Section: 4.7.3.3 Uplink Scheduling Latency
Content: The IAB-node can reduce UL scheduling latency through signalling of a Pre-emptive BSR to its parent node. The IAB-node can send the Pre-emptive BSR based on UL grants it has provided to child nodes and/or UEs, or based on BSRs it has received from child nodes or UEs (Figure 4.7.3.3-1). The Pre-emptive BSR conveys the data expected rather than the data buffered. Figure 4.7.3.3-1: Scheduling of BSR in IAB: a) regular BSR based on buffered data, b) Pre-emptive BSR based on UL grant, c) Pre-emptive BSR based on reception of regular BSR