SYNCHRONIZED UNIVERSAL TIME COORDINATED FOR DISTRIBUTED REAL-TIME SYSTEMS

This paper presents a novel technique for establishing a highly accura te global time in fault-tolerant, large-scale distributed real-time sy stems. Unlike the usual clock synchronization approaches, the proposed clock validation technique provides a precise system time that also r elates to an external time standard like UTC with high accuracy. The u nderlying idea is to validate time information of external time source s like GPS-receivers against a global time maintained by the local clo cks in the system. As an example, a promising interval-based clock val idation algorithm ICV that exhibits excellent fault-tolerance properti es is outlined and analyzed. It requires only a few highly accurate ex ternal time sources and provides each node with the actual accuracy of its clock.