IEEE 802.1Qbu describes frame preemption to reduce latency for time-sensitive Ethernet frames.

IEEE 802.1Qbu describes frame preemption in bridged Ethernet networks. It allows the transmission of a non-time-critical frame to be interrupted so that a time-critical frame can be sent immediately; afterward, the interrupted frame is resumed. In the TSN/automotive context, this reduces the latency for critical data streams and, particularly in combination with TAS, reduces the required guard bands.