UE (user equipment)

Abstract

To provide, in 5GS, communication means and UE (User Equipment) for continuing services of a PDU session in a network slice in a case where the network slice is congested, a case where network performance of the network slice does not satisfy an SLA, or the like.SOLUTION: The invention is for, in 5GS, performing a PDU session modification procedure (S802-S812), and / or a PDU session release procedure, and / or a PDU session establishment procedure, and / or a PDU session anchor change procedure, for implementing session and / or service continuity by changing a slice and changing a PDU session anchor, in a case where a network slice is congested, a case where network performance of the network slice does not satisfy an SLA, or the like.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to User Equipment (UE). [Background technology]

[0002] 3GPP (3rd Generation Partnership Project), which is involved in the standardization of recent mobile communication systems, is currently studying SAE (System Architecture Evolution), which is the system architecture of LTE (Long Term Evolution).

[0003] In recent years, 3GPP has also been studying next-generation communication technologies and system architectures for 5G (5th Generation) mobile communication systems, and in particular has been working on the specification of 5GS (5G System) as a system for realizing the 5G mobile communication system (see Non-Patent Document 1). In 5GS, technical issues for connecting a wide variety of terminals to a cellular network are being extracted and solutions are being specified. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 24.501 V17.5.0 (2022-01); 3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3 (Release 17) [Non-Patent Document 2] 3GPP TR 23.700-41 V0.1.0 (2022-02); 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Study on enhancement of network slicing; Phase 3 (Release 18) Summary of the Invention [Problem to be solved by the invention]

[0005] In the 5GS (5G System), a new core network, 5GCN (5G Core Network), is being considered in order to provide a wide variety of services.

[0006] Furthermore, in 5G, network slices, which are logical networks that provide specific network functions or specific network characteristics for a specific service type or a specific group, are defined. For example, a network slice may be a logical network provided for a terminal with a low latency function, or a logical network provided for a sensor terminal used in the Internet of Things (IoT).

[0007] Furthermore, in 3GPP, in order to study further functions related to network slices, eNS (Enhancement of Network Slicing) is being studied. In 3GPP, as a study of phase 3 of eNS, a technology for continuing the service of a PDU session in a network slice is being studied in cases where the network slice is congested without mobility, where the network performance of the network slice does not satisfy a service level agreement (also called SLA) without mobility, or where the network slice is congested with mobility (see Non-Patent Document 2).

[0008] However, a practical method for meeting the above requirements is not clear.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a method for implementing functions for NS and / or SNPN in 5GS. [Means for solving the problem]

[0010] One embodiment of the UE (User Equipment) of the present invention is characterized in that it comprises a transceiver unit and a control unit, wherein the transceiver unit receives a PDU session change command message including an S-NSSAI, the transceiver unit transmits the S-NSSAI and a PDU session establishment request message, the control unit establishes a second PDU session, and after the second PDU session is established, the first PDU session is released. Effect of the Invention

[0011] According to the present invention, it is possible to provide a means for continuing service of a PDU session in a network slice in cases where the network slice is congested when no mobility is involved, where the network performance of the network slice does not meet a service level agreement (also referred to as SLA) when no mobility is involved, or where the network slice is congested when mobility is involved. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating an overview of a mobile communication system (EPS / 5GS). [Diagram 2] A diagram explaining the detailed configuration of a mobile communication system (EPS / 5GS). [Diagram 3] A diagram explaining the device configuration of a UE. [Figure 4]A diagram explaining the configuration of an access network device (gNB) in 5GS. [Diagram 5] A diagram explaining the configuration of core network devices (AMF / SMF / UPF) in 5GS. [Figure 6] A diagram explaining the PDU session change procedure. [Figure 7] A diagram explaining the PDU session release procedure. [Figure 8] A diagram explaining the PDU session establishment procedure. [Figure 9] FIG. 1 is a diagram illustrating a first embodiment. [Figure 10] FIG. 11 is a diagram illustrating a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the present invention will now be described with reference to the drawings. In this embodiment, as an example, an embodiment of a mobile communication system to which the present invention is applied will be described.

[0014] [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.

[0015] 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.

[0016] In the following, these devices and functions may be described with abbreviated symbols, such as UE, access network_A, core network_A, PDN, access network_B, core network_B, DN, etc.

[0017] 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.

[0018] 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.

[0019] In addition, the 4G system EPS (Evolved Packet System) is configured to include an access network _A and a core network _A, but may further include a UE and / or a PDN. In addition, the 5G system 5GS (5G System) is configured to include a UE, an access network _B, and a core network _B, but may further include a DN.

[0020] The UE is a device that can connect to a network service via 3GPP access (also referred to as a 3GPP access network, 3GPP AN) and / or non-3GPP access (also referred to as a non-3GPP access network, non-3GPP AN). The 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. The UE may include a Universal Integrated Circuit Card (UICC) or an Embedded UICC (eUICC). The UE may be expressed as a user device or a terminal device.

[0021] Moreover, the access network_A corresponds to an E-UTRAN (Evolved Universal Terrestrial Radio Access Network) and / or a wireless LAN access network. In the E-UTRAN, one or more eNBs (evolved Node B) 45 are arranged. In the following, the eNB 45 may be written with the symbol omitted, such as eNB. In addition, when there are multiple eNBs, the eNBs are connected to each other, for example, by an X2 interface. In addition, one or more access points are arranged in the wireless LAN access network.

[0022] Moreover, the 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 arranged in the NG-RAN. In the following, the gNB 122 may be described with the symbol omitted, such as eNB. The gNB is a node that provides the NR (New Radio) user plane and control plane to the UE, and is a node that connects to the 5GCN via an NG interface (including an N2 interface or an N3 interface). That is, the gNB is a base station device newly designed for the 5GS, and has a different function from the base station device (eNB) used in the EPS, which is a 4G system. In addition, when there are multiple gNBs, each gNB is connected to each other, for example, by an Xn interface.

[0023] 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 defined by 3GPP, and may include a trusted non-3GPP access point (TNAP) and a trusted non-3GPP Gateway function (TNGF).

[0024] NG-RAN refers to a radio access network that connects to a 5GCN, and NR or E-UTRA or both may be used. In other words, NG-RAN may be E-UTRAN.

[0025] In the following, E-UTRAN and NG-RAN may be referred to as 3GPP access. In addition, wireless LAN access networks and non-3GPP AN may be referred to as non-3GPP access. In addition, nodes arranged in the access network_B may be collectively referred to as NG-RAN nodes.

[0026] In addition, 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.

[0027] Moreover, the core network_A corresponds to an EPC (Evolved Packet Core). In the EPC, 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), an HSS (Home Subscriber Server), etc. are arranged.

[0028] Moreover, the core network_B corresponds to a 5G Core Network (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), and a Unified Data Management (UDM) are arranged in the 5GCN. Here, the 5GCN may be expressed as a 5GC.

[0029] 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 a core network.

[0030] 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 such as an MVNO (Mobile Virtual Network Operator) or MVNE (Mobile Virtual Network Enabler) or a virtual mobile communication service provider.

[0031] The core network (core network_A and / or core network_B) and the access network (access network_A and / or access network_B) may differ depending on the mobile communication operator.

[0032] Also, in FIG. 1, the PDN and the DN are the same, but they may be different. The PDN may be a DN (Data Network) that provides a communication service 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 communication terminal connected thereto. Therefore, connecting to the PDN may be connecting to a communication terminal or a server device arranged in the PDN. Furthermore, transmitting and receiving user data to and from the PDN may be transmitting and receiving user data to and from a communication terminal or a server device arranged in the PDN. The PDN may be expressed as the DN, and the DN may be expressed as the PDN.

[0033] In addition, in the following, 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 transmits or receives a message and / or executes 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 transmits or receives a message and / or executes a procedure.

[0034] 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 between the PDN or DN. When transmitting and receiving user data, not only IP (Internet Protocol) communication but also non-IP communication may be used.

[0035] Here, IP communication refers to data communication using IP, and data is transmitted and received by IP packets. The IP packet is composed of an IP header and a payload section. The payload section may include data transmitted and received by devices and functions included in EPS and devices and functions included in 5GS. In addition, non-IP communication refers to data communication that does not use IP, and data is transmitted and received in a format different from the structure of an IP packet. For example, non-IP communication may be data communication realized by transmitting and receiving application data to which an IP header is not attached, or may be user data transmitted and received by a UE with another header such as a MAC header or an Ethernet (registered trademark) frame header attached.

[0036] In addition, the access network_A, the core network_A, the access network_B, the core network_B, the PDN_A, and the DN_A may include devices not shown in Fig. 2. For example, the core network_A and / or the core network_B and / or the PDN_A and / or the DN_A may include an AUSF (Authentication Server Function) and an AAA (Authentication, authorization, and accounting) server (AAA-S). The AAA server may be located outside the core network.

[0037] 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 an authentication procedure.

[0038] The AAA server is a device that is connected to the AUSF directly or indirectly via another network device and has authentication, authorization, and accounting functions. The AAA server may be a network device in the core network. The AAA server may not be included in the core network_A and / or the core network_B, but may be included in the PLMN and / or the SNPN. 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 in the PLMN and / or the SNPN managed by a third party.

[0039] In this document, when we refer to NW, it can mean either the core network or the access network, or both.

[0040] 2, for the sake of simplicity, one of each device and function is shown, but a plurality of similar devices and functions may be configured in the mobile communication system 1. Specifically, the mobile communication system 1 may be configured with a plurality of 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.

[0041] Furthermore, the mobile communication system 1 may include devices and / or functions other than those described above, for example, a Network Slice Selection Function (NSSF).

[0042] [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, may be configured as logical (virtual) hardware configured on general-purpose hardware, or may be configured 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.

[0043] Each memory unit (memory unit_A340, memory unit_A440, memory unit_B540, memory unit_A640, memory unit_B740) in each device / function described below is composed of, for example, a semiconductor memory, a solid state drive (SSD), a hard disk drive (HDD), etc. 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 the device / function other than the device / function itself (for example, UE, and / or access network device, and / or core network device, and / or PDN, and / or DN). Each memory unit can store identification information, control information, flags, parameters, etc. included in control messages transmitted and received in various communication procedures described later. Each memory unit may store this information for each UE. Each memory unit can store control messages and user data transmitted and received between the device / function included in the 5GS and / or EPS when interworking is performed between the 5GS and EPS. At this time, not only those transmitted and received via the N26 interface but also those transmitted and received without passing through the N26 interface can be stored.

[0044] [2.1. UE device configuration] First, an example of the device configuration of UE (User Equipment) will be described with reference to Fig. 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.

[0045] 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.

[0046] The transceiver unit _A320 is a functional unit for wirelessly communicating with a base station device (eNB or gNB) in an 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.

[0047] Explaining in detail with reference to FIG. 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.

[0048] The memory unit _A340 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the UE.

[0049] [2.2. gNB device configuration] Next, an example of the device configuration of the gNB will be described with reference to Fig. 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.

[0050] 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.

[0051] 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 transmit and receive user data and / or control information between the AMF and / or UPF using the network connection unit _B520.

[0052] The transceiver unit _B530 is a functional unit for wirelessly communicating with the UE via the antenna 510. That is, the gNB can transmit and receive user data and / or control information between the UE and the transceiver unit _B530.

[0053] 2, the gNB in ​​the 5G AN can communicate with the AMF via the N2 interface by using the network connection unit _B 520, and can communicate with the UPF via the N3 interface. The gNB can also communicate with the UE by using the transceiver unit _B 530.

[0054] The memory unit _B540 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the gNB.

[0055] [2.3. AMF device configuration] Next, an example of the device configuration of the AMF will be described with reference to 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.

[0056] 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.

[0057] The network connection unit _B720 is a functional unit for the AMF to connect to a base station device (gNB), and / or an SMF, and / or a PCF, and / or an UDM, and / or an SCEF in a 5G AN. That is, the AMF can use the network connection unit _B720 to transmit and receive user data and / or control information between a base station device (gNB), and / or an SMF, and / or a PCF, and / or an UDM, and / or an SCEF in a 5G AN.

[0058] Explaining in detail with reference to FIG. 2, the AMF in the 5GCN can communicate with the gNB via the N2 interface by using the network connection unit_A620, can communicate with the UDM via the N8 interface, can communicate with the SMF via the N11 interface, and can communicate with the PCF via the N15 interface. In addition, the AMF can transmit and receive NAS messages to and from the UE via the N1 interface by using the network connection unit_A620. However, since the N1 interface is logical, in reality, communication between the UE and the AMF is performed via the 5G AN. In addition, if the AMF supports the N26 interface, it can communicate with the MME via the N26 interface by using the network connection unit_A620.

[0059] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of AMF.

[0060] In addition, the AMF has a function of exchanging control messages with the RAN using the N2 interface, a function of exchanging NAS messages with the UE using the N1 interface, a function of encrypting and protecting the integrity of NAS messages, a registration management (RM) function, a connection management (CM) function, a reachability management function, a mobility management function for UEs, etc., a function of transferring SM (Session Management) messages between the UE and the SMF, an access authentication (access authorization) function, a security anchor functionality (SEA), a security context management (SCM) function, a function of supporting the N2 interface for the N3IWF (Non-3GPP Interworking Function), a function of supporting the transmission and reception of NAS signals with the UE via the N3IWF, and a function of authenticating UEs connected via the N3IWF.

[0061] In addition, in the registration management, the RM state of each UE is managed. The RM state may be synchronized between the UE and the AMF. The RM state includes a non-registered state (RM-DEREGISTERED state) and a registered state (RM-REGISTERED state). In the RM-DEREGISTERED state, the UE is not registered in 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 in the network, and therefore the UE can receive services that require registration with the network. The RM state may 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.

[0062] In other words, 5GMM-REGISTERED may be a state in which each device has established a 5GMM context, or may be a state in which each device has established 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 execute a registration procedure other than the registration procedure for initial registration, and / or a service request procedure.

[0063] Furthermore, 5GMM-DEREGISTERED may be a state in which each device has not established a 5GMM context, a state in which the location information of UE_A10 is not known to the network, or a state in which the network cannot reach UE_A10. Note that when each device is 5GMM-DEREGISTERED, UE_A10 may initiate a registration procedure or establish a 5GMM context by executing the registration procedure.

[0064] In addition, in the connection management, the CM state of each UE is managed. 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 a connection (N2 connection) of the N2 interface and a connection (N3 connection) of the N3 interface. 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 a connection (N2 connection) of the N2 interface and / or a connection (N3 connection) of the N3 interface.

[0065] Furthermore, in connection management, a CM state in 3GPP access and a CM state in non-3GPP access may be managed separately. In this case, the CM state in 3GPP access may be 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 be 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). The non-connected state may be expressed as an idle mode, and the connected state mode may be expressed as a connected mode.

[0066] The CM state may be expressed as a 5GMM mode. In this case, the unconnected state may be expressed as a 5GMM unconnected 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 unconnected mode in 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.

[0067] 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 between multiple NSIs.

[0068] 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.

[0069] [2.4. SMF device configuration] Next, an example of the device configuration of the SMF 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.

[0070] 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.

[0071] The network connection unit _B720 is a functional unit for connecting the SMF to the AMF, and / or the UPF, and / or the PCF, and / or the UDM. In other words, the SMF can use the network connection unit _B720 to transmit and receive user data and / or control information between the AMF, and / or the UPF, and / or the PCF, and / or the UDM.

[0072] Explaining in detail with reference to Figure 2, the SMF in the 5GCN can communicate with the AMF via the N11 interface, can communicate with the UPF via the N4 interface, can communicate with the PCF via the N7 interface, and can communicate with the UDM via the N10 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. necessary for each operation of the SMF.

[0074] The SMF has a session management function such as establishing, modifying, and releasing PDU sessions, an IP address allocation for UEs and its management function, a UPF selection and control function, a UPF setting function for routing traffic to the appropriate destination (destination), a function for sending and receiving the SM part of NAS messages, a function for notifying that downlink data has arrived (Downlink Data Notification), a function for providing AN-specific (for each AN) SM information to be sent to the AN via the N2 interface via the AMF, a function for determining the SSC mode (Session and Service Continuity mode) for the session, and a roaming function.

[0075] [2.5. UPF device configuration] Next, an example of the device configuration of the UPF will be described with reference to Fig. 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.

[0076] 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.

[0077] 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 in the 5G AN. In other words, the UPF can transmit and receive user data and / or control information between the base station device (gNB), and / or SMF, and / or DN in the 5G AN using the network connection unit _B720.

[0078] Explaining in detail with reference to Figure 2, by using network connection unit _A620, the UPF in the 5GCN can communicate with a gNB via an N3 interface, can communicate with an SMF via an N4 interface, can communicate with a DN via an N6 interface, and can communicate with other UPFs via an N9 interface.

[0079] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the UPF.

[0080] 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 function for forwarding user data as a gateway between DN and core network_B), a packet routing and forwarding function, a UL CL (Uplink Classifier) ​​function that supports routing of multiple traffic flows for 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, a downlink packet buffering function, and a function for triggering downlink data notification.

[0081] 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 may also have a function for converting non-IP communication and IP communication. Furthermore, the 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.

[0082] The user plane refers to user data transmitted and received between the UE and the 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 an 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 expressed as U-Plane.

[0083] Furthermore, the control plane refers to a control message transmitted and received to control communication of the UE. The control plane may be transmitted and received using a NAS (Non-Access-Stratum) signaling connection between the UE and the 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 the NG RAN and the N2 interface. Hereinafter, the control plane may be expressed as the control plane or the C-Plane.

[0084] 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.

[0085] [2.6. Other devices and / or functions and / or terms used in this embodiment] Next, other devices, functions, terms, and / or identification information and / or messages transmitted, received, stored, and managed by each device will be described.

[0086] The network refers to at least a part of the access network _B, the core network _B, and the DN. Furthermore, one or more devices included in at least a part of the access network _B, the core network _B, and the 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 a device in the network (a network device and / or a control device) transmits, receives, and / or processes messages. Conversely, when a device in the network transmits, receives, receives, and / or processes messages, it may mean that the network transmits, receives, and / or processes messages.

[0087] In addition, the SM (Session Management) message (also referred to as a NAS (Non-Access-Stratum) SM message) may be a NAS message used in procedures for SM, and may be a control message transmitted and received between UE_A10 and SMF_A230 via AMF_A240. Further, 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, and the like.

[0088] Furthermore, the procedure for SM or the SM procedure 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 may be initiated by the NW (network).

[0089] Also, an MM (Mobility management) message (also referred to as an NAS MM message) may be an NAS message used in a procedure 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, and the like.

[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, 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_B 190. 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] Additionally, 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 rather via a communication method other than IP.

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

[0095] Each device (UE, and / or access network device, and / or core network device) may manage one or more identification information in association with a PDU session. The identification information may include one or more of DNN, QoS rule, PDU session type, application identification information, NSI identification information, access network identification information, and SSC mode (also referred to as SSC mode), or may further include other information. Furthermore, when multiple PDU sessions are established, each identification information associated with a PDU session 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 may 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 the PDU session, and may be IPv4, IPv6, Ethernet, or Unstructured. If IPv4 is specified, it indicates that data is transmitted and received using IPv4. If IPv6 is specified, it indicates that data is transmitted and received using IPv6. If Ethernet is specified, it indicates that Ethernet frames are transmitted and received. Also, Ethernet may indicate that communication using IP is not performed. If Unstructured is specified, it indicates that data is transmitted and received to an application server or the like in a 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 include IP. IP can be specified when the UE is capable of using both IPv4 and IPv6.

[0098] Moreover, a PLMN (Public Land Mobile Network) is a communication network that provides mobile wireless communication services. A PLMN is a network managed by an operator, which is a (mobile) communications carrier, and the operator can be identified by a PLMN ID. In this document, PLMN may mean 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). PLMN may mean a core network.

[0099] Furthermore, the UE may store an Equivalent HPLMN list in the USIM to identify one or more EHPLMNs (Equivalent HPLMNs). A PLMN different from the HPLMN and / or the EHPLMN may be a Visited PLMN (VPLMN).

[0100] A PLMN to which the UE has successfully registered may be a Registered PLMN (RPLMN). Each device may receive, maintain, and / or store an Equivalent PLMN list from the RPLMN to identify one or more Equivalent PLMNs (EPLMNS) that can be used equivalently to the RPLMN in the UE's PLMN selection.

[0101] The current PLMN may be the PLMN requested by the UE, and / or the PLMN selected by the UE, and / or the RPLMN, and / or the PLMN allowed by the network, and / or the PLMN to which the core network device sending or receiving the message belongs.

[0102] The requested PLMN means a destination network of a message when the UE sends a message. Specifically, it may be a PLMN selected by the UE when the UE sends a message. The requested PLMN is a PLMN requested by the UE, and may be a current PLMN. Also, when the UE is in a registered state, the requested PLMN may be a registered PLMN.

[0103] NPN (Non-public network) is a network for non-public specifications. There are two types of NPN: SNPN (Stand-alone non-public network) and PNI-NPN (Public network integrated non-public network). SNPN and PNI-NPN may be deployed in 5GS. In this document, when referring to NPN, it may mean SNPN, PNI-NPN, or both.

[0104] A Stand-alone non-public network (SNPN) is a network operated by an NPN operator and does not depend on network functions provided by a PLMN. In other words, an SNPN is a network independent of a PLMN and can only be accessed by a specific UE. An SNPN may be identified by a PLMN ID and a Network identifier (NID).

[0105] Note that the PLMN ID identifying the SNPN does not need to be unique, for example one or more PLMN IDs reserved for use in private networks may be used for the NPN.

[0106] Also, a Stand-alone Non-Public Network (SNPN) is a network that is identified by an SNPN ID consisting of a combination of a PLMN ID and a Network Identifier (NID) and that only certain UEs are permitted to connect to. The SNPN may also refer to a core network. Here, a UE permitted to connect to the SNPN may be an SNPN enabled UE.

[0107] Furthermore, the UE may store an Equivalent SNPN list in the USIM to identify one or more ESNPNs (Equivalent SNPNs). An SNPN different from the HSNPN and / or the ESNPN may be a Visited PLMN (VPLMN).

[0108] The SNPN to which the UE successfully registers may be the Registered SNPN (RSNPN). Each device may receive from the RSNPN and / or maintain and / or store an Equivalent SNPN list to identify one or more ESNPNs (Equivalent PLMNs) that can be used equivalently to the RSNPN in the UE's PLMN selection or SNPN selection.

[0109] A PNI-NPN (Public network integrated non-public network) is an NPN deployed with the support of a PLMN, in other words, a network that uses the capabilities of a PLMN to implement non-public specifications.

[0110] Onboarding services in SNPN allow an MS (UE) to access an SNPN indicating onboarding using default UE credentials.

[0111] The registration procedure for onboarding services in the SNPN may be an initial registration for onboarding services in the SNPN. Additionally, or the registration procedure for onboarding services in the SNPN may be a registration procedure for registration update due to mobility when the UE is registered for onboarding services in the SNPN. The registration procedure for onboarding services in the SNPN may be expressed as SNPN onboarding registration.

[0112] In the registration procedure for the SNPN onboarding service, MM-based slice admission control for the S-NSSAI for the SNPN onboarding service may not be performed by the AMF or the NF in the core network.

[0113] A network slice (NS) is a logical network that provides specific network capabilities and network characteristics. A UE and / or a network can support a network slice (NW slice; NS) in 5GS. A network slice may also be simply referred to as a slice.

[0114] A network slice instance (NSI) is composed of an instance (entity) of a network function (NF) and a set of necessary resources, and forms a deployed network slice. Here, an NF is a processing function in a network, which is adopted or defined by 3GPP. An NSI is an entity of an NS, of which one or more are configured in a core network_B. An NSI may also be composed of a virtual network function (NF) generated using a network slice template (NST).

[0115] Here, an NST is associated with resource requirements for providing a required communication service or capability, and is a logical representation of one or more NFs. In other words, an NSI may be a collection within a core network_B190 configured with multiple NFs. An NSI may also be a logical network configured to separate user data delivered by services, etc. An NS may be configured with one or more NFs. An NF configured in an NS may or may not be a device shared with other NSs.

[0116] A UE and / or a device in the network may 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 NSI IDs, and / or an APN. The UE usage type is a parameter value included in the registration information of the UE that is 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.

[0117] Also, S-NSSAI (Single Network Slice Selection Assistance Information) is information for identifying an NS. S-NSSAI may be composed of only SST (Slice / Service type) or may be composed of both SST and SD (Slice Differentiator). Here, SST is information indicating the expected operation of an NS in terms of functions and services. Also, SD may be information for interpolating SST when selecting one NSI from multiple NSIs indicated by SST. S-NSSAI may be information specific to each PLMN or SNPN, or may be standard information common to PLMNs or SNPNs.

[0118] The S-NSSAI may also be transmitted and received between each device using the 5GS S-NSSAI IE, in which case the S-NSSAI may be composed of the S-NSSAI (SST and / or SD) associated with the current PLMN or SNPN, and / or the S-NSSAI (SST and / or SD) of the HPLMN (if any, e.g., when the UE is roaming or the current PLMN or SNPN is a VPLMN or SNPN).

[0119] The network may also store one or more S-NSSAIs in the registration information of the UE as default S-NSSAIs, and if the S-NSSAI is the default S-NSSAI, the network may provide the NS related to the UE when the UE does not send a valid S-NSSAI to the network in the registration request message.

[0120] Furthermore, the S-NSSAI transmitted and received between the UE and the NW may be expressed as an S-NSSAI IE (Information element). Furthermore, the S-NSSAI IE transmitted and received between the UE and the NW may be configured with an S-NSSAI configured with an SST and / or SD of a registered PLMN or SNPN, and / or an SST and / or SD indicating an S-NSSAI of an HPLMN or HSNPN to which the S-NSSAI is mapped. One or more S-NSSAIs stored by the UE and / or the NW may be configured with an SST and / or SD, or may be configured with an S-NSSAI configured with an SST and / or SD, and / or an SST and / or SD indicating an S-NSSAI of an HPLMN to which the S-NSSAI is mapped.

[0121] Moreover, NSSAI (Network Slice Selection Assistance Information) is a collection of S-NSSAI. Each S-NSSAI included in NSSAI is information to assist the access network or core network in selecting an NSI. The UE may store an NSSAI allowed by the network for each PLMN or SNPN. The NSSAI may be information used to select an AMF. The UE may apply each NSSAI (allowed NSSAI, and / or configured NSSAI, and / or rejected NSSAI, and / or pending NSSAI) to a PLMN and an EPLMN, or to an SNPN and an ESNPN.

[0122] A mapped S-NSSAI is an S-NSSAI of a HPLMN that is mapped to an S-NSSAI of a registered PLMN in a roaming scenario. The UE may store one or more mapped S-NSSAIs that are mapped to the configured NSSAI and the S-NSSAI included in the allowed NSSAI for each access type. In addition, the UE may store one or more mapped S-NSSAIs of the rejected NSSAI and / or the S-NSSAI included in the pending NSSAI.

[0123] If a roaming scenario of an SNPN is supported, the mapped S-NSSAI may be the S-NSSAI of the HSNPN mapped to the S-NSSAI of the registered SNPN.

[0124] The Network Slice-Specific Authentication and Authorization (NSSAA) function is a function for realizing authentication and authorization specific to a network slice. With network slice-specific authentication and authorization, authentication and authorization of a UE can be performed outside the core network, such as by a 3rd party. A PLMN or SNPN and a network device equipped with the NSSAA function can perform an NSSAA procedure for a certain S-NSSAI based on the registration information of the UE. Furthermore, a UE equipped with the NSSAA function can manage, store, and transmit / receive a pending NSSAI and a third rejected NSSAI. In this document, NSSAA may be referred to as a network slice-specific authentication and authorization procedure or an authentication and authorization procedure.

[0125] The S-NSSAI requiring an NSSAA is an S-NSSAI requiring an NSSAA that is managed by a core network and / or a core network device. Furthermore, during roaming, the S-NSSAI requiring an NSSAA may be an S-NSSAI other than the HPLMN or HSNPN, where the S-NSSAI of the HPLMN or HSNPN requiring an NSSAA that is managed by the core network and / or a core network device becomes the mapped S-NSSAI.

[0126] The core network and / or core network device may store an S-NSSAI that requires an NSSAA by associating the S-NSSAI with information indicating whether an NSSAA is required. The core network and / or core network device may further store an S-NSSAI that requires an NSSAA with information indicating whether the NSSAA has been completed, or information indicating that the NSSAA has been completed and is permitted or successful. The core network and / or core network device may manage an S-NSSAI that requires an NSSAA as information unrelated to the access network.

[0127] Also, a configured NSSAI is an NSSAI that is provisioned and stored in the UE. The UE may store a configured NSSAI for each PLMN or SNPN. The UE may store a configured NSSAI in association with a PLMN or SNPN.

[0128] In this document, a configured NSSAI associated with a PLMN may be expressed as a configured NSSAI for the PLMN, or a configured NSSAI of the PLMN, or a configured NSSAI for the PLMN, or a configured NSSAI associated with the PLMN. Similarly, a configured NSSAI associated with an SNPN may be expressed as a configured NSSAI for the SNPN, or a configured NSSAI of the SNPN, or a configured NSSAI for the SNPN, or a configured NSSAI associated with the SNPN.

[0129] Also, the UE may not be associated with a PLMN and may store a configured NSSAI that is valid for all PLMNs, and may refer to such configured NSSAI as the "default configured NSSAI." Similarly, the UE may not be associated with a SNPN and may store a configured NSSAI that is valid for all SNPNs, and may refer to such configured NSSAI as the "default configured NSSAI." The UE may not be associated with a PLMN or SNPN and may store a configured NSSAI that is valid for all PLMNs and SPNNs, and may refer to such configured NSSAI as the "default configured NSSAI."

[0130] The configured NSSAI may be associated with multiple PLMNs or SNPNs, where the multiple PLMNs may be EPLMNs and the multiple SNPNs may be ESNPNs.

[0131] The configured NSSAI may be information configured by the network (or PLMN or SNPN). The S-NSSAI included in the configured NSSAI may be expressed as the configured S-NSSAI. The configured S-NSSAI may be transmitted or received using the S-NSSAI IE, in which case the configured S-NSSAI may be configured to include the S-NSSAI (SST and / or SD) and the mapped S-NSSAI (SST of the mapped HPLMN or SNPN and / or SD of the mapped HPLMN or SNPN) (if any, e.g., when the UE is roaming or the associated PLMN or SNPN is a VPLMN or VSNPN).

[0132] Alternatively, the S-NSSAI (SST and / or SD) of the PLMN or SNPN and the S-NSSAI (SST and / or SD) of the HPLMN or SNPN may be treated independently. Specifically, the configured S-NSSAI of the PLMN or SNPN may be expressed as a "configured S-NSSAI for the PLMN or SNPN" or a "configured S-NSSAI of the PLMN or SNPN" or a "configured S-NSSAI for the PLMN or SNPN."

[0133] Furthermore, the one or more S-NSSAIs of the HPLMN or HSNPN to which the configured S-NSSAI is mapped may be expressed as "one or more mapped S-NSSAIs for the configured NSSAI of the PLMN or SNPN" or "one or more mapped S-NSSAIs of the configured NSSAI of the PLMN or SNPN."

[0134] In other words, the UE may store a "configured NSSAI of the current PLMN or SNPN" in which the S-NSSAI of the current PLMN or SNPN is configured, and may also store "one or more mapped S-NSSAIs for the configured NSSAI of the current PLMN or SNPN" when roaming. The one or more mapped S-NSSAIs for the configured NSSAI may be 3GPP's mapped S-NSSAI(s) for the configured NSSAI.

[0135] The configured NSSAI may be updated by the NW at any time, and the updated configured NSSAI may be transmitted from the NW to the UE based on the update.

[0136] In addition, the requested NSSAI is an NSSAI provided from the UE to the network during the registration procedure. In the registration procedure, the S-NSSAI included in the requested NSSAI sent by the UE may be the S-NSSAI included in the allowed NSSAI or the configured NSSAI stored by the UE.

[0137] The requested NSSAI may be information indicating a network slice requested by the UE. The S-NSSAI included in the requested NSSAI may be expressed as a requested S-NSSAI. For example, the requested NSSAI is transmitted and received in a NAS message or a Radio Resource Control (RRC) message including a Non-Access-Stratum (NAS) message transmitted from the UE to the network, such as a registration request message or a PDU session establishment request message. Here, in a roaming case, the requested NSSAI may include the S-NSSAI of the VPLMN and the S-NSSAI of the mapped HPLMN. In other words, the S-NSSAI (requested S-NSSAI) included in the requested NSSAI may be composed of the S-NSSAI and the mapped S-NSSAI.

[0138] The requested NSSAI may be information including one or more S-NSSAIs associated with a network slice requested by the UE. Note that the network slice requested by the UE may be a network slice that the UE wants to use, or a network slice that the UE requests to be allowed to use from the network. The S-NSSAI included in the requested NSSAI may be an S-NSSAI included in a configured NSSAI associated with the current PLMN, or an S-NSSAI included in an allowed NSSAI associated with the current PLMN.

[0139] In other words, the requested NSSAI may be an S-NSSAI included in a configured NSSAI associated with one or more current PLMNs, or an S-NSSAI included in an allowed NSSAI associated with one or more current PLMNs, or a combination of the two. More specifically, the allowed NSSAI associated with the current PLMN may be an allowed NSSAI associated with the current PLMN and the current access type. Furthermore, the requested NSSAI may be a 5GS requested NSSAI.

[0140] In addition, the S-NSSAI included in the requested NSSAI may be an S-NSSAI stored by the UE and not included in the rejected NSSAI associated with the current PLMN or SNPN, and / or an S-NSSAI stored by the UE and not included in the pending NSSAI associated with the current PLMN or SNPN, or an S-NSSAI stored by the UE and not included in the fourth rejected NSSAI associated with the current PLMN or SNPN.

[0141] Furthermore, the S-NSSAI included in the requested NSSAI may be an S-NSSAI for which the back-off timer associated with that S-NSSAI and / or the mapped S-NSSAI of that S-NSSAI is not running in the UE.

[0142] Also, the allowed NSSAI is information indicating one or more network slices for which the UE is allowed. In other words, the allowed NSSAI is information identifying a network slice to which the network allows the UE to connect. The allowed NSSAI may be an allowed NSSAI stored in the UE and / or NW, or may be an allowed NSSAI transmitted from the NW to the UE. In this case, the allowed NSSAI may refer to the allowed NSSAI IE of 3GPP.

[0143] The allowed NSSAI IE sent from the NW to the UE may include a list of S-NSSAIs of the current PLMN or SNPN that are valid for the current PLMN or SNPN when not roaming.

[0144] When roaming, the allowed NSSAI IE sent from the NW to the UE may include a list of S-NSSAIs of the current PLMN or SNPN that are valid for the current PLMN or SNPN, and may further include a list of mapped S-NSSAIs, which are the S-NSSAIs of the HPLMN or HSNPN to which the S-NSSAI of the current PLMN or SNPN is mapped.

[0145] In addition, a list of S-NSSAIs of the current PLMN or SNPN that are included in the allowed NSSAI IE and are valid for the current PLMN or SNPN may be referred to as the Allowed NSSAI, and a list of mapped S-NSSAIs that are S-NSSAIs of the HPLMN or HSNPN to which the S-NSSAI of the current PLMN or SNPN is mapped may be referred to as the list of mapped S-NSSAIs of the Allowed NSSAI. Here, the list of mapped S-NSSAIs of the Allowed NSSAI may be the mapped S-NSSAI(s) for the allowed NSSAI for a PLMN of 3GPP. Similarly, the Allowed NSSAI may mean the allowed NSSAI for a PLMN or an SNPN of 3GPP.

[0146] The UE and / or the NW may store and manage the allowed NSSAI for each access (3GPP access or non-3GPP access) as information of the UE. The UE and / or the NW may further manage the allowed NSSAI in association with a registration area.

[0147] Furthermore, the UE and / or NW may store and manage an allowed NSSAI in association with a PLMN or an SNPN as information of the UE. The allowed NSSAI may be associated with multiple PLMNs, where the multiple PLMNs may be EPLMNs, and the multiple SNPNs may be ESNPNs.

[0148] In this document, an allowed NSSAI associated with a PLMN or SNPN and an access type may be expressed as an "allowed NSSAI for a PLMN or SNPN and an access type" or an "allowed NSSAI for an access type of a PLMN or SNPN."

[0149] The S-NSSAI included in the allowed NSSAI may be expressed as the allowed S-NSSAI. The allowed S-NSSAI may be transmitted or received using the S-NSSAI IE, in which case the allowed S-NSSAI (SST and / or SD) may be comprised of the S-NSSAI and the mapped S-NSSAI (SST of the mapped HPLMN or SNPN and / or SD of the mapped HPLMN or SNPN) (if any, e.g., when the UE is roaming or the associated PLMN or SNPN is a VPLMN or VSNPN).

[0150] Alternatively, the S-NSSAI (SST and / or SD) of the PLMN or SNPN and the S-NSSAI (SST of the mapped HPLMN or SNPN and / or SD of the mapped HPLMN or SNPN) of the HPLMN or SNPN may be treated independently. Specifically, the Allowed S-NSSAI of the PLMN or SNPN may be expressed as "allowed S-NSSAI for the PLMN or SNPN" or "allowed S-NSSAI of the PLMN or SNPN" or "allowed S-NSSAI for the PLMN or SNPN."

[0151] Furthermore, one or more S-NSSAIs of the HPLMN or HSNPN to which the allowed S-NSSAI is mapped may be expressed as "one or more mapped S-NSSAIs for an allowed NSSAI of a PLMN or SNPN" or "one or more mapped S-NSSAIs of an allowed NSSAI of a PLMN or SNPN."

[0152] Also, the rejected NSSAI is information indicating one or more network slices that the UE is not permitted to use or request. In other words, the rejected NSSAI is information identifying a network slice to which the network does not permit the UE to connect. The rejected NSSAI transmitted from the NW to the UE may be included in the rejected NSSAI IE or the extended rejected NSSAI IE.

[0153] The rejected NSSAI transmitted and received using the rejected NSSAI IE may be information including one or more combinations of the S-NSSAI (SST and / or SD) and a rejection reason value (rejected S-NSSAI). The rejected NSSAI transmitted and received using the Extended rejected NSSAI IE may be information including one or more combinations of the S-NSSAI (SST and / or SD) and the mapped S-NSSAI (SST of the mapped HPLMN or SNPN and / or SD of the mapped HPLMN or SNPN) (if any, e.g., when the UE is roaming or when the associated PLMN or SNPN is a VPLMN or VSNPN) and a rejection reason value (rejected S-NSSAI) in roaming.

[0154] The Extended rejected NSSAI IE may include one or more Rejected S-NSSAs and / or NSSAI sets (5GS Partial extended rejected NSSAI list), and the Rejected S-NSSAI set may include information indicating the type of the set.

[0155] The information indicating the type of the set may be, for example, information indicating that the set includes one or more rejected S-NSSAIs (SST and / or SD) with associated back-off timer values, or information indicating that the set includes one or more rejected S-NSSAIs (SST and / or SD) without associated back-off timer values.

[0156] If the information indicating the type of the set is information indicating that the set contains one or more rejected S-NSSAIs with associated back-off timer values, the set of rejected S-NSSAIs may include a back-off timer value.

[0157] Here, the S-NSSAI included in the rejected NSSAI may be associated with a PLMN ID or an SNPN ID. Note that the PLMN or SNPN indicated by the PLMN ID or SNPN ID associated with the S-NSSAI included in the rejected NSSAI may be the current PLMN or the current SNPN. Alternatively, the PLMN ID or SNPN ID associated with the S-NSSAI included in the rejected NSSAI may be information indicating an HPLMN or an HSNPN, regardless of the current PLMN or SNPN.

[0158] Here, the rejection reason value is information indicating the reason why the network rejects the corresponding S-NSSAI or the combination of the corresponding S-NSSAI and the mapped S-NSSAI (if any). The UE and / or the network may store and manage each S-NSSAI and / or the mapped S-NSSAI (if any) as an appropriate rejected NSSAI and / or the mapped S-NSSAI of the rejected NSSAI based on the rejection reason value associated with each S-NSSA or the combination of the corresponding S-NSSAI and the mapped S-NSSAI.

[0159] Furthermore, the rejected NSSAI may be included in an NAS message transmitted from the network to the UE, such as a registration accept message, a configuration update command, a registration reject message, etc., or an RRC message including an NAS message. The S-NSSAI included in the rejected NSSAI may be expressed as the rejected S-NSSAI.

[0160] The rejected NSSAI may be transmitted using the Rejected NSSAI IE when the UE is roaming, or may be transmitted using the Extended rejected NSSAI IE. The Extended rejected NSSAI IE may include one or more rejected S-NSSAI (IEs) consisting of the S-NSSAI (SST and / or SD) of the current PLMN or SNPN, the mapped S-NSSAI (SST of the mapped HPLMN or SNPN and / or SD of the mapped HPLMN or SNPN) and a rejection reason value, and the UE may understand that the request to the NW for the received S-NSSAI of the current PLMN or SNPN together with the received mapped S-NSSAI has been rejected. On the other hand, the Rejected NSSAI IE may include a rejected S-NSSAI IE with the S-NSSAI of the current PLMN or SNPN and a rejection reason value, and the UE may understand that the request to the NW for the S-NSSAI associated with the received S-NSSAI of the current PLMN or SNPN, or the S-NSSAI of the HPLMN or HSNPN, has been rejected.

[0161] The rejected NSSAI may be any one of the first to fourth rejected NSSAIs, one or more mapped S-NSSAIs for the first rejected NSSAI, one or more mapped S-NSSAIs for the second rejected NSSAI, and one or more mapped S-NSSAIs for the fourth rejected NSSAI, or a combination thereof. The S-NSSAI included in the rejected NSSAI may be expressed as the rejected S-NSSAI. The rejected S-NSSAI may be transmitted and received between each device using the S-NSSAI IE, and the S-NSSAI IE indicating the rejected NSSAI may be configured to include the S-NSSAI and the mapped S-NSSAI.

[0162] The UE and / or NW may store and manage the rejected NSSAI associated with the PLMN or SNPN as information of the UE. The rejected NSSAI may be further associated with one or more other PLMNs or SNPNs, where the one or more other PLMNs may be EPLMNs and the one or more other SNPNs may be ESNPNs.

[0163] In this document, the rejected NSSAI associated with the PLMN or SNPN may be expressed as a rejected NSSAI for the PLMN or SNPN, a rejected NSSAI of the PLMN or SNPN, or a rejected NSSAI for the PLMN or SNPN. The UE and / or NW may further store the second rejected NSSAI and / or the second rejected S-NSSAI in association with the registration area. The UE and / or NW may store the second rejected NSSAI and / or the second rejected S-NSSAI in association with the access type and / or the registration area.

[0164] Here, the first rejected NSSAI is a set of one or more S-NSSAIs that are unavailable in the current PLMN or the current SNPN. The first rejected NSSAI may be a rejected NSSAI for the current PLMN or SNPN of 5GS, a rejected S-NSSAI for the current PLMN or SNPN, an S-NSSAI included in the rejected NSSAI for the current PLMN or SNPN, a mapped S-NSSAI(s) for rejected S-NSSAI for the current PLMN or SNPN, or an S-NSSAI included in the mapped S-NSSAI(s) for rejected S-NSSAI for the current PLMN or SNPN. The list (set) of mapped S-NSSAIs for the first rejected NSSAI may be one or more mapped S-NSSAIs for the first rejected NSSAI, or may be the 5GS mapped S-NSSAI(s) for the rejected NSSAI for the current PLMN or SNPN. The first rejected NSSAI may be a rejected NSSAI stored by the UE or NW, or may be a rejected NSSAI transmitted from the NW to the UE.

[0165] When the first rejected NSSAI is a rejected NSSAI transmitted from the NW to the UE, it includes one or more S-NSSAIs that are rejected because they are not available in the current PLMN or the current SNPN among the S-NSSAIs included in the requested NSSAI transmitted by the UE to the NW. In this case, the first rejected NSSAI may be information including one or more combinations of an S-NSSAI and a rejection reason value. The rejection reason value at this time may be "S-NSSAI not available in the current PLMN or SNPN" and may be information indicating that the S-NSSAI associated with the rejection reason value is not available in the current PLMN or SNPN. The S-NSSAI included in the first rejected NSSAI may be expressed as a first rejected S-NSSAI.

[0166] If the first rejected NSSAI is a rejected NSSAI sent from the NW to the UE, the first rejected NSSAI may be transmitted and received in a rejected NSSAI IE or an extended rejected NSSAI IE. The rejected NSSAI IE or the extended rejected NSSAI IE may include at least one combination of the S-NSSAI of the current PLMN or SNPN and a rejection reason value. If the UE is roaming, the combination may further include a mapped S-NSSAI, which is the S-NSSAI of the HPLMN.

[0167] In other words, in a roaming case, the first rejected NSSAI sent from the NW to the UE may include at least one combination of the S-NSSAI of the current PLMN or SNPN, the mapped S-NSSAI, and a rejection reason value.

[0168] The first rejected NSSAI may be applied to the entire registered PLMN or the entire registered SNPN. The UE and / or NW may treat the first rejected NSSAI and the S-NSSAI included in the first rejected NSSAI as information that does not depend on the access type. In other words, the first rejected NSSAI may be information that is valid for 3GPP access and non-3GPP access.

[0169] The UE may delete the first rejected NSSAI from memory when the UE transitions to an unregistered state in both 3GPP access and non-3GPP access for the current PLMN. In other words, when the UE transitions to an unregistered state for the current PLMN via an access, or when the UE successfully registers to a new PLMN via an access, or when the UE fails to register to the new PLMN via an access and transitions to an unregistered state, and when the UE is not registered via the other access (unregistered state), the UE deletes the first rejected NSSAI. In other words, when the UE transitions to an unregistered state for the current PLMN via an access, and when the UE is registered to the current PLMN via the other access (registered state), the UE does not need to delete the first rejected NSSAI.

[0170] The S-NSSAI or the first rejected NSSAI included in the first rejected NSSAI may be the S-NSSAI of the current PLMN. In other words, the S-NSSAI or the first rejected NSSAI included in the first rejected NSSAI may be associated with only the current PLMN ID or SNPN ID and may be stored and / or managed and / or transmitted and received. Further / or, the S-NSSAI included in the first rejected NSSAI may be the S-NSSAI of the HPLMN or the S-NSSAI of the current PLMN.

[0171] The second rejected NSSAI is a set of one or more S-NSSAIs that are unavailable in the current registration area. The second rejected NSSAI may be a rejected NSSAI of 5GS for the current registration area, may be a mapped S-NSSAI(s) for rejected NSSAI for the current registration area, or may be an S-NSSAI included in the mapped S-NSSAI(s) for rejected NSSAI for the current registration area. The list (set) of mapped S-NSSAI of the second rejected NSSAI may be one or more mapped S-NSSAIs for the second rejected NSSAI, or may be the mapped S-NSSAI(s) of 5GS for the rejected NSSAI for the current registration area. The second rejected NSSAI may be a rejected NSSAI stored by the UE or NW, or may be a rejected NSSAI transmitted from the NW to the UE. When the second rejected NSSAI is a rejected NSSAI transmitted from the NW to the UE, the second rejected NSSAI may be information including one or more combinations of an S-NSSAI and a reason value. In this case, the rejection reason value may be "S-NSSAI not available in the current registration area" and may be information indicating that the S-NSSAI associated with the reason value is not available in the current registration area. The S-NSSAI included in the second rejected NSSAI may be expressed as a second rejected S-NSSAI.

[0172] If the second rejected NSSAI is a rejected NSSAI sent from the NW to the UE, the UE includes one or more S-NSSAIs that were rejected because they are not available in the current registration area among the S-NSSAIs included in the requested NSSAI by the UE. In this case, the second rejected NSSAI may be transmitted and received in a rejected NSSAI IE or an extended rejected NSSAI IE. The rejected NSSAI IE or the extended rejected NSSAI IE may include at least one combination of the S-NSSAI of the current PLMN or SNPN and a rejection reason value. If the UE is roaming, the combination may further include a mapped S-NSSAI, which is the S-NSSAI of the HPLMN.

[0173] In other words, in a roaming case, the second rejected NSSAI sent from the NW to the UE may include at least one combination of the S-NSSAI of the current PLMN or SNPN, the mapped S-NSSAI, and a rejection reason value.

[0174] The second rejected NSSAI may be valid in the current registration area and may be applied to the current registration area. The UE and / or NW may treat the second rejected NSSAI and the S-NSSAI included in the second rejected NSSAI as information for each access type. That is, the second rejected NSSAI may be information valid for each of 3GPP access and non-3GPP access. That is, once the UE transitions to an unregistered state for an access, the UE may delete the second rejected NSSAI associated with the access from memory.

[0175] The S-NSSAI or the second rejected NSSAI included in the second rejected NSSAI may be the S-NSSAI of the current PLMN. In other words, the S-NSSAI or the second rejected NSSAI included in the second rejected NSSAI may be associated with only the current PLMN ID or SNPN ID and may be stored and / or managed and / or transmitted / received. Or, the S-NSSAI included in the second rejected NSSAI may be the S-NSSAI of the HPLMN or the S-NSSAI of the current PLMN.

[0176] The third rejected NSSAI is a set of one or more S-NSSAIs that require an NSSAA and for which the NSSAA for the S-NSSAI has failed or been revoked. The third rejected NSSAI may be an NSSAI stored by the UE and / or the NW, or may be an NSSAI transmitted and received between the NW and the UE. When the third rejected NSSAI is transmitted from the NW to the UE, the third rejected NSSAI may be information including one or more combinations of an S-NSSAI and a rejection reason value. The rejection reason value at this time may be "S-NSSAI not available due to the failed or revoked NSSAA" or may be information indicating that the NSSAA for the S-NSSAI associated with the rejection reason value has failed or been revoked. The S-NSSAI included in the third rejected NSSAI may be expressed as the third rejected S-NSSAI.

[0177] If the third rejected NSSAI is an NSSAI sent from the NW to the UE, the third rejected NSSAI may be transmitted or received using a rejected NSSAI IE or an extended rejected NSSAI IE.

[0178] The third rejected NSSAI may apply to a registered PLMN or a registered SNPN, or may apply to a registered PLMN and / or EPLMN, or may apply to a registered SNPN and / or ESNPN, or may apply to all PLMNs or SNPNs. The third rejected NSSAI applies to all PLMNs may mean that the third rejected NSSAI is not associated with a PLMN, or may mean that the third rejected NSSAI is associated with a HPLMN or HSNPN.

[0179] Furthermore, the UE and / or NW may treat the third rejected NSSAI and the third rejected S-NSSAI as information independent of the access type. That is, the third rejected NSSAI may be information valid for 3GPP access and non-3GPP access. The third rejected NSSAI may be an NSSAI different from the rejected NSSAI. The third rejected NSSAI may be the first rejected NSSAI. The third rejected NSSAI may be the rejected NSSAI for the failed or revoked NSSAA of 5GS, the rejected S-NSSAI for the failed or revoked NSSAA, or the S-NSSAI included in the rejected NSSAI for the failed or revoked NSSAA.

[0180] The third rejected NSSAI is a rejected NSSAI that identifies a slice that the UE has rejected due to a failure or revocation of the NSSAA from the core network. Specifically, while the UE stores the third rejected NSSAI, the UE does not initiate a registration request procedure for the S-NSSAI included in the third rejected NSSAI. The third rejected NSSAI may be identification information including one or more S-NSSAIs received from the core network in association with a rejection reason value indicating a failure of the NSSAA.

[0181] The third rejected NSSAI is information that does not depend on the access type. Specifically, when the UE stores the third rejected NSSAI, the UE does not need to attempt to transmit a registration request message including the S-NSSAI included in the third rejected NSSAI to both 3GPP access and non-3GPP access. Alternatively, the UE can transmit a registration request message including the S-NSSAI included in the third rejected NSSAI based on a UE policy.

[0182] Alternatively, the UE may delete the third rejected NSSAI based on the UE policy and transition to a state in which the UE can transmit a registration request message including an S-NSSAI included in the third rejected NSSAI. In other words, when the UE transmits a registration request message including an S-NSSAI included in the third rejected NSSAI based on the UE policy, the UE may delete the S-NSSAI from the third rejected NSSAI.

[0183] During roaming, the S-NSSAI included in the third rejected NSSAI may be the S-NSSAI of the HPLMN. In other words, the third rejected NSSAI received by the UE from the VPLMN or VSNPN may include the S-NSSAI of the HPLMN or HSNPN.

[0184] In other words, the UE and / or each device may store the "third rejected NSSAI" in which the S-NSSAI of the HPLMN or HSNPN is configured. That is, even during roaming, the "third rejected NSSAI" may be stored without being associated with the mapped S-NSSAI.

[0185] The fourth rejected NSSAI is information including one or more S-NSSAIs that have reached the maximum number of UEs per network slice. The fourth rejected NSSAI may be an NSSAI stored by the UE and / or the NW, or may be an NSSAI transmitted from the NW to the UE.

[0186] The fourth rejected NSSAI may be a 5GS rejected NSSAI for the maximum number of UEs reached, may be a rejected S-NSSAI for the maximum number of UEs reached, may be an S-NSSAI included in the rejected NSSAI for the maximum number of UEs reached, may be a mapped S-NSSAI(s) for the maximum number of UEs reached, or may be an S-NSSAI included in the mapped S-NSSAI(s) for the maximum number of UEs reached. The list (set) of mapped S-NSSAI for the fourth rejected NSSAI may be one or more mapped S-NSSAI for the fourth rejected NSSAI, or may be a 5GS mapped S-NSSAI(s) for the maximum number of UEs reached.

[0187] When the fourth rejected NSSAI is transmitted from the NW to the UE, the fourth rejected NSSAI may include one or more pieces of information including at least one of an S-NSSAI (SST and / or SD), a mapped S-NSSAI (SST and / or SD) (if any), a rejection reason value, and a back-off timer value. In this case, the rejection reason value may be "S-NSSAI not available due to maximum number of UEs reached per network slice" or may be information indicating that the S-NSSAI associated with the rejection reason value can be notified as an Allowed NSSAI or that the maximum number of allowed UEs has been reached.

[0188] Here, the rejection reason value may be a rejection reason value included in the rejected NSSAI. Furthermore, at this time, the back-off timer value may be information indicating a period during which the UE is prohibited from transmitting an MM message using the S-NSSAI of the current PLMN or SNPN associated with one or more S-NSSAIs and / or one or more mapped S-NSSAIs associated with the back-off timer value.

[0189] The fourth rejected NSSAI may apply to a registered PLMN and / or EPLMN, or may apply to a registered SNPN and / or ESNPN, or may apply to one or more PLMNs or SNPNs to which a TAI included in the TA list (TAI list or registration area) belongs.

[0190] The UE and / or NW may treat the fourth rejected NSSAI and the S-NSSAI included in the fourth rejected NSSAI as information for each access type.

[0191] When the fourth rejected NSSAI is an NSSAI transmitted from the NW to the UE, the fourth rejected NSSAI may be transmitted or received using a rejected NSSAI IE or an extended rejected NSSAI IE.

[0192] When the first to fourth rejected NSSAIs are transmitted or received using the rejected NSSAI IE or the extended rejected NSSAI IE, the rejected NSSAI IE and the extended rejected NSSAI IE may include a list of rejected S-NSSAIs.

[0193] When the first to fourth rejected NSSAIs are transmitted and received using the rejected NSSAI IE, the list of rejected S-NSSAIs included in the rejected NSSAI IE may be one or more 5GS Rejected S-NSSAIs. The Rejected S-NSSAI may be configured with the S-NSSAI (SST and / or SD) of the current PLMN or SNPN and the corresponding rejection reason value.

[0194] When the first to fourth rejected NSSAIs are transmitted and received using an Extended rejected NSSAI IE, the list of rejected S-NSSAIs included in the Extended rejected NSSAI IE may be a 5GS Partial extended rejected NSSAI list.

[0195] The rejected S-NSSAI list includes a first type list that does not include a back-off timer value and a second type list that includes a back-off timer value that applies to all S-NSSAIs included in the rejected S-NSSAI list. One or more first type lists and / or one or more second type lists may be configured in the Extended rejected NSSAI IE.

[0196] The first type list may include information indicating that the list is the first type and one or more 5GS Rejected S-NSSAIs. The Rejected S-NSSAI may include the S-NSSAI (SST and / or SD) of the current PLMN or SNPN and a corresponding rejection reason value. Furthermore, the Rejected S-NSSAI may include a mapped S-NSSAI (SST and / or SD).

[0197] The information indicating that the list is of a first type may mean that the list includes one or more S-NSSAIs not with corresponding back-off timer values, in other words, that the list does not include back-off timer values ​​corresponding to one or more S-NSSAIs included in the list.

[0198] The second type list may include information indicating that the list is of the second type, a back-off timer value, and one or more 5GS Rejected S-NSSAIs. The Rejected S-NSSAI may include the S-NSSAI (SST and / or SD) of the current PLMN or SNPN and a corresponding rejection reason value. Furthermore, the Rejected S-NSSAI may include a mapped S-NSSAI (SST and / or SD).

[0199] The information indicating that the list is of the second type may be information indicating that the list contains one or more S-NSSAIs and corresponding back-off timer values, and that the back-off timer value applies to all S-NSSAIs.

[0200] In addition, the back-off timer value included in the second type list may be a value that is applied to all S-NSSAIs included in the same second type list.

[0201] The pending NSSAI may be a pending NSSAI of 5GS. The pending NSSAI may be an NSSAI stored by the UE and / or the NW, or may be an NSSAI transmitted and received between the NW and the UE.

[0202] If the pending NSSAI is an NSSAI sent from the NW to the UE, the pending NSSAI may be sent or received using a pending NSSAI IE configured with one or more S-NSSAI IEs, which may include the S-NSSAI (SST and / or SD) and the mapped S-NSSAI (SST of the mapped HPLMN or HSNPN and / or SD of the mapped HPLMN or HSNPN) (if any, e.g., when the UE is roaming or the associated PLMN or SNPN is a VPLMN or VSNPN).

[0203] The pending NSSAI may apply to the entire registered PLMN or registered SNPN, or may apply to the registered PLMN and one or more EPLMNs of the registered PLMN, or may apply to the registered SNPN and one or more ESNPNs of the registered SNPN.

[0204] The UE and / or NW may treat the S-NSSAI included in the pending NSSAI as information independent of the access type, that is, the pending NSSAI may be common information for 3GPP access and non-3GPP access.

[0205] The pending NSSAI is an NSSAI consisting of one or more S-NSSAIs that identify slices for which the UE is pending a procedure. Specifically, while the UE stores the pending NSSAI, the UE does not initiate a registration request procedure for an S-NSSAI included in the pending NSSAI or a mapped S-NSSAI of the pending NSSAI.

[0206] In other words, the UE does not use the S-NSSAI included in the pending NSSAI during the registration procedure until the NSSAA for the S-NSSAI included in the stored pending NSSAI is completed. The pending NSSAI is information independent of the access type. Specifically, when the UE stores the pending NSSAI, the UE does not attempt to transmit a registration request message including the S-NSSAI included in the pending NSSAI to both 3GPP access and non-3GPP access.

[0207] During roaming (roaming scenario), the S-NSSAI included in the pending NSSAI stored by the UE may be the S-NSSAI of the HPLMN or HSNPN. In other words, the pending NSSAI IE received by the UE from the VPLMN or VSNPN may include the S-NSSAI of the HPLMN or SNPN. Such a pending NSSAI may be referred to as a first pending NSSAI.

[0208] In other words, a UE that stores a first pending NSSAI does not store a mapped S-NSSAI for the first pending NSSAI, and the S-NSSAI configured in the first pending NSSAI stored by the UE is the S-NSSAI of the HPLMN or HSNPN regardless of whether the UE is roaming or not.

[0209] However, when the first pending NSSAI is sent from the NW to the UE, in other words, when the UE receives a pending NSSAI from the NW, the pending NSSAI IE including the pending NSSAI may include the mapped S-NSSAI of the current S-NSSAI or may include only the mapped S-NSSAI.

[0210] On the other hand, during roaming (roaming scenario), the S-NSSAI included in the pending NSSAI stored by the UE may be the S-NSSAI of the current PLMN (VPLMN) or SNPN (VSNPN). In other words, the pending NSSAI received by the UE from the VPLMN or VSNPN may include the S-NSSAI of the VPLMN or VSNPN. Such a pending NSSAI may be referred to as a second pending NSSAI.

[0211] In other words, when roaming, there may be one or more mapped S-NSSAIs for the second pending NSSAI. The S-NSSAI configured in the second pending NSSAI may be the S-NSSAI of the current PLMN or SNPN regardless of whether roaming or not.

[0212] In this document, a reference to a pending NSSAI may mean the first pending NSSAI, the second pending NSSAI, both pending NSSAIs, or any other pending NSSAI.

[0213] A tracking area 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 a range in which control messages such as paging are broadcast, or a range 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 to these. Hereinafter, a tracking area may be a TA (Tracking Area). A tracking area may be identified by a TAI (Tracking Area Identity) composed of a TAC (Tracking area code) and a PLMN.

[0214] A registration area is a collection of one or more TAs that the AMF assigns to a UE. 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 a signal for tracking area update. In other words, a registration area may be a group of information indicating an area in which UE_A10 can move without performing a tracking area update procedure. A registration area may be identified by a TAI list consisting of one or more TAIs.

[0215] The TAIs included in the TAI list may belong to one PLMN or to multiple PLMNs. If multiple TAIs included in the TAI list belong to different PLMNs, those PLMNs may be EPLMNs.

[0216] The UE ID is information for identifying a UE. Specifically, for example, the UE ID may be a SUCI (Subscription Concealed Identifier), or a SUPI (Subscription Permanent Identifier), or a GUTI (Globally Unique Temporary Identifier), or an IMEI (International Mobile Subscriber Identity), or an IMEISV (IMEI Software Version), or a TMSI (Temporary Mobile Subscriber Identity). Alternatively, the UE ID may be other information set in an application or a network. Furthermore, the UE ID may be information for identifying a user.

[0217] The management of the maximum number of UEs connected to a slice refers to managing and / or controlling the maximum number of UEs that can be registered in a network slice or an S-NSSAI at the same time, or managing and / or controlling the maximum number of UEs that can establish a PDU session using a network slice or an S-NSSAI at the same time. The management of the maximum number of UEs connected to a slice may be NSAC (network slice admission control) of 5GS. NSAC may be expressed as slice admission control.

[0218] The management and / or control of the maximum number of UEs that can be simultaneously registered in a network slice or an S-NSSAI may be expressed as MM-based slice admission control (Mobility management based slice admission control). The management and / or control of the maximum number of UEs that can simultaneously establish a PDU session using a network slice or an S-NSSAI may be expressed as SM-based slice admission control (Session management based slice admission control). Slice admission control may mean NSAC (Network Slice Admission Control).

[0219] Here, a UE to be registered in a network slice or an S-NSSAI may be stored by including an S-NSSAI indicating a network slice in an allowed NSSAI. A device in a network that supports a function of managing the maximum number of UEs connected to a slice or a function of managing and / or controlling the maximum number of UEs that can be simultaneously registered in a network slice or an S-NSSAI may store, for each S-NSSAI, whether or not management of the maximum number of UEs connected to a slice is required, and may further check whether or not the number of registered UEs has reached a constant, which is the maximum number, during a registration procedure.

[0220] Further, each device that supports a function of managing the maximum number of UEs connected to a slice, or a function of managing and / or controlling the maximum number of UEs that can be simultaneously registered in a network slice or an S-NSSAI, may be capable of storing a fourth rejected NSSAI. In this document, the maximum number of UEs connected to a slice may be expressed as the maximum number of UEs connected per slice, or the maximum number of UEs that can be registered in a network slice or an S-NSSAI, or the maximum number of UEs, or a constant.

[0221] SSC (Session and Service Continuity) is a technique for maintaining a session and / or a service. Here, a session may refer to a PDU session established between a UE and a NW, and a service may refer to a service provided to a UE by a PDU session established between a UE and a NW. Various modes may exist.

[0222] In other words, the SSC (Session and Service Continuity) mode indicates a mode of service session continuity supported by a system and / or each device in 5GC. More specifically, it may be a mode indicating a type of service session continuity supported by a PDU session established between UE_A10 and an anchor point.

[0223] Here, the anchor point may be a UPGW or a UPF. The UPF may be a terminating user-plane function (TUPF). The TUPF is a UPF at the end of each interface and has a PDU session anchor function. In other words, the anchor point may be a PDU session anchor.

[0224] For SSC, switching the anchor point may be referred to as anchor relocation and / or PDU session anchor change, which may also be referred to as anchor relocation procedure and PDU session anchor change procedure.

[0225] In anchor relocation, the PDU session established in the initial state may be referred to as the first PDU session, and the PDU session established after the procedure is completed may be referred to as the second PDU session.

[0226] In addition, the SSC mode may be a mode indicating a type of service session continuity set for each PDU session. In other words, the SSC mode may be associated with the PDU session.

[0227] And / or, the SSC mode may be associated with an anchor point and controlled so that it cannot be changed while the PDU session is established. During the lifetime of the PDU session, the SSC mode associated with the PDU session may not be changed. Each SSC mode is described below.

[0228] SSC mode 1 is a service session continuity mode in which the same UPF is maintained as the anchor point regardless of the access technology, such as the RAT (Radio Access Technology) or cell, that UE_A10 uses when connecting to the network. More specifically, SSC mode 1 may be a mode that realizes service session continuity without changing the anchor point used by the established PDU session even when mobility of UE_A10 occurs.

[0229] SSC mode 2 is a service session continuation mode in which, when a PDU session includes one anchor point, the PDU session is first released and then a new PDU session is established. More specifically, SSC mode 2 is a mode in which, when an anchor point relocation occurs, the PDU session is deleted once and then a new PDU session is established.

[0230] SSC mode 2 is a service session continuity mode in which the same UPF is maintained as an anchor point only within the serving area of ​​the UPF. More specifically, SSC mode 2 may be a mode that realizes service session continuity without changing the UPF used by the established PDU session as long as UE_A10 is within the serving area of ​​the UPF. Furthermore, SSC mode 2 may be a mode that realizes service session continuity by changing the UPF used by the established PDU session when mobility of UE_A10 occurs, such as moving out of the serving area of ​​the UPF.

[0231] Here, the serving area of ​​the UPF may be an area where one UPF can provide a service session continuity function, or may be a subset of an access network such as a RAT or a cell used when UE_A10 connects to a network. Furthermore, the subset of the access network may be a network composed of one or more RATs and / or cells, or may be a TA.

[0232] In the case of continuing a session in SSC mode 2, if a change in S-NSSAI is not permitted, it may be referred to as a first SSC mode 2. On the other hand, in the case of continuing a session in SSC mode 2, if a change in S-NSSAI is permitted, it may be referred to as a second SSC mode 2. In other words, a case of continuing a session in SSC mode 2 while changing the S-NSSAI or the network slice may be referred to as a second SSC mode 2. In other words, a case of continuing a PDU session in SSC mode 2 while changing the S-NSSAI or the network slice may be referred to as a second SSC mode 2. When simply referred to as SSC mode 2, it may mean the first SSC mode 2 and / or the second SSC mode 2.

[0233] SSC mode 3 is a service session continuity mode in which a PDU session between a UE and an anchor point can be established for the same DN between the UE and the anchor point without releasing the PDU session between the UE and the anchor point.

[0234] SSC mode 3 is a service session continuity mode that allows a new PDU session and / or communication path to be established via a new UPF for the same DN before disconnecting the PDU session and / or communication path established between UE_A10 and the UPF. Furthermore, SSC mode 3 may be a service session continuity mode that allows UE_A10 to be multi-homing.

[0235] And / or, SSC mode 3 may be a mode in which service session continuity using multiple PDU sessions and / or UPFs associated with the PDU sessions is permitted. In other words, in the case of SSC mode 3, each device may realize service session continuity using multiple PDU sessions, or may realize service session continuity using multiple UPFs.

[0236] In the case of continuing a session in SSC mode 3, if a change in S-NSSAI is not permitted, it may be referred to as a first SSC mode 3. On the other hand, in the case of continuing a session in SSC mode 3, if a change in S-NSSAI is permitted, it may be referred to as a second SSC mode 3. In other words, a case of continuing a session in SSC mode 3 while changing the S-NSSAI or the network slice may be referred to as a second SSC mode 3. In other words, a case of continuing a PDU session in SSC mode 3 while changing the S-NSSAI or the network slice may be referred to as a second SSC mode 3. When simply referred to as SSC mode 3, it may mean the first SSC mode 3 and / or the second SSC mode 3.

[0237] SSC mode 4 may be a second SSC mode 2.

[0238] In other words, SSC mode 4 is a service session continuation mode in which, when a PDU session includes one anchor point, the PDU session is first released and then established while changing the S-NSSAI or network slice. More specifically, SSC mode 4 is a mode in which, when an anchor point relocation occurs, the PDU session is deleted once while changing the S-NSSAI or network slice, and then a new PDU session is established.

[0239] SSC mode 4 is a service session continuity mode in which the same UPF is maintained as an anchor point while changing the S-NSSAI or network slice only within the serving area of ​​the UPF. More specifically, SSC mode 4 may be a mode that realizes service session continuity without changing the UPF used by the established PDU session while changing the S-NSSAI or network slice as long as UE_A10 is within the serving area of ​​the UPF. Furthermore, SSC mode 4 may be a mode that realizes service session continuity by changing the UPF used by the established PDU session while changing the S-NSSAI or network slice when mobility of UE_A10 occurs, such as moving out of the serving area of ​​the UPF.

[0240] Here, the serving area of ​​the UPF may be an area where one UPF can provide a service session continuity function, or may be a subset of an access network such as a RAT or a cell used when UE_A10 connects to a network. Furthermore, the subset of the access network may be a network composed of one or more RATs and / or cells, or may be a TA.

[0241] SSC mode 5 may be a second SSC mode 3.

[0242] In other words, SSC mode 5 is a service session continuity mode that allows a PDU session to be established between a new anchor point and a UE for the same DN while changing the S-NSSAI or network slice without releasing the PDU session between the UE and the anchor point.

[0243] SSC mode 5 is a service session continuity mode that allows a new PDU session and / or communication path to be established via a new UPF for the same DN before disconnecting a PDU session and / or communication path established between UE_A10 and the UPF while changing the S-NSSAI or network slice. Furthermore, SSC mode 5 may be a service session continuity mode that allows UE_A10 to be multi-homing.

[0244] And / or, SSC mode 5 may be a mode in which service session continuity using multiple PDU sessions and / or UPFs associated with the PDU sessions is permitted. In other words, in the case of SSC mode 5, each device may realize service session continuity using multiple PDU sessions, or may realize service session continuity using multiple UPFs.

[0245] The first identity may be information indicating a new S-NSSAI. The first identity may be information indicating an updated or modified S-NSSAI. The first identity may be information indicating an S-NSSAI with which the newly established second PDU session is associated. The first identity may be an S-NSSAI assigned by the network to the second PDU session and / or the UE.

[0246] The S-NSSAI indicated by the first identification information may be the same S-NSSAI as the S-NSSAI associated with the first PDU session, or may be a different S-NSSAI. The SST of the S-NSSAI indicated by the first identification information may be the same as the SST of the S-NSSAI associated with the first PDU session, or may be different.

[0247] And / or, the first identification information is information indicating updated or changed preference information. The first identification information may be information for notifying the network of an update or change of preference information of a route or anchor point included in the PDU session.

[0248] The second identification information is information indicating a reason. The second identification information may be a reason value, and may be a 5GSM cause IE. The second identification information may be information indicating an update or change of Preference information. In other words, the second identification information may be information indicating that the network has updated or changed the Preference information. Furthermore, the second identification information may be information indicating an update or change of a PDU session due to the movement of the UE. In other words, the second identification information may be information indicating that the network has updated or changed information related to the PDU session in accordance with an update of the UE location information. For example, the second identification information may be information indicating that the S-NSSAI related to the PDU session is no longer available, or a change of the S-NSSAI.

[0249] The second identification information may be 5GSM cause #39 "reactivation requested" or may be information indicated by 5GSM cause #39 "reactivation requested".

[0250] The eleventh identity is information indicating a new S-NSSAI. The eleventh identity may be associated with a PDU session ID that is transmitted and received together. The eleventh identity may be the same as the first identity.

[0251] The twelfth identity may be a cause value. The twelfth identity may be information indicating a request to initiate a PDU session establishment procedure for re-establishment of a PDU session for the same DN. Further, the twelfth identity may be information indicating a request to initiate a PDU session establishment procedure for re-establishment of a PDU session for the same S-NSSAI, or may be information indicating a request to initiate a PDU session establishment procedure for re-establishment of a PDU session for a different S-NSSAI.

[0252] The 12th identification information may be 5GSM cause #39 "reactivation requested" or may be information indicated by 5GSM cause #39 "reactivation requested".

[0253] The 21st identification information may be the requested S-NSSAI information. The 21st identification information may be null information. The 21st identification information may be the S-NSSAI notified from the NW. Specifically, the S-NSSAI included in the 21st identification information may be the S-NSSAI indicated by the first identification information and / or the 11th identification information.

[0254] The 22nd identification information may be information indicating a requested SSC mode. The 22nd identification information may indicate at least one of SSC mode 1 to SSC mode 5.

[0255] The 23rd identification information may be information indicating whether the UE supports a change in the S-NSSAI due to anchor relocation. The 23rd identification information may be information indicating that the UE supports a change in the S-NSSAI due to anchor relocation. The 23rd identification information may be, for example, information included in the 5GSM capability IE and / or the 5GSM capability IE.

[0256] The 31st identification information may be information indicating whether the NW and / or the established PDU session supports the change of the S-NSSAI due to anchor relocation. The 31st identification information may be information indicating that the NW and / or the established PDU session supports the change of the S-NSSAI due to anchor relocation. The 31st identification information may be capability information, for example, 5GS network feature support and / or information included in 5GS network feature support.

[0257] The 31st identification information may be associated with the SSC mode and / or PDU session ID and / or anchor point transmitted and received together.

[0258] The 32nd identity may indicate that the NW has changed the S-NSSAI due to anchor relocation. The 32nd identity may be a changed S-NSSAI. The 32nd identity may be an S-NSSAI IE.

[0259] The 35th identification information may be information indicating that the NW does not support changing the S-NSSAI due to anchor relocation and / or information indicating that the PDU session cannot be established because the NW does not support changing the S-NSSAI due to anchor relocation. The 35th identification information may be a cause value, for example, a 5GSM cause IE.

[0260] The 35th identification information may be 5GSM cause #39 "reactivation requested" or may be information indicated by 5GSM cause #39 "reactivation requested".

[0261] [3. Description of procedures used in each embodiment] Next, the procedures used in each embodiment will be described. The procedures used in each embodiment include a PDU session change procedure, a PDU session release procedure, and / or a PDU session establishment procedure. Each procedure will be described below.

[0262] In each embodiment, as shown in FIG. 2, the case where 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 (i.e., the same physical hardware, or the same logical hardware, or the same software) will be described as an example. However, the contents described in this embodiment are also applicable to the case where these are configured as different devices (i.e., different physical hardware, or different logical hardware, or different software). For example, data may be transmitted and received directly between these, or data may be transmitted and received via the N26 interface between the AMF and MME, or data may be transmitted and received via the UE.

[0263] [3.1. PDU Session Change Procedure] Next, the behavior of each device when the NW executes the PDU session change procedure will be described with reference to FIG. 6. Hereinafter, the PDU session change procedure may be referred to as this procedure. The PDU session change procedure may also be an SM procedure.

[0264] This procedure is a procedure for each device to update the state of a PDU session. Each device may execute this procedure after completing the PDU session establishment procedure, or may execute it during the PDU session establishment procedure. Each device may start this procedure in a registered state, or may start this procedure at any time after the PDU session establishment procedure. Each device may update the state of a PDU session based on the completion of a PDU session change procedure. Furthermore, when multiple PDU sessions are established, each device may update the state of each PDU session by executing this procedure multiple times.

[0265] Each step of this procedure will be described below. The SMF sends a PDU session modification command message to the UE via the AMF (S802) (S804). Specifically, the SMF_A230 sends a PDU session modification command message to the AMF using the N11 interface (S802), and the AMF that receives the PDU session modification command message sends a PDU session modification command message to the UE using the N1 interface (S804).

[0266] The trigger for the SMF to send a PDU session change command message may be the receipt of a state change notification message sent from the AMF, the receipt of a request message from the AF, or the detection of a state change in the SMF itself.

[0267] In addition, the trigger for the SMF to send a PDU session change command message may be that the SMF and / or AMF detect that the use of the S-NSSAI associated with the PDU session is no longer permitted. When the AMF detects that the use of the S-NSSAI is no longer permitted, the SMF may receive a state change notification message from the AMF.

[0268] Furthermore, the PDU session change command message may be a NAS message transmitted and received on the N11 interface and the N1 interface, or may be transmitted and received as part of a NAS message. Furthermore, the PDU session change command message is not limited to this, and may be any message indicating that a PDU session change has been decided.

[0269] Furthermore, the state change notification message may be a message sent by the AMF to the SMF using the N11 interface, and may be information indicating that the state of the UE has changed due to the mobility of the UE, etc. Furthermore, the state change notification message may be information indicating that the state of the UE and / or the network device has changed due to changes in the subscriber information, and / or the operator policy, and / or the UE policy. Furthermore, the request message from the AF may be a request message sent from the AF, or may be a request message sent by another network device on its behalf.

[0270] Here, the SMF may include at least one or more of the first and second identification information in the PDU session change command message, or may indicate the SMF's request by including these identification information.

[0271] Furthermore, the SMF may request a change in the PDU session destination or information related to the PDU session by transmitting one or more of the first and second identities. More specifically, the SMF may request an update of preference information, request a change in the default route, or notify a mobility change by transmitting the second identity and / or transmitting the second identity in association with the first identity.

[0272] The SMF may notify of a change in the S-NSSAI and / or a new S-NSSAI by sending the second identity and / or by sending the first identity.

[0273] In addition, the SMF may determine which of the first and second identification information to include in the PDU session change request message based on network capability information, and / or policies such as operator policies, and / or network conditions. In addition, the SMF's decision on which identification information to include in the PDU session change request message is not limited to this.

[0274] The UE may recognize the request of the NW by receiving one or more of the first and second identification information. Specifically, the UE may recognize a change in the connection destination of the PDU session, information related to the PDU session, or a change in the S-NSSAI based on the reception of the second identification information.

[0275] And / or, based on the first identification information, the UE may recognize the S-NSSAI to which the second PDU session is associated and / or the S-NSSAI requested by the UE in a subsequently executed PDU session establishment request procedure.

[0276] In addition, if the S-NSSAI indicated in the first identification information is not included in the Allowed NSSAI stored by the UE, a registration request message may be sent before the PDU session establishment request procedure, and the registration request message may include a requested NSSAI IE that includes the S-NSSAI indicated in the first identification information.

[0277] The UE that receives the PDU session modification command message sends a PDU session establishment accept message to the SMF via the AMF (S806) (S808).

[0278] Specifically, UE_A10 sends a PDU session change acceptance message to AMF_A240 using the N1 interface (S806), and the AMF, which receives the PDU session change request message, sends a PDU session change acceptance message to the SMF using the N11 interface (S808).

[0279] The PDU session change acceptance message may be a NAS message transmitted and received on the N1 interface and the N11 interface, or may be included in a NAS message and transmitted and received. The PDU session change acceptance message is not limited to this, and may be any message indicating that the establishment of a PDU session has been accepted.

[0280] The SMF receives the PDU session modification accept message, transmits a session modification request message (Session Modification request) to the UPF (S810), and further receives a session modification response message (Session Modification response) transmitted by the UPF that received the session modification request message (S812). Each device completes this procedure based on the transmission and reception of the PDU session modification accept message and / or the transmission and reception of the session modification response message.

[0281] In addition, if the address assigned to the UE is not notified to the UE during this procedure, the SM may send an RA via the UPF that serves as the anchor point.

[0282] This allows each device to update the status of the PDU session.

[0283] [3.2. PDU Session Release Procedure] First, an overview of the PDU session release procedure will be described. Hereinafter, this procedure refers to the PDU session release procedure. Note that a PDU session may include one or more routes. In other words, a PDU session may be assigned one or more anchor points.

[0284] This procedure is a procedure for each device to release a PDU session. Each device may execute this procedure after completing the PDU session establishment procedure. Each device may also start this procedure in a registered state, or at any time after the PDU session establishment procedure.

[0285] An example of a procedure for executing a PDU session establishment procedure will be described below with reference to FIG. 7. Each step of this procedure will be described below. First, the SMF decides to start a PDU session release procedure. The condition for the SMF to decide to start a PDU session release procedure may be that the SMF decides to start executing anchor (UPF) relocation. Furthermore, the condition for the SMF to decide to execute anchor relocation may be the reception of a state change notification message sent from the AMF, the reception of a request message from the AF, or the detection of a state change of the SMF itself.

[0286] In addition, the trigger for the SMF to decide to start the PDU session release procedure may be that the SMF and / or AMF detect that the use of the S-NSSAI associated with the PDU session is no longer permitted. When the AMF and / or NSSF detect that the use of the S-NSSAI is no longer permitted, the SMF may receive a state change notification message from the AMF and / or NSSF. Note that the factors for deciding to relocate the anchor are not limited to this.

[0287] Next, the SMF sends a session release request message to the relocation source UPF (S910) to start a session release procedure between the SMF and the UPF. Here, the SMF may select one or more UPFs based on the UPF relocation decision and / or based on the context already held by the SMF. If multiple UPFs are selected, the SMF may send a session release request message to each UPF.

[0288] The UPF receives the session release request message and deletes the context for the PDU session. Furthermore, the UPF transmits a session release response message to the SMF based on receiving the session release request message and / or deleting the context for the PDU session (S912). Furthermore, the SMF receives the session release response message. Note that the session release request message and the session release response message may be control messages transmitted and received on the N4 interface. Furthermore, the session release response message may be a response message to the session release request message.

[0289] Next, the SMF sends a PDU session release command message to the UE via the AMF based on receipt of the PDU session release response message and / or the decision on PDU session anchor relocation (S902) (S904).

[0290] Specifically, the SMF sends a PDU session release command message to the AMF (S902), and the AMF, having received the PDU session release command message, sends a PDU session release command message to the UE (S904).

[0291] The PDU session release command message may be a NAS message transmitted and received on the N11 interface and the N1 interface, or may be included in a NAS message and transmitted. The PDU session release command message is not limited to this, and may be any message indicating that the network has requested the release of the PDU session and / or that the network has decided to release the PDU session.

[0292] Here, the SMF and / or AMF may include at least one or more of the identification information 11 to 12 in the PDU session release command message and / or NAS message, and may indicate a request for release of the PDU session by including this identification information.

[0293] Further, the SMF and / or AMF may indicate that the network has accepted a request to establish a PDU session connected to the DN or may indicate that the network has allowed the establishment of a PDU session connected to the DN by sending one or more of the identification information 11 to 12.

[0294] More specifically, the SMF and / or AMF may indicate that it will maintain information about the released PDU session for a certain period of time after the PDU session is released by sending one or more of the identification information 11 to 12.

[0295] Further, the SMF and / or AMF may indicate that release of the PDU session is performed for PDU session anchor relocation by sending one or more of the identification information 11 to 12.

[0296] In addition, the SMF and / or AMF may determine which identification information among the 11th to 12th identification information to put into the PDU session release command message and / or the NAS message based on the received identification information, and / or the network capability information, and / or a policy such as an operator policy, and / or a network state. In addition, the determination by the SMF and / or AMF of which identification information to put into the PDU session release command message and / or the NAS message is not limited to this.

[0297] The UE may recognize the request of the NW by receiving one or more of the identification information from the 11th to 12th. Specifically, the UE may recognize a change in the connection destination of the PDU session, information related to the PDU session, or a change in the S-NSSAI based on the reception of the 12th identification information.

[0298] And / or, based on the 11th identification information, the UE may recognize the S-NSSAI to which the second PDU session is associated and / or the S-NSSAI requested by the UE in a subsequently executed PDU session establishment request procedure.

[0299] In addition, if the S-NSSAI indicated in the 11th identification information is not included in the Allowed NSSAI stored by the UE, a registration request message may be sent before the PDU session establishment request procedure, and the registration request message may include a requested NSSAI IE that includes the S-NSSAI indicated in the 11th identification information.

[0300] The UE receives the PDU session release command message and further sends a PDU session release accept message to the SMF via the AMF (S906) (S908).

[0301] Specifically, the UE sends a PDU session release acceptance message to the AMF using the N1 interface (S906), and the AMF that receives the PDU session release acceptance message sends a PDU session release acceptance message to the SMF using the N11 interface (S908).

[0302] The PDU session release acceptance message may be a NAS message transmitted and received on the N1 interface and the N11 interface, or may be transmitted and received as part of a NAS message. The PDU session release acceptance message may be a response message to a PDU session release command message, but is not limited to this, and may be any message indicating that the PDU session release procedure is completed.

[0303] Next, the SM transmits a PDU session release notification message to the AMF (S912). By transmitting the PDU session release notification message, the SMF_A230 may notify the completion of the release of the PDU session, or may notify that the PDU session has been released but that some information is still stored for relocation. Note that the PDU session release notification message is not limited to this, and may be any message that notifies the release of the PDU session.

[0304] In addition, the AMF may start counting a timer using a timer that manages the storage of information about the PDU session based on the reception of a PDU session release accept message and / or based on the reception of a PDU session release notification message and / or based on the transmission of a PDU session release command message. The AMF may recognize and store information indicated by each message and / or identification information included in each message based on the reception of a PDU session release accept message and / or based on the reception of a PDU session release notification message and / or based on the transmission of a PDU session release command message.

[0305] Furthermore, when a timer used to manage the storage of information about the PDU session expires, the AMF may release information and / or context about the PDU session.

[0306] The SMF may start counting a timer using a timer that manages the storage of information regarding the PDU session based on receiving a PDU session release accept message and / or based on sending a PDU session release notification message and / or based on receiving a PDU session release command message.

[0307] Furthermore, when a timer used to manage the storage of information about the PDU session expires, the SMF may release information and / or context about the PDU session.

[0308] Each device completes this procedure based on the transmission and reception of S906 and / or S908 and / or S912. Each device may transition to a state in which the PDU session is released based on the completion of this procedure. Furthermore, each device may perform processing based on the identification information transmitted and received in this procedure based on the completion of this procedure.

[0309] For example, when the UE receives one or more of the identification information from the 11th to the 12th identification information, it may immediately start a PDU session establishment procedure using the 11th identification information.

[0310] Furthermore, when the UE receives one or more of the identification information from the eleventh to twelfth identification information, the information regarding the PDU session may not be temporarily released or may be released immediately.

[0311] Based on the fact that the time limit (lifetime) of the S-NSSAI to which the current PDU session is associated is approaching expiration, and further based on the fact that the current PDU session is associated with SSC mode 2 or SSC mode 4, the UE may send a PDU session release request message to the AMF. Furthermore, the AMF may send the received PDU session release request message to the SMF. Here, the UE_A10 may include, in the PDU session release request message, identification information indicating that the above-mentioned current PDU session requests anchor relocation by the associated S-NSSAI and / or SSC. Note that the procedure after the SMF receives the PDU session release request message may be the procedure after S910 described using FIG. 7.

[0312] [3.3. PDU Session Establishment Procedure] Next, the behavior of each device when the UE executes the PDU session establishment procedure will be described with reference to Fig. 8. Hereinafter, the PDU session establishment procedure may be referred to as this procedure. The PDU session establishment procedure may also be an SM procedure.

[0313] This procedure may be performed after the registration procedure has been performed one or more times.

[0314] First, the UE transmits a PDU session establishment request message to the SMF (S1400) (S1402) (S1404) to start a PDU session establishment procedure. Then, the SMF receives the PDU session establishment request message from the UE.

[0315] Specifically, the UE initiates the PDU session establishment procedure by sending a NAS message including an N1 SM container including a PDU session establishment request message to the AMF via the access network (S1400). The NAS message is, for example, a message sent via the N1 interface and may be an uplink NAS transport (UL NAS TRANSPORT) message.

[0316] Further, the AMF may determine an SMF based on a NAS message received from the UE and / or a network state (S1402). Further, the AMF may forward identification information included in the received PDU session establishment request message and / or NAS message to the selected SMF (S1404).

[0317] The UE may send a PDU session establishment request message based on receiving at least one of the first to second identification information and / or the eleventh to twelfth identification information.

[0318] Here, the UE may include at least one of the identification information items 21 to 23 in the PDU session establishment request message or the NAS message and transmit it. The UE may include other identification information in the PDU session establishment request message or the NAS message. Specifically, the UE may include a requested DNN or a PDU session ID in the PDU session establishment request message or the NAS message.

[0319] By transmitting these pieces of identification information, the UE may indicate that the UE supports each function, or may indicate a request from the UE. 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. Furthermore, 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.

[0320] Here, the UE may indicate the contents of the above identification information to the network by sending a PDU session establishment request message or a NAS message.

[0321] The UE may transmit an empty 21st identification information or may decide not to transmit the 21st identification information based on reception of at least one of the first to second identification information and / or the 11th to 12th identification information. In other words, the UE may transmit a PDU session establishment request message using no S-NSSAI based on reception of at least one of the first to second identification information and / or the 11th to 12th identification information.

[0322] Next, when the AMF receives the NAS message, it can recognize what the UE is requesting and / or the contents of the information, etc. (message, container, information) contained in the NAS message.

[0323] Next, the AMF selects an SMF as a transfer destination of at least a part of the information, etc. (message, container, information) included in the NAS message received from the UE (S1402). 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.

[0324] Specifically, the AMF may select an SMF for establishing a PDU session for a DNN similar to the DNN with which the first PDU session is associated. Similarly, the AMF may select an SMF for establishing a PDU session for an S-NSSAI similar to the S-NSSAI with which the first PDU session is associated.

[0325] Alternatively, the AMF may select an SMF for establishing a PDU session for an S-NSSAI for which an SST similar to the SST of the S-NSSAI to which the first PDU session is associated is configured, or the AMF may select an SMF for establishing a PDU session for an S-NSSAI different from the S-NSSAI to which the first PDU session is associated.

[0326] 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 (S1404).

[0327] Next, when the SMF receives information etc. (message, container, information) sent from the AMF, it can recognize what the UE is requesting and / or the content of the information etc. (message, container, information) received from the AMF.

[0328] Here, the SMF may perform a second condition determination. The second condition determination may be for determining whether the network accepts the request of the UE. If the SMF determines that the second condition determination is true, it may start the procedure of (A) in Figure 8, and if the SMF determines that the second condition determination is false, it may start the procedure of (B) in Figure 8.

[0329] The second condition determination may be performed by an NF other than the SMF. The NF may be, for example, an NSSF, an NWDAF, a PCF, or an NRF. When an NF other than the SMF performs the second condition determination, the SMF may provide the NF with information necessary for performing the second condition determination, specifically, at least a part of the information received from the UE (S1406). Then, when the NF determines whether the second condition determination is true or false based on the information received from the SMF, the SMF may convey information including the result of the second condition determination (i.e., true or false) to the SMF. The SMF may determine the identification information and / or the control message to be transmitted to the UE based on the result of the second condition determination received from the NF.

[0330] 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.

[0331] For example, if the network permits the request of the UE, the second condition determination may be determined as true, and if the network does not permit the request of the UE, the second condition determination may be determined as false. Also, if the network to which the UE is connected and / or a device in the network supports the function requested by the UE, the second condition determination may be determined as true, and if the network does not support the function requested by the UE, the second condition determination may be determined as false. Also, if the transmitted and received identification information is permitted, the second condition determination may be determined as true, and if the transmitted and received identification information is not permitted, the second condition determination may be determined as false.

[0332] The conditions for determining whether the second condition determination is true or false are not limited to the above-mentioned conditions.

[0333] Next, each step of the procedure in FIG. 8(A) will be described.

[0334] The SMF may select a UPF for the PDU session to be established and may transmit an N4 session establishment request message to the selected UPF, for example, via the N4 interface (S1408). The N4 session establishment request message may include at least a portion of the PCC rules received from the PCF.

[0335] The SMF may decide whether to perform approval of C2 communication during this procedure based on information received from the AMF (message, container, information), and / or information such as PCC rules 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.

[0336] If approval of C2 communication is performed during this procedure, the SMF may determine approval of the establishment of the PDU session requested by the UE based on at least one of the identification information 21 to 23.

[0337] Here, the SMF may select one or more UPFs based on information received from the AMF (message, container, information), and / or information such as PCC rules 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. In addition, if multiple UPFs are selected, the SMF may send an N4 session establishment request message to each UPF. Here, it is assumed that a UPF is selected.

[0338] Next, when the UPF receives the N4 session establishment request message (S1408), the UPF can recognize the contents of the information received from the SMF. In addition, the UPF may send an N4 session establishment response message to the SMF, for example, via the N4 interface, based on the reception of the N4 session establishment request message (S1410).

[0339] 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.

[0340] Next, the SMF sends a PDU session establishment accept message to the UE 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, etc. Then, the UE receives the PDU session establishment accept message and / or the identification information from the SMF (S1418) (S1420) (S1422).

[0341] Specifically, the SMF sends an N1 SM container and / or N2 SM information and / or a PDU session ID to the AMF, for example via an N11 interface, based on receiving a PDU session establishment request message and / or selecting a UPF and / or receiving an N4 session establishment response message (S1412). Here, the N1 SM container may include a PDU session establishment accept message. Furthermore, the PDU session ID may be included in the PDU session establishment accept message.

[0342] Next, the AMF that receives 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 first base station device included in the access network (S1414) (S1416). Here, the NAS message is transmitted, for example, via an N1 interface. In addition, the NAS message may be a downlink NAS transport (DL NAS TRANSPORT) message.

[0343] Specifically, when the AMF transmits an N2 PDU session request message to a base station device included in the access network (S1414), the base station device that receives the N2 PDU session request message transmits a NAS message to the UE (S1416). Here, the N2 PDU session request message may include a NAS message and / or N2 SM information. In addition, the NAS message may include a PDU session ID and / or an N1 SM container.

[0344] 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.

[0345] Here, the SMF and / or AMF may indicate that at least a portion 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 a NAS message, and / or N2 SM information, and / or an N2 PDU session request message.

[0346] Here, the SMF and / or AMF may send a PDU session establishment acceptance message, and / or an N1 SM container, and / or an NAS message, and / or an N2 SM information, and / or an N2 PDU session request message including at least one of the identification information 31 to 32.

[0347] The SMF may transmit the 31st identification information to the UE when the NW supports the change of the S-NSSAI due to the anchor relocation. The SMF may transmit the 32nd identification information when the change of the S-NSSAI due to the anchor relocation occurs.

[0348] In addition, the SMF may indicate that the network supports each function, may indicate that the UE request has been accepted, may indicate that the request from the UE has not been permitted, or may indicate a combination of these by transmitting these identification information and / or a PDU session establishment acceptance message. Furthermore, when multiple identification information are transmitted and received, two or more of these identification information may be configured as one or more identification information. And / or, when one identification information has multiple meanings, it may be divided into multiple identification information and transmitted and received. For example, the information indicating support of 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.

[0349] Specifically, the SMF may indicate that the network has changed the S-NSSAI by anchor relocation by sending the 31st identification information, may send information indicating whether the network supports a function that can change the S-NSSAI by anchor relocation, or may indicate that the network supports a function that can change the S-NSSAI by anchor relocation.

[0350] If the NW and / or the established PDU session supports S-NSSAI change due to anchor relocation, the SMF may send a 31st identification indicating that the NW and / or the established PDU session supports S-NSSAI change due to anchor relocation.

[0351] The SMF may transmit at least one of the 31st to 32nd identification information based on receiving at least one of the 21st to 23rd identification information.

[0352] Here, the network may indicate the content of the above identification information to the UE by sending a PDU session establishment accept message.

[0353] In addition, the network may transmit identification information other than the identification information from 31 to 32 in the PDU session establishment acceptance message. Specifically, the network may transmit information indicating the SSC mode associated with the established PDU session and / or anchor point in the Selected SSC mode IE. The network may transmit information indicating the SSC mode associated with the established PDU session and / or anchor point in the Selected SSC mode IE.

[0354] And / or, the network may send the S-NSSAI and / or DNN associated with the established PDU session in a PDU session establishment accept message.

[0355] In addition, when this procedure is a PDU session establishment procedure for a second PDU session in anchor relocation of a PDU session of SSC mode 2 to 5, the S-NSSAI transmitted by the SMF may be an S-NSSAI associated with the second PDU session and may be different from the S-NSSAI associated with the first PDU session. And / or, the SST included in the S-NSSAI transmitted by the SMF may be controlled to be the same as the SST of the S-NSSAI associated with the first PDU session.

[0356] 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.

[0357] Next, when the UE receives the NAS message, for example via the N1 interface (S1416), 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, etc. (message, container, information) contained in the NAS message.

[0358] Next, each step of the procedure in FIG. 8B will be described.

[0359] 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 (S1418). Here, the N1 SM container may include a PDU session establishment rejection message. Further, the PDU session ID may be included in the PDU session establishment rejection message.

[0360] 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 base station device included in the access network (S1420) (S1422). 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.

[0361] 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.

[0362] Here, the SMF and / or AMF may indicate that the UE's request for 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 a NAS message.

[0363] In addition, the SMF may indicate that the UE request has been rejected, or that the request from the UE has not been authorized, by sending a PDU session establishment rejection message, or may indicate a combination of these.

[0364] Here, the SMF and / or AMF may send the 35th identification information including in the PDU session establishment rejection 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.

[0365] Furthermore, the SMF and / or AMF may determine which identification information to include in the PDU session establishment rejection 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.

[0366] Next, when the UE receives a NAS message, for example via the N1 interface (S1422), it can recognize that the UE's request in the PDU session establishment request message has been rejected and / or the contents of the information, etc. (message, container, information) contained in the NAS message.

[0367] Furthermore, when the UE receives the 35th identification information, the UE may recognize the content indicated by the received identification information. The UE may recognize the content of the above identification information by receiving a NAS message, a PDU session establishment acceptance message, or a PDU session establishment rejection message.

[0368] Specifically, the UE may recognize that the NW does not support changing the S-NSSAI due to anchor relocation based on the reception of the 35th identification information, and / or the UE may recognize that the NW has requested that the UE resubmit the PDU session establishment request based on the reception of the 35th identification information.

[0369] Based on receiving the 35th identification information, the UE may again initiate a registration request procedure, and at that time may request an S-NSSAI from the NW that is similar to the S-NSSAI associated with the first PDU session.

[0370] Each device may complete this procedure based on sending and receiving a PDU session establishment acceptance message. At this time, each device may transition to a state in which it can communicate with the DN using the established PDU session.

[0371] Each device may complete this procedure based on sending and receiving a PDU session establishment acceptance message or a PDU session establishment rejection message. At this time, each device cannot establish a PDU session, and therefore cannot communicate with the DN if there is no already established PDU session.

[0372] In addition, each process that the UE performs 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.

[0373] 4. EMBODIMENTS OF THE PRESENT ART An embodiment of the present invention may be a combination of one or more of the procedures described in Chapter 3. For example, in this embodiment, a UE in a registered state may execute the PDU session establishment procedure described in Chapter 3.3 one or more times to establish a PDU session. Furthermore, in a state where at least one first PDU session is established between the UE and the NW, the PDU session release procedure of Chapter 3.1 and / or the PDU session release procedure of Chapter 3.2 and / or the PDU session establishment procedure of Chapter 3.3 may be executed one or more times.

[0374] Hereinafter, a specific example of an embodiment of the present invention will be described.

[0375] [4.1. First embodiment] The first embodiment (hereinafter, this embodiment) will be described below.

[0376] In the following, in the first embodiment, a procedure for changing an anchor point in SSC mode 3 or SSC mode 5 will be described. In other words, a procedure for changing a PDU session anchor of a first PDU session associated with SSC mode 3 and / or SSC mode 5 and for continuing a session and a service will be described. The first embodiment will be described with reference to FIG.

[0377] Note that SSC mode 3 here may mean the second SSC mode 3. In the following, unless otherwise specified, a PDU session and / or anchor point associated with SSC mode 3 may also mean that support for changing the S-NSSAI due to anchor relocation is also associated with it.

[0378] Also, SMF#1 and SMF#2 in FIG. 9 may be devices in the same PLMN or in different PLMNs. SMF#1 and SMF#2 may be SMF132. Similarly, UPF#1 and UPF#2 in FIG. 9 may be devices in the same PLMN or in different PLMNs. UPF#1 and UPF#2 may be UPF130.

[0379] First, as an initial state, the UE may be in a state in which a first PDU session is established via UPF#1. Note that the first PDU session may be managed by SMF#1 and associated with SSC mode 3 and / or SSC mode 5.

[0380] For each device to transition to the initial state, each device may perform the PDU session establishment procedure of Chapter 3.3 and establish a first PDU session via UPF#1 associated with SSC mode 3 and / or SSC mode 5. The first PDU session may be associated with S-NSSAI#1 and / or DNN#1.

[0381] Next, SMF#1 determines the relocation of the UPF and / or SMF of the first PDU session (S1500). That is, SMF#1 determines the anchor relocation. The decision of anchor relocation of SMF#1 may be the same as the trigger for the SMF to send a PDU session change command message in the PDU session change procedure in Chapter 3.1.

[0382] Specifically, for example, the SMF may determine relocation of the UPF and / or the SMF and / or the S-NSSAI based on receiving a state change notification message sent from the AMF and / or the NSSF. For example, the AMF and / or the NSSF may send a message to the SMF#1 notifying the change of the S-NSSAI based on the approaching expiration of the life time of the S-NSSAI#1.

[0383] Or, for example, the AMF and / or NSSF may send a message to SMF#1 notifying the S-NSSAI of a change in the S-NSSAI based on the S-NSSAI#1 and / or the NSI indicated by S-NSSAI#1 being overloaded in the core network.

[0384] Next, SMF#1 starts a PDU session change procedure and executes the PDU session change procedure for the first PDU session (S1502). Note that S1502 may be realized by the procedures of S802 to S812 in FIG.

[0385] Specifically, the SMF#1 sends a PDU session modification command message to the UE via the AMF. The PDU session modification command may include at least one of the first and second identification information. The UE receives information and / or messages sent from the SMF and / or the AMF.

[0386] For example, SMF#1 may transmit the first identity including S-NSSAI#2, and / or SMF#1 may indicate anchor relocation associated with the change of S-NSSAI in the second identity.

[0387] The UE may recognize the initiation of anchor relocation of a PDU session anchor associated with SSC mode 3 and / or SSC mode 5 based on one or more of the first to second identification information and / or based on the reception of a PDU session change command message.

[0388] Specifically, the UE recognizes the anchor relocation of the first PDU session based on receiving the first identity and / or the second identity, where the first identity may be S-NSSAI#2 different from S-NSSAI#1, or the first identity may be null, in which case no S-NSSAI may be requested.

[0389] If the UE accepts the request from the NW, the UE sends a PDU session modification accept message to the SMF#1. The SMF#1 may exchange a session modification request and / or a session modification response message with the UPF#1.

[0390] Next, the UE starts a PDU session establishment procedure via UPF#2, and each device executes a PDU session establishment procedure via UPF#2 (S1504). S1504 may be realized by the procedures of S1400 to S1416 in FIG.

[0391] Specifically, the UE transmits a PDU session establishment request message and / or at least one of the identification information 21 to 23 to the SMF#2 via the AMF. The UE may transmit at least one of the identification information 21 to 23 in the PDU session establishment request message or the NAS message.

[0392] When the UE receives the first identification information from the NW, and further, when the first identification information is not null, the UE may include the S-NSSAI included in the first identification information in the 21st identification information and transmit it. When the UE receives the null first identification information from the NW, the UE may not transmit the 21st identification information to the NW.

[0393] In other words, when the UE receives information indicating an empty S-NSSAI from the NW, the UE may transmit an empty 21st identification information or may not transmit the 21st identification information.

[0394] The SMF#2 selects the UPF#2 based on the received information, and each device establishes a second PDU session via the UPF#2. The second PDU session may be associated with the S-NSSAI#2 and / or the DNN#1.

[0395] Further, each device releases the first PDU session via UPF#1 (S1506). The PDU session release procedure for releasing the first PDU session may be initiated from the UE, may be initiated from the SMF, or may be both. For example, S1506 may be the PDU session release procedure shown in FIG. 7. However, in this case, the cause value is different from 5GSM cause #39 "reactivation requested".

[0396] As a result, each device changes the PDU session anchor of the PDU session associated with SSC mode 3 and / or SSC mode 5, thereby realizing the continuity of the session and / or service. In other words, each device changes the PDU session anchor while changing the network slice, thereby realizing the continuity of the session and / or service.

[0397] [4.2. Second embodiment] The second embodiment (hereinafter, this embodiment) will be described below.

[0398] In the second embodiment, a procedure for changing the anchor point in SSC mode 2 or SSC mode 4 will be described.

[0399] In the second embodiment, a procedure for changing an anchor point in SSC mode 2 or SSC mode 4 will be described below. In other words, a procedure for changing a PDU session anchor of a first PDU session associated with SSC mode 2 and / or SSC mode 4 and for continuing a session and a service will be described. The second embodiment will be described with reference to FIG.

[0400] Note that SSC mode 2 may refer to the second SSC mode. In the following, unless otherwise specified, a PDU session and / or anchor point associated with SSC mode 2 may also mean that support for changing the S-NSSAI due to anchor relocation is also associated with it.

[0401] Also, SMF#1 and SMF#2 in FIG. 10 may be devices in the same PLMN or in different PLMNs. SMF#1 and SMF#2 may be SMF132. Similarly, UPF#1 and UPF#2 in FIG. 10 may be devices in the same PLMN or in different PLMNs. UPF#1 and UPF#2 may be UPF130.

[0402] First, as an initial state, the UE may be in a state in which a first PDU session is established via UPF#1. Note that the first PDU session may be managed by SMF#1 and associated with SSC mode 2 and / or SSC mode 4.

[0403] For each device to transition to the initial state, each device may perform the PDU session establishment procedure of Chapter 3.3 and establish a first PDU session via UPF#1 associated with SSC mode 2 and / or SSC mode 4. The first PDU session may be associated with S-NSSAI#1 and / or DNN#1.

[0404] Next, SMF#1 determines the relocation of the UPF and / or SMF of the first PDU session (S1600). That is, SMF#1 determines the anchor relocation. The decision of anchor relocation of SMF#1 may be the same as the trigger for the SMF to send a PDU session release command message and / or release request message in the PDU session change procedure in Chapter 3.2.

[0405] Specifically, for example, the SMF may determine the relocation of the UPF and / or the S-NSSAI based on receiving a state change notification message sent from the AMF and / or the NSSF. For example, the AMF and / or the NSSF may send a message to the SMF#1 notifying the change of the S-NSSAI based on the approaching expiration of the life time of the S-NSSAI#1.

[0406] Or, for example, the AMF and / or NSSF may send a message to SMF#1 notifying the S-NSSAI of a change in the S-NSSAI based on the S-NSSAI#1 and / or the NSI indicated by S-NSSAI#1 being overloaded in the core network.

[0407] Next, the SMF#1 sends DNAI information, which is information for selecting an SMF (SMF#2) for establishing a second PDU session, to the AMF (S1602), and the AMF that receives the DNAI information sends a response message to the SMF#1 (S1604). Here, the DNAI information may be configured with information indicating the DNN#1 and / or the S-NSSAI#2.

[0408] Next, SMF#1 executes a PDU session release procedure to release the first PDU session via UPF#1 (S1608). Note that S1608 may be realized by the procedures of S902 to S912 in FIG.

[0409] Specifically, SMF#1 sends a PDU session release command message to the UE via AMF.

[0410] Here, the SMF and / or AMF may include at least one or more of the identification information 11 to 12 in the PDU session release command message and / or NAS message, and may indicate a request for release of the PDU session by including this identification information.

[0411] For example, SMF#1 may transmit the eleventh identity including the S-NSSAI#2, and / or SMF#1 may indicate anchor relocation associated with the change of the S-NSSAI in one or more identities among the twelfth to twelfth identities.

[0412] The UE receives one or more of the 11th to 12th identities and / or a PDU session modification command message. The UE may recognize an initiation of anchor relocation of a PDU session anchor associated with SSC mode 2 and / or SSC mode 4 based on the reception of one or more of the 11th to 12th identities and / or the PDU session modification command message.

[0413] Specifically, the UE recognizes the anchor relocation of the first PDU session based on receiving one or more of the 11th to 12th identities, where the 11th identity may be S-NSSAI#2 different from S-NSSAI#1, or the 11th identity may be null, in which case no S-NSSAI may be requested.

[0414] When the UE accepts the request from the NW, the UE sends a PDU session release accept message to the SMF#1. The SMF#1 may exchange a session change request and / or a session change response message with the UPF#1. As a result, each device releases the first PDU session.

[0415] Next, the UE starts a PDU session establishment procedure via UPF#2, and each device executes a PDU session establishment procedure via UPF#2 (S1610). S1610 may be realized by the procedures of S1400 to S1416 in FIG.

[0416] Specifically, the UE transmits a PDU session establishment request message and / or at least one of the identification information 21 to 23 to the SMF#2 via the AMF. The UE may transmit at least one of the identification information 21 to 23 in the PDU session establishment request message or the NAS message.

[0417] When the UE receives the 11th identification information from the NW, and further, when the 11th identification information is not null, the UE may include the S-NSSAI included in the 11th identification information in the 21st identification information and transmit it. When the UE receives the null first identification information from the NW, the UE may not transmit the 21st identification information to the NW.

[0418] In other words, when the UE receives information indicating an empty S-NSSAI from the NW, the UE may transmit an empty 21st identification information or may not transmit the 21st identification information.

[0419] The SMF#2 selects the UPF#2 based on the received information, and each device establishes a second PDU session via the UPF#2. The second PDU session may be associated with the S-NSSAI#2 and / or the DNN#1.

[0420] As a result, each device changes the PDU session anchor of the PDU session associated with SSC mode 2 and / or SSC mode 4, thereby realizing the continuity of the session and / or service. In other words, each device changes the PDU session anchor while changing the network slice, thereby realizing the continuity of the session and / or service.

[0421] 5. Variations The program that runs on the device according to the present invention may be a program that controls a Central Processing Unit (CPU) or the like to make a computer function so as to realize the functions of the embodiments 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 other storage device system.

[0422] A program for implementing the functions of the embodiments of the present invention may be recorded on a computer-readable recording medium. The program may be read into a computer system and executed to implement the functions. The "computer system" here refers to a computer system built into an apparatus, and includes hardware such as an operating system and peripheral devices. The "computer-readable recording medium" may be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a medium that dynamically holds a program for a short period of time, or any other computer-readable recording medium.

[0423] In addition, each functional block or feature of the device used in the above-mentioned embodiment may be implemented or performed by an electric circuit, for example, an integrated circuit or a plurality of integrated circuits. The electric 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 electric circuit described above may be composed of a digital circuit or an analog circuit. In addition, when an integrated circuit technology that replaces the current integrated circuits appears due to the progress of semiconductor technology, one or more aspects of the present invention may use a new integrated circuit according to the technology.

[0424] The present invention is not limited to the above-mentioned embodiment. In the embodiment, one example of the device is described, but the present invention is not limited to this and can be applied to stationary or non-movable electronic devices installed indoors or outdoors, such as terminal devices or communication devices of AV equipment, kitchen equipment, cleaning / washing equipment, air conditioners, office equipment, vending machines, and other household appliances.

[0425] 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 design changes and the like within the scope of the gist of the present invention are also included. Furthermore, the present invention can be modified in various ways 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 replaced with elements that have the same effect are also included. [Explanation of symbols]

[0426] 1 Mobile communication systems 10 UE_A 30 PGW-U 32 PGW-C 35 SGW 40 MME 45 eNB 50 HSS 60 PCRF 80 Access Network_A (E-UTRAN) 90 Core Network_A 120 Access Network_B (5G AN) 122 gNB 130 UPF 132 SMF 140 AMF 150 UDM 160 PCF 190 Core Network_B

Claims

[Claim 1] A UE (User Equipment), A transmitter / receiver and a controller are provided, The transceiver unit receives a PDU session modification command message including an S-NSSAI; The transceiver unit transmits the S-NSSAI and a PDU session establishment request message; The control unit establishes a second PDU session; After the second PDU session is established, the first PDU session is released. A UE characterized by:

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