QoS Evaluation of In-Class Control in IEEE 802.1 TSN

Since, over an in-vehicle network, the kind of traffic exceeds the number of priorities that IEEE 802.1TSN can support, utilization of in-class QoS control is inevitable. Thus, this paper evaluates the effect of the in-class control on QoS over Ethernet-based in-vehicle networks by experiment. This experiment assumes that each ECU can generate traffic of multiple priorities; it compares the QoS when QoS control is performed within the ECU (in-class control) or switch and when QoS control is used only at the switch. The experiments treat CBS, one of the QoS controls of IEEE 802.1TSN; it adopts the mean delay, maximum delay, and delay jitter as QoS parameters. The experimental results indicate that in-class control is only necessary when the network is heavily congested. The paper concludes that it is essential to maintain QoS for high-priority traffic when the network is highly congested by low-priority traffic.