  In this paper, we propose a refinement-based adaptation approach for the
architecture of distributed group communication support applications. Unlike
most of previous works, our approach reaches implementable, context-aware and
dynamically adaptable architectures. To model the context, we manage
simultaneously four parameters that influence Qos provided by the application.
These parameters are: the available bandwidth, the exchanged data communication
priority, the energy level and the available memory for processing. These
parameters make it possible to refine the choice between the various
architectural configurations when passing from a given abstraction level to the
lower level which implements it. Our approach allows the importance degree
associated with each parameter to be adapted dynamically. To implement
adaptation, we switch between the various configurations of the same level, and
we modify the state of the entities of a given configuration when necessary. We
adopt the direct and mediated Producer- Consumer architectural styles and
graphs for architecture modelling. In order to validate our approach we
elaborate a simulation model.
