Core network becoming aware of PLMNs with disaster conditions
Systems and methods for enabling User Equipments (UEs) to use a Public Land Mobile Network (PLMN) failing service under disaster conditions and to receive services from alternative PLMNs. In some embodiments, a method performed by a first network node comprises receiving, from a second network node, a first disaster roaming PLMN list. The method also comprises determining that a UE is to be authenticated. The method further comprises providing, to a third network node, a request including the disaster roaming PLMN list, responsive to determining that the UE is to be authenticated. In this way, an interruption of the service at the UE is minimized in case of the disaster conditions.
1 . A method performed by a first network node, the method comprising: obtaining a first disaster roaming Public Land Mobile Network, PLMN, list from a Radio Access Network, RAN, serving a User Equipment, UE; determining that the UE requests disaster roaming service by determining that a PLMN Identifier, ID of an International Mobile Subscriber Identity, IMSI based Subscription Concealed Identifier, SUCI of the UE is in the first disaster roaming PLMN list; and sending to an Authentication Server Function, AUSF a Nausf_UEAuthentication_Authenticate Request including the disaster roaming request indication, responsive to determining that the UE requests disaster roaming service and determining that the UE is to be authenticated.
2 . The method of claim 1 , wherein:
the first network node comprises an Access Management Function, AMF.
3 . The method of claim 1 , wherein determining that the UE is to be authenticated further comprises determining that the UE is identified by a UE identifier.
4 . The method of claim 3 , wherein the UE identifier is a network-specific identifier based Subscription Concealed Identifier, SUCI, or International Mobile Subscriber Identity, IMSI, based SUCI.
5 . The method of claim 3 , wherein the IMSI based SUCI indicates a PLMN ID of a home PLMN (HPLMN) of the UE in disaster condition.
6 . The method of claim 5 , wherein in the HPLMN in disaster condition is in the first disaster roaming PLMN list.
7 . The method of claim 5 , further comprising:
obtaining a second disaster roaming PLMN list that does not include the HPLMN of the UE.
8 . The method of claim 7 , further comprising:
determining that the UE is in a 5GMM-CONNECTED mode; and
performing a UE configuration update procedure with an indication that a disaster condition of the HPLMN of the UE was resolved, or triggering the UE to perform a mobility registration update and rejecting the mobility registration update with an indication that the disaster condition in the HPLMN of the UE is resolved.
9 . The method of claim 5 , further comprising:
determining that the UE is in a 5GMM-IDLE mode and attempts to move to a 5GMM-CONNECTED mode; and
rejecting an initial Non-Access Stratum, NAS, request with an indication that a disaster condition in the HPLMN of the UE was resolved.
10 . A first network node comprising processing circuitry configured to cause the first network node to: obtain a first disaster roaming Public Land Mobile Network, PLMN, list from a Radio Access Network, RAN, serving a User Equipment, UE; determining that the UE requests disaster roaming service by determining that a PLMN Identifier, ID of an International Mobile Subscriber Identity, IMSI based Subscription Concealed Identifier, SUCI of the UE is in the first disaster roaming PLMN list; and send to an Authentication Server Function, AUSF a Nausf_UEAuthentication_Authenticate Request including the disaster roaming request indication, responsive to determining that the UE requests disaster roaming service and determining that the UE is to be authenticated.