A time and interaction model for open distributed timing computation

A time and interaction coordination model is presented to address the dynamic changes of interaction topology and real-time constraints among autonomous entities in open distributed timing computation. Driven by events, the model distinguishes between three kinds of entities: time coordinators, interaction coordinators and computation entities, which are separated from traditional autonomous entities based on the separation of concerns. A time coordinator is responsible for controlling real-time behaviors; an interaction coordinator is to coordinate interaction and reconfigure interconnection topology among computation entities; a computation entity is only responsible for performing pure computation. An implementation framework is additionally suggested based on Java Message Service and EJB technology. Finally, an application to a vehicle navigation system is presented, including several traffic control centers, a GPS and a navigator. It illustrates how the model and the framework can be used to achieve both the interaction topology and the timing constraints.