UE and communication control method

Abstract

According to one aspect of the present invention, a communication control method is provided for determining whether to continue congestion management in a destination PLMN when a PLMN change is performed during congestion management application, and the PLMN before the change is the home PLMN. Furthermore, if a PLMN change occurs while a backoff timer received along with a congestion management reason value is active, and the PLMN before the change is the home PLMN, whether to permit transmission of a UE's SM request message in the destination is determined based on the presence or absence of an information element notified by the network.

Description

Technical Field

[0001] This application claims priority to Japanese Patent Application No. 2019-70074, filed on April 1, 2019, the entire contents of which are incorporated herein by reference. Background Art

[0002] The 3rd Generation Partnership Project (3GPP), which has been conducting recent mobile communication system standardization activities, has been researching SAE (System Architecture Evolution), the system framework for LTE (Long Term Evolution). 3GPP has also standardized EPS (Evolved Packet System), a communications system that implements all-IP (Internet Protocol). The core network that constitutes EPS is called EPC (Evolved Packet Core).

[0003] Furthermore, in recent years, 3GPP has also been conducting research on the next-generation communication technology and system architecture of the 5G (5th Generation) mobile communication system, specifically the 5GS (5G System) specification, which is intended to implement the 5G mobile communication system (see Non-Patent Documents 1 and 2). 5GS identifies the technical challenges of connecting various terminals to cellular networks and specifies solutions.

[0004] Examples of the request conditions include optimization and diversification of communication procedures for supporting continuous mobile communication services corresponding to terminals supporting various access networks, and optimization of a system framework that matches the optimization and diversification of communication procedures.

[0005] Prior art literature

[0006] Non-patent literature

[0007] Non-patent literature 1: 3GPP TS 23.501v15.5.0; 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; System Architecture for the 5G System; Stage 2 (Release 15)

[0008] Non-patent document 2: 3GPP TS 23.502v15.5.0; 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Procedures for the5G System; Stage 2 (Release 15)

[0009] Non-patent literature 3: 3GPP TS 24.501v15.2.1; 3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3 (Release15) Summary of the Invention

[0010] Problems to be solved by the invention

[0011] In 5GS, in addition to providing a mechanism that provides a function equivalent to congestion management, control signal management based on reasons other than congestion management is also being studied (see Non-Patent Documents 1, 2, and 3).

[0012] However, if the UE changes its PLMN while congestion management is applied, and the PLMN before the change is the home PLMN, it is unclear whether congestion management should also be continued in the destination PLMN.

[0013] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a mechanism and a communication control method for realizing a control signal management process for the purpose of congestion management during system modification.

[0014] Technical Solution

[0015] The UE of the present invention is a UE (User Equipment) having a transceiver unit and a control unit, characterized in that, during a PDU (Protocol Data Unit) session establishment process, the transceiver unit receives a PDU (Protocol Data Unit) session establishment rejection message from a control device, wherein the PDU session establishment rejection message includes first information and a backoff timer value, and when certain S-NSSAI (Single Network Slice Selection Assistance Information) is provided during the PDU session establishment process, the control unit uses the backoff timer value to start the backoff timer, the first information is a reason value indicating insufficient resources for a specific slice, and the PDU session establishment rejection message includes the first information and a reason value indicating that the backoff timer is applied to all PLMNs (Public Land Mobile In the case where the second identification information of the S-NSSAI is included in the PDU session establishment rejection message and indicates that the back-off timer is applied to the logged-in PLMN, during the back-off timer is started, the transceiver does not send other PDU session establishment request messages or PDU session change request messages for the S-NSSAI in all PLMNs. In the case where the PDU session establishment rejection message includes the first information and the second identification information indicating that the back-off timer is applied to the logged-in PLMN, during the back-off timer is started, the transceiver does not send other PDU session establishment request messages or PDU session change request messages for the S-NSSAI in the logged-in PLMN.

[0016] In addition, the UE of the present invention is a UE (User Equipment) having a transceiver unit and a control unit, characterized in that, during a PDU (Protocol Data Unit) session establishment process, the transceiver unit receives a PDU (Protocol Data Unit) session establishment rejection message from a control device, the PDU session establishment rejection message includes first information and a backoff timer value, and when a certain S-NSSAI (Single Network Slice Selection Assistance Information) is provided during the PDU session establishment process, the control unit uses the backoff timer value to start the backoff timer, the first information is a reason value indicating insufficient resources for a specific slice, the PDU session establishment rejection message includes the first information and a reason value indicating that the backoff timer is applied to all PLMNs (Public Land Mobile In the case where the second identification information of the S-NSSAI indicates that the back-off timer is applied to the logged-in PLMN, during the start-up of the back-off timer, the control unit does not send other PDU session establishment request messages or PDU session change request messages for the S-NSSAI in all PLMNs; and in the case where the PDU session establishment rejection message includes the first information and the second identification information indicating that the back-off timer is applied to the logged-in PLMN, during the start-up of the back-off timer, the control unit does not send other PDU session establishment request messages or PDU session change request messages for the S-NSSAI in the logged-in PLMN.

[0017] In addition, the UE of the present invention is a UE (User Equipment) having a transceiver unit and a control unit, characterized in that, during a PDU (Protocol Data Unit) session establishment process, the transceiver unit receives a PDU (Protocol Data Unit) session establishment rejection message from a control device, the PDU session establishment rejection message includes first information and a backoff timer value, and when a certain S-NSSAI (Single Network Slice Selection Assistance Information) is provided during the PDU session establishment process, the control unit uses the backoff timer value to start the backoff timer, the first information is a reason value indicating insufficient resources for a specific slice, the PDU session establishment rejection message includes the first information and a reason value indicating that the backoff timer is applied to all PLMNs (Public Land Mobile In the case where the second identification information indicating that the backoff timer is applied to the logged-in PLMN is included in the PDU session establishment rejection message, during the start-up of the backoff timer, the control unit sets the transceiver unit so as not to send other PDU session establishment request messages or PDU session change request messages in all PLMNs for the S-NSSAI. In the case where the first information and the second identification information indicating that the backoff timer is applied to the logged-in PLMN are included in the PDU session establishment rejection message, during the start-up of the backoff timer, the transceiver unit sets the transceiver unit so as not to send other PDU session establishment request messages or PDU session change request messages in the logged-in PLMN for the S-NSSAI.

[0018] Beneficial effects

[0019] According to one solution of the present invention, it is characterized in that the terminal devices constituting 5GS and the devices within the core network implement congestion management and other management processing for different systems according to the network slice and / or DNN dominated by each terminal device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a diagram showing an overview of a mobile communication system.

[0021] Figure 2 This is a diagram showing an example of the configuration of an access network within a mobile communication system.

[0022] Figure 3 This is a diagram showing an example of the structure of the core network_A within the mobile communication system.

[0023] Figure 4 This is a diagram showing an example of the structure of the core network_B within the mobile communication system.

[0024] Figure 5 It is a diagram showing the device structure of UE.

[0025] Figure 6 This is a diagram showing the device structure of the eNB / NR node (NR node).

[0026] Figure 7 This is a diagram showing the device structure of MME / AMF.

[0027] Figure 8 This is a diagram showing the device configuration of SMF / PGW / UPF.

[0028] Figure 9 It is a diagram showing the initial process.

[0029] Figure 10 This is a diagram showing the login process.

[0030] Figure 11 It is a diagram showing the PDU session establishment process.

[0031] Figure 12 It is a diagram showing the network-led session management process. DETAILED DESCRIPTION

[0032] Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings. Note that, in this embodiment, an embodiment of a mobile communication system to which the present invention is applied will be described as an example.

[0033] [1. System Overview]

[0034] use Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 The outline of the mobile communication system according to this embodiment will be described. Figure 2 It is recorded Figure 1 A diagram showing details of an access network in a mobile communication system. Figure 3 It is the main record Figure 1 A diagram showing the detailed contents of the core network_A90 in the mobile communication system. Figure 4 It is the main record Figure 1 The detailed contents of the core network_B190 in the mobile communication system are shown in FIG. Figure 1As shown, the mobile communication system 1 of this embodiment is composed of a terminal device (also called a user device or mobile terminal device) UE (User Equipment)_A10, an access network (AN)_A, an access network_B, a core network (CN)_A90, a core network_B190, a packet data network (PDN)_A6, and a data network (DN)_A5. It should be noted that the combination of the access network_A and the core network_A90 may also be referred to as an EPS (Evolved Packet System; 4G mobile communication system), and the combination of the access network_B, the core network_B190, and the UE_A10 may also be referred to as a 5GS (5G System; 5G mobile communication system). The configuration of the 5GS and EPS is not limited to these. It should be noted that, for convenience, core network_A90, core network_B190 or their combination are also referred to as core networks, access network_A, access network_B or their combination are also referred to as access networks or wireless access networks, and DN_A5, PDN_A6 or their combination are also referred to as DNs.

[0035] Here, UE_A10 can be a device that can connect to a network service via 3GPP access (also known as 3GPP access or 3GPP access network) and / or non-3GPP access (non-3GPP access, also known as non-3GPP access or non-3GPP access network). In addition, UE_A10 can have a UICC (Universal Integrated Circuit Card), an eUICC (Embedded UICC). In addition, UE_A10 can also be a terminal device that can perform wireless connection, or it can be an ME (Mobile Equipment), an MS (Mobile Station), or a CIoT (Cellular Internet of Things) terminal (CIoT UE), etc.

[0036] In addition, UE_A10 can be connected to the access network and / or the core network. In addition, UE_A10 can be connected to DN_A and / or PDN_A via the access network and / or the core network. UE_A10 uses PDU (Protocol Data Unit or Packet Data Unit: Protocol Data Unit or Packet Data Unit) session and / or PDN (Packet Data Network) connection (also called PDN connection) to send and receive (communicate) user data between DN_A and / or PDN_A. Moreover, the communication of user data is not limited to IP (Internet Protocol: Network Protocol) communication (IPv4 or IPv6), for example, it can be non-IP communication in EPS, and it can be Ethernet (registered trademark) communication or unstructured communication in 5GS.

[0037] Here, IP communication refers to data communication using IP, which is data communication achieved by sending and receiving IP packets assigned an IP header. It should be noted that the payload portion constituting the IP packet may include user data sent and received by UE_A10. In addition, non-IP communication refers to data communication that does not use IP, which is data communication achieved by sending and receiving data that is not assigned an IP header. For example, non-IP communication can be data communication achieved by sending and receiving application data that is not assigned an IP address, or it can be data communication achieved by sending and receiving user data sent and received by UE_A10 by assigning other headers such as a MAC header and an Ethernet (registered trademark) frame header.

[0038] In addition, a PDU session refers to the connectivity established between UE_A10 and DN_A5 in order to provide a PDU connection service. More specifically, a PDU session may be the connectivity established between UE_A10 and an external gateway. Here, the external gateway may be a UPF, a PGW (Packet Data Network Gateway), etc. In addition, a PDU session may be a communication path established for sending and receiving user data between UE_A10 and the core network and / or DN, or a communication path for sending and receiving PDUs. Moreover, a PDU session may be a session established between UE_A10 and the core network and / or DN, or a logical communication path consisting of one or more bearer or other transmission paths between devices within the mobile communication system 1. More specifically, a PDU session may be a connection established between UE_A10 and the core network_B190 and / or an external gateway, or a connection established between UE_A10 and UPF. In addition, a PDU session may also be connectivity and / or connection between UE_A10 and UPF_A235 via NR node_A122. Moreover, a PDU session may be identified by a PDU session ID and / or an EPS bearer ID.

[0039] It should be noted that UE_A10 can use PDU sessions to send and receive user data with devices such as application servers configured for DN_A5. In other words, PDU sessions can transmit user data sent and received between UE_A10 and devices such as application servers configured for DN_A5. Furthermore, each device (UE_A10, devices within the access network and / or devices within the core network and / or devices within the data network) can manage one or more pieces of identification information in correspondence with the PDU session establishment. It should be noted that this identification information can include at least one of the following: APN (Access Point Name), TFT (Traffic Flow Template), session type, application identification information, DN_A5 identification information, NSI (Network Slice Instance) identification information, DCN (Dedicated Core Network) identification information, and access network identification information, and may further include other information. Furthermore, when multiple PDU sessions are established, the identification information corresponding to the PDU session establishment can be the same or different. Moreover, the NSI identification information is information for identifying the NSI, and may also be the following NSI ID or Slice Instance ID.

[0040] In addition, if Figure 2As shown, access network_A and access network_B can be any one of UTRAN (Universal Terrestrial Radio Access Network)_A20, E-UTRAN (Evolved Universal Terrestrial Radio Access Network)_A80, and NG-RAN (5G-RAN)_A120. It should be noted that, hereinafter, UTRAN_A20 and / or E-UTRAN_A80 and / or NG-RAN_A120 are referred to as 3GPP access or 3GPP access network, and wireless LAN access network and non-3GPP AN (non-3GPP AN) are referred to as non-3GPP access or non-3GPP access network. Each wireless access network includes devices to which UE_A10 is actually connected (such as base station devices, access points), etc.

[0041] For example, E-UTRAN_A80 is an LTE access network and is composed of one or more eNB_A45. eNB_A45 is a wireless base station to which UE_A10 connects via E-UTRA (Evolved Universal Terrestrial Radio Access). Furthermore, if multiple eNBs exist within E-UTRAN_A80, the eNBs can be interconnected.

[0042] In addition, NG-RAN_A120 is the access network of 5G, which can also be Figure 4 The (R)AN described in the specification is composed of one or more NR nodes (New Radio Access Technology node: new radio access technology node) _A122 and / or ng-eNB. It should be noted that the NR node _A122 is a wireless base station to which the UE_A10 is connected through 5G radio access (5G Radio Access), also known as gNB. It should be noted that the ng-eNB can be an eNB (E-UTRA) constituting the access network of 5G, and can be connected to the core network _B190 via the NR node _A (NR node_A) or directly connected to the core network _B190. In addition, when there are multiple NR nodes _A122 and / or ng-eNBs in the NG-RAN_A120, each NR node _A122 and / or ng-eNB can be connected to each other.

[0043] It should be noted that NG-RAN_A120 can be an access network consisting of E-UTRA and / or 5G radio access. In other words, NG-RAN_A120 can include eNB_A45, NR Node_A122, or both. In this case, eNB_A45 and NR Node_A122 can also be the same device. Therefore, NR Node_A122 is interchangeable with eNB_A45.

[0044] UTRAN_A20 is the access network of the 3G mobile communication system and is composed of an RNC (Radio Network Controller)_A24 and a NB (Node B)_A22. NB_A22 is a radio base station to which UE_A10 connects via UTRA (Universal Terrestrial Radio Access). UTRAN_A20 can be composed of one or more radio base stations. Furthermore, RNC_A24 is a control unit that connects the core network_A90 and NB_A22. UTRAN_A20 can be composed of one or more RNCs. Furthermore, RNC_A24 can be connected to one or more NB_A22.

[0045] It should be noted that, in this specification, "UE_A10 is connected to each radio access network" refers to being connected to the base stations, access points, etc. included in each radio access network, and that data and signals transmitted and received also pass through the base stations and access points. It should be noted that, regardless of the type of access network, the control messages transmitted and received between UE_A10 and core network_B190 can be identical. Therefore, the transmission and reception of messages between UE_A10 and core network_B190 via NR node_A122 can be the same as the transmission of messages between UE_A10 and core network_B190 via eNB_A45.

[0046] Furthermore, the access network is a wireless network connected to UE_A10 and / or the core network. The access network can be a 3GPP access network or a non-3GPP access network. It should be noted that a 3GPP access network can be UTRAN_A20, E-UTRAN_A80, or NG-RAN (Radio Access Network)_A120, and a non-3GPP access network can be a wireless LAN access point (WLAN AN). It should be noted that in order to connect to the core network, UE_A10 can connect to the access network or to the core network via the access network.

[0047] In addition, DN_A5 and PDN_A6 are data networks (Data Network) that provide communication services to UE_A10, and can be configured as a packet data service network or configured for each service. Moreover, DN_A5 can include connected communication terminals. Therefore, connecting to DN_A5 can refer to connecting to a communication terminal or server device configured for DN_A5. Moreover, sending and receiving user data with DN_A5 can refer to sending and receiving user data with a communication terminal or server device configured for DN_A5. In addition, in Figure 1 DN_A5 is located outside the core network, but can also be located inside the core network.

[0048] Furthermore, Core Network_A90 and / or Core Network_B190 may constitute one or more core network devices. Here, a core network device may be a device included in Core Network_A90 and / or Core Network_B190 that performs some or all of the processing or functions of each device. It should be noted that a core network device may also be referred to as a core network device.

[0049] Furthermore, the core network is an IP mobile communication network operated by a mobile communication operator (MNO) connected to the access network and / or DN. The core network can be a core network used by a mobile communication operator that operates and manages the mobile communication system 1, or it can be a core network for virtual mobile communication operators such as MVNOs (Mobile Virtual Network Operators) and MVNEs (Mobile Virtual Network Enablers), or virtual mobile communication service providers. It should be noted that Core Network_A90 can be the Evolved Packet Core (EPC) that constitutes the EPS (Evolved Packet System), and Core Network_B190 can be the 5G Core Network (5G Core Network) that constitutes the 5GS. Furthermore, Core Network_B190 can also be the core network of a system providing 5G communication services. Conversely, the EPC can be Core Network_A90, and the 5GC can be Core Network_B190. It should be noted that Core Network_A90 and / or Core Network_B190 are not limited to these and can also be networks used to provide mobile communication services.

[0050] Next, the core network_A90 is explained. The core network_A90 may include at least one of HSS (Home Subscriber Server)_A50, AAA (Authentication Authorization Accounting), PCRF (Policy and Charging Rules Function), PGW_A30, ePDG, SGW_A35, MME (Mobility Management Entity)_A40, SGSN (Serving GPRS Support Node) and SCEF. Moreover, these can be constituted as NF (Network Function). NF can refer to a processing function constituted within the network. In addition, the core network_A90 can be connected to multiple radio access networks (UTRAN_A20, E-UTRAN_A80).

[0051] For convenience, Figure 3 Only the HSS (HSS_A50), PGW (PGW_A30), SGW (SGW_A35), and MME (MME_A40) are described, but this does not mean that other devices and / or NFs are not included. It should be noted that, for convenience, UE_A10 is also referred to as UE, HSS_A50 is also referred to as HSS, PGW_A30 is also referred to as PGW, SGW_A35 is also referred to as SGW, MME_A40 is also referred to as MME, and DN_A5 and / or PDN_A6 are also referred to as DN or PDN.

[0052] The following is a brief description of the various devices included in the core network_A90.

[0053] PGW_A30 is a relay device that connects to the DN, SGW_A35, ePDG, WLAN ANa70, PCRF, and AAA, and serves as a gateway between the DN (DN_A5 and / or PDN_A6) and the Core Network_A90 to transmit user data. It should be noted that PGW_A30 can be a gateway for IP communication and / or non-IP communication. Furthermore, PGW_A30 can have the function of transmitting IP communication or converting non-IP communication into IP communication. It should be noted that multiple such gateways can be configured for the Core Network_A90. Furthermore, the multiple configured gateways can be gateways that connect the Core Network_A90 to a single DN.

[0054] It should be noted that the user plane (U-Plane, User Plane: UP) can be a communication path for sending and receiving user data and can be composed of multiple bearers. In addition, the control plane (C-Plane, Control Plane: CP) can be a communication path for sending and receiving control messages and can be composed of multiple bearers.

[0055] Furthermore, PGW_A30 can be connected to the SGW, DN, and UPF (User Plane Function) and / or SMF (Session Management Function), and can also be connected to UE_A10 via the user plane. Furthermore, PGW_A30 can be configured together with UPF_A235 and / or SMF_A230.

[0056] SGW_A35 is a relay device connected to PGW_A30, MME_A40, E-UTRAN_A80, SGSN, and UTRAN_A20, and serves as a gateway between the core network_A90 and the 3GPP access network (UTRAN_A20, GERAN, E-UTRAN_A80) to transmit user data.

[0057] MME_A40 is a control device that is connected to SGW_A35, the access network, HSS_A50, and the SCEF, and performs location information management and access control, including mobility management of UE_A10, via the access network. Furthermore, MME_A40 may function as a session management device that manages sessions established by UE_A10. Furthermore, a plurality of such control devices may be configured for the core network_A90; for example, a location management device different from MME_A40 may be configured. A location management device different from MME_A40 may be connected to SGW_A35, the access network, the SCEF, and the HSS_A50, similarly to MME_A40. Furthermore, MME_A40 may be connected to AMF (Access and Mobility Management Function).

[0058] Furthermore, when the Core Network_A90 includes multiple MMEs, they can be interconnected. This allows for the exchange of UE_A10 contexts between MMEs. Thus, the MME_A40 only needs to be a management device that transmits and receives control information related to mobility management and session management with the UE_A10. In other words, it only needs to be a control plane (CP) controller.

[0059] Furthermore, while the example in which MME_A40 is included in Core Network_A90 has been described, MME_A40 may also be a management device configured within one or more core networks, DCNs, or NSIs, or may be a management device connected to one or more core networks, DCNs, or NSIs. Multiple DCNs or NSIs may be used by a single carrier or by different carriers.

[0060] In addition, MME_A40 can be a relay device that acts as a gateway between the core network_A90 and the access network to transmit user data. It should be noted that the user data sent and received using MME_A40 as a gateway can be small data.

[0061] Moreover, MME_A40 can be an NF that plays the role of mobility management of UE_A10, etc., or an NF that manages one or more NSIs. In addition, MME_A40 can be an NF that plays one or more of the above roles. It should be noted that the NF can be one or more devices configured in the core network_A90, or a CP function for control information and / or control messages (hereinafter also referred to as CPF (Control Plane Function: Control Plane Function) or Control Plane Network Function: Control Plane Network Function), or a shared CP function shared among multiple network slices.

[0062] Here, NF refers to the processing functions within the network. Specifically, NFs can be functional devices such as MME, SGW, PGW, CPF, AMF, SMF, and UPF, or they can represent functions and capability information such as MM (Mobility Management) and SM (Session Management). Furthermore, NFs can be functional devices that implement a single function or multiple functions. For example, there can be separate NFs for implementing MM functions and NFs for implementing SM functions, or there can be NFs that implement both MM and SM functions.

[0063] The HSS_A50 is a management node that connects to the MME_A40, AAA, and SCEF and manages subscriber information. HSS_A50's subscriber information is referenced during access control by the MME_A40, for example. Furthermore, the HSS_A50 can connect to a location management device other than the MME_A40. For example, the HSS_A50 can connect to the CPF_A140.

[0064] Furthermore, in HSS_A50, UDM (Unified Data Management)_A245 may be configured as different devices and / or NFs, or may be configured as the same device and / or NF.

[0065] AAA is connected to PGW30, HSS_A50, PCRF, and WLAN ANa70, and performs access control on UE_A10 connected via WLAN ANa70.

[0066] The PCRF connects to PGW_A30, WLAN ANa75, AAA, DN_A5, and / or PDN_A6 to manage QoS for data delivery. For example, it manages QoS for the communication path between UE_A10 and DN_A5 and / or PDN_A6. Furthermore, the PCRF can be a device that creates and / or manages PCC (Policy and Charging Control) rules and / or routing rules used by various devices when sending and receiving user data.

[0067] In addition, the PCRF may be a PCF (Policy Control Function) that creates and / or manages policies. In more detail, the PCRF may be connected to the UPF_A 235 .

[0068] ePDG is connected to PGW30 and WLAN ANb75, and serves as the gateway between core network_A90 and WLAN ANb75 to distribute user data.

[0069] The SGSN is a control device that connects to UTRAN_A20, GERAN, and SGW_A35 and manages location between the 3G / 2G access network (UTRAN / GERAN) and the LTE (4G) access network (E-UTRAN). The SGSN also has functions for selecting the PGW and SGW, managing the time zone of the UE_A10, and selecting the MME_A40 during handover to E-UTRAN.

[0070] The SCEF is connected to DN_A5 and / or PDN_A6, MME_A40, and HSS_A50, acting as a relay device that connects DN_A5 and / or PDN_A6 with the gateway of the Core Network_A90 to transmit user data. It should be noted that the SCEF can be a gateway for non-IP communications. Furthermore, the SCEF can have the function of converting non-IP communications and IP communications. Furthermore, multiple such gateways can be configured for the Core Network_A90. Furthermore, multiple gateways connecting the Core Network_A90 to a single DN_A5 and / or PDN_A6 and / or DN can also be configured. It should be noted that the SCEF can be located outside or inside the Core Network.

[0071] Next, the core network B190 is described. The core network B190 may include at least one of the following: AUSF (Authentication Server Function), AMF (Access and Mobility Management Function) A240, UDSF (Unstructured Data Storage Function), NEF (Network Exposure Function), NRF (Network Repository Function), PCF (Policy Control Function), SMF (Session Management Function) A230, UDM (Unified Data Management), UPF (User Plane Function) A235, AF (Application Function), and N3IWF (Non-3GPP InterWorking Function). Furthermore, these may be configured as NFs (Network Functions). NFs may refer to processing functions configured within a network.

[0072] For convenience, Figure 4Only the AMF (AMF_A240), SMF (SMF_A230), and UPF (UPF_A235) are recorded, but this does not mean that other devices (devices and / or NF (Network Function)) are not included. It should be noted that, for convenience, UE_A10 is also called UE, AMF_A240 is also called AMF, SMF_A230 is also called SMF, UPF_A235 is also called UPF, and DN_A5 is also called DN.

[0073] In addition, Figure 4 The N1 interface (hereinafter also referred to as reference point), N2 interface, N3 interface, N4 interface, N6 interface, N9 interface, and N11 interface are described. Here, the N1 interface is the interface between the UE and the AMF, the N2 interface is the interface between the (R)AN (access network) and the AMF, the N3 interface is the interface between the (R)AN (access network) and the UPF, the N4 interface is the interface between the SMF and the UPF, the N6 interface is the interface between the UPF and the DN, the N9 interface is the interface between the UPF and the UPF, and the N11 interface is the interface between the AMF and the SMF. These interfaces can be used to communicate between the devices. Here, the (R)AN is also called the NG RAN.

[0074] The following is a brief description of each device included in the core network_B190.

[0075] First, the AMF_A240 connects to other AMFs, SMFs (SMF_A230), access networks (i.e., UTRAN_A20, E-UTRAN_A80, and NG-RAN_A120), UDMs, AUSFs, and PCFs. The AMF_A240 performs the following functions: registration management, connection management, reachability management, mobility management for UE_A10 and others, transmission of SM (Session Management) messages between the UE and SMF, access authentication (Access Authorization), security anchor function (SEA), security context management (SCM), support for the N2 interface for the N3IWF, support for NAS signaling with the UE via the N3IWF, authentication of UEs connected via the N3IWF, management of RM (Registration Management) states, and management of CM (Connection Management) states. Furthermore, AMF_A240 can be deployed within more than one Core Network_B 190. Furthermore, AMF_A240 can be an NF that manages more than one NSI (Network Slice Instance). Furthermore, AMF_A240 can also be a Common CPNF (Control Plane Network Function) shared across multiple NSIs.

[0076] In addition, the RM state includes a non-registered state (RM-DEREGISTERED state) and a registered state (RM-REGISTERED state). In the non-registered state, the UE is not logged into the network. Therefore, the UE context in the AMF does not have information about the location or routing information that is valid for the UE, so the AMF is unable to reach the UE. In the registered state, the UE is logged into the network, so the UE can receive services that require logging into the network.

[0077] In addition, as CM states, there are a non-connected state (CM-IDLE state) and a connected state (CM-CONNECTED state). In the non-connected state, the UE is in a logged-in state, but does not have a NAS signaling connection (NAS signaling connection) established with the AMF via the N1 interface. In addition, in the non-connected 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 connected state, it has a NAS signaling connection (NAS signaling connection) established with the AMF via the N1 interface. In addition, in the connected state, the UE may also have a connection (N2 connection) of the N2 interface and / or a connection (N3 connection) of the N3 interface.

[0078] In addition, the SMF_A230 may have the following functions: session management (SM) functions for PDU sessions, etc., IP address allocation and management functions for UEs, UPF selection and control functions, UPF setting functions for routing services to appropriate destinations, downlink data arrival notification functions (Downlink Data Notification) functions, functions for providing AN-specific (each AN) SM information sent to the AN via the AMF via the N2 interface, functions for determining the SSC mode (Session and Service Continuity mode) for a session, roaming functions, etc. In addition, the SMF_A230 may be connected to the AMF_A240, UPF_A235, UDM, and PCF.

[0079] In addition, UPF_A235 is connected to DN_A5, SMF_A230, other UPFs, and access networks (i.e., UTRAN_A20, E-UTRAN_A80, and NG-RAN_A120). UPF_A235 can play the following roles: anchor for intra-RAT mobility or inter-RAT mobility, packet routing and forwarding, UL CL (Uplink Classifier) function to support routing of multiple service flows for one DN, branching point function to support multi-homed PDU sessions, QoS processing for the user plane, verification of uplink services, buffering of downlink packets, triggering of downlink data notifications, etc. Furthermore, UPF_A235 can be a relay device that acts as a gateway between DN_A5 and Core Network_B190, transmitting user data. It should be noted that UPF_A235 can be a gateway for IP communications and / or non-IP communications. Furthermore, UPF_A235 can have the function of transmitting IP communications or converting non-IP communications into IP communications. Furthermore, the multiple gateways configured can be gateways connecting Core Network_B190 and a single DN. It should be noted that UPF_A235 can have connectivity with other NFs and can also connect to various devices via other NFs.

[0080] It should be noted that between UPF_A235 and the access network, UPF_C239 (also known as a branch point or uplink classifier) may exist as a device or NF, which is a UPF different from UPF_A235. In the presence of UPF_C239, the PDU session between UE_A10 and DN_A5 is established via the access network, UPF_C239, and UPF_A235.

[0081] In addition, AUSF is connected to UDM and AMF_A240. AUSF functions as an authentication server.

[0082] UDSF provides a function for all NFs to save or retrieve information as unstructured data.

[0083] NEF provides methods to securely deliver services and capabilities provided through the 3GPP network and stores information received from other NFs as structured data.

[0084] When the NRF receives an NF Discovery Request from an NF instance, it provides the NF with information about the discovered NF instance or maintains information about available NF instances and services supported by the instance.

[0085] The PCF is connected to the SMF (SMF_A230), AF, and AMF_A240, and provides policy rules and other functions.

[0086] The UDM connects to the AMF_A240, SMF (SMF_A230), AUSF, and PCF. The UDM includes the UDM FE (Application Front End) and the UDR (User Data Repository). The UDM FE handles authentication information (credentials), location management, and subscription management. The UDR stores data required by the UDM FE and policy profiles required by the PCF.

[0087] The AF is connected to the PCF. The AF affects service routing or participates in policy control.

[0088] N3IWF provides the following functions: establishment of IPsec tunnel with UE, relaying of NAS (N1) signaling between UE and AMF, processing of N2 signaling sent from SMF and relayed by AMF, establishment of IPsec Security Association (IPsec SA), relaying of user plane packets between UE and UPF, AMF selection, etc.

[0089] In addition, the S1 mode is a UE mode that can use the S1 interface to send and receive messages. It should be noted that the S1 interface can be composed of the S1-MME interface, the S1-U interface, and the X2 interface connecting wireless base stations.

[0090] A UE in S1 mode can access the EPC via an eNB providing E-UTRA functionality or an en-gNB providing NR functionality.

[0091] It should be noted that although access to EPC via eNB providing E-UTRA functions and access to EPC via en-gNB providing NR functions are set as S1 mode, they can also be constructed into different modes.

[0092] In addition, N1 mode is a UE mode in which the UE can access the 5GC via the 5G access network. In addition, N1 mode can also be a UE mode in which messages can be sent and received using the N1 interface. It should be noted that the N1 interface can be composed of an Xn interface connecting the N1 interface and the wireless base station.

[0093] For example, a UE in N1 mode can access the 5GC via an ng-eNB providing E-UTRA functionality or via a gNB providing NR functionality.

[0094] It should be noted that although access to 5GC via ng-eNB providing E-UTRA function and access to 5GC via gNB providing NR function are set as N1 mode, they can also be constructed into different modes.

[0095] [1.2. Configuration of Each Device]

[0096] The following describes the configuration of each device. It should be noted that part or all of the functions of each device and each part of each device described below may be executed on physical hardware or on logical hardware virtually configured on general-purpose hardware.

[0097] [1.2.1. UE Configuration]

[0098] First, in Figure 5 An example of the device configuration of UE_A10 is shown in FIG. Figure 5 As shown, UE_A10 is composed of a control unit_A500, a transceiver_A520, and a storage unit_A540. The transceiver_A520 and the storage unit_A540 are connected to the control unit_A500 via a bus. In addition, the transceiver_A520 is connected to an external antenna 410.

[0099] The control unit_A500 is a functional unit for controlling the entire UE_A10, and implements various processes of the entire UE_A10 by reading and executing various information and programs stored in the storage unit_A540.

[0100] The transceiver_A520 is a functional unit that enables the UE_A10 to connect to base stations (UTRAN_A20, E-UTRAN_A80, and NG-RAN_A120) and / or wireless LAN access points (WLAN AN) within the access network, thereby connecting to the access network. In other words, the UE_A10 can connect to base stations and / or access points within the access network via the external antenna 410 connected to the transceiver_A520. Specifically, the UE_A10 can transmit and receive user data and / or control information to and from base stations and / or access points within the access network via the external antenna 410 connected to the transceiver_A520.

[0101] The storage unit_A540 is a functional unit that stores programs and data required for various operations of the UE_A10. It is composed of, for example, a semiconductor memory, an HDD (Hard Disk Drive), or an SSD (Solid State Drive). The storage unit_A540 stores identification information, control information, flags, parameters, rules, policies, and other information included in control messages sent and received during the communication process described later.

[0102] [1.2.2.eNB / NR Node]

[0103] Then, in Figure 6 An example of the device configuration of eNB_A45 and NR node_A122 is shown in FIG. Figure 6 As shown, the eNB_A45 and NR node_A122 are composed of a control unit_B600, a network connection unit_B620, a transceiver_B630, and a storage unit_B640. The network connection unit_B620, the transceiver_B630, and the storage unit_B640 are connected to the control unit_B600 via a bus. In addition, the transceiver_B630 is connected to the external antenna 510.

[0104] The control unit _B600 is a functional unit for controlling the eNB_A45 and NR node _A122 as a whole, and implements various processing of the eNB_A45 and NR node _A122 as a whole by reading and executing various information and programs stored in the storage unit _B640.

[0105] The Network Connector_B620 is a functional unit that connects the eNB_A45 and NR Node_A122 to the AMF_A240 and UPF_A235 within the core network. In other words, the eNB_A45 and NR Node_A122 can connect to the AMF_A240 and UPF_A235 within the core network via the Network Connector_B620. Specifically, the eNB_A45 and NR Node_A122 can transmit and receive user data and / or control information with the AMF_A240 and / or UPF_A235 via the Network Connector_B620.

[0106] The transceiver_B630 is a functional unit used to connect the eNB_A45 and NR node_A122 with the UE_A10. In other words, the eNB_A45 and NR node_A122 can transmit and receive user data and / or control information with the UE_A10 via the transceiver_B630.

[0107] Storage_B640 is a functional unit that stores programs and data required for the various operations of the eNB_A45 and NR node_A122. Storage_B640 is composed of, for example, a semiconductor memory, HDD, or SSD. Storage_B640 stores identification information, control information, flags, parameters, and other information included in control messages sent and received during the communication process described later. Storage_B640 can store this information as context for each UE_A10.

[0108] 1.2.3. MME / AMF Configuration

[0109] Then, in Figure 7 An example of the device configuration of MME_A40 or AMF_A240 is shown in FIG. Figure 7 As shown, MME_A40 or AMF_A240 is composed of a control unit_C700, a network connection unit_C720, and a storage unit_C740. The network connection unit_C720 and the storage unit_C740 are connected to the control unit_C700 via a bus. In addition, the storage unit_C740 stores a context 642.

[0110] The control unit _C700 is a functional unit for controlling the entire MME_A40 or AMF_A240, and implements various processes of the entire AMF_A240 by reading and executing various information and programs stored in the storage unit _C740.

[0111] The Network Connection Unit_C720 is a functional unit that connects the MME_A40 or AMF_A240 with other MME_A40, AMF_240, SMF_A230, base stations (UTRAN_A20, E-UTRAN_A80, and NG-RAN_A120) within the access network, and / or wireless LAN access points (WLANAN), UDM, AUSF, and PCF. In other words, the MME_A40 or AMF_A240 can transmit and receive user data and / or control information with base stations and / or access points, UDM, AUSF, and PCF within the access network via the Network Connection Unit_C720.

[0112] The storage unit_C740 is a functional unit that stores programs, data, and other information required for various operations of the MME_A40 or AMF_A240. The storage unit_C740 is composed of, for example, a semiconductor memory, a HDD, or an SSD. The storage unit_C740 stores identification information, control information, flags, parameters, and other information included in control messages sent and received during the communication process described later. The context 642 stored in the storage unit_C740 can be stored per UE, per PDU session, or per bearer. The context stored for each UE may include IMSI, MSISDN, MM status, GUTI, ME Identity, UE Radio Access Capability, UE Network Capability, MS Network Capability, Access Restriction, MME F-TEID, SGW F-TEID, eNB Address, MME UE S1APID, eNB UE S1AP ID, NR node Address, NR node ID, WAG Address, and WAG ID. In addition, the context stored for each PDU session may include the APN in use, Assigned Session Type, IP Address(es), PGW F-TEID, SCEF ID, and Default bearer. In addition, the context stored for each bearer may include EPS bearer ID (EPS bearer ID), TI, TFT, SGW F-TEID, PGW F-TEID, MME F-TEID, eNB address, NR node address, WAG address, eNB ID, NR node ID, and WAG ID.

[0113] [1.2.4. SMF composition]

[0114] Then, in Figure 8 An example of the device configuration of SMF_A230 is shown in FIG. Figure 8 As shown, SMF_A230 is composed of a control unit D800, a network connection unit D820, and a storage unit D840. The network connection unit D820 and the storage unit D840 are connected to the control unit D800 via a bus. The storage unit D840 also stores the context 742.

[0115] The control unit _D800 of SMF_A230 is a functional unit for controlling the entire SMF_A230, and realizes various processing of the entire SMF_A230 by reading and executing various information and programs stored in the storage unit _D840.

[0116] Furthermore, the SMF_A230's network connection unit_D820 is a functional unit for connecting the SMF_A230 with the AMF_A240, UPF_A235, UDM, and PCF. In other words, the SMF_A230 can transmit and receive user data and / or control information with the AMF_A240, UPF_A235, UDM, and PCF via the network connection unit_D820.

[0117] Furthermore, the storage unit_D840 of SMF_A230 is a functional unit that stores programs, data, and other information required for various operations of SMF_A230. The storage unit_D840 of SMF_A230 is comprised of, for example, a semiconductor memory, an HDD, or an SSD. The storage unit_D840 of SMF_A230 stores identification information, control information, flags, parameters, and other information included in control messages sent and received during the communication process described later. Furthermore, the context 742 stored in the storage unit_D840 of SMF_A230 may include contexts stored per UE, per APN, per PDU session, and per bearer. The context stored per UE may include the IMSI, ME identity, MSISDN, and RAT type. The context stored per APN may include the APN in use. It should be noted that the context stored per APN may also be stored per data network identifier. The context stored per PDU session can include the specified session type, IP address, SGW F-TEID, PGW F-TEID, and default bearer. The context stored per bearer can include the EPS bearer ID, TFT, SGW F-TEID, and PGW F-TEID.

[0118] [1.2.5. PGW / UPF Configuration]

[0119] Then, in Figure 8 An example of the device configuration of PGW_A30 or UPF_A235 is shown in FIG. Figure 8 As shown, PGW_A30 or UPF_A235 is composed of a control unit_D800, a network connection unit_D820, and a storage unit_D840. The network connection unit_D820 and the storage unit_D840 are connected to the control unit_D800 via a bus. In addition, the storage unit_D840 stores the context 742.

[0120] The control unit _D800 of PGW_A30 or UPF_A235 is a functional unit for controlling the entire PGW_A30 or UPF_A235, and implements various processing of the entire PGW_A30 or UPF_A235 by reading and executing various information and programs stored in the storage unit _D840.

[0121] Furthermore, the Network Connection Unit_D820 of the PGW_A30 or UPF_A235 is a functional unit for connecting the PGW_A30 or UPF_A235 to the DN (i.e., DN_A5), SMF_A230, other UPF_A235, and the access network (i.e., UTRAN_A20, E-UTRAN_A80, and NG-RAN_A120). In other words, the UPF_A235 can transmit and receive user data and / or control information between the DN (i.e., DN_A5), SMF_A230, other UPF_A235, and the access network (i.e., UTRAN_A20, E-UTRAN_A80, and NG-RAN_A120) via the Network Connection Unit_D820.

[0122] Furthermore, the storage unit_D840 of the UPF_A235 is a functional unit that stores programs, data, and other information required for various operations of the UPF_A235. The storage unit_D840 of the UPF_A235 is comprised of, for example, a semiconductor memory, an HDD, an SSD, or the like. The storage unit_D840 of the UPF_A235 stores identification information, control information, flags, parameters, and the like included in control messages sent and received during the communication process described later. Furthermore, the context 742 stored in the storage unit_D840 of the UPF_A235 may include contexts stored per UE, per APN, per PDU session, and per bearer. The context stored per UE may include the IMSI, ME identity, MSISDN, and RAT type. The context stored per APN may include the APN in use. It should be noted that the context stored per APN may also be stored per data network identifier. The context stored for each PDU session may include the specified session type, IP address, SGW F-TEID, PGW F-TEID, and default bearer. The context stored for each bearer may include the EPS bearer ID, TFT, SGW F-TEID, and PGW F-TEID. [1.2.6. Information stored in the storage unit of each of the above devices]

[0123] Next, each information stored in the storage unit of each of the above-mentioned devices will be described.

[0124] The IMSI (International Mobile Subscriber Identity) is permanent identification information of a subscriber (user) and is assigned to a user using a UE. The IMSI stored by UE_A10, MME_A40 / CPF_A140 / AMF_A2400, and SGW_A35 may be equivalent to the IMSI stored by HSS_A50.

[0125] The EMM state / MM state (EMM State / MM State) represents the mobility management state of UE_A10 or MME_A40 / CPF_A140 / AMF_A240. For example, the EMM state / MM state can be the EMM-REGISTERED state (login state) in which UE_A10 logs into the network and / or the EMM-DEREGISTERD state (non-login state) in which UE_A10 does not log into the network. In addition, the EMM state / MM state can also be the ECM-CONNECTED state that maintains the connection between UE_A10 and the core network and / or the ECM-IDLE state that releases the connection. It should be noted that the EMM state / MM state can also be information that can distinguish the state of UE_A10 logging into the EPC and the state of logging into the NGC or 5GC.

[0126] GUTI (Globally Unique Temporary Identity) is the temporary identification information of UE_A10. GUTI is composed of the identification information of MME_A40 / CPF_A140 / AMF_A240 (GUMMEI (Globally Unique MME Identifier)) and the identification information of UE_A10 within a specific MME_A40 / CPF_A140 / AMF_A240 (M-TMSI (M-Temporary Mobile Subscriber Identity)). ME identity is the ID of UE_A10 or ME, for example, it can be IMEI (International Mobile Equipment Identity) or IMEISV (IMEI Software Version). MSISDN indicates the basic telephone number of UE_A10. The MSISDN stored in MME_A40 / CPF_A140 / AMF_A240 can be information indicated by the storage unit of HSS_A50. It should be noted that the GUTI may include information for identifying the CPF_140.

[0127] The MME F-TEID is information that identifies the MME_A40 / CPF_A140 / AMF_A240. The MME F-TEID can include the IP address of the MME_A40 / CPF_A140 / AMF_A240, the TEID (Tunnel Endpoint Identifier) of the MME_A40 / CPF_A140 / AMF_A240, or both. Furthermore, the IP address of the MME_A40 / CPF_A140 / AMF_A240 and the TEID of the MME_A40 / CPF_A140 / AMF_A240 can be stored independently. Furthermore, the MME F-TEID can be used for identification of user data or control information.

[0128] The SGW F-TEID is information that identifies the SGW_A35. The SGW F-TEID can include the SGW_A35 IP address, the SGW_A35 TEID, or both. Furthermore, the SGW_A35 IP address and the SGW_A35 TEID can be stored independently. Furthermore, the SGW F-TEID can be used to identify user data or control information.

[0129] The PGW F-TEID is information identifying the PGW_A30 / UPGW_A130 / SMF_A230 / UPF_A235. The PGW F-TEID may include the IP address of the PGW_A30 / UPGW_A130 / SMF_A230 / UPF_A235, the TEID of the PGW_A30 / UPGW_A130 / SMF_A230 / UPF_A235, or both. Furthermore, the IP address of the PGW_A30 / UPGW_A130 / SMF_A230 / UPF_A235 and the TEID of the PGW_A30 / UPGW_A130 / SMF_A230 / UPF_A235 may be stored independently. Furthermore, the PGW F-TEID may be identification information for user data or control information.

[0130] The eNB F-TEID is information that identifies the eNB_A45. The eNB F-TEID can include the eNB_A45 IP address, the eNB_A45 TEID, or both. Furthermore, the eNB_A45 IP address and the SGW_A35 TEID can be stored independently. Furthermore, the eNB F-TEID can be used for either user data or control information.

[0131] Furthermore, the APN can be used to identify external networks such as the core network and DN. Furthermore, the APN can be used to select gateways such as PGW_A30 / UPGW_A130 / UPF_A235 that connect to the core network_A90. It should be noted that the APN can also be a DNN (Data Network Name). Therefore, the APN can be represented as a DNN, and the DNN can also be represented as an APN.

[0132] It should be noted that the APN can be identification information for identifying such a gateway, or it can be identification information for identifying an external network such as a DN. It should be noted that when multiple gateways are configured to connect to the core network and DN, there may be multiple gateways that can be selected by the APN. Furthermore, a gateway can be selected from these gateways using other methods that use identification information other than the APN.

[0133] UE Radio Access Capabilities is identification information indicating the radio access capabilities of UE_A10. UE Network Capabilities includes the security algorithms and key derivation functions supported by UE_A10. MS Network Capabilities includes one or more pieces of information required by SGSN_A42 for UE_A10 with GERAN_A25 and / or UTRAN_A20 functionality. Access Restrictions is access restriction registration information. eNB Address is the IP address of eNB_A45. MME UE S1AP ID is information used to identify UE_A10 within MME_A40 / CPF_A140 / AMF_A240. eNB UE S1AP ID is information used to identify UE_A10 within eNB_A45.

[0134] The APN in use is the most recently used APN. The APN in use can also be a data network identifier. The APN can be composed of network identification information and default operator identification information. Furthermore, the APN in use can also be information that identifies the DN of the destination for establishing a PDU session.

[0135] The designated session type is information indicating the type of the PDU session. The designated session type may also be the designated PDN type (Assigned PDN Type). The PDU session type may be IP or non-IP. Moreover, when the PDU session type is IP, information indicating the type of the PDN assigned by the network may be further included. It should be noted that the designated session type may be IPv4, IPv6, or IPv4v6.

[0136] In addition, unless otherwise specified, the IP address is the IP address assigned to the UE. The IP address can be an IPv4 address, an IPv6 address, an IPv6 prefix, or an interface ID. It should be noted that when the specified session type indicates non-IP, the IP address element may not be included.

[0137] DNN is identification information for external networks such as the Core Network_B190 and DN. It is also used as information for selecting gateways such as UPGW_A130 and PF_A235 that connect to the Core Network_B190.

[0138] It should be noted that the DNN can be identification information for identifying such a gateway, or it can be identification information for identifying an external network such as a DN. It should be noted that if multiple gateways are configured to connect to the core network_B190 and the DN, there may be multiple gateways that can be selected by the DNN. Furthermore, it is also possible to select a gateway from such multiple gateways using other methods that utilize identification information other than the DNN.

[0139] Furthermore, the DNN may be information equivalent to or different from the APN. It should be noted that when the DNN and APN are different information, each device may manage information indicating the correspondence between the DNN and the APN, implement a process of querying the APN using the DNN, and implement a process of querying the DNN using the APN.

[0140] The SCEF ID is the IP address of the SCEF_A46 used in the PDU session. The default bearer is information obtained and / or generated when establishing a PDU session and is EPS bearer identification information used to identify the default bearer corresponding to the PDU session.

[0141] EPS bearer ID is identification information of EPS bearer. In addition, EPS bearer ID can be identification information for identifying SRB (Signalling Radio Bearer) and / or CRB (Control-plane Radio Bearer), or identification information for identifying DRB (Data Radio Bearer). TI (Transaction Identifier) is identification information for identifying a bidirectional message flow (Transaction). It should be noted that EPS bearer ID can be EPS bearer identification information for identifying a dedicated bearer. Therefore, it can be identification information for identifying an EPS bearer different from the default bearer. TFT represents all packet filters associated with the EPS bearer. TFT is information that identifies a part of the user data being sent and received, and UE_A10 uses the EPS bearer associated with TFT to send and receive user data identified by TFT. In other words, UE_A10 uses the RB (Radio Bearer) associated with TFT to send and receive user data identified by TFT. In addition, TFT can establish a correspondence between user data such as application data being sent and received and an appropriate transmission path, and can be identification information for identifying application data. In addition, UE_A10 can use the default bearer to send and receive user data that cannot be identified by the TFT. In addition, UE_A10 can pre-store the TFT associated with the default bearer.

[0142] The default bearer is EPS bearer identification information that identifies the default bearer corresponding to the PDN session. It should be noted that the EPS bearer can be a logical communication path established between UE_A10 and PGW_A30 / UPGW_A130 / UPF_A235, or a communication path that constitutes a PDU connection / PDU session. Moreover, the EPS bearer can be a default bearer or a dedicated bearer. Moreover, the EPS bearer can be constituted as an RB established between UE_A10 and a base station and / or access point in the access network. Moreover, the RB can be mapped one-to-one with the EPS bearer. Therefore, the identification information of the RB can be mapped one-to-one with the identification information of the EPS bearer, or it can be the same identification information. It should be noted that the RB can be an SRB and / or a CRB, or it can be a DRB. In addition, the default bearer can be information obtained by UE_A10 and / or SGW_A35 and / or PGW_A30 / UPGW_A130 / SMF_A230 / UPF_A235 from the core network when establishing a PDU session. It should be noted that the default bearer is the EPS bearer initially established in a PDN connection / PDU session. Only one EPS bearer can be established in a PDN connection / PDU session. The default bearer can be an EPS bearer that can be used in communications for which corresponding user data is not established with a TFT. In addition, a dedicated bearer is an EPS bearer that is established after the default bearer is established in a PDN connection / PDU session. Multiple EPS bearers can be established in a PDN connection / PDU session. A dedicated bearer is an EPS bearer that can be used in communications for which corresponding user data is established with a TFT.

[0143] User Identity (UI) is information that identifies the subscriber. It can be either an IMSI or an MSISDN. Furthermore, the UI can be information other than IMSI or MSISDN. Serving Node Information (SNI) identifies the MME_A40 / CPF_A140 / AMF_A240 used in the PDU session and can be the IP address of the MME_A40 / CPF_A140 / AMF_A240.

[0144] The eNB address is the IP address of eNB_A45. The eNB ID is information that identifies the UE within eNB_A45. The MME address (MMEAddress) is the IP address of MME_A40 / CPF_A140 / AMF_A240. The MME ID is information that identifies MME_A40 / CPF_A140 / AMF_A240. The NR node address is the IP address of NR node_A122. The NR node ID is information that identifies NR node_A122. The WAG address is the IP address of the WAG. The WAG ID is information that identifies the WAG.

[0145] An anchor or anchor point refers to a UPF that has the gateway function of DN and PDU session. The UPF that becomes an anchor point can be a PDU session anchor or an anchor.

[0146] The SSC mode represents the mode of service session continuity (Session and Service Continuity) supported by the system and / or each device in 5GC. In more detail, it can be a mode that represents the type of service session continuity supported by the PDU session established between UE_A10 and the anchor point. Here, the anchor point can be UPGW or UPF_A235. It should be noted that the SSC mode can also be a mode that represents the type of service session continuity set for each PDU session. Moreover, the SSC mode can be composed of three modes: SSC mode 1 (SSC mode 1), SSC mode 2 (SSC mode 2), and SSC mode 3 (SSCmode 3). The SSC mode (SSC mode) is associated with the anchor point and cannot be changed between states where a PDU session is established.

[0147] Furthermore, SSC Mode 1 of this embodiment maintains service session continuity using the same UPF as an anchor point, regardless of the access technology used by UE_A10 when connecting to the network, such as the RAT (Radio Access Technology) or cell. More specifically, SSC Mode 1 allows for service session continuity without changing the anchor point used for established PDU sessions, even if UE_A10 moves.

[0148] Furthermore, SSC Mode 2 in this embodiment is a service session continuity mode in which, when a PDU session includes an anchor point associated with SSC Mode 2, the PDU session is released before the PDU session is established. Specifically, SSC Mode 2 is a mode in which, when an anchor point is relocated, a PDU session is deleted and then a new one is created.

[0149] Furthermore, SSC Mode 2 is a mode that maintains service session continuity with the same UPF as the anchor point only within the UPF's service area. More specifically, as long as UE_A10 is within the UPF's service area, SSC Mode 2 can achieve service session continuity without changing the UPF used for established PDU sessions. Furthermore, if UE_A10 moves, such as leaving the UPF's service area, SSC Mode 2 can achieve service session continuity by changing the UPF used for established PDU sessions.

[0150] Here, the service area of the TUPF can be an area where the UPF can provide service session continuity functions, or it can be a subset of the access network, such as the RAT and cell, used by the UE_A10 when connecting to the network. Moreover, the subset of the access network can be a network including one or more cells, or a TA.

[0151] Furthermore, SSC mode 3 in this embodiment is a service session continuity mode that enables establishment of a PDU session between a new anchor point and the UE for the same DN without releasing the PDU session between the UE and the anchor point.

[0152] Furthermore, SSC Mode 3 allows service session continuity by establishing a new PDU session and / or communication path 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 mode that allows service session continuity when UE_A10 becomes multi-homed.

[0153] And / or SSC mode 3 may also be a mode that allows continuity of service sessions using multiple PDU sessions and / or establishing corresponding UPFs for PDU sessions. In other words, in the case of SSC mode 3, each device can use multiple PDU sessions to achieve service session continuity, and can also use multiple TUPFs to achieve service session continuity.

[0154] When each device establishes a new PDU session and / or communication path, the network may select a new UPF, which may be the most suitable UPF for the location where UE_A10 is connected to the network. Furthermore, if multiple PDU sessions and / or UPFs used by PDU sessions are available, UE_A10 may immediately associate the communication of the application and / or flow with the newly established PDU session, or may do so upon completion of the communication.

[0155] [1.3. Description of the initial process]

[0156] Next, before describing the details of the initial process of this embodiment, terminology unique to this embodiment and main identification information used in each process will be described in advance to avoid duplication of descriptions.

[0157] In this embodiment, the network refers to at least a portion of the access network_A20 / 80, access network_B80 / 120, core network_A90, core network_B190, DN_A5, and PDN_A6. Furthermore, one or more devices included in at least a portion of the access network_A20 / 80, access network_B80 / 120, core network_A90, core network_B190, DN_A5, and PDN_A6 may also be referred to as a network or network device. Specifically, the network performing message transmission and / or processing refers to devices (network devices) within the network performing message transmission and / or processing.

[0158] The session management (SM) message (also called NAS (Non-Access-Stratum) SM message or SM message) of this embodiment can be a NAS message used in the process for SM (also called session management process or SM process), or it can be a control message sent and received between UE_A10 and SMF_A230 via AMF_A240. In addition, the SM message includes a PDU session establishment request message, a PDU session establishment acceptance message, a PDU session completion message, a PDU session rejection message, a PDU session change request message, a PDU session change acceptance message, a PDU session change rejection message, etc. In addition, the process for SM includes a PDU session establishment process, a PDU session change process, etc.

[0159] It should be noted that the message sent by UE_A10 in the SM message is represented as an SM request message. Specifically, the PDU session establishment request message and the PDU session change request message are SM request messages.

[0160] The Tracking Area (TA) in this embodiment is a range managed by the core network that can be represented by the location information of UE_A10. For example, it can be composed of one or more cells. In addition, the TA can be the range for broadcasting control messages such as paging messages, or the range within which UE_A10 can move without performing a handover process.

[0161] The TA list in this embodiment includes one or more TAs assigned by the network to UE_A10. It should be noted that UE_A10 can move within one or more TAs included in the TA list without performing a login procedure. In other words, the TA list may be a set of information indicating areas where UE_A10 can move without performing a login procedure.

[0162] The network slice in this embodiment refers to a logical network that provides specific network capabilities and network characteristics. Hereinafter, the network slice is also referred to as the NW slice.

[0163] The NSI (Network Slice Instance) of this embodiment refers to an entity in which one or more network slices (Network Slice) are configured in the core network_B190. In addition, the NSI of this embodiment can be composed of a virtual NF (Network Function) generated using the NST (Network Slice Template). Here, NST refers to a logical expression of one or more NFs (Network Function) associated with a resource request for providing the requested communication service and capability. That is, NSI can refer to an aggregate within the core network_B190 composed of multiple NFs. In addition, NSI can be a logical network configured to divide the user data sent according to services, etc. There can be at least one or more NFs in a network slice. The NF constituted in the network slice may be a device shared with other network slices, or may not be a device shared with other network slices. UE_A10 and / or devices within the network can be assigned to one or more network slices based on login information and / or APN such as NSSAI and / or S-NSSAI and / or UE usage type and / or one or more network slice type IDs and / or one or more NS IDs.

[0164] The S-NSSAI of this embodiment is the abbreviation of Single Network Slice Selection Assistance information, which is information used to identify network slices. S-NSSAI can be composed of SST (Slice / Service type) and SD (Slice Differentiator). S-NSSAI can be composed of SST only, or can be composed of both SST and SD. Here, SST refers to information that represents the expected actions of the network slice in terms of functions and services. In addition, SD can be information that supplements SST when selecting an NSI from multiple NSIs shown in SST. S-NSSAI can be information specific to each PLMN (Public Land Mobile Network), standard information common between PLMNs, or information specific to different communication operators for each PLMN.

[0165] More specifically, the SST and / or SD may be standard information (Standard Value) common among PLMNs, or may be information specific to a communication operator (Non-Standard Value) that differs for each PLMN.

[0166] In addition, the network can store one or more S-NSSAIs in the login information of UE_A10 as the default S-NSSAI.

[0167] The NSSAI (Single Network Slice Selection Assistance Information) of this embodiment is a collection of S-NSSAIs. Each S-NSSAI included in the NSSAI is information that assists the access network or core network in selecting the NSI. The UE_A10 can store the network-allowed NSSAI for each PLMN. In addition, the NSSAI can be information used to select the AMF_A240.

[0168] The operator A network in this embodiment is a network operated by network operator A (operator A). Here, for example, operator A may also deploy a NW slice shared with operator B described later.

[0169] The operator B network in this embodiment is a network operated by network operator B (operator B). Here, for example, operator B may also deploy a NW slice shared with operator A.

[0170] The first NW slice of this embodiment is the NW slice to which the PDU session is established when the UE is connected to a specific DN. It should be noted that, for example, the first NW slice can be an NW slice managed within the network of operator A or an NW slice jointly managed within the network of operator B.

[0171] The second NW slice of this embodiment is a NW slice to which other PDU sessions can be connected to a DN that uses the PDU session belonging to the first NW slice as the connection destination. It should be noted that the first NW slice and the second NW slice can be operated by the same operator or by different operators.

[0172] The equivalent PLMN in this embodiment is a PLMN that is handled as the same PLMN as any other PLMN in the network.

[0173] The DCN (Dedicated Core Network) of this embodiment refers to one or more core networks dedicated to a specific subscriber type constructed within the core network_A90. Specifically, for example, the DCN for the UE logged in as a user of the M2M (Machine to Machine) communication function can be constructed within the core network_A90. In addition, in addition to this, a default DCN for the UE for which there is no appropriate DCN can also be constructed within the core network_A90. Moreover, the DCN can be configured with at least one or more MME_40 or SGSN_A42, and can also be configured with at least one or more SGW_A35 or PGW_A30 or PCRF_A60. It should be noted that the DCN can be identified by the DCN ID, and the UE can also be assigned to a DCN based on information such as the UE usage type and / or DCN ID.

[0174] The first timer of this embodiment is a timer for managing the start of a process for session management such as a PDU session establishment process and / or the sending of an SM (Session Management) message such as a PDU session establishment request message, and may also be information indicating the value of a backoff timer for managing the behavior of session management. Hereinafter, the first timer and / or the backoff timer are sometimes referred to as a timer. During the execution of the first timer, each device may be prohibited from starting a process for session management and / or sending and receiving SM messages. It should be noted that the first timer may be set to establish an association with at least one of the congestion management units applied by the NW and / or the congestion management units identified by the UE. For example, it may be set by an APN / DNN unit and / or an identification information unit representing one or more NW slices and / or a rejection reason value unit in the session management process and / or a session unit indicating rejection in the session management process and / or a PTI unit of the session management process.

[0175] It should be noted that SM messages can be NAS messages used in session management processes, or control messages sent and received between UE_A10 and SMF_A230 via AMF_A240. Furthermore, SM messages include PDU Session Establishment Request messages, PDU Session Establishment Accept messages, PDU Session Complete messages, PDU Session Reject messages, PDU Session Change Request messages, PDU Session Change Accept messages, and PDU Session Change Reject messages. Furthermore, processes used for session management can include PDU Session Establishment and PDU Session Change processes. Furthermore, during these processes, messages received by UE_A10 may also include a backoff timer value. The UE can set the backoff timer received from the NW as the first timer, set the timer value using other methods, or set a random value. Furthermore, if multiple backoff timers are received from the NW, the UE can manage multiple "first timers" corresponding to the multiple backoff timers, or select a timer value from the multiple backoff timer values received from the NW based on a policy maintained by the UE, set it as the first timer, and manage it accordingly. For example, if two backoff timer values are received, the UE sets the backoff timer values received from the NW as "first timer #1" and "first timer #2," respectively, and manages these backoff timers. Alternatively, based on a policy maintained by the UE, the UE may select one backoff timer value from among the multiple backoff timer values received from the NW and set it as the first timer for management.

[0176] When UE_A10 receives multiple backoff timer values from the NW, it can manage multiple "first timers" corresponding to the multiple backoff timers. To distinguish the multiple "first timers" received by UE_A10, they may sometimes be referred to as "first timer #1" or "first timer #2" below. It should be noted that multiple backoff timers can be obtained during a single session management process or during separate, separate session management processes.

[0177] Here, the first timer can be a back-off timer set for multiple associated NW slices based on the information used to identify an NW slice as described above, and used to suppress reconnection, or set in units of a combination of APN / DNN and an NW slice, and used to prevent reconnection, but is not limited to this. It can also be a back-off timer set in units of a combination of APN / DNN and multiple NW slices associated based on the information used to identify an NW slice, and used to suppress reconnection.

[0178] The re-attempt (Re-attempt) information included in the eleventh identification information of this embodiment is information in which the network (NW) indicates whether UE_A10 is allowed to reconnect the rejected PDU session establishment request (S1100) using the same DNN information and or S-NSSAI information.

[0179] At this time, in the PDU session establishment request (1100), when the UE executes the PDU session establishment request (S1100) not including the DNN, the information not including the DNN is referred to as the same information. In addition, in the PDU session establishment request (1100), when the UE executes the PDU session establishment request (S1100) not including the S-NSSAI, the information not including the S-NSSAI is referred to as the same information.

[0180] It should be noted that the re-attempt information can be set in units of UTRAN access and / or E-UTRAN access and / or NR access and / or slice information and / or equivalent PLMN and / or S1 mode and / or NW mode.

[0181] Furthermore, the re-attempt information specified per access (UTRAN access, E-UTRAN access, NR access) may indicate reconnection to the network using the same information as a prerequisite for access change. The re-attempt information specified per slice may specify slice information different from the rejected slice, or may allow reconnection using the specified slice information.

[0182] Furthermore, the re-attempt information specified in equivalent PLMN units may indicate that, when a PLMN is changed, if the destination PLMN is an equivalent PLMN, reconnection using the same information is permitted. Alternatively, the information may indicate that, if the destination PLMN is not an equivalent PLMN, reconnection using this procedure is not permitted.

[0183] Furthermore, the re-attempt information specified in mode units (S1 mode, N1 mode) may indicate that, when a mode is changed, reconnection using the same information is permitted if the mode of the changed destination is S1 mode. Alternatively, the re-attempt information may indicate that reconnection using the same information is not permitted if the mode of the changed destination is S1 mode.

[0184] The network slice association rule of this embodiment refers to a rule for associating information that identifies multiple network slices. It should be noted that the network slice association rule can be received in a PDU session rejection message, or it can be set in advance for UE_A10. Moreover, the network slice association rule can also apply the latest rules in UE_A10. Conversely, UE_A10 can perform actions based on the latest network slice association rule. For example, in a state where the network slice association rule is set in advance for UE_A10, when a new network slice association rule is received through a PDU session rejection message, UE_A10 can update the network slice association rule maintained in UE_A10.

[0185] The priority management rule of the backoff timer in this embodiment refers to the rule set for UE_A10, which is used to centralize the multiple backoff timers occurring in multiple PDU sessions into one backoff timer for management. For example, when contention or repetitive congestion management is applied, and when the UE maintains multiple backoff timers, UE_A10 can centrally manage the multiple backoff timers based on the priority management rule of the backoff timer. It should be noted that in a mode where contention or repetitive congestion management occurs, when congestion management based only on DNN and congestion management based on both DNN and slice information are applied at the same time, in this case, congestion management based only on DNN is given priority. It should be noted that the priority management rule of the backoff timer may not be limited to this. It should be noted that the backoff timer may be the first timer included in the PDU session reject message.

[0186] The first state of this embodiment refers to a state in which each device has completed the login process and the PDU session establishment process, and is a state in which UE_A10 and / or each device has applied one or more of the first to fourth congestion management methods. Here, UE_A10 and / or each device may be in a state in which UE_A10 is logged into the network (RM-REGISTERED state) based on the completion of the login process, and the completion of the PDU session establishment process may be a state in which UE_A10 receives a PDU session establishment rejection message from the network.

[0187] The congestion management of this embodiment is composed of one or more congestion managements from the first congestion management to the fourth congestion management. It should be noted that the control of the UE by the NW can be achieved through the first timer and the congestion management identified by the UE, and the UE can store the association of this information.

[0188] The first congestion management of this embodiment means control signal congestion management with the parameters of DNN as the object. For example, in the NW, when congestion is sensed for DNN#A, the NW can apply the first congestion management when the NW identifies it as a UE-led session management request with only the parameters of DNN#A as the object. It should be noted that even if the UE-led session management request does not include DNN information, the NW can still select the default DNN as the congestion management object under the NW's leadership. Alternatively, even in the case of a UE-led session management request identified by the NW as including DNN#A and S-NSSAI#A, the NW can also apply the first congestion management. When the first congestion management is applied, the UE can suppress the UE-led session management request with only DNN#A as the object.

[0189] In other words, the first congestion management of this embodiment is control signal congestion management targeting the DNN, and may be congestion management caused by a congested state of connectivity to the DNN. For example, the first congestion management may be congestion management for limiting connections to DNN#A in all connectivity. Here, the connection to DNN#A in all connectivity may be a connection to DNN#A in connectivity using any S-NSSAI that the UE can utilize, or a connection to DNN#A via a network slice that the UE can connect to. Furthermore, connectivity to DNN#A that does not pass through a network slice may be included.

[0190] The second congestion management in this embodiment refers to control signal congestion management targeting S-NSSAI parameters. For example, if the NW detects control signal congestion for S-NSSAI#A and identifies a UE-initiated session management request targeting only S-NSSAI#A parameters, the NW may apply the second congestion management. When the second congestion management is applied, the UE may suppress UE-initiated session management requests targeting only S-NSSAI#A.

[0191] In other words, the second congestion management in this embodiment is control signal congestion management targeting S-NSSAI, and can be congestion management caused by a congested state in the network slice selected based on S-NSSAI. For example, the second congestion management can also be used to limit congestion for all connections based on S-NSSAI#A. In other words, it can also be used to limit congestion for all connections to the DNN via the network slice selected based on S-NSSAI#A.

[0192] The third congestion management of this embodiment represents control signal congestion management with the parameters of DNN and S-NSSAI as the objects. For example, in the NW, when the control signal congestion for DNN#A and the control signal congestion for S-NSSAI#A are sensed at the same time, when the NW identifies it as a UE-led session management request with the parameters of DNN#A and S-NSSAI#A as the objects, the NW can apply the third congestion management. It should be noted that even if the NW does not include information representing the DNN in the UE-led session management request, the NW can also select the default DNN as the congestion management object under the NW's leadership. When the third congestion management is applied, the UE can suppress the UE-led session management request with the parameters of DNN#A and S-NSSAI#A as the objects.

[0193] In other words, the third congestion management in this embodiment is control signal congestion management targeting DNN and S-NSSAI parameters. This can be congestion management caused by congestion in connectivity to the DNN via a network slice selected based on S-NSSAI. For example, the third congestion management can be congestion management for limiting connectivity to DNN#A based on S-NSSAI#A connectivity.

[0194] The fourth congestion management of this embodiment represents control signal congestion management with at least one parameter in DNN and / or S-NSSAI as the object. For example, in the NW, when the control signal congestion for DNN#A and the control signal congestion for S-NSSAI#A are sensed at the same time, when the NW identifies it as a UE-led session management request with at least one parameter in DNN#A and / or S-NSSAI#A as the object, the NW can apply the fourth congestion management. It should be noted that even if the NW does not include information representing the DNN in the UE-led session management request, the NW can also select the default DNN as the congestion management object through NW leadership. When the fourth congestion management is applied, the UE can suppress the UE-led session management request with at least one parameter in DNN#A and / or S-NSSAI#A as the object.

[0195] In other words, the fourth congestion management of this embodiment is control signal congestion management with the parameters of DNN and S-NSSAI as the object, and can be congestion management caused by the network slice selected based on S-NSSAI and the connectivity to DNN being in a congested state. For example, the fourth congestion management can be congestion management for limiting all connections based on S-NSSAI#A, and can be congestion management for limiting connections to DNN#A in all connectivity. That is, it can be congestion management for limiting all connections to DNN via the network slice selected according to S-NSSAI#A, and can be congestion management for limiting connections to DNN#A in all connectivity. Here, the connection to DNN#A in all connectivity can be a connection to DNN#A in the connectivity using any S-NSSAI that the UE can use, or a connection to DNN#A via a network slice that the UE can connect to. Moreover, connectivity to DNN#A that does not pass through a network slice can be included.

[0196] Therefore, the fourth congestion management using DNN#A and S-NSSAI#A as parameters may be congestion management that simultaneously performs the first congestion management using DNN#A as a parameter and the second congestion management using S-NSSAI#A as a parameter.

[0197] The first behavior of this embodiment refers to the behavior of the UE storing the slice information sent in the first PDU session establishment request message in association with the PDU session identification information that has been sent. In the first behavior, the UE can store the slice information sent in the first PDU session establishment request message, and can also store the slice information received when the first PDU session establishment request is rejected.

[0198] The second behavior of this embodiment refers to the behavior of the UE sending a PDU session establishment request for connecting to the same APN / DNN as the first PDU session establishment request using other slice information different from the slice information specified in the first PDU session establishment. Specifically, the second behavior may be the following behavior: when the backoff timer value received from the network is zero or invalid, the UE sends a PDU session establishment request for connecting to the same APN / DNN as the first PDU session establishment request using slice information different from the slice information specified in the first PDU session establishment. Alternatively, the second behavior may also be the following behavior: when the first PDU session is rejected due to unsupported wireless access to a specific PLMN to which the specified APN / DNN is connected, or when the first PDU session is rejected due to temporary reasons, the UE sends a PDU session establishment request for connecting to the same APN / DNN as the APN / DNN included in the first PDU session establishment request using slice information different from the slice information specified in the first PDU session establishment.

[0199] The third behavior of this embodiment refers to the behavior that when the PDU session establishment request is rejected, the UE does not send a new PDU session establishment request using the same identification information before the expiration of the first timer. Specifically, the third behavior may be the following behavior: when the backoff timer value received from the network is not zero or invalid, the UE does not send a new PDU session establishment request using the same identification information before the expiration of the first timer. Here, the same identification information may mean whether the first identification information and / or second identification information loaded in the new PDU session establishment request is the same as the first identification information and / or second identification information sent in the rejected PDU session establishment request.

[0200] Alternatively, the third behavior may also be the following behavior: when another PLMN is selected or another NW slice is selected, and when a rejection reason related to a setting failure of the network operation is received, when a backoff timer received when the first PDU session establishment request is rejected is started, a new PDU session establishment request using the same identification information is not sent before the expiration of the first timer.

[0201] In detail, the PDU session for which a new PDU session establishment request is not sent in the third behavior may be a PDU session to which congestion management corresponding to the first timer is applied. More specifically, in the third behavior, it may be the connectivity corresponding to the congestion management category corresponding to the first timer, and it may be the behavior of not resending the PDU session establishment request for the PDU session using the DNN and / or S-NSSAI corresponding to the congestion management. It should be noted that the processing prohibited by the UE through this behavior may be the start of a process for session management including a PDU session establishment request and / or the sending and receiving of SM messages.

[0202] The fourth behavior of this embodiment refers to the behavior that when the PDU session establishment request is rejected, the UE does not send a new PDU session establishment request that does not load slice information and DNN / APN information before the expiration of the first timer. Specifically, the fourth behavior may be the following behavior: when the backoff timer received from the network is not zero or invalid, the UE does not send a new PDU session establishment request that does not load slice information and DNN / APN information before the expiration of the first timer.

[0203] The fifth behavior of this embodiment refers to the behavior that the UE does not send a new PDU session establishment request using the same identification information when the PDU session establishment request is rejected. Specifically, the fifth behavior may be the following behavior: when the PDP types supported by the UE and the network are different and they are in an equivalent PLMN, the UE does not send a new PDU session establishment request using the same identification information.

[0204] The sixth behavior of this embodiment refers to the behavior of the UE sending a new PDU session establishment request using the same identification information as the initial procedure when the PDU session establishment request is rejected. Specifically, the sixth behavior may be the following behavior: when the first PDU session establishment request is rejected due to the absence of the target PDN session context in the handover from the non-3GPP access, the UE sends a new PDU session establishment request using the same identification information as the initial procedure.

[0205] The seventh behavior of this embodiment refers to a behavior in which, when another NW slice is selected during the PLMN selection process, the UE continues the backoff timer received when the previous PDU session establishment request was rejected. Specifically, the seventh behavior may be the following behavior: when PLMN selection is performed when the first PDU session establishment request is rejected, and when a NW slice that is common to the NW slice specified in the first PDU session establishment request can be specified in the selected target PLMN, the UE continues the backoff timer received when the first PDU session establishment request was rejected.

[0206] The eighth behavior of this embodiment refers to the behavior that the UE may set a value notified by the network or a value pre-set for the UE as the first timer value. Specifically, the eighth behavior may be the behavior that the UE sets the backoff timer value received in the rejection notification of the first PDU session establishment request as the first timer value, or may be the behavior that the UE sets a value pre-set or maintained in the UE as the first timer value. It should be noted that when the timer pre-set or maintained in the UE is set to the first timer value, it may also be limited to when the UE is in the HPLMN or an equivalent PLMN.

[0207] The ninth behavior of this embodiment refers to the behavior that when the PDU session establishment request is rejected, the UE does not send a new PDU session establishment request before the terminal is powered on / off or the USIM (Universal Subscriber Identity Module) is unplugged. Specifically, in the ninth behavior, when the back-off timer received from the network is invalid or the reason for the rejection of the first PDU session is that the PDP type between the UE and the network is different, the UE does not send a new PDU session establishment request before the terminal is powered on / off or the USIM is unplugged. Alternatively, the ninth behavior may be the following behavior: when the first PDU session is rejected because it is not supported in the wireless of the PLMN to which the specified APN / DNN is connected, and there is no information element of the back-off timer from the network, there is no Re-attempt information, or reconnection of the PDU session with the equivalent PLMN is allowed, in the connected PLMN, a new PDU session establishment request is not sent before the terminal is powered on / off or the USIM is unplugged. Alternatively, the ninth behavior may also be the following behavior: when the first PDU session is rejected due to non-support in the radio of the PLMN to which the specified APN / DNN is connected, and there is no information element for the backoff timer from the network, no re-attempt information, or when reconnection of the PDU session with the equivalent PLMN is not allowed, in the connected PLMN, a new PDU session establishment request is not sent before the terminal is powered on / off or the USIM is unplugged. Alternatively, the ninth behavior may also be the following behavior: when the first PDU session is rejected due to non-support in the radio of the PLMN to which the specified APN / DNN is connected, and the backoff timer from the network is not zero or invalid, a new PDU session establishment request is not sent before the terminal is powered on / off or the USIM is unplugged. Alternatively, the ninth behavior may also be the following behavior: when the first PDU session is rejected due to non-support in the radio of the PLMN to which the specified APN / DNN is connected, and the backoff timer from the network is invalid, a new PDU session establishment request is not sent before the terminal is powered on / off or the USIM is unplugged.

[0208] The tenth behavior of this embodiment refers to the behavior of the UE sending a new PDU session establishment request when the PDU session establishment request is rejected. Specifically, the tenth behavior may be the following behavior: when the backoff timer received from the network is zero, or when the first PDU session establishment request is rejected due to temporary reasons, and when there is no backoff timer information element itself notified from the network, the UE sends a new PDU session establishment request. Alternatively, the tenth behavior may also be the following behavior: when another PLMN is selected or another NW slice is selected, and when the first PDU session establishment request is rejected due to temporary reasons, and when the backoff timer is not started for the target APN / DNN in the selected PLMN, or when the backoff timer received from the network is invalid, a new PDU session establishment request is sent. Alternatively, the tenth behavior may be as follows: when the first PDU session establishment request is rejected due to a difference in PDP types between the UE and the network, and when a different PLMN is selected, no Re-attempt information is received, or a PLMN not included in the equivalent PLMN list is selected, or the PDP type is changed, or the terminal is powered on / off or the USIM is removed or plugged in, a new PDU session establishment request is sent. Alternatively, the tenth behavior may be as follows: when the first PDU session is rejected due to unsupported wireless in the PLMN to which the specified APN / DNN is connected, and when the backoff timer notified from the network is zero, a new PDU session establishment request is sent.

[0209] The eleventh behavior of this embodiment refers to the behavior of the UE ignoring the first timer and the Re-attempt information. Specifically, the eleventh behavior may be the following behavior: when the first PDU session establishment request is rejected because the object PDN session context does not exist in the handover from the non-3GPP access, or when the first PDU session establishment is rejected because the number of bearers set in the PDN connection reaches the maximum allowed number, the UE ignores the first timer and the Re-attempt information.

[0210] The twelfth behavior of this embodiment refers to the following behavior: the UE determines the information for identifying the associated multiple NW slices based on the information for identifying one NW slice received in the rejection notification for the first PDU session establishment request, and suppresses reconnection for the associated multiple NW slices based on the information for identifying one NW slice. Specifically, the twelfth behavior may be the following behavior: the UE establishes association rules based on network slices, and derives information for identifying other NW slices associated with the information for identifying the NW slice notified in the rejection of the first PDU session establishment request. It should be noted that the network slice establishment association rules can be set for the UE in advance, or can be notified by the network in the rejection notification of the PDU session establishment.

[0211] The thirteenth behavior of this embodiment may refer to the behavior of the UE managing the timer based on the priority management rule of the backoff timer when different multiple congestion managements are started for one or more PDU sessions by the same UE and multiple timers are provided by the network. For example, the first PDU session establishment request made by the UE for the combination of DNN_1 and slice_1 is set as the congestion management object based on both DNN and slice information, and the UE receives the first timer #1. Moreover, the UE makes a second PDU session establishment request for the combination of DNN_1 and slice_2, which is set as the object of congestion management based only on DNN, and receives the first timer #2. At this time, the UE can manage the behavior of the UE's PDU session re-establishment based on the priority management rule of the backoff timer through the first timer #2 that has been assigned priority. Specifically, the value of the timer maintained by the UE can be overwritten with the timer value generated according to the congestion control set as priority.

[0212] The fourteenth behavior of this embodiment may refer to the behavior of managing timers by session management instance (PDU session unit) when different congestion management is applied to one or more PDU sessions by the same UE and multiple timers are provided by the network. For example, when the first PDU session establishment performed by the UE for the combination of DNN#1 and slice#1 is set as a congestion object based on both DNN and slice information, the UE manages the backoff timer value of the object as the first timer#1. Afterwards, when the UE further attempts to establish a PDU session for the combination of DNN#1 and slice#2 as the second PDU session, when it is set as a congestion object based only on DNN, the UE manages the backoff timer value of the object as the first timer#2. At this time, the UE manages multiple timers (here, the first timer#1 and the first timer#2) at the same time. Specifically, the UE manages timers in units of session management instance / PDU session. In addition, when the UE receives multiple timers simultaneously in one session management process, the UE manages the backoff timer of the object at the same time in units of the congestion management identified by the UE.

[0213] The fifteenth behavior of this embodiment may refer to the behavior of performing the first identification processing and the second identification processing, wherein the first identification processing identifies which congestion management category of the first to fourth congestion management is applied by UE_A10, and the second identification processing identifies the DNN and / or S-NSSAI corresponding to the applied congestion management. It should be noted that the first identification processing can be based on at least one or more identification information from the first to fourth identification information and / or at least one or more identification information from the eleventh to eighteenth identification information for identification. Similarly, the second identification processing can be based on at least one or more identification information from the first to fourth identification information and / or at least one or more identification information from the eleventh to eighteenth identification information for identification.

[0214] An example of the first identification process is described below. In the first identification process, when any one or two or more combinations of the following conditions are satisfied, the applied congestion management type can be identified as the first congestion management.

[0215] At least the fifteenth identification information is a value corresponding to the first congestion management.

[0216] At least the sixteenth identification information is a value corresponding to the first congestion management.

[0217] A case where information indicating the first congestion management is included in at least the fourteenth identification information.

[0218] At least the seventeenth identification information includes only DNN but not S-NSSAI.

[0219] When the sixteenth identification information is information for identifying either the first congestion management or the second congestion management, and only a value corresponding to the second congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0220] When the sixteenth identification information is information for identifying either the first congestion management or the fourth congestion management, and only a value corresponding to the fourth congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0221] The sixteenth identification information is information for identifying any one of the first congestion management, the second congestion management, and the fourth congestion management, and when only a value corresponding to the second congestion management and a value corresponding to the fourth congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0222] However, it is not limited to the above examples. UE_A10 can be identified based on at least one of the first to fourth identification information and / or at least one of the eleventh to eighteenth identification information or a combination of two or more identification information.

[0223] In the first identification process, when any one or two or more combinations of the following conditions are satisfied, the applied congestion management type may be identified as the second congestion management.

[0224] At least the fifteenth identification information is a value corresponding to the second congestion management.

[0225] At least the sixteenth identification information is a value corresponding to the second congestion management.

[0226] A case where information indicating the second congestion management is included in at least the fourteenth identification information.

[0227] At least the seventeenth identification information includes only S-NSSAI but not DNN.

[0228] When the sixteenth identification information is information for identifying either the first congestion management or the second congestion management and only a value corresponding to the first congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0229] When the sixteenth identification information is information for identifying either the second congestion management or the third congestion management, and only a value corresponding to the third congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0230] The sixteenth identification information is information for identifying any one of the second congestion management, the third congestion management, and the fourth congestion management, and when only a value corresponding to the third congestion management and a value corresponding to the fourth congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0231] However, it is not limited to the above examples. UE_A10 can be identified based on at least one of the first to fourth identification information and / or at least one of the eleventh to eighteenth identification information or a combination of two or more identification information.

[0232] In the first identification process, when any one or two or more combinations of the following conditions are satisfied, the applied congestion management type may be identified as the third congestion management.

[0233] At least the fifteenth identification information is a value corresponding to the third congestion management.

[0234] At least the sixteenth identification information is a value corresponding to the third congestion management.

[0235] A case where information indicating the third congestion management is included in at least the fourteenth identification information.

[0236] At least the fifteenth identification information is a value corresponding to a plurality of congestion managements including the third congestion management and excluding the fourth congestion management, and the seventeenth identification information includes S-NSSAI and DNN.

[0237] When the sixteenth identification information is information for identifying either the third congestion management or the fourth congestion management, and only a value corresponding to the fourth congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0238] When the sixteenth identification information is information for identifying either the second congestion management or the third congestion management, and only a value corresponding to the second congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0239] The sixteenth identification information is information for identifying any one of the second congestion management, the third congestion management, and the fourth congestion management, and when only a value corresponding to the second congestion management and a value corresponding to the fourth congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0240] However, it is not limited to the above examples. UE_A10 can be identified based on at least one of the first to fourth identification information and / or at least one of the eleventh to eighteenth identification information or a combination of two or more identification information.

[0241] In the first identification process, when any one or two or more combinations of the following conditions are satisfied, the applied congestion management type may be identified as the fourth congestion management.

[0242] At least the fifteenth identification information is a value corresponding to the fourth congestion management.

[0243] At least the sixteenth identification information is a value corresponding to the fourth congestion management.

[0244] A case where information indicating the fourth congestion management is included in at least the fourteenth identification information.

[0245] At least the fifteenth identification information is a value corresponding to a plurality of congestion managements including the fourth congestion management and excluding the third congestion management, and the seventeenth identification information includes S-NSSAI and DNN.

[0246] When the sixteenth identification information is information for identifying either the third congestion management or the fourth congestion management, and only a value corresponding to the third congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0247] When the sixteenth identification information is information for identifying either the second congestion management or the fourth congestion management, and only a value corresponding to the second congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0248] When the sixteenth identification information is information for identifying either the first congestion management or the fourth congestion management, and only a value corresponding to the first congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0249] The sixteenth identification information is information for identifying any one of the second congestion management, the third congestion management, and the fourth congestion management, and when only a value corresponding to the second congestion management and a value corresponding to the third congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0250] The sixteenth identification information is information for identifying any one of the first congestion management, the second congestion management, and the fourth congestion management, and when only a value corresponding to the first congestion management and a value corresponding to the second congestion management can be set for the sixteenth identification information, at least the sixteenth identification information is not received.

[0251] However, it is not limited to the above examples. UE_A10 can be identified based on at least one or more identification information from the first to fourth identification information and / or at least one identification information from the eleventh to eighteenth identification information or a combination of two or more identification information, or other methods can be used for identification.

[0252] As described above, the congestion management class can be identified through the first identification process.

[0253] Next, an example of the second identification process is described. It should be noted that the second identification process may be a process of identifying the corresponding DNN and / or S-NSSAI for the congestion management category identified by the first identification process.

[0254] More specifically, the DNNs corresponding to the first, third, and fourth congestion management may be determined based on the twelfth identification information. Furthermore, the DNNs corresponding to the first, third, and fourth congestion management may be determined based on the seventeenth identification information. Furthermore, the DNNs corresponding to the first, third, and fourth congestion management may be determined based on the second identification information.

[0255] Therefore, the DNN corresponding to the first, third, and fourth congestion management may be the DNN indicated by the twelfth identification information. And / or the DNN corresponding to the first, third, and fourth congestion management may be the DNN included in the seventeenth identification information. And / or the DNN corresponding to the first, third, and fourth congestion management may be the DNN indicated by the second identification information.

[0256] In addition, the S-NSSAI corresponding to the second congestion management, the third congestion management, and the fourth congestion management may be determined based on the seventeenth identification information, and / or the DNN corresponding to the first congestion management, the third congestion management, and the fourth congestion management may be determined based on the first identification information.

[0257] Therefore, the DNN corresponding to the first congestion management, the third congestion management, and the fourth congestion management may be the S-NSSAI indicated by the seventeenth identification information. And / or the DNN corresponding to the first congestion management, the third congestion management, and the fourth congestion management may be the S-NSSAI included in the first identification information.

[0258] However, it is not limited to the above examples. UE_A10 can be identified based on at least one or more identification information from the first to fourth identification information and / or at least one identification information from the eleventh to eighteenth identification information or a combination of two or more identification information, or other methods can be used for identification.

[0259] Based on the fifteenth behavior above, UE_A10 can identify the congestion management applied by the core network_B190 to UE_A10. In other words, UE_A10 can identify the corresponding congestion management category and the corresponding S-NSSAI and / or DNN as the applied congestion management based on the fifteenth behavior. It should be noted that UE_A10 can store and manage one or more identification information from the first to fourth identification information and the eleventh to eighteenth identification information in association with the applied congestion management. Here, the third identification information and / or the fourth identification information and / or the thirteenth identification information can be stored and managed as information for identifying the applied congestion management.

[0260] The sixteenth behavior of this embodiment is to stop the first timer when the UE starts the first timer and performs the NW-led session management process.

[0261] For example, the following behavior may be used: if multiple first timers are activated, the first timer to be stopped among the activated first timers may be identified based on the twenty-first identification information and stopped. And / or the first timer associated with the congestion management system identified in the seventeenth behavior may be stopped. It should be noted that if multiple congestion management systems are identified in the seventeenth behavior, the timers associated with each congestion management system may be stopped separately.

[0262] The seventeenth behavior of this embodiment may be the UE behavior of identifying, based on receiving the control message sent by the core network, stopping the congestion management being applied by the UE among one or more congestion managements being applied. For example, the UE may identify stopping or changing the applied congestion management based on the twenty-first identification information.

[0263] Specifically, as described above, the UE can store the third identification information and / or the fourth identification information and / or the thirteenth identification information, etc. as identification congestion management information in the fourth processing, and identify the congestion management that is consistent with the thirteenth identification information included in the twenty-first identification information as the congestion management to be stopped.

[0264] Alternatively, the UE may identify that congestion management has been stopped based on a combination of one or more of the eleventh to eighteenth identification information included in the twenty-first identification information. The details of the identification method may be the same as the identification process of the fifteenth behavior described in the fourth process in the PDU session establishment procedure example described later. That is, the UE may identify that congestion management has been stopped using the same method as that used to identify congestion management.

[0265] It should be noted that the UE can identify multiple congestion managements that have been stopped. In the following, the congestion management identified by the above method is referred to as the first congestion management, and a method for identifying a second congestion management that is different from the first congestion management is described.

[0266] For example, the UE may identify the congestion management corresponding to the same DNN as the DNN established for the first congestion management as the second congestion management. And / or the UE may identify the congestion management corresponding to the same S-NSSAI as the S-NSSAI established for the first congestion management as the second congestion management. It should be noted that the congestion management for identifying multiple stopped applications can be set to be executed only when the first congestion management and / or the second congestion management belong to a specific congestion management category.

[0267] Specifically, when the first congestion management is any one of the first to fourth congestion managements, the UE can identify the second congestion management. And / or when determining the second congestion management, when the congestion management to be searched is any one of the first to fourth congestion managements, the UE can identify the second congestion management. It should be noted that the categories in which the first congestion management and / or second identification information can identify multiple congestion managements can be pre-set in the core network and / or the UE. It should be noted that the specific congestion management category allowed for identification does not need to be determined as one and can also be set to multiple.

[0268] The first identification information of this embodiment is information for identifying the first NW slice. In other words, the first identification information may be information indicating that the UE wishes to establish a PDU session belonging to the first NW slice. Specifically, for example, the first identification information may be information for identifying the first NW slice. It should be noted that the slice information may be identification information representing a specific S-NSSAI. It should be noted that the first identification information may be information for identifying a specific NW slice within the network of operator A, or information for identifying the same NW slice within operator B (other operators other than operator A). Moreover, the first identification information may be information for identifying the first NW slice set by the HPLMN, or information for identifying the first NW slice obtained from the AMF during the registration process, or information for identifying the first NW slice allowed by the network. Moreover, the first identification information may be information for identifying the first NW slice stored for each PLMN.

[0269] The second identification information in this embodiment may be DNN (Data Network Name), that is, information used to identify DN (Data Network).

[0270] The third identification information in this embodiment may be a PDU session ID (PDU Session ID), that is, information used to identify a PDU session (PDU Session).

[0271] The fourth identification information of this embodiment is PTI (Procedure transaction identity), which is information that identifies the sending and receiving of a series of messages of a specific session management process as a group. It can also be information used to identify and / or distinguish the sending and receiving of another series of session management-related messages.

[0272] The eleventh identification information of this embodiment may be information indicating rejection of a request to establish a PDU session or a request to change a PDU session (PDU session modification). It should be noted that the request to establish a PDU session or the request to change a PDU session is a request made by the UE and includes a DNN and / or S-NSSAI. That is, the eleventh identification information may be information indicating that the NW rejects the request to establish or change a PDU session corresponding to these DNNs and / or S-NSSAs.

[0273] Furthermore, the eleventh identification information may be information indicating re-attempt (Re-attempt: retry) information.

[0274] In addition, the NW sends at least one identification information from the twelfth identification information to the eighteenth identification information together with the eleventh identification information to the UE, thereby indicating congestion management to the UE. In other words, the NW can notify the UE of the congestion management corresponding to the combination of one or more identification information from the twelfth identification information to the eighteenth identification information. On the other hand, the UE can also identify the congestion management corresponding to the combination of one or more identification information from the twelfth identification information to the eighteenth identification information, and perform processing based on the identified congestion management. Specifically, the UE can start counting the first timer corresponding to the identified congestion management. It should be noted that the timer value of the first timer can be determined using the fourteenth identification information, or can be set by using a timer value set by other methods such as a value pre-saved by the UE, or can be set as a random value.

[0275] The twelfth identification information of this embodiment can be a DNN, that is, a DNN that is not allowed by the network, or information indicating that the DNN identified by the second identification information is not allowed. Moreover, the twelfth identification information can also be the same DNN as the second identification information.

[0276] The thirteenth identification information of this embodiment may be a PDU session ID and / or PTI, i.e., a PDU session ID and / or PTI not permitted by the network, or may be information indicating that the PDU session ID and / or PTI identified by the third identification information is not permitted. Furthermore, the PDU session ID of the thirteenth identification information may be the same as the PDU session ID of the third identification information. Furthermore, the PTI of the thirteenth identification information may be the same as the PTI of the fourth identification information.

[0277] Here, the thirteenth identification information can be used as information for identifying the congestion management notified to the UE by the NW based on the rejection of the PDU session establishment. In other words, the UE stores and manages the thirteenth identification information in correspondence with the congestion management establishment performed based on the fifteenth behavior, and can use it as information for identifying the congestion management being performed. It should be noted that the information identifying the congestion management can be composed of a combination of one or more of the identification information from the fourteenth to eighteenth identification information, in addition to the thirteenth identification information.

[0278] The fourteenth identification information of this embodiment may be information indicating the value of the backoff timer. In other words, the backoff timer may be a value indicating the effective period of the congestion management notified to the UE by the NW based on the rejection of the PDU session establishment. In other words, the UE may use the fourteenth identification information as the value of the timer in the fifteenth behavior performed upon receiving the fourteenth identification information. Moreover, in addition to the timer value, the fourteenth identification information may also include information identifying the congestion management category. Specifically, it may include information identifying which of the first to fourth congestion managements is. For example, the information identifying the congestion management category may be a timer name identifying each congestion management, or a flag identifying each congestion management. It is not limited to this, and identification may also be performed by other methods such as identification based on the location stored in the control message.

[0279] The fifteenth identification information of this embodiment is information indicating one or more cause values (Cause Values) indicating the reason why this process was rejected. In other words, the cause value can be information indicating that congestion management of the NW was applied to this process, or information indicating that the process was rejected with the NW applied other than congestion management.

[0280] It should be noted that the reason value may be information used to identify which of the first to fourth congestion management types the congestion management type notified by the NW to the UE regarding the rejection of PDU session establishment represents. In this case, the NW may send different values as reason values to the UE depending on each of the first to fourth congestion management types. The UE may pre-understand the meaning of each value sent as the reason value and, in the fifteenth action, identify which of the first to fourth congestion management types the congestion management type represents based on at least the fifteenth identification information.

[0281] Alternatively, the reason value may be information used to identify whether the congestion management system notified to the UE by the NW for rejecting the PDU session establishment is the first congestion management system or any of the second, third, or fourth congestion management systems. In this case, when the first congestion management system is used, the NW may send different reason values to the UE depending on whether the second, third, or fourth congestion management system is used. The UE may pre-understand the meaning of each reason value sent and, in the fifteenth action, identify whether the first congestion management system is used or any of the second, third, or fourth congestion management systems based on at least the fifteenth identification information.

[0282] Alternatively, the reason value may be information used to identify whether the congestion management system notified to the UE by the NW for rejecting the PDU session establishment is the first congestion management system, the second congestion management system, the third congestion management system, or the fourth congestion management system. In this case, the NW may send different values as reason values to the UE depending on whether the congestion management system is the first congestion management system, the second congestion management system, the third congestion management system, or the fourth congestion management system. The UE may pre-understand the meaning of each value sent as the reason value and, in the fifteenth action, identify whether the congestion management system is the first congestion management system, the second congestion management system, the third congestion management system, or the fourth congestion management system based on at least the fifteenth identification information.

[0283] Alternatively, the reason value may be information used to identify whether the congestion management system notified to the UE by the NW regarding the rejection of PDU session establishment is the first congestion management system, the second congestion management system, the third congestion management system, or the fourth congestion management system. In this case, the NW may send different reason values to the UE depending on whether the reason value is the first congestion management system, the second congestion management system, or the third congestion management system, or the fourth congestion management system. The UE may pre-understand the meaning of each reason value sent and, in the fifteenth action, identify whether the reason value is the first congestion management system, the second congestion management system, the third congestion management system, or the fourth congestion management system based on at least the fifteenth identification information.

[0284] Alternatively, the reason value may be information used to identify whether the congestion management notification notified to the UE by the NW based on the PDU session establishment rejection is the second or third congestion management, or the first or fourth congestion management. In this case, the NW may send different values as reason values to the UE depending on whether the second or third congestion management is used, or the first or fourth congestion management is used. The UE may pre-understand the meaning of each value sent as the reason value and, in the fifteenth action, identify whether the second or third congestion management, the first or fourth congestion management, is used based on at least the fifteenth identification information.

[0285] Alternatively, the reason value may be information used to identify whether the congestion management notification notified to the UE by the NW based on the PDU session establishment is the second or fourth congestion management, or the first or third congestion management. In this case, the NW may send different values as reason values to the UE depending on whether the notification is for the second or fourth congestion management, or for the first or third congestion management. The UE may pre-understand the meaning of each value sent as the reason value and, in the fifteenth action, identify whether the notification is for the second or fourth congestion management, or for the first or third congestion management, based on at least the fifteenth identification information.

[0286] Alternatively, the reason value may be information indicating that the NW has refused to perform congestion management on the UE based on the PDU session establishment. In other words, the reason value may be information for performing any of the first to fourth congestion management on the UE. In this case, the reason value may not be information that can identify a specific congestion management.

[0287] Moreover, as a more detailed example of the reason value applied by the NW for rejecting this process other than the above-mentioned congestion management, it may be a reason value (Missing or unknown DNN) notified to the UE by the NW indicating that the external DN rejects this process on the grounds that the DNN information is not included in this process or that it is an unknown DNN. In addition, it may be a reason value (Unknown PDU session type) notified to the UE by the NW indicating that the external DN rejects this process on the grounds that the PDU session type of this process cannot be identified or is not allowed. In addition, it may be a reason value (User authentication or authorization failed) notified to the UE by the NW indicating that the external DN rejects this process on the grounds of failure of user authentication and approval in this process or invalidation of authentication and approval implemented by the external DN or invalidation of authentication and approval implemented by the NW. In addition, it may be a reason value (Request rejected, unspecified) that the NW notifies the UE that a service, operation, or resource assurance request requested based on an unspecified reason is rejected. In addition, it may be a reason value (Service option temporarily outof order) that the NW notifies the UE that the NW is temporarily unable to accept a service request from the UE. In addition, it may also be a reason value for the NW to notify the UE that the PTI inserted by the UE is already in use (PTI already in use). In addition, it may also be a reason value for the NW to notify the UE that the UE is outside the LADN service area (service area) (Out of LADN service area). In addition, it may also be a reason value for the NW to notify the UE that only the PDU session type (session type) IPv4 is allowed (PDU session type IPv4 only allowed). In addition, it may also be a reason value for the NW to notify the UE that only the PDU session type IPv6 is allowed (PDUsession type IPv6 only allowed). In addition, it may also be a reason value for the NW to notify the UE that the object PDU session is not maintained when the NW moves from non-3GPP access to 3GPP access or the UE moves the PDU session from EPS to 5GS (PDUsession does not exist). In addition, it may also be a reason value for the NW to notify the UE that the NW does not support the SSC mode requested by the UE (Not supported SSC mode).Alternatively, it may be a reason value (Missing or unknown DNN in a slice) notified to the UE by the NW indicating that the external DN rejected this procedure because the DNN was not included in this procedure via a specific slice or was an unknown DNN. Alternatively, it may be a reason value (Maximum data rate per UE for user-plane integrity protection is too low) notified to the UE by the NW indicating that the UE does not meet the necessary conditions for the maximum data transmission rate for user plane confidentiality protection required for the service requested by the UE to the NW.

[0288] It should be noted that in this embodiment, when the third congestion management is not performed, the meaning of the reason value in the fifteenth identification information corresponding to the third congestion management is unnecessary. The processing, explanation, and meaning related to the third congestion management can be omitted from the above description of the reason value in the fifteenth identification information. Furthermore, in this embodiment, when the fourth congestion management is not performed, the meaning of the reason value in the fifteenth identification information corresponding to the fourth congestion management is unnecessary. The processing, explanation, and meaning related to the fourth congestion management can be omitted from the above description of the reason value in the fifteenth identification information.

[0289] As a detailed example, the fifteenth identification information identifying the first congestion management may be a reason value indicating insufficient resources. Furthermore, the fifteenth identification information identifying the second congestion management may be a reason value indicating insufficient resources for a specific slice. Furthermore, the fifteenth identification information identifying the third congestion management may be a reason value indicating insufficient resources for a specific slice and DNN.

[0290] In this way, the fifteenth identification information may be information that can identify the type of congestion management, or may be information indicating to which type of congestion management the backoff timer and / or backoff timer value indicated by the fourteenth identification information corresponds.

[0291] Therefore, UE_A10 can identify the type of congestion management based on the fifteenth identification information. Furthermore, it can also determine which type of congestion management the backoff timer and / or backoff timer value indicated by the fourteenth identification information corresponds to based on the fifteenth identification information.

[0292] The sixteenth identification information of this embodiment is one or more identifiers indicating that this process is rejected. In other words, the identifier information may be information indicating the congestion management applied by the NW to this process. The NW may indicate the congestion management applied by the NW based on the sixteenth identification information.

[0293] For example, the identifier information may be information indicating whether the NW restricts the UE to which of two or more congestion managements from the first to the fourth congestion management. Therefore, the NW may send a value corresponding to the restriction management applied to the UE as the identifier information. The UE may grasp the meaning of each value sent as the identifier information in advance, and in the fifteenth behavior, identify which of the first to the fourth congestion management is based on at least the sixteenth identification information. Here, the two or more congestion managements from the first to the fourth congestion management may refer to congestion managements that can be identified using the identifier information, and the congestion managements that become the identification object may be all four congestion managements, or the first and second congestion managements, or the third and fourth congestion managements, or the second to the fourth congestion managements, or any other combination.

[0294] It should be noted that identifier information does not necessarily need to be set to values corresponding to all congestion managements to be identified. For example, if identifier information values are assigned to each congestion management other than congestion management A, it is not necessary to set an identifier information value for congestion management A. In this case, the first congestion management can be identified by the NW and UE not transmitting or receiving identifier information. It should be noted that congestion management A can be any of the first to fourth congestion managements.

[0295] Furthermore, when notifying the UE of congestion management based on the transmission of a PDU Session Establishment Reject message, there is a case where the congestion management categories according to the first to fourth congestion management are not included but an identification is included. In other words, the NW may use identification information as information indicating congestion management based on the congestion management category, or may not use identification information but use other identification information as information indicating congestion management based on the congestion management category.

[0296] It should be noted that, in this embodiment, when the third congestion management is not implemented, the meaning of the identifier information in the sixteenth identification information corresponding to the third congestion management is unnecessary, and the processing, explanation, and meaning related to the third congestion management can be omitted from the above description of the identifier information in the sixteenth identification information. Furthermore, in this embodiment, when the fourth congestion management is not implemented, the meaning of the identifier information in the sixteenth identification information corresponding to the fourth congestion management is unnecessary, and the processing, explanation, and meaning related to the fourth congestion management can be omitted from the above description of the identifier information in the sixteenth identification information.

[0297] The seventeenth identification information of this embodiment is one or more value information indicating that this process is rejected. In other words, the value information may be information indicating the congestion management applied by the NW to this process. It should be noted that the seventeenth identification information is used to identify one or more NW slices included in the eighteenth identification information and / or includes at least one of the twelfth identification information.

[0298] The NW can indicate the congestion management applied by the NW based on the seventeenth identification information. In other words, the NW can indicate which of the first to fourth congestion managements is applied based on the seventeenth identification information. Moreover, the NW can indicate the DNN and / or S-NSSAI that become the object of congestion management applied to the UE based on the sending of the PDU session reject message based on the seventeenth identification information. For example, in the case where the seventeenth identification information is only DNN#1, it can be indicated that the first congestion management with DNN#1 as the object is applied. In the case where the seventeenth identification information is only S-NSSAI#1, it can be indicated that the second congestion management with S-NSSAI#1 as the object is applied. In the case where the seventeenth information is composed of DNN#1 and S-NSSAI#1, it can be indicated that the third congestion management or the fourth congestion management with at least one of DNN#1 and / or S-NSSAI#1 as the object is applied.

[0299] It should be noted that the seventeenth identification information does not need to be information that can identify which of the first to fourth congestion management is applied. The seventeenth identification information can be information indicating the DNN and / or S-NSSAI that are the objects of congestion management, identified by other methods such as identification based on other identification information.

[0300] The eighteenth identification information of this embodiment may be information indicating that the request for establishing a PDU session belonging to the first NW slice is rejected, or information indicating that the request for establishing a PDU session belonging to the first NW slice or a PDU session change (PDU session modification) is not allowed. Here, the first NW slice may be the NW slice identified by the first identification information, or may be a different NW slice. Moreover, the eighteenth identification information may be information indicating that the establishment of a PDU session belonging to the first NW slice is not allowed in the DN identified by the twelfth identification information, or information indicating that the establishment of a PDU session belonging to the first NW slice is not allowed in the PDU session identified by the thirteenth identification information. Moreover, the eleventh identification information may also be information indicating that the establishment of a PDU session belonging to the first slice is not allowed in the registration area and / or tracking area to which UE_A10 currently belongs, or information indicating that the establishment of a PDU session belonging to the first NW slice is not allowed in the access network to which UE_A10 is connected. Moreover, the eleventh identification information may also be identification information for identifying the NW slice to which the rejected PDU session request belongs or identifying one or more NW slices. Furthermore, the eighteenth identification information may be identification information indicating auxiliary information for the wireless access system to select an appropriate MME when the UE switches its connection destination to the EPS. It should be noted that the auxiliary information may be information indicating a DCN ID. Furthermore, the eighteenth identification information may be a network slice association rule that is a rule for associating multiple slice information.

[0301] The twenty-first identification information of this embodiment may be information for stopping one or more first timers started by the UE, or information indicating the first timer to be stopped among the first timers started by the UE. Specifically, the twenty-first identification information may be information indicating the thirteenth identification information associated with the first timer and stored by the UE. Furthermore, the twenty-first identification information may be information indicating at least one of the twelfth to eighteenth identification information associated with the first timer and stored by the UE.

[0302] Furthermore, the twenty-first identification information may be information that changes the association between the first timer stored by the UE and information representing at least one of the thirteenth to seventeenth identification information. For example, when the first timer for UE-led session management that suppresses the combination of DNN#A and S-NSSAI#A is activated, upon receiving a NW-led session management request including the twenty-first identification information permitting connection to DNN#A, the UE may change the association of the activated timer to only S-NSSAI#A, thereby recognizing that the UE-led session management request for DNN#A is permitted. In other words, the twenty-first identification information may be information indicating that the congestion management applied upon receiving the twenty-first identification information is changed to another congestion management option from the first to fourth congestion management options.

[0303] Next, use Figure 9 The initial process of this embodiment is described. Hereinafter, the initial process is also referred to as this process, which includes a registration procedure, a UE-led PDU session establishment procedure, and a network-led session management procedure. The details of the registration procedure, the PDU session establishment procedure, and the network-led session management procedure will be described later.

[0304] Specifically, each device executes the login process (S900), whereby UE_A10 transitions to a state logged into the network (RM-REGISTERED state). Next, each device executes the PDU session establishment process (S902), whereby UE_A10 establishes a PDU session with DN_A5 providing PDU connection service via the core network_B190, and each device migrates to the first state (S904). It should be noted that it is assumed that the PDU session is established via the access network and UPF_A235, but is not limited to this. That is, a UPF (UPF_C239) different from UPF_A235 may also exist between UPF_A235 and the access network. At this time, the PDU session is established via the access network, UPF_C239, and UPF_A235. Next, each device in the first state can execute the network-led session management process (S906) at any timing.

[0305] It should be noted that each device can exchange various capability information and / or various request information of each device during the login process and / or the PDU session establishment process and / or the network-led session management process. In addition, when each device implements the exchange of various information and / or the negotiation of various requests during the login process, it may implement the exchange of various information and / or the negotiation of various requests during the PDU session establishment process and / or the network-led session management process, or it may not implement the exchange of various information and / or the negotiation of various requests. In addition, when each device does not implement the exchange of various information and / or the negotiation of various requests during the login process, it may implement the exchange of various information and / or the negotiation of various requests during the PDU session establishment process and / or the network-led session management process. In addition, even when each device implements the exchange of various information and / or the negotiation of various requests during the login process, it may implement the exchange of various information and / or the negotiation of various requests during the PDU session establishment process and / or the network-led session management process.

[0306] In addition, each device may execute the PDU session establishment process during the login process, or may execute it after the login process is completed. In addition, in the case where the PDU session establishment process is executed during the login process, the PDU session establishment request message may be included in the login request message for transmission and reception, the PDU session establishment acceptance message may be included in the login acceptance message for transmission and reception, the PDU session establishment completion message may be included in the login completion message for transmission and reception, and the PDU session establishment rejection message may be included in the login rejection message for transmission and reception. In addition, in the case where the PDU session establishment process is executed during the login process, each device may establish a PDU session based on the completion of the login process, or may transition to a state where a PDU session is established between each device.

[0307] In addition, each device involved in this process can send and receive each control message described in this process, send and receive one or more identification information included in each control message, and store the sent and received identification information as a context.

[0308] [1.3.1. Overview of the Login Process]

[0309] First, an overview of the login process is described. The login process is a process led by UE_A10 to log in to the network (access network and / or core network_B190 and / or DN_A5). When not logged in to the network, UE_A10 can execute this process at any time, such as when the power is turned on. In other words, when in a non-logged-in state (RM-DEREGISTERED state), UE_A10 can start this process at any time. In addition, each device can transition to a logged-in state (RM-REGISTERED) based on the completion of the login process.

[0310] Furthermore, this process can be a process of updating the location login information of UE_A10 in the network and / or periodically notifying the network of the status of UE_A10 from UE_A10 and / or updating specific parameters related to UE_A10 in the network.

[0311] UE_A10 can start this process when moving across a TA. In other words, UE_A10 can start this process when moving to a TA that is different from the TA shown in the maintained TA list. Moreover, UE_A10 can start this process when the executing timer expires. Moreover, UE_A10 can also start this process when the context of each device needs to be updated due to the disconnection or disabling (also called deactivation) of the PDU session. Moreover, UE_A10 can also start this process when the capability information and / or preference related to the establishment of the PDU session of UE_A10 changes. Moreover, UE_A10 can also start this process periodically. It should be noted that UE_A10 is not limited to this, and as long as the PDU session is established, this process can be executed at any time.

[0312] [1.3.1.1. Login process example]

[0313] use Figure 10 This section describes an example of the steps involved in the login process. In this chapter, this process is referred to as the login process. The following describes each step in this process.

[0314] First, UE_A10 initiates a registration procedure by sending a Registration Request message (S1000)(S1002)(S1004) to AMF_A240 via the NR node (also known as gNB)_A122 and / or ng-eNB. Furthermore, UE_A10 may initiate a session management (SM) procedure, such as a PDU session establishment procedure, during the registration process by including an SM message (e.g., a PDU session establishment request message) in the Registration Request message or by sending an SM message (e.g., a PDU session establishment request message) along with the Registration Request message.

[0315] Specifically, UE_A10 sends an RRC (Radio Resource Control) message including a login request message to NR node_A122 and / or ng-eNB (S1000). Upon receiving the RRC message including the login request message, NR node_A122 and / or ng-eNB extract the login request message from the RRC message and select AMF_A240 as the NF or shared CP function of the routing destination of the login request message (S1002). Here, NR node_A122 and / or ng-eNB can select AMF_A240 based on the information included in the RRC message. NR node_A122 and / or ng-eNB sends or transmits the login request message to the selected AMF_A240 (S1004).

[0316] It should be noted that the login request message may be a NAS (Non-Access-Stratum) message sent and received on the N1 interface. Furthermore, the RRC message is a control message sent and received between the UE_A10 and the NR node_A122 and / or ng-eNB. Furthermore, NAS messages are processed at the NAS layer, while RRC messages are processed at the RRC layer. The NAS layer is a layer above the RRC layer.

[0317] In addition, when there are multiple NSIs requesting login, UE_A10 can send a login request message for each NSI, or it can include multiple login request messages in one or more RRC messages and send them. In addition, the above-mentioned multiple login request messages can also be included in one or more RRC messages as one login request message and sent.

[0318] AMF_A240 performs a first conditional determination upon receiving a login request message and / or a control message different from the login request message. The first conditional determination is used to determine whether AMF_A240 accepts UE_A10's request. In the first conditional determination, AMF_A240 determines whether the first conditional determination is true or false. If the first conditional determination is true (i.e., if the network accepts UE_A10's request), AMF_A240 initiates process (A) of this process. If the first conditional determination is false (i.e., if the network does not accept UE_A10's request), AMF_A240 initiates process (B) of this process.

[0319] The following describes the steps for the case where the first condition is true, that is, the steps of process (A) in this process. AMF_A240 performs the fourth condition and begins process (A) in this process. The fourth condition is used to determine whether AMF_A240 is sending and receiving SM messages with SMF_A230. In other words, the fourth condition can determine whether AMF_A240 is implementing the PDU session establishment process in this process. If the fourth condition is true (i.e., AMF_A240 is sending and receiving SM messages with SMF_A230), AMF_A240 selects SMF_A230 and sends and receives SM messages with the selected SMF_A230. If the fourth condition is false (i.e., AMF_A240 is not sending and receiving SM messages with SMF_A230), the description thereof is omitted (S1006). It should be noted that AMF_A240 can terminate process (A) in this process and start process (B) in this process when it receives an SM message indicating rejection from SMF_A230.

[0320] Moreover, AMF_A240 sends a Registration Accept message (S1008) to UE_A10 via NR Node_A122 based on the reception of the Login Request message from UE_A10 and / or the completion of the transmission and reception of SM messages with SMF_A230. For example, when the fourth condition is judged to be true, AMF_A240 can send a Registration Accept message based on the reception of the Login Request message from UE_A10. In addition, when the fourth condition is judged to be false, AMF_A240 can send a Registration Accept message based on the completion of the transmission and reception of SM messages between it and SMF_A230. Here, the Registration Accept message can be sent as a response message to the Login Request message. In addition, the Registration Accept message is a NAS message transmitted and received on the N1 interface. For example, AMF_A240 can send it to NR Node_A122 as a control message of the N2 interface. NR Node_A122, which receives the message, includes it in the RRC message and sends it to UE_A10.

[0321] Moreover, when the fourth condition is judged to be true, AMF_A240 may include an SM message (such as a PDU session establishment acceptance message) in the login acceptance message and send it, or send an SM message (such as a PDU session establishment acceptance message) together with the login acceptance message. In this sending method, an SM message (such as a PDU session establishment request message) may be included in the login request message, and executed when the fourth condition is judged to be true. In addition, in this sending method, an SM message (such as a PDU session establishment request message) may be included together with the login request message, and executed when the fourth condition is judged to be true. AMF_A240 can indicate that it has accepted the process for SM use by performing such a sending method.

[0322] UE_A10 receives the login acceptance message (S1008) via NR node_A122. UE_A10 identifies the contents of various identification information included in the login acceptance message by receiving the login acceptance message.

[0323] Then, UE_A10 sends a Registration Complete message to AMF_A240 (S1010) based on the reception of the Registration Accept message. It should be noted that, when UE_A10 receives an SM message such as a PDU Session Establishment Accept message, it may include an SM message such as a PDU Session Establishment Complete message in the Registration Complete message and send it, or it may indicate the completion of the SM process by including an SM message. Here, the Registration Complete message may be sent as a response message to the Registration Accept message. In addition, the Registration Complete message is a NAS message sent and received on the N1 interface, and may be, for example, UE_A10 includes it in an RRC message and sends it to NR Node_A122, and NR Node_A122, which receives the message, sends it to AMF_A240 as a control message of the N2 interface.

[0324] AMF_A240 receives the login completion message (S1010). In addition, each device completes the (A) process in this process based on the transmission and reception of the login acceptance message and / or the login completion message.

[0325] Next, the steps for the case where the first condition is judged to be false, that is, the steps of the (B) process in this process, are explained. AMF_A240 sends a registration reject message (S1012) to UE_A10 via NR node_A122, thereby starting the (B) process in this process. Here, the registration reject message can be sent as a response message to the registration request message. In addition, the registration reject message is a NAS message sent and received on the N1 interface, and can be, for example, AMF_A240 sending it as a control message of the N2 interface to NR node_A122, and the NR node_A122 that receives the message includes it in the RRC message and sends it to UE_A10. In addition, the registration reject message sent by AMF_A240 is not limited to any message as long as it is a message rejecting the request of UE_A10.

[0326] It should be noted that sometimes process (B) in this process may be started when process (A) in this process is terminated. In process (A), if the fourth condition is judged to be true, AMF_A240 can include an SM message indicating rejection, such as a PDU session establishment rejection message, in the login rejection message and send it, or it can indicate that the process for SM is rejected by including an SM message indicating rejection. In this case, UE_A10 can further receive an SM message indicating rejection, such as a PDU session establishment rejection message, and can also recognize that the process for SM is rejected.

[0327] Furthermore, UE_A10 can recognize that its request has been rejected by receiving a login rejection message or by not receiving a login acceptance message. Each device completes process (B) in this process based on the transmission and reception of the login rejection message.

[0328] Each device completes this process (login process) based on the completion of process (A) or (B) in this process. It should be noted that each device can transition to a state where UE_A10 is logged into the network (RM_REGISTERED state) based on the completion of process (A) in this process, or maintain a state where UE_A10 is not logged into the network (RM_DEREGISTERED state) based on the completion of process (B) in this process. In addition, the transition of each device to each state can be based on the completion of this process or the establishment of a PDU session.

[0329] Furthermore, upon completion of this process, each device can perform processing based on the identification information sent and received during this process.

[0330] In addition, the first condition determination can be performed based on the identification information and / or subscriber information and / or operator policy included in the login request message. For example, the first condition determination can be true when the network allows the request of UE_A10. In addition, the first condition determination can be false when the network does not allow the request of UE_A10. Moreover, the first condition determination can be true when the network of UE_A10's login destination and / or the device within the network supports the function requested by UE_A10, and can be false when not supported. Moreover, the first condition determination can be true when the network is judged to be in a congested state, and can be false when the network is judged to be in a non-congested state. It should be noted that the conditions that determine the truth or falsity of the first condition determination may not be limited to the above-mentioned conditions.

[0331] In addition, the fourth conditional determination can be performed based on whether AMF_A240 receives an SM or whether the login request message includes an SM message. For example, the fourth conditional determination can be true if AMF_A240 receives an SM and / or if the login request message includes an SM message, and can be false if AMF_A240 does not receive an SM and / or if the login request message does not include an SM message. It should be noted that the conditions for determining the truth or falsity of the fourth condition are not limited to the above conditions.

[0332] [1.3.2. Overview of PDU Session Establishment Process]

[0333] Next, an overview of the PDU session establishment process performed to establish a PDU session for DN_A5 is described. Hereinafter, the PDU session establishment process is also referred to as this process. This process is a process performed by each device to establish a PDU session. It should be noted that each device can execute this process after completing the login process, or it can execute this process during the login process. In addition, each device can start this process in the login state, or it can start this process at any time after the login process. In addition, each device can establish a PDU session based on the completion of the PDU session establishment process. Moreover, each device can establish multiple PDU sessions by executing this process multiple times. [1.3.2.1. PDU Session Establishment Process Example]

[0334] use Figure 11 , an example of the steps for performing the PDU session establishment process is described. The following describes each step of this process. First, UE_A10 starts the PDU session establishment process by sending a PDU session establishment request (PDUSession Establishment Request) message (S1100) to the core network_B via the access network_B.

[0335] Specifically, UE_A10 uses the N1 interface to send a PDU session establishment request message (S1100) to the AMF_A240 in the core network_B190 via the NR node_A122. AMF_A receives the PDU session establishment request message and performs the third condition judgment. The third condition judgment is used to determine whether AMF_A accepts the request of UE_A10. In the third condition judgment, AMF_A determines whether the fifth condition judgment is true or false. Core network_B starts processing #1 (S1101) in the core network when the third condition judgment is true, and starts process (B) in this process when the third condition judgment is false. It should be noted that the steps for the case where the third condition judgment is false will be described later. Here, processing #1 in the core network can be the SMF selection performed by AMF_A in the core network_B190 and / or the sending and receiving of PDU session establishment request messages between AMF_A and SMF_A.

[0336] Core network_B190 starts processing #1 within the core network. In processing #1 within the core network, AMF_A240 can select SMF_A230 as the NF of the routing destination of the PDU session establishment request message, and use the N11 interface to send or transmit the PDU session establishment request message to the selected SMF_A230. Here, AMF_A240 can select the SMF_A230 of the routing destination based on the information included in the PDU session establishment request message. In more detail, AMF_A240 can select the SMF_A230 of the routing destination based on the various identification information and / or subscriber information and / or network capability information and / or operator policy and / or network status and / or context maintained by AMF_A240 obtained based on the reception of the PDU session establishment request message.

[0337] It should be noted that the PDU session establishment request message may be a NAS message. In addition, the PDU session establishment request message may be any message requesting establishment of a PDU session, and is not limited thereto.

[0338] Here, UE_A10 may include one or more of the first to fourth identification information in the PDU session establishment request message, and may indicate the request of UE_A10 by including these identification information. It should be noted that two or more of these identification information may constitute one or more identification information.

[0339] Moreover, UE_A10 can request the establishment of a PDU session belonging to the network slice by including the first identification information and / or the second identification information and / or the third identification information and / or the fourth identification information in the PDU session establishment request message and sending it, and can also indicate the network slice to which the PDU session requested by UE_A10 belongs, and can also indicate the predetermined network slice to which the PDU session belongs from then on.

[0340] In more detail, UE_A10 can request the establishment of a PDU session belonging to a network slice in a PDU session established for a DN identified by the second identification information by sending the first identification information in correspondence with the second identification information. It can also indicate the network slice to which the PDU session requested by UE_A10 belongs, and can also indicate the network slice to which the PDU session is scheduled to belong in the future.

[0341] Furthermore, UE_A10 may also send a request combining the above items by combining two or more of the first to fourth identification information. It should be noted that the items indicated by UE_A10 by sending each identification information may not be limited to these.

[0342] It should be noted that UE_A10 may determine which of the first to fourth identification information to include in the PDU session establishment request message based on UE_A10's capability information and / or policies such as UE policies and / or UE_A10's preferences and / or an application (upper layer). It should be noted that the determination by UE_A10 of which identification information to include in the PDU session establishment request message is not limited to this.

[0343] SMF_A230 within Core Network_B190 receives the PDU Session Establishment Request message and performs the third conditional check. The third conditional check determines whether SMF_A230 accepts UE_A10's request. During the third conditional check, SMF_A230 determines whether the third conditional check is true or false. If the third conditional check is true, SMF_A230 initiates process (A) of this process; if the third conditional check is false, SMF_A230 initiates process (B) of this process. It should be noted that the steps for when the third conditional check is false will be described later.

[0344] The following describes the steps in the case where the third condition is true, that is, the steps of process (A) in this process. The SMF_A 230 selects the UPF_A 235 as the destination for establishing the PDU session and performs the eleventh condition.

[0345] Here, the eleventh conditional judgment is used to determine whether each device executes processing #2 within the core network. Here, processing #2 within the core network may include the start and / or execution of the PDU session establishment authentication process performed by each device and / or the sending and receiving of session establishment request (Session Establishment request) messages and / or session establishment response (Session Establishment response) messages between SMF_A and UPF_A within the core network_B190 (S1103). In the eleventh conditional judgment, SMF_A230 determines whether the eleventh conditional judgment is true or false. SMF_A230 starts the PDU session establishment authentication permission process when the eleventh conditional judgment is true, and omits the PDU session establishment authentication permission process when the eleventh conditional judgment is false. It should be noted that the details of the PDU session establishment authentication permission process of processing #2 within the core network will be described later.

[0346] Next, based on the eleventh condition determination and / or the completion of the PDU session establishment authentication permission process, the SMF_A230 sends a session establishment request message to the selected UPF_A235 and starts process (A) of this process. It should be noted that the SMF_A230 may also start process (B) of this process based on the completion of the PDU session establishment authentication permission process, instead of starting process (A) of this process.

[0347] Here, the SMF_A230 may select one or more UPF_A235 based on the identification information and / or network capability information and / or subscriber information and / or operator policy and / or network status and / or context maintained by the SMF_A230 obtained based on the reception of the PDU session establishment request message. It should be noted that when multiple UPF_A235 are selected, the SMF_A230 may send a session establishment request message to each UPF_A235.

[0348] UPF_A235 receives the Session Establishment Request message and generates a context for the PDU session. Furthermore, based on receiving the Session Establishment Request message and / or generating the context for the PDU session, UPF_A235 sends a Session Establishment Response message to SMF_A230. Furthermore, SMF_A230 receives the Session Establishment Response message. It should be noted that the Session Establishment Request message and the Session Establishment Response message may be control messages sent and received over the N4 interface. Furthermore, the Session Establishment Response message may be a response message to the Session Establishment Request message.

[0349] Furthermore, SMF_A230 may allocate the address allocated to UE_A10 based on the receipt of the PDU session establishment request message and / or the selection of UPF_A235 and / or the receipt of the session establishment response message. It should be noted that SMF_A230 may allocate the address allocated to UE_A10 during the PDU session establishment process, or may allocate the address allocated to UE_A10 after the PDU session establishment process is completed.

[0350] Specifically, SMF_A230 can perform address allocation during the PDU session establishment process without using DHCPv4 to allocate IPv4 addresses, and can also send the allocated address to UE_A10. Moreover, SMF_A230 can perform address allocation after the PDU session establishment process when using DHCPv4 or DHCPv6 or SLAAC (Stateless Address Autoconfiguration) to allocate IPv4 addresses and / or IPv6 addresses and / or IPv6 prefixes, and can also send the allocated address to UE_A10. It should be noted that the address allocation implemented by SMF_A230 is not limited to this.

[0351] Moreover, SMF_A230 may also include the allocated address in the PDU session establishment acceptance message and send it to UE_A10 based on the completion of the address allocation of the address allocated to UE_A10, or may send it to UE_A10 after completing the PDU session establishment process.

[0352] Based on the reception of the PDU session establishment request message and / or the selection of UPF_A235 and / or the reception of the session establishment response message and / or the completion of the address allocation of the address allocated to UE_A10, SMF_A230 sends a PDU session establishment accept message (S1110) to UE_A10 via AMF_A240.

[0353] Specifically, SMF_A230 uses the N11 interface to send a PDU session establishment acceptance message to AMF_A240, and AMF_A240, which receives the PDU session establishment acceptance message, uses the N1 interface to send a PDU session establishment acceptance message to UE_A10.

[0354] It should be noted that, when the PDU session is a PDN connection, the PDU session establishment accept message may be a PDN connectivity accept message. Furthermore, the PDU session establishment accept message may be a NAS message sent and received on the N11 interface and the N1 interface. In addition, the PDU session establishment accept message is not limited thereto and may also be a message indicating that the establishment of the PDU session has been accepted.

[0355] UE_A10 receives the PDU session establishment accept message from SMF_A230. By receiving the PDU session establishment accept message, UE_A10 identifies the contents of various identification information included in the PDU session establishment accept message.

[0356] Next, upon completion of the reception of the PDU session establishment accept message, UE_A10 sends a PDU session establishment complete message to SMF_A230 via AMF_A240 (S1114). Furthermore, SMF_A230 receives the PDU session establishment complete message and performs the second condition determination.

[0357] Specifically, UE_A10 uses the N1 interface to send a PDU session establishment completion message to AMF_A240, and AMF_A240, which receives the PDU session establishment completion message, uses the N11 interface to send a PDU session establishment completion message to SMF_A230.

[0358] It should be noted that, when the PDU session is a PDN connection, the PDU session establishment complete message may be a PDN connectivity complete message or an Activate default EPS bearer context accept message. Moreover, the PDU session establishment complete message may be a NAS message sent and received on the N1 interface and the N11 interface. In addition, the PDU session establishment complete message may be a response message to the PDU session establishment accept message, but is not limited thereto, and may also be a message indicating that the PDU session establishment process is completed.

[0359] The second conditional judgment allows SMF_A230 to determine the type of message being sent or received on the N4 interface. If the second conditional judgment is true, process #3 within the core network can be initiated (S1115). Process #3 within the core network may include sending and receiving a Session Modification Request message and / or a Session Modification Response message. SMF_A230 sends a Session Modification Request message to UPF_A235 and then receives a Session Modification Accept message from UPF_A235 upon receiving the Session Modification Request message. Furthermore, if the second conditional judgment is false, SMF_A230 executes process #2 within the core network. Specifically, SMF_A sends a Session Establishment Request message to UPF_A235 and then receives a Session Establishment Accept message from UPF_A235 upon receiving the Session Establishment Request message.

[0360] Each device completes process (A) in this process by sending and receiving a PDU session establishment completion message and / or a session change response message and / or a session establishment response message and / or a RA (Router Advertisement).

[0361] Next, the steps for the case where the third condition is judged to be false, that is, the steps of process (B) in this process are described. SMF_A230 sends a PDU session establishment reject message (S1122) to UE_A10 via AMF_A240, starting process (B) in this process.

[0362] Specifically, SMF_A230 uses the N11 interface to send a PDU session establishment rejection message to AMF_A240, and AMF_A240, which receives the PDU session establishment request message, uses the N1 interface to send a PDU session establishment rejection message to UE_A10.

[0363] It should be noted that, when the PDU session is a PDN connection, the PDU session establishment reject message may be a PDN connectivity reject message. Furthermore, the PDU session establishment reject message may be a NAS message sent and received on the N11 interface and the N1 interface. In addition, the PDU session establishment reject message is not limited thereto and may also be a message indicating that the establishment of the PDU session is rejected.

[0364] Here, SMF_A230 may include one or more of the eleventh to eighteenth identification information in the PDU session establishment rejection message, or may indicate that the request of UE_A10 is rejected by including these identification information. It should be noted that two or more of these identification information may constitute one or more identification information.

[0365] Moreover, SMF_A230 may also send the eleventh identification information and / or the twelfth identification information and / or the thirteenth identification information and / or the fourteenth identification information and / or the fifteenth identification information and / or the sixteenth identification information and / or the seventeenth identification information and / or the eighteenth identification information in the PDU session establishment rejection message, indicating that the request to establish the PDU session belonging to the network slice is rejected, and may also indicate that the network slice to which the PDU session belongs is not allowed.

[0366] In more detail, SMF_A230 may also indicate that the request to establish a PDU session belonging to the network slice in the PDU session established for the DN identified by the twelfth identification information is rejected by sending the eighteenth identification information in correspondence with the twelfth identification information, or it may indicate that the network slice to which the PDU session belongs is not allowed.

[0367] Moreover, SMF_A230 can also indicate that the request to establish a PDU session belonging to the network slice in the registration area and / or tracking area to which UE_A10 currently belongs is rejected by including the eighteenth identification information in the PDU session establishment rejection message, or it can indicate that the network slice to which the PDU session belongs is not allowed.

[0368] Moreover, SMF_A230 can also include the eighteenth identification information in the PDU session establishment reject message to indicate that the request to establish a PDU session belonging to the network slice in the access network to which UE_A10 is currently connected is rejected, or it can indicate that the network slice to which the PDU session belongs is not allowed.

[0369] Moreover, SMF_A230 can also indicate the value of the first timer by including the eleventh identification information and / or the fourteenth identification information in the PDU session establishment rejection message and sending it, or it can indicate that the same process as this process is implemented again after the completion of this process.

[0370] Furthermore, SMF_A230 may also send a request combining the above items by combining two or more of the eleventh to eighteenth identification information. It should be noted that the items indicated by SMF_A230 by sending each identification information may not be limited to these.

[0371] It should be noted that SMF_A230 can determine which identification information from the eleventh to eighteenth identification information to add to the PDU session establishment rejection message based on the received identification information and / or network capability information and / or operator policies and / or network status.

[0372] Furthermore, the twelfth identification information may be information indicating the same DNN as the DNN indicated by the second identification information. Furthermore, the thirteenth identification information may be information indicating the same PDU session ID as the PDU session ID indicated by the third identification information. Furthermore, the eighteenth identification information may be information sent when the first identification information is received and / or the network does not allow the network slice indicated by the first identification information. It should be noted that the determination by SMF_A230 of which identification information to add to the PDU session establishment rejection message is not limited to this.

[0373] As described above, Core Network_B190 notifies UE_A10 of the applied congestion management by sending a PDU Session Reject message. It should be noted that, in this manner, Core Network_B190 may notify UE_A10 of the application of congestion management and / or instruct UE_A10 to execute congestion management, and / or information identifying the type of congestion management applied and / or information identifying the object of congestion management, such as a DNN and / or S-NSSAI, corresponding to the applied congestion management and / or the value of a timer corresponding to the applied congestion management.

[0374] Here, each of the above-mentioned information may be information identified by one or more of the eleventh to eighteenth identification information.

[0375] The PDU session establishment rejection message received by UE_A10 from SMF_A230 may include one or more identification information from the eleventh identification information to the eighteenth identification information.

[0376] Next, UE_A10 performs the fourth process (S1124) based on the reception of the PDU session establishment rejection message. In addition, UE_A10 may also perform the fourth process based on the completion of this process.

[0377] Hereinafter, a first example of the fourth process will be described.

[0378] Here, the fourth process may be a process in which UE_A10 recognizes the matter indicated by SMF_A230. Furthermore, the fourth process may be a process in which UE_A10 stores the received identification information as a context, or a process in which the received identification information is transmitted to an upper layer and / or a lower layer. Furthermore, the fourth process may be a process in which UE_A10 recognizes that the request for this process has been rejected.

[0379] Furthermore, when UE_A10 receives the fourteenth identification information and the eleventh identification information, the fourth processing may be a process in which UE_A10 sets the value indicated by the fourteenth identification information as the first timer value, or a process in which the first timer with the set timer value is started. Furthermore, when UE_A10 receives the eleventh identification information, the fourth processing may be a process in which one or more of the first to eleventh actions are performed.

[0380] Moreover, when UE_A10 receives the eighteenth identification information and the eleventh identification information, the fourth processing can be as follows: UE_A10 establishes an association rule based on the information identifying the NW slice included in the eighteenth identification information and the network slice included in the eighteenth identification information, or performs the twelfth behavior based on the network slice association rule pre-set by UE_A10.

[0381] Moreover, when UE_A10 receives multiple fourteenth identification information and eleventh identification information, the fourth processing can be as follows: UE_A10 performs the thirteenth behavior based on the priority management rules of the multiple first timers included in each fourteenth identification information and the backoff timer maintained by UE_A10.

[0382] Moreover, in the case where UE_A10 receives multiple fourteenth identification information and eleventh identification information, the fourth processing may be a processing in which UE_A10 performs the fourteenth behavior based on multiple first timers included in each fourteenth identification information.

[0383] Here, the twelfth to fifteenth behaviors may be congestion management that is led by UE_A10 based on rules and / or policies within UE_A10. Specifically, for example, UE_A10 may be configured such that the storage unit and / or control unit within UE_A10 has: policies (UE policy) and / or rules, management functions of policies and / or rules, a policy executor that enables UE_A10 to act based on policies and / or rules, one or more applications, and a session management instance (session manager) for managing one or more PDU sessions established or attempted to be established based on requests from each application. Congestion management led by UE_A10 may also be achieved by executing any one of the twelfth to fifteenth behaviors as a fourth process based on these. Here, the policies and / or rules may include any one or more of the network slice establishment association rules and / or backoff timer priority management rules and / or NSSP (Network Slice Selection Policy), and these may be set in advance for UE_A10, or received from the network. In addition, here, the policy executor may be an NSSP enforcer. In addition, here, the application can be a protocol of the application layer, and a PDU session can be established or attempted to be established based on a request from the protocol of the application layer. In addition, here, the session management instance can be a software element dynamically generated in units of PDU sessions. In addition, here, as an internal process of UE_A10, S-NSSAI can be grouped, and processing based on the grouping of S-NSSAI can be performed. It should be noted that the internal structure and processing of UE_A10 are not limited to these, and each element can be implemented by software or executed as a software process within UE_A10.

[0384] Furthermore, UE_A10 may switch to the EPS during or upon completion of the fourth process, or may initiate location registration in the EPS based on the DCN ID included in the eighteenth identification information. It should be noted that UE_A10's switching to the EPS may be based on a handover procedure or may be a RAT handover initiated by UE_A10. Furthermore, upon receiving the eighteenth identification information including the DCN ID, UE_A10 may perform a handover to the EPS during or upon completion of the fourth process.

[0385] Moreover, the fourth processing may also be a processing in which UE_A10 restarts this process after a certain period of time, or a processing in which a state is transitioned to which the request of UE_A10 is limited or restricted.

[0386] It should be noted that UE_A10 can transition to the first state upon completion of the fourth process.

[0387] Next, a second example of the fourth process will be described.

[0388] Here, the fourth process may be a process in which UE_A10 recognizes the matter indicated by SMF_A230. Furthermore, the fourth process may be a process in which UE_A10 stores the received identification information as a context, or may be a process in which the received identification information is transmitted to an upper layer and / or a lower layer.

[0389] Furthermore, in the fourth process, a process of identifying the application congestion management may be performed based on one or more pieces of identification information from the eleventh to eighteenth pieces of identification information.

[0390] Furthermore, in the fourth process, based on one or more of the identification information from the eleventh to eighteenth identification information, processing may be performed to identify which congestion management type, from the first to fourth congestion management, is to be applied, and to identify the DNN and / or S-NSSAI associated with the applied congestion management. More specifically, this process may be the process described in the fifteenth behavior.

[0391] Furthermore, in the fourth process, based on one or more of the eleventh to eighteenth identification information, the value set for the first timer indicated by the fourteenth identification information associated with the applied congestion management may be identified and set, and counting of the first timer may be started. More specifically, this process may be the process described in the eighth behavior.

[0392] Furthermore, in the fourth process, along with the start or completion of any of the above processes, one or more of the first to seventh actions may be executed.

[0393] Furthermore, in the fourth process, along with the start or completion of any of the above processes, one or more of the ninth to fifteenth acts may be executed.

[0394] It should be noted that UE_A10 can transition to the first state upon completion of the fourth process.

[0395] The fourth process has been described above using the first and second examples. However, the fourth process is not limited to these examples. For example, the fourth process may be a combination of some of the detailed processes described in the first example and some of the detailed processes described in the second example.

[0396] Furthermore, UE_A10 can recognize that its request is rejected by receiving a PDU session establishment reject message or by not receiving a PDU session establishment reject message. Each device completes process (B) in this process based on the transmission and reception of the PDU session establishment reject message.

[0397] Each device completes this process based on the completion of process (A) or (B) in this process. It should be noted that each device can transition to a state where a PDU session is established based on the completion of process (A) in this process, or can recognize that this process is rejected based on the completion of process (B) in this process, or can transition to a state where a PDU session is not established, or can transition to the first state.

[0398] Furthermore, each device may perform processing based on the identification information sent and received during this process upon completion of this process. In other words, UE_A10 may perform the fourth process upon completion of this process, or may transition to the first state after completion of the fourth process.

[0399] In addition, the third condition determination can be performed based on the identification information and / or subscriber information and / or operator policy included in the PDU session establishment request message. For example, the third condition determination can be true when the network allows the request of UE_A10. In addition, the third condition determination can be false when the network does not allow the request of UE_A10. Moreover, the third condition determination can be true when the network of the connection destination of UE_A10 and / or the device within the network supports the function requested by UE_A10, and can be false when not supported. Moreover, the third condition determination can be true when it is judged that the network is in a congested state, and can be false when it is judged that it is in a non-congested state. It should be noted that the conditions that determine the truth or falsity of the third condition are not limited to the above-mentioned conditions.

[0400] Furthermore, the second conditional determination can be performed based on whether a session on the N4 interface for the PDU session has been established. For example, the second conditional determination can be true if a session on the N4 interface for the PDU session has been established, and false if not. It should be noted that the conditions for determining the truth or falsity of the second condition are not limited to the above-mentioned conditions.

[0401] Furthermore, the eleventh conditional determination can be performed based on the identification information and / or subscriber information and / or operator policy included in the PDU Session Establishment Request message. For example, the eleventh conditional determination can be true if the network allows authentication and / or authorization based on DN_A5 to be implemented in this process. Furthermore, the eleventh conditional determination can be false if the network does not allow authentication and / or authorization based on DN_A5 to be implemented in this process. Furthermore, the eleventh conditional determination can be true if the network and / or devices within the network to which UE_A10 is connected support authentication and / or authorization based on DN_A5 to be implemented in this process, and false if they do not. Furthermore, the eleventh conditional determination can be true if the sixty-first identification information is received, and false if it is not. In other words, the eleventh conditional determination can be true if a container including information such as an SM PDU DN Request Container and / or multiple information is received, and false if it is not received. It should be noted that the conditions determining the truth or falsity of the eleventh conditional determination are not limited to the above-mentioned conditions.

[0402] By sending and receiving the PDU session rejection message in the above process, the core network_B190 notifies UE_A10 of the applied congestion management, and UE_A10 can apply the congestion management indicated by the core network_B190. It should be noted that the core network_B190 and UE_A10 can apply multiple congestion management by executing the processes and processing described in this process multiple times. It should be noted that the congestion management applied can be different congestion management categories and / or congestion management corresponding to different DNNs and / or congestion management corresponding to different S-NSSAIs and / or congestion management that is different in the combination of DNN and S-NSSAI.

[0403] [1.3.3. Overview of the Network-Driven Session Management Process]

[0404] Next, an overview of the network-led session management process is described. Hereinafter, the network-led session management process is also referred to as this process. This process is a process for session management that is performed by the network for an established PDU session. It should be noted that this process can be performed at any timing after the above-mentioned login process and / or PDU session establishment process is completed and each device transitions to the first state. In addition, each device can send and receive messages including identification information for stopping or changing congestion management in this process, and can also start new congestion management behavior instructed by the network based on the completion of this process.

[0405] Furthermore, UE_A10 can disable the application of congestion management identified based on the control information sent and received through this procedure. In other words, by leading this procedure and further sending control messages and control information of this procedure to UE_A10, Core Network_B190 can use this control information to notify UE_A10 to disable the identified congestion management application.

[0406] It should be noted that this process can be a network-led PDU session change (PDU session modification) process and / or a network-led PDU session release (PDU session release) process, etc., and can also execute network-led session management processes other than these. It should be noted that each device can send and receive PDU session change messages during the network-led PDU session change process, and can also send and receive PDU session release messages during the network-led PDU session release process.

[0407] [1.3.3.1. Example of Session Management Process Initiated by the First Network]

[0408] use Figure 12 This section describes an example of a network-driven session management process. In this chapter, this process is referred to as the network-driven session management process. The following describes each step of this process.

[0409] As described above, upon completion of the login process and / or PDU session establishment process, UE_A10 and each device within Core Network_B190, which transitions to the first state (S1200), initiate a network-led session management process at any desired timing. The device within Core Network_B190 that initiates this process may be SMF_A and / or AMF_A, and UE_A may transmit and receive messages in this process via AMF_A and / or Access Network_B.

[0410] Specifically, the device in core network_B190 sends a network-initiated session management request message to UE_A (S1202). Here, the device in core network_B190 may include the twenty-first identification information in the network-initiated session management request message, and may indicate the request of core network_B190 by including the identification information.

[0411] Next, UE_A, having received the network-initiated session management request message, sends a network-initiated session management complete message ( S1204 ). Furthermore, UE_A may perform the fifth process ( S1206 ) based on the twenty-first identification information received from Core Network_B 190, completing this process. Furthermore, UE_A 10 may perform the fifth process upon completion of this process.

[0412] Hereinafter, an example of the fifth process will be described.

[0413] Here, the fifth process may be a process in which UE_A10 recognizes a matter instructed by core network_B190, or a process in which UE_A10 recognizes a request from core network_B190. Furthermore, the fifth process may be a process in which UE_A10 stores the received identification information as a context, or a process in which UE_A10 transmits the received identification information to an upper layer and / or a lower layer.

[0414] In addition, the message sent and received through the network-led session management request may be a PDU session modification command (PDUSESSION MODIFICATION COMMAND) or a PDU session release command (PDU SESSION RELEASE COMMAND), but is not limited thereto.

[0415] It should be noted that, in the fifth process, UE_A10 may perform the congestion management identification process applied by UE_A10 based on the received twenty-first identification information. Here, the congestion management identification process may be the seventeenth behavior.

[0416] Furthermore, when UE_A10 receives the twenty-first identification information, the fifth process may be the sixteenth behavior. Specifically, for example, it may be a process of stopping one or more timers executed based on the fourth process.

[0417] In other words, UE_A10 that receives the twenty-first identification information identifies the congestion management that is stopped or changed as instructed by the network by executing the seventeenth behavior, and then implements the identified stop or change of congestion management by executing the sixteenth behavior.

[0418] Furthermore, each device may perform processing based on the identification information sent and received in this process upon completion of this process. In other words, UE_A10 may perform the fifth process upon completion of this process, or may complete this process after completion of the fifth process.

[0419] In the above process, through the sending and receiving of network-led session management request messages, the core network_B190 can instruct UE_A10 to stop or change the congestion management that UE_A10 has applied. Then, UE_A10 can implement the stopping or changing of the congestion management applied by UE_A10 based on the network-led session management request message. Here, in the case where UE_A10 applies more than one congestion management, the congestion management to be stopped or changed can be identified based on the reception of the identification information included in the network-led session management request message from the core network_B190. It should be noted that the congestion management applied can be different congestion management categories and / or congestion management corresponding to different DNNs and / or congestion management corresponding to different S-NSSAIs and / or congestion management that is different in the combination of DNN and S-NSSAI.

[0420] [1.3.3.2. Example of Session Management Process Initiated by the Second Network]

[0421] In the first network-led session management process example described in Chapter 1.3.3.1, an example of stopping congestion management during the process is described regardless of which of the first to fourth congestion managements is applied to UE_A10.

[0422] Without limitation, the process described in the example of the first network-led session management process described in Section 1.3.3.1 may be performed based on congestion management. For example, the process may be performed based on one or more congestion management types applied to UE_A10, which are classified as the first congestion management type, the third congestion management type, and the fourth congestion management type.

[0423] In other words, UE_A10 can stop the congestion management corresponding to the first congestion management, the third congestion management, and the fourth congestion management through the fifth process.

[0424] During the counting of the back-off timer corresponding to the second congestion management, if UE_10 receives a network-led session management request message for the second congestion management, UE_A10 can respond to the core network_B190 without stopping the back-off timer corresponding to the second congestion management.

[0425] In other words, during the counting of the backoff timer corresponding to S-NSSAI#A, when UE_A10 receives a network-led session management request message for the congested S-NSSAI#A and any DNN, UE_A10 can respond to the core network_B190 without stopping the backoff timer corresponding to S-NSSAI#A.

[0426] In this manner, for the second congestion management, while receiving a network-initiated session management request message, UE_A10 sends a response message to Core Network_B190, but congestion management can continue. Therefore, the state in which the transmission of UE-initiated session management request messages is suppressed, as restricted by the second congestion management, can continue.

[0427] Here, as described above, the network-led session management request message of this embodiment can be a PDU session change command (PDU SESSIONMODIFICATION COMMAND) message in the network-led PDU session change (PDU SESSION MODIFICATION) process, or it can be a PDU session release command (PDU SESSION RELEASE COMMAND) message in the network-led PDU session release process.

[0428] Furthermore, as described above, the network-initiated session management completion message in response to the PDU session modification command message in this embodiment may be a PDU session modification complete message (PDU SESSION MODIFICATION COMPLETE), and the network-initiated session management completion message in response to the PDU session release command message in this embodiment may be a PDU session release complete message (PDU SESSION RELEASE COMPLETE). Furthermore, it may be configured so that, in addition to the above-described processing, UE_A10 and core network_B190 perform the more detailed processing described below when the network-initiated session management request message is a PDU session modification command and / or a PDU session release message.

[0429] For example, when the core network_B190 includes information indicating a reactivation request (Reactivation Required) in a network-led session management request message, the processing described below may be performed. It should be noted that the information indicating a reactivation request (Reactivation Required) is information indicating an activation request, and as a specific example, may be 5G Session Management Reason Value #39 (5GSM Cause #39).

[0430] Next, a first process and a procedure example when information indicating a reactivation request is received will be described.

[0431] Upon receiving a network-led session management request message including information indicating a reactivation request (Reactivation Required), UE_A10 does not immediately initiate the UE-led PDU session establishment procedure again after the network-led session management procedure is completed. Instead, UE_A10 waits for congestion management to be released before initiating the UE-led PDU session establishment procedure again. Here, the UE-led PDU session establishment procedure may be the UE-led PDU session establishment procedure for the PDU session type, SSC mode, DNN, and S-NSSAI provided in the UE-led PDU establishment procedure when the PDU session to be changed or released is established.

[0432] It should be noted that waiting for congestion management to be released may mean executing the operation after the timer corresponding to the second congestion management expires. In other words, the operation may be executed after the timer corresponding to the second congestion management completes counting and / or after the timer value corresponding to the second congestion management reaches zero.

[0433] Moreover, UE_A10 may also include the following supplementary information in the network-led session management completion message.

[0434] The supplementary information may include information indicating the expiration of a waiting timer and / or information indicating the remaining timer value. Here, the timer may be a timer associated with the second congestion management system. Furthermore, waiting for the expiration of the timer may mean executing the action after the timer expires (Expire). In other words, the action may be executed after the timer associated with the second congestion management system completes counting and / or after the timer value associated with the second congestion management system reaches zero.

[0435] It should be noted that the core network_B 190 may receive a network-led session management completion message including supplementary information and identify the value of the remaining timer. Furthermore, after the value indicated by the remaining timer has elapsed, the core network_B 190 may identify the UE-led PDU session establishment process.

[0436] Here, the remaining timer identified by the core network_B190 can be the value indicated by the received supplementary information, or it can be the value indicated by the received supplementary information taking into account the offset between the time when UE_A10 sends the network-led session management completion message and the reception time of the core network_B190.

[0437] Furthermore, the present invention is not limited to the first processing and procedure example when information indicating a reactivation request is received. A second processing and procedure example when information indicating a reactivation request is received may be executed as shown below.

[0438] As described above, with respect to the second congestion management, while receiving a network-initiated session management request message, UE_A10 sends a response message to the core network_B190. However, congestion management can continue. Therefore, the suppression of UE-initiated session management request messages, which is restricted by the second congestion management, persists. However, this can be allowed as long as UE_A10 and / or the core network_B190 again initiates a UE-initiated PDU session establishment procedure.

[0439] In other words, upon receiving a network-led session management request message including information indicating a reactivation request (Reactivation Required), UE_A10 again initiates the UE-led PDU session establishment procedure after the network-led session management procedure is completed. Here, the UE-led PDU session establishment procedure may be the UE-led PDU session establishment procedure for the PDU session type, SSC mode, DNN, and S-NSSAI provided in the UE-led PDU establishment procedure when establishing the PDU session to be changed or released.

[0440] It should be noted that while UE_A10 continues to apply congestion management, UE_A10 and core network_B190 can execute and complete the process allowed as an exception, but UE_A10 can suppress the dominance of other UE-led session management processes that are suppressed by the second congestion management.

[0441] Furthermore, the present invention is not limited to the first and second processing and process examples when information indicating a reactivation request is received. A third processing and process example when information indicating a reactivation request is received may be executed as shown below.

[0442] As described above, regarding the second congestion management, upon receiving the network-initiated session management request message, UE_A10 sends a response message to the core network_B190. Furthermore, upon receiving the network-initiated session management request message including information indicating a reactivation request (Reactivation Required), UE_A10 may stop applying the second congestion management.

[0443] In other words, UE_A10 can continue congestion management without including information indicating a reactivation request (Reactivation Required) in the network-led session management request message. In this case, the state in which the transmission of UE-led session management request messages is suppressed by the second congestion management restriction can continue.

[0444] Therefore, when UE_A10 receives a network-led session management request message including information indicating a reactivation request (Reactivation Required), it again leads the UE-led PDU session establishment process after the network-led session management process is completed. Here, the UE-led PDU session establishment process may be the UE-led PDU session establishment process for the PDU session type, SSC mode, DNN, and S-NSSAI provided in the UE-led PDU establishment process when the PDU session to be changed or released is established.

[0445] In addition, without being limited to the first, second, and third processing and process examples when information indicating a reactivation request is received, as described below, it can also be set that the information indicating a reactivation request is not sent by the core network_B190.

[0446] More specifically, it can be set to suppress information indicating a reactivation request (Reactivation Required) when the core network_B190 sends a network-led session management request message to the UE_A10 that applies congestion management.

[0447] Alternatively, it can be set to suppress the information indicating the reactivation request (Reactivation Required) when the core network_B190 sends a network-led session management request message to the UE_A10 applying the second congestion management.

[0448] The above describes the processing and procedures of UE_A10 and Core Network_B190. However, the Core Network_B190 processing described in this chapter may more specifically be processing performed by a control device such as SMF_A230 and / or AMF_A240, which are devices within Core Network_B190. Therefore, the Core Network_B190 sending and receiving control messages may refer to the SMF_A230 and / or AMF_A240, which are devices within Core Network_B190, sending and receiving control messages.

[0449] Moreover, without limitation to this chapter, in the expressions used in the description of this embodiment, releasing the application of congestion management or stopping congestion management may refer to processing including stopping a backoff timer corresponding to congestion management, and continuing the application of congestion management or continuing congestion management may refer to counting a backoff timer corresponding to congestion management.

[0450] In addition, in the first, second, and third processing and process examples described in this chapter when receiving information indicating a reactivation request, the network-led session management request message and / or network-led session management process for UE_A10 for the congested S-NSSAI#A and any DNN is described.

[0451] In other words, the S-NSSAI#A and any DNN in the congestion can be the S-NSSAI#A and any DNN associated with the PDU session with the network-led session management request message and / or network-led session management process of this chapter as the target.

[0452] It should be noted that UE_A10 and Core Network_B190 can perform the SSC Mode 2 anchor relocation procedure, including the procedures in this section, to switch to the anchor of the PDU session or to a PDU session with a different anchor and continue communication. The SSC Mode 2 anchor relocation procedure is initiated by Core Network_B190, and the procedure accompanying the sending of the PDU Session Release Command within this procedure can be any of the procedures described in this section.

[0453] Furthermore, UE_A10 and Core Network_B190 can perform the SSC Mode 3 anchor relocation procedure, including the procedures in this section, to switch to the anchor of the PDU session or to a PDU session with a different anchor, while continuing communication. The SSC Mode 3 anchor relocation procedure is initiated by Core Network_B190, and the procedures accompanying the transmission of the PDU Session Change Command within this procedure can be any of the procedures described in this section.

[0454] Next, a description will be given of a process when the UE moves with a change of PLMN while congestion management is applied.

[0455] Here, the processing when UE_A10 changes PLMN in the state of applying the first congestion management will be described in particular. Here, the processing when the first congestion management and the application of the first congestion management are limited can be as described above.

[0456] When repeated, the first congestion management may be DNN-based congestion management. For example, the first congestion management may be a congestion management applied by the NW to the UE_A10 based on a message rejecting the UE-led session management request when the NW receives a UE-led session management request using DNN#A from the UE_A10 and congestion for a specific DNN, such as DNN#A, is sensed in the NW. In this case, it can be set that, in the application of the first congestion management, the UE_A10 starts counting the backoff timer corresponding to the first congestion management received from the NW, and does not send the UE-led session management request using DNN#A until the backoff timer expires. It should be noted that using DNN may mean including DNN information in a UE-led session management request such as a PDU session establishment request message.

[0457] Here, for the sake of explanation, the first congestion management set in this way is expressed as “first congestion management for a specific DNN”.

[0458] In addition, in the first congestion management, even when the DNN information is not included in the UE-led session management request, the NW can select the default DNN as the congestion management object through NW leadership. In other words, the first congestion management can be a congestion management that the NW applies to UE_A10 based on a message rejecting the UE-led session management request when the NW receives a UE-led session management request that does not use DNN information from UE_A10 and congestion for the default DNN is sensed in the NW. In this case, it can be set that, in the application of the first congestion management, UE_A10 starts counting the backoff timer corresponding to the first congestion management received from the NW, and does not send a UE-led session management request that does not use DNN until the backoff timer expires. It should be noted that not using DNN can mean not including DNN information in UE-led session management requests such as PDU session establishment request messages.

[0459] For illustrative purposes, the first congestion management for the default DNN configured in this manner is applied based on a UE-led session management request that does not utilize DNN information. Therefore, to distinguish it from the first congestion management for a specific DNN, it is referred to as "congestion management for no DNN (No DNN)." Furthermore, UE-led session management requests, such as a PDU session establishment request message that does not utilize a DNN, are referred to as UE-led session management requests that utilize no DNN. For example, a PDU session establishment request message that utilizes no DNN refers to a PDU session establishment request message that does not utilize a DNN.

[0460] It is possible to configure such that, when UE_A10 continues counting the backoff timer associated with the first congestion management setup for a specific DNN during a PLMN change, or when the backoff timer associated with the first congestion management setup for a specific DNN is deactivated, UE_A10 can send a PDU session establishment request message using the specific DNN in the new PLMN. Therefore, based on this configuration, UE_10 can send a PDU session establishment request message using the specific DNN.

[0461] Here, UE_A10 may not stop the counting back-off timer, but continue counting until the timer expires. Alternatively, UE_A10 may keep the disabled back-off timer in the disabled state.

[0462] In this way, the first congestion management for a specific DNN can be established in correspondence with the PLMN.

[0463] For example, when the first congestion management for a specific DNN is applied, the UE starts counting by associating the backoff timer with the PLMN and the specific DNN. When the backoff timer is zero or is not deactivated, the PDU session establishment using the specific DNN associated with the backoff timer is not implemented in the PLMN associated with the backoff timer. In addition, when the backoff timer is in a deactivated state, the PDU session establishment using the specific DNN associated with the backoff timer is not implemented in the PLMN associated with the backoff timer until the power of the terminal is turned off or the USIM is removed. In addition, when the backoff timer is zero, the PDU session establishment using the specific DNN associated with the backoff timer can be implemented in the PLMN associated with the backoff timer.

[0464] In other words, it can be configured so that, when UE_A10 counts the backoff timer associated with the first congestion management between a specific DNN and the PLMN before the change, or when the backoff timer associated with the first congestion management between the specific DNN and the PLMN before the change is deactivated, and when the backoff timer associated with the first congestion management between the specific DNN and the PLMN after the change is not counted and the backoff timer associated with the first congestion management between the specific DNN and the PLMN after the change is not deactivated, UE_A10 can send a PDU session establishment request message using the specific DNN in the new PLMN. Furthermore, based on this configuration, UE_10 can send a PDU session establishment request message using the specific DNN.

[0465] If UE_A10 continues counting the backoff timer associated with the first congestion management setup for a non-DNN during a PLMN change, or if the backoff timer associated with the first congestion management setup for a non-DNN is deactivated, UE_A10 can send a PDU session establishment request message that does not use a DNN in the new PLMN. Therefore, based on this setting, UE_10 can send a PDU session establishment request message that uses the specific DNN.

[0466] Here, UE_A10 may not stop the counting back-off timer, but continue counting until the timer expires. Alternatively, UE_A10 may keep the disabled back-off timer in the disabled state.

[0467] In this way, the first congestion management for a DNN-free network can be associated with the PLMN. In other words, if UE_A10 counts the backoff timer for the first congestion management for a DNN-free network associated with the PLMN before the change, or if the backoff timer for the first congestion management for a DNN-free network associated with the PLMN before the change is deactivated, and if the backoff timer for the first congestion management for a DNN-free network associated with the PLMN after the change is not counted and the backoff timer for the first congestion management for a DNN-free network associated with the PLMN after the change is not deactivated, UE_A10 can send a PDU session establishment request message in the new PLMN without using a DNN. Furthermore, based on this configuration, UE_10 can send a PDU session establishment request message without using a DNN.

[0468] As described above, UE_A10 can perform the same processing regardless of whether the first congestion management is for a specific DNN or for no DNN.

[0469] That is, it can be set that, when UE_A10 counts the back-off timer for the first congestion management corresponding to the PLMN before the change during the PLMN change, or when the back-off timer for the first congestion management corresponding to the PLMN before the change is deactivated, and when the back-off timer for the first congestion management corresponding to the PLMN after the change is not counted and the back-off timer for the first congestion management corresponding to the PLMN after the change is not deactivated, UE_A10 can send a PDU session establishment request message using a specific DNN restricted by the congestion management corresponding to the PLMN before the change and / or a PDU session establishment request message not using the DNN in the new PLMN.

[0470] Alternatively, UE_A10 may perform different processing depending on whether the first congestion management is for a specific DNN or for no DNN.

[0471] If the backoff timer associated with the first congestion management setup for a specific DNN is counting during a PLMN change or the backoff timer associated with the first congestion management setup for a specific DNN is deactivated, UE_A10 may be configured not to send a PDU session establishment request message using the specific DNN in the new PLMN. Therefore, based on this configuration, UE_10 may limit the transmission of PDU session establishment request messages using the specific DNN.

[0472] Here, UE_A10 may not stop the counting back-off timer, but continue counting until the timer expires. Alternatively, UE_A10 may keep the disabled back-off timer in the disabled state.

[0473] In this way, the first congestion management for a specific DNN can be applied even in different PLMNs.

[0474] On the other hand, if UE_A10 continues counting the backoff timer associated with the first congestion management setup for a non-DNN during a PLMN change, or if the backoff timer associated with the first congestion management setup for a non-DNN is deactivated, UE_A10 can send a PDU session establishment request message that does not use a DNN in the new PLMN. Therefore, based on this setting, UE_10 can send a PDU session establishment request message that uses the specific DNN.

[0475] Here, UE_A10 may not stop the counting back-off timer, but continue counting until the timer expires. Alternatively, UE_A10 may keep the disabled back-off timer in the disabled state.

[0476] In this way, the first congestion management for the non-DNN can be established in correspondence with the PLMN.

[0477] For example, when the first congestion management for a non-DNN is applied, the UE starts counting by associating the backoff timer with the PLMN and the non-DNN. When the backoff timer is zero or is not deactivated, the establishment of a PDU session without a DNN associated with the backoff timer is not implemented in the PLMN associated with the backoff timer. In addition, when the backoff timer is deactivated, the establishment of a PDU session without a DNN associated with the backoff timer is not implemented in the PLMN associated with the backoff timer until the terminal is powered off or the USIM is removed. In addition, when the backoff timer is zero, the establishment of a PDU session without a DNN associated with the backoff timer can be implemented in the PLMN associated with the backoff timer.

[0478] In other words, it is possible to configure such that, when UE_A10 is counting the backoff timer for the first congestion management without a DNN established with the PLMN before the change, or when the backoff timer for the first congestion management without a DNN established with the PLMN before the change is deactivated, and if the backoff timer for the first congestion management without a DNN established with the PLMN after the change is not counting and the backoff timer for the first congestion management without a DNN established with the PLMN after the change is not deactivated, UE_A10 can send a PDU session establishment request message without using a DNN in the new PLMN. Furthermore, based on this configuration, UE_10 can send a PDU session establishment request message without using a DNN.

[0479] Here, the processing associated with the aforementioned PLMN change can be configured based on information previously configured for UE_A10 to determine whether the same or different processing is performed regardless of whether the first congestion management is for a specific DNN or for no DNN. Alternatively, the processing can be determined based on whether the second PLMN after the change is an equivalent PLMN to the first PLMN before the change. For example, if the second PLMN after the change is not an equivalent PLMN to the first PLMN before the change, the same processing can be applied. Alternatively, if the second PLMN after the change is an equivalent PLMN to the first PLMN before the change, different processing can be performed.

[0480] Furthermore, UE_A10 can determine its behavior based not only on whether the PLMN is an equivalent PLMN, but also on further detailed conditions. For example, it can be configured so that UE_A10 performs different behaviors depending on whether the second PLMN after the change is an equivalent PLMN to the first PLMN before the change and the registration area is not changed during the PLMN change, and depending on whether the second PLMN after the change is an equivalent PLMN to the first PLMN before the change and the registration area is changed during the PLMN change.

[0481] It should be noted that the behavior of UE_A10 performed in each case can be one of the behaviors when the PLMN is changed described so far.

[0482] For example, let's consider a first example where the second PLMN after the change is an equivalent PLMN to the first PLMN before the change, and the registration area is not changed during the PLMN change. It can be configured so that if UE_A10 continues counting the backoff timer associated with the first congestion management setup for a specific DNN during such a PLMN change, or if the backoff timer associated with the first congestion management setup for the specific DNN is deactivated, UE_A10 does not send a PDU session establishment request message using the specific DNN in the new PLMN. Therefore, based on this configuration, UE_10 can limit the transmission of PDU session establishment request messages using the specific DNN.

[0483] Furthermore, a second example will be described, in which the second PLMN after the change is an equivalent PLMN to the first PLMN before the change, and the registration area is not changed during the PLMN change. If UE_A10 continues counting the backoff timer associated with the first congestion management setup for a non-DNN during such a PLMN change, or if the backoff timer associated with the first congestion management setup for a non-DNN is deactivated, UE_A10 may not transmit a PDU session establishment request message without a DNN in the new PLMN. Therefore, based on this setting, UE_10 may limit the transmission of PDU session establishment request messages without a DNN.

[0484] Next, we will describe a first example in which the post-change second PLMN is an equivalent PLMN to the pre-change first PLMN, and the PLMN change is accompanied by a change in registration area. In such a PLMN change, if UE_A10 counts the backoff timer for the first congestion management without a DNN associated with the pre-change PLMN, or if the backoff timer for the first congestion management without a DNN associated with the pre-change PLMN is deactivated, and if the backoff timer for the first congestion management without a DNN associated with the post-change PLMN is not counted and the backoff timer for the first congestion management without a DNN associated with the PLMN is not deactivated, UE_A10 can send a PDU session establishment request message in the new PLMN without using a DNN. Furthermore, based on this configuration, UE_A10 can send a PDU session establishment request message without using a DNN.

[0485] Next, a second example will be described, in which the second PLMN after the change is an equivalent PLMN to the first PLMN before the change, and the PLMN change is accompanied by a change in the registration area. In such a PLMN change, if UE_A10 counts the backoff timer for the first congestion management for a specific DNN associated with the previous PLMN, or if the backoff timer for the first congestion management for a specific DNN associated with the previous PLMN is deactivated, and if the backoff timer for the first congestion management for a specific DNN associated with the previous PLMN is not counted and the backoff timer for the first congestion management for a specific DNN associated with the new PLMN is not deactivated, UE_A10 can send a PDU session establishment request message using the specific DNN in the new PLMN. Furthermore, based on this configuration, UE_10 can send a PDU session establishment request message using the specific DNN.

[0486] Next, a third example is described in which the second PLMN after the change is an equivalent PLMN relative to the first PLMN before the change, and the PLMN change is accompanied by a change in the registration area. UE_A10 can stop the backoff timer corresponding to the first congestion management establishment for a specific DNN and / or no DNN in such a PLMN change. Thus, it can be set so that UE_A10UE_A10 can send a PDU session establishment request message using a specific DNN and / or a PDU session establishment request message not using a specific DNN in the new PLMN. Moreover, based on this setting, UE_10 can also send a PDU session establishment request message using a specific DNN and / or a PDU session establishment request message not using a specific DNN.

[0487] Furthermore, whether the first congestion management is performed the same or differently, regardless of whether it is for a specific DNN or for no DNN, can be determined based on information previously set for UE_A10. Alternatively, the determination can be based on whether the second PLMN after the change is an equivalent PLMN to the first PLMN before the change. Furthermore, different processing can be performed for the second to fourth congestion managements regardless of the first congestion management. For example, if the second PLMN after the change is not an equivalent PLMN to the first PLMN before the change, the same processing can be applied. Furthermore, if the second PLMN after the change is an equivalent PLMN to the first PLMN before the change, different processing can be performed.

[0488] Furthermore, UE_A10 can determine its behavior based not only on whether the PLMN is an equivalent PLMN but also on further detailed conditions. For example, it can be configured to perform different behaviors depending on whether the second PLMN after the change is an equivalent PLMN to the first PLMN before the change and the registration area is not changed during the PLMN change, and depending on whether the second PLMN after the change is an equivalent PLMN to the first PLMN before the change and the registration area is changed during the PLMN change.

[0489] It should be noted that the behavior of UE_A10 performed in each case can be one of the behaviors when the PLMN is changed described so far.

[0490] Hereinafter, an example in which the second congestion management is applied will be described.

[0491] For example, the first example will be described, where the second PLMN after the change is an equivalent PLMN to the first PLMN before the change, and the registration area is not changed during the PLMN change. It can be configured so that if UE_A10 counts the backoff timer associated with the second congestion management setup for a specific S-NSSAI during such a PLMN change, or if the backoff timer associated with the second congestion management setup for a specific S-NSSAI is deactivated, UE_A10 does not send a PDU session establishment request message using that specific S-NSSAI in the new PLMN. Therefore, based on this configuration, UE_10 can limit the transmission of PDU session establishment request messages using that specific S-NSSAI.

[0492] Furthermore, a second example will be described, in which the second PLMN after the change is an equivalent PLMN to the first PLMN before the change, and the registration area is not changed during the PLMN change. It can be configured so that when UE_A10 counts the backoff timer associated with the second congestion management setup for No S-NSSAI (No S-NSSAI) during such a PLMN change, or when the backoff timer associated with the first congestion management setup for No S-NSSAI is deactivated, UE_A10 does not send a PDU Session Establishment Request message without S-NSSAI in the new PLMN. Therefore, based on this configuration, UE_10 can limit the transmission of PDU Session Establishment Request messages without S-NSSAI.

[0493] Next, a first example will be described, in which the post-change second PLMN is an equivalent PLMN to the pre-change first PLMN, and the PLMN change is accompanied by a change in registration area. In such a PLMN change, if UE_A10 counts the backoff timer for the second congestion management without S-NSSAI established with the pre-change PLMN, or if the backoff timer for the second congestion management without S-NSSAI established with the pre-change PLMN is deactivated, and if the backoff timer for the second congestion management without S-NSSAI established with the post-change PLMN is not counted and the backoff timer for the second congestion management without S-NSSAI established with the PLMN is not deactivated, UE_A10 can send a PDU Session Establishment Request message in the new PLMN without using S-NSSAI. Furthermore, based on this configuration, UE_A10 can send a PDU Session Establishment Request message without using S-NSSAI.

[0494] Next, a second example will be described, in which the second PLMN after the change is an equivalent PLMN to the first PLMN before the change, and the PLMN change is accompanied by a change in the registration area. It can be configured so that, during such a PLMN change, UE_A10 counts the backoff timer for the second congestion management for a specific S-NSSAI established with the previous PLMN, or deactivates the backoff timer for the second congestion management for a specific S-NSSAI established with the previous PLMN. Furthermore, if the backoff timer for the second congestion management for a specific S-NSSAI established with the previous PLMN is not counted and the backoff timer for the second congestion management for a specific S-NSSAI established with the previous PLMN is not deactivated, UE_A10 can send a PDU session establishment request message using the specific S-NSSAI in the new PLMN. Furthermore, based on this configuration, UE_10 can send a PDU session establishment request message using the specific S-NSSAI.

[0495] Next, a third example is described in which the second PLMN after the change is an equivalent PLMN relative to the first PLMN before the change, and the PLMN change is accompanied by a change in the registration area. UE_A10 can stop establishing a corresponding backoff timer with the second congestion management for a specific S-NSSAI and / or no S-NSSAI in such a PLMN change. Thus, it can be set so that UE_A10UE_A10 can send a PDU session establishment request message using a specific S-NSSAI and / or a PDU session establishment request message not using a specific S-NSSAI in the new PLMN. Moreover, based on this setting, UE_10 can also send a PDU session establishment request message using a specific S-NSSAI and / or a PDU session establishment request message not using a specific S-NSSAI.

[0496] Hereinafter, an example in which the third congestion management is applied will be described.

[0497] For example, the first example will be described, where the second PLMN after the change is an equivalent PLMN to the first PLMN before the change, and the registration area is not changed during the PLMN change. It can be configured so that if UE_A10 counts the backoff timer associated with the third congestion management setup for a specific [S-NSSAI, DNN] during such a PLMN change, or if the backoff timer associated with the third congestion management setup for a specific [S-NSSAI, DNN] is deactivated, UE_A10 does not send a PDU session establishment request message using the specific [S-NSSAI, DNN] in the new PLMN. Therefore, based on this configuration, UE_10 can limit the transmission of PDU session establishment request messages using the specific [S-NSSAI, DNN].

[0498] Furthermore, a second example will be described, in which the second PLMN after the change is an equivalent PLMN to the first PLMN before the change, and the registration area is not changed during the PLMN change. It can be configured so that if UE_A10 counts the backoff timer associated with the third congestion management setup for [no S-NSSAI, DNN] during such a PLMN change, or if the backoff timer associated with the third congestion management setup for [no S-NSSAI, DNN] is deactivated, UE_A10 does not send a PDU Session Establishment Request message for [no S-NSSAI, DNN] in the new PLMN. Therefore, based on this configuration, UE_10 can limit the transmission of PDU Session Establishment Request messages for [no S-NSSAI, DNN].

[0499] Next, a first example will be described in which the second PLMN after the change is an equivalent PLMN to the first PLMN before the change, and the PLMN change is accompanied by a change in the registration area. It can be assumed that, in such a PLMN change, if UE_A10 counts the backoff timer for the third congestion management method for [no S-NSSAI, DNN] established with the previous PLMN, or if the backoff timer for the third congestion management method for [no S-NSSAI, DNN] established with the previous PLMN is deactivated, and if the backoff timer for the third congestion management method for [no S-NSSAI, DNN] established with the previous PLMN is not counted and the backoff timer for the third congestion management method for [no S-NSSAI, DNN] established with the previous PLMN is not deactivated, UE_A10 can send a PDU Session Establishment Request message for [no S-NSSAI, DNN] in the new PLMN. Moreover, UE_10 can send a PDU session establishment request message for [no S-NSSAI, DNN] based on this setting.

[0500] Next, a second example will be described, in which the second PLMN after the change is an equivalent PLMN to the first PLMN before the change, and the PLMN change is accompanied by a change in the registration area. It can be configured so that, in such a PLMN change, if UE_A10 counts the backoff timer for the third congestion management for the specific [S-NSSAI, DNN] established with the previous PLMN, or if the backoff timer for the third congestion management for the specific [S-NSSAI, DNN] established with the previous PLMN is deactivated, and if the backoff timer for the third congestion management for the specific [S-NSSAI, DNN] established with the previous PLMN is not counted and the backoff timer for the third congestion management for the specific [S-NSSAI, DNN] established with the previous PLMN is not deactivated, UE_A10 can send a PDU session establishment request message using the specific [S-NSSAI, DNN] in the new PLMN. Moreover, UE_10 can send a PDU session establishment request message using a specific [S-NSSAI, DNN] based on this setting.

[0501] Next, a third example is described in which the second PLMN after the change is an equivalent PLMN to the first PLMN before the change, and the PLMN change is accompanied by a change in the registration area. UE_A10 can stop establishing a corresponding backoff timer for the third congestion management for a specific [S-NSSAI, DNN] and / or [no S-NSSAI, DNN] during such a PLMN change. Thus, it can be configured so that UE_A10 can send a PDU session establishment request message using a specific [S-NSSAI, DNN] and / or a PDU session establishment request message for [no S-NSSAI, DNN] in the new PLMN. Furthermore, based on this configuration, UE_10 can also send a PDU session establishment request message using a specific [S-NSSAI, DNN] and / or a PDU session establishment request message for [no S-NSSAI, DNN].

[0502] It should be noted that, in this embodiment, the deactivation of the backoff timer may refer to the transition of the backoff timer and / or the congestion management corresponding to the backoff timer to a deactivated state. It should be noted that UE_A10 may deactivate the backoff timer and / or the congestion management corresponding to the backoff timer upon receiving a timer value indicating deactivation.

[0503] Here, the backoff timer to be deactivated and / or the congestion management corresponding to the backoff timer may correspond to congestion management categories 1 to 4. Upon receiving the backoff timing, it may be determined and identified which congestion management category the backoff timer to be deactivated and / or the congestion management corresponding to the backoff timer corresponds to.

[0504] More specifically, UE_A10 can receive the fourteenth identification information and the fifteenth identification information from NW indicating that the backoff timer and / or the congestion management corresponding to the backoff timer will be deactivated, and the backoff timer for the congestion management of the category indicated by the fifteenth identification information will be deactivated.

[0505] Furthermore, when the backoff timer and / or congestion management are disabled, congestion management may continue to be applied until the terminal is powered off or the USIM is removed. Furthermore, the processing restricted at this time may be the same as the processing restricted when the backoff timer is counted according to each congestion management type.

[0506] The above description of the processing of UE_A10 and NW associated with a PLMN change focuses on the first congestion management and / or the backoff timer for the first congestion management. However, the same processing can be applied to the second, third, and fourth congestion management. However, the PDU session establishment request message that is restricted or permitted to be sent can be a message corresponding to each category.

[0507] In other words, congestion management and / or a back-off timer associated with congestion management may be associated with the PLMN regardless of the type of congestion management.

[0508] Alternatively, any congestion management and / or a backoff timer associated with the congestion management may be associated with the PLMN. Therefore, for the first, second, and third congestion management, the backoff timer associated with the congestion management and / or the congestion management may be associated with the PLMN. Alternatively, for the first, second, and third congestion management for a non-DNN, the backoff timer associated with the congestion management and / or the congestion management may be associated with the PLMN, while the first congestion management for a specific DNN may not be associated with the PLMN.

[0509] It should be noted that, in the processing of situations where each congestion management corresponds to the PLMN and / or the processing of the backoff timer corresponding to each congestion management, the first congestion management described above in the processing of the first congestion management corresponding to the PLMN and / or the processing of the backoff timer corresponding to the first congestion management corresponding to the PLMN can be replaced with the second to fourth congestion management of each category.

[0510] In addition, in the processing of the situation where each congestion management does not establish a correspondence with the PLMN and / or the processing of the backoff timer corresponding to each congestion management, the first congestion management described above in the processing of the first congestion management that does not establish a correspondence with the PLMN and / or the processing of the backoff timer corresponding to the first congestion management that does not establish a correspondence with the PLMN can be replaced with the second to fourth congestion management of each category.

[0511] However, as described above, the PDU session establishment request message that is restricted or allowed to be sent may be a message corresponding to each category.

[0512] Alternatively, the behavior when the PLMN is changed when counting of the backoff timer associated with the second congestion management and / or the third congestion management is executed may be performed as follows in addition to the above-described processing.

[0513] It should be noted that the back-off timer corresponding to the second congestion management may be a back-off timer for slice-based congestion management, as described so far.

[0514] Specifically, the slice-based backoff timer may be a timer associated with a specific S-NSSAI and used to prohibit the transmission of an SM request message using the specific S-NSSAI. In other words, it may be configured so that UE_A10 does not transmit an SM request message using the specific S-NSSAI while the timer counts.

[0515] Furthermore, UE_A10 may be configured to allow, in the new PLMN, transmission of SM request messages that were prohibited in the PLMN before the change, based on specific conditions described later, during the counting of this timer. It should be noted that allowing transmission of SM request messages that were prohibited in the PLMN before the change may also mean allowing transmission of SM request messages using the same S-NSSAI as the S-NSSAI associated with the backoff timer.

[0516] In addition, the slice-based backoff timer can be a timer that corresponds to the absence of S-NSSAI and is used to prohibit the sending of SM request messages using no S-NSSAI. In other words, it can also be set so that UE_A10 does not send SM request messages using no S-NSSAI during the count of this timer. Moreover, it can also be set so that UE_A10 allows the sending of SM request messages that were prohibited in the PLMN before the change in the new PLMN based on specific conditions described later during the count of this timer. It should be noted that when it is expressed as allowing the sending of SM request messages that were prohibited in the PLMN before the change, it can also mean allowing the sending of SM request messages using no S-NSSAI.

[0517] Furthermore, as described above, the back-off timer associated with the third congestion management may be a back-off timer for congestion management for a combination of S-NSSAI and DNN.

[0518] Specifically, the backoff timer for congestion management of a combination of S-NSSAI and DNN may be a timer that corresponds to a specific combination of S-NSSAI and a specific DNN and is used to prohibit the sending of SM request messages using the specific S-NSSAI and the specific DNN. In other words, it may be configured so that UE_A10 does not send SM request messages using the specific S-NSSAI and the specific DNN during the counting of the timer. Furthermore, it may be configured so that UE_A10 allows the sending of SM request messages that were prohibited in the PLMN before the change in the new PLMN based on specific conditions described later during the counting of the timer. It should be noted that when it is expressed as allowing the sending of SM request messages that were prohibited in the PLMN before the change, it may also mean allowing the sending of SM request messages that use the same S-NSSAI as the S-NSSAI corresponding to the backoff timer and the same DNN as the DNN corresponding to the backoff timer.

[0519] In addition, the backoff timer for congestion management of the combination of S-NSSAI and DNN may be a timer that corresponds to the combination of no S-NSSAI and a specific DNN and is used to prohibit the sending of SM request messages using no S-NSSAI and a specific DNN. In other words, it may be set so that UE_A10 does not send SM request messages including no S-NSSAI and a specific DNN during the count of this timer. Moreover, it may be set so that UE_A10 allows the sending of SM request messages that were prohibited in the PLMN before the change in the new PLMN based on specific conditions described later during the count of this timer. It should be noted that when it is expressed as allowing the sending of SM request messages that were prohibited in the PLMN before the change, it may also mean allowing the sending of SM request messages using no S-NSSAI and the same DNN as the DNN corresponding to the backoff timer.

[0520] In addition, the backoff timer for congestion management of the combination of S-NSSAI and DNN may be a timer that corresponds to a specific combination of S-NSSAI and no DNN and is used to prohibit the transmission of SM request messages using a specific S-NSSAI and no DNN. In other words, it may be set so that UE_A10 does not transmit SM request messages using a specific S-NSSAI and no DNN during the counting of the timer. Moreover, it may be set so that UE_A10 allows the transmission of SM request messages that were prohibited in the PLMN before the change in the new PLMN based on specific conditions described later during the counting of the timer. It should be noted that when it is expressed as allowing the transmission of SM request messages that were prohibited in the PLMN before the change, it may also mean allowing the transmission of SM request messages using the same S-NSSAI as the S-NSSAI corresponding to the backoff timer and no DNN.

[0521] In addition, the backoff timer for congestion management of the combination of S-NSSAI and DNN may be a timer that corresponds to the combination of no S-NSSAI and no DNN and is used to prohibit the sending of SM request messages using no S-NSSAI and no DNN. In other words, it may be set so that UE_A10 does not send SM request messages using no S-NSSAI and no DNN during the counting of this timer. Moreover, it may be set so that UE_A10 allows the sending of SM request messages that were prohibited in the PLMN before the change in the new PLMN based on specific conditions described later during the counting of this timer. It should be noted that when it is expressed that the sending of SM request messages that were prohibited in the PLMN before the change is allowed, it may also mean that the sending of SM request messages using no S-NSSAI and no DNN is allowed.

[0522] It should be noted that in this embodiment, when the SM request message is sent using no S-NSSAI, the SM request message may be sent without including a specific S-NSSAI. The network receiving such an SM request message does not include the S-NSSAI, and therefore can recognize that it is a request for the default S-NSSAI and / or the default network slice. Therefore, no S-NSSAI may refer to information indicating that the S-NSSAI is not included in the SM request message and / or information indicating that the default network slice is requested.

[0523] Furthermore, in this embodiment, when an SM request message is sent using no DNN, the SM request message may be sent without including a specific DNN. A network receiving such an SM request message does not include a DNN and can therefore recognize that the request is for the default DNN. Therefore, "no DNN" may indicate that the SM request message does not include the S-NSSAI and / or requests the default DNN.

[0524] Moreover, UE_A10 may start a backoff timer corresponding to the second congestion management system based on the reception of the fifteenth identification information. Moreover, UE_A10 may set the fourteenth identification information as the timer value of the backoff timer based on the reception of the fourteenth identification information. Moreover, UE_A10 may establish a correspondence between the S-NSSAI and the backoff timer if the S-NSSAI is provided during the PDU session establishment process. Conversely, UE_A10 may establish a correspondence between no S-NSSAI and the backoff timer if the S-NSSAI is not provided during the PDU session establishment process.

[0525] Moreover, UE_A10 can start a back-off timer corresponding to the third congestion management system based on the reception of the fifteenth identification information. Moreover, UE_A10 can set the fourteenth identification information as the timer value of the back-off timer based on the reception of the fourteenth identification information. Moreover, UE_A10 can establish a correspondence between the S-NSSAI and the DNN and the back-off timer when the S-NSSAI and the DNN are provided during the PDU session establishment process. Moreover, UE_A10 can establish a correspondence between the S-NSSAI and the DNN and the back-off timer when the S-NSSAI is provided during the PDU session establishment process but the DNN is not provided. Moreover, UE_A10 can establish a correspondence between the S-NSSAI and the DNN and the back-off timer when the S-NSSAI is not provided but the DNN is provided during the PDU session establishment process. Moreover, UE_A10 can establish a correspondence between the no S-NSSAI and the DNN and the back-off timer when the S-NSSAI is not provided but the DNN is provided during the PDU session establishment process. Moreover, UE_A10 can establish a correspondence between no S-NSSAI and the DNN and the back-off timer when the S-NSSAI and the DNN are not provided during the PDU session establishment process.

[0526] It should be noted that the fourteenth identification information and / or the fifteenth identification information may be included in a PDU session establishment reject message sent and received during the PDU session establishment process. Furthermore, the fourteenth identification information and / or the fifteenth identification information may be included in a PDU session change reject message sent and received during the PDU session change process. Furthermore, the fourteenth identification information and / or the fifteenth identification information may be included in a PDU session release command message sent and received during the PDU session release process.

[0527] It can be set that when counting any one or more backoff timers in the two examples of the backoff timer for the second congestion management and the four examples of the backoff timer for the third congestion management mentioned above, UE_A10 performs any one of the first to eighth processing examples shown below.

[0528] First, the first processing example will be described.

[0529] It should be noted that, in the first processing example, the twentieth identification information may be an information element indicating whether S-NSSAI-based congestion management is applied in the current PLMN and PLMNs other than the PLMN. It should be noted that S-NSSAI-based congestion management may be the second congestion management or the third congestion management.

[0530] In this case, the 20th identification information may include information indicating that S-NSSAI-based congestion management is applied to the current PLMN and PLMNs other than the PLMN, or information indicating that S-NSSAI-based congestion management is applied only to the current PLMN. In other words, the 20th identification information may include the 21st identification information or the 22nd identification information.

[0531] Here, the twenty-first identification information may be information indicating that S-NSSAI-based congestion management is applied to the current PLMN and PLMNs other than the PLMN. Furthermore, the twenty-second identification information may be information indicating that S-NSSAI-based congestion management is applied only to the current PLMN.

[0532] Furthermore, the twentieth identification information may be an information element indicating whether the back-off timer to be counted is valid in all PLMNs. It should be noted that the back-off timer may be a back-off timer used in congestion management based on S-NSSAI.

[0533] In this case, the 20th identification information may include information indicating whether the back-off timer being counted is valid in all PLMNs or information indicating that the back-off timer being counted is valid only in the current PLMN. In other words, the 20th identification information may include information including the 21st identification information or the 22nd identification information.

[0534] Here, the twenty-first identification information may be information indicating that the back-off timer being counted is valid in all PLMNs, and the twenty-second identification information may be information indicating that the back-off timer being counted is valid only in the current PLMN.

[0535] Furthermore, the twentieth identification information may be an information element indicating whether the home PLMN is congested. It should be noted that home PLMN congestion may refer to slice congestion in the home PLMN. Furthermore, home PLMN congestion may be a state in which congestion management based on S-NSSAI is being performed in the home PLMN.

[0536] In this case, the 20th identification information may include information indicating that the home PLMN is congested or information indicating that the home PLMN is not congested. In other words, the 20th identification information may include the 21st identification information or the 22nd identification information.

[0537] Here, the twenty-first identification information may be information indicating that the home PLMN is congested, and the twenty-second identification information may be information indicating that the home PLMN is not congested.

[0538] Furthermore, the twentieth identification information may be information indicating whether the S-NSSAI corresponding to the S-NSSAI-based congestion management is the S-NSSAI of the home PLMN or the S-NSSAI of the visited PLMN.

[0539] In this case, the 20th identification information may include information indicating that the S-NSSAI associated with the S-NSSAI-based congestion management is the S-NSSAI of the home PLMN, or information indicating that the S-NSSAI associated with the S-NSSAI-based congestion management is the S-NSSAI of the visited PLMN. In other words, the 20th identification information may include the 21st identification information or the 22nd identification information.

[0540] Here, the twenty-first identification information may be information indicating that the S-NSSAI associated with the S-NSSAI-based congestion management is the S-NSSAI of the home PLMN. Furthermore, the twenty-second identification information may be information indicating that the S-NSSAI associated with the S-NSSAI-based congestion management is the S-NSSAI of the visited PLMN.

[0541] Furthermore, in the case of the first processing example, the twentieth identification information is identification information transmitted and received in the visited PLMN, but may be identification information not transmitted and received in the home PLMN.

[0542] The following describes the processing performed by UE_A10 when, in the first processing example, a backoff timer is received in the home PLMN and then the UE_A10 moves from the home PLMN to another PLMN. In other words, the following describes the processing performed by UE_A10 when, in the first processing example, the UE_A10 moves from the home PLMN to another PLMN while the backoff timer is being executed.

[0543] When UE_A10 changes PLMNs, if the previous PLMN is the home PLMN, the restrictions on sending SM request messages described in the examples may be continued in the destination PLMN based on the backoff timer. In other words, in this case, the UE_A10 may be prohibited from sending SM request messages described in the examples in the destination PLMN based on the backoff timer.

[0544] In this way, UE_A10 can execute the first processing example regardless of whether it receives the 20th identification information described later when the backoff timer is received. In other words, UE_A10 can be configured to execute the first processing example even if it does not receive the 20th identification information described later when the backoff timer is received. In other words, UE_A10 can be configured to continue the restrictions imposed by the backoff timer received in the home PLMN even if the PLMN changes.

[0545] Next, the processing in the first processing example when a backoff timer is received in the visited PLMN and then moves to another PLMN will be described. In other words, the processing in the first processing example when UE_A10 moves from the visited PLMN to another PLMN while the backoff timer is executing will be described below.

[0546] When UE_A10 changes PLMNs, if the 22nd identification information is received during the reception backoff timer and / or if the 20th identification information is not received during the reception backoff timer, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN based on the backoff timer being counted. In other words, in this case, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN based on the backoff timer being counted. In other words, in this case, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN, which was prohibited in the PLMN before the change, based on the backoff timer being counted.

[0547] However, when UE_A10 changes PLMNs and receives the twenty-first identification information during the reception backoff timer, the restriction on the transmission of SM request messages described in the examples may be continued in the destination PLMN based on the backoff timer being counted. In other words, in this case, the transmission of SM request messages described in the examples may be prohibited in the destination PLMN based on the backoff timer being counted.

[0548] Furthermore, when UE_A10 changes PLMNs and the previous PLMN is the visited PLMN, and a backoff timer is counting in the previous PLMN, and UE_A10 receives the 20th identification information set as the 21st identification information along with the backoff timer value, the restriction on the transmission of SM request messages described in the respective examples may be continued based on the backoff timer being counted. In other words, in this case, the transmission of SM request messages described in the respective examples may be prohibited in the destination PLMN based on the backoff timer being counted.

[0549] Furthermore, when UE_A10 changes PLMNs and the previous PLMN is the visited PLMN, and a backoff timer is counting in the previous PLMN, and the 21st identification information is received along with the backoff timer value, the restriction on the transmission of SM request messages described in the respective examples may be continued based on the backoff timer being counted. In other words, in this case, the transmission of SM request messages described in the respective examples may be prohibited in the destination PLMN based on the backoff timer being counted.

[0550] Furthermore, when UE_A10 changes PLMNs, while counting a backoff timer in the previous PLMN and also in the destination PLMN, the restrictions on the transmission of SM request messages described in the examples may be continued based on the counting backoff timer. In other words, in this case, the transmission of SM request messages described in the examples may be prohibited in the destination PLMN based on the counting backoff timer.

[0551] Next, the second processing example will be described.

[0552] It should be noted that, in the second processing example, the twentieth identification information may be an information element indicating that S-NSSAI-based congestion management is applied in the current PLMN and PLMNs other than the PLMN. It should be noted that S-NSSAI-based congestion management may be the second congestion management or the third congestion management.

[0553] In this case, the 20th identification information may include information indicating that S-NSSAI-based congestion management is applied to the current PLMN and PLMNs other than the PLMN. Furthermore, the 20th identification information may be an information element that cannot include information indicating that S-NSSAI-based congestion management is applied only to the current PLMN. In other words, the 20th identification information may include the 21st identification information.

[0554] Here, the twenty-first identification information may be information indicating that congestion management based on S-NSSAI is applied in the current PLMN and PLMNs other than the PLMN.

[0555] Furthermore, the twentieth identification information may be an information element indicating that the backoff timer to be counted is valid in all PLMNs. It should be noted that the backoff timer may be a backoff timer used in congestion management based on S-NSSAI.

[0556] In this case, the 20th identification information may include information indicating that the backoff timer being counted is valid in all PLMNs. Furthermore, the 20th identification information may be an information element that cannot include information indicating that the backoff timer being counted is valid only in the current PLMN. In other words, the 20th identification information may include the 21st identification information.

[0557] Here, the twenty-first identification information may be information indicating that the backoff timer being counted is valid in all PLMNs.

[0558] Furthermore, the twentieth identification information may be an information element indicating home PLMN congestion. It should be noted that home PLMN congestion may refer to slice congestion in the home PLMN. Furthermore, home PLMN congestion may be a state in which congestion management based on S-NSSAI is being performed in the home PLMN.

[0559] In this case, the 20th identification information may include information indicating that the home PLMN is congested. Furthermore, the 20th identification information may be an information element that cannot include information indicating that the home PLMN is not congested. In other words, the 20th identification information may be information including the 21st identification information.

[0560] Here, the twenty-first identification information may be information indicating that the home PLMN is congested.

[0561] Furthermore, the twentieth identification information may be information indicating that the S-NSSAI associated with the congestion management based on the S-NSSAI is the S-NSSAI of the home PLMN.

[0562] In this case, the 20th identification information may include information indicating that the S-NSSAI associated with S-NSSAI-based congestion management is the S-NSSAI of the home PLMN. Furthermore, the 20th identification information may be an information element that cannot include information indicating that the S-NSSAI associated with S-NSSAI-based congestion management is the S-NSSAI of the visited PLMN. In other words, the 20th identification information may include the 21st identification information.

[0563] Here, the twenty-first identification information may be information indicating that the S-NSSAI associated with the S-NSSAI-based congestion management is the S-NSSAI of the home PLMN.

[0564] Furthermore, the twentieth identification information is identification information transmitted and received in the visited PLMN, and may also be identification information not transmitted and received in the home PLMN.

[0565] The following describes the processing of UE_A10 in the second processing example when receiving the backoff timer in the home PLMN and then moving from the home PLMN to another PLMN. In other words, the following describes the processing of UE_A10 in the second processing example when moving from the home PLMN to another PLMN while the backoff timer is executing.

[0566] When UE_A10 changes PLMNs, if the previous PLMN is the home PLMN, the restrictions on sending SM request messages described in the examples may be continued in the destination PLMN based on the backoff timer. In other words, in this case, the UE_A10 may be prohibited from sending SM request messages described in the examples in the destination PLMN based on the backoff timer.

[0567] In this way, UE_A10 can execute the second processing example regardless of whether it receives the 20th identification information described later when the backoff timer is received. In other words, UE_A10 can also execute the second processing example even if it does not receive the 20th identification information described later when the backoff timer is received. In other words, UE_A10 can also be configured to continue the restrictions imposed by the backoff timer received in the home PLMN even if the PLMN changes.

[0568] Next, the processing for the second processing example when receiving the backoff timer in the visited PLMN and then moving to another PLMN will be described. In other words, the processing of UE_A10 in the second processing example when moving from the visited PLMN to another PLMN while the backoff timer is executing will be described below.

[0569] Alternatively, when UE_A10 changes PLMNs, if the 20th identification information is not received during the reception backoff timer, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN, based on the counted backoff timer. In other words, in this case, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN, based on the counted backoff timer. Furthermore, in this case, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN, based on the counted backoff timer.

[0570] However, when UE_A10 changes PLMNs and receives the twenty-first identification information during the reception backoff timer, the restriction on the transmission of SM request messages described in the examples may be continued in the destination PLMN based on the backoff timer being counted. In other words, in this case, the transmission of SM request messages described in the examples may be prohibited in the destination PLMN based on the backoff timer being counted.

[0571] Furthermore, when UE_A10 changes PLMNs and the previous PLMN is the visited PLMN, and a backoff timer is counting in the previous PLMN, and UE_A10 receives the 20th identification information and / or the 21st identification information along with the backoff timer value, the restriction on the transmission of SM request messages described in the respective examples may be continued based on the backoff timer being counted. In other words, in this case, the transmission of SM request messages described in the respective examples may be prohibited based on the backoff timer being counted in the destination PLMN.

[0572] Furthermore, when UE_A10 changes PLMNs, while counting a backoff timer in the previous PLMN and also in the destination PLMN, the restrictions on the transmission of SM request messages described in the examples may be continued based on the counting backoff timer. In other words, in this case, the transmission of SM request messages described in the examples may be prohibited in the destination PLMN based on the counting backoff timer.

[0573] Next, the third processing example will be described.

[0574] It should be noted that, in the third processing example, the twentieth identification information, the twenty-first identification information, and the twenty-second identification information may be the same as the identification information described in the first processing example.

[0575] Furthermore, in the case of the third processing example, the twentieth identification information may be identification information that can be transmitted and received in both the home PLMN and the visited PLMN.

[0576] The following describes the processing performed by UE_A10 when, in the third processing example, a backoff timer is received in the home PLMN and then the UE_A10 moves from the home PLMN to another PLMN. In other words, the following describes the processing performed by UE_A10 when, in the third processing example, the UE_A10 moves from the home PLMN to another PLMN while the backoff timer is being executed.

[0577] Alternatively, when UE_A10 changes PLMNs, if the PLMN before the change is the home PLMN and the 22nd identification information is received during the reception backoff timer, and / or if UE_A10 changes PLMNs, if the PLMN before the change is the home PLMN and the 20th identification information is not received during the reception backoff timer, then, in the destination PLMN, the SM request message described in each example may be permitted to be sent based on the backoff timer being counted. In other words, in this case, the UE_A10 may be permitted to send the SM request message described in each example based on the backoff timer being counted. Furthermore, in this case, the UE_A10 may be permitted to send the SM request message described in each example, which was prohibited in the PLMN before the change, based on the backoff timer being counted, in the destination PLMN.

[0578] More specifically, when UE_A10 changes PLMNs, if the previous PLMN is the home PLMN and the backoff timer is not counting in the destination PLMN, and if the 20th identification information is not received while receiving the backoff timer, and / or if the 20th identification information including the 22nd identification information is received while receiving the backoff timer, and / or if the 22nd identification information is received while receiving the backoff timer, then in the destination PLMN, transmission of the SM request message described in the examples may be permitted based on the backoff timer being counted. In other words, in this case, transmission of the SM request message described in the examples may be permitted in the destination PLMN based on the backoff timer being counted. Furthermore, in this case, transmission of the SM request message described in the examples, which was prohibited in the previous PLMN, may be permitted in the destination PLMN based on the backoff timer being counted.

[0579] However, when UE_A10 changes PLMNs, if the previous PLMN is the home PLMN and the 21st identification information is received during the reception backoff timer, the restriction on the transmission of SM request messages described in the examples may be continued in the destination PLMN based on the backoff timer being counted. In other words, in this case, the transmission of SM request messages described in the examples may be prohibited in the destination PLMN based on the backoff timer being counted.

[0580] Furthermore, when UE_A10 changes PLMNs, and the previous PLMN is the home PLMN, and a backoff timer is counting in the previous PLMN, and UE_A10 receives the 20th identification information set as the 21st identification information along with the backoff timer value, the restriction on the transmission of SM request messages described in the respective examples may be continued based on the backoff timer being counted. In other words, in this case, the transmission of SM request messages described in the respective examples may be prohibited based on the backoff timer being counted in the destination PLMN.

[0581] Furthermore, when UE_A10 changes PLMNs, and the previous PLMN is the home PLMN, and a backoff timer is counting in the previous PLMN, and the 21st identification information is received along with the backoff timer value, the restriction on the transmission of SM request messages described in the respective examples may be continued based on the backoff timer being counted. In other words, in this case, the transmission of SM request messages described in the respective examples may be prohibited based on the backoff timer being counted in the destination PLMN.

[0582] Furthermore, when UE_A10 changes PLMNs, if the previous PLMN is the home PLMN and a backoff timer is counting in the previous PLMN and the backoff timer is also counting in the destination PLMN, the restrictions on the transmission of SM request messages described in the examples may continue based on the counting backoff timer. In other words, in this case, the transmission of SM request messages described in the examples may be prohibited in the destination PLMN based on the counting backoff timer.

[0583] Next, the processing for the case where the backoff timer is received in the visited PLMN and then moves to another PLMN in the third processing example will be described. In other words, the processing of UE_A10 in the third processing example when moving from the visited PLMN to another PLMN while the backoff timer is executing will be described below.

[0584] If UE_A10 does not receive the 20th identification information during the reception backoff timer and / or receives the 22nd identification information during the reception backoff timer when changing PLMNs, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN based on the counted backoff timer. In other words, in this case, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN based on the counted backoff timer. In other words, in this case, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN based on the counted backoff timer. Furthermore, in this case, the UE_A10 may allow the transmission of the SM request message described in each example, which was prohibited in the PLMN before the change, based on the counted backoff timer in the destination PLMN.

[0585] However, when UE_A10 changes PLMNs and receives the twenty-first identification information during the reception backoff timer, the restriction on the transmission of SM request messages described in the examples may be continued in the destination PLMN based on the backoff timer being counted. In other words, in this case, the transmission of SM request messages described in the examples may be prohibited in the destination PLMN based on the backoff timer being counted.

[0586] Furthermore, when UE_A10 changes PLMNs, it may be configured such that, when a backoff timer is counted in the PLMN prior to the change and UE_A10 receives the 20th identification information set as the 21st identification information along with the backoff timer value, the restriction on the transmission of SM request messages described in the respective examples may be continued based on the backoff timer being counted. In other words, in this case, UE_A10 may be configured to prohibit the transmission of SM request messages described in the respective examples in the destination PLMN based on the backoff timer being counted.

[0587] Furthermore, when UE_A10 changes PLMNs, it may be configured such that, while counting a backoff timer in the PLMN prior to the change, if the 21st identification information is received along with the backoff timer value, the restriction on the transmission of SM request messages described in the respective examples may be continued based on the backoff timer being counted. In other words, in this case, the UE_A10 may be configured such that, in the destination PLMN, the transmission of SM request messages described in the respective examples may be prohibited based on the backoff timer being counted.

[0588] Furthermore, when UE_A10 changes PLMNs, while counting a backoff timer in the previous PLMN and also in the destination PLMN, the restrictions on the transmission of SM request messages described in the examples may be continued based on the counting backoff timer. In other words, in this case, the transmission of SM request messages described in the examples may be prohibited in the destination PLMN based on the counting backoff timer.

[0589] Next, the fourth processing example will be described.

[0590] It should be noted that, in the fourth processing example, the twentieth identification information, the twenty-first identification information, and the twenty-second identification information may be the same as the identification information described in the first processing example.

[0591] Furthermore, in the case of the fourth processing example, the twentieth identification information may be identification information that can be transmitted and received in both the home PLMN and the visited PLMN.

[0592] The following describes the processing performed by UE_A10 when, in the fourth processing example, a backoff timer is received in the home PLMN and then the UE_A10 moves from the home PLMN to another PLMN. In other words, the following describes the processing performed by UE_A10 when, in the fourth processing example, the UE_A10 moves from the home PLMN to another PLMN while the backoff timer is executing.

[0593] Alternatively, when UE_A10 changes PLMNs, if the PLMN before the change is the home PLMN and the 22nd identification information is received during the reception backoff timer, the UE_A10 may allow the transmission of the SM request message described in the examples in the destination PLMN, based on the backoff timer being counted. In other words, in this case, the UE_A10 may allow the transmission of the SM request message described in the examples in the destination PLMN, based on the backoff timer being counted. Furthermore, in this case, the UE_A10 may allow the transmission of the SM request message described in the examples, which was prohibited in the PLMN before the change, in the destination PLMN, based on the backoff timer being counted.

[0594] More specifically, when UE_A10 changes PLMNs, if the PLMN before the change is the home PLMN and the backoff timer is not being counted in the destination PLMN, and if the 20th identification information including the 22nd identification information is received during the backoff timer reception and / or if the 22nd identification information is received during the backoff timer reception, then in the destination PLMN, the SM request message described in the examples may be permitted to be sent based on the backoff timer being counted. In other words, in this case, the UE_A10 may be permitted to send the SM request message described in the examples in the destination PLMN based on the backoff timer being counted. Furthermore, in this case, the UE_A10 may be permitted to send the SM request message described in the examples in the destination PLMN based on the backoff timer being counted.

[0595] However, when UE_A10 changes PLMNs, if the previous PLMN is the home PLMN and the 21st identification information is received during the reception backoff timer, and / or if UE_A10 changes PLMNs, if the previous PLMN is the home PLMN and the 20th identification information is not received during the reception backoff timer, the restriction on the transmission of the SM request message described in each example may be continued in the destination PLMN based on the counting backoff timer. In other words, in this case, the transmission of the SM request message described in each example may be prohibited in the destination PLMN based on the counting backoff timer.

[0596] Next, the fourth processing example will be described for the case where a backoff timer is received in a visited PLMN and then the UE moves to another PLMN. In other words, the fourth processing example will be described for the case where UE_A10 moves from the visited PLMN to another PLMN while the backoff timer is executing.

[0597] If UE_A10 does not receive the 20th identification information during the reception backoff timer and / or receives the 22nd identification information during the reception backoff timer when changing PLMNs, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN based on the counted backoff timer. In other words, in this case, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN based on the counted backoff timer. In other words, in this case, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN based on the counted backoff timer. Furthermore, in this case, the UE_A10 may allow the transmission of the SM request message described in each example, which was prohibited in the PLMN before the change, based on the counted backoff timer in the destination PLMN.

[0598] However, when UE_A10 changes PLMNs and receives the twenty-first identification information during the reception backoff timer, the restriction on the transmission of SM request messages described in the examples may be continued in the destination PLMN based on the backoff timer being counted. In other words, in this case, the transmission of SM request messages described in the examples may be prohibited in the destination PLMN based on the backoff timer being counted.

[0599] Furthermore, when UE_A10 changes PLMNs, it may be configured such that, when a backoff timer is counted in the PLMN prior to the change and UE_A10 receives the 20th identification information set as the 21st identification information along with the backoff timer value, the restriction on the transmission of SM request messages described in the respective examples may be continued based on the backoff timer being counted. In other words, in this case, UE_A10 may be configured to prohibit the transmission of SM request messages described in the respective examples in the destination PLMN based on the backoff timer being counted.

[0600] Furthermore, when UE_A10 changes PLMNs, it may be configured such that, while counting a backoff timer in the PLMN prior to the change, if the 21st identification information is received along with the backoff timer value, the restriction on the transmission of SM request messages described in the respective examples may be continued based on the backoff timer being counted. In other words, in this case, the UE_A10 may be configured such that, in the destination PLMN, the transmission of SM request messages described in the respective examples may be prohibited based on the backoff timer being counted.

[0601] Furthermore, when UE_A10 changes PLMNs, while counting a backoff timer in the previous PLMN and also in the destination PLMN, the restrictions on the transmission of SM request messages described in the examples may be continued based on the counting backoff timer. In other words, in this case, the transmission of SM request messages described in the examples may be prohibited in the destination PLMN based on the counting backoff timer.

[0602] Next, the fifth processing example will be described.

[0603] It should be noted that, in the fifth processing example, the twentieth identification information and the twenty-first identification information may be the same as the identification information described in the second processing example.

[0604] Furthermore, in the case of the fifth processing example, the twentieth identification information may be identification information that can be transmitted and received in both the home PLMN and the visited PLMN.

[0605] The following describes the processing performed by UE_A10 when, in the fifth processing example, a backoff timer is received in the Home PLMN and then the UE_A10 moves from the Home PLMN to another PLMN. In other words, the following describes the processing performed by UE_A10 when, in the fifth processing example, the UE_A10 moves from the Home PLMN to another PLMN while the backoff timer is executing.

[0606] Alternatively, when UE_A10 changes PLMNs and the previous PLMN is the home PLMN, and the 20th identification information is not received during the reception backoff timer, and / or when UE_A10 changes PLMNs and the previous PLMN is the home PLMN, and the 20th identification information that does not include the 21st identification information is received during the reception backoff timer, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN based on the backoff timer being counted. In other words, in this case, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN based on the backoff timer being counted. Furthermore, in this case, the UE_A10 may allow the transmission of the SM request message described in each example, which was prohibited in the previous PLMN, based on the backoff timer being counted, in the destination PLMN.

[0607] More specifically, when UE_A10 changes PLMNs, if the previous PLMN is the home PLMN and the backoff timer is not counting in the destination PLMN, and if the 20th identification information is not received when receiving the backoff timer and / or if the 20th identification information is received without the 21st identification information, then in the destination PLMN, the SM request message described in the examples may be permitted to be sent based on the backoff timer being counted. In other words, in this case, the UE_A10 may be permitted to send the SM request message described in the examples in the destination PLMN based on the backoff timer being counted. Furthermore, in this case, the UE_A10 may be permitted to send the SM request message described in the examples in the destination PLMN based on the backoff timer being counted.

[0608] However, when UE_A10 changes PLMNs, if the previous PLMN is the home PLMN and the 21st identification information is received during the reception backoff timer, the restriction on the transmission of SM request messages described in the examples may be continued in the destination PLMN based on the backoff timer being counted. In other words, in this case, the transmission of SM request messages described in the examples may be prohibited in the destination PLMN based on the backoff timer being counted.

[0609] Furthermore, when UE_A10 changes PLMNs, and the previous PLMN is the home PLMN, and a backoff timer is counting in the previous PLMN, and UE_A10 receives the 20th identification information and / or the 21st identification information along with the backoff timer value, the restriction on the transmission of SM request messages described in the respective examples may be continued based on the backoff timer being counted. In other words, in this case, the transmission of SM request messages described in the respective examples may be prohibited based on the backoff timer being counted in the destination PLMN.

[0610] Furthermore, when UE_A10 changes PLMNs, if the previous PLMN is the home PLMN and a backoff timer is counting in the previous PLMN and the backoff timer is also counting in the destination PLMN, the restrictions on the transmission of SM request messages described in the examples may continue based on the counting backoff timer. In other words, in this case, the transmission of SM request messages described in the examples may be prohibited in the destination PLMN based on the counting backoff timer.

[0611] Next, the fifth processing example will be described for the case where a backoff timer is received in a visited PLMN and then the UE moves to another PLMN. In other words, the fifth processing example will be described for the case where UE_A10 moves from the visited PLMN to another PLMN while the backoff timer is executing.

[0612] When UE_A10 changes PLMNs, if the 20th identification information is not received during the reception backoff timer, and / or if UE_A10 receives the 20th identification information that does not include the 21st identification information during the reception backoff timer, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN based on the counted backoff timer. In other words, in this case, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN based on the counted backoff timer. In other words, in this case, the UE_A10 may allow the transmission of the SM request message described in each example in the destination PLMN based on the counted backoff timer. Furthermore, in this case, the UE_A10 may allow the transmission of the SM request message described in each example, which was prohibited i...

Claims

1. A user equipment (UE), characterized in that: include: a transceiver unit, which receives a PDU session establishment rejection message from the control device during a protocol data unit PDU session establishment process; as well as a control unit that, if the first information and the backoff timer value are included in the PDU session establishment reject message and single network slice selection assistance information S-NSSAI is provided during the PDU session establishment procedure, starts the backoff timer using the backoff timer value, The first information is a reason value indicating insufficient resources for a specific slice, The backoff timer is a timer used for congestion control based on S-NSSAI. The back-off timer is associated with the S-NSSAI provided from the UE during the PDU session establishment procedure, In the case where the first information and the second information indicating whether the back-off timer is applied to the registered public land mobile network PLMN or to all PLMNs are included in the PDU session establishment reject message, When the second information indicates that the back-off timer is applied to the registered PLMN, during the activation of the back-off timer, no other PDU session establishment request message or PDU session change request message is sent in the registered PLMN for the S-NSSAI. When the second information indicates that the back-off timer is applied to all the PLMNs, during the activation of the back-off timer, no other PDU session establishment request message or PDU session change request message is sent in all the PLMNs for the S-NSSAI.

2. The UE according to claim 1, wherein In the case where the first information and the second information indicating that the backoff timer is applied to all PLMNs are included in the PDU session establishment reject message, and when the PLMN is changed, no other PDU session establishment request message or PDU session change request message is sent for the S-NSSAI during the activation of the backoff timer.

3. A communication control method, which is a communication control method performed by a user equipment UE, characterized in that: During the protocol data unit PDU session establishment process, receiving a PDU session establishment rejection message from the control device; In case the first information and the back-off timer value are included in the PDU session establishment reject message and single network slice selection assistance information S-NSSAI is provided during the PDU session establishment procedure, starting the back-off timer using the back-off timer value, The first information is a reason value indicating insufficient resources for a specific slice, The backoff timer is a timer used for congestion control based on S-NSSAI. The back-off timer is associated with the S-NSSAI provided from the UE during the PDU session establishment procedure, In the case where the first information and the second information indicating whether the back-off timer is applied to the registered public land mobile network PLMN or to all PLMNs are included in the PDU session establishment reject message, When the second information indicates that the back-off timer is applied to the registered PLMN, during the activation of the back-off timer, no other PDU session establishment request message or PDU session change request message is sent in the registered PLMN for the S-NSSAI, When the second information indicates that the back-off timer is applied to all the PLMNs, during the activation of the back-off timer, no other PDU session establishment request message or PDU session change request message is sent in all the PLMNs for the S-NSSAI.

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