13 research outputs found

    Hybrid routing in delay tolerant networks

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    This work addresses the integration of today\\u27s infrastructure-based networks with infrastructure-less networks. The resulting Hybrid Routing System allows for communication over both network types and can help to overcome cost, communication, and overload problems. Mobility aspect resulting from infrastructure-less networks are analyzed and analytical models developed. For development and deployment of the Hybrid Routing System an overlay-based framework is presented

    Hybrid Routing in Delay Tolerant Networks

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    This work addresses the integration of today\u27s infrastructure-based networks with infrastructure-less networks. The resulting Hybrid Routing System allows for communication over both network types and can help to overcome cost, communication, and overload problems. Mobility aspect resulting from infrastructure-less networks are analyzed and analytical models developed. For development and deployment of the Hybrid Routing System an overlay-based framework is presented

    Impacts of Mobility Models on RPL-Based Mobile IoT Infrastructures: An Evaluative Comparison and Survey

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    With the widespread use of IoT applications and the increasing trend in the number of connected smart devices, the concept of routing has become very challenging. In this regard, the IPv6 Routing Protocol for Low-power and Lossy Networks (PRL) was standardized to be adopted in IoT networks. Nevertheless, while mobile IoT domains have gained significant popularity in recent years, since RPL was fundamentally designed for stationary IoT applications, it could not well adjust with the dynamic fluctuations in mobile applications. While there have been a number of studies on tuning RPL for mobile IoT applications, but still there is a high demand for more efforts to reach a standard version of this protocol for such applications. Accordingly, in this survey, we try to conduct a precise and comprehensive experimental study on the impact of various mobility models on the performance of a mobility-aware RPL to help this process. In this regard, a complete and scrutinized survey of the mobility models has been presented to be able to fairly justify and compare the outcome results. A significant set of evaluations has been conducted via precise IoT simulation tools to monitor and compare the performance of the network and its IoT devices in mobile RPL-based IoT applications under the presence of different mobility models from different perspectives including power consumption, reliability, latency, and control packet overhead. This will pave the way for researchers in both academia and industry to be able to compare the impact of various mobility models on the functionality of RPL, and consequently to design and implement application-specific and even a standard version of this protocol, which is capable of being employed in mobile IoT applications

    Leveraging Cloud-based NFV and SDN Platform Towards Quality-Driven Next-Generation Mobile Networks

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    Network virtualization has become a key approach for Network Service Providers (NSPs) to mitigate the challenge of the continually increasing demands for network services. Tightly coupled with their software components, legacy network devices are difficult to upgrade or modify to meet the dynamically changing end-user needs. To virtualize their infrastructure and mitigate those challenges, NSPs have started to adopt Software Defined Networking (SDN) and Network Function Virtualization (NFV). To this end, this thesis addresses the challenges faced on the road of transforming the legacy networking infrastructure to a more dynamic and agile virtualized environment to meet the rapidly increasing demand for network services and serve as an enabler for key emerging technologies such as the Internet of Things (IoT) and 5G networking. The thesis considers different approaches and platforms to serve as an NFV/SDN based cloud applications while closely considering how such an environment deploys its virtualized services to optimize the network and reducing their costs. The thesis starts first by defining the standards of adopting microservices as architecture for NFV. Then, it focuses on the latency-aware deployment approach of virtual network functions (VNFs) forming service function chains (SFC) in a cloud environment. This approach ensures that NSPs still meet their strict quality of service and service level agreements while considering both functional and non-functional constraints of the NFV-based applications such as, delay, resource allocation, and intercorrelation between VNF instances. In addition, the thesis proposes a detailed approach on recovering and handling of those instances by optimizing the decision of migrating or re-instantiating the virtualized services upon a sudden event (failure/overload…). All the proposed approaches contribute to the orchestration of NFV applications to meet the requirements of the IoT and NGNs era

    Unmanned Aerial Vehicle (UAV)-Enabled Wireless Communications and Networking

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    The emerging massive density of human-held and machine-type nodes implies larger traffic deviatiolns in the future than we are facing today. In the future, the network will be characterized by a high degree of flexibility, allowing it to adapt smoothly, autonomously, and efficiently to the quickly changing traffic demands both in time and space. This flexibility cannot be achieved when the network’s infrastructure remains static. To this end, the topic of UAVs (unmanned aerial vehicles) have enabled wireless communications, and networking has received increased attention. As mentioned above, the network must serve a massive density of nodes that can be either human-held (user devices) or machine-type nodes (sensors). If we wish to properly serve these nodes and optimize their data, a proper wireless connection is fundamental. This can be achieved by using UAV-enabled communication and networks. This Special Issue addresses the many existing issues that still exist to allow UAV-enabled wireless communications and networking to be properly rolled out

    Designing and Deploying Internet of Things Applications in the Industry: An Empirical Investigation

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    RÉSUMÉ : L’Internet des objets (IdO) a pour objectif de permettre la connectivité à presque tous les objets trouvés dans l’espace physique. Il étend la connectivité aux objets de tous les jours et o˙re la possibilité de surveiller, de suivre, de se connecter et d’intéragir plus eÿcacement avec les actifs industriels. Dans l’industrie de nos jours, les réseaux de capteurs connectés surveillent les mouvements logistiques, fabriquent des machines et aident les organisations à améliorer leur eÿcacité et à réduire les coûts. Cependant, la conception et l’implémentation d’un réseau IdO restent, aujourd’hui, une tâche particulièrement diÿcile. Nous constatons un haut niveau de fragmentation dans le paysage de l’IdO, les développeurs se complaig-nent régulièrement de la diÿculté à intégrer diverses technologies avec des divers objets trouvés dans les systèmes IdO et l’absence des directives et/ou des pratiques claires pour le développement et le déploiement d’application IdO sûres et eÿcaces. Par conséquent, analyser et comprendre les problèmes liés au développement et au déploiement de l’IdO sont primordiaux pour permettre à l’industrie d’exploiter son plein potentiel. Dans cette thèse, nous examinons les interactions des spécialistes de l’IdO sur le sites Web populaire, Stack Overflow et Stack Exchange, afin de comprendre les défis et les problèmes auxquels ils sont confrontés lors du développement et du déploiement de di˙érentes appli-cations de l’IdO. Ensuite, nous examinons le manque d’interopérabilité entre les techniques développées pour l’IdO, nous étudions les défis que leur intégration pose et nous fournissons des directives aux praticiens intéressés par la connexion des réseaux et des dispositifs de l’IdO pour développer divers services et applications. D’autre part, la sécurité étant essen-tielle au succès de cette technologie, nous étudions les di˙érentes menaces et défis de sécurité sur les di˙érentes couches de l’architecture des systèmes de l’IdO et nous proposons des contre-mesures. Enfin, nous menons une série d’expériences qui vise à comprendre les avantages et les incon-vénients des déploiements ’serverful’ et ’serverless’ des applications de l’IdO afin de fournir aux praticiens des directives et des recommandations fondées sur des éléments probants relatifs à de tels déploiements. Les résultats présentés représentent une étape très importante vers une profonde compréhension de ces technologies très prometteuses. Nous estimons que nos recommandations et nos suggestions aideront les praticiens et les bâtisseurs technologiques à améliorer la qualité des logiciels et des systèmes de l’IdO. Nous espérons que nos résultats pourront aider les communautés et les consortiums de l’IdO à établir des normes et des directives pour le développement, la maintenance, et l’évolution des logiciels de l’IdO.----------ABSTRACT : Internet of Things (IoT) aims to bring connectivity to almost every object found in the phys-ical space. It extends connectivity to everyday things, opens up the possibility to monitor, track, connect, and interact with industrial assets more eÿciently. In the industry nowadays, we can see connected sensor networks monitor logistics movements, manufacturing machines, and help organizations improve their eÿciency and reduce costs as well. However, designing and implementing an IoT network today is still a very challenging task. We are witnessing a high level of fragmentation in the IoT landscape and developers regularly complain about the diÿculty to integrate diverse technologies of various objects found in IoT systems, and the lack of clear guidelines and–or practices for developing and deploying safe and eÿcient IoT applications. Therefore, analyzing and understanding issues related to the development and deployment of the Internet of Things is utterly important to allow the industry to utilize its fullest potential. In this thesis, we examine IoT practitioners’ discussions on the popular Q&A websites, Stack Overflow and Stack Exchange, to understand the challenges and issues that they face when developing and deploying di˙erent IoT applications. Next, we examine the lack of interoper-ability among technologies developed for IoT and study the challenges that their integration poses and provide guidelines for practitioners interested in connecting IoT networks and de-vices to develop various services and applications. Since security issues are center to the success of this technology, we also investigate di˙erent security threats and challenges across di˙erent layers of the architecture of IoT systems and propose countermeasures. Finally, we conduct a series of experiments to understand the advantages and trade-o˙s of serverful and serverless deployments of IoT applications in order to provide practitioners with evidence-based guidelines and recommendations on such deployments. The results presented in this thesis represent a first important step towards a deep understanding of these very promising technologies. We believe that our recommendations and suggestions will help practitioners and technology builders improve the quality of IoT software and systems. We also hope that our results can help IoT communities and consortia establish standards and guidelines for the development, maintenance, and evolution of IoT software and systems

    Performance of management solutions and cooperation approaches for vehicular delay-tolerant networks

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    A wide range of daily-life applications supported by vehicular networks attracted the interest, not only from the research community, but also from governments and the automotive industry. For example, they can be used to enable services that assist drivers on the roads (e.g., road safety, traffic monitoring), to spread commercial and entertainment contents (e.g., publicity), or to enable communications on remote or rural regions where it is not possible to have a common network infrastructure. Nonetheless, the unique properties of vehicular networks raise several challenges that greatly impact the deployment of these networks. Most of the challenges faced by vehicular networks arise from the highly dynamic network topology, which leads to short and sporadic contact opportunities, disruption, variable node density, and intermittent connectivity. This situation makes data dissemination an interesting research topic within the vehicular networking area, which is addressed by this study. The work described along this thesis is motivated by the need to propose new solutions to deal with data dissemination problems in vehicular networking focusing on vehicular delay-tolerant networks (VDTNs). To guarantee the success of data dissemination in vehicular networks scenarios it is important to ensure that network nodes cooperate with each other. However, it is not possible to ensure a fully cooperative scenario. This situation makes vehicular networks suitable to the presence of selfish and misbehavior nodes, which may result in a significant decrease of the overall network performance. Thus, cooperative nodes may suffer from the overwhelming load of services from other nodes, which comprises their performance. Trying to solve some of these problems, this thesis presents several proposals and studies on the impact of cooperation, monitoring, and management strategies on the network performance of the VDTN architecture. The main goal of these proposals is to enhance the network performance. In particular, cooperation and management approaches are exploited to improve and optimize the use of network resources. It is demonstrated the performance gains attainable in a VDTN through both types of approaches, not only in terms of bundle delivery probability, but also in terms of wasted resources. The results and achievements observed on this research work are intended to contribute to the advance of the state-of-the-art on methods and strategies for overcome the challenges that arise from the unique characteristics and conceptual design of vehicular networks.O vasto número de aplicações e cenários suportados pelas redes veiculares faz com que estas atraiam o interesse não só da comunidade científica, mas também dos governos e da indústria automóvel. A título de exemplo, estas podem ser usadas para a implementação de serviços e aplicações que podem ajudar os condutores dos veículos a tomar decisões nas estradas, para a disseminação de conteúdos publicitários, ou ainda, para permitir que existam comunicações em zonas rurais ou remotas onde não é possível ter uma infraestrutura de rede convencional. Contudo, as propriedades únicas das redes veiculares fazem com que seja necessário ultrapassar um conjunto de desafios que têm grande impacto na sua aplicabilidade. A maioria dos desafios que as redes veiculares enfrentam advêm da grande mobilidade dos veículos e da topologia de rede que está em constante mutação. Esta situação faz com que este tipo de rede seja suscetível de disrupção, que as oportunidades de contacto sejam escassas e de curta duração, e que a ligação seja intermitente. Fruto destas adversidades, a disseminação dos dados torna-se um tópico de investigação bastante promissor na área das redes veiculares e por esta mesma razão é abordada neste trabalho de investigação. O trabalho descrito nesta tese é motivado pela necessidade de propor novas abordagens para lidar com os problemas inerentes à disseminação dos dados em ambientes veiculares. Para garantir o sucesso da disseminação dos dados em ambientes veiculares é importante que este tipo de redes garanta a cooperação entre os nós da rede. Contudo, neste tipo de ambientes não é possível garantir um cenário totalmente cooperativo. Este cenário faz com que as redes veiculares sejam suscetíveis à presença de nós não cooperativos que comprometem seriamente o desempenho global da rede. Por outro lado, os nós cooperativos podem ver o seu desempenho comprometido por causa da sobrecarga de serviços que poderão suportar. Para tentar resolver alguns destes problemas, esta tese apresenta várias propostas e estudos sobre o impacto de estratégias de cooperação, monitorização e gestão de rede no desempenho das redes veiculares com ligações intermitentes (Vehicular Delay-Tolerant Networks - VDTNs). O objetivo das propostas apresentadas nesta tese é melhorar o desempenho global da rede. Em particular, as estratégias de cooperação e gestão de rede são exploradas para melhorar e optimizar o uso dos recursos da rede. Ficou demonstrado que o uso deste tipo de estratégias e metodologias contribui para um aumento significativo do desempenho da rede, não só em termos de agregados de pacotes (“bundles”) entregues, mas também na diminuição do volume de recursos desperdiçados. Os resultados observados neste trabalho procuram contribuir para o avanço do estado da arte em métodos e estratégias que visam ultrapassar alguns dos desafios que advêm das propriedades e desenho conceptual das redes veiculares

    Multi-Robot Systems: Challenges, Trends and Applications

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    This book is a printed edition of the Special Issue entitled “Multi-Robot Systems: Challenges, Trends, and Applications” that was published in Applied Sciences. This Special Issue collected seventeen high-quality papers that discuss the main challenges of multi-robot systems, present the trends to address these issues, and report various relevant applications. Some of the topics addressed by these papers are robot swarms, mission planning, robot teaming, machine learning, immersive technologies, search and rescue, and social robotics

    Anchor Vertex Selection for Enhanced Reliability of Traffic Offloading Service in Edge-Enabled Mobile P2P Social Networks

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    As the rapid growth of mobile social networks, mobile peer-to-peer (P2P) communications and mobile edge computing (MEC) have been developed to reduce the traffic load and improve the computation capacity of cellular networks. However, the stability of social network is largely ignored in the advances of P2P and MEC, which is related to the social relations between users. It plays a vital role in improving the efficiency and reliability of traffic offloading service. In this paper, we integrate an edge node and the nearby P2P users as a mobile P2P social network and introduce the problem of adaptive anchored (k,r)-core to maintain the stability of multiple mobile P2P networks. It aims to adaptively select and retain a set of critical users for each network, whose participation is critical to overall stability of the network, and allocate certain resource for them so that the maximum number of users of all networks will remain engaged and the traffic of cellular network can be minimized. We called the retained users as anchor vertices. To address it, we devise a peer-edge-cloud framework to achieve the adaptive allocation of resources. We also develop a similarity based onion layers anchored (k,r)-core (S-OLAK) algorithm to explore the anchor vertices. Experimental results based on a real large-scale mobile P2P data set demonstrate the effectiveness of our method
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