Time-Sensitive Networking (TSN) enhances Ethernet based In-Vehicle Networks (IVNs) with real-time capabilities. Different traffic shaping algorithms have been proposed for time-critical communication, of which the Asynchronous Traffic Shaper (ATS) is an upcoming candidate. However, recent research has shown that ATS can introduce unbounded latencies when shaping traffic from non-FIFO systems. This impacts the applicability of ATS in IVNs, as these networks often use redundancy mechanisms that can cause non-FIFO behavior. In this paper, we approach the problem of accumulated delays from ATS by analyzing the scenarios that generate latency and by devising placement and configurations of ATS schedulers to prevent this behavior. Our solution successfully mitigates problematic preconditions that lead to unbounded delays, which we evaluate in simulations. Through a realistic IVN simulation case study, we demonstrate the occurrence of unbounded latencies and validate the effectiveness of our approach in avoiding them.

翻译：时间敏感网络（TSN）通过实时能力增强了基于以太网的车载网络（IVN）。针对时间关键型通信，已提出了多种流量整形算法，其中异步流量整形器（ATS）是一种新兴的候选方案。然而，近期研究表明，当对来自非先进先出（FIFO）系统的流量进行整形时，ATS可能引入无界延迟。这影响了ATS在车载网络中的适用性，因为这些网络常采用可能导致非FIFO行为的冗余机制。本文通过分析产生延迟的场景，并设计ATS调度器的部署与配置方案来防止此类行为，从而解决ATS导致的累积延迟问题。我们的方案成功缓解了导致无界延迟的问题性先决条件，并通过仿真进行了评估。通过一个现实的车载网络仿真案例研究，我们展示了无界延迟的发生情况，并验证了所提方法在避免此类延迟方面的有效性。