Suporte a aplicações sensíveis ao contexto no cenário do sistema brasileiro de televisão digital

Abstract

Context-aware applications use contextual information to customize services according to the dynamicity of the situations and needs of its users. One of the promising scenarios for the development of this class of applications is that provided by the interactive digital television, particularly in the context of the Brazilian Digital Television System (SBTVD). Even though it presents features which can be used to facilitate the development of context-aware applications, such as content presentation adaptation and multiple devices support, the current middleware standard for the SBTVD, named Ginga, still lacks a context management infrastructure that favors the development of complex, domain independent and designed to reuse context-aware applications. Among the many challenges of building this infrastructure, providing Ginga with a generic service for the acquisition of contextual information can be a major task, particularly due to the heterogeneous nature of context sources devices and their varying data. Starting from a generic conceptual architecture defined for the Ginga s Context Manager component in a earlier project, this work presents an implementation for the Context Sources Manager , a key element of architecture, whose responsibility is to provide a standardized interface for the communication between the middleware and the heterogeneous devices that are responsible for the acquisition of contextual information. The implementation is carried out based on the use of scripts NCLua, the Ginga s imperative language, and OSGI, a framework for the management of electronic devices in home networks. The dissertation also proposes a new methodology for the development of context-aware applications using the developed infrastructure.