UE(User Equipment)

Abstract

The present invention provides a method for efficiently selecting the S-NSSAI required to connect one or more IMS services to one or more IMS networks via one or more network slices in 5GS. UE that: receives a registration acceptance message that includes allowed NSSAI that includes first S-NSSAI that is for SIP signaling for a first IMS service and second S-NSSAI that is for media for the first IMS service; receives a UE policy management command that includes a URSP that includes the first S-NSSAI, the second S-NSSAI, and information that indicates registration areas in which the first S-NSSAI and / or the second S-NSSAI can be used; and, when requesting the establishment of a PDU session for the first IMS service, selects the first S-NSSAI and the second S-NSSAI for the first IMS service when it has been determined on the basis of the URSP that the first S-NSSAI and the second S-NSSAI can be used in the present registration area.

Description

[Technical Field]

[0001] The present invention relates to UE (User Equipment). This application claims priority to Japanese Patent Application No. 2020-184768, filed on November 5, 2020, the contents of which are incorporated herein by reference. [Background technology]

[0002] The 3GPP (3rd Generation Partnership Project) is studying the system architecture of the 5G System (5GS), a fifth-generation (5G) mobile communication system, and is discussing how to support new procedures and new functions (see Non-Patent Documents 1 to 3). Release 15, the initial release of the 5G standard, introduced the concept of network slicing, and Release 17 is studying functional extensions of network slicing related to the IP Multimedia Subsystem (IMS) (see Non-Patent Document 4). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP TS 23.501 V16.6.0 (2020-09); 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; System Architecture for the 5G System; Stage 2 (Release 16) [Non-patent document 2] 3GPP TS 23.502 V16.6.0 (2020-09); 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Procedures for the 5G System; Stage 2 (Release 16) [Non-patent document 3] 3GPP TS 24.501 V16.6.0 (2020-09); 3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3 (Release 16) [Non-patent document 4] 3GPP TR 23.794 V17.0.0 (2019-12); 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Study on enhanced IP Multimedia Subsystem (IMS) to 5GC integration (Release 17); Pages 10-12, 37-42 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Non-Patent Document 4 does not clarify how to select an S-NSSAI to be used for communication for IMS (hereinafter also referred to as IMS service) using SIP (Session Initiation Protocol). In particular, it does not clarify an efficient method for selecting an S-NSSAI required to connect one or more IMS services to one or more IMS networks via one or more network slices.

[0005] The object of one aspect of the present invention has been made in consideration of the above circumstances, and is to provide an efficient method for selecting an S-NSSAI, which is required in 5GS to connect one or more IMS services to one or more IMS networks via one or more network slices. [Means for solving the problem]

[0006] A UE according to one aspect of the present invention is a UE (User Equipment) including a transceiver unit and a controller, wherein the transceiver unit receives a registration accept message including an Allowed Network Slice Selection Assistance Information (NSSAI) from an Access and Mobility Management Function (AMF) in a registration procedure, and receives a configuration update command including a UE policy management command message including a UE Route Selection Policy (URSP) from a Policy Control Function (PCF) in a UE configuration update procedure, the configuration update command including a UE policy management command message including a UE Route Selection Policy (URSP), and the Allowed NSSAI is a first Single Network Slice Selection Assistance Information (S-NSSAI) for SIP signaling for a first IMS service. and a second S-NSSAI for media for the first IMS service, the URSP includes the first S-NSSAI, the second S-NSSAI, and first information, the first information being information indicating a registration area in which the first S-NSSAI and / or the second S-NSSAI can be used, and when the control unit requests establishment of a PDU session for the first IMS service, if it determines based on the URSP that the first S-NSSAI and the second S-NSSAI are usable in the current registration area, it selects the first S-NSSAI and the second S-NSSAI for the first IMS service.

[0007] Another aspect of the present invention provides a UE (User Equipment) including a transceiver unit and a controller, wherein the transceiver unit receives a registration accept message including an Allowed NSSAI (Network Slice Selection Assistance Information) from an Access and Mobility Management Function (AMF) in a registration procedure, and receives a configuration update command including a UE policy management command message including a UE Route Selection Policy (URSP) from a Policy Control Function (PCF) in a UE configuration update procedure, the configuration update command including a UE policy management command message including a UE Route Selection Policy (URSP), and the Allowed NSSAI is a first S-NSSAI (Single Network Slice Selection Assistance Information) for SIP signaling for a first IMS service. the first information is information indicating a registration area in which the first S-NSSAI and / or the second S-NSSAI and / or the third S-NSSAI can be used; and when the control unit requests establishment of a PDU session for the first IMS service, if the control unit determines, based on the URSP, that the first S-NSSAI, the second S-NSSAI, and the third S-NSSAI are usable in the current registration area, the control unit selects the first S-NSSAI, the second S-NSSAI, and the third S-NSSAI for the first IMS service.

[0008] In yet another aspect of the present invention, there is provided a UE (User Equipment) including a transceiver unit and a controller, wherein the transceiver unit receives a registration accept message including an Allowed NSSAI (Network Slice Selection Assistance Information) from an Access and Mobility Management Function (AMF) in a registration procedure, and receives a configuration update command including a UE policy management command message including an URSP (UE Route Selection Policy) from a Policy Control Function (PCF) in a UE configuration update procedure, the configuration update command including a UE policy management command message including an URSP (UE Route Selection Policy), and the Allowed NSSAI is a first S-NSSAI (Single Network Slice Selection Assistance Information) for a first IMS service. the control unit selects the first S-NSSAI for the first IMS service when it determines, based on the URSP, that the first S-NSSAI is usable in the current registration area, and when it determines, based on the URSP, that the second S-NSSAI included in the Allowed NSSAI is usable in the current registration area, and when it determines, based on the URSP, that the second S-NSSAI included in the Allowed NSSAI is usable in the current registration area, and when it determines, based on the URSP, that the second S-NSSAI included in the Allowed NSSAI is usable in the current registration area, and when it determines, based on the URSP, that the second S-NSSAI included in the Allowed NSSAI is usable in the current registration area, [Effects of the Invention]

[0009] According to one aspect of the present invention, in 5GS, an efficient method for selecting an S-NSSAI required to connect one or more IMS services to one or more IMS networks via one or more network slices can be provided. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an outline of a mobile communication system (EPS / 5GS). [Figure 2] FIG. 1 is a diagram illustrating the detailed configuration of a mobile communication system (EPS / 5GS). [Figure 3] FIG. 1 is a diagram illustrating the device configuration of a UE. [Figure 4] A diagram explaining the configuration of an access network device (gNB) in 5GS. [Figure 5] A diagram explaining the configuration of core network devices (AMF / SMF / UPF / PCF, etc.) in 5GS. [Figure 6] FIG. 10 is a diagram illustrating a registration procedure. [Figure 7] FIG. 10 is a diagram illustrating a generic UE configuration update procedure. [Figure 8] FIG. 10 is a diagram illustrating a UE policy management procedure. [Figure 9] A diagram explaining the PDU session establishment procedure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, a best mode for carrying out one aspect of the present invention will be described with reference to the drawings. In this embodiment, an embodiment of a mobile communication system to which one aspect of the present invention is applied will be described as an example.

[0012] [1. System Overview] First, FIG. 1 is a diagram for explaining an outline of a mobile communication system 1 used in each embodiment, and FIG. 2 is a diagram for explaining a detailed configuration of the mobile communication system 1. As shown in FIG.

[0013] FIG. 1 shows that the mobile communication system 1 is composed of UE_A10, access network _A80, core network _A90, PDN (Packet Data Network) _A5, access network _B120, core network _B190, and DN (Data Network) _A6.

[0014] In the following, these devices and functions may be referred to by abbreviating the symbols, such as UE, access network_A, core network_A, PDN, access network_B, core network_B, DN, etc.

[0015] Figure 2 also shows devices and functions such as UE_A10, E-UTRAN80, MME40, SGW35, PGW-U30, PGW-C32, PCRF60, HSS50, 5G AN120, AMF140, UPF130, SMF132, PCF160, UDM150, and N3IWF170, as well as interfaces that connect these devices and functions to each other.

[0016] In the following, these devices and functions may be referred to by abbreviated symbols such as UE, E-UTRAN, MME, SGW, PGW-U, PGW-C, PCRF, HSS, 5G AN, AMF, UPF, SMF, PCF, UDM, N3IWF, etc.

[0017] The 4G system EPS (Evolved Packet System) includes an access network _A and a core network _A, but may further include a UE and / or a PDN. The 5G system 5GS (5G System) includes a UE, an access network _B, and a core network _B, but may further include a DN.

[0018] A UE is a device that can connect to a network service via 3GPP access (also referred to as a 3GPP access network, or 3GPP AN) and / or non-3GPP access (also referred to as a non-3GPP access network, or non-3GPP AN). A UE may be a terminal device capable of wireless communication, such as a mobile phone or a smartphone, and may be a terminal device that can connect to both EPS and 5GS. A UE may include a UICC (Universal Integrated Circuit Card) or an eUICC (Embedded UICC). Note that a UE may be referred to as a user device or a terminal device.

[0019] Furthermore, access network_A corresponds to an E-UTRAN (Evolved Universal Terrestrial Radio Access Network) and / or a wireless LAN access network. One or more eNBs (evolved Node Bs) 45 are deployed in the E-UTRAN. Note that, hereinafter, the eNB 45 may be referred to by abbreviating the symbol eNB. If there are multiple eNBs, the eNBs are connected to each other, for example, via an X2 interface. Furthermore, one or more access points are deployed in the wireless LAN access network.

[0020] Furthermore, access network_B corresponds to a 5G access network (5G AN). The 5G AN is composed of an NG-RAN (NG Radio Access Network) and / or a non-3GPP access network. One or more gNBs (NR NodeBs) 122 are deployed in the NG-RAN. Note that, hereinafter, the gNB 122 may be referred to by its symbol abbreviated as eNB. The gNB is a node that provides the NR (New Radio) user plane and control plane to UEs and connects to the 5GCN via an NG interface (including an N2 interface or an N3 interface). In other words, the gNB is a base station device newly designed for 5GS, and has different functions from the base station device (eNB) used in the 4G EPS system. Furthermore, when there are multiple gNBs, the gNBs are connected to each other, for example, via an Xn interface.

[0021] Furthermore, the non-3GPP access network may be an untrusted non-3GPP access network or a trusted non-3GPP access network. Here, the untrusted non-3GPP access network may be a non-3GPP access network that does not perform security management within the access network, such as a public wireless LAN. On the other hand, the trusted non-3GPP access network may be an access network specified by 3GPP, and may include a trusted non-3GPP access point (TNAP) and a trusted non-3GPP gateway function (TNGF).

[0022] In the following, E-UTRAN and NG-RAN may be referred to as 3GPP access. Also, wireless LAN access networks and non-3GPP AN may be referred to as non-3GPP access. Also, nodes located in access network_B may be collectively referred to as NG-RAN nodes.

[0023] Furthermore, in the following, access network _A, and / or access network _B, and / or devices included in access network _A, and / or devices included in access network _B may be referred to as access networks or access network devices.

[0024] The core network_A corresponds to an EPC (Evolved Packet Core), which includes, for example, an MME (Mobility Management Entity), an SGW (Serving Gateway), a PGW (Packet Data Network Gateway)-U, a PGW-C, a PCRF (Policy and Charging Rules Function), and an HSS (Home Subscriber Server).

[0025] Furthermore, the core network_B corresponds to a 5G Core Network (5GCN). In the 5GCN, for example, an Access and Mobility Management Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), a Policy Control Function (PCF), a Unified Data Management (UDM), etc. are arranged. Here, the 5GCN may be expressed as a 5GC.

[0026] In addition, in the following, core network _A and / or core network _B, devices included in core network _A, and / or devices included in core network _B may be referred to as core networks, core network devices, or devices within the core network.

[0027] The core network (core network _A and / or core network _B) may be an IP mobile communication network operated by a mobile network operator (MNO) that connects the access network (access network _A and / or access network _B) to the PDN and / or DN, or it may be a core network for a mobile network operator that operates and manages the mobile communication system 1, or it may be a core network for a virtual mobile communication operator or virtual mobile communication service provider such as an MVNO (Mobile Virtual Network Operator) or MVNE (Mobile Virtual Network Enabler).

[0028] Also, while FIG. 1 illustrates a case where the PDN and the DN are the same, they may be different. The PDN may be a DN (Data Network) that provides communication services to the UE. The DN may be configured as a packet data service network, or may be configured for each service. Furthermore, the PDN may include a connected communication terminal. Therefore, connecting to the PDN may mean connecting to a communication terminal or a server device located in the PDN. Furthermore, transmitting and receiving user data to and from the PDN may mean transmitting and receiving user data to and from a communication terminal or a server device located in the PDN. The PDN may be referred to as the DN, and the DN may be referred to as the PDN.

[0029] In addition, hereinafter, at least a portion of the access network _A, the core network _A, the PDN, the access network _B, the core network _B, and the DN, and / or one or more devices included therein may be referred to as a network or a network device. In other words, when a network and / or a network device sends or receives a message and / or performs a procedure, it means that at least a portion of the access network _A, the core network _A, the PDN, the access network _B, the core network _B, and the DN, and / or one or more devices included therein send or receive a message and / or perform a procedure.

[0030] The UE can also connect to an access network. The UE can also connect to a core network via the access network. The UE can also connect to a PDN or DN via the access network and the core network. That is, the UE can transmit and receive (communicate) user data with the PDN or DN. When transmitting and receiving user data, not only IP (Internet Protocol) communication but also non-IP communication can be used.

[0031] Here, IP communication refers to data communication using IP, and data is transmitted and received using IP packets. An IP packet consists of an IP header and a payload. The payload may include data transmitted and received by devices and functions included in EPS or devices and functions included in 5GS. Non-IP communication refers to data communication that does not use IP, and data is transmitted and received in a format different from the IP packet structure. For example, non-IP communication may be data communication achieved by transmitting and receiving application data without an IP header, or it may be user data transmitted and received by a UE with a different header, such as a MAC header or an Ethernet (registered trademark) frame header, added.

[0032] In addition, access network _A, core network _A, access network _B, core network _B, PDN_A, and DN_A may be configured with devices not shown in Fig. 2. For example, core network _A and / or core network _B may include an AUSF (Authentication Server Function) and an AAA (Authentication, authorization, and accounting) server (AAA-S).

[0033] Here, the AUSF is a core network device having an authentication function for 3GPP access and non-3GPP access, specifically, a network function unit that receives an authentication request for 3GPP access and / or non-3GPP access from a UE and executes the authentication procedure.

[0034] The AAA server is a device that has authentication, authorization, and accounting functions and is connected to the AUSF directly or indirectly via another network device. The AAA server may be a network device within the core network. The AAA server may not be included in the core network _A and / or core network _B, but may be included in the PLMN. In other words, the AAA server may be a core network device or a device outside the core network. For example, the AAA server may be a server device within the PLMN managed by a third party.

[0035] 2, for the sake of simplicity, each device and function is shown one by one, but multiple similar devices and functions may be configured in the mobile communication system 1. Specifically, the mobile communication system 1 may be configured with multiple devices and functions such as UE_A10, E-UTRAN80, MME40, SGW35, PGW-U30, PGW-C32, PCRF60, HSS50, 5G AN120, AMF140, UPF130, SMF132, PCF160, and / or UDM150.

[0036] [2. Configuration of each device] Next, the configuration of each device (UE, and / or access network device, and / or core network device) used in each embodiment will be described with reference to the drawings. Each device may be configured as physical hardware, as logical (virtual) hardware configured on general-purpose hardware, or as software. Furthermore, at least a part (including all) of the functions of each device may be configured as physical hardware, logical hardware, or software.

[0037] Note that each memory unit (memory unit_A340, memory unit_A440, memory unit_B540, memory unit_A640, memory unit_B740) in each device / function mentioned below is configured with, for example, a semiconductor memory, a solid state drive (SSD), a hard disk drive (HDD), etc. Furthermore, each memory unit can store not only information that was originally set at the time of shipment, but also various information transmitted and received between devices / functions other than the device / function itself (e.g., UE, and / or access network device, and / or core network device, and / or PDN, and / or DN). Furthermore, each memory unit can store identification information, control information, flags, parameters, etc. included in control messages transmitted and received in various communication procedures described below. Furthermore, each memory unit may store this information for each UE. Furthermore, when interworking between 5GS and EPS is performed, each memory unit can store control messages and user data transmitted and received between 5GS and / or devices / functions included in EPS. At this time, not only those transmitted and received via the N26 interface but also those transmitted and received without going through the N26 interface can be stored.

[0038] [2.1. UE Device Configuration] First, an example of the device configuration of UE (User Equipment) will be explained using Figure 3. The UE is composed of a control unit _A300, an antenna 310, a transceiver unit _A320, and a memory unit _A340. The control unit _A300, the transceiver unit _A320, and the memory unit _A340 are connected via a bus. The transceiver unit _A320 is connected to the antenna 310.

[0039] The control unit _A300 is a functional unit that controls the operation and functions of the entire UE.The control unit _A300 realizes various processing in the UE by reading and executing various programs stored in the memory unit _A340 as necessary.

[0040] The transceiver unit _A320 is a functional unit for wireless communication with a base station device (eNB or gNB) in the access network via an antenna. That is, the UE can use the transceiver unit _A320 to transmit and receive user data and / or control information between an access network device, and / or a core network device, and / or a PDN, and / or a DN.

[0041] Explaining in detail with reference to Figure 2, the UE can communicate with a base station device (eNB) in the E-UTRAN via the LTE-Uu interface by using the transceiver unit _A320. The UE can also communicate with a base station device (gNB) in the 5G AN by using the transceiver unit _A320. The UE can also transmit and receive AMF and NAS (Non-Access-Stratum) messages via the N1 interface by using the transceiver unit _A320. However, since the N1 interface is logical, in reality, communication between the UE and the AMF is performed via the 5G AN.

[0042] The memory unit _A340 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the UE.

[0043] [2.2. gNB device configuration] Next, an example of the gNB device configuration will be described using Figure 4. The gNB is composed of a control unit _B500, an antenna 510, a network connection unit _B520, a transceiver unit _B530, and a memory unit _B540. The control unit _B500, the network connection unit _B520, the transceiver unit _B530, and the memory unit _B540 are connected via a bus. The transceiver unit _B530 is connected to the antenna 510.

[0044] The control unit _B500 is a functional unit that controls the operation and functions of the entire gNB. The control unit _B500 realizes various processes in the gNB by reading and executing various programs stored in the memory unit _B540 as necessary.

[0045] The network connection unit _B520 is a functional unit for the gNB to communicate with the AMF and / or UPF. That is, the gNB can send and receive user data and / or control information between the AMF and / or UPF using the network connection unit _B520.

[0046] The transceiver unit _B530 is a functional unit for wireless communication with the UE via the antenna 510. That is, the gNB can transmit and receive user data and / or control information to and from the UE using the transceiver unit _B530.

[0047] 2, a gNB in ​​a 5G AN can communicate with an AMF via an N2 interface by using a network connection unit _B 520, and can communicate with a UPF via an N3 interface, and can communicate with a UE by using a transceiver unit _B 530.

[0048] The memory unit _B540 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the gNB.

[0049] [2.3. AMF device configuration] Next, an example of the AMF device configuration will be explained using Figure 5. The AMF is composed of a control unit _B700, a network connection unit _B720, and a memory unit _B740. The control unit _B700, the network connection unit _B720, and the memory unit _B740 are connected via a bus. The AMF may be a node that handles the control plane.

[0050] The control unit _B700 is a functional unit that controls the operation and functions of the entire AMF.The control unit _B700 realizes various processing in the AMF by reading and executing various programs stored in the memory unit _B740 as necessary.

[0051] The network connection unit _B720 is a functional unit for the AMF to connect to a base station device (gNB), and / or SMF, and / or PCF, and / or UDM, and / or SCEF in a 5G AN. In other words, the AMF can use the network connection unit _B720 to send and receive user data and / or control information between a base station device (gNB), and / or SMF, and / or PCF, and / or UDM, and / or SCEF in a 5G AN.

[0052] Explaining in detail with reference to FIG. 2, the AMF in the 5GCN can communicate with a gNB via the N2 interface by using the network connection unit _A620, can communicate with a UDM via the N8 interface, can communicate with an SMF via the N11 interface, and can communicate with a PCF via the N15 interface. The AMF can also send and receive NAS messages with a UE via the N1 interface by using the network connection unit _A620. However, since the N1 interface is logical, communication between the UE and the AMF is actually performed via a 5G AN. Furthermore, if the AMF supports the N26 interface, it can communicate with an MME via the N26 interface by using the network connection unit _A620.

[0053] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the AMF.

[0054] The AMF has functions such as exchanging control messages with the RAN using the N2 interface, exchanging NAS messages with the UE using the N1 interface, encrypting and protecting the integrity of NAS messages, registration management (RM) functions, connection management (CM) functions, reachability management functions, mobility management functions for UEs, etc., transferring SM (Session Management) messages between the UE and the SMF, access authentication (Access Authorization) functions, security anchor functionality (SEA), security context management (SCM), a function to support the N2 interface for the N3IWF (Non-3GPP Interworking Function), a function to support sending and receiving NAS signals with the UE via the N3IWF, and a function to authenticate UEs connected via the N3IWF.

[0055] In addition, registration management manages the RM state for each UE. The RM state may be synchronized between the UE and the AMF. The RM state includes an unregistered state (RM-DEREGISTERED state) and a registered state (RM-REGISTERED state). In the RM-DEREGISTERED state, the UE is not registered with the network, and therefore the UE context in the AMF does not have valid location information or routing information for the UE, and therefore the AMF cannot reach the UE. In the RM-REGISTERED state, the UE is registered with the network, and therefore the UE can receive services that require registration with the network. Note that the RM state may also be expressed as a 5GMM state. In this case, the RM-DEREGISTERED state may be expressed as a 5GMM-DEREGISTERED state, and the RM-REGISTERED state may be expressed as a 5GMM-REGISTERED state.

[0056] In other words, 5GMM-REGISTERED may be a state in which each device has established a 5GMM context or a PDU session context. When each device is 5GMM-REGISTERED, UE_A10 may start transmitting and receiving user data and control messages, or may respond to paging. Furthermore, when each device is 5GMM-REGISTERED, UE_A10 may perform registration procedures other than the registration procedure for initial registration, and / or service request procedures.

[0057] Furthermore, 5GMM-DEREGISTERED may be a state in which each device has not established a 5GMM context, a state in which UE_A10's location information is not known to the network, or a state in which UE_A10 is unreachable from the network. Note that when each device is 5GMM-DEREGISTERED, UE_A10 may initiate a registration procedure or may establish a 5GMM context by performing the registration procedure.

[0058] In addition, connection management manages the CM state for each UE. The CM state may be synchronized between the UE and the AMF. The CM state includes a non-connected state (CM-IDLE state) and a connected state (CM-CONNECTED state). In the CM-IDLE state, the UE is in the RM-REGISTERED state but does not have a NAS signaling connection established with the AMF via the N1 interface. In the CM-IDLE state, the UE does not have an N2 interface connection or an N3 interface connection. On the other hand, in the CM-CONNECTED state, the UE has a NAS signaling connection established with the AMF via the N1 interface. In the CM-CONNECTED state, the UE may have an N2 interface connection and / or an N3 interface connection.

[0059] Furthermore, in connection management, the CM state in 3GPP access and the CM state in non-3GPP access may be managed separately. In this case, the CM state in 3GPP access may include a non-connected state in 3GPP access (CM-IDLE state over 3GPP access) and a connected state in 3GPP access (CM-CONNECTED state over 3GPP access). Furthermore, the CM state in non-3GPP access may include a non-connected state in non-3GPP access (CM-IDLE state over non-3GPP access) and a connected state in non-3GPP access (CM-CONNECTED state over non-3GPP access). Note that the non-connected state may be expressed as an idle mode, and the connected state mode may be expressed as a connected mode.

[0060] The CM state may be expressed as a 5GMM mode. In this case, the unconnected state may be expressed as a 5GMM-IDLE mode, and the connected state may be expressed as a 5GMM-CONNECTED mode. Furthermore, the unconnected state in 3GPP access may be expressed as a 5GMM-IDLE mode over 3GPP access, and the connected state in 3GPP access may be expressed as a 5GMM-CONNECTED mode over 3GPP access. Furthermore, the unconnected state in non-3GPP access may be expressed as 5GMM unconnected mode in non-3GPP access (5GMM-IDLE mode over non-3GPP access), and the connected state in non-3GPP access may be expressed as 5GMM connected mode in non-3GPP access (5GMM-CONNECTED mode over non-3GPP access). Note that the 5GMM unconnected mode may be expressed as idle mode, and the 5GMM connected mode may be expressed as connected mode.

[0061] In addition, one or more AMFs may be placed in the core network B. In addition, the AMF may be an NF that manages one or more NSIs (Network Slice Instances). In addition, the AMF may be a shared CP function (CCNF; Common CPNF (Control Plane Network Function)) shared among multiple NSIs.

[0062] In addition, the N3IWF is a device and / or function located between the non-3GPP access and the 5GCN when the UE connects to the 5GS via the non-3GPP access.

[0063] [2.4. SMF device configuration] Next, an example of the SMF device configuration will be explained using Figure 5. The SMF is composed of a control unit _B700, a network connection unit _B720, and a memory unit _B740. The control unit _B700, the network connection unit _B720, and the memory unit _B740 are connected via a bus. The SMF may be a node that handles the control plane.

[0064] The control unit _B700 is a functional unit that controls the operation and functions of the entire SMF.The control unit _B700 realizes various processing in the SMF by reading and executing various programs stored in the memory unit _B740 as necessary.

[0065] The network connection unit _B720 is a functional unit for the SMF to connect with the AMF, and / or UPF, and / or PCF, and / or UDM. In other words, the SMF can send and receive user data and / or control information between the AMF, and / or UPF, and / or PCF, and / or UDM using the network connection unit _B720.

[0066] Explaining in more detail with reference to Figure 2, the SMF in the 5GCN can communicate with the AMF via the N11 interface, with the UPF via the N4 interface, with the PCF via the N7 interface, and with the UDM via the N10 interface by using the network connection unit _A620.

[0067] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. required for each operation of the SMF.

[0068] The SMF has session management functions such as establishing, modifying, and releasing PDU sessions, IP address allocation for UEs and its management, UPF selection and control, UPF configuration for routing traffic to the appropriate destination, sending and receiving the SM portion of NAS messages, Downlink Data Notification, providing AN-specific (for each AN) SM information to be sent to the AN via the N2 interface via the AMF, determining the SSC mode (Session and Service Continuity mode) for the session, and roaming functions.

[0069] [2.5. UPF device configuration] Next, an example of the device configuration of the UPF will be explained using Figure 5. The UPF is composed of a control unit _B700, a network connection unit _B720, and a memory unit _B740. The control unit _B700, the network connection unit _B720, and the memory unit _B740 are connected via a bus. The UPF may be a node that handles the control plane.

[0070] The control unit _B700 is a functional unit that controls the operation and functions of the entire UPF.The control unit _B700 realizes various processing in the UPF by reading and executing various programs stored in the memory unit _B740 as necessary.

[0071] The network connection unit _B720 is a functional unit for the UPF to connect to a base station device (gNB), and / or SMF, and / or DN within the 5G AN. In other words, the UPF can use the network connection unit _B720 to transmit and receive user data and / or control information between the base station device (gNB), and / or SMF, and / or DN within the 5G AN.

[0072] Explaining in more detail with reference to Figure 2, a UPF in a 5GCN can communicate with a gNB via the N3 interface, with an SMF via the N4 interface, with a DN via the N6 interface, and with other UPFs via the N9 interface by using the network connection unit _A620.

[0073] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. required for each operation of the UPF.

[0074] The UPF has functions such as an anchor point for intra-RAT mobility or inter-RAT mobility, an external PDU session point for interconnecting to DNs (i.e., a gateway between DNs and core network_B that forwards user data), packet routing and forwarding functions, an UL CL (Uplink Classifier) ​​function that supports routing of multiple traffic flows to one DN, a branching point function that supports multi-homed PDU sessions, a QoS (Quality of Service) processing function for the user plane, an uplink traffic verification function, downlink packet buffering, and a function to trigger downlink data notifications.

[0075] The UPF may also be a gateway for IP communication and / or non-IP communication. The UPF may also have a function for forwarding IP communication and a function for converting non-IP communication and IP communication. Furthermore, multiple gateways may be gateways that connect the core network_B to a single DN. The UPF may also have connectivity with other NFs and may be connected to each device via other NFs.

[0076] The user plane refers to user data transmitted and received between a UE and a network. The user plane may be transmitted and received using a PDN connection or a PDU session. Furthermore, in the case of EPS, the user plane may be transmitted and received using the LTE-Uu interface, and / or the S1-U interface, and / or the S5 interface, and / or the S8 interface, and / or the SGi interface. Furthermore, in the case of 5GS, the user plane may be transmitted and received via the interface between the UE and the NG RAN, and / or the N3 interface, and / or the N9 interface, and / or the N6 interface. Hereinafter, the user plane may be referred to as the U-Plane.

[0077] Furthermore, the control plane refers to control messages transmitted and received to control UE communications, etc. The control plane may be transmitted and received using a NAS (Non-Access-Stratum) signaling connection between the UE and MME. Furthermore, in the case of EPS, the control plane may be transmitted and received using the LTE-Uu interface and the S1-MME interface. Furthermore, in the case of 5GS, the control plane may be transmitted and received using the interface between the UE and NG RAN and the N2 interface. Hereinafter, the control plane may be referred to as the control plane or the C-Plane.

[0078] Furthermore, the U-Plane (User Plane; UP) may be a communication path for transmitting and receiving user data and may be composed of multiple bearers. Furthermore, the C-Plane (Control Plane; CP) may be a communication path for transmitting and receiving control messages and may be composed of multiple bearers.

[0079] [2.6. PCF device configuration] Next, an example of the device configuration of the PCF used in each embodiment will be described using Figure 5. The PCF is composed of a control unit 700, a network connection unit 720, and a memory unit 740. The control unit 700, the network connection unit 720, and the memory unit 740 are connected via a bus.

[0080] The control unit _700 is a functional unit that controls the operation and functions of the entire PCF. Note that the control unit _700 may process all functions that other functional units in the PCF (network connection unit _720, memory unit _740) do not have. The control unit _700 realizes various processes in the PCF by reading and executing various programs stored in the memory unit _740 as needed.

[0081] The network connection unit _720 is a functional unit for connecting the PCF to the AMF, and / or SMF, and / or AF (Application Function). That is, the PCF can use the network connection unit _720 to send and receive control information between the AMF, and / or SMF, and / or AF.

[0082] By using the network connection section _720, the PCF can communicate with the AMF via the N15 interface, with the SMF via the N7 interface, and with the AF via the N5 interface (the interface between the PCF and the AF).

[0083] The memory unit _740 is a functional unit for storing programs, user data, control information, etc. required for each operation of the UPF.

[0084] The PCF has functions to support a unified policy framework, provide policy rules to control plane functions to enforce them, and access subscription information. The PCF also has functions to generate URSP (UE Route Selection Policy) rules, etc. All of these functions may be controlled by the control unit 700.

[0085] [2.7. Explanation of technical terms and identification information in this embodiment] Next, technical terms used in this embodiment will be explained.

[0086] A network refers to at least a portion of an access network _B, a core network _B, and a DN. Furthermore, one or more devices included in at least a portion of an access network _B, a core network _B, and a DN may be referred to as a network or a network device. In other words, when a network transmits, receives, and / or processes messages, it may mean that devices within the network (network devices and / or control devices) transmit, receive, receive, and / or process messages. Conversely, when a device within the network transmits, receives, receives, and / or processes messages, it may mean that the network transmits, receives, receives, and / or processes messages.

[0087] In addition, the SM (Session Management) message (also referred to as an NAS (Non-Access-Stratum) SM message) may be an NAS message used in a procedure for SM (hereinafter also referred to as an SM procedure), or may be a control message transmitted and received between UE_A10 and SMF_A230 via AMF_A240. Furthermore, the SM message may include a PDU session establishment request message, a PDU session establishment accept message, a PDU session establishment reject message, a PDU session modification request message, a PDU session modification command message, a PDU session modification complete message, a PDU session modification command reject message, a PDU session modification reject message, a PDU session release request message, a PDU session release reject message, a PDU session release command message, a PDU session release complete message, etc.

[0088] The procedures for SM may include a PDU session establishment procedure, a PDU session modification procedure, and a UE-requested PDU session release procedure. Each procedure may be initiated by the UE or the NW.

[0089] Furthermore, an MM (Mobility management) message (also referred to as an NAS MM message) may be an NAS message used in procedures for MM, and may be a control message transmitted and received between UE_A10 and AMF_A240. Furthermore, the MM message may include a registration request message, a registration accept message, a registration reject message, a de-registration request message, a de-registration accept message, a configuration update command message, a configuration update complete message, a service request message, a service accept message, a service reject message, a notification message, a notification response message, etc.

[0090] In addition, the procedures for MM or MM procedures may include a registration procedure, a de-registration procedure, a generic UE configuration update procedure (hereinafter also referred to as the UE configuration update procedure), an authentication and authorization procedure, a service request procedure, a paging procedure, and a notification procedure.

[0091] In addition, the 5GS (5G System) service may be a connection service provided using the core network_B190. Furthermore, the 5GS service may be a service different from the EPS service or may be a service similar to the EPS service.

[0092] In addition, non-5GS services may be services other than 5GS services, and may include EPS services and / or non-EPS services.

[0093] Also, the PDN (Packet Data Network) type indicates the type of PDN connection, and can be IPv4, IPv6, IPv4v6, or non-IP. If IPv4 is specified, it indicates that data will be sent and received using IPv4. If IPv6 is specified, it indicates that data will be sent and received using IPv6. If IPv4v6 is specified, it indicates that data will be sent and received using either IPv4 or IPv6. If non-IP is specified, it indicates that communication will not be via IP, but via a communication method other than IP.

[0094] Furthermore, a PDU (Protocol Data Unit / Packet Data Unit) session can be defined as an association between a DN that provides a PDU connectivity service and a UE, but it may also be connectivity established between a UE and an external gateway. In 5GS, a UE can transmit and receive user data to and from a DN by establishing a PDU session via an access network _B and a core network _B. Here, this external gateway may be a UPF, SCEF, or the like. The UE can transmit and receive user data to and from a device such as an application server located in the DN using the PDU session.

[0095] Each device (UE, and / or access network device, and / or core network device) may associate one or more pieces of identification information with a PDU session and manage them. These pieces of identification information may include one or more of the following: DNN, QoS rule, PDU session type, application identification information, NSI identification information, access network identification information, and SSC mode, or may further include other information. Furthermore, when multiple PDU sessions are established, the identification information associated with the PDU sessions may be the same or different.

[0096] Furthermore, the DNN (Data Network Name) may be identification information for identifying a core network and / or an external network such as a DN. Furthermore, the DNN can also be used as information for selecting a gateway such as PGW_A30 / UPF_A235 that connects the core network B190. Furthermore, the DNN may be equivalent to an APN (Access Point Name).

[0097] Furthermore, the PDU (Protocol Data Unit / Packet Data Unit) session type indicates the type of PDU session, and can be IPv4, IPv6, Ethernet, or Unstructured. If IPv4 is specified, it indicates that data will be sent and received using IPv4. If IPv6 is specified, it indicates that data will be sent and received using IPv6. If Ethernet is specified, it indicates that Ethernet frames will be sent and received. Furthermore, Ethernet may indicate that communication using IP is not performed. If Unstructured is specified, it indicates that data will be sent and received to an application server or the like in the DN using Point-to-Point (P2P) tunneling technology. As the P2P tunneling technology, for example, UDP / IP encapsulation technology may be used. In addition to the above, the PDU session type may also include IP. IP can be specified if the UE is capable of using both IPv4 and IPv6.

[0098] A PLMN (Public Land Mobile Network) is a communication network that provides mobile radio communication services. A PLMN is a network managed by an operator, which is a communications carrier, and the operator can be identified by a PLMN ID. A PLMN that matches the MCC (Mobile Country Code) and MNC (Mobile Network Code) of a UE's IMSI (International Mobile Subscriber Identity) may be a Home PLMN (HPLMN). Furthermore, the UE may store an Equivalent HPLMN list in its USIM to identify one or more Equivalent HPLMNs (EPLMNs). A PLMN that is different from the HPLMN and / or EPLMN may be a Visited PLMN (VPLMN). A PLMN to which a UE has successfully registered may be a Registered PLMN (RPLMN).

[0099] A network slice (NS) is a logical network that provides specific network capabilities and network characteristics. UEs and / or networks can support network slices (NW slices; NS) in 5GS. A network slice may also be simply referred to as a slice.

[0100] A network slice instance (NSI) is composed of an instance (entity) of a network function (NF) and a set of required resources, forming a deployed network slice. Here, an NF is a processing function in a network, adopted or defined by 3GPP. An NSI is an entity of one or more NSs configured within a core network _B. An NSI may also be composed of virtual network functions (NFs) generated using a network slice template (NST). Here, an NST is associated with resource requirements for providing required communication services and capabilities, and is a logical representation of one or more NFs. In other words, an NSI may be a collection of multiple NFs within the core network _B 190. An NSI may also be a logical network configured to separate user data delivered by services, etc. One or more NFs may be configured within an NS. The NFs configured in an NS may or may not be devices shared with other NSs. A UE and / or a device in the network can be assigned to one or more NSs based on registration information such as an NSSAI, an S-NSSAI, an UE usage type, an NSI ID, or one or more APNs. The UE usage type is a parameter value included in the UE registration information and used to identify the NSI. The UE usage type may be stored in the HSS. The AMF may select an SMF and a UPF based on the UE usage type.

[0101] Furthermore, S-NSSAI (Single Network Slice Selection Assistance Information) is information for identifying an NS. The S-NSSAI may consist of only an SST (Slice / Service type) or may consist of both an SST and an SD (Slice Differentiator). Here, the SST is information indicating the expected behavior of the NS in terms of functions and services. The SD may be information that interpolates the SST when selecting one NSI from multiple NSIs indicated by the SST. The S-NSSAI may be information specific to each PLMN, or may be standard information common among PLMNs. The network may store one or more S-NSSAIs as default S-NSSAIs in the registration information of the UE. Note that when the S-NSSAI is the default S-NSSAI, if the UE does not send a valid S-NSSAI to the network in a registration request message, the network may provide an NS related to the UE.

[0102] Also, NSSAI (Network Slice Selection Assistance Information) is a collection of S-NSSAIs. Each S-NSSAI included in the NSSAI is information that assists the access network or core network in selecting an NSI. The UE may store the NSSAI authorized by the network for each PLMN. Also, the NSSAI may be information used to select an AMF.

[0103] Furthermore, the requested NSSAI (hereinafter also referred to as the requested NSSAI) is an NSSAI provided from the UE to the network during the registration procedure. The requested NSSAI may be an allowed NSSAI or a configured NSSAI stored by the UE. Specifically, the requested NSSAI may be information indicating a network slice that the UE wishes to access. The S-NSSAI included in the requested NSSAI may be expressed as a requested S-NSSAI. For example, the requested NSSAI is transmitted in a NAS message, such as a registration request message or a PDU session establishment request message, transmitted from the UE to the network, or in a Radio Resource Control (RRC) message including a NAS (Non-Access-Stratum) message.

[0104] Furthermore, the allowed NSSAI (hereinafter also referred to as the permitted NSSAI or the Allowed NSSAI) is information indicating one or more network slices to which the UE is allowed to connect. In other words, the allowed NSSAI is information identifying the network slices to which the network has permitted the UE to connect. The UE and the network each store and manage the allowed NSSAI for each access (3GPP access or non-3GPP access) as UE information. The S-NSSAI included in the allowed NSSAI may be expressed as the allowed S-NSSAI. The allowed S-NSSAI may be configured to include the S-NSSAI and the mapped S-NSSAI. Furthermore, the SST or SD constituting the S-NSSAI included in the allowed NSSAI may indicate an IMS service. In other words, the value of the SST or SD constituting the S-NSSAI included in the allowed NSSAI may correspond to the IMS service. That is, the value of the SST corresponding to the IMS service may be predetermined, and the value of the SD corresponding to the IMS service may be predetermined.

[0105] Furthermore, the first S-NSSAI is information that identifies a network slice corresponding to IMS (hereinafter also referred to as an IMS service, an IMS session, a SIP session, a PDU session for IMS, or a service provided by IMS). In other words, the first S-NSSAI may be information that identifies a network slice that supports communication using IMS. Furthermore, the first S-NSSAI may be included in an Allowed NSSAI or a default NSSAI (hereinafter also referred to as a default NSSAI). Furthermore, the first S-NSSAI may be an S-NSSAI stored by the UE and / or NW, or may be an S-NSSAI transmitted from the NW to the UE. Furthermore, the first S-NSSAI for an IMS service may be predefined by a specification or an operator.

[0106] The first S-NSSAI may be valid (usable) in a first registration area (hereinafter also referred to as a registration area, RA) for IMS services, but not valid in a second registration area. The first S-NSSAI may be valid (usable) in a first registration area for IMS services, but valid in a second registration area for services other than IMS services.

[0107] Furthermore, the second S-NSSAI is information that identifies a network slice corresponding to IMS. In other words, the second S-NSSAI may be information that identifies a network slice that supports communication using IMS. Furthermore, the second S-NSSAI may be included in the Allowed NSSAI or the default NSSAI. Furthermore, the second S-NSSAI may be an S-NSSAI stored by the UE and / or the NW, or may be an S-NSSAI transmitted from the NW to the UE. Furthermore, the second S-NSSAI for an IMS service may be predefined by a specification or an operator.

[0108] Furthermore, the second S-NSSAI may be an S-NSSAI that is valid (usable) in the second registration area for IMS services, but is valid or not valid in the first registration area.

[0109] Furthermore, the third S-NSSAI, the fourth S-NSSAI, the fifth S-NSSAI, the sixth S-NSSAI, the seventh S-NSSAI, the eighth S-NSSAI, the ninth S-NSSAI, the tenth S-NSSAI, the eleventh S-NSSAI, the twelfth S-NSSAI, and the thirteenth S-NSSAI are information that identifies the network slice corresponding to the IMS, respectively.

[0110] For example, the third S-NSSAI may be information identifying a network slice for SIP signaling for the first IMS service. The fourth S-NSSAI may be information identifying a network slice for media (e.g., voice and video) for the first IMS service. The ninth S-NSSAI may be information identifying a network slice for media (e.g., voice) for the first IMS service. The tenth S-NSSAI may be information identifying a network slice for media (e.g., video) for the first IMS service. Note that here, voice and video are assumed as media for the first IMS service, and the case in which voice and video are treated as a single entity is represented as the fourth S-NSSAI, and the case in which voice and video are treated as separate entities is represented as the ninth S-NSSAI and the tenth S-NSSAI, respectively. That is, the fourth S-NSSAI may be associated with the ninth S-NSSAI and the tenth S-NSSAI. In other words, the fourth S-NSSAI may be a concept that includes the ninth S-NSSAI and the tenth S-NSSAI. In other words, a description of the fourth S-NSSAI may be read as a description of the ninth S-NSSAI and the tenth S-NSSAI, and a description of the ninth S-NSSAI and the tenth S-NSSAI may be read as a description of the fourth S-NSSAI.

[0111] Furthermore, for example, the fifth S-NSSAI may be information identifying a network slice for SIP signaling for the second IMS service. Furthermore, the sixth S-NSSAI may be information identifying a network slice for media (e.g., voice and video) for the second IMS service. Furthermore, the eleventh S-NSSAI may be information identifying a network slice for media (e.g., voice) for the second IMS service. Furthermore, the twelfth S-NSSAI may be information identifying a network slice for media (e.g., video) for the second IMS service. Note that here, voice and video are assumed as media for the second IMS service, and the case in which voice and video are treated as a single entity is expressed as the sixth S-NSSAI, and the case in which voice and video are treated as separate entities is expressed as the eleventh S-NSSAI and the twelfth S-NSSAI, respectively. That is, the sixth S-NSSAI may be associated with the eleventh S-NSSAI and the twelfth S-NSSAI. In other words, the sixth S-NSSAI may be a concept that includes the eleventh S-NSSAI and the twelfth S-NSSAI. In other words, a description regarding the sixth S-NSSAI may be read as a description regarding the eleventh S-NSSAI and the twelfth S-NSSAI, and a description regarding the eleventh S-NSSAI and the twelfth S-NSSAI may be read as a description regarding the sixth S-NSSAI.

[0112] Furthermore, at least some of the third S-NSSAI, the fourth S-NSSAI, the fifth S-NSSAI, the sixth S-NSSAI, the ninth S-NSSAI, the tenth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI may have the same value, or may all have different values. Here, the same value of the S-NSSAI may mean that the network slices identified by the S-NSSAI are the same. Furthermore, different values ​​of the S-NSSAI may mean that the network slices identified by the S-NSSAI are different.

[0113] Also, for example, the seventh S-NSSAI may be information identifying a network slice of the first IMS service, and the eighth S-NSSAI may be information identifying a network slice of the second IMS service.

[0114] Furthermore, the seventh S-NSSAI may be associated with the third S-NSSAI and the fourth S-NSSAI. In other words, the seventh S-NSSAI may be a concept including the third S-NSSAI and the fourth S-NSSAI. In other words, a description regarding the seventh S-NSSAI may be read as a description regarding the third S-NSSAI and the fourth S-NSSAI, and a description regarding the third S-NSSAI and the fourth S-NSSAI may be read as a description regarding the seventh S-NSSAI.

[0115] Furthermore, the seventh S-NSSAI may be associated with the third S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI. In other words, the seventh S-NSSAI may be a concept including the third S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI. In other words, a description regarding the seventh S-NSSAI may be replaced with a description regarding the third S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI, and a description regarding the third S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI may be replaced with a description regarding the seventh S-NSSAI.

[0116] Furthermore, the eighth S-NSSAI may be associated with the fifth S-NSSAI and the sixth S-NSSAI. In other words, the eighth S-NSSAI may be a concept including the fifth S-NSSAI and the sixth S-NSSAI. In other words, a description regarding the eighth S-NSSAI may be read as a description regarding the fifth S-NSSAI and the sixth S-NSSAI, and a description regarding the fifth S-NSSAI and the sixth S-NSSAI may be read as a description regarding the eighth S-NSSAI.

[0117] Furthermore, the eighth S-NSSAI may be associated with the fifth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI. In other words, the eighth S-NSSAI may be a concept including the fifth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI. In other words, a description regarding the eighth S-NSSAI may be replaced with a description regarding the fifth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI, and a description regarding the fifth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI may be replaced with a description regarding the eighth S-NSSAI.

[0118] Furthermore, the seventh S-NSSAI and the eighth S-NSSAI may be the same value or different values.

[0119] Furthermore, the values ​​of the seventh S-NSSAI and the eighth S-NSSAI being the same may mean that the values ​​of the third S-NSSAI, the fourth S-NSSAI, the fifth S-NSSAI, and the sixth S-NSSAI are all the same.

[0120] Furthermore, the values ​​of the seventh S-NSSAI and the eighth S-NSSAI being different may mean that at least some of the values ​​of the third S-NSSAI, the ninth S-NSSAI, the tenth S-NSSAI, the fifth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI are different.

[0121] Furthermore, the thirteenth S-NSSAI is defined herein to mean the first S-NSSAI, and / or the second S-NSSAI, and / or the third S-NSSAI, and / or the fourth S-NSSAI, and / or the fifth S-NSSAI, and / or the sixth S-NSSAI, and / or the seventh S-NSSAI, and / or the eighth S-NSSAI, and / or the ninth S-NSSAI, and / or the tenth S-NSSAI, and / or the eleventh S-NSSAI, and / or the twelfth S-NSSAI. That is, for the sake of simplicity, the thirteenth S-NSSAI is used as a general term for all combinations of the first to twelfth identification information. Thus, for example, in some places in this specification, the 13th S-NSSAI may refer to the first S-NSSAI, in other places the 13th S-NSSAI may refer to the third S-NSSAI and the fourth S-NSSAI, and in other places the 13th S-NSSAI may refer to the third S-NSSAI, the ninth S-NSSAI and the tenth S-NSSAI, so the 13th S-NSSAI may have more than one meaning and does not have only a single meaning.

[0122] Furthermore, when a PDU session establishment procedure is performed using the same S-NSSAI value, it may mean that the network slices used by the established PDU sessions are the same. Furthermore, when a PDU session establishment procedure is performed using different S-NSSAI values, it may mean that the network slices used by the established PDU sessions are different.

[0123] An IMS network is composed of devices and / or functions that provide IMS services and may exist within a DN. When multiple IMS services exist, devices, functions, and / or networks that provide the respective IMS services may exist within the same DN or different DNs. In other words, PDU sessions for the respective IMS services may be established for the same or different DNs via the same or different network slices.

[0124] Furthermore, a PDU session for an IMS service may be established for each slice. Specifically, a PDU session for SIP signaling and a PDU session for media for the IMS service may be established for each slice. Conversely, a PDU session for one IMS service may be established for each slice, and the PDU session for the IMS service may be used to transmit and receive SIP signaling and data for media for the IMS service.

[0125] In addition, the third S-NSSAI, the fourth S-NSSAI, the fifth S-NSSAI, the sixth S-NSSAI, the seventh S-NSSAI, the eighth S-NSSAI, and / or the ninth S-NSSAI, and / or the tenth S-NSSAI, and / or the eleventh S-NSSAI, and / or the twelfth S-NSSAI may be included in the Allowed NSSAI or the default NSSAI (hereinafter also referred to as the default NSSAI).

[0126] Furthermore, the default NSSAI (hereinafter also referred to as default NSSAI) is information including one or more default S-NSSAIs (hereinafter also referred to as default S-NSSAI) corresponding to the IMS (hereinafter also referred to as supporting the IMS service). In other words, the default NSSAI may be information including a default S-NSSAI that supports communication using the IMS. Here, the default S-NSSAI may be one or more S-NSSAIs constituting the thirteenth S-NSSAI. Furthermore, the default NSSAI and / or default S-NSSAI may be an S-NSSAI stored by the UE and / or NW. Furthermore, the default S-NSSAI may be valid in all PLMNs (hereinafter also referred to as usable or applicable), or may be valid within the current PLMN. Furthermore, a default S-NSSAI for an IMS service may be predefined by a specification or an operator.

[0127] In addition, an IMS service may refer to SIP signaling (hereinafter sometimes simply referred to as signaling) which corresponds to control signals (also referred to as control information) in the SIP layer, and / or media which corresponds to user data (also referred to as non-control signals) in the SIP layer.

[0128] Furthermore, an IMS service may refer to a service provided by the IMS. In this case, for example, the IMS service may be an MMTEL (Multimedia Telephony) communication service. Specifically, the IMS service may be an MMTEL video service, an MMTEL voice service, and / or other services using MMTEL communication. Furthermore, for example, the IMS service may be a voice service (also referred to as an IMS Voice service), a video service (also referred to as an IMS Video service), and / or RCS (Rich Communication Services), and / or other services.

[0129] A tracking area (hereinafter also referred to as TA) is a single or multiple ranges managed by the core network that can be represented by the location information of UE_A10. A tracking area may be composed of multiple cells. Furthermore, a tracking area may be an area in which control messages such as paging are broadcast, or an area in which UE_A10 can move without performing a handover procedure. Furthermore, a tracking area may be a routing area, a location area, or anything similar. A tracking area may be identified by a TAI (Tracking Area Identity) consisting of a TAC (Tracking area code) and a PLMN.

[0130] A registration area is a collection of one or more TAs assigned to a UE by the AMF. Note that while UE_A10 is moving within one or more TAs included in the registration area, it may be able to move without sending or receiving signals for tracking area updates. In other words, a registration area may be a group of information indicating an area in which UE_A10 can move without performing a registration procedure. A registration area may be identified by a TAI list consisting of one or more TAIs.

[0131] A URSP (UE Route Selection Policy) may be configured as a list of one or more URSP rules (UE Route Selection Policy Rules), and each URSP rule may be configured as a rule precedence, a traffic descriptor, and / or a list of route selection descriptors.

[0132] Here, the rule priority indicates the order in which the URSP rules are enforced in the UE. When the UE receives a URSP, that is, when it receives one or more URSP rules, it may refer to the priority of each rule and apply the URSP rules in order from the highest priority rule.

[0133] The traffic descriptor indicates when to apply the URSP rule and may consist of application descriptors, IP descriptors, domain descriptors, non-IP descriptors, data network names (DNNs), and connection capabilities.

[0134] Here, the application descriptor may include an OS ID and an OS application ID. The IP descriptor indicates information identifying the destination of IP traffic, and may include, for example, an IP address, an IPv6 network prefix, a port number, a protocol number, etc. The domain descriptors may indicate a fully qualified domain name (FQDN) of the destination. The non-IP descriptor may indicate information identifying the destination of non-IP traffic (e.g., ethernet traffic or unstructured traffic). The DNN may be information related to the DNN provided by the application. The connection capability may indicate information provided by the UE application when the UE requests connection to a network using a certain capability. Here, the connection capability may indicate IMS.

[0135] Additionally, a Route Selection Descriptor List may consist of one or more Route Selection Descriptors, each of which may consist of a Route Selection Descriptor Precedence and / or Route selection components.

[0136] Here, the rule selection descriptor priority indicates the order in which the route selection descriptors are applied. When the UE receives a route selection descriptor list, that is, when it receives one or more route selection descriptors, it may refer to the rule selection descriptor priority in each route selection descriptor and apply the route selection descriptors in order from the highest priority to the lowest priority.

[0137] The route selection configuration may also include SSC Mode Selection, and / or Network Slice Selection, and / or DNN Selection, and / or PDU Session Type Selection, and / or Non-Seamless Offload indication, and / or Access Type preference.

[0138] Here, the SSC mode selection may indicate routing of application traffic through a PDU session of the specified SSC mode. The network slice selection may indicate routing of application traffic using a PDU session supporting one or more indicated S-NSSAIs. Here, the network slice selection may indicate a thirteenth S-NSSAI supporting IMS. The DNN selection may indicate routing of application traffic using a PDU session supporting one or more indicated DNNs. The PDU session type selection may indicate routing of application traffic using a PDU session supporting the indicated PDU session type. The non-seamless offload indication may indicate offloading of application traffic to a non-3GPP access. The access type preference may indicate an access type for establishing a PDU session if the UE needs to establish a PDU session. Here, the access type may indicate 3GPP, non-3GPP, or multi-access.

[0139] Next, the identification information transmitted, received, stored, and managed by each device in this embodiment will be described.

[0140] First, the first identification information is a default S-NSSAI (hereinafter also referred to as default S-NSSAI). Also, the first identification information may be the same as the 11th identification information and / or the 21st identification information and / or the 31st identification information. Also, the first identification information may be selected from the 11th identification information and / or the 21st identification information and / or the 31st identification information. Also, the first identification information may be at least one of the S-NSSAIs indicated by the third identification information.

[0141] Furthermore, the second identification information is information indicating a request for information on a registration area that can use the S-NSSAI. Specifically, the second identification information may be information indicating a request for information on a registration area that can use the S-NSSAI that supports IMS.

[0142] Furthermore, the third identification information is the 13th S-NSSAI that supports IMS. Furthermore, the third identification information may be the same as or different from the S-NSSAI included in the 15th identification information. Furthermore, the third identification information may be the same as or different from the S-NSSAI included in the 25th identification information. Furthermore, the third identification information may be the same as the 36th identification information.

[0143] Furthermore, the fourth identification information is UE capability information. The fourth identification information may be 5GMM capability. The fourth identification information may indicate whether the UE supports a certain function. The fourth identification information may be capability information indicating whether the UE is capable of providing an IMS service via multiple slices. The fourth identification information may be capability information indicating that communication is possible using a PDU session for media using a network slice different from the network slice used for a PDU session for SIP signaling.

[0144] Furthermore, the fifth identification information is information indicating a request for provision of a service by IMS via multiple slices. The fifth identification information may also be information indicating a request for establishment of a PDU session for SIP signaling for the IMS service, and / or information indicating a request for establishment of a PDU session for media for the IMS service, and / or information indicating a request for establishment of a PDU session for the IMS service.

[0145] The sixth identification information is information that includes at least a part of the first to fifth identification information.

[0146] The 11th identification information is a default S-NSSAI. The 11th identification information may be the same as or different from the 1st identification information and / or the 21st identification information and / or the 31st identification information. The 11th identification information may be at least one of the S-NSSAIs indicated by the 16th identification information.

[0147] In addition, the 12th identification information may be information indicating the registration area in which the S-NSSAI included in the Allowed NSSAI is valid, and / or information indicating whether the S-NSSAI included in the Allowed NSSAI is valid in the current registration area, and / or information indicating whether the S-NSSAI included in the Allowed NSSAI is valid within the current PLMN, and / or information indicating whether the S-NSSAI included in the Allowed NSSAI is valid in all PLMNs.

[0148] Furthermore, the 12th identification information may be information indicating the registration area in which the 13th S-NSSAI is valid, and / or information indicating whether the 13th S-NSSAI is valid in the current registration area, and / or information indicating whether the 13th S-NSSAI is valid in the current PLMN, and / or information indicating whether the 13th S-NSSAI is valid in all PLMNs. Note that, when there are two or more S-NSSAIs that constitute the 13th S-NSSAI included in the 15th identification information, the 12th identification information may be configured as information for each S-NSSAI. In other words, the 12th identification information may be configured and transmitted for the same number of S-NSSAIs included in the 15th identification information.

[0149] Furthermore, the twelfth identification information may be configured as information for each access type for a registration area. That is, the twelfth identification information may be information indicating whether the thirteenth S-NSSAI is valid in the current registration area for 3GPP access, and / or information indicating whether the thirteenth S-NSSAI is valid in the current registration area for non-3GPP access, and / or information indicating whether the thirteenth S-NSSAI is valid in the current PLMN (Public Land Mobile Network), and / or information indicating whether the thirteenth S-NSSAI is valid in all PLMNs.

[0150] Furthermore, the twelfth identification information may include information about the access type and may be configured as information associated with the access type for the registration area. That is, the twelfth identification information may be information indicating whether the thirteenth S-NSSAI is valid in the current registration area, and / or information indicating whether the thirteenth S-NSSAI is valid in the current PLMN (Public Land Mobile Network), and / or information indicating whether the thirteenth S-NSSAI is valid in all PLMNs, for each access type. Here, the information about the access type may be information indicating 3GPP access or non-3GPP access, as described above.

[0151] Furthermore, the 12th identification information may be configured as a plurality of individual pieces of information for each access unit associated with an access type. For example, the 12th identification information #A may be information indicating whether the 13th S-NSSAI is valid in the current registration area in 3GPP access, and the 12th identification information #B may be information indicating whether the 13th S-NSSAI is valid in the current registration area in non-3GPP access.

[0152] Furthermore, the 13th identification information is information indicating that the Allowed NSSAI includes an S-NSSAI for an IMS service, and / or that the first S-NSSAI included in the Allowed NSSAI is an S-NSSAI for an IMS service, and / or that the last S-NSSAI included in the Allowed NSSAI is an S-NSSAI for an IMS service. Furthermore, the 13th identification information may be information indicating the ordinal position of the S-NSSAI for an IMS service included in the Allowed NSSAI.

[0153] The fourteenth identification information is information for identifying an IMS service. The fourteenth identification information may be associated with an S-NSSAI that supports the IMS.

[0154] Furthermore, the 15th identification information is an Allowed NSSAI. Furthermore, the 15th identification information may include the 11th identification information and / or the 14th identification information and / or the 16th identification information. Furthermore, the positions and order of the one or more S-NSSAIs included in the 15th identification information and the IMS service may be specified in advance by a specification or by an operator. For example, it may be specified in advance that the first S-NSSAI of the one or more S-NSSAIs included in the 15th identification information is an S-NSSAI corresponding to an IMS service. Furthermore, it may be specified in advance that the last S-NSSAI of the one or more S-NSSAIs included in the 15th identification information is an S-NSSAI corresponding to an IMS service. Furthermore, it may be specified in advance that the nth S-NSSAI from the top (where n is a value greater than 1) of the one or more S-NSSAIs included in the 15th identification information is an S-NSSAI corresponding to an IMS service. Furthermore, it may be specified in advance that the nth (n being a value greater than 1) S-NSSAI from the end of the one or more S-NSSAIs included in the 15th identification information is an S-NSSAI corresponding to the IMS service. Furthermore, the S-NSSAI included in the 15th identification information may be an S-NSSAI configured by an SST (Slice / Service type) and / or an SD (Slice Differentiator). Furthermore, the 15th identification information may include one or more S-NSSAIs that do not support the IMS service.

[0155] Furthermore, the 16th identification information is a 13th S-NSSAI that supports IMS. Furthermore, the 16th identification information may be the same as or different from the S-NSSAI included in the 15th identification information. Furthermore, the 16th identification information may be the same as or different from the S-NSSAI included in the 25th identification information. Furthermore, the 16th identification information may be the same as or different from the 26th identification information. Furthermore, the 16th identification information may be the same as or different from the 36th identification information. Furthermore, the 16th identification information may be an S-NSSAI configured by an SST (Slice / Service type) and / or an SD (Slice Differentiator).

[0156] Furthermore, the 17th identification information is network capability information. The 17th identification information may be 5GS network feature support. The 17th identification information may indicate whether the network supports a certain function. The 17th identification information may be capability information indicating whether the network can support provision of IMS services via multiple slices.

[0157] Furthermore, the 18th identification information is information indicating that provision of a service by IMS via multiple slices is permitted. Furthermore, the 18th identification information may be information indicating that establishment of a PDU session for SIP signaling for the IMS service is permitted, and / or information indicating that establishment of a PDU session for media for the IMS service is permitted, and / or information indicating that establishment of a PDU session for the IMS service is permitted.

[0158] Furthermore, the nineteenth identification information may be information that includes at least a part of the eleventh to eighteenth identification information.

[0159] Furthermore, the 21st identification information is a default S-NSSAI. Furthermore, the 21st identification information may be the same as or different from the first identification information and / or the 11th identification information and / or the 31st identification information. Furthermore, the 21st identification information may be at least one of the S-NSSAIs indicated by the 26th identification information.

[0160] Furthermore, the 22nd identification information is information indicating the registration area in which the 13th S-NSSAI is valid, and / or information indicating whether the 13th S-NSSAI is valid in the current registration area, and / or information indicating whether the 13th S-NSSAI is valid in the current PLMN, and / or information indicating whether the 13th S-NSSAI is valid in all PLMNs. Note that, when there are two or more S-NSSAIs that constitute the 13th S-NSSAI included in the 25th identification information, the 22nd identification information may be configured as information for each S-NSSAI. In other words, the 22nd identification information may be configured and transmitted for the same number of S-NSSAIs included in the 25th identification information.

[0161] Furthermore, the 22nd identification information may be configured as information for each access type for a registration area. That is, the 22nd identification information may be information indicating whether the 13th S-NSSAI is valid in the current registration area for 3GPP access, and / or information indicating whether the 13th S-NSSAI is valid in the current registration area for non-3GPP access, and / or information indicating whether the 13th S-NSSAI is valid in the current PLMN (Public Land Mobile Network), and / or information indicating whether the 13th S-NSSAI is valid in all PLMNs.

[0162] Furthermore, the 22nd identification information may include information about the access type and may be configured as information associated with the access type for the registration area. That is, the 22nd identification information may be information indicating whether the 13th S-NSSAI is valid in the current registration area, and / or information indicating whether the 13th S-NSSAI is valid in the current PLMN (Public Land Mobile Network), and / or information indicating whether the 13th S-NSSAI is valid in all PLMNs, for each access type. Here, the information about the access type may be information indicating 3GPP access or non-3GPP access, as described above.

[0163] Furthermore, the 22nd identification information may be configured as a plurality of individual pieces of information for each access unit associated with an access type. For example, the 22nd identification information #A may be information indicating whether the 13th S-NSSAI is valid in the current registration area in 3GPP access, and the 22nd identification information #B may be information indicating whether the 13th S-NSSAI is valid in the current registration area in non-3GPP access.

[0164] Furthermore, the 23rd identification information is information indicating that the Allowed NSSAI includes an S-NSSAI for an IMS service, and / or that the first S-NSSAI included in the Allowed NSSAI is an S-NSSAI for an IMS service, and / or that the last S-NSSAI included in the Allowed NSSAI is an S-NSSAI for an IMS service. Furthermore, the 23rd identification information may be information indicating the ordinal position of the S-NSSAI for an IMS service included in the Allowed NSSAI.

[0165] The 24th identification information is information for identifying an IMS service. The 24th identification information may be associated with an S-NSSAI that supports the IMS.

[0166] Furthermore, the 25th identification information is an Allowed NSSAI. Furthermore, the 25th identification information may include the 21st identification information and / or the 24th identification information and / or the 26th identification information. Furthermore, the S-NSSAI included in the 25th identification information may be an S-NSSAI configured by an SST (Slice / Service type) and / or an SD (Slice Differentiator). Furthermore, the 15th identification information may include one or more S-NSSAIs that do not support IMS services.

[0167] Furthermore, the 26th identification information is the 13th S-NSSAI that supports IMS. Furthermore, the 26th identification information may be the same as or different from the S-NSSAI included in the 15th identification information. Furthermore, the 26th identification information may be the same as or different from the 16th identification information. Furthermore, the 26th identification information may be the same as or different from the S-NSSAI included in the 25th identification information. Furthermore, the 26th identification information may be the same as or different from the 36th identification information. Furthermore, the 26th identification information may be an S-NSSAI configured by an SST (Slice / Service type) and / or an SD (Slice Differentiator).

[0168] Furthermore, the 27th identification information may be information that includes at least a part of the 21st to 26th identification information.

[0169] Furthermore, the 31st identification information is a default S-NSSAI. Furthermore, the 31st identification information may be the same as or different from the first identification information and / or the 11th identification information and / or the 21st identification information. Furthermore, the 31st identification information may be included in an Allowed NSSAI. Furthermore, the 31st identification information may be at least one of the S-NSSAIs indicated by the 36th identification information.

[0170] Furthermore, the 32nd identification information is information indicating the registration area in which the 13th S-NSSAI is valid, and / or information indicating whether the 13th S-NSSAI is valid in the current registration area, and / or information indicating whether the 13th S-NSSAI is valid in the current PLMN, and / or information indicating whether the 13th S-NSSAI is valid in all PLMNs. Note that, when there are two or more S-NSSAIs that constitute the 13th S-NSSAI included in the 33rd identification information, the 32nd identification information may be configured as information for each S-NSSAI. In other words, the 32nd identification information may be configured and transmitted for the same number of S-NSSAIs included in the 33rd identification information.

[0171] Furthermore, the 32nd identification information may be configured as information for each access type for a registration area. That is, the 32nd identification information may be information indicating whether the 13th S-NSSAI is valid in the current registration area for 3GPP access, and / or information indicating whether the 13th S-NSSAI is valid in the current registration area for non-3GPP access, and / or information indicating whether the 13th S-NSSAI is valid in the current PLMN (Public Land Mobile Network), and / or information indicating whether the 13th S-NSSAI is valid in all PLMNs.

[0172] Furthermore, the 32nd identification information may include information about the access type and may be configured as information associated with the access type for the registration area. That is, the 32nd identification information may be information indicating whether the 13th S-NSSAI is valid in the current registration area, and / or information indicating whether the 13th S-NSSAI is valid in the current PLMN (Public Land Mobile Network), and / or information indicating whether the 13th S-NSSAI is valid in all PLMNs, for each access type. Here, the information about the access type may be information indicating 3GPP access or non-3GPP access, as described above.

[0173] Furthermore, the 32nd identification information may be configured as a plurality of individual pieces of information for each access unit associated with an access type. For example, the 32nd identification information #A may be information indicating whether the 13th S-NSSAI is valid in the current registration area in 3GPP access, and the 32nd identification information #B may be information indicating whether the 13th S-NSSAI is valid in the current registration area in non-3GPP access.

[0174] Furthermore, the 33rd identity information is an URSP. The 33rd identity information may include at least one of the 32nd, 34th to 36th identities. The 33rd identity information may also include one or more S-NSSAIs that do not support IMS services.

[0175] Furthermore, the 34th identification information may be mapping information with the 32nd identification information, and / or the 35th identification information, and / or the 36th identification information. The 34th identification information may be information that explicitly indicates that the 32nd identification information, and / or the 35th identification information, and / or the 36th identification information correspond to the 34th identification information.

[0176] Furthermore, the 35th identification information is information indicating a service type. Furthermore, the 35th identification information may indicate IMS or an IMS service. Furthermore, the 35th identification information may be information indicating whether the S-NSSAI can be used for an IMS service. Furthermore, the 35th identification information may be connection capabilities indicating IMS or an IMS service. Furthermore, the 35th identification information may be connection capabilities indicating whether the S-NSSAI can be used for an IMS service. Furthermore, the 35th identification information may be associated with an S-NSSAI that supports IMS.

[0177] Furthermore, the 36th identity information is a 13th S-NSSAI that supports IMS. Furthermore, the 36th identity information may be the same as or different from the S-NSSAI included in the 15th identity information. Furthermore, the 36th identity information may be the same as or different from the 16th identity information. Furthermore, the 36th identity information may be the same as or different from the S-NSSAI included in the 25th identity information. Furthermore, the 36th identity information may be the same as or different from the 26th identity information. Furthermore, when the PCF receives information regarding an Allowed NSSAI from the AMF, the 36th identity information may be at least a part of a 13th S-NSSAI selected from one or more S-NSSAIs included in the Allowed NSSAI. Furthermore, the 36th identity information may be at least a part of a 13th S-NSSAI that supports IMS services and is valid (usable) in the new registration area. Furthermore, the 36th identity information may be included in the Allowed NSSAI. Furthermore, the 36th identification information may be an S-NSSAI composed of an SST (Slice / Service type) and / or an SD (Slice Differentiator).

[0178] Furthermore, the 37th identification information may be information that includes at least a part of the 31st to 36th identification information.

[0179] Furthermore, the 41st identification information is a cause value indicating the reason for the rejection. Furthermore, the 41st identification information may be a cause value indicating "unavailable at current registration area." Furthermore, the 41st identification information may be a cause value indicating "S-NSSAI unavailable at current registration area" for the provided S-NSSAI (including the 13th S-NSSAI). Furthermore, the 41st identification information may be associated with 3GPP access and / or non-3GPP access. That is, the 41st identification information may be a cause value indicating "unavailable at current registration area for 3GPP access and / or non-3GPP access." The 41st identification information may also be a reason value indicating that the provided S-NSSAI is unavailable at current registration area for 3GPP access and / or non-3GPP access.

[0180] Furthermore, the 51st identification information is a PDU session ID that identifies the PDU session. Furthermore, the 51st identification information may be a PDU session ID that identifies the PDU session that is requested to be established.

[0181] The 52nd identification information may be a PDU session type that identifies the type of the PDU session. The 52nd identification information may be a PDU session type requested by the UE for the PDU session. The 52nd identification information may indicate any of IPv4, IPv6, IPv4v6, Unstructured, and Ethernet (registered trademark).

[0182] Furthermore, the 53rd identification information is an SSC mode. Furthermore, the 53rd identification information may be an SSC mode requested by the UE for the PDU session. Furthermore, the 53rd identification information may indicate any of SSC mode 1, SSC mode 2, and SSC mode 3.

[0183] Furthermore, the 54th identification information may be UE capability information. The 54th identification information may be 5GSM capability. The 54th identification information may indicate whether the UE supports a certain function. The 54th identification information may be capability information indicating whether the UE can support the provision of services via IMS via multiple slices.

[0184] Furthermore, the 55th identification information is information indicating a request for provision of an IMS service via multiple slices. The 55th identification information may also be information indicating a request for establishment of a PDU session for SIP signaling for the IMS service, and / or information indicating a request for establishment of a PDU session for media for the IMS service, and / or information indicating a request for establishment of a PDU session for the IMS service.

[0185] Furthermore, the 56th identification information may be one or more S-NSSAIs. Furthermore, the 56th identification information may be one or more S-NSSAIs requested by the UE for the PDU session to be established. Furthermore, the 56th identification information may be at least one of the first to twelfth S-NSSAIs.

[0186] In addition, the 57th identification information is a DNN. In addition, the 57th identification information may be a DNN that identifies a DN to which a PDU session that the UE requests to establish is connected.

[0187] Furthermore, the 58th identification information is a PDU session ID for identifying a PDU session. Furthermore, the 58th identification information may be a PDU session ID for identifying an already established PDU session. For example, if PDU sessions for an IMS service have already been established, the 58th identification information may be a PDU session ID for identifying those PDU sessions.

[0188] The 59th identification information is identification information that includes at least two of the 51st to 58th identification information.

[0189] Furthermore, the 61st identification information is a PDU session ID that identifies a PDU session. It may be a PDU session ID that identifies a PDU session that is permitted to be established by the network.

[0190] The 62nd identification information may be a PDU session type that identifies the type of the PDU session. The 62nd identification information may be a PDU session type selected by the network. The 62nd identification information may indicate any of IPv4, IPv6, IPv4v6, Unstructured, and Ethernet (registered trademark).

[0191] The 63rd identification information may also be an SSC mode. The 63rd identification information may also be an SSC mode selected by the network for the PDU session. The 63rd identification information may also indicate SSC mode 1, SSC mode 2, or SSC mode 3.

[0192] Furthermore, the 64th identification information is network capability information. The 64th identification information may be 5GSM network feature support. The 64th identification information may indicate whether the network supports a certain function. The 64th identification information may be capability information indicating whether the network can support the provision of IMS services via multiple slices.

[0193] Furthermore, the 65th identification information is information indicating that provision of an IMS service via multiple slices is permitted. The 65th identification information may also be information indicating that establishment of a PDU session for SIP signaling for the IMS service is permitted, and / or information indicating that establishment of a PDU session for media for the IMS service is permitted, and / or information indicating that establishment of a PDU session for the IMS service is permitted.

[0194] Also, the 66th identification information is one or more S-NSSAIs.

[0195] In addition, the 67th identification information is a DNN. In addition, the 67th identification information may be a DNN that identifies the DN to which the PDU session is connected.

[0196] The 68th identification information is identification information that includes at least two of the 61st to 67th identification information.

[0197] 3. First Embodiment [3.1. Procedures used in the first embodiment] First, the procedures used in the first embodiment will be described, including the registration procedure in Chapter 3.2, and / or the generic UE configuration update procedure (UE configuration update procedure) in Chapter 3.3, and / or the UE policy update procedure (UE policy management procedure) in Chapter 3.4, and / or the PDU session establishment procedure in Chapter 3.5.

[0198] In the first embodiment, as shown in FIG. 2, an example will be described in which the HSS and UDM, the PCF and PCRF, the SMF and PGW-C, and the UPF and PGW-U are configured as the same device (that is, the same physical hardware, the same logical hardware, or the same software). However, the contents described in this embodiment are also applicable to cases in which these are configured as different devices (that is, different physical hardware, different logical hardware, or different software). For example, data may be transmitted and received directly between these devices, or may be transmitted and received via the N26 interface between the AMF and MME, or may be transmitted and received via the UE.

[0199] 3.2. Registration Procedures First, the registration procedure will be described with reference to FIG. 6. Hereinafter, this procedure refers to the registration procedure. The registration procedure is a procedure initiated by the UE to register with the access network _B and / or the core network _B and / or the DN. If the UE is not registered with a network, it can execute this procedure at any time, for example, when it is powered on. In other words, if the UE is in a deregistered state (5GMM-DEREGISTERED state), it can start this procedure at any time. Furthermore, each device (especially the UE and the AMF) can transition to a registered state (5GMM-REGISTED state) based on the completion of the registration procedure. Note that each registration state may be managed by each device for each access. Specifically, each device may independently manage the registration state (registered state or unregistered state) for 3GPP access and the registration state for non-3GPP access.

[0200] Furthermore, the registration procedure may be a procedure for updating the location registration information of the UE in the network, and / or for the UE to periodically notify the network of the status of the UE, and / or for updating certain parameters related to the UE in the network.

[0201] A UE may initiate the registration procedure when it performs mobility across TAs. In other words, a UE may initiate the registration procedure when it moves to a TA different from the TAs indicated in its TA list. Furthermore, a UE may initiate this procedure when a running backoff timer or other timer expires. Furthermore, a UE may initiate the registration procedure when a context update for each device is required due to a PDU session disconnection or invalidation. Furthermore, a UE may initiate the registration procedure when a change occurs in the UE's capability information and / or preferences regarding PDU session establishment. Furthermore, a UE may initiate the registration procedure periodically. Furthermore, a UE may initiate the registration procedure based on the completion of the registration procedure in Chapter 3.2, the completion of the generic UE configuration update procedure in Chapter 3.3, the completion of the UE policy management procedure in Chapter 3.4, or the completion of a procedure for SM (including, for example, the PDU session establishment procedure in Chapter 3.5). Note that the UE may perform the registration procedure at any timing, not limited to these.

[0202] The procedure for the UE to transition from a state where it is not registered in the network (unregistered state) to a state where it is registered (registered state) may be called an initial registration procedure or a registration procedure for initial registration. Also, the registration procedure performed when the UE is registered in the network (registered state) may be called a registration procedure for mobility and periodic registration update or a mobility and periodic registration procedure.

[0203] The new AMF (hereinafter simply referred to as AMF) in Figure 6 indicates the AMF to which the UE is registered through this procedure, and the old AMF refers to the AMF to which the UE was registered through a registration procedure prior to this procedure. If no AMF change occurs during this procedure, the interface between the old AMF and the new AMF and the procedure between the old AMF and the new AMF do not occur, and the new AMF may be the same device as the old AMF. In this embodiment, when AMF is written, it may refer to the new AMF, the old AMF, or both.

[0204] First, the UE starts the registration procedure by transmitting a registration request message to the new AMF (S600) (S602) (S604). Specifically, the UE transmits an RRC message including a registration request message to the 5G AN (or gNB) (S600). The registration request message is a NAS message transmitted and received on the N1 interface. The RRC message may be a control message transmitted and received between the UE and the 5G AN (or gNB). The NAS message is processed in the NAS layer, and the RRC message is processed in the RRC layer. The NAS layer is a layer higher than the RRC layer.

[0205] Here, the UE may transmit one or more of the identification information items 1 to 6 in the registration request message and / or the RRC message. Here, the identification information items 1 to 6 may be as described in Chapter 2.7. Furthermore, the UE may transmit the registration request message and / or the RRC message including identification information indicating the type of this procedure. Here, the identification information indicating the type of this procedure may be a 5GS registration type IE, and may be information indicating that this procedure is a registration procedure for initial registration, mobility registration updating, periodic registration updating, or emergency registration. In particular, if this procedure is performed when the registration area changes due to UE movement, the UE may set this 5GS registration type IE to mobility registration updating.

[0206] The UE may transmit these pieces of identification information by including them in a control message different from the above, for example, a control message of a layer lower than the RRC (Radio Resource Control) layer (for example, a MAC (Medium Access Control) layer, an RLC (Radio Link Control) layer, or a PDCP (Packet Data Convergence Protocol) layer). By transmitting these pieces of identification information, the UE may indicate that the UE supports each function, may indicate a request from the UE, or may indicate both. Furthermore, when multiple pieces of identification information are transmitted and received, two or more pieces of identification information may be configured as one or more pieces of identification information. Note that the information indicating support for each function and the information indicating a request to use each function may be transmitted and received as the same identification information, or may be transmitted and received as different identification information.

[0207] In addition, the UE may select and decide whether to transmit the first to sixth identification information to the network based on the UE's capability information, and / or UE policy, and / or UE status, and / or user registration information, and / or context held by the UE, etc.

[0208] Furthermore, the UE may perform the following process when determining whether to transmit at least one piece of information among the first to sixth identification information.

[0209] For example, if the UE has already received the 15th identification information and the 33rd identification information from the core network, the UE may select an S-NSSAI that is valid (usable) in the current registration area as the third identification information for the IMS service from one or more S-NSSAIs included in the 15th identification information and an S-NSSAI indicated by the 36th identification information included in the 33rd identification information based on the 15th identification information and the 33rd identification information, and transmit the third identification information.

[0210] Furthermore, if the UE has already received the 15th identification information and the 33rd identification information from the core network and the 33rd identification information does not include the 32nd identification information, the UE may determine that the S-NSSAI indicated by the 36th identification information included in the 33rd identification information is valid in the current registration area, or valid within the current PLMN, or valid in all PLMNs, and may select an S-NSSAI that is valid (usable) in the current registration area as the third identification information for the IMS service from one or more S-NSSAIs included in the 15th identification information and the S-NSSAI indicated by the 36th identification information included in the 33rd identification information, and transmit the third identification information.

[0211] In addition, if the UE has already received the 15th identification information and the 33rd identification information from the core network, and the 36th identification information included in the 33rd identification information is the 13th S-NSSAI selected by the PCF from the Allowed NSSAIs, the UE may select the 13th S-NSSAI indicated by the 36th identification information as the third identification information for the IMS service based on the 33rd identification information and transmit the third identification information.

[0212] Furthermore, if the UE has already received the 15th identity and the 33rd identity from the core network, the UE may check whether the 36th identity included in the 33rd identity is included in the 15th identity, and if the 36th identity is included in the 15th identity, select the 36th identity as the third identity for the IMS service and transmit the third identity. Furthermore, the UE may check whether the 36th identity is included in the 15th identity, and if the 36th identity is not included in the 15th identity, not select the 36th identity as the third identity for the IMS service. In this case, the UE may not transmit the third identity.

[0213] Furthermore, the UE may check for each access whether the 36th identity included in the 33rd identity is included in the 15th identity. That is, the UE may check for each of 3GPP access and non-3GPP access whether the 36th identity included in the 33rd identity is included in the 15th identity. For example, if the 36th identity included in the 33rd identity is included in the 15th identity for 3GPP access but the 36th identity included in the 33rd identity is not included in the 15th identity for non-3GPP access, the UE may select the 36th identity as the third identity for the IMS service and transmit the third identity via the 3GPP access. Furthermore, when the 36th identification information included in the 33rd identification information is not included in the 15th identification information for 3GPP access, and the 36th identification information included in the 33rd identification information is included in the 15th identification information for non-3GPP access, the UE may select the 36th identification information as the third identification information for the IMS service and transmit the third identification information via the non-3GPP access. Furthermore, when the 36th identification information included in the 33rd identification information is included in the 15th identification information for 3GPP access, and the 36th identification information included in the 33rd identification information is included in the 15th identification information for non-3GPP access, the UE may select the 36th identification information as the third identification information for the IMS service, select whether the third identification information is to be transmitted from the 3GPP access or the non-3GPP access, and transmit the third identification information via the selected access. Furthermore, if the 36th identity included in the 33rd identity is not included in the 15th identity for 3GPP access, and the 36th identity included in the 33rd identity is not included in the 15th identity for non-3GPP access, the UE does not need to select the 36th identity as the third identity for the IMS service. In this case, the UE does not need to transmit the third identity.

[0214] Furthermore, if the UE has already received an eleventh identity from the core network, the UE may store the eleventh identity in association with the IMS service. In this case, if the eleventh identity is valid in all PLMNs and the UE moves to a new registration area different from the current registration area, and the UE has not received a thirteenth S-NSSAI (the sixteenth identity, the twenty-sixth identity, and / or the thirty-sixth identity) valid in the new registration area (supporting the IMS service), the UE may select a default S-NSSAI indicated by the eleventh identity as the first identity for the IMS service and transmit the first identity, regardless of whether the new registration area belongs to the current PLMN. Also, if the 11th identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, and / or the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting IMS services), and the new registration area belongs to the current PLMN, the UE may select the default S-NSSAI indicated by the 11th identity as the first identity for IMS services and send the first identity. Furthermore, if the 11th identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting the IMS service), and the new registration area does not belong to the current PLMN, the UE may not select the default S-NSSAI indicated by the 11th identity as the first identity for the IMS service. In this case, the UE may not transmit the first identity.Also, if the 11th identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has received a 13th S-NSSAI (the 16th identity, and / or the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting IMS services), the UE may select the 13th S-NSSAI (the 16th identity, and / or the 26th identity, and / or the 36th identity) as the third identity for the IMS service and transmit the third identity.

[0215] Furthermore, if the UE has already received the 21st identity from the core network, the UE may store the 21st identity in association with the IMS service. In this case, if the 21st identity is valid in all PLMNs and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, the 26th identity, and / or the 36th identity) valid in the new registration area (supporting the IMS service), the UE may select the default S-NSSAI indicated by the 21st identity as the first identity for the IMS service and transmit the first identity, regardless of whether the new registration area belongs to the current PLMN. Also, if the 21st identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, and / or the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting IMS services), and the new registration area belongs to the current PLMN, the UE may select the default S-NSSAI indicated by the 21st identity as the first identity for IMS services and send the first identity. Furthermore, if the 21st identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting the IMS service), and the new registration area does not belong to the current PLMN, the UE may not select the default S-NSSAI indicated by the 21st identity as the first identity for the IMS service. In this case, the UE may not transmit the first identity.Also, if the 21st identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area and the UE has received a 13th S-NSSAI (16th identity, and / or 26th identity, and / or 36th identity) that is valid in the new registration area (supporting IMS services), the UE may select the 13th S-NSSAI (16th identity, and / or 26th identity, and / or 36th identity) as the third identity for the IMS service and transmit the third identity.

[0216] Furthermore, if the UE has already received the 31st identity from the core network, the UE may store the 31st identity in association with the IMS service. In this case, if the 31st identity is valid in all PLMNs and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, the 26th identity, and / or the 36th identity) valid in the new registration area (supporting the IMS service), the UE may select a default S-NSSAI indicated by the 31st identity as the first identity for the IMS service and transmit the first identity, regardless of whether the new registration area belongs to the current PLMN. Also, if the 31st identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, and / or the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting IMS services), and the new registration area belongs to the current PLMN, the UE may select the default S-NSSAI indicated by the 31st identity as the first identity for IMS services and send the first identity. Furthermore, if the 31st identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, and / or the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting the IMS service), and the new registration area does not belong to the current PLMN, the UE may not select the default S-NSSAI indicated by the 31st identity as the first identity for the IMS service. In this case, the UE may not transmit the first identity.Also, if the 31st identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has received a 13th S-NSSAI (16th identity, and / or 26th identity, and / or 36th identity) that is valid in the new registration area (supporting IMS services), the UE may select the 13th S-NSSAI (16th identity, and / or 26th identity, and / or 36th identity) as the third identity for the IMS service and transmit the third identity.

[0217] In addition, when communicating using an IMS service, the UE may transmit the second identification information when it wants to know the validity range of the registration area of ​​the 13th S-NSSAI that supports the IMS service, in other words, when it wants to obtain information about the registration area in which the 13th S-NSSAI that supports the IMS service can be used.

[0218] Furthermore, if the UE has already received the 12th identity, the 15th identity, and the 33rd identity from the core network, the UE may store the 33rd identity and further associate and store the 12th identity with the 15th identity or the S-NSSAI included in the 15th identity. Then, for the IMS service, the UE may select an S-NSSAI that is valid (usable) in the current registration area as a third identity from the S-NSSAI included in the 15th identity and the 13th S-NSSAI indicated by the 36th identity based on the 12th identity, the 15th identity, and the 33rd identity, and transmit the third identity.

[0219] In addition, when the UE is communicating using an IMS service and has already received the 14th identification information, the 15th identification information, and / or the 16th identification information from the core network, the UE may store the S-NSSAI indicated by the 15th identification information and / or the 16th identification information in association with the IMS service, and may select the requested S-NSSAI (hereinafter also referred to as Requested S-NSSAI) based on the current registration area and the stored S-NSSAI and transmit that S-NSSAI.

[0220] In addition, when the UE is communicating using an IMS service and has already received the 12th identification information, the 14th identification information, the 15th identification information and / or the 16th identification information from the core network, the UE may store the S-NSSAI indicated by the 15th identification information and / or the 16th identification information in association with the IMS service and the 12th identification information, and may select the requested S-NSSAI based on the current registration area and the stored S-NSSAI and transmit the S-NSSAI.

[0221] In addition, when the UE is communicating using an IMS service and has already received the 24th identification information, the 25th identification information, and / or the 26th identification information from the core network, the UE may store the S-NSSAI indicated by the 25th identification information and / or the 26th identification information in association with the IMS service, and may select the requested S-NSSAI based on the current registration area and the stored S-NSSAI and transmit the S-NSSAI.

[0222] In addition, when the UE is communicating using an IMS service and has already received the 22nd identification information, the 24th identification information, the 25th identification information and / or the 26th identification information from the core network, the UE may store the S-NSSAI indicated by the 25th identification information and / or the 26th identification information, the IMS service, and the 22nd identification information in association with each other, and may select the requested S-NSSAI based on the current registration area and the stored S-NSSAI and transmit the S-NSSAI.

[0223] In addition, when the UE is communicating using an IMS service and has already received 15th identification information from the core network, if the value of the SST or SD constituting the S-NSSAI included in the 15th identification information is an S-NSSAI that indicates an IMS service, the UE may select that S-NSSAI as the third identification information and transmit the third identification information.

[0224] In addition, when the UE is communicating using an IMS service and has already received 25th identification information from the core network, if the value of the SST or SD constituting the S-NSSAI included in the 25th identification information is an S-NSSAI that indicates an IMS service, the UE may select that S-NSSAI as the third identification information and transmit the third identification information.

[0225] Furthermore, when the UE performs communication using an IMS service, if the UE has already received a 15th identity from the core network and knows that the position and order of the 13th S-NSSAI (supporting IMS) included in the 15th identity and the association between the IMS service and the position and order are predefined by a specification or an operator, the UE may select the 13th S-NSSAI supporting the IMS service from one or more S-NSSAIs included in the 15th identity based on the information and transmit the 13th S-NSSAI as the third identity. In this way, when the UE knows in advance the position of the 13th S-NSSAI in the Allowed NSSAIs, the UE may be able to identify the 13th S-NSSAI even if it has not received, from the core network, information that explicitly indicates the association between the IMS service and the 13th S-NSSAI, such as the 14th identity, the 24th identity, and the 34th identity.

[0226] Furthermore, when the UE performs communication using an IMS service, if the UE has already received the 25th identity from the core network and knows that the position and order of the 13th S-NSSAI (supporting IMS) included in the 25th identity and the association between the IMS service and the position and order are predefined by a specification or an operator, the UE may select the 13th S-NSSAI supporting the IMS service from one or more S-NSSAIs included in the 25th identity based on the information and transmit the 13th S-NSSAI as the third identity. In this way, when the UE knows in advance the position of the 13th S-NSSAI in the Allowed NSSAIs, the UE may be able to identify the 13th S-NSSAI even if it has not received, from the core network, information that explicitly indicates the association between the IMS service and the 13th S-NSSAI, such as the 14th identity, the 24th identity, and the 34th identity.

[0227] In addition, when communicating using an IMS service, if the UE has already received the 13th identification information and the 15th identification information from the core network, the UE may select the 13th S-NSSAI (that supports IMS) from one or more S-NSSAIs included in the 15th identification information based on the information indicated by the 13th identification information, and transmit the 13th S-NSSAI as the third identification information.

[0228] In addition, when communicating using an IMS service, if the UE has already received the 23rd identification information and the 25th identification information from the core network, the UE may select the 13th S-NSSAI (that supports IMS) from one or more S-NSSAIs included in the 25th identification information based on the information indicated by the 23rd identification information, and transmit the 13th S-NSSAI as the third identification information.

[0229] In addition, if the UE has previously stored an IMS service in association with the default S-NSSAI and / or the 13th S-NSSAI, the UE may transmit the first identification information and / or the third identification information when communicating using the IMS service.

[0230] In addition, when communicating using an IMS service, if the UE has already received a 15th identification information including the 16th identification information and the 14th identification information from the core network, the UE may send a 13th S-NSSAI indicated by the 16th identification information as the third identification information.

[0231] In addition, when the UE transmits a selected S-NSSAI and / or a first identification information and / or a selected third identification information, the UE may transmit a requested NSSAI including the S-NSSAI and / or the first identification information and / or the third identification information.

[0232] Furthermore, one or more pieces of third identification information may be transmitted. In this case, a requested NSSAI including one or more pieces of third identification information may be transmitted. Furthermore, transmitting at least one of the first to third identification information may mean transmitting a fourth identification information.

[0233] The UE may include identification information other than the first to sixth identification information in the registration request message and / or the RRC message including the registration request message, for example, may include a UE ID and / or a PLMN ID and / or AMF identification information and transmit it. Here, the AMF identification information may be information that identifies an AMF or a set of AMFs, for example, a 5G-S-TMSI (5G S-Temporary Mobile Subscription Identifier) ​​or a GUAMI (Globally Unique AMF Identifier).

[0234] Next, when the 5G AN (or gNB) receives an RRC message including a registration request message, it selects an AMF to which to transfer the registration request message (S602). Note that the 5G AN (or gNB) can select an AMF based on one or more identification information included in the registration request message and / or the RRC message. Specifically, the 5G AN (or gNB) may select a new AMF to which to send the registration request message based on at least one of the first to sixth identification information.

[0235] Then, the 5G AN (or gNB) forwards the identification information included in the registration request message and / or the RRC message, and / or the registration request message, to the selected new AMF (S604).

[0236] Next, when the new AMF receives the registration request message, it can perform a first condition determination. The first condition determination is for determining whether the network (or the new AMF) accepts the UE's request. If the first condition determination is true, the new AMF performs the procedures from S606 to S612. On the other hand, if the first condition determination is false, the new AMF may perform the procedure of S610 without performing the procedures from S606 to S608.

[0237] Furthermore, the new AMF may perform a first condition determination after requesting the UE context from the old AMF and receiving the UE context from the old AMF (S606, S608). In this case, the new AMF executes S610 and S612 if the first condition determination is true. On the other hand, the new AMF may execute S610 if the first condition determination is false.

[0238] Furthermore, if the first condition determination is true, the control message sent and received in S610 may be a Registration accept message, and if the first condition determination is false, the control message sent and received in S610 may be a Registration reject message.

[0239] In addition, the first condition determination may be performed based on the receipt of a registration request message, and / or each identification information contained in the registration request message, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the new AMF, etc.

[0240] For example, if the network permits the UE's request, the first condition determination may be true, and if the network does not permit the UE's request, the first condition determination may be false. Furthermore, if the network to which the UE is registered and / or a device within the network supports the function requested by the UE, the first condition determination may be true, and if the function requested by the UE is not supported, the first condition determination may be false. Furthermore, if the identification information to be transmitted and received is permitted, the first condition determination may be true, and if the identification information to be transmitted and received is not permitted, the first condition determination may be false.

[0241] Furthermore, the new AMF may determine the first condition as true if the UE has an allowed NSSAI (Allowed NSSAI). Furthermore, the new AMF may determine the first condition as true if the UE has an allowed NSSAI (Allowed NSSAI), regardless of whether the NSSAI includes a thirteenth S-NSSAI that supports IMS. Furthermore, the new AMF may determine the first condition as true if the UE has an allowed NSSAI (Allowed NSSAI) and the UE includes a thirteenth S-NSSAI that supports IMS. Furthermore, the new AMF may determine the first condition as false if the UE has an allowed NSSAI (Allowed NSSAI) and the UE does not include a thirteenth S-NSSAI that supports IMS.

[0242] Next, if the new AMF is different from the AMF indicated in the AMF identification information included in the message received from the UE, the new AMF executes the procedures of S606 and S608, and if the new AMF is the same as the AMF indicated in the AMF identification information included in the message received from the UE, the procedures of S606 and S608 are not executed. In other words, if an AMF change occurs due to this procedure, the procedures of S606 and S608 are executed, and if an AMF change does not occur, the procedures of S606 and S608 are skipped.

[0243] The UE context transfer procedure (S606, S608) will be described. The new AMF sets the AMF indicated in the AMF identification information as the old AMF and sends a UE context request message to the old AMF (S606). The old AMF sends the UE context to the new AMF based on the received UE context request message. The new AMF generates a UE context based on the received UE context.

[0244] Here, the UE context transmitted from the new AMF to the old AMF may include a UE ID and an allowed NSSAI. Furthermore, the UE context may include a configured NSSAI and / or a rejected NSSAI, an NSSAI and / or a pending NSSAI, and / or a first NSSAI. Furthermore, the allowed NSSAI, and / or the configured NSSAI, and / or the rejected NSSAI, and / or the pending NSSAI, and / or the first NSSAI included in the UE context, and the S-NSSAI included in each NSSAI may be linked to information on whether notification to the UE has been completed.

[0245] Next, the new AMF sends a control message to the UE based on the determination of the first condition determination and / or based on receiving the UE context from the old AMF (S610). The control message may be a registration acceptance message or a registration rejection message.

[0246] Here, the new AMF may transmit a control message including one or more pieces of identification information among at least the 11th to 19th pieces of identification information. Here, the 11th to 19th pieces of identification information may be as described in Chapter 2.7. By transmitting this identification information and / or the control message, the new AMF may indicate that the network supports each function, may indicate that the UE's request has been accepted, may indicate that the request from the UE has not been permitted, or may indicate a combination of these pieces of information. Furthermore, when multiple pieces of identification information are transmitted and received, two or more pieces of identification information may be configured as one or more pieces of identification information. Note that the information indicating support for each function and the information indicating permission to use each function may be transmitted and received as the same identification information or as different identification information.

[0247] The new AMF may also select and determine which of the 11th to 19th identification information to include in the control message based on each received identification information, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the new AMF, etc.

[0248] For example, when the new AMF receives at least one of identification information 1 to 6 from the UE, it may transmit at least one of identification information 11 to 19 in a control message.

[0249] In addition, when at least one of identification information 1 to 6 is received from the UE and the UE's configuration information has been updated since the previous registration procedure, the new AMF may be sent with the updated information included in identification information 11 to 19.

[0250] Furthermore, the new AMF may indicate that the UE's request has been accepted by sending a registration acceptance message based on the received identification information, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the AMF, etc., or may indicate that the UE's request has been rejected by sending a registration rejection message.

[0251] Next, when the UE receives a control message via the 5G AN (gNB) (S610), it may recognize the content of the control message and / or the received information.

[0252] For example, if the control message is a registration accept message, the UE can recognize that the UE's request in the registration request message has been accepted and the contents of various identification information included in the registration accept message by receiving the registration accept message. Also, if the control message is a registration reject message, the UE can recognize that the UE's request in the registration request message has been rejected and the contents of various identification information included in the registration reject message by receiving a registration reject message. Furthermore, if the UE does not receive a control message within a predetermined period after sending the registration request message, the UE may recognize that the UE's request has been rejected.

[0253] Furthermore, the UE may perform the following processes based on receiving at least one of the 11th to 19th identification information and / or receiving a control message. Note that the UE may perform these processes during this procedure or after completing this procedure.

[0254] For example, if a UE receives a 15th identification including a third S-NSSAI and a fourth S-NSSAI from the core network, when requesting establishment of a PDU session for a first IMS service, it may select the third S-NSSAI and the fourth S-NSSAI from the 15th identification for the first IMS service, perform the PDU session establishment procedure of Chapter 3.5 using the third S-NSSAI (hereinafter simply referred to as the PDU session establishment procedure) to establish a PDU session for SIP signaling for the first IMS service, and perform the PDU session establishment procedure using the fourth S-NSSAI to establish a PDU session for media for the first IMS service.

[0255] Furthermore, when the UE receives a 15th identification information including a third S-NSSAI, a ninth S-NSSAI, and a tenth S-NSSAI from the core network, when requesting establishment of a PDU session for the first IMS service, the UE may select the third S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI from the 15th identification information for the first IMS service, perform a PDU session establishment procedure using the third S-NSSAI to establish a PDU session for SIP signaling for the first IMS service, perform a PDU session establishment procedure using the ninth S-NSSAI to establish a PDU session for media (voice) for the first IMS service, and perform a PDU session establishment procedure using the tenth S-NSSAI to establish a PDU session for media (video) for the first IMS service.

[0256] Furthermore, when the UE receives a 15th identification including a 7th S-NSSAI from the core network, when requesting establishment of a PDU session for the first IMS service, the UE may select the 7th S-NSSAI from the 15th identification for the first IMS service and perform a PDU session establishment procedure using the 7th S-NSSAI to establish a PDU session for the first IMS service.

[0257] Furthermore, when the UE receives 15th identification information including the third S-NSSAI, the fourth S-NSSAI, and the seventh S-NSSAI from the core network, when requesting establishment of a PDU session for the first IMS service, the UE may select the third S-NSSAI and the fourth S-NSSAI, which are information identifying the network slice corresponding to the seventh S-NSSAI, from the 15th identification information for the first IMS service, perform a PDU session establishment procedure using the third S-NSSAI to establish a PDU session for SIP signaling for the first IMS service, and perform a PDU session establishment procedure using the fourth S-NSSAI to establish a PDU session for media for the first IMS service.

[0258] Furthermore, when the UE receives 15th identification information including the third S-NSSAI, the seventh S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI from the core network, when requesting establishment of a PDU session for the first IMS service, the UE may select the third S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI from the 15th identification information for the first IMS service, which are information identifying the network slice corresponding to the seventh S-NSSAI, and perform a PDU session establishment procedure using the third S-NSSAI to establish a PDU session for SIP signaling for the first IMS service, perform a PDU session establishment procedure using the ninth S-NSSAI to establish a PDU session for media (voice) for the first IMS service, and perform a PDU session establishment procedure using the tenth S-NSSAI to establish a PDU session for media (video) for the first IMS service.

[0259] Furthermore, when the UE receives a 15th identification information including a fifth S-NSSAI and a sixth S-NSSAI from the core network, when requesting establishment of a PDU session for a second IMS service, the UE may select the fifth S-NSSAI and the sixth S-NSSAI from the 15th identification information for the second IMS service, perform a PDU session establishment procedure using the fifth S-NSSAI to establish a PDU session for SIP signaling for the second IMS service, and perform a PDU session establishment procedure using the sixth S-NSSAI to establish a PDU session for media for the second IMS service.

[0260] Furthermore, when the UE receives a 15th identification information including a 5th S-NSSAI, an 11th S-NSSAI, and a 12th S-NSSAI from the core network, when requesting establishment of a PDU session for a second IMS service, the UE may select the 5th S-NSSAI, the 11th S-NSSAI, and the 12th S-NSSAI from the 15th identification information for the second IMS service, perform a PDU session establishment procedure using the 5th S-NSSAI to establish a PDU session for SIP signaling for the second IMS service, perform a PDU session establishment procedure using the 11th S-NSSAI to establish a PDU session for media (voice) for the second IMS service, and perform a PDU session establishment procedure using the 12th S-NSSAI to establish a PDU session for media (video) for the second IMS service.

[0261] Furthermore, when the UE receives a 15th identification including an 8th S-NSSAI from the core network, when requesting establishment of a PDU session for a second IMS service, the UE may select the 8th S-NSSAI from the 15th identification for the first IMS service and perform a PDU session establishment procedure using the 8th S-NSSAI to establish a PDU session for the second IMS service.

[0262] Furthermore, when the UE receives 15th identification information including the 5th S-NSSAI, the 6th S-NSSAI, and the 8th S-NSSAI from the core network, when requesting establishment of a PDU session for the second IMS service, the UE may select the 5th S-NSSAI and the 6th S-NSSAI from the 15th identification information for the second IMS service, which are information that identify the network slice corresponding to the 8th S-NSSAI, and perform a PDU session establishment procedure using the 5th S-NSSAI to establish a PDU session for SIP signaling for the second IMS service, and perform a PDU session establishment procedure using the 6th S-NSSAI to establish a PDU session for media for the second IMS service.

[0263] Furthermore, when the UE receives 15th identification information including the 5th S-NSSAI, the 8th S-NSSAI, the 11th S-NSSAI, and the 12th S-NSSAI from the core network, when requesting establishment of a PDU session for the second IMS service, the UE may select the 5th S-NSSAI, the 11th S-NSSAI, and the 12th S-NSSAI from the 15th identification information for the second IMS service, which are information that identify the network slice corresponding to the 8th S-NSSAI, and perform a PDU session establishment procedure using the 5th S-NSSAI to establish a PDU session for SIP signaling for the second IMS service, perform a PDU session establishment procedure using the 11th S-NSSAI to establish a PDU session for media (voice) for the second IMS service, and perform a PDU session establishment procedure using the 12th S-NSSAI to establish a PDU session for media (video) for the second IMS service.

[0264] As described above, the network slices used by the PDU sessions established for the first IMS service and / or the second IMS service may be at least partially (including entirely) the same or all different. Also, the DNNs identifying the DNs to which the PDU sessions are connected may be at least partially (including entirely) the same or all different.

[0265] Furthermore, when the UE has already received a 33rd identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the ninth S-NSSAI and / or the tenth S-NSSAI from the core network, and when the UE receives a 15th identity including the third S-NSSAI and the fourth S-NSSAI in this procedure, when requesting establishment of a PDU session for the first IMS service, the UE may use the third S-NSSAI included in the 15th identity and / or the 33rd identity based on the information included in the 33rd identity. When it is determined that the SAI and the fourth S-NSSAI are available in the current registration area, the third S-NSSAI and the fourth S-NSSAI may be selected from the 15th identity or the 33rd identity for the first IMS service, and a PDU session establishment procedure using the third S-NSSAI may be performed to establish a PDU session for SIP signaling for the first IMS service, and a PDU session establishment procedure using the fourth S-NSSAI may be performed to establish a PDU session for media for the first IMS service.

[0266] Furthermore, when the UE has already received a 33rd identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the ninth S-NSSAI and / or the tenth S-NSSAI from the core network, and when the UE receives a 15th identity including the third S-NSSAI and the ninth S-NSSAI and the tenth S-NSSAI in this procedure, when requesting establishment of a PDU session for the first IMS service, the UE determines, based on the information included in the 33rd identity, that the 15th identity and / or the third S-NSSAI, the ninth S-NSSAI and the tenth S-NSSAI included in the 33rd identity are registered in the current registration area. When it is determined that the S-NSSAI can be used, the third S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI may be selected from the fifteenth identification information or the thirty-third identification information for the first IMS service, and a PDU session establishment procedure using the third S-NSSAI may be performed to establish a PDU session for SIP signaling for the first IMS service, a PDU session establishment procedure using the ninth S-NSSAI may be performed to establish a PDU session for media (voice) for the first IMS service, and a PDU session establishment procedure using the tenth S-NSSAI may be performed to establish a PDU session for media (video) for the first IMS service.

[0267] Furthermore, when the UE has already received a 33rd identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the ninth S-NSSAI and / or the tenth S-NSSAI from the core network, if the UE receives a 15th identity including the seventh S-NSSAI in this procedure, and when requesting establishment of a PDU session for the first IMS service, if the UE determines, based on the information included in the 33rd identity, that the 15th identity and / or the seventh S-NSSAI included in the 33rd identity is usable in the current registration area, the UE may select the seventh S-NSSAI from the 15th identity or the 33rd identity for the first IMS service and perform a PDU session establishment procedure using the seventh S-NSSAI to establish a PDU session for the first IMS service.

[0268] Furthermore, when the UE has already received a 33rd identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the ninth S-NSSAI and / or the tenth S-NSSAI from the core network, and when the UE receives a 15th identity including the third S-NSSAI, the fourth S-NSSAI, and the seventh S-NSSAI in this procedure, when requesting establishment of a PDU session for the first IMS service, the UE determines based on the information included in the 33rd identity that the 15th identity and / or the seventh S-NSSAI included in the 33rd identity are currently When it is determined that the seventh S-NSSAI is available in the current registration area, the third S-NSSAI and fourth S-NSSAI, which are information identifying the network slice corresponding to the seventh S-NSSAI, may be selected from the 15th identification information or the 33rd identification information for the first IMS service, and a PDU session establishment procedure using the third S-NSSAI may be performed to establish a PDU session for SIP signaling for the first IMS service, and a PDU session establishment procedure using the fourth S-NSSAI may be performed to establish a PDU session for media for the first IMS service.

[0269] Furthermore, when the UE has already received a 33rd identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the ninth S-NSSAI and / or the tenth S-NSSAI from the core network, if the UE receives a 15th identity including the third S-NSSAI, the seventh S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI in this procedure, and when the UE requests establishment of a PDU session for the first IMS service, if the UE determines based on the information included in the 33rd identity that the 15th identity and / or the seventh S-NSSAI included in the 33rd identity are usable in the current registration area, the UE may request establishment of a PDU session for the first IMS service. For the service, a third S-NSSAI, a ninth S-NSSAI, and a tenth S-NSSAI, which are information identifying the network slice corresponding to the seventh S-NSSAI, may be selected from the fifteenth identification information or the thirty-third identification information, and a PDU session establishment procedure using the third S-NSSAI may be performed to establish a PDU session for SIP signaling for the first IMS service, a PDU session establishment procedure using the ninth S-NSSAI may be performed to establish a PDU session for media (voice) for the first IMS service, and a PDU session establishment procedure using the tenth S-NSSAI may be performed to establish a PDU session for media (video) for the first IMS service.

[0270] Furthermore, when the UE has already received a 33rd identity including the fifth S-NSSAI and / or the sixth S-NSSAI and / or the eighth S-NSSAI and / or the eleventh S-NSSAI and / or the twelfth S-NSSAI from the core network, and receives a 15th identity including the fifth S-NSSAI and the sixth S-NSSAI in this procedure, when requesting establishment of a PDU session for the second IMS service, the UE may use the 15th identity and / or the fifth S-NSSAI included in the 33rd identity based on the information included in the 33rd identity. When it is determined that the SAI and the sixth S-NSSAI are available in the current registration area, the fifth S-NSSAI and the sixth S-NSSAI may be selected from the fifteenth identification information or the thirty-third identification information for the second IMS service, and a PDU session establishment procedure using the fifth S-NSSAI may be performed to establish a PDU session for SIP signaling for the second IMS service, and a PDU session establishment procedure using the sixth S-NSSAI may be performed to establish a PDU session for media for the second IMS service.

[0271] Furthermore, when the UE has already received a 33rd identity including the fifth S-NSSAI and / or the sixth S-NSSAI and / or the eighth S-NSSAI and / or the eleventh S-NSSAI and / or the twelfth S-NSSAI from the core network, and when the UE receives a 15th identity including the fifth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI in this procedure, when requesting establishment of a PDU session for the second IMS service, the UE may determine, based on the information included in the 33rd identity, that the 15th identity and / or the fifth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI included in the 33rd identity are registered in the current registration area. If it is determined that the S-NSSAI can be used, the fifth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI may be selected from the fifteenth identification information or the thirty-third identification information for the second IMS service, and a PDU session establishment procedure using the fifth S-NSSAI may be performed to establish a PDU session for SIP signaling for the second IMS service, a PDU session establishment procedure using the eleventh S-NSSAI may be performed to establish a PDU session for media (voice) for the second IMS service, and a PDU session establishment procedure using the twelfth S-NSSAI may be performed to establish a PDU session for media (video) for the second IMS service.

[0272] Furthermore, when the UE has already received a 33rd identity including the 5th S-NSSAI and / or the 6th S-NSSAI and / or the 8th S-NSSAI and / or the 11th S-NSSAI and / or the 12th S-NSSAI from the core network, and when the UE receives a 15th identity including the 8th S-NSSAI in this procedure, and when requesting establishment of a PDU session for a second IMS service, if the UE determines based on the information included in the 33rd identity that the 15th identity and / or the 8th S-NSSAI included in the 33rd identity is usable in the current registration area, the UE may select the 8th S-NSSAI from the 15th identity or the 33rd identity for the second IMS service and perform a PDU session establishment procedure using the 8th S-NSSAI to establish a PDU session for the second IMS service.

[0273] Furthermore, when the UE has already received a 33rd identity including the fifth S-NSSAI and / or the sixth S-NSSAI and / or the eighth S-NSSAI and / or the eleventh S-NSSAI and / or the twelfth S-NSSAI from the core network, and when the UE receives a 15th identity including the fifth S-NSSAI, the sixth S-NSSAI, and the eighth S-NSSAI in this procedure, when requesting establishment of a PDU session for the second IMS service, the UE determines that the 15th identity and / or the eighth S-NSSAI included in the 33rd identity is a PDU session number based on the information included in the 33rd identity. When it is determined that the eighth S-NSSAI is available in the current registration area, the fifth S-NSSAI and sixth S-NSSAI, which are information identifying the network slice corresponding to the eighth S-NSSAI, may be selected from the fifteenth identification information or the thirty-third identification information for the second IMS service, and a PDU session establishment procedure using the fifth S-NSSAI may be performed to establish a PDU session for SIP signaling for the second IMS service, and a PDU session establishment procedure using the sixth S-NSSAI may be performed to establish a PDU session for media for the second IMS service.

[0274] Furthermore, when the UE has already received a 33rd identity including the fifth S-NSSAI and / or the sixth S-NSSAI and / or the eighth S-NSSAI and / or the eleventh S-NSSAI and / or the twelfth S-NSSAI from the core network, if the UE receives a 15th identity including the fifth S-NSSAI, the eighth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI in this procedure, and when the UE requests establishment of a PDU session for a second IMS service, if the UE determines, based on the information included in the 33rd identity, that the 15th identity and / or the eighth S-NSSAI included in the 33rd identity can be used in the current registration area, the UE may request establishment of a PDU session for the second IMS service. For the service, the fifth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI, which are information identifying the network slice corresponding to the eighth S-NSSAI, may be selected from the fifteenth identification information or the thirty-third identification information, and a PDU session establishment procedure using the fifth S-NSSAI may be performed to establish a PDU session for SIP signaling for the second IMS service, a PDU session establishment procedure using the eleventh S-NSSAI may be performed to establish a PDU session for media (voice) for the second IMS service, and a PDU session establishment procedure using the twelfth S-NSSAI may be performed to establish a PDU session for media (video) for the second IMS service.

[0275] As described above, the network slices used by the PDU sessions established for the first IMS service and / or the second IMS service may be at least partially (including entirely) the same or all different. Also, the DNNs identifying the DNs to which the PDU sessions are connected may be at least partially (including entirely) the same or all different.

[0276] For example, if the UE has already received the 33rd identification information from the core network, when the UE receives the 15th identification information in this procedure and requests the establishment of a PDU session for an IMS service, the UE may select an S-NSSAI that is valid (usable) in the current registration area from one or more S-NSSAIs included in the 15th identification information and the S-NSSAI indicated by the 36th identification information included in the 33rd identification information based on the 15th identification information and the 33rd identification information, and may send a registration request message including that S-NSSAI, or send a PDU session establishment request message together with that S-NSSAI.

[0277] Furthermore, if the UE has already received the 15th identification information and the 33rd identification information from the core network and the 33rd identification information does not include the 32nd identification information, the UE may determine that the S-NSSAI indicated by the 36th identification information included in the 33rd identification information is valid in the current registration area, or valid within the current PLMN, or valid in all PLMNs, and may select an S-NSSAI that is valid (usable) in the current registration area for the IMS service from one or more S-NSSAIs included in the 15th identification information and the S-NSSAI indicated by the 36th identification information included in the 33rd identification information, and may send a registration request message including that S-NSSAI or send a PDU session establishment request message together with that S-NSSAI.

[0278] Furthermore, when the UE receives the 15th identification information from the core network, the UE may store the 15th identification information or the S-NSSAI included in the 15th identification information. Then, when the UE requests establishment of a PDU session for an IMS service after receiving the 33rd identification information, the UE may select an S-NSSAI that is valid (usable) in the current registration area from one or more S-NSSAIs included in the 15th identification information and an S-NSSAI indicated by the 36th identification information included in the 33rd identification information based on the 15th identification information and the 33rd identification information, and transmit a registration request message including the S-NSSAI or transmit a PDU session establishment request message together with the S-NSSAI. Note that whether the selected S-NSSAI is valid (usable) in the current registration area may be determined based on the 32nd identification information.

[0279] In addition, if the UE has already received the 33rd identification information from the core network, when the UE receives the 15th identification information in this procedure, and the 36th identification information included in the 33rd identification information is the 13th S-NSSAI selected by the PCF from the Allowed NSSAIs, and when the UE requests establishment of a PDU session for an IMS service, the UE may select the 13th S-NSSAI (the 36th identification information included in the 33rd identification information) based on the 33rd identification information, and send a registration request message including the 13th S-NSSAI, or send a PDU session establishment request message together with the 13th S-NSSAI.

[0280] Furthermore, when the UE has already received the 33rd identity from the core network and receives the 15th identity in this procedure and requests establishment of a PDU session for an IMS service, the UE may check whether the 36th identity included in the 33rd identity is included in the 15th identity, and if the 36th identity is included in the 15th identity, select the 13th S-NSSAI indicated by the 36th identity and transmit a registration request message including the 13th S-NSSAI or transmit a PDU session establishment request message together with the 13th S-NSSAI. Furthermore, the UE may check whether the 36th identity is included in the 15th identity, and if the 36th identity is not included in the 15th identity, not select the 13th S-NSSAI indicated by the 36th identity for the IMS service, not transmit a registration request message including the 13th S-NSSAI, or not transmit a PDU session establishment request message together with the 13th S-NSSAI.

[0281] Furthermore, the UE may check for each access whether the 36th identity included in the 33rd identity is included in the 15th identity. That is, the UE may check for each of 3GPP access and non-3GPP access whether the 36th identity included in the 33rd identity is included in the 15th identity. For example, if the 36th identity included in the 33rd identity is included in the 15th identity for 3GPP access but the 36th identity included in the 33rd identity is not included in the 15th identity for non-3GPP access, the UE may send a registration request message including the 13th S-NSSAI indicated by the 36th identity via the 3GPP access for the IMS service, or may send a PDU session establishment request message with the 13th S-NSSAI indicated by the 36th identity via the 3GPP access. Furthermore, if the 36th identification information included in the 33rd identification information is not included in the 15th identification information for 3GPP access, and the 36th identification information included in the 33rd identification information is included in the 15th identification information for non-3GPP access, the UE may send a registration request message including the 13th S-NSSAI indicated by the 36th identification information via non-3GPP access for IMS services, or may send a PDU session establishment request message together with the 13th S-NSSAI indicated by the 36th identification information via non-3GPP access. Furthermore, if the 36th identification information included in the 33rd identification information is included in the 15th identification information for 3GPP access, and the 36th identification information included in the 33rd identification information is included in the 15th identification information for non-3GPP access, the UE may select whether to transmit from 3GPP access or non-3GPP access for the IMS service, and may transmit a registration request message including the 13th S-NSSAI indicated by the 36th identification information, or transmit a PDU session establishment request message together with the 13th S-NSSAI indicated by the 36th identification information via the selected access.Furthermore, if the 36th identification information included in the 33rd identification information is not included in the 15th identification information for 3GPP access, and the 36th identification information included in the 33rd identification information is not included in the 15th identification information for non-3GPP access, the UE will not select the 13th S-NSSAI indicated by the 36th identification information for the IMS service, will not send a registration request message including the 13th S-NSSAI, or will not send a PDU session establishment request message together with the 13th S-NSSAI.

[0282] Furthermore, when the UE receives an eleventh identity from the core network, the UE may store the eleventh identity in association with the IMS service. In this case, if the eleventh identity is valid in all PLMNs and the UE moves to a new registration area different from the current registration area, and the UE has not received a thirteenth S-NSSAI (the sixteenth identity, the twenty-sixth identity, and / or the thirty-sixth identity) valid in the new registration area (supporting the IMS service), the UE may select a default S-NSSAI indicated by the eleventh identity for the IMS service, regardless of whether the new registration area belongs to the current PLMN. Also, if the 11th identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, and / or the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting IMS services), and the new registration area belongs to the current PLMN, the UE may select the default S-NSSAI indicated by the 11th identity for IMS services. Also, if the 11th identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, and / or the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting IMS services), and the new registration area does not belong to the current PLMN, the UE may not select the default S-NSSAI indicated by the 11th identity for IMS services.Also, if the 11th identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE receives a 13th S-NSSAI (the 16th identity, the 26th identity, and / or the 36th identity) valid in the new registration area (supporting the IMS service), the UE may select the 13th S-NSSAI (the 16th identity, the 26th identity, and / or the 36th identity) for the IMS service. Then, the UE may send a registration request message including the selected default S-NSSAI or the 13th S-NSSAI, or may send a PDU session establishment request message together with the selected default S-NSSAI or the 13th S-NSSAI. In other words, if the UE selects an S-NSSAI, it may send a registration request message including the selected default S-NSSAI or the thirteenth S-NSSAI, or may send a PDU session establishment request message together with the selected default S-NSSAI or the thirteenth S-NSSAI. If the UE does not select an S-NSSAI, it may send a registration request message without including an S-NSSAI. If the UE does not select an S-NSSAI, it may not send a registration request message.

[0283] Furthermore, if the UE has already received the 33rd identification information from the core network, the UE may store the 33rd identification information. In this case, when the UE receives the 12th identification information and the 15th identification information from the core network, the UE may store the 12th identification information in association with the 15th identification information or the S-NSSAI included in the 15th identification information. Then, when the UE requests establishment of a PDU session for an IMS service, the UE may select an S-NSSAI that is valid (usable) in the current registration area from the S-NSSAI included in the 15th identification information and the 13th S-NSSAI indicated by the 36th identification information based on the 12th identification information, the 15th identification information, and the 33rd identification information, and transmit a registration request message including the S-NSSAI or transmit a PDU session establishment request message together with the S-NSSAI.

[0284] Furthermore, when the UE receives the 12th identification information and the 15th identification information from the core network, the UE may store the 12th identification information in association with the 15th identification information or the S-NSSAI included in the 15th identification information. Then, when the UE requests establishment of a PDU session for an IMS service after receiving the 33rd identification information, the UE may select an S-NSSAI that is valid (usable) in the current registration area from the S-NSSAI included in the 15th identification information and the 13th S-NSSAI indicated by the 36th identification information based on the 12th identification information, the 15th identification information, and the 33rd identification information, and transmit a registration request message including the S-NSSAI or transmit a PDU session establishment request message together with the S-NSSAI. Note that whether the selected S-NSSAI is valid (usable) in the current registration area may be determined based on the 32nd identification information.

[0285] Furthermore, if the UE has established a PDU session using a thirteenth S-NSSAI for an IMS service in the first registration area, and the thirteenth S-NSSAI is valid (usable) in the first registration area but not valid in the second registration area for the IMS service, the UE receives, from the core network in the second registration area, fifteenth identification information including the thirteenth S-NSSAI, sixteenth identification information indicating the second S-NSSAI, and fourteenth identification information indicating the IMS service corresponding to the second S-NSSAI, and the second S-NSSAI is valid (usable) in the first registration area for the IMS service, If the S-NSSAI is valid in the second registration area, the UE may initiate a PDU session establishment procedure for the IMS service using the second S-NSSAI (supporting the IMS service in the second registration area) based on receiving the fourteenth identity and the sixteenth identity, and then initiate a PDU session release procedure to release the PDU session using the thirteenth S-NSSAI (not supporting the IMS service in the second registration area), or may initiate a PDU session release procedure to release the PDU session using the thirteenth S-NSSAI, and then initiate a PDU session establishment procedure for the IMS service using the second S-NSSAI. Note that in this case, the UE may use the thirteenth S-NSSAI indicated by the fifteenth identity in the second registration area for communications other than the IMS service.

[0286] Furthermore, when a UE communicates using an IMS service and receives the 14th identification information, the 15th identification information, and / or the 16th identification information from the core network, the UE may store the S-NSSAI indicated by the 15th identification information and / or the 16th identification information in association with the IMS service, and may select the requested S-NSSAI based on the current registration area and the stored S-NSSAI, and may send a registration request message including the S-NSSAI, or send a PDU session establishment request message together with the S-NSSAI.

[0287] Furthermore, when a UE communicates using an IMS service and receives the 12th identification information, the 14th identification information, the 15th identification information, and / or the 16th identification information from the core network, the UE may store the S-NSSAI indicated by the 15th identification information and / or the 16th identification information, the IMS service, and the 12th identification information in association with each other, and may select the requested S-NSSAI based on the current registration area and the stored S-NSSAI, and may send a registration request message including the S-NSSAI, or send a PDU session establishment request message together with the S-NSSAI.

[0288] In addition, when a UE communicates using an IMS service, when it receives 15th identification information from the core network, if the value of the SST or SD constituting the S-NSSAI included in the 15th identification information is an S-NSSAI that indicates an IMS service, it may select that S-NSSAI and send a registration request message including that S-NSSAI, or send a PDU session establishment request message together with that S-NSSAI.

[0289] In addition, when the UE communicates using an IMS service, it receives 15th identification information from the core network, and if the correspondence between the position and order of the 13th S-NSSAI (supporting IMS) included in the 15th identification information and the IMS service is pre-defined by a specification or pre-defined by an operator, the UE may select the 13th S-NSSAI supporting the IMS service from one or more S-NSSAIs included in the 15th identification information based on its position and order, and send a registration request message including the 13th S-NSSAI, or send a PDU session establishment request message together with the 13th S-NSSAI. In this way, if the UE knows in advance the position of the 13th S-NSSAI in the Allowed NSSAI, it may be able to identify the 13th S-NSSAI even if it has not received information from the core network that explicitly indicates the correspondence between the IMS service and the 13th S-NSSAI, such as the 13th identification information, and / or the 14th identification information, and / or the 23rd identification information, and / or the 24th identification information, and / or the 34th identification information.

[0290] In addition, when the UE communicates using an IMS service, if it receives 13th identification information and 15th identification information from the core network, it may select a 13th S-NSSAI (that supports IMS) from one or more S-NSSAIs included in the 15th identification information based on the information indicated by the 13th identification information, and send a registration request message including the 13th S-NSSAI, or send a PDU session establishment request message together with the 13th S-NSSAI.

[0291] In addition, if the UE has previously stored an association between an IMS service and the default S-NSSAI and / or the 13th S-NSSAI, when communicating using the IMS service, the UE may select the default S-NSSAI or the 13th S-NSSAI and send a registration request message including the default S-NSSAI or the 13th S-NSSAI, or send a PDU session establishment request message together with the default S-NSSAI or the 13th S-NSSAI.

[0292] In addition, when the UE communicates using an IMS service, if the UE receives a 15th identification information including the 16th identification information and the 14th identification information from the core network, the UE may select a 13th S-NSSAI indicated by the 16th identification information and send a registration request message including the 13th S-NSSAI, or send a PDU session establishment request message together with the 13th S-NSSAI.

[0293] Next, if the control message is a registration accept message, the UE may further send a registration complete message to the AMF via the 5G AN (gNB) as a response message to the registration accept message (S612). Here, the registration complete message is an NAS message transmitted and received on the N1 interface, but is transmitted and received between the UE and the 5G AN (gNB) in an RRC message.

[0294] The AMF receives a registration completion message via the 5G AN (gNB) (S612). In addition, each device completes this procedure based on the transmission and reception of the registration acceptance message and / or the registration completion message.

[0295] Alternatively, each device may complete this procedure based on sending and receiving a registration rejection message.

[0296] Each device may transition to or maintain a state in which the UE is registered in the network (RM_REGISTERED state or 5GMM-REGISTERED state) based on the transmission and reception of a registration accept message and / or a registration complete message, or may transition to or maintain a state in which the UE is not registered in the network on the access from which the registration reject message was received for the current PLMN (RM_DEREGISTERED state or 5GMM-DEREGISTERED state) based on the transmission and reception of a registration reject message. Also, the transition to each state of each device may be based on the transmission and reception of a registration accept message and / or a registration complete message and / or a registration reject message, or the completion of this procedure.

[0297] In addition, each device may store the information sent and received in the registration request message and / or registration acceptance message and / or registration completion message and / or registration rejection message, or may recognize the network's decision based on the sending and receiving of the registration request message and / or registration acceptance message and / or registration completion message and / or registration rejection message, or the completion of this procedure.

[0298] Furthermore, based on receiving the control message and / or the identification information contained in the control message, the UE may initiate the registration procedure of Chapter 3.2, or the generic UE configuration update procedure of Chapter 3.3, or the UE policy management procedure of Chapter 3.4, or a procedure for SM (including, for example, the PDU session establishment procedure of Chapter 3.5).

[0299] [3.3. Generic UE Configuration Update Procedure (UE Configuration Update Procedure)] Next, the generic UE configuration update procedure will be described with reference to FIG.

[0300] This procedure may be initiated when the AMF updates the UE configuration for access and mobility management-related parameters. This procedure may also be initiated when the AMF requests the UE to perform a registration procedure for mobility and periodic registration update to update the access and mobility management-related parameters. Furthermore, the UE may initiate the generic UE configuration update procedure based on the completion of the registration procedure in Chapter 3.2, the completion of the generic UE configuration update procedure in Chapter 3.3, the completion of the UE policy management procedure in Chapter 3.4, or the completion of a procedure for SM (including, for example, the PDU session establishment procedure in Chapter 3.5).

[0301] This procedure begins when the AMF sends a configuration update command to the UE via the access network (S800).

[0302] Here, the setting update command may include at least part of the identification information 21 to 27. Here, the identification information 21 to 27 may be as described in Chapter 2.7. Furthermore, it is preferable that at least one of the pieces of information indicated by the identification information 21 to 27 included in the setting update command has been updated from the information indicated by the identification information 11 to 16 and 19 transmitted and received in the control message (registration accept message or registration reject message) in the registration procedure described in Chapter 3.2, but it does not have to be updated.

[0303] Furthermore, by receiving the setting update command (S800), the UE may be able to understand the meaning of each piece of identification information included in the setting update command and / or the meaning indicated by a combination of each piece of identification information.

[0304] Furthermore, upon receiving the configuration update command, the UE may update the identification information that it has already stored, or may store the received identification information if it has not yet stored the identification information.

[0305] Furthermore, the UE may perform the following processes based on receiving at least one of the identification information items 21 to 27 and / or receiving a configuration update command. Note that the UE may perform these processes during this procedure or after completing this procedure.

[0306] For example, if a UE receives a 25th identification information including a third S-NSSAI and a fourth S-NSSAI from the core network, when requesting establishment of a PDU session for a first IMS service, it may select the third S-NSSAI and the fourth S-NSSAI from the 25th identification information for the first IMS service, and perform the PDU session establishment procedure of Chapter 3.5 using the third S-NSSAI (hereinafter simply referred to as the PDU session establishment procedure) to establish a PDU session for SIP signaling for the first IMS service, and perform the PDU session establishment procedure using the fourth S-NSSAI to establish a PDU session for media for the first IMS service.

[0307] Furthermore, when the UE receives 25th identification information including the third S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI from the core network, when requesting establishment of a PDU session for the first IMS service, it may select the third S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI from the 25th identification information for the first IMS service, perform a PDU session establishment procedure using the third S-NSSAI to establish a PDU session for SIP signaling for the first IMS service, perform a PDU session establishment procedure using the ninth S-NSSAI to establish a PDU session for media (voice) for the first IMS service, and perform a PDU session establishment procedure using the tenth S-NSSAI to establish a PDU session for media (video) for the first IMS service.

[0308] Furthermore, when the UE receives a 25th identification information including a 7th S-NSSAI from the core network, when requesting establishment of a PDU session for the first IMS service, the UE may select the 7th S-NSSAI from the 25th identification information for the first IMS service and perform a PDU session establishment procedure using the 7th S-NSSAI to establish a PDU session for the first IMS service.

[0309] Furthermore, when the UE receives 25th identification information including the third S-NSSAI, the fourth S-NSSAI, and the seventh S-NSSAI from the core network, when requesting establishment of a PDU session for the first IMS service, the UE may select the third S-NSSAI and the fourth S-NSSAI, which are information identifying the network slice corresponding to the seventh S-NSSAI, from the 25th identification information for the first IMS service, and perform a PDU session establishment procedure using the third S-NSSAI to establish a PDU session for SIP signaling for the first IMS service, and perform a PDU session establishment procedure using the fourth S-NSSAI to establish a PDU session for media for the first IMS service.

[0310] Furthermore, when the UE receives 25th identification information including the third S-NSSAI, the seventh S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI from the core network, when requesting establishment of a PDU session for the first IMS service, the UE may select the third S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI from the 25th identification information for the first IMS service, which are information identifying the network slice corresponding to the seventh S-NSSAI, and perform a PDU session establishment procedure using the third S-NSSAI to establish a PDU session for SIP signaling for the first IMS service, perform a PDU session establishment procedure using the ninth S-NSSAI to establish a PDU session for media (voice) for the first IMS service, and perform a PDU session establishment procedure using the tenth S-NSSAI to establish a PDU session for media (video) for the first IMS service.

[0311] Furthermore, when the UE receives a 25th identification information including a fifth S-NSSAI and a sixth S-NSSAI from the core network, when requesting establishment of a PDU session for a second IMS service, the UE may select the fifth S-NSSAI and the sixth S-NSSAI from the 25th identification information for the second IMS service, perform a PDU session establishment procedure using the fifth S-NSSAI to establish a PDU session for SIP signaling for the second IMS service, and perform a PDU session establishment procedure using the sixth S-NSSAI to establish a PDU session for media for the second IMS service.

[0312] Furthermore, when the UE receives 25th identification information including the 5th S-NSSAI, the 11th S-NSSAI, and the 12th S-NSSAI from the core network, when requesting establishment of a PDU session for the second IMS service, the UE may select the 5th S-NSSAI, the 11th S-NSSAI, and the 12th S-NSSAI from the 25th identification information for the second IMS service, perform a PDU session establishment procedure using the 5th S-NSSAI to establish a PDU session for SIP signaling for the second IMS service, perform a PDU session establishment procedure using the 11th S-NSSAI to establish a PDU session for media (voice) for the second IMS service, and perform a PDU session establishment procedure using the 12th S-NSSAI to establish a PDU session for media (video) for the second IMS service.

[0313] Furthermore, when the UE receives the 25th identification information including the 8th S-NSSAI from the core network, when requesting the establishment of a PDU session for the second IMS service, the UE may select the 8th S-NSSAI from the 25th identification information for the first IMS service and perform a PDU session establishment procedure using the 8th S-NSSAI to establish a PDU session for the second IMS service.

[0314] Furthermore, when the UE receives 25th identification information including the fifth S-NSSAI, the sixth S-NSSAI, and the eighth S-NSSAI from the core network, when requesting establishment of a PDU session for the second IMS service, the UE may select the fifth S-NSSAI and the sixth S-NSSAI, which are information identifying the network slice corresponding to the eighth S-NSSAI, from the 25th identification information for the second IMS service, perform a PDU session establishment procedure using the fifth S-NSSAI to establish a PDU session for SIP signaling for the second IMS service, and perform a PDU session establishment procedure using the sixth S-NSSAI to establish a PDU session for media for the second IMS service.

[0315] Furthermore, when the UE receives 25th identification information including the 5th S-NSSAI, the 8th S-NSSAI, the 11th S-NSSAI, and the 12th S-NSSAI from the core network, when requesting establishment of a PDU session for the second IMS service, the UE may select the 5th S-NSSAI, the 11th S-NSSAI, and the 12th S-NSSAI from the 25th identification information for the second IMS service, which are information that identify the network slice corresponding to the 8th S-NSSAI, and perform a PDU session establishment procedure using the 5th S-NSSAI to establish a PDU session for SIP signaling for the second IMS service, perform a PDU session establishment procedure using the 11th S-NSSAI to establish a PDU session for media (voice) for the second IMS service, and perform a PDU session establishment procedure using the 12th S-NSSAI to establish a PDU session for media (video) for the second IMS service.

[0316] As described above, the network slices used by the PDU sessions established for the first IMS service and / or the second IMS service may be at least partially (including entirely) the same or all different. Also, the DNNs identifying the DNs to which the PDU sessions are connected may be at least partially (including entirely) the same or all different.

[0317] Furthermore, when the UE has already received a 33rd identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the ninth S-NSSAI and / or the tenth S-NSSAI from the core network, and when the UE receives a 25th identity including the third S-NSSAI and the fourth S-NSSAI in this procedure, when requesting establishment of a PDU session for the first IMS service, the UE may use the third S-NSSAI included in the 25th identity and / or the 33rd identity based on the information included in the 33rd identity. When it is determined that the SAI and the fourth S-NSSAI are available in the current registration area, the third S-NSSAI and the fourth S-NSSAI may be selected from the 25th identification information or the 33rd identification information for the first IMS service, and a PDU session establishment procedure using the third S-NSSAI may be performed to establish a PDU session for SIP signaling for the first IMS service, and a PDU session establishment procedure using the fourth S-NSSAI may be performed to establish a PDU session for media for the first IMS service.

[0318] Furthermore, when the UE has already received a 33rd identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the ninth S-NSSAI and / or the tenth S-NSSAI from the core network, and when the UE receives a 25th identity including the third S-NSSAI and the ninth S-NSSAI and the tenth S-NSSAI in this procedure, when requesting establishment of a PDU session for the first IMS service, the UE determines, based on the information included in the 33rd identity, that the third S-NSSAI, the ninth S-NSSAI and the tenth S-NSSAI included in the 25th identity and / or the 33rd identity belong to the current registration area. When it is determined that the S-NSSAI can be used, the third S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI may be selected from the 25th identification information or the 33rd identification information for the first IMS service, and a PDU session establishment procedure using the third S-NSSAI may be performed to establish a PDU session for SIP signaling for the first IMS service, a PDU session establishment procedure using the ninth S-NSSAI may be performed to establish a PDU session for media (voice) for the first IMS service, and a PDU session establishment procedure using the tenth S-NSSAI may be performed to establish a PDU session for media (video) for the first IMS service.

[0319] Furthermore, when the UE has already received a 33rd identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the ninth S-NSSAI and / or the tenth S-NSSAI from the core network, if the UE receives a 25th identity including the seventh S-NSSAI in this procedure, and when requesting establishment of a PDU session for the first IMS service, if the UE determines, based on the information included in the 33rd identity, that the 25th identity and / or the seventh S-NSSAI included in the 33rd identity is usable in the current registration area, the UE may select the seventh S-NSSAI from the 25th identity or the 33rd identity for the first IMS service and perform a PDU session establishment procedure using the seventh S-NSSAI to establish a PDU session for the first IMS service.

[0320] Furthermore, when the UE has already received a 33rd identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the ninth S-NSSAI and / or the tenth S-NSSAI from the core network, if the UE receives a 25th identity including the third S-NSSAI, the fourth S-NSSAI, and the seventh S-NSSAI in this procedure, when requesting establishment of a PDU session for the first IMS service, the UE determines based on the information included in the 33rd identity that the 25th identity and / or the seventh S-NSSAI included in the 33rd identity are currently When it is determined that the seventh S-NSSAI is available in the current registration area, the third S-NSSAI and fourth S-NSSAI, which are information identifying the network slice corresponding to the seventh S-NSSAI, may be selected from the 25th identification information or the 33rd identification information for the first IMS service, and a PDU session establishment procedure using the third S-NSSAI may be performed to establish a PDU session for SIP signaling for the first IMS service, and a PDU session establishment procedure using the fourth S-NSSAI may be performed to establish a PDU session for media for the first IMS service.

[0321] Furthermore, when the UE has already received a 33rd identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the ninth S-NSSAI and / or the tenth S-NSSAI from the core network, if the UE receives a 25th identity including the third S-NSSAI, the seventh S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI in this procedure, and when the UE requests establishment of a PDU session for the first IMS service, if the UE determines, based on the information included in the 33rd identity, that the 25th identity and / or the seventh S-NSSAI included in the 33rd identity are usable in the current registration area, For the service, a third S-NSSAI, a ninth S-NSSAI, and a tenth S-NSSAI, which are information identifying the network slice corresponding to the seventh S-NSSAI, may be selected from the 25th identification information or the 33rd identification information, and a PDU session establishment procedure using the third S-NSSAI may be performed to establish a PDU session for SIP signaling for the first IMS service, a PDU session establishment procedure using the ninth S-NSSAI may be performed to establish a PDU session for media (voice) for the first IMS service, and a PDU session establishment procedure using the tenth S-NSSAI may be performed to establish a PDU session for media (video) for the first IMS service.

[0322] Furthermore, when the UE has already received a 33rd identity including the fifth S-NSSAI and / or the sixth S-NSSAI and / or the eighth S-NSSAI and / or the eleventh S-NSSAI and / or the twelfth S-NSSAI from the core network, and when the UE receives a 25th identity including the fifth S-NSSAI and the sixth S-NSSAI in this procedure, when requesting establishment of a PDU session for the second IMS service, the UE may use the 25th identity and / or the fifth S-NSSAI included in the 33rd identity based on the information included in the 33rd identity. When it is determined that the SAI and the sixth S-NSSAI are available in the current registration area, the fifth S-NSSAI and the sixth S-NSSAI may be selected from the 25th identity or the 33rd identity for the second IMS service, and a PDU session establishment procedure using the fifth S-NSSAI may be performed to establish a PDU session for SIP signaling for the second IMS service, and a PDU session establishment procedure using the sixth S-NSSAI may be performed to establish a PDU session for media for the second IMS service.

[0323] Furthermore, when the UE has already received a 33rd identity including the fifth S-NSSAI and / or the sixth S-NSSAI and / or the eighth S-NSSAI and / or the eleventh S-NSSAI and / or the twelfth S-NSSAI from the core network, and when the UE receives a 25th identity including the fifth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI in this procedure, when requesting establishment of a PDU session for the second IMS service, the UE may determine, based on the information included in the 33rd identity, that the fifth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI included in the 25th identity and / or the 33rd identity are registered in the current registration area. If it is determined that the S-NSSAI can be used, the fifth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI may be selected from the twenty-fifth identification information or the thirty-third identification information for the second IMS service, and a PDU session establishment procedure using the fifth S-NSSAI may be performed to establish a PDU session for SIP signaling for the second IMS service, a PDU session establishment procedure using the eleventh S-NSSAI may be performed to establish a PDU session for media (voice) for the second IMS service, and a PDU session establishment procedure using the twelfth S-NSSAI may be performed to establish a PDU session for media (video) for the second IMS service.

[0324] Furthermore, when the UE has already received a 33rd identity including the 5th S-NSSAI and / or the 6th S-NSSAI and / or the 8th S-NSSAI and / or the 11th S-NSSAI and / or the 12th S-NSSAI from the core network, and when the UE receives a 25th identity including the 8th S-NSSAI in this procedure, and when requesting establishment of a PDU session for a second IMS service, if the UE determines, based on the information included in the 33rd identity, that the 25th identity and / or the 8th S-NSSAI included in the 33rd identity is usable in the current registration area, the UE may select the 8th S-NSSAI from the 25th identity or the 33rd identity for the second IMS service, and perform a PDU session establishment procedure using the 8th S-NSSAI to establish a PDU session for the second IMS service.

[0325] Furthermore, when the UE has already received a 33rd identity including the fifth S-NSSAI and / or the sixth S-NSSAI and / or the eighth S-NSSAI and / or the eleventh S-NSSAI and / or the twelfth S-NSSAI from the core network, and when the UE receives a 25th identity including the fifth S-NSSAI, the sixth S-NSSAI, and the eighth S-NSSAI in this procedure, when requesting establishment of a PDU session for the second IMS service, the UE determines that the 25th identity and / or the eighth S-NSSAI included in the 33rd identity are the same as the 25th identity based on the information included in the 33rd identity. When it is determined that the eighth S-NSSAI is available in the current registration area, the fifth S-NSSAI and sixth S-NSSAI, which are information identifying the network slice corresponding to the eighth S-NSSAI, may be selected from the twenty-fifth identification information or the thirty-third identification information for the second IMS service, and a PDU session establishment procedure using the fifth S-NSSAI may be performed to establish a PDU session for SIP signaling for the second IMS service, and a PDU session establishment procedure using the sixth S-NSSAI may be performed to establish a PDU session for media for the second IMS service.

[0326] Furthermore, when the UE has already received a 33rd identity including the fifth S-NSSAI and / or the sixth S-NSSAI and / or the eighth S-NSSAI and / or the eleventh S-NSSAI and / or the twelfth S-NSSAI from the core network, if the UE receives a 25th identity including the fifth S-NSSAI, the eighth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI in this procedure, and when the UE requests establishment of a PDU session for a second IMS service, if the UE determines, based on the information included in the 33rd identity, that the 25th identity and / or the eighth S-NSSAI included in the 33rd identity can be used in the current registration area, the UE may request establishment of a PDU session for the second IMS service. For the service, a fifth S-NSSAI, an eleventh S-NSSAI, and a twelfth S-NSSAI, which are information identifying the network slice corresponding to the eighth S-NSSAI, may be selected from the twenty-fifth identification information or the thirty-third identification information, and a PDU session establishment procedure using the fifth S-NSSAI may be performed to establish a PDU session for SIP signaling for the second IMS service, a PDU session establishment procedure using the eleventh S-NSSAI may be performed to establish a PDU session for media (voice) for the second IMS service, and a PDU session establishment procedure using the twelfth S-NSSAI may be performed to establish a PDU session for media (video) for the second IMS service.

[0327] As described above, the network slices used by the PDU sessions established for the first IMS service and / or the second IMS service may be at least partially (including entirely) the same or all different. Also, the DNNs identifying the DNs to which the PDU sessions are connected may be at least partially (including entirely) the same or all different.

[0328] For example, when the UE receives the 21st identity from the core network, the UE may store the 21st identity in association with the IMS service. In this case, if the 21st identity is valid in all PLMNs and the UE moves to a new registration area different from the current registration area, and the UE does not receive a 13th S-NSSAI (the 16th identity, the 26th identity, and / or the 36th identity) valid in the new registration area (supporting the IMS service), the UE may select the default S-NSSAI indicated by the 21st identity for the IMS service, regardless of whether the new registration area belongs to the current PLMN. Also, if the 21st identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, and / or the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting IMS services), and the new registration area belongs to the current PLMN, the UE may select the default S-NSSAI indicated by the 21st identity for IMS services. Also, if the 21st identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, and / or the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting IMS services), and the new registration area does not belong to the current PLMN, the UE may not select the default S-NSSAI indicated by the 21st identity for IMS services.Also, if the 21st identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE receives a 13th S-NSSAI (the 16th identity, the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting the IMS service), the UE may select the 13th S-NSSAI (the 16th identity, the 26th identity, and / or the 36th identity) for the IMS service. Then, the UE may send a registration request message including the selected default S-NSSAI or the 13th S-NSSAI, or may send a PDU session establishment request message together with the selected default S-NSSAI or the 13th S-NSSAI. In other words, if the UE selects an S-NSSAI, it may send a registration request message including the selected default S-NSSAI or the thirteenth S-NSSAI, or may send a PDU session establishment request message together with the selected default S-NSSAI or the thirteenth S-NSSAI. If the UE does not select an S-NSSAI, it may send a registration request message without including an S-NSSAI. If the UE does not select an S-NSSAI, it may not send a registration request message.

[0329] Furthermore, if the UE has established a PDU session using the 13th S-NSSAI for an IMS service in the first registration area, and the 13th S-NSSAI is valid (usable) for the IMS service in the first registration area but not in the second registration area, and the UE has already received, in the second registration area, a 15th identity or a 25th identity including the 13th S-NSSAI from the core network, or has received, in this procedure, a 25th identity including the 13th S-NSSAI, and further has received, in this procedure, a 26th identity indicating the second S-NSSAI and a 24th identity indicating the IMS service corresponding to the second S-NSSAI; If the second S-NSSAI is valid for the IMS service in the second registration area, the UE may initiate a PDU session establishment procedure for the IMS service using the second S-NSSAI (supporting the IMS service in the second registration area) based on receiving the 24th identity and the 26th identity, and then initiate a PDU session release procedure to release the PDU session using the 13th S-NSSAI (not supporting the IMS service in the second registration area), or may initiate a PDU session release procedure to release the PDU session using the 13th S-NSSAI, and then initiate a PDU session establishment procedure for the IMS service using the second S-NSSAI. Note that in this case, the UE may use the 13th S-NSSAI indicated by the 15th identity in the second registration area for communications other than the IMS service.

[0330] Furthermore, when the UE communicates using an IMS service and receives the 24th identification information, the 25th identification information, and / or the 26th identification information from the core network, the UE may store the S-NSSAI indicated by the 25th identification information and / or the 26th identification information in association with the IMS service, and may select the requested S-NSSAI based on the current registration area and the stored S-NSSAI, and may send a registration request message including the S-NSSAI, or send a PDU session establishment request message together with the S-NSSAI.

[0331] Furthermore, when a UE communicates using an IMS service and receives the 22nd identification information, the 24th identification information, the 25th identification information and / or the 26th identification information from the core network, the UE may store the S-NSSAI indicated by the 25th identification information and / or the 26th identification information, the IMS service, and the 22nd identification information in association with each other, and may select the requested S-NSSAI based on the current registration area and the stored S-NSSAI, and may send a registration request message including the S-NSSAI, or send a PDU session establishment request message together with the S-NSSAI.

[0332] In addition, when a UE communicates using an IMS service, when it receives 25th identification information from the core network, if the value of the SST or SD constituting the S-NSSAI included in the 25th identification information is an S-NSSAI that indicates an IMS service, it may select that S-NSSAI and send a registration request message including that S-NSSAI, or send a PDU session establishment request message together with that S-NSSAI.

[0333] In addition, when the UE communicates using an IMS service, it receives 25th identification information from the core network, and if the correspondence between the position and order of the 13th S-NSSAI (supporting IMS) included in the 25th identification information and the IMS service is pre-defined by a specification or pre-defined by an operator, the UE may select the 13th S-NSSAI supporting the IMS service from one or more S-NSSAIs included in the 25th identification information based on its position and order, and send a registration request message including the 13th S-NSSAI, or send a PDU session establishment request message together with the 13th S-NSSAI. In this way, if the UE knows in advance the position of the 13th S-NSSAI in the Allowed NSSAI, it may be able to identify the 13th S-NSSAI even if it has not received information from the core network that explicitly indicates the correspondence between the IMS service and the 13th S-NSSAI, such as the 13th identification information, and / or the 14th identification information, and / or the 23rd identification information, and / or the 24th identification information, and / or the 34th identification information.

[0334] In addition, when the UE communicates using an IMS service and receives the 23rd identification information and the 25th identification information from the core network, the UE may select the 13th S-NSSAI (that supports IMS) from one or more S-NSSAIs included in the 25th identification information based on the information indicated by the 23rd identification information, and send a registration request message including the 13th S-NSSAI, or send a PDU session establishment request message together with the 13th S-NSSAI.

[0335] In addition, if the UE has previously stored an association between an IMS service and the default S-NSSAI and / or the 13th S-NSSAI, when communicating using the IMS service, the UE may select the default S-NSSAI or the 13th S-NSSAI and send a registration request message including the default S-NSSAI or the 13th S-NSSAI, or send a PDU session establishment request message together with the default S-NSSAI or the 13th S-NSSAI.

[0336] Furthermore, each device completes this procedure based on the sending and receiving of the setting update command.

[0337] Furthermore, based on receiving the configuration update command and / or the identification information included in the configuration update command, the UE may initiate the registration procedure of Chapter 3.2, or the generic UE configuration update procedure of Chapter 3.3, or the UE policy management procedure of Chapter 3.4, or a procedure for SM (including, for example, the PDU session establishment procedure of Chapter 3.5).

[0338] Also, as described in Section 3.4, the PCF may send a control message (hereinafter also referred to as a container) including the UE policy management command of Section 3.4 to the AMF, and the AMF may start this procedure upon receiving the control message (container). In this case, the AMF may send a configuration update command including the UE policy management command to the UE (S800).

[0339] 3.4. UE Policy Management Procedures Next, the UE policy management procedure will be explained with reference to FIG.

[0340] This procedure is used by the PCF to provide one or more UE policies to the UE. For example, the network can perform this procedure to add one or more new UE policies to the UE. The network can also perform this procedure to modify or delete one or more UE policies stored in the UE. Furthermore, the UE may initiate the UE policy management procedure based on the completion of the registration procedure in Chapter 3.2, the generic UE configuration update procedure in Chapter 3.3, the UE policy management procedure in Chapter 3.4, or the procedure for SM (including, for example, the PDU session establishment procedure in Chapter 3.5).

[0341] This procedure begins when the PCF sends a UE policy management command (MANAGE UE POLICY COMMAND) to the UE via the AMF (S900).

[0342] Here, the UE policy management command may include at least some of the identification information 31 to 37. Here, the identification information 31 to 37 may be as described in Chapter 2.7. The PCF may select and determine which of the identification information 31 to 37 to include in the control message based on the received identification information, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the PCF, etc.

[0343] In addition, by receiving a UE policy management command from the PCF (S900), the UE may be able to understand the meaning of each piece of identification information included in the UE policy management command and / or the meaning indicated by the combination of each piece of identification information.

[0344] Furthermore, upon receiving a UE policy management command, the UE may update the identification information that it has already stored, or may store the received identification information if it has not yet stored the identification information.

[0345] Furthermore, the UE may perform the following processes based on receiving at least one of the identification information items 31 to 37 and / or receiving a UE policy management command. Note that the UE may perform these processes during this procedure or after completing this procedure.

[0346] Furthermore, when the UE has already received the 15th identity and / or the 25th identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the 9th S-NSSAI and / or the tenth S-NSSAI from the core network, and when the UE receives the 33rd identity including the third S-NSSAI and the fourth S-NSSAI in this procedure, when requesting establishment of a PDU session for the first IMS service, the UE may use the information included in the 15th identity and / or the 25th identity and / or the 33rd identity based on the information included in the 33rd identity. When it is determined that the third S-NSSAI and the fourth S-NSSAI are available in the current registration area, the third S-NSSAI and the fourth S-NSSAI may be selected from the 15th identity, the 25th identity, or the 33rd identity for the first IMS service, and a PDU session establishment procedure using the third S-NSSAI may be performed to establish a PDU session for SIP signaling for the first IMS service, and a PDU session establishment procedure using the fourth S-NSSAI may be performed to establish a PDU session for media for the first IMS service.

[0347] Furthermore, when the UE has already received the 15th identity and / or the 25th identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the 9th S-NSSAI and / or the tenth S-NSSAI from the core network, and when the UE receives the 33rd identity including the third S-NSSAI and the 9th S-NSSAI and the tenth S-NSSAI in this procedure, when requesting establishment of a PDU session for the first IMS service, the UE may determine, based on the information included in the 33rd identity, that the 15th identity and / or the 25th identity and / or the 33rd identity include the third S-NSSAI, the 9th S-NSSAI and the tenth S-NSSAI as the currently registered S-NSSAI. If it is determined that the S-NSSAI can be used in the distribution area, the third S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI may be selected from the fifteenth identification information, the twenty-fifth identification information, or the thirty-third identification information for the first IMS service, and a PDU session establishment procedure using the third S-NSSAI may be performed to establish a PDU session for SIP signaling for the first IMS service, a PDU session establishment procedure using the ninth S-NSSAI may be performed to establish a PDU session for media (voice) for the first IMS service, and a PDU session establishment procedure using the tenth S-NSSAI may be performed to establish a PDU session for media (video) for the first IMS service.

[0348] Furthermore, if the UE has already received the 15th identity and / or the 25th identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the 9th S-NSSAI and / or the tenth S-NSSAI from the core network, when the UE receives the 33rd identity including the seventh S-NSSAI in this procedure, and when requesting establishment of a PDU session for the first IMS service, if the UE determines based on the information included in the 33rd identity that the 15th identity and / or the 25th identity and / or the seventh S-NSSAI included in the 33rd identity is usable in the current registration area, the UE may select the seventh S-NSSAI from the 15th identity, the 25th identity, or the 33rd identity for the first IMS service, and perform a PDU session establishment procedure using the seventh S-NSSAI to establish a PDU session for the first IMS service.

[0349] Furthermore, when the UE has already received the 15th identity and / or the 25th identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the 9th S-NSSAI and / or the tenth S-NSSAI from the core network, and when the UE receives the 33rd identity including the third S-NSSAI, the fourth S-NSSAI, and the seventh S-NSSAI in this procedure, when requesting establishment of a PDU session for the first IMS service, the UE may use the 15th identity and / or the 25th identity and / or the seventh identity included in the 33rd identity based on the information included in the 33rd identity. When it is determined that the S-NSSAI is available in the current registration area, for the first IMS service, a third S-NSSAI and a fourth S-NSSAI, which are information identifying the network slice corresponding to the seventh S-NSSAI, may be selected from the 15th identification information, the 25th identification information, or the 33rd identification information, and a PDU session establishment procedure using the third S-NSSAI may be performed to establish a PDU session for SIP signaling for the first IMS service, and a PDU session establishment procedure using the fourth S-NSSAI may be performed to establish a PDU session for media for the first IMS service.

[0350] Furthermore, when the UE has already received the 15th identity and / or the 25th identity including the third S-NSSAI and / or the fourth S-NSSAI and / or the seventh S-NSSAI and / or the 9th S-NSSAI and / or the tenth S-NSSAI from the core network, and when the UE receives the 33rd identity including the third S-NSSAI, the seventh S-NSSAI, the 9th S-NSSAI, and the tenth S-NSSAI in this procedure, when requesting establishment of a PDU session for the first IMS service, the UE determines, based on the information included in the 33rd identity, that the 15th identity and / or the 25th identity and / or the seventh S-NSSAI included in the 33rd identity can be used in the current registration area. In this case, for the first IMS service, the third S-NSSAI, the ninth S-NSSAI, and the tenth S-NSSAI, which are information identifying the network slice corresponding to the seventh S-NSSAI, may be selected from the fifteenth identification information, the twenty-fifth identification information, or the thirty-third identification information, and a PDU session establishment procedure using the third S-NSSAI may be performed to establish a PDU session for SIP signaling for the first IMS service, a PDU session establishment procedure using the ninth S-NSSAI may be performed to establish a PDU session for media (voice) for the first IMS service, and a PDU session establishment procedure using the tenth S-NSSAI may be performed to establish a PDU session for media (video) for the first IMS service.

[0351] Furthermore, when the UE has already received the 15th identity and / or the 25th identity including the 5th S-NSSAI and / or the 6th S-NSSAI and / or the 8th S-NSSAI and / or the 11th S-NSSAI and / or the 12th S-NSSAI from the core network, and when the UE receives the 33rd identity including the 5th S-NSSAI and the 6th S-NSSAI in this procedure, when requesting establishment of a PDU session for the second IMS service, the UE shall use the information included in the 15th identity and / or the 25th identity and / or the 33rd identity based on the information included in the 33rd identity. When it is determined that the fifth S-NSSAI and the sixth S-NSSAI are usable in the current registration area, it may select the fifth S-NSSAI and the sixth S-NSSAI from among the fifteenth identity, the twenty-fifth identity, or the thirty-third identity for the second IMS service, perform a PDU session establishment procedure using the fifth S-NSSAI to establish a PDU session for SIP signaling for the second IMS service, and perform a PDU session establishment procedure using the sixth S-NSSAI to establish a PDU session for media for the second IMS service.

[0352] Furthermore, when the UE has already received the 15th identity and / or the 25th identity including the 5th S-NSSAI and / or the 6th S-NSSAI and / or the 8th S-NSSAI and / or the 11th S-NSSAI and / or the 12th S-NSSAI from the core network, and when the UE receives the 33rd identity including the 5th S-NSSAI and / or the 11th S-NSSAI and / or the 12th S-NSSAI in this procedure, when requesting establishment of a PDU session for the second IMS service, the UE may determine that the 5th S-NSSAI and / or the 11th S-NSSAI and the 12th S-NSSAI included in the 15th identity and / or the 25th identity and / or the 33rd identity are the current registered S-NSSAIs based on the information included in the 33rd identity. If it is determined that the S-NSSAI can be used in the communication area, the fifth, eleventh, and twelfth S-NSSAIs may be selected from the fifteenth, twenty-fifth, or thirty-third identification information for the second IMS service, and a PDU session establishment procedure using the fifth S-NSSAI may be performed to establish a PDU session for SIP signaling for the second IMS service, a PDU session establishment procedure using the eleventh S-NSSAI may be performed to establish a PDU session for media (voice) for the second IMS service, and a PDU session establishment procedure using the twelfth S-NSSAI may be performed to establish a PDU session for media (video) for the second IMS service.

[0353] In addition, if the UE has already received the 15th identity and / or the 25th identity including the 5th S-NSSAI and / or the 6th S-NSSAI and / or the 8th S-NSSAI and / or the 11th S-NSSAI and / or the 12th S-NSSAI from the core network, when the UE receives the 33rd identity including the 8th S-NSSAI in this procedure, the UE shall use the information included in the 33rd identity when requesting establishment of a PDU session for the second IMS service. If, based on the information, it is determined that the eighth S-NSSAI included in the 15th identity and / or the 25th identity and / or the 33rd identity is usable in the current registration area, the eighth S-NSSAI may be selected from the 15th identity or the 25th identity or the 33rd identity for the second IMS service, and a PDU session establishment procedure using the eighth S-NSSAI may be performed to establish a PDU session for the second IMS service.

[0354] Furthermore, when the UE has already received the 15th identity and / or the 25th identity including the 5th S-NSSAI and / or the 6th S-NSSAI and / or the 8th S-NSSAI and / or the 11th S-NSSAI and / or the 12th S-NSSAI from the core network, and when the UE receives the 33rd identity including the 5th S-NSSAI, the 6th S-NSSAI, and the 8th S-NSSAI in this procedure, when requesting establishment of a PDU session for the second IMS service, the UE may use the 15th identity and / or the 25th identity and / or the 8th identity included in the 33rd identity based on the information included in the 33rd identity. When it is determined that the S-NSSAI is usable in the current registration area, for the second IMS service, a fifth S-NSSAI and a sixth S-NSSAI, which are information identifying the network slice corresponding to the eighth S-NSSAI, may be selected from the fifteenth identification information, the twenty-fifth identification information, or the thirty-third identification information, and a PDU session establishment procedure using the fifth S-NSSAI may be performed to establish a PDU session for SIP signaling for the second IMS service, and a PDU session establishment procedure using the sixth S-NSSAI may be performed to establish a PDU session for media for the second IMS service.

[0355] Furthermore, when the UE has already received the 15th identity and / or the 25th identity including the 5th S-NSSAI and / or the 6th S-NSSAI and / or the 8th S-NSSAI and / or the 11th S-NSSAI and / or the 12th S-NSSAI from the core network, and when the UE receives the 33rd identity including the 5th S-NSSAI, the 8th S-NSSAI, the 11th S-NSSAI, and the 12th S-NSSAI in this procedure, when requesting establishment of a PDU session for the second IMS service, the UE determines, based on the information included in the 33rd identity, that the 15th identity and / or the 25th identity and / or the 8th S-NSSAI included in the 33rd identity can be used in the current registration area. In this case, for the second IMS service, the fifth S-NSSAI, the eleventh S-NSSAI, and the twelfth S-NSSAI, which are information identifying the network slice corresponding to the eighth S-NSSAI, may be selected from the fifteenth identification information, the twenty-fifth identification information, or the thirty-third identification information, and a PDU session establishment procedure using the fifth S-NSSAI may be performed to establish a PDU session for SIP signaling for the second IMS service, a PDU session establishment procedure using the eleventh S-NSSAI may be performed to establish a PDU session for media (voice) for the second IMS service, and a PDU session establishment procedure using the twelfth S-NSSAI may be performed to establish a PDU session for media (video) for the second IMS service.

[0356] As described above, the network slices used by the PDU sessions established for the first IMS service and / or the second IMS service may be at least partially (including entirely) the same or all different. Also, the DNNs identifying the DNs to which the PDU sessions are connected may be at least partially (including entirely) the same or all different.

[0357] For example, if the UE has already received the 15th identification information from the core network, when the UE receives the 33rd identification information in this procedure and requests the establishment of a PDU session for an IMS service, the UE may select an S-NSSAI that is valid (usable) in the current registration area from one or more S-NSSAIs included in the 15th identification information and the S-NSSAI indicated by the 36th identification information included in the 33rd identification information based on the 15th identification information and the 33rd identification information, and may send a registration request message including that S-NSSAI, or send a PDU session establishment request message together with that S-NSSAI.

[0358] Furthermore, if the UE has already received the 15th identification information and the 33rd identification information from the core network and the 33rd identification information does not include the 32nd identification information, the UE may determine that the S-NSSAI indicated by the 36th identification information included in the 33rd identification information is valid in the current registration area, or valid within the current PLMN, or valid in all PLMNs, and may select an S-NSSAI that is valid (usable) in the current registration area for the IMS service from one or more S-NSSAIs included in the 15th identification information and the S-NSSAI indicated by the 36th identification information included in the 33rd identification information, and may send a registration request message including that S-NSSAI or send a PDU session establishment request message together with that S-NSSAI.

[0359] In addition, if the UE has already received the 15th identification information from the core network, and receives the 33rd identification information in this procedure, and the 36th identification information included in the 33rd identification information is the 13th S-NSSAI selected by the PCF from the Allowed NSSAIs, and when requesting establishment of a PDU session for an IMS service, the UE may select the 13th S-NSSAI (the 36th identification information included in the 33rd identification information) based on the 33rd identification information, and send a registration request message including the 13th S-NSSAI, or send a PDU session establishment request message together with the 13th S-NSSAI.

[0360] Furthermore, when the UE receives the 33rd identification information in this procedure after having already received the 15th identification information from the core network and requests establishment of a PDU session for an IMS service, the UE may check whether the 36th identification information included in the 33rd identification information is included in the 15th identification information, and if the 36th identification information is included in the 15th identification information, select the 13th S-NSSAI indicated by the 36th identification information and transmit a registration request message including the 13th S-NSSAI or transmit a PDU session establishment request message together with the 13th S-NSSAI. Furthermore, the UE may check whether the 36th identification information is included in the 15th identification information, and if the 36th identification information is not included in the 15th identification information, not select the 13th S-NSSAI indicated by the 36th identification information for the IMS service, and not transmit a registration request message including the 13th S-NSSAI or transmit a PDU session establishment request message together with the 13th S-NSSAI. Furthermore, in this case, the UE may send a UE policy management command rejection message including the 41st identification information (S902).

[0361] Furthermore, the UE may check for each access whether the 36th identification information included in the 33rd identification information is included in the 15th identification information. That is, the UE may check for each of 3GPP access and non-3GPP access whether the 36th identification information included in the 33rd identification information is included in the 15th identification information.

[0362] For example, if the 36th identity included in the 33rd identity is included in the 15th identity for 3GPP access, but the 36th identity included in the 33rd identity is not included in the 15th identity for non-3GPP access, the UE may send, for an IMS service, a registration request message including the 13th S-NSSAI indicated by the 36th identity via the 3GPP access, or may send a PDU session establishment request message together with the 13th S-NSSAI indicated by the 36th identity via the 3GPP access. In this case, the UE may send, for non-3GPP access, a UE policy management command rejection message including the 41st identity indicating that the S-NSSAI is unavailable in the current registration area or that the provided S-NSSAI is unavailable in the current registration area (S902).

[0363] Furthermore, if the 36th identity included in the 33rd identity is not included in the 15th identity for 3GPP access, and the 36th identity included in the 33rd identity is included in the 15th identity for non-3GPP access, the UE may send, for an IMS service, a registration request message including the 13th S-NSSAI indicated by the 36th identity via the non-3GPP access, or may send a PDU session establishment request message together with the 13th S-NSSAI indicated by the 36th identity via the non-3GPP access. In this case, the UE may send, for 3GPP access, a UE policy management command rejection message including the 41st identity indicating that the S-NSSAI is unavailable in the current registration area or that the provided S-NSSAI is unavailable in the current registration area (S902).

[0364] Furthermore, when the 36th identity included in the 33rd identity is included in the 15th identity for 3GPP access and the 36th identity included in the 33rd identity is included in the 15th identity for non-3GPP access, the UE may select whether to transmit from the 3GPP access or the non-3GPP access for the IMS service, and may transmit a registration request message including the 13th S-NSSAI indicated by the 36th identity or a PDU session establishment request message together with the 13th S-NSSAI indicated by the 36th identity via the selected access. In this case, the UE does not need to transmit a UE policy management command reject message including the 41st identity.

[0365] Furthermore, if the 36th identity included in the 33rd identity is not included in the 15th identity for 3GPP access, and the 36th identity included in the 33rd identity is not included in the 15th identity for non-3GPP access, the UE may not select the 13th S-NSSAI indicated by the 36th identity for the IMS service, and may not send a registration request message including the 13th S-NSSAI or may not send a PDU session establishment request message together with the 13th S-NSSAI. In this case, the UE may send a UE policy management command rejection message including the 41st identity for 3GPP access and non-3GPP access, indicating that the S-NSSAI is unavailable in the current registration area or that the provided S-NSSAI is unavailable in the current registration area (S902).

[0366] Furthermore, when the UE receives the 31st identity from the core network, the UE may store the 31st identity in association with the IMS service. In this case, if the 31st identity is valid in all PLMNs and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, the 26th identity, and / or the 36th identity) valid in the new registration area (supporting the IMS service), the UE may select the default S-NSSAI indicated by the 31st identity for the IMS service, regardless of whether the new registration area belongs to the current PLMN. Also, if the 31st identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, and / or the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting IMS services), and the new registration area belongs to the current PLMN, the UE may select the default S-NSSAI indicated by the 31st identity for IMS services. Also, if the 31st identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has not received a 13th S-NSSAI (the 16th identity, and / or the 26th identity, and / or the 36th identity) that is valid in the new registration area (supporting IMS services), and the new registration area does not belong to the current PLMN, the UE may not select the default S-NSSAI indicated by the 31st identity for IMS services.Also, if the 31st identity is valid in the current PLMN and the UE moves to a new registration area different from the current registration area, and the UE has received a 13th S-NSSAI (the 16th identity, the 26th identity, and / or the 36th identity) valid in the new registration area (supporting the IMS service), the UE may select the 13th S-NSSAI (the 16th identity, the 26th identity, and / or the 36th identity) for the IMS service. Then, the UE may send a registration request message including the selected default S-NSSAI or the 13th S-NSSAI, or a PDU session establishment request message together with the selected default S-NSSAI or the 13th S-NSSAI.

[0367] Furthermore, if the UE has already received the 12th identification information and the 15th identification information from the core network, the UE may store the 12th identification information in association with the 15th identification information or the S-NSSAI included in the 15th identification information. In this case, when the UE receives the 33rd identification information from the core network in this procedure, the UE may store the 33rd identification information. Then, when requesting establishment of a PDU session for an IMS service, the UE may select an S-NSSAI that is valid (usable) in the current registration area from the S-NSSAI included in the 15th identification information and the 13th S-NSSAI indicated by the 36th identification information based on the 12th identification information, the 15th identification information, and the 33rd identification information, and transmit a registration request message including the S-NSSAI or transmit a PDU session establishment request message together with the S-NSSAI.

[0368] Furthermore, if the UE has established a PDU session using the 13th S-NSSAI for an IMS service in the first registration area, and the 13th S-NSSAI is valid (usable) for the IMS service in the first registration area but not in the second registration area, and the UE has already received the 15th identity, the 25th identity, or the 36th identity including the 13th S-NSSAI from the core network in the second registration area, or has received the 36th identity including the 13th S-NSSAI in this procedure, and further has received the 36th identity indicating the second S-NSSAI and the 35th identity indicating the IMS service corresponding to the second S-NSSAI in this procedure, If the UE receives the 13th S-NSSAI and the second S-NSSAI is valid for the IMS service in the second registration area, the UE may, based on the reception of the 35th identity and the 36th identity, initiate a PDU session establishment procedure for the IMS service using the second S-NSSAI (supporting the IMS service in the second registration area) and then initiate a PDU session release procedure to release the PDU session using the 13th S-NSSAI (not supporting the IMS service in the second registration area), or may initiate a PDU session release procedure to release the PDU session using the 13th S-NSSAI and then initiate a PDU session establishment procedure for the IMS service using the second S-NSSAI. Note that in this case, the UE may use the 13th S-NSSAI indicated by the 15th identity in the second registration area for communications other than the IMS service.

[0369] In addition, if the UE has previously stored an association between an IMS service and the default S-NSSAI and / or the 13th S-NSSAI, when communicating using the IMS service, the UE may select the default S-NSSAI or the 13th S-NSSAI and send a registration request message including the default S-NSSAI or the 13th S-NSSAI, or send a PDU session establishment request message together with the default S-NSSAI or the 13th S-NSSAI.

[0370] In addition, each device completes this procedure based on sending and receiving a UE policy management command and / or a UE policy management command rejection message.

[0371] Furthermore, based on receiving the UE Policy Management Command message and / or the identification information included in the UE Policy Management Command message, the UE may initiate the registration procedure of Chapter 3.2, or the generic UE configuration update procedure of Chapter 3.3, or the UE Policy Management procedure of Chapter 3.4, or a procedure for SM (including, for example, the PDU Session Establishment procedure of Chapter 3.5).

[0372] Alternatively, the PCF may send a control message (container) including a UE policy management command, and the AMF that receives the control message (container) may initiate the generic UE configuration update procedure of Chapter 3.3. That is, the AMF that receives the policy management command from the PCF may send a configuration update command including the UE policy management command to the UE. In this case, the UE policy management procedure of this chapter may be referred to as a UE configuration update procedure. That is, the UE policy management procedure of this chapter may be executed as a UE configuration update procedure.

[0373] [3.5. PDU Session Establishment Procedure] Next, the PDU session establishment procedure initiated by the UE to establish a PDU session will be described with reference to Figure 9. Hereinafter, the PDU session establishment procedure will also be referred to as this procedure. The UE may initiate this procedure based on the completion of the registration procedure in Chapter 3.2, the completion of the generic UE configuration update procedure in Chapter 3.3, the completion of the UE policy management procedure in Chapter 3.4, or the completion of a procedure for SM (including, for example, the PDU session establishment procedure in this chapter).

[0374] This procedure may be performed as a procedure for establishing a PDU session for an IMS service, and may be performed multiple times depending on the number of IMS services requested or required by a user and / or application. More specifically, this procedure may establish a PDU session for an IMS service used by a UE. Furthermore, the multiple PDU sessions for IMS services established by this procedure may be used for transmitting and receiving IMS signaling (SIP signaling for the IMS service) associated with each session and / or media for the IMS service, as described below.

[0375] First, the UE initiates a PDU session establishment procedure by sending a NAS message including an N1 SM container containing a PDU session establishment request message to the AMF via an access network_B (3GPP access or non-3GPP access) (S1000). Here, the access network may include a base station device. That is, the UE sends the NAS message to the AMF via the base station device. The NAS message is, for example, a message sent via the N1 interface and may be an uplink NAS transport (UL NAS TRANSPORT) message.

[0376] In addition, the UE can notify the network side of its request by sending a PDU session establishment request message, and / or an N1 SM container, and / or an NAS message containing at least one of the identification information items 51 to 59.

[0377] Furthermore, the UE may determine which of the identification information 51 to 59 to send to the network based on the UE's capability information, and / or UE policy, and / or UE status, and / or user registration information, and / or context held by the UE, etc.

[0378] For example, when a UE has not established a PDU session for a certain (first or second) IMS service and requests the establishment of a PDU session for that IMS service, the UE may include identification information 51 indicating a new PDU session ID in the PDU session establishment request message, and / or the N1 SM container, and / or the NAS message.

[0379] In addition, when a UE has already established a PDU session for a certain (first or second) IMS service and requests the establishment of the remaining PDU sessions related to that IMS service, the UE may include 51st identification information indicating a PDU session ID different from the already established PDU session ID in the PDU session establishment request message, and / or the N1 SM container, and / or the NAS message.

[0380] In addition, when the UE requests the establishment of a PDU session for a certain IMS service (first or second) if the UE has not established a PDU session for that IMS service, the UE may set the contents of the 52nd identification information and the 53rd identification information and include the 52nd identification information and the 53rd identification information in the PDU session establishment request message, and / or the N1 SM container, and / or the NAS message.

[0381] Furthermore, when a UE has already established some PDU sessions for a certain (first or second) IMS service and requests the establishment of the remaining PDU sessions related to that IMS service, the UE may set the information indicated by the 62nd identification information and the 63rd identification information set for the already established PDU sessions to the 52nd identification information and the 53rd identification information, respectively, and include these 52nd identification information and the 53rd identification information in the PDU session establishment request message, and / or the N1 SM container, and / or the NAS message.

[0382] In addition, if the UE has not sent the fourth identification information during the registration procedure, it may include the fifty-fourth identification information in the PDU session establishment request message, and / or the N1 SM container, and / or the NAS message.

[0383] In addition, when the UE requests establishment of a PDU session for SIP signaling for a certain (first or second) IMS service, or when requesting establishment of a PDU session for media for a certain (first or second) IMS service, or when requesting establishment of a PDU session for media (voice) for a certain (first or second) IMS service, or when requesting establishment of a PDU session for media (video) for a certain (first or second) IMS service, or when requesting establishment of a PDU session for a certain (first or second) IMS service, the UE may include the 55th identification information in the PDU session establishment request message, and / or the N1 SM container, and / or the NAS message.

[0384] The UE also receives the 56th identification information and the 57th identification information included when requesting establishment of a PDU session for SIP signaling for the first IMS service, the 56th identification information and the 57th identification information included when requesting establishment of a PDU session for media for the first IMS service, the 56th identification information and the 57th identification information included when requesting establishment of a PDU session for media (voice) for the first IMS service, the 56th identification information and the 57th identification information included when requesting establishment of a PDU session for media (video) for the first IMS service, the 56th identification information and the 57th identification information included when requesting establishment of a PDU session for media (video) for the first IMS service, and the 56th identification information and the 57th identification information included when requesting establishment of a PDU session for the second IMS service. The 56th identification information and the 57th identification information included when requesting the establishment of a PDU session for SIP signaling for the first IMS service, the 56th identification information and the 57th identification information included when requesting the establishment of a PDU session for media for the second IMS service, the 56th identification information and the 57th identification information included when requesting the establishment of a PDU session for media (voice) for the second IMS service, the 56th identification information and the 57th identification information included when requesting the establishment of a PDU session for media (video) for the second IMS service, and the 56th identification information and the 57th identification information included when requesting the establishment of a PDU session for the second IMS service may be identical to or different from each other.

[0385] Furthermore, if the UE has not established a PDU session for a certain (first or second) IMS service, when the UE requests the establishment of a PDU session for that IMS service, the UE may not include the 58th identification information in the PDU session establishment request message, and / or the N1 SM container, and / or the NAS message.

[0386] Furthermore, when a UE has already established some PDU sessions for a certain (first or second) IMS service and requests the establishment of the remaining PDU sessions related to that certain (first or second) IMS service, the UE may include identification information 58 indicating the already established PDU session IDs in the PDU session establishment request message, and / or the N1 SM container, and / or the NAS message.

[0387] In addition, the UE may transmit this identification information in a control message other than the above, such as a control message of a layer lower than the NAS layer (e.g., RRC layer, MAC layer, RLC layer, PDCP layer, SDAP layer, etc.) or a control message of a layer higher than the NAS layer (e.g., transport layer, session layer, presentation layer, application layer, etc.).

[0388] Next, when the AMF receives the NAS message, it can recognize what the UE is requesting and / or the contents of the information contained in the NAS message (message, container, information, etc.).

[0389] Next, the AMF selects an SMF as a transfer destination for at least part of the information, etc. (message, container, information) included in the NAS message received from the UE (S1002). The AMF may select the transfer destination SMF based on the information, etc. (message, container, information) included in the NAS message, and / or subscriber information, and / or network capability information, and / or UE policy, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the AMF, etc.

[0390] Next, the AMF sends at least a portion of the information (message, container, information) contained in the NAS message received from the UE to the selected SMF, for example via the N11 interface (S1004).

[0391] Next, when the SMF receives information (messages, containers, information) sent from the AMF, it can recognize what the UE is requesting and / or the content of the information (messages, containers, information) received from the AMF.

[0392] Here, the SMF may perform a second condition determination. The second condition determination may be for determining whether the network accepts the UE request. If the SMF determines that the second condition determination is true, it may start the procedure of (A) in Figure 9, and if the SMF determines that the second condition determination is false, it may start the procedure of (B) in Figure 9.

[0393] Furthermore, the second condition determination may be performed based on information received from the AMF (message, container, information), and / or subscription information, and / or network capability information, and / or UE policy, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the SMF, etc.

[0394] For example, if the network permits the UE's request, the determination of the second condition may be true, and if the network does not permit the UE's request, the determination of the second condition may be false. Furthermore, if the network to which the UE is connected and / or a device within the network supports the function requested by the UE, the determination of the second condition may be true, and if the function requested by the UE is not supported, the determination of the second condition may be false. Furthermore, if the transmitted and received identification information is permitted, the determination of the second condition may be true, and if the transmitted and received identification information is not permitted, the determination of the second condition may be false. The conditions for determining whether the second condition is true or false are not limited to the above-described conditions.

[0395] Next, each step of the procedure in FIG. 9(A) will be explained.

[0396] Next, the SMF may select a UPF for the PDU session to be established and send an N4 session establishment request message to the selected UPF, for example, via the N4 interface (S1008). The N4 session establishment request message may include at least a portion of the URSP received from the PCF.

[0397] Here, the SMF may select one or more UPFs based on information received from the AMF (message, container, information), and / or information included in the URSP received from the PCF, and / or subscriber information, and / or network capability information, and / or UE policy, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the SMF, etc. Furthermore, if multiple UPFs are selected, the SMF may send an N4 session establishment request message to each UPF.

[0398] Next, when the UPF receives the N4 session establishment request message (S1008), it can recognize the content of the information received from the SMF. Furthermore, based on the reception of the N4 session establishment request message, the UPF may send an N4 session establishment response message to the SMF, for example, via the N4 interface (S1010).

[0399] Next, when the SMF receives an N4 session establishment response message as a response message to the N4 session establishment request message, it can recognize the contents of the information received from the UPF.

[0400] Next, the SMF sends an N1 SM container, N2 SM information, and / or PDU session ID to the AMF, for example, via the N11 interface, based on the reception of the PDU session establishment request message, and / or the selection of the UPF, and / or the reception of the N4 session establishment response message (S1012), where the N1 SM container may include a PDU session establishment accept message.

[0401] Next, the AMF that has received the N1 SM container, and / or the N2 SM information, and / or the PDU session ID, transmits a NAS message to the UE via a base station device included in the access network (S1014) (S1016). Here, the NAS message is transmitted, for example, via the N1 interface. The NAS message may be a downlink NAS transport (DL NAS TRANSPORT) message.

[0402] Specifically, the AMF transmits an N2 PDU session request message to a base station device included in the access network (S1014). The base station device that receives the N2 PDU session request message transmits an NAS message to the UE (S1016). Here, the N2 PDU session request message may include an NAS message and / or N2 SM information. The NAS message may also include a PDU session ID and / or an N1 SM container.

[0403] The PDU session establishment acceptance message may be a response message to a PDU session establishment request, and may indicate that the establishment of the PDU session has been accepted.

[0404] Here, the SMF and / or AMF may indicate that at least part of the UE's request in the PDU session establishment request message has been accepted by sending a PDU session establishment acceptance message, and / or an N1 SM container, and / or a PDU session ID, and / or an NAS message, and / or N2 SM information, and / or an N2 PDU session request message.

[0405] Here, the SMF and / or AMF may include at least one of the identification information 61 to 68 in the PDU session establishment accept message, and / or the N1 SM container, and / or the NAS message, and / or the N2 SM information, and / or the N2 PDU session request message and send it. Here, the identification information 61 to 63 may be the same as or different from the identification information 51 to 53 of this procedure.

[0406] By transmitting these identification information and / or the PDU session establishment acceptance message, the SMF may indicate that the network supports each function, that the UE request has been accepted, that the UE request has not been permitted, or a combination of these. Furthermore, when multiple identification information is transmitted and received, two or more of these identification information may be configured as one or more identification information. Note that the information indicating support of each function and the information indicating a request for use of each function may be transmitted and received as the same identification information or as different identification information.

[0407] The SMF and / or AMF can notify the UE of the contents of these identification information by transmitting at least one of these identification information.

[0408] Furthermore, the SMF and / or AMF may determine which identification information to include in the PDU session establishment acceptance message, and / or the N1 SM container, and / or the NAS message, and / or the N2 SM information, and / or the N2 PDU session request message based on each received identification information, and / or subscriber information, and / or network capability information, and / or UE policy, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the SMF and / or AMF, etc.

[0409] For example, the SMF and / or AMF may include a 61st identification information having the same content as the 51st identification information in a PDU session establishment acceptance message, and / or an N1 SM container, and / or an NAS message, and / or N2 SM information, and / or an N2 PDU session request message.

[0410] Furthermore, the SMF and / or AMF may include the 62nd identification information and the 63rd identification information selected by the SMF in the PDU session establishment accept message, and / or the N1 SM container, and / or the NAS message, and / or the N2 SM information, and / or the N2 PDU session request message. Note that the content of the 62nd identification information may be the same as or different from the content of the 52nd identification information. Also, the content of the 63rd identification information may be the same as or different from the content of the 53rd identification information.

[0411] Furthermore, the SMF and / or AMF may include the 64th identification information in the PDU session establishment accept message, and / or the N1 SM container, and / or the NAS message, and / or the N2 SM information, and / or the N2 PDU session request message only when the 54th identification information is received from the UE. Furthermore, the SMF and / or AMF may include the 64th identification information in the PDU session establishment accept message, and / or the N1 SM container, and / or the NAS message, and / or the N2 SM information, and / or the N2 PDU session request message regardless of whether the 54th identification information is received from the UE.

[0412] Furthermore, when the SMF and / or AMF authorizes the establishment of a PDU session for SIP signaling for a certain (first or second) IMS service, or when authorizing the establishment of a PDU session for media for a first IMS service, or when authorizing the establishment of a PDU session for media (voice) for the first IMS service, or when authorizing the establishment of a PDU session for media (video) for the first IMS service, or when authorizing the establishment of a PDU session for the first IMS service, it may include the 65th identification information in the PDU session establishment accept message, and / or the N1 SM container, and / or the NAS message, and / or the N2 SM information, and / or the N2 PDU session request message.

[0413] The UE also includes the 66th identification information and the 67th identification information to be included when authorizing the establishment of a PDU session for SIP signaling for the first IMS service, the 66th identification information and the 67th identification information to be included when authorizing the establishment of a PDU session for media for the first IMS service, the 66th identification information and the 67th identification information to be included when authorizing the establishment of a PDU session for media (voice) for the first IMS service, the 66th identification information and the 67th identification information to be included when authorizing the establishment of a PDU session for media (video) for the first IMS service, the 66th identification information and the 67th identification information to be included when authorizing the establishment of a PDU session for the first IMS service, and the 66th identification information and the 67th identification information to be included when authorizing the establishment of a PDU session for media for the second IMS service. The 66th and 67th identification information included when authorizing the establishment of a PDU session for SIP signaling for the first IMS service, the 66th and 67th identification information included when authorizing the establishment of a PDU session for media for the second IMS service, the 66th and 67th identification information included when requesting the establishment of a PDU session for media (voice) for the second IMS service, the 66th and 67th identification information included when requesting the establishment of a PDU session for media (video) for the second IMS service, and the 66th and 67th identification information included when requesting the establishment of a PDU session for the second IMS service may be the same as or different from each other. Note that the content of the 66th identification information may be the same as or different from the content of the 56th identification information. Also, the content of the 67th identification information may be the same as or different from the content of the 57th identification information.

[0414] Next, when the UE receives the NAS message (S1016), for example, via the N1 interface, it can recognize that the UE's request in the PDU session establishment request message has been accepted and / or the contents of the information (message, container, information) included in the NAS message. For example, the UE may recognize the PDU session type and SSC mode configured for the PDU session identified by the 31st identification based on the received 61st, 62nd, and 63rd identifications. The UE may also recognize the functions supported by the network based on the received 64th identification. The UE may also recognize that the network has granted the UE's request based on the received 65th identification.

[0415] Each device may establish a PDU session based on the sending and receiving of the PDU session establishment acceptance message and may complete this procedure. That is, each device may transition to a state in which it can communicate with the DN using the established PDU session.

[0416] Furthermore, when the UE has established some PDU sessions for a certain (first or second) IMS service by completing this procedure, it may perform this procedure to establish the remaining PDU sessions for that IMS service.

[0417] Next, each step of the procedure in FIG. 9(B) will be explained.

[0418] First, based on receiving the PDU session establishment request message, the SMF sends an N1 SM container and / or a PDU session ID to the AMF, for example, via the N11 interface (S1018), where the N1 SM container may include a PDU session establishment rejection message.

[0419] Next, the AMF that has received the N1 SM container and / or the PDU session ID transmits a NAS message to the UE via a first base station device included in the access network (S1020) (S1022). Here, the NAS message is transmitted, for example, via an N1 interface. The NAS message may be a downlink NAS transport (DL NAS TRANSPORT) message. The NAS message may include the PDU session ID and / or the N1 SM container.

[0420] The PDU session establishment rejection message may be a response message to a PDU session establishment request, and may indicate that the establishment of the PDU session has been rejected.

[0421] Here, the SMF and / or AMF may indicate that the UE's request via the PDU session establishment request message has been rejected by sending a PDU session establishment rejection message, and / or an N1 SM container, and / or a PDU session ID, and / or an NAS message.

[0422] By sending a PDU session establishment rejection message, the SMF may indicate that the network does not support each function, that the UE request has been rejected, that the UE request has not been authorized, or a combination of these. Furthermore, when multiple identification information is transmitted and received, two or more of these identification information may be configured as one or more identification information. Note that the information indicating support of each function and the information indicating a request for use of each function may be transmitted and received as the same identification information or as different identification information.

[0423] The SMF and / or AMF can notify the UE of the contents of these identification information by transmitting at least one of these identification information.

[0424] Next, when the UE receives the NAS message, for example via the N1 interface (S1022), it can recognize that the UE's request via the PDU session establishment request message has been rejected and / or the contents of the information (message, container, information) contained in the NAS message.

[0425] Each device may complete this procedure based on sending and receiving a PDU session establishment rejection message. At this time, each device cannot establish a PDU session through this procedure, so if there is no already established PDU session, it cannot communicate with the DN. If there is already an established PDU session, it can communicate with the DN using that PDU session.

[0426] In addition, each of the processes performed by the UE based on the reception of each identification information shown above may be performed during this procedure or after completion of this procedure, or may be performed after completion of this procedure based on the completion of this procedure.

[0427] Furthermore, each device may store the information transmitted and received in this procedure in association with each other.

[0428] 4. Variations A program running on an apparatus according to one aspect of the present invention may be a program that controls a central processing unit (CPU) or the like to cause a computer to function so as to realize the functions of an embodiment according to the present invention. The program or information handled by the program is temporarily stored in a volatile memory such as a random access memory (RAM), a non-volatile memory such as a flash memory, a hard disk drive (HDD), or another storage device system.

[0429] A program for implementing the functions of an embodiment according to one aspect of the present invention may be recorded on a computer-readable recording medium. The program may be loaded into a computer system and executed. The term "computer system" as used herein refers to a computer system built into a device, including hardware such as an operating system and peripheral devices. The term "computer-readable recording medium" may refer to a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a medium that dynamically stores a program for a short period of time, or any other computer-readable recording medium.

[0430] Additionally, each functional block or feature of the device used in the above-described embodiments may be implemented or performed by an electrical circuit, such as an integrated circuit or multiple integrated circuits. The electrical circuit designed to perform the functions described herein may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or a combination thereof. The general-purpose processor may be a microprocessor, or a conventional processor, controller, microcontroller, or state machine. The electrical circuit may be composed of digital circuits or analog circuits. Furthermore, as advances in semiconductor technology emerge, one or more aspects of the present invention may utilize new integrated circuit technologies that replace current integrated circuits.

[0431] The present invention is not limited to the above-described embodiment. Although one example of a device has been described in the embodiment, one aspect of the present invention is not limited to this and can be applied to terminal devices or communication devices of stationary or non-movable electronic devices installed indoors or outdoors, such as AV equipment, kitchen equipment, cleaning / washing equipment, air conditioning equipment, office equipment, vending machines, and other household appliances.

[0432] Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the gist of the present invention. Furthermore, various modifications of one aspect of the present invention are possible within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, configurations in which elements described in the above embodiments are substituted with elements that achieve the same effect are also included.

Claims

1. A UE (User Equipment) including a transceiver unit and a control unit, The transmitting / receiving unit During the registration process, Sending a registration request message to an Access and Mobility Management Function (AMF), the registration request message including information indicating a request for information on a registration area in which Single Network Slice Selection Assistance Information (S-NSSAI) supporting an IMS service can be used, and information indicating a request for provision of an IMS service via multiple slices; Receive a registration acceptance message including an Allowed NSSAI (Network Slice Selection Assistance Information) from the AMF in response to the registration request message; In a UE configuration update procedure, a configuration update command including a UE policy management command message including a UE Route Selection Policy (URSP) is received from a PCF (Policy Control Function); the Allowed NSSAIs include a first Single Network Slice Selection Assistance Information (S-NSSAI) for SIP signaling for a first IMS service and a second S-NSSAI for media for the first IMS service; the URSP includes the first S-NSSAI, the second S-NSSAI, first information, and second information; the first information is information indicating a registration area in which the first S-NSSAI can be used, the second information is information indicating a registration area in which the second S-NSSAI can be used, When the control unit requests establishment of a PDU session for the first IMS service, if the control unit determines based on the URSP that the first S-NSSAI and the second S-NSSAI are usable in a current registration area, the control unit selects the first S-NSSAI and the second S-NSSAI for the first IMS service. A UE characterized by:

2. the value of the first S-NSSAI and the value of the second S-NSSAI are different; 2. The UE of claim 1 .

3. A UE (User Equipment) including a transceiver unit and a control unit, The transmitting / receiving unit During the registration process, Sending a registration request message to an Access and Mobility Management Function (AMF), the registration request message including information requesting information on a registration area in which Single Network Slice Selection Assistance Information (S-NSSAI) supporting an IMS service can be used, and information requesting provision of an IMS service via multiple slices; Receive a registration acceptance message including an Allowed NSSAI (Network Slice Selection Assistance Information) from the AMF in response to the registration request message; In a UE configuration update procedure, a configuration update command including a UE policy management command message including a UE Route Selection Policy (URSP) is received from a PCF (Policy Control Function); the Allowed NSSAI includes a first Single Network Slice Selection Assistance Information (S-NSSAI) for a first IMS service and a second S-NSSAI for a second IMS service; the URSP includes the first S-NSSAI, the second S-NSSAI, first information, and second information; the first information is information indicating a registration area in which the first S-NSSAI can be used, the second information is information indicating a registration area in which the second S-NSSAI can be used, The control unit When requesting establishment of a PDU session for the first IMS service, if it is determined based on the URSP that the first S-NSSAI is available in the current registration area, select the first S-NSSAI for the first IMS service; When requesting establishment of a PDU session for the second IMS service, if it is determined based on the URSP that the second S-NSSAI included in the Allowed NSSAI is usable in a current registration area, select the second S-NSSAI for the second IMS service. A UE characterized by:

4. the value of the first S-NSSAI and the value of the second S-NSSAI are different; 4. The UE according to claim 3,

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