The Centralized Unit of the gNB (gNB CU/gNB CU-UP) can be configured with the level of activity notification and inactivity timer as well during the PDU Session Setup or Modification, to perform user inactivity monitoring and further informs its inactivity or (re)activation to the node having C-plane connection towards the 5G core network (e.g. gNB CU or gNB CU-CP over E1 interface).
The Distributed Unit of the gNB (gNB-DU) may perform user inactivity monitoring and further inform its inactivity or (re)activation to the node hosting control plane (e.g. gNB-CU or gNB-CU-CP) over F1-C) .
Here I try to depict how the functional entities of a gNB are informed to perform user inactivity monitoring during the PDU Session Setup/Modification.
I prepared a video concerned to this topic and the C-RAN as well. You can watch this video on my YouTube channel:
Linkedin: Rahim Navaei on LinkedIn: #5g #5gnr #4g