Method and apparatus for session management of terminal in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. The present disclosure relates to a method and an apparatus for supporting a terminal supporting simultaneous access to a plurality of wireless communication networks through 3GPP access to move a PDU session to another wireless communication network.

Description

Method and device for managing a terminal's session in a wireless communication system

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for supporting a terminal supporting simultaneous access to multiple wireless communication networks in a wireless communication system to move a PDU session to another wireless communication network.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

[0004] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0005] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0006] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] As a result of the development of wireless communication systems and the aforementioned advancements in technology, various services have become available, and methods for effectively providing these services are required. In particular, methods for managing sessions of terminals supporting simultaneous access to multiple communication networks are required.

[0009] The disclosed embodiment is intended to provide a device and method capable of effectively providing a service in a wireless communication system.

[0010] Based on the discussion as described above, the present disclosure provides a method for processing a control signal in a wireless communication system, which may include the steps of receiving a first control signal transmitted from a base station, processing the received first control signal, and transmitting a second control signal generated based on the processing to the base station.

[0011] The disclosed embodiment provides a device and method capable of effectively providing a service in a mobile communication system.

[0012] The effects that can be obtained from the present disclosure are not limited to the effects mentioned in the various embodiments, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0013] FIG. 1 is a diagram illustrating the structure of a wireless communication system in which terminals receive services through communication networks of different operators according to one embodiment of the present disclosure.

[0014] FIG. 2 is a diagram illustrating a procedure in which terminals according to one embodiment of the present disclosure simultaneously register with communication networks of different operators.

[0015] FIG. 3 is a diagram illustrating a procedure in which a terminal according to one embodiment of the present disclosure moves a PDU (protocol data unit) session created through one operator's communication network to another operator's communication network.

[0016] FIG. 4 is a diagram illustrating a procedure in which a terminal according to one embodiment of the present disclosure moves a PDU session created through one operator's communication network to another operator's communication network.

[0017] FIG. 5 is a diagram illustrating an example configuration of a network entity in a wireless communication system according to various embodiments of the present disclosure.

[0018] FIG. 6 is a diagram showing an example configuration of a base station in a wireless communication system according to various embodiments of the present disclosure.

[0019] FIG. 7 is a diagram showing an example configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure.

[0020] The operating principles of the present disclosure are described in detail below with reference to the attached drawings. In the following description of the present disclosure, detailed descriptions of related known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on the functions of the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0021] For the same reason, some components in the attached drawings are omitted or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect the actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0022] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. The various embodiments are provided to ensure that the disclosure is complete and to fully convey the scope of the disclosure to those skilled in the art, and the disclosure is defined solely by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0023] At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0024] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0025] The term "~unit" used in various embodiments of the present disclosure refers to a software or hardware component, and the "~unit" performs certain roles. However, the "~unit" is not limited to software or hardware. The "~unit" may be configured to reside on an addressable storage medium and may be configured to regenerate one or more processors. Thus, as an example, the "~unit" includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and "~units" may be combined into a smaller number of components and "~units" or further separated into additional components and "~units." In addition, the components and "~units" may be implemented to regenerate one or more CPUs within a device or a secure multimedia card. Additionally, in various embodiments of the present disclosure, '~bu' may include one or more processors.

[0026] In various embodiments of the present disclosure, a terminal may be referred to as a user equipment (UE), a terminal, a mobile station (MS), a cellular phone, a smartphone, a computer, or any other electronic device capable of performing a communication function.

[0027] Furthermore, the various embodiments of the present disclosure described below may be applied to other communication systems with similar technical backgrounds or channel configurations. Furthermore, the various embodiments of the present disclosure may be applied to other communication systems with some modifications, as determined by a person skilled in the art, without significantly departing from the scope of the present disclosure.

[0028] In specifically describing various embodiments of the present disclosure, the communication system may utilize a wireless communication system, for example, the 3rd Generation Partnership Project (3GPP), a wireless communication standard standardization organization, may utilize NR (New RAN), a wireless access network, and Packet Core (5G System, or 5G Core Network, or NG Core (Next Generation Core)), a core network, in the 5G communication standard. In addition, it may be applied to other communication systems with similar technical backgrounds with slight modifications within a range that does not significantly deviate from the scope of the present disclosure, and this will be possible at the discretion of a person skilled in the art of the present disclosure.

[0029] The terms used in the various embodiments of the present disclosure below to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network functions (NFs), terms referring to various identification information, etc. are provided for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

[0030] 5G systems support network slices, and traffic for different network slices can be processed by different protocol data unit (PDU) sessions. A PDU session may refer to an association between a data network providing a PDU connection service and a terminal. A network slice can be understood as a technology that logically configures a network as a set of Network Functions (NFs) (or network entities) to support various services with different characteristics, such as broadband communication services, massive IoT, and mission-critical services such as V2X, and separates different network slices. Therefore, even if a communication failure occurs in a network slice, the communication in other network slices is not affected, enabling the provision of stable communication services. In various embodiments of the present disclosure, “slice” may be used interchangeably with the term “network slice.” In such a network environment, a terminal may connect to multiple network slices when receiving various services. The NF may be a software instance running on hardware, or may be implemented as a network element or a virtualized function instantiated on an appropriate platform. Of course, it is not limited to the above examples, and NF may be composed of independent hardware or a combination of software and hardware.

[0031] Mobile operators can configure network slices and allocate network resources appropriate for specific services, either individually or across network slices. Network resources can include NFs, logical resources provided by NFs, or radio resources allocated by base stations.

[0032] For example, a mobile communication operator can configure network slice A to provide a mobile broadband service, network slice B to provide a vehicular communication service, and network slice C to provide an eXtended Reality (XR) service, which will be described later. That is, in this way, a 5G network can efficiently provide the corresponding service to a terminal through a network slice specialized according to the characteristics of each service. In a 5G system, a network slice can be represented by S-NSSAI (Single-Network Slice Selection Assistance Information). The S-NSSAI can include an SST (Slice / Service Type) value and an SD (Slice Differentiator) value. The SST can indicate the characteristics of the service supported by the network slice (e.g., enhanced mobile broadband (eMBB), IoT, URLLC (ultra reliability low latency communication), V2X, XR service, etc.). The SD can be a value used as an additional identifier for a specific service referred to as the SST.

[0033] Hereinafter, various embodiments of the present disclosure will be described with reference to the drawings.

[0034] According to the present disclosure, a terminal supporting simultaneous access to multiple wireless communication networks can simultaneously access wireless communication networks of different operators and register with each network. A method for enabling a terminal to create a PDU session through one wireless communication network and then move to a different operator's wireless communication network while maintaining its IP address can be described. For example, a method for supporting a terminal to select and move to a preferred operator's wireless communication network according to a service for which the terminal wishes to utilize the PDU session can be described based on a user's preference or a user policy set in the terminal.

[0035] More specifically, according to various embodiments of the present disclosure, a terminal can simultaneously access wireless communication networks of different operators, register with each communication network, and provide services by creating a PDU session through each registered network. In the above situation, a method may be provided for moving a PDU session to another communication network according to the terminal's situation, a user policy set in the terminal, or a user's preference. According to various embodiments of the present disclosure, a terminal can receive services without interruption even when moving, or a terminal can provide a better user experience through operations such as moving to a wireless communication network that provides a specific service at a lower cost.

[0036] FIG. 1 is a diagram illustrating the structure of a wireless communication system in which terminals receive services through communication networks of different operators according to one embodiment of the present disclosure.

[0037] Referring to FIG. 1, this is a diagram illustrating a structure in which a terminal accesses a 5G network and registers the network through two different 3GPP accesses based on one subscriber's information.

[0038] For example, FIG. 1 can be viewed as a situation in which a terminal registers with a 5G network through PLMN A of operator A and PLMN B of operator B (e.g., through 3GPP access) in a situation in which PLMN C of operator C is the home operator network to which the terminal is subscribed. In particular, at least two PLMNs among PLMN A, PLMN B, or PLMN C may be the same PLMN.

[0039] The network technology used in various embodiments of the present disclosure may refer to standard specifications defined by the International Telecommunication Union (ITU) or 3GPP (e.g., TS 23.501, TS 23.502, TS 23.503, etc.), and the components included in the network structure of Fig. 1 may each mean a physical entity, or may mean software performing an individual function, or hardware combined with software. Hereinafter, the components included in the network structure of Fig. 1 will be referred to as NFs.

[0040] Interfaces known in the 5G Core Network (5GC) can be used between NFs. Since the related description can be referred to the standard specification (TS 23.501), a detailed description will be omitted.

[0041] The wireless communication system of FIG. 1 may include an NG-RAN and a 5GC. The NG-RAN may be a base station (e.g., gNB, IAB (Integrated Access and Backhaul), etc.) that supports wireless access technology in a 5G system.

[0042] In Fig. 1, 5GC may include network entities such as AMF (Access and Mobility Management Function), SMF (Session Management Function), UPF (User Plane Function), PCF (Policy Control Function), and UDM (Unified Data Management).

[0043] According to one embodiment of the present disclosure, the AMF may be an entity for managing terminal access and mobility. For example, the AMF may perform network functions such as terminal registration, connection, reachability, mobility management, access verification, authentication, and mobility event generation. Of course, the present invention is not limited to the above examples.

[0044] According to one embodiment of the present disclosure, the SMF can perform management functions for the Protocol Data Unit (PDU) sessions of the terminal. For example, the SMF can perform network functions such as session management functions through the establishment, modification, and termination of sessions and the maintenance of tunnels between the UPF and the NG-RAN required for these functions; Internet Protocol (IP) address allocation and management functions for the terminal; user plane selection and control; traffic processing control in the UPF; and charging data collection control. Of course, the above examples are not limited thereto.

[0045] According to one embodiment of the present disclosure, the UPF may perform functions for processing user data of a terminal. For example, the UPF may perform network functions such as serving as an anchor between Radio Access Technologies (RATs), providing connections between PDU sessions and AF / AS, routing and forwarding packets, inspecting packets, applying user plane policies, generating traffic usage reports, and buffering. Of course, the present invention is not limited to the above examples.

[0046] According to one embodiment of the present disclosure, the UDM may perform functions such as generating authentication information for 3GPP security, processing user identifiers (IDs), managing a list of NFs supporting terminals, and managing subscription information. The Unified Data Repository (UDR) may perform functions such as storing and providing subscription information managed by the UDM, structured data for exposure, and application data associated with the Network Exposure Function (NEF) or services. Of course, the present invention is not limited to the above examples.

[0047] According to one embodiment of the present disclosure, the PCF can manage operator policy information for providing services in a 5G system. The UDR can store terminal subscription information and provide the stored subscription information to the UDM. Furthermore, the UDR can store operator policy information and provide the stored operator policy information to the PCF. Of course, the above examples are not limited to this example.

[0048] According to one embodiment of the present disclosure, the NEF can perform functions such as externally transmitting or receiving events occurring in the 5G system and supported capabilities. For example, the NEF can perform functions such as securely supplying AF / AS information to the 5GC, converting internal / external information, and storing and redistributing information received from other NFs in the UDR. Of course, the above examples are not limited to these functions.

[0049] According to one embodiment of the present disclosure, a terminal may connect to an NG-RAN and register with a 5G system. For example, the terminal may connect to the NG-RAN and perform a terminal registration procedure with the AMF. During the registration procedure, the AMF may determine a network slice available to the terminal connected to the NG-RAN and allocate it to the terminal. The terminal may select a network slice and establish a PDU session for communication with an AF (Application Function) / AS (Application Server). One PDU session may include one or more QoS Flows, and each QoS Flow may be configured with different QoS parameters to provide different transmission performances required for each application service. Of course, the present invention is not limited to the above examples.

[0050] In describing the embodiments of this document, a terminal may be composed of terminal 1 and terminal 2 (e.g., UE1 and UE2). However, if there is no need to distinguish between UE1 and UE2 in the context, each may be expressed as a UE or terminal. In addition, a device that integrates UE1 and UE2 may also be expressed as a UE or terminal. Hereinafter, in the embodiments of the present disclosure, terminal 1, terminal 2, and terminals including terminal 1 and terminal 2 may be used in the same manner as UE1, UE2, and UEs including UE1 and UE2.

[0051] Terminal 1 and Terminal 2 may have different subscription data for a single home network operator. Accordingly, Terminal 1 and Terminal 2 may have different subscription permanent identifiers (SUPIs) and may be assigned different temporary IDs (e.g., different globally unique temporary identifiers (GUTIs)) from the 5G core network. However, user information, such as subscription profiles managed by the home network operator, may be shared between Terminal 1 and Terminal 2. Although it is assumed that Terminal 1 and Terminal 2 have different terminal IDs (e.g., different SUPIs), the embodiments of this document may be applied to the same purpose even when Terminal 1 and Terminal 2 have the same terminal ID (e.g., the same SUPI).

[0052] Figure 2 is a diagram illustrating a procedure for terminals to simultaneously register with different carriers' communication networks, according to one embodiment of the present disclosure. For example, this may be the case where terminals 1 and 2 receive services through different carriers' communication networks.

[0053] Referring to FIG. 2, in step 1, when a terminal has the capability to simultaneously access and register to a 5G network through two or more 3gpp accesses (for example, when terminal 1 and terminal 2 each access and register to a 5G network), terminal 1 can register to the network through the AMF of PLMN A by including a UE ID (for example, SUPI) and an indicator indicating that it has the capability (for example, a dual 3gpp access registration support indicator or a multi-3gpp accesses registration support indicator) when sending a registration request.

[0054] To this end, in step 0, the UDM may include the ID of terminal 2, which is the ID of a terminal capable of dual 3gpp access registration, in the context stored by the UDM for the ID of terminal 1 (e.g., SUPI). In addition, since the information about the ID of the terminal capable of dual 3gpp access registration described above for terminal 1 is included in the UDR, when the UDM requests information about the terminal ID from the UDR, it may include information about the ID of the terminal capable of dual 3gpp access registration with terminal 1 (e.g., SUPI of terminal 2).

[0055] As an example of indicating that terminal 1 and terminal 2 are capable of dual 3GPP access registration, the user profile ID may be included in the UDM context or UDR context of terminal 1 and terminal 2. Accordingly, dual 3GPP access registration may be indicated for terminals corresponding to the same user profile ID.

[0056] In step 2a, the AMF of PLMN A, which receives the registration request message, may transmit a Nudm_UECM_registration request to the UDM to notify that the terminal has attempted registration. The Nudm_UECM_registration request may include at least one of a terminal ID (e.g., SUPI), an indicator indicating that the terminal has the capability to simultaneously access and register with a 5G network via two or more 3GPP accesses (e.g., a dual 3GPP access registration support indicator or a multi-3GPP accesses registration support indicator), or a value indicating that the terminal's access type is 3GPP access. In addition, the Nudm_UECM_registration request may also include a RAT type value indicating which RAT is used among the 3GPP accesses. For example, the RAT type may be at least one of “NR(LEO)”, “NR(MEO)”, “NR(GEO)”, “NR(OTHER SAT)”, or NR. The UDM may store the received registration information (e.g., an indicator indicating that the terminal has the ability to simultaneously access and register with a 5G network through two or more 3gpp accesses, and at least one of the terminal ID, access type, or RAT type) in the SUPI of the terminal.

[0057] In one embodiment, the UDM may receive a Nudm_UECM_registration request from the AMF of PLMN A, which includes information about the access type and RAT type. Accordingly, the UDM may store information about the RAT type as well as the access type. Furthermore, the UDM may perform the registration procedure from step 5 onward, taking into account at least one of the stored information about the access type or RAT type. Of course, the present invention is not limited to the above example.

[0058] In step 2b, the UDM may inform the AMF of PLMN A of the result of the registration request. The message in step 2b may include an NR RAT#1 indicator to indicate that this is the first registration of the terminal for 3gpp access.

[0059] Additionally, in step 3, the AMF of PLMN A may request the UDM to notify about an event in which registration occurs through another 3gpp access for the same terminal (e.g., SUPI of terminal 2 among SUPIs of terminals performing dual 3gpp access registration). In this case, the present disclosure exemplifies requesting notification through the Nudm_SDM_dual3GPPregistrationNotification Subscribe message, but it is of course possible to use a message other than Nudm_SDM_dual3GPPregistrationNotification Subscribe.

[0060] After registration is completed as in step 4, the terminal can also create a PDU Session through the connected PLMN A.

[0061] Meanwhile, a situation in which a terminal registers with another operator's communication network, such as step 5, may be considered. For example, if a terminal has the capability to simultaneously access and register with a 5G network through two or more 3GPP accesses, when terminal 2 sends a registration request to the AMF of PLMN B, it may include a terminal ID (e.g., SUPI) and an indicator indicating that it has the capability (e.g., a dual 3GPP access registration support indicator or a multi-3GPP accesses registration support indicator) to register with the network through the AMF of PLMN B.

[0062] In step 6a, the AMF of PLMN B, which receives the registration request message, may transmit a Nudm_UECM_registration request to the UDM to notify that the terminal has attempted registration. The Nudm_UECM_registration request may include at least one of an ID of terminal 2 (e.g., SUPI), an indicator indicating that the terminal has the capability to simultaneously access and register with a 5G network via two or more 3GPP accesses (e.g., a dual 3GPP access registration support indicator or a multi-3GPP accesses registration support indicator), or a value indicating that the access type of the terminal is 3GPP access. In addition, the Nudm_UECM_registration request may also include a RAT type value indicating which RAT it is among the 3GPP accesses. For example, the RAT type may be at least one of “NR(LEO)”, “NR(MEO)”, “NR(GEO)”, “NR(OTHER SAT)”, or NR.

[0063] In one embodiment, in step 6b, the UDM may include an indicator indicating that the UE subscription for the terminal corresponding to the SUPI of the terminal 2 allows the terminal to access and register on the 5G network simultaneously via two or more 3GPP accesses (e.g., a dual 3GPP access registration allowed indicator or a multi-3GPP accesses registration allowed indicator), or the message of step 6a may include the ID of the terminal 2 and an indicator indicating that the terminal has the capability to access and register on the 5G network simultaneously via two or more 3GPP accesses (e.g., a dual 3GPP access registration support indicator or a multi-3GPP accesses registration support indicator). If the terminal 1 is already connected to the network and the terminal 2 is additionally registered on the network via step 6a, the UDM may allow the dual 3GPP access registration for the terminal 1 and the terminal 2 if it is confirmed that the terminal 1 and the terminal 2 support dual 3GPP access registration.

[0064] To determine whether to allow dual 3GPP access registration, the UDM can check whether the context stored in the UDM of terminal 2 includes the terminal 1 ID, which is the ID of a terminal capable of dual 3GPP access registration, or whether the ID of the user profile of terminal 1 is the same as that of terminal 2. In addition, the UDM can confirm that the ID of the user profile of terminal 1 is the same as that of terminal 2 by requesting the UDR to retrieve the context of the terminal supporting dual 3GPP access registration, if necessary.

[0065] If the UDM determines that dual 3GPP access registration is not permitted for both Terminal 1 and Terminal 2, the UDM may accept the registration request from Terminal 2. However, the UDM may transmit an indication to the AMF indicating that the dual 3GPP access registration request is not applicable. The indication indicating that the dual 3GPP access registration request is not applicable may be included in the registration access notifying Terminal 2.

[0066] Meanwhile, if the SUPIs of terminal 1 and terminal 2 are the same, the following additional operations may be performed. For example, if the access type for network registration through steps 2a and 6a is 3gpp access, UDM can allow access through both 3gpp accesses, unlike the operation where it deregistered or canceled the access of the previously registered terminal. Of course, it is not limited to the above example.

[0067] In one embodiment, UDM may allow both connection and registration when both access types are the same (3GPP access). In another embodiment, UDM may allow registration for both connections only when the access types are the same (3GPP access) but the RAT types are different. In another embodiment, UDM may deregister the registration that was previously connected when the RAT types are the same. Of course, the above examples are not limited to the above examples, and the above examples may be operated individually or organically combined to form a single embodiment.

[0068] Meanwhile, the UDM may store the received registration information (e.g., an indicator indicating that the terminal has the capability to simultaneously access and register with a 5G network via two or more 3gpp accesses, and at least one of the ID, access type, or RAT type of terminal 1) for the SUPI of terminal 2. In addition, the UDM may store the received registration information (e.g., an indicator indicating that the terminal has the capability to simultaneously access and register with a 5G network via two or more 3gpp accesses, and at least one of the ID, access type, or RAT type of terminal 2) for the SUPI of terminal 1.

[0069] In step 6c, the UDM may notify the AMF of PLMN B of the result of the registration request. The message of step 6c may include an NR RAT#2 indicator to indicate that this is the second registration of the 3gpp access of the terminal. In addition, the UDM may include a dual 3gpp access registered indicator in the message of step 6c to indicate that all connections with the access type of 3gpp access have been registered. The dual 3gpp access registered indicator and the AMF ID of the AMF of PLMN B where the 3gpp access was registered or the IP address information of the AMF of PLMN B may be included in the message of step 6c.

[0070] In step 7a, the AMF of PLMN B may perform a procedure to retrieve subscriber information for terminal 2. At this time, the AMF of PLMN B may request information stored in the UDM regarding the PDU Session created by terminal 2 to retrieve subscriber information for terminal 2. For example, the AMF of PLMN B may request subscriber information for terminal 2 from the UDM by specifying the subscription data type as UE context in SMF data.

[0071] In step 7b, the UDM may transmit a message to the AMF of PLMN B, which includes information about the subscription data type, the ID of terminal 1 (e.g., SUPI or GUTI), the PDU Session ID generated by terminal 1, and at least one of the SMF ID of the SMF managing the PDU Session or the IP address of the SMF.

[0072] If the dual 3gpp access registered indicator is not included in the message of step 6c, then in step 8, the AMF of PLMN B may request the UDM to notify of an event in which registration occurs for the same terminal (e.g., the same SUPI) through another 3gpp access. In this case, the present disclosure exemplifies requesting notification through the Nudm_SDM_dual3GPPregistrationNotification Subscribe message, but it is to be understood that a message other than Nudm_SDM_dual3GPPregistrationNotification Subscribe may be used.

[0073] In step 6b, if two 3gpp accesses of the same terminal are registered respectively, in step 9, UDM can send Nudm_SDM_dual3GPPregistrationNotification message to AMF of PLMN A according to subscription request for event of step 3, and can deliver information that the terminal has newly accessed and registered to AMF (e.g., AMF of PLMN A) in which the terminal has previously registered through Nudm_SDM_dual3GPPregistrationNotification message. Information about newly accessed and registered may include at least one of AMF ID of new AMF (e.g., AMF of PLMN B), IP address of AMF, information of PLMN to which the terminal has newly accessed (e.g., PLMN ID of PLMN B), access type, RAT type, or NR RAT#2 indicator to indicate second registration.

[0074] In step 10, the AMF of PLMN A, which received the message of step 9, can recognize that registration was made simultaneously through another 3gpp access.

[0075] In step 11, the UDM may transmit information about the previously accessed and registered terminal to the AMF of PLMN B, which the terminal newly accesses and registers, through a Nudm_SDM_dual3GPPregistrationNotification message according to the subscription request for the event in step 8. The information about the previously accessed and registered terminal may include at least one of the AMF ID of the previously accessed AMF (e.g., the AMF of PLMN A), the IP address of the AMF, information about the PLMN that the terminal first accessed (e.g., the PLMN ID of PLMN A), access type, RAT type, or an NR RAT#1 indicator to indicate that it is information about the first registration.

[0076] In step 12, the AMF of PLMN B, which received the message of step 11, can recognize that registration was made simultaneously through another 3gpp access.

[0077] At step 13, the AMF of PLMN B can send a registration accept to the terminal for connecting to the new 3gpp access.

[0078] In step 14, the terminal that receives the registration accept from the AMF of PLMN B can recognize that two registrations have been made simultaneously through two 3gpp accesses.

[0079] As an example, the method of using the Nudm_SDM_dual3GPPregistrationNotification message when the UDM sends a message to the AMF of PLMN B in step 11 is described, but it is of course possible to use a message other than the Nudm_SDM_dual3GPPregistrationNotification message. For example, in the process of step 7b, the UDM may use the Nudm_SDM_Get response as a response to the Nudm_SDM_Get request. That is, the Nudm_SDM_Get response message may include information about registration that the terminal has previously accessed. The information about registration that the terminal has previously accessed may include at least one of the AMF ID of the AMF that the terminal has previously accessed (e.g., the AMF of PLMN A), the IP address of the AMF, information about the PLMN that the terminal has first accessed (e.g., the PLMN ID of PLMN A), access type, RAT type, and an NR RAT#1 indicator for notifying that it is information about the first registration.

[0080] Meanwhile, the terminal can later connect and create a new PDU Session for the network of the registered operator.

[0081] When information about a new PDU session is known to the UDM in step 15, the UDM can send a Nudm_SDM_Notification message to the AMF (e.g., AMF of PLMN A) that it has previously accessed and registered. At this time, the Nudm_SDM_Notification message can include at least one of the ID of UE 2 (e.g., SUPI or GUTI), information corresponding to the UE context in SMF data (e.g., PDU Session ID generated by UE 2), or the SMF ID of the SMF that manages the PDU Session (or the IP address of the SMF).

[0082] In one embodiment, when the UE sends a registration request message to the AMF of PLMN B as in steps 1 and 5, the UE may include an indicator (e.g., a dual 3GPP access registration support indicator or a multi-3GPP accesses registration support indicator) indicating that the UE has the capability to simultaneously access and register on a 5G network via two or more 3GPP accesses, as well as an indication indicating whether the UE is requesting registration via another 3GPP access or updating an existing registration. For example, the UE may include a dual 3GPP access registration trial indicator in the registration request message together with the dual 3GPP access registration support indicator or the multi-3GPP accesses registration support indicator. Alternatively, the UE may notify the communication network of the UE's intention to register by including the dual 3GPP access registration support indicator or the multi-3GPP accesses registration support indicator in the registration request message only when the UE desires or requests to simultaneously access a 5G network via two or more 3GPP accesses.

[0083] For example, if the system is designed to allow the terminal to indicate that it wants to register simultaneously through other 3GPP accesses through a dual 3GPP access registration trial indicator, the UDM can recognize that the terminal wants to register simultaneously through other 3GPP accesses by having the terminal transmit the dual 3GPP access registration trial indicator to the AMF of PLMN B in step 5 and having the AMF of PLMN B transmit the dual 3GPP access registration trial indicator to the UDM in step 6a. In this case, the UDM may allow the terminal to register simultaneously if the terminal is allowed to access the 5G network through two or more 3GPP accesses simultaneously.

[0084] In explaining the above embodiment, the wireless communication network of the operator to which the terminal is subscribed may be referred to as PLMN C. In addition, the wireless communication network of the operator to which the terminal wishes to connect may be referred to as PLMN A, and PLMN A may be a network supporting 3GPP access based on satellite communication. In addition, the wireless communication network of another operator may be referred to as PLMN B, and PLMN B is assumed to be a network supporting 3GPP access based on a terrestrial network. However, it is to be understood that the same method as the above embodiment may also be applied in cases where two or more PLMNs among PLMN A, PLMN B, or PLMN C are the same.

[0085] FIG. 3 is a diagram illustrating a procedure in which a terminal according to one embodiment of the present disclosure moves a PDU session created through one operator's communication network to another operator's communication network.

[0086] Referring to FIG. 3, when a terminal having PLMN C as its home operator simultaneously accesses a 5G network through PLMN A and PLMNB as different 3gpp accesses (for example, terminal 1 accesses PLMN A and terminal 2 accesses PLMN B), this may be a description of a method for moving a PDU Session created in one PLMN to another PLMN depending on the terminal's situation or policy. In addition, referring to FIG. 3, the present disclosure may be described focusing on a scenario in which a terminal (for example, terminal 1 and terminal 2) is already registered in each of two PLMNs, PLMN A and PLMN B, in step 1 (for example, when steps 1 to 14 in FIG. 2 are performed), a home routed PDU Session is created, and the created PDU Session is moved to another PLMN. For example, a new Home routed PDU Session can be created in steps 2 and 3, and a method for handing over to another PLMN from step 5 can be described based on the decision in step 4.

[0087] In step 2, when terminal 1 requests the creation of a PDU Session through PLMN A, which is a roaming network to which the PDU Session is connected, a Home routed PDU Session can be created through PLMN C, which is a home network. The SMF of the home network PLMN C can manage the Home routed PDU Session, and in step 2a, the SMF can store at least one of the PDU Session ID and SMF ID or the IP address information of the SMF in the UDM.

[0088] In step 3, the UDM can notify the AMF of PLMN B, where terminal 2 simultaneously registered with terminal 1 and terminals supporting dual 3gpp access registration, of updated information about the subscription type of the UE context in SMF data. The information of the UE context in SMF data can include at least one of terminal 1's ID, PDU Session ID, or SMF ID (or IP address) information of the serving SMF.

[0089] In step 4, the terminal (or terminal 1) may decide to handover the PDU Session from the existing communication network (e.g., PLMN A) to another communication network (e.g., PLMN B) based on the terminal's policy information received from the communication network or the user's selection. A separate embodiment regarding the information included in the terminal's policy information and the method of transmitting it to the terminal may be described later.

[0090] In step 5, terminal 2 can send a PDU Session establishment request message in a NAS (Non Access Stratum) message to the AMF of another network to which it wants to move (e.g., PLMN B). At this time, terminal 2 can inform the AMF of PLMN B of the PDU Session ID of the PDU Session to be moved and the ID of terminal 1 (e.g., SUPI or GUTI). In addition, the terminal can notify the AMF of PLMN B through the NAS message that it is attempting a handover by changing the existing PDU Session for terminal 1 to a PDU Session for terminal 2 by setting the request type to “existing PDU Session” or “dual 3gpp access PDU Session.”

[0091] In step 6, when the AMF of PLMN B, which has received the NAS message, recognizes that the request type is “existing PDU session” or “dual 3gpp access PDU Session” and that the terminal is simultaneously registered in PLMN A and PLMN B as terminal 1 and terminal 2, it can recognize that the PDU Session is being handed over between the PLMNs.

[0092] Meanwhile, in steps 7a and 7b, if the AMF of PLMN B that received the request (e.g., NAS message) does not have information about the ID of the requested terminal 1 and the PDU Session ID of the PDU Session, the AMF of PLMN B can verify from the AMF of PLMN A, to which terminal 1 is simultaneously connected and registered, whether the PDU Session requested by terminal 2 is actually a PDU Session created and existing in PLMN A. In addition, if verification is successful, the AMF of PLMN A can include at least one of the ID of terminal 1, the PDU Session ID, or the SMF ID (or the IP address of the SMF) of the SMF that manages the PDU Session in step 7b. Alternatively, if verified, the AMF of PLMN A may include at least one of the ID of terminal 1, the PDU Session ID, or the SMF ID (or the IP address of the SMF) of the SMF corresponding to the PDU Session ID in step 7b for all PDU Session IDs generated for the PLMN A. Accordingly, the AMF of PLMN B may obtain at least one of the ID of terminal 1, the PDU Session ID, or the SMF ID (or the IP address of the SMF) of the SMF managing the PDU Session.

[0093] Alternatively, in steps 8a and 8b, the AMF of PLMN B may transmit a Nudm_SDM_Get request message to the UDM, which includes subscription data type UE context in SMF data as information about PDU Sessions generated for the UE (e.g., a message requesting UE context in SMF data). Alternatively, the AMF of PLMN B may add the ID and PDU Session ID of UE1 to the Nudm_SDM_Get request message. Accordingly, the UDM may transmit UE context in SMF data corresponding to all PDU Session IDs generated for SUPI of UE1 to the AMF of PLMN B through the Nudm_SDM_Get response message in response to the request of the AMF of PLMN B (e.g., the Nudm_SDM_Get request message). Alternatively, UDM may transmit to AMF of PLMN B (e.g., AMF of terminal 2) at least one of the ID of terminal 1, PDU Session ID, and SMF ID (or IP address of SMF) information of SMF managing PDU Session as UE context in SMF data corresponding to PDU Session ID when the ID and PDU Session ID of terminal 1 are included in the request (e.g., Nudm_SDM_Get request message). Of course, it is not limited to the above example.

[0094] In one embodiment, the AMF of PLMN B (e.g., the AMF of UE 2) may perform steps 7a and 7b or 8a and 8b as described above, or may perform both steps 7a and 7b and 8a and 8b. The case where the AMF of PLMN B does not have the requested PDU Session ID may occur when the UE attempts to handover the PDU Session before updating the UE context in SMF data including information about the newly created PDU Session through UE 1 to the AMF of PLMN B in the UDM.

[0095] In step 9, an AMF (e.g., an AMF of PLMN B) that has acquired at least one of the IDs or IP addresses for the SMF of the home PLMN that manages the PDU Session can select a Visited SMF in PLMN B, which is the PLMN to which the terminal wants to move, and can select an SMF of the home PLMN as the home SMF during the process of selecting an SMF.

[0096] In steps 10 and 11, the AMF (e.g., the AMF of PLMN B) can perform the process of creating a PDU Session through the visited SMF and the home SMF.

[0097] In step 12, the remaining operations of the PDU Session establishment process may be performed. For example, the PDU Session establishment process between the terminal and PLMN B (e.g., home PLMN) may be completed by performing the remaining procedures excluding the procedures described above (e.g., steps 1 to 11) in the PDU Session establishment process. With respect to the PDU session corresponding to the PDU Session ID, the PDU Session created as a home-routed PDU Session through PLMN A may be handed over to a home-routed PDU Session through PLMN B.

[0098] In step 13, the home SMF can notify the SMF of the existing PLMN A (e.g., the v-SMF of UE1) that the PDU Session has been successfully moved from the PDU Session of UE1 to the PDU Session of UE2 when the visited SMF changes from the SMF of the existing PLMN A (e.g., the v-SMF of UE1) to the SMF of the new PLMN B (e.g., the v-SMF of UE2). At this time, the home SMF can send a PDU Session HO complete notification message and a PDU Session ID. Alternatively, the home SMF can also send a PDU Session release command message to the SMF of PLMN A along with the ID and PDU Session ID of UE1. At this time, the SMF of PLMN A that receives the PDU Session release command message can forward the message as a NAS SM (session management) message to UE1 and request the AMF of UE1 to delete the context of the corresponding PDU Session. Additionally, the SMF of PLMN A that received the PDU Session release command message can request the NG-RAN that was servicing the PDU Session to clear the UE context for the PDU session.

[0099] As an example, when a terminal (or terminal 1) accesses a network of one operator via 3gpp access and creates a PDU Session to provide a service, and then attempts to handover the PDU Session to another operator's network (e.g., PLMN B) according to the terminal's preference as in step 4, the terminal (terminal 2) can perform simultaneous network registration with the other operator's network (e.g., PLMN B). For example, as in steps 5 to 13 of FIG. 2, when terminals (terminal 1 and terminal 2) access different operator's networks and perform network registration through two accesses simultaneously, the PDU Session created in the operator's network (e.g., PLMN A) where the terminal (or terminal 1) initially registered can be handed over to the 3gpp access of the other operator's network (e.g., PLMN B) via terminal 2. For example, steps 2 and 3 may not be performed, and the PDU Session may be handed over through the process from step 5 to the last step (e.g., step 12).

[0100] In explaining the above embodiment, the wireless communication network of the operator to which the terminal is subscribed may be referred to as PLMN C. The wireless communication network of the operator to which the terminal wishes to connect may be referred to as PLMN A, and PLMN A may be a network supporting 3GPP access based on satellite communication. The wireless communication network of another operator may be referred to as PLMN B, and PLMN B is assumed to be a network supporting 3GPP access based on a terrestrial network. However, the same method as the above embodiment may be applied even when two or more PLMNs among PLMN A, PLMN B, or PLMN C are the same.

[0101] In step 4 of the above-described FIG. 3, the terminal policy for allowing the terminal to handover any PDU session to a 3GPP access of another PLMN may be the terminal's URSP (UE route selection policy) or a separate UE policy for the terminal. In addition, the terminal policy may be a parameter that can be included in the UE policy during the process of updating the UE policy from the home operator (e.g., PLMN C) through the terminal's registration process, the terminal's UCU (UE configuration update) procedure, or the UPU (UE parameter update) procedure. For example, the terminal policy may be named a Routing selection among multi-3GPP access policy.

[0102] Table 1 illustrates an example of routing selection among multi-3gpp access policies. In the process of selecting a route for application 2, in addition to 3gpp access, RAT type may be additionally considered as a preference for access type. As a way to express that in addition to 3gpp access, RAT type may be additionally considered, the access type and RAT type may be expressed together, such as 3gpp NR(TN) or 3gpp NR(LEO) / NR(MEO) / NR(GEO), or the access type may be set to 3gpp access and an additional RAT type preference may be set to NR or NR(TN) to indicate access via new radio of terrestrial networks, or the RAT type preference may be set to NR(LEO), NR(MEO), or NR(GEO).

[0103] Preferences may be determined by RAT type, or a preferred PLMN may be separately determined. Therefore, for a terminal that supports simultaneous network registration through two or more 3GPP accesses, a route can be selected in the order of the highest precedence (or lowest precedence value) of the route selection descriptor for any application, depending on the preferred RAT type or preferred PLMN. In addition, the traffic selection description of URSP may include an indication (e.g., dual 3GPP access allowed indication) to indicate whether the PDU session created by a terminal (terminal 1 or terminal 2) is a PDU session that can be handed over to another PLMN through another terminal (terminal 2 or terminal 1) of the same user.

[0104]

[0105] FIG. 4 is a diagram illustrating a procedure in which a terminal according to one embodiment of the present disclosure moves a PDU session created through one operator's communication network to another operator's communication network.

[0106] Referring to FIG. 4, it can be explained how the operation of FIG. 3 is applied when PLMN B is identical to PLMN C in FIG. 3. It can also be explained how the operation of FIG. 3 is applied when PLMN A is identical to PLMN C or when PLMN A, PLMN B, and PLMN C are identical.

[0107] Referring to FIG. 4, when a terminal having PLMN B as its home operator simultaneously accesses a 5G network through PLMN A and PLMN B with different 3gpp accesses (for example, terminal 1 accesses PLMN A and terminal 2 accesses PLMN B), a method can be described in which a PDU Session created as home routed in PLMN A must be moved to PLMN B depending on the terminal's situation or policy.

[0108] Assuming that terminals (terminal 1, terminal 2) are already registered in the networks of PLMN A and PLMN B respectively in step 1 (for example, when steps 1 to 14 in FIG. 2 are performed), a scenario can be described in which a home routed PDU session is created and the created PDU session is moved to PLMN B. For example, a method can be described in which a new home routed PDU session is created in steps 2 and 3, and a PLMN B handover is performed from step 5 based on the decision in step 4.

[0109] In step 2, when terminal 1 requests creation of a PDU Session through PLMN A, which is a roaming network to which the PDU Session is connected, a home routed PDU Session can be created through PLMN B, which is a home network. In step 2a, the SMF of the home network PLMN B can manage the home routed PDU Session and transmit at least one of the PDU Session ID and SMF ID or IP address information of the SMF to the UDM. In addition, the UDM can store at least one of the PDU Session ID and SMF ID or IP address information of the SMF received from the SMF of PLMN B.

[0110] In step 3, the UDM can notify the AMF of PLMN B, where terminal 2 simultaneously registered with terminal 1 and terminals supporting dual 3gpp access registration, of updated information about the subscription type of the UE context in SMF data. The information of the UE context in SMF data can include at least one of the ID of terminal 1, the PDU Session ID, and the SMF ID (or IP address information) of the SMF of the serving PLMN B.

[0111] In step 4, the terminal (or terminal 1) may decide to handover the PDU Session from the existing communication network (e.g., PLMN A) to another communication network (e.g., PLMN B) based on the terminal's policy information received from the communication network or based on the user's selection. The information contained in the terminal's policy information and the method of transmitting it to the terminal may follow the description of Routing selection among multi-3gpp access policies described in the separate embodiment of FIG. 3 described above.

[0112] In step 5, terminal 2 can send a PDU Session establishment request message to the AMF of another network to which it wants to move (e.g., PLMN B) by including it in a NAS message. At this time, terminal 2 can inform the AMF of PLMN B of the PDU Session ID of the PDU Session to be moved along with the ID of terminal 1 (e.g., SUPI or GUTI). In addition, terminal 2 can inform the AMF of PLMN B of the attempt to perform a handover by changing the existing PDU Session for terminal 1 to a PDU Session for terminal 2 by setting the request type to “existing PDU Session” or “dual 3gpp access PDU Session” through the NAS message.

[0113] In step 6, the AMF of PLMN B, which receives the NAS message, can recognize that the PDU Session is being handed over between PLMN A and PLMN B if the request type is “existing PDU session” or “dual 3gpp access PDU Session” and the terminal is simultaneously registered in PLMN A and PLMN B as terminal 1 and terminal 2.

[0114] In steps 7a and 7b, if the AMF of PLMN B that received the request (e.g., NAS message) does not have information about the ID of the requested terminal 1 and the PDU Session ID of the PDU Session, the AMF of PLMN B can verify from the AMF of PLMN A that terminal 1 is simultaneously connected and registered whether the PDU Session requested by terminal 2 is actually a PDU Session created and existing in PLMN A. In addition, if verification is successful, the AMF of PLMN A can include in step 7b at least one of the ID of terminal 1, the PDU Session ID, or the SMF ID (or the IP address of the SMF) of the SMF that manages the PDU Session, or can include in step 7b at least one of the ID and PDU Session ID of terminal 1 and the SMF ID or the IP address of the SMF of the corresponding SMF for all PDU Session IDs created for PLMN A. Therefore, the AMF of PLMN B can obtain the ID of terminal 1, the PDU Session ID, and the SMF ID or IP address of the SMF that manages the PDU Session.

[0115] In steps 8a and 8b, the AMF of PLMN B may transmit a Nudm_SDM_Get request message to the UDM as a message requesting information about PDU Sessions created for the UE (e.g., UE context in SMF data). And the Nudm_SDM_Get request message may include a subscription data type UE context in SMF data. Alternatively, the AMF of PLMN B may add the ID and PDU Session ID of UE1 to the Nudm_SDM_Get request message. Accordingly, the UDM may transmit the UE context in SMF data corresponding to all PDU Session IDs created for the SUPI of UE1 to the AMF of PLMN B through the Nudm_SDM_Get response message in response to the request of the AMF of PLMN B (e.g., Nudm_SDM_Get request message). Alternatively, if the ID and PDU Session ID of terminal 1 are included in the request (e.g., Nudm_SDM_Get request message), the UDM may respond to the AMF (e.g., the AMF of terminal 2) by including at least one of the ID of terminal 1, the PDU Session ID, or the SMF ID (or the IP address of the SMF) information of the SMF managing the PDU Session as the UE context in SMF data corresponding to the PDU Session ID. Of course, the present invention is not limited to the above examples.

[0116] In one embodiment, the AMF of PLMN B (e.g., the AMF of UE 2) may perform steps 7a and 7b or 8a and 8b as described above, or may perform both steps 7a and 7b and 8a and 8b. The case where the AMF of PLMN B does not have the requested PDU Session ID may occur when the UE attempts to handover the PDU Session before updating the UE context in SMF data including information about the newly created PDU Session through UE 1 to the AMF of PLMN B in the UDM.

[0117] In step 9, an AMF (e.g., an AMF of PLMN B) that has acquired at least one of the ID or IP address for an SMF of a home PLMN (e.g., PLMN B) managing a PDU Session can select the SMF of the home PLMN acquired as an SMF during the process of selecting an SMF.

[0118] In step 10, the AMF (e.g., the AMF of PLMN B) can perform the process of creating a PDU Session through the SMF of PLMN B.

[0119] In step 11, the remaining operations of the PDU Session establishment process can be performed. For example, the PDU Session establishment process between the terminal and PLMN B (e.g., home PLMN) can be completed by performing the remaining procedures excluding the procedures described above (e.g., steps 1 to 10) in the PDU Session establishment process. With respect to the PDU session corresponding to the PDU Session ID, the PDU Session created as a home-routed PDU Session through PLMN A can be handed over to a home-routed PDU Session through PLMN B.

[0120] In step 12, the SMF of PLMN B can notify the SMF of the existing PLMN A that the PDU Session has been successfully transferred. At this time, the SMF of PLMN B can send a PDU Session HO complete notification message along with the ID and PDU Session ID of UE1 to the SMF of PLMN A. Alternatively, the SMF of PLMN B can also forward a PDU Session release command message along with the ID and PDU Session ID of UE1 to the SMF of PLMN A. At this time, the SMF of PLMN A that has received the PDU Session release command message can request the AMF of UE1 to clear the context of the corresponding PDU Session while forwarding the PDU session release command message as a NAS SM message to UE1. In addition, the SMF of PLMN A that has received the PDU Session release command message can request the NG-RAN that was servicing the PDU Session to clear the UE context for the corresponding PDU session.

[0121] Unlike the above description, if a non-roaming PDU Session can be created in PLMN B, and the created non-roaming PDU Session is moved to a PDU Session that roams in PLMN A as a home-routed PDU Session, the PDU Session can be handed over in the same manner, except that in the process of selecting an SMF by the AMF in step 9 of the above-described process of FIG. 4, the visited SMF is selected in PLMN A, and the original SMF is selected as the home SMF to create the PDU Session.

[0122] As an example, when a terminal (or terminal 1) accesses a network of one operator via 3gpp access, creates a PDU Session, and provides a service, and then tries to hand over the PDU Session to another operator's network (e.g., PLMN B) according to the terminal's preference as in step 4, the terminal (terminal 2) can perform simultaneous network registration with the other operator's network (e.g., PLMN B). For example, as in steps 5 to 13 of FIG. 2, when terminals (terminal 1 and terminal 2) access different operator's networks and perform network registration through two accesses simultaneously, the PDU Session created in the operator's network (e.g., PLMN A) where the terminal (or terminal 1) initially registered can be handed over to the 3gpp access of the other operator's network (e.g., PLMN B) via terminal 2. For example, steps 2 and 3 may not be performed, and the PDU Session may be handed over through the process from step 5 to the last step (e.g., step 11).

[0123] FIG. 5 is a diagram illustrating an example configuration of a network entity in a wireless communication system according to various embodiments of the present disclosure.

[0124] The network entity of FIG. 5 may be one of the network entities described in the embodiments of FIGS. 1 to 4.

[0125] A network entity according to one embodiment of the present disclosure may include a processor (510) that controls the overall operation of the network entity, a transceiver (520) including a transmitter and a receiver, and a memory (530). Of course, the present invention is not limited to the above example, and the network entity may include more or fewer components than those illustrated in FIG. 5.

[0126] According to one embodiment of the present disclosure, the transceiver (520) can transmit and receive signals with at least one of other network entities or terminals. The transmitted and received signals may include at least one of control information and data. If the network entity of FIG. 5 is a core network entity (NF), the signals transmitted and received between the network entity and the terminal may be transmitted and received via the RAN.

[0127] According to one embodiment of the present disclosure, the processor (510) may control the overall operation of the corresponding network entity to perform an operation according to one or a combination of two or more of the embodiments of FIGS. 1 to 4 described above. Meanwhile, the processor (510), the transceiver (520), and the memory (530) do not necessarily have to be implemented as separate modules, and may of course be implemented as a single component in the form of a single chip. In addition, the processor (510) may be an Application Processor (AP), a Communication Processor (CP), a circuit, an application-specific circuit, or at least one processor. The transceiver (520) may include at least one communication interface for transmitting and receiving signals with another network entity via wired / wireless.

[0128] According to one embodiment of the present disclosure, the memory (530) can store data such as basic programs, application programs, and setting information for the operation of the corresponding network entity. In addition, the memory (530) provides the stored data upon request of the processor (510). The memory (530) can be configured as a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, there can be a plurality of memories (530). In addition, the processor (510) can perform at least one of the above-described embodiments based on a program for performing an operation according to at least one of the above-described embodiments of the present disclosure stored in the memory (530).

[0129] FIG. 6 is a diagram illustrating an example configuration of a base station in a wireless communication system according to various embodiments of the present disclosure. The base station of FIG. 6 may refer to the RAN node described in the embodiments of FIGS. 1 to 4.

[0130] A base station according to one embodiment of the present disclosure may include a processor (610) that controls the overall operation of the base station, a transceiver (620) including a transmitter and a receiver, and a memory (630). Of course, the present invention is not limited to the above example, and the base station may include more or fewer components than those illustrated in FIG. 6.

[0131] According to one embodiment of the present disclosure, a transceiver (620) can transmit and receive signals with at least one of a terminal, another base station, or a network entity. The transmitted and received signals can include at least one of control information and data.

[0132] According to one embodiment of the present disclosure, the processor (610) may control the overall operation of the base station to perform operations according to one or a combination of two or more of the embodiments of FIGS. 1 to 4 described above. Meanwhile, the processor (610), the transceiver (620), and the memory (630) do not necessarily have to be implemented as separate modules, and may of course be implemented as a single component in the form of a single chip. In addition, the processor (610) may be an Application Processor (AP), a Communication Processor (CP), a circuit, an application-specific circuit, or at least one processor. The transceiver (620) may include at least one communication interface for transmitting and receiving signals wired / wirelessly to and from a terminal, another base station, or a network entity.

[0133] According to one embodiment of the present disclosure, the memory (630) can store data such as basic programs, application programs, and setting information for the operation of the corresponding base station. In addition, the memory (630) provides the stored data upon request of the processor (610). The memory (630) can be configured as a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, there can be a plurality of memories (630). In addition, the processor (610) can perform at least one of the above-described embodiments based on a program for performing an operation according to at least one of the above-described embodiments of the present disclosure stored in the memory (630).

[0134] FIG. 7 is a diagram showing an example configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure.

[0135] A terminal according to one embodiment of the present disclosure may include a processor (710) that controls the overall operation of the terminal, a transceiver (720) including a transmitter and a receiver, and a memory (730). Of course, the terminal is not limited to the above example, and the terminal may include more or fewer components than those illustrated in FIG. 7.

[0136] According to one embodiment of the present disclosure, a transceiver (720) can transmit and receive signals with at least one other terminal, base station, or network entity. The transmitted and received signals can include at least one of control information and data.

[0137] According to one embodiment of the present disclosure, the processor (710) may control the overall operation of the terminal to perform an operation according to one or a combination of two or more of the embodiments of FIGS. 1 to 7 described above. Meanwhile, the processor (710), the transceiver (720), and the memory (730) do not necessarily have to be implemented as separate modules, and may of course be implemented as a single component in the form of a single chip. In addition, the processor (710) may be an Application Processor (AP), a Communication Processor (CP), a circuit, an application-specific circuit, or at least one processor. The transceiver (720) may include at least one communication interface for transmitting and receiving signals with another terminal, a base station, or a network entity via wired / wireless.

[0138] According to one embodiment of the present disclosure, the memory (730) can store data such as basic programs, application programs, and setting information for the operation of the terminal. In addition, the memory (730) provides the stored data upon request of the processor (710). The memory (730) can be configured as a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, there can be a plurality of memories (730). In addition, the processor (710) can perform at least one of the above-described embodiments based on a program for performing an operation according to at least one of the above-described embodiments of the present disclosure stored in the memory (730).

[0139] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0140] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

[0141] These programs (software modules, software) may be stored in a non-volatile memory including random access memory, flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage devices, compact disc ROMs (CD-ROMs), digital versatile discs (DVDs) or other forms of optical storage devices, magnetic cassettes, or may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0142] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device implementing an embodiment of the present disclosure.

[0143] In the specific embodiments of the present disclosure described above, components included in the present disclosure are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0144] Meanwhile, a part or all of one or more embodiments proposed in the present disclosure may be applied in combination with a part or all of one or more other embodiments, and such combination forms are also included within the scope of the present disclosure.

[0145] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below but also by equivalents thereof. Furthermore, the above-described embodiments may be combined and operated as needed, as long as there is no technical contradiction.

Claims

1. A method performed by a UDM (unified data management) entity of a wireless communication system, A step of receiving a registration request message including information about a first terminal associated with the first AMF (access and mobility management function) entity from the first AMF entity; and A step of transmitting a registration response message including information related to a second terminal to the first AMF entity, The first SUPI (subscription permanent identifier) ​​of the first terminal and the second SUPI of the second terminal are associated with each other, A method, wherein information related to the first SUPI, the second SUPI, and the second terminal is stored in the UDM.

2. In paragraph 1, A method according to claim 1, wherein the information related to the second terminal includes at least one of identification information of a second AMF entity associated with the second terminal, first information regarding a PDU (protocol data unit) session for the second SUPI, or identification information of a session management function (SMF) entity managing the PDU session.

3. In paragraph 1, The second information about the PDU session for the second SUPI is included in a NAS (non-access stratum) message transmitted from the first terminal to the first AMF entity, A method wherein an SMF entity for providing a service to the first terminal is identified based on the NAS message and information related to the second terminal.

4. In paragraph 3, A method wherein, through the SMF entity, the PDU session for the second SUPI is changed to a PDU session for the first SUPI.

5. A method performed by a first AMF (access and mobility management function) entity of a wireless communication system, A step of transmitting a registration request message including information about a first terminal associated with the first AMF entity to a UDM (unified data management) entity; and A step of receiving a registration response message including information related to a second terminal from the first AMF entity, The first SUPI (subscription permanent identifier) ​​of the first terminal and the second SUPI of the second terminal are associated with each other, A method, wherein information related to the first SUPI, the second SUPI, and the second terminal is stored in the UDM.

6. In paragraph 5, A method according to claim 1, wherein the information related to the second terminal includes at least one of identification information of a second AMF entity associated with the second terminal, first information regarding a PDU (protocol data unit) session for the second SUPI, or identification information of a session management function (SMF) entity managing the PDU session.

7. In paragraph 5, the method, A step of receiving, from the first terminal, a NAS (non-access stratum) message including second information about a PDU session for the second SUPI; and A method further comprising the step of identifying an SMF entity for providing a service to the first terminal based on the NAS message and information related to the second terminal.

8. In paragraph 7, A method wherein, through the SMF entity, the PDU session for the second SUPI is changed to a PDU session for the first SUPI.

9. In the UDM (unified data management) entity of the wireless communication system, Transmitter and receiver; and At least one control unit connected to the above transceiver unit, At least one of the above control units: Receive a registration request message from a first AMF (access and mobility management function) entity, including information about a first terminal associated with the first AMF entity, and The first AMF entity is configured to transmit a registration response message including information related to the second terminal, The first SUPI (subscription permanent identifier) ​​of the first terminal and the second SUPI of the second terminal are associated with each other, A UDM entity, wherein information related to the first SUPI, the second SUPI, and the second terminal is stored in the UDM.

10. In paragraph 9, A UDM entity, wherein the information related to the second terminal includes at least one of identification information of a second AMF entity associated with the second terminal, first information regarding a PDU (protocol data unit) session for the second SUPI, or identification information of a SMF (session management function) entity managing the PDU session.

11. In paragraph 9, A UDM entity, wherein the second information about the PDU session for the second SUPI is included in a NAS (non-access stratum) message transmitted from the first terminal to the first AMF entity, and an SMF entity for providing a service to the first terminal is identified based on the NAS message and the information related to the second terminal.

12. In paragraph 11, A UDM entity, through which the PDU session for the second SUPI is changed to a PDU session for the first SUPI.

13. In the first AMF (access and mobility management function) entity of the wireless communication system, Transmitter and receiver; and At least one control unit connected to the above transceiver unit, At least one of the above control units: As a UDM (unified data management) entity, a registration request message is sent including information about a first terminal associated with the first AMF entity, and It is configured to receive a registration response message including information related to the second terminal from the first AMF entity, The first SUPI (subscription permanent identifier) ​​of the first terminal and the second SUPI of the second terminal are associated with each other, A first AMF entity, wherein information related to the first SUPI, the second SUPI, and the second terminal is stored in the UDM.

14. In paragraph 13, A first AMF entity, wherein the information related to the second terminal includes at least one of identification information of a second AMF entity associated with the second terminal, first information about a PDU (protocol data unit) session for the second SUPI, or identification information of a session management function (SMF) entity managing the PDU session.

15. In paragraph 13, at least one control unit: Receive, from the first terminal, a NAS (non-access stratum) message including second information about a PDU session for the second SUPI, and Based on the above NAS message and the information related to the second terminal, it is further configured to identify an SMF entity for providing a service to the first terminal, A first AMF entity, through which the PDU session for the second SUPI is changed to a PDU session for the first SUPI.

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