[ main page ] [ back ]

9/2004 : Integration of Internal and External Clock Synchronization by the Combination of Clock-State and Clock-Rate Correction in Fault-Tolerant Distributed Systems

RR Number
9/2004
Comment
Conference
The 25th IEEE International Real-Time Systems Symposium, Lisbon, Portugal, Dec. 2004
Author(s)
Hermann Kopetz, Astrit Ademaj, Alexander Hanzlik
Abstract
This paper proposes a combination of a fault-tolerant distributed algorithm for clock state correction with a fault-tolerant algorithm for clock rate correction in order to improve the precision of the global time base in a distributed computing system while reducing the need for high-quality oscillators. The state correction part compensates the drift rates and achieves a synchronization of distributed clocks within a specified precision. The rate correction part of the algorithm contributes to a much tighter synchronization by eliminating systematic rate errors. A failure in the clock rate correction will not hinder the distributed fault-tolerant clock state synchronization algorithm, since the state correction operates independently from the rate correction. It is shown that these combined algorithms are also ideally suited to solve the problem of external clock synchronization in multi-cluster systems. The paper introduces new algorithms and presents experimental results on the achieved improvements in the precision measured in a TTP cluster. Results of simulation experiments of the new algorithms in single-cluster and multi-cluster configurations are also presented.
Bibtex
@article{ kopetz:2004-9,
  author =       "Hermann Kopetz and Astrit Ademaj and Alexander Hanzlik",
  title =        "Clock-State and Clock-Rate Correction in Fault-Tolerant Distributed Systems",
  journal =      "The 25th IEEE International Real-Time Systems Symposium, Lisbon, Portugal, Dec. 2004",
  year =         "2004",
  month =        "Dec."
}
Download
Get main.zip - ZIP-compressed file, (278.8535 KB; posted at July 09 2013)

[ main page ] [ back ]