Real-time Role Coordination for Ambient Intelligence

We propose group communication for agent coordination within "active rooms" and other pervasive computing scenarios featuring strict real-time requirements, inherently unreliable communication, and a large but continuously changing set of context-aware autonomous systems. Messages are exchanged over \emph{multicast channels}, which may remind of chat rooms in which everybody hears everything being said. The issues that have to be faced (e.g., changing users' preferences and locations; performance constraints; redundancies of sensors and actuators; agents on mobile devices continuously joining and leaving) require the ability of dynamically selecting the "best" agents for providing a service in a given context. Our approach is based on the idea of \emph{implicit organization}, which refers to the set of all agents willing to play a given role on a given channel. An implicit organization is a special form of team with no explicit formation phase and a single role involved. No middle agent is required. A set of protocols, designed for unreliable group communication, are used to negotiate a coordination policy, and for team coordination. We sketch a general computational model for an agent participating to an implicit organization