3GPP 23.501 v20.2.0 — the document's own text

5.49.3.2 MWAB-UE authorization

Taught in 26. Relays, satellites, femtos and shared networks (The 5G system architecture, in depth).

The MWAB-UE is authorized based on its subscription information which includes dedicated S-NSSAI(s) and DNN for MWAB operation. Such dedicated S-NSSAI(s) and DNN(s) shall be part of the subscription information for the MWAB-UE as specified in clause 5.2.3.3.1 of TS 23.502 [3].

The authorization of the MWAB-UE to establish connectivity in a BH PLMN/SNPN is based on whether dedicated S-NSSAI(s) for MWAB operations are received as part of Allowed NSSAI in BH PLMN/SNPN following existing procedures as described in clause 5.15 and whether it can establish BH PDU session(s) in the BH PLMN/SNPN using the dedicated S-NSSAI(s) and DNN(s).

The MWAB-UE authorization supports time-based or location-based control.

For time-based control, existing time-based network slice subscription control can be reused (including the enhancements in clause 5.15.16).
For location-based control, existing mechanism, e.g. service area restriction, LADN based control (see e.g. clauses 5.6.5 and 5.6.5a) can be reused.

NOTE 1: When the MWAB-UE can no longer use S-NSSAI(s) dedicated to MWAB operation,, e.g. the dedicated S-NSSAIs and DNNs for MWAB operation are removed from the subscription (i.e. the MWAB becomes unauthorized) and a UE subscription update (including a UE configuration update) step happens, or the MWAB-UE moves to an area where the S-NSSAI is not available, if the AMF is configured to do so for the dedicated S-NSSAI and DNN for MWAB operation, the AMF delays the corresponding PDU session release based on an operator configuration (e.g. a local configured timer to allow time for the MWAB-gNB to handover the UE(s) it serves to other cells).

NOTE 2: If the S-NSSAI(s) used by BH PLMN for MWAB operation is not dedicated for MWAB, the behaviours of AMF as in NOTE 1 cannot be limited to MWAB-UEs only. Additionally, it may also not be possible to configure specific treatment for MWAB-UEs (different from other UEs) in the NG-RAN.

The MWAB-UE may be connected to the BH PLMN/SNPN for other services, if allowed by the subscription data, even if the S-NSSAIs and DNNs for Backhaul PDU sessions are no longer authorized.