The effect of quartz drift on convergence-average based clock synchronization

The aim of this work is to study how the temporal behavior of time-triggered distributed systems is influenced by a drift of their underlying quartz. More especially, we focus on convergence-average clock synchronization used e.g. for TTP/C and FlexRay. We show that, for a fault free system in a stable environment, the global time converges to an interval spanned by the accuracies of the physical clocks independently of the system history. Although this result seems quite intuitive, it is not self-evident, given the complex behavior of distributed clock synchronization. Moreover, this proof allows to derive diagnosis information about the underlying quartz and is the enabler of remote system test.