Performance Analysis of IEEE 802.1Qch for Automotive Networks: Compared with IEEE 802.1 Qbv

TSN (Time Sensitive Networks) is an attractive solution for latency-critical frame transmission built upon IEEE 802 architecture for automotive Ethernet. In particular, IEEE 802.1Qbv defines a time-triggered communication paradigm with the addition of a time-aware shaper governing the selection of frames at the egress queues according to a predefined schedule. In contrast, IEEE 802.1Qch proposes another scheduling mechanism called CQF (Cyclic Queuing and Forwarding) based on the original IEEE 802.1Qbv time-aware scheduling. This paper focuses on studying the performance of Ethernet with IEEE 802.1Qch enhancement and comparing the performance between IEEE 802.1Qbv and IEEE 802.1Qch. In order to describe the scheduling mechanism, this paper proposes the scheduling algorithms of the two different scheduling mechanisms. Then, implementing the above scheduling algorithm in OMNeT++, an open-source network simulator. Lastly, comparing the performance of the two algorithms, end-to-end delay is collected to assess the performance. In this way, a result shows that the CQF has a better performance about the jitter of end-to-end delay than the time-aware scheduling mechanism, but CQF increases the worst end-to-end delay. However, a single mechanism is imperfect, and the study on the two scheduling mechanisms working in coordination needs to be further researched.