CANcentrate: an active star topology for CAN networks

Distributed embedded systems that require real-time performance need a network capable of deterministic access delay. CAN is one such network that became widespread in recent years due to its electrical robustness, low price, and priority-based access control. However, its use in safety-critical applications has been controversial due to dependability limitations that arise from its bus topology and non-guaranteed atomic broadcast. In this paper, we propose an active star topology that allows solving many of the limitations related to the first aspect by means of strong error confinement. Nodes are interconnected through an active hub that is fully compatible with existing CAN controllers. The paper compares bus and star topologies, analyzes related work and discusses the hub implementation and dependability properties.