An example of real-time group communication system

We describe a group communication system for real-time systems and show how to use it. This system, we call the synchronized phase system (SPS) ensures a property weaker than the classical virtual synchrony, but SPS, with some liveness properties is powerful enough to build an atomic broadcast service. Moreover, for real-time systems we can give explicit bounds on the size of good periods (periods without timing failure) to ensure the timeliness properties on message delivery. This system has been implemented to build a real time atomic broadcast service in the French project ATR.