5.40.2 UE configuration and provisioning for Disaster Roaming

A 5GS UE supporting Disaster Roaming is configured with the following information:

• Optionally, indication of whether disaster roaming in 5GS is enabled in the UE;
• Optionally, indication of 'applicability of "lists of PLMN(s) to be used in disaster condition" provided by a VPLMN';
• Optionally, list of PLMN(s) to be used in Disaster Condition.

The Activation of Disaster Roaming is performed by the HPLMN by setting the indication of whether Disaster roaming is enabled in the UE to "disaster roaming is enabled in the UE" using the UE Parameters Update Procedure as defined in TS 23.502 [3]. The UE shall only perform disaster roaming if the HPLMN has configured the UE with the indication of whether disaster roaming is enabled in the UE and set the indication to "disaster roaming is enabled in the UE". The UE, registered for Disaster Roaming service, shall deregister from the PLMN providing Disaster Roaming service if the received indication of whether disaster roaming is enabled in the UE is set to "disaster roaming is disabled in the UE".

The optional 'list of PLMN(s) to be used in Disaster Condition' may be pre-configured in USIM or provided by the HPLMN during and after a successful registration procedure over 3GPP access or non-3GPP access via Registration Request procedure or UE Configuration Update procedure as defined in TS 23.502 [3]. The 'list of PLMN(s) to be used in Disaster Condition' may be configured over non-3GPP access before disaster condition has occurred.

While roaming (i.e. not in HPLMN), the Registered PLMN may provide the 'list of PLMN(s) to be used in Disaster Condition' during and after a successful registration procedure to the UE via Registration Request procedure or UE Configuration Update procedure as specified in TS 23.502 [3]. This list shall not alter any list provided by the HPLMN and shall only be used if the UE is configured by the HPLMN using the UE Parameters Update Procedure as defined in TS 23.502 [3] with the indication of 'applicability of "lists of PLMN(s) to be used in disaster condition" provided by a VPLMN' set to "True".

The details of the UE behaviour regarding the usage of this list are described in TS 23.122 [17] and TS 24.501 [47]. If the UE is not configured with 'list of PLMN(s) to be used in Disaster Condition', the UE follows the procedure described in TS 23.122 [17] to select PLMN to be used in Disaster Condition.

The HPLMN may use UE Parameters Update Procedure as defined in TS 23.502 [3] to update the Disaster Roaming information configuration in UE, if the UDM has received MINT support indication as indicated in 5GMM capability from the AMF. The UE indicates the support of MINT in 5GMM capability as specified in clause 5.4.4a, during registration procedure as defined in TS 23.502 [3].