Dynamic Slot Extension-Based High-Criticality Tasks Scheduling in TSN-Based DMCS

With the development of Industry 4.0, Distributed Mixed-Criticality Systems (DMCS) have been widely applied to handle various complex tasks in IoT and aerospace fields. To ensure the reliability and end-to-end Quality of Service (QoS) of high-criticality tasks in DMCS, Time-Sensitive Networking (TSN) with inherent determinism can be adopted to provide deterministic low-latency transmission service. However, in modern DMCS, the emergency burst high-criticality tasks and the event-triggered scheduling mechanism used on end systems (ESs) conflict significantly with the time-triggered scheduling mechanism adopted in TSN. In this paper, we modify the standard static scheduling constraints in TSN and introduce new constraints to enforce time-triggered scheduling behavior on ESs based on the original event-triggered scheduling mechanism. Additionally, we propose a Priority-based Dynamic Slot Extension (PDSE) method to handle the emergency high-criticality tasks generated in DMCS. The simulation results show that our proposed time-triggered constraint is compatible with the standard TSN scheduling, enabling time-triggered scheduling of periodic high-criticality tasks on even-triggered ESs. Moreover, the results of end-to-end delays and delay jitters indicate that compared to other methods, PDSE can better schedule emergency high-criticality tasks in DMCS while exerting a lower impact on other high-criticality tasks.