Evaluation of Communication Architectures for Switched Real-Time Ethernet

Safety-critical distributed real-time applications operating with strict temporal constraints rely on deterministic networks with low latency and jitter. Traditional fieldbus systems deliver these guarantees, but they have limited compatibility with open infrastructures and limited support for high transmission rates. Ethernet technology rises as a low-cost, high-speed, and ubiquitous alternative to fieldbus systems; however, standard Ethernet requires special arbitration mechanisms to support real-time traffic because of the standard's inherent nondeterministic behavior. This work explores the associated tradeoffs for three different solutions for real-time communication over switched Ethernet. The paper presents and discusses three architectures that modify different network components, enhancing them with additional customized modules to support time-triggered communication based on Network Code. Using the NetFPGA platform as the unified prototyping technology for all the components, we developed an open-source framework to characterize each solution using experimental data for the latency, jitter, throughput, robustness, and cost in logical resources. The results provide insights to help future developers of real-time communication technology decide which components to modify according to the requirements of their applications.