Loosely Coupled Hybrid Scheduling of Processing and Communication for TSN-Based IMA Systems

Time-sensitive networking (TSN) has great potential as an airborne network to interconnect modules in integrated modular avionics (IMA) system. For TSN-based IMA system, the hybrid scheduling of processing in modules and communication in TSN can guarantee its real-time performance. However, traditional task-message scheduling methods still lack applicability and scalability due to their incompatibility with the partition-task hierarchical architecture in modules and high complexity brought by the tight coupling of tasks and messages. Partition-message scheduling methods can ensure this applicability and scalability, but cannot coordinate tasks with messages well, thus sacrificing real-time guarantee capabilities. Namely, existing methods cannot comprehensively ensure the scheduling performance, including applicability, real-time, and scalability. Therefore, we propose a novel loosely coupled partition-(task)-message scheduling framework. It takes partitions and messages as scheduling objects and uses tasks as their coordination medium, to overcome the dependencies of existing methods on time-triggered tasks and guarantee applicability. Besides, it can also enhance real-time performance by analyzing task execution boundaries and application-layer end-to-end delays, and improve scalability through parallel optimizing and the incremental solving with block identification and adaptive adjustment. Experiments validate that it can schedule complex systems with up to 150 partitions, 1000 tasks, and 600 messages. Compared with the existing methods, it can accelerate the solving speed by 41% and reduce end-to-end delays by 27%.