Orthogonal, Fault-Tolerant, and High-Precision Clock Synchronization for the Controller Area Network

The controller area network (CAN) is facing a great opportunity. The maturity of this technology makes many researchers believe that CAN may be adopted in more critical systems. However, the suitability of CAN for these challenging applications strongly depends on our capacity to integrate all the solutions already available into a single, comprehensive architecture. We claim that clock synchronization plays a fundamental role in such architecture. Therefore, the means to achieve a solution fulfilling the expected requirements on reliability, cost, and precision must be deeply investigated. This paper discusses the relevance of clock synchronization in the future of CAN systems and describes a novel solution to supply this service. This solution exhibits several advantages: it provides very high precision, causes very low communication and computation overhead, and includes mechanisms to provide fault tolerance. Moreover, and in contrast to previous proposals, it is designed to be orthogonal to the rest of the system. Thus, it can be directly incorporated to any CAN system, without having to replace any of the components, which reduces the cost increment caused by the new service.