Method for managing user equipment registration with access and mobility management function during disaster condition

A method performed by a first access and mobility management function (AMF), the method comprising:

• receiving, from a user equipment (UE), a registration request message including information regarding a public land mobile network (PLMN) with a disaster condition, wherein the information regarding the PLMN with the disaster condition indicates a PLMN of the UE which has faced the disaster condition;
• storing the information regarding the PLMN with the disaster condition included in the registration request message as a part of a UE context;
• receiving, from a second AMF, a UE context transfer request message;
• and
• transmitting, to the second AMF, a UE context transfer response message in response to the UE context transfer request message, the UE context transfer response message comprising the UE context.

A method performed by a second access and mobility management function (AMF), the method comprising:

• transmitting, to a first AMF, a user equipment (UE) context transfer request message;
• receiving, from the first AMF, a UE context transfer response message comprising a UE context, wherein the UE context includes information regarding a public land mobile network (PLMN) with a disaster condition;
• determining whether the second AMF supports a disaster roaming service for the PLMN with the disaster condition to a UE;
• and
• in case that the second AMF determines not to support the disaster roaming service for the PLMN with disaster condition to the UE, transmitting, to the UE, a registration reject message indicating that the disaster roaming service for the PLMN with the disaster condition is not allowed.

A method performed by a user equipment (UE), the method comprising:

• transmitting, to a first access and mobility management function (AMF), a registration request message including information regarding a public land mobile network (PLMN) with a disaster condition, wherein the information regarding the PLMN with the disaster condition indicates a PLMN of the UE which has faced disaster condition;
• and
• receiving, from a second AMF, a registration reject message indicating that a disaster roaming service for the PLMN with the disaster condition is not allowed,
• wherein the UE does not attempt to register for disaster roaming on the PLMN with the disaster condition for a certain period of time.