Apparatus, method and computer program product for fifth generation system multiple registration using evolved packet system network interworking

Abstract

An apparatus, method, and computer program product are described for enabling splitting, handover, and boot of access traffic in a system, such as a 5th Generation (5G) system. An access and mobility management function (AMF) of the 5G system forwards one or more of the registration requests to a unified data management (UDM) function of the PLMN. The UDM function determines whether Evolved Packet System (EPS) Interworking (IWK) is allowed for a respective registration request based on subscription, deployment, system capabilities, Radio Access Technology (RAT) of an access path between the UE and the 5G system, etc. The UE may include an indication in the registration request that the EPS IWK is requested and / or required.

Description

Technical Field

[0001] This patent application claims priority to U.S. patent application No. 18 / 067,488, filed on December 12, 2022, which is incorporated herein by reference as if reproduced in its entirety.

[0002] Some example embodiments of the subject matter described herein may generally relate to mobile or wireless telecommunication systems, such as the Long Term Evolution (LTE) Universal Mobile Telecommunications System or the Fifth Generation Communication System (5GS). Background Art

[0003] Examples of mobile or wireless telecommunication systems may include: Universal Mobile Telecommunications System (UMTS) (which includes the UMTS Terrestrial Radio Access Network (UTRAN)), Long Term Evolution UMTS (which includes Long Term Evolution (LTE) Evolved UTRAN (E-UTRAN)), Advanced LTE (LTE-A), MulteFire, LTE-A Pro, and / or fifth generation (5G) or new radio (NR) wireless communication systems. A 5G wireless communication system refers to a wireless communication system that operates using next generation (NG) radio access technology and has a system architecture defined in the 3rd Generation Partnership Project Technical Specifications 23.501 and 23.502. A 5G wireless communication system (5GS) is mostly built based on fifth generation (5G) or new radio (NR) radio access technology, but 5GS may also be built based on fourth generation radio access technology. It is estimated that a 5GS built on 5G or NR radio access technology can communicate with wireless communication devices (such as mobile stations or user equipment) connected thereto at bit rates of 10-20 Gbit / s or higher, and can be configured to provide services such as enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC). The 5GS may include a next-generation radio access network (NG-RAN) that can provide both NR and LTE (and LTE-Advanced) radio access. It should be noted that in an NG-RAN, a radio access network (RAN) node (also known as a base station) can provide radio access to wireless communication devices (such as user equipment) (i.e., in a manner similar to a Node B (i.e., NB) in UTRAN or an evolved NB (i.e., eNB) in E-UTRAN), and may be referred to as a next-generation NB (gNB) when built on NR, and as a next-generation eNB (NG-eNB) when built on e-UTRA. Summary of the Invention

[0004] This document describes an apparatus, method, and computer program product for multiple registrations for a fifth generation communication system (5GS), as well as decision making and signaling for selection of registrations for Evolved Packet System (EPS) network interworking. Apparatus, methods, and computer program products for enabling splitting, switching, and steering of services in a system (e.g., 5GS) are described. 5GS and / or EPS may be part of a public land mobile network (PLMN), for example, implemented by a specific operator in a specific country. In some embodiments, the access and mobility management function (AMF) of the 5GS forwards one or more registration requests received from a user equipment to a unified data management (UDM) function of the PLMN. In some embodiments, based on the subscription data of the user equipment, the architecture of the 5GS, the capabilities of the 5GS, and the radio access technology (RAT) of the access path on which the corresponding registration request is received, the UDM function determines whether Evolved Packet System (EPS) interworking (IWK) is allowed for a corresponding registration request in one or more registration requests. In some embodiments, the UE may include in the registration request an indication that EPS IWK is requested and / or an indication that EPS interworking is required.

[0005] According to an embodiment, a device may be provided, comprising components such as at least one processor and at least one memory storing instructions, wherein when the instructions are executed by the at least one processor, the device at least: generates a registration request for registration of a user equipment with a fifth generation (5G) system; adds an indication of whether the registration is requested for an evolved packet system network interworking in the registration request; and provides the registration request to an access and mobility management function of the 5G system, the registration request including an indication of whether the registration is requested for an evolved packet system network interworking. In some embodiments, the at least one memory and the program code are further configured to, together with the at least one processor, cause the device at least: receive a response to the registration request from the access and mobility management function of the 5G system, the response including an additional indication of whether the registration requested in the registration request is allowed for the evolved packet system network interworking.

[0006] According to another embodiment, a method may be performed, for example, by a component such as a processor and a memory storing program code, or the above-mentioned apparatus. In some embodiments, the method may include: generating, at a user equipment, a registration request for registration to a fifth generation (5G) system; adding an indication in the registration request as to whether the registration is requested for an evolved packet system network interworking; and providing the registration request to an access and mobility management function of the 5G system, the registration request including: an indication as to whether the registration is requested for an evolved packet system network interworking. In some embodiments, the method may further include: receiving a response to the registration request from the access and mobility management function, the response including: an additional indication as to whether the registration requested in the registration request is allowed for the evolved packet system network interworking.

[0007] According to another embodiment, a non-transitory computer-readable medium storing program code may be provided, the program code being operable, when executed by a processor, to at least cause: generating, at a user equipment, a registration request for registration with a fifth generation (5G) system; adding an indication in the registration request as to whether Evolved Packet System network interworking is requested for registration; and providing the registration request to an access and mobility management function of the 5G system, the registration request including the indication as to whether Evolved Packet System network interworking is requested for registration. In some embodiments, the program code, when executed by the processor, further causes at least: receiving a response to the registration request from the access and mobility management function, the response including an additional indication as to whether Evolved Packet System network interworking is allowed for the registration requested in the registration request.

[0008] According to an embodiment, a device may be provided, which includes components for executing a method or participating in a process, such as at least one processor and at least one memory storing program code. For example, in some embodiments, the at least one memory and program code are configured to, together with the at least one processor, enable the device to at least: receive a registration response from an access and mobility management function of a fifth generation (5G) system in response to a registration request for registration with a 5G system, the registration response including: an indication of whether an evolved packet system network intercommunication is allowed for the registration; and based on the indication, determine whether the evolved packet system network intercommunication is allowed for the registration. In some embodiments, the at least one memory and program code are configured to, together with the at least one processor, enable the device to at least: provide a registration request for registration with a 5G system to an access and mobility management function of the 5G system, wherein the registration request includes: another indication that an evolved packet system network intercommunication is requested for registration with the 5G system.

[0009] According to another embodiment, a method may be performed, for example, by components such as a processor and a memory storing program code, or the above-mentioned apparatus. In some embodiments, the method may include: at a user equipment, in response to a registration request for registration to a 5G system, receiving a registration response from an access and mobility management function of a fifth generation (5G) system, the registration response including: an indication as to whether evolved packet system network intercommunication is allowed for the registration; and based on the indication, determining whether evolved packet system network intercommunication is allowed for the registration. In some embodiments, the method may further include: providing a registration request for registration to the 5G system from the user equipment to the access and mobility management function of the 5G system, wherein the registration request includes: another indication that evolved packet system network intercommunication is requested for registration to the 5G system.

[0010] According to another embodiment, a non-transitory computer-readable medium storing program code may be provided, the program code being operable, when executed by a processor, to at least cause: at a user equipment, in response to a registration request for registration with the 5G system, receiving a registration response from an access and mobility management function of a fifth generation (5G) system, the registration response including: an indication as to whether Evolved Packet System network interworking is allowed for the registration; and determining, based on the indication, whether Evolved Packet System network interworking is allowed for the registration. In some embodiments, when executed by the processor, the program code further causes at least: providing, from the user equipment, to the access and mobility management function of the 5G system, a registration request for registration with the 5G system, wherein the registration request includes: another indication that Evolved Packet System network interworking is requested for registration with the 5G system.

[0011] According to an embodiment, an apparatus may be provided that includes components for performing a method or participating in a process, such as at least one processor and at least one memory storing program code. For example, in some embodiments, the at least one memory and program code are configured to, together with the at least one processor, cause the apparatus to at least: provide a first registration request for a first registration with the first fifth generation (5G) system to a first access and mobility management function of a first 5G system; provide a second registration request for a second registration with the second 5G system to a second access and mobility management function of a second 5G system; and receive an indication from the first access and mobility management function that an evolved packet system network interworking is allowed for the first registration; or receive an indication from the second access and mobility management function that an evolved packet system network interworking is allowed for the second registration.

[0012] According to another embodiment, a method may be performed, for example, by a component such as a processor and a memory storing program code, or the above-mentioned apparatus. In some embodiments, the method may include: providing, from a user equipment, a first registration request for a first registration to a first 5G system to a first access and mobility management function of a first communication system; providing, from the user equipment, a second registration request for a second registration to a second 5G system to a second access and mobility management function of a second communication system; and, at the user equipment, receiving, from the first access and mobility management function, an indication that evolved packet system network interworking is allowed for the first registration; or, at the user equipment, receiving, from the second access and mobility management function, an indication that evolved packet system network interworking is allowed for the second registration.

[0013] According to another embodiment, a non-transitory computer-readable medium storing program code may be provided, which program code is operable when executed by a processor to at least cause: a first registration request for a first registration to a first fifth generation (5G) system is provided from a user device to a first access and mobility management function of a first 5G system; a second registration request for a second registration to a second 5G system is provided from the user device to a second access and mobility management function of a second 5G system; and at the user device, an indication is received from the first access and mobility management function that evolved packet system network intercommunication is allowed for the first registration; or an indication is received at the user device from the second access and mobility management function that evolved packet system network intercommunication is allowed for the second registration.

[0014] According to an embodiment, an apparatus may be provided that includes components for performing a method or participating in a process, such as at least one processor and at least one memory storing program code. For example, in some embodiments, the at least one memory and program code are configured to, together with the at least one processor, cause the apparatus to at least: receive a registration request from a user equipment regarding a registration between the user equipment and a fifth generation (5G) system, the registration request including: an indication of whether an evolved packet system network interworking is requested for the registration; generate a message regarding the registration requested in the registration request; add an additional indication in the message regarding whether the user equipment is requesting an evolved packet system network interworking for the registration; and provide the message to a unified data management function associated with the 5G system or a home network of the user equipment.

[0015] According to another embodiment, a method may be performed, for example, by a component such as a processor and a memory storing program code, or the above-mentioned apparatus. In some embodiments, the method may include: receiving, at an access and mobility management function of a fifth generation (5G) system, a registration request from a user equipment regarding registration between the user equipment and the 5G system, the registration request including: an indication of whether an evolved packet system network interworking is requested for the registration; generating a message regarding the registration requested in the registration request; adding an additional indication in the message regarding whether the user equipment is requesting evolved packet system network interworking for the registration; and providing the message from the access and mobility management function to a unified data management function associated with the 5G system or a home network of the user equipment.

[0016] According to another embodiment, a non-transitory computer-readable medium storing program code may be provided, which program code is operable when executed by a processor to at least cause: at an access and mobility management function of a fifth generation (5G) system, receiving a registration request from a user equipment regarding a registration between the user equipment and a 5G system, the registration request including: an indication as to whether evolved packet system network intercommunication is requested for the registration; generating a message regarding the registration requested in the registration request; adding an additional indication in the message as to whether the user equipment is requesting evolved packet system network intercommunication for the registration; and providing the message from the access and mobility management function to a unified data management function associated with the 5G system or a home network of the user equipment.

[0017] According to an embodiment, an apparatus may be provided, comprising means for performing a method or participating in a process, such as at least one processor and at least one memory storing program code. For example, in some embodiments, the at least one memory and program code are configured to, with the at least one processor, cause the apparatus to at least: receive from a unified data management function an indication of whether an evolved packet system network interworking is allowed for registration with a fifth generation (5G) system, the registration being associated with a user equipment; and transmit to the user equipment an indication of whether the evolved packet system network interworking is allowed for the registration. In some embodiments, the at least one memory and program code are further configured to, with the at least one processor, cause the apparatus to at least: provide a registration response to the user equipment, the registration response including an indication of whether the evolved packet system network interworking is allowed for registration associated with the user equipment. In some embodiments, the at least one memory and program code are further configured to, with the at least one processor, cause the apparatus to at least: provide a user equipment configuration update to the user equipment, the user equipment configuration update including an indication of whether the evolved packet system network interworking is allowed for registration associated with the user equipment.

[0018] According to another embodiment, a method may be performed, for example, by a component such as a processor and a memory storing program code, or the above-mentioned apparatus. In some embodiments, the method may include: receiving, at an access and mobility management function, a unified data management function indication from a unified data management function regarding whether an evolved packet system network intercommunication is allowed for registration to a fifth generation (5G) system, the registration being associated with a user equipment; and transmitting to the user equipment whether the evolved packet system network intercommunication is allowed for the registration associated with the user equipment. In some embodiments, the method may further include: providing a registration response to the user equipment, the registration response including an access and mobility management function indication, the access and mobility management function indication being regarding whether the evolved packet system network intercommunication is allowed for the registration associated with the user equipment. In some embodiments, the method may further include: providing a user equipment configuration update to the user equipment, the user equipment configuration update including an access and mobility management function indication, the access and mobility management function indication being regarding whether the evolved packet system network intercommunication is allowed for the registration associated with the user equipment.

[0019] According to another embodiment, a non-transitory computer-readable medium storing program code may be provided, the program code being operable, when executed by a processor, to at least cause: receiving, at an access and mobility management function, a unified data management function indication from a unified data management function regarding whether evolved packet system network interworking is allowed for registration with a fifth generation (5G) system, the registration being associated with a user equipment; and transmitting to the user equipment whether the evolved packet system network interworking is allowed for the registration associated with the user equipment. In some embodiments, the program code, when executed by the processor, further causes at least: providing to the user equipment a registration response, the registration response including: an access and mobility management function indication regarding whether the evolved packet system network interworking is allowed for the registration associated with the user equipment by the 5G system. In some embodiments, the program code, when executed by the processor, further causes at least: providing to the user equipment a user equipment configuration update, the user equipment configuration update including: an access and mobility management function indication regarding whether the evolved packet system network interworking is allowed for the registration associated with the user equipment by the 5G system.

[0020] According to an embodiment, an apparatus may be provided, the apparatus comprising means for executing a method or participating in a process, such as at least one processor and at least one memory storing program code. For example, in some embodiments, the at least one memory and program code are configured to, together with the at least one processor, cause the apparatus to at least: receive a registration request for registration with a fifth generation (5G) system from a user equipment of a 5G system, the registration request including: a user equipment indication of whether Evolved Packet System network interworking for the registration is requested; provide an access and mobility management function indication of whether the user equipment requests Evolved Packet System network interworking for the registration to a unified data management function of the 5G system; receive a unified data management function indication of whether Evolved Packet System network interworking for the registration of the user equipment is allowed from the unified data management function; and communicate with the user equipment regarding whether Evolved Packet System network interworking for the registration is allowed. In some embodiments, the indication of whether registration is allowed for Evolved Packet System network interworking is determined based on at least one of the following: subscription information, deployment information, 5G system capabilities, or information about the radio access technology of the access path between the user equipment and the 5G system.

[0021] According to another embodiment, a method may be performed, for example, by a component such as a processor and a memory storing program code, or the above-mentioned apparatus. In some embodiments, the method may include: receiving, at an access and mobility management function of a fifth generation (5G) system, a registration request for registration with the 5G system from a user equipment of the 5G system, the registration request including: a user equipment indication of whether an evolved packet system network interworking for the registration is requested; providing an access and mobility management function indication of whether the user equipment requests the evolved packet system network interworking for the registration to a unified data management function of the 5G system; receiving a unified data management function indication of whether the evolved packet system network interworking is allowed for the registration from the unified data management function; and communicating with the user equipment whether the evolved packet system network interworking is allowed for the registration. In some embodiments, the indication of whether the evolved packet system network interworking is allowed for the registration is determined based on at least one of the following items: subscription information, deployment information, 5G system capabilities, or information about the radio access technology of the access path between the user equipment and the 5G system.

[0022] According to another embodiment, a non-transitory computer-readable medium storing program code may be provided, the program code being operable when executed by a processor to at least cause: receiving, at an access and mobility management function of a fifth generation (5G) system, a registration request for registration with the 5G system from a user equipment of the 5G system, the registration request including: a user equipment indication as to whether EPS network interworking is requested for the registration; providing an access and mobility management function indication to a unified data management function of the 5G system as to whether the user equipment requests EPS network interworking for the registration; receiving from the unified data management function an indication of whether EPS network interworking is allowed for the registration; and communicating with the user equipment as to whether EPS network interworking is allowed for the registration. In some embodiments, the indication of whether the EPS network interworking is allowed for the registration is determined based on at least one of the following: subscription information, deployment information, 5G system capabilities, or information about a radio access technology of an access path between the user equipment and the 5G system.

[0023] According to an embodiment, a device may be provided, which includes components for executing a method or participating in a process, such as at least one processor and at least one memory storing program code. For example, in some embodiments, the at least one memory and the program code are configured to, together with the at least one processor, cause the device to at least: receive a registration request for registration of the user equipment to the 5G system from a user equipment of a fifth generation (5G) system, wherein the registration request includes: an indication of whether the registration requires an evolved packet system network interoperability; and determine whether the 5G system supports evolved packet system network interoperability. In some embodiments, determining whether the 5G system supports evolved packet system network interoperability for registration of the user equipment to the 5G system includes determining one or more of the following items: subscription information, deployment information, 5G system capabilities, or information about the radio access technology of the access path between the user equipment and the 5G system. In some embodiments, the at least one memory and the program code are also configured, together with the at least one processor, to cause the apparatus to at least: provide a message regarding the registration request and the indication to a unified data management function of the 5G system or the home network of the user equipment; and in response to the message, receive from the unified data management function an additional indication regarding whether the registration requested in the registration request is allowed for the evolved packet system network intercommunication.

[0024] According to another embodiment, a method may be performed, for example, by a component such as a processor and a memory storing program code, or the above-mentioned apparatus. In some embodiments, the method may include: receiving, at an access and mobility management function of a fifth generation (5G) system, a registration request for registration of the user equipment with the 5G system from a user equipment of the 5G system, wherein the registration request includes: an indication as to whether the registration requires an evolved packet system network interworking; and determining whether the 5G system supports the evolved packet system network interworking. In some embodiments, determining whether the 5G system supports the evolved packet system network interworking for registration of the user equipment with the 5G system includes determining one or more of the following: subscription information, deployment information, 5G system capabilities, or information about the radio access technology of an access path between the user equipment and the 5G system. In some embodiments, the method may further include: providing, from the access and mobility management function, a message regarding the registration request and the indication to a unified data management function of the 5G system or a home network of the user equipment; and at the access and mobility management function, in response to the message, receiving from the unified data management function an additional indication as to whether the evolved packet system network interworking is allowed for the registration requested in the registration request.

[0025] According to another embodiment, a non-transitory computer-readable medium storing program code may be provided, the program code being operable when executed by a processor to at least cause: at an access and mobility management function of a fifth generation (5G) system, receiving a registration request from a user equipment of the 5G system for registration of the user equipment with the 5G system, wherein the registration request includes: an indication as to whether the registration requires an evolved packet system network interworking; and determining whether the 5G system supports evolved packet system network interworking. In some embodiments, determining whether the 5G system supports evolved packet system network interworking for registration of the user equipment with the 5G system includes determining one or more of the following: subscription information, deployment information, 5G system capabilities, or information about a radio access technology of an access path between the user equipment and the 5G system. In some embodiments, the program code, when executed by the processor, further causes at least: providing a message about the registration request and the indication from the access and mobility management function to the unified data management function of the 5G system or the home network of the user equipment; and at the access and mobility management function, in response to the message, receiving from the unified data management function an additional indication as to whether the evolved packet system network intercommunication is allowed for the registration requested in the registration request.

[0026] According to an embodiment, an apparatus may be provided that includes components for performing a method or participating in a process, such as at least one processor and at least one memory storing program code. For example, in some embodiments, the at least one memory and program code are configured to, together with the at least one processor, cause the apparatus to at least: receive information about a registration request from a user equipment for registration with the 5G system from an access and mobility management function of a fifth generation (5G) system, the information including: an access and mobility management function indication regarding whether the registration request includes a user equipment indication regarding whether evolved packet system network interworking for the registration is requested; determine whether evolved packet system network interworking is allowed for the registration; and provide a unified data management function indication regarding whether evolved packet system network interworking is allowed for the registration to the access and mobility management function. In some embodiments, the determination of whether evolved packet system network interworking is allowed for the registration includes determining whether evolved packet system network interworking is allowed for the registration based on at least one of the following: subscription information, deployment information, 5G system capabilities, or information regarding a radio access technology of an access path between the user equipment and the 5G system.

[0027] According to another embodiment, a method may be performed, for example, by a component such as a processor and a memory storing program code, or the above-mentioned apparatus. In some embodiments, the method may include: receiving, at a unified data management function, information about a registration request for registration of a user equipment to a 5G system from an access and mobility management function of a fifth generation (5G) system, the information including: an access and mobility management function indication as to whether the registration request includes a user equipment indication as to whether evolved packet system network intercommunication for the registration is requested; determining whether evolved packet system network intercommunication is allowed for the registration; and providing a unified data management function indication as to whether evolved packet system network intercommunication is allowed for the registration to the access and mobility management function. In some embodiments, the determination as to whether evolved packet system network intercommunication is allowed for the registration includes: determining whether evolved packet system network intercommunication is allowed for the registration based on at least one of the following: subscription information, deployment information, 5G system capabilities, or information about a radio access technology of an access path between the user equipment and the 5G system.

[0028] According to another embodiment, a non-transitory computer-readable medium storing program code may be provided, the program code being operable, when executed by a processor, to at least cause: receiving, at a unified data management function, information regarding a registration request from a user equipment for registration with the 5G system from an access and mobility management function of a fifth generation (5G) system, the information including: an access and mobility management function indication regarding whether the registration request includes a user equipment indication regarding whether evolved packet system network interworking for the registration is requested; determining whether evolved packet system network interworking is allowed for the registration; and providing the unified data management function indication regarding whether evolved packet system network interworking is allowed for the registration to the access and mobility management function. In some embodiments, determining whether evolved packet system network interworking is allowed for the registration includes determining whether evolved packet system network interworking is allowed for the registration based on at least one of the following: subscription information, deployment information, 5G system capabilities, or information regarding a radio access technology of an access path between the user equipment and the 5G system.

[0029] According to an embodiment, a device may be provided, the device including components for executing a method or participating in a process, such as at least one processor and at least one memory storing program code. For example, in some embodiments, the at least one memory and program code are configured to, together with the at least one processor, enable the device to at least: receive a message about a registration request associated with a user equipment from a unified data management function of a fifth generation (5G) system, the message including: an indication of whether the registration requested in the registration request by the evolved packet system network intercommunication is allowed between the user equipment and the 5G system or another communication system; generate a registration response message; if the indication is an indication that the evolved packet system network intercommunication is not allowed for the registration, modify the registration response message to indicate to the user equipment that the evolved packet system network intercommunication is not allowed for the registration; if the indication is an indication that the evolved packet system network intercommunication is allowed for the registration, modify the registration response message to indicate to the user equipment that the evolved packet system network intercommunication is allowed for the registration; and provide the registration response message to the user equipment.

[0030] According to another embodiment, a method can be performed, for example, by a component such as a processor and a memory storing program code or the above-mentioned device. In some embodiments, the method may include: at an access and mobility management function of a fifth generation (5G) system, receiving a message about a registration request associated with a user equipment from a unified data management function, the message including: an indication of whether the registration requested in the registration request by the evolved packet system network intercommunication is allowed between the user equipment and the 5G system or another communication system; generating a registration response message; if the indication is an indication that the evolved packet system network intercommunication is not allowed for the registration, modifying the registration response message to indicate to the user equipment that the evolved packet system network intercommunication is not allowed for the registration; if the indication is an indication that the evolved packet system network intercommunication is allowed for the registration, modifying the registration response message to indicate to the user equipment that the evolved packet system network intercommunication is allowed for the registration; and providing the registration response message from the access and mobility management function to the user equipment.

[0031] According to another embodiment, a non-transitory computer-readable medium storing program code may be provided, which program code is operable when executed by a processor to at least cause: at an access and mobility management function of a fifth generation (5G) system, receiving a message about a registration request associated with a user equipment from a unified data management function, the message including: an indication as to whether the registration requested in the registration request by the evolved packet system network intercommunication is allowed between the user equipment and the 5G system or another communication system; generating a registration response message; in a case where the indication is an indication that the evolved packet system network intercommunication is not allowed for the registration, modifying the registration response message to indicate to the user equipment that the evolved packet system network intercommunication is not allowed for the registration; in a case where the indication is an indication that the evolved packet system network intercommunication is allowed for the registration, modifying the registration response message to indicate to the user equipment that the evolved packet system network intercommunication is allowed for the registration; and providing the registration response message from the access and mobility management function to the user equipment.

[0032] According to an embodiment, an apparatus may be provided that includes components for performing a method or participating in a process, such as at least one processor and at least one memory storing program code. For example, in some embodiments, the at least one memory and program code are configured to, together with the at least one processor, cause the apparatus to at least: receive information about multiple registration requests for multiple registrations associated with a user equipment from one or more access and mobility management functions of one or more fifth generation (5G) systems; determine a specific registration for which evolved packet system network intercommunication is allowed from the multiple registrations; determine the specific access and mobility management function from which the specific registration is received based on the information about the multiple registration requests received from the one or more access and mobility management functions; and provide an indication to the specific access and mobility management function that evolved packet system network intercommunication is allowed for the specific registration. In some embodiments, at least one of the multiple registration requests includes: an indication of whether evolved packet system network intercommunication is requested for a corresponding registration associated with at least one of the multiple registration requests.

[0033] According to another embodiment, a method may be performed, for example, by a component such as a processor and a memory storing program code, or the above-mentioned apparatus. In some embodiments, the method may include: receiving, at a unified data management function, information about multiple registration requests for multiple registrations associated with a user equipment from one or more access and mobility management functions of one or more fifth generation (5G) systems; determining a specific registration for which evolved packet system network intercommunication is allowed from the multiple registrations; determining, based on the information about the multiple registration requests received from the one or more access and mobility management functions, the specific access and mobility management function from which the specific registration is received; and providing, from the unified data management function to the specific access and mobility management function, an indication that evolved packet system network intercommunication is allowed for the specific registration. In some embodiments, at least one registration request of the multiple registration requests includes: an indication as to whether evolved packet system network intercommunication is requested for a corresponding registration associated with at least one registration request of the multiple registration requests.

[0034] According to another embodiment, a non-transitory computer-readable medium storing program code may be provided, the program code being operable, when executed by a processor, to at least cause: receiving, at a unified data management function, information about a plurality of registration requests for a plurality of registrations associated with a user equipment from one or more access and mobility management functions of one or more fifth generation (5G) systems; determining, from the plurality of registrations, a specific registration for which evolved packet system network interworking is allowed; determining, based on the information about the plurality of registration requests received from the one or more access and mobility management functions, a specific access and mobility management function from which the specific registration was received; and providing, from the unified data management function to the specific access and mobility management function, an indication that evolved packet system network interworking is allowed for the specific registration. In some embodiments, at least one of the plurality of registration requests includes an indication as to whether evolved packet system network interworking is requested for a corresponding registration associated with the at least one of the plurality of registration requests. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] For a proper understanding of the example embodiments, reference should be made to the accompanying drawings, in which:

[0036] Figure 1 illustrates a user equipment having dual registration with two different mobile or wireless communication networks according to an embodiment;

[0037] Figure 2 illustrates a user equipment having dual registration with two different mobile or wireless communication networks according to another example embodiment;

[0038] Figure 3 illustrates a user equipment having dual registration with two different mobile or wireless communication networks according to another example embodiment;

[0039] Figure 4 illustrates a user equipment having dual registration with two different mobile or wireless communication networks according to another example embodiment;

[0040] Figure 5 illustrates an example signaling flow diagram according to an embodiment;

[0041] Figure 6 illustrates an example signaling flow diagram according to an embodiment;

[0042] Figure 7 illustrates an example signaling flow diagram according to an embodiment;

[0043] Figure 8A illustrates an example block diagram of an apparatus according to an example embodiment;

[0044] Figure 8Billustrates an example block diagram of an apparatus according to an example embodiment;

[0045] Figure 8C illustrates an example block diagram of an apparatus according to an example embodiment;

[0046] Figure 9 illustrates an example flow chart of a method according to an embodiment;

[0047] Figure 10 illustrates an example flow chart of a method according to an embodiment;

[0048] Figure 11 illustrates an example flow chart of a method according to an embodiment; and

[0049] Figure 12 An example flow chart of a method according to an embodiment is illustrated. DETAILED DESCRIPTION

[0050] It will be readily appreciated that the components of certain example embodiments, as generally described and illustrated in the figures herein, may be arranged and designed in a variety of different configurations. Thus, in the following detailed description of some example embodiments, a user equipment (UE) may be dual-registered (i.e., have two registrations with) a core network of a mobile network (e.g., a public land mobile network) via multiple 3GPP accesses and / or multiple non-3GPP accesses, or may be dual-registered with the core networks of two different mobile networks (e.g., a public land mobile network (PLMN) and a non-public network (NPN) or two different PLMNs).

[0051] The features, structures, or characteristics of the example embodiments described throughout this specification may be combined in any suitable manner in one or more example embodiments. For example, use of the phrases "certain embodiments," "some embodiments," or other similar language throughout this specification means that a particular feature, structure, or characteristic described in conjunction with an embodiment may be included in at least one embodiment. Thus, the appearance of the phrases "in certain embodiments," "in some embodiments," "in other embodiments," or other similar language throughout this specification does not necessarily refer to the same set of embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more example embodiments.

[0052] In a mobile network (e.g., a fifth generation (5G) system), a user equipment (UE) may establish multiple registrations with one or more core networks (e.g., a 5G core network). While a 5GS of a mobile network may be configured to allow a UE to dually register with the mobile network by access type (i.e., two accesses via the same access type), for example, in relatively lower and higher frequencies of the same or different frequency bands / sub-bands, several issues have been identified with respect to interworking (IWK) and inter / intra-system interoperability. For example, there are issues and concerns with respect to UE mobility, cancellation of the correct registration as needed, determination of a preferred registration for interworking (IWK) with an evolved packet system (EPS) (also referred to herein as EPSIWK), etc.

[0053] For example, when a UE moves outside or toward the edge of a service area or registration area for a 5G system, the UE may be downgraded from one or more 5G core networks to a legacy network, such as a 4G network, a 4G LTE network, or another EPS network. Although a UE can maintain multiple simultaneous registrations with one or more 5G core networks in a 5G system due to the specific architecture of the 5G system, the EPS network does not allow a single UE to maintain multiple simultaneous registrations. Therefore, when a UE is downgraded or otherwise moved from one or more 5G core networks to a single EPS network, the UE typically deregisters from all 5G core networks and then performs a new registration request procedure, a new attach request procedure, etc., with the EPS network.

[0054] However, the global deregistration of the UE from all 5G core networks and the process for requesting a new registration or attachment to the EPS network represents a time-consuming, computationally expensive, bandwidth-intensive, and overall inefficient process for performing an inter-system change or network handover for a UE that is already registered with the Unified Data Management (UDM) function of the mobile network. In order to more efficiently and quickly perform an inter-system change or network handover from (multiple) 5G core networks to a single EPC, one of the multiple registrations established for the UE with (multiple) 5G core networks can be maintained and used for single registration communications between the UE and the EPS. However, problems arise during the inter-system change or network handover of the UE from the 5G system to the EPS because some or all of the various access and mobility management functions (AMFs), mobility management entities (MMEs), UDM functions, UEs, and / or other elements of the 5G system do not know which of the multiple registrations to maintain during the inter-system change or network handover.

[0055] The decision as to which registration to retain may be made based on a number of factors, such as UE preference or request, network-side instructions, network traffic / paging density, Quality of Service (QoS) / Quality of Experience (QoE) issues, service type, emergency service status, and / or a combination of such characteristics and considerations. For example, a UE may have a first registration with a 5G core network that is used for emergency messaging, short messaging service (SMS), high priority telephony, UE location services, etc., and the UE may have one or more other registrations with the same or different 5G core networks that are used for other services, messaging, control signaling, data transfer, user plane communications, physical layer signaling, etc. Due to the importance of the services provisioned to the UE that are associated with the first registration or sent using registration information of the first registration, the UE may determine that it wishes to maintain the first registration during an inter-system change or network handover from a 5G system to EPS. In such an example, the UE may wish to request that EPS interworking be allowed (EPSIWK) for the first registration. This may be achieved via ad hoc or dedicated signaling, may be achieved during the registration request / attach request process, or may be achieved through combined signaling / messaging between the UE and the 5G core network at some point in time after the establishment of the UE's first registration with the 5G core network.

[0056] An element of the 5G core network (e.g., the AMF) may receive a request from the UE indicating that the EPS IWK is allowed for a first registration and provide the request or information about the request to another element or function, such as the UDM. The UDM may determine whether the EPS IWK is to be allowed for the first registration based on factors such as those discussed above and elsewhere in this disclosure. The UDM may provide the UE with an indication of whether the EPS IWK is allowed for the first registration, for example via the AMF or otherwise. Thereafter, if the UE is downgraded from the 5G core network to the EPS, the UE, the AMF, and the UDM all know whether the first registration is to be maintained and used for communication between the UE and an element or function of the EPS (e.g., the MME). This may be done in a discrete manner for each of a plurality of registrations associated with the UE, or may be done in a deterministic manner only for a particular one of a plurality of registrations associated with the UE for which the EPS IWK is allowed.

[0057] Described herein are systems, methods, apparatus, and computer program products for a UE to request an EPS IWK for a particular registration, for a network element, such as a UDM, to determine that a UE is requesting an EPS IWK for a particular registration, for deciding whether an EPS IWK is to be allowed for a particular registration, for deciding for which particular registration among a plurality of registrations EPS IWK is to be indicated as allowed, for signaling an indication that an EPS IWK is allowed for a particular registration and / or that an EPS IWK is not allowed for a particular registration, and for receiving an indication at a UE that an EPS IWK is allowed for a particular registration.

[0058] In addition, if desired, the different functions or processes discussed below can be performed in different orders and / or concurrently with each other. In addition, if desired, one or more of the functions or processes described can be optional or can be combined. Therefore, the following description should be regarded as an illustration of the principles and teachings of certain example embodiments, rather than a limitation thereof.

[0059] A mobile network comprising a fifth generation wireless communication system (5GS) (e.g., a public land mobile PLMN or as a standalone non-public network (SNPN)) enables a UE to register simultaneously with the 5GS core network of the mobile network (e.g., PLMN or SNPN) through multiple accesses, each of which has an access type defined in the third generation partnership project (3GPP). The AMF in the core network of the 5GS of the mobile network may include a registration management (RM) state that reflects the registration state of the UE in the mobile network. The RM state of the UE in the mobile network (e.g., PLMN or SNPN) may be an RM-DEREGISTERED state (when the UE is registered with the mobile network) or an RM-REGISTERED state (when the UE is not registered with the mobile network).

[0060] The UE may register simultaneously (i.e., register at the same time) with two mobile networks (e.g., two independent non-public networks (SNPNs), one PLMN and one SNPN, or two different PLMNs) using the same home network credentials over the same access type, and may even register with both networks over the same access node or access point (e.g., gNb) in a network sharing scenario. As described in 5.18 of TS 23.501, the network sharing architecture may allow multiple participating network operators (i.e., operations of mobile networks) to share resources (e.g., radio resources) of a single shared radio access network according to an agreement between the network operators.

[0061] When the UE initiates a registration procedure to register the UE with a home mobile network (home network) using home network credentials, the Access and Mobility Management Function (AMF) of the core network of the home network determines whether to accept or authorize the UE's registration. After accepting or authorizing the UE's registration with the home network, the AMF stores the UE's registration (commonly referred to as UE registration) using the home network credentials in a unified data management (UDM) entity of the core network of the home network. However, when the UE initiates a second registration procedure to register the UE with a second mobile network or a third (or another) mobile network (e.g., another PLMN or SNPN) via 3GPP access, it is unclear which of the two UE registrations is eligible for interworking with the Evolved Packet System of the second network or the third (or other) network. In some examples, the UE's initiation of registration for 3GPP access to the second network or the third (or another) network may include registering with 5G NR via a first Visited Public Land Mobile Network (VPLMN) and a second VPLMN. In EPS, multiple simultaneous registrations are not allowed. When a UE has multiple registrations with (multiple) PLMNs (such as a home network, including 5GS and EPS), the UE will want to reserve a seat in the HSS / UDM for EPS 3GPP access and will need to know which of the multiple registrations is eligible for EPS interworking.

[0062] As will be discussed in detail below, according to certain example embodiments of the subject matter described herein, a UE is capable of simultaneously registering with more than one mobile or wireless communication network (mobile network) (e.g., two or more PLMNs, one PLMN and one SNPN, or two or more SNPNs) using one home network credential (such as a Universal Subscriber Identity Module (USIM)) over the same access type (e.g., 3GPP access).

[0063] The UE may register with a first mobile network (e.g., PLMN) using a home network credential (e.g., a USIM) and simultaneously or subsequently register with a second mobile network (e.g., SNPN). As an example, the UE may use IMS services provided by the IMS in the first mobile network (e.g., PLMN) and simultaneously register with a second mobile network (e.g., SNPN) that is an enterprise network.

[0064] The UE may register with two mobile networks (e.g., two PLMNs, two SNPNs, or one PLMN and one NPN) based on subscriber preferences, UE settings, and / or UE configuration. The UE may register with the first of the two mobile networks by issuing a registration request, the registration request including one or more of the following: registration type, SUCI, 5G-GUTI, PEI, last visited TAI (if available), security parameters, requested NSSAI, mapping of requested NSSAI, default configuration NSSAI indication, UE radio capability update, UE MM core network capabilities, PDU session state, list of PDU sessions to be activated, follow-up request, (multiple) MICO mode preferences, requested DRX parameters, (multiple) LADN DNNs, an indicator requesting LADN information, a NAS message container, a UE policy container including a PSI list, an indication of UE support for ANDSP, and an operating system identifier. The registration request may include other suitable information, such as encryption keys and / or integrity keys.

[0065] After receiving the Registration Request from the UE, the Radio Access Network (RAN) or Access Network (AN) may perform an AMF Selection procedure to select an AMF and provide the Registration Request to the selected AMF. The selected AMF may then initiate an Identity Request procedure by issuing an Identity Request message to the UE, requesting the UE's SUCI. The UE responds to the Identity Request message by providing an Identity Response message including the UE's SUCI to the AMF. The AMF may then initiate an AUSF Selection procedure, authentication / security checks, and may notify the previous / old AMF (if applicable) about the UE's registration with the core network via the AMF. After the selected AMF performs a Registration Check with the UDM, an Acquisition procedure with the UDM, and a PCF Selection procedure to select a PCF, the AMF may provide a Registration Accept message to the UE.

[0066] After detecting that a first mobile network (e.g., PLMN) supports (i.e., is capable of) multiple UE registrations per access of the same access type, the UE may select a second mobile network (e.g., PLMN or NPN) to register with the second mobile network using the same home credentials (e.g., USIM) and an access with the same access type as the access with which the UE is registered on the first mobile network. For the same access type (e.g., the maximum number of simultaneous registrations supported by the UE, AMF, and UDM over 3GPP access allowed by the operator of the first network, etc.), more than two mobile networks (e.g., two PLMNs, one PLMN and one NPN, or two NPNs) may be considered.

[0067] The UE may indicate to the mobile network (e.g., the UDM of the core network of the mobile network) that it supports multiple registrations per home credential (e.g., USIM) over the same access type by including a registration identifier in the registration request (e.g., if more is supported, the registration identifier is set to 1 for the first registration of the UE over an access with access type, the registration identifier is set to 2 for the second registration of the UE to the network over an access with the same access type, and so on). In some examples, the UDM may provide separate access paths, such as an access path or bearer route for 3GPP access and a separate access path or bearer route for non-3GPP access. However, in other examples, the UDM may provide a single access path for multiple registrations between the UE and the core network.

[0068] The supporting AMF of a serving mobile network (e.g., an NPN or PLMN) may be configured to check whether there is a UE context for the subscription permanent identifier (SUPI) included in the registration request issued by the UE for the registration identifier (Registration ID) included by the UE in the registration request when the UE registers with the serving network. If the UE context already exists, the AMF does not need to contact the UDM and the AMF may retain (e.g., store) the UE context associated with the SUPI for each Registration ID. In some examples, the AMF may register with the UDM for each UE registration served by the AMF. If the AMF has already registered the Registration ID of the UE registration with the UDM, the AMF may not need to re-register the Registration ID of the UE registration with the UDM. If the AMF does not have the UE context of the UE that issued the Registration Request including the Registration ID, the AMF may report the UE's registration with the serving mobile network to the UDM using the Registration ID provided by the UE in the Registration Request issued by the UE to the serving mobile network. At this point, the mobile network (eg, PLMN or NPN) may determine whether its UDM supports (ie, is configured to allow) multiple UE registrations per access type (ie, multiple registrations over multiple accesses with the same access type).

[0069] If its UDM does not support multiple UE registrations, the mobile network's AMF may behave as if it does not support multiple UE registrations per access type. However, if the UDM does support multiple UE registrations per access type, the mobile network's UDM may store, for each UE registration, the address of the AMF (AMF Address) associated with the Registration ID of the UE registration.

[0070] If the AMF of the network serving the UE (e.g., PLMN or NPN) (commonly referred to as the serving network) supports multiple registrations per access type, and the UDM of that network also supports multiple registrations per access type, the AMF of the serving mobile network (e.g., PLMN or NPN) may indicate to the UE that it supports multiple registrations per access type. The AMF of the serving mobile network may indicate to the UE that it supports multiple registrations per access type by generating a Registration Accept message when the AMF accepts or authorizes a registration request issued by the UE, and including in the Registration Accept message an indication that the serving mobile network supports multiple UE registrations per access type per home credential (USIM), and confirming the UE's registration with the mobile network by including a Globally Unique Temporary Identifier (GUTI) and a Registration ID in the Registration Accept message. The Registration ID may be used for subsequent mobility registration updates after the initial registration. If the AMF and / or UDM do not support multiple registrations per access type, the Registration ID is not included in the Registration Accept message issued by the AMF to the UE. In other examples, if the UE has already received another Registration ID associated with the same registration, the UE should not use the newly received Registration ID.

[0071] If the AMF and / or UDM does support multiple registrations per access type, the UE may use the registration ID for other appropriate interactions with the network in various procedures described in the 3GPP standards (such as a deregistration procedure, a session establishment procedure, a session modification procedure, etc.). In some examples, the AMF may accept or authorize the above registration over an access with the access type, and the UDM may delete any other UE registrations over an access with the same access type. The registration ID may also be included in session management messages (e.g., in the case where two mobile networks (e.g., two PLMNs, one PLMN and one NPN, or two NPNs) are provided to the same core network in an HPLMN / H-NPN) to indicate to the core network (e.g., SMF) the registration to which each session establishment request is associated.

[0072] The UE is configured by the HPLMN to support (i.e. be capable of) multiple registrations per access type, and the UE may assume that the UDM supports multiple registrations per access type. Then, an indication by the PLMN or NPN that the PLMN does not support multiple registrations per access type indicates that the AMF does not support multiple registrations per access type. This may enable the UE to have a configuration where the UE is capable of multiple registrations per access type, where one of the registrations is with a PLMN or NPN that does not support multiple registrations per access type, as the UDM may still support at most one registration per access type without a Registration ID.

[0073] In some cases, two mobile networks (eg, a first PLMN and a second PLMN, or a PLMN and an NPN) are managed by the same network operator or different network operators (eg, two different network operators with a service agreement therebetween).

[0074] Other issues have been identified with current methods for EPS interworking, as well as with other aspects of the present disclosure. For example, current methods for EPS interworking allow for a maximum of one registration on 3GPP and one registration on non-3GPP. Furthermore, core network elements (e.g., AMF, UDM, and / or PCF) can support EPS IWK for simultaneous UE registrations over multiple 3GPP and / or non-3GPP accesses. Current UEs also cannot perform EPS IWK when dual-registering with two different mobile networks.

[0075] For example, when a UE registers with a mobile network, such as dual 3GPP access RATs (NR+NR, NR+LTE), including simultaneous registration of TN (terrestrial) and / or NTN (non-terrestrial, such as satellite) 3GPP access, core network elements have not considered support for EPS IWKs before this disclosure. Furthermore, with respect to current network limitations, the lack of support means that networks including 5GS and EPS (e.g., PLMN or SNPN) cannot provide connectivity services to UEs that are dual-registered with both networks via access types.

[0076] In addition, when the UE has multiple registrations to a single network (e.g., PLMN) or to two different but equivalent networks (e.g., two PLMNs, PLMN and SNPN, or SNPN and SNPN) through multiple accesses of the same access type, the current core network elements of the mobile network (or multiple mobile networks) do not support indicating which of the multiple registrations to maintain for EPSIWK when changing between systems from a 5G or NR network to a legacy EPS network.

[0077] It should be noted that the UE cannot maintain dual registration or multiple registration with mobile networks including 5GS and EPS, because EPS does not support (i.e., cannot implement) dual registration.

[0078] Some, but not all, embodiments relate to dual registration of a UE with one mobile network via two accesses of the same access type, or multiple registrations with two different mobile networks via accesses of the same access type. However, some embodiments relate to a UE having multiple registrations with a 5GC of a mobile network via a 3GPP access, or a UE having multiple registrations with a 5G of the mobile network via a non-3GPP access. When a UE receives a registration accept message from a mobile network, the UE typically has a registration with the mobile network, or a registration with the mobile network via a 3GPP access (or via a non-3GPP access); in this context, the AMF (or the network function responsible for connection and mobility management tasks for the mobile network) may have a registration with the UE via 3GPP when the AMF accepts the UE's registration with the mobile network (i.e. authorizes the UE's registration). Other embodiments of the present disclosure relate to single registration scenarios, where the UE may have a first registration with a mobile network via a first access having a first access type, and if the UE registers with the mobile network (or another mobile network) via another access of the same access type at the same time, later, synchronously, asynchronously, and without the mobile network being aware of the new registration, the UE or the network still needs to identify whether the EPSIWK is allowed for the first registration.

[0079] As described above, by generating a registration request for each corresponding registration of the UE to the mobile network, and issuing a registration request to the AMF of the corresponding mobile network through the access, the UE can register with multiple mobile networks (e.g., PLMN and NPN) through multiple accesses with the same access type. The registration request issued by the UE to each corresponding mobile network includes a "Registration ID", and when the AMF of the corresponding mobile network accepts or authorizes the registration request, the AMF of the corresponding mobile network issues a registration accept message including the "Registration ID" to the UE.

[0080] The present disclosure is provided to expand upon the related concepts described above, which relate to enabling a UE to register with multiple PLMNs and NPNs over multiple accesses of the same access type, and using a "Registration ID" as a non-limiting example of a component that enables this functionality. For example, a UE may not want to indicate a Registration ID when registering over a 3GPP access, may not want to perform multiple registrations with the same mobile network (e.g., the same AMF of a PLMN) over accesses of the same access type, may not know which of the different registrations can / should have an EPS IWK, and may not know the impact of multiple registrations over accesses of the same access type.

[0081] In some embodiments, the access and mobility management function (AMF) of the serving 5GC of the mobile network (e.g., PLMN or SNPN) forwards one or more of the registrations to the unified data management (UDM) function of the home mobile network of the user equipment. Based on subscription data, deployment, capabilities of the 5GS of the mobile network, radio access technology (RAT) of the access through which the UE registers with the mobile network, etc., the UDM determines whether Evolved Packet System (EPS) Interworking (IWK) is allowed for the corresponding registration. In some embodiments, the UE may include an indication that an EPS IWK is requested / required for the requested registration in the registration request used to register the UE with the mobile network, and the AMF forwards the indication to the UDM.

[0082] For example, in a dual registration scenario where a UE registers with a mobile network via two 3GPP accesses, only one of the two registrations (e.g., the registration with the 5GS via the 3GPP access) may be moved to the MME of the EPS to enable seamless interworking with legacy EPS. The present disclosure provides several non-limiting solutions to ensure that even if a UE dual registers with a mobile network, the UE may only register once with the EPC of the EPS. For example, the UDM of the 5GC of the mobile network provides information about UE registrations (for which EPS IWK can be supported or not supported) to the AMF of the 5GC of the mobile network; thus, for a given UE registration with the mobile network, the AMF may authorize EPS IWK or reject EPS IWK. In other words, the UDM only selects UE registrations for which EPS IWK is allowed in the UE registrations. In another example, when a UE registers with a mobile network via an access, the UE indicates to the mobile network (e.g., the 5GS of the mobile network) whether it prefers that the registration be subject to EPS IWK, or whether EPS IWK is required for the registration. Based on the UE's indication, the mobile network (e.g., the 5GS of the mobile network) determines whether EPSIWK is supported for registration.

[0083] In some embodiments, the mobile network may use UE capabilities and information indicative of its own deployment (i.e., architecture) to determine whether the mobile network supports (i.e., is capable of EPSIWKing) a registration. In some embodiments, the methods described herein relating to multiple registrations over accesses having the same access type and signaling of EPS interworking eligibility for one or more of the multiple registrations over accesses having the same access type may be applicable in any combination to UE registrations over multiple 3GPP and / or non-3GPP accesses and are not limited to only dual (two) registration scenarios.

[0084] When determining which of multiple registrations over multiple accesses of the same access type are or should be EPSIWKed, the mobile network, network element, UE, or other parties may consider different factors, characteristics, information, elements, features, etc. For example, the factors / characteristics may include, but are not limited to: feature capabilities of the mobile network, services requested / provided / received over the access, subscription information of the UE, roaming agreement, congestion history of the mobile network, Quality of Experience (QoE) statistics, network overload and bottleneck predictions, N26 availability, deployment details, 5GS capabilities of the mobile network, slices supported by the mobile network, and / or UE capabilities.

[0085] The EPS IWK preference / capability / designation in the uplink or downlink direction may be indicated by the UE, the system / network, a network element, or otherwise using various means (such as discrete signaling, combined signaling, signaling bits, information elements (IEs), etc.). For example, the means for indicating the EPS IWK preference / capability / designation in the uplink / downlink direction may include, but are not limited to, a Registration Request message, a Registration Accept message, an Attach Request message, an Attach Accept message, a GET Response message, a UECM Registration message, a Registration Modify Request message, a Registration Modify Accept message, a Service Request message, etc. By way of example only, in a discrete signaling scenario, the network (e.g., the AMF) may provide a unique message to the UE in response to a Registration Request received from the UE during a registration procedure, a session establishment procedure, a session modification procedure, a deregistration procedure, etc. For example, the AMF, etc., from the network side may generate an EPS IWK message indicating which of multiple different registrations is authorized for EPS IWK and send the EPS IWK message to the UE. Alternatively, a network entity of the first network (e.g., AMF 1) may provide an EPS IWK message as described above to another network entity of the second network (e.g., AMF 2), so that the first network indicates to the second network which of the multiple registrations associated with the first network / second network is authorized for EPS IWK. In a combined signaling scenario, the network may include the EPS IWK message or signaling bit in another message between the network and the UE (such as a Registration Accept message, a System Information Block, etc.).

[0086] Now refer to Figure 1, illustrates a scenario where a UE is dual registered with a first mobile network (PLMN-1) and a second mobile network (PLMN-2 or SNPN-2). In the illustrated scenario, the first mobile network is the home network of the UE. The first mobile network includes two radio access networks, namely NG-RAN and E-UTRAN, 5GC including AMF and UDM, and EPC including Mobility Management Entity (MME) (for example, with LTE EPC architecture). The second mobile network includes NG-RAN and AMF. For ease of illustration, the various network functions of 5GC and network entities of EPC are shown in Figure 1. Figure 1 Not shown in the figure. The UE is dual registered with a first mobile network via a 3GPP access and is registered with a second mobile network via another 3GPP access. In other words, the UE has a first registration with the first mobile network via a first 3GPP access (i.e., via the NG-RAN of the first mobile network) and has a second registration with the second network via a second 3GPP access (i.e., via the NG_RAN of the second mobile network). In the scenario shown, the first registration (associated with the UE's home network) is determined (e.g., by the UDM) to be subject to EPS IWK. As shown, the UDM of the first mobile network (the UE's home network) can be configured to provide information to the AMF of the second mobile network (PLMN-2 or SNPN-2) indicating that EPS IWK should be prohibited for the UE's second registration with the second network via the second 3GPP access. In some embodiments, the AMF of the first mobile network may receive an indication from the UDM of the first network that the EPS IWK is allowed (or that the EPS IWK is not allowed) for the first registration of the UE with the first network, and the AMF may provide (e.g., send, issue, or signal) to the UE an indication that the EPS IWK is allowed (or that the EPS IWK is not allowed) for the first registration of the UE with the first network. In some embodiments, the UDM of the mobile network may provide (e.g., send, signal, or issue) an indication of the second registration of the UE with the second network.

[0087] For example, in response to receiving a registration request from the UE through 3GPP access, the registration request including a registration ID indicating a second registration of the UE with the second mobile network, and in response to determining through communication with the UDM of the first mobile network that EPS IWK is not allowed for the second registration, the AMF of the second mobile network may issue a registration accept message to the UE, the message including an indication that EPS IWK is not allowed for the second registration. Alternatively, in response to receiving a registration request for a second registration with the second mobile network from the UE through 3GPP access, and in response to determining through communication with the UDM of the first mobile network that EPS IWK is allowed (or EPS IWK is required) for the second registration, the AMF of the second mobile network may issue a registration accept message to the UE, the message including an indication that EPS IWK is allowed (or EPS IWK is required) for the second registration.

[0088] Additionally or alternatively, in response to receiving a registration request from the UE regarding a first registration with a first mobile network via 3GPP access, the first mobile network may determine that it is the home mobile network for the UE and, based on one or more factors / characteristics, such as services provided to the UE via each of a plurality of registrations associated with the UE and / or other factors / characteristics described elsewhere herein, determine that an EPS IWK is not allowed for the first registration. The UDM of the first mobile network may then signal or message to the AMF of the second mobile network, the signal or message including an indication that an EPS IWK is allowed (or required) for the second registration of the UE with the second network via 3GPP access. The first network may then, when registering the UE with the first network, issue a registration accept message to the UE, the message including an indication regarding the first registration of the UE with the first network via 3GPP access.

[0089] Alternatively, in response to receiving a registration request from the UE for a first registration with a first mobile network, the first mobile network may determine that it is the home mobile network of the UE and, based on one or more factors and / or characteristics (such as those described herein), determine that an EPS IWK is allowed (or an EPS IWK is required) for the first registration of the UE with the first mobile network. The UDM of the first mobile network may signal (e.g., issue a message) to the AMF of the second mobile network indicating that the EPS IWK is not allowed (i.e., prohibited) for the second registration of the UE with the second mobile network. Upon registering the UE with the first mobile network, the AMF of the first mobile network may issue a Registration Accept message to the UE, the message including an indication that the EPS IWK is allowed (or an EPS IWK is required) for the first registration of the UE with the first mobile network.

[0090] Now refer to Figure 2, illustrates a scenario where a UE is dual registered or is being dual registered with a first mobile network (referred to as PLMN-1) and a second mobile network (referred to as PLMN-2 or SNPN-2). Figure 2 In the scenario shown in , the second mobile network is the UE's home network (HPLMN). In some embodiments, the first mobile network (PLMN-1) may be an equivalent PLMN (EPLMN) with respect to the HPLMN (the second network). In some embodiments, registration (e.g., registration identifier) ​​with the first mobile network may therefore be allowed / authorized for EPS IWK, which may indicate that EPS IWK is allowed for the UE's registration with the first mobile network. This may have an impact on the types of services provided by the first network to the UE (e.g., emergency services, SMS, etc.). If the first mobile network is allowed / authorized for EPS IWK, the first network may be required to include EPS (e.g., EPC, LTE, etc.). In this case, the UDM of the second network (HPLMN) provides information to the AMF of the second network indicating that EPS IWK is prohibited for the UE's second registration with the second network. In addition, the UDM of the second network may provide an indication to the AMF of the first network indicating that EPS IWK is allowed or required for the UE's first registration with the first network.

[0091] In addition, if the first registration is indicated as allowed for EPS IWK, this means that the first registration is retained during an inter-system change or network handover between the 5G system and EPS, which may be due to various reasons.

[0092] Now refer to Figure 3 , illustrates another scenario in which a UE is dual-registered with a first network (PLMN-1) and a second network (PLMN-2 / SNPN-2), both of which are visited PLMNs (VPLMNs). In some embodiments, the AMF of the first network and / or the AMF of the second network may communicate with the UDM of the UE's home network (not shown) after receiving a registration request from the UE, such as to verify subscriber information associated with the first registration request / second registration request received from the UE. The UDM may then determine, based on any factors or characteristics described elsewhere herein, whether an EPS IWK is allowed / required for the first registration or the second registration. By way of example only, the UDM may determine that an EPS IWK is allowed / required only for the first registration with the first network, or that an EPS IWK is allowed / required only for the second registration with the second network.

[0093] In some embodiments, the AMF of the first network may send a message (e.g., a Registration Accept message) to the UE, including an indication from the EPS IWK of whether the UE's first registration with the first network is allowed. In some embodiments, the AMF of the second network may send a message (e.g., a Registration Accept message) to the UE, including an indication from the EPS IWK of whether the UE's second registration with the second network is allowed. In some embodiments, the UDM of the first network (e.g., the HPLMN) or another network function of the first network (e.g., the HPLMN) may send a message to the UE, including an indication from the EPS IWK that the UE's first registration with the first network is allowed or required, or an indication from the EPS IWK that the UE's second registration with the second network is allowed or required. After the first network (e.g., HPLMN) determines that the EPS IWK should be allowed for the first registration of the UE with the first network (first UE registration), the UDM of the first network (e.g., HPLMN) can provide information to the AMF of the first network, which indicates that the EPS IWK should be allowed or the EPS IWK is required for the first UE registration, so that the AMF of the first network includes the information indicating that the EPS IWK is allowed or the EPS IWK is required for the first UE registration in the registration accept message issued to the UE in response to the first registration request issued by the UE, and can provide information indicating that the EPS IWK should be prohibited for the second registration of the UE with the second network (second UE registration), so that the AMF of the second network includes the information indicating that the EPS IWK is not allowed or prohibited for the second UE registration in the registration accept message issued to the UE in response to the second registration request message issued by the UE.

[0094] Now refer to Figure 4 , illustrates another scenario where the UE registers twice with the same network (PLMN-1) via the same AMF. In some embodiments, in this case, the UDM of the network may inform the AMF of the network which of the two registrations is not allowed for IWK with the EPS. As described elsewhere, this determination by the UDM may be based on one or more factors / characteristics, such as those described herein regarding whether EPS IWK is allowed between the UE and the network for the first registration / second registration. The signaling / communication means between the UDM and the AMF, and between the AMF and the UE regarding the allowability of EPS IWK for the first registration and the second registration, may include any suitable means, such as the Registration message, Registration Accept message, Authentication Request message, Authentication Response message, other messages, indications, and signals disclosed elsewhere herein.

[0095] Now refer to Figure 5 , according to one embodiment, shows example signaling between the UE and various elements and features of the network regarding EPSIWK. Figure 5 In the embodiment of the present invention, the UE is attempting to establish a dual registration with 5GS, for example with two different PLMNs (including AMF1 and AMF2 respectively) or with the same PLMN (in which case AMF1 and AMF2 are the same element or function). The decision as to which registration will undergo EPS IWK is performed by the UDM. Reference to two different PLMNs is only an example of a UE multi-registration scenario; the same or similar EPS IWK signaling methods can be used for other networks and multi-registration scenarios, for example, for two SNPNs, PLMN-SNPN, etc. In addition, although many of the examples and embodiments described herein include "dual" or "two" registrations and / or "dual" or "two" networks, it will be readily understood by those skilled in the art that similar or identical EPS IWK decisions and EPS IWK signaling methods can be used in scenarios and embodiments in which more than two registrations are established with the UE and / or the UE is registered with more than two networks.

[0096] like Figure 5 As shown in FIG, at 1a, the UE issues a first registration request to the AMF 1 of the first network, for example, via NG-RAN 1, to register the UE with the first mobile network. The first registration request includes a first registration ID. According to some embodiments, the registration ID may include a unique value or identifier that may be associated with the requested registration during the request process, during authentication by, for example, an AAA server, and during approval of the registration. The registration ID may additionally or alternatively be used to identify the registration after registration establishment and during ongoing signaling, messaging, paging, and data / control information transmission. In some embodiments, the UDM may perform one or more steps of the registration process outlined in Section 4.2.2.2.2 of 3GPP TS 23.502. For example, if the AMF has changed since the last registration procedure, or if the SUPI provided by the UE does not reference a valid context in the AMF, or if the UE registers to the same AMF to which it has already registered for non-3GPP access (i.e. the user equipment registers over non-3GPP access and initiates this registration procedure to add 3GPP access), the new AMF registers with the UDM using Nudm_UECM_Registration and subscribes to be notified when the UDM deregisters the AMF. The UDM stores the AMF identity associated with the access type and does not delete the AMF identity associated with other access types. The UDM can store the information provided at registration in the UDR via Nudr_UDM_Update.

[0097] The AMF retrieves access and mobility subscription data, SMF selection subscription data and UE context in the SMF data using Nudm_SDM_Get. This requires that the UDM can retrieve this information from the UDR via Nudr_UDM_Query. After a successful response is received, the AMF subscribes using Nudm_SDM_Subscribe to be notified when the requested data is modified, and the UDM can subscribe to the UDR via Nudr_UDM_Subscribe. If the GPSI is available in the UE subscription data, the GPSI is provided to the AMF in the access and mobility subscription data from the UDM. The UDM can provide an indication that the UE's network slice subscription data has been updated. If the UE subscribes to MPS in the serving PLMN, the "MPS priority" is included in the access and mobility subscription data provided to the AMF.

[0098] The new AMF provides the UDM with the access type it serves for the UE, and the access type is set to "3GPP access". The UDM stores the relevant access type in the UDR together with the serving AMF via Nudr_UDM_Update. After obtaining the access and mobility subscription data from the UDM, the new AMF creates a UE context for the UE.

[0099] For emergency registrations where the UE is not successfully authenticated, the AMF shall not register with the UDM. For emergency registrations, the AMF shall not check access restrictions, regional restrictions, or subscription restrictions. For emergency registrations, the AMF shall ignore any unsuccessful registration response from the UDM and continue with the registration procedure.

[0100] When the UDM stores the associated access type (e.g. 3GPP) with the serving AMF, it will cause the UDM to initiate a Nudm_UECM_DeregistrationNotification to the old AMF (if present) corresponding to the same (e.g. 3GPP) access. The old AMF deletes the UE context of the UE. If the serving NF deletion reason indicated by the UDM is initial registration, the old AMF calls the Nsmf_PDUSession_ReleaseSMContext(SUPI, PDU Session ID) service operation to all relevant SMFs of the UE to notify that the UE has been deregistered from the old AMF. The SMFs shall release the PDU Session after receiving this notification.

[0101] At 1b, the AMF1 of the first mobile network sends a message to the UDM, denoted as Nudm_UECM_Registration and Nudm_SDM_Get, which includes the first registration ID. After the UDM receives the Nudm_UECM_Registration and Nudm_SDM_Get messages from the AMF1, it can perform validity checks on these messages, perform authentication checks, verify subscriber information, verify whether the network is capable of withstanding the additional network load expected after the establishment of the registration for the UE, determine or generate a network key for registration, etc., and can evaluate whether registration can be established for the UE in other ways.

[0102] At 1c, the UDM responds to the AMF1 with a Nudm_UECM_Registration / Nudm_SDM_Get response, which includes the first Registration ID and an indication as to whether the EPS IWK is allowed for the first registration of the UE with the first mobile network. At 1d, the AMF1 responds to the first Registration Request message by issuing a First Registration Accept message to the UE, which includes the first Registration ID received from the UDM and an indication as to whether the EPS IWK is allowed for the first registration.

[0103] In some embodiments, at 1a to 1d, the UE indicates a first value of the first Registration ID to AMF1 (via NG-RAN1) in a first Registration Request message, and AMF1 provides the first Registration ID to the UDM. The UDM decides (e.g., based on the UE's subscription data, deployment, and / or UE capabilities) to allow EPS IWK for the first registration with the first Registration ID, so the UDM includes an indication that EPS IWK is allowed in a response message to AMF1, and AMF1 provides this value to the UE in a first Registration Accept message. Additionally or alternatively, the parameter "EPS AWK Allowed" may not be indicated if the absence of this parameter indicates a default value of "EPS IWK Allowed."

[0104] At step 2a, the UE provides a second Registration Request, including a second Registration ID, to AMF2, for example, via NG-RAN2. At step 2b, AMF2 issues a second set of Nudm_UECM_Regication and Nudm_SDM_Get messages to the UDM, including the second Registration ID. At step 2c, the UDM responds to AMF2 with a Nudm_UECM_Registration / Nudm_SDM_Get response, which includes the second Registration ID and an indication of whether the EPS IWK is allowed for the second registration. At step 2d, AMF2 responds to the UE with a Second Registration Accept message, which includes the second Registration ID and an indication of whether the EPS IWK is allowed for the second registration.

[0105] In some embodiments, in steps 2a to 2d, the second registration request enters AMF2 and may include the second value. In some embodiments, the UDM decides not to allow EPS IWK for the second registration (e.g., based on subscription, deployment, capabilities, etc., based on EPS IWK being allowed for the first registration ID), so the UDM indicates "EPS IWK not allowed" in the response, and this parameter is propagated to the UE in the Registration Accept message. In some embodiments, the UDM may be configured to ensure that at most one registration accessed via 3GPP is eligible for EPS interworking.

[0106] Based on the above steps, the UE and the network function now know which registrations will undergo EPS IWK and which registrations will not undergo EPS IWK.

[0107] In steps 3a to 3c, assuming that mobility to the EPS has already occurred for the first Registration ID, indicating that the UE must perform or will perform an inter-system change or network handover between the 5G system and the EPS, the UE will know to use the first Registration ID to perform or participate in the handover from the 5G system to the EPS because the UDM indicates that the EPS IWK is allowed for the registration associated with the first Registration ID. Therefore, when such mobility occurs or is determined to occur between the 5G system and the EPS, the UE can trigger a TAU procedure using the first Registration ID because the EPS IWK is allowed for the first Registration ID. It should be noted that the Registration ID may not be included in the normal TAU procedure. In other cases, the Registration ID may be included in the normal TAU procedure. In some embodiments, the UDM may know that an EPS IWK is possible for the first Registration ID and may choose to deregister AMF1 instead of AMF2 due to the UE's mobility to the EPS.

[0108] Before, during, or after mobility to the EPS occurs for the first Registration ID, the UE, AMF1, EPC, MME of the EPS, HSS, or other element of the mobile network may provide an indication to the UDM that mobility has occurred. For example, when an element or function of the EPC (e.g., MME) receives a TAU request from the UE indicating intended mobility to the EPS for the first Registration ID, it may issue an Update Location Request to the HSS and indicate to the UDM that mobility is occurring for the first Registration ID, or the HSS may receive the Update Location Request and separately indicate to the UDM that mobility is occurring for the first Registration ID. In either case, the UDM identifies the multiple Registration IDs associated with the UE, notes that the first Registration ID is already permitted for use with the EPS IWK, and knows to initiate a deregistration procedure for all other Registration IDs except the first. For example, the UDM may issue a Nudm_UECM_DeregistrationNotification message to the AMF1 indicating that the second Registration ID and / or other Registration IDs are no longer in use and are no longer valid for communications between the UE and the 5GS. The UDM may additionally or alternatively issue a deregistration message to AMF2 and / or other AMFs to indicate that no other registration IDs other than the first registration ID will be allowed to be moved from the 5G core to the EPC. Additionally or alternatively, the UDM may provide authentication, verification, or confirmation to the EPC directly or via the AMF that the first registration ID is associated with the EPCIWK for which registration is allowed. Thereafter, the EPS may perform connection reestablishment procedures, etc., to continue provisioning services to the UE via the EPC, continue uplink and downlink communication of data and control information between the UE and the EPC, and, if necessary, perform other necessary functions, data transmission, paging, messaging, or other signaling using the first registration ID.

[0109] In some embodiments, a security context for the first registration may be established between the UE and the 5GS and associated with the first registration ID, and following mobility of the first registration ID to the EPS, the same security context may be used or maintained for secure communications with the EPC.

[0110] Now refer to Figure 6 , according to one embodiment, shows example signaling between the UE and various elements and features of the network regarding EPSIWK. Figure 6 In this case, the UE is attempting to establish a dual registration with 5GS, for example with two different PLMNs (including AMF1 and AMF2 respectively) or with the same PLMN (in which case AMF1 and AMF2 are the same element or function). Figure 6In an embodiment, the decision on which registration to proceed with the EPS IWK is requested by the UDM. Here, reference to two different PLMNs is only an example, as the same or similar mechanism can also be applied to, for example, two SNPNs, a PLMN and a SNPN, etc.

[0111] like Figure 6 As shown in FIG, at step 1a, the UE may provide a first Registration Request to AMF1, for example, via NG-RAN1, the first Registration Request including a first Registration ID and an indication of whether an EPS IWK is requested or required for the first registration. At step 1b, AMF1 issues a first Nudm_UECM_Registration and Nudm_SDM_Get message set to the UDM, the first Nudm_UECM_Registration and Nudm_SDM_Get message set including the first Registration ID and an indication of whether an EPS IWK is requested or required. At step 1c, the UDM responds to AMF1 with a first Nudm_UECM_Registration / Nudm_SDM_Get Response including the first Registration ID and an indication of whether an EPS IWK is allowed for the first registration. At step 1d, AMF1 responds to the UE with a first Registration Accept message including the first Registration ID and an indication of whether an EPS IWK is allowed for the first registration.

[0112] In some embodiments, in steps 1a to 1d, the UE indicates to the AMF1 (via the NG-RAN1) in the Registration Request message that "EPS IWK is required" for the first registration, which may be considered a request / preference from the UE. The AMF1 then provides this Registration ID to the UDM along with the parameter "EPS IWK is required" indication. Additionally or alternatively, the UE may not indicate the parameter "EPS IWK is required", in which case the absence of this parameter indicates a default value of "EPS IWK is required". Additionally or alternatively, the parameter "EPS IWK is not required" may be indicated by the UE for the first registration. The UDM then confirms with the AMF1 (based on subscription, deployment, capabilities, etc.) whether EPS IWK is allowed for the first registration, and the AMF1 provides this value (e.g., "EPS IWK is allowed") to the UE in the first Registration Accept message.

[0113] In step 2a, the UE may provide a second Registration Request to AMF2, for example, via NG-RAN2, at step 2a, including the second Registration ID and an indication of whether the EPS IWK is requested or required for the second registration. At step 2b, AMF2 issues a second set of Nudm_UECM_Registration and Nudm_SDM_Get messages to the UDM, including the second Registration ID and an indication of whether the EPS IWK is requested or required. At step 2c, the UDM responds to AMF2 with a second Nudm_UECM_Registration / Nudm_SDM_Get Response, including the second Registration ID and an indication of whether the EPS IWK is allowed for the second registration. At step 2d, AMF2 responds to the UE with a second Registration Accept message, including the second Registration ID and an indication of whether the EPS IWK is allowed for the second registration.

[0114] In some embodiments, in steps 2a to 2d, the UE indicates to the AMF2 (via the NG-RAN2) in the second Registration Request message that "EPS IWK is required" for this second registration, which may be considered a request / preference from the UE. The AMF2 then provides the second Registration ID to the UDM along with the parameter "EPS IWK is required" indication. Additionally or alternatively, the UE may not indicate the parameter "EPS IWK is required", in which case the absence of this parameter indicates a default value of "EPS IWK is required". Additionally or alternatively, the parameter "EPS IWK is not required" may be indicated by the UE for the second registration. The UDM then confirms with the AMF2 (based on subscription, deployment, capabilities, etc.) whether EPS IWK is allowed for the second registration, and the AMF2 provides this value (e.g., "EPS IWK is not allowed") to the UE in a second Registration Accept message.

[0115] Now both the UE and the network function know which registration, the first registration or the second registration, will undergo EPS IWK and which registration will not undergo EPS IWK.

[0116] In some embodiments, in steps 3a to 3c, assuming that mobility to EPS has already occurred for Registration ID 1, the UE may trigger a normal TAU procedure because the EPS IWK is allowed for the first Registration ID. In some embodiments, the first Registration ID may not be included in the TAU procedure. According to some embodiments, the UDM knows that the EPS IWK is allowed for the first Registration ID / first registration to the first network, and the UDM correctly deregisters AMF1 due to the UE's mobility to EPS.

[0117] In accordance with some embodiments, it is important to ensure that only a single EPS registration is maintained. Therefore, in some embodiments, in a connected mode HO, the NG-RAN is configured not to trigger a HO of the EPS IWK for registrations for which it is not allowed, based on an indication received from the 5GC. In some embodiments, in an idle mode HO, the network (5GS) may only transfer context to the UE's EPS for "EPS IWK allowed" registrations, e.g., 5GS registrations for which the 5GS allows EPS IWK. In some embodiments, the MME may reject the TAU request if triggered from the UE (e.g., applying the currently used NAS signaling and rejecting the cause code). In some embodiments, the AMF may only transfer context to the MME for "EPS IWK allowed" registrations. The UE, when attempting to trigger idle mode mobility from the 5GS to the EPS, shall provide an EPS GUTI (a temporary identifier issued to the MME) mapped from the 5G-GUTI corresponding to the 5GS registration for which the UE has received an indication that EPS interworking is allowed.

[0118] In some embodiments, the AMF may be configured to provide a Registration ID to the UDM only if the UE provides one and the AMF supports it. In some implementations, whenever a UE has multiple registrations with the same AMF on a given PLMN / SNPN, the AMF assigns the same GUTI to all registrations of the UE. In some embodiments, the AMF and the UE may maintain a context for each registration separately and associate each corresponding context with the correct Registration ID. In some embodiments, to support NTN, for a UE that is initially registered in a non-geographic AMF, when the UE registers for TN access, it may be necessary to hand over NTN N2 related terminals from a non-geographic NTN AMF to an AMF that supports terrestrial network access.

[0119] Now refer to Figure 7 Another aspect of intra-network mobility to be considered is the UE mobility within the 5GS and the impact of the EPS IWK on the cancellation of the location procedure when the UE moves to a new AMF within the same 5GC. Figure 7 As shown, it is assumed that the UE has dual-registered with the first AMF (AMF1) of the 5GC and the second AMF (AMF2) of the same 5GC, and when the UE registers with a new AMF (AMF3) of the same 5GC, one of the first registration or the second registration with the first AMF or the second AMF must be cancelled.

[0120] Here, with Figure 5 and Figure 6 Similar to the signaling shown in , the UE establishes a dual registration with the 5GC. Figure 5 or Figure 6Steps 1a-2d are the same as or similar to steps (1 and 2) for the UE to dual register with the 5GS via two different access paths (e.g., via NG-RAN1 and AMF1, or via NG-RAN2 and AMF2).

[0121] In some embodiments, in steps 3a to 3c, the registration ID previously used for the first registration in the registration process via AMF1 has been moved to another 5G cell controlled by another AMF (AMF3). Here, the UE can indicate the first registration ID in the mobility registration request process to AMF3. AMF3 can provide the first registration ID and the third Nudm_UECM_Registration request to the UDM. The UDM knows that the first registration ID has been moved from AMF1 to AMF3. Therefore, the UDM will deregister or perform a cancel location procedure with the correct AMF (AMF1) during or after a successful mobility registration request process. This can be achieved by issuing a Nudm_UECM_DeregistrationNotification message to AMF1.

[0122] In some embodiments, as part of the mobility registration request process, the UDM may reference previously cached information or indications associated with the first registration ID to determine whether the EPS IWK for the first registration ID or the first registration associated with the first registration ID was previously determined to be requested / required / allowed.

[0123] For example, if the UDM receives a first registration ID through the Mobility Registration Request procedure and then determines that EPS IWK is not requested / needed / allowed for the first registration ID or the first registration associated with the first registration ID, the UDM may perform a Cancel Location procedure, for example by issuing a Nudm_UECM_DeregistrationNotification message to AMF1.

[0124] However, if, for example, the UDM receives a first Registration ID and a request to initiate a Mobility Registration Request procedure and then determines that EPS IWK is requested / needed / allowed for the first Registration ID or the first registration associated with the first Registration ID, the UDM may avoid performing the Cancel Location procedure, for example by issuing a Nudm_UECM_DeregistrationNotification message to the AMF 1. In this case, the UDM may reject the Mobility Registration Request and indicate to the AMF 3 that an incorrect Registration ID was provided.

[0125] The procedures described herein provide a simple and practical solution to support dual registration of a UE with a mobile or wireless communication network (such as a PLMN or SNPN comprising both 5GS and EPS) without replacing EPS with a 5GS comprising NG-RAN and 5GC. In some embodiments, a network (e.g., a PLMN or SNPN) allows multiple UEs to register with it, but EPS IWK is only allowed for one of the multiple UE registrations.

[0126] Figure 8A An example of an apparatus 10 according to an embodiment is shown. In one embodiment, the apparatus 10 may be an access node of a mobile or wireless communication network. For example, the apparatus 10 may be a satellite, a Node B, an evolved Node B (eNB), a 5G Node B, a next-generation Node B (NG-NB or gNB), a WLAN access point, a Transmission Relay Protocol (TRP), an IAB node, or a High-Aided Public Transport (HAPS). In an example embodiment, the apparatus 10 may be a gNB of an NG-RAN or an eNB of an E-UTRAN.

[0127] It should be understood that in some example embodiments, the apparatus 10 may be part of, or include, a distributed computing system, e.g., the server and the radio node may be separate devices that communicate with each other via a radio path or via a wired connection, or they may be located in the same entity that communicates via a wired connection. For example, in certain example embodiments where the apparatus 10 represents a gNB, it may be configured in a central unit (CU) and distributed unit (DU) architecture that partitions the gNB functionality. In such an architecture, the CU may be a logical node that includes gNB functionality such as transmission of user data, mobility control, radio access network sharing, positioning, and / or session management. The CU may control the operation of the DU(s) via a fronthaul interface. The DU may be a logical node that includes a subset of the gNB functionality, depending on the functional split option. It should be noted that one of ordinary skill in the art will understand that the apparatus 10 may include Figure 8A Components or features not shown.

[0128] like Figure 8A As shown in the example of , the device 10 may include a processor 12 for processing information and executing instructions or operations. The processor 12 may be any type of general-purpose or special-purpose processor. In fact, for example, the processor 12 may include one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), and a processor based on a multi-core processor architecture. Although Figure 8AA single processor 12 is shown in FIG. 1 , but according to other embodiments, multiple processors may be used. For example, it should be understood that in some embodiments, apparatus 10 may include two or more processors that may form a multi-processor system that can support multi-processing (e.g., in this case, processor 12 may represent a multi-processor). In some embodiments, the multi-processor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster). Processor 12 may perform functions associated with the operation of apparatus 10, which may include, for example, precoding of antenna gain parameters and phase parameters, encoding and decoding of individual bits forming communication messages, formatting of information, and overall control of apparatus 10, including processes related to management of communication resources.

[0129] The device 10 may also include or be coupled to a memory 14 (internal or external), which may be coupled to the processor 12 and used to store information and instructions that can be executed by the processor 12. The memory 14 may be one or more memories and may be any suitable volatile or non-volatile data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. For example, the memory 14 may include any combination of the following: random access memory (RAM), read-only memory (ROM), static storage devices such as magnetic disks or optical disks, hard disk drives (HDDs), or any other type of non-transitory machine or computer-readable media. The instructions stored in the memory 14 may include program instructions or computer program code that, when executed by the processor 12, enables the device 10 to perform the tasks described herein.

[0130] In one embodiment, the device 10 may also include or be coupled to a (internal or external) drive or port configured to accept and read an external computer-readable storage medium, such as an optical disk, a USB drive, a flash drive, or any other storage medium. For example, the external computer-readable storage medium may store a computer program or software for execution by the processor 12 and / or the device 10.

[0131] In some embodiments, the device 10 may further include or be coupled to one or more antennas 15 for transmitting signals and / or data to and receiving signals and / or data from the device 10. The device 10 may further include or be coupled to a transceiver 18 configured to transmit and / or receive information. The transceiver 18 may include, for example, multiple radio interfaces that may be coupled to (multiple) antennas 15. The radio interfaces may correspond to one or more of the following: multiple radio access technologies, including GSM, NB-IoT, LTE, 5G, WLAN, Bluetooth, BT-LE, NFC, radio frequency identifier (RFID), ultra-wideband (UWB), MulteFire, etc. The radio interfaces may include components such as filters, converters (e.g., digital-to-analog converters, etc.), mappers, fast Fourier transform (FFT) modules, etc., which are used to generate symbols for transmission via one or more downlinks and to receive symbols (e.g., via an uplink).

[0132] Thus, the transceiver 18 can be configured to modulate information onto a carrier waveform for transmission by the antenna(s) 15 and demodulate information received via the antenna(s) 15 for further processing by other elements of the apparatus 10. In other embodiments, the transceiver 18 can be capable of directly transmitting and receiving signals or data. Additionally or alternatively, in some embodiments, the apparatus 10 can include input devices and / or output devices (I / O devices).

[0133] In one embodiment, memory 14 may store software modules that provide functionality when executed by processor 12. Such modules may include, for example, an operating system that provides operating system functionality for device 10. Memory may also store one or more functional modules, such as applications or programs, that provide additional functionality for device 10. Components of device 10 may be implemented in hardware, or as any suitable combination of hardware and software.

[0134] According to some embodiments, processor 12 and memory 14 may be included in, or may form part of, processing circuitry or control circuitry.Furthermore, in some embodiments, transceiver 18 may be included in, or may form part of, transceiver circuitry.

[0135] As used herein, the term "circuitry" may refer to any portion of a hardware circuit implementation (e.g., analog and / or digital circuitry), a combination of hardware circuitry and software, a combination of analog and / or digital hardware circuitry with software and / or firmware, hardware processor(s) (including digital signal processors) with software that work together to enable a device (e.g., device 10) to perform various functions, and / or hardware circuit(s) and / or processor(s) or portions thereof that operate using software but that may not be present when not required for operation. As a further example, as used herein, the term "circuitry" may also encompass an implementation of only a hardware circuit or processor (or processors), or a portion of a hardware circuit or processor, and its accompanying software and / or firmware. The term circuitry may also encompass, for example, a baseband integrated circuit in a server, cellular network node or device, or other computing or network device.

[0136] As discussed in more detail elsewhere, in some embodiments, the apparatus 10 may be a NW node or RAN node, such as a base station, access point, Node B, eNB, gNB, WLAN access point, etc. In one embodiment, the apparatus 10 may be an access node or AMF of a network, etc. For example, in some embodiments, the apparatus 10 may be configured to be used in any suitable scenario (such as Figures 1-4 Any flowchart or signaling diagram described herein (such as Figure 5-Figure 7 In some embodiments, as described herein, the apparatus 10 may be configured to perform processes related to enabling or facilitating a UE to register with multiple PLMNs and / or NPNs using the same access type, such as those described elsewhere herein.

[0137] Figure 8B An example of an apparatus 20 according to another embodiment is illustrated. In one embodiment, the apparatus 20 may be a user equipment. The user equipment may be a mobile device (ME), a mobile station, a mobile device, a fixed device, an IoT device, or other device. As described herein, a UE may alternatively be referred to as, for example, a mobile station, a mobile device, a mobile unit, a mobile device, a user equipment, a subscriber station, a wireless terminal, a tablet, a smartphone, an IoT device, a sensor or an NB-IoT device, a watch or other wearable device, a head-mounted display (HIMD), a vehicle, a drone, a medical device and its applications (e.g., remote surgery), an industrial device and its applications (e.g., a robot and / or other wireless device operating in an industrial and / or automated processing chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. As an example, the apparatus 20 may be implemented in, for example, a wireless handheld device, a wireless plug-in accessory, etc. It should be noted that a person skilled in the art will understand that the apparatus 20 may include Figure 8BComponents or features not shown.

[0138] In some example embodiments, the apparatus 20 may include one or more processors, one or more computer-readable storage media (e.g., memory, storage, etc.), one or more radio access components (e.g., modems, transceivers, etc.), and / or a user interface. In some embodiments, the apparatus 20 may be configured to operate using one or more radio access technologies, such as GSM, LTE, LTE-A, NR, 5G, WLAN, WiFi, NB-IoT, Bluetooth, NFC, MulteFire, and / or any other radio access technology. It should be noted that persons of ordinary skill in the art will appreciate that the apparatus 20 may include Figure 8B Components or features not shown.

[0139] like Figure 8B As shown in the example of , the device 20 may include or be coupled to a processor 22 for processing information and executing instructions or operations. The processor 22 may be any type of general-purpose or special-purpose processor. In fact, for example, the processor 22 may include one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), and a processor based on a multi-core processor architecture. Although Figure 8B A single processor 22 is shown in FIG. 1 , but multiple processors may be used according to other embodiments. For example, it should be understood that in some embodiments, apparatus 20 may include two or more processors that may form a multiprocessor system that can support multiprocessing (e.g., in which case processor 22 may represent a multiprocessor). In some embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster).

[0140] Processor 22 may perform functions associated with the operation of apparatus 20, including, as some examples, precoding of antenna gain parameters and phase parameters, encoding and decoding of individual bits forming communication messages, formatting of information, and overall control of apparatus 20, including processes associated with management of communication resources.

[0141] The device 20 may also include or be coupled to a memory 24 (internal or external), which may be coupled to the processor 22 and used to store information and instructions that can be executed by the processor 22. The memory 24 may be one or more memories and of any type suitable for the local application environment and may be implemented using any suitable volatile or non-volatile data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. For example, the memory 24 may include any combination of the following: random access memory (RAM), read-only memory (ROM), static storage devices such as magnetic disks or optical disks, hard disk drives (HDDs), or any other type of non-transitory machine or computer-readable media. The instructions stored in the memory 24 may include program instructions or computer program code that, when executed by the processor 22, enables the device 20 to perform the tasks described herein.

[0142] In one embodiment, the device 20 may also include or be coupled to a (internal or external) drive or port configured to accept and read an external computer-readable storage medium, such as an optical disk, a USB drive, a flash drive, or any other storage medium. For example, the external computer-readable storage medium may store a computer program or software for execution by the processor 22 and / or the device 20.

[0143] In some embodiments, the apparatus 20 may further include or be coupled to one or more antennas 25 for receiving downlink signals and for transmitting from the apparatus 20 via an uplink. The apparatus 20 may further include a transceiver 28 configured to send and receive information. The transceiver 28 may further include a radio interface (e.g., a modem) coupled to the antenna 25. The radio interface may correspond to one or more of the following: a variety of radio access technologies, including GSM, LTE, LTE-A, 5G, NR, WLAN, NB-IoT, Bluetooth, BT-LE, NFC, RFID, UWB, etc. The radio interface may include other components such as filters, converters (e.g., digital-to-analog converters, etc.), symbol demappers, signal shaping components, inverse fast Fourier transform (IFFT) modules, etc., which are used to process symbols carried by the downlink or uplink, such as OFDMA symbols.

[0144] For example, the transceiver 28 may be configured to modulate information onto a carrier waveform for transmission by the antenna(s) 25 and to demodulate information received via the antenna(s) 25 for further processing by other elements of the apparatus 20. In other embodiments, the transceiver 28 may be capable of directly transmitting and receiving signals or data. Additionally or alternatively, in some embodiments, the apparatus 20 may include input and / or output devices (I / O devices). In certain embodiments, the apparatus 20 may also include a user interface, such as a graphical user interface or a touch screen.

[0145] In one embodiment, the memory 24 stores software modules that provide functionality when executed by the processor 22. The modules may include, for example, an operating system that provides operating system functionality for the device 20. The memory may also store one or more functional modules, such as applications or programs, for providing additional functionality for the device 20. The components of the device 20 may be implemented in hardware or as any suitable combination of hardware and software. According to an example embodiment, the device 20 may optionally be configured to communicate with the device 10 or the device 30 via a wireless or wired communication link or interface 70 according to any radio access technology, such as NR.

[0146] According to some embodiments, the processor 22 and the memory 24 may be included in, or may form part of, a processing circuit system, a processing component, a control circuit system, or a control component. In addition, in some embodiments, the transceiver 28 may be included in, or may form part of, a transceiver circuit system or a transceiver component.

[0147] As discussed in more detail elsewhere, according to some embodiments, the apparatus 20 may be, for example, a UE, a communication node, a mobile equipment (ME), a mobile station, a mobile device, a fixed device, an IoT device. According to certain embodiments, the apparatus 20 may be controlled by the memory 24 and the processor 22 to perform functions associated with the example embodiments described herein. For example, in some embodiments, the apparatus 20 may be configured to execute any of the flow charts or signaling diagrams described herein (such as Figure 5-Figure 7 Thus, according to one embodiment, the apparatus 20 may be configured to perform procedures related to enabling a UE to register with multiple PLMNs and / or NPNs using the same access type, such as described elsewhere herein.

[0148] Figure 8CAn example of an apparatus 30 according to another example embodiment is illustrated. In an example embodiment, the apparatus 30 may be a node or element in a communication network, or associated with such a communication network, such as a satellite, a base station, a Node B, an evolved Node B (eNB), a 5G Node B or access point, a next generation Node B (NG-NB or gNB), and / or a WLAN access point associated with a radio access network (such as an LTE network, 5G or NR). According to one embodiment, for example, the apparatus 30 may be a UDM, or may be included therein.

[0149] In some example embodiments, the apparatus 30 may include one or more processors, one or more computer-readable storage media (e.g., memory, storage, etc.), one or more radio access components (e.g., modems, transceivers, etc.), and / or a user interface. In some example embodiments, the apparatus 30 may be configured to operate using one or more radio access technologies, such as GSM, LTE, LTE-A, NR, 5G, WLAN, WiFi, NB-IoT, MulteFire, and / or any other radio access technology. It should be noted that persons of ordinary skill in the art will appreciate that the apparatus 30 may include Figure 8C Components or features not shown.

[0150] like Figure 8C As shown in the example of , the device 30 may include or be coupled to a processor 32 for processing information and executing instructions or operations. The processor 32 may be any type of general-purpose or special-purpose processor. In fact, for example, the processor 32 may include one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), and a processor based on a multi-core processor architecture. Although Figure 8C A single processor 32 is shown in FIG. 1 , but according to other example embodiments, multiple processors may be used. For example, it should be understood that in some example embodiments, apparatus 30 may include two or more processors that may form a multiprocessor system that may support multiprocessing (e.g., in which case processor 32 may represent a multiprocessor). In some example embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster).

[0151] Processor 32 may perform functions associated with the operation of device 30, including, as some examples, precoding of antenna gain parameters and / or phase parameters, encoding and decoding of individual bits that form communication messages, formatting of information, and overall control of device 30, including processes related to management of communication resources.

[0152] The device 30 may also include or be coupled to a memory 34 (internal or external), which may be coupled to the processor 32 and used to store information and instructions that can be executed by the processor 32. The memory 34 may be one or more memories and of any type suitable for the local application environment and may be implemented using any suitable volatile or non-volatile data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. For example, the memory 34 may include any combination of the following: random access memory (RAM), read-only memory (ROM), static storage devices such as magnetic disks or optical disks, hard disk drives (HDDs), or any other type of non-transitory machine or computer-readable media. The instructions stored in the memory 34 may include program instructions or computer program code that, when executed by the processor 32, enables the device 30 to perform the tasks described herein.

[0153] In an example embodiment, the apparatus 30 may also include or be coupled to a (internal or external) drive or port configured to accept and read an external computer-readable storage medium, such as an optical disk, a USB drive, a flash drive, or any other storage medium. For example, the external computer-readable storage medium may store a computer program or software for execution by the processor 32 and / or the apparatus 30.

[0154] In some example embodiments, the apparatus 30 may further include or be coupled to one or more antennas 35 for receiving downlink signals and for transmitting from the apparatus 30 via an uplink. The apparatus 30 may further include a transceiver 38 configured to transmit and receive information. The transceiver 38 may further include a radio interface (e.g., a modem) coupled to the antenna 35. The radio interface may correspond to a variety of radio access technologies, including one or more of GSM, LTE, LTE-A, 5G, NR, WLAN, NB-IoT, BT-LE, RFID, UWB, etc. The radio interface may include other components such as filters, converters (e.g., digital-to-analog converters), symbol demappers, signal shaping components, inverse fast Fourier transform (IFFT) modules, etc., for processing symbols carried by the downlink or uplink, such as OFDMA symbols.

[0155] For example, the transceiver 38 may be configured to modulate information onto a carrier waveform for transmission by the antenna(s) 35 and to demodulate information received via the antenna(s) 35 for further processing by other elements of the apparatus 30. In other example embodiments, the transceiver 38 may be capable of directly transmitting and receiving signals or data. Additionally or alternatively, in some example embodiments, the apparatus 30 may include input and / or output devices (I / O devices). In certain example embodiments, the apparatus 30 may also include a user interface, such as a graphical user interface or a touch screen.

[0156] In an example embodiment, memory 34 stores software modules that provide functionality when executed by processor 32. Such modules may include, for example, an operating system that provides operating system functionality for device 30. Memory may also store one or more functional modules, such as applications or programs, for providing additional functionality for device 30. Components of device 30 may be implemented in hardware, or as any suitable combination of hardware and software. According to an example embodiment, device 30 may optionally be configured to communicate with device 10 via a wireless or wired communication link 71 and / or communicate with device 20 via a wireless or wired communication link 72 in accordance with any radio access technology, such as NR.

[0157] According to some example embodiments, the processor 32 and the memory 34 may be included in, or may form part of, the processing circuitry or control circuitry.Furthermore, in some example embodiments, the transceiver 38 may be included in, or may form part of, the transceiver circuitry.

[0158] As discussed in more detail elsewhere, according to some example embodiments, for example, the apparatus 30 may be included in the UDM. According to certain example embodiments, the apparatus 30 may be controlled by the memory 34 and the processor 32 to perform functions associated with the example embodiments described herein. For example, in some example embodiments, the apparatus 30 may be configured to perform any of the diagrams or signaling flow diagrams described herein (such as Figure 5-Figure 7 According to certain example embodiments, apparatus 30 may be configured to perform processes related to enabling a UE to register with multiple PLMNs and / or NPNs using the same access type, such as described elsewhere herein.

[0159] In some embodiments, an apparatus (e.g., apparatus 10 and / or apparatus 20 and / or apparatus 30) may include components for performing the methods, processes, or any variations discussed herein. Examples of such components may include one or more processors, memories, controllers, transmitters, receivers, and / or computer program codes for enabling the execution of the aforementioned operations.

[0160] For example, Figure 9 As shown in , an apparatus (e.g., apparatus 10 and / or apparatus 20 and / or apparatus 30) may include components for performing method 40. According to some embodiments, the apparatus may be configured to perform method 40 by being configured at 41 to receive information about a first registration between a user equipment and the first communication network and a second registration between the user equipment and the first communication network or the second communication network from a unified data management function of the first communication network. In some embodiments, the information includes: a first indication indicating whether the apparatus can authorize Evolved Packet System network interworking for the first registration of the user equipment, and a second indication indicating whether the apparatus can authorize Evolved Packet System network interworking for the second registration of the user equipment. In some embodiments, the apparatus may also be configured to perform method 40 by being configured to determine, based on the information, one of the first registration or the second registration for which Evolved Packet System network interworking is allowed.

[0161] In some embodiments, the information also includes one or more of the following: subscription information, deployment information, communication network capabilities, or information about the radio access technology of the access path between the user equipment and the first communication network or the second communication network. For various reasons, the UE may need to switch from multiple registrations to one or more 5GS to a single registration to EPS. The UE can determine or know which of the first registration or the second registration the UDM allows EPSIWK for. Before, during, or after the first registration or the second registration moves from 5GS to EPS, the UE can provide a TAU request to the EPC that is used to initiate a switch of EPSIWK for the specific registration for which it is allowed.

[0162] Now refer to Figure 10 , an apparatus (e.g., apparatus 10 and / or apparatus 20 and / or apparatus 30) may include means for performing another method 50. According to some embodiments, the apparatus may be configured to perform the method 50 by being configured to receive, at 51, a first registration request for a first registration to the communication network from a user equipment of the communication network. According to some embodiments, the apparatus may also be configured to perform the method 50 by being configured to receive, at 52, a second registration request for a second registration to the communication network from the user equipment. According to some embodiments, the apparatus may be configured to perform the method 50 by being configured to provide, at 53, information about the first registration request and the second registration request to a unified data management function of the communication network. According to some embodiments, the apparatus may be configured to perform the method 50 by being configured to receive, at 54, an indication from the unified data management function as to whether Evolved Packet System network interworking is allowed for the first registration or the second registration.

[0163] In some embodiments, an indication of whether the user equipment is allowed to interoperate with the evolved packet system network via the first access path or the second access path is determined based on at least one of: subscription information, deployment information, communication network capabilities, or information about the radio access technology of the first access path or the second access path between the user equipment and the communication network. Although method 50 is described as including two registration requests, in other implementations, a method may include receiving requests for three or more registrations, providing the three or more registration requests to the UDM, and receiving an indication of which registration the UDM allows EPSIWK for. The indication that EPSIWK is allowed for a particular registration may be provided to the UE and / or another network element, may be stored for later use if registration mobility between the 5GS and EPS is required, and / or may be used later during a TAU request by the UE to retain the registrations for which EPSIWK is allowed during mobility from the 5GS and EPS.

[0164] Now refer to Figure 11 , an apparatus (e.g., apparatus 10 and / or apparatus 20 and / or apparatus 30) may include means for performing another method 60. According to some embodiments, the apparatus may be configured to perform method 60 by being configured to receive, at 61, a registration request for registration of a user equipment with the communication network from a user equipment of the communication network. According to some embodiments, the apparatus may also be configured to perform method 60 by being configured to receive, at 62, a registration request for registration of a user equipment with the communication network from a user equipment of the communication network. According to some embodiments, the registration request may include an indication as to whether the registration requires Evolved Packet System network interworking. According to some embodiments, the apparatus may be configured to perform method 60 by being configured to determine, at 62, whether the communication network supports Evolved Packet System network interworking if the registration request includes an indication that the registration requires Evolved Packet System network interworking.

[0165] In some embodiments, determining whether the communication network supports Evolved Packet System network interworking for registration of the user equipment with the communication network comprises determining one or more of subscription information, deployment information, communication network capabilities, or information about a radio access technology of an access path between the user equipment and the communication network.

[0166] Now refer to Figure 12, an apparatus (e.g., apparatus 10 and / or apparatus 20 and / or apparatus 30) may include means for performing another method 70. According to some embodiments, the apparatus may be configured to perform method 70 by being configured to provide, at 71, a first registration request for registration of a user equipment with the communication network via a first access path to an access and mobility management function of the communication network via a radio access network, wherein the first registration request includes an indication as to whether registration via the first access path requires an evolved packet system network interworking. According to some embodiments, the apparatus may also be configured to perform method 70 by being configured to provide, at 72, a second registration request for registration of the user equipment with the communication network via a second access path to the access and mobility management function via the radio access network, wherein the second registration request includes an indication as to whether registration via the second access path requires an evolved packet system network interworking. According to some embodiments, the apparatus may be configured to perform method 70 by being configured to receive a first registration response from the access and mobility management function at 73, the first registration response indicating whether registration of the user equipment with the communication network via the first access path requiring interworking with the evolved packet system network is approved. According to some embodiments, the apparatus may be configured to perform method 70 by being configured to receive a second registration response from the access and mobility management function at 74, the second registration response indicating whether registration of the user equipment with the communication network via the second access path requiring interworking with the evolved packet system network is approved.

[0167] In view of the foregoing, certain example embodiments provide several technical improvements, enhancements, and / or advantages over prior art procedures and constitute at least an improvement in the field of radio network control and / or management technology. For example, as discussed in detail elsewhere in this disclosure, certain embodiments provide methods for enabling a UE to register with multiple PLMNs and / or NPNs using the same access type. As a result of some example embodiments, it is now possible to register with multiple networks using a single credential or USIM using the same 3GPP access type. Consequently, the use of certain example embodiments improves the functionality of communication networks and their nodes (such as base stations, eNBs, gNBs, and / or IoT devices, UEs, or mobile stations).

[0168] In some example embodiments, the functionality of any method, process, signaling diagram, algorithm, or flow chart described herein may be implemented by software and / or computer program code or code portions stored in a memory or other computer-readable or tangible medium and executable by a processor.

[0169] In some example embodiments, a device may include or be associated with at least one software application, module, unit, or entity configured to perform (multiple) arithmetic operations, or configured to be a program or program portion (including added or updated software routines) executed by at least one operating processor or controller. A program (also referred to as a program product or computer program, including software routines, applets, and macros) may be stored in any device-readable data storage medium and may include program instructions for performing specific tasks. A computer program product may include one or more computer-executable components that, when the program is run, are configured to perform some example embodiments. One or more computer-executable components may be at least one software code or code portion. Modifications and configurations required to implement the functionality of an example embodiment may be performed as (multiple) routines, which may be implemented as (multiple) added or updated software routines. In one example, (multiple) software routines may be downloaded to the device.

[0170] For example, software or computer program code or code portions may be in source code form, object code form, or some intermediate form, and may be stored in some carrier, distribution medium, or computer-readable medium, which may be any entity or device capable of carrying the program. For example, such carriers may include recording media, computer memory, read-only memory, optoelectronic and / or electrical carrier signals, telecommunication signals, and / or software distribution packages. Depending on the processing power required, the computer program may be executed in a single electronic digital computer or distributed across multiple computers. The computer-readable medium or computer-readable storage medium may be a non-transitory medium.

[0171] In other example embodiments, the functions of the example embodiments may be performed by hardware or circuitry included in a device, such as by using an application specific integrated circuit (ASIC), a programmable gate array (PGA), a field programmable gate array (FPGA), or any other combination of hardware and software. In yet another example embodiment, the functions of the example embodiments may be implemented as signals carried by electromagnetic signals downloaded from the Internet or other networks, such as non-tangible components.

[0172] According to example embodiments, an apparatus such as a node, a device or a corresponding component may be configured as a circuit system, a computer or a microprocessor, such as a single-chip computer element, or as a chipset, which may include at least a memory for providing storage capacity for (multiple) arithmetic operations and / or an operation processor for performing (multiple) arithmetic operations.

[0173] The example embodiments described herein may apply to both singular and plural implementations, regardless of whether singular or plural language is used in conjunction with describing certain embodiments. For example, an embodiment describing the operation of a single network node may also apply to example embodiments including multiple instances of the network node, and vice versa.

[0174] Those skilled in the art will readily appreciate that the example embodiments discussed in this disclosure can be practiced with processes in a different order and / or with hardware elements in a different configuration than that disclosed. Therefore, although some embodiments have been described based on these example embodiments, it will be apparent to those skilled in the art that certain modifications, variations, and alternative constructions will be apparent while remaining within the spirit and scope of the example embodiments.

Claims

1. A device comprising: at least one processor; as well as at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: generating a registration request for registration of the apparatus with a core network of a communication network; Sending the registration request to the access and mobility management function AMF of the core network; as well as A response to the registration request is received from the AMF, the response including an Evolved Packet System Interworking (EPSIWK) indication indicating whether interworking with an Evolved Packet System (EPS) network is allowed for the registration. 2 . The apparatus of claim 1 , wherein the EPS IWK in the response indicates that interworking with an EPS network is allowed for the registration.

3. The apparatus of claim 2, wherein the instructions, when executed by the at least one processor, further cause the apparatus to at least: In the event that the device is downgraded to an EPS network, the registration is maintained to communicate with the EPS network. 4 . The apparatus of claim 1 , wherein the EPS IWK in the response indicates that interworking with an EPS network is not allowed for the registration.

5. The apparatus of claim 4, wherein the instructions, when executed by the at least one processor, further cause the apparatus to at least: In a case where the device is downgraded to an EPS network, deregistering the device from the core network for the registration; and / or In a case where the EPS IWK is not authorized for the registration, upon inter-system change from the 5G core network to the EPS, determining that the device must be deregistered from the 5G core network for the registration.

6. The apparatus according to any one of claims 1 to 5, wherein the instructions, when executed by the at least one processor, further cause the apparatus to at least: issuing one or more further registration requests to the AMF of the core network for one or more further registrations of the apparatus with the core network of the communications network; and receiving one or more other responses to the one or more other registration requests from the AMF.

7. The apparatus of claim 6 , wherein a respective one of the one or more other responses comprises: Interworking with the EPS network is not allowed for the EPSIWK indication of the registration.

8. The apparatus according to any one of claims 1 to 7, wherein the response to the registration request comprises a registration accept message, and the registration request message comprises: EPSIWK indicates that the registration is permitted.

9. The apparatus of any one of claims 1 to 8, wherein the core network comprises a fifth generation (5G) core network.

10. The apparatus of claim 9, wherein the at least one memory stores further instructions that, when executed by the at least one processor, cause the apparatus to at least: determining, based on the EPSIWK indication in the registration response, that interworking with the EPS network is permitted for the registration; maintaining the registration to communicate with the EPS upon intersystem change from the 5G core network to the EPS if an EPS IWK is authorized for the registration; and In a case where the EPS IWK is not authorized for the registration, upon inter-system change from the 5G core network to the EPS, determining that the device must be deregistered from the 5G core network for the registration.

11. The apparatus of claim 10, wherein the at least one memory stores further instructions that, when executed by the at least one processor, cause the apparatus to at least: A registration is determined to be another registration of the one or more other registrations that is authorized for use with the EPSIWK, and the another registration is maintained to communicate with the EPS.

12. An apparatus according to any one of claims 1 to 11, wherein the EPSIWK is determined based on at least one of the following items: subscription information, deployment information, 5G system capabilities, or information about the radio access technology of the access path between the user equipment and the 5G system.

13. An apparatus comprising: at least one processor; as well as at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: generating a first message, the first message comprising: a first registration request for establishing a first registration of the apparatus with a core network; inserting into the first message an indication that the apparatus requests authorization for Evolved Packet System Interworking (EPSIWK) for the first registration; Sending the first registration request to an access and mobility management function (AMF) of the first core network; generating one or more second messages, wherein a respective second message of the one or more second messages comprises: another registration request for establishment of one or more second registrations of the apparatus with the core network and / or one or more other core networks; Sending a corresponding registration request from the one or more registration requests to the AMF and / or one or more other AMFs of the one or more other core networks; receiving a first response to the first message from the AMF, the first response indicating whether EPSIWK is allowed for the first registration; receiving one or more second responses to the one or more second messages from the AMF and / or the one or more other AMFs; and In the event that the device is required to be moved to an EPS network, it is determined that the first registration is retained for the EPS IWK and the one or more second registrations are to be deregistered.

14. The apparatus of claim 13, wherein the first response to the first message comprises a registration accept message, the registration accept message comprising: EPS IWK for an indication that the first registration is permitted.

15. The apparatus of claim 13 or 14, wherein the first core network comprises a fifth generation (5G) core network, and the one or more other core networks comprise a 5G core network.

16. An apparatus according to any one of claims 13 to 15, wherein the EPSIWK is determined based on at least one of the following items: subscription information, deployment information, 5G system capabilities, or information about the radio access technology of the access path between the apparatus and the 5G core network.

17. An apparatus comprising: one or more processors; as well as one or more memories storing program code, wherein the one or more memories and the program code are configured to, together with the one or more processors, cause the apparatus to at least: receiving, from an access and mobility management function of a fifth generation (5G) system, information regarding a registration request from a user equipment to register with the 5G system; determining whether evolved packet system network interworking is allowed for the registration; as well as A unified data management function indication is provided to the access and mobility management function as to whether evolved packet system network interworking is allowed for the registration.

18. The apparatus of claim 17, wherein the determination of whether the registration is allowed with respect to Evolved Packet System network interworking comprises: Determining whether evolved packet system network interworking is allowed for the registration is based on at least one of the following: subscription information, deployment information, 5G system capabilities, or information about a radio access technology of an access path between the user equipment and the 5G system.

19. The apparatus according to claim 17 or 18, wherein the information received from the AMF of the 5G system further includes an access and mobility management function indication, wherein the access and mobility management function indication is about whether the registration request includes a request for interworking with an evolved packet system network from the user equipment for the registration. wherein the at least one memory stores further instructions that, when executed by the at least one processor, cause the apparatus to at least: Based on the access and mobility management function indication, it is determined whether the user equipment requests evolved packet system network interworking for the registration.

20. The apparatus of any one of claims 17 to 19, wherein the at least one memory stores further instructions that, when executed by the at least one processor, cause the apparatus to at least: receiving, from the AMF and / or one or more other AMFs, information about one or more other registrations associated with the user equipment; and In a case where evolved packet system intercommunication is determined to be allowed for the registration, one or more other unified data management function indications are provided to the AMF and / or the one or more other AMFs, the one or more other unified data management function indications indicating that evolved packet system network intercommunication is not allowed for the one or more other registrations associated with the user equipment.

21. A method for an apparatus, the method comprising: generating a registration request for registration of the apparatus with a core network of a communication network; Sending the registration request to the access and mobility management function AMF of the core network; as well as A response to the registration request is received from the AMF, the response including an Evolved Packet System Interworking (EPSIWK) indication indicating whether interworking with an Evolved Packet System (EPS) network is allowed for the registration.

22. The method of claim 21, wherein the EPS IWK in the response indicates that interworking with an EPS network is allowed for the registration.

23. The method of claim 22, wherein the instructions, when executed by the at least one processor, further cause the apparatus to at least: In the event that the device is downgraded to an EPS network, the registration is maintained to communicate with the EPS network.

24. The method of claim 21, wherein the EPS IWK in the response indicates that interworking with an EPS network is not allowed for the registration.

25. The method according to claim 24, further comprising: deregistering the device from the core network for the registration if the device is downgraded to the EPS network; and / or In a case where the EPS IWK is not authorized for the registration, upon inter-system change from the 5G core network to the EPS, determining that the device must be deregistered from the 5G core network for the registration.

26. The method according to any one of claims 21 to 25, further comprising: issuing one or more further registration requests to the AMF of the core network for one or more further registrations of the apparatus with the core network of the communications network; as well as receiving one or more other responses to the one or more other registration requests from the AMF.

27. The method of claim 26, wherein a respective one of the one or more other responses comprises: Interworking with the EPS network is not allowed for the EPSIWK indication of the registration.

28. The method according to any one of claims 21 to 27, wherein the response to the registration request comprises a registration accept message, and the registration request message comprises: EPSIWK indicates that the registration is permitted.

29. The method of any one of claims 21 to 28, wherein the core network comprises a fifth generation (5G) core network.

30. The method of claim 29, further comprising: determining, based on the EPS IWK indication in the registration response, that interworking with the EPS network for the registration is permitted; maintaining the registration to communicate with the EPS upon an intersystem change from the 5G core network to the EPS if an EPS IWK is authorized for the registration; as well as In a case where the EPS IWK is not authorized for the registration, upon inter-system change from the 5G core network to the EPS, determining that the device must be deregistered from the 5G core network for the registration.

31. The method of claim 30, further comprising: A registration is determined to be another registration of the one or more other registrations that is authorized for use with the EPSIWK, and the another registration is maintained to communicate with the EPS.

32. The method according to any one of claims 21 to 31, wherein the EPS IWK determines whether the registration is allowed based on at least one of the following items: subscription information, deployment information, 5G system capabilities, or information about the radio access technology of the access path between the user equipment and the 5G system.

33. A method for an apparatus, the method comprising: generating a first message, the first message comprising: a first registration request for establishing a first registration of the apparatus with a core network; inserting into the first message an indication that the apparatus requests authorization for Evolved Packet System Interworking (EPSIWK) for the first registration; Sending the first registration request to an access and mobility management function (AMF) of the first core network; generating one or more second messages, wherein a respective second message of the one or more second messages comprises: another registration request for establishment of one or more second registrations of the apparatus with the core network and / or one or more other core networks; Sending a corresponding registration request from the one or more registration requests to the AMF and / or one or more other AMFs of the one or more other core networks; receiving a first response to the first message from the AMF, the first response indicating whether EPSIWK is allowed for the first registration; receiving one or more second responses to the one or more second messages from the AMF and / or the one or more other AMFs; and In the event that the device is required to be moved to the EPS network, it is determined that the first registration is retained for EPSIWK and the one or more second registrations are to be deregistered.

34. The apparatus of claim 33, wherein the first response to the first message comprises a registration accept message, the registration accept message comprising: EPS IWK for an indication that the first registration is permitted.

35. The method of claim 33 or 34, wherein the first core network comprises a fifth generation (5G) core network, and the one or more other core networks comprise a 5G core network.

36. An apparatus according to any one of claims 33 to 35, wherein the EPSIWK is determined based on at least one of the following items: subscription information, deployment information, 5G system capabilities, or information about the radio access technology of the access path between the apparatus and the 5G core network.

37. A method comprising: receiving, from an access and mobility management function of a fifth generation (5G) system, information regarding a registration request from a user equipment to register with the 5G system; determining whether evolved packet system network interworking is allowed for the registration; as well as A unified data management function indication is provided to the access and mobility management function as to whether evolved packet system network interworking is allowed for the registration.

38. The apparatus of claim 37, wherein the determination of whether the registration is allowed with respect to Evolved Packet System network interworking comprises: Determining whether evolved packet system network interworking is allowed for the registration is based on at least one of the following: subscription information, deployment information, 5G system capabilities, or information about a radio access technology of an access path between the user equipment and the 5G system.

39. The method according to claim 37 or 38, wherein the information received from the AMF of the 5G system further includes an access and mobility management function indication, the access and mobility management function indication being about whether the registration request includes a request from the user equipment for interworking with an evolved packet system network for the registration. The method further comprises: Based on the access and mobility management function indication, it is determined whether the user equipment requests evolved packet system network intercommunication for the registration.

40. The method according to claims 37 to 39, further comprising: receiving, from the AMF and / or one or more other AMFs, information about one or more other registrations associated with the user equipment; as well as In a case where evolved packet system intercommunication is determined to be allowed for the registration, one or more other unified data management function indications are provided to the AMF and / or the one or more other AMFs, the one or more other unified data management function indications indicating that evolved packet system network intercommunication is not allowed for the one or more other registrations associated with the user equipment.

41. An apparatus comprising: Means for performing the method according to any one of claims 21 to 40.

42. A computer readable medium storing program code, which, when executed by a processor, causes an apparatus to perform the method according to any one of claims 21 to 40.

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