Um servidor de gerenciamento de eventos para o compartilhamento de dados de perfil e contexto em aplicações móveis

Abstract

Ubiquitous computing defines a new computational model of human-machine interaction in which information processing is integrated with daily objects and activities for the user. In this new paradigm, a user can activate and participate in several tasks and activities, in some cases not even being aware of the surrounding environment. This introduces the need of context-aware computing, which proposes the capability of devices to sense changes in mobile and/or ubiquitous environments and in the user's behavior.In these environments, user/application profile and context information and state in mobile computing systems constantly change over a period of time. Services located at mobile devices as well as in remote servers also need to effortlessly access the information generated by these changes in order to provide the adaptation of activities from the mobile user. These issues present the need for ubiquitous systems to manage and share these changes amongst other components or systems. This work proposes an event-based system for managing context information in ubiquitous services and applications. Based on the Publish/Subscribe model, the event service used in this work creates the events representing changes in the environment, publishes these events and notifies interested consumers in these events, allowing relevant information to be shared amongst interested applications and services. In our work, we have implemented two application prototypes: an electronic tourist guide and an emergency context service. In both prototypes implemented, the event service proved useful in disseminating changes in profile and context information between peers in a emulated ubiquitous environment. The service collects the changes in profile and context information at the client side (e.g., mobile device or Web client) and sends them to the server for processing and sharing amongst other event consumers. The service also shares the changes in profile and context information occurring remotely, by the means of Web-based services that are offered to mobile applications and services.