Section: 4.15.9.5.2 5G access stratum time distribution status reporting to the UE
Content: Figure 4.15.9.5.2-1: Procedure for reporting RAN timing synchronization status to subscribed UE 1. Creation or update of ASTI or PTP based time synchronization service (AF requested ASTI or PTP based time synchronization service is described in clauses 4.15.9.4 and 4.15.9.3; subscription based ASTI is described in clause 4.28.2.1) including in the request clock quality detail level indication and optionally the clock quality acceptance criteria. The clock quality level indication and optionally the clock quality acceptance criteria are sent to the NG-RAN and the UE reconnect indication is sent to the UE as described in clause 4.15.9.4. 2. The RAN node is pre-configured for the thresholds for each timing synchronization status attribute as described in clause 5.27.1.12 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2]. If there is a change on its primary source so that the thresholds are exceeded or met again, the NG-RAN node indicates the status via SIB information as described in clause 5.27.1.12 in TS 23.501[ System architecture for the 5G System (5GS) ]  [2]. 3. (When the UE is in RRC_INACTIVE or RRC_IDLE state): If supported by the UE and If the UE determines, based on the reading of SIB9 information as described in clause 5.27.1.12 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2], a clock quality information update is available, and the AMF has provided the UE reconnection indication in step 10 of clause 4.15.9.4, the UE reconnects to the network as described in TS 24.501[ Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3 ]  [25]. 4. (When the UE is in RRC_CONNECTED state): The NG-RAN node notifies the UE providing clock quality information as configured in step 0 (i.e. sending clock quality metrics or acceptable/not acceptable indication) using unicast RRC signalling whenever the UE enters RRC_CONNECTED state and while the UE remains in RRC_CONNECTED, when any of the clock quality metrics or the acceptable/not acceptable indication for the UE changes.