Geographically distributed networks of acoustic sensors can be used to identify and localize the origin of acoustic phenomena. One area of use is localization of snipers by detecting the bullet's shock wave and the muzzle blast. At FOI Linköping, this system is planned to be adapted from a wire bounded sensor network into a wireless sensor network (WSN). When changing from wire bounded communication to wireless, the issue of synchronization becomes present. Synchronization can be achieved in multiple ways with different benefits depending of the method of choice. This thesis studies the synchronization method of using the highly accurate clock in Global Navigation Satellite System (GNSS) modules. This synchronization method is developed into an independent time stamping device that can be connected to each sensor in the WSN. This ensure that all sensors are synchronized to Coordinated Universal Time (UTC). The thesis starts with a pre-study where different solutions are investigated and evaluated. After the pre-study, a development stage is begun where the best solution is developed into a model to be easily implemented in the future. The result is a model existing of a microcontroller, a timing module and an ADC with built in filter and amplification.

<div>In 21st century, interoperability in remote locations has always been a matter of contention. Interoperability is very closely related to internet and an efficient process saves a lot of time and money. With the advent of Wireless Sensor Networks (WSN), Native Internet Protocol (NIP) is considered as one of the most pragmatic solutions in market to address interoperability challenges and is gaining more attention in research. However, challenges like reliability, security of data, power consumption, range and maintenance, and accessibility of such internet in remote locations still remain a matter of concern, creating further barriers for interoperability. This research aims at proposing a viable solution to interoperability issues at remote locations, irrespective of its network or payload size, by integrating more advanced Wireless Sensor Protocols like Thread Protocol with a proposed Over The Air (OTA) file transfer functionality, into UAVs. Furthermore, this study analyzes power consumption, reliability, latency and scope of the proposed system and their applications in health care and industries.</div>

Submitted by Geyciane Santos (geyciane_thamires@hotmail.com) on 2015-06-18T13:09:51Z No. of bitstreams: 1 Dissertação - Daniel Frazão Luiz.pdf: 4676951 bytes, checksum: fcf45baa0188561b5fb832534e0a0736 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-18T20:31:05Z (GMT) No. of bitstreams: 1 Dissertação - Daniel Frazão Luiz.pdf: 4676951 bytes, checksum: fcf45baa0188561b5fb832534e0a0736 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-18T20:32:03Z (GMT) No. of bitstreams: 1 Dissertação - Daniel Frazão Luiz.pdf: 4676951 bytes, checksum: fcf45baa0188561b5fb832534e0a0736 (MD5) / Made available in DSpace on 2015-06-18T20:32:03Z (GMT). No. of bitstreams: 1 Dissertação - Daniel Frazão Luiz.pdf: 4676951 bytes, checksum: fcf45baa0188561b5fb832534e0a0736 (MD5) Previous issue date: 2014-02-25 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Many applications in Wireless Sensor Networks (WSNs) consider remote and large scale monitoring. For those scenarios, the whole network is hardly fully connected all the time. A possible vision is the union of WSNs and Disruptive Tolerant Network(DTNs) concepts, where mobile nodes make collect data in sparse networks and deliver them to a base station. This work presents a buffer management strategy, which is a basic principle in DTN networks. The proposed solution considers the global coverage to choose which messages are dropped, therefore, minimizing the impact on monitoring application. Such solution is important for WSNs applications with limited resources. We show through simulation that the proposed Coverage-Based Drop-Policy in Wireless Sensor Network with Disruptive Connections (CBDP) improves the network coverage compared to traditional DTN drop policies like Drop Last (DL) and Drop First (DF). / Sensores Sem Fio (RSSFs) consideram o monitoramento de localidades afastadas, de difícil acesso e em larga escala. Para tais cenários, é difícil imaginar que todos os segmentos da rede estão interconectados ou têm conectividade direta com uma central de processamento. Uma visão possível é o uso conjunto dos conceitos de RSSFs e redes tolerantes a desconexões (DTNs - Disruptive-tolerant networks), em que nós móveis podem ser responsáveis por coletar dados de redes esparsas e entregá-los a um ponto central. Esta dissertação apresenta uma estratégia de gerenciamento de buffers, que é uma das funções fundamentais das DTNs. A solução proposta baseia-se no cálculo da cobertura para o descarte de pacotes de dados que menos contribuam para a cobertura global do sistema, favorecendo sua aplicação em redes de sensores com recursos limitados mas de alta escala. Através de simulações, mostramos que a Política de Descarte Baseada em Cobertura (CBDP) melhora a cobertura da rede em comparação às políticas de descarte normalmente encontradas nas DTNs, como Drop Last (DL) e Drop First (DF).

Submitted by SBI Biblioteca Digital (sbi.bibliotecadigital@puc-campinas.edu.br) on 2017-01-30T12:31:14Z No. of bitstreams: 1 PEDRO RINALDO CHAVES.pdf: 3607910 bytes, checksum: e6c9f208a2f52773a6226da6c4212ab9 (MD5) / Made available in DSpace on 2017-01-30T12:31:14Z (GMT). No. of bitstreams: 1 PEDRO RINALDO CHAVES.pdf: 3607910 bytes, checksum: e6c9f208a2f52773a6226da6c4212ab9 (MD5) Previous issue date: 2016-12-05 / The demand for wireless sensor networks (WSN) applied to industrial process monitoring and control should increase as the forth industrial revolution (Industry 4.0) gathers pace, since one if its main caracteristics is about flexible plant set-up. Flexibility and low cost make the WSN the perfect choice for the modern 21st century manufacturing plants. Small and medium enterprises (SMEs) have an important role in the development of the Latin America economies. This paper first describes the tests done in two industrial environments, analyses the results and examines the behaviour of a low cost, centralized WSN in industrial environments to ascertain the impact of the processes and environment (topology, distances, barriers, machines and people) in the radio signal and discuss the reliability and applicability of WSNs in process monitoring and control. The results obtained with the tests indicated a relationship between the received signal strength indicator (RSSI), the packet error rate (PER), the environment and the processes generating subsidies to the network management system. Subsequently, a new management strategy is presented, it includes two RSSI tracking indexes that guarantee an early warning in case the radio signal deteriorates. With the knowledge gathered, a set of best practices is presented; it covers the planning, installation and commissioning of centralized low cost WSNs for SMEs. / A demanda por redes de sensores sem fio (RSSF) aplicadas ? monitora??o e controle de processos em ambientes industriais de todos os tamanhos tende a aumentar ? medida que a quarta revolu??o industrial (Industry 4.0) avan?a, sendo que uma das suas caracter?sticas ? a flexibiliza??o da disposi??o dos equipamentos (plant set-up). A flexibilidade e baixo custo das RSSF as tornam a escolha perfeita para estas novas instala??es manufatureiras do s?culo 21. As pequenas e m?dias manufaturas (SMEs) tem um papel importante no desenvolvimento das economias da Am?rica Latina. Neste trabalho, primeiro descrevem-se os testes e analisa-se o comportamento de uma rede centralizada de sensores sem fio (RCSSF) de baixo custo, em dois ambientes industriais de m?dio porte de forma a se determinar como o ambiente (topologia, dist?ncias, barreiras, maquin?rio e pessoas) e os processos impactam o sinal de r?dio. Pondera-se tamb?m sobre a confiabilidade e aplicabilidade das RCSSF na monitora??o e controle de processos industriais que, por vezes, podem ser cr?ticos. Os resultados mostram uma rela??o entre par?metros como o indicador da intensidade do sinal recebido (RSSI), a taxa de erros do pacote (PER), o ambiente e os processos fornecendo assim subs?dios para a ger?ncia da rede. Posteriormente, apresenta-se uma nova estrat?gia de ger?ncia que consiste em dois ?ndices que rastreiam e monitoram o n?vel do RSSI garantindo um alerta precoce caso o sinal de r?dio apresente deteriora??o. Com os conhecimentos adquiridos, conclui-se o trabalho com a apresenta??o de um conjunto de melhores pr?ticas para auxiliar no planejamento, implanta??o e comissionamento de RCSSF de baixo custo voltadas ?s SMEs.

Les systèmes embarqués sont utilisés dans de nombreux systèmes critiques, depuis les automobiles jusqu'aux les systèmes de contrôle industriels. La plupart des recherches sur ces systèmes embarqués se sont concentrés sur l'amélioration de leur fiabilité face à des fautes ou erreurs de fonctionnent non intentionnelles, moins de travaux on été réalisés considérant les attaques intentionnelles. Ces systèmes embarqués sont de plus en plus connectés, souvent à Internet, via des réseaux sans fils, par exemple pour leur administration à distance. Cela augmente les risques d'attaques à distance ou d'injection de code malicieux. Les fautes de fonctionnement de ces équipements peuvent causer des dommages physiques comme par example rendre des appareils médicaux dangereux. Par conséquent, il est primordial de protéger ces systèmes embarqués contre les attaques. Dans cette thèse nous présentons des attaques et défenses contre les systèmes embarqués contraints. Nous présentons plusieurs attaques contre des techniques d'attestation logicielle utilisées dans les systèmes embarqués. Puis nous présentons la conception et l'implémentation d'une technique d'attestation logicielle qui est résistante aux attaque présentées précédemment. Finalement, nous présentons la conception d'une solution permettant de réaliser l'attestation de code ainsi que la création d'une racine de confiance dynamique (dynamic root of trust) pour les systèmes embarqués. Cette solution est prouvée sure et ne dépend pas d'assomptions fortes faites dans le cas de l'attestation logicielle.

Ubiquitous computing and Internet-of-Things (IoT) implies an untapped opportunity in the realm of information and communication technology, in which a large number of micro-devices with communication and/or computing capabilities, provides connectivity for anything, by anyone at anytime and anywhere. Especially, these devices can be equipped with sensors and actuators that interact with our living environment. Barcode, smart contactless card, Radio Frequency Identification (RFID) systems, wireless sensor network (WSN), and smart mobile phones are some examples which can be utilized in ubiquitous computing. RFIDs and WSN have been recognized as the two promising enablers for realization of ubiquitous computing. They have some great features such as low-cost and small- size implementation, non-line of sight operation, sensing possibilities, data storing ability, and positioning. However, there are several challenges which need to be addressed, such as limited life time for battery powered device, maintenance cost, longer operation range, higher data rate, and operation in dense multipath and multiuser environment. Ultra-Wideband Impulse Radio (UWB-IR) with its huge advantages has been recognized as a great solution for future WSN and RFID. UWB-IR technique has the possibility of achieving Gb/s data rate, hundreds of meter operation range, pJ energy per bit, centimeter accuracy of positioning, and low cost implementation. In this work utilization of UWB-IR in WSN and RFID is investigated. A wireless sensor network based on UWB-IR is proposed focusing on low-cost and low-power implementation. Our contribution is to imply two different architectures in base station and sensor nodes to satisfy power, complexity and cost constraints. For sensor nodes, an autonomous UWB-IR detection is proposed, which detects the UWB signal autonomously and no restrict synchronization is required. It reduces the circuit complexity significantly. The performance in term of bit-error-rate is compared with two other common detection techniques. It is shown that the new detection is more robustness to timing jitter and clock skew, which consequently reduces the clock and synchronization requirements considerably. A novel wireless sensing and identification system, based on remote-powered tag with asymmetric wireless link, is proposed. Our innovative contribution is to deploy two different UWB and UHF communication techniques in uplink and downlink respectively. In the proposed system, tags capture the required power supply from different environmental sources (e.g. electromagnetic wave transmitted by a reader) and transmit data through an ultra-low power impulse UWB link. A new communication protocol is devised based on slotted-aloha anti-collision algorithm. By introducing several improvements including of pipelined communication, adaptive frame size, and skipping idle slots, the system throughput of more than 2000 tags/s is achieved. To prove the system concept a single chip integrated tag is implemented in UMC 0.18μm CMOS process. The measurement results show the minimum sensitivity of -18.5 dB (14.1 μW) and adaptive data rate up to 10 Mb/s. It corresponds to 13.9 meters operation range, considering 4W EIRP, a matched antenna to the tag with 0dB gain, and free space path loss. This is a great improvement in operation range and data rate, compared with conventional passive RFID, which data rate is limited to a few hundreds of Kb/s. System integration in a Liquid-Crystal-polymer (LCP) substrate is investigated. The integration of a tunable UWB-IR transmitter and a power scavenging unit are studied. Our contribution includes embedding and modeling the RF components and antenna in substrate and co-optimizing the chip and package with on-chip versus off-chip passives trade-offs. Simulation results verify the potential of system-on-package solution for UWB integration. The effect of antenna miniaturization in a UWB system is studied. Our focus is to scale down a UWB antenna and optimize the performance through the chip-antenna co-design. A tunable impulse- UWB transmitter is designed in two cases - a conventional 50Ω design and a co-design methodology. The simulation results show that the standard 50Ω design technique can not reach the best condition in all cases, when a real antenna is placed into the system. The performance can be improved significantly when doing codesign. The antennas and UWB transmitter performances are evaluated in a given UWB systems. It is shown that the operation distance at a target performance is reduced with antenna scaling factor and it can be compensated by antenna-transceiver co-design. The result proves the importance of antenna-transceiver codesign, which needs to be addressed in the earliest phases of the design flow. / QC 20100701

The main focus of the work presented in this licentiate thesis concerns antenna design, adaptive antenna control and investigation on how the performance of small wireless nodes can be increased by inclusion of multiple antennas. In order to provide an end-user suitable solution for wireless nodes the devices require both small form factor and good performance in order to be competitive on the marked and thus the main part of this thesis focuses on techniques developed to achieve these goals. Two prototype systems have been developed where one has been used by National Defence Research Agency (FOI) to successfully monitor a test-subject moving in an outdoor terrain. The other prototype system shows the overall performance gain achievable in a wireless sensor node when multiple antennas and antenna beam steering is used. As an example of how to include multiple antennas in a wireless node the concept of using dual conformal patch antennas for wireless nodes is presented. The proposed antenna showed an excess of 10 dB gain when using a single driven antenna element as would be the case in a system utilizing antenna selection combining. When used as a 2-element phased array, up to 19 dB gain was obtained in a multiscattering environment. Using the second order resonance the proposed antenna structure achieves low mutual coupling and a reflection coefficient lower than -15 dB. The presented antenna design shows how a dual antenna wireless node can be designed using discrete phase control with passive matching which provides a good adaptive antenna solution usable for wireless sensor networks. The inclusion of discrete phase sweep diversity in a wireless node has been evaluated and shown to provide a significant diversity gain. The diversity gain of a discrete phase sweep diversity based system was measured in both a reverberation chamber and a real life office environment. The former environment showed between 5.5 to 10.3 dB diversity gain depending on the detector architecture and the latter showed a diversity gain ranging from 1 to 5.4 dB. Also the performance of nodes designed to be placed in a high temperature and multiscattering environment (the fan stage of a jet engine) has been evaluated. The work was carried out in order to verify that a wireless sensor network is able to operate in such a multiscattering environment. It was shown that the wireless nodes are able to operate in an emulated turbine environment based on real-life measured turbine fading data. The tested sensor network was able to transmit 32 byte packages using cyclic redundancy check at 2 Mbps at an engine speed of 13.000 rpm. / WISENET / WISEJET

In this thesis, an investigation of the performance of multipath routing in Wireless Sensor Networks (WSN) is performed. The communication in the network under study is to take place from individual nodes to the sink node. The investigation involved multipath finding methods in WSN. Also, it involves investigating the weight assignment, traffic splitting and route selection methods for the different paths discovered by each node in the WSN. Also, a comparison between Hybrid Routing Protocol, Source Routing Protocol and Diffusion Routing Protocol is performed. A simple traffic routing algorithm for each routing protocol has been developed to conceptualize how the network traffic is routed on a set of active paths. The investigation of the Hybrid, Source and Diffusion Routing Protocol involved using multiple paths simultaneously to transmit messages that belong to the same flow by using a weight assigned to each path and transmit each message as a whole. Finally, the power consumption and the QoS in terms of message delays for a WSN were investigated and compared between different protocols.

During the last century, the significant increase in electricity demand, and its consequences, has appeared as a serious concern for the utility companies, but no essential change has been applied to the conventional power grid infrastructure till now. Recently, researchers have identified efficient control and power distribution mechanisms as the immediate challenges for conventional power grids. Hence, the next step for conventional power grid toward Smart Grid is to provide energy efficiency management along with higher reliability via smart services, in which the application of Information and Communication Technology (ICT) is inevitable. ICT introduces powerful tools to comply with the smart grid requirements. Among various ICT properties, the telecommunication network plays a key role for providing a secure infrastructure. The two-way digital communication system provides an interaction between energy suppliers and consumers for managing, controlling and optimizing energy distribution. We can also define the smart grid as a two-way flow of energy and control information, where the electricity consumers can generate energy using green energy resources. The main objective of this thesis is to select an effective communication infrastructure to support the smart grid services by considering wireless and optical communication technologies. Fiber-wireless (FiWi) networks are considered as a potential solution to provide a fast and reliable network backbone with the optical access network integration and the flexibility and mobility of the wireless network. Therefore, we adopt the integration of the wireless sensor network (WSN) to Ethernet Passive Optical Network (EPON) as a broadband access network to transmit smart meter data along with the Fiber To The Home/Building/Curb (FTTX) traffic through the shared fiber. Finally, we present and analyze the simulation results for the aforementioned infrastructure based on our adopted priority-based FTTX-WSN integration model.

Les progrès technologiques permettent aujourd'hui l'intégration à bas coût d'objets multi-capteurs hétérogènes communicants sans fil notamment pour la surveillance dans les environnements considérés à risques ou non accessibles. Le but de ces travaux de thèse est de contribuer à la sécurisation des personnes et de leur environnement de vie par la mise en réseau de dispositifs multi-capteurs de mesures sans fil. Ceux-ci doivent être spécifiés et configurés pour rendre par exemple l'environnement qu'ils surveillent intelligent et sécurisé. Le travail effectué porte sur la conception et le prototypage réel d'un réseau composé de dispositifs hétérogènes autonomes en énergie. Nos contributions comportent trois volets essentiels :Le premier volet concerne la conception d'un modèle de réseau ambiant adapté : nous avons proposé un modèle qui repose sur une architecture multi-niveaux caractérisée par des nœuds hétérogènes dont le captage (détection), le traitement et le stockage des données sont distribués par niveau. Cette architecture hiérarchique offre plusieurs avantages par rapport aux architectures linéaires classiques en termes d'évolutivité, de faible coût, de meilleure couverture, de hautes fonctionnalités et de fiabilité. Nous avons défini le comportement adapté pour chaque nœud dans le modèle et montré l'avantage de la solution par la simulation.Le deuxième volet concerne la proposition originale d'un protocole d'accès au médium efficace en énergie nommé " T-TMAC " et adapté à l'application, permettant d'organiser les échanges des messages dans l'architecture du réseau retenu. L'originalité du protocole est qu'il est composé de mécanismes de maintenance performants permettant la gestion de la mobilité et la reconfiguration du réseau (ajout et suppression d'un capteur). Pour cela, une adaptation et un paramétrage du standard IEEE 802.15.4 sont proposés.Le dernier volet présente l'évaluation et l'analyse de performances du protocole développé dans le cadre de scénarios de tests. Nous avons étudié en particulier l'impact de la taille des données et la périodicité de transfert sur l'énergie et le délai. Le protocole est validé à l'aide d'un modèle analytique dont les résultats ont été comparés à ceux obtenus par prototypage matériel.