An infrastructure for context-awareness based on first order logic

Context simplifies and enriches human-human interaction. However, enhancing human-computer interaction through the use of context remains a difficult task. Applications in pervasive and mobile environments need to be context-aware so that they can adapt themselves to rapidly changing situations. One of the problems is that there is no common, reusable model for context used by these environments. In this paper, we propose a model of context that is based on first order predicate calculus. The first order model allows complex rules involving contexts to be written. It also enables automated inductive and deductive reasoning to be done on contextual information. The first order model allows an expressive description of context using Boolean operators and existential and universal quantifiers. Based on this model, an infrastructure to enable contextawareness in ubiquitous computing environments has been developed. The infrastructure allows the easy development and deployment of various sensors and context-aware applications. It also allows distributed reasoning to take place. This context infrastructure is part of our smart spaces framework for ubiquitous computing, Gaia.