A Location Routing Protocol Based on Smart Antennas for Wireless Sensor Networks

RÉSUMÉ Les réseaux de capteurs sans fil sont une technologie émergente pour la surveillance de l’environnement. Un réseau de capteurs typique se compose d'un grand nombre de capteurs miniatures (noeuds) multifonctionnels, à faible coût et à faible consommation d’énergie, équipés d’un radio émetteur-récepteur et d’un ensemble de transducteurs pour récolter et transmettre des données environnementales d'une manière autonome. Une des contraintes les plus importantes de capteurs est la nécessitée d’économiser de l’énergie puisqu’ils utilisent des batteries de duré limitée, généralement irremplaçables. En outre, ils se caractérisent également par une faible vitesse de traitement, capacité de stockage et de bande passante, qui nécessite une gestion des ressources très attentive. En raison des limitations et caractéristiques inhérentes aux capteurs, le routage dans les réseaux de capteurs sans fil suppose un vrai défi. La tâche de trouver et de maintenir des routes n'est pas triviale étant donné les restrictions d'énergie et les changements soudains dans l'état des noeuds (exemple: mal-fonctionnement) qui entrainent des changements fréquents et imprévisibles dans la structure topologique. Ce travail présente LBRA, un nouveau protocole de routage géolocalisé qui utilise des antennes intelligentes pour estimer les positions des noeuds dans le réseau, et qui base les décisions de routage sur l’état de connexion des voisins et leur position relative. L'objectif principal de LBRA est d'éliminer le trafic de contrôle du réseau autant que possible. Pour atteindre cet objectif, l'algorithme emploie la position locale pour prendre des décisions de routage, met en oeuvre un nouveau mécanisme pour recueillir les informations de localisation et utilise seulement les noeuds impliqués dans la route pour faire la synchronisation des données de positionnement. De plus, le protocole considère le niveau de la batterie au moment de prendre des décisions de routage afin de balancer la dépense d’énergie du réseau. LBRA est une version améliorée du routage de ZigBee (norme actuelle pour les réseaux à faible coût et à faible consommation d’énergie) qui se base, lui aussi, sur AODV. Afin d'évaluer dans quelle mesure LBRA représente vraiment une amélioration par rapport au routage de ZigBee, une série de simulations a été effectué à l'aide du logiciel Network Simulator (ns). Les deux protocoles ont été implantés dans le simulateur. Les performances ont été comparées dans une variété de scenarios, dans des conditions différentes tels que les charges de trafic, les tailles de réseau et les conditions de mobilité. Les résultats des expériences ont montré que LBRA réussi à réduire le trafic de contrôle et la charge de routage, tout en améliorant le taux de livraison des paquets, à la fois pour les réseaux fixes et les réseaux mobiles. L'abaissement de l'alimentation du réseau est aussi plus équilibré, puisque les décisions de routage sont prises en fonction du niveau de la batterie des noeuds.----------ABSTRACT Wireless sensor networks are an emerging technology for environmental monitoring. A typical sensor network is composed of a large number of low-cost, low-power, multi-functional miniature sensor devices (nodes) equipped with a radio transceiver and a set of transducers utilized to acquire information about the surrounding environment. One of the most important constraints of sensor nodes is the low power consumption requirement since they carry limited, generally irreplaceable, batteries. In addition, they are also characterized by scarce processing speed, storage capacity and communication bandwidth, thus requiring careful resource management. Due to the inherent characteristics and restrictions of sensor nodes, routing in WSNs is very challenging. The task of finding and maintaining routes is nontrivial since energy restrictions and sudden changes in node status (e.g. failure) cause frequent and unpredictable topological changes. This work introduces a novel location routing protocol that uses smart antennas to estimate nodes positions into the network and to deliver information basing routing decisions on neighbour’s status connection and relative position, named LBRA. The main purpose of LBRA is to eliminate network control overhead as much as possible. To achieve this goal, the algorithm employs local position for route decision, implements a novel mechanism to collect the location information and involves only route participants in the synchronization of location information. In addition, the protocol uses node battery information to make power aware routing decisions. LBRA is an enhanced version of the ZigBee routing, which is the current standard for reliable, cost-effective and low power wireless networking, and like the latter is prototyped from AODV. In order to asses to what extent LBRA truly represents an improvement with respect to the ZigBee routing, a series of simulations were designed with the help of the Network Simulator (ns). Basically, both protocols were implemented in the simulator and its performance was compared in a variety of traffic load, network size and mobility conditions. The experiment results showed that LBRA succeed in reducing the control overhead and the routing load, improving the packet delivery rate for both static and mobile networks. Additionally, network power depletion is more balanced, since routing decisions are made depending on nodes’ battery level

Wireless Sensor Networks

The aim of this book is to present few important issues of WSNs, from the application, design and technology points of view. The book highlights power efficient design issues related to wireless sensor networks, the existing WSN applications, and discusses the research efforts being undertaken in this field which put the reader in good pace to be able to understand more advanced research and make a contribution in this field for themselves. It is believed that this book serves as a comprehensive reference for graduate and undergraduate senior students who seek to learn latest development in wireless sensor networks

Wireless Sensor Networks for Monitoring Applications

Wireless Sensor Networks (WSNs) are getting wide-spread attention since they became easily accessible with their low costs. One of the key elements of WSNs is distributed sensing. When the precise location of a signal of interest is unknown across the monitored region, distributing many sensors randomly/uniformly may yield with a better representation of the monitored random process than a traditional sensor deployment. In a typical WSN application the data sensed by nodes is usually sent to one (or more) central device, denoted as sink, which collects the information and can either act as a gateway towards other networks (e.g. Internet), where data can be stored, or be processed in order to command the actuators to perform special tasks. In such a scenario, a dense sensor deployment may create bottlenecks when many nodes competing to access the channel. Even though there are mitigation methods on the channel access, concurrent (parallel) transmissions may occur. In this study, always on the scope of monitoring applications, the involved development progress of two industrial projects with dense sensor deployments (eDIANA Project funded by European Commission and Centrale Adritica Project funded by Coop Italy) and the measurement results coming from several different test-beds evoked the necessity of a mathematical analysis on concurrent transmissions. To the best of our knowledge, in the literature there is no mathematical analysis of concurrent transmission in 2.4 GHz PHY of IEEE 802.15.4. In the thesis, experience stories of eDIANA and Centrale Adriatica Projects and a mathematical analysis of concurrent transmissions starting from O-QPSK chip demodulation to the packet reception rate with several different types of theoretical demodulators, are presented. There is a very good agreement between the measurements so far in the literature and the mathematical analysis

Remote aerial data acquisition and capture project (RADAC)

The RADAC Project encompasses the design and prototype implementation of a system for low-cost aerial data sensor acquisition. It includes a Ground Transponder Unit (GTU), and Aerial Interrogation System (AIS) mounted under an aircraft. The GTU captures and transmits water-meter readings; the AIS initiates’ measurements and processes and displays the results. The proposed system is based on RF devices in association with a small low-cost single chip camera and microcontrollers. During a consultancy to a large Queensland government authority which has approximately 8000 water meters in regional and remote parts of the state. It was realised that considerable savings could be made in the management of water resources and human resources needed to read these at three month intervals. This project will calculate the RF subsystem performance in terms of gain, beamwidth, return loss, bandwidth, and matching of the antenna into the RF transceiver device Design Executive Data Acquisition System and Design and implement Interrogation Microcontrollerand Design PCB for RF Transceiver and Design and calculate power usage and Power Supply design and calculate High-Gain Helical Antenna. The solution based on using RF devices based on IEEE802.15.4 (IEEE 2006) in association with a small low cost single chip camera andmicrocontroller. Figure 1 shows the Block Diagram of the Ground Transponder Unit and symbolic AIS. The potential saving in maintenance costs to industry by remotely taking measurements is significant enough to warrant furtherinvestigation with industry. There is the potential for its adaption in other resource sector

Enabling Parallel Wireless Communication in Mobile Robot Teams

Wireless inter-robot communication enables robot teams to cooperatively solve complex problems that cannot be addressed by a single robot. Applications for cooperative robot teams include search and rescue, exploration and surveillance. Communication is one of the most important components in future autonomous robot systems and is essential for core functions such as inter-robot coordination, neighbour discovery and cooperative control algorithms. In environments where communication infrastructure does not exist, decentralised multi-hop networks can be constructed using only the radios on-board each robot. These are known as wireless mesh networks (WMNs). However existing WMNs have limited capacity to support even small robot teams. There is a need for WMNs where links act like dedicated point-to-point connections such as in wired networks. Addressing this problem requires a fundamentally new approach to WMN construction and this thesis is the first comprehensive study in the multi-robot literature to address these challenges. In this thesis, we propose a new class of communication systems called zero mutual interference (ZMI) networks that are able to emulate the point-to-point properties of a wired network over a WMN implementation. We instantiate the ZMI network using a multi-radio multi-channel architecture that autonomously adapts its topology and channel allocations such that all network edges communicate at the full capacity of the radio hardware. We implement the ZMI network on a 100-radio testbed with up to 20-individual nodes and verify its theoretical properties. Mobile robot experiments also demonstrate these properties are practically achievable. The results are an encouraging indication that the ZMI network approach can facilitate the communication demands of large cooperative robot teams deployed in practical problems such as data pipe-lining, decentralised optimisation, decentralised data fusion and sensor networks

Indoor wireless metering networks - A collection of algorithms enabling low power / low duty-cycle operations

Die Bezeichnung Wireless Metering Network (WMN) identifiziert eine spezifische Klasse von drahtlosen Sensornetzwerken. Solche Netze bestehen aus einer Vielzahl von kleinen, kostengünstigen batteriebetriebenen Knoten und bieten eine mögliche Lösung für unterschiedliche Aufgaben in der Gebäudeautomatisierung, vorausgesetzt dass die erwartete Lebensdauer des Netzes mindestens 10 Jahre betragt, um die Netzwerkwartung im selben Raster mit den Gebäudewartungsarbeiten planen zu können. Die starken Energieeinschränkungen erfordern die Einführung von Energiesparmaßnahmen und insbesondere die Auswahl einer durch einen extrem geringen Arbeitszyklus charakterisierten Aktivierungsstrategie. Schlüsselelemente für den Erfolg eines WMN-Projektes sind die Existenz eines energieeffizienten MAC-Protokolls, der Einsatz eines robusten Zeitsynchronisationsmechanismus und die Implementierung von effizienten Strategien für die Netzwerkinitialisierung und die Netzwerkwartung. Hauptziel dieser Arbeit war die Entwicklung von Algorithmen und Protokollen, mit denen der energieeffiziente Betrieb einer spezifischen Familie von WSN ermöglicht wird. Die Entwicklung und die Validierung eines Ausbreitungsmodells für den Indoor-Funkkanal war ein erforderlicher Schritt, um die Untersuchung der entwickelten Verfahren zu ermöglichen. Das erste im Rahmen des Projektes entstandene Ergebnis war ein heuristischer, robuster verteilter Algorithmus, der eine energieeffiziente Integration aller Sensorknoten und die Bildung einer robusten baumförmigen Routingstruktur ermöglicht. Derselbe Algorithmus ermöglicht eine begrenzte Anpassung der Netzstruktur an die wechselnden Charakteristiken des Funkkanals. Einfache Erweiterungen des ursprünglichen Algorithmus wurden hinzugefügt, um die Selbstheilungsfähigkeiten des Netzes zu verbessern. Ein auf einer neuen Formulierung des Synchronisationsproblems basierendes Verfahren wurde entwickelt. Es gewährleistet eine energieeffiziente und robuste Zeitsynchronisation zwischen Nachbarnknoten und, indirekt, die Synchronisation aller Netzelemente. Obwohl die vorgeschlagenen Lösungen für eine spezifische Netzkategorie entwickelt wurden, ist der Autor überzeugt, dass sich die Lösungsansätze auf ein weites Spektrum von Problemen anwenden lassen.Wireless Metering Networks (WMN), a special class of Wireless Sensor Networks (WSN), consisting of a large number of tiny inexpensive sensor nodes are a viable solution for many problems in the field of building automation especially if the expected lifetime of the network permits to synchronize the network maintenance with the schedule for routine maintenance of the building. In order to meet the resulting energy constraints, the nodes have to operate according to an extremely low duty cycle schedule. The existence of an energy efficient MAC Layer protocol, the adoption of a robust time synchronization mechanism and the implementation of effective network discovery and maintenance strategies are key elements for the success of a WMN project. The main goal of this work was the development of a set of algorithms and protocols which enable the low energy / low power operation in the considered family of WMNs. The development and validation of a propagation model reproducing the characteristics of the indoor radio environment was a necessary step in order to obtain appropriate instruments for the evaluation of the quality of the proposed solutions. The author suggests a simple localized heuristic algorithm which permits the integration of all sensor nodes into a tree-like failure tolerant routing structure and also provides some basic continuous adaptation capabilities of the network structure.\\ A subsequent extension of the basic algorithm makes the network able of self healing. An innovative approach to the solution of the synchronization problem based on a reformulation of the original problem into an estimation problem permitted the development of an efficient time synchronization mechanism. This mechanism, which makes an opportunistic usage of the beacon signals generated by the MAC layer protocol, permits an effective reduction of the synchronization error between directly communicating nodes and, indirectly, introduces a global synchronization among all nodes. All the proposed solutions have been developed for a specific network class. However, since the presence of a low duty cycle scheduling, the adoption of a beacon enabled MAC protocol and the presence of limited hardware resources are quite general assumptions, the author feels confident about the applicability of the proposed solution to a much wider spectrum of problems

Smart Sensor Technologies for IoT

The recent development in wireless networks and devices has led to novel services that will utilize wireless communication on a new level. Much effort and resources have been dedicated to establishing new communication networks that will support machine-to-machine communication and the Internet of Things (IoT). In these systems, various smart and sensory devices are deployed and connected, enabling large amounts of data to be streamed. Smart services represent new trends in mobile services, i.e., a completely new spectrum of context-aware, personalized, and intelligent services and applications. A variety of existing services utilize information about the position of the user or mobile device. The position of mobile devices is often achieved using the Global Navigation Satellite System (GNSS) chips that are integrated into all modern mobile devices (smartphones). However, GNSS is not always a reliable source of position estimates due to multipath propagation and signal blockage. Moreover, integrating GNSS chips into all devices might have a negative impact on the battery life of future IoT applications. Therefore, alternative solutions to position estimation should be investigated and implemented in IoT applications. This Special Issue, “Smart Sensor Technologies for IoT” aims to report on some of the recent research efforts on this increasingly important topic. The twelve accepted papers in this issue cover various aspects of Smart Sensor Technologies for IoT

Routin in wireless sensor networks

Internet of Things (IoT) paradigm envisages to expand the current Internet witha huge number of intelligent communicating devices. Wireless Sensor Networks(WSN) deploy the devices running on meagre energy supplies and measuring environmental phenomena (like temperature, radioactivity, or CO 2 ). WSN popularapplications include monitoring, telemetry, and natural disaster prevention. Major WSN challenges are energy efficiency, overcome impairments of wireless medium, and operate in the self-organisation. The WSN integrating IoT will rely on a set of the open standards striving to offer scalability and reliability in a variety of the operating scenarios and conditions. Nevertheless, the current state of the standards have interoperability issues and can benefit from further improvements. The contributions of the thesis work are:We performed an extensive study of Bloom Filters and their use in storing nodetext-based elements in IP address. Different techniques of compression andvariants of filters allowed us to develop an efficient system closing the gapbetween feature-routing and classic approach compatible with IPv6 networks.We propose Featurecast, a routing protocol/naming service for WSN. It allowsto query sensor networks using a set of characteristics while fitting in anIPv6 packet header. We integrate our protocol in RPL and introduce a newmetric, which increase the routing efficiency. We check its performance inboth extensive simulations and experimentations on real sensors in a large-scale Senslab testbed. Large-scale simulations demonstrate the advantagesof our protocol in terms of memory usage, control overhead, packet deliveryrate and energy consumption.We introduce WEAVE - a routing protocol for networks with geolocation. Our so-lution does not use any control message and learn its paths only by observingthe traffic. Several mechanisms are introduce to keep a fixed-size header andbypass both small as well as large obstacles and provide an efficient communication between nodes. We performed simulations on large scale involvingmore than 19000 nodes and real-sensor experimentations on IoT-lab testbed. Our results show that we achieve much better performance especially in large and dynamic networks without introducing any control overhead.Le paradigme d’Internet des objets (IoT) envisage d’élargir Internet actuelle avec un grand nombre de dispositifs intelligents. Réseaux de Capteurs sans Fil (WSN) déploie les dispositifs fonctionnant sur des approvisionnements énergétiques maigres et mesurant de phénomènes environnementaux (comme la température, la radioactivité, ou CO 2). Des applications populaires de WSN comprennent la surveillance, le télémétrie, et la prévention des catastrophes naturelles. Des défis majeurs de WSN sont comment permettre à l’efficacité énergétique, surmonter les déficiences de support sans fil, et d’opérer dans à la manière auto-organisée. L’intégration de WSN dans IoT se posera sur des standards ouvertes efforçant d’offrir évolutivité et de fiabilité dans une variété de scénarios et conditions de fonctionnement. Néanmoins, l’état actuel des standards a les problèmes d’interopérabilité et peuvent bénéficier de certaines améliorations. Les contributions de la thèse sont :Nous avons effectué une étude approfondie des filtres de Bloom et de leur utilisation dans le stockage de caractéristiques de nœud dans l’adresse IP. Différentes techniques de compression et de variantes de filtres nous ont permisde développer un système efficace qui comble l’écart entre le routage de caractéristiques et l’approche classique compatible avec les réseaux IPv6.Nous proposons Featurecast, un protocole de routage / service de nommage pourWSN. Il permet d’interroger les réseaux de capteurs en utilisant un ensemble de caractéristiques tout raccord en entête de paquet IPv6. Nous intégrons notre protocole dans RPL et introduisons une nouvelle mesure, qui augmentent l’efficacité de routage. Nous vérifions sa performance contre dans des simulations approfondies et des test sur des capteurs réels dans un bancd’essai à grande échelle. Simulations approfondies démontrent les avantagesde notre protocole en termes d’utilisation de la mémoire, le surcharge de con-trôle, le taux de livraison de paquets et la consommation d’énergie.Nous introduisons WEAVE - un protocole de routage pour les réseaux avec géolo-calisation. Notre solution n’utilise pas de message de contrôle et apprend sesvoies seulement en observant le trafic. Plusieurs mécanismes sont introduitspour garder un en-tête de taille fixe, contourner à la fois les petits commeles grands obstacles et fournir une communication efficace entre les nœuds.Nous avons effectué des simulations à grande échelle impliquant plus de 19000noeuds et des expériences avec des capteurs réels sur banc d’essai IoT-lab.Nos résultats montrent que nous atteignons bien meilleures performances enparticulier dans les réseaux grands et dynamiques sans introduire de surcharg