Context-aware workflow language based on Web services for ubiquitous computing

The services for a ubiquitous computing environment have to automatically provide users with adaptive services according to dynamically changing context information, which is obtained from both the users and their environment. Workflows used in business processes and distributed computing environments have supported service automation by connecting many tasks with rules and/or orderings. To adapt these workflows to ubiquitous computing, we must specify the context information on their transition conditions. In this paper, we propose uWDL, Ubiquitous Workflow Description Language, to specify the context information on the transition constraints of a workflow in order to support adaptive services. And it is designed based on Web services, which are standardized and independent of heterogeneous and various platforms, protocols, and languages. In order to verify the effectiveness of uWDL, we designed and implemented a scenario described with uWDL. And we demonstrated that the uWDL system provides users with autonomic services in ubiquitous computing environments.