4.9.4 Disabling and re-enabling of UE's satellite NG-RAN capability

Disable of the satellite NG-RAN capability shall only be performed when the UE is in 5GMM-IDLE mode.

When disabling the satellite NG-RAN capability, the UE:

• may disable the NR NTN access capability (see 3GPP TS 38.304 [28] and 3GPP TS 38.306 [28A]);
• shall memorize the identity of the PLMN where the satellite NG-RAN capability was disabled; and
• shall use that stored information in subsequent PLMN selections as specified in 3GPP TS 23.122 [5].

NOTE 1: As an implementation option, the UE can disable satellite NG-RAN capability by disabling N1 mode capability for satellite NG-RAN access.

As an implementation option, the UE may start a timer for enabling satellite NG-RAN capability when the UE disables satellite NG-RAN capability, and on expiry of this timer:

• if the UE is in IDLE mode, the UE should enable satellite NG-RAN capability; and
• if the UE is in CONNECTED mode, the UE should delay enabling the satellite NG-RAN capability until the NAS signalling connection is released.

When the UE enables satellite NG-RAN capability for 3GPP access, the UE shall remove the PLMN from the memorized identity of the PLMNs where the satellite NG-RAN capability was disabled.

NOTE 2: As described in 3GPP TS 23.122 [5], if the UE is in automatic PLMN selection mode, the UE does not consider the memorized PLMNs as PLMN selection candidates for satellite NG-RAN access technology until the timer expires.

If the disabling of satellite NG-RAN capability was due to IMS voice is not available and the UE's usage setting is "voice centric", the UE shall re-enable the satellite NG-RAN capability when the UE's usage setting is changed from "voice centric" to "data centric", as specified in clauses 4.3.3.

The UE shall re-enable the satellite NG-RAN capability when the UE is switched off or the USIM is removed.

If the satellite NG-RAN capability of the current PLMN is disabled due to the reception of 5GMM cause #15 with Extended 5GMM cause IE value set to "Satellite NG-RAN not allowed in PLMN" and the UE receives an access technology utilization control information indicating that satellite NG-RAN is not restricted, the UE may enable the satellite NG-RAN capability for the current PLMN after the ongoing NAS signalling connection is released.