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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Digital forensic readiness for wireless sensor network environments

Mouton, Francois 24 January 2012 (has links)
The new and upcoming field of wireless sensor networking is unfortunately still lacking in terms of both digital forensics and security. All communications between different nodes (also known as motes) are sent out in a broadcast fashion. These broadcasts make it quite difficult to capture data packets forensically and, at the same time, retain their integrity and authenticity. The study presents several attacks that can be executed successfully on a wireless sensor network, after which the dissertation delves more deeply into the flooding attack as it is one of the most difficult attacks to address in wireless sensor networks. Furthermore, a set of factors is presented to take into account while attempting to achieve digital forensic readiness in wireless sensor networks. The set of factors is subsequently discussed critically and a model is proposed for implementing digital forensic readiness in a wireless sensor network. The proposed model is next transformed into a working prototype that is able to provide digital forensic readiness to a wireless sensor network. The main contribution of this research is the digital forensic readiness prototype that can be used to add a digital forensics layer to any existing wireless sensor network. The prototype ensures the integrity and authenticity of each of the data packets captured from the existing wireless sensor network by using the number of motes in the network that have seen a data packet to determine its integrity and authenticity in the network. The prototype also works on different types of wireless sensor networks that are in the frequency range of the network on which the prototype is implemented, and does not require any modifications to be made to the existing wireless sensor network. Flooding attacks pose a major problem in wireless sensor networks due to the broadcasting of communication between motes in wireless sensor networks. The prototype is able to address this problem by using a solution proposed in this dissertation to determine a sudden influx of data packets within a wireless sensor network. The prototype is able to detect flooding attacks while they are occurring and can therefore address the flooding attack immediately. Finally, this dissertation critically discusses the advantages of having such a digital forensic readiness system in place in a wireless sensor network environment. Copyright / Dissertation (MSc)--University of Pretoria, 2012. / Computer Science / unrestricted
202

A Low-Complexity Intrusion Detection Algorithm For Surveillance Using PIR Sensors In A Wireless Sensor Network

Sajana, Abu R 05 1900 (has links) (PDF)
A Wireless Sensor Network (WSN) is a dense network of autonomous devices (or motes) with sensors that cooperatively monitor some physical or environmental conditions. These devices are resource constrained -limited memory, power and computational resources. Thus, any algorithm developed for WSN should be deigned such that the algorithm consumes the resources as minimal as possible. The problem addressed in this thesis is developing a low-complexity algorithm for intrusion detection in the presence of clutter arising from moving vegetation, using Passive Infra-Red (PIR) sensors. The algorithm is based on a combination of Haar Transform (HT) and Support-Vector-Machine (SVM) based training. The spectral signature of the waveforms is used to separate between the intruder and clutter waveforms. The spectral signature is computed using HT and this is fed to SVM which returns an optimal hyperplane that separates the intruder and clutter signatures. This hyperplane obtained by offline training is used online in the mote for surveillance. The algorithm is field-tested in the Indian Institute of Science campus. Based on experimental observations about the PIR sensor and the lens system, an analytical model for the waveform generated by an intruder moving along a straight line with uniform velocity in the vicinity of the sensor is developed. Analysis on how this model can be exploited to track the intruder path by optimally positioning multiple sensor nodes is provided. Algorithm for tracking the intruder path using features of the waveform from three sensors mounted on a single mote is also developed.
203

A Low-Complexity Algorithm For Intrusion Detection In A PIR-Based Wireless Sensor Network

Subramanian, Ramanathan 05 1900 (has links) (PDF)
This thesis investigates the problem of detecting an intruder in the presence of clutter in a Passive Infra-Red (PIR) based Wireless Sensor Network (WSN). As one of the major objectives in a WSN is to maximize battery life, data transmission and local computations must be kept to a minimum as they are expensive in terms of energy. But, as intrusion being a rare event and cannot be missed, local computations expend more energy than data transmission. Hence, the need for a low-complexity algorithm for intrusion detection is inevitable. A low-complexity algorithm for intrusion detection in the presence of clutter arising from wind-blown vegetation, using PIR sensors is presented. The algorithm is based on a combination of Haar Transform (HT) and Support Vector Machine (SVM) based training. The amplitude and frequency of the intruder signature is used to differentiate it from the clutter signal. The HT was preferred to Discrete Fourier Transform (DFT) in computing the spectral signature because of its computational simplicity -just additions and subtractions suffice (scaling coefficients taken care appropriately). Intruder data collected in a laboratory and clutter data collected from various types of vegetation were fed into SVM for training. The optimal decision rule returned by SVM was then used to separate intruder from clutter. Simulation results along with some representative samples in which intrusions were detected and the clutter being rejected by the algorithm is presented. The implementation of the proposed intruder-detection algorithm in a network setting comprising of 20 sensing nodes is discussed. The field testing performance of the algorithm is then discussed. The limitations of the algorithm is also discussed. A closed-form analytical expression for the signature generated by a human moving along a straight line in the vicinity of the PIR sensor at constant velocity is provided. It is shown to be a good approximation by showing a close match with the real intruder waveforms. It is then shown how this expression can be exploited to track the intruder from the signatures of three well-positioned sensing nodes.
204

Routing algorithm dedicated to environmental data collection : precision agriculture / Algorithme de routage dédié à la collecte de données environnementales : Agriculture de précision

Chen, Yibo 19 May 2015 (has links)
Les Réseaux de Capteurs Sans Fil (RCSF ou Wireless Sensor Network - WSN) sont l'une des technologies les plus importantes du 21ème siècle. La plupart des chercheurs et les analystes estiment que, dans un proche avenir, ces micro-capteurs seront intégrés partout dans l’environnement de notre vie quotidienne. Ces dernières années, l'Internet des Objets (Internet of Things - IoT) est également une des technologies émergentes qui se développe rapidement. Deux nouveaux standards permettent de déployer des réseaux sans fil de faible consommation énergétique connectés à internet : le protocole 6LowPAN (Low power Wireless Personal Area Networks) qui permet notamment d’apporter l’adressage IPv6 aux capteurs grâce à l’encapsulation et la compression des données et le protocole de routage RPL (IPv6 routing protocol for low-power and lossy network) qui permet à l’information de circuler dans les WSN de proche en proche à un faible coût énergétique. Bien que le développement de ces techniques soit extrêmement rapide, plusieurs problèmes causés principalement par le manque de ressources des micro-capteurs (puissance limitée de traitement, problèmes de bande passante et de connexion des liens avec perte de données, problème de ressource énergétique limitée) demeurent et doivent être résolus, notamment pour les applications agro-environnementales. / The wireless sensor network (WSN) is one of the most important technologies of the 21st century. Most researchers and technical analysts believe that in the near future, these micro-sensors will be integrated into the environment of our daily lives. In recent years, the IoT (Internet of Things) and WoT (Web of Things) technologies also have great forwarding. Especially, the IPv6 over Low power Wireless Personal Area Networks (6LoWPAN) protocol has allowed the use of IPv6 protocol stack in the field of WSN, thanks to its encapsulation and compression mechanisms in IPv6 packet header. Moreover, the RPL (IPv6 Routing Protocol for Low-power and Lossy Network) provides such a powerful routing function that can be applied for a variety of application scenarios. These two key standards of IoT and WoT technologies for WSN can be used in an IPv6 stack, and they will successfully achieve the connection between Internet and micro-sensors. Thus, due to the availability of IPv6 address (128-bit), all the communicating objects, such as smart device, sensor, and actuator, can be connected to the Internet. That is the greatest advantage brought by the IoT. Although the progress of these techniques is extremely fast, several issues caused by resource constraints of micro-sensor (limited processing power, bandwidth and lossy connection link, and energy), such as QoS, energy efficient, robustness and lifetime of WSN, and the most important, the special requirement of agricultural applications. Notice that Precision Agriculture is are still very challenging and waiting to be solved. Essentially, these open questions would dabble in the aspects like telemedicine, remote home automation, industrial control etc. Thus, the results obtained in this work will have a significant impact on both economic and scientific. Economically, it can offer a solution for WSN to support sustainable development in the field of agriculture automation. While scientifically, we will contribute to the routing protocol standardization of wireless micro-sensors in the domain of environmental monitoring.
205

Design and Implementation of a Communication Protocol to Improve Multimedia QoS and QoE in Wireless Ad Hoc Networks

Díaz Santos, Juan Ramón 05 April 2016 (has links)
[EN] This dissertation addresses the problem of multimedia delivery over multi-hop ad hoc wireless networks, and especially over wireless sensor networks. Due to their characteristics of low power consumption, low processing capacity and low memory capacity, they have major difficulties in achieving optimal quality levels demanded by end users in such communications. In the first part of this work, it has been carried out a study to determine the behavior of a variety of multimedia streams and how they are affected by the network conditions when they are transmitted over topologies formed by devices of different technologies in multi hop wireless ad hoc mode. To achieve this goal, we have performed experimental tests using a test bench, which combine the main codecs used in audio and video streaming over IP networks with different sound and video captures representing the characteristic patterns of multimedia services such as phone calls, video communications, IPTV and video on demand (VOD). With the information gathered in the laboratory, we have been able to establish the correlation between the induced changes in the physical and logical topology and the network parameters that measure the quality of service (QoS) of a multimedia transmission, such as latency, jitter or packet loss. At this stage of the investigation, a study was performed to determine the state of the art of the proposed protocols, algorithms, and practical implementations that have been explicitly developed to optimize the multimedia transmission over wireless ad hoc networks, especially in ad hoc networks using clusters of nodes distributed over a geographic area and wireless sensor networks. Next step of this research was the development of an algorithm focused on the logical organization of clusters formed by nodes capable of adapting to the circumstances of real-time traffic. The stated goal was to achieve the maximum utilization of the resources offered by the set of nodes that forms the network, allowing simultaneously sending reliably and efficiently all types of content through them, and mixing conventional IP data traffic with multimedia traffic with stringent QoS and QoE requirements. Using the information gathered in the previous phase, we have developed a network architecture that improves overall network performance and multimedia streaming. In parallel, it has been designed and programmed a communication protocol that allows implementing the proposal and testing its operation on real network infrastructures. In the last phase of this thesis we have focused our work on sending multimedia in wireless sensor networks (WSN). Based on the above results, we have adapted both the architecture and the communication protocol for this particular type of network, whose use has been growing hugely in recent years. / [ES] Esta tesis doctoral aborda el problema de la distribución de contenidos multimedia a través de redes inalámbricas ad hoc multisalto, especialmente las redes inalámbricas de sensores que, debido a sus características de bajo consumo energético, baja capacidad de procesamiento y baja capacidad de memoria, plantean grandes dificultades para alcanzar los niveles de calidad óptimos que exigen los usuarios finales en dicho tipo de comunicaciones. En la primera parte de este trabajo se ha llevado a cabo un estudio para determinar el comportamiento de una gran variedad de flujos multimedia y como se ven afectados por las condiciones de la red cuando son transmitidos a través topologías formadas por dispositivos de diferentes tecnologías que se comunican en modo ad hoc multisalto inalámbrico. Para ello, se han realizado pruebas experimentales sobre una maqueta de laboratorio, combinando los principales códecs empleados en la transmisión de audio y video a través de redes IP con diversas capturas de sonido y video que representan patrones característicos de servicios multimedia tales como las llamadas telefónicas, videoconferencias, IPTV o video bajo demanda (VOD). Con la información reunida en el laboratorio se ha podido establecer la correlación entre los cambios inducidos en la topología física y lógica de la red con los parámetros que miden la calidad de servicio (QoS) de una transmisión multimedia, tales como la latencia el jitter o la pérdida de paquetes. En esta fase de la investigación se realiza un estudio para determinar el estado del arte de las propuestas de desarrollo e implementación de protocolos y algoritmos que se han generado de forma explícita para optimizar la transmisión de tráfico multimedia sobre redes ad hoc inalámbricas, especialmente en las redes inalámbricas de sensores y redes ad hoc utilizando clústeres de nodos distribuidos en un espacio geográfico. El siguiente paso en la investigación ha consistido en el desarrollo de un algoritmo propio para la organización lógica de clústeres formados por nodos capaces de adaptarse a las circunstancias del tráfico en tiempo real. El objetivo planteado es conseguir un aprovechamiento máximo de los recursos ofrecidos por el conjunto de nodos que forman la red, permitiendo de forma simultánea el envío de todo tipo de contenidos a través de ellos de forma confiable y eficiente, permitiendo la convivencia de tráfico de datos IP convencional con tráfico multimedia con requisitos exigentes de QoS y QoE. A partir de la información conseguida en la fase anterior, se ha desarrollado una arquitectura de red que mejora el rendimiento general de la red y el de las transmisiones multimedia de audio y video en particular. De forma paralela, se ha diseñado y programado un protocolo de comunicación que permite implementar el modelo y testear su funcionamiento sobre infraestructuras de red reales. En la última fase de esta tesis se ha dirigido la atención hacia la transmisión multimedia en las redes de sensores inalámbricos (WSN). Partiendo de los resultados anteriores, se ha adaptado tanto la arquitectura como el protocolo de comunicaciones para este tipo concreto de red, cuyo uso se ha extendido en los últimos años de forma considerable / [CAT] Esta tesi doctoral aborda el problema de la distribució de continguts multimèdia a través de xarxes sense fil ad hoc multi salt, especialment les xarxes sense fil de sensors que, a causa de les seues característiques de baix consum energètic, baixa capacitat de processament i baixa capacitat de memòria, plantegen grans dificultats per a aconseguir els nivells de qualitat òptims que exigixen els usuaris finals en eixos tipus de comunicacions. En la primera part d'este treball s'ha dut a terme un estudi per a determinar el comportament d'una gran varietat de fluxos multimèdia i com es veuen afectats per les condicions de la xarxa quan són transmesos a través topologies formades per dispositius de diferents tecnologies que es comuniquen en mode ad hoc multi salt sense fil. Per a això, s'han realitzat proves experimentals sobre una maqueta de laboratori, combinant els principals códecs empleats en la transmissió d'àudio i vídeo a través de xarxes IP amb diverses captures de so i vídeo que representen patrons característics de serveis multimèdia com son les cridades telefòniques, videoconferències, IPTV o vídeo baix demanda (VOD). Amb la informació reunida en el laboratori s'ha pogut establir la correlació entre els canvis induïts en la topologia física i lògica de la xarxa amb els paràmetres que mesuren la qualitat de servei (QoS) d'una transmissió multimèdia, com la latència el jitter o la pèrdua de paquets. En esta fase de la investigació es realitza un estudi per a determinar l'estat de l'art de les propostes de desenvolupament i implementació de protocols i algoritmes que s'han generat de forma explícita per a optimitzar la transmissió de tràfic multimèdia sobre xarxes ad hoc sense fil, especialment en les xarxes sense fil de sensors and xarxes ad hoc utilitzant clusters de nodes distribuïts en un espai geogràfic. El següent pas en la investigació ha consistit en el desenvolupament d'un algoritme propi per a l'organització lògica de clusters formats per nodes capaços d'adaptar-se a les circumstàncies del tràfic en temps real. L'objectiu plantejat és aconseguir un aprofitament màxim dels recursos oferits pel conjunt de nodes que formen la xarxa, permetent de forma simultània l'enviament de qualsevol tipus de continguts a través d'ells de forma confiable i eficient, permetent la convivència de tràfic de dades IP convencional amb tràfic multimèdia amb requisits exigents de QoS i QoE. A partir de la informació aconseguida en la fase anterior, s'ha desenvolupat una arquitectura de xarxa que millora el rendiment general de la xarxa i el de les transmissions multimèdia d'àudio i vídeo en particular. De forma paral¿lela, s'ha dissenyat i programat un protocol de comunicació que permet implementar el model i testejar el seu funcionament sobre infraestructures de xarxa reals. En l'última fase d'esta tesi s'ha dirigit l'atenció cap a la transmissió multimèdia en les xarxes de sensors sense fil (WSN). Partint dels resultats anteriors, s'ha adaptat tant l'arquitectura com el protocol de comunicacions per a aquest tipus concret de xarxa, l'ús del qual s'ha estés en els últims anys de forma considerable. / Díaz Santos, JR. (2016). Design and Implementation of a Communication Protocol to Improve Multimedia QoS and QoE in Wireless Ad Hoc Networks [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62162 / TESIS
206

Návrh paketového analyzátoru pro bezdrátové senzorové sítě založené na standardu IEEE 802.15.4 / Packet analyser for a Wireless Sensor Networks based on the standard IEEE 802.15.4

Bednařík, Martin January 2011 (has links)
The objective of this thesis is to get familiar with wireless sensor networks technologies and with standard IEEE 802.15.4. and communication principle in wireless sensor networks built on this standard. Main goal of this project is to design a packet analyzer, which is capable to catch data on chosen channel and this data is able to analyze. Part of this project is production of necessary microcontroller software equipment. Another output of this project is do a research of available packet analyzers on market and compare them with analyzer build by this thesis.
207

Bezdrátové senzorové sítě s využitím mobilních zařízení / Wireless Sensor Networks Based on Mobile Devices

Dorazil, Jan January 2013 (has links)
This master's thesis deals with the idea of using mobile devices as sensor nodes in wireless sensor network. Focused mostly on Android platform, we explore possibilities of wireless communication, and describe various types of sensors on mobile devices. We design and implement wireless sensor network based on mobile devices running Android operating system. The network performs real-time capturing of data from all sensors available and optionally from GPS. All measurements are visualized at the base station, which is Java Standard Edition desktop application. Wi-Fi, Bluetooth or even cellular internet can be used for communication within the network. Nodes can be remotely configured via SMS messages.
208

State of Secure Application Development for 802.15.4

Armstrong, Janell 16 April 2009 (has links) (PDF)
A wireless sensor network consists of small, limited-resource embedded systems exchanging environment data and activating controls. These networks can be deployed in hostile environments to monitor wildlife habitats, implemented in factories to locate mobile equipment, and installed in home environments to optimize the use of utilities. Each of these scenarios requires network security to protect the network data. The IEEE 802.15.4 standard is designed for WSN communication, yet the standard states that it is not responsible for defining the initialization, distribution, updating, or management of network public keys. Individuals seeking to research security topics will find that there are many 802.15.4-compliant development hardware kits available to purchase. However, these kits are not easily compared to each other without first-hand experience. Further, not all available kits are suitable for research in WSN security. This thesis evaluates a broad spectrum of 802.15.4 development kits for security studies. Three promising kits are examined in detail: Crossbow MICAz, Freescale MC1321x, and the Sun SPOT. These kits are evaluated based on their hardware, software, development environment, additional libraries, additional tools, and cost. Recommendations are made to security researchers advising which kits to use depending on their design needs and priorities. Suggestions are made to each company on how to further improve their kits for security research.
209

A CoAP Publish-Subscribe Broker for More Resource-Efficient Wireless Sensor Networks

Oudishu, Ramcin, Gärdborn, Pethrus January 2018 (has links)
With the rapid development of the Internet of Things, Wireless Sensor Networks (WSNs) are deployed increasingly all over the world, providing data that can help increase sustainable development. Currently in Uppsala, Sweden, the GreenIoT project monitors air pollution by using WSNs. The resource constrained nature of WSNs demand that special care is taken in the design of communication models and communication protocols. The publish-subscribe (pub/sub) model suits WSNs very well since it puts an intermediary the broker server between sensor nodes and clients, thus alleviating the workload of the sensor nodes. The IETF (Internet Engineering Task Force) is currently in the process of standardizing a pub/sub extension to the Constrained Application Protocol (CoAP). Since the extension is such a recent addition to CoAP and not yet standardized, there are very few actual implementations of it and little is known of how it would work in practice. The GreenIoT project is considering replacement of their current pub/sub broker with the CoAP pub/sub broker since its underlying implementation is likely to be more energy efficient and the standardizing organization behind CoAP is the well-esteemed IETF. On a general level, this report offers an investigation of the problems and challenges faced when implementing the CoAP pub/sub extension with respect to design choices, implementation and protocol ambiguities. More specifically, a CoAP pub/sub broker is implemented for the GreenIoT project. By means of carefully analyzing the CoAP protocol and CoAP pub/sub draft as well as other necessary protocols, then proceeding to make decisions of what programming language to use as well as what existing CoAP library to use, a broker server was implemented and tested iteratively as the work proceeded. The implementation gave rise to several questions regarding the pub/sub draft which are also discussed in the report. / Den hastiga utvecklingen av Sakernas Internet över hela världen har medfört ett ökat användande av trådlösa sensornätverk vars datainsamling kan bidra till en mer hållbar utveckling. För närvarande använder sig GreenIoT-projektet i Uppsala av trådlösa sensornätverk för att övervaka halterna av luftföroreningar. Resursbegränsningarna för dylika nätverk medför att särskild hänsyn måste tas vid design av såväl kommunikationsmodeller som kommunikationsprotokoll. Modellen Publicera-Prenumerera (pub/pre) passar ypperligt för trådlösa sensornätverk då en mellanhand placeras mellan klient och server en s.k. broker vilket får den positiva effekten att att sensornoderna avlastas. För närvarande är IETF (Internet Engineering Task Force) i färd med att standardisera en pub/pre-utvidgning av det redan standardiserade CoAP (Constrained Application Protocol). Eftersom att utvidgningen är så pass ny finns ytterst få implementationer av den och man vet därmed väldigt lite om hur den faktiskt fungerar i praktiken. GreenIoT-projektet överväger att ersätta sin nuvarande pub/pre-broker med en CoAP pub/pre-broker eftersom att energianvändningen kan antas bli lägre samt att standardiseringsorganisationen bakom CoAP är det välrenommerade IETF. Sett ur ett större perspektiv erbjuder denna rapport en undersökning av de problem och utmaningar man ställs inför vid implementation av CoAP pub/pre-utvidgningen med avseende på designval, implementationsval, och protokolltvetydigheter. Mer konkret implementeras en CoAP pub/pre-broker åt GreenIoT-projektet. Genom att först noggrant analysera CoAP-protokollet, CoAP pub/pre-utkastet, liksom andra nödvändiga protokoll, för att därefter bestämma vilket programmeringsspråk och vilket existerande CoAP-bibliotek som skulle användas, implementerades en broker server som testades iterativt under processens gång. Ett flertal frågor som uppstod rörande pub/pre-utkastet presenteras och diskuteras i rapporten.
210

A service orientated architecture and wireless sensor network approach applied to the measurement and visualisation of a micro injection moulding process. Design, development and testing of an ESB based micro injection moulding platform using Google Gadgets and business processes for the integration of disparate hardware systems on the factory shop floor

Raza, Umar January 2014 (has links)
Factory shop floors of the future will see a significant increase in interconnected devices for monitoring and control. However, if a Service Orientated Architecture (SOA) is implemented on all such devices then this will result in a large number of permutations of services and composite services. These services combined with other business level components can pose a huge challenge to manage as it is often difficult to keep an overview of all the devices, equipment and services. This thesis proposes an SOA based novel assimilation architecture for integrating disparate industrial hardware based processes and business processes of an enterprise in particular the plastics machinery environment. The key benefits of the proposed architecture are the reduction of complexity when integrating disparate hardware platforms; managing the associated services as well as allowing the Micro Injection Moulding (µIM) process to be monitored on the web through service and data integration. An Enterprise Service Bus (ESB) based middleware layer integrates the Wireless Sensor Network (WSN) based environmental and simulated machine process systems with frontend Google Gadgets (GGs) based web visualisation applications. A business process framework is proposed to manage and orchestrate the resulting services from the architecture. Results from the analysis of the WSN kits in terms of their usability and reliability showed that the Jennic WSN was easy to setup and had a reliable communication link in the polymer industrial environment with the PER being below 0.5%. The prototype Jennic WSN based µIM process monitoring system had limitations when monitoring high-resolution machine data, therefore a novel hybrid integration architecture was proposed. The assimilation architecture was implemented on a distributed server based test bed. Results from test scenarios showed that the architecture was highly scalable and could potentially allow a large number of disparate sensor based hardware systems and services to be hosted, managed, visualised and linked to form a cohesive business process.

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