8.3.11 Activity Notification
38.4233GPPNG-RANRelease 17TSXn Application Protocol (XnAP)
8.3.11.1 General
The purpose of the Activity Notification procedure is to allow an NG-RAN node to send notification to another NG-RAN node concerning:
– user data traffic activity for the UE, or
– user data traffic activity of already established QoS flows or PDU sessions, or
– RAN Paging failure.
The procedure uses UE-associated signalling.
8.3.11.2 Successful Operation
Figure 8.3.11.2-1: Activity Notification, successful operation
NG-RAN node1 initiates the procedure by sending the ACTIVITY NOTIFICATION message to NG-RAN node2.
The ACTIVITY NOTIFICATION message may contain one or more of the below:
– notification for UE context level user plane activity in the UE Context level user plane activity report IE.
– notification of user plane activity for the already established PDU sessions within the PDU Session Resource Activity Notify List IE.
– notification of user plane activity for the already established QoS flows within the PDU Session Resource Activity Notify List IE.
– notification of RAN Paging failure.
If the ACTIVITY NOTIFICATION message contains the RAN Paging Failure IE, NG-RAN node2 shall consider that RAN Paging has failed in NG-RAN node1 for the UE. NG-RAN node2 may discard the user plane data for that UE and consider that the UE context is unchanged.
NOTE: As specified in TS 37.340 [8], in case of user data activity notification, NG-RAN node1 acts as a Secondary Node, while in case of RAN Paging failure indication, NG-RAN node1 acts as a Master Node.
8.3.11.3 Abnormal Conditions
If the User Plane traffic activity report IE for a reporting object is reported by NG-RAN node1 as "re-activated" and the reporting object was not reported as "inactive", the report for the concerned reporting object shall be ignored by NG-RAN node2.