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Abstract

This paper presents a framework of architecture-centric models to support the automated and adaptive deployment of communication services for QoS-enabled end-to-end group communication systems. The Transport level (TCP, UDP level) and the above messaging Middleware level are considered as the two communication levels targeted by the QoS-driven adaptation process. Application to crisis management systems (CMS) is considered as a case study from the more general domain to which our results apply: cooperative activity support systems. The adaptation rules rely on graph matching and graph rewriting. The adaptation enactment is based on the dynamic composition of micro-protocols at the Transport level and on the dynamic binding of software components and services at the Middleware level. The deployment model is used as a central feature of service provisioning. The influence of the cooperation and the communication contexts is expressed and maintained consistent by automated graph-based model refinement and transformation.

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Abstract

Future network environments are likely to be used by cooperative applications. Indeed, the recent advent of peer to peer systems motivates this assumption. In this paper, we present a method that relies on graphs and graph grammar productions to automatically refine a high level service interactions representation of an activity into a deployment topology at the Middleware and the Transport level. At both levels, algorithms for service optimization are presented. The different models and algorithms are implemented in a case study of CMS-like operations for crisis management.

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Abstract

Self-adaptation of communication protocols is a major issue in the conception of future services for the ambient Internet. These protocols will have to provide adequate services to complex, mobile, cooperative application with dynamic requirements distributed in highly heterogeneous environments, partially wireless and ad hoc with variable and evolutive constraints. In this highly dynamic context, providing efficient solutions requires handling adaptability not only at the behavioral level, but also at the architectural level. End-to-end modular architecture protocols are a promising solution to support architectural self-adaptation to the context. Following this approach, the contributions presented in this paper address the automated choice of internal architecture for configurable transport level protocols. Tackling this need by means of informal models may lead to non generic and suboptimal solutions due to the complexity of the problem. We propose to guide adaptation by an analytical model which is then evaluated against simulation results.

Mots-Clés / Keywords

Abstract

Future network environments are likely to be used by cooperative applications. Indeed, the recent advent of peer to peer systems motivates this assumption. In this paper, we present a method that relies on graphs and graph grammar productions to automatically refine a high level service interactions representation of an activity into a deployment topology at the Middleware and the Transport level. At both levels, algorithms for service optimization are presented. The different models and algorithms are implemented in a case study of CMS-like operations for crisis management.

Mots-Clés / Keywords

Abstract

Handling context-aware dynamically adaptable architectures contributes to the design of self-configuring software systems. Dealing with such a problem for communicating systems is even more challenging since adaptation should address simultaneously the different communication levels. This is necessary for handling both unpredictable changes in the low level constraints and predictable evolutions in the high level requirements. In this paper, we address this problem by providing a model-based, rule-oriented approach that supports the adaptation process based on a run-time transformation of the system architecture. Such architecture may represent the different possible service compositions and the associated architectural configurations. We consider the multi-level models of the communicating system architecture. We consider the intra-level architecture transformations as the elementary adaptation actions. We handle consistently the related inter-level adaptation actions by considering additional architectural relationships viewing the lower level architecture as a refinement or a mapping of the upper level.We provide the algorithms characterizing the multi-level architecture-based adaptation process. We then develop a rule-oriented implementation using graph grammar and handling architectural transformations as graph rewriting rules. We consider Crisis Management Systems (CMS) as a case study from the more general group communication systems to which our results apply.

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Abstract

The talks about technological convergence had been around for almost twenty years. Today Internet made it possible. And this is not only technical evolution. The way it changed our lives reflected in variety of applications, services and technologies used in day-to-day life. Such benefits imposed even more requirements on heterogeneous and unreliable IP networks. Current paper outlines QoS management system developed in the NetQoS [1] project. It describes an overall architecture of management system for heterogeneous networks and proposes automated multi-layer QoS management. Paper focuses on the structure of the most crucial modules of the system that enable autonomous and multi-layer provisioning and dynamic adaptation.

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