15.5.3 Support for RACH Optimization

RACH optimization is supported by UE reported information made available at the NG RAN node as specified in TS 38.331 [12] and by PRACH parameters exchange between NG RAN nodes.

The contents of the RA Report comprise of the following:

• Contention detection indication per RACH attempt;
• Indexes of the SSBs and number of RACH preambles sent on each tried SSB listed in chronological order of attempts;
• Indication whether the selected SSB is above or below the configured RSRP threshold per RACH attempt;
• 2-step RACH information as specified in clause 5.7.10.4 of TS 38.331 [12];
• Indication of LBT failures detected during the random access.

SN RA Reports

The UE may also support collection of SN RA Reports.

The SN RA report retrieval and forwarding is specified in TS 37.340 [21].