Network interworking systems and methods

A non-transitory computer-readable medium that has instructions stored thereon that, when executed by at least one physical computing processor, cause a computing device to perform operations comprising:

• accessing, by a User Data Management (UDM) function of a mobile network, in response to receiving a registration request from a User Equipment (UE), a network interworking support database that supports interworking between the mobile network and a legacy network that operates using a mobile network standard for a specific subscriber in a roaming scenario that is of an earlier generation than the mobile network primarily uses for the specific subscriber;
• determining, by the UDM function, whether the network interworking support database contains Visitor Location Register (VLR) information for the UE associated with the legacy network;
• and
• transmitting, by the UDM function based on determining that the network interworking support database contains VLR information for the UE associated with the legacy network, a deregistration request to a Home Location Register (HLR) of the mobile network such that the HLR clears the VLR information of the UE from the network interworking support database and sends a cancellation message to a VLR of the legacy network to remove registration information for the UE such that the mobile network avoids redirecting a call for the UE to the legacy network after the UE has returned to a coverage area of the mobile network after roaming in a coverage area of the legacy network.

A system comprising:

• at least one physical computing processor of a computing device;
• and
• a non-transitory computer-readable medium that has instructions stored thereon that, when executed by the at least one physical computing processor, cause the computing device to perform operations comprising:
• accessing, by a User Data Management (UDM) function of a mobile network, in response to receiving a registration request from a User Equipment (UE), a network interworking support database that supports interworking between the mobile network and a legacy network that operates using a mobile network standard for a specific subscriber in a roaming scenario that is of an earlier generation than the mobile network primarily uses for the specific subscriber;
• determining, by the UDM function, whether the network interworking support database contains Visitor Location Register (VLR) information for the UE associated with the legacy network;
• and
• transmitting, by the UDM function based on determining that the network interworking support database contains VLR information for the UE associated with the legacy network, a deregistration request to a Home Location Register (HLR) of the mobile network such that the HLR clears the VLR information of the UE from the network interworking support database and sends a cancellation message to a VLR of the legacy network to remove registration information for the UE such that the mobile network avoids redirecting a call for the UE to the legacy network after the UE has returned to a coverage area of the mobile network after roaming in a coverage area of the legacy network.