At operation 2, in an embodiment shown in the current drawing, the 5G-AN 300 and the 5GC network 400 may broadcast its SNPN ID and the onboarding indication indicating whether onboarding is supported, through broadcast system information. In an embodiment shown in the current drawing, the 5G-AN 300 and the 5GC network 400 may broadcast an onboarding indication indicating SNPN #1 and SNPN #2 support onboarding, through the broadcast system information.

At operation 3, the UE 200 performing network selection in the onboarding mode may request, through a system information request message, a list of DCS group IDs supported by the SNPN network from SNPN networks (SNPN #1 and SNPN #2) supporting onboarding based on the received onboarding indication.

At operation 4, each of SNPN #1 and SNPN #2 having received the system information request may transmit a DCS group ID supported by each SNPN or a list of DCS group IDs to the UE 200 through a system information message.

The UE 200 may identify a DCS group ID supported by an SNPN network from the received system information message and select one SNPN network including a DCS group ID preconfigured in the UE 200. When there are a plurality of SNPN networks including a DCS group ID preconfigured in the UE 200, the UE 200 may select an SNPN network based on priority information. The priority information may be preconfigured in the UE 200, and the UE may reflect and configure information included in a received signal.

In an embodiment of the current drawing, at operation 5, the UE 200 may perform initial access for registration in the selected SNPN #1.