Combination of clock-state and clock-rate correction in fault-tolerant distributed systems

This paper proposes the integration of internal and external clock synchronization by a combination of a fault-tolerant distributed algorithm for clock state correction with a central algorithm for clock rate correction. By means of hardware and simulation experiments it is shown that this combination improves the precision of the global time base in a distributed single cluster system while reducing the need for high-quality oscillators. Simulation results have shown that the rate-correction algorithm contributes not only in the internal clock synchronization of a single cluster system, but it can be used for external clock synchronization of a multi-cluster system with a reference clock. Therefore, deployment of the rate-correction algorithm integrates internal and external clock synchronization in one mechanism. Experimental results show that a failure in the clock rate correction will not hinder the distributed fault-tolerant clock state synchronization algorithm, since the state c...

• Type: Journal
• Year: 2006
• Where: RTS
• Authors: Hermann Kopetz, Astrit Ademaj, Alexander Hanzlik
• Keywords: Clock, Clock Synchronization, External Clock Synchronization, RTS 2006