Architectural abstractions for spaces-based communication in responsive environments

Responsive Environments are ordinary environments augmented with input devices (e.g., sensors, cameras, vision and tracking systems, tangible and wearable interfaces) and output devices (e.g., screens, lights, speakers and mechanical actuators) that are able to sense and respond to the users who inhabit them. Whatever the computing approach behind the scenes, a Responsive Environment requires the establishment of rich and flexible information flows between users and the environments in which they live. From a Software Architecture point of view, information flows between users and their environments are mediated by software components that manage specific devices, perform customized tasks and coordinate activities. Hence Responsive Environments necessitates a technological platform supporting the seamless integration of multifarious components via suitable communication mechanisms. The platform should capture metaphors that are widely and effectively exploited in Responsive Environments. The platform should also be lightweight and efficient. Therefore, the challenge is to identify a few domain-oriented concepts that are both general and simple enough to be effectively reified by a technological platform supporting Responsive Environments. The concept of space is a good candidate for reification in terms of communication mechanisms. Space and related keywords (e.g., position, location, area, proximity and distance) are natural reference concepts that users exploit to communicate with and through an environment according to different representations (e.g., name space, organizational space, grid space and so on). However, few approaches in the literature focus on space as a provider of communication mechanisms. Moreover, the existing approaches exclusively consider geo-referenced spatial representations. This thesis proposes a set of architectural abstractions and a related technological platform to establish information flows in Responsive Environments through a multiplespaces metaphor. An environment space is a set of locations defined according to a specific spatial model (e.g., grid-based, graph-based or name-based). Different environment spaces that model subjective views of the overall environments can co-exist. For example, the physical environment may be modeled by a grid space, where cells represent small portions of the physical space. The topology of a building can be modeled by a graph space, where nodes represent rooms and arcs represent passages. Users' names can be represented by name spaces and users' roles by graph spaces. Mappings relate different environment spaces by, for example, associating cells of a grid space representing geo-referenced cells to nodes of a graph space representing rooms. Software components communicate by publishing and receiving information on multiple spatial contexts. Each component may be aware of different environment spaces. Mappings enable communication among components, even if they rely on different environment spaces. The architectural abstractions are supported by a concrete framework called Space Integration Services (SIS), which implements the proposed spaces-based communication. The proposed abstractions and related framework have been tested in several Responsive Environment applications. The experiments confirmed that the approach based on multiple spaces can be effectively implemented and facilitates the development of Responsive Environments.