Base-T1S Ethernet is a promising technology for integrating low-rate electronic control units (ECUs) in invehicle and industrial networks, because it supports multidrop communication over a single-pair physical layer while preserving an Ethernet-based architecture. Its Physical Layer Collision Avoidance (PLCA) mechanism assigns deterministic transmission opportunities to nodes in a round-robin manner. IEEE 802.1Qav Credit-Based Shaper (CBS) is widely adopted in TSN/AVB networks to regulate class-based bandwidth and suppress traffic burstiness, and can be deployed locally within each ECU before frames are forwarded to the PLCA MAC-PHY. Existing CBS analyses typically assume full-duplex point-to-point Ethernet links, where an eligible queue, once selected by the local scheduler, can receive continuous transmission service at the link rate. This assumption does not directly hold in PLCA-based multidrop networks, where an ECU can transmit only during its assigned transmission opportunities. For control, diagnostic, and safety-related traffic, average delay or finite simulation traces are insufficient to certify whether timing requirements are always met; designers instead need deterministic upper bounds on the worst-case delay. However, in PLCA-based 10Base-T1S networks, the service available to CBS-shaped traffic is determined by the interaction among CBS credit evolution, PLCA access timing, and local non-preemptive priority scheduling. Therefore, these mechanisms must be modeled jointly to derive such bounds. This paper develops a network-calculus model for CBS-shaped traffic over PLCA-based 10Base-T1S networks. Numerical examples and simulation results demonstrate how CBS parameters and PLCA configurations influence the resulting delay bounds.
Taiki Nonaka, Han Nay Aung, Yasuhiro Yamasaki et al.· Annual International Compute...· 0 citations
Ensuring deterministic and reliable communication is essential for in-vehicle networks supporting autonomous driving and safety-critical functions. Time-Sensitive Networking has emerged as a key enabler for such systems. Among its mechanisms, the IEEE 802.1Qcr Asynchronous Traffic Shaper (ATS) offers fine-grained traffic control without requiring global time synchronization. However, the practical deployment of ATS in Automotive Ethernet networks remains challenging due to the difficulty of parameter configuration. The performance of ATS strongly depends on the appropriate setting of key parameters such as the Committed Information Rate (CIR) and Committed Burst Size (CBSz), which are highly sensitive to both network topology and traffic workload. Conventional approaches relying on static configuration or empirical tuning may face difficulties in ensuring QoS when network conditions change. This paper proposes a method for automated, high-precision optimization of ATS parameters in automotive networks. We analyze the impact of key parameters—CIR and CBSz—on delay and frame loss, and develop a machine learning model to select optimal settings under dynamic traffic conditions. Our results reveal that proper ATS parameter configuration is essential for deterministic latency and reliability in Automotive Ethernet networks. CIR mainly governs bandwidth, affecting queuing delay and frame loss, while CBSz balances delay reduction against burst-induced congestion. Furthermore, tree-based ensemble models such as LightGBM and Gradient Boosting achieved high prediction accuracy and QoS satisfaction under varying traffic conditions.
Taisei Isobe, Han Nay Aung, Yasuhiro Yamasaki et al.· Annual International Compute...· 0 citations