Self-Adaptive Communication for Collaborative Mobile Entities in ERCMS

International audienceAdaptation of communication is required for maintaining the connectivity and the quality of communication in group-wide collaborative activities. This becomes challenging to handle when considering mobile entities in a wireless environment, requiring responsiveness and availability of the communication system. We address these challenges in the context of the ROSACE project where mobile ground and flying robots have to collaborate with each other and with remote human and artificial actors to save and rescue in case of disasters such as forest fires. This paper aims to expose a communication component architecture allowing to manage a cooperative adaptation which is aware of the activity and resource context into pervasive environment. This allows to provide the appropriate adaptation of the activity in response to evolutions of the activity requirements and the changes in relation with the communication resource constraints. In this paper, we present a simulation of a ROSACE use case. The results show how ROSACE entities collaborate to maintain the connectivity and to enhance the quality of communications

Caractérisation de la reconfiguration dynamique des architectures logicielles par les grammaires de graphe

National audienceL'adaptabilité automatique d'une application est devenue impérative dans un contexte dynamique de syst emes complexes fortement distribués et contenant un grand nombre de composants. La résolution de cette problématique peut etre obtenue grâcè a l'adaptation structurelle impliquant une re-configuration de la structure architecturale de l'application. Nous présentons dans cet article un formalisme permettant, en utilisant les grammaires de graphes, de caractériser le style architectural d'une application et les transformations applicables lors de son exécution

Generic approach for graph-based description of dynamically reconfigurable architectures

Architectural adaptation is studied for handling adaptation in autonomic distributed systems. It is achieved by implementing a model-based approach for managing reconfiguration of dynamic architectures. Describing such architectures includes defining rules for describing both architectural styles and theirs reconfiguration mechanisms. Within this research context, the work presented in this paper is conducted using formal specification based on graphs and graph rewriting appropriately for tackling architectural adaptation problems. A graph-based general approach for describing architectures and handling their dynamic reconfiguration is introduced. Our approach is illustrated in the context of a distributed hierarchical application. The formal models that allow the generation of a graph grammar for dynamic architecture description and the automatic definition of transformation rules for achieving intern self-protecting during the adaptation are elaborated

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

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

Dynamic software architecture management for collaborative communicating systems. Gestion dynamique des architectures logicielles pour les systèmes communicants collaboratifs

In this work, we study dynamic reconfiguration of collaborative communicating applications. Providing generic and scalable solutions for automated self-reconfiguration in group collaboration support systems can be driven by rule-based reconfiguration policies. To achieve this goal, we elaborate a dynamic graph-based modelling approach and we develop structural models that can represent the different interaction dependencies from different configurationrelated point of views: communication flows between the distributed machines, the networked deployment nodes, and the service composition. Our solution is based on graph grammars rewriting. We provide graph transformation to specify rules for changing deployment architecture while being in conformance to an architectural style. In order to handle the complex design of communicating collaborative system architectures and the related adaptation issues, we propose a multi-layer modelling approach. This approach assures generic solutions for automatic context aware adaptation. Our approach is based on the observation that semantic data analysis that can be exploited to manage priorities and more generally to manage communications. This allows us to represent, in a richer way, the semantics of the managed systems.Dans ce manuscrit, nous proposons de concevoir et de mettre en oeuvre un environnement logiciel pour une "gestion guidée par les modèles" des changements dans les architectures des applications distribuées coopératives. Les aspects adaptabilité des applications, les aspects transformations de graphe et les aspects particuliers des applications distribuées coopératives sont étudiés. Une approche d'adaptation s'appuyant sur une modélisation par les graphes et un style architectural de type Poducteur/Consommateur est présentée pour des applications communicantes collaboratives sensibles au contexte. Une démarche de raffinement est proposée permettant de garantir un certain degré d'adaptabilité en faisant un compromis entre les différents paramètres du contexte. Ces travaux de recherche ont aussi permis de définir un cadre algorithmique générique de reconfiguration architecturale multi-niveaux pour la sélection des architectures de déploiement les plus adaptées à un contexte et aux situations associées. Ce cadre a été appliqué au cas de la communication et de la coopération de groupe. Elle a aussi permis de modéliser le style architectural Producteur/Consommateur pour une communication orientée évènement. Des règles d'adaptation ont été définies. Elles comportent une partie basée sur SWRL pour la description du contexte et des règles d'adaptation, et une partie basée sur les grammaires de graphes pour la transformation des configurations de déploiemen

Threshold-based context analysis approach for ubiquitous systems

International audienceIn ubiquitous computing systems, applications must be able to respond to dynamic context changes in order to provide suitable services to users. A promising solution consists of developing context aware applications which automatically change their behavior according to the user needs, the user preferences, the available resources and the surrounding environment. Furthermore, a context aware application is characterized by a closed feed back loop (MAPE) with four phases: Monitoring, Analysis, Planning and Execution. In this paper, we focus on the second phase of the MAPE loop. We elaborate a layered approach composed of a context capture layer, a context management layer and a context adaptation layer. Our approach enables systems to become pervasive in a transparent manner handling context monitoring and context analysis. We focus our work on the second layer (i.e context management). We propose first a context classification which takes into acount the context parameters evolution behavior. Then, we propose a context analysis approach for ubiquitous systems which aims at analyzing context information and detecting significant changes. The proposed approach uses a threshold based technique in order to detect context changes. When relevant context changes are detected, the context aware application will be notified to trigger its suitable process dynamically in order to deal with the changes

Towards a novel analysis approach for collaborative ubiquitous systems

International audienceIn ubiquitous computing systems, applications must be able to respond to dynamic context changes in order to maintain collaboration between entities. A promising solution consists of developing context aware applications which automatically change their behavior according to the user needs, the available resources and the surrounding environment. Furthermore, a context aware application is characterized by a closed feed back loop with four phases: Monitoring, Analysis, Planning and Execution. In this paper, we focus on the second phase and we propose an analysis approach of collaborative ubiquitous systems which aims at analyzing context information and detecting significant abnormal changes. The proposed approach relies on thresholds in order to track down context changes. Once relevant context changes occur, the context aware application will be notified to trigger its suitable process dynamically in order to deal with the changes

Threshold-based context analysis approach for ubiquitous systems

International audienceIn ubiquitous computing systems, applications must be able to respond to dynamic context changes in order to provide suitable services to users. A promising solution consists of developing context aware applications which automatically change their behavior according to the user needs, the user preferences, the available resources and the surrounding environment. Furthermore, a context aware application is characterized by a closed feed back loop (MAPE) with four phases: Monitoring, Analysis, Planning and Execution. In this paper, we focus on the second phase of the MAPE loop. We elaborate a layered approach composed of a context capture layer, a context management layer and a context adaptation layer. Our approach enables systems to become pervasive in a transparent manner handling context monitoring and context analysis. We focus our work on the second layer (i.e context management). We propose first a context classification which takes into acount the context parameters evolution behavior. Then, we propose a context analysis approach for ubiquitous systems which aims at analyzing context information and detecting significant changes. The proposed approach uses a threshold based technique in order to detect context changes. When relevant context changes are detected, the context aware application will be notified to trigger its suitable process dynamically in order to deal with the changes

A Demonstration of an Efficient Tool for Graph Matching and Transformation

Nous avons implanté un outil efficace de recherche de morphismes et de transformation de grands graphes et l'avons utilisé pour modéliser les architectures dynamiques, les activités coopératives et d'autres applications. L'outil est en cours d'extension avec des interfaces graphiques et un module d'interopérabilité en XML. Une version préliminaire est disponible sous http://homepages.laas.fr/khalil/GTE