Speaker
Prof.
Hermann Kopetz
(Technical University of Vienna)
Description
This lecture starts by presenting some reasons for deterministic networks in high-dependability application, where the mean-time-to-fail (MTTF) of a critical system service must be higher than the MTTF of any of the constituent components. The required notion of determinism is examined and it is shown that predictable timeliness and consistent order are the important characteristics of a deterministic transport service. It is shown that the realization of consistent order requires a sparse time-base and agreement protocols for non-sparse events. The quality of the required fault-tolerant clock synchronization, the precision, determines the parameters of the sparse time base and in consequence the limits of the resolution of quasi-simultaneous events. The inherent conflict between fidelity of a digital model of the physical environment and consistency within the digital model can be reduced by an improved precision of the global time, but can never be fully resolved.
