Heuristic list scheduler for time triggered traffic in time sensitive networks

Abstract

Time Sensitive Networks (TSN) are a novel technology that combines the larger bandwidth capabilities of Ethernet with determinism and fault tolerance for safety relevant real time systems. TSN offers bounded latency for the time triggered (TT) communication by transmitting messages according to a global schedule. Most of the scheduling algorithms in this context provide the solution only from the perspective of scheduling constraints and do not consider the impacts of routing on the scheduling problem. Therefore, these algorithms are not capable to provide effective results in the domain of many real time systems. To address interdependence of routing and scheduling constraints, we introduce a heuristic list scheduler (HLS). Our approach generates valid schedules using joint routing and scheduling constraints in one step. Due to this approach, ability to find feasible schedules is dramatically increased in comparison to the schedulers with fixed routing. In addition, HLS supports multi-cast communication, distributed real time applications and inter-flow dependencies. Experimental results shows the significant increase in the schedulability because of the task and message scheduling combined with routing.