Página 1 dos resultados de 2590 itens digitais encontrados em 0.013 segundos

Instrumentalização de redes de sensores sem fio.; Instrumentation of wireless sensor networks.

Cansado, Jacinto Carlos Ascencio
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 16/12/2011 Português
Relevância na Pesquisa
96.41%
Este trabalho apresenta um estudo da instrumentalização de software em Redes de Sensores Sem Fio, complementado pela aplicação, em um estudo de caso, de uma instrumentalização. A proposta da instrumentalização visa ampliar o conhecimento sobre essas redes em termos de desempenho, permitindo ao usuário tomar decisões suportadas pelo instrumento. Nesse sentido, foi realizada a abordagem conceitual em termos de Redes de Sensores Sem Fio, da tendência de padronização para essas redes e de instrumentalização por meio de software. Para a comprovação dos benefícios da adoção da utilização do conceito de instrumentalização de software nessas redes, foi desenvolvida uma rede de sensores utilizando esses conceitos, na qual foi possível avaliar o perfil dos aspectos temporais e da manutenção da qualidade da conexão. Os resultados obtidos evidenciam que é possível conhecer, com maiores detalhes, o comportamento da rede, o que melhora a qualidade da tomada de decisão do usuário em relação à sua utilização em aplicações com restrições temporais, nas quais os tempos de resposta envolvidos devem respeitar os limites máximos permitidos.; This thesis aims at the study of software instrumentation handling in terms of wireless sensor networks which is supplemented with the its application in a case study. The instrumentation purposes go towards the networks knowledge extension concerning its performance by allowing the user to make decisions based on software instrument reading. In this sense...

Arquitetura de segurança fim-a-fim para redes de sensores sem fio.; End-to-end security architecture for wireless sensor networks.

Oliveira, Bruno Trevizan de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 03/08/2012 Português
Relevância na Pesquisa
96.4%
Diversas aplicações de redes de sensores sem fio necessitam de serviços de segurança, como confidencialidade, integridade e autenticação de origem de dados. Contudo, dadas as limitações de processamento, memória e suprimento de energia dos dispositivos, os mecanismos de segurança tradicionais podem causar efeitos indesejáveis na rede, como atraso na comunicação e aumento no consumo de energia, impondo obstáculos para seu uso na tecnologia em questão. Muitas propostas de esquemas de segurança baseados em criptografia simétrica projetados especificamente para redes de sensores sem fio são encontradas na literatura. Contudo, essas soluções são focadas na segurança salto-a-salto. Tal abordagem é adequada para garantir a segurança dos enlaces deste tipo de rede, mas não garante a segurança na comunicação fim-a-fim. Neste trabalho são apresentados cenários e desafios de implementação de segurança neste tipo de rede, e a concepção, o projeto e a implementação de uma arquitetura de segurança para redes de sensores sem fio, que tem como objetivos: prover segurança na comunicação fim-a-fim; permitir a interoperabilidade entre diferentes sistemas; e possibilitar uma maior flexibilidade em relação à utilização de chaves criptográficas em diferentes cenários e topologias. Adicionalmente...

Protocolo de roteamento de dados para redes de sensores sem fio com nó coletor móvel para controle da deriva em pulverização agrícola.; Routing data protocol for wireless sensor networks with mobile sink to spray drift control in crop spraying.

Santos, Ivairton Monteiro
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 17/12/2013 Português
Relevância na Pesquisa
96.43%
A aplicação eficiente de agrotóxicos é um desafio na produção agrícola, mesmo considerando os avanços com a agricultura de precisão. O efeito deriva é o principal responsável pela ineficiência no controle das pragas ou doenças, pelo desperdício de recursos e pela contaminação ambiental. Para minimizar a deriva é essencial conhecer as condições ambientais como vento, temperatura e umidade. Esta pesquisa propõe o uso das redes de sensores sem fio como sistema de monitoramento ambiental e de suporte ao processo de pulverização agrícola, especialmente a pulverização executada por aeronave. São propostas três funcionalidades para o sistema: avaliação das condições ambientais, verificando se as condições estão apropriadas para a pulverização, buscando minimizar a ocorrência da deriva; suporte na definição e manutenção da rota do veículo pulverizador por meio dos dados do vento, de modo a efetuar ajustes na rota de pulverização e manter a aplicação do defensivo agrícola na área alvo; e a avaliação da eficácia da pulverização por meio dos dados da deposição do produto pulverizado coletados pela rede de sensores. Para viabilizar a utilização das redes de sensores sem fio no controle da deriva é proposto um protocolo de roteamento de dados que visa garantir a coleta dos dados pelos nós e a entrega para o veículo pulverizador...

Núcleo de simulação computacional baseado na sincronização por barreiras com aplicação em redes de sensores sem fio; Computer simulation core based on barrier synchronization with application in wireless sensor networks

Rogério Esteves Salustiano
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 27/06/2014 Português
Relevância na Pesquisa
96.45%
O principal objetivo deste trabalho é a proposta e a implementação de um núcleo de simulação do tipo event-driven baseado em agentes destinado ao estudo e previsão de desempenho de Redes de Sensores Sem Fio. O núcleo de simulação, BaSS ¿ Barrier Synchronization Simulator, foi desenvolvido a partir do modelo básico de sincronização por barreiras, cujas funcionalidades foram ampliadas com a inclusão de temporização e interrupção nos eventos de sincronização, sendo esta a contribuição mais relevante do trabalho. Sendo parte de um projeto com metas mais ambiciosas, em particular a busca de estruturas de Redes de Sensores Sem Fio mais eficientes, contando para isto com o envolvimento de múltiplas expertises, dentre as quais projeto de circuitos integrados, eficiência energética e protocolos de comunicação, o presente trabalho foi motivado pela necessidade de uma ferramenta de simulação suficientemente flexível para acomodar os dispositivos que estariam sendo desenvolvidos e usados nas novas Redes de Sensores Sem Fio. Como resultado, considera-se que os frutos tangíveis deste trabalho são: primeiro, um framework que pode ser utilizado no desenvolvimento de simuladores do tipo event-driven com aplicações diversas e...

Efficient aggregate computations in large-scale dense wireless sensor networks

Pereira, Nuno Alexandre Magalhães
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Tese de Doutorado
Publicado em 10/09/2010 Português
Relevância na Pesquisa
96.52%
Tese de doutoramento em Informática; Assuming a world where we can be surrounded by hundreds or even thousands of inexpensive computing nodes densely deployed, each one with sensing and wireless communication capabilities, the problem of efficiently dealing with the enormous amount of information generated by those nodes emerges as a major challenge. The research in this dissertation addresses this challenge. This research work proves that it is possible to obtain aggregate quantities with a timecomplexity that is independent of the number of nodes, or grows very slowly as the number of nodes increases. This is achieved by co-designing the distributed algorithms for obtaining aggregate quantities and the underlying communication system. This work describes (i) the design and implementation of a prioritized medium access control (MAC) protocol which enforces strict priorities over wireless channels and (ii) the algorithms that allow exploiting this MAC protocol to obtain the minimum (MIN), maximum (MAX) and interpolation of sensor values with a time-complexity that is independent of the number of nodes deployed, whereas other state-of-the-art approaches have a time-complexity that is dependent on the number of nodes. These techniques also enable to efficiently obtain estimates of the number of nodes (COUNT) and the median of the sensor values (MEDIAN). The novel approach proposed to efficiently obtain aggregate quantities in large-scale...

Intrusion tolerant routing with data consensus in wireless sensor networks

Almeida, João Carlos Andrade de
Fonte: Faculdade de Ciências e Tecnologia Publicador: Faculdade de Ciências e Tecnologia
Tipo: Dissertação de Mestrado
Publicado em //2013 Português
Relevância na Pesquisa
96.38%
Dissertação para obtenção do Grau de Mestre em Engenharia Informática; Wireless sensor networks (WSNs) are rapidly emerging and growing as an important new area in computing and wireless networking research. Applications of WSNs are numerous, growing, and ranging from small-scale indoor deployment scenarios in homes and buildings to large scale outdoor deployment settings in natural, industrial, military and embedded environments. In a WSN, the sensor nodes collect data to monitor physical conditions or to measure and pre-process physical phenomena, and forward that data to special computing nodes called Syncnodes or Base Stations (BSs). These nodes are eventually interconnected, as gateways, to other processing systems running applications. In large-scale settings, WSNs operate with a large number of sensors – from hundreds to thousands of sensor nodes – organised as ad-hoc multi-hop or mesh networks, working without human supervision. Sensor nodes are very limited in computation, storage, communication and energy resources. These limitations impose particular challenges in designing large scale reliable and secure WSN services and applications. However, as sensors are very limited in their resources they tend to be very cheap. Resilient solutions based on a large number of nodes with replicated capabilities...

Adaptive Distributed Resource Allocation in Wireless Sensor Networks

Lim, Hock Beng; Lam, Vinh The; Foo, Mao Ching; Zeng, Yulian
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
Tipo: Artigo de Revista Científica Formato: 480608 bytes; application/pdf
Português
Relevância na Pesquisa
96.45%
Wireless sensor networks have emerged as a promising technology for a wide range of important applications. A major research challenge in this field is the distributed resource allocation problem, which concerns how the limited resources in a wireless sensor network should be allocated or scheduled to minimize costs and maximize the network capability. In this paper, we propose the Adaptive Distributed Resource Allocation (ADRA) scheme, an adaptive approach for distributed resource allocation in wireless sensor networks. Our scheme specifies relatively simple local actions to be performed by individual sensor nodes in a wireless sensor network for mode management. Each node adapts its operation over time in response to the status and feedback of its neighboring nodes. Desirable global behavior results from the local interactions between nodes. We study the effectiveness of the ADRA scheme for a realistic application scenario; namely, the sensor mode management in an acoustic sensor network to track vehicle movement. We evaluated the scheme via simulations, and also prototyped it using the Crossbow MICA2 motes. Our simulation and hardware implementation results indicate that the ADRA scheme provides a good tradeoff between performance objectives such as coverage area...

Adaptability in wireless sensor networks through cross-layer protocols and architectures

Merlin, Christophe J. (1980 - ); Heinzelman, Wendi
Fonte: University of Rochester Publicador: University of Rochester
Tipo: Tese de Doutorado Formato: Number of Pages:xxi, 241 leaves
Português
Relevância na Pesquisa
96.42%
Thesis (Ph. D.)--University of Rochester. Dept. of Electrical and Computer Engineering, 2009.; Complex applications and increased sensor capabilities will help proliferate wireless sensor networks into everyday life. However, as sensor nodes are battery-operated, sensor networks will require protocols to spare every possible bit of energy. This can be accomplished through cross-layer protocol optimizations that specialize the protocols for specific application requirements. However, as researchers continue to contribute to the field of sensor networks, protocols will evolve, and more efficient work will replace older ideas. Therefore, flexibility and eased maintenance of the network will be required to make sensor networks feasible for new deployments and customers. Thus there are competing goals of energy-efficiency, achieved by specialization through cross-layer protocol design, and flexibility, achieved through modularity in a layered protocol design. My thesis shows that these competing goals can be balanced by the use of crosslayer information exchange that enables the protocols (and hence the network) to adapt to current application and network conditions. Adapting the protocols via cross-layer information exchange allows the network to make best use of the limited energy resources of the sensor nodes while maintaining required application quality of service and retaining a flexible protocol stack. In support of this thesis...

Collaborative information processing techniques for target tracking in wireless sensor networks.

Ma, Hui
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2008 Português
Relevância na Pesquisa
96.57%
Target tracking is one of the typical applications of wireless sensor networks: a large number of spatially deployed sensor nodes collaboratively sense, process and estimate the target state (e.g., position, velocity and heading). This thesis aimed to develop the collaborative information processing techniques that jointly address information processing and networking for the distributive estimation of target state in the highly dynamic and resources constrained wireless sensor networks. Taking into account the interplay between information processing and networking, this thesis proposed a collaborative information processing framework. The framework integrates the information processing which is responsible for the representation, fusion and processing of data and information with networking which caters for the formation of network, the delivery of information and the management of wireless channels. Within the proposed collaborative information processing framework, this thesis developed a suite of target tracking algorithms on the basis of the recursive Bayesian estimation method. For tracking a single target in wireless sensor networks, this thesis developed the sequential extended Kalman filter (S-EKF), the sequential unscented Kalman filter (S-UKF) and the Particle filter (PF). A novel extended Kalman filter and Particle filter hybrid algorithm...

Efficient data transport in wireless sensor networks.

Zhang, Haibo
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2009 Português
Relevância na Pesquisa
96.46%
Providing efficient data transport is one of the uppermost objectives in the design of wireless sensor networks (WSNs) since the primary role for each sensor is to report the sensed data to the data sink(s). This thesis focuses on designing efficient data transport schemes for WSNs in the dimensions of energy consumption and time respectively. The developed schemes can be directly applied in a number of applications such as intrusion detection, target tracking, environment monitoring, etc., and can be further extended to underwater acoustic sensor networks and unmanned aerial vehicles (UAVs) networks. With the development of WSN technologies, new challenging research problems such as real-time streaming data gathering and intelligent data communication are emerging. This thesis provides useful foundation for designing next-generation data transport schemes for WSNs. Energy is the most important resource in WSNs because sensor nodes are commonly powered by small batteries, and energy is directly related to the lifetime of nodes and the network. In this thesis, energy-efficient data transport schemes are designed for two major types of WSNs: event-driven sensor networks and time-driven sensor networks. A novel on-line routing scheme called EBGR (Energy-efficient Beaconless Geographic Routing) is designed for event-driven sensor networks characterized by dynamic network topology. The main advantage of EBGR is that it can provide energy-efficient sensor-to-sink routing without any prior neighborhood knowledge. Moreover...

Energy-efficient beaconless geographic routing in wireless sensor networks

Zhang, H.; Shen, H.
Fonte: IEEE Computer Soc Publicador: IEEE Computer Soc
Tipo: Artigo de Revista Científica
Publicado em //2010 Português
Relevância na Pesquisa
96.4%
Geographic routing is an attractive localized routing scheme for wireless sensor networks (WSNs) due to its desirable scalability and efficiency. Maintaining neighborhood information for packet forwarding can achieve a high efficiency in geographic routing, but may not be appropriate for WSNs in highly dynamic scenarios where network topology changes frequently due to nodes mobility and availability. We propose a novel online routing scheme, called Energy-efficient Beaconless Geographic Routing (EBGR), which can provide loop-free, fully stateless, energy-efficient sensor-to-sink routing at a low communication overhead without the help of prior neighborhood knowledge. In EBGR, each node first calculates its ideal next-hop relay position on the straight line toward the sink based on the energy-optimal forwarding distance, and each forwarder selects the neighbor closest to its ideal next-hop relay position as the next-hop relay using the Request-To-Send/Clear-To-Send (RTS/CTS) handshaking mechanism. We establish the lower and upper bounds on hop count and the upper bound on energy consumption under EBGR for sensor-to-sink routing, assuming no packet loss and no failures in greedy forwarding. Moreover, we demonstrate that the expected total energy consumption along a route toward the sink under EBGR approaches to the lower bound with the increase of node deployment density. We also extend EBGR to lossy sensor networks to provide energy-efficient routing in the presence of unreliable communication links. Simulation results show that our scheme significantly outperforms existing protocols in wireless sensor networks with highly dynamic network topologies.; Haibo Zhang and Hong Shen

A generic software architecture for portable applications in heterogeneous wireless sensor networks

Escolar Díaz, María Soledad
Fonte: Universidade Carlos III de Madrid Publicador: Universidade Carlos III de Madrid
Tipo: info:eu-repo/semantics/doctoralThesis; info:eu-repo/semantics/doctoralThesis Formato: application/octet-stream; application/octet-stream; application/pdf
Português
Relevância na Pesquisa
96.49%
In the last years, wireless sensor networks (WSNs) are acquiring more importance as a promising technology based on tiny devices called sensor nodes or motes able to monitor a wide range of physical phenomenon through sensors. Numerous branches of science are being benefited. The intrinsic ubiquity of sensor nodes and the absence of network infrastructure make possible their deployment in hostile or, up to now, unknown environments which have been typically unaccessible for humans such as volcanos or glaciers, providing precise and up-to-date data. As potential applications continue arising, both new technical and conceptual challenges appear. The severe hardware restrictions of sensor nodes in relation to computation, communication and specifically, energy, have posed new and exciting requirements. In particular, research is moving towards heterogeneous networks that will contain different devices running custom WSN operating systems. Operating systems specifically designed for sensor nodes are intended to efficiently manage the hardware resources and facilitate the programming. Nevertheless, they often lack the generality and the high-level abstractions expected at this abstraction layer. Consequently, they do not completely hide either the underlying platform or its execution model...

Particle filters for tracking in wireless sensor networks

Achutegui Roncal, Katrin
Fonte: Universidade Carlos III de Madrid Publicador: Universidade Carlos III de Madrid
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
96.44%
The goal of this thesis is the development, implementation and assessment of efficient particle filters (PFs) for various target tracking applications on wireless sensor networks (WSNs). We first focus on developing efficient models and particle filters for indoor tracking using received signal strength (RSS) in WSNs. RSS is a very appealing type of measurement for indoor tracking because of its availability on many existing communication networks. In particular, most current wireless communication networks (WiFi, ZigBee or even cellular networks) provide radio signal strength (RSS) measurements for each radio transmission. Unfortunately, RSS in indoor scenarios is highly influenced by multipath propagation and, thus, it turns out very hard to adequately model the correspondence between the received power and the transmitterto- receiver distance. Further, the trajectories that the targets perform in indoor scenarios usually have abrupt changes that result from avoiding walls and furniture and consequently the target dynamics is also difficult to model. In Chapter 3 we propose a flexible probabilistic scheme that allows the description of different classes of target dynamics and propagation environments through the use of multiple switching models. The resulting state-space structure is termed a generalized switching multiple model (GSMM) system. The drawback of the GSMM system is the increase in the dimension of the system state and...

A framework for the security configuration of wireless sensor networks.

Cionca, Victor
Fonte: University of Limerick Publicador: University of Limerick
Tipo: Doctoral thesis; all_ul_research; ul_published_reviewed; ul_theses_dissertations; none
Português
Relevância na Pesquisa
96.49%
peer-reviewed; The future of our society, the connected world of tomorrow, will be one of better integration with, and more awareness of our surroundings. Wireless sensor networks will breathe life into objects and allow us to extend our sensory perception to every square of land and water. Before large amounts of information regarding our private lives and surroundings start being sent around the world,privacy issues have to be addressed. At the moment there is no transparent or holistic security solution for wireless sensor networks. Because sensor networks have a wide range of applications with very di erent requirements, and because they have constrained hardware, security solutions can't be static but need to be con gured, tailored, for every single applications, to make effi cient use of the available resources while providing the required security level. Furthermore, the control over the security con guration needs to be placed in the hands of the sensor network's user, because only the user knows the details of the application and can control its parameters. This thesis presents a framework for the security con guration of wireless sensor networks (WSNs), which provides complete and transparent communication security to any data stream...

Cellular Automaton Based Algorithms for Wireless Sensor Networks

Choudhury, Salimur
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
96.46%
Wireless sensor networks have been used in different applications due to the advancement of sensor technology. These uses also have raised different optimization issues. Most of the algorithms proposed as solutions to the various optimization problems are either centralized or distributed which are not ideal for these real life applications. Very few strictly local algorithms for wireless sensor networks exist in the literature. In this thesis, we consider some of these optimization problems of sensor networks, for example, sleep-wake scheduling, mobile dispersion, mobile object monitoring, and gathering problems. We also consider the depth adjustment problem of underwater sensor networks. We design cellular automaton based local algorithms for these problems. The cellular automaton is a bioinspired model used to model different physical systems including wireless sensor networks. One of the main advantages of using cellular automaton based algorithms is that they need very little local information to compute a solution. We perform different simulations and analysis and find that our algorithms are efficient in practice.; Thesis (Ph.D, Computing) -- Queen's University, 2012-11-25 13:37:36.854

Lower protocol layers for wireless sensor networks: a survey

Koubâa, Anis; Alves, Mário; Tovar, Eduardo
Fonte: IPP-Hurray Group Publicador: IPP-Hurray Group
Tipo: Relatório
Publicado em //2005 Português
Relevância na Pesquisa
96.4%
Wireless Sensor Networks (WSNs) have been attracting increasing interests in the development of a new generation of embedded systems with great potential for many applications such as surveillance, environment monitoring, emergency medical response and home automation. However, the communication paradigms in Wireless Sensor Networks differ from the ones attributed to traditional wireless networks, triggering the need for new communication protocols and mechanisms. In this Technical Report, we present a survey on communication protocols for WSNs with a particular emphasis on the lower protocol layers. We give a particular focus to the MAC (Medium Access Control) sub-layer, since it has a prominent influence on some relevant requirements that must be satisfied by WSN protocols, such as energy consumption, time performance and scalability. We overview some relevant MAC protocol solutions and discuss how they tackle the trade-off between the referred requirements.

Urubu: energy scavenging in wireless sensor networks

Ribeiro, Rui Filipe de Sá
Fonte: Instituto Politécnico do Porto. Instituto Superior de Engenharia do Porto Publicador: Instituto Politécnico do Porto. Instituto Superior de Engenharia do Porto
Tipo: Dissertação de Mestrado
Publicado em //2010 Português
Relevância na Pesquisa
96.44%
For the past years wireless sensor networks (WSNs) have been coined as one of the most promising technologies for supporting a wide range of applications. However, outside the research community, few are the people who know what they are and what they can offer. Even fewer are the ones that have seen these networks used in real world applications. The main obstacle for the proliferation of these networks is energy, or the lack of it. Even though renewable energy sources are always present in the networks environment, designing devices that can efficiently scavenge that energy in order to sustain the operation of these networks is still an open challenge. Energy scavenging, along with energy efficiency and energy conservation, are the current available means to sustain the operation of these networks, and can all be framed within the broader concept of “Energetic Sustainability”. A comprehensive study of the several issues related to the energetic sustainability of WSNs is presented in this thesis, with a special focus in today’s applicable energy harvesting techniques and devices, and in the energy consumption of commercially available WSN hardware platforms. This work allows the understanding of the different energy concepts involving WSNs and the evaluation of the presented energy harvesting techniques for sustaining wireless sensor nodes. This survey is supported by a novel experimental analysis of the energy consumption of the most widespread commercially available WSN hardware platforms.; Há já alguns anos que as redes de sensores sem fios (do Inglês Wireless Sensor Networks - WSNs) têm sido apontadas como uma das mais promissoras tecnologias de suporte a uma vasta gama de aplicações. No entanto...

Estimating the impact of adding sensor nodes to biomedical wireless sensor networks

Abreu, Carlos; Miranda, Francisco; Mendes, Paulo Mateus
Fonte: AIP - American Institute of Physics Publicador: AIP - American Institute of Physics
Tipo: Conferência ou Objeto de Conferência
Português
Relevância na Pesquisa
96.41%
Biomedical wireless sensor networks enable the development of real-time patient monitoring systems, either to monitor chronically ill persons in their homes or to monitor patients in step-down hospital units. However, due to the critical nature of medical data, these networks have to meet demanding quality of service requirements, ensuring high levels of confidence to their users. These goals depend on several factors, such as the characteristics of the network deployment area or the network topology. In such context, this work proposes a method to find the best network physical topology in order to maximise the quality of service provided by the network. The proposed method makes use of “virtual sensor nodes” to estimate the impact of adding real sensor nodes to the network in a specific location. Thus, assessing different locations, it is possible to find the best location to place the new sensor node while maximising the quality of service provided by the network. In particular, this work studies the feasibility of using “virtual sensor nodes” to assess the impact of adding a new sensor node to a biomedical wireless sensor network and presents some results showing the viability of the proposed method.

Maximizing the capability of wireless sensor networks

Cress, Cory
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
96.46%
Wireless micro-sensors introduce a new frontier in sensing devices and data acquisition capabilities. These sensors, capable of sensing, processing data, and short-range communication, can be spread over regions to form ad hoc wireless sensor networks (WSN) so as to deliver aggregate information from geographically diverse areas. This aggregate data gathering and processing induces a synergistic effect and enables a sensor network to complete sensing tasks that may never be feasible using a single, perhaps powerful, sensor. This new paradigm in sensing devices is not without many fundamental challenges, one being a constrained energy resource, which first need to be solved before the true capabilities of these networks may be realized. This thesis will discuss the models and techniques developed as an attempt to maximize the capability of a WSN. The premise used in the research is that the capability of a WSN can be maximize by developing a scheme that can duplicate the optimal energy efficient behavior of individual wireless sensors in a contention dominated, distributed decision-making, network environment. This optimal energy efficient behavior as determined by an analytically derived model and a mixed integer programming model will be presented. The analytical model enables the optimal sensor behavior to be calculated given a contention-less environment...

Securing location discovery in wireless sensor networks

Kadhim, Wisam F.
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
96.4%
Providing security for wireless sensor networks in hostile environments has a significant importance. Resilience against malicious attacks during the process of location discovery has an increasing need. There are many applications that rely on sensor nodes' locations to be accurate in order to function correctly. The need to provide secure, attack resistant location discovery schemes has become a challenging research topic. In this thesis, location discovery techniques are discussed and the security threats and attacks are explained. I also present current secure location discovery schemes which are developed for range-based location discovery. The thesis goal is to develop a secure range-free location discovery scheme. This is accomplished by enhancing the voting-based scheme developed in [8, 9] to be used as the bases for developing a secure range-free location discovery scheme. Both the enhancement voting-based and the secure range-free schemes are implemented on Sun SPOT wireless sensors and subjected to various levels of location discovery attacks and tested under different sensor network scales using a simulation program developed for testing purposes.