Coping with Episodic Connectivity in Heterogeneous Networks

International audienceIn this paper, we present an efficient message delivery mechanism that enables distribution/dissemination of messages in an internet connecting heterogeneous networks and prone to disruptions in connectivity. We call our protocol MeDeHa (pronounced “medea”) for Message Delivery in Heterogeneous, Disruptionprone Networks. MeDeHa is complementary to the IRTF's Bundle Architecture: while the Bundle Architecture provides storage above the transport layer in order to enable interoperability among networks that support different types of transport layers, MeDeHa stores data at the link layer addressing heterogeneity at lower layers (e.g., when intermediate nodes do not support higher-layer protocols). MeDeHa also takes advantage of network heterogeneity (e.g., nodes supporting more than one network) to improve message delivery. For example, in the case of IEEE 802.11 networks, participating nodes may use both infrastructure- and ad hoc modes to deliver data to otherwise unavailable destinations. Another important feature of MeDeHa is that there is no need to deploy special-purpose nodes such as message ferries, data mules, or throwboxes in order to relay data to intended destinations, or to connect to the backbone network wherever infrastructure is available. The network is able to store data destined to temporarily unavailable nodes for some time depending upon existing storage as well as quality-of-service issues such as delivery delay bounds imposed by the application. We evaluate MeDeHa via simulations using indoor scenarios (e.g. convention centers, exposition halls, museums etc.) and show significant improvement in delivery ratio in the face of episodic connectivity. We also showcase MeDeHa's support for different levels of quality-of-service through traffic differentiation and message prioritization

Software-Defined Networking Enabled Capacity Sharing in User Centric Networks

International audienceIn this paper, we discuss User Centric Networks (UCNs) as a way of, if not completely solving, considerably mitigating the problem of sharing limited network capacity and resources efficiently and fairly. UCNs are self-organizing networks where the end-user plays an active role in delivering networking functions such as providing Internet access to other users. We propose to leverage the recently proposed Software Defined Networking (SDN) paradigm to enable cooperation between wireless nodes and provide capacity sharing services in UCNs. Our SDN-based approach allows to extend coverage of existing network infrastructure (such as WiFi or 3GPP) to other end-users or ad hoc networks that would otherwise not be able to have access to network connectivity and services. Moreover, the proposed SDN-based architecture also takes into account current network load and conditions, and quality-of service (QoS) requirements. Another important feature of our framework is that security is an integral part of the architecture and protocols. We discuss the requirements for enabling capacity sharing services in the context of UCNs (e.g., resource discovery, node admission control, cooperation incentives, QoS, security, etc) and how SDN can aid in enabling such services. The paper also describes the proposed SDN-enabled capacity sharing framework for UCNs

Mobilities of knowledge: an introduction

Mobilities of Knowledge examines how geographical mobility of people and (im)material things has impacted epistemic systems of knowledge in different historical and geographical contexts. In this chapter, the authors introduce concepts and debates in interdisciplinary research on spatial mobility and the production, dissemination, and transfer of knowledge. They suggest extending Urry’s (2007) typology of interdependent mobilities that constitute the space of flows and the space of places (Castells, 1996) from five to six dimensions through the consideration of mobile knowledges, concepts, and practices. Finally, they outline how the chapters of this volume help to identify generic as well as context-specific practices and processes of knowledge production, dissemination, and transfer and call for more empirical case studies to further the collective development of flexible conceptual understandings

Redefining the anthology : forms and affordances in digital culture

Alors que le modèle économique de la télévision américaine, longtemps dominant, a été mis au défi de diverses manières par les changements industriels et technologiques de ces dernières années, des formes narratives de plus en plus hétérogènes sont apparues, qui se sont ajoutées aux structures sérielles originaires. La diversité des formes télévisuelles est devenue particulièrement évidente depuis que les paysages télévisuels nationaux et locaux ont commencé à s’ouvrir aux marchés étrangers situés en dehors des États-Unis, pour finalement adopter une perspective transnationale et globale. La transition vers la télévision distribuée sur Internet a joué un rôle central dans cette fragmentation formelle et la nouvelle dynamique de la diffusion en ligne a ouvert une different perspective pour comprendre le flux mondial de contenus télévisuels, qui reflète aujourd'hui un environnement multimédia et numérique hautement interconnecté et mis en réseau. En effet, la multiplication des services de vidéo à la demande oblige la sérialité à s’adapter au paysage médiatique contemporain, donnant naissance à des produits audiovisuels pouvant être transférés en ligne et présentant des spécificités de production, de distribution et de réception. L’un des résultats de tels changements dans les séries télévisées américaines à l’aube du XXIe siècle est la série anthologique divisée en différentes saisons avec des histoires distinctes, et pourtant liées par le ton et le style. Ma recherche se situe dans un tel contexte technologique, industriel et culturel, où le contenu télévisuel est de plus en plus fragmenté. Compte tenu de cette fragmentation des contenus, cette thèse examine la manière dont les contenus télévisuels contemporains sont distribués, dans l'interaction entre les processus de recommandation basés sur des algorithmes et les pratiques éditoriales plus traditionnelles. L’objectif de ce projet est donc d’étudier la manière dont certaines structures narratives typiques de la forme de l’anthologie apparaissent dans le contexte de la sérialité de la télévision nord-américaine, à partir de conditions spécifiques de production, de distribution et de consommation dans l’industrie des médias. En se concentrant sur l'évolution (dimension temporelle et historique) et sur la circulation numérique (dimension spatiale, géographique) des séries d'anthologies américaines, et en observant les particularités de leur production et de leur style, ainsi que leurs réseaux de distribution et les modes de consommation qu'elles favorisent, cette thèse s’inscrit finalement dans une conversation plus vaste sur les études culturelles et numériques. L’objectif final est d’étudier la relation entre les formes anthologiques, les plateformes de distribution et les modèles de consommation, en proposant une approche comparative de l’anthologie qui soit à la fois cross-culturelle, crosshistorique, cross-genre et qui prenne en consideration les pratiques pre- et post-numériques pour l’organisation de contenus culturels.As the longtime dominant U.S. television business model has been challenged in various ways by industrial and technological changes in recent years, more heterogeneous narrative forms have emerged in addition to original serial structures. The diversity of televisual forms became particularly evident since national, local television landscapes started opening up to foreign markets outside of the U.S., finally embracing a transnational, global perspective and tracing alternative value-chains. The transition to internet-distributed television played a pivotal role in this formal fragmentation and new dynamics of online streaming opened up another path for understanding the flow of television content, which today reflects a highly interconnected, networked media and digital environment. Indeed, the proliferation of video-on-demand services is forcing seriality to adapt to the contemporary mediascape, giving rise to audiovisual products that can be transferred online and present specificities in production, distribution and reception. One of the outcomes of such changes in U.S. television series at the dawn of the twenty-first century is the anthology series divided in different seasons with separate stories, yet linked by tone and style. My research positions itself in such a technological, industrial and cultural context, where television content is increasingly fragmented. Given such a fragmentation, this thesis considers the ways contemporary television content is distributed in the interaction between algorithmic-driven recommendation processes and more traditional editorial practices. The aim of the project is to investigate the way certain narrative structures typical of the anthology form emerge in the context of U.S. television seriality, starting from specific conditions of production, distribution and consumption in the media industry. By focusing on the evolution (temporal, historical dimension) and on the digital circulation (spatial, geographic dimension) of U.S. anthology series, and observing the peculiarities in their production and style, as well as their distributional networks and the consumption patterns they foster, this thesis ultimately insert itself into a larger conversation on digital-cultural studies. The final purpose is to examine the relation between anthological forms, distribution platforms and consumption models, by proposing a comparative approach to the anthology that is at the same time cross-cultural, cross-historical, cross-genre and accounting for both pre- and post-digital practices for cultural content organization

Resource management in future mobile networks: from millimetre-wave backhauls to airborne access networks

The next generation of mobile networks will connect vast numbers of devices and support services with diverse requirements. Enabling technologies such as millimetre-wave (mm-wave) backhauling and network slicing allow for increased wireless capacities and logical partitioning of physical deployments, yet introduce a number of challenges. These include among others the precise and rapid allocation of network resources among applications, elucidating the interactions between new mobile networking technology and widely used protocols, and the agile control of mobile infrastructure, to provide users with reliable wireless connectivity in extreme scenarios. This thesis presents several original contributions that address these challenges. In particular, I will first describe the design and evaluation of an airtime allocation and scheduling mechanism devised specifically for mm-wave backhauls, explicitly addressing inter-flow fairness and capturing the unique characteristics of mm-wave communications. Simulation results will demonstrate 5x throughput gains and a 5-fold improvement in fairness over recent mm-wave scheduling solutions. Second, I will introduce a utility optimisation framework targeting virtually sliced mm-wave backhauls that are shared by a number of applications with distinct requirements. Based on this framework, I will present a deep learning solution that can be trained within minutes, following which it computes rate allocations that match those obtained with state-of-the-art global optimisation algorithms. The proposed solution outperforms a baseline greedy approach by up to 62%, in terms of network utility, while running orders of magnitude faster. Third, the thesis investigates the behaviour of the Transport Control Protocol (TCP) in Long-Term Evolution (LTE) networks and discusses the implications of employing Radio Link Control (RLC) acknowledgements under different link qualities, on the performance of transport protocols. Fourth, I will introduce a reinforcement learning approach to optimising the performance of airborne cellular networks serving users in emergency settings, demonstrating rapid convergence (approx. 2.5 hours on a desktop machine) and a 5dB improvement of the median Signal-to-Noise-plus-Interference-Ratio (SINR) perceived by users, over a heuristic based benchmark solution. Finally, the thesis discusses promising future research directions that follow from the results obtained throughout this PhD project

A Survey of Software-Defined Networking: Past, Present, and Future of Programmable Networks

accepted in IEEE Communications Surveys & TutorialsInternational audienceThe idea of programmable networks has recently re-gained considerable momentum due to the emergence of the Software-Defined Networking (SDN) paradigm. SDN, often referred to as a ''radical new idea in networking'', promises to dramatically simplify network management and enable innovation through network programmability. This paper surveys the state-of-the-art in programmable networks with an emphasis on SDN. We provide a historic perspective of programmable networks from early ideas to recent developments. Then we present the SDN architecture and the OpenFlow standard in particular, discuss current alternatives for implementation and testing of SDN-based protocols and services, examine current and future SDN applications, and explore promising research directions based on the SDN paradigm

Hybrid routing in delay tolerant networks

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

The future of Cybersecurity in Italy: Strategic focus area

This volume has been created as a continuation of the previous one, with the aim of outlining a set of focus areas and actions that the Italian Nation research community considers essential. The book touches many aspects of cyber security, ranging from the definition of the infrastructure and controls needed to organize cyberdefence to the actions and technologies to be developed to be better protected, from the identification of the main technologies to be defended to the proposal of a set of horizontal actions for training, awareness raising, and risk management

Hybrid Routing in Delay Tolerant Networks

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