Investigating and Analyzing CAN-to-TSN Gateway Forwarding Techniques

Controller Area Network (CAN) and Ethernet network are expected to co-exist in automotive industry as Ethernet provides a high-bandwidth communication, while CAN is a legacy cost-effective solution. Due to the shortcomings of conventional switched Etherent, such as determinism, IEEE Time Sensitive Networking (TSN) task group developed a set of standards to enhance the switched Ethernet technology providing low-jitter and deterministic communication. Considering these two network domains, we investigate various design approaches for a gateway that connects a CAN domain to a TSN domain. We present three gateway forwarding techniques and we develop end-to-end delay analysis methods for them. Via the analysis methods and applying them to synthetic use cases we show that the intuitive existing approach of encapsulating multiple CAN frames into a single Ethernet frame is not necessarily an efficient solution. In fact, we demonstrate several cases where it is preferable to encapsulate only one CAN frame into a TSN frame, in particular when we use a high speed TSN network. The results have a significant impact on developing such gateways as the implementation of the one-to-one frame encapsulation is considerably simpler than other complex gateway-forwarding techniques.