Modeling and Verification of Context-Awareness Service for Time Critical Applications Using Colored Petri-Net

Context-awareness is one of the key features of ubiquitous paradigm. To intelligently and sensitively deal with dynamic environment, a methodology specifying the relationships between the contexts and services needs to be developed. It is difficult to verify the correctness of the existing models on context with respect to timeliness. In this paper we propose an approach which includes timing constraint in the relations of the context model, and verify its effectiveness using colored Petri-net. Moreover, a context-modeling toolkit including context-awareness engine and simulator is developed to support agent-based context-aware service. The effectiveness of the proposed methodology is demonstrated using an example of Usilvercare.