An example of real-time Group Communication System

In this paper we describe a Group Communication System for real-rime systems and show how to use it. This System, we call Synchronized Phase System (SPS) ensures a property weaker than the classical Virtual Synchrony: but SPS, with some liveness properties is powerful enough to build Atomic Broadcast Service. Moreover; for real-rime system 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.