Study on Effect of Variable Traffic on QoS of ATS and TAS in IEEE 802.1TSN on In-Vehicle Ethernet

This paper evaluates the QoS of ATS, one of the QoS controls defined in IEEE 802.1TSN, in an Ethernet-based in-vehicle network by comparing it with TAS by experiment. The experiments consider the maximum delay, the delay jitter, and the frame loss rate as QoS parameters and evaluate the effect of the number of switches on the QoS parameters. In the experiment, the authors use two types of traffic whose transmission intervals are fixed and unfixed. The experimental results indicate that TAS can suppress the maximum delay and the delay jitter more than ATS at fixed transmission intervals. However, ATS is more appropriate in delay than TAS at unfixed transmission intervals. The authors also show that the QoS of TAS deteriorates more at fixed transmission intervals as the number of switches increases. Moreover, the authors mention that a few frame losses can occur in the ATS when the transmission interval becomes large.