Apparatus and method for supporting nas in various network environments

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method for operating a user equipment (UE) (101) according to an embodiment of the present disclosure may comprise: an operation (201) of transmitting, to a first access and mobility management function (AMF) (111) of a first network, a first registration request message including information indicating that the UE (101) is capable of supporting a second network; an operation (205) of receiving, from the first AMF (111), a first registration approval message including information related to the second network; and an operation (207) of storing the information related to the second network. The information related to the second network may include information indicating that the first AMF (111) is capable of supporting the second network, and an information list corresponding to the second network.

Description

Devices and methods for supporting NAS in various network environments

[0001] The present disclosure relates to a device and method for supporting NAS (Non Access Stratum) in various network environments, and more specifically, to a processing method and device for supporting traffic steering, traffic switching, traffic split, etc. in an environment where a UE (user equipment) uses two 3GPP access networks.

[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] The present disclosure relates to a processing method and device for supporting traffic steering, traffic switching, traffic split, etc. in an environment where a UE uses two 3GPP access networks. Here, the two 3GPP access networks may be 3GPP access networks, or may be a public network and a non-public network among 3GPP access networks, or may be a network composed of a terrestrial network and a non-terrestrial network among 3GPP access networks. The present disclosure relates to a processing method and device for supporting traffic steering, traffic switching, traffic split, etc. in the various network environments described above.

[0009] An operating method of a terminal (user equipment, UE) (101) according to an embodiment of the present disclosure may include an operation (201) of transmitting a first registration request message including information indicating that the terminal (101) can support a second network to a first AMF (access and mobility management function) (111) of a first network; an operation (205) of receiving a first registration approval message including information related to the second network from the first AMF (111); and an operation (207) of storing information related to the second network. The information related to the second network may include information indicating that the first AMF (111) can support the second network, and an information list corresponding to the second network.

[0010] The above operating method may further include an operation (211) of transmitting a first packet data unit session (PDU) request message including information indicating to the session management function (SMF) (121) of the first network that the terminal (101) can support the second network.

[0011] The above operating method may further include an operation (213) of receiving a first PDU session response message from the SMF (121).

[0012] The above operation method may further include an operation (233) of determining whether the traffic can be distributed and processed through the second network based on the stored information related to the second network when the size of the traffic transmitted and received through the terminal (101) exceeds a predetermined threshold size.

[0013] The above operating method may further include an operation (235) of determining whether the second network is the same network as the first network or a different network based on information related to the second network.

[0014] The above operating method may further include an operation (237) of selecting the second network based on information related to the second network.

[0015] The above method of operation may further include an operation (241) of transmitting a second registration request message to a second AMF (111-3) of the selected second network.

[0016] The above method of operation may further include an operation (245) of receiving a second registration approval message from the second AMF (111-3) including a function indicator indicating that the second AMF (111-3) can distribute and process the traffic.

[0017] The above operating method may further include an operation (251) of transmitting a second PDU session request message including information instructing the SMF (121) to distribute and process the traffic through the second network.

[0018] The above operating method may further include an operation (257) of receiving a second PDU session response message from the SMF (121).

[0019] A terminal (600) according to an embodiment of the present disclosure may include a transceiver (610); a memory (620) electrically coupled to the transceiver (610) and storing various commands for controlling the terminal (600); and a processor (630) electrically coupled to the transceiver (610) and the memory (620). The processor (630) may be controlled to perform an operation of receiving a first registration request message including information indicating to a first AMF (111) of a first network that the terminal (101) can support a second network; an operation of receiving a first registration approval message including information related to the second network from the first AMF (111); and an operation (207) of storing information related to the second network. The information related to the second network may include information indicating that the first AMF (111) can support the second network and an information list corresponding to the second network.

[0020] The processor (630) may further control the operation (211) of transmitting a first packet data unit session (PDU) request message including information indicating to the session management function (SMF) (121) of the first network that the terminal (101) can support the second network.

[0021] The above processor (630) can further control to perform an operation (213) of receiving a first PDU session response message from the SMF (121).

[0022] The processor (630) may further control to perform an operation (233) of determining whether the traffic can be distributed and processed through the second network based on the stored information related to the second network when the size of the traffic transmitted and received through the terminal (101) exceeds a predetermined threshold size.

[0023] The processor (630) may further control the processor to perform an operation (235) of determining whether the second network is the same network as the first network or a different network based on information related to the second network.

[0024] The processor (630) may further control the operation (237) of selecting the second network based on information related to the second network.

[0025] The above processor (630) can further control to perform an operation (241) of transmitting a second registration request message to the second AMF (111-3) of the selected second network.

[0026] The processor (630) may further perform an operation (245) of receiving a second registration approval message from the second AMF (111-3) that includes a function indicator indicating that the second AMF (111-3) can distribute and process the traffic.

[0027] The processor (630) may further perform an operation (251) of transmitting a second PDU session request message including information instructing the SMF (121) to distribute and process the traffic through the second network.

[0028] The above processor (630) can further control to perform an operation (257) of receiving a second PDU session response message from the SMF (121).

[0029] According to one embodiment of the present disclosure, a UE can support traffic steering, traffic switching, traffic splitting, etc. in an environment where two 3GPP access networks are used. Here, the two 3GPP access networks may be, for example, 3GPP access networks, or may be a public network and a non-public network among 3GPP access networks, or may be a network composed of a terrestrial network and a non-terrestrial network among 3GPP access networks. In such an environment, traffic steering, traffic switching, (traffic split), etc. can be supported.

[0030] FIG. 1A is a conceptual diagram illustrating terminals and network entities for performing communication in a network environment including two or more 3GPP access networks according to one embodiment of the present disclosure.

[0031] FIG. 1b is a conceptual diagram illustrating terminals and network entities for performing communication in a network environment including two or more 3GPP access networks according to one embodiment of the present disclosure.

[0032] FIG. 2 is a flowchart illustrating a procedure for performing communication in a network environment including two or more 3GPP access networks according to one embodiment of the present disclosure.

[0033] FIG. 3 is a flowchart illustrating a procedure for performing communication in a network environment including two or more 3GPP access networks according to one embodiment of the present disclosure.

[0034] FIG. 4 is a flowchart illustrating a procedure for performing communication in a network environment including two or more 3GPP access networks according to one embodiment of the present disclosure.

[0035] FIG. 5 is a flowchart illustrating a procedure for performing communication in a network environment including two or more 3GPP access networks according to one embodiment of the present disclosure.

[0036] FIG. 6 is a block diagram illustrating the configuration of a terminal according to one embodiment of the present disclosure.

[0037] FIG. 7 is a block diagram illustrating a configuration of a network entity according to one embodiment of the present disclosure.

[0038] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. In describing the embodiments, descriptions of technical details that are well-known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to avoid obscuring the gist of the present disclosure by omitting unnecessary explanations and to convey the gist more clearly.

[0039] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0040] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the invention, and the present disclosure is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0041] 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.

[0042] 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.

[0043] Here, the term '~ part' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be on an addressable storage medium or may be configured to play one or more processors. Therefore, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. Additionally, the components and '~parts' may be implemented to activate one or more CPUs within a device or secure multimedia card. In addition, in an embodiment, the '~parts' may include one or more processors.

[0044] The terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, and terms referring to various identification information are provided as examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects with equivalent technical meanings may be used.

[0045] For the convenience of explanation below, this disclosure uses terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP) LTE standard, or terms and names modified therefrom. However, this disclosure is not limited to the above-described terms and names, and can be equally applied to systems conforming to other standards. In this disclosure, eNB may be used interchangeably with gNB for the convenience of explanation. That is, a base station described as an eNB may represent a gNB. In this disclosure, the term "terminal" may refer to various wireless communication devices, including mobile phones, NB-IoT devices, and sensors.

[0046] That is, in specifically explaining the embodiments of the present disclosure, the communication standards specified by 3GPP will be the main target, but the main gist of the present disclosure can 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 can be done at the discretion of a person skilled in the technical field of the present disclosure.

[0047] In 5G or NR systems, the Access and Mobility Management Function (AMF), which is the management entity that manages the mobility of terminals, and the Session Management Function (SMF), which is the entity that manages sessions, are separated. Accordingly, unlike in 4G LTE communication systems where the Mobility Management Entity (MME) performed mobility management and session management together, in 5G or NR systems, the entities that perform mobility management and session management are separated, which has changed the communication method and communication management method between terminals and network entities.

[0048] In 5G or NR systems, mobility management for non-3GPP access is performed via the Non-3GPP Inter-Working Function (N3IWF) and AMF, while session management is performed via the SMF. Furthermore, security-related information, a crucial element in mobility management, is also processed through the AMF.

[0049] As described above, in 4G LTE systems, the MME is responsible for both mobility management and session management. 5G or NR systems can support a non-standalone architecture that utilizes these network entities from the 4G LTE system to perform communications.

[0050] The present disclosure relates to a processing method and device for supporting traffic steering, traffic switching, (traffic split), etc. in an environment where a UE uses two 3GPP accesses. Here, the two 3GPP networks may be, for example, 3GPP access networks, a public network and a non-public network among 3GPP networks, or a network composed of a terrestrial network and a non-terrestrial network among 3GPP networks. The present disclosure relates to a processing method and device for supporting traffic steering, traffic switching, (traffic split), etc. in such an environment.

[0051] FIG. 1A and FIG. 1B are conceptual diagrams illustrating a first embodiment of a terminal and a network environment for communication with improved communication performance in a 5G network according to one embodiment of the present disclosure.

[0052] Referring to FIGS. 1A and 1B, a 5G or NR core network may be composed of network functions (NFs) such as a User Plane Function (UPF, 131, 131-3), a Session Management Function (SMF, 121, 121-3), an Access and Mobility Management Function (AMF, 111, 111-3), a 5G Radio Access Network (RAN, 103, 103-3), a User Data Management (UDM, 151), and a Policy Control Function (PCF, 141). In addition, for authentication of these entities, entities such as an Authentication Server Function (AUSF, not shown) and an authentication, authorization, and accounting (AAA, not shown) may be included. A UE (User Equipment, Terminal) (101) can access a 5G core network through a base station (5G RAN, Radio Access Network, basestation, BS, 103, 103-3). Meanwhile, for cases where the UE (101) communicates through non-3GPP access, an N3IWF (N3 interworking function) exists, and in the case of non-3GPP access, session management can be controlled through the UE (101), non-3GPP access, N3IWF, and SMF (121, 121-3), and mobility management can be controlled through the UE (101), non-3GPP access, N3IWF, and AMF (111, 111-3).

[0053] In a 5G or NR system, entities that perform mobility management and session management are separated into AMF (111, 111-3) and SMF (121, 121-3). Meanwhile, a stand-alone deployment structure in which communication is performed only with 5G or NR entities and a non-stand-alone deployment structure in which 4G entities and 5G or NR entities are used together are being considered for the 5G or NR system.

[0054] As shown in FIGS. 1A and 1B, when a UE (101) communicates with a network, control is performed by an eNB (103, 103-3), and deployment in which a 5G entity of a core network is used may be possible. In this case, mobility management between the UE (101) and the AMF (111, 111-3) and session management between the UE (101) and the SMF (121, 121-3) may be performed in the NAS (Non Access Stratum) layer, which is layer 3.

[0055] The communication network on which this disclosure is based assumes a 5G or 4G LTE network, but the same concept can be applied to other systems within a scope that can be understood by a person with ordinary technical skills.

[0056] Referring to FIGS. 1A and 1B, the present disclosure relates to a processing method and device that supports traffic steering, traffic switching, traffic split, etc. in an environment where a UE uses two 3GPP access networks (103, 103-3). Here, the two 3GPP access networks (103, 103-3) may be, in one embodiment, 3GPP access networks, a public network and a non-public network among 3GPP networks, or a network composed of a terrestrial network and a non-terrestrial network among 3GPP networks. The present disclosure relates to a processing method and device that supports traffic steering, traffic switching, (traffic split), etc. in various network environments.

[0057] Also, referring to FIGS. 1A and 1B, the UE (101) or UPF (131, 131-3) may be a dual steer device with dual steering functionality, a dual steer UPF.

[0058] FIG. 2 is a flowchart illustrating a procedure for performing communication in a 3GPP network environment according to one embodiment of the present disclosure.

[0059] FIG. 2 is an example of a case where access networks (103, 103-3) (e.g., two 3GPP networks) to which a UE (101) is connected for traffic steering, traffic switching, (traffic split), etc. belong to the same PLMN.

[0060] In such cases, for example, the same PLMN may be recognized as two virtual PLMNs depending on how the network is configured within the operator network.

[0061] Alternatively, as an example, two virtual PLMNs may transmit additional information elements to be recognized as different networks.

[0062] Alternatively, as an example, for two PLMNs, information on PLMNs (named T-PLMN in the present invention as an example) that can be additionally used for traffic steering, (traffic splitting), and traffic switching for a specific PLMN (e.g., a main PLMN, a PLMN that has previously performed communication, or a registered PLMN) may be transmitted together.

[0063] [Example 1]

[0064] In one embodiment, steps 201, 205, 207, 211, and 213 below may be processes performed in the home network (VPLMN) of the UE (101). In one embodiment, when performed in the home network, the UE (101) may receive / store information received in steps 205, etc. in the home network and use the information when moving to the VPLMN or when using another (additional) access network.

[0065] [Example 2]

[0066] In one embodiment, steps 201, 205, 207, 211, and 213 below may be processes performed in a visited network (VPLMN) of a UE (101). When performed in a visited network, the UE (101) may receive / store information received in steps 205, etc. in the visited network and use the information when using another (additional) access network in subsequent steps.

[0067] In step 201, the UE (101) can transmit a registration request message to the AMF (111).

[0068] Information included in the registration request at this time may include:

[0069] The UE (101) can transmit an indication of T-PLMN support to the network.

[0070] The above T-PLMN support indicator may be an indicator that indicates that the UE (101) has the ability to support functions such as traffic steering, traffic switching, (traffic split) even when there are two 3GPP networks / 3GPP access networks, or may be an information element, parameter, or bit information in one embodiment.

[0071] At step 205, AMF (113) can send a registration accept message to UE (101).

[0072] The information included in the registration accept message at this time may be as follows:

[0073] - An information element, bit, or parameter may be transmitted indicating that AMF (111) supports T-PLMN. That is, this information element may be information indicating that when the network supports functions such as traffic steering, traffic switching, (traffic split), etc., it can support these functions by using two 3GPP access networks, and also supports a PLMN selection function to support such functions.

[0074] - PLMN information list and T-PLMN information can be transmitted together. If (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is referred to as T-PLMN, the T-PLMNs can be RPLMNs, i.e. PLMNs that can support functions such as traffic steering, switching, and split by mapping to the registered PLMN registered by the UE (101). Or, in one embodiment, the T-PLMN can be a PLMN corresponding to (mapped to) a VPLMN, i.e. a visited PLMN, for traffic steering, switching, traffic split, etc. Or, it can be a PLMN corresponding to an operator controlled PLMN managed by an operator. Here, the term “corresponding” or “mapping” may refer to PLMN information that can be used to switch, steer, or split traffic of an RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in the RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN by mapping 1:1 or 1:n with an RPLMN, VPLMN, or operator controlled PLMN. Accordingly, the above information may be transmitted together with (corresponding / mapping) information of an RPLMN, VPLMN, or operator controlled PLMN or user defined PLMN.Alternatively, it may be transmitted as a separate information element together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN.

[0075] At step 207, the UE (101) can store the information. The information stored at this time may be as follows.

[0076] - An information element, bit, or parameter may be transmitted to indicate that AMF (111) supports T-PLMN, and the UE may store this information and use it later when selecting a PLMN. In other words, this information element may be information indicating that the network can support functions such as traffic steering, traffic switching, (traffic split) by using two 3GPP access networks, and also supports a PLMN selection function to support the functions.

[0077] - The PLMN information list and T-PLMN information can be stored together. If the (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, these T-PLMNs can be PLMNs that can support functions such as traffic steering, switching, and split by mapping to the RPLMN, i.e., the registered PLMN registered by the UE. Or, as an example, the T-PLMN can be a PLMN corresponding to (mapped to) the VPLMN, i.e., the visited PLMN, for traffic steering, switching, traffic split, etc. Or, it can be a PLMN corresponding to an operator controlled PLMN managed by the operator. Here, the term “corresponding” or “mapping” may refer to PLMN information that can be used to switch, steer, or split traffic of an RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in the RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN by mapping 1:1 or 1:n with an RPLMN, VPLMN, or operator controlled PLMN. Accordingly, the above information may be transmitted together with (corresponding / mapping) information of an RPLMN, VPLMN, or operator controlled PLMN or user defined PLMN.Alternatively, it may be transmitted as a separate information element together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN, and the transmitted information may be stored in the UE and used as information necessary for making a decision when selecting a PLMN later.

[0078] In step 211, the UE (101) can transmit a PDU session establishment request message to the SMF (121).

[0079] At this time, the UE (101) can transmit information such as function indication indicator information, information elements, and parameters to the SMF (121) to inform that the UE (101) has the capability to support even when there are two 3GPP access networks for traffic steering, (split), switching, etc.

[0080] At step 213, SMF (121) may transmit a PDU session establishment response message to UE (101).

[0081] In step 233, the UE (101) can determine whether services such as traffic steering, traffic switching, (traffic split), or temporary services such as distributing traffic are supported through another 3GPP access network / network when traffic is heavy through two (or more) 3GPP networks.

[0082] - For the above judgment, information on whether the UE (101) has the corresponding capability and whether the terminal is a terminal version (e.g., release 19) or higher that supports the corresponding function can be utilized.

[0083] - In addition, for the above judgment, information provided by the network, i.e. information received and stored by the terminal (101) regarding whether the network supports the relevant function, can be utilized.

[0084] The information provided by the network may be the PLMN info list received in step 205, i.e., PLMN information, and T-PLMN information for providing the corresponding function in response to the PLMN when the PLMN requires a function to reduce traffic load, such as traffic steering or switching.

[0085] At step 235, the UE (101) can determine whether the PLMN is the same PLMN or a different PLMN.

[0086] - Depending on whether the PLMN providing traffic steering and switching is the same PLMN or a different PLMN, there may be additional information to consider.

[0087] - For example, as an example, UE (101) may select a PLMN by considering access technology if it is the same PLMN. Or, as another example, if the same PLMN or network is divided into sub-networks to configure the network, information for distinguishing the sub-networks is transmitted from the network to UE (101), and UE (101) can use the information to determine whether it is within the same PLMN or whether to steer or switch traffic to another PLMN.

[0088] At step 237, the UE (101) may perform PLMN selection. At this time, the following procedure is followed, and the information described below may be used as a basis for judgment in this PLMN selection.

[0089] [PLMN selection example 1]

[0090] Case 1)

[0091] The following is the automatic PLMN selection method, and the priority order of the PLMN selection method is as follows.

[0092] In one embodiment, the UE (101) selects a PLMN in the following order.

[0093] Order 1) RPLMN or EPLMN or VPLMN or T-PLMN

[0094] Here, T-PLMN refers to a PLMN in which the UE (101) can receive services by connecting to and registering in two 3GPP access networks / networks when the network to which the UE (101) is connected / registered has heavy traffic or requires traffic steering, traffic switching, etc.

[0095] In one embodiment, when the UE (101) successfully registers with the HPLMN, the T-PLMN may be included in a registration accept message and transmitted from the AMF (111) to the UE (101).

[0096] Sequence 1-1: case 1-1)

[0097] In one embodiment, it may be transmitted by being included in the T-PLMN list of the registration accept message.

[0098] As an example, the T-PLMN here refers to a PLMN in which a UE (101) can receive services by connecting to and registering in two 3GPP access networks / networks when the network to which the UE (101) is connected / registered has heavy traffic or requires traffic steering, traffic switching, etc.

[0099] Among the PLMNs that the UE (101) can access, there may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0100] In one embodiment, there may be a preferred PLMN or preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0101] Or, in order 1-2: Case 1-2) As an example, the T-PLMN may be included in the EPLMN list of the registration accept message and transmitted.

[0102] That is, in this case, the UE (101) may transmit PLMN information, i.e., T-PLMN, that can be used in situations such as traffic steering, traffic switching, (traffic split) to the EPLMN using a list, i.e., an information element, from the AMF (111) to the UE (101).

[0103] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0104] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0105] Or, in one embodiment of Case 1-3, the T-PLMN may be included in the VPLMN list of the registration accept message and transmitted.

[0106] That is, in this case, the UE (101) may transmit PLMN information, i.e., T-PLMN, that can be used in situations such as traffic steering, traffic switching, (traffic split), to the UE (101) using a list, i.e., an information element, that transmits VPLMN from the AMF (111).

[0107] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0108] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0109] Step 2) User-controlled PLMN and access technology

[0110] Step 3) Operator controlled PLMN and access technology

[0111] Order 4) PLMN reported as high quality PLMN by AS

[0112] That is, as seen in case 1, the PLMN is selected by making a judgment in the order of order 1), order 2), order 3), and order 4). In the case of order 1, Case 1-1, case 1-2, or case 1-3 are possible.

[0113] Therefore, since the PLMN is selected by considering this information, when selecting the PLMN by considering traffic steering, traffic switching, (traffic split), it is possible to select the PLMN by raising the priority.

[0114] [PLMN selection example 2]

[0115] Another example could be Case 2.

[0116] case 2)

[0117] This is when there is a change in order 2).

[0118] In one embodiment, the T-PLMN may be included in the list of User controlled PLMN and access technology information transmitted in the registration accept message.

[0119] That is, in this case, the UE (101) may transmit PLMN information, i.e., T-PLMN, that can be used in situations such as traffic steering, traffic switching, (traffic split), to the UE (101) using a list, i.e., an information element, that transmits the user controlled PLMN from the AMF (111).

[0120] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0121] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0122] In the case of Case 2, the PLMN is selected by judging in the order of order 1), order 2), order 3), and order 4. In the case of order 1, RPLMN or EPLMN or VPLMN is selected with priority, and then T-PLMN information is sent while transmitting the user controlled PLMN in order 2, that is, order 2 with lower priority, so that the UE (101) that receives it can use it in situations such as traffic steering, traffic switching, and (traffic split).

[0123] [PLMN selection example 3]

[0124] Another example could be Case 3.

[0125] case 3)

[0126] This is when there is a change in order 3).

[0127] In one embodiment, the T-PLMN may be included in the list of operator controlled PLMN and access technology information transmitted in the registration accept message.

[0128] That is, in this case, the UE (101) may transmit PLMN information that can be used in situations such as traffic steering, traffic switching, (traffic split) from the AMF (111) to the UE (101) using a list, i.e., an information element, that transmits the operator controlled PLMN, i.e., the T-PLMN.

[0129] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0130] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0131] Subsequent order 3) Operator controlled PLMN and access technology

[0132] Afterwards, the PLMNs reported as high quality PLMNs by the AS corresponding to order 4) are sequentially judged and PLMN selection can be performed.

[0133] In the case of Case 3, the PLMN is selected by making judgments in the order of order 1), order 2), order 3), and order 4), and in the case of order 1, RPLMN or EPLMN or VPLMN is selected with priority, and then in order 2), that is, in order 2 with a lower priority, the user controlled PLMN is selected, and then in order 3), operator controlled PLMN information is transmitted while T-PLMN information is sent, so that the UE (101) that received it can use it in situations such as traffic steering, traffic switching, and (traffic split).

[0134] Afterwards, the PLMNs reported as high quality PLMNs by the AS corresponding to order 4) are sequentially judged and PLMN selection can be performed.

[0135] At step 241, the UE (101) can transmit a registration request message to the AMF (111-3).

[0136] At this time, the registration request message can be transmitted via T-PLMN.

[0137] This allows UE (101) to register through T-PLMN through the PLMN selection process of process 237 among the PLMN information list and T-PLMN information received from the previous registration.

[0138] - That is, the previous PLMN information list and T-PLMN information are transmitted together and saved, and when selecting a PLMN, the information is used to select the PLMN and perform registration with the PLMN.

[0139] If (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, these T-PLMNs are PLMNs that can support functions such as traffic steering, switching, and split by mapping to RPLMN, i.e., registered PLMN registered by UE (101). Or, as an example, T-PLMN can be PLMN that corresponds (is mapped) to VPLMN, i.e., visited PLMN for traffic steering, switching, traffic split, etc. Or, it can be PLMN that corresponds to operator controlled PLMN managed by operator. Here, the term “corresponding” or “mapping” means PLMN information that can be used to switch, steer, or split traffic of RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in RPLMN, VPLMN, or operator controlled PLMN by mapping 1:1 or 1:n with RPLMN, VPLMN, or operator controlled PLMN. Therefore, this information can be transmitted (corresponding / mapping) with information such as RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN. Alternatively, it can be utilized by transmitting it as a separate information element together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN.

[0140] At step 243, AMF (111-3) can map mobility contexts for UE (101).

[0141] If the newly connected AMF (111-3) and the previous AMF (111) belong to the same PLMN, the information of the UE (101) in the previous AMF (111) and the information of the UE (101) in the newly connected AMF (111-3) must be managed for the same UE (101). For example, in one embodiment, in terms of the UE identifier (UE (101) ID, e.g., SUPI, IMSI, GUTI, etc.), information such as mobility-related information and security-related keys in AMF1 (111) (the previous AMF) and AMF2 (111-3) (the newly additionally registered AMF) must be managed together with the UE identifier as primary information.

[0142] In step 245, AMF (111-3) transmits a registration accept message to UE (101).

[0143] At this time, AMF (111-3) can transmit to UE (101) information, indicators, and capabilities that AMF (111-3) itself can process and support additional 3GPP access network, i.e., additional PLMN, for example, T-PLMN information for traffic control, in order to switch, steer, or split traffic.

[0144] In step 251, the UE (101) can transmit a PDU session establishment request message to the SMF (121).

[0145] As an example (case1),

[0146] - At this time, UE (101) was already transmitting traffic in the previous network, and in order to control traffic and to steer and switch traffic through an additional T-PLMN, UE (101) can transmit information, an indicator, an information element, or bit information to the network or SMF (121) indicating that it is sending the request through T-PLMN.

[0147] As an example (case 2),

[0148] - The following information may be transmitted together. When steering traffic through a newly created PDU session, information elements may be transmitted that indicate that the newly added traffic was steered from the same UE (101) as the previous traffic.

[0149] As an example (case 3)

[0150] - Information such as information elements and bits that indicate traffic steering can be transmitted from the UE (101) to the SMF (121).

[0151] At step 253, SMF (121) can map the flow to UE (101).

[0152] As an example (case 1)

[0153] - SMF (121) can perform operations (management) such as mapping PDU session information to UE (101) and mapping (corresponding) to PDU session Identity (ID) to manage steering, switching, and (split) traffic for the corresponding UE (101) in PDU sessions that UE (101) was communicating on a previous network and PDU sessions added in an additionally registered network by mapping the identity of UE (101) or identifier (SUPI, IMSI, GUTI, etc.) of UE (101).

[0154] At step 257, SMF (121) may transmit a PDU session establishment response to UE (101).

[0155] FIG. 3 is a flowchart illustrating a procedure for performing communication in a 3GPP network environment according to one embodiment of the present disclosure.

[0156] FIG. 3 is an example of a case where the access networks (e.g., two 3GPP networks) to which the UE (101) is connected for traffic steering, traffic switching, (traffic split), etc., belong to different PLMNs.

[0157] In one embodiment, for two PLMNs, information on PLMNs (named as T-PLMN in one embodiment of the present invention) that can be additionally used for traffic steering, (traffic splitting), and traffic switching for a specific PLMN (e.g., a main PLMN, a PLMN that has previously performed communication, or a registered PLMN) can be transmitted together.

[0158] [Example 1]

[0159] As an example, steps 301, 305, 307, 311, and 313 below may be processes performed in the home network (VPLMN) of the UE (101).

[0160] In one embodiment, when performed in a home network, the UE (101) may receive / store information received in steps 305, etc. in the home network and use the information when moving to a VPLMN or when using another (additional) access network.

[0161] [Example 2]

[0162] As an example, steps 301, 305, 307, 311, and 313 below may be processes performed in a visited network (VPLMN) of the UE (101).

[0163] When performed in a visited network, the UE (101) receives / stores information received in steps 305, etc. from the visited network and can use the information when using other (additional) access networks in subsequent processes.

[0164] In step 301, the UE (101) can transmit a registration request message to the AMF (111).

[0165] Information included in the registration request at this time may include:

[0166] The UE (101) can transmit an indication for T-PLMN support to the network.

[0167] The above T-PLMN support indicator may be an indicator that indicates that the UE (101) has the ability to support functions such as traffic steering, traffic switching, (traffic split) even when there are two 3GPP networks / 3GPP access networks, or may be an information element, parameter, or bit information in one embodiment.

[0168] At step 305, AMF (111) can send a registration accept message to UE (101).

[0169] Information included in the registration accept message may include:

[0170] -An information element, bit, or parameter may be transmitted indicating that AMF (111) supports T-PLMN. That is, the information element may be information indicating that when the network supports functions such as traffic steering, traffic switching, (traffic split), etc., the network can support the functions using two 3GPP access networks, and also supports a PLMN selection function to support the functions.

[0171] - PLMN information list and T-PLMN information can be transmitted together. If (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, the T-PLMNs can be RPLMNs, i.e. PLMNs that can support functions such as traffic steering, switching, and split by mapping to the registered PLMN registered by the UE (101). Or, in one embodiment, the T-PLMN can be a PLMN corresponding to (mapped to) a VPLMN, i.e. a visited PLMN, for traffic steering, switching, traffic split, etc. Or, it can be a PLMN corresponding to an operator controlled PLMN managed by an operator. Here, the term “corresponding” or “mapping” may refer to PLMN information that can be used to switch, steer, or split traffic of an RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in the RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN by mapping 1:1 or 1:n with an RPLMN, VPLMN, or operator controlled PLMN. Accordingly, the above information may be transmitted together with (corresponding / mapping) information of an RPLMN, VPLMN, or operator controlled PLMN or user defined PLMN.Alternatively, it may be transmitted as a separate information element together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN.

[0172] At step 307, the UE (101) can store the information. The information stored at this time may be as follows.

[0173] - An information element, bit, or parameter may be transmitted to indicate that AMF (111) supports T-PLMN, and the UE (101) may store the information and use it when selecting a PLMN later. In other words, the information element may be information indicating that when the network supports functions such as traffic steering, traffic switching, (traffic split), etc., the network may support the functions using two 3GPP access networks, and also supports a PLMN selection function to support the functions.

[0174] - The PLMN information list and T-PLMN information can be stored together. If the (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, these T-PLMNs are PLMNs that can support functions such as traffic steering, switching, and split by mapping to the RPLMN, i.e., the registered PLMN registered by the UE (101). Or, in one embodiment, the T-PLMN can be a PLMN corresponding to (mapped to) a VPLMN, i.e., a visited PLMN, for traffic steering, switching, traffic split, etc. Or, it can be a PLMN corresponding to an operator controlled PLMN managed by an operator. Here, the term “corresponding” or “mapping” may refer to PLMN information that can be used to switch, steer, or split traffic of an RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in the RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN by mapping 1:1 or 1:n with an RPLMN, VPLMN, or operator controlled PLMN. Accordingly, the above information may be transmitted together with (corresponding / mapping) information of an RPLMN, VPLMN, or operator controlled PLMN or user defined PLMN.Alternatively, it may be transmitted as a separate information element together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN, and the transmitted information may be stored in the UE (101) and used as information necessary for judgment when selecting a PLMN later.

[0175] In step 311, the UE (101) can transmit a PDU session establishment request message to the SMF (121).

[0176] At this time, the UE (101) can transmit information such as function indication indicator information, information elements, and parameters to the SMF (121) to inform that the UE (101) has the capability to support even when there are two 3GPP access networks for traffic steering, (split), switching, etc.

[0177] At step 313, SMF (121) may transmit a PDU session establishment response message to UE (101).

[0178] In step 333, the UE (101) can determine whether services such as traffic steering, traffic switching, (traffic split), or temporary services such as traffic distribution are supported through another 3GPP access network / network when traffic is heavy through two (or more) 3GPP networks.

[0179] - For the above judgment, information on whether the UE (101) has the corresponding capability and whether the terminal is a terminal version (e.g., release 19) or higher that supports the corresponding function can be utilized.

[0180] - In addition, for the above judgment, information provided by the network, i.e. information received and stored by the terminal (101) regarding whether the network supports the relevant function, can be utilized.

[0181] The information provided by the network may be the PLMN info list received in step 305, i.e., PLMN information, and T-PLMN information for providing the corresponding function in response to the PLMN when the PLMN requires a function to reduce traffic load, such as traffic steering or switching.

[0182] At step 335, the UE (101) can determine whether the PLMN is the same PLMN or a different PLMN.

[0183] - Depending on whether the PLMN providing traffic steering and switching is the same PLMN or a different PLMN, there is additional information to consider.

[0184] - For example, as an example, UE (101) may select a PLMN by considering access technology if it is the same PLMN. Or, as another example, if the same PLMN or network is divided into sub-networks to configure the network, information for distinguishing the sub-networks is transmitted from the network to UE (101), and UE (101) can use the information to determine whether it is within the same PLMN or whether to steer or switch traffic to another PLMN.

[0185] At step 337, the UE (101) may perform PLMN selection. At this time, the following procedure is followed, and the information described below may be used as a basis for judgment in this PLMN selection.

[0186] [PLMN selection example 1]

[0187] Case 1)

[0188] The following is the automatic PLMN selection method, and the priority order of the PLMN selection method is as follows.

[0189] In one embodiment, the UE (101) may select a PLMN in the following order.

[0190] Order 1) RPLMN or EPLMN or VPLMN or T-PLMN

[0191] Here, T-PLMN refers to a PLMN in which a UE (101) can receive services by connecting to and registering in two 3GPP access networks / networks when the network to which the UE (101) is connected / registered has heavy traffic or requires traffic steering, traffic switching, etc.

[0192] In one embodiment, such T-PLMN may be included in a registration accept message and transmitted from AMF (111) to UE (101) when UE (101) successfully registers with HPLMN.

[0193] Sequence 1-1: case 1-1)

[0194] In one embodiment, it may be transmitted by being included in the T-PLMN list of the registration accept message.

[0195] As an example, the T-PLMN here may be a PLMN in which the UE (101) can receive services by connecting to and registering in two 3GPP access networks / networks when the network to which the UE (101) is connected / registered has heavy traffic or requires traffic steering, traffic switching, etc.

[0196] Among the PLMNs that the UE (101) can access, there may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0197] In one embodiment, there may be a preferred PLMN or preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0198] Or, in order 1-2: Case 1-2) As an example, the T-PLMN may be included in the EPLMN list of the registration accept message and transmitted.

[0199] That is, in this case, the UE (101) may transmit PLMN information, i.e., T-PLMN, that can be used in situations such as traffic steering, traffic switching, (traffic split) to the EPLMN using a list, i.e., an information element, from the AMF (111) to the UE (101).

[0200] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE can use in situations such as traffic steering, traffic switching, (traffic split).

[0201] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0202] Or, in one embodiment of Case 1-3, the T-PLMN may be included in the VPLMN list of the registration accept message and transmitted.

[0203] That is, in this case, the UE (101) transmits PLMN information, that is, T-PLMN, that can be used in situations such as traffic steering, traffic switching, (traffic split), to the UE (101) using a list, that is, an information element, that transmits VPLMN from the AMF (111).

[0204] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0205] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0206] Step 2) User-controlled PLMN and access technology

[0207] Step 3) Operator controlled PLMN and access technology

[0208] Order 4) PLMN reported as high quality PLMN by AS

[0209] That is, as seen in case 1, the PLMN is selected by making a judgment in the order of order 1), order 2), order 3), and order 4). In the case of order 1, Case 1-1, case 1-2, or case 1-3 may be possible.

[0210] Therefore, since the PLMN is selected by considering this information, if the PLMN is selected by considering traffic steering, traffic switching, (traffic split), it may be possible to select the PLMN by raising the priority.

[0211] [PLMN selection example 2]

[0212] Another example could be Case 2.

[0213] case 2)

[0214] There may be a change in order 2).

[0215] In one embodiment, the T-PLMN may be included in the list of User controlled PLMN and access technology information transmitted in the registration accept message.

[0216] That is, in this case, the UE (101) transmits PLMN information that can be used in situations such as traffic steering, traffic switching, (traffic split) to the UE from the AMF using the list, that is, the information element, that transmits the user controlled PLMN.

[0217] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0218] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0219] In the case of Case 2, the PLMN is selected by making a judgment in the order of order 1), order 2), order 3), and order 4. In the case of order 1, RPLMN or EPLMN or VPLMN is selected by giving priority, and then T-PLMN information is sent while transmitting the user controlled PLMN in order 2, that is, order 2 with lower priority, so that the UE (101) that receives it can use it in situations such as traffic steering, traffic switching, and (traffic split).

[0220] [PLMN selection example 3]

[0221] Another example could be Case 3.

[0222] case 3)

[0223] This is when there is a change in order 3).

[0224] In one embodiment, the T-PLMN may be included in the list of operator controlled PLMN and access technology information transmitted in the registration accept message.

[0225] That is, in this case, the UE (101) may transmit PLMN information that can be used in situations such as traffic steering, traffic switching, (traffic split) to the UE (101) using a list, i.e., an information element, that transmits the operator controlled PLMN, i.e., the T-PLMN, from the AMF (111) to the UE (101).

[0226] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0227] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0228] Subsequent order 3) Operator controlled PLMN and access technology

[0229] Afterwards, the PLMNs reported as high quality PLMNs by the AS corresponding to order 4) are sequentially judged and PLMN selection can be performed.

[0230] In the case of Case 3, the PLMN is selected by making judgments in the order of order 1), order 2), order 3), and order 4), and in the case of order 1, RPLMN or EPLMN or VPLMN is selected with priority, and then in order 2), that is, in order 2 with a lower priority, the user controlled PLMN is selected, and then in order 3), operator controlled PLMN information is transmitted while T-PLMN information is sent, so that the UE (101) that receives it can use it in situations such as traffic steering, traffic switching, and (traffic split).

[0231] Afterwards, the PLMNs reported as high quality PLMNs by the AS corresponding to order 4) are sequentially judged and PLMN selection can be performed.

[0232] At step 341, the UE (101) can transmit a registration request message to the AMF (111-3).

[0233] At this time, the registration request message can be transmitted via T-PLMN.

[0234] This allows UE (101) to register through T-PLMN through the PLMN selection process of step 337 among the PLMN information list and T-PLMN information received from the previous registration.

[0235] - That is, the previous PLMN information list and T-PLMN information may be transmitted together and stored, and then when selecting a PLMN, the information may be used to select a PLMN and perform registration with the PLMN.

[0236] If (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, these T-PLMNs can be RPLMNs, i.e. PLMNs that can support functions such as traffic steering, switching, and split by mapping to the registered PLMN registered by the UE (101). Or, as an example, the T-PLMN can be a PLMN corresponding to (mapped to) a VPLMN, i.e. a visited PLMN, for traffic steering, switching, traffic split, etc. Or, it can be a PLMN corresponding to an operator controlled PLMN managed by an operator. Here, the term “corresponding” or “mapping” may refer to PLMN information that can be used to switch, steer, or split traffic of an RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in the RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN by mapping 1:1 or 1:n with an RPLMN, VPLMN, or operator controlled PLMN. Accordingly, the above information may be transmitted together with (corresponding / mapping) information of an RPLMN, VPLMN, or operator controlled PLMN, or user defined PLMN, etc. Or, it may be utilized as a separate information element transmitted together with an RPLMN, VPLMN, or operator controlled PLMN, or user defined PLMN, etc.

[0237] At step 343, AMF (111-3) can create mobility contexts for UE (101).

[0238] If the newly connected AMF (111-3) and the previous AMF (111) belong to different PLMNs, the information of the UE (101) held in the previous AMF (111) and the information of the UE (101) held in the newly connected AMF (111-3) may need to be managed for the same UE (101). For example, in one embodiment, in terms of the UE identifier (UE (101) ID, e.g., SUPI, IMSI, GUTI, etc.), information such as mobility-related information and security-related keys held by AMF1 (111) (the previous AMF) and AMF2 (111-3) (the newly additionally registered AMF) may need to be managed together with the UE identifier as the primary information. Accordingly, when creating information about UE (101) in a newly registered AMF (111-3_), but since it is a different PLMN and UE (101) is the same UE (101), the created information can be managed with relevance to provide a connection with the information that the previous AMF (111) has about UE (101). In one embodiment, the identity of UE (101) can be utilized as key information for linking and finding key information. That is, it can be known that the mobility context managed by another AMF (111-3) for UE (101) is for the same UE (101) through the identifier of UE (101).

[0239] At step 345, AMF (111-3) may send a registration accept message to UE (101).

[0240] At this time, AMF (111-3) can transmit to UE (101) information, indicators, and capabilities about the ability of AMF (111-3) to process and support additional 3GPP access network, i.e., additional PLMN, for example, T-PLMN information for traffic control, in order to switch, steer, or split traffic.

[0241] In step 347, the UE (101) may need to generate information related to the context managed by the newly registered AMF (111-3). In one embodiment, as in step 349, the UE (101) may have a mobility context managed by the previous AMF (111) (AMF1) and a mobility context managed by the newly connected AMF (111-3) (AMF2).

[0242] And since this mobility context is information about the corresponding UE (101) along with the session context and information necessary for traffic steering, switching, and splitting, it may need to be managed by mapping it together with the UE identifier to indicate that it is information about the corresponding UE (101). That is, in one embodiment, there are two mobility contexts, security contexts, etc. in the UE identifier, and these are not separate pieces of information, but may be related or have a 1:1 mapping or a 1:n mapping.

[0243] Accordingly, when creating information about the UE (101) in the newly registered AMF (111-3), since it is a different PLMN and the UE (101) is the same UE (101), the created information can be managed with relevance to provide a connection with the information that the previous AMF (111) has about the UE (101). In one embodiment, the identity of the UE (101) can be utilized as key information for linking and finding key information. That is, it can be known that the mobility context UE (101) managed by another AMF (111) for the UE (101) is for the same UE (101).

[0244] In step 351, the UE (101) can transmit a PDU session establishment request message to the SMF (121-3).

[0245] As an example (case1),

[0246] - At this time, UE (101) was already transmitting traffic in the previous network, and in order to control traffic and to steer and switch traffic through an additional T-PLMN, UE (101) can transmit information, an indicator, an information element, or bit information to the network or SMF (121) indicating that it is sending the request through T-PLMN.

[0247] As an example (case 2),

[0248] - The following information may be transmitted together. When steering traffic through a newly created PDU session, information elements may be transmitted that indicate that the newly added traffic was steered from the same UE (101) as the previous traffic.

[0249] As an example (case 3)

[0250] - Information such as information elements and bits that indicate traffic steering can be transmitted from the UE (101) to the SMF (121-3).

[0251] At step 353, SMF (121-3) can map the flow to UE (101).

[0252] As an example (case 1)

[0253] - SMF (121-3) can perform operations (management) such as mapping PDU session information to UE (101) and mapping (corresponding) to PDU session Identity (ID) to manage steering, switching, and (split) traffic for the corresponding UE (101) in PDU sessions that UE (101) was communicating on a previous network and PDU sessions added in an additionally registered network by mapping the identity of UE (101) or identifier (SUPI, IMSI, GUTI, etc.) of UE (101).

[0254] At step 357, SMF (121-3) may transmit a PDU session establishment response to UE (101).

[0255] FIG. 4 is a flowchart illustrating a procedure for performing communication in a 3GPP network environment according to one embodiment of the present disclosure.

[0256] FIG. 4 is an example of a case where the access networks (e.g., two 3GPP networks) to which the UE (101) is connected for traffic steering, traffic switching, (traffic split), etc., belong to different PLMNs.

[0257] This embodiment is an embodiment of performing traffic steering, traffic switching, (traffic split), etc. through PDU session modification.

[0258] In one embodiment, for two PLMNs, information on PLMNs (named as T-PLMN in one embodiment of the present invention) that can be additionally used for traffic steering, (traffic splitting), and traffic switching for a specific PLMN (e.g., a main PLMN, a PLMN that has previously performed communication, or a registered PLMN) can be transmitted together.

[0259] [Example 1]

[0260] As an example, steps 401, 405, 407, 411, and 413 below may be processes performed in the home network (VPLMN) of the UE (101).

[0261] In one embodiment, when performed in a home network, the UE (101) may receive / store information received in steps 405, etc. in the home network and use the information when moving to a VPLMN or when using another (additional) access network.

[0262] [Example 2]

[0263] As an example, steps 401, 405, 407, 411, and 413 below may be processes performed in a visited network (VPLMN) of the UE (101).

[0264] When performed in a visited network, the UE (101) receives / stores information received in steps 405, etc. from the visited network and can use the information when using other (additional) access networks in subsequent processes.

[0265] In step 401, the UE (101) can transmit a registration request message to the AMF (111).

[0266] Information included in the registration request at this time may include:

[0267] The UE (101) can transmit an indication of T-PLMN support to the network.

[0268] The above T-PLMN support indicator may be an indicator that indicates that the UE (101) has the ability to support functions such as traffic steering, traffic switching, (traffic split) even when there are two 3GPP networks / 3GPP access networks, or may be an information element, parameter, or bit information in one embodiment.

[0269] At step 405, AMF (111) can send a registration accept message to UE (101).

[0270] Information included in the registration accept message may include:

[0271] - An information element, bit, or parameter may be transmitted to indicate that AMF (111) supports T-PLMN. The information element may be information indicating that the network can support functions such as traffic steering, traffic switching, (traffic split) by using two 3GPP access networks, and also supports a PLMN selection function to support such functions.

[0272] - PLMN information list and T-PLMN information can be transmitted together. If (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, the T-PLMNs can be RPLMNs, i.e. PLMNs that can support functions such as traffic steering, switching, and split by mapping to the registered PLMN registered by the UE (101). Or, in one embodiment, the T-PLMN can be a PLMN corresponding to (mapped to) a VPLMN, i.e. a visited PLMN, for traffic steering, switching, traffic split, etc. Or, it can be a PLMN corresponding to an operator controlled PLMN managed by an operator. Here, the term “corresponding” or “mapping” may refer to PLMN information that can be used to switch, steer, or split traffic of an RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in the RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN by mapping 1:1 or 1:n with an RPLMN, VPLMN, or operator controlled PLMN. Accordingly, the above information may be transmitted together with (corresponding / mapping) information of an RPLMN, VPLMN, or operator controlled PLMN or user defined PLMN.Alternatively, it may be transmitted as a separate information element together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN.

[0273] At step 407, the UE (101) can store the information. The information stored at this time may be as follows.

[0274] - An information element, bit, or parameter may be transmitted to indicate that AMF (111) supports T-PLMN, and the UE (101) may store the information and use it when selecting a PLMN later. The information element may be information indicating that the network can support functions such as traffic steering, traffic switching, (traffic split) by using two 3GPP access networks, and also supports a PLMN selection function to support such functions.

[0275] - PLMN information list and T-PLMN information can be stored together. If (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, these T-PLMNs can be PLMNs that can support functions such as traffic steering, switching, and split by mapping to RPLMN, i.e. registered PLMN registered by UE. Or, as an example, T-PLMN can be PLMN corresponding to (mapped to) VPLMN, i.e. visited PLMN for traffic steering, switching, traffic split, etc. Or, it can be PLMN corresponding to operator controlled PLMN managed by operator. Here, the term “corresponding” or “mapping” may refer to PLMN information that can be used to switch, steer, or split traffic of an RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in the RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN by mapping 1:1 or 1:n with an RPLMN, VPLMN, or operator controlled PLMN. Accordingly, the above information may be transmitted together with (corresponding / mapping) information of an RPLMN, VPLMN, or operator controlled PLMN or user defined PLMN.Alternatively, it may be transmitted as a separate information element together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN, and the transmitted information may be stored in the UE (101) and used as information necessary for judgment when selecting a PLMN later.

[0276] In step 411, the UE (101) can transmit a PDU session establishment request message to the SMF (121).

[0277] At this time, the UE (101) can transmit information such as function indication indicator information, information elements, and parameters to the SMF (121) to inform that the UE (101) has the capability to support even when there are two 3GPP access networks for traffic steering, (split), switching, etc.

[0278] At step 413, SMF (121) may transmit a PDU session establishment response message to UE (101).

[0279] In step 433, the UE (101) can determine whether services such as traffic steering, traffic switching, (traffic split), or temporary services such as distributing traffic are supported through another 3GPP access network / network when traffic is heavy through two (or more) 3GPP networks.

[0280] - For the above judgment, information on whether the UE (101) has the corresponding capability and whether the terminal is a terminal version (e.g., release 19) or higher that supports the corresponding function can be utilized.

[0281] - In addition, for the above judgment, information provided by the network, i.e. information received and stored by the terminal (101) regarding whether the network supports the relevant function, can be utilized.

[0282] The information provided by the network may be the PLMN info list received in step 405, i.e., PLMN information, and T-PLMN information for providing the corresponding function in response to the PLMN when a function to reduce traffic load, such as traffic steering or switching, is required for the PLMN.

[0283] At step 435, the UE (101) can determine whether the PLMN is the same PLMN or a different PLMN.

[0284] - Depending on whether the PLMN providing traffic steering and switching is the same PLMN or a different PLMN, there may be additional information to consider.

[0285] - For example, in one embodiment, if it is the same PLMN, the PLMN may be selected by considering the access technology. Or, in another embodiment, if the same PLMN or network is divided into sub-networks to configure the network, information for distinguishing the sub-networks is transmitted from the network to the UE (101), and the UE (101) can use the information to determine whether it is within the same PLMN or to steer or switch traffic to another PLMN.

[0286] At step 437, the UE (101) may perform PLMN selection. At this time, the following procedure is followed, and the information described below may be used as a basis for judgment in this PLMN selection.

[0287] [PLMN selection example 1]

[0288] Case 1)

[0289] The following is an automatic PLMN selection method, and the priority order of the PLMN selection method can be as follows.

[0290] In one embodiment, the UE (101) may select a PLMN in the following order.

[0291] Order 1) RPLMN or EPLMN or VPLMN or T-PLMN

[0292] Here, T-PLMN may be a PLMN in which the UE (101) can receive services by connecting to and registering in two 3GPP access networks / networks when the network to which the UE (101) is connected / registered has heavy traffic or requires traffic steering, traffic switching, etc.

[0293] In one embodiment, such a T-PLMN may be included in a registration accept message and transmitted from AMF (111) to UE (101) when UE (101) successfully registers with HPLMN.

[0294] Sequence 1-1: case 1-1)

[0295] In one embodiment, it may be transmitted by being included in the T-PLMN list of the registration accept message.

[0296] As an example, the T-PLMN here may be a PLMN in which the UE (101) can receive services by connecting to and registering in two 3GPP access networks / networks when the network to which the UE (101) is connected / registered has heavy traffic or requires traffic steering, traffic switching, etc.

[0297] Among the PLMNs that the UE (101) can access, there may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0298] In one embodiment, there may be a preferred PLMN or preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0299] Or, in order 1-2: Case 1-2) As an example, the T-PLMN may be included in the EPLMN list of the registration accept message and transmitted.

[0300] That is, in this case, the UE (101) may transmit PLMN information, i.e., T-PLMN, that can be used in situations such as traffic steering, traffic switching, (traffic split) to the EPLMN using a list, i.e., an information element, from the AMF (111) to the UE (101).

[0301] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0302] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0303] Or, in one embodiment of Case 1-3, the T-PLMN may be included in the VPLMN list of the registration accept message and transmitted.

[0304] That is, in this case, the UE (101) may transmit PLMN information, i.e., T-PLMN, to the UE (101) using a list, i.e., an information element, that transmits VPLMN information that can be used in situations such as traffic steering, traffic switching, (traffic split) from the AMF (111) to the UE (101).

[0305] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0306] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0307] Step 2) User-controlled PLMN and access technology

[0308] Step 3) Operator controlled PLMN and access technology

[0309] Order 4) PLMN reported as high quality PLMN by AS

[0310] That is, as seen in case 1, the PLMN is selected by making a judgment in the order of order 1), order 2), order 3), and order 4). In the case of order 1, Case 1-1, case 1-2, or case 1-3 may be possible.

[0311] Therefore, since the PLMN is selected by considering this information, if the PLMN is selected by considering traffic steering, traffic switching, (traffic split), it may be possible to select the PLMN by raising the priority.

[0312] [PLMN selection example 2]

[0313] Another example could be Case 2.

[0314] case 2)

[0315] There may be a change in order 2).

[0316] In one embodiment, the T-PLMN may be included in the list of User controlled PLMN and access technology information transmitted in the registration accept message.

[0317] That is, in this case, the UE (101) may transmit PLMN information that can be used in situations such as traffic steering, traffic switching, (traffic split) to the UE (101) using a list, i.e., an information element, that transmits the user controlled PLMN, i.e., the T-PLMN, from the AMF to the UE (101).

[0318] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0319] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0320] In the case of Case 2, the PLMN is selected by making a judgment in the order of order 1), order 2), order 3), and order 4. In the case of order 1, RPLMN or EPLMN or VPLMN is selected by giving priority, and then T-PLMN information is sent while transmitting the user controlled PLMN in order 2, that is, order 2 with lower priority, so that the UE (101) that receives it can use it in situations such as traffic steering, traffic switching, and (traffic split).

[0321] [PLMN selection example 3]

[0322] Another example could be Case 3.

[0323] case 3)

[0324] This is when there is a change in order 3).

[0325] In one embodiment, the T-PLMN may be included in the list of operator controlled PLMN and access technology information transmitted in the registration accept message.

[0326] That is, in this case, the UE (101) may transmit PLMN information that can be used in situations such as traffic steering, traffic switching, (traffic split) from the AMF (111) to the UE (101) using a list, i.e., an information element, that transmits the operator controlled PLMN, i.e., the T-PLMN.

[0327] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0328] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0329] Subsequent order 3) Operator controlled PLMN and access technology

[0330] Afterwards, the PLMNs reported as high quality PLMNs by the AS corresponding to order 4) are sequentially judged and PLMN selection can be performed.

[0331] In the case of Case 3, the PLMN is selected by making judgments in the order of order 1), order 2), order 3), and order 4), and in the case of order 1, RPLMN or EPLMN or VPLMN is selected with priority, and then in order 2), that is, in order 2 with a lower priority, the user controlled PLMN is selected, and then in order 3), operator controlled PLMN information is transmitted while T-PLMN information is sent, so that the UE (101) that receives it can use it in situations such as traffic steering, traffic switching, and (traffic split).

[0332] Afterwards, the PLMNs reported as high quality PLMNs by the AS corresponding to order 4) are sequentially judged and PLMN selection can be performed.

[0333] At step 441, the UE (101) may transmit a registration request message to the AMF (111-3).

[0334] At this time, the registration request message can be transmitted via T-PLMN.

[0335] This allows UE (101) to register through T-PLMN through the PLMN selection process of step 437 among the PLMN information list and T-PLMN information received from the previous registration.

[0336] - That is, the previous PLMN information list and T-PLMN information may be transmitted together and stored, and then when selecting a PLMN, the information may be used to select a PLMN and perform registration with the PLMN.

[0337] If (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, the T-PLMNs are PLMNs that can support functions such as traffic steering, switching, and split by mapping to RPLMN, i.e., registered PLMN registered by UE. Or, as an example, T-PLMN can be PLMN corresponding (mapped) to VPLMN, i.e., visited PLMN for traffic steering, switching, and traffic split, etc. Or, it can be PLMN corresponding to operator controlled PLMN managed by operator. Here, the term “corresponding” or “mapping” can mean PLMN information that can be used to switch, steer, or split traffic of RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in RPLMN, VPLMN, or operator controlled PLMN by mapping 1:1 or 1:n with RPLMN, VPLMN, or operator controlled PLMN. Accordingly, the above information may be transmitted (corresponding / mapping) with information such as RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN. Alternatively, it may be utilized as a separate information element transmitted together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN.

[0338] At step 443, AMF (111-3) can create mobility contexts for UE (101).

[0339] If the newly connected AMF (111-3) and the previous AMF (111) belong to different PLMNs, the information of the UE (101) held by the previous AMF (111) and the information of the UE (101) held by the newly connected AMF (111-3) may need to be managed for the same UE (101). For example, in one embodiment, in terms of the UE identifier (UE (101) ID, e.g., SUPI, IMSI, GUTI, etc.), information such as mobility-related information and security-related keys held by AMF1 (111) (the previous AMF) and AMF2 (111-3) (the newly additionally registered AMF) may need to be managed together with the UE identifier as primary information. Accordingly, when information about the UE (101) is created in the newly registered AMF (111-3), but since it is a different PLMN and the UE (101) is the same UE (101), the created information can be managed with relevance to provide a connection with the information that the previous AMF (111) has about the UE (101). In one embodiment, the identity of the UE (101) can be utilized as key information for linking and finding key information. That is, the mobility context managed by another AMF (111), etc. for the UE (101), can be known to be for the same UE (101) through the identifier of the UE (101).

[0340] At step 445, AMF (111-3) may send a registration accept message to UE (101).

[0341] At this time, AMF (111-3) can transmit to UE (101) information, indicators, and capabilities that AMF (111-3) can process and support additional 3GPP access network, i.e., additional PLMN, for traffic control, for example, T-PLMN information, in order to switch, steer, or split traffic.

[0342] In step 447, the UE (101) may need to generate information related to the context managed by the newly registered AMF (111-3). In one embodiment, as in step 449, the UE (101) may have a mobility context of the UE (101) managed by the previous AMF (111) (AMF1) and a mobility context managed by the newly connected AMF (111-3) (AMF2). In addition, the mobility context, along with the session context, is information about the corresponding UE (101) and information necessary for traffic steering, switching, and splitting, so it may need to be managed by mapping it together with the UE identifier to indicate that it is information about the corresponding UE (101). That is, in one embodiment, there are two mobility contexts, security contexts, etc. in the UE identifier, and these are not separate pieces of information, but may be related, have a 1:1 mapping, or have a 1:n mapping.

[0343] Accordingly, when creating information about the UE (101) in the newly registered AMF (111-3), since it is a different PLMN and the UE (101) is the same UE (101), the created information can be managed with relevance to provide a connection with the information that the previous AMF (111) has about the UE (101). In one embodiment, the identity of the UE (101) can be utilized as key information for linking and finding key information. That is, the mobility context managed by another AMF (111), etc. for the UE (101), can be known to be for the same UE (101) through the identifier of the UE (101).

[0344] In step 451, the UE (101) can transmit a PDU session modification request message to the SMF (121).

[0345] As an example (case1),

[0346] - At this time, the UE (101) was already transmitting traffic in the previous network, and in order to control traffic and to steer and switch traffic through an additional T-PLMN, the UE (101) can transmit information, an indicator, an information element, or bit information to the network or SMF (121) indicating that it is sending the request through the T-PLMN.

[0347] As an example (case 2),

[0348] - The following information may be transmitted together. When steering traffic through a newly created PDU session, information elements may be transmitted that indicate that the newly added traffic was steered from the same UE (101) as the previous traffic.

[0349] As an example (case 3)

[0350] - Information such as information elements and bits that indicate traffic steering can be transmitted from the UE (101) to the SMF (121).

[0351] At step 453, SMF (121) can map the flow to UE (101).

[0352] As an example (case 1)

[0353] - SMF (121) can perform operations (management) such as mapping PDU session information to UE (101) and mapping (corresponding) to PDU session Identity (ID) to manage steering, switching, and (split) traffic for the corresponding UE (101) in PDU sessions that UE (101) was communicating on a previous network and PDU sessions added in an additionally registered network by mapping the identity of UE (101) or identifier (SUPI, IMSI, GUTI, etc.) of UE (101).

[0354] At step 457, SMF (121) may transmit a PDU session modification response to UE (101).

[0355] FIG. 5 is a flowchart illustrating a procedure for performing communication in a 3GPP network environment according to one embodiment of the present disclosure.

[0356] FIG. 5 is an example of a case where the access networks (e.g., two 3GPP networks) to which the UE (101) is connected for traffic steering, traffic switching, (traffic split), etc., belong to different PLMNs.

[0357] This embodiment is an example of performing traffic steering, traffic switching, (traffic split), etc. through deregistration. In particular, when traffic is switched from a previously connected 3GPP access network to another access network, deregistration may need to be performed to manage mobility management, etc. involved in the previous traffic. Accordingly, this embodiment may include such a deregistration process.

[0358] In one embodiment, for two PLMNs, information on PLMNs (named as T-PLMN in one embodiment of the present invention) that can be additionally used for traffic steering, (traffic splitting), and traffic switching for a specific PLMN (e.g., a main PLMN, a PLMN that has previously performed communication, or a registered PLMN) can be transmitted together.

[0359] [Example 1]

[0360] As an example, steps 501, 505, 507, 511, and 513 below may be processes performed in the home network (VPLMN) of the UE (101).

[0361] In one embodiment, when performed in a home network, the UE (101) may receive / store information received in steps 505, etc. in the home network and use the information when moving to a VPLMN or when using another (additional) access network.

[0362] [Example 2]

[0363] In one embodiment, steps 501, 505, 507, 511, and 513 below may be processes performed in a visited network (VPLMN) of the UE (101).

[0364] When performed in a visited network, the UE (101) receives / stores information received in steps 505, etc. from the visited network and can use the information when using other (additional) access networks in subsequent processes.

[0365] In step 501, the UE (101) can transmit a registration request message to the AMF (111).

[0366] Information included in the registration request at this time may include:

[0367] The UE (101) can transmit an indication for T-PLMN support to the network.

[0368] The above T-PLMN support indicator may be an indicator that indicates that the UE (101) has the ability to support functions such as traffic steering, traffic switching, (traffic split) even when there are two 3GPP networks / 3GPP access networks, or may be an information element, parameter, or bit information in one embodiment.

[0369] At step 505, AMF (111) can send a registration accept message to UE (101).

[0370] The information included in the registration accept message at this time may be as follows:

[0371] - An information element, bit, or parameter may be transmitted to indicate that AMF (111) supports T-PLMN. The information element may be information indicating that the network can support functions such as traffic steering, traffic switching, (traffic split) by using two 3GPP access networks, and also supports a PLMN selection function to support the functions.

[0372] - The PLMN information list and T-PLMN information can be transmitted together. If the (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, the T-PLMNs can be RPLMNs, i.e. PLMNs that can support functions such as traffic steering, switching, and split by mapping to the registered PLMN registered by the UE (101). Or, in one embodiment, the T-PLMN can be a PLMN corresponding to (mapped to) a VPLMN, i.e. a visited PLMN, for traffic steering, switching, traffic split, etc. Or, it can be a PLMN corresponding to an operator controlled PLMN managed by an operator. Here, the term “corresponding” or “mapping” may refer to PLMN information that can be used to switch, steer, or split traffic of an RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in the RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN by mapping 1:1 or 1:n with an RPLMN, VPLMN, or operator controlled PLMN. Accordingly, the above information may be transmitted together with (corresponding / mapping) information of an RPLMN, VPLMN, or operator controlled PLMN or user defined PLMN.Alternatively, it may be transmitted as a separate information element together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN.

[0373] At step 507, the UE (101) can store the information. The information stored at this time may be as follows.

[0374] - An information element, bit, or parameter may be transmitted to indicate that AMF (111) supports T-PLMN, and the UE (101) may store the information and use it when selecting a PLMN later. The information element may be information indicating that the network can support functions such as traffic steering, traffic switching, (traffic split) by using two 3GPP access networks, and also supports a PLMN selection function to support such functions.

[0375] - The PLMN information list and T-PLMN information can be stored together. If the (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, these T-PLMNs are PLMNs that can support functions such as traffic steering, switching, and split by mapping to the RPLMN, i.e., the registered PLMN registered by the UE (101). Or, in one embodiment, the T-PLMN can be a PLMN corresponding to (mapped to) a VPLMN, i.e., a visited PLMN, for traffic steering, switching, traffic split, etc. Or, it can be a PLMN corresponding to an operator controlled PLMN managed by an operator. Here, the term “corresponding” or “mapping” may refer to PLMN information that can be used to switch, steer, or split traffic in an RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required by mapping 1:1 or 1:n with an RPLMN, VPLMN, or operator controlled PLMN. Accordingly, this information may be transmitted together with (corresponding / mapping) information of an RPLMN, VPLMN, or operator controlled PLMN or user defined PLMN.Alternatively, it may be transmitted as a separate information element together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN, and the transmitted information may be stored in the UE (101) and used as information necessary for judgment when selecting a PLMN later.

[0376] In step 511, the UE (101) can transmit a PDU session establishment request message to the SMF (111).

[0377] At this time, the UE (101) can transmit information such as function indication indicator information, information elements, and parameters to the SMF (111) to inform that the UE (101) has the capability to support even when there are two 3GPP access networks for traffic steering, (split), switching, etc.

[0378] In step 513, SMF (111) may transmit a PDU session establishment response message to UE (101).

[0379] In step 533, the UE (101) can determine whether services such as traffic steering, traffic switching, (traffic split), or temporary services such as distributing traffic are supported through another 3GPP access network / network when traffic is heavy through two (or more) 3GPP networks.

[0380] - For the above judgment, information on whether the UE (101) has the corresponding capability and whether the terminal is a terminal version (e.g., release 19) or higher that supports the corresponding function can be utilized.

[0381] - In addition, for the above judgment, information provided by the network, i.e. information received and stored by the terminal (101) regarding whether the network supports the relevant function, can be utilized.

[0382] The information provided by the network may be the PLMN info list received in step 505, i.e., PLMN information, and T-PLMN information for providing the corresponding function in response to the PLMN when the PLMN requires a function to reduce traffic load, such as traffic steering or switching.

[0383] At step 535, the UE (101) can determine whether the PLMN is the same PLMN or a different PLMN.

[0384] - Depending on whether the PLMN providing traffic steering and switching is the same PLMN or a different PLMN, there may be additional information to consider.

[0385] - For example, in one embodiment, if it is the same PLMN, the PLMN may be selected by considering the access technology. Or, in another embodiment, if the same PLMN or network is divided into sub-networks to configure the network, information for distinguishing the sub-networks may be transmitted from the network to the UE (101), and the UE (101) may use the information to determine whether it is within the same PLMN or whether to steer or switch traffic to another PLMN.

[0386] At step 537, the UE (101) may perform PLMN selection. At this time, the following procedure is followed, and the information described below may be used as a basis for judgment in this PLMN selection.

[0387] [PLMN selection example 1]

[0388] Case 1)

[0389] The following is an automatic PLMN selection method, and the priority order of the PLMN selection method can be as follows.

[0390] In one embodiment, the UE (101) may select a PLMN in the following order.

[0391] Order 1) RPLMN or EPLMN or VPLMN or T-PLMN

[0392] Here, T-PLMN may be a PLMN in which the UE (101) can receive services by connecting to and registering in two 3GPP access networks / networks when the network to which the UE (101) is connected / registered has heavy traffic or requires traffic steering, traffic switching, etc.

[0393] In one embodiment, such T-PLMN may be included in a registration accept message and transmitted from AMF (111) to UE (101) when UE (101) successfully registers with HPLMN.

[0394] Sequence 1-1: case 1-1)

[0395] In one embodiment, it may be transmitted by being included in the T-PLMN list of the registration accept message.

[0396] As an example, the T-PLMN here may be a PLMN in which the UE (101) can receive services by connecting to and registering in two access networks / networks of 3GPP when the network to which the UE (101) is connected / registered has heavy traffic or requires traffic steering, traffic switching, etc.

[0397] Among the PLMNs that the UE (101) can access, the above T-PLMN may include a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0398] In one embodiment, there may be a preferred PLMN or preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0399] Or, in order 1-2: Case 1-2) As an example, the T-PLMN may be included in the EPLMN list of the registration accept message and transmitted.

[0400] That is, in this case, the UE (101) may transmit PLMN information, i.e., T-PLMN, that can be used in situations such as traffic steering, traffic switching, (traffic split) to the EPLMN using a list, i.e., an information element, from the AMF (111) to the UE (101).

[0401] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0402] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0403] Or, in one embodiment of Case 1-3, the T-PLMN may be included in the VPLMN list of the registration accept message and transmitted.

[0404] That is, in this case, the UE (101) may transmit PLMN information, i.e., T-PLMN, that can be used in situations such as traffic steering, traffic switching, (traffic split), to the UE (101) using a list, i.e., an information element, that transmits VPLMN from the AMF (111).

[0405] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0406] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0407] Step 2) User-controlled PLMN and access technology

[0408] Step 3) Operator controlled PLMN and access technology

[0409] Order 4) PLMN reported as high quality PLMN by AS

[0410] That is, as seen in case 1, the PLMN is selected by making a judgment in the order of order 1), order 2), order 3), and order 4). In the case of order 1, Case 1-1, case 1-2, or case 1-3 may be possible.

[0411] Therefore, the PLMN may be selected by considering the above information, and when selecting the PLMN by considering traffic steering, traffic switching, (traffic split), it may be possible to select the PLMN by increasing the priority.

[0412] [PLMN selection example 2]

[0413] Another example could be Case 2.

[0414] case 2)

[0415] There may be a change in order 2).

[0416] In one embodiment, the T-PLMN may be included in the list of User controlled PLMN and access technology information transmitted in the registration accept message.

[0417] That is, in this case, the UE (101) may transmit PLMN information, i.e., T-PLMN, that can be used in situations such as traffic steering, traffic switching, (traffic split), to the UE (101) using a list, i.e., an information element, that transmits the user controlled PLMN from the AMF (111).

[0418] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0419] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0420] In the case of Case 2, the PLMN is selected by making a judgment in the order of order 1), order 2), order 3), and order 4. In the case of order 1, RPLMN or EPLMN or VPLMN is selected by giving priority, and then T-PLMN information is sent while transmitting the user controlled PLMN in order 2, that is, order 2 with lower priority, so that the UE (101) that receives it can use it in situations such as traffic steering, traffic switching, and (traffic split).

[0421] [PLMN selection example 3]

[0422] Another example could be Case 3.

[0423] case 3)

[0424] There may be a change in order 3).

[0425] In one embodiment, the T-PLMN may be included in the list of operator controlled PLMN and access technology information transmitted in the registration accept message.

[0426] That is, in this case, the UE (101) may transmit PLMN information that can be used in situations such as traffic steering, traffic switching, (traffic split) from the AMF (111) to the UE (101) using a list, i.e., an information element, that transmits the operator controlled PLMN, i.e., the T-PLMN.

[0427] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may be a subscribed PLMN or non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0428] In one embodiment, the T-PLMN information that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split) may have a preferred PLMN or a preferred non-public network (NPN) that the UE (101) can use in situations such as traffic steering, traffic switching, (traffic split).

[0429] Subsequent order 3) Operator controlled PLMN and access technology

[0430] Afterwards, the PLMNs reported as high quality PLMNs by the AS corresponding to order 4) are sequentially judged and PLMN selection can be performed.

[0431] In the case of Case 3

[0432] The PLMN is selected by making a judgment in the order of order 1), order 2), order 3), and order 4), and in the case of order 1, RPLMN or EPLMN or VPLMN is selected with priority, and then in order 2), that is, in order 2 with a lower priority, the user controlled PLMN is selected, and then in order 3), operator controlled PLMN information is transmitted while T-PLMN information is sent, so that the UE (101) that receives it can use it in situations such as traffic steering, traffic switching, and (traffic split).

[0433] Afterwards, the PLMNs reported as high quality PLMNs by the AS corresponding to order 4) are sequentially judged and PLMN selection can be performed.

[0434] At step 541, the UE (101) may transmit a registration request message to the AMF (111-3).

[0435] At this time, the registration request message can be transmitted via T-PLMN.

[0436] This allows UE (101) to register through T-PLMN through the PLMN selection process of step 537 among the PLMN information list and T-PLMN information received from the previous registration.

[0437] - That is, the previous PLMN information list and T-PLMN information may be transmitted together and stored, and then when selecting a PLMN, the information may be used to select a PLMN and perform registration with the PLMN.

[0438] If (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, these T-PLMNs are PLMNs that can support functions such as traffic steering, switching, and split by mapping to RPLMN, i.e., registered PLMN registered by UE (101). Or, as an example, T-PLMN can be PLMN that corresponds (is mapped) to VPLMN, i.e., visited PLMN for traffic steering, switching, traffic split, etc. Or, it can be PLMN that corresponds to operator controlled PLMN managed by operator. Here, the term “corresponding” or “mapping” means PLMN information that can be used to switch, steer, or split traffic of RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in RPLMN, VPLMN, or operator controlled PLMN by mapping 1:1 or 1:n with RPLMN, VPLMN, or operator controlled PLMN. Therefore, this information can be transmitted (corresponding / mapping) with information such as RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN. Alternatively, it can be utilized by transmitting it as a separate information element together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN.

[0439] At step 543, AMF (111-3) can create mobility contexts for UE (101).

[0440] If the newly connected AMF (111-3) and the previous AMF (111) belong to different PLMNs, the information of the UE (101) held by the previous AMF (111) and the information of the UE (101) held by the newly connected AMF (111-3) may need to be managed for the same UE (101). For example, in one embodiment, in terms of the UE identifier (UE (101) ID, e.g., SUPI, IMSI, GUTI, etc.), information such as mobility-related information and security-related keys held by AMF1 (111) (the previous AMF) and AMF2 (111-3) (the newly additionally registered AMF) may need to be managed together with the UE identifier as primary information. Accordingly, when creating information about the UE (101) in the newly registered AMF (111-3), since it is a different PLMN and the UE (101) is the same UE (101), the created information can be managed with relevance to provide a connection with the information that the previous AMF (111-3) has about the UE (101). In one embodiment, the identity of the UE (101) can be utilized as key information for connecting and finding key information. That is, the mobility context managed by another AMF (111), etc. for the UE (101), can be known to be for the same UE (101) through the identifier of the UE (101).

[0441] At step 545, AMF (111-3) may send a registration accept message to UE (101).

[0442] At this time, AMF (111-3) can transmit to UE (101) information, indicators, and capabilities that AMF (111-3) can process and support additional 3GPP access network, i.e., additional PLMN, for traffic control, for example, T-PLMN information, in order to switch, steer, or split traffic.

[0443] In step 547, the UE (101) may need to generate information related to the context managed by the newly registered AMF (111-3). In one embodiment, as in step 549, the UE (101) may have a mobility context of the UE (101) managed by the previous AMF (111) (AMF1) and a mobility context managed by the newly connected AMF (111-3) (AMF2). In addition, the mobility context, along with the session context, is information about the corresponding UE (101) and information necessary for traffic steering, switching, and splitting, so it may need to be managed by mapping it together with the UE identifier to indicate that it is information about the corresponding UE (101). That is, in one embodiment, two mobility contexts, security contexts, etc. exist in the UE identifier, and these are not separate pieces of information, but may be related, have a 1:1 mapping, or have a 1:n mapping.

[0444] Accordingly, when creating information about the UE (101) in the newly registered AMF (111-3), since it is a different PLMN and the UE (101) is the same UE (101), the created information can be managed with relevance to provide a connection with the information that the previous AMF (111) has about the UE (101). In one embodiment, the identity of the UE (101) can be utilized as key information for linking and finding key information. That is, the mobility context managed by another AMF (111), etc. for the UE (101), can be known to be for the same UE (101) through the identifier of the UE (101).

[0445] In step 551, the UE (101) may transmit a PDU session modification request message to the SMF (121-3).

[0446] Alternatively, in one embodiment, the UE (101) may transmit a PDU session establishment request message to the SMF (121-3).

[0447] As an example (case1),

[0448] - At this time, UE (101) was already transmitting traffic in the previous network, and in order to control traffic and to steer and switch traffic through an additional T-PLMN, UE (101) can transmit information, an indicator, an information element, or bit information to the network or SMF (121-3) indicating that it is sending the request through T-PLMN.

[0449] As an example (case 2),

[0450] - The following information may be transmitted together. When steering traffic through a newly created PDU session, information elements may be transmitted that indicate that the newly added traffic was steered from the same UE (101) as the previous traffic.

[0451] As an example (case 3)

[0452] - Information such as information elements and bits that indicate traffic steering can be transmitted from the UE (101) to the SMF (121-3).

[0453] At step 553, SMF (121-3) can map the flow to UE (101).

[0454] As an example (case 1)

[0455] - SMF (121-3) can perform operations (management) such as mapping PDU session information to UE (101) and mapping (corresponding) to PDU session Identity (ID) to manage steering, switching, and (split) traffic for the corresponding UE (101) in PDU sessions that UE (101) was communicating on a previous network and PDU sessions added in an additionally registered network by mapping the identity of UE (101) or identifier (SUPI, IMSI, GUTI, etc.) of UE (101).

[0456] At step 557, SMF (121-3) may transmit a PDU session modification response to UE (101).

[0457] Alternatively, in one embodiment, the SMF (121-3) may transmit a PDU session establishment response message to the UE (101).

[0458] Two possible embodiments are as follows:

[0459] That is, case 1) when UE (101) triggers deregistration (steps 561, 563)

[0460] Or case 2) when the network triggers deregistration (step 563-2)

[0461] In step 561, the UE (101) sends a deregistration request message to the AMF (111).

[0462] Information included in the deregistration request at this time may include:

[0463] The UE (101) can transmit an indication of T-PLMN support to the network.

[0464] The above T-PLMN support indicator may be an indicator that indicates that the UE (101) has the ability to support functions such as traffic steering, traffic switching, (traffic split) even when there are two 3GPP networks / 3GPP access networks, or may be an information element, parameter, or bit information in one embodiment.

[0465] At step 563, AMF (111) may transmit a deregistration accept message to UE (101).

[0466] The information included in the deregistration accept message (from the network to the UE) at this time may be as follows:

[0467] - An information element, bit, or parameter may be transmitted to indicate that AMF (111) supports T-PLMN. The information element may be information indicating that the network can support functions such as traffic steering, traffic switching, (traffic split) by using two 3GPP access networks, and also supports a PLMN selection function to support such functions.

[0468] - The PLMN information list and T-PLMN information can be transmitted together. This means that (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, and the T-PLMNs are PLMNs that can support functions such as traffic steering, switching, and split by mapping to the RPLMN, i.e., the registered PLMN registered by the UE. Or, in one embodiment, the T-PLMN can be a PLMN corresponding to (mapped to) a VPLMN, i.e., a visited PLMN, for traffic steering, switching, traffic split, etc. Or, it can be a PLMN corresponding to an operator controlled PLMN managed by an operator. Here, the term “corresponding” or “mapping” may refer to PLMN information that can be used to switch, steer, or split traffic of an RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in the RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN by mapping 1:1 or 1:n with an RPLMN, VPLMN, or operator controlled PLMN. Accordingly, the above information may be transmitted together with (corresponding / mapping) information of an RPLMN, VPLMN, or operator controlled PLMN or user defined PLMN.Alternatively, it may be transmitted as a separate information element together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN.

[0469] Case 2)

[0470] Or, in another embodiment, or when AMF (111) triggers deregistration, AMF (111) may skip step 561 and transmit a deregistration request message to UE (101) by triggering of AMF (111) in step 563-2.

[0471] The information included in the deregistration request message (network→UE direction) may be as follows:

[0472] - An information element, bit, or parameter may be transmitted to indicate that AMF (111) supports T-PLMN. The information element may be information indicating that the network can support functions such as traffic steering, traffic switching, (traffic split) by using two 3GPP access networks, and also supports a PLMN selection function to support such functions.

[0473] - The PLMN information list and T-PLMN information can be transmitted together. If the (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, these T-PLMNs are PLMNs that can support functions such as traffic steering, switching, and split by mapping to the RPLMN, i.e., the registered PLMN registered by the UE (101). Or, in one embodiment, the T-PLMN can be a PLMN corresponding to (mapped to) a VPLMN, i.e., a visited PLMN, for traffic steering, switching, traffic split, etc. Or, it can be a PLMN corresponding to an operator controlled PLMN managed by an operator. Here, the term “corresponding” or “mapping” may refer to PLMN information that can be used to switch, steer, or split traffic of an RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in the RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN by mapping 1:1 or 1:n with an RPLMN, VPLMN, or operator controlled PLMN. Accordingly, the above information may be transmitted together with (corresponding / mapping) information of an RPLMN, VPLMN, or operator controlled PLMN or user defined PLMN.Alternatively, it may be transmitted as a separate information element together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN.

[0474] At step 565, the UE (101) may store the information. The information stored at this time may be as follows.

[0475] - An information element, bit, or parameter may be transmitted to indicate that AMF (111-3) supports T-PLMN, and the UE (101) may store the information and use it when selecting a PLMN later. In other words, the information element may be information indicating that when the network supports functions such as traffic steering, traffic switching, (traffic split), etc., it can support these functions by using two 3GPP access networks, and also supports a PLMN selection function to support such functions.

[0476] - The PLMN information list and T-PLMN information can be stored together. If the (additional) PLMN information for traffic steering, traffic switching, traffic split, etc. is called T-PLMN, the T-PLMNs can be RPLMNs, i.e. PLMNs that can support functions such as traffic steering, switching, and split by mapping to the registered PLMN registered by the UE (101). Or, in one embodiment, the T-PLMN can be a PLMN corresponding to (mapped to) a VPLMN, i.e. a visited PLMN, for traffic steering, switching, traffic split, etc. Or, it can be a PLMN corresponding to an operator controlled PLMN managed by an operator. Here, the term “corresponding” or “mapping” may refer to PLMN information that can be used to switch, steer, or split traffic of an RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN when traffic increases or traffic control is required in the RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN by mapping 1:1 or 1:n with an RPLMN, VPLMN, or operator controlled PLMN. Accordingly, the above information may be transmitted together with (corresponding / mapping) information of an RPLMN, VPLMN, or operator controlled PLMN or user defined PLMN.Alternatively, it may be transmitted as a separate information element together with RPLMN, VPLMN, operator controlled PLMN, or user defined PLMN, and the transmitted information may be stored in the UE and used as information necessary for making a decision when selecting a PLMN later.

[0477] FIG. 6 is a block diagram showing the configuration of a terminal according to one embodiment of the present disclosure.

[0478] As illustrated in FIG. 6, the terminal (600) of the present disclosure may include a transceiver (610), a memory (620), and a processor (630). The processor (630), the transceiver (610), and the memory (620) of the terminal (600) may operate according to the communication method of the terminal (600) described above. However, the components of the terminal (600) are not limited to the examples described above. For example, the terminal (600) may include more or fewer components than the components described above. In addition, the processor (630), the transceiver (610), and the memory (620) may be implemented in the form of a single chip. The terminal (600) may be substantially the same as or similar to the UE (101) of FIGS. 1 to 5.

[0479] The transceiver (610) is a general term for the receiver and transmitter of the terminal (600), and can transmit and receive signals with a base station or a network entity. The signals transmitted and received with the base station may include control information and data. To this end, the transceiver (610) may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-down-converts the received signal. However, this is only one embodiment of the transceiver (610), and the components of the transceiver (610) are not limited to an RF transmitter and an RF receiver.

[0480] Additionally, the transceiver (610) may include a wired or wireless transceiver and may include various configurations for transmitting and receiving signals.

[0481] Additionally, the transceiver (610) can receive a signal through a wireless channel and output it to the processor (630), and transmit the signal output from the processor (630) through the wireless channel.

[0482] In addition, the transceiver (610) can receive a communication signal and output it to the processor, and transmit the signal output from the processor to a network entity via a wired or wireless network.

[0483] The memory (620) can store programs and data required for the operation of the terminal (600). In addition, the memory (620) can store control information or data included in a signal obtained from the terminal (600). The memory (620) 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.

[0484] The processor (630) can control a series of processes so that the terminal (600) can operate according to the above-described embodiment of the present disclosure. The processor (630) may include at least one processor. For example, the processor (630) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as application programs.

[0485] FIG. 7 is a diagram illustrating a configuration of a network entity according to one embodiment of the present disclosure.

[0486] As illustrated in FIG. 7, a network entity (700) of the present disclosure may include a transceiver (710), a memory (720), and a processor (730). The processor (730), the transceiver (710), and the memory (720) of the network entity (700) may operate according to the communication method of the network entity (700) described above. However, the components of the network entity (700) are not limited to the examples described above. For example, the network entity (700) may include more or fewer components than the components described above. In addition, the processor (730), the transceiver (710), and the memory (720) may be implemented in the form of a single chip. The network entity may include network functions (NF) such as the Access and Mobility Management Function (AMF), the Session Management Function (SMF), the Policy and Charging Function (PCF), the Network Exposure Function (NEF), the Unified Data Management (UDM), and the User Plane Function (UPF) described above. It may also include a base station. The network entity (700) may be substantially the same as or similar to at least one of the RAN (103, 103-3), the AMF (103, 103-1), the SMF (121, 121-3), the UPF (131, 131-3), the PCF (141), or the UDM (151) of FIGS. 1 to 5.

[0487] The transceiver (710) is a general term for the receiver of the network entity (700) and the transmitter of the network entity (700), and can transmit and receive signals with the terminal (600) or other network entities. At this time, the transmitted and received signals may include control information and data. To this end, the transceiver (710) may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-downconverts the received signal. However, this is only one embodiment of the transceiver (710), and the components of the transceiver (710) are not limited to the RF transmitter and RF receiver. The transceiver (710) may include wired and wireless transceivers, and may include various configurations for transmitting and receiving signals.

[0488] In addition, the transceiver (710) can receive a signal through a communication channel (e.g., a wireless channel) and output the signal to the processor (730), and transmit the signal output from the processor (730) through the communication channel.

[0489] In addition, the transceiver (710) can receive a communication signal and output it to the processor, and transmit the signal output from the processor to a terminal or network entity via a wired or wireless network.

[0490] The memory (720) can store programs and data required for the operation of the network entity (700). In addition, the memory (720) can store control information or data included in a signal acquired from the network entity (700). The memory (720) 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.

[0491] The processor (730) may control a series of processes so that the network entity (700) can operate according to the embodiments of the present disclosure described above. The processor (730) may include at least one processor. 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.

[0492] 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 the embodiments described in the claims or specification of the present disclosure.

[0493] These programs (software modules, software) may be stored in random access memory, non-volatile memory including 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 memories formed by a combination of some or all of these. In addition, each configuration memory may include multiple copies.

[0494] 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 area network (WAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing 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 performing an embodiment of the present disclosure.

[0495] In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed in the singular or plural form, 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 the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0496] 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.

Claims

1. In the operating method of a terminal (user equipment, UE) (101), An operation (201) of transmitting a first registration request message including information indicating that the terminal (101) can support the second network to the first AMF (access and mobility management function) (111) of the first network; An operation (205) of receiving a first registration approval message including information related to the second network from the first AMF (111); and Includes an operation (207) of storing information related to the second network, An operating method, wherein the information related to the second network includes information indicating that the first AMF (111) can support the second network, and an information list corresponding to the second network.

2. In paragraph 1, An operating method further comprising an operation (211) of transmitting a first PDU session (packet data unit session) request message including information indicating that the terminal (101) can support the second network to the SMF (session management function) (121) of the first network.

3. In paragraph 2, An operating method further comprising an operation (213) of receiving a first PDU session response message from the SMF (121).

4. In paragraph 3, An operating method further comprising an operation (233) of determining whether the traffic can be distributed and processed through the second network based on the stored information related to the second network when the size of the traffic transmitted and received through the terminal (101) exceeds a predetermined threshold size.

5. In paragraph 4, An operating method further comprising an operation (235) of determining whether the second network is the same network as the first network or a different network based on information related to the second network.

6. In paragraph 5, An operating method further comprising an operation (237) of selecting the second network based on information related to the second network.

7. In paragraph 6, An operating method further comprising an operation (241) of transmitting a second registration request message to a second AMF (111-3) of the selected second network.

8. In paragraph 6, An operating method further comprising the step (245) of receiving a second registration approval message from the second AMF (111-3) including a function indicator indicating that the second AMF (111-3) can distribute and process the traffic.

9. In paragraph 8, An operating method further comprising an operation (251) of transmitting a second PDU session request message including information instructing the SMF (121) to distribute and process the traffic through the second network.

10. In paragraph 9, An operating method further comprising an operation (257) of receiving a second PDU session response message from the SMF (121).

11. In the terminal (600), Transmitter and receiver (610); A memory (620) electrically coupled to the above-mentioned transmitter / receiver (610) and storing various commands for controlling the terminal (600); and It includes a processor (630) electrically coupled to the above-mentioned transceiver (610) and the above-mentioned memory (620), The above processor (630) An action of receiving a first registration request message including information indicating to a first AMF (111) of a first network that a terminal (101) can support a second network; An operation of receiving a first registration approval message including information related to the second network from the first AMF (111); and Control to perform an operation (207) of storing information related to the second network, A terminal (600), wherein the information related to the second network includes information indicating that the first AMF (111) can support the second network, and an information list corresponding to the second network.

12. In paragraph 11, The above processor (630) A terminal (600) that further controls the operation (211) of transmitting a first PDU session (packet data unit session) request message including information indicating that the terminal (101) can support the second network to the SMF (session management function) (121) of the first network.

13. In paragraph 12, The above processor (630) A terminal (600) that further controls the operation (213) of receiving a first PDU session response message from the above SMF (121).

14. In paragraph 13, The above processor (630) A terminal (600) that controls to further perform an operation (233) of determining whether the traffic can be distributed and processed through the second network based on the stored information related to the second network when the size of the traffic transmitted and received through the terminal (101) exceeds a predetermined threshold size.

15. In paragraph 14, The above processor (630) A terminal (600) that further controls an operation (235) of determining whether the second network is the same network as the first network or a different network based on information related to the second network.

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