CA3M: A Runtime Model and a Middleware for Dynamic Context Management

Abstract

In ubiquitous environments, context-aware applications need to monitor their execution context. They use middleware services such as context managers for this purpose. The space of monitorable entities is huge and each context-aware application has specic monitoring requirements which can change at runtime as a result of new opportunities or constraints due to context variations. The issues dealt with in this paper are 1) to guide context-aware application designers in the specication of the monitoring of distributed context sources, and 2) to allow the adaptation of context management capabilities by dynamically taking into account new context data collectors not foreseen during the development process. The solution we present, CA3M, follows the model-driven engineering approach for answering the previous questions: 1) designers specialised into context management specify context-awareness concerns into models that conform to a context-awareness meta-model, and 2) these context-awareness models are present at runtime and may be updated to cater with new application requirements. This paper presents the whole chain from the context-awareness model denition to the dynamic instantiation of context data collectors following modications of context-awareness models at runtime.

Context Aware and Adaptive Systems

“…Most of the existing approaches have only a design time context model (e.g. Bettini et al 2010), and even those approaches that have a runtime context representation do not provide a method for dynamically managing the context model (Taconet et al 2009;Sheng et al 2009;Reichle et al 2008). This makes it more difficult to deal with unanticipated runtime context changes.…”

Managing Dynamic Context to Optimize Smart Interactions and Services

“…The first one, observation mode, corresponds to top-down interactions where applications synchronously request context observations. The second one, notification mode, transmits context information to applications based on conditions defined in contracts [15]. Finally, context must be considered independently from applications [25].…”

“…Object-oriented models are based on the object-oriented paradigm to face the representation of dynamic characteristics of context [13], [14]. Meta-model-based models emerged recently in Model Driven Engineering (MDE) domains to support the dynamic generation of new model instances based on meta-models defined at design-time [15], [16], [17], [18]. Logic-based and ontology-based models are used to define formal specifications of context entities and the relations among them in a particular domain [19], [20].…”

Analysis process for context aware applications in pervasive environments

“…In [6], Taconet et al have presented CA3M, a context aware middleware that enables applications to adapt their behavior according to the context changes. The authors have modelled the application by "entities" and "observable".…”