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 (TT) scheduling mechanism adopted in TSN. In this article, we modify the standard static scheduling constraints in TSN and introduce new constraints to enforce TT 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 TT constraint is compatible with the standard TSN scheduling, enabling TT 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.