Integration of existing ethernet devices into time-division-multiplexing ethernet

Along with the development of industrial systems, real-time Ethernet (RTE) is widely utilized for control systems. S-TDMA is one of the RTE protocols, and it is a concept realizing a coexistence of real-time and best-effort communication over the Ethernet by time-division multiplexing. In previous work, a special switching hub capable of S-TDMA was implemented, and the capability of real-time communication on multi-hop topology was shown. It is expected to apply S-TDMA for the Internet; it is not practical that all nodes in the network support S-TDMA. Therefore, this paper proposes the integration method of existing Ethernet devices into S-TDMA network by using a pause frame. The performance of best-effort traffic between these devices over S-TDMA network was evaluated. The results verify the superiority of the proposed method. The proposed design greatly suppressed the performance deterioration of best-effort traffic. The throughput of the proposed method was 670 Mbps higher than that of the previous implementation at the effective bandwidth of 950 Mbps. The results also show the comparable performance, even if the number of hops has increased.