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Chaque année, des millions de personnes meurent et beaucoup d'autres subissent des séquelles graves à la suite d'accidents de la route. Malgré une multitude d’initiatives, le nombre de cas mortels et d'accidents graves augmente chaque année en engendrant des problèmes préoccupants à la fois sociaux, économiques et sanitaires. En raison de leur nombre élevé et de l'absence de protection personnelle, plus de la moitié de ces décès concerne les usagers vulnérables (en anglais, vulnerable road users - VRU) regroupant les piétons, cyclistes et motocyclistes. Les appareils mobiles, combinés à la technologie de Fog Computing (ou informatique géodistribuée, ou même informatique en brouillard), représentent une solution réaliste à court terme pour les protéger en les avertissant de l’imminence d'un accident de circulation. L’omniprésence des appareils mobiles et leurs capacités de calcul élevées font de ces appareils un élément important à considérer dans les solutions de sécurité routière. Le Fog Computing offre des fonctionnalités adaptées aux applications de sécurité routière, puisqu’il s’agit d’une extension du Cloud Computing permettant de rapprocher les services informatiques, le stockage et le réseau au plus près des utilisateurs finaux. Par conséquent, dans cette thèse, nous proposons une architecture réseau sans infrastructure supplémentaire (PV-Alert) pour des fins de sécurité routière et reposant uniquement sur les appareils mobiles des VRU et des conducteurs sur la route avec l’aide du concept de Fog Computing. Les données géographiques et cinématiques de ces appareils sont collectées et envoyées périodiquement au serveur fog situé à proximité. Le serveur fog traite ces données en exécutant un algorithme de calcul de risque d’accident de circulation et renvoie des notifications en cas d'accident imminent. L’évaluation de cette architecture montre qu’elle est capable de générer des alertes en temps réel et qu’elle est plus performante que d’autres architectures en termes de fiabilité, d’évolutivité et de latence. / Annually, millions of people die and many more sustain non-fatal injuries because of road traffic crashes. Despite multitude of countermeasures, the number of causalities and disabilities owing to traffic accidents are increasing each year causing grinding social, economic, and health problems. Due to their high volume and lack of protective-shells, more than half of road traffic deaths are imputed to vulnerable road users (VRUs): pedestrians, cyclists and motorcyclists. Mobile devices combined with fog computing can provide feasible solutions to protect VRUs by predicting collusions and warning users of an imminent traffic accident. Mobile devices’ ubiquity and high computational capabilities make the devices an important components of traffic safety solutions. Fog computing has features that suits to traffic safety applications as it is an extension of cloud computing that brings down computing, storage, and network services to the proximity of end user. Therefore, in this thesis, we have proposed an infrastructure-less traffic safety architecture that depends on fog computing and mobile devices possessed by VRUs and drivers. The main duties of mobile devices are extracting their positions and other related data and sending cooperative awareness message to a nearby fog server using wireless connection. The fog server estimates collision using a collision prediction algorithm and sends an alert message, if an about-to-occur collision is predicted. Evaluation results shows that the proposed architecture is able to render alerts in real time. Moreover, analytical and performance evaluations depict that the architecture outperforms other related road safety architectures in terms of reliability, scalability and latency. However, before deploying the architecture, challenges pertaining to weaknesses of important ingredients of the architecture should be treated prudently. Position read by mobile devices are not accurate and do not meet maximum position sampling rates traffic safety applications demand. Moreover, continuous and high rate position sampling drains mobile devices battery quickly. From fog computing’s point of view, it confronts new privacy and security challenges in addition to those assumed from cloud computing. For aforementioned challenges, we have proposed new solutions: (i) In order to improve GPS accuracy, we have proposed an efficient and effective two-stage map matching algorithm. In the first stage, GPS readings obtained from smartphones are passed through Kalman filter to smooth outlier readings. In the second stage, the smoothed positions are mapped to road segments using online time warping algorithm. (ii) position sampling frequency requirement is fulfilled by an energy efficient location prediction system that fuses GPS and inertial sensors’ data. (iii) For energy efficiency, we proposed an energy efficient fuzzy logic-based adaptive beaconing rate management that ensures safety of VRUs. (iv) finally, privacy and security issues are addressed indirectly using trust management system. The two-way subjective logic-based trust management system enables fog clients to evaluate the trust level of fog servers before awarding the service and allows the servers to check out the trustworthiness of the service demanders. Engaging omnipresent mobile device and QoS-aware fog computing paradigm in active traffic safety applications has the potential to reduce overwhelming number of traffic accidents on VRUs.

Sensors are widely deployed in our environment, and their number is increasing rapidly. In the near future, billions of devices will all be connected to each other, creating an Internet of Things. Furthermore, computational intelligence is needed to make applications involving these devices truly exciting. In IoT, however, the vast amounts of data will not be statically prepared for batch processing, but rather continually produced and streamed live to data consumers and intelligent algorithms. We refer to applications that perform live analysis on live data streams, bringing intelligence to IoT, as the Analysis of Things. However, the Analysis of Things also comes with a new set of challenges. The data sources are not collected in a single, centralized location, but rather distributed widely across the environment. AoT applications need to be able to access (consume, produce, and share with each other) this data in a way that is natural considering its live streaming nature. The data transport mechanism must also allow easy access to sensors, actuators, and analysis results. Furthermore, analysis applications require computational resources on which to run. We claim that system support for AoT can reduce the complexity of developing and executing such applications. To address this, we make the following contributions: - A framework for systems support of Live Streaming Analysis in the Internet of Things, which we refer to as the Analysis of Things (AoT), including a set of requirements for system design - A system implementation that validates the framework by supporting Analysis of Things applications at a local scale, and a design for a federated system that supports AoT on a wide geographical scale - An empirical system evaluation that validates the system design and implementation, including simulation experiments across a wide-area distributed system We present five broad requirements for the Analysis of Things and discuss one set of specific system support features that can satisfy these requirements. We have implemented a system, called \textsubscript{SS}IoTa, that implements these features and supports AoT applications running on local resources. The programming model for the system allows applications to be specified simply as operator graphs, by connecting operator inputs to operator outputs and sensor streams. Operators are code components that run arbitrary continuous analysis algorithms on streaming data. By conforming to a provided interface, operators may be developed that can be composed into operator graphs and executed by the system. The system consists of an Execution Environment, in which a Resource Manager manages the available computational resources and the applications running on them, a Stream Registry, in which available data streams can be registered so that they may be discovered and used by applications, and an Operator Store, which serves as a repository for operator code so that components can be shared and reused. Experimental results for the system implementation validate its performance. Many applications are also widely distributed across a geographic area. To support such applications, \textsubscript{SS}IoTa must be able to run them on infrastructure resources that are also distributed widely. We have designed a system that does so by federating each of the three system components: Operator Store, Stream Registry, and Resource Manager. The Operator Store is distributed using a distributed hast table (DHT), however since temporal locality can be expected and data churn is low, caching may be employed to further improve performance. Since sensors exist at particular locations in physical space, queries on the Stream Registry will be based on location. We also introduce the concept of geographical locality. Therefore, range queries in two dimensions must be supported by the federated Stream Registry, while taking advantage of geographical locality for improved average-case performance. To accomplish these goals, we present a design sketch for SkipCAN, a modification of the SkipNet and Content Addressable Network DHTs. Finally, the fundamental issue in the federated Resource Manager is how to distributed the operators of multiple applications across the geographically distributed sites where computational resources can execute them. To address this, we introduce DistAl, a fully distributed algorithm that assigns operators to sites. DistAl also respects the system resource constraints and application preferences for performance and quality of results (QoR), using application-specific utility functions to allow applications to express their preferences. DistAl is validated by simulation results.

Industrial automation is critical in today's industry. The majority of new scientific and technological advancements are either enabling technologies or industrial automation application areas. In the past, the two main forms of control systems were distributed control systems (DCS) and programmable logic controllers (PLCs). PLCs have been referred as the "brain" of production systems because they provide the capacity to meet interoperability, reconfigurability, and portability criteria. Today's industrial automation systems rely heavily on control software to ensure that the automation process runs smoothly and efficiently. Furthermore, requirements like flexibility, adaptability, and robustness add to the control software's complexity. As a result, new approaches to building control software are required. The International Electrotechnical Commission attempted to meet these new and impending demands with the new IEC 61499 family of standards for distributed automation systems. The IEC 61499 standard specifies a high-level system design language for distributed data and control. With the advancement of these technologies like edge/fog computing and IIoT, how the control software in future smart factory managed is discussed here. This study aims to do a systematic literature review on PLC, software containers, edge/fog computing and IIoT for future industrial use. The objective is to identify the correspondence between the functional block (IEC 61499) and the container technology such as Docker. The impact of edge computing and the internet of things in industrial automation is also analysed. Since the aim is to do a comparative study, a qualitative explorative study is done, with the purpose to gather rich insight about the field. The analysis of the study mainly focused on four major areas such as deployment, run time, performance and security of these technologies. The result shows that containerisation or container based solutions is the basis for future automation as it outperforms virtual machines in terms of deployment, run time, performance and security.

This thesis tackles the topic of serving IoT applications in the computing continuum. It proposes an approach to place applications in the tiers of the continuum, considering latency and energy as predefined metrics. It presents a system model to represent the computing continuum environment, and then, defines an optimization function that is tailored to meet the specific requirements of the IoT applications. The optimization function addresses the relationship between latency and energy consumption in the framework of IoT service provision, and it is implemented in two different directions: (1) the first direction uses a modified Genetic algorithm, and (2) the second direction utilizes the Machine learning concept. To evaluate the performance of the proposed approach, we incorporate different testbed setups and network configurations. All the setups and configurations are designed to represent the diverse demands of IoT applications. Then, different algorithms (such as Non-dominated Sorting Genetic Algorithm (NSGA), Brute Force, and Machine Learning) are implemented to provide different application placement scenarios. The results highlight the efficiency of the proposed approach in comparison with the Brute Force optimal solution while meeting the application requirements. This thesis proposes an optimized solution for serving IoT applications in the computing continuum environment. It considers two essential metrics (latency and energy consumption) in the applications placement processes while meeting the diverse functional and non-functional requirements of these applications. The study provides insights and ideas for future research to refine strategies that will minimize latency and energy consumption. It also urges researchers to consider more metrics while developing and implementing IoT applications. The requirements related to computing resources and performance levels make the development and implementation of these applications complex and challenging. This study serves as a foundational stepping stone towards addressing those challenges.

[ES] En los últimos años, Internet de las cosas (``Internet of Things'' o ``IoT'') ha evolucionado de ser simplemente un concepto académico, construido alrededor de protocolos de comunicación y dispositivos, a ser un ecosistema con aplicaciones industriales y de negocio con implicaciones tecnológicas y sociales sin precedentes. Gracias a las nuevas redes de acceso inalámbricas emergentes, sensores mejorados y sistemas embebidos con procesadores cada vez más eficientes y baratos, una gran cantidad de objetos (tanto de nuestra vida cotidiana como de sistemas y procesos industriales) están interconectados entre sí, trasladando la información del mundo físico a las aplicaciones y servicios de Internet. A través de las pasarelas IoT los dispositivos que interactúan con el mundo físico son capaces de conectarse a las redes de comunicación e intercambiar información. Son varios los retos que deben afrontar las pasarelas en su papel dentro del Internet de las Cosas, entre ellas, la escalabilidad, seguridad, la gestión de dispositivos y, recientemente, la interoperabilidad. La falta de interoperabilidad entre los dispositivos provoca importantes problemas tecnológicos y empresariales, tales como la imposibilidad de conectar dispositivos IoT no interoperables a plataformas IoT heterogéneas, la imposibilidad de desarrollar aplicaciones IoT que exploten múltiples plataformas en dominios homogéneos y/o cruzados, la lentitud en la introducción de la tecnología IoT a gran escala, el desánimo en la adopción de la tecnología IoT, el aumento de los costes, la escasa reutilización de las soluciones técnicas y la insatisfacción de los usuarios. El propósito de esta tesis doctoral es la búsqueda de una solución óptima para la interoperabilidad entre dispositivos de Internet de las Cosas mediante la definición de una pasarela IoT genérica, modular y extensible; sin dejar de lado aspectos esenciales como la seguridad, escalabilidad y la calidad de servicio. Se completa esta tesis doctoral con una implementación software de la pasarela IoT siguiendo la definición propuesta, así como el despliegue y la evaluación de los resultados obtenidos en numerosos casos de uso pertenecientes a pilotos del proyecto de investigación Europeo ``INTER-IoT'' financiado a través del programa marco Horizonte 2020. / [CA] En els últims anys, Internet de les coses (``Internet of Things'' o ``IoT'') ha evolucionat de ser simplement un concepte acadèmic, construït al voltant de protocols de comunicació i dispositius, a ser un ecosistema amb aplicacions industrials i de negoci amb implicacions tecnològiques i socials sense precedents. Gràcies a les noves xarxes d'accés ``wireless'' emergents, sensors millorats i sistemes embeguts amb processadors cada vegada més eficients i barats, una gran quantitat d'objectes (tant de la nostra vida quotidiana com de sistemes i processos industrials) estan interconnectats entre si, traslladant la informació del món físic a les aplicacions i serveis d'Internet. A través de les passarel·les IoT els dispositius que interactuen amb el món físic són capaços de connectar-se a les xarxes de comunicació i intercanviar informació. Són diversos els reptes que han d'afrontar les passarel·les en el seu paper dins de la Internet de les Coses, entre elles, l'escalabilitat, seguretat, la gestió de dispositius i, recentment, la interoperabilitat. La falta d'interoperabilitat entre els dispositius provoca importants problemes tecnològics i empresarials, com ara la impossibilitat de connectar dispositius IoT no interoperables a plataformes IoT heterogènies, la impossibilitat de desenvolupar aplicacions IoT que exploten múltiples plataformes en dominis homogenis i/o croats, la lentitud en la introducció de la tecnologia IoT a gran escala, el descoratjament en l'adopció de la tecnologia IoT, l'augment dels costos, l'escassa reutilització de les solucions tècniques i la insatisfacció dels usuaris. El propòsit d'aquesta tesi doctoral és la cerca d'una solució òptima per a la interoperabilitat entre dispositius d'Internet de les Coses mitjançant la definició d'una passarel·la IoT genèrica, modular i extensible; sense deixar de costat aspectes essencials com la seguretat, escalabilitat i la qualitat de servei. Es completa aquesta tesi doctoral amb una implementació programari de la passarel·la IoT seguint la definició proposada, així com el desplegament i l'avaluació dels resultats obtinguts en nombrosos casos d'ús pertanyents a pilots del projecte d'investigació Europeu ``INTER-IoT'' finançat a través del programa marc Horitzó 2020. / [EN] In recent years, the Internet of Things (``IoT") has evolved from being simply an academic concept, built around communication protocols and devices, to an ecosystem with industrial and business applications with unprecedented technological and social implications. Thanks to new emerging wireless access networks, improved sensors and embedded systems with increasingly efficient and inexpensive processors, a large number of objects (both in our daily lives and in industrial systems and processes) are interconnected with each other, moving information from the physical world to Internet applications and services. Through IoT gateways, devices that interact with the physical world are able to connect to communication networks and exchange information. There are several challenges that gateways must face in their role within the Internet of Things, including scalability, security, device management and, recently, interoperability. The lack of interoperability between devices causes major technological and business problems, such as the impossibility of connecting non-interoperable IoT devices to heterogeneous IoT platforms, the impossibility of developing IoT applications that exploit multiple platforms in homogeneous and/or cross-domains, the slow introduction of IoT technology on a large scale, discouragement in the adoption of IoT technology, increased costs, low utilization of technical solutions and user dissatisfaction. The purpose of this doctoral thesis is the search for an optimal solution for interoperability between Internet of Things devices by defining a generic, modular and extensible IoT gateway; without neglecting essential aspects such as security, scalability and quality of service. This doctoral Thesis is completed with a software implementation of the IoT gateway following the proposed definition, as well as the deployment and evaluation of the results obtained in numerous use cases belonging to the pilots of the European research project ``INTER-IoT'' funded through the Horizon 2020 framework program. / Esta tesis doctoral se completa con una implementación software de la pasarela IoT siguiendo la definición propuesta, así como el despliegue y la evaluación de los resultados obtenidos en numerosos casos de uso pertenecientes a pilotos del proyecto de investigación Europeo “INTER-IoT” financiado a través del programa marco Horizonte 2020. / Olivares Gorriti, E. (2022). Especificación y desarrollo de una pasarela física y virtual para interoperabilidad de dispositivos heterogéneos en el ámbito de Internet de las Cosas [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/181492

Cyber-Physical Systems (CPS) have become one of the greatest research topics today; because they pose a new complex discipline, which addresses big existing and future systems as the Internet, the Internet of Things, sensors networks and smart grids. As a recent discipline, there are many possibilities to improve the state of the art, interoperability being one of the most relevant. Thus, this thesis has been created within the framework of interoperability for CPS, by using the SOS (Sensor Observation Service) standard, which belongs to the SWE (Sensor Web Enablement) framework of the OGC (Open Geospatial Consortium). It has been developed to give rise to a new line of research within the Distributed Real-Time Systems and Applications group (SATRD for its acronym in Spanish) from the Communications Department of the Polytechnic University of Valencia (UPV for its acronym in Valencian). The approach, with which the interoperability in the CPS has been addressed, is of synthetic type (from parts to whole), starting from a verifiable and workable solution for interoperability in sensor networks, one of the most significant CPSs because it is integrated in many other CPSs, next adapting and testing the solution in more complex CPS, such as the Internet of Things. In this way, an interoperability solution in sensor networks is proposed based on the SOS, but adapted to some requirements that makes of this mechanism a lighter version of the standard, which facilitates the deployment of future implementations due to the possibility of using limited devices for this purpose. This theoretical solution is brought to a first implementation, called SOSLite, which is tested to determine its characteristic behavior and to verify the fulfillment of its purpose. Analogously, and starting from the same theoretical solution, a second implementation is projected called SOSFul, which proposes an update to the SOS standard so that it is lighter, more efficient and easier to use. The SOSFul, has a more ambitious projection by addressing the Internet of Things, a more complex CPS than sensors networks. As in the case of the SOSLite, tests are performed and validation is made through a use case. So, both the SOSLite and the SOSFul are projected as interoperability solutions in the CPS. Both implementations are based on the theoretical proposal of a light SOS and are available for free and under open source licensing so that it can be used by the research community to continue its development and increase its use. / Los Sistemas Ciber-Físicos (CPS) se han convertido en uno de los temas de investigación con mayor proyección en la actualidad; debido a que plantean una nueva disciplina compleja, que aborda sistemas existentes y futuros de gran auge como: la Internet, la Internet de las Cosas, las redes de sensores y las redes eléctricas inteligentes. Como disciplina en gestación, existen muchas posibilidades para aportar al estado del arte, siendo la interoperabilidad uno de los más relevantes. Así, esta tesis se ha creado en el marco de la interoperabilidad para los CPS, mediante la utilización del estándar SOS (Sensor Observation Service) perteneciente al marco de trabajo SWE (Sensor Web Enablement) del OGC (Open Geospatial Consortium). Se ha desarrollado para dar surgimiento a una nueva línea de investigación dentro del grupo SATRD (Sistemas y Aplicaciones de Tiempo Real Distribuidos) del Departamento de Comunicaciones de la UPV (Universitat Politècnica de València). La aproximación con la cual se ha abordado la interoperabilidad en los CPS es de tipo sintética (pasar de las partes al todo), iniciando desde una solución, verificable y realizable, para la interoperabilidad en las redes de sensores, uno de los CPS más significativos debido a que se integra en muchos otros CPS, y pasando a adaptar y comprobar dicha solución en CPS de mayor complejidad, como la Internet de las Cosas. De esta forma, se propone una solución de interoperabilidad en las redes de sensores fundamentada en el SOS, pero adaptada a unos requerimientos que hacen de este mecanismo una versión más ligera del estándar, con lo que se facilita el despliegue de futuras implementaciones debido a la posibilidad de emplear dispositivos limitados para tal fin. Dicha solución teórica, se lleva a una primera implementación, denominada SOSLite, la cual se prueba para determinar su comportamiento característico y verificar el cumplimiento de su propósito. De forma análoga y partiendo de la misma solución teórica, se proyecta una segunda implementación, llamada SOSFul, la cual propone una actualización del estándar SOS de forma que sea más ligero, eficiente y fácil de emplear. El SOSFul, tiene una proyección más ambiciosa al abordar la Internet de las Cosas, un CPS más complejo que las redes de sensores. Como en el caso del SOSLite, se realizan pruebas y se valida mediante un caso de uso. Así, tanto el SOSLite como el SOSFul se proyectan como soluciones de interoperabilidad en los CPS. Ambas implementaciones parten de la propuesta teórica de SOS ligero y se encuentran disponibles de forma gratuita y bajo código libre, para ser empleados por la comunidad investigativa para continuar su desarrollo y aumentar su uso. / Els sistemes ciberfísics (CPS, Cyber-Physical Systems) s'han convertit en un dels temes de recerca amb major projecció en l'actualitat, a causa del fet que plantegen una nova disciplina complexa que aborda sistemes existents i futurs de gran auge, com ara: la Internet, la Internet de les Coses, les xarxes de sensors i les xarxes elèctriques intel·ligents. Com a disciplina en gestació, hi ha moltes possibilitats per a aportar a l'estat de la qüestió, sent la interoperabilitat una de les més rellevants. Així, aquesta tesi s'ha creat en el marc de la interoperabilitat per als CPS, mitjançant la utilització de l'estàndard SOS (Sensor Observation Service) pertanyent al marc de treball SWE (Sensor Web Enablement) de l'OGC (Open Geospatial Consortium). S'ha desenvolupat per a iniciar una nova línia de recerca dins del Grup de SATRD (Sistemes i Aplicacions de Temps Real Distribuïts) del Departament de Comunicacions de la UPV (Universitat Politècnica de València). L'aproximació amb la qual s'ha abordat la interoperabilitat en els CPS és de tipus sintètic (passar de les parts al tot), iniciant des d'una solució, verificable i realitzable, per a la interoperabilitat en les xarxes de sensors, un dels CPS més significatius pel fet que s'integra en molts altres CPS, i passant a adaptar i comprovar aquesta solució en CPS de major complexitat, com la Internet de les Coses. D'aquesta forma, es proposa una solució d'interoperabilitat en les xarxes de sensors fonamentada en el SOS, però adaptada a uns requeriments que fan d'aquest mecanisme una versió més lleugera de l'estàndard, amb la qual cosa es facilita el desplegament de futures implementacions per la possibilitat d'emprar dispositius limitats a aquest fi. Aquesta solució teòrica es porta a una primera implementació, denominada SOSLite, que es prova per a determinar el seu comportament característic i verificar el compliment del seu propòsit. De forma anàloga i partint de la mateixa solució teòrica, es projecta una segona implementació, anomenada SOSFul, que proposa una actualització de l'estàndard SOS de manera que siga més lleuger, eficient i fàcil d'emprar. El SOSFul té una projecció més ambiciosa quan aborda la Internet de les Coses, un CPS més complex que les xarxes de sensors. Com en el cas del SOSLite, es realitzen proves i es valida mitjançant un cas d'ús. Així, tant el SOSLite com el SOSFul, es projecten com a solucions d'interoperabilitat en els CPS. Ambdues implementacions parteixen de la proposta teòrica de SOS lleuger, i es troben disponibles de forma gratuïta i en codi lliure per a ser emprades per la comunitat investigadora a fi de continuar el seu desenvolupament i augmentar-ne l'ús. / Pradilla Ceron, JV. (2016). SOSLite: Soporte para Sistemas Ciber-Físicos y Computación en la Nube [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/76808

I takt med den exponentiella tillväxten av Internet of Things (IoT) har utmaningen att hantera den enorma mängden genererade data blivit allt större. Denna studie undersöker paradigmen med distribuerade dimdatorer, där kostnadseffektiva IoT-enheter används som dimnoder, som en potentiell lösning på de utmaningarna som det centraliserade molnet står inför. Skalbarheten och prestandan hos ett dimdatorsystem utvärderades under en rad olika arbetsbelastningar genererade av beräkningsintensiva uppgifter. Resultaten visade att en ökning av antal dimnoder förbättrade systemets skalbarhet och minskade den totala latensen. Dock visade det sig att konfigurationer med färre dimnoder presterade bättre vid lägre arbetsbelastningar, vilket understryker vikten av balansen mellan beräkningsuppgifter och kommunikationskostnaden. Sammantaget framhäver denna studie dimdatorkonceptets genomförbarhet som en effektiv och skalbar lösning för beräkningsintensiva databearbetning inom IoT. Trots att studiens fokus låg på latens, kan de insikter som vunnits vägleda framtida design och implementering av dimdatorsystem och bidra till de pågående diskussionerna om strategier för datahantering inom IoT. / With the exponential growth of the Internet of Things (IoT), managing the enormous amount of data generated has become a significant challenge. This study investigates the distributed paradigm of fog computing, using cost-effective IoT devices as fog nodes, as a potential solution for the centralized cloud. The scalability and performance of a fog computing system were evaluated under a range of workloads, using computationally intensive tasks reflective of real-world scenarios. Results indicated that with an increase in the number of fog nodes, system scalability improved, and the overall latency decreased. However, at lower workloads, configurations with fewer fog nodes outperformed those with more, highlighting the importance of the balance between computation and communication overheads. Overall, this study emphasizes the viability of fog computing as an efficient and scalable solution for data processing in IoT systems. Although the study primarily focused on latency, the insights gained could guide future design and implementation of fog computing systems and contribute to the ongoing discussions on IoT data processing strategies.

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Le concept de Ville Intelligent concerne l’interconnectivité totale de plusieurs industries vers l’amélioration des modes de vie des résidents. Ceci est rendu possible par la croissance et l'utilisation généralisée de l'Internet des objets (IoT), un vaste réseau de dispositifs de collecte de données répartis dans de multiples applications. Cependant, la plupart des appareils IoT disposent de peu de ressources et s'appuient sur des serveurs externes pour traiter et stocker les données collectées. En raison de la congestion et de la distance élevées, les centres de données Nuage (Cloud) peuvent entraîner une latence élevée dans leur réponse IoT, ce qui peut être inacceptable dans certaines applications IoT. Au lieu de cela, l'informatique Brouillard (fog-computing) a été proposé comme une couche hétérogène hautement virtualisée de serveurs à la périphérie du réseau, ce qui permet un traitement des données IoT à faible latence. Les contributions actuelles au brouillard informatique supposent qu'une infrastructure de brouillard est déjà en place. De plus, chaque contribution nécessite des caractéristiques différentes sur l’infrastructure du brouillard. Cette thèse formule un schéma de conception et de dimensionnement évolutif et modifiable pour une infrastructure de brouillard généralisée. Ceci est modélisé et résolu sous la forme d'un programme linéaire à nombres entiers mixtes (MILP), et détendu à l'aide de plusieurs techniques telles que la génération de colonnes et la décomposition de Benders. De nombreuses préoccupations concernant les performances du réseau brouillard sont prises en compte et résolues, telles que le trafic IoT élevé, la congestion du réseau et les dysfonctionnements des nœuds brouillard. Les nœuds de brouillard dynamiques, tels que les nœuds de brouillard à la demande et les véhicules aériens sans pilote mobiles (UAV-brouillard) sont intégrés dans les modèles de conception et de dimensionnement actuels pour ajouter de la flexibilité et de la robustesse au réseau. Un système basé sur la blockchain et des preuves de connaissance nulle est introduit pour renforcer l'intégrité des nœuds de brouillard. Le résultat est un schéma de conception et de dimensionnement évolutif pour une infrastructure de brouillard robuste, flexible et fiable dans un environnement de brouillard-IoT dynamique et malveillant. / The concept of a Smart City relies on the full interconnectivity of several industries towards the amelioration of resident lifestyles. This is made possible by the growth and wide-spread use of the Internet of Things (IoT) -- a large network of data collection devices throughout multiple applications. However, most IoT devices have few resources, and rely on external servers to process and store the collected data. Due to high congestion and distance, Cloud data centres may cause high latency in their IoT response, which may be unacceptable in certain IoT applications. Instead, fog-computing has been proposed as a highly-virtualized heterogeneous layer of servers on the network edge, resulting in low-latency IoT data processing. Current contributions in fog-computing assume a fog infrastructure is already in-place. Furthermore, each contribution requires different characteristics on the fog infrastructure. This thesis formulates a scalable and modifiable design & dimensioning scheme for a generalized fog infrastructure. This is modeled and solved as a mixed-integer linear program (MILP), and relaxed using several techniques such as Column Generation and Benders Decomposition. Many concerns on the fog network performance are considered and addressed, such as high IoT traffic, network congestion, and fog node malfunctions. Dynamic fog nodes, such as on-demand fog nodes and mobile fog-enabled unmanned aerial vehicles (fog-UAVs) are integrated into current design & dimensioning models to add flexibility and robustness to the network. A system based on blockchain and zero-knowledge proofs is introduced to enforce integrity on the fog nodes. The result is a scalable design & dimensioning scheme for a robust, flexible, and reliable fog infrastructure in a dynamic and malicious IoT-fog environment.