e. Sensor nodes) is a challenging task.
A number of key management schemes have been introduced by researchers all over the world for such resource constrained networks. For example, light weight PKI and elliptic curve cryptography schemes are computationally expensive for these resource constrained devices. So far the symmetric key approach is considered best for these constrained networks and different variants of it been developed for these networks (i.e. probabilistic key distribution approach). The probabilistic key distribution approach consumes less memory than the standard symmetric key approach but it suffers from the connectivity issues (i.e. the connectivity depends on the common shared keys between the nodes).
Most of those schemes were proposed by considering static sensor networks (e.g. Industrial process monitoring, Environmental monitoring, movement detection in military applications, forests etc.). However, the use of these existing key management schemes for mobile wireless sensor networks applications introduces more challenges in terms of network connectivity, energy consumption, memory cost, communication overhead and protection of key materials against some well known attacks. Keeping these challenges in mind, previous research has proposed some key management schemes considering the mobility scenarios in ad hoc networks and wireless sensor networks (e.g. vehicular networks, health monitoring systems).However these schemes consume more resource because of a much higher communication packet exchange during the handover phase for the authentication of joining and leaving nodes than the static networks where there is no extra communication for the handover and authentication.
The motivation of this research work is to investigate and propose new algorithms not only to improve the efficiency of these existing authentication and key management schemes in terms of connectivity, memory and security by considering the mobility scenario in wireless sensor networks, but also to develop new algorithms that suit these constrained networks than the existing schemes.
First, we choose the existing key pool approach for authentication and key management and improve its network connectivity and resilience against some well known attacks (e.g. node capturing attacks) while reduce the memory cost by storing those key pools in each sensor node. In the proposed solution, we have divided the main key pool into two virtual mutually exclusive key pools. This division and constructing a key from two chosen keys, one from each key pool, helps to reduce the memory cost of each node by assigning fewer keys for the same level of network connectivity as the existing key pool frameworks.
Although, the proposed key pool approach increases the network resilience against node compromission attacks because of the smaller number of keys assigned to each node, however it does not completely nullify the effect of the attacks. Hence we proposed an online mutual authentication and key establishment and management scheme for sensor networks that provides almost 100\% network connectivity and also nullifies the effect of node compromission attacks. In the proposed online key generation approach, the secret key is dependent on both communicating parties. Once the two communicating parties authenticate each other, they would successfully establish a secret communication key, otherwise they stop communication and inform the network manager about the intruder detection and activity.
The last part of the thesis considers the integration of two different technologies (i.e. wireless sensor networks and IP networks). This is a very interesting and demanding research area because of its numerous applications, such as smart energy, smart city etc.. However the security requirements of these two kind of networks (resource constrained and resourceful) make key management a challenging task. Hence we use an online key generation approach using elliptic curve cryptography which gives the same security level as the standard PKI approach used in IP networks with smaller key length and is suited for the sensor network packet size limitations. It also uses a less computationally expensive approach than PKI and hence makes ECC suitable to be adopted in wireless sensor networks. In the key management scheme for IP based sensor networks, we generate the public private key pair based on ECC for each individual sensor node. However the public key is not only dependent on the node's parameter but also the parameters of the network to which it belongs. This increases the security of the proposed solution and avoids intruders pretending to be authentic members of the network(s) by spreading their own public keys.
In the last part of the thesis we consider Content Centric Networking (CCN) which is a new routing architecture for the internet of the future. Building on the observation that today's communications are more oriented towards content retrieval (web, P2P, etc.) than point-to-point communications (VoIP, IM, etc.), CCN proposes a radical revision of the Internet architecture switching from named hosts (TCP/IP protocols) to named data to best match its current usage. In a nutshell, content is addressable, routable, self-sufficient and authenticated, while locations no longer matter. Data is seen and identified directly by a routable name instead of a location (the address of the server). Consequently, data is directly requested at the network level not from its holder, hence there is no need for the DNS). To improve content diffusion, CCN relies on data distribution and duplication, because storage is cheaper than bandwidth: every content - particularly popular one - can be replicated and stored on any CCN node, even untrustworthy. People looking for particular content can securely retrieve it in a P2P-way from the best locations available.
So far, there has been little investigation of the security of CCNs and there is no specific key management scheme for that. We propose an authentication and key establishment scheme for CCNs in which the contents are authenticated by the content generating node, using pre-distributed shares of encryption keys. The content requesting node can get those shares from any node in the network, even from malicious and intruder ones, in accordance with a key concept of CCNs. In our work we also provide means to protect the distributed shares from modification by these malicious/intruder nodes. The proposed scheme is again an online key generation approach but including a relation between the content and its encryption key. This dependency prevents the attackers from modifying the packet or the key shares.
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Shen, Fangyang Sun Min-Te. "Improving system performance for wireless networks." Auburn, Ala, 2008. http://hdl.handle.net/10415/1544.
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Hasir, Ibrahim. "The Effect of Mobility on Wireless Sensor Networks." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc699868/.
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Wireless sensor networks (WSNs) have gained attention in recent years with the proliferation of the micro-electro-mechanical systems, which has led to the development of smart sensors. Smart sensors has brought WSNs under the spotlight and has created numerous different areas of research such as; energy consumption, convergence, network structures, deployment methods, time delay, and communication protocols. Convergence rates associated with information propagations of the networks will be questioned in this thesis. Mobility is an expensive process in terms of the associated energy costs. In a sensor network, mobility has significant overhead in terms of closing old connections and creating new connections as mobile sensor nodes move from one location to another. Despite these drawbacks, mobility helps a sensor network reach an agreement more quickly. Adding few mobile nodes to an otherwise static network will significantly improve the network’s ability to reach consensus. This paper shows the effect of the mobility on convergence rate of the wireless sensor networks, through Eigenvalue analysis, modeling and simulation.
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She, Huimin. "Network-Calculus-based Performance Analysis for Wireless Sensor Networks." Licentiate thesis, KTH, Electronic, Computer and Software Systems, ECS, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10686.
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Recently, wireless sensor network (WSN) has become a promising technologywith a wide range of applications such as supply chain monitoringand environment surveillance. It is typically composed of multiple tiny devicesequipped with limited sensing, computing and wireless communicationcapabilities. Design of such networks presents several technique challengeswhile dealing with various requirements and diverse constraints. Performanceanalysis techniques are required to provide insight on design parametersand system behaviors.
Based on network calculus, we present a deterministic analysis methodfor evaluating the worst-case delay and buffer cost of sensor networks. Tothis end, three general traffic flow operators are proposed and their delayand buffer bounds are derived. These operators can be used in combinationto model any complex traffic flowing scenarios. Furthermore, the methodintegrates a variable duty cycle to allow the sensor nodes to operate at lowrates thus saving power. In an attempt to balance traffic load and improveresource utilization and performance, traffic splitting mechanisms areintroduced for mesh sensor networks. Based on network calculus, the delayand buffer bounds are derived in non-splitting and splitting scenarios.In addition, analysis of traffic splitting mechanisms are extended to sensornetworks with general topologies. To provide reliable data delivery in sensornetworks, retransmission has been adopted as one of the most popularschemes. We propose an analytical method to evaluate the maximum datatransmission delay and energy consumption of two types of retransmissionschemes: hop-by-hop retransmission and end-to-end retransmission.
We perform a case study of using sensor networks for a fresh food trackingsystem. Several experiments are carried out in the Omnet++ simulationenvironment. In order to validate the tightness of the two bounds obtainedby the analysis method, the simulation results and analytical results arecompared in the chain and mesh scenarios with various input traffic loads.From the results, we show that the analytic bounds are correct and tight.Therefore, network calculus is useful and accurate for performance analysisof wireless sensor network.
Ipack VINN Excellence Center
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Samarasinghe, Kasun. "Network Coding with Limited Overhearing in Wireless Sensor Networks." Thesis, KTH, Kommunikationsnät, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-53518.
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Network Coding as a recently emerged concept in Communication Networks Research, has attracted a lot of attention in networking research community. Previous research on applying Network Coding in Wireless Sensor Networks, do not consider most crucial constraints inherent to sensor networks. Especially most of them assume overhearing of neighboring transmissions for free, which is unrealistic in practical sensor network environments where nodes have limited energy. Therefore these applications fail to make an impact on real world sensor network deployments. In some sensor networking scenarios it is possible to manipulate overhearing in a controlled manner. In this research we apply network coding in to improve throughput of a Time Division Multiple Access(TDMA) based Medium Access Control(MAC) protocol called GINMAC , manipulating overhearing appropriately. Our results show that network coding can improve the throughput while trading owith other network performance characteristics like reliability and power consumption.
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Al-Hoqani, Noura Y. S. "In-network database query processing for wireless sensor networks." Thesis, Loughborough University, 2018. https://dspace.lboro.ac.uk/2134/36226.
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In the past research, smart sensor devices have become mature enough for large, distributed networks of such sensors to start to be deployed. Such networks can include tens or hundreds of independent nodes that can perform their functions without human interactions such as recharging of batteries, the configuration of network routes and others. Each of the sensors in the wireless sensor network is considered as microsystem, which consists of memory, processor, transducers and low bandwidth as well as a low range radio transceiver. This study investigates an adaptive sampling strategy for WSS aimed at reducing the number of data samples by sensing data only when a significant change in these processes is detected. This detection strategy is based on an extension to Holt's Method and statistical model. To investigate this strategy, the water consumption in a household is used as a case study. A query distribution approach is proposed, which is presented in detail in chapter 5. Our developed wireless sensor query engine is programmed on Sensinode testbed cc2430. The implemented model used on the wireless sensor platform and the architecture of the model is presented in chapters six, seven, and eight. This thesis presents a contribution by designing the experimental simulation setup and by developing the required database interface GUI sensing system, which enables the end user to send the inquiries to the sensor s network whenever needed, the On-Demand Query Sensing system ODQS is enhanced with a probabilistic model for the purpose of sensing only when the system is insufficient to answer the user queries. Moreover, a dynamic aggregation methodology is integrated so as to make the system more adaptive to query message costs. Dynamic on-demand approach for aggregated queries is implemented, based in a wireless sensor network by integrating the dynamic programming technique for the most optimal query decision, the optimality factor in our experiment is the query cost. In-network query processing of wireless sensor networks is discussed in detail in order to develop a more energy efficient approach to query processing. Initially, a survey of the research on existing WSN query processing approaches is presented. Building on this background, novel primary achievements includes an adaptive sampling mechanism and a dynamic query optimiser. These new approaches are extremely helpful when existing statistics are not sufficient to generate an optimal plan. There are two distinct aspects in query processing optimisation; query dynamic adaptive plans, which focus on improving the initial execution of a query, and dynamic adaptive statistics, which provide the best query execution plan to improve subsequent executions of the aggregation of on-demand queries requested by multiple end-users. In-network query processing is attractive to researchers developing user-friendly sensing systems. Since the sensors are a limited resource and battery powered devices, more robust features are recommended to limit the communication access to the sensor nodes in order to maximise the sensor lifetime. For this reason, a new architecture that combines a probability modelling technique with dynamic programming (DP) query processing to optimise the communication cost of queries is proposed. In this thesis, a dynamic technique to enhance the query engine for the interactive sensing system interface is developed. The probability technique is responsible for reducing communication costs for each query executed outside the wireless sensor networks. As remote sensors have limited resources and rely on battery power, control strategies should limit communication access to sensor nodes to maximise battery life. We propose an energy-efficient data acquisition system to extend the battery life of nodes in wireless sensor networks. The system considers a graph-based network structure, evaluates multiple query execution plans, and selects the best plan with the lowest cost obtained from an energy consumption model. Also, a genetic algorithm is used to analyse the performance of the approach. Experimental testing are provided to demonstrate the proposed on-demand sensing system capabilities to successfully predict the query answer injected by the on-demand sensing system end-user based-on a sensor network architecture and input query statement attributes and the query engine ability to determine the best and close to the optimal execution plan, given specific constraints of these query attributes . As a result of the above, the thesis contributes to the state-of-art in a network distributed wireless sensor network query design, implementation, analysis, evaluation, performance and optimisation.
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Liu, Yunhuai. "Probabilistic topology control in wireless sensor networks /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?CSED%202008%20LIU.
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Paturu, Raghunatha Rao Nityananda Suresh. "Path Planning under Failures in Wireless Sensor Networks." Thesis, North Dakota State University, 2013. http://hdl.handle.net/10365/22971.
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This paper explores how an all pair shortest path can be obtained in a wireless sensor network when sensors fail. Sensors are randomly deployed in a predefined geographical area, simulating the deployment of sensors from an airplane, and finding shortest path between all the sensors deployed based on distance. A major problem to address in wireless sensor networks is the impact of sensor failures on existing shortest paths in the network. An application is developed to simulate a network and find shortest paths affected by a sensor failure and find alternative shortest path. When a sensor fails, all the shortest paths and all the remaining sensors in the network are checked to see if the sensor failure has any impact on the network. Alternative shortest path is calculated for those paths affected by sensor failures.
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Prasad, Pratap Simha. "Energy efficiency in wireless sensor networks." Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Spring%20Theses/PRASAD_PRATAP_30.pdf.
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Zhang, Hongwei. "Dependable messaging in wireless sensor networks." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1155607973.
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Voruganti, Anupama. "Key distribution for wireless sensor networks." Master's thesis, Mississippi State : Mississippi State University, 2007. http://library.msstate.edu/etd/show.asp?etd=etd-03052008-130408.
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Salatas, Vlasios. "Object tracking using wireless sensor networks." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Sep%5FSalatas.pdf.
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Thesis (M.S. in Computer Science)--Naval Postgraduate School, September 2005.Thesis Advisor(s): Gurminder Singh, Arijit Das. Includes bibliographical references (p. 271-273). Also available online.
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Calabrese, Giovanni. "Wireless Sensor Networks: An Industrial Approach." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
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The goal of this project is to create a Wireless Sensor Network (WSN) within a company.We will then talk about WSN within Industry 4.0. The company has a large productionwarehouse, where numerous machines form their production process. Currently, theproduction machines are disconnected from the data network, so everything that happensmust be manually verified by the operators.It will need to connect the machines to the network to make the production processinnovative. The choice of technologies to be used will fall on wireless technologies, whichhave numerous advantages: not laying cables, being able to create various types ofnetworks and quickly connecting many machines. During the project, it will look for thebest solutions to interconnect the machines, selecting specific devices able to satisfy allrequests.The reference scenario is a production warehouse of a company operating in themetalworking sector. Inside the warehouse, there are numerous production machines,which form a heterogeneous machine park. All these machines, which have no possibilityof data exchange, must be equipped with devices capable of communicating the extracteddata.As the reference scenario is an industrial production warehouse, it can speak of In-dustry 4.0.Various communication technologies will be studied, to update the machines to havea digital representation of the production process. These communication technologieswill be partially wireless, in particular for devices to be attached to the machines, andpartly wired, to interface with the external network.It will see how it is possible to extract data from the machines, send them via devicesto a central node, which will process them to give a digital vision of the production.
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Tan, Kok Sin Stephen. "Source localization using wireless sensor networks." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Jun%5FTan.pdf.
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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, June 2006.Thesis Advisor(s): Murali Tummala, John McEachen. "June 2006." Includes bibliographical references (p. 77-78). Also available in print.
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Barros, João. "Reachback communication in wireless sensor networks." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973065753.
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Kirykos, Georgios. "Traffic profiling of wireless sensor networks." Thesis, Monterey, Calif. : Naval Postgraduate School, 2006. http://bosun.nps.edu/uhtbin/hyperion.exe/06Dec%5FKirykos.pdf.
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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 2006.Thesis Advisor(s): John C. McEachen. "December 2006." Includes bibliographical references (p.65-66). Also available in print.
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Li, Qian. "Cooperating Tools for Wireless Sensor Networks." Thesis, Uppsala University, Department of Information Technology, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-129466.
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Wireless Sensor Network (WSN) simulators, testbeds, and environment simulators are indispensable tools for WSN research. Existing WSN tools were developed with different purposes without the intention of cooperation. Nevertheless, the development of a WSN technology (e.g, a middleware, a protocol, or an application) usually requires the cooperation among multiple tools. This calls upon a breaking of the incompatible barriers between any pair of tools.
In this thesis, I propose the Common Input and Output integration approach (the CIO approach). This approach attempts to define a standard configuration file format containing input and output data common to WSN tools. In hope that by supporting this standard configuration file format, tools can cooperate. The WiseML [23] format defined by the WISEBED [29] project is fully in compliance with the requirement of the CIO format. Therefore, it is chosen as a concrete representation of the CIO format.
To evaluate the CIO approach, I developed a bidirectional online converter for one of the WSN simulators - COOJA [42]. The converter is capable of converting between the WiseML format and COOJA's native CSC format on-the-fly. It provides not only the support for both the input and output of the WiseML format but also the functionality of converting the text format temperature log file generated by testbeds to WiseML format.
While I was working on this work, a number of other international organizations were also adding WiseML supports to their own tools. We exchanged our WiseML files and observed gratifying results: (1) WSN simulators can load each other's WiseML files and reproduce the same network topologies and scenarios in their own simulation frameworks; (2) The WiseML format scenarios generated by testbeds and environment simulators can be directly inserted into a WiseML file, and take effect during simulations; (3) The time and space overheads of the converter is acceptable and proportional to the complexity of a simulation. A WiseML file of a few hundreds KB and a format converting time of a few hundreds milliseconds can meet the requirements of most of the simulations. For example, a WiseML file containing 800 motes without scenario and trace sections has a size of approximately 200 KB, and a format converting time of around 500 milliseconds.
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Khan, Muhammad Waqas. "Optimised localisation in wireless sensor networks." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/13399/.
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Wireless sensor networks (WSNs) comprise of tens, hundreds or thousands of low powered, low cost wireless nodes, capable of sensing environmental data such as humidity and temperature. Other than these sensing abilities, these nodes are also able to locate themselves. Different techniques can be found in literature to localise wireless nodes in WSNs. These localisation algorithms are based on the distance estimates between the nodes, the angle estimates between the nodes or hybrid schemes. In the context of range based algorithms, two prime techniques based on the time of arrival (ToA) and the received signal strength (RSS) are commonly used. On the other hand, angle based approach is based on the angle of arrival (AoA) of the signal. A hybrid approach is sometimes used to localise wireless nodes. Hybrid algorithms are more accurate than range and angle based algorithms because of additional observations. Modern WSNs consist of a small group of highly resourced wireless nodes with known locations called anchor nodes (ANs) and a large group of low resourced wireless nodes known as the target nodes (TNs). The ANs can locate themselves through GPS or they may have a predetermined location given to them during network deployment. Based on these known locations and the range/angle estimates, the TNs are localised. Since hybrid algorithms (a combination of RSS, ToA and AoA) are more accurate than other algorithms, a major portion of this thesis will focus on these approaches. Two prime hybrid signal models are discussed: i) The AoA-RSS hybrid model and ii) the AoA-ToA hybrid signal model. A hybrid AoA-ToA model is first studied and is further improved by making the model unbiased and by developing a new weighted linear least squares algorithm for AoA-ToA signal (WLLS-AoA-ToA) that capitalise on the covariance matrix of the incoming signal. A similar approach is taken in deriving a WLLS algorithm for AoA-RSS signal (WLLS-AoA-RSS). Moreover expressions of theoretical mean square error (MSE) of the location estimate for both signal models are derived. Performances of both signal models are further improved by designing an optimum anchor selection (OAS) criterion for AoA-ToA signal model and a two step optimum anchor selection (TSOAS) criterion for AoA-RSS signal model. To bound the performance of WLLS algorithms linear Cramer Rao bounds (LCRB) are derived for both models, which will be referred to as LCRB-AoA-ToA and LCRB-AoA-RSS, for AoA-ToA and AoA-RSS signal models, respectively. These hybrid localisation schemes are taken one step further and a cooperative version of these algorithms (LLS-Coop) is designed. The cooperation between the TNs significantly improves the accuracy of final estimates. However this comes at a cost that not only the ANs but the TNs must also be able to estimate AoA and ToA/RSS simultaneously. Thus another version of the same cooperative model is designed (LLS-Coop-X) which eliminates the necessity of simultaneous angle-range estimation by TNs. A third version of cooperative model is also proposed (LLS-Opt-Coop) that capitalises the covariance matrix of incoming signal for performance improvement. Moreover complexity analysis is done for all three versions of the cooperative schemes and is compared with its non cooperative counterparts. In order to extract the distance estimate from the RSS the correct knowledge of path-loss exponent (PLE) is required. In most of the studies this PLE is assumed to be accurately known, also the same and fixed PLE value is used for all communication links. This is an oversimplification of real conditions. Thus error analysis of location estimates with incorrect PLE assumptions for LLS technique is done in their respective chapters. Moreover a mobile TN and an unknown PLE vector is considered which is changing continuously due to the motion of TN. Thus the PLE vector is first estimated using the generalized pattern search (GenPS) followed by the tracking of TN via the Kalman filter (KF) and the particle filter (PF). The performance comparison in terms of root mean square error (RMSE) is also done for KF, extended Kalman filter (EKF) and PF.
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Lv, Xiaowei. "Indoor localization in wireless sensor networks." Thesis, Troyes, 2015. http://www.theses.fr/2015TROY0009/document.
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Ce manuscrit est dédié à la résolution du problème de localisation dans les réseaux de capteurs sans fil mobiles. Les méthodes développées se basent principalement sur des caractéristiques de fingerprints ainsi que sur des informations de mobilité. Les premières s'attaquent aux valeurs de RSSI entre capteurs tandis que les deuxièmes prennent en considération la mobilité des capteurs mesurée à l'aide d'accéléromètres et de gyroscopes. La combinaison des données collectées est effectuée dans le cadre de l'analyse par intervalles, ou bien du filtrage de Kalman. Les travaux proposés introduisent des modèles de mobilité d'ordres un, deux ou trois, permettant d'approximer au mieux les trajectoires des capteurs à l'aide des accélérations mesurées. Ceux-là sont couplés à l'algorithme des K plus proches voisins, d'abord dans un système centralisé. Ensuite, les modèles de mobilités sont améliorés pour prendre en compte les rotations des nœuds. Une méthode de localisation décentralisée est également proposée dans ce qui suit, s'adaptant au mécanisme fonctionnel des réseaux de capteurs de grande échelle. Enfin, ce manuscrit propose une méthode de zonage visant à déterminer les zones dans lesquelles les capteurs résident. La méthode proposée aborde le problème de zonage en utilisant à la fois la théorie des fonctions de croyance et l'analyse par intervallesThis thesis is dedicated to solve the localization problem in mobile wireless sensor networks. It works mainly with fingerprints features and inertial movements information. The former tackles the RSSIs values between sensors while the latter deals with the objets movement attitude by using accelerometer and gyroscope. The combination of both information is performed in terms of interval analysis, or Kalman filtering. The proposed work introduces three orders mobility models to approximate nodes trajectories using accelerations, combined then to the weighted K nearest neighbors algorithm in a centralized scheme. Then the mobility models are extended up to the inertial information taking into consideration the rotations of the nodes. A decentralized localization method is also proposed in the following in view of the working mechanism of large scale sensor networks. Finally, this thesis proposes a zoning localization method aiming at determining the zones in which the nodes reside. The proposed method addresses the zoning problem by using both the belief functions theory and the interval analysis
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Cui, Jin. "Data aggregation in wireless sensor networks." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI065/document.
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Depuis plusieurs années, l’agrégation de données sont considérés comme un domaine émergent et prometteur tant dans le milieu universitaire que dans l’industrie. L’énergie et la capacité du réseau seront donc économisées car il y aura moins de transmissions de données. Le travail de cette thèse s’intéresse principalement aux fonctions d’agrégation Nous faisons quatre contributions principales. Tout d’abord, nous proposons deux nouvelles métriques pour évaluer les performances des fonctions d’agrégations vue au niveau réseau : le taux d’agrégation et le facteur d’accroissement de la taille des paquets. Le taux d’agrégation est utilisé pour mesurer le gain de paquets non transmis grâce à l’agrégation tandis que le facteur d’accroissement de la taille des paquets permet d’évaluer la variation de la taille des paquets en fonction des politiques d’agrégation. Ces métriques permettent de quantifier l’apport de l’agrégation dans l’économie d’énergie et de la capacité utilisée en fonction du protocole de routage considéré et de la couche MAC retenue. Deuxièmement, pour réduire l’impact des données brutes collectées par les capteurs, nous proposons une méthode d’agrégation de données indépendante de la mesure physique et basée sur les tendances d’évolution des données. Nous montrons que cette méthode permet de faire une agrégation spatiale efficace tout en améliorant la fidélité des données agrégées. En troisième lieu, et parce que dans la plupart des travaux de la littérature, une hypothèse sur le comportement de l’application et/ou la topologie du réseau est toujours sous-entendue, nous proposons une nouvelle fonction d’agrégation agnostique de l’application et des données devant être collectées. Cette fonction est capable de s’adapter aux données mesurées et à leurs évolutions dynamiques. Enfin, nous nous intéressons aux outils pour proposer une classification des fonctions d’agrégation. Autrement dit, considérant une application donnée et une précision cible, comment choisir les meilleures fonctions d’agrégations en termes de performances. Les métriques, que nous avons proposé, sont utilisées pour mesurer la performance de la fonction, et un processus de décision markovien est utilisé pour les mesurer. Comment caractériser un ensemble de données est également discuté. Une classification est proposée dans un cadre précisWireless Sensor Networks (WSNs) have been regarded as an emerging and promising field in both academia and industry. Currently, such networks are deployed due to their unique properties, such as self-organization and ease of deployment. However, there are still some technical challenges needed to be addressed, such as energy and network capacity constraints. Data aggregation, as a fundamental solution, processes information at sensor level as a useful digest, and only transmits the digest to the sink. The energy and capacity consumptions are reduced due to less data packets transmission. As a key category of data aggregation, aggregation function, solving how to aggregate information at sensor level, is investigated in this thesis. We make four main contributions: firstly, we propose two new networking-oriented metrics to evaluate the performance of aggregation function: aggregation ratio and packet size coefficient. Aggregation ratio is used to measure the energy saving by data aggregation, and packet size coefficient allows to evaluate the network capacity change due to data aggregation. Using these metrics, we confirm that data aggregation saves energy and capacity whatever the routing or MAC protocol is used. Secondly, to reduce the impact of sensitive raw data, we propose a data-independent aggregation method which benefits from similar data evolution and achieves better recovered fidelity. Thirdly, a property-independent aggregation function is proposed to adapt the dynamic data variations. Comparing to other functions, our proposal can fit the latest raw data better and achieve real adaptability without assumption about the application and the network topology. Finally, considering a given application, a target accuracy, we classify the forecasting aggregation functions by their performances. The networking-oriented metrics are used to measure the function performance, and a Markov Decision Process is used to compute them. Dataset characterization and classification framework are also presented to guide researcher and engineer to select an appropriate functions under specific requirements
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Yoon, Suyoung. "Power Management in Wireless Sensor Networks." NCSU, 2007. http://www.lib.ncsu.edu/theses/available/etd-01232007-222425/.
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One of the unique characteristics of wireless sensor networks (WSNs) is that sensor nodes have very constrained resources. Typical sensor nodes have lower computing power, communication bandwidth, and smaller memory than other wireless devices, and operate on limited capacity batteries. Hence power efficiency is very important in WSNs because power failure of some sensor nodes may lead to total network failure. In many cases the WSNs have to operate in harsh environments without human intervention for expended period time. Thus, much research on reducing or minimizing the power consumption, and thereby increasing the network lifetime, has been performed at each layer of the network layers. In this dissertation we approach three important issues related power management in WSNs: routing, time synchronization, and medium access control (MAC). We first discuss the effect of selecting routing protocols on the lifetime of the WSNs. The maximum and minimum bounds of the lifetime with respect to the routing protocols are derived. The routing protocols corresponding to the bounds are also presented. The simulation results show that the choice of the routing protocol has very little impact on the lifetime of the network and that simple routing protocols such as shortest path routing perform very close to the the maximum bound of the lifetime of the network. Next, we propose a simple and accurate time synchronization protocol that can be used a a fundamental component of other synchronization-based protocols in WSNs. Analytical bounds on the synchronization errors of proposed protocol are discussed. The implementation results on Mica2 and Telos motes show that proposed time synchronization protocol outperforms existing ones in terms of the precision and required resources. Finally, we model the power consumption of WSN MAC protocols. We derive analytically the power consumption of well known MAC protocols for WSNs, and analyze and compare their performance. We validate the models by measuring the power consumption on Mica 2 motes and comparing those measured power consumption with the analytical results.
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Borbash, Steven A. "Design considerations in wireless sensor networks." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/1764.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2004.Thesis research directed by: Electrical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Ren, Kui. "Communication security in wireless sensor networks." Worcester, Mass. : Worcester Polytechnic Institute, 2007. http://www.wpi.edu/Pubs/ETD/Available/etd-040607-174308/.
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