Rozprawy doktorskie: „Multi-Hop Wireless Sensor Network”

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Pinto, Luis Ramos. "Aerial Multi-hop Sensor Networks". Research Showcase @ CMU, 2018. http://repository.cmu.edu/dissertations/1180.

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Unmanned Aerial Vehicles (UAVs) recently enabled a myriad of new applications spanning domains from personal entertainment and industrial inspection, to criminal surveillance and forest monitoring. A combination of sensor collection, wireless communication and path planning between multiple distributed agents is the natural way to support applications. Several small UAVs working collaboratively can rapidly provide extended reach, at low cost, and efficiently stream sensor information to operators on a ground station. A significant amount of previous work has addressed each of these topics independently, but in this dissertation we propose a holistic approach for joint coordination of networking and topology (placement of mobile nodes). Our thesis is that this approach improves user-interactive control of UAVs for live-streaming applications in terms of throughput, delay and reliability. In order to defend these claims, this dissertation begins by experimentally evaluating and modeling the wireless link between two UAVs, under different conditions. Due to limited link range, and the need for wide-area operation, the model is extended to encompass a multi-hop topology. We show that the performance of such networks using COTS devices is typically poor, and solutions must rely on coordination of network protocol and topology, simultaneously. At the network layer, we introduce a novel Time-division Multiple Access (TDMA) scheme called Distributed Variable Slot Protocol that relies on adaptive slot-length. We prove its convergence as well as its meliorated performance experimentally validated, namely 50% higher packet delivery. In terms of network topology, we show that without node placement control overall performance of the network is severely penalized, due to natural link asymmetries. We propose a novel protocol, named Dynamic Relay Placement, that is able to do both online link quality model-estimation and in a distributed fashion decide the best location for each network node, increasing throughput by 300%. Finally, we demonstrate the end-to-end system in a multi-vehicle monitoring mission. We show that coordination of multiple UAVs increases the sensor sampling rate up to 7 times in wide areas when compared to a naive approach. This work considers environmental constraints such as wind, as well as the intrinsic limitations of the vehicles such as maximum acceleration.

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Guercin, Sergio Rolando. "Performance Evaluation of Opportunistic Routing Protocols for Multi-hop Wireless Networks". Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/38904.

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Nowadays, Opportunistic Routing (OR) is widely considered to be the most important paradigm for Multi-hop wireless networks (MWNs). It exploits the broadcast nature of wireless medium to propagate information from one point to another within the network. In OR scheme, when a node has new information to share, it rst needs to set its forwarding list which include the IDs and/or any relevant information to its best suited neighboring nodes. This operation is supported by the use of appropriate metrics. Then, it executes a coordination algorithm allowing transmission reliability and high throughput among the next-hop forwarders. In this paper, we provide a comprehensive guide to understand the characteristics and challenges faced in the area of opportunistic routing protocols in MWNs. Moreover, since the planet we live on is largely covered by water, OR protocols have gained much attention during the last decade in real-time aquatic applications, such as oil/chemical spill monitoring, ocean resource management, anti-submarine missions and so on. One of the major problems in Underwater Wireless Sensor Network (UWSNs) is determining an e cient and reliable routing methodology between the source node and the destination node. Therefore, designing e cient and robust routing protocols for UWSNs became an attractive topic for researchers. This paper seeks to address in detail the key factors of underwater sensor network. Furthermore, it calls into question 5 state-of-the-art routing protocols proposed for UWSN: The Depth-Based Routing protocol (DBR), the Energy-E cient Depth-Based Routing protocol (EEDBR), the Hydraulic-pressure-based anycast routing protocol (Hydrocast), the Geographic and opportunistic routing protocol with Depth Adjustment for mobile underwater sensor networks (GEDAR), and the Void- Aware Pressure Routing for underwater sensor networks (VAPR). Finally, it covers the performance of those protocol through the use of the R programming language.

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Jung, Jin Woo. "Methods of cooperative routing to optimize the lifetime of multi-hop wireless sensor networks". Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47622.

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This dissertation presents methods of extending the network lifetime of multi-hop wireless sensor networks (WSNs) through routing that uses cooperative transmission (CT), referred to as cooperative routing. CT can have a signal-to-noise ratio (SNR) advantage over non-CT schemes through cooperative diversity and simple aggregation of transmit power, and one of its abilities is to extend the communication range of a wireless device using this SNR advantage. In this research, we use the range-extension ability of CT as a tool to mitigate the energy-hole problem of multi-hop WSNs and extend the network lifetime. The main contributions of this research are (i) an analytical model for a cooperative routing protocol with a deployment method, (ii) cooperative routing protocols that can extend the network lifetime, and (iii) formulating the lifetime-optimization problem for cooperative routing. The analytical model developed in this research theoretically proves that, in a situation where non-CT routing cannot avoid the energy-hole problem, our CT method can solve the problem. PROTECT, a CT method based on the analytical model, provides a very simple way of doing cooperative routing and can improve the lifetime of non-CT networks significantly. REACT, a cooperative routing protocol that uses the energy information of nodes, overcomes some of the limitations of PROTECT and can be applied to any existing non-CT routing protocol to improve the network lifetime. Using REACT and analytical approaches, we also show that cooperative routing can be beneficial in multi-hop energy-harvesting WSNs. By formulating and solving the lifetime-optimization problem of cooperative routing, which requires a much more sophisticated formulation than that of non-CT routing, we explore the optimal lifetime bounds and behaviors of cooperative routing. Finally, we study and design online cooperative routing methods that can perform close to the optimal cooperative routing.

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Zhang, Xin. "Network Formation and Routing for Multi-hop Wireless Ad-Hoc Networks". Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11470.

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An energy-aware on-demand Bluetooth scatternet formation and routing protocol taking into account network architecture and traffic pattern is proposed. The scatternet formation protocol is able to cope with multiple sources initiating traffic simultaneously as well as prolong network lifetime. A modified Inquiry scheme using extended ID packet is introduced for fast device discovery and power efficient propagation of route request messages with low delay. A mechanism employing POLL packets in Page processes is proposed to transfer scatternet formation and route reply information without extra overhead. In addition, the energy aware forwarding nodes selection scheme is based on local information and results in more uniform network resource utilization and improved network lifetime. Simulation results show that this protocol can provide scatternet formation with reasonable delay and with good load balance which results in prolonged network lifetime for Bluetooth-based wireless sensor networks. In this research, a metric-based scatternet formation algorithm for the Bluetooth-based sensor motes is presented. It optimizes the Bluetooth network formation from the hop distance and link quality perspectives. In addition, a smart repair mechanism is proposed to deal with link/node failure and recover the network connectivity promptly with low overhead. The experiments with the Intel Mote platform demonstrate the effectiveness of the optimizations. This research also investigates the scalability of ad hoc routing protocols in very large-scale wireless ad hoc networks. A comprehensive simulation study is conducted of the performance of an on-demand routing protocol on a very large-scale, with as many as 50,000 nodes in the network. The scalability analysis is addressed based on various network sizes, node density, traffic load, and mobility. The reasons for packet loss are analyzed and categorized at each network layer. Based on the observations, we observe the effect of the parameter selection and try to exhaust the scalability boundary of the on-demand routing protocol for wireless ad hoc networks.

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Chen, Quanjun Computer Science &amp Engineering Faculty of Engineering UNSW. "Analysis and application of hop count in multi-hop wireless ad-hoc networks". Awarded By:University of New South Wales. Computer Science & Engineering, 2009. http://handle.unsw.edu.au/1959.4/44769.

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Hop count, i.e., the number of wireless hops a packet has to go through to reach the destination, is a fundamental metric in multi-hop wireless ad-hoc networks. Network performance, such as throughput, end-to-end delay, energy consumption, and so on, depends critically on hop count. Previous work on modeling hop count is limited in making unrealistic simplifying assumptions either at the physical or network, or both layers of the communication protocol stack. A key contribution of this thesis is to present an analytical model to derive the probability distribution of hop count under realistic assumptions at both physical and network layers. Specifically, the model considers a log-normal shadowing radio propagation capable of accommodating the random signal fading observed in most wireless communication environments, and the widely used geographic routing at the network layer. Validation of the model is achieved by a comprehensive set of simulation experiments including a trace driven simulation of a real-word vehicular ad-hoc network. The model reveals that the presence of randomness in radio propagation reduces the required number of hops to reach a given destination significantly. To demonstrate the utility of the proposed hop count model, the thesis proposes three new applications which address some of the key challenges in multi-hop wireless networks. The first application derives the per-node packet forwarding load in multi-hop wireless sensor networks and reveals that the nodes in the vicinity of the base station has a significantly less forwarding load than previously thought under simplifying radio propagation and routing assumptions. The second application demonstrates that using hop count as a measure of distance traveled by a data packet, geocasting can be achieved in multi-hop wireless networks in situations when some of the network nodes do not have access to reliable location information. Finally, the proposed hop count model is used to evaluate the performance of the third application which demonstrates that the overhead of geographic routing can be reduced significantly by embracing a position update philosophy which adapts to the mobility and communication patterns of the underlying ad-hoc network.

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Mortada, Mohamad Rida. "Multi-hop routing for cognitive radio sensor network". Thesis, Brest, École nationale supérieure de techniques avancées Bretagne, 2021. http://www.theses.fr/2021ENTA0010.

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Le réseau de capteurs sans fil (WSN) se compose d'un grand nombre de minuscules dispositifs appelés nœuds, et ces nœuds sont généralement limités en puissance et ils sont déployés de manière aléatoire dans une zone géographique à des fins de surveillance. En raison du grand nombre de nœuds dans le WSN, leur demande en ressources de fréquence devient un véritable défi en raison de la rareté du spectre. La radio cognitive (CR) a été introduite pour améliorer l'efficacité spectrale. La CR classe les utilisateurs entre l'utilisateur principal (PU) qui détient une licence sur une bande passante du spectre et l'utilisateur secondaire (SU), c'est-à-dire un utilisateur opportuniste. L'intégration de CR dans WSN se traduit par un réseau de capteurs radio cognitifs (CRSN). Dans le CRSN, les nœuds se comportent comme des SU. Cependant, l'adoption du CRSN peut être confrontée à plusieurs défis. En effet, les nœuds du réseau peuvent arrêter de transmettre pour éviter toute interférence nuisible pour PU. De plus, la contrainte de consommation d'énergie doit être respectée. D'autres fonctionnalités peuvent être affectées par l'adoption du CRSN, telles que le processus de regroupement et l'agrégation de données dans le réseau, en particulier dans un CRSN basé sur un routage multi-sauts. Dans ce manuscrit, nous abordons les défis du CRSN à différents niveaux. Premièrement, le regroupement des nœuds améliore l'efficacité du réseau. En pratique, le regroupement des nœuds du réseau permet d'économiser de l'énergie lors de la transmission des données. Ainsi, nous étudions le nombre optimal de clusters dans le réseau en fonction de la consommation d'énergie lors de la transmission de données et de la détection du spectre pour prolonger la durée de vie du réseau. Ensuite, nous présentons LIBRO, un nouveau protocole de routage multi-sauts montant basé sur les informations de localisation géographique. LIBRO assure la livraison de paquets de données rectifiés dans des réseaux denses sans connaissance de la topologie ou des nœuds de chemin. Enfin, nous avons utilisé LIBRO et la technique de récupération d'énergie pour prolonger la durée de vie du CRSN. Ainsi, en résolvant un problème d'optimisation joignant la probabilité de collision, la consommation d'énergie, le délai de livraison des paquets et le taux de livraison des paquets, les paramètres appropriés sont trouvés. [Google traduction]
The Wireless Sensor Network (WSN) consists of a large number of tiny devices called nodes, and these nodes are generally limited in power and they are randomly deployed in a geographical area for monitoring purpose. Because of the large number of nodes in the WSN, their demand on the frequency resources becomes a real challenge due to the spectrum scarcity. Cognitive Radio (CR) was introduced to enhance the spectral efficiency. The CR classifies users into the Primary User (PU) that holds a license over a spectrum bandwidth, and the Secondary User (SU), i.e., an opportunistic user. The integration of CR into WSN results in a cognitive radio sensor network (CRSN). In CRSN, the nodes behave as SUs. However,the adoption of CRSN may face several challenges. Indeed, network nodes may stop transmitting to avoid any harmful interference for PU. In addition, energy consumption constraint should be respected. Other features may be impacted by the adoption of CRSN, such as the clustering process and the in-network data aggregation, especially in a multi-hop routing based CRSN. In this manuscript, we tackle the challenges of the CRSN from different levels. Firstly, clustering nodes enhances network efficiency. In practice, grouping the network nodes saves energy during data transmission. Thus, we investigate the optimal number of clusters in the network based on energy consumption during data transmission and spectrum sensing to extend network lifespan. Then, we present LIBRO, a new uplink multi-hop routing protocol based on the geographical location information. LIBRO ensures delivery of rectified data packets in dense networks without knowledge of topology or path nodes. Finally, we used LIBRO and the energy harvesting technique to extend the CRSN's lifespan. Thus, by solving an optimization problem jointing the collision probability, energy consumption, packet delivery delay and packet delivery ratio, the appropriate parameters are found

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Katayama, Masaaki, Takaya Yamazato i Zheng Huang. "Optimal Cluster Partitioning for Wireless Sensor Networks with Cooperative MISO Scheme". IEEE, 2010. http://hdl.handle.net/2237/14500.

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Hassan, Syed Ali. "Stochastic modeling of cooperative wireless multi-hop networks". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42799.

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Multi-hop wireless transmission, where radios forward the message of other radios, is becoming popular both in cellular as well as sensor networks. This research is concerned with the statistical modeling of multi-hop wireless networks that do cooperative transmission (CT). CT is a physical layer wireless communication scheme in which spatially separated wireless nodes collaborate to form a virtual array antenna for the purpose of increased reliability. The dissertation has two major parts. The first part addresses a special form of CT known as the Opportunistic Large Array (OLA). The second part addresses the signal-to-noise ratio (SNR) estimation for the purpose of recruiting nodes for CT. In an OLA transmission, the nodes from one level transmit the message signal concurrently without any coordination with each other, thereby producing transmit diversity. The receiving layer of nodes receives the message signal and repeats the process using the decode-and-forward cooperative protocol. The key contribution of this research is to model the transmissions that hop from one layer of nodes to another under the effects of channel variations, carrier frequency offsets, and path loss. It has been shown for a one-dimensional network that the successive transmission process can be modeled as a quasi-stationary Markov chain in discrete time. By studying various properties of the Markov chain, the system parameters, for instance, the transmit power of relays and distance between them can be optimized. This optimization is used to improve the performance of the system in terms of maximum throughput, range extensions, and minimum delays while delivering the data to the destination node using the multi-hop wireless communication system. A major problem for network sustainability, especially in battery-assisted networks, is that the batteries are drained pretty quickly during the operation of the network. However, in dense sensor networks, this problem can be alleviated by using a subset of nodes which take part in CT, thereby saving the network energy. SNR is an important parameter in determining which nodes to participate in CT. The more distant nodes from the source having least SNR are most suitable to transmit the message to next level. However, practical real-time SNR estimators are required to do this job. Therefore, another key contribution of this research is the design of optimal SNR estimators for synchronized as well as non-synchronized receivers, which can work with both the symbol-by-symbol Rayleigh fading channels as well as slow flat fading channels in a wireless medium.

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Zhang, Ruifeng. "Analysis of energy-delay performance in multi-hop wireless sensor networks". Lyon, INSA, 2009. http://theses.insa-lyon.fr/publication/2009ISAL0109/these.pdf.

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Wireless sensor networks (WSNs) have introduced a new paradigm of communication between devices, which are applied to different scenarios. These applications demand three important performance parameters: the end-to-end reliability, the end-to-end delay and the overall energy consumption. Due to the fundamentality of reliability in many applications, we consider it in this thesis as a hard constraint, and the other two performance criteria, i. E. , energy and delay are exploited as a couple of competing criteria. Meanwhile, since unreliability is an inherent property of wireless channels, unreliable links are efficiently exploited to improve the energy-delay performance. We propose a metric for energy efficiency: mean energy distance ratio per bit and a metric for mean delay: mean delay distance, which are combine with the unreliable link model. Using these two metrics and a realistic unreliable link model, the lower bounds and the Pareto front of energy-delay trade-off are derived for three kinds of communication schemes: traditional multi-hop communications, opportunistic communications and cooperative MIMO (CMIMO) communications in three different channels: Additive White Gaussian Noise (AWGN) channel, Rayleigh block fading channel and Rayleigh flat fading channel. The close-form expression of these low bounds are obtained and verified by the simulations in 2-dimension Poisson networks. Furthermore, these results are applied to optimise the parameters of a network including physical and protocol layers. Finally, the lower bounds of the above three communication schemes are compared in different channels respectively. The results show that in order to achieve better energy-delay performance, the corresponding communication scheme should be adopted for different channels: traditional multi-hop communications for AWGN channel, opportunistic communications for Rayleigh block fading channel and CMIMO for Rayleigh flat fading channel
Les réseaux de capteurs sans fil représentent un nouveau paradigme dans les réseaux de communication qui permet de développer de nombreuses applications allant de la surveillance de l’environnement aux applications militaires. Les performances de ces réseaux peuvent être caractérisées par trois fonctions objectives caractérisant les transmissions de bout en bout: la fiabilité, le délai et la consommation d’énergie. Cette thése a pour but de trouver les param¨¨tres optimaux afin d’améliorer les performances de la couche physique, la couche MAC ainsi que la couche protocolaire des réseaux de capteurs. Dans ce travail, nous considérons la fiabilité comme un critère prépondérant et la traitons comme une contrainte dure. La consommation d’énergie et le délai de transmission sont considérés comme des contraintes secondaires concurrentes. Comme dans tous les réseaux radio, dans les réseaux de capteurs sans fil, les canaux radios ne sont pas fiables. Pour assurer la fiabilité bout-en-bout, la plupart des travaux existants, excluent les liens radios non fiables de la communication et se focalisent sur la sélection des liens fiables. Nous nous différencions par rapport à ces travaux par la prise en compte aussi bien des liens fiables que des liens non fiables. Nous démontrons aussi que les performances telles que la consommation d’énergie et le délai de transmission sont considérablement améliorées en exploitant efficacement les liens non fiables dans les réseaux, et tout en garantissant une fiabilité de bout en bout importante. Dans une première partie de la thèse, nous analysons le compromis entre la consommation d’énergie et le délai dans les réseaux multi-saut classiques. Nous proposons deux métriques. La première exprime l’efficacité énergétique sous la forme du rapport moyen énergie-distance par bit. La seconde exprime le délai sous la forme du rapport moyen délai-distance par bit. En utilisant ces deux métriques et un modèle réaliste de liaison radio à erreur, nous déduisons l’ensemble des solutions de compromis Energie-Délai sous la forme du front de Pareto à partir des performances d’une transmission à un saut, et obtenons une formule exprimant le compromis Energie-Délai. Ces résultats sont étendus aux transmissions multi-sauts. Ensuite, nous validons la limite inférieure à l’aide de simulations, sur des réseaux 2-D, issues d’une distribution Poissonnienne. Les analyses théoriques et les simulations montrent que les liens non-fiables dans les transmissions multi-sauts contribuent à améliorer l’efficacité énergétique du système ix évanouissements rapides de Rayleigh et le canal à évanouissements de Rayleigh par blocs. Sur la base de l’expression de la borne inférieure du compromis Energie-Délai, un cadre multi-couche est fourni pour optimiser les param¨¨tres des couches physique, MAC et routage sous contrainte de délai. Dans la seconde partie de la thèse, nous abordons après la non-fiabilité, une autre caractéristique importante des canaux sans fil, qui a trait à la nature diffusante des communications radio. Les communications opportunistes exploitent ces deux propriétés pour améliorer la performance du réseau. Nous analysons les performances d’énergie et de délai des communications opportunistes ainsi que l’optimisation des paramètres connexes. D’abord, nous proposons un cadre de conception pour évaluer l’efficacitè énergétique des communications opportunistes. Ce dernier fournit une méthode pour optimiser les différents mécanismes opportunistes. Ensuite, nous déduisons la borne inférieure du compromis Energie-Délais dans les communications opportunistes, tout en tenant compte du mécanisme de sélection des candidats pour une transmission optimale. La fromule exprimant la borne inférieure est obtenue sous l’hypothèse d’un nombre fixe de candidats à retransmettre. Un algorithme de recherche du nombre optimal de candidats est également proposé. Selon les analyses théoriques obtenues, nous proposons un nouvel algorithme opportuniste pour minimiser la consommation d’énergie face à une limite de délai moyen et intégrant les couches MAC et routage. Les résultats des simulations sur les mécanismes opportunistes proposés dans un réseau issu d’une distribution Poissonnienne correspondent à la limite inférieure théorique du compromis Energie-Délai. Enfin, nous discutons l’optimisation des paramètres de la couche physique. Dans la troisième partie de la thèse, nous considérons l’aspect coopératif des transmissions. Dans les communications opportunistes, seule la coopération de réception est réalisée, tandis que dans les communications coopératives prennent en compte une coopération des deux côtés : récepteur et émetteur. Dans cette partie, nous considérons l’approche CMIMO (cooperative multiple input multiple output). D’abord, nous analysons la baisse liée au compromis Energie-Délai de CMIMO par l’exploitation d’un modèle de liaison non fiable lorsque le nombre d’émetteurs et de récepteurs coopératifs est fixe. Ensuite, nous fournissons un algorithme de recherche du nombre optimal de noeuds coopératifs de chaque côté. Enfin, nous comparons les limites inférieures de ces trois schémas de communication dans les différents canaux respectivement. Les résultats obtenus montrent que pour parvenir à une meilleure performance Energie-Délai, les mécanismes de communication suivants devraient être adoptés selon le type de canal : les communications multi-saut traditionnelles sont les plus performantes pour le canal à bruit additif blanc Gaussien, alors que les communications opportunistes le sont pour les canaux à évanouissements de Rayleigh par blocs et enfin le CMIMO pour les canaux à évanouissements rapides de Rayleigh

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Kim, Seong-Pyo Mitchell Kenneth H. "Analytical models of throughput performance over multi-hop wireless and sensor networks". Diss., UMK access, 2004.

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Thesis (Ph. D.)--School of Computing and Engineering. University of Missouri--Kansas City, 2004.
"A dissertation in telecommunications networking and computer networking." Advisor: Ken Mitchell. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed Feb. 24, 2006. Includes bibliographical references (leaves 141-146). Online version of the print edition.

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Huang, Zheng, Takaya Yamazato i Masaaki Katayama. "Energy Efficiency of Cooperative MISO Technique in Multi-hop Wireless Sensor Networks". IEEE, 2008. http://hdl.handle.net/2237/12137.

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Ait, Saadi Nadjib. "Multi-objective wireless sensor network deployment". Paris 6, 2010. http://www.theses.fr/2010PA066004.

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Lin, Jian. "Design and analysis of MAC protocols for wireless multi-hop sensor and terahertz networks". Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54866.

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The contributions of this thesis include designing and analyzing novel medium access control (MAC) protocols for two types of wireless networks: (1) duty-cycling cooperative multi-hop wireless sensor networks (MHWSNs), and (2) single-hop Terahertz networks (TeraNets). For MHWSNs, the specific contributions are two new scalable MAC protocols for alleviating the “energy-hole” problem with cooperative transmission (CT). The energy-hole is known to limit the life of battery-powered MHWSNs. The hole occurs when nodes near the Sink exhaust their energy first because their load is heavier: they must transmit packets they originate and relay packets from and to other nodes farther from the Sink. Effective techniques for extending lifetime in MHWSNs include duty cycling (DC) and, more recently introduced, cooperative transmission (CT) range extension. However, a scalable MAC protocol has not been presented that combines both. From the MAC perspective, conducting CT in an asynchronous duty-cycling network is extremely challenging. On the one hand, the source, the cooperators and the destination need to reach consensus about a wake-up period, during which CT can be performed. This dissertation develops novel MAC protocols that solve the challenge and enable CT in an asynchronous duty-cycling network. On the other hand, the question arises, “Does the energy cost of the MAC cancel out the lifetime benefits of CT range extension?” We show that CT still gives as much as 200% increase in lifetime, in spite of the MAC overhead. The second contribution of this dissertation is a comprehensive analytical framework for MHWSNs. The network performance of a MHWSN is a complex function of the traffic volume, routing protocol, MAC technique, and sensors' harvested energy if sensors are energy-harvesting (EH) enabled. The optimum performance provides a benchmark for heuristic routing and MAC protocols. However, there does not exist such an optimization framework that is able to capture all of these protocol aspects. The problems and performance metrics of non-EH networks and EH networks are different. Because the non-EH nodes depend on a battery, a suitable performance metric is the lifetime, defined as the number of packets delivered upon the first or a portion of nodes' death. Thus, the lifetime is governed by the absorbing states in a controlled dynamic system with finite decision horizon. On the other hand, the lifetime of an EH network is theoretically infinite unless the sensors are broken or destroyed. Therefore, an infinite horizon problem is formulated towards the performance of EH networks. The proposed model departs significantly from past analyses for single-hop networks that do not capture routing and past analyses for multi-hop networks that miss MAC aspects. To our knowledge, this is the first work to model the optimal performance of MHWSNs, by jointly considering MAC layer link admission, routing queuing, energy evolution, and cooperative transmission. The third contribution of this dissertation is a novel MAC protocol for Terahertz (THz) Band wireless networks, which captures the peculiarities of the THz channel and takes advantage of large antenna arrays with fast beam steering capabilities. Communication in THz Band (0.1-10THz) is envisioned as a key wireless technology in the next decade to provide Terabits-per-second links, however, the enabling technology is still in its infancy. Existing MAC protocols designed for classical wireless networks that provide Megabits-per-second to Gigabits-per-second do not scale to THz networks, because they do not capture the peculiarities of the THz Band, e.g., the very high molecular absorption loss or the very high reflection loss at THz Band frequencies. In addition, to overcome the high path loss and extend communication range, the proposed MAC design takes advantage of fast beam steering capabilities provided by the large antenna arrays, in particular, beam-switching at the pulse level.

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White, Kevin A. "Tactical network load balancing in multi-gateway wireless sensor networks". Thesis, Monterey, California: Naval Postgraduate School, 2013. http://hdl.handle.net/10945/39036.

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Approved for public release; distribution is unlimited.
A tactical wireless sensor network (WSN) is a distributed network that facilitates wireless information gathering within a region of interest. For this reason, WSNs are finding increased use by the Department of Defense. A challenge in the deployment of WSNs is the limited battery power of each sensor node. This has a significant impact on the service life of the network. In order to improve the lifespan of the network, load balancing techniques using efficient routing mechanisms must be employed such that traffic is distributed between sensor nodes and gateway(s). In this thesis, we study load balancing from a cross-layer point of view, specifically considering energy efficiency. We investigate the impact of deploying single and multiple gateways on the following established energy aware load balancing routing techniques: direct routing, minimum transmission energy, low energy adaptive cluster head routing, and zone clustering. Based on the node die out statistics observed with these protocols, we develop a novel, energy efficient zone clustering algorithm called EZone. Via extensive simulations using MATLAB, we analyze the effectiveness of these algorithms on network performance for single and multiple gateway scenarios and show that the EZone algorithm maximizes network lifetime and service area coverage.

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Raghunathan, Arun Roppel Thaddeus A. "Ad-hoc and multi-hop wireless sensor networks for activity capture in cooperative robotics". Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Summer/Theses/RAGHUNATHAN_ARUN_24.pdf.

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SAYADI, Afef. "Medium access protocol (MAC) design for wireless multi-hop ad hoc and sensor networks". Phd thesis, Institut National des Télécommunications, 2013. http://tel.archives-ouvertes.fr/tel-00997665.

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Wireless multi-hop ad hoc and sensor networks provide a promising solution to ensure ubiquitous connectivity for the Future Internet. Good network connectivity requires designing a reliable Medium Access Control (MAC) protocol, which is a challenging task in the ad hoc and sensor environments. The broadcast and shared nature of the wireless channel renders the bandwidth resources limited and expose the transmissions to relatively high collisions and loss rates. The necessity to provide guaranteed Quality of Service (QoS) to the upper layers triggered the design of conflict-free MAC protocols. The TDMA synchronization constraint is basically behind the rush of MAC protocol design based on a fixed frame size. This design shows inflexibility towards network variations and creates a network dimensioning issue that leads to a famine risk in case the network is under-dimensioned, and to a waste of resources, otherwise. Moreover, the alternative dynamic protocols provide more adaptive solutions to network topology variations at the expense of a fair access to the channel. Alongside with the efficient channel usage and the fair medium access, reducing the energy consumption represents another challenge for ad hoc and sensor networks. Solutions like node activity scheduling tend to increase the network lifetime while fulfilling the application requirements in terms of throughput and delay, for instance. Our contributions, named OSTR and S-OSTR, address the shortcomings of the medium access control protocol design in the challenging environment of wireless multi-hop ad hoc and sensor networks, respectively. For OSTR the idea consists in adopting a dynamic TDMA frame size that increases slot-by-slot according to the nodes arrival/departure to/from the network, and aiming to achieve a minimum frame size. For this end, OSTR couples three major attributes: (1) performing slot-by-slot frame size increase, (2) providing a spatial reuse scheme that favors the reuse of the same slot if possible, (3) and ensuring an on-demand frame size increase only according to the node requirements in terms of throughput. To tackle different frame sizes co-existence in the network, OSTR brings a cooperative solution that consists in fixing an appointment, a date when the frame size in the network is increased. Concerning S-OSTR, it is an amendment of OSTR for wireless sensor networks. It brings the idea of a dynamic active period, since it deploys a dynamic frame size that is built slot-by-slot according to nodes arrival to the network. S-OSTR enforces the slot-by-slot frame size increase by a node activity scheduling to prolong the inactivity period in the network, and hence prolong the overall network lifetime for wireless sensor networks. Our contributions are both based on the new dynamic TDMA frame size increase that consists in increasing the frame size slot-by-slot aiming to achieve a shorter frame size, and hence improve the channel utilization, and reduce the energy consumption. The performance analysis of OSTR and S-OSTR shows that they present good potentials to support QoS requirements, to provide energy-efficiency, to ensure fair medium access, to accommodate network topology changes and finally, to enhance robustness against scalability. The impact of this new TDMA frame size increase technique on the medium access control protocol performance is highlighted through multiple simulations of OSTR and S-OSTR. Multiple comparative studies are also handled to point out the effectiveness of this new technique and the soundness of our contributions

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17

Sayadi, Afef. "Medium access protocol (MAC) design for wireless multi-hop ad hoc and sensor networks". Thesis, Evry, Institut national des télécommunications, 2013. http://www.theses.fr/2013TELE0002/document.

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Les réseaux sans fil multi-sauts ad hoc et les réseaux de capteurs présentent une solution prometteuse pour assurer une connectivité quasi-permanente dans l'Internet du Futur. Cette connectivité, néanmoins, nécessite la conception d'un protocole d'accès au canal radio fiable, ce qui défi les caractéristiques hostiles et instables des réseaux ad hoc et des réseaux de capteurs. Cet environnement, en effet, est caractérisé par la rareté des ressources radio disponibles, la perte de la bande passante due aux collisions et aux interférences. La nécessité de garantir une meilleure qualité de service aux couches applicatives a promu la conception des protocoles MAC basés sur la technique d'accès TDMA. Essayant de contourner la contrainte d’une fine synchronisation horloge imposée par ce type de protocoles, les recherches se sont orientées vers une conception de protocoles MAC basés sur la technique TDMA dont la taille de la trame est fixe. Cependant, cette conception présente deux principaux inconvénients: d'une part elle procure une inflexibilité quant à la variation de la topologie du réseau suite aux mouvements des nœuds. D'une autre part, elle soulève un problème de dimensionnement : si la taille de la trame est surdimensionnée par rapport au nombre de nœuds présents dans le réseau, des slots non alloués apparaissent induisant la perte de la bande passante. Toutefois, si la taille de la trame est sous-dimensionnée, un risque de famine surgit. Les protocoles MAC basés sur la technique TDMA à taille de trame dynamique présentent une alternative, qui réussit à augmenter le débit au détriment d’une non-équité entre les nœuds dans le réseau. Outre l'utilisation optimale et équitable de la bande passante disponible, la réduction de la consommation d'énergie constitue un autre défi majeur pour les réseaux ad hoc et les réseaux de capteurs. Dans ce travail, deux contributions nommées OSTR et S-OSTR, sont conçues pour améliorer le débit, l'équité et la réduction de la consommation d'énergie dans l'environnement des réseaux ad hoc et des réseaux de capteurs. L'idée motrice d'OSTR consiste à augmenter la taille de la trame TDMA dynamiquement de manière à aboutir à une taille de trame réduite. Dans ce but, OSTR met en place une augmentation à la demande de la taille de la trame. Cette augmentation est établie slot par slot. OSTR se base sur une réutilisation spatiale des times slots ; i.e. un même slot peut être utilisé au même moment par plusieurs nœuds dans le réseau. Afin de prévenir les collisions dues à la coexistence de plusieurs tailles de trames au même temps dans le réseau, OSTR déploie une solution coopérative qui consiste à fixer un rendez-vous au moment duquel la taille de la trame est augmentée simultanément par tous les nœuds dans le réseau. S-OSTR constitue une adaptation du protocole OSTR à l'environnement des réseaux de capteurs. S-OSTR vise à augmenter la durée de vie du réseau. Il déploie ainsi une période d'activité dynamique qui consiste en une trame TDMA augmentant slot-par-slot. S-OSTR effectue également un ordonnancement des activités des nœuds afin de prolonger la période d'inactivité, et par suite prolonger la durée de vie du réseau. Nos deux contributions se basent sur une nouvelle technique d'augmentation dynamique de la taille de la trame TDMA qui consiste à augmenter la taille slot-par-slot. Cette technique permet d'atteindre une taille réduite, et par conséquent d’améliorer l'utilisation de la bande passante et de minimiser la consommation de l'énergie dans le réseau. L'analyse des performances d'OSTR et de S-OSTR souligne leurs potentiels pour s'adapter aux exigences des applications en termes de QoS, pour assurer un accès équitable au canal radio, pour réduire la consommation de l'énergie et pour s'adapter aux différents changements de la topologie du réseau
Wireless multi-hop ad hoc and sensor networks provide a promising solution to ensure ubiquitous connectivity for the Future Internet. Good network connectivity requires designing a reliable Medium Access Control (MAC) protocol, which is a challenging task in the ad hoc and sensor environments. The broadcast and shared nature of the wireless channel renders the bandwidth resources limited and expose the transmissions to relatively high collisions and loss rates. The necessity to provide guaranteed Quality of Service (QoS) to the upper layers triggered the design of conflict-free MAC protocols. The TDMA synchronization constraint is basically behind the rush of MAC protocol design based on a fixed frame size. This design shows inflexibility towards network variations and creates a network dimensioning issue that leads to a famine risk in case the network is under-dimensioned, and to a waste of resources, otherwise. Moreover, the alternative dynamic protocols provide more adaptive solutions to network topology variations at the expense of a fair access to the channel. Alongside with the efficient channel usage and the fair medium access, reducing the energy consumption represents another challenge for ad hoc and sensor networks. Solutions like node activity scheduling tend to increase the network lifetime while fulfilling the application requirements in terms of throughput and delay, for instance. Our contributions, named OSTR and S-OSTR, address the shortcomings of the medium access control protocol design in the challenging environment of wireless multi-hop ad hoc and sensor networks, respectively. For OSTR the idea consists in adopting a dynamic TDMA frame size that increases slot-by-slot according to the nodes arrival/departure to/from the network, and aiming to achieve a minimum frame size. For this end, OSTR couples three major attributes: (1) performing slot-by-slot frame size increase, (2) providing a spatial reuse scheme that favors the reuse of the same slot if possible, (3) and ensuring an on-demand frame size increase only according to the node requirements in terms of throughput. To tackle different frame sizes co-existence in the network, OSTR brings a cooperative solution that consists in fixing an appointment, a date when the frame size in the network is increased. Concerning S-OSTR, it is an amendment of OSTR for wireless sensor networks. It brings the idea of a dynamic active period, since it deploys a dynamic frame size that is built slot-by-slot according to nodes arrival to the network. S-OSTR enforces the slot-by-slot frame size increase by a node activity scheduling to prolong the inactivity period in the network, and hence prolong the overall network lifetime for wireless sensor networks. Our contributions are both based on the new dynamic TDMA frame size increase that consists in increasing the frame size slot-by-slot aiming to achieve a shorter frame size, and hence improve the channel utilization, and reduce the energy consumption. The performance analysis of OSTR and S-OSTR shows that they present good potentials to support QoS requirements, to provide energy-efficiency, to ensure fair medium access, to accommodate network topology changes and finally, to enhance robustness against scalability. The impact of this new TDMA frame size increase technique on the medium access control protocol performance is highlighted through multiple simulations of OSTR and S-OSTR. Multiple comparative studies are also handled to point out the effectiveness of this new technique and the soundness of our contributions

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18

Levy, Daniel M. G. H. (Daniel Matthew Guy Ho) 1979. "A wireless, low power, asynchronous, multi-sensor, temperature network". Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/28459.

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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.
Includes bibliographical references (leaves 63-64).
Wireless communication is not new. Radio and television broadcasting, as well as air traffic control have used wireless signals in their products for decades. The transmitters for these applications require large antennas and a lot of power to drive the signal to many receivers, certainly too much for any kind of battery to provide. However, a lot of new products today are moving toward wireless data transfer, and the majority of these require power levels low enough that they can run off of a battery. Examples include cellular phones, personal digital assistants, and ethernet cards for personal computers with the battery life ranging from a few hours to a few days. This thesis creates a low-power, battery-operated transmitter that reads the temperature from a sensor and then sends the data through an RF connection to a receiver, which then converts the information to human readable form. The transmitter can. perform a conversion about every minute and then go to sleep, allowing the battery to last for significantly longer than the wireless examples mentioned above. The temperature sensor system was developed and tested at the MIT High Voltage Research Laboratory. Low-power Motorola microcontrollers coded in assembly physically implement the transmitter receiver pair. A Dallas Semiconductor sensor performs the conversions, and an external system called TINI reads the data from the receiver and posts it to a web server as well as outputting it to a computer screen. Results indicate that the system works under most conditions, but long-term robustness and multiple sensor protocol need more development.
by Daniel M.G.H. Levy.
M.Eng.

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19

Cho, Sunghwan. "Cooperative analog and digital (CANDI) time synchronization protocol for large multi-hop networks". Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42915.

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For large multihop networks, the time synchronization (TS) error accumulates as the hop number increases with conventional methods, such as Timing-sync Protocol for Sensor Networks (TPSN), Reference Broadcast Synchronization (RBS), and Flooding Time Synchronization Protocol (FTSP). In this paper, to reduce the number of hops to cover the large network and exploit the spatial averaging of TS error between clusters, a novel method combining Concurrent Cooperative Transmission (CCT) and Semi-Cooperative Spectrum Fusion (SCSF) is proposed. This novel method named Cooperative Analog and Digital (CANDI) Time Synchronization protocol consists of two phases: The digital stage and the analog stage. The digital stage uses CCT to broadcast TS packet containing the time information. Cooperating nodes transmit the digitally encoded message in orthogonal channels simultaneously, so the receiver combines the multiple packet to acheive significant SNR advantage. In the analog stage, the cooperating nodes simultaneously transmit their slightly different individual estimates of the propagation time by using frequency shift modulation. Nodes receiving this signal combat fading and reduce estimation error in one step through the averaging inherent in diversity combining. Simulation results for two-dimension (2-D) networks are given to evaluate the performance of CANDI, and CANDI is compared with TPSN.

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20

Rao, Shehryar. "A COMPOSITE APPROACH TO DEAL WITH LOCALIZATION PROBLEMS IN WIRELESS SENSOR NETWORK". Thesis, Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3399.

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Universal algorithm approach is very a unique and quite useful. It can be used for most of the localization problems. A number of research studies have been taken to evaluate the different algorithms. The literature review and surveys are the key sources to get the resultant algorithm. This thesis addresses different kind of localization problems and provides a universal solution for these problems. I have done a very important literature review and some industry based surveys. The result of surveys and literature review was a bit same, so it was quite easy to find solution for those similar problems. The idea behind this universal solution is very simple. I chose two algorithms which were quite useful in the localization and merge. The resultant algorithm proves more useful than other two algorithms. The author finds it very healthy and useful algorithm. Moreover, there is need to improve some aspects. There is need to implement this algorithm practically. Some sort of professional skills are required to make this algorithm worthy.

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21

Apavatjrut, Anya. "De l'usage des codes fontaines dans les réseaux de capteurs multisauts". Phd thesis, INSA de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00708449.

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Important sujet de recherche dans les télécommunications contemporaines, les réseaux de capteurs sont des réseaux sans fil constitués de plusieurs nœuds pouvant communiquer entre eux. Chaque capteur est autonome et possède une durée de vie limitée, liée à la taille de sa batterie. Dans ce contexte, l'énergie est une ressource critique qui peut être économisée en minimisant le nombre de paquets émis. De part la nature du médium radio, les données transmises subissent des pertes du canal. La fiabilisation de données dans ce contexte n'est pas simple et devient d'autant plus problématique lorsque la taille de réseau augmente. C'est dans ce contexte que s'inscrit cette thèse qui vise à fournir une technique de fiabilisation des transmissions dans un réseau de capteur. Pour cela, nous proposons de mettre en oeuvre un mécanisme de transmission qui exploite le code fontaine. Ce code est sans rendement et les symboles de redondance sont générés à la volée. Il permet de fiabiliser la transmission avec l'utilisation d'un canal de retour limité. Le code fontaine permet d'alléger le mécanisme de contrôle des transmissions tout en assurant un lien complètement fiable, ce qui permet de réduire la latence et la consommation énergétique d'une transmission. Afin d'optimiser la performance globale du réseau, nous étudions également dans cette thèse le cas où les nœuds sont autorisés à coopérer pour le relayage multi-sauts de paquets destinés à des nœuds distants. Nous montrons dans cette thèse que la technique de codage réseau permet d'introduire de la diversité d'information et ainsi d'améliorer la performance globale de transmissions multi-sauts mono-chemin. Ce résultat a été étendu à la transmission coopérative pour laquelle nous avons à la fois pu exploiter la diversité d'information et la diversité spatiale.

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22

Yang, Fei. "Reliable and time-constrained communication in wireless sensor networks". Phd thesis, INSA de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00706211.

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Wireless Sensor Networks (WSNs) are composed of a large number of battery-powered sensor nodes that have the ability to sense the physical environment, compute the obtained information and communicate using the radio interfaces. Because sensor nodes are generally deployed on a large and wild area, they are powered by embedded battery. And it is difficult to change or recharge the battery, thus to reduce the energy consumption when sensors and protocols are designed is very important and can extend the lifetime of WSNs. So sensor nodes transmit packets with a lower transmission power (e.g. OdBm). With this transmission power, a packet can only be transmitted dozens of meters away. Therefore, when a sensor detects an event, a packet is sent in a multi-hop, ad-hoc manner (without fixed infrastructure and each sensor is able to relay the packet) to the sink (specific node which gathers information and reacts to the network situation). In this thesis, we first give an elaborate state of the art of WSNs. Then the impacts of duty-cycle and unreliable links or the performances of routing layer are analyzed. Based on the analytical results, we then propose three new simple yet effective methods to construct virtual coordinates under unreliable links in WSNs. By further taking the duty-cycle and real-time constraints into consideration we propose two cross-layer forwarding protocols which can have a greater delivery ratio and satisfy the deadline requirements. In order to have protocols for the WSNs that have dynamic topology, we then propose a robust forwarding protocol which can adapt its parameters when the topology changes. At last, we conclude this thesis and give some perspectives.

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23

Mei, Jian. "Distributed Coverage Control of Multi-Agent System in Convective–Diffusive Time Evolving Environments". Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39601.

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Using multi-agent systems to execute a variety of missions such as environmental monitoring and target tracking has been made possible by the advances in control techniques and computational capabilities. Communication abilities between agents allow them to coact and execute several coordinated missions, among which there is optimal coverage. The optimal coverage problem has several applications in engineering theory and practice, as for example in environmental monitoring, which belongs to the broad class of resource allocation problems, in which a ﬁnite number of mobile agents have to be deployed in a given spatial region with the assignment of a sub-region to each agents with respect to a suitable coverage metric. The coverage metric encodes the sensing performance of individual agent with respect to points inside the domain of interest, and a distribution of risk density. Usually the risk density function measures the relative importance assigned to inner regions. The optimal coverage problem in which the risk density is time-invariant has been widely studied in previous research. The solution to this class of problems is centroidal Voronoi tessellation, in which each agent is located on the centroid of the related Voronoi cell. However, there are many scenarios that require to be modelled by time-varying risk density rather than time-invariant one, as for example in area coverage problems where the environment evolves independently of the evolution for the robotic agents deployed to cover the area. In this work, the changing environment is modeled by a time-varying density function which is governed by a convection-diffusion equation. Mixed boundary conditions are considered to model a scenario in which a diffusive substance (e.g., oil from a leaking event or radioactive material from a nuclear accident) enters the area with convective component from the boundary. A non-autonomous feed- back law is employed whose generated trajectories maximize the coverage metric. The asymptotic stability of the multi-agent system is proven by using Barbalat’s lemma, and then theoretical predictions are illustrated by several simulations that represent idealized scenarios.

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24

Diab, Rana. "HMC-MAC : un protocole MAC hybride et multi-canal pour les réseaux de capteurs sans fil". Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22580/document.

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L'utilisation des canaux multiples améliore significativement les performances globales des réseaux de capteurs sans fil (RCSF) en permettant des transmissions parallèles sur plusieurs canaux. Cependant, la mise en place d’un protocole MAC multi-canal dans un réseau multisauts nécessite une méthode efficace d’allocation des canaux pour permettre une coordination entre les nœuds afin de partager les canaux disponibles. Dans cette thèse, nous nous intéressons à la conception d’un protocole MAC multi-canal qui répond aux exigences des applications de collecte de données à haut débit dans un réseau multi-saut. Pour ce faire, nous abordons d’abord les principales façons d’utiliser plusieurs canaux pour réaliser le partage du médium. Ensuite, nous proposons un protocole MAC multi-canal, répondant aux exigences des RCSF à haut débit, qui combine les trois techniques TDMA, CSMA et FDMA. En effet, nous utilisons une nouvelle méthode d’allocation des canaux qui permet aux nœuds de choisir le canal de réception le plus convenable dans leurs voisinages jusqu’à 3-sauts d’une façon distribuée afin de minimiser les effets des interférences et des collisions. Enfin, nous évaluons par simulation les performances de notre protocole et nous le comparons à d’autres protocoles proposés dans la littérature. Les résultats obtenus montrent l’efficacité de notre proposition dans les différents scénarios étudiés
The use of multi-channel significantly improves the overall network performance of wireless sensor networks (WSNs) by allowing parallel transmissions over multiple channels. However, the design of a multi-channel MAC protocol in a multi-hop network requires an efficient channel allocation method that allows the coordination between the nodes in order to share available channels. In this thesis, we focus on the conception of a multi-channel MAC protocol that meets the requirements of high data collection applications in a multi-hop network. In order to achieve this goal, we first present the main techniques to use multiple channels to realize medium access sharing. Then, we propose a multi-channel MAC protocol that meets the requirements of high data rate WSNs, which combines three techniques TDMA, FDMA and CSMA. Indeed, we use a new channel assignment method that enables nodes to choose the most convenient channel in their 3-hop neighborhood in a distributed manner in order to minimize the effects of interferences and collisions. Finally, we evaluate by simulation the performance of our protocol and we compare it to other protocols proposed in the literature. The results show the efficiency of our proposition in the different studied scenarios

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25

Nawaz, Shah. "Performance Study of ZigBee-based Green House Monitoring System". Thesis, Mittuniversitetet, Avdelningen för informations- och kommunikationssystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-24963.

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Wireless Sensor Network (WSN) is an emerging multi-hop wireless network technology, and the greenhouse network monitoring system is one of the key applications of WSNs in which various parameters such as temperature, humidity, pressure and power can be monitored. Here, we aim to study the performance of a simulation-based greenhouse monitoring system. To design the greenhouse monitoring system based on WSN, we have used ZigBee-based devices (end devices, routers, coordinators, and actuators. Our proposed greenhouse monitoring network has been designed and simulated using the network simulator OPNET Modeller.The investigation is split into two; first, the aim is to find the optimal Transmit (Tx) power set out at sensor nodes and second, the focus is on studying how increasing the number of sensor nodes in the same greenhouse network will affect the overall network performance. ZigBee-based greenhouses corresponded to 4 network scenarios and are simulated using OPNET Modeller in which 22 different transmit (Tx) power (22 cases) in Scenario 1 is simulated, scenario 2, 3 and 4 estimated to 63, 126, 189 number of sensor nodes respectively. Investigating the performance of the greenhouse monitoring network performance metrics such as network load, throughput, packets sent/received and packets loss are considered to be evaluated under varied transmit (Tx) power and increasing number of sensor nodes. Out of the comprehensive studies concerning simulation results for 22 different transmit (Tx) power cases underlying the greenhouse monitoring network (Scenario1), it is found that packets sent/received and packets loss perform the best with the transmitted (Tx) power falling in a range of 0.9 mWatt to 1.0 mWatt while packet sent/received and packet loss are found to perform moderately with the transmitted (Tx) power values that lie in a range of 0.05 mWatt to 0.8 mWatt. Less than 0.05 mWatt and greater than 0.01 microWatt Tx power experience, the worst performance in terms of particularly packet dropped case. For instance, in the case of the packet dropped (not joined packet, i.e., generated at the application layer but not able to join the network due to lack of Tx power), with a Tx power of 0.01 mWatt, 384 packets dropped with a Tx power of 0.02 and 0.03 mWatt, 366 packets dropped, and with a Tx power of 0.04 and 0.05, 336 packet dropped.While increasing the number of sensor nodes, as in scenario 2, 3 and 4, dealing with sensor nodes 63, 126 and 189 correspondingly, the MAC load, MAC throughput, packet sent/received in scenario 2 are found to perform better than that of scenario 3 and scenario 4, while packet loss in scenarios 2, 3 and 4 appeared to be 15%, 12% and 83% correspondingly.

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26

Tsiontsiou, Evangelia. "Multi-constrained QoS Routing and Energy Optimization for Wireless Sensor Networks". Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0340/document.

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La thèse porte sur la conception de protocoles de routage pour les réseaux de capteurs. Les problèmes de recherche du routage de données dans un réseau multi-sauts sont d’une part l’optimisation de l’énergie et d’autre part le routage sous contraintes de la qualité de service (QoS) multicritères (e.g., énergie, fiabilité, délai, …). Cette thèse apporte deux contributions par rapport à l’état de l’art : une optimisation d'un protocole de routage probabiliste pour l'équilibre de l'usage d'énergie et un protocole de routage capable de prendre en compte simultanément des métriques de QoS multiples. En effet, pour équilibrer la consommation de l’énergie du routage lorsque des chemins multiples existent, les protocoles de routage probabiliste existants affectent une probabilité de choix à chaque chemin, soit de façon empirique, soit proportionnelle au niveau de l’énergie disponible du chemin. Nous ne savions pas quelles sont les probabilités optimales qui permettent d’avoir la durée de vie maximale du réseau. Cette thèse a permis d’établir ces probabilités optimales à l’aide de la modélisation sous forme d’un problème d’optimisation linéaire. Quant au problème du routage multicritères, bien que des métriques multiples soient définies par RPL (un standard d’IETF), les protocoles existants choisissent la route soit sur une métrique, soit sur une fonction de coût combinant plusieurs (qui introduit par conséquent un biais de pondération), mais jamais plusieurs simultanément. Dans cette thèse, nous avons d’abord évalué numériquement les performances de l’approche « operator calculus algebra » introduit par R. Schott et S. Staples qui définit un algorithme efficace permettant de trouver tous les chemins satisfaisant les contraintes multiples dans un graphe , puis dérivé une version distribuée sur laquelle nous avons conçu un protocole de routage multi-métriques. Ces deux contributions ont été implémentées dans l’environnement Contiki et émulées/simulées sous Cooja (un logiciel permettant de simuler des protocoles des réseaux de capteurs)
In this thesis, we focus on routing protocols for Wireless Sensor Networks (WSNs). The main research problems in the domain of routing data packets in a multi-hop network are the optimisation of the energy and the routing under multi-criteria QoS constraints (e.g., energy, reliability, delay, …). To address these problems, this dissertation proposes two contributions. Firstly, an optimal probabilistic routing protocol which balances the usage of energy and secondly, a routing protocol which is able to simultaneously take into account multiple QoS metrics. In fact, for balancing the energy consumption between the multiple existing links, the existing probabilistic routing protocols assign a probability to each link, either in an empirical way or depending on proportional energy level of the path. We did not know what are the optimal probabilities which lead to the optimal network lifetime. Our first contribution proposes optimal probabilities by modeling and solving a linear programming problem. As for the multi-constrainted QoS routing problem, multiple metrics are defined by RPL (a standard of IETF) but the existing protocols chose paths either according to only one metric or using a single aggregated function with multiple metrics, but never all the metrics simultaneously. In this dissertation, we first evaluate the performance of the operator calculus algebra introduced by R. Schott and S. Staples which defines an efficient algorithm allowing to find all the paths which satisfy the multiple constraints in a graph, and secondly we proposed a distributed version of this algorithm based on which a routing protocol has been designed. Both contributions are implemented in Contiki environment and simulated/emulated under Cooja (a software designed for simulating protocols of WSNs)

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27

Rahat, Alma As-Aad Mohammad. "Hybrid evolutionary routing optimisation for wireless sensor mesh networks". Thesis, University of Exeter, 2015. http://hdl.handle.net/10871/21330.

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Battery powered wireless sensors are widely used in industrial and regulatory monitoring applications. This is primarily due to the ease of installation and the ability to monitor areas that are difficult to access. Additionally, they can be left unattended for long periods of time. However, there are many challenges to successful deployments of wireless sensor networks (WSNs). In this thesis we draw attention to two major challenges. Firstly, with a view to extending network range, modern WSNs use mesh network topologies, where data is sent either directly or by relaying data from node-to-node en route to the central base station. The additional load of relaying other nodes’ data is expensive in terms of energy consumption, and depending on the routes taken some nodes may be heavily loaded. Hence, it is crucial to locate routes that achieve energy efficiency in the network and extend the time before the first node exhausts its battery, thus improving the network lifetime. Secondly, WSNs operate in a dynamic radio environment. With changing conditions, such as modified buildings or the passage of people, links may fail and data will be lost as a consequence. Therefore in addition to finding energy efficient routes, it is important to locate combinations of routes that are robust to the failure of radio links. Dealing with these challenges presents a routing optimisation problem with multiple objectives: find good routes to ensure energy efficiency, extend network lifetime and improve robustness. This is however an NP-hard problem, and thus polynomial time algorithms to solve this problem are unavailable. Therefore we propose hybrid evolutionary approaches to approximate the optimal trade-offs between these objectives. In our approach, we use novel search space pruning methods for network graphs, based on k-shortest paths, partially and edge disjoint paths, and graph reduction to combat the combinatorial explosion in search space size and consequently conduct rapid optimisation. The proposed methods can successfully approximate optimal Pareto fronts. The estimated fronts contain a wide range of robust and energy efficient routes. The fronts typically also include solutions with a network lifetime close to the optimal lifetime if the number of routes per nodes were unconstrained. These methods are demonstrated in a real network deployed at the Victoria & Albert Museum, London, UK.

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Zhao, Yi. "Combination of Wireless sensor network and artifical neuronal network : a new approach of modeling". Thesis, Toulon, 2013. http://www.theses.fr/2013TOUL0013/document.

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Face à la limitation de la modélisation paramétrique, nous avons proposé dans cette thèse une procédure standard pour combiner les données reçues a partir de Réseaux de capteurs sans fils (WSN) pour modéliser a l'aide de Réseaux de Neurones Artificiels (ANN). Des expériences sur la modélisation thermique ont permis de démontrer que la combinaison de WSN et d'ANN est capable de produire des modèles thermiques précis. Une nouvelle méthode de formation "Multi-Pattern Cross Training" (MPCT) a également été introduite dans ce travail. Cette méthode permet de fusionner les informations provenant de différentes sources de données d'entraînements indépendants (patterns) en un seul modèle ANN. D'autres expériences ont montré que les modèles formés par la méthode MPCT fournissent une meilleure performance de généralisation et que les erreurs de prévision sont réduites. De plus, le modèle de réseau neuronal basé sur la méthode MPCT a montré des avantages importants dans le multi-variable Model Prédictive Control (MPC). Les simulations numériques indiquent que le MPC basé sur le MPCT a surpassé le MPC multi-modèles au niveau de l'efficacité du contrôle
A Wireless Sensor Network (WSN) consisting of autonomous sensor nodes can provide a rich stream of sensor data representing physical measurements. A well built Artificial Neural Network (ANN) model needs sufficient training data sources. Facing the limitation of traditional parametric modeling, this paper proposes a standard procedure of combining ANN and WSN sensor data in modeling. Experiments on indoor thermal modeling demonstrated that WSN together with ANN can lead to accurate fine grained indoor thermal models. A new training method "Multi-Pattern Cross Training" (MPCT) is also introduced in this work. This training method makes it possible to merge knowledge from different independent training data sources (patterns) into a single ANN model. Further experiments demonstrated that models trained by MPCT method shew better generalization performance and lower prediction errors in tests using different data sets. Also the MPCT based Neural Network Model has shown advantages in multi-variable Neural Network based Model Predictive Control (NNMPC). Software simulation and application results indicate that MPCT implemented NNMPC outperformed Multiple models based NNMPC in online control efficiency

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Bonifácio, Tatiana Giorgenon. "Implementação de um protocolo mesh multi-hop baseado em algoritmo de roteamento geográfico para redes de sensores sem fio". Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/18/18153/tde-04032011-150720/.

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As tecnologias de redes sem fio passaram a atender não só às aplicações corporativas mais sofisticadas como também àquelas envolvendo desde o rastreamento de animais, monitoramento de estruturas e automação industrial até o gerenciamento de utilidades urbanas. Este projeto de pesquisa aborda o desenvolvimento de um protocolo de rede mesh multi-hop segundo a especificação IEEE 802.15.4, com o uso de coordenadas geográficas de cada nó para o roteamento de dados em aplicações de iluminação pública. Para o desenvolvimento do protocolo de rede, é considerada a biblioteca de rotinas de interface de rede denominada Simple MAC (SMAC). Tal biblioteca pode ser utilizada para a elaboração do protocolo de roteamento geográfico destinado à rede mesh multi-hop. Paralelamente, propõe-se a descrição de um método a ser adotado para a inserção do protocolo de roteamento geográfico no SMAC. Os códigos, desenvolvidos em linguagem de programação C, são portados para a plataforma de desenvolvimento dos nós de comunicação de um toolkit específico e submetidos a ensaios experimentais. Os resultados englobam a geração de conhecimento teórico e prático a respeito das redes de sensores sem fio, bem como o desenvolvimento de um software aberto para este tipo de rede. As propriedades de auto-organização da rede, robustez e baixa latência são comprovadas nos ensaios experimentais.
The technologies of wireless networks have to serve not only the most sophisticated business applications but also those that involve the tracking of animals, monitoring of structures, industrial automation and the management of urban utilities. This research project addresses the development of a protocol for multi-hop mesh network according to IEEE 802.15.4, with the use of geographical coordinates of each node for routing data in applications such as street lighting. In order to develop the network protocol, the routines library of the network interface, called Simple MAC (SMAC), is considered. This library can be used for establishing the geographic routing protocol destined for the multi-hop mesh network. In parallel it is proposed to describe a method to be adopted for the inclusion of geographic routing protocol in SMAC. The codes, developed in C programming language, are ported to the development platform of communication nodes of a specific toolkit and subjected to experimental tests. The results include the generation of theoretical and practical knowledge regarding the wireless sensor networks, as well as the development of open software for this type of network. The properties of self-organization of the network, robustness and low latency are proven in experimental tests.

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Baccelli, Emmanuel. "IP-Disruptive Wireless Networking: Integration in the Internet". Habilitation à diriger des recherches, Université Pierre et Marie Curie - Paris VI, 2012. http://tel.archives-ouvertes.fr/tel-00770791.

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The super collision between the Internet phenomenon and the wireless communication revolution gives birth to a wealth of novel research problems, design challenges and standardization activities. Within this domain, spontaneous wireless IP networking are probably the most extreme example of new ''particles'' born from the collision. Indeed, these particles defy the laws of the Internet in many ways. The absorption of such peculiar particles in the global IP network has already started thanks to pioneering algorithmic and protocol work -- for instance OLSR -- and through the deployment of wireless mesh networks around the world, such as urban community wireless networks. With the recent revolutions in North Africa, and movements such as Occupy Wall Street, the prospect of spontaneous wireless IP networking has become even more attractive on social and political grounds. Dedicated conferences have recently been organized, and as a result, ambitious, multi-million dollar initiatives have been launched (e.g. the US Government-funded project Commotion Wireless, or the EU-funded initiative CONFINE). However, spontaneous IP wireless networks are not yet widely deployed because pioneer work such as OLSR is vastly insufficient to fully bridge the gap between the Internet and these new networks. This thesis presents work that analyzes this gap and proposes some solutions as to how to bridge it. The focus is put on three domains: a first part presents work in the domain of wireless mesh and ad hoc networks. A second part presents work on sensor networks and in the Internet of Things. And the last part presents work in the domain of delay tolerant networking and vehicular networks.

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Diallo, Chérif. "Techniques d’amélioration du routage et de la formation des clusters multi-sauts dans les réseaux de capteurs sans fil". Thesis, Evry, Institut national des télécommunications, 2010. http://www.theses.fr/2010TELE0017/document.

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Cette thèse a pour objectif de développer des techniques permettant d'améliorer l'efficacité énergétique des réseaux de capteurs destinés à la surveillance d'une chaîne de froid. La première approche développée dans cette thèse concerne la phase de transport des produits alimentaires. Les protocoles proposés VBS, WaS et eVBS s'adressent à la problématique posée par l'absence de station de base permanente au sein du petit réseau déployé dans un camion où les nœuds sont en visibilité directe. Ces méthodes ont le triple avantage de présenter un faible overhead, d'accroître l'ergonomie de l'application et l'intérêt économique du réseau. Dans l'état de l'art, il n'existe pas de déploiement de très grands réseaux de capteurs sans fil destinés à la surveillance d'une chaîne de froid. Le cœur de cette thèse se positionne ainsi autour de la problématique du passage à l'échelle, en proposant plusieurs approches permettant d'améliorer l'efficacité énergétique du réseau. Ainsi des optimisations du routage et des techniques de formation de clusters multi-sauts sont proposées grâce à quelques idées originales d'utilisation de l'indicateur de la qualité de lien. Le protocole L2RP de routage par répartition de charge, le mécanisme SNCR de réduction des clusters singletons ainsi que le protocole LQI-DCP d'optimisation du positionnement des chefs de clusters sont des contributions de cette thèse exploitant le LQI afin d'accroître l'efficacité énergétique du réseau. De plus, nous avons montré que l'heuristique MaxMin de formation de clusters multi-sauts n'est pas compatible avec la topologie de déploiement en grille qui est la plus fréquente dans les architectures de réseaux de capteurs
Wireless Sensor Networks (WSN) are used today in many applications that differ in their own objectives and specific constraints. However the common challenge in designing WSN applications comes from the specific constraints of micro-sensors because of their limited physical resources such as limited battery lifetime, weak computational capability and small memory capacity. This thesis aims to develop techniques to improve the energy efficiency of wireless sensor networks intended to a cold chain monitoring application. In such area, existing solutions consist of walled temperature recorders in warehouses and transport vehicles, which essentially control the room storage temperature which is not necessarily the product one. By integrating wireless micro-sensor devices with pallets and trays, one allows full real-time tracking of the cold chain originating from factories to the shelves of retailers. The first approach developed in this thesis concerns the phase of transporting food. The proposed VBS, WaS and eVBS protocols address the main issue resulting from the absence of a permanent base station in the small network deployed in a truck where nodes are generally in the same transmission range. These methods have the triple advantages of having a low overhead, increasing the ergonomics of the application and enhancing the economic interest of the network. In the state of art, there is no very large scale deployment of WSN for a cold chain monitoring system. Thus, the core of this thesis addresses the scalability issues by offering several ways to improve overall energy efficiency of the network. So, routing techniques improvement and efficient multi-hop clustering protocols are proposed through some original ideas using the Link Quality Indicator (LQI) provided by the MAC sublayer. The LQI is defined in the IEEE 802.15.4 standard in which its context of use is not specified. The link reliability based routing protocol (L2RP) which load balances the traffic between nodes, the single-node cluster reduction mechanism (SNCR) and the LQI-DCP multi-hop clusters formation protocol which improves clusterhead locations are some of contributions of this thesis which exploit the LQI to, significantly, increase the WSN efficiency. We also show that the MaxMin d-cluster formation heuristic does not support the grid deployment topology which is the more often used in WSN architectures

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Ali, Mohamad Jaafar. "Wireless body area networks : co-channel interference mitigation & avoidance". Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCB252/document.

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L’amélioration de la qualité et de l’efficacité en santé est un réel enjeu sociétal. Elle implique la surveillance continue des paramètres vitaux ou de l’état mental du sujet. Les champs d’applications sont vastes : l’application la plus importante est la surveillance des patients à distance. Les avancées en micro-électronique, capteurs et réseaux sans-fil permettent aujourd’hui le développement de systèmes ambulatoires performants pour le monitoring de paramètres physiologiques, capables de prendre en compte d’importantes contraintes techniques : forte intégration pour la réduction de la taille et faible consommation pour une plus grande autonomie [1]. Cependant, la conception de ce type de réseaux de capteurs médicaux WBANs (Wireles Body Area Networks) se heurte à un certain nombre de difficultés techniques, provenant des contraintes imposées par les capacités réduites des capteurs individuels : basse puissance, énergie limitée et faible capacité de stockage. Ces difficultés requièrent des solutions différentes, encore très embryonnaires, selon l’application visée (monitoring à but médical). La forte mobilité et le changement rapide de la topologie du réseau dévoilent un verrou scientifique et social. En outre, l’interférence de différents capteurs constituant le WBAN augmente la difficulté de la mise en place de ce type de réseaux. De nombreuses solutions dans la littérature ont été étudiées, comme nous allons illustrer dans ce manuscrit, néanmoins elles restent limitées. Nous nous intéresserons tout particulièrement à la gestion des interférences Intra- et Inter-WBAN, leur impacte sur la fiabilité des transmissions (des liens) et la durée de vie de ce type de réseaux. Plus précisément, nous abordons ces problématiques en se basant sur des modélisations théoriques et analytiques et avec une conception pratique des solutions proposées. Afin d’atteindre les objectifs cités ci-dessous, nous abordons quatre solutions : • Une gestion des interférences intra-WBAN • Une gestion coopérative des interférences Inter-WBAN • Une gestion non coopérative des interférences, Inter-WBAN • Une gestion des interférences WBAN dans un contexte IoT Dans la première partie de cette thèse et afin de répondre en partie aux problèmes de gestion des interférences Intra-WBAN. Nous présentons deux mécanismes pour le WBAN : (a) CFTIM qui alloue dynamiquement des slots et des canaux dit- stables (avec un taux d’interférences le bas possible dans le temps) pour réduire les interférences intra-WBAN. (b) IAA ajuste dynamiquement la taille du superframe et limite le nombre de canaux à 2 pour abaisser les interférences Intra-WBAN et ainsi économiser l’énergie. Une validation avec un model probabiliste est proposé afin de valider théoriquement l’efficacité de notre solution. Les résultats de la simulation démontrent l’efficacité du CFTIM et de l’IAA en termes de réduction de la probabilité d’interférence, l’extension de la durée de vie du réseau et l’amélioration du débit et de la fiabilité des transmissions. Notre seconde contribution, propose une gestion coopératives des interférences Inter-WBAN en utilisant des codes orthogonaux. Motivé par un approvisionnement temporel distribué basé sur la norme [2] IEEE 802.15.6, nous proposons deux solutions. (a) DTRC qui fournit à chaque WBAN les connaissances sur les superframes qui se chevauchent. Le second, (b) OCAIM qui attribue des codes orthogonaux aux capteurs appartenant à deux listes de groupe de capteur en interférences de deux WBAN différents (SIL). Les résultats démontrent qu’OCAIM diminue les interférences, améliore le débit et préserve la ressources énergétiques. La troisième partie nous a permis d’aborder la gestion des interférences, mais cette fois ci d’une manière non-coopérative en se basant sur l’affectation couple Slot/Canal. Plus précisément, nous proposons deux schémas basés sur les carrés latins. (...)
A Wireless Body Area Network (WBAN) is a short-range network that consists of a coordinator (Crd) and a collection of low-power sensors that can be implanted in or attached to the human body. Basically, WBANs can provide real-time patient monitoring and serve in various applications such as ubiquitous health-care, consumer electronics, military, sports, etc. [1]. As the license-free 2.4 GHz ISM band is widely used among WBANs and across other wireless technologies, the fundamental problem is to mitigate the resulting co-channel interference. Other serious problems are to extend the network lifetime and to ensure reliable transmission within WBANs, which is an urgent requirement for health-care applications. Therefore, in this thesis, we conduct a systematic research on a few number of research problems related to radio co-channel interference, energy consumption, and network reliability. Specifically, we address the following problems ranging from theoretical modeling and analysis to practical protocol design: • Intra-WBAN interference mitigation and avoidance • Cooperative inter-WBAN interference mitigation and avoidance • Non-cooperative inter-WBAN interference mitigation and avoidance • Interference mitigation and avoidance in WBANs with IoT Firstly, to mitigate the intra-WBAN interference, we present two mechanisms for a WBAN. The first is called CSMA to Flexible TDMA combination for Interference Mitigation, namely, CFTIM, which dynamically allocates time-slots and stable channels to lower the intra-WBAN interference. The second is called Interference Avoidance Algorithm, namely IAA that dynamically adjusts the superframe length and limits the number of channels to 2 to lower the intra-WBAN interference and save energy. Theoretically, we derive a probabilistic model that proves the SINR outage probability is lowered. Simulation results demonstrate the effectiveness and the efficiency of CFTIM and IAA in terms of lowering the probability of interference, extending network lifetime, improving throughput and reliability. Secondly, we address the problem of interference among cooperative WBANs through using orthogonal codes. Motivated by distributed time provisioning supported in IEEE 802.15.6 standard [2], we propose two schemes. The first is called Distributed Time Correlation Reference, namely, DTRC that provides each WBAN with the knowledge about which superframes overlap with each other. The second is called Orthogonal Code Allocation Algorithm for Interference Mitigation, namely, OCAIM, that allocates orthogonal codes to interfering sensors belonging to sensor interference lists (SILs), which are generated based on the exchange of power-based information among WBANs. Mathematically, we derive the successful and collision probabilities of frames transmissions. Extensive simulations are conducted and the results demonstrate that OCAIM can diminish the interference, improve the throughput and save the power resource. Thirdly, we address the problem of co-channel interference among non-cooperative WBANs through time-slot and channel hopping. Specifically, we propose two schemes that are based on Latin rectangles. The first is called Distributed Algorithm for Interference mitigation using Latin rectangles, namely, DAIL that allocates a single channel to a timeslot combination to each sensor to diminish inter-WBAN interference and to yield better schedules of the medium access within each WBAN. The second is called Channel Hopping for Interference Mitigation, namely, CHIM, which generates a predictable interference free transmission schedule for all sensors within a WBAN. CHIM applies the channel switching only when a sensor experiences interference to save the power resource. Furthermore, we present an analytical model that derives bounds on collision probability and throughput for sensors transmissions. (...)

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Pulugurtha, Satya Venkata Sidhi Vinayak, i Kishore Kumar Atragadda. "A Multi-layered Routing Technique for Sensing Train Integrity and Composition". Thesis, Blekinge Tekniska Högskola, Institutionen för tillämpad signalbehandling, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-19489.

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This thesis deals with an approach to monitor the integrity and composition of cargo wagons withthe help of Wireless Sensor Network (WSN). The WSN is to be fully automated that does notneed any human intervention for gathering information about the composition and integrity ofcargo trains, which are the most necessary factors for Cargo Logistics. The nodes are deployed inevery wagon along with the master node in the main locomotive. The master node in thelocomotive gets the information from the slave nodes placed in the cargo wagons in successivesessions. If there are any unexpected changes in the composition of the wagon, theacknowledgments to the locomotive will be terminated. This approach mainly focuses ondesigning energy-efficient as well as cost-efficient WSN. The designed WSN can accommodateto changes, which are caused by external conditions. The designed approach is also scalable. TheWSN is designed with the usage of Zigbee mesh protocol with Arduino Microcontroller as thebrain of the system that is validated and verified in the indoor, imitating the railway environment.

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Meghji, Mahir Lumumba. "On a Joint Physical Layer and Medium Access Control Sublayer Design for Efficient Wireless Sensor Networks and Applications". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/590.

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Wireless sensor networks (WSNs) are distributed networks comprising small sensing devices equipped with a processor, memory, power source, and often with the capability for short range wireless communication. These networks are used in various applications, and have created interest in WSN research and commercial uses, including industrial, scientific, household, military, medical and environmental domains. These initiatives have also been stimulated by the finalisation of the IEEE 802.15.4 standard, which defines the medium access control (MAC) and physical layer (PHY) for low-rate wireless personal area networks (LR-WPAN). Future applications may require large WSNs consisting of huge numbers of inexpensive wireless sensor nodes with limited resources (energy, bandwidth), operating in harsh environmental conditions. WSNs must perform reliably despite novel resource constraints including limited bandwidth, channel errors, and nodes that have limited operating energy. Improving resource utilisation and quality-of-service (QoS), in terms of reliable connectivity and energy efficiency, are major challenges in WSNs. Hence, the development of new WSN applications with severe resource constraints will require innovative solutions to overcome the above issues as well as improving the robustness of network components, and developing sustainable and cost effective implementation models. The main purpose of this research is to investigate methods for improving the performance of WSNs to maintain reliable network connectivity, scalability and energy efficiency. The study focuses on the IEEE 802.15.4 MAC/PHY layers and the carrier sense multiple access with collision avoidance (CSMA/CA) based networks. First, transmission power control (TPC) is investigated in multi and single-hop WSNs using typical hardware platform parameters via simulation and numerical analysis. A novel approach to testing TPC at the physical layer is developed, and results show that contrary to what has been reported from previous studies, in multi-hop networks TPC does not save energy. Next, the network initialization/self-configuration phase is addressed through investigation of the 802.15.4 MAC beacon interval setting and the number of associating nodes, in terms of association delay with the coordinator. The results raise doubt whether that the association energy consumption will outweigh the benefit of duty cycle power management for larger beacon intervals as the number of associating nodes increases. The third main contribution of this thesis is a new cross layer (PHY-MAC) design to improve network energy efficiency, reliability and scalability by minimising packet collisions due to hidden nodes. This is undertaken in response to findings in this thesis on the IEEE 802.15.4 MAC performance in the presence of hidden nodes. Specifically, simulation results show that it is the random backoff exponent that is of paramount importance for resolving collisions and not the number of times the channel is sensed before transmitting. However, the random backoff is ineffective in the presence of hidden nodes. The proposed design uses a new algorithm to increase the sensing coverage area, and therefore greatly reduces the chance of packet collisions due to hidden nodes. Moreover, the design uses a new dynamic transmission power control (TPC) to further reduce energy consumption and interference. The above proposed changes can smoothly coexist with the legacy 802.15.4 CSMA/CA. Finally, an improved two dimensional discrete time Markov chain model is proposed to capture the performance of the slotted 802.15.4 CSMA/CA. This model rectifies minor issues apparent in previous studies. The relationship derived for the successful transmission probability, throughput and average energy consumption, will provide better performance predictions. It will also offer greater insight into the strengths and weaknesses of the MAC operation, and possible enhancement opportunities. Overall, the work presented in this thesis provides several significant insights into WSN performance improvements with both existing protocols and newly designed protocols. Finally, some of the numerous challenges for future research are described.

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Al-Olimat, Hussein S. "Optimizing Cloudlet Scheduling and Wireless Sensor Localization using Computational Intelligence Techniques". University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1403922600.

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Peng, Tingqing. "WSN Routing Schedule Based on Energy-aware Adaptation". Thesis, Mittuniversitetet, Institutionen för informationssystem och –teknologi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-39223.

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In view of the problem of uneven load distribution and energy consumption among nodes in a multi-hop wireless sensor network, this research constructs the routing schedule problem as a MOP (Multi-objective Optimization Problem), and proposed an energy-aware routing optimization scheme RDSEGA based on multi-objective optimization. In this scheme, in order to avoid the searching space explosion problem caused by the increase of nodes, KSP Yen's algorithm was applied to prune the searching space, and the candidate paths selected after pruning are recoded based on priority. Then adopted the improved strengthen elitist genetic algorithm to get the entire network routing optimization scheme with the best energy efficiency. At the same time, in view of the problem of routing discontinuity in the process of path crossover and mutation, new crossover and mutation method was proposed that based on the gene fragments connected by the adjacent node or the same node to maximize the effectiveness of the evolution result. The experimental results prove that the scheme reduced the energy consumption of nodes in the network, the load between nodes becomes more balanced, and the working time of the network has been prolonged nearly 40% after the optimization. This brings convenience to practical applications, especially for those that are inconvenient to replace nodes.

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Benatia, Mohamed Amin. "Optimisation multi-objectives d’une infrastructure réseau dédiée aux bâtiments intelligents". Thesis, Rouen, INSA, 2016. http://www.theses.fr/2016ISAM0024/document.

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Au cours de cette thèse, nous avons étudié le problème de déploiement des Réseaux de Capteurs Sans-Fil (RCSF) pour des applications indoor tel que le bâtiment intelligent. Le but de notre travail était de développer un outil de déploiement capable d'assister les concepteurs de RCSF lors de la phase de déploiement de ces derniers. Nous avons commencé cette thèse par la modélisation de tous les paramètres qui interviennent lors du déploiement des RCSF, à savoir : coût, connectivité, couverture et durée de vie. Par la suite, nous avons implémenté cinq algorithmes d'optimisation, dont trois multi-objectifs afin de résoudre le problème de déploiement. Deux cas d'études réelles (grande et petite instance) ont été identifiés afin de tester ces algorithmes. Les résultats obtenus ont montré que ces algorithmes sont efficaces quand il s'agit d'un petit bâtiment (petit espace). Par contre, dès que la surface du bâtiment augmente les performances des algorithmes étudiés se dégradent. Pour répondre à cela, nous avons développé et implémenté un algorithme d'optimisation multi-objectifs hybride. Cet algorithme se base sur des notions de clustering et d'analyse de données afin de limiter le nombre d'évaluations directes qu'entreprennent ces méthodes pendant chaque itération. Afin d'assurer cette limitation d'évaluation les fonctions de fitness sont approximées grâce aux réseaux de neurones et l'algorithme de classification K-means. Les résultats obtenus ont montré une très bonne performance sur les deux instances de tailles différentes. Ces résultats ont été comparés à ceux obtenus avec les méthodes classiques utilisées et sont compétitives et prometteuses
In this thesis, we studied the Wireless Sensor Network deployment for indoor environments with a focus on smart building application. The goal of our work was to develop a WSN deployment tool which is able to assist network designers in the deployment phase. We begin this thesis with network modeling of all the deployment parameters and requirement, such as : cost, coverage, connectivity and network lifetime. Thereafter, we implement five optimisation methods, including three multi-objective optimization agorithms, to resolve WSN deployment problem. Then, two realistics study cases were identified to test the performances of the aforementioned algorithms. The obtained results shows that these algorithms are very efficient for deploying a small scale network in small buildings. However, when the building surface becomes more important the algorithms tends to converge to local optimum while consuming high processing time. To resolve this problem, we develop and implement a new Hybrid multi-objectif optimization algorithm wich limits the number of direct evaluation. This algorithm is based on data-mining methods (Artificial Neural Networks and K-means) and tries to approximate the fitness value of each individual in each generation. At every generation of the algorithm, the population is divided to K clusters and we evaluate only the closest individual to cluster centroide. The fitness value of the rest of population is approximated using a trained ANN. A comparative study was made and the obtained results show that our method outperformes others in the two sudy cases (small and big buildings)

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Niklasson, Johan, i Oskar Hahr. "Topology optimization for distributed consensus in multi-agent networks". Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-259352.

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Distributed networks, meaning a network in which several agents work together unanimously to perform some task in order to reach goals has become a field with a wide range of applications. One such applications may exist in the form of drones with a purpose of observing and detecting forest fires. In such applications it can be of paramount importance to be able to agree over some opinions or values between the agents. This value could be something such as event detection or a general direction to fly in. However in such a network there might not exist a central hub and it would not be possible for all drones to communicate directly with each other. In order for such a network to be able to reach consensus or agreement, values have to be exchanged between the agents. This thesis focuses on a subset of this problem known as distributed averaging. In the thesis it is investigated how a networks ability to detect forest fires and communicate both efficiently and quickly can change when the number of agents are adjusted in the network. The results showed that, when operating in a fixed area, for a small network of drones the increasing effective energy cost per drone were higher, than that of a larger network. It was also discovered that the speed at which a network could reach an agreement was not necessarily affected by the size of the network. But as the field area being observed was increased, adverse effects were observed in terms of communication and event detection.
Distribuerade nätverk bestående av flera agenter som har som uppgift att tillsammans nå gemensamma resultat har blivit allt mer populärt. Ett sådant användningsområde är hur drönare kan användas för att observera och upptäcka skogsbränder över en given yta. I en sådan tillämpning är det av stor vikt att drönarnätverket kan kommunicera och kongruera över värden nätverket delar med varandra. Dessa värden kan representera händelser som nätverket har som uppgift att upptäcka eller en riktning för drönarna att flyga i. Det är inte alltid garanterat att det finns en central kommunikationscentral för sådana nätverk, utan blir beroende på att kommunicera med varandra för att utbyta och kongruera över värden. Den här rapporten fokuserar på en avgränsad del av det ovanstående problemet som kallas för distribuerat konsensusvärde (eng. distributed averaging). Rapporten undersöker hur ett sådant nätverks konvergeringsförmåga, totala energikostnad samt täckning påverkas när fler drönare tillförs till nätverket. När arbetsytan var satt till statisk storlek visade resultaten att den tillförda energikostnaden per drönare var högre för små nätverk än för större nätverk. Det visades också att hastigheten som nätverket når ett kongruerande värde inte nödvändigtvis påverkas av storleken av nätverket. När arbetsytan ökade i takt med storleken på nätverket observerades däremot motsatt effekt för energikostnad och hastigheten för att nå ett konsensusvärde.

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Scofield, Dan. "Hop-by-hop transport control for multi-hop wireless networks /". Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1812.pdf.

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Sarr, Moussa Dethié. "Spécification d’un mécanisme de construction automatique de topologies et d'adressage permettant la gestion dynamique des réseaux de capteurs sans fil linéaires". Thesis, Université Clermont Auvergne‎ (2017-2020), 2018. http://www.theses.fr/2018CLFAC001/document.

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Les réseaux de capteurs sans fils linéaires (RdCSL) sont un cas particulier de réseaux de capteurs sans fils où les nœuds de capteurs sont déployés le long de multiples lignes. les RdCSL sont utilisés pour la surveillance des infrastructures routières, ferroviaires, des conduites de gaz, d’eau, de pétrole et de cours d’eau. Les solutions classiques de formation de topologie et d’adressage proposées ne sont pas adaptées à l’environnement des RdCSFL. En effet les paramètres initiaux utilisés par ces protocoles tels que le nombre maximum de nœuds fils (Cm), nombre maximum de nœuds routeurs fils Rm, profondeur maximum de l’arbre (Lm), occasionnent un gaspillage de l’espace d’adressage disponible pour les nœuds et limitent la profondeur de l’arbre adressable (15 sauts pour ZigBee). D’autres solutions adaptées pour les RdCSFL utilisent une organisation en cluster des nœuds du réseau et sont basées elles aussi sur des paramètres fixés à l’avance tels quel le nombre maximum de cluster fils par cluster. De plus, ces solutions requièrent beaucoup d’interventions manuelles sur les nœuds de capteurs (choix des chefs de cluster par exemple) et ne favorisent pas une adaptation face aux changements du RdCSL tels que l’ajout d’un ensemble de nœuds de capteurs. Dans cette thèse, nous proposons donc des protocoles permettant la construction automatique de topologies logiques, l’adressage et le routage pour des réseaux de capteurs sans fil linéaires. Nos protocoles fournissent aussi des mécanismes de gestion dynamique d’un RdSFL avec l’ajout de nouveaux nœuds, la réallocation d’adresses pour les nœuds en cas d’épuisement de blocs d’adresses et la gestion du routage vers plusieurs puits du réseau. Nos différents protocoles sont évalués grâce au simulateur Castalia/Omnet++. Les résultats de nos simulations montrent que nos protocoles permettent de construire un RdCSFL connecté avec peu de nœuds orphelins (nœuds sans adresses logiques) et sans limitations de profondeur. Nous montrons aussi, grâce à nos simulations, que nos contributions permettent d’ajouter un grand nombres de nœuds à un RdCSFL existant de n’importe quelle taille et s’adaptent au déploiement de plusieurs puits et au routage multi-puits et permettent d’améliorer le ratio et la latence de paquets livrés dans les RdCSFL
Linear wireless sensor network (LWSN) are a sub-case of wireless sensor network where sensor nodes are roughly deployed through multiple long lines with branches. LWSN are used to monitor infrastructures such as roads, pipelines, and naturals entities such as rivers.Classical solutions of topology construction and addressing are inefficient on LWSN . Indeed, with initials networks parameters such as the maximum number of children per node (Cm), the maximum number of children routers per node (Rm), and the maximum tree depth, a solution like ZigBee causes a waste of available address space of network nodes and limit the depth of the addressable tree to 15 hops. Other solutions proposed for LWSN use a cluster-tree organisation and are based on initial network parameters such as the maximum number of children clusters per cluster. In addition, these solutions require a lot of manual intervention on different sensor nodes and do not allow adaptation for a network extension (addition of a set of new sensor nodes). In this thesis, we propose protocols to allow the automatic construction of topologies, the addressing and the data routing for linear wireless sensor networks. Our contribution also provides mechanisms for dynamic management of LWSN (addition of new nodes, addresses reallocation, and data routing to multiple sink nodes). Our different protocols are evaluated using Castalia/Omnet++ simulator. Results of our simulations show that our protocols allow a construction of connected LWSN with very few orphan nodes and without depth limitations. We also show that our contribution allows to add many new nodes on different LWSN, and adapts to the deployment of multiple sinks to improve the ratio and the latency of data delivery packets

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Chaltseva, Anna. "Network state estimation in wireless multi-hop networks". Licentiate thesis, Luleå tekniska universitet, Datavetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26357.

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Multi-hop wireless networks in general and those built upon IEEE 802.11 standard in particular are known for their highly dynamic and unstable performance. The commonly accepted way for improving the situation is to jointly optimize the performance of protocols across different communications layers. Being able to characterize a state of the network is essential to enable the cross-layer optimization. This licentiate thesis investigates methods for passive characterization of network state at medium access control and transport layers based on information accessible from the corresponding layers below.Firstly, the thesis investigates a possibility for characterizing traffic intensity relying solely on the statistics of measurements from the physical layer. An advantage of this method is that it does not require decoding of the captured packets, by this accounting for the effect from long-range interferences introduced by transmissions at the border of the communication range of a receiver.Secondly, a question of predicting TCP throughput over a multi-hop wireless path is addressed. The proposed predictor is a practically usable function of statistically significant parameters at transport, medium access control and physical communication layers. The presented model is able to predict the TCP throughput with 99% accuracy, which provides an essential input for various cross-layer optimization processes.Finally, during the course of the experimental work the issues of accuracy of simulation-based modeling of communication processes were investigated. The thesis is concluded by presenting a comparative study of the performance characteristics measured in a single channel multi-hop wireless network test-bed and the corresponding measurements obtained from popular network simulators ns-2 and ns-3 when configured with identical settings. The thesis presents the evaluation of the mismatch between the results obtained in the test-bed and the simulators with their standard empirical radio models.
Godkänd; 2012; 20111215 (anncha); LICENTIATSEMINARIUM Ämnesområde: Datorkommunikation/Computer Networking Examinator: Docent Evgeny Osipov, Institutionen för system- och rymdteknik, Luleå tekniska universitet Diskutant: Universitetslektor Olov Schelén, Luleå tekniska universitet samt Xarepo AB, Luleå Tid: Måndag den 20 februari 2012 kl 10.00 Plats: A1514 Demostudion, Luleå tekniska universitet

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OKADA, Hiraku, Nobuyuki NAKAGAWA, Tadahiro WADA, Takaya YAMAZATO i Masaaki KATAYAMA. "Multi-Route Coding in Wireless Multi-Hop Networks". IEICE, 2006. http://hdl.handle.net/2237/9581.

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Okada, Hiraku, Nobuyuki Nakagawa, Tadahiro Wada, Takaya Yamazato i Masaaki Katayama. "Multi-Route Coding in Wireless Multi-Hop Networks". IEICE, 2006. http://hdl.handle.net/2237/7836.

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Pereira, Luiz Arthur Malta. "Desenvolvimento de uma linha experimental de escala reduzida para produção de biscoitos utilizando uma rede de multi sensores com protocolo \"ZIG-BEE\"". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/74/74132/tde-14032013-154613/.

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Aproximadamente 15% do faturamento das indústrias brasileiras são provenientes da indústria alimentícia, responsáveis por empregar mais de um milhão de pessoas. Para produção em larga escala é necessário que estas indústrias estejam preparadas tecnologicamente, no entanto grande parte da instrumentação eletrônica e controle ainda requer tecnologia estrangeira. Para acompanhar o crescimento e as tendências mundiais nesta área, faz-se necessário fomento para as pesquisas e inovações tecnológicas. Essas inovações podem trazer a este setor maior faturamento, principalmente nos setores de alimentos saudáveis e de preparo rápido. Ao contrário disso, muitas dessas empresas sequer possuem departamentos de pesquisa e desenvolvimento, principalmente no que se refere ao uso da tecnologia da informação agregada à instrumentação eletrônica, com foco na produção de alimentos. Que é justamente onde se insere este projeto que tem como objetivo o desenvolvimento de uma mini linha experimental de produção de biscoitos com monitoramento eletrônico e computacional, que possa estimar o ponto ideal da massa e controlar a produção de biscoitos automaticamente. Para provar a viabilidade da aplicação das tecnologias desenvolvidas na indústria alimentícia, uma linha de produção de biscoitos foi projetada e construída em escala laboratorial, sensores e atuadores que utilizam tecnologia sem fio com protocolo zigbee foram instalados ao longo da linha. Para que se pudesse analisar a temperatura interna do biscoito durante seu assamento, um encapsulamento a base de cimento refratário foi desenvolvido para proteger o nó sensor, permitindo que esse possa acompanhar o biscoito dentro do forno e coletar a temperatura interna do biscoito. Desenvolveu-se também um sensor capaz de captar, em tempo real, dados referente à massa, através da leitura da corrente utilizada pelo motor do misturador, pois esta corrente está relacionada com o torque aplicado à massa. A metodologia proposta comprovou a viabilidade da utilização de sensores sem fio com protocolo zigbee, e mostrou ser possível estimar o ponto ideal da massa através do sistema desenvolvido, iniciar o processo de fabricação automaticamente e controlar todos os processos envolvidos
Approximately 15% of the revenues of Brazilian industries from the food industry is responsible for employing over a million people. For large scale production is necessary for these industries are technologically prepared, however much of the electronic instrumentation and control equipment still requires foreign technology. To keep up with growth and global trends in this area, it is necessary to promote research and technological innovation. These innovations can improve sales to this sector, mainly in health food and fast preparation. By contrast, many of these companies even have departments of research and development, especially regarding the use of information technology to aggregate electronic instrumentation, focusing on food production. That is precisely where it belongs this project aims to develop an experimental production line mini biscuits with electronic monitoring and computing, which can estimate the ideal point of the mass and control the production of biscuits automatically. To prove the feasibility of applying the technologies developed in the food industry, a biscuit production line was designed and built at the laboratory scale, using sensors and actuators with wireless zigbee protocol were installed along the line. In order to examine the internal temperature of the cookie during its baking, a tunnel-based refractory cement is designed to protect the sensor node, allowing it to follow the cookie into the oven and the temperature inside the collecting biscuit. It was also developed a sensor capable of capturing real time data regarding the mass, by reading the current used by the motor of the mixer, since this current is related to the torque applied to the mass. The proposed methodology proved the feasibility of using wireless sensor zigbee-protocol, and shown to be possible to estimate the ideal point of the mass through the system developed, start the manufacturing process and automatically control all processes involved

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Kovacevic, I. (Ivana). "Congestion control and spectrum sharing in multi-operator multi-hop wireless network". Master's thesis, University of Oulu, 2015. http://urn.fi/URN:NBN:fi:oulu-201503111139.

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Emergence of dramatic increase in applications provided by smart devices, such as smart phones, is no longer supported by traditional telecommunications systems such as wireless cellular systems. Arising challenges are ever increasing traffic demand, shortage of available spectrum and congestion over wireless systems. On the other hand, network resources such as spectrum and computational capability, are severely under-utilized. With regard to efficient use the available resources, promising trend is to develop heterogeneous networks (HetNets) such that different operators can share their excess capacities among themselves with the previous agreement. The most research done in spectrum sharing is focused only on the network access point. In this thesis work we extend the modelling of the spectrum sharing problem to include all links on the route for a given session. While this problem might have been analyzed from the point of view of route availability our control system is focused on queue management across the network that maintains predetermined spectra sharing rules at the session level of each operator. Addressing an issue of congestion over wireless system different congestion control mechanisms are presented and analyzed enabling a variety of options for managing traffic across the spectra sharing network. These models are generalized to include different pricing mechanisms. Two approaches are taken for analyzing pricing models with congestion control mechanism. First, network nodes are modeled as two-dimensional Markov processes. Since memoryless nature of Markov process imposes restrictions on analyzed system, in order to generalize analysis, averaged non-Markov models are introduced. Performance metric used for assessing different models is average packet dropping rate.

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Chi, Yang. "Effective Use of Network Coding in Multi-hop Wireless Networks". University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1384428269.

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Vaidyanathan, Sivaramakrishnan. "Efficient Reorganization of a multi-hop Wireless Body Area Network". University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1413472078.

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Al-Kofahi, Osameh. "Network coding-based survivability techniques for multi-hop wireless networks". [Ames, Iowa : Iowa State University], 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3389283.

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Yue, Jing. "Distributed Joint Network-Channel Coding in Multi-Hop Wireless Networks". Thesis, The University of Sydney, 2016. http://hdl.handle.net/2123/15884.

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This thesis focuses on the design of distributed joint network-channel coding in multi-hop wireless networks. There are two main research focuses in this thesis, the first one is applying the low-density generator matrix (LDGM) codes to the design of joint network-channel coding, and the second one is designing joint network-channel coding schemes based on fountain codes. To begin with, I apply the LDGM codes to the design of joint network-channel coding. A multiple transmission session model with network code division multiplexing (NCDM) scheme is proposed to remove the inter-session interference at each destination. New code design criteria for the construction of the generator matrix are proposed. Another focus of this thesis is the design of joint network-channel coding using fountain codes. I first propose a distributed network coding (DNC) scheme based on the Raptor codes for wireless sensor networks (WSNs), where a group of sensor nodes, acting as source nodes, communicates with a single sink through other sensor nodes, serving as relay nodes, in a multi-hop fashion. To satisfy the various performance requirements of different source nodes, I propose an unequal error protection (UEP) DNC scheme based on fountain codes to provide arbitrary error protection (i.e., infinite protection levels) to all the source nodes in wireless relay networks (WRNs). Then I investigate the effect from different parameters of the degree distributions. A degree distribution design criteria are proposed for the DNC scheme based on fountain codes over Rayleigh fading channels. In addition to minimizing the overall recovery time among all protection groups, I develop an adaptive UEP DNC scheme to realize adaptive UEP in WRNs. The transmitted data from the source nodes in different protection groups can be recovered successfully under their performance requirements in a shorter time by using the adaptive UEP DNC scheme.

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Liu, Lu. "Performance Analysis and Optimization of One-hop Network Coding in Multi-hop Wireless Networks". Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-150817.

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In this paper, we analyze the performance of one-hop network coding in multi-hop networks and optimize it by two solutions. One is evaluating cost-delay tradeoff of opportunistic network coding in a two-way relay network with asymmetric arrival rates, we first formulate the variance of the queue into a Markov chain and derive the transition probability and the stable distribution. Then we analyze the average power cost and delay, formulate the optimal power-delay tradeoff, and propose a heuristic discrete solution. We also show that the performance degradation of the proposed discrete solution is limited. Another solution is intelligent overhear to mainly reduce overhead of power consumption. After that, we present numerical results for the cost-delay tradeoff solution and evaluate the result of intelligent overhear by COPE simulation using network simulator ns-2.

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