A Software Component for Real-Time Automotive Communications Over Ethernet 10BASE-T1S

The Ethernet 10BASE-T1S Physical Layer Collision Avoidance mechanism ensures collision-free communications with bounded delays over multidrop bus networks, but does not implement Quality of Service (QoS), and therefore, when multiple flows are generated by the same node, the frames are transmitted by the node in FIFO order. This article proposes a lightweight software component, called Frame Segmentation and Shaping (FS2), running on top of the node Ethernet controller, that segments and delays the Ethernet frames in a way that provides different QoS to the different flows transmitted by a node. FS2 maintains the compliance with the Ethernet 10BASE-T1S standard and does not require to redesign the silicon or add an expensive, programmable MCU. The article presents the FS2 concept, design, and configuration and discusses the results of a comparative performance evaluation with other approaches in the literature, obtained through OMNeT++ simulations in a zonal-based automotive scenario.