Makespan minimization of Time-Triggered traffic on a TTEthernet network
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The reliability of the increasing number of modern applications and systems strongly depends on interconnecting technology. Complex systems which usually need to exchange, among other things, multimedia data together with safety-related information, as in the automotive or avionic industry, for example, make demands on both the high bandwidth and the deterministic behavior of the communication. TTEthernet is a protocol that has been developed to face these requirements while providing the generous bandwidth of Ethernet up to 1 Gbit/s and enhancing its determinism by the Time-Triggered message transmission which follows the predetermined schedule. Therefore, synthesizing a good schedule which meets all the real-time requirements is essential for the performance of the whole system. In this paper, we study the concept of creating the communication schedules for the Time-Triggered traffic while minimizing its makespan. The aim is to maximize the uninterrupted gap for remaining traffic classes in each integration cycle. The provided scheduling algorithm, based on the Resource-Constrained Project Scheduling Problem formulation and the load balancing heuristic, obtains near-optimal (within 15% of non-tight lower bound) solutions in 5 minutes even for industrial sized instances. The universality of the provided method allows easily modify or extend the problem statement according to particular industrial demands. Finally, the studied concept of makespan minimization is justified through the concept of scheduling with porosity according to the worst-case delay analysis of Event-Triggered traffic.
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