16.15.4.2.1 Assistance Information

In order to enhance the scheduling of uplink resources for XR, the following improvements are introduced:

• One additional buffer size table to reduce the quantisation errors in BSR and DSR (defined below) reporting (e.g. for high bit rates):
• Whether, for an LCG, the new table can be used in addition to the regular one is configured by the gNB;
• When the new table is configured for an LCG, it is used whenever the amount of the buffered data of that LCG to be reported is within the range of the new table, otherwise the regular table is used.
• Delay Status Report (DSR) of buffered data via a dedicated MAC CE:
• Triggered for an LCH when the remaining time before discard of any buffered PDCP SDU goes below a configured threshold (threshold configured per LCG by the gNB);
• When triggered for an LCH, reports for each threshold configured , the buffer size and the shortest remaining time before discard of buffered PDCP SDUs associated to this threshold.
• Reporting of uplink assistance information (jitter range, burst arrival time, UL data burst periodicity, possibility for the UE to identify PDU sets and/or PSI) per QoS flow by the UE via UE Assistance Information. In case target gNB receives the burst arrival time from source gNB during the handover preparation procedure, the target gNB may use it by considering the SFN offset of the source gNB.