Adopting context awareness in service composition

Service composition is one of the most important features of Service-Oriented Architecture (SOA), where it is imperative to automatically adapting changing context in the environment. This paper adopts context-awareness to service composition to construct SOA based systems/applications where contexts are behavior-integrated, user-centered and changing-adaptable. An overall framework of a context agent is established, which consists of behavior interpreter, ontology context repository, inference engine, contexture behavior sequence planner and evaluation repository. We formalize behaviors of context entity and services, and take them into consideration in behavior-planning based service composition. An ontology model of context environment is built to describe context semantic in order to enable knowledge sharing. The predictability and controllability of context entities are addressed and corresponding evaluation mechanism and planning algorithm are proposed. Dynamic Description Logic is applied in contextual behavior sequence decision, and its satiability-checking algorithm is extended to enhance the constraining power of pre-conditions in a contextual behavior.