Techniques for event exposure subscription in dual core network

Abstract

Embodiments include a method for an exposure function configured to operate in a communication network including a first core network and a second core network. The methods include sending a first event exposure (EE) subscription request for a notification from a first core network related to a user equipment (UE) to a first data management function of the first core network. The first EE subscription request includes an indication of a corresponding EE subscription for a notification from the second core network related to the UE. The methods include receiving a first EE subscription response from the first data management function, the response including a first indication of whether an EE subscription for a notification related to the UE was successfully created in the first core network, and a second indication of whether a subscription for the UE is present in the second core network. The methods include selectively sending, to a second data management function, a second EE subscription request for a UE-related notification from a second core network based on the second indication. Other embodiments include a complementary method for a first data management function.

Description

Technical Field

[0001] This disclosure generally relates to a communication network comprising two distinct core networks, and more specifically, to techniques for managing the subscription of network functions (NFs) to event notifications related to user equipment (UEs), which may have subscriptions in either or both of the two core networks. Background Technology

[0002] Long Term Evolution (LTE) is a general term referring to fourth-generation radio access technology developed within 3GPP, initially standardized in Release 8 (Rel-8) and Release 9 (Rel-9), also known as Evolved UTRAN (E-UTRAN). LTE targets a variety of licensed frequency bands and is accompanied by improvements to non-radio aspects commonly referred to as System Architecture Evolution (SAE), including the Evolved Packet Core (EPC) network.

[0003] Figure 1 An exemplary architecture of an LTE network is shown. Figure 1 The network shown includes an evolved UTRAN (E-UTRAN, 100), comprising one or more evolved NodeBs (eNBs, e.g., 105, 110, 115) and one or more User Equipments (UEs, e.g., 120). The eNB is responsible for radio-related functions in the LTE network, including radio bearer control, radio access control, radio mobility control, scheduling, dynamic resource allocation to UEs in the uplink and downlink, and security of communications with UEs. Each eNB can serve a geographic coverage area including one or more cells (e.g., 106, 111, and 115).

[0004] eNBs communicate with each other via the X2 interface and with the evolved packet core (EPC) network (130) via the S1 interface, particularly with the Mobility Management Entity (MME) and the Serving Gateway (SGW), such as Figure 1 The MME / S-GW (134, 138) is shown in the diagram. The MME / S-GW handles both the overall control of the UE and the data flow between the UE and the rest of the EPC. More specifically, the MME handles the signaling between the UE and the EPC. For example These are control plane protocols, also known as Non-Access Stratum (NAS) protocols. In contrast, the S-GW handles all Internet Protocol (IP) data packets between the UE and EPC. For example (User plane), and acts as a local mobility anchor for data bearer when the UE moves between eNBs.

[0005] The EPC also includes a Home Subscriber Server (HSS, 131) that manages user and subscriber-related information. The HSS can also provide support functions for mobility management, call and session setup, user authentication, and access authorization. HSS functionality can be associated with traditional Home Location Register (HLR) and Certification Authority (AuC) functions or operations. The HSS can communicate with the MME via a corresponding S6a interface. In some embodiments, the HSS can communicate with the User Data Repository (EPS-UDR, e.g., 135) via a Ud interface. The EPS-UDR can store user credentials encrypted using the AuC algorithm. The EPS-UDR is also known as a 4G-UDR.

[0006] Furthermore, the EPC may include a Service Capability Exposure (SCEF, 139) function, introduced in Rel-13, to securely expose services and capabilities provided by the 3GPP network interface. For example, the SCEF can expose services and capabilities provided by the HSS to application servers (AS) inside or outside the LTE network. As a more concrete example, machine-type communication (MTC) applications hosted by the AS can communicate directly with the SCEF, or through an intermediate Service Capability Server (SCS) that communicates with MTC UEs in the LTE network. In this way, the SCEF provides access to network capabilities through a homogeneous network application programming interface (API), thereby abstracting services from the underlying 3GPP network interface and protocols.

[0007] Currently, the 3rd Generation Partnership Project (3GPP) is standardizing fifth-generation (5G) cellular systems. NR development offers the greatest flexibility, supporting a wide variety of use cases. These include MTC, enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), sidelink device-to-device (D2D), and several other use cases.

[0008] One change in 5G networks is the modification and / or replacement of traditional peer-to-peer interfaces and protocols found in earlier generations of networks (such as EPC) by a service-based architecture (SBA). In SBA, network functions (NFs) provide one or more services to one or more service consumers. This can be achieved, for example, through Hypertext Transfer Protocol / Representation State Transport (HTTP / REST) ​​application programming interfaces (APIs). Generally, the various services are self-contained functions that can be changed and modified in isolation without affecting other services. Furthermore, services are composed of various "service operations," which are finer-grained divisions of the overall service functionality. The 5G SBA model, based on the principles of modularity, reusability, and self-containment, allows network deployments to leverage the latest virtualization and software technologies.

[0009] In 5G SBA, the Network Repository Function (NRF) allows each network function to discover services offered by other network functions, and the Data Storage Function (DSF) allows each network function to store its context. The Unified Data Management (UDM) function supports the generation of 3GPP authentication certificates, user identity processing, access authorization based on subscription data, and other subscriber-related functions. In other words, the functions provided by UDM for 5GC are similar to those provided by HSS for EPC.

[0010] The Network Exposure Function (NEF) acts as an entry point to the operator's core network (CN) by securely exposing network capabilities and events provided by other NFs and by providing a method for Application Functions (AFs) to securely provide information to (or securely receive information from) the CN. When operators deploy EPC (4G) and 5GC (5G) networks, the SCEF and NEF functions can be combined into a single entity, referred to in this paper as SCEF / NEF. Summary of the Invention

[0011] In networks supporting both 4G and 5G, the AS / SCS or AF can subscribe to UE-specific event notifications (also known as "Event Exposure" or EE) via the SCEF / NEF. The SCEF / NEF sends an EE subscription request to the UDM, HSS, or both. When sending an EE subscription request to the UDM, if the UE has a 5G subscription, the UDM returns a success message; if the UE does not have a 5G subscription, the UDM returns an error message. However, neither of these messages informs the SCEF / NEF whether the UE has a 4G subscription. This can lead to various problems, puzzles, and / or difficulties.

[0012] Section 5.6 of 3GPP TS 23.632 (v18.2.0) describes “Common Network Exposure Scenarios”, in which SCEF / NEF can configure monitoring events applicable to both EPC and 5GC using a 5GC procedure directed only to the UDM. If the interested UE does not have a 5G subscription, the UDM will return an error indicating USER_NOT_FOUND to SCEF / NEF. This leaves ambiguity regarding whether the interested UE has a 4G subscription, which can lead to various problems, puzzles, and / or difficulties.

[0013] The purpose of embodiments of this disclosure is, for example, to improve EE subscriptions in networks supporting both 4G and 5G by facilitating solutions to the exemplary problems described in more detail above and below.

[0014] Some embodiments of this disclosure include methods (e.g., processes) for exposing functionality configured to operate in a communication network including a first core network and a second core network.

[0015] These exemplary methods include sending a first EE subscription request to a first data management function of a first core network for a UE-related notification from the first core network. The first EE subscription request includes an indication of a corresponding EE subscription for a UE-related notification from a second core network. These exemplary methods also include receiving a first EE subscription response from the first data management function, the response including the following: • Whether the first instruction for the EE subscription to notifications related to the UE was successfully created in the first core network, and • Whether the UE's subscription exists in the second core network is indicated by a second instruction; and These exemplary methods include selectively sending a second EE subscription request to a second data management function, based on a second instruction, for UE-related notifications from a second core network.

[0016] In some embodiments, when the first indication indicates that an EE subscription for a notification related to the UE has not been successfully created in the first core network, the first EE subscription response may also include another second indication of whether a subscription for the UE exists in the first core network.

[0017] Other embodiments include methods (e.g., procedures) for a first data management function configured to operate in a first core network of a communication network, which also includes a second core network. Generally, these embodiments complement the methods described above for exposing functionality.

[0018] These exemplary methods include receiving a first EE subscription request for a UE-related notification from a first core network from an exposure function of a communication network. The first EE subscription request includes an indication of a corresponding EE subscription for a UE-related notification from a second core network. These exemplary methods include determining whether a subscription for the UE exists in the first core network and whether a subscription for the UE exists in the second core network. These exemplary methods include, when it is determined that a subscription for the UE exists in the first core network, attempting to create an EE subscription for the UE-related notification from the first core network based on the first EE subscription request. These exemplary methods include sending a first EE subscription response to the exposure function, the response including the following: • Whether the first instruction for the EE subscription to notifications related to the UE was successfully created in the first core network, and • Whether the UE's subscription exists in the second core network is a second indication.

[0019] In some embodiments, when the first indication indicates that an EE subscription for a notification related to the UE has not been successfully created in the first core network, the first EE subscription response may also include another second indication of whether a subscription for the UE exists in the first core network.

[0020] In some embodiments, the first core network is a 5G core network (5GC), the second core network is a 4G evolved packet core network (EPC), the exposure function is a network exposure function (NEF) or a service capability exposure function (SCEF), the first data management function is a unified data management (UDM) function, and the second data management function is a home subscriber server (HSS).

[0021] These exemplary methods include sending a first event exposure (EE) subscription request to a first data management function of a first core network for a UE-related notification from the first core network. The first EE subscription request includes an indication of a corresponding EE subscription for a UE-related notification from a second core network. These exemplary methods also include receiving a first EE subscription response from the first data management function, the response including the following: • Whether the first instruction for the EE subscription to notifications related to the UE was successfully created in the second core network, and • A second indication regarding whether the UE's subscription does not exist in the first core network.

[0022] These exemplary methods also include, based on a first instruction, selectively sending a second EE subscription request to a second data management function for UE-related notifications from a second core network. In some embodiments, the first indication indicates that an EE subscription for UE-related notifications has been successfully created in the second core network. In some of these embodiments, the first EE subscription request includes an indication of a first event for which state monitoring needs to be synchronized between the first and second data management functions. In some variations of these embodiments, the first event is one of the following: a UE roaming state change event, or a UE IMEI (SV) / PEI change event. In some variations of these embodiments, the first EE subscription request also includes an indication for immediate event reporting.

[0023] Other embodiments include methods (e.g., procedures) for a first data management function configured to operate in a first core network of a communication network, which also includes a second core network. Generally, these embodiments complement the methods described above for exposing functions.

[0024] These exemplary methods include receiving a first EE subscription request for a UE-related notification from a first core network from an exposure function of a communication network. The first EE subscription request includes an indication of a corresponding EE subscription for the UE-related notification from a second core network. These exemplary methods also include determining that the subscription for the UE does not exist in the first core network. These exemplary methods further include determining the following: • Whether user subscription data for the second core network can be accessed by the first data management function, and • If access is determined, determine whether user subscription data for the second core network includes subscriptions for the UE; These exemplary methods also include, in response to each of the following conditions, attempting to create an EE subscription for UE-related notifications from the second core network, based on the first EE subscription request: • User subscription data for the second core network includes subscriptions for UEs; and • The first data management function cannot determine whether user subscription data for the second core network includes subscriptions for the UE.

[0025] These exemplary methods also include sending a first EE subscription response to the exposed function, which includes the following: • Whether the first instruction for the EE subscription to notifications related to the UE was successfully created in the second core network, and • A second indication for the UE's subscription that does not exist in the first core network.

[0026] In some of these embodiments, the first indication indicates that an EE subscription for UE-related notifications has been successfully created in the second core network. In some variations of these embodiments, the first and second EE subscription requests include an indication of a first event for which state monitoring needs to be synchronized between the first and second data management functions. In some further variations, the first event is one of the following: a UE roaming state change event, or a UE IMEI (SV) / PEI change event. In some further variations, the first EE subscription request also includes an indication for immediate event reporting.

[0027] Other embodiments include methods (e.g., procedures) for a second data management function configured to operate in a second core network of a communication network that also includes a first core network. Generally, these embodiments complement the methods for exposing the function and the first data management function described above.

[0028] These exemplary methods include receiving a second EE subscription request for a UE-related notification from a second core network from a first data management function of a first core network. The subscription for the UE does not exist in the first core network. These exemplary methods also include attempting to create an EE subscription for the UE-related notification from the second core network based on the second EE subscription request. These exemplary methods also include sending a second EE subscription response to the first data management function, the response including a first indication of whether the EE subscription for the UE-related notification was successfully created in the second core network.

[0029] In some embodiments, the first indication indicates that an EE subscription for UE-related notifications has been successfully created in the second core network. In some of these embodiments, the second EE subscription request includes an indication of a first event for which state monitoring needs to be synchronized between the first and second data management functions. In some variations of these embodiments, the first event is one of the following: a UE roaming state change event, or a UE IMEI (SV) / PEI change event. In some variations of these embodiments, the second EE subscription request also includes an indication for immediate event reporting.

[0030] Other embodiments include exposure functionality ( For example (NEF, SCEF or a combination thereof) and data management functions ( For example A UDM (User-Defined Machine) is configured to perform operations corresponding to any of the exemplary methods described herein. Other embodiments include a non-transitory computer-readable medium storing program instructions that, when executed by processing circuitry, configure such exposure or data management functions to perform operations corresponding to any of the exemplary methods described herein.

[0031] These and other embodiments disclosed herein can provide solutions to various advantages, benefits, and / or problems. For example, embodiments can reduce the signaling load required in dual-core networks (e.g., 4G and 5G) by informing the exposure function of the existence of a user subscription in the data management function (e.g., HSS) of another core network via a data management function (e.g., UDM) in one of the core networks, allowing the exposure function to contact the database management function of the other core network only when a user subscription exists. For example, embodiments can reduce the signaling performed by exposure functions (e.g., SCEF / NEF) regarding EE subscriptions associated with the UE in a dual-core network. Furthermore, the exposure function does not need to know whether the UE has subscribed to a first (e.g., 5G), a second (e.g., 4G), or both network types, because this ambiguity is managed by the data management function (e.g., UDM) associated with the first network type. Additionally, embodiments enable the data management function to determine whether the UE has subscribed to the second network type, regardless of whether the user subscription information is merged in a single database (e.g., UDR) or stored in separate databases (e.g., 5G-UDR and 4G-UDR). More generally, the implementation improves EE subscription management in dual-core networks, such as networks with 5GC and EPC.

[0032] These and other objects, features, and advantages of embodiments of the present disclosure will become apparent after reading the following detailed description with reference to the accompanying drawings, which are briefly described below. Attached Figure Description

[0033] Figure 1 A high-level view of an exemplary LTE network architecture is shown.

[0034] Figure 2 A high-level view of an exemplary 5G / NR network architecture is shown.

[0035] Figure 3-5 Signaling diagrams are shown for various processes between AS / SCS / AF, SCEF / NF, UDM in 5GC, and HSS in EPC.

[0036] Figure 6 The signaling diagram shows the process between AS / SCS / AF, SCEF / NF, UDM in 5GC and HSS in EPC.

[0037] Figure 7-8 Signaling diagrams of the processes between AS / SCS / AF, SCEF / NF, UDM in 5GC, and HSS in EPC according to various embodiments of the present disclosure are shown.

[0038] Figure 9 This is a flowchart of an exemplary method (e.g., process) for exposing the functionality of a communication network according to various embodiments of this disclosure.

[0039] Figure 10 This is a flowchart of an exemplary method (e.g., process) for a first data management function for a communication network according to various embodiments of the present disclosure.

[0040] Figure 11 This is a flowchart of an exemplary method (e.g., process) for a second data management function for a communication network according to various embodiments of the present disclosure.

[0041] Figure 12-14 Signaling diagrams of the processes between AS / SCS / AF, SCEF / NF, UDM in 5GC, and HSS in EPC according to various embodiments of the present disclosure are shown.

[0042] Figure 15 This is a flowchart of an exemplary method (e.g., process) for exposing the functionality of a communication network according to various embodiments of this disclosure.

[0043] Figure 16 This is a flowchart of an exemplary method (e.g., process) for a first data management function for a communication network according to various embodiments of the present disclosure.

[0044] Figure 17 Communication systems according to various embodiments of the present disclosure are shown.

[0045] Figure 18 Network nodes according to various embodiments of this disclosure are shown.

[0046] Figure 19 This is a block diagram of a virtualized environment in which functionality implemented by some embodiments of this disclosure can be virtualized. Detailed Implementation

[0047] Some embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. However, other embodiments are included within the scope of the subject matter disclosed herein, and the disclosed subject matter should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided as examples to convey the scope of the subject matter to those skilled in the art.

[0048] Generally, all terms used herein should be interpreted according to their common meaning to those skilled in the art, unless a different meaning is expressly defined and / or implied from the context of use. Unless otherwise expressly stated or implied from the context of use, all references to elements, devices, components, parts, steps, etc., should be interpreted as references to at least one instance of an element, device, component, part, step, etc. Operation of any methods and / or processes disclosed herein need not be performed in the exact order disclosed, unless operations are expressly described as occurring after or before another operation and / or implicitly indicate that an operation must occur after or before another operation. Any feature of any embodiment disclosed herein may be suitably applied to any other disclosed embodiment. Similarly, any advantage of any embodiment described herein may be suitably applied to any other disclosed embodiment.

[0049] In addition, the following terms are used throughout the description given below: Radio Access Node: As used herein, a “radio access node” (or equivalently a “radio network node,” “radio access network node,” or “RAN node”) can be any node in a radio access network (RAN) that operates to wirelessly transmit and / or receive signals. Some examples of radio access nodes include, but are not limited to, base stations ( For example, gNB in ​​3GPP 5G / NR networks or enhanced or eNB in ​​3GPP LTE networks), base station distributed components ( For example, CU and DU), high-power or macro base stations, low-power base stations ( For example Micro base stations, pico base stations, femtobase stations or home base stations, etc.), integrated access backhaul (IAB) nodes, transmission points (TP), transmission receiver points (TRP), remote radio units (RRU or RRH) and relay nodes.

[0050] Core Network Nodes: As used in this document, a “core network node” is any type of node in the core network. Some examples of core network nodes include, for example, Mobility Management Entity (MME), Serving Gateway (SGW), PDN Gateway (P-GW), Policy and Charging Rules Function (PCRF), Access and Mobility Management Function (AMF), Session Management Function (SMF), User Plane Function (UPF), Charging Function (CHF), Policy Control Function (PCF), Authentication Server Function (AUSF), Location Management Function (LMF), etc.

[0051] Wireless Device: As used herein, a “wireless device” (or “WD” for short) is any type of device capable of, configured, arranged, and / or operable to wirelessly communicate with network nodes and / or other wireless devices. Wireless communication may involve transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for transmitting information through the air. Unless otherwise stated, the term “wireless device” is used interchangeably herein with the term “user equipment” (or “UE” for short), which have different meanings from the term “network node”.

[0052] Radio node: As used herein, “radio node” can be a “radio access node” (or equivalent term) or a “wireless device”. Network node: As used in this article, a "network node" is a radio access network that serves as a cellular communication network. For example, Radio access node (or equivalent) or core network ( For example Any node that is part of the core network node described above. Functionally, a network node is a device that is capable of being configured, arranged, and / or operated to communicate directly or indirectly with wireless devices and / or other network nodes or devices in a cellular communication network to enable and / or provide wireless access to the wireless devices, and / or perform other functions (e.g., management) within the cellular communication network.

[0053] Node: As used herein, the term “node” (without prefix) can be any type of node that can operate in or with a wireless network, including a radio access node (or equivalent term), a core network node, or a wireless device. However, the term “node” can be limited to a specific type (e.g., radio access node, IAB node) based on its particular characteristics in any given context.

[0054] The above definitions are not intended to be exclusive. In other words, the same or similar terms may be used to interpret and / or describe various terms mentioned above elsewhere in this disclosure. However, if any such other interpretation and / or description conflicts with the above definitions, the above definitions shall prevail.

[0055] Note that the descriptions presented herein focus on 3GPP cellular communication systems; therefore, 3GPP terminology or similar terms are frequently used. However, the concepts disclosed herein are not limited to 3GPP systems and can be applied to any communication system from which it may benefit. Furthermore, although the term "cell" is used herein, it should be understood that (especially for 5G NR) a beam can be used instead of a cell; therefore, the concepts described herein also apply to cells and beams.

[0056] Figure 2 An exemplary non-roaming reference architecture for a 5G network (200) is shown, including the following NFs and service-based interfaces defined by 3GPP: Application Functions (AF, with NAF interface) interact with the 5GC to provide information to the network operator and subscribe to certain events occurring in the operator's network. AF provides services at a different layer (i.e., the transport layer) than the layer requesting the service (i.e., the signaling layer), controlling traffic resources based on content negotiated with the network. AF transmits dynamic session information to the PCF (via the N5 interface), including a description of the media to be transmitted by the transport layer.

[0057] The Policy Control Function (PCF, with NPCF interface) supports a unified policy framework for managing network behavior by providing PCC rules (e.g., processing of each service data flow under PCC control) to the SMF via the N7 reference point. The PCF provides policy control decisions and flow-based charging control, including service data flow detection, gating, QoS, and flow-based charging (excluding credit management) for the SMF. The PCF receives session and media-related information from the AF and notifies the AF of service (or user) plane events.

[0058] User Plane Functions (UPFs) – These functions support the processing of user plane traffic according to rules received from the SMF, including packet inspection and various execution operations (e.g., event detection and reporting). UPFs communicate with the RAN (e.g., NG-RAN) via reference point N3, with the SMF (discussed below) via reference point N4, and with the external Packet Data Network (PDN) via reference point N6. Reference point N9 is used for communication between two UPFs.

[0059] The Session Management Function (SMF, with an NSMF interface) interacts with the decoupled business (or user) plane, including creating, updating, and deleting Protocol Data Unit (PDU) sessions, and managing session contexts using User Plane Functions (UPFs), such as for event reporting. For example, the SMF performs data flow inspection (based on filter definitions contained in PCC rules), online and offline billing interactions, and policy enforcement.

[0060] The Billing Function (CHF, with Nchf interface) is responsible for integrating online and offline billing functions. It provides quota management (for online billing), reauthorization triggers, rating conditions, and receives usage report notifications from the SMF. Quota management involves granting a specific number of units (e.g., bytes, seconds) to a service. The CHF also interacts with the billing system.

[0061] The Access and Mobility Management Function (AMF, with a Namf interface) terminates at the RAN CP interface and handles all mobility and connectivity management for the UE (similar to the MME in the EPC). The AMF communicates with the UE via the N1 reference point and with the RAN (e.g., NG-RAN) via the N2 reference point.

[0062] Network Exposure Function (NEF, with Nnef interface) – acts as an entry point to the operator's network by securely exposing network capabilities and events provided by the 3GPP NF to the AF and providing the AF with a method to securely provide information to the 3GPP network. For example, NEF provides a service that allows the AF to provide specific subscription data (e.g., expected UE behavior) to various UEs. Generally, the services provided by NEF are similar to those provided by SCEF in EPC.

[0063] Network Repository Function (NRF, with Nnrf interface) – provides service registration and discovery, enabling NFs to identify the appropriate services provided by other NFs.

[0064] Network Slice Selection Function (NSSF, with NSSF interface) – A “network slice” is a logical partition of a 5G network that provides specific network capabilities and features, such as supporting specific services. A network slice instance is a collection of NF instances that provide the capabilities and features of a network slice and the required network resources (e.g., compute, storage, communication). NSSF enables other NFs (e.g., AMFs) to identify network slice instances suitable for the services required by the UE.

[0065] The Authentication Server Function (AUSF, with Nausf interface) is based on the user's Home Network (HPLMN) and performs user authentication and computes security key material for various purposes.

[0066] Network Data Analysis Function (NWDAF, with Nnwdaf interface) – provides network analysis information (e.g., statistics and / or predictions of past events) to other NFs at the network slice instance level.

[0067] Unified Data Management (UDM, with Nudm interface) functions—generating 3GPP authentication certificates, handling user identity, granting access based on subscription data, and other subscriber-related functions. UDM obtains subscription data (including authentication data) from the 5G Unified Data Repository (5GS-UDR, with Nudr interface). 5GS-UDR supports PCF for storing and retrieving policy data, and NEF for storing and retrieving application data. 5GS-UDR is also known as 5G-UDR.

[0068] The NRF allows each NF to discover services offered by other NFs, and the Data Storage Function (DSF) allows each NF to store its context. Furthermore, the NRF exposes 5GC capabilities and events to AFs both inside and outside the 5GC. For example, the NRF provides a service that allows AFs to provide specific subscription data to various UEs (...). For example (Expected UE behavior).

[0069] The services provided by various Service Providers (NFs) consist of "service operations," which are finer-grained divisions of the overall service functionality. The interaction between service consumers and producers can be of the "request / response" or "subscription / notification" type. In the latter type, the service consumer NF (or equivalent "consumer NF") requests the service producer NF (or equivalent "producer NF") to subscribe to the service consumer NF in order to receive notifications from the service producer NF under the conditions specified in the subscription.

[0070] Furthermore, LTE EPC may include a Service Capability Exposure Function (SCEF), introduced in Rel-13, to securely expose services and capabilities provided by the 3GPP network interface. For example, the SCEF can expose services and capabilities provided by the HSS to application servers (AS) inside or outside the LTE network. As a more concrete example, machine-type communication (MTC) applications hosted by the AS can communicate directly with the SCEF or through an intermediate Service Capability Server (SCS) to communicate with MTC UEs in the LTE network. In this way, the SCEF provides access to network capabilities through a homogeneous network application programming interface (API), thereby abstracting services from the underlying 3GPP network interface and protocols.

[0071] Therefore, SCEF provides similar functionality for 4G LTE networks as NEF provides for 5G networks. When operators deploy both 4G and 5G networks, the SCEF and NEF functions can be combined into a single entity, referred to in this paper as SCEF / NEF.

[0072] In networks supporting both 4G and 5G, the AS / SCS or AF can subscribe to UE-specific event notifications (also known as "event exposure" or EE) via the SCEF / NEF. The SCEF / NEF sends an EE subscription request to the UDM, HSS, or both. This choice depends on whether the specific UE is only 5G, only 4G, or subscribed to both. This choice also depends on whether UDM-HSS interoperability is supported in the network.

[0073] Section 5.6 of 3GPP TS 23.632 (v18.2.0) describes “Common Network Exposure Scenarios”, in which SCEF / NEF can configure monitoring events applicable to both EPC and 5GC using the 5GC procedure, which is only for UDM. In this case, SCEF / NEF indicates that the monitoring event also applies to both EPC and SCEF identities, meaning that both 5GC and EPC must report the event.

[0074] Clause 5.6.3 of 3GPP TS 23.632 (v18.2.0) specifies that the status of certain specific monitoring events detected locally by the HSS and UDM should be kept synchronized between the UDM and HSS. For example, EE subscriptions for certain events are managed by the UDM and do not require the HSS to receive EE subscription requests, but the HSS will keep notifying the UDM of the status of these events, depending on the configuration of both the HSS and UDM. This synchronization applies to certain specific monitoring events detected locally by the HSS and UDM, such as IMEI (SV) / PEI changes, roaming status changes, etc. After receiving notification from the HSS about such events occurring in the EPS, the UDM can use the SBA procedure to send a message about such events to the combined SCEF+NEF.

[0075] Section 5.6 of 3GPP TS 23.632 (v18.2.0) describes "Common Network Exposure Scenarios," in which SCEF / NEF can configure monitoring events applicable to both EPC and 5GC using the 5GC procedure, which is only for UDM. In this case, SCEF / NEF indicates that the monitoring event also applies to both EPC and SCEF identities, meaning that both 5GC and EPC must report the event.

[0076] Clause 5.6.3 of 3GPP TS 23.632 (v18.2.0) specifies that the status of certain specific monitoring events detected locally by the HSS and UDM should be kept synchronized between the UDM and HSS. For example, EE subscriptions for certain events are managed by the UDM and do not require the HSS to receive EE subscription requests, but the HSS will keep notifying the UDM of the status of these events, depending on the configuration of both the HSS and UDM. This synchronization applies to certain specific monitoring events detected locally by the HSS and UDM, such as IMEI (SV) / PEI changes, roaming status changes, etc. After receiving notification from the HSS about such events occurring in the EPS, the UDM can use the SBA procedure to send a message about such events to the combined SCEF+NEF.

[0077] Figure 3 The signaling diagram illustrates the processes between AS / SCS / AF, SCEF / NF, UDM in 5GC, and HSS in EPC. 5GC and EPC are part of the same operator network, such as a "dual-core" network. In this example, the UE of interest has neither a 4G subscription stored in the HSS nor a 5G subscription stored in the UDM.

[0078] In Operation 1, the AS / SCS / AF sends an Nnef_EventExposure_Subscribe request to the SCEF / NEF for UE-related event notifications. This message includes the UE identifier. In Operation 2, the SCEF / NEF sends a Nudm_EventExposure_Subscribe request to the UDM to subscribe to EE notifications for the UE. The SCEF / NEF also includes an "epcAppliedInd" flag set to true in the request, which instructs the UDM that it should also create a corresponding EE subscription in the HSS.

[0079] In this example, the UE does not have a 5G subscription stored in the UDM. Therefore, in Operation 3, the UDM sends an Nnef_EventExposure_Subscribe response indicating USER_NOT_FOUND. However, this message only indicates that there is no 5G subscription for the UE in the UDM; it does not indicate whether the UE has a 4G subscription stored in the HSS. Given this uncertainty, the SCEF / NEF will need to send another EE subscription request to the HSS. In this example, since the UE does not have a 4G subscription in the HSS, this request will fail, causing the HSS to return an error message.

[0080] Figure 4 Signaling diagrams for another process between AS / SCS / AF, SCEF / NF, UDM in 5GC, and HSS in EPC are shown. 5GC and EPC are part of the same operator network, such as a "dual-core" network. In this example, the UE of interest has a 4G subscription stored in the HSS but not a 5G subscription stored in the UDM.

[0081] In Operation 1, the AS / SCS / AF sends an Nnef_EventExposure_Subscribe request to the SCEF / NEF for UE-related event notifications. This message includes the UE identifier. In Operation 2, the SCEF / NEF sends a Nudm_EventExposure_Subscribe request to the UDM to subscribe to EE notifications for the UE. The SCEF / NEF also includes an "epcAppliedInd" flag set to true in the request, instructing the UDM that it should also create a corresponding EE subscription in the HSS.

[0082] In this example, the UE does not have a 5G subscription stored in the UDM. Therefore, in Operation 3, the UDM sends an Nnef_EventExposure_Subscribe response indicating USER_NOT_FOUND. However, this message only indicates that a 5G subscription for the UE does not exist in the UDM; it does not indicate whether the UE has a 4G subscription stored in the HSS. Given this uncertainty, the SCEF / NEF will need to send another EE subscription request to the HSS. In this example, since the UE has a 4G subscription in the HSS, this request will succeed.

[0083] Please note the error message in operation 3. Figure 3-4 The two cases shown are identical. Therefore, SCEF / NEF cannot distinguish between these two cases based on the error message.

[0084] Figure 5Another signaling diagram is shown between AS / SCS / AF, SCEF / NF, UDM in 5GC, and HSS in EPC. 5GC and EPC are part of the same operator network, such as a "dual-core" network. In this example, the UE of interest stores a 5G subscription in the UDM but not a 4G subscription in the HSS.

[0085] Operations 1-2 and Figure 3-4 The corresponding operation is the same. In operation 3, the UDM sends an Nnef_EventExposure_Subscribe response to indicate that the EE subscription was successful in 5G, but also includes the "epcStatusInd=false" flag to indicate that the EE subscription has not been successfully created in 4G.

[0086] While "epcStatusInd=false" indicates that a 4G EE subscription has not been created, it provides no information about the reason or justification, which may not be because the UE does not have a 4G subscription in the HSS. For example, the UDM might also set this flag to "false" when interoperability between the UDM and HSS is not supported in the operating network. Given this uncertainty, the SCEF / NEF will need to send another EE subscription request to the HSS. In this example, since the UE does not have a 4G subscription in the HSS, this request will fail, causing the HSS to return an error message.

[0087] Embodiments of this disclosure address these and other problems, difficulties, or challenges through techniques for a first data management function (e.g., UDM) associated with a first network type (e.g., 5G) to provide specific information in the EE subscription response to an EE subscription request for an exposure function (e.g., SCEF / NEF) associated with an EE notification for a specific UE. This specific information enables the exposure function to determine whether a UE subscription for a second network type (e.g., 4G) exists, and therefore whether the exposure function should send (or avoid sending) a second subscription request for the UE-related EE notification to a second data management function (e.g., HSS) associated with the second network type. Notably, the first data management function may provide such information in response to a successful or unsuccessful subscription to an EE notification related to the first network type associated with the UE.

[0088] The embodiments of this disclosure can provide solutions to various advantages, benefits, and / or problems. For example, embodiments can notify an exposure function of the presence of a user subscription in a data management function (e.g., HSS) of another core network via a data management function (e.g., UDM) in one core network, thereby reducing the signaling load required in a dual-core network (e.g., 4G and 5G), allowing the exposure function to contact the data management function of the other core network only when a user subscription exists. More generally, embodiments improve EE subscription management in a dual-core network (e.g., a network with 5GC and EPC).

[0089] Figure 6 The signaling diagram illustrates the processes between AS / SCS / AF, SCEF / NF, UDM in 5GC, and HSS in EPC. 5GC and EPC are part of the same operator network, such as a "dual-core" network. In this example, the UE of interest stores a 4G subscription in the HSS but not a 5G subscription in the UDM.

[0090] In Operation 1, the AS / SCS / AF sends an Nnef_EventExposure_Subscribe request to the SCEF / NEF for UE-related event notifications. This message includes the UE identifier. In Operation 2, the SCEF / NEF sends a Nudm_EventExposure_Subscribe request to the UDM to subscribe to EE notifications for the UE. The SCEF / NEF also includes an "epcAppliedInd" flag set to true in the request, instructing the UDM that it should also create a corresponding EE subscription in the HSS.

[0091] In this example, the UE does not have a 5G subscription stored in the UDM. Therefore, in Operation 3, the UDM determines that the common exposure scenario for 5GC / EPC does not apply to this UE. In Operation 4, the UDM sends an Nnef_EventExposure_Subscribe response indicating USER_NOT_FOUND, without attempting to create an EE subscription in the HSS. However, this message only indicates that a 5G subscription for the UE does not exist in the UDM; it does not indicate whether the UE has a 4G subscription stored in the HSS. Given this uncertainty, the SCEF / NEF will need to send another EE subscription request to the HSS. In this example, since the UE has a 4G subscription in the HSS, this request will succeed, but it will require additional network signaling and processing resources to handle the additional request to the HSS.

[0092] The embodiments of this disclosure address these and other problems, difficulties, or challenges by employing a first data management function (e.g., UDM) associated with a first network type (e.g., 5G). When an EE subscription request is received from an exposure function (e.g., SCEF / NEF) also applicable to a second network type (e.g., 4G), an EE subscription is created in the second network category even if the UE to which the EE subscription request belongs does not have a subscription to the first network type. The first data management function can create such an EE subscription by sending a corresponding EE subscription request to a second data management function (e.g., HSS) associated with the second network type. The first data management function can also notify the exposure function that the EE subscription was created in the second network type, but the UE does not have a subscription to the first network type.

[0093] The embodiments disclosed herein can provide solutions to various advantages, benefits, and / or problems. For example, embodiments can reduce the signaling performed by exposure functions (e.g., SCEF / NEF) regarding UE-related EE subscriptions in dual-core networks (e.g., EPC / 5GC). Furthermore, the exposure function does not need to know whether the UE is subscribed to a first (e.g., 5G), a second (e.g., 4G), or both network types, as this ambiguity is managed by a first data management function (e.g., UDM) associated with the first network type. Moreover, embodiments avoid using the conventional “Diameter” interface in the exposure domain while enabling the first data management function to determine whether the UE is subscribed to a second network type, regardless of whether user subscription information is merged in a single database (e.g., UDR) or stored in separate databases (e.g., 5G-UDR and 4G-UDR). More generally, embodiments improve EE subscription management in dual-core networks (e.g., networks with 5GC and EPC).

[0094] Figure 7 Signaling diagrams illustrating the processes between AS / SCS / AF (710), SCEF / NF (720), UDM (730) in 5GC, and HSS (740) in EPC according to some embodiments of this disclosure are shown. 5GC and EPC are part of the same operator network, such as a "dual-core" network. In this example, the UE of interest stores a 4G subscription in the HSS but not a 5G subscription in the UDM.

[0095] Operations 1-2 are similar to those described above. Figure 6The corresponding operation is described in operation 3. In operation 3, the UDM determines whether a merged 4G-UDR and 5G-UDR exist so that the UDM can access both the 4G and 5G subscription information in the merged UDR. This determination can be based on a configuration flag or indicator. If the flag indicates a merged UDR, the UDM queries this database to obtain the 4G and 5G subscriptions for the UE. In this case, the UDM determines that the UE has a 4G subscription but no 5G subscription.

[0096] On the other hand, if the flag indicates that there is no merged UDR, the UDM can query the 5G-UDR to determine whether the UE has a 5G subscription, but cannot determine whether the UE has a 4G subscription in a separate 4G-UDR. Therefore, from the UDM's perspective, even if a 4G subscription exists, it is ambiguous whether the UE has a 4G subscription.

[0097] In operation 5, if the UE's 4G subscription is confirmed (e.g., merged UDR) or remains unclear from the UDM's perspective (e.g., standalone 4G-UDR), the UDM sends an Nhss_EventExposure_Subscribe request to the HSS. In operation 6, the HSS sends an Nhss_EventExposure_Subscribe response to the UDM, including a flag epcStatusInd set to "true" indicating that the requested EE subscription has been created in the EPC. In operation 7, the UDM sends an Nnef_EventExposure_Subscribe response to the SCEF / NEF, including a flag epcStatusInd set to "true" to indicate that the EE subscription has been successfully created in the EPC, and a second flag indicating that a 5G subscription for the UE does not exist.

[0098] Based on the message received in Operation 7, SCEF / NEF avoids sending another EE subscription request to HSS, as is done in traditional solutions.

[0099] When the relevant UE does not have a 5G subscription, the monitoring event state synchronization between the HSS and UDM described in Clause 5.6.3 of 3GPP TS 23.632 (v18.2.0) is not applicable. Traditionally, EE subscriptions are discarded without attempting to create a 4G EE subscription for the UE in the EPC, such as... Figure 6 As shown. If instead a 4G EE subscription for the UE is created in the EPC, as follows: Figure 7 As shown, some event synchronization must be provided. Nowadays, this event synchronization applies to events detected locally in the HSS / UDM, such as IMEI (SV) / PEI changes, roaming status changes, etc.

[0100] Figure 8 A signaling diagram illustrating the processes between AS / SCS / AF (710), SCEF / NF (720), UDM (730) in 5GC, and HSS (740) in EPC, according to other embodiments of this disclosure, is shown. 5GC and EPC are part of the same operator network (e.g., a "dual-core" network). In this example, the UE of interest stores a 4G subscription in the HSS but not a 5G subscription in the UDM.

[0101] Operations 1-2 are similar Figure 7 Operations 1-2 in the above examples, except that in this case, the requested EE subscription is eventType=EventX, which is subject to UDM-HSS synchronization. For example, event X could be ROAMING_STATUS (indicating a roaming status change) or SUPI_PEI_CHANGE (indicating an IMEI(SV) / PEI change). In some embodiments, when the SCEF / NEF wants to receive a report for EventX in the response message, the message in operation 2 may include the “immediateReport” flag, assuming that such an immediate report is available and supported by the relevant NF.

[0102] Operations 3-4 are similar Figure 7 Operations 3-5 in step 2 involve the UDM sending an Nhss_EventExposure_Subscribe request to the HSS for eventType=EventX, because from the UDM's perspective, the UE's 4G subscription has been confirmed (e.g., merged UDR) or remains ambiguous (e.g., standalone 4G-UDR). If the message in step 2 includes the "immediateReport" flag, the UDM includes this flag in the message sent in step 4.

[0103] Because the synchronization of eventType=EventX between the HSS and UDM described in Clause 5.6.3 of 3GPP TS 23.632 (v18.2.0) is not applicable when the UE's 5G subscription does not exist, creating an EE subscription for EventX in the UDM within the HSS allows the HSS to monitor and report these events independently without needing to synchronize with the UDM. 3GPP TS 29.563 (v18.2.0) defines the interoperability interface between the UDM and HSS, which includes the Nhss_EventExposure service (also known as "Nhss_EE"). This service includes the "EventType" data type, which is defined in Clause 6.4.6.3.3 of this document. Note that the current definition does not include event types subject to UDM-HSS synchronization constraints as specified in Clause 5.6.3 of 3GPP TS 23.632 (v18.2.0). Therefore, in some embodiments, the definition in Clause 6.4.6.3.3 of 3GPP TS 29.563 (v18.2.0) can be extended to include such event types. The following table illustrates this, with underlines indicating additions.

[0104] In Operation 5, the HSS sends an Nhss_EventExposure_Subscribe response to the UDM, which includes a flag epcStatusInd set to "true" indicating that the requested EE subscription has been created in the EPC. In some embodiments, the HSS may include monitoring reports for EventX, for example, where immediate reporting is required in Operation 5 and is currently available.

[0105] In Operation 6, the UDM sends an Nnef_EventExposure_Subscribe response to the SCEF / NEF. This response includes a flag epcStatusInd set to "true" to indicate that the EE subscription has been successfully created in the EPC, and a second flag indicating that the 5G subscription for the UE does not exist. If the UDM received a monitoring report from the HSS in Operation 5, the UDM also includes that monitoring report in the response sent to the SCEF / NEF in Operation 6. Based on the message received in Operation 6, the SCEF / NEF avoids sending another EE subscription request to the HSS, as is done in traditional solutions.

[0106] In operation 7, the HSS detects the occurrence of EventX corresponding to the previously established EE subscription. In operation 8, the HSS sends an Nhss_EventExposure_Notification request to the UDM, which includes a monitoring report for EventX and a flag epcStatusInd set to "true" to indicate that the EE subscription is in EPC. In operation 9, the UDM sends a Nudm_EventExposure_Notification request to the SCEF / NEF, which includes the content received from the HSS in operation 8.

[0107] The above embodiments can be referred to Figure 9-11 To further explain, Figure 9-11 Exemplary methods (e.g., processes) performed by the exposure function, the first data management function, and the second data management function are illustrated respectively. In other words, the various features of the operations described below correspond to the various embodiments described above. These exemplary methods can be used in combination to provide various exemplary benefits and / or advantages. Although Figure 9-11 Specific boxes are shown in a particular order, but the operations of the corresponding methods may be performed in a different order than shown, and may be combined and / or divided into boxes with functions different from those shown. Optional boxes or operations are indicated by dashed lines.

[0108] Specifically, Figure 9 A flowchart is shown of an exemplary method (e.g., process) for exposing functionality according to various embodiments of the present disclosure, the exposed functionality being configured to operate in a communication network including a first core network and a second core network. For example, the exemplary method may be performed by NEF, SCEF, or a combination thereof, as described elsewhere herein.

[0109] The exemplary method includes the operation at box 920, wherein the exposure function may send a first event exposure (EE) subscription request for a UE-related notification from the first core network to a first data management function of the first core network. The first EE subscription request includes an indication of a corresponding EE subscription for a UE-related notification from a second core network. The exemplary method also includes the operation at box 930, wherein the exposure function may receive a first EE subscription response from the first data management function, the response including the following: In the second core network, was the first instruction for the EE subscription to notifications related to the UE successfully created? The second instruction indicates that the subscription for the UE does not exist in the first core network.

[0110] The exemplary method also includes the operation of block 940, wherein, based on a first instruction, the exposure function may selectively send a second EE subscription request to a second data management function for UE-related notifications from a second core network. In some embodiments, the first indication indicates that an EE subscription for notifications related to the UE has been successfully created in the second core network. In some of these embodiments, the first EE subscription request includes an indication of a first event for which state monitoring needs to be synchronized between the first and second data management functions. In some variations of these embodiments, the first event is one of the following: a UE roaming state change event, or a UE IMEI (SV) / PEI change event.

[0111] In some variations of these embodiments, the first EE subscription request also includes an indication for immediate event reporting. When the first indication indicates that an EE subscription for a notification related to the UE has been successfully created in the second core network, the first EE subscription response, in accordance with the immediate event reporting indication, also includes a monitoring report for the first event. Figure 8 Examples of these embodiments are shown.

[0112] In some variations of these embodiments, the exemplary method may further include the operation of block 950, wherein when the first indication in block 930 indicates that an EE subscription for a notification related to the UE has been successfully created in the second core network, the exposure function may subsequently receive an EE notification from the first data management function, the EE notification including the following: Another first instruction for EE subscriptions related to UE notifications was successfully created in the second core network, and Monitoring report from the second core network regarding the first event.

[0113] Figure 8 Examples of these embodiments are shown.

[0114] In some embodiments, the exemplary method may further include the operation of block 910, wherein the exposure function may receive an EE subscription request from an application function (AF) or application server (AS) associated with the communication network in response to a UE-related notification received from the communication network. In this case, sending the first EE subscription request in block 920 is a response to receiving the EE subscription request from the AF or AS in block 910.

[0115] In some embodiments, selectively sending a second EE subscription request to a second data management function in block 940 includes the following operations, marked with the corresponding sub-block number: (941) When the first indication indicates that an EE subscription for a notification related to the UE has not been successfully created in the second core network, a second EE subscription request is sent to the second data management function; and (942) When the first indication indicates that an EE subscription for a notification related to the UE has been successfully created in the second core network, avoid sending a second EE subscription request to the second data management function.

[0116] In some embodiments, the second indication is the 5G_USER_DOES_NOT_EXIST application error code. In some embodiments, the first indication indicates that an EE subscription for notifications related to the UE was not successfully created in the second core network based on the USER_NOT_FOUND application error code.

[0117] In some embodiments, the first core network is a 5G core network (5GC), the second core network is a 4G evolved packet core network (EPC), the exposure function is a network exposure function (NEF) or a service capability exposure function (SCEF), the first data management function is a unified data management (UDM) function, and the second data management function is a home subscriber server (HSS).

[0118] also, Figure 10 A flowchart is shown of an exemplary method (e.g., process) for a first data management function according to various embodiments of the present disclosure, the first data management function being configured to operate in a first core network (e.g., 5GC) of a communication network that also includes a second core network (e.g., EPC). For example, the exemplary method may be performed by a UDM, as described elsewhere herein.

[0119] An exemplary method may include the operation of block 1010, wherein a first data management function may receive a first EE subscription request for a UE-related notification from a first core network from an exposure function of a communication network. The first EE subscription request includes an indication of a corresponding EE subscription for a UE-related notification from a second core network. The exemplary method also includes the operation of block 1020, wherein the first data management function may determine that a subscription for the UE does not exist in the first core network. The exemplary method further includes the operation of block 1030, wherein the first data management function may determine the following: Regarding whether user subscription data for the second core network can be accessed by the first data management function, and If access is determined, determine whether the user subscription data for the second core network includes subscriptions for the UE; The exemplary method also includes the operation of box 1040, wherein the first data management function may, in response to each of the following conditions, attempt to create an EE subscription for a UE-related notification from the second core network, based on a first EE subscription request: User subscription data for the second core network includes subscriptions for UEs; and The first data management function cannot determine whether user subscription data for the second core network includes subscriptions for the UE.

[0120] The exemplary method also includes the operation of box 1050, wherein the first data management function can send a first EE subscription response to the exposure function, the first EE subscription response including the following: In the second core network, was the first instruction for the EE subscription to notifications related to the UE successfully created? The second instruction indicates that the subscription for the UE does not exist in the first core network.

[0121] In some embodiments, attempting to create an EE subscription for a UE-related notification from the second core network in box 1040 includes the following operations, which are marked with the corresponding sub-box numbers: (1041) Send a second EE subscription request to the second data management function of the second core network for notifications related to the UE from the second core network; and (1042) Receive a second EE subscription response from the second data management function, the response including a first indication of whether an EE subscription for a notification related to the UE has been successfully created in the second core network.

[0122] The first EE subscription response is based on the second EE subscription response.

[0123] In some of these embodiments, the first indication indicates that an EE subscription for notifications related to the UE has been successfully created in the second core network. In some variations of these embodiments, the first and second EE subscription requests include an indication of a first event for which the state needs to be monitored synchronously between the first and second data management functions. In some further variations, the first event is one of the following: a UE roaming state change event, or a UE IMEI (SV) / PEI change event.

[0124] In some further variations, the first EE subscription request also includes an indication for immediate event reporting. When the first indication indicates that an EE subscription for a notification related to the UE has been successfully created in the second core network, the first EE subscription response also includes a monitoring report for the first event, in accordance with the immediate event reporting indication. Figure 8 Examples of these variations are shown.

[0125] In some further variations, the exemplary method may also include the operations of blocks 1060-1070. In block 1060, when a first indication indicates that an EE subscription for a notification related to the UE has been successfully created in the second core network, the first data management function can then receive a first EE notification from the second data management function including the following: Another first instruction for EE subscriptions related to UE notifications was successfully created in the second core network, and Monitoring reports on the first incident; and In box 770, the first data management function can send a second EE notification to the exposure function, which includes another first instruction and a monitoring report.

[0126] In some embodiments, the second indication is the 5G_USER_DOES_NOT_EXIST application error code. In some embodiments, the first indication indicates that an EE subscription for notifications related to the UE was not successfully created in the second core network based on the USER_NOT_FOUND application error code.

[0127] In some embodiments, determining in block 1030 whether user subscription data for the second core network is accessible by the first data management function includes the operation in sub-block 1031, wherein the first data management function may determine, based on configuration flags, whether the user subscription repository of the second core network is merged with the user subscription repository of the first core network accessible by the first data management function.

[0128] In some embodiments, the first core network is a 5G core network (5GC), the second core network is a 4G evolved packet core network (EPC), the exposure function is a network exposure function (NEF) or a service capability exposure function (SCEF), and the first data management function is a unified data management (UDM) function.

[0129] also, Figure 11A flowchart illustrating an exemplary method (e.g., process) for a second data management function according to various embodiments of the present disclosure is shown. This function is configured to operate in a second core network (e.g., EPC) that also includes a first core network (e.g., 5GC). For example, this exemplary method may be performed by an HSS, as described elsewhere herein.

[0130] An exemplary method includes the operation at box 1110, wherein a second data management function can receive a second EE subscription request for a UE-related notification from a second core network from a first data management function of a first core network. The subscription for the UE does not exist in the first core network. The exemplary method also includes the operation at box 1130, wherein the second data management function can attempt to create an EE subscription for the UE-related notification from the second core network based on the second EE subscription request. The exemplary method may further include the operation at box 1150, wherein the second data management function can send a second EE subscription response to the first data management function, the second EE subscription response including a first indication of whether an EE subscription for the UE-related notification has been successfully created in the second core network.

[0131] In some embodiments, the first indication indicates that an EE subscription for notifications related to the UE has been successfully created in the second core network. In some of these embodiments, the second EE subscription request includes an indication of a first event for which state monitoring needs to be synchronized between the first and second data management functions. In some variations of these embodiments, the first event is one of the following: a UE roaming state change event, or a UE IMEI (SV) / PEI change event.

[0132] In some variations of these embodiments, the second EE subscription request also includes an indication for immediate event reporting, and the exemplary method further includes the operation of block 1140, wherein the second data management function may detect the first event after successfully creating an EE subscription for a notification related to the UE in the second core network. In this case, the second EE subscription response, according to the indication for immediate event reporting, also includes a monitoring report for the detected first event. Figure 8 Examples of these variations are shown.

[0133] In some variations of these embodiments, the exemplary method also includes the following operations marked with the corresponding box numbers: (1160) Detect a first event after sending a second EE subscription response including a first indication that an EE subscription for a notification related to the UE has been successfully created in the second core network; and (1170) Send a first EE notification to the first data management function, the first EE notification including the following: another first indication that an EE subscription for a notification related to the UE has been successfully created in the second core network, and a monitoring report for a detected first event.

[0134] In some embodiments, the exemplary method may further include the operation of block 1120, wherein the second data management function can determine whether a subscription for the UE exists in the second core network. In these embodiments, in block 1130, attempting to create an EE subscription for a notification from the second core network is based on the determination in block 1120 that the subscription for the UE exists in the second core network. In some embodiments, when it is determined that the subscription for the UE does not exist in the second core network, a first indication indicates that an error code based on USER_NOT_FOUND has been applied, and the EE subscription for the notification related to the UE was not successfully created in the second core network.

[0135] In some embodiments, the first data management function cannot determine whether user subscription data for the second core network includes subscriptions for the UE. In other embodiments, user subscription data for the second core network can be accessed by the first data management function and includes subscriptions for the UE.

[0136] In some embodiments, the first core network is a 5G core network (5GC), the second core network is a 4G evolved packet core network (EPC), the first data management function is a unified data management (UDM) function, and the second data management function is a home subscriber server (HSS).

[0137] Figure 12 Signaling diagrams illustrating the processes between AS / SCS / AF (1210), SCEF / NF (1220), UDM (1230) in 5GC, and HSS (1240) in EPC according to some embodiments of this disclosure are shown. 5GC and EPC are part of the same operator network (e.g., a "dual-core" network). In this example, the UE of interest does not store a 4G subscription in the HSS, nor a 5G subscription in the UDM.

[0138] Operations 1-2 are similar to those described above. Figure 3-5The corresponding operation in step 3. In step 3, the UDM sends an Nnef_EventExposure_Subscribe response containing information indicating that this UE has neither a 4G subscription nor a 5G subscription. In some embodiments, this information may be included separately from the UE_NOT_FOUND indicator, for example, via an application error code such as 4G_5G_USER_DOES_NOT_EXIST. In some embodiments, this information may be included as part of the ProblemDetails field, which would allow backward compatibility with existing fields. In other embodiments, this information may be part of a new error field added to the response message. In other embodiments, this information may be an existing USER_NOT_FOUND application error indicator, which may be clarified or expanded to indicate this new information.

[0139] Based on the response in Operation 3, the SCEF / NEF knows that the UE does not have a 4G subscription in the HSS, and therefore avoids sending a second subscription request to the HSS. In Operation 4, the SCEF / NEF sends an Nnef_EventExposure_Subscribe response to the AS / SCS / AF, which contains information indicating that this UE does not have either a 4G or 5G subscription. For example, this information can be indicated by an application error code (such as 4G_5G_USER_DOES_NOT_EXIST), which can be added to Table 5.3.5.3-1 of 3GPP TS 29.122 (v18.2.0), as shown below. This table defines application errors defined for the MonitoringEvent Application Programming Interface (API). Alternatively, existing application errors defined in this table can be clarified and / or redefined to indicate that this UE does not have either a 4G or 5G subscription.

[0140] Figure 13 A signaling diagram illustrating another process between AS / SCS / AF (1210), SCEF / NF (1220), UDM (1230) in 5GC, and HSS (1240) in EPC, according to other embodiments of this disclosure, is shown. 5GC and EPC are part of the same operator network (e.g., a "dual-core" network). In this example, the UE of interest stores a 4G subscription in the HSS but not a 5G subscription in the UDM.

[0141] Operations 1-2 are similar to those described above. Figure 3-5 The corresponding operation is as follows. In operation 3, the UDM sends an Nnef_EventExposure_Subscribe response, which contains information indicating that this UE has a 4G subscription but not a 5G subscription.

[0142] In some embodiments, this information may be indicated by corresponding application error codes, such as 4G_USER_EXISTS and 5G_USER_DOES_NOT_EXISTS. In other embodiments, this information may be indicated only by the application error code 4G_USER_EXISTS, where the indication that the UE does not have a 5G subscription is implicit. In other embodiments, when only the application error code 4G_USER_EXISTS is included, this indicates that the UDM cannot identify whether the UE has a 5G subscription.

[0143] In other embodiments, this information may be indicated by the existing application error code UE_NOT_FOUND, which, in conjunction with the above, Figure 12 The error code 4G_5G_USER_DOES_NOT_EXIST is explained in the discussion. In other words, since 4G_5G_USER_DOES_NOT_EXIST is used to indicate that this UE has neither a 4G subscription nor a 5G subscription, the existing USER_NOT_FOUND indicates a different condition where a 4G subscription exists but a 5G subscription does not.

[0144] In some embodiments, this information may be included as part of the ProblemDetails field, which would allow for backward compatibility with existing fields. In other embodiments, the information may be part of a new error field added to the response message. In still other embodiments, the information may be an existing USER_NOT_FOUND application error indicator, which may be clarified or expanded to indicate this new information.

[0145] Based on the response in Operation 3, SCEF / NEF knows that the UE has a 4G subscription in HSS, so it can send a second subscription request to HSS for the EE notification.

[0146] Figure 14 A signaling diagram illustrating another process between AS / SCS / AF (1210), SCEF / NF (1220), UDM (1230) in 5GC, and HSS (1240) in EPC, according to other embodiments of this disclosure, is shown. 5GC and EPC are part of the same operator network (e.g., a "dual-core" network). In this example, the UE of interest stores a 5G subscription in the UDM but not a 4G subscription in the HSS.

[0147] Operations 1-2 are similar to those described above. Figure 3-5The corresponding operation is as follows. In operation 3, the UDM sends an Nnef_EventExposure_Subscribe response to indicate that the EE subscription was successful in 5G, sends the "epcStatusInd=false" flag to indicate that the EE subscription was not successfully created in 4G, and sends a message indicating that this UE does not have a 4G subscription.

[0148] Based on the response in Operation 3, the SCEF / NEF knows that the UE does not have a 4G subscription in the HSS, and therefore avoids sending a second subscription request to the HSS. In some embodiments, the SCEF / NEF may send an Nnef_EventExposure_Subscribe response to the AS / SSC / AF, which contains information indicating that the UE does not have a 4G subscription.

[0149] The embodiments described above can be referred to. Figure 15-16 To further explain, Figure 15-16 Exemplary methods (e.g., processes) performed by the exposure function and the first data management function are illustrated respectively. In other words, various features of the operations described below correspond to the various embodiments described above. These exemplary methods can be used in combination to provide various exemplary benefits and / or advantages. Although Figure 15-16 Specific boxes are shown in a particular order, but the operations of the corresponding methods may be performed in a different order than shown, and may be combined and / or divided into boxes with functions different from those shown. Optional boxes or operations are indicated by dashed lines.

[0150] Specifically, Figure 15 A flowchart is shown of an exemplary method (e.g., process) for exposing functionality according to various embodiments of the present disclosure, the exposed functionality being configured to operate in a communication network including a first core network and a second core network. For example, the exemplary method may be performed by NEF, SCEF, or a combination thereof, as described elsewhere herein.

[0151] The exemplary method includes the operation at box 1520, wherein the exposure function may send a first event exposure (EE) subscription request for a UE-related notification from the first core network to a first data management function of the first core network. The first EE subscription request includes an indication of a corresponding EE subscription for a UE-related notification from a second core network. The exemplary method also includes the operation at box 1530, wherein the exposure function may receive a first EE subscription response from the first data management function, the response including the following: Whether the first instruction for the EE subscription to notifications related to the UE was successfully created in the first core network, and Whether the UE's subscription exists in the second core network is indicated by a second instruction; and The exemplary method also includes the operation of block 1540, wherein, based on the second instruction, the exposure function may selectively send a second EE subscription request to the second data management function for UE-related notifications from the second core network.

[0152] In some embodiments, when the first indication indicates that an EE subscription for a notification related to the UE was not successfully created in the first core network, the first EE subscription response further includes another second indication regarding whether the UE's subscription exists in the first core network. In some embodiments of these embodiments, when the other second indication indicates that the UE's subscription does not exist in the first core network, one of the following applies: The second indication and another second indication are a single indication that the UE does not have a subscription in the first core network or the second core network (e.g., such as...). Figure 12 (as shown); or The second instruction and the other second instruction are separate instructions.

[0153] In some of these embodiments, the exemplary method may also include the operation of block 1510, wherein the exposure function may receive an EE subscription request for a UE-related notification from the communication network from an application function (AF) or application server (AS) associated with the communication network. In this case, sending the first EE subscription request in block 1520 is a response to receiving the EE subscription request from the AF or AS in block 1510.

[0154] In some variations of these embodiments, the exemplary method may also include the operation of block 1550, wherein when a second indication indicates that the UE’s subscription does not exist in a second core network and another second indication indicates that the UE’s subscription does not exist in a first core network, the exposure function may send an EE subscription response to the AF or AS, the EE subscription response indicating that the subscription for the UE does not exist in the communication network.

[0155] In some embodiments, selectively sending a second EE subscription request to a second data management function in block 1540 includes the following operations, which are marked with corresponding sub-block numbers: (1541) When the second indication indicates that a subscription for the UE exists in the second core network, a second EE subscription request is sent to the second data management function; and (1542) When the second indication indicates that there is no subscription for the UE in the second core network, avoid sending the second EE subscription request to the second data management function.

[0156] In some embodiments, the first core network is a 5G core network (5GC), the second core network is a 4G evolved packet core network (EPC), the exposure function is a network exposure function (NEF) or a service capability exposure function (SCEF), the first data management function is a unified data management (UDM) function, and the second data management function is a home subscriber server (HSS).

[0157] In some of these embodiments, the second indication is one of the following application error codes: 4G_5G_USER_DOES_NOT_EXIST (e.g., as...). Figure 12 As shown), 4G_USER_EXISTS (for example, as shown) Figure 13 (as shown) or 4G_USER_DOES_NOT_EXIIST (for example, as shown) Figure 14 (As shown). In some of these embodiments, the first indication that an EE subscription for a notification related to the UE was not successfully created in the first core network is the UE_NOT_FOUND application error code.

[0158] also, Figure 16 A flowchart is shown of an exemplary method (e.g., process) for a first data management function according to various embodiments of the present disclosure, the first data management function being configured to operate in a first core network (e.g., 5GC) of a communication network, which also includes a second core network (e.g., EPC). For example, the exemplary method may be performed by a UDM, as described elsewhere herein.

[0159] An exemplary method includes the operation of box 1610, wherein a first data management function can receive a first EE subscription request for a UE-related notification from a first core network from an exposure function of a communication network. The first EE subscription request includes an indication of a corresponding EE subscription for a UE-related notification from a second core network. The exemplary method also includes the operation of box 1620, wherein the first data management function can determine whether a subscription for the UE exists in the first core network and whether a subscription for the UE exists in the second core network. The exemplary method further includes the operation of box 1630, wherein when it is determined that a subscription for the UE exists in the first core network, the first data management function can attempt to create an EE subscription for the UE-related notification from the first core network based on the first EE subscription request. The exemplary method also includes the operation of box 1640, wherein the first data management function can send a first EE subscription response to an exposure function, the first EE subscription response including the following: Whether the first instruction for the EE subscription to notifications related to the UE was successfully created in the first core network, and A second indication of whether the UE's subscription exists in the second core network.

[0160] In some embodiments, when the first indication indicates that an EE subscription for a notification related to the UE was not successfully created in the first core network, the first EE subscription response further includes another second indication regarding whether the UE's subscription exists in the first core network. In some embodiments of these embodiments, when the other second indication indicates that the UE's subscription does not exist in the first core network, one of the following applies: The second indication and another second indication are a single indication that the UE does not have a subscription in the first core network or the second core network (e.g., such as...). Figure 12 (as shown); or The second instruction and the other second instruction are separate instructions.

[0161] In some embodiments, the first core network is a 5G core network (5GC), the second core network is a 4G evolved packet core network (EPC), the exposure function is a network exposure function (NEF) or a service capability exposure function (SCEF), the first data management function is a unified data management (UDM) function, and the second data management function is a home subscriber server (HSS).

[0162] In some of these embodiments, the second indication is one of the following application error codes: 4G_5G_USER_DOES_NOT_EXIST (e.g., as...). Figure 12 As shown), 4G_USER_EXISTS (for example, as shown) Figure 13 (as shown) or 4G_USER_DOES_NOT_EXIIST (for example, as shown) Figure 14 (As shown). In some of these embodiments, the first indication that an EE subscription for a notification related to the UE was not successfully created in the first core network is the UE_NOT_FOUND application error code.

[0163] exist Figure 15-16 In this context, it should be understood that although a first data management function (e.g., UDM) belongs to, is associated with, or is included in a first core network (e.g., 5GC), this does not limit its interaction with a second core network (e.g., EPC), such as through a second data management function (e.g., HSS). Similarly, it should be understood that although a second data management function belongs to, is associated with, or is included in a second core network, this does not limit its interaction with a first core network, such as through a first data management function.

[0164] Although various embodiments have been described above in relation to methods, apparatuses, devices, computer-readable media, and receivers, those skilled in the art will readily understand that these methods can be implemented by various combinations of hardware and software in various systems, communication devices, computing devices, control devices, apparatuses, non-transitory computer-readable media, etc.

[0165] Figure 17 An example of a communication system 1700 according to some embodiments is shown. In this example, the communication system 1700 includes a telecommunications network 1702 and a core network 1706. The telecommunications network 1702 includes an access network 1704, such as a RAN, and the core network 1706 includes one or more core network nodes 1708. The access network 1704 includes one or more access network nodes, such as network nodes 1710a-b (one or more of which may generally be referred to as network node 1710), or any other similar 3GPP access node or non-3GPP access point. Furthermore, as those skilled in the art will understand, network nodes are not necessarily limited to implementations in which the radio portion and the baseband portion are provided and integrated by a single vendor. Therefore, it is understood that network nodes include decomposed implementations or portions thereof. For example, in some embodiments, the telecommunications network 1702 includes one or more Open RAN (ORAN) network nodes. An ORAN network node is a node in telecommunications network 1702 that supports ORAN specifications (e.g., specifications published by the O-RAN Alliance or any similar organization) and can operate alone or with other nodes to perform one or more functions of any node in telecommunications network 1702 (including one or more network nodes 1710 and / or core network node 1708).

[0166] Examples of ORAN network nodes include Open Radio Units (O-RUs), Open Distributed Units (O-DUs), Open Central Units (O-CUs) (including O-CU Control Plane (O-CU-CP) or O-CU User Plane (O-CU-UP)), RAN Intelligent Controllers (near real-time or non-real-time) that host software or software plugins (such as near real-time control applications (e.g., xApp) or non-real-time control applications (e.g., rApp)), or any combination thereof (the adjective "open" indicates support for the ORAN specification). Network nodes can support the specification by, for example, supporting interfaces defined by the ORAN specification (e.g., A1, F1, W1, E1, E2, X2, Xn interfaces, Open Fronthaul User Plane Interface, or Open Fronthaul Management Plane Interface). Furthermore, ORAN access nodes can be logical nodes within physical nodes. Additionally, ORAN network nodes can be implemented in a virtualized environment (described further below) where one or more network functions are virtualized. For example, a virtualized environment may include an O-Cloud computing platform orchestrated by a service management and orchestration framework using the O-2 interface or similar technologies defined by the O-RAN Consortium. Network node 1710 facilitates direct or indirect connections for UEs, such as connecting UEs 1712a-d (one or more of which may generally be referred to as UE 1712) to core network 1706 via one or more wireless connections.

[0167] Examples of wireless communication via wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for transmitting information without the use of wires, cables, or other conductors. Furthermore, in various embodiments, communication system 1700 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that can facilitate or participate in the communication of data and / or signals, whether via wired or wireless connections. Communication system 1700 may include any type of communication, telecommunications, data, cellular, radio network, and / or other similar system and / or be connected to any type of communication, telecommunications, data, cellular, radio network, and / or other similar system via an interface.

[0168] UE 1712 can be any communication device of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with network node 1710 and other communication devices. Similarly, network node 1710 is arranged, capable, configured, and / or operable to communicate directly or indirectly with UE 1712 and / or with other network nodes or devices in telecommunication network 1702 to enable and / or provide network access (such as wireless network access) and / or to perform other functions (such as management in telecommunication network 1702).

[0169] In the depicted example, core network 1706 connects network node 1710 to one or more hosts (such as host 1716). These connections may be direct or indirect, via one or more intermediate networks or devices. In other examples, network nodes may be directly coupled to hosts. Core network 1706 includes one or more core network nodes (e.g., 1708) constructed from hardware and software components. The characteristics of these components may be substantially similar to those described with respect to UEs, network nodes, and / or hosts, such that the description generally applies to the corresponding components of core network node 1708. Example core network nodes include functions of one or more of the following: Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier Dehiding Function (SIDF), Unified Data Management (UDM), Secure Edge Protection Agent (SEPP), Network Exposure Function (NEF), and / or User Plane Function (UPF).

[0170] Host 1716 may be owned or controlled by a service provider other than the operator or provider of telecommunications network 1702 and / or access network 1704, and may be operated by or on behalf of the service provider. Host 1716 may host various applications to provide one or more services. Examples of such applications include: live and pre-recorded audio / video content, data collection services (such as retrieving and compiling data on various environmental conditions detected by multiple UEs), analytics functions, social media, functions for controlling or otherwise interacting with remote devices, functions for alarm and monitoring centers, or any other such functions performed by the server.

[0171] on the whole, Figure 17 The 1700 communication system enables connectivity between UEs, network nodes, and hosts. In that sense, the communication system can be configured to operate according to predefined rules or procedures, such as specific standards, including but not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable next-generation standard (e.g., 6G); Wireless Local Area Network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard (WiFi); and / or any other suitable wireless communication standards, such as WiMax, Bluetooth, Z-Wave, Near Field Communication (NFC), ZigBee, LiFi, and / or any Low Power Wide Area Network (LPWAN) standards such as LoRa and Sigfox.

[0172] In some examples, telecommunications network 1702 is a cellular network implementing 3GPP standardized features. Therefore, telecommunications network 1702 can support network slicing to provide different logical networks to different devices connected to it. For example, telecommunications network 1702 can provide ultra-reliable low-latency communication (URLLC) services to some UEs while providing enhanced mobile broadband (eMBB) services to other UEs, and / or massive machine-type communication (mMTC) / massive IoT services to yet another UE.

[0173] In some examples, UE 1712 is configured to transmit and / or receive information without direct human interaction. For example, the UE may be designed to transmit information to access network 1704 on a predetermined schedule when triggered by internal or external events or in response to requests from access network 1704. Additionally, the UE may be configured to operate in single or multiple RAT or multi-standard modes. For example, the UE may operate with any or a combination of Wi-Fi, NR (New Radio), and LTE, i.e., configured for multiple radio dual connectivity (MR-DC), such as E-UTRAN (Evolved UMTS Terrestrial Radio Access Network) NR-Dual Connectivity (EN-DC).

[0174] In the example, hub 1714 communicates with access network 1704 to facilitate indirect communication between one or more UEs (e.g., UE 1712c and / or 1712d) and network nodes (e.g., network node 1710b). In some examples, hub 1714 may be a controller, router, content source, and analyzer, or any other communication device described herein with respect to a UE. For example, hub 1714 may be a broadband router for enabling access to core network 1706 for a UE. As another example, hub 1714 may be a controller that sends commands or instructions to one or more actuators in a UE. Commands or instructions may be received from the UE, network node 1710, or may be received via executable code, scripts, procedures, or other instructions in hub 1714. As another example, hub 1714 may be a data collector that acts as a temporary storage device for UE data, and in some embodiments, hub 1714 may perform data analysis or other processing. As another example, hub 1714 may be a content source. For example, for a UE that is a VR headset, display, speaker, or other media delivery device, hub 1714 can retrieve VR assets, video, audio, or other media or data related to sensory information via a network node. Hub 1714 then provides the VR assets, video, audio, or other media or data related to sensory information to the UE directly, after performing local processing, and / or after adding additional local content. In another example, hub 1714 acts as a proxy server or coordinator for the UE, particularly if one or more of the UEs are low-power IoT devices.

[0175] Hub 1714 may have a constant / persistent or intermittent connection to network node 1710b. Hub 1714 may also be designed with different communication schemes and / or scheduling between hub 1714 and UEs (e.g., UEs 1712c and / or 1712d) and between hub 1714 and core network 1706. In other examples, hub 1714 is connected to core network 1706 and / or one or more UEs via a wired connection. Furthermore, hub 1714 may be configured to connect to an M2M service provider via access network 1704 and / or to another UE via a direct connection. In some scenarios, a UE can establish a wireless connection to network node 1710 while still being connected via hub 1714, either via a wired or wireless connection. In some embodiments, hub 1714 may be a dedicated hub—that is, a hub whose primary function is to route communication from network node 1710b to UE / to network node 1710b. In other embodiments, hub 1714 may be a non-dedicated hub—that is, a device capable of operating to route communication between the UE and network node 1710b, but also capable of operating as a communication start and / or end point for certain data channels.

[0176] Figure 18 A network node 1800 according to some embodiments is shown. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, node Bs, eNBs, gNBs), and O-RAN nodes or components of O-RAN nodes (e.g., O-RUs, O-DUs, O-CUs).

[0177] Base stations can be classified based on the coverage they provide (or, in other words, their transmit power levels), and therefore, depending on the coverage provided, a base station can be referred to as a femtobase, picobase, microbase, or macrobase. A base station can be a relay node or a relay donor node controlling a relay. Network nodes can also include one or more (or all) portions of a distributed radio base station such as a centralized digital unit, a distributed unit (e.g., in an O-RAN access node), and / or a remote radio unit (RRU) sometimes referred to as a remote radio headend (RRH). Such a remote radio unit may or may not be integrated with an antenna as an antenna-integrated radio device. A portion of a distributed radio base station can also be referred to as a node in a distributed antenna system (DAS).

[0178] Other examples of network nodes include multi-transmission point (multi-TRP) 5G access nodes, MSR devices such as multi-standard radio (MSR) BS, network controllers such as radio network controller (RNC) or base station controller (BSC), base transceiver station (BTS), transmission point, transmission node, multi-cell / multicast coordination entity (MCE), operation and maintenance (O&M) node, operation support system (OSS) node, self-organizing network (SON) node, location node (e.g., evolved servicing mobile location center (E-SMLC)), and / or minimized drive test (MDT).

[0179] Network node 1800 includes processing circuitry 1802, memory 1804, communication interface 1806, and power supply 1808. Network node 1800 may consist of multiple physically separate components (e.g., node B components and RNC components, or BTS components and BSC components, etc.), each of which may have its own corresponding components. In some scenarios where network node 1800 includes multiple separate components (e.g., BTS and BSC components), one or more of these separate components may be shared among several network nodes. For example, a single RNC can control multiple node Bs. In such scenarios, each unique node B and RNC pair may be considered a single independent network node in some instances. In some embodiments, network node 1800 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 1804 for different RATs) and some components may be reused (e.g., the same antenna 1810 may be shared by different RATs). Network node 1800 may also include a collection of various described components for integrating into network node 1800, such as different wireless technologies like GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, RFID, or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chips or chipsets and other components within network node 1800.

[0180] Processing circuitry 1802 may include: a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field-programmable gate array or any other suitable computing device, resource, or combination of hardware, software and / or coding logic operable to provide network node 1800 functionality, either alone or in combination with other network node 1800 components such as memory 1804.

[0181] In some embodiments, the processing circuitry 1802 includes a system-on-a-chip (SOC). In some embodiments, the processing circuitry 1802 includes a radio frequency (RF) transceiver circuitry 1812 and / or a baseband processing circuitry 1814. In some embodiments, the RF transceiver circuitry 1812 and / or the baseband processing circuitry 1814 may be on separate chips (or chipsets), boards, or units such as radio units and digital units. In alternative embodiments, some or all of the RF transceiver circuitry 1812 and / or the baseband processing circuitry 1814 may be on the same chip or chipset, board, or unit.

[0182] Memory 1804 may include any form of volatile or non-volatile computer-readable memory, including, but not limited to, permanent storage devices, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (e.g., hard disks), removable storage media (e.g., flash drives, CDs, or DVDs), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory that stores information, data, and / or instructions that can be used by processing circuitry 1802. Memory 1804 may store any suitable instructions, data, or information, including applications, software, computer programs, and / or other instructions that can be executed by processing circuitry 1802 and utilized by network node 1800, including logic, rules, codes, tables, etc. (collected as computer program 1804a, which may be in the form of a computer program product). Memory 1804 may be used to store any calculations performed by processing circuitry 1802 and / or any data received via communication interface 1806. In some embodiments, the processing circuitry 1802 and the memory 1804 are integrated.

[0183] Communication interface 1806 is used in wired or wireless communication of signaling and / or data between network nodes, access networks, and / or UEs. As illustrated, communication interface 1806 includes one or more ports / terminals 1816 for transmitting data to and receiving data from the network, for example, via a wired connection. Communication interface 1806 also includes radio front-end circuitry 1818 that may be coupled to antenna 1810 or, in some embodiments, is part of antenna 1810. Radio front-end circuitry 1818 includes filter 1820 and amplifier 1822. Radio front-end circuitry 1818 may be connected to antenna 1810 and processing circuitry 1802. Radio front-end circuitry 1818 may be configured to modulate the signal transmitted between antenna 1810 and processing circuitry 1802. Radio front-end circuitry 1818 may receive digital data to be transmitted to other network nodes or UEs via a wireless connection. Radio front-end circuitry 1818 may use a combination of filter 1820 and / or amplifier 1822 to convert digital data into radio signals with appropriate channel and bandwidth parameters. Radio signals can then be transmitted via antenna 1810. Similarly, when receiving data, antenna 1810 can collect radio signals and then convert them into digital data via radio front-end circuitry 1818. The digital data can then be passed to processing circuitry 1802. In other embodiments, the communication interface may include different components and / or different combinations of components.

[0184] In some alternative embodiments, network node 1800 does not include a separate radio front-end circuitry 1818; instead, processing circuitry 1802 includes radio front-end circuitry and is connected to antenna 1810. Similarly, in some embodiments, all or some of the RF transceiver circuitry 1812 is part of communication interface 1806. In other embodiments, communication interface 1806 includes one or more ports or terminals 1816, radio front-end circuitry 1818, and RF transceiver circuitry 1812 as part of a radio unit (not shown), and communication interface 1806 communicates with baseband processing circuitry 1814, which is part of a digital unit (not shown).

[0185] Antenna 1810 may include one or more antennas or antenna arrays configured to transmit and / or receive wireless signals. Antenna 1810 may be coupled to radio front-end circuitry 1818 and may be any type of antenna capable of wirelessly transmitting and receiving data and / or signals. In some embodiments, antenna 1810 is decoupled from network node 1800 and may be connected to network node 1800 via an interface or port.

[0186] Antenna 1810, communication interface 1806, and / or processing circuitry 1802 can be configured to perform any receive operation and / or certain acquire operation described herein as being performed by a network node. Any information, data, and / or signals can be received from the UE, another network node, and / or any other network device. Similarly, antenna 1810, communication interface 1806, and / or processing circuitry 1802 can be configured to perform any transmit operation described herein as being performed by a network node. Any information, data, and / or signals can be transmitted to the UE, another network node, and / or any other network device.

[0187] Power supply 1808 provides power to the various components of network node 1800 in a form suitable for the respective components (e.g., at the voltage and current levels required by each respective component). Power supply 1808 may also include or be coupled to power management circuitry to power the components of network node 1800 for performing the functions described herein. For example, network node 1800 may be connectable to an external power source (e.g., mains or electrical outlet) via input circuitry or interface such as a cable, thereby supplying power to the power circuitry of power supply 1808. As another example, power supply 1808 may include a power source in the form of a battery or battery pack, connected to or integrated into the power circuitry. The battery can provide backup power in the event of an external power failure.

[0188] Embodiments of network node 1800 may include, except Figure 18 Additional components beyond those shown herein are used to provide certain aspects of the functionality of the network node, including any of the functions described herein and / or any functions necessary to support the topics described herein. For example, network node 1800 may include user interface devices for allowing information to be input to and output from network node 1800. This allows users to perform diagnostic, maintenance, repair, and other management functions for network node 1800.

[0189] Figure 19This is a block diagram illustrating a virtualization environment 1900 that can virtualize functionality implemented by some embodiments. In this context, virtualization means creating a virtual version of a device or apparatus that may include a virtualized hardware platform, storage devices, and networking resources. As used herein, virtualization can be applied to any apparatus or component thereof described herein and relates to the implementation of at least a portion of functionality as one or more virtual components. Some or all of the functionality described herein can be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 1900 hosted by one or more hardware nodes, such as hardware computing devices operating as network nodes, UEs, core network nodes, or hosts. Furthermore, in embodiments where virtual nodes do not require radio connectivity (e.g., core network nodes or hosts), the nodes can be fully virtualized. In some embodiments, the virtualization environment 1900 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a service management and orchestration framework via an O-2 interface.

[0190] Running application 1902 (which may alternatively be referred to as a software instance, virtual device, network function, virtual node, virtual network function, etc.) in virtualization environment 1900 to implement some of the features, functions and / or benefits of some embodiments disclosed herein.

[0191] Hardware 1904 includes processing circuitry, memory storing software and / or instructions executable by the hardware processing circuitry (collected and represented as computer program 1904a, which may be in the form of a computer program product), and / or other hardware devices as described herein, such as network interfaces, input / output interfaces, etc. The processing circuitry can execute software to instantiate one or more virtualization layers 1906 (also referred to as a hypervisor or virtual machine monitor (VMM)), provide VMs 1908a-b (one or more of which may be commonly referred to as VM 1908), and / or perform any functions, features, and / or benefits described in relation to some embodiments described herein. Virtualization layer 1906 can present a virtual operating platform to VM 1908 that appears to be networked hardware.

[0192] VM 1908 includes virtual processing, virtual memory, virtual networking or interfaces, and virtual storage devices, and can run through a corresponding virtualization layer 1906. Different embodiments of instances of virtual device 1902 can be implemented on one or more VMs 1908, and can be implemented in different ways. Hardware virtualization is referred to in some contexts as Network Functions Virtualization (NFV). NFV can be used to consolidate many types of network devices into industry-standard high-capacity server hardware, physical switches, and physical storage devices that can be located in data centers and customer premises.

[0193] In the context of NFV, each VM 1908 can be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each VM 1908, and the portion of the hardware 1904 that executes that VM—whether it's dedicated hardware for that VM and / or hardware shared by that VM with other VMs—forms an independent virtual network element. Still within the NFV context, the virtual network function is responsible for handling specific network functions running on one or more VMs 1908 above the hardware 1904 and corresponds to application 1902.

[0194] Hardware 1904 can be implemented in a standalone network node with general or specific components. Hardware 1904 can utilize virtualization to implement some functions. Alternatively, hardware 1904 can be part of a larger hardware cluster (e.g., in a data center or CPE), where many hardware nodes work together and are managed via management and orchestration function 1910, which in particular also oversees the lifecycle management of application 1902. In some embodiments, hardware 1904 is coupled to one or more radio units, each including one or more transmitters and one or more receivers that can be coupled to one or more antennas. The radio units can communicate directly with other hardware nodes via one or more suitable network interfaces and can be combined with virtual components to provide radio capabilities to virtual nodes, such as radio access nodes or base stations. In some embodiments, control system 1912 can be used to provide signaling; control system 1912 can alternatively be used for communication between hardware nodes and radio units.

[0195] The foregoing only illustrates the principles of this disclosure. In light of the teachings herein, those skilled in the art will understand various modifications and changes to the described embodiments. Therefore, it should be understood that those skilled in the art will be able to design numerous systems, apparatuses, and processes that, although not expressly shown or described herein, embody the principles of this disclosure and are thus within its spirit and scope. Those skilled in the art should understand that various exemplary embodiments can be used together and interchangeably.

[0196] As used herein, the term "unit" may have a conventional meaning in the field of electronic, electrical and / or electronic devices, and may include, for example, electrical and / or electronic circuits, devices, modules, processors, memories, logic solid-state and / or discrete devices, computer programs or instructions for performing corresponding tasks, processes, calculations, outputs and / or display functions, such as those described herein.

[0197] Any suitable steps, methods, features, functions, or benefits disclosed herein may be performed by one or more functional units or modules of one or more virtual devices. Each virtual device may include multiple such functional units. These functional units may be implemented by processing circuitry, which may include one or more microprocessors or microcontrollers, as well as other digital hardware, including digital signal processors (DSPs), application-specific digital logic, etc. The processing circuitry may be configured to execute program code stored in memory, which may include one or more types of memory, such as read-only memory (ROM), random access memory (RAM), cache, flash memory devices, optical storage devices, etc. The program code stored in memory includes program instructions for executing one or more telecommunications and / or data communication protocols, and instructions for executing one or more techniques described herein. In some implementations, according to one or more embodiments of this disclosure, the processing circuitry may be used to cause corresponding functional units to perform corresponding functions.

[0198] As described herein, devices and / or apparatuses may be represented by semiconductor chips, chipsets, or (hardware) modules including such chips or chipsets; however, this does not preclude the possibility that the functionality of a device or apparatus may be implemented as a software module (rather than a hardware implementation), such as a computer program or computer program product comprising executable software code portions for execution or execution on a processor. Furthermore, the functionality of a device or apparatus may be implemented by any combination of hardware and software. A device or apparatus may also be considered as a combination of multiple devices and / or apparatuses, whether functionally cooperative or independent. Moreover, devices and apparatuses can be implemented in a distributed manner throughout a system, provided that the functionality of the device or apparatus is preserved. These and similar principles are considered to be known to those skilled in the art.

[0199] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that the terms used herein shall be interpreted as having the same meaning as they have in this specification and the relevant technical context, and shall not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0200] Furthermore, some terms used in this disclosure, including the specification and drawings, may be used synonymously in certain circumstances ( For example (“data” and “information”). It should be understood that although these terms (and / or other terms that may be synonymous with each other) may be used synonymously in this document, in some cases these words may not be used synonymously.

[0201] The technologies and devices described herein include, but are not limited to, the following examples: A1. A method for exposing a function configured to operate in a communication network including a first core network and a second core network, the method comprising: Send a first event exposure (EE) subscription request to a first data management function of the first core network for a notification related to a user equipment (UE) from the first core network, wherein the first EE subscription request includes an indication of a corresponding EE subscription for a notification related to the UE from the second core network; The first EE subscription response is received from the first data management function, and the first EE subscription response includes the following: Whether a first indication was successfully created in the first core network for an EE subscription to a notification related to the UE, and A second indication regarding whether the UE's subscription exists in the second core network; and Based on the second instruction, a second EE subscription request for notifications related to the UE from the second core network is selectively sent to the second data management function.

[0202] A2. The method according to embodiment A1, wherein when the first indication indicates that an EE subscription for a notification related to the UE has not been successfully created in the first core network, the first EE subscription response further includes another second indication as to whether a subscription for the UE exists in the first core network.

[0203] A3. The method according to embodiment A2, wherein when the other second indication indicates that the UE's subscription does not exist in the first core network, one of the following applies: The second indication and the other second indication are a single indication that there is no subscription for the UE in the first core network or the second core network; or The second instruction and the other second instruction are separate instructions.

[0204] A4. The method according to any one of embodiments A2 to A3 further includes receiving an EE subscription request from an application function (AF) or application server (AS) associated with the communication network for a notification related to the UE from the communication network, wherein sending the first EE subscription request is a response to receiving the EE subscription request from the AF or the AS.

[0205] A5. The method according to embodiment A4 further includes: when the second indication indicates that the UE's subscription does not exist in the second core network, and the other second indication indicates that the UE does not have a subscription in the first core network, sending an EE subscription response to the AF or the AS to indicate that there is no subscription for the UE in the communication network.

[0206] A6. The method according to any one of embodiments A1 to A5, wherein selectively sending the second EE subscription request to the second data management function includes: When the second indication indicates that a subscription for the UE exists in the second core network, the second EE subscription request is sent to the second data management function; and When the second indication indicates that there is no subscription for the UE in the second core network, the second EE subscription request should not be sent to the second data management function.

[0207] A7. The method according to any one of embodiments A1 to A6, wherein: The first core network is the 5G core network (5GC). The second core network is the 4G Evolved Packet Core (EPC). The exposure function is either Network Exposure Function (NEF) or Service Capability Exposure Function (SCEF). The first data management function is the Unified Data Management (UDM) function; and The second data management function is the Home Subscriber Server (HSS).

[0208] A8. The method according to embodiment A7, wherein the second indication is one of the following application error codes: 4G_5G_USER_DOES_NOT_EXIST, 4G_USER_EXISTS, or 4G_USER_DOES_NOT_EXIST.

[0209] A9. The method according to any one of embodiments A7 to A8, wherein the first indication that an EE subscription for a notification related to the UE was not successfully created in the first core network is a UE_NOT_FOUND application error code.

[0210] B1. A method for a first data management function, the first data management function being configured to operate in a first core network of a communication network, the communication network further comprising a second core network, the method comprising: The first event exposure (EE) subscription request is received from the exposure function of the communication network for a notification related to a user equipment (UE) from the first core network, wherein the first EE subscription request includes an indication of a corresponding EE subscription for a notification related to the UE from the second core network; Determine whether the subscription for the UE exists in the first core network and whether the subscription for the UE exists in the second core network; When it is determined that a subscription for the UE exists in the first core network, based on the first EE subscription request, an attempt is made to create an EE subscription for notifications related to the UE from the first core network; and Send a first EE subscription response to the exposed function, the first EE subscription response including the following: Whether a first indication was successfully created in the first core network for an EE subscription to a notification related to the UE, and A second indication of whether the UE's subscription exists in the second core network.

[0211] B2. The method according to embodiment B1, wherein when the first indication indicates that an EE subscription for a notification related to the UE has not been successfully created in the first core network, the first EE subscription response further includes another second indication as to whether a subscription for the UE exists in the first core network.

[0212] B3. The method according to embodiment B2, wherein when the other second indication indicates that the UE's subscription does not exist in the first core network, one of the following applies: The second indication and the other second indication are a single indication that there is no subscription for the UE in the first core network or the second core network; or The second instruction and the other second instruction are separate instructions.

[0213] B4. The method according to any one of embodiments B1 to B3, wherein: The first core network is the 5G core network (5GC). The second core network is the 4G Evolved Packet Core (EPC). The exposure function is either Network Exposure Function (NEF) or Service Capability Exposure Function (SCEF). The first data management function is the Unified Data Management (UDM) function; and The second data management function is the Home Subscriber Server (HSS).

[0214] B5. The method according to embodiment B4, wherein the second indication is one of the following application error codes: 4G_5G_USER_DOES_NOT_EXIST, 4G_USER_EXISTS, or 4G_USER_DOES_NOT_EXIST.

[0215] B6. The method according to any one of embodiments B4 to B5, wherein the first indication that an EE subscription for a notification related to the UE was not successfully created in the first core network is a UE_NOT_FOUND application error code.

[0216] C1. An exposure function configured to operate in a communication network including a first core network and a second core network, said exposure function comprising: A communication interface circuit is configured to communicate with a first data management function, which is associated with the first core network; and A processing circuit is operatively coupled to the radio transceiver circuit, wherein the processing circuit and the radio receiver circuit are configured to perform operations corresponding to the method of any one of embodiments A1 to A9.

[0217] C2. An exposure function configured to operate in a communication network including a first core network and a second core network, the exposure function further configured to perform operations corresponding to the method of any one of embodiments A1 to A9.

[0218] C3. A non-transitory computer-readable medium storing computer-executable instructions, which, when executed by processing circuitry configured to operate in a communication network including a first core network and a second core network, configures the exposure function to perform operations corresponding to the method of any one of embodiments A1 to A9.

[0219] C4. A computer program product including computer-executable instructions, which, when executed by a processing circuitry configured to operate in a communication network including a first core network and a second core network, configures the exposure function to perform operations corresponding to the method of any one of embodiments A1 to A9.

[0220] D1. A first data management function configured to operate in a first core network of a communication network, the communication network further comprising a second core network, the first data management function comprising: A communication interface circuit is configured to communicate with the exposure function of the communication network and the second data management function of the second core network; and A processing circuit is operatively coupled to the communication interface circuit, wherein the processing circuit and the communication interface circuit are configured to perform operations corresponding to the method of any one of embodiments B1 to B6.

[0221] D2. A first data management function configured to operate in a first core network of a communication network that also includes a second core network, the first data management function being further configured to perform operations corresponding to the method of any one of embodiments B1 to B6.

[0222] D3. A non-transitory computer-readable medium storing computer-executable instructions, which, when executed by a processing circuit configured to operate in a first data management function within a first core network of a communication network including a second core network, configures the first data management function to perform operations corresponding to the method of any one of embodiments B1 to B6.

[0223] D4. A computer program product including computer-executable instructions, which, when executed by a processing circuit configured to operate in a first data management function within a first core network of a communication network including a second core network, configure the first data management function to perform an operation corresponding to the method of any one of embodiments B1 to B6.

[0224] E1. A method for exposing a function configured to operate in a communication network including a first core network and a second core network, the method comprising: Send a first event exposure (EE) subscription request to a first data management function of the first core network for a notification related to a user equipment (UE) from the first core network, wherein the first EE subscription request includes an indication of a corresponding EE subscription for a notification related to the UE from the second core network; The first EE subscription response is received from the first data management function, and the first EE subscription response includes the following: Whether a first indication was successfully created in the second core network for an EE subscription to a notification related to the UE, and A second indication that the UE's subscription does not exist in the first core network; and Based on the first instruction, a second EE subscription request for notifications related to the UE from the second core network is selectively sent to the second data management function.

[0225] E2. The method according to embodiment E1, wherein the first indication indicates that an EE subscription for a notification related to the UE has been successfully created in the second core network.

[0226] E3. The method according to embodiment E2, wherein the first EE subscription request includes an indication of a first event, for which the status needs to be monitored synchronously between the first data management function and the second data management function.

[0227] E4. The method according to embodiment E3, wherein the first event is one of the following events: UE roaming status change event, or UE IMEI (SV) / PEI change event.

[0228] E4a. The method according to any one of embodiments E3 to E4, wherein: The first EE subscription request also includes an indication for immediate event reporting; and When the first indication indicates that an EE subscription for a notification related to the UE has been successfully created in the second core network, the first EE subscription response, according to the indication in the instant event report, also includes a monitoring report for the first event.

[0229] E5. The method according to any one of embodiments E3 to E4a further includes, when the first indication indicates that an EE subscription for a notification related to the UE has been successfully created in the second core network, subsequently receiving an EE notification from the first data management function, the EE notification including the following: Another first indication for an EE subscription related to a notification associated with the UE was successfully created in the second core network, and Monitoring reports from the second core network regarding the first event.

[0230] E6. The method according to any one of embodiments E1 to E5 further includes receiving an EE subscription request from an application function (AF) or application server (AS) associated with the communication network for a notification related to the UE from the communication network, wherein sending the first EE subscription request is a response to receiving the EE subscription request from the AF or the AS.

[0231] E7. The method according to any one of embodiments E1 to E6, wherein selectively sending the second EE subscription request to the second data management function includes: When the first indication indicates that an EE subscription for a notification related to the UE has not been successfully created in the second core network, a second EE subscription request is sent to the second data management function; and When the first indication indicates that an EE subscription for a notification related to the UE has been successfully created in the second core network, the second EE subscription request should not be sent to the second data management function.

[0232] E8. The method according to any one of embodiments E1 to E7, wherein one or more of the following are applicable: The second indication is the 5G_USER_DOES_NOT_EXIST application error code; and The first indication indicates that an EE subscription for a notification related to the UE was not successfully created in the second core network based on the USER_NOT_FOUND application error code.

[0233] E9. The method according to any one of embodiments E1 to E8, wherein: The first core network is the 5G core network (5GC). The second core network is the 4G Evolved Packet Core (EPC). The exposure function is either Network Exposure Function (NEF) or Service Capability Exposure Function (SCEF). The first data management function is the Unified Data Management (UDM) function; and The second data management function is the Home Subscriber Server (HSS).

[0234] F1. A method for a first data management function, the first data management function being configured to operate in a first core network of a communication network, the communication network further comprising a second core network, the method comprising: The first event exposure (EE) subscription request is received from the exposure function of the communication network for a notification related to a user equipment (UE) from the first core network, wherein the first EE subscription request includes an indication of a corresponding EE subscription for a notification related to the UE from the second core network; It is determined that the subscription for the UE does not exist in the first core network; Confirm the following: Regarding whether user subscription data of the second core network can be accessed by the first data management function, and If it is determined to be accessible, then determine whether the user subscription data for the second core network includes subscriptions for the UE; In response to each of the following conditions, based on the first EE subscription request, attempt to create an EE subscription for notifications related to the UE from the second core network: The user subscription data for the second core network includes subscriptions for the UE; and The first data management function cannot determine whether the user subscription data for the second core network includes subscriptions for the UE; and Send a first EE subscription response to the exposed function, the first EE subscription response including the following: Whether a first indication was successfully created in the second core network for an EE subscription to a notification related to the UE, and A second indication that the UE's subscription does not exist in the first core network.

[0235] F2. The method according to embodiment F1, wherein attempting to create an EE subscription for a notification related to the UE from the second core network includes: Send a second EE subscription request to the second data management function of the second core network for notifications related to the UE from the second core network; and The second data management function receives a second EE subscription response, which includes a first indication of whether an EE subscription for a notification related to the UE has been successfully created in the second core network. The first EE subscription response is based on the second EE subscription response.

[0236] F3. The method according to embodiment F2, wherein the first indication indicates that an EE subscription for a notification related to the UE has been successfully created in the second core network.

[0237] F4. The method according to embodiment F3, wherein the first EE subscription request and the second EE subscription request include an indication of a first event, for which the status needs to be monitored synchronously between the first data management function and the second data management function.

[0238] F5. The method according to embodiment F4, wherein the first event is one of the following events: UE roaming status change event, or UE IMEI (SV) / PEI change event.

[0239] F5a. The method according to any one of embodiments F4 to F5, wherein: The first EE subscription request also includes an indication for immediate event reporting; and When the first indication indicates that an EE subscription for a notification related to the UE has been successfully created in the second core network, the first EE subscription response, according to the indication in the instant event report, also includes a monitoring report for the first event.

[0240] F6. The method according to any one of embodiments F4 to F5a further includes: When the first indication indicates that an EE subscription for a notification related to the UE has been successfully created in the second core network, a first EE notification including the following is subsequently received from the second data management function: Another first indication for the EE subscription of notifications related to the UE was successfully created in the second core network, and Monitoring report on the first event; and Send a second EE notification to the exposure function, including the other first indication and the monitoring report.

[0241] F7. The method according to any one of embodiments F1 to F6, wherein one or more of the following are applicable: The second indication is the 5G_USER_DOES_NOT_EXIST application error code; and The first indication indicates that an EE subscription for a notification related to the UE was not successfully created in the second core network based on the USER_NOT_FOUND application error code.

[0242] F8. The method according to any one of embodiments F1 to F7, wherein determining whether user subscription data for the second core network is accessible by the first data management function includes: determining, based on a configuration flag, whether the user subscription repository of the second core network is merged with the user subscription repository of the first core network, wherein the user subscription repository of the first core network is accessible by the first data management function.

[0243] F9. The method according to any one of embodiments F1 to F8, wherein: The first core network is the 5G core network (5GC). The second core network is the 4G Evolved Packet Core (EPC). The exposure function is either Network Exposure Function (NEF) or Service Capability Exposure Function (SCEF); and The first data management function is the Unified Data Management (UDM) function.

[0244] G1. A method for a second data management function configured to operate in a second core network of a communication network, the communication network further comprising a first core network, the method comprising: The system receives a second event exposure (EE) subscription request from a first data management function of the first core network for a notification related to a user equipment (UE) from the second core network, wherein there is no subscription for the UE in the first core network. Based on the second EE subscription request, attempt to create an EE subscription for notifications related to the UE from the second core network; and Send a second EE subscription response to the first data management function, the second EE subscription response including a first indication of whether an EE subscription for a notification related to the UE has been successfully created in the second core network.

[0245] G2. The method according to embodiment G1, wherein the first indication indicates that an EE subscription for a notification related to the UE has been successfully created in the second core network.

[0246] G3. The method according to embodiment G2, wherein the second EE subscription request includes an indication of a first event, for which the status needs to be monitored synchronously between the first data management function and the second data management function.

[0247] G4. The method according to embodiment G3, wherein the first event is one of the following events: UE roaming status change event, or UE IMEI (SV) / PEI change event.

[0248] G4a. The method according to any one of embodiments G3 to G4, wherein: The second EE subscription request also includes instructions for immediate event reporting; The method further includes detecting the first event after successfully creating an EE subscription for a notification related to the UE in the second core network; and The second EE subscription response also includes a monitoring report for the detected first event based on the instructions of the real-time event report.

[0249] G5. The method according to any one of embodiments G3 to G4a further includes: The first event is detected after sending the second EE subscription response, which includes a first indication indicating that an EE subscription for a notification related to the UE has been successfully created in the second core network; and Send a first EE notification to the first data management function, including the following: Another first indication for an EE subscription related to a notification associated with the UE was successfully created in the second core network, and A monitoring report on the first detected event.

[0250] G6. The method according to any one of embodiments G1 to G5 further includes determining whether a subscription for the UE exists in the second core network, wherein attempting to create the EE subscription for a notification from the second core network is based on determining that a subscription for the UE exists in the second core network. G7. The method according to embodiment G6, wherein when it is determined that the subscription for the UE does not exist in the second core network, the first indication indicates that an error code based on USER_NOT_FOUND has not been successfully created in the second core network for the EE subscription of the notification related to the UE.

[0251] G8. The method according to any one of embodiments G1 to G7, wherein one of the following applies: The first data management function cannot determine whether the user subscription data for the second core network includes subscriptions for the UE; or User subscription data for the second core network can be accessed by the first data management function, including subscriptions for the UE.

[0252] G9. The method according to any one of embodiments G1 to G8, wherein: The first core network is the 5G core network (5GC). The second core network is the 4G Evolved Packet Core (EPC). The first data management function is the Unified Data Management (UDM) function; and The second data management function is the Home Subscriber Server (HSS).

[0253] H1. An exposure function configured to operate in a communication network including a first core network and a second core network, the exposure function comprising: A communication interface circuit is configured to communicate with a first data management function, which is associated with the first core network; and A processing circuit operatively coupled to the radio transceiver circuit, wherein the processing circuit and the radio receiver circuit are configured to perform operations corresponding to the method of any one of embodiments E1 to E9.

[0254] H2. An exposure function configured to operate in a communication network including a first core network and a second core network, the exposure function further configured to perform operations corresponding to the method of any one of embodiments E1 to E9.

[0255] H3. A non-transitory computer-readable medium storing computer-executable instructions, which, when executed by a processing circuitry configured to operate in a communication network including a first core network and a second core network, configures the exposure function to perform operations corresponding to the method of any one of embodiments E1 to E9.

[0256] H4. A computer program product including computer-executable instructions, which, when executed by a processing circuitry configured to operate in a communication network including a first core network and a second core network, configures the exposure function to perform an operation corresponding to the method of any one of embodiments E1 to E9.

[0257] I1. A first data management function configured to operate in a first core network of a communication network, the communication network further comprising a second core network, the first data management function comprising: A communication interface circuit is configured to communicate with the exposure function of the communication network and the second data management function of the second core network; and A processing circuit is operatively coupled to the communication interface circuit, wherein the processing circuit and the communication interface circuit are configured to perform operations corresponding to the method of any one of embodiments F1 to F9.

[0258] I2. A first data management function configured to operate in a first core network of a communication network, the communication network further comprising a second core network, the first data management function being further configured to perform an operation corresponding to the method of any one of embodiments F1 to F9.

[0259] I3. A non-transitory computer-readable medium storing computer-executable instructions, which, when executed by a processing circuit configured to operate in a first data management function within a first core network of a communication network including a second core network, configures the first data management function to perform operations corresponding to the method of any one of embodiments F1 to F9.

[0260] I4. A computer program product including computer-executable instructions, which, when executed by a processing circuit configured to operate in a first data management function within a first core network of a communication network including a second core network, configure the first data management function to perform an operation corresponding to the method of any one of embodiments F1 to F9.

[0261] J1. A second data management function configured to operate in a second core network of a communication network, the communication network further comprising a first core network, the second data management function comprising: A communication interface circuit is configured to communicate with the exposure function of the communication network and the first data management function of the first core network; and A processing circuit operatively coupled to the communication interface circuit, wherein the processing circuit and the communication interface circuit are configured to perform operations corresponding to the method of any one of embodiments G1 to G9.

[0262] J2. A second data management function configured to operate in a second core network of a communication network, the communication network further comprising a first core network, the second data management function being further configured to perform operations corresponding to the method of any one of embodiments G1 to G9.

[0263] J3. A non-transitory computer-readable medium storing computer-executable instructions, which, when executed by a processing circuit configured to operate in a second data management function within a second core network including a first core network, configures the second data management function to perform operations corresponding to the method of any one of embodiments G1 to G9.

[0264] J4. A computer program product including computer-executable instructions, which, when executed by a processing circuitry configured to operate in a second data management function within a second core network including a first core network, configure the second data management function to perform an operation corresponding to the method of any one of embodiments G1 to G9.

Claims

1. A method for exposing a function, the exposed function being configured to operate in a communication network including a first core network and a second core network, the method comprising: Send (1520) a first event exposure EE subscription request to a first data management function of the first core network for a notification related to a user equipment (UE) from the first core network, wherein the first EE subscription request includes an indication of a corresponding EE subscription for a notification related to the UE from the second core network; Receive (1530) a first EE subscription response from the first data management function, the first EE subscription response including the following: Whether a first indication was successfully created in the first core network for an EE subscription to a notification related to the UE, and A second indication regarding whether the UE's subscription exists in the second core network; as well as Based on the second instruction, a second EE subscription request for notifications related to the UE from the second core network is selectively sent (1540) to the second data management function.

2. The method according to claim 1, wherein, When the first indication indicates that an EE subscription for a notification related to the UE has not been successfully created in the first core network, the first EE subscription response also includes a second indication as to whether a subscription for the UE exists in the first core network.

3. The method according to claim 2, wherein, When the other second indication indicates that the UE's subscription does not exist in the first core network, one of the following applies: The second indication and the other second indication are a single indication that there is no subscription for the UE in the first core network or the second core network; or The second instruction and the other second instruction are separate instructions.

4. The method according to any one of claims 2 to 3, further comprising receiving an EE subscription request from an application function AF or application server AS associated with the communication network for a notification related to the UE from the communication network, wherein sending the first EE subscription request is a response to receiving the EE subscription request from the AF or the AS.

5. The method according to claim 4, further comprising: When the second indication indicates that the UE's subscription does not exist in the second core network, and the other second indication indicates that the UE does not have a subscription in the first core network, an EE subscription response is sent to the AF or the AS to indicate that there is no subscription for the UE in the communication network.

6. The method according to any one of claims 1 to 5, wherein, Selectively sending the second EE subscription request to the second data management function includes: When the second indication indicates that a subscription for the UE exists in the second core network, the second EE subscription request is sent to the second data management function; and When the second indication indicates that there is no subscription for the UE in the second core network, the second EE subscription request should not be sent to the second data management function.

7. The method according to any one of claims 1 to 6, wherein: The first core network is the 5G core network 5GC; The second core network is the 4G evolved packet core network (EPC). The exposure function is either Network Exposure Function (NEF) or Service Capability Exposure Function (SCEF); The first data management function is the Unified Data Management (UDM) function; and The second data management function is the Home Subscriber Server (HSS).

8. The method according to claim 7, wherein, The second indication is one of the following application error codes: 4G_5G_USER_DOES_NOT_EXIST, 4G_USER_EXISTS, or 4G_USER_DOES_NOT_EXIST.

9. The method according to any one of claims 7 to 8, wherein, The first indication that an EE subscription for a notification related to the UE was not successfully created in the first core network is the UE_NOT_FOUND application error code.

10. A method for a first data management function, the first data management function being configured to operate in a first core network of a communication network, the communication network further comprising a second core network, the method comprising: The first event exposure EE subscription request is received (1610) from the exposure function of the communication network for a notification related to a user equipment (UE) from the first core network, wherein the first EE subscription request includes an indication of a corresponding EE subscription for a notification related to the UE from the second core network; Determine (1620) whether the subscription for the UE exists in the first core network and whether the subscription for the UE exists in the second core network; When it is determined that a subscription for the UE exists in the first core network, based on the first EE subscription request, an attempt is made (1630) to create an EE subscription for notifications related to the UE from the first core network; and Send a first EE subscription response (1640) to the exposure function, the first EE subscription response including the following: Whether a first indication was successfully created in the first core network for an EE subscription to a notification related to the UE, and A second indication of whether the UE's subscription exists in the second core network.

11. The method according to claim 10, wherein, When the first indication indicates that an EE subscription for a notification related to the UE has not been successfully created in the first core network, the first EE subscription response also includes a second indication as to whether a subscription for the UE exists in the first core network.

12. The method according to claim 11, wherein, When the other second indication indicates that the UE's subscription does not exist in the first core network, one of the following applies: The second indication and the other second indication are a single indication that there is no subscription for the UE in the first core network or the second core network; or The second instruction and the other second instruction are separate instructions.

13. The method according to any one of claims 10 to 12, wherein: The first core network is the 5G core network 5GC; The second core network is the 4G evolved packet core network (EPC). The exposure function is either Network Exposure Function (NEF) or Service Capability Exposure Function (SCEF); The first data management function is the Unified Data Management (UDM) function; and The second data management function is the Home Subscriber Server (HSS).

14. The method according to claim 13, wherein, The second indication is one of the following application error codes: 4G_5G_USER_DOES_NOT_EXIST, 4G_USER_EXISTS, or 4G_USER_DOES_NOT_EXIST.

15. The method according to any one of claims 13 to 14, wherein, The first indication that an EE subscription for a notification related to the UE was not successfully created in the first core network is the UE_NOT_FOUND application error code.

16. An exposure function configured to operate in a communication network including a first core network and a second core network, the exposure function comprising: A communication interface circuit is configured to communicate with a first data management function, which is associated with the first core network. as well as A processing circuit is operatively coupled to the radio transceiver circuit, wherein the processing circuit and the radio receiver circuit are configured to perform operations corresponding to the method of any one of claims 1 to 9.

17. An exposure function configured to operate in a communication network including a first core network and a second core network, said exposure function further configured to perform an operation corresponding to the method of any one of claims 1 to 9.

18. A non-transitory computer-readable medium storing computer-executable instructions, which, when executed by processing circuitry configured to operate in a communication network including a first core network and a second core network, configures the exposure function to perform operations corresponding to the method of any one of claims 1 to 9.

19. A computer program product including computer-executable instructions, which, when executed by a processing circuitry configured to operate in a communication network including a first core network and a second core network, configures the exposure function to perform an operation corresponding to the method of any one of claims 1 to 9.

20. A first data management function configured to operate in a first core network of a communication network, the communication network further comprising a second core network, the first data management function comprising: The communication interface circuit is configured to communicate with the exposure function of the communication network and the second data management function of the second core network; as well as A processing circuit operatively coupled to the communication interface circuit, wherein the processing circuit and the communication interface circuit are configured to perform operations corresponding to the method of any one of claims 10 to 15.

21. A first data management function configured to operate in a first core network of a communication network including a second core network, the first data management function further configured to perform operations corresponding to the method of any one of claims 10 to 15.

22. A non-transitory computer-readable medium storing computer-executable instructions, which, when executed by a processing circuit configured to operate in a first data management function within a first core network of a communication network including a second core network, configures the first data management function to perform operations corresponding to the method of any one of claims 10 to 15.

23. A computer program product including computer-executable instructions, which, when executed by a processing circuitry configured to operate in a first data management function within a first core network of a communication network including a second core network, configure the first data management function to perform an operation corresponding to the method of any one of claims 10 to 15.

24. A method for exposing a function, the exposed function being configured to operate in a communication network including a first core network and a second core network, the method comprising: Send (920) a first event exposure EE subscription request to a first data management function of the first core network for a notification related to a user equipment (UE) from the first core network, wherein the first EE subscription request includes an indication of a corresponding EE subscription for a notification related to the UE from the second core network; Receive (930) a first EE subscription response from the first data management function, the first EE subscription response including the following: Whether a first indication was successfully created in the second core network for an EE subscription to a notification related to the UE, and A second indication that the UE's subscription does not exist in the first core network; as well as Based on the first instruction, a second EE subscription request for notifications related to the UE from the second core network is selectively sent to the second data management function (940).

25. A method for a first data management function, the first data management function being configured to operate in a first core network of a communication network, the communication network further comprising a second core network, the method comprising: The first event exposure EE subscription request is received (1010) from the exposure function of the communication network for a notification related to a user equipment (UE) from the first core network, wherein the first EE subscription request includes an indication of a corresponding EE subscription for a notification related to the UE from the second core network; It is determined (1020) that the subscription for the UE does not exist in the first core network; Confirm (1030) the following content: Regarding whether user subscription data of the second core network can be accessed by the first data management function, and If it is determined to be accessible, then determine whether the user subscription data for the second core network includes subscriptions for the UE; In response to each of the following conditions, based on the first EE subscription request, attempt (1040) to create an EE subscription for notifications related to the UE from the second core network: The user subscription data for the second core network includes subscriptions for the UE; and The first data management function cannot determine whether the user subscription data for the second core network includes subscriptions for the UE; and Send a (1050) first EE subscription response to the exposure function, the first EE subscription response including the following: Whether a first indication was successfully created in the second core network for an EE subscription to a notification related to the UE, and A second indication that the UE's subscription does not exist in the first core network.

26. A method for a second data management function, the second data management function being configured to operate in a second core network of a communication network, the communication network further comprising a first core network, the method comprising: A second event exposure EE subscription request is received (1110) from the first data management function of the first core network for a notification related to a user equipment (UE) from the second core network, wherein there is no subscription for the UE in the first core network; Based on the second EE subscription request, attempt (1130) to create an EE subscription for notifications related to the UE from the second core network; and Send a second EE subscription response (1150) to the first data management function, the second EE subscription response including a first indication of whether an EE subscription for a notification related to the UE has been successfully created in the second core network.

27. An exposure function configured to operate in a communication network including a first core network and a second core network, the exposure function comprising: A communication interface circuit is configured to communicate with a first data management function, which is associated with the first core network. as well as A processing circuit operatively coupled to the radio transceiver circuit, wherein the processing circuit and the radio receiver circuit are configured to perform operations corresponding to the method of claim 24.

28. An exposure function configured to operate in a communication network including a first core network and a second core network, the exposure function further configured to perform operations corresponding to the method of claim 24.

29. A non-transitory computer-readable medium storing computer-executable instructions, which, when executed by processing circuitry configured to operate in a communication network including a first core network and a second core network, configures the exposure function to perform operations corresponding to the method of claim 24.

30. A computer program product including computer-executable instructions, which, when executed by a processing circuitry configured to operate in a communication network including a first core network and a second core network, configures the exposure function to perform operations corresponding to the method of claim 24.

31. A first data management function configured to operate in a first core network of a communication network, the communication network further comprising a second core network, the first data management function comprising: The communication interface circuit is configured to communicate with the exposure function of the communication network and the second data management function of the second core network; as well as A processing circuit operatively coupled to the communication interface circuit, wherein the processing circuit and the communication interface circuit are configured to perform operations corresponding to the method of claim 25.

32. A first data management function configured to operate in a first core network of a communication network, the communication network further comprising a second core network, the first data management function being further configured to perform an operation corresponding to the method of claim 25.

33. A non-transitory computer-readable medium storing computer-executable instructions, which, when executed by a processing circuit configured to operate in a first data management function within a first core network of a communication network including a second core network, configures the first data management function to perform operations corresponding to the method of claim 25.

34. A computer program product including computer-executable instructions, which, when executed by a processing circuit configured to operate in a first data management function within a first core network of a communication network including a second core network, configure the first data management function to perform an operation corresponding to the method of claim 25.

35. A second data management function configured to operate in a second core network of a communication network, the communication network further comprising a first core network, the second data management function comprising: The communication interface circuit is configured to communicate with the exposure function of the communication network and the first data management function of the first core network; as well as A processing circuit operatively coupled to the communication interface circuit, wherein the processing circuit and the communication interface circuit are configured to perform operations corresponding to the method of claim 26.

36. A second data management function configured to operate in a second core network of a communication network, the communication network further comprising a first core network, the second data management function being further configured to perform an operation corresponding to the method of claim 26.

37. A non-transitory computer-readable medium storing computer-executable instructions, which, when executed by a processing circuit configured to operate in a second data management function operating in a second core network including a first core network, configures the second data management function to perform operations corresponding to the method of claim 26.

38. A computer program product including computer-executable instructions, which, when executed by a processing circuitry configured to operate in a second data management function within a second core network including a first core network, configure the second data management function to perform an operation corresponding to the method of claim 26.

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