The derivation and experimental verification of clocksynchronization theory
Palumbo, D.L.
Computers, IEEE Transactions on
Volume 43, Issue 6, Jun 1994 Page(s):676 - 686
Digital Object Identifier 10.1109/12.286301
Summary:The 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
View citation and abstract |
Cart
