75 research outputs found

    Ontology-based collaborative framework for disaster recovery scenarios

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    This paper aims at designing of adaptive framework for supporting collaborative work of different actors in public safety and disaster recovery missions. In such scenarios, firemen and robots interact to each other to reach a common goal; firemen team is equipped with smart devices and robots team is supplied with communication technologies, and should carry on specific tasks. Here, reliable connection is mandatory to ensure the interaction between actors. But wireless access network and communication resources are vulnerable in the event of a sudden unexpected change in the environment. Also, the continuous change in the mission requirements such as inclusion/exclusion of new actor, changing the actor's priority and the limitations of smart devices need to be monitored. To perform dynamically in such case, the presented framework is based on a generic multi-level modeling approach that ensures adaptation handled by semantic modeling. Automated self-configuration is driven by rule-based reconfiguration policies through ontology

    Building self-optimized communication systems based on applicative cross-layer information

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    This article proposes the Implicit Packet Meta Header(IPMH) as a standard method to compute and represent common QoS properties of the Application Data Units (ADU) of multimedia streams using legacy and proprietary streams’ headers (e.g. Real-time Transport Protocol headers). The use of IPMH by mechanisms located at different layers of the communication architecture will allow implementing fine per-packet selfoptimization of communication services regarding the actual application requirements. A case study showing how IPMH is used by error control mechanisms in the context of wireless networks is presented in order to demonstrate the feasibility and advantages of this approach

    A cross-layer approach to enhance QoS for multimedia applications over satellite

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    The need for on-demand QoS support for communications over satellite is of primary importance for distributed multimedia applications. This is particularly true for the return link which is often a bottleneck due to the large set of end-users accessing a very limited uplink resource. Facing this need, Demand Assignment Multiple Access (DAMA) is a classical technique that allows satellite operators to offer various types of services, while managing the resources of the satellite system efficiently. Tackling the quality degradation and delay accumulation issues that can result from the use of these techniques, this paper proposes an instantiation of the Application Layer Framing (ALF) approach, using a cross-layer interpreter(xQoS-Interpreter). The information provided by this interpreter is used to manage the resource provided to a terminal by the satellite system in order to improve the quality of multimedia presentations from the end users point of view. Several experiments are carried out for different loads on the return link. Their impact on QoS is measured through different application as well as network level metrics

    Adaptive Communication Agent for Group Communication activities

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    14International audienceIn group-wide collaborative environment, managing the adaptive communication is a challenging task. It implies the monitoring of sudden change in the activities while providing a solution to maintain the connection with the available resources. In this work, we design a software agent that supports autonomic computing to ensure reliable communications among the mobile devices and Autonomous Ground vehicles (AAV). This issue is addressed in the context of save and rescue missions carried out during natural disasters such as floods and forest fires by human and voluntary operators within the framework of wireless environment. The paper focuses the autonomic functionalities of the components used to monitor, analyze, plan, and execute the adaptive mechanisms in case of evolution (mission/environment). We distribute this agent among devices and vehicles to ensure the adaptive task and it is tackled by using appropriate policies used to select the decision and executed without manual intervention. This research is applied to a Crisis Management System (CMS) within the context of the French RTRA project (ROSACE)

    Model-based provisioning and management of adaptive distributed communication in mobile cooperative systems

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    Adaptation of communication is required to maintain the reliable connection and to ensure the minimum quality in collaborative activities. Within the framework of wireless environment, how can host entities be handled in the event of a sudden unexpected change in communication and reliable sources? This challenging issue is addressed in the context of Emergency rescue system carried out by mobile devices and robots during calamities or disaster. For this kind of scenario, this book proposes an adaptive middleware to support reconfigurable, reliable group communications. Here, the system structure has been viewed at two different states, a control center with high processing power and uninterrupted energy level is responsible for global task and entities like autonomous robots and firemen owning smart devices act locally in the mission. Adaptation at control center is handled by semantic modeling whereas at local entities, it is managed by a software module called communication agent (CA). Modeling follows the well-known SWRL instructions which establish the degree of importance of each communication link or component. Providing generic and scalable solutions for automated self-configuration is driven by rule-based reconfiguration policies. To perform dynamically in changing environment, a trigger mechanism should force this model to take an adaptive action in order to accomplish a certain task, for example, the group chosen in the beginning of a mission need not be the same one during the whole mission. Local entity adaptive mechanisms are handled by CA that manages internal service APIs to configure, set up, and monitors communication services and manages the internal resources to satisfy telecom service requirements

    QdS requise par une application de simulation interactive distribuée dans un environnement réseau grande distance

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    Ces derniĂšres annĂ©es, les Ă©volutions technologiques conjointes de l'informatique et des tĂ©lĂ©communications ont conduit au dĂ©veloppement de nouvelles applications distribuĂ©es, multimĂ©dias, nĂ©cessitant le traitement informatique et le transfert diffĂ©rĂ© ou en temps rĂ©el de tous les types de donnĂ©es. Parmi ces applications, les applications de simulation interactive distribuĂ©e (DIS : Distributed Interactive Simulation) prĂ©sentent des caractĂ©ristiques trĂšs contraignantes (trafic Ă©volutif, contraintes de temps rĂ©el et de fiabilitĂ© notamment) qui rendent difficile tant la caractĂ©risation de leur trafic que la spĂ©cification de la QoS (QoS : Quality of service) dont elles ont besoin. Cet article prĂ©sente tout d’abord les caractĂ©ristiques majeures des applications DIS ; dans un second temps sont exposĂ©s les rĂ©sultats d’une analyse de la QoS requise par ce type d’application dans un environnement rĂ©seau grande distance. Enfin, les conclusions de l’article prĂ©sentent les principes de conception d’une architecture de bout en bout garantissant la QoS proposĂ©e dans un environnement Internet nouvelle gĂ©nĂ©ration

    Contribution aux protocoles et aux architectures de communication de bout en bout pour la QdS dans l'internet

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    These latest years, the evolutions of computer science and telecommunications led to a radical modification of the communication landscape, and consequently of the Internet and its services: applications are now multimedia, multi users and co-operatives; networks now provide high transmission rates, at local scale or long distance, and make it possible to be connected to the Internet via various types of terminals and wire/wireless access points. In spite of these advances, the Internet communication services are still insufficient, in this way that they provide no guarantee on the performances, particularly as far as the end-to-end transit delay is concerned. This problem is targeted by our work, which addresses the need of new services, protocols and communication architectures for the Internet, aimed at providing end-to-end Quality of Service (QdS) guarantees. We start from a formal expression of the application needs, and lead to end-end solutions which try: (1) to integrate the considered levels (Application, Transport and IP); (2) to minimize resources utilization (band-width, buffer...); and (3) to abstract the application level from the choice and the configuration of the underlying services. Our contributions address three research topics: (1) the multimedia Transport services and protocols aimed at optimizing QdS in the Best Effort Internet; (2) the architectures providing guaranteed QdS, by coordinating the new services of the Internet at both Transport and IP levels (IntServ and DiffServ mono then multi domains); and (3) the signalling for QdS in a multi domains DiffServ Internet. Our research prospective concerns: (1) the signaling for QoS considering the heterogeneity of the multi domains Internet, and (2) the dynamic architecture and the configurable protocols to optimize the quality of the communication and the cooperation in the future ambient networks (mobile and ad hoc networks, sensors...) by taking into account the dynamicity of the context both at the user level (mobile and cooperating), and at the network level (mobile and with variable resources). null nullCes derniÚres années, les évolutions de linformatique et des télécommunications ont conduit à une modification drastique du paysage de la communication informatique, et en conséquence de lInternet et de ses services : les applications sont désormais à la fois multimédias, multi utilisateurs et coopératives ; les technologies réseaux offrent à présent de hauts débits de transmission, à échelle locale ou grande distance, et permettent de se connecter à lInternet via différents types de terminaux et de points daccÚs, filaires ou sans fil. En dépit de ces avancées, les services de communication offerts par lInternet sont encore trÚs insuffisants, en ceci quils noffrent aucune garantie sur les performances offertes, notamment en termes de délai de bout en bout. Cest dans cette problématique que sinscrivent nos travaux, qui adressent le besoin de nouveaux services, protocoles et architectures de communication pour lInternet, dans le but doffrir des garanties de Qualité de Service (QdS). Notre démarche part dune expression formelle des besoins applicatifs et aboutit à des solutions de bout en bout visant à : (1) intégrer les niveaux considérés (Application, Transport et IP) ; (2) minimiser lutilisation des ressources (bande passante, buffer, &) ; et (3) abstraire le niveau applicatif de la complexité du choix et du paramétrage des services sous-jacents. Trois thÚmes de recherche sont explorés : (1) les services et protocoles de Transport multimédia pour optimiser la QdS dans un contexte IP de type Best Effort ; (2) les architectures de bout en bout pour garantir la QdS, en coordonnant les nouveaux services de lInternet aux niveaux Transport et IP (IntServ et DiffServ mono puis multi domaines) ; et (3) la signalisation pour la QdS, dans un contexte IP de type DiffServ multi domaines. Notre prospective concerne dune part la signalisation pour la QdS en considérant à présent lhétérogénéité de lInternet multi domaines, et dautre part, les protocoles de Transp ort auto configurables et les architectures dynamiques, pour optimiser la qualité des communications et des coopérations dans les futurs réseaux ambiants (réseaux mobiles et ad hoc, capteurs, &) en tenant compte dune dynamicité du contexte à la fois au niveau utilisateur, mobile et coopérant, et au niveau du réseau, mobile et aux ressources variables. null nul

    Architecture de transport multimedia Ă  connexions d'ordre partiel

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    Les travaux prĂ©sentĂ©s dans ce mĂ©moire ont pour cadre la recherche de nouveaux services et protocoles de Transport, aptes Ă  supporter le transfert de donnĂ©es multimĂ©dia en tenant compte des exigences applicatives en termes de hauts dĂ©bits et de synchronisation. L'approche proposĂ©e repose sur la dĂ©finition et le dĂ©veloppement d'un nouveau concept: la connexion d'ordre partiel (POC - Partial Order Connection), Ă©tablissant un lien conceptuel entre les modes de service/protocole orientĂ©s-connexion tels que TCP, et sans connexion tels que UDP. Une POC est une connexion de bout en bout permettant de dĂ©finir et de mettre en Ɠuvre tous les services et protocoles d'ordre partiel entre deux entitĂ©s communicantes ; dans une POC, la dĂ©livrance des donnĂ©es Ă  l'utilisateur rĂ©cepteur peut ĂȘtre effectuĂ©e dans un ordre diffĂ©rent de l'ordre de soumission de ces donnĂ©es par l'utilisateur Ă©metteur: la diffĂ©rence (acceptable) entre ces deux ordres rĂ©sulte de la dĂ©finition, par l'utilisateur, d'un ordre partiel de dĂ©livrance lors de l'ouverture de la connexion. Une formalisation des mĂ©canismes correspondants est proposĂ©e au moyen de la technique de description formelle Estelle. Les caractĂ©ristiques intrinsĂšques des diffĂ©rents mĂ©dia d'un flux multimĂ©dia ont conduit ces derniĂšres annĂ©es au dĂ©veloppement d'architectures de communication intĂ©grant la prise en compte des contraintes applicatives Ă  diffĂ©rents niveaux conceptuels, et notamment au niveau Transport du modĂšle OSI ; Ă  partir d'une modĂ©lisation de ces contraintes utilisant le formalisme des rĂ©seaux de Petri (le modĂšle TSPN), l'auteur propose d'intĂ©grer le concept de POC dans une architecture de Transport multimĂ©dia autorisant une prise en compte globale des contraintes d'ordre et de fiabilitĂ© d'un flux multimĂ©dia. Les mĂ©canismes de gestion de l'ordre et de la fiabilitĂ© qui sont proposĂ©s permettent de dĂ©finir un service de Transport multimĂ©dia offrant une hypothĂšse nouvelle aux utilisateurs vis Ă  vis de la problĂ©matique de la synchronisation. Une Ă©tude de la faisabilitĂ© d'un protocole multimĂ©dia d'ordre partiel Ă  l'aide des procĂ©dures XTP est finalement prĂ©sentĂ©e: elle conclut en la possibilitĂ© d'une telle rĂ©alisatio

    On the enhancement of non-functional requirements for cloud-assisted middleware-based IoT and other applications

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    International audienceThe Internet of objects (IoT) will have to meet the non-functional needs (QoS, security, etc.) of new business applications supported by the cloud. To do this, the interactions between the underlying application software and the communicating objects will rely on networks and communication middleware with configurable, programmable and dynamically deployable capabilities. These capabilities will be available both on pre-existing entities but also on virtual entities, i.e. that will be dynamically created in the Cloud according to the need. In this new ecosystem, meeting the end-to-end QoS needs of these future applications is a major challenge. This challenge has particularly to be tackled both at the level of the Middleware intermediary entities and at the level of the networks interconnecting these entities. In this context, this paper presents our approach for a self-adaptive QoS management at the middleware level for IoT applications. This approach is aimed at: 1) taking advantage of the technological opportunities offered by the Cloud, the dynamic deployment of processing functions and the autonomic computing paradigm, 2) taking into account the hetero-geneity of the solutions that will coexist in this landscape, and 3) ensuring the consistency of the (re) configuration choices thanks to appropriate theoretical tools
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