Deterministic real-time communication with bounded delay is an essential requirement for many safety-critical cyber-physical systems, and has received much attention from major standardization bodies such as IEEE and IETF. In particular, Ethernet technology has been extended by time-triggered scheduling mechanisms in standards like TTEthernet and Time-Sensitive Networking. Although the scheduling mechanisms have become part of standards, the traffic planning algorithms to create time-triggered schedules are still an open and challenging research question due to the problem's high complexity. In particular, so-called plug-and-produce scenarios require the ability to extend schedules on the fly within seconds. The need for scalable scheduling and routing algorithms is further supported by large-scale distributed real-time systems like smart energy grids with tight communication requirements. In this paper, we tackle this challenge by proposing two novel algorithms called Hierarchical Heuristic Scheduling (H2S) and Cost-Efficient Lazy Forwarding Scheduling (CELF) to calculate time-triggered schedules for TTEthernet. H2S and CELF are highly efficient and scalable, calculating schedules for more than 45,000 streams on random networks with 1,000 bridges as well as a realistic energy grid network within sub-seconds to seconds.

翻译：确定性实时通信具有有限延迟，是许多安全关键型信息物理系统的基本要求，并已引起IEEE和IETF等主要标准化机构的广泛关注。特别是，以太网技术通过TTEthernet和时间敏感网络等标准中的时间触发调度机制得到了扩展。尽管调度机制已成为标准的一部分，但由于问题的高度复杂性，创建时间触发调度的流量规划算法仍是一个开放且具有挑战性的研究问题。尤其是即插即用场景要求在数秒内动态扩展调度。对可扩展调度和路由算法的需求进一步得到具有严格通信要求的大规模分布式实时系统（如智能电网）的支持。本文通过提出两种新型算法——分层启发式调度（H2S）和成本高效懒惰转发调度（CELF）来应对这一挑战，用于计算TTEthernet的时间触发调度。H2S和CELF高效且可扩展，能在亚秒至秒级内，为包含1000个网桥的随机网络以及真实电网网络中的超过45000条流计算调度方案。