Fault-tolerant clock synchronization in CAN

This paper presents a new fault-tolerant clock synchronization algorithm designed for the Controller Area Network (CAN). The algorithm provides all correct processes of the system with a global timebase, despite the occurrence of faults in the network or in a minority of processes. Such global time-frame is a requirement of many distributed real-time control systems. Designing protocols for CAN is justified by the increasing use of this network in industrial automation applications. CAN owns a number of unique properties that can be used to improve the precision and performance of a clock synchronization algorithm. Unfortunately, some of its features also make the implementation of a fault-tolerant clock synchronization service a non-trivial task. Our algorithm addresses both the positive and the negative aspects of CAN.