An algorithm for fault-tolerant clock state & rate synchronization

• Published in: Proceedings - Symposium on Reliable Distributed Systems pp. 36 - 47
• Main Authors: Schossmaier, K., Weiss, B.
• Format: Conference Proceeding Journal Article
• Language: English
• Published: IEEE 1999
• Subjects: Analytical models; Clocks; Convergence; Delay; Fault tolerance; Fault tolerant systems; Oscillators; Stability analysis; Synchronization; Uncertainty
• ISBN: 9780769502908; 0769502903; 0769502911; 9780769502915
• ISSN: 1060-9857; 2575-8462
• DOI: 10.1109/RELDIS.1999.805081

We propose a fault-tolerant algorithm for synchronizing both state and rate of clocks in a distributed system. This algorithm is based on rounds, uses our fault-tolerant optimal precision (OF) convergence function as the means of synchronization, and maintains a collection of intervals to keep track of real-time, internal global time, and clock rates. The analysis shows that the interlocking between state and rate synchronization can be easily solved, and that oscillator stabilities together with the transmission delay uncertainties of packets predominate the internal synchronization. In addition, average case results gathered from simulation experiments with our SimUTC toolkit prove to be about one order of magnitude better than the worst case ones from the analysis of our state & rate algorithm.