5G NR-NR Dual Connectivity (NR-DC/NRDC) SN (Secondary Node) Addition Procedure

:white_check_mark: For instance, a 5G Base Station(gNB) as a Master Node(MN) with the FR1 NR cells (N78, 3500 MHz) requests the UE to send the radio network capability (NR-DC capability) to setup NR-DC, i.e. add a gNB as Secondary Node(SN) with FR2 NR cells(N257, 28 GHz).

:white_check_mark: If the UE is NR-DC capable and NR-DC is operation on the MN, then the MN configures the UE an A4 measurement through the RRC Reconfiguration to determine whether the UE has suitable coverage from an FR2 NR cell/cells to set up NR-DC.

:white_check_mark: When the UE finds an FR2 NR cell that satisfies the Event A4 measurement criteria, the UE sends an Event A4 measurement report to the MN.

:white_check_mark: The MN evaluates the reported cell to determine whether it is a valid candidate for setting up NR-DC. If the reported cell is suitable, the MN initiates SN addition procedure.

:white_check_mark: Here I am trying to depict the Event A4 measurement criteria for triggering the UE to report the measurement as well as the procedure for NR-DC SN addition.

LinkedIn: :point_down:

:white_check_mark: In addition, I also prepared a video related to this topic and uploaded it on my YouTube channel, here you can find the video link: 5G NR-NR Dual Connectivity (NR-DC/NRDC) #5g #4g #telecom - YouTube