Automotive Ethernet: Construction and Performance Analysis of a 10BASE-T1S Network

During the latter half of the 20th century, advancements in electronics had a profound impact on the automotive industry. Specifically, they paved the way for numerous opportunities to enhance performance, reliability, passenger safety, and overall comfort. To meet these evolving demands, in-vehicle networks were introduced. While the Controller Area Network (CAN) emerged as the most prevalent technology, other alternatives such as LIN, FlexRay, MOST, and Ethernet also gained prominence. Notably, Ethernet networks have garnered increased attention for future development due to their ability to fulfill the requirements for high data rates. To cope with the growing complexity of modern systems like ADAS (Advanced Driver Assistance Systems), automobile manufacturers are adopting innovative approaches. They're streamlining wiring harnesses, reducing vehicle weight, and simultaneously enhancing software complexity. The integration of Ethernet Networks foresees a shift from domain-based to zonal architecture. This entails clustering domain functions based on their physical location within the vehicle. This transition empowers sensors and actuators to operate autonomously, independent of the central vehicle compute node. The thesis will illustrate the structure of the Ethernet frame and its interactions with the MAC sublayer. Subsequently, it will provide a comprehensive overview of the upper OSI (Open System Interconnection) layers, offering valuable insights into their composition and functions. It will provide a comprehensive overview of the IEEE 802.3 standard and trace the development of Ethernet technologies from 10BASE5 to 10BASE-T1S, with a specific emphasis on the latter in the experimental section. In 10BASE-T1S communication among nodes can be managed through two access control methods: CSMA/CD (Carrier Sense Multiple Access with Collision Detection) and PLCA (PHY-Level Collision Avoidance); their operational principles will be elaborated upon to provide a deeper understanding of their functioning. The primary objective of this study was to thoroughly examine and assess the capabilities of an automotive Ethernet network utilizing the 10BASE-T1S protocol. The environment within which the experimental tests are conducted consists of four integral elements, including a computer equipped with Vehiclespy software, a RAD-Comet, and two RAD-Meteors, all developed by Intrepid Control Systems and provided by Teoresi S.p.A., the company where the thesis was conducted. Operating from the central computer, each simulation was meticulously orchestrated to facilitate data transmission among the RAD-Meteor devices and the PC itself, offering a unique opportunity to observe the interplay of their activities within the shared network. Data traffic flowing through the network was captured by Vehiclespy and recorded in .pcap files for further analysis. Moreover, a custom Matlab script was devised to extract and analyze message data from each file, shedding light on how message traffic influences network performance metrics such as latency and jitter. Additionally, comparative evaluations were conducted to discern the impact of different network access control methods, namely PLCA and CSMA/CD, on overall network performance.