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Derivation and Experimental Verification of Clock Synchronization TheoryThe objective of this work is to validate mathematically derived clock synchronization theories and their associated algorithms through experiment. Two theories are considered, the Interactive Convergence Clock Synchronization Algorithm and the Mid-Point Algorithm. Special clock circuitry was designed and built so that several operating conditions and failure modes (including malicious failures) could be tested. Both theories are shown to predict conservative upper bounds (i.e., measured values of clock skew were always less than the theory prediction). Insight gained during experimentation led to alternative derivations of the theories. These new theories accurately predict the clock system's behavior. It is found that a 100% penalty is paid to tolerate worst case failures. It is also shown that under optimal conditions (with minimum error and no failures) the clock skew can be as much as 3 clock ticks. Clock skew grows to 6 clock ticks when failures are present. Finally, it is concluded that one cannot rely solely on test procedures or theoretical analysis to predict worst case conditions. conditions.
Document ID
19950039292
Acquisition Source
Langley Research Center
Document Type
Reprint (Version printed in journal)
Authors
Daniel L Palumbo
(Langley Research Center Hampton, Virginia, United States)
Date Acquired
August 16, 2013
Publication Date
June 1, 1994
Publication Information
Publication: IEEE Transactions on Computers
Publisher: Institute of Electrical and Electronics Engineers
Volume: 43
Issue: 6
Issue Publication Date: June 1, 1994
ISSN: 0018-9340
e-ISSN: 1557-9956
Subject Category
Computer Programming And Software
Accession Number
95A70891
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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