Omnipresent: um sistema ciente de contexto baseado em arquitetura orientada a serviço.

Abstract

The rise of sensors and mobile devices has demanded for applications which enable environmental monitoring and may offer personalized services to users. These applications are known as context aware ones. They provide more comfort, by simplifying daily activities and improving the quality of life. The development of such context aware applications brings new challenges. It is necessary to use sensors to perceive the environment and transmit the data to a remote system, which should analyze and execute some action concerning user's interest. The user is always moving, changing both physical and physiologic conditions. Due to the complexity of context, it seems to be mandatory the provision of a system with capabilities of inference on surrounding data. Also, the system should be able to present information based on this new knowledge. This dissertation proposes a distributed architecture, based on mobile devices and service-oriented architecture, which enables the monitoring of user's context and may fire messages based on context changes. A user may monitor his own context, or relatives and friends ones. He may be alerted when certain conditions happen. Different from other applications, these conditions are described through rules that can be either inserted or removed by the user at any time. Furthermore, new context categories may be added to the system at runtime, because the context is described through an ontology. The ontology permits to deduce new information that is not explicit, but may be obtained through inference rules.