UE(User Equipment)

Abstract

This provides a UE that clarifies the policy management for switching between UE-to-UE communication using the Uu interface to UE-to-UE communication using the PC5 interface, and clarifies the behavior when each device does not support the provision of emergency services via another UE. [Solution] In 5G ProSe communication via U2N Relay UE, the Remote UE uses a path selection policy or path switching policy to select the appropriate communication path and indicate whether or not it supports emergency services using U2N Relay UE. If the network does not support emergency services using relay, it sends a PDU session establishment rejection message.

Description

Technical Field

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

Background Art

[0002] In 3GPP (3rd Generation Partnership Project), the system architecture of 5GS (5G System), which is a fifth-generation (5G) mobile communication system, is being studied, and discussions are being held to support new procedures and new functions (see Non-Patent Documents 1 to 4). In recent years, discussions on the expansion of functions in ProSe (Proximity based Services) have become active (see Non-Patent Document 5).

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

[0004] In order to provide a wide variety of services in 5GS (5G System), a new core network called 5GCN (5G Core Network) is being considered. Furthermore, in 5GS, functionality to realize ProSe (Proximity-based Services), which provides proximity wireless communication between UEs (Unified Users), is also being considered.

[0005] Currently, we are considering expanding the functionality of the ProSe service. Specifically, we are exploring methods to switch from communication between UEs using the Uu interface to communication between UEs using the PC5 interface. Furthermore, while emergency services are normally provided directly from the network to the UE, we are also considering methods for the network to provide these emergency services via another UE. However, these considerations only examine the normal operation of each device, and the behavior of each device when an anomaly occurs is not yet clear.

[0006] One aspect of the present invention has been made in view of the above circumstances. In this invention, the management of policies for switching between UEs using the Uu interface to UEs using the PC5 interface is clarified. Furthermore, the behavior when each device does not support the provision of emergency services via another UE is clarified. [Means for solving the problem]

[0007] User Equipment (UE) according to one aspect of the present invention operates as a Remote UE, and the UE comprises a transceiver unit and a control unit, wherein the transceiver unit transmits a registration request message to the network including first identification information, the first identification information being information indicating that the UE supports emergency services using relays, the transceiver unit receives a registration acceptance message from the network including second identification information, the second identification information being information indicating that the network does not support emergency services using relays, the control unit recognizes, based on the second identification information, that the network does not support emergency services using relays, and the transceiver unit does not transmit a ProSe direct link establishment request message even if it receives a Relay Service Code (RSC) for emergency services from a Layer-3 UE-to-Network Relay UE. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to clarify the management of policies for switching between UE communication using the Uu interface to UE communication using the PC5 interface. Furthermore, it is possible to clarify the behavior when each device does not support the provision of emergency services via another UE. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram illustrating the general outline of the mobile communication system (EPS / 5GS). [Figure 2] This diagram illustrates the detailed configuration of the mobile communication system (EPS / 5GS). [Figure 3] This is a diagram illustrating the equipment configuration of the UE. [Figure 4] This diagram illustrates the configuration of the access network device (gNB) in 5GS. [Figure 5] This diagram illustrates the configuration of the core network equipment (AMF / SMF / UPF) in 5GS. [Figure 6] This is a diagram explaining the registration procedure. [Figure 7] This diagram illustrates the procedure for establishing a PDU session. [Figure 8] This diagram illustrates the network request UE policy management procedure. [Figure 9] This diagram illustrates the procedure for providing UE requests (ProSeP). [Figure 10] This is a diagram illustrating the discovery procedure. [Figure 11] This diagram illustrates the procedure for establishing a direct link with ProSe. [Figure 12] This diagram illustrates an example of 5G ProSe communication via U2N Relay. [Modes for carrying out the invention]

[0010] Hereinafter, the best mode for implementing one aspect of the present invention will be described with reference to the drawings. In this embodiment, as an example, an embodiment of a mobile communication system when one aspect of the present invention is applied will be described.

[0011] [1. Overview of the System] First, FIG. 1 is a diagram for explaining the outline of the mobile communication system 1 used in each embodiment, and FIG. 2 is a diagram for explaining the detailed configuration of the mobile communication system 1.

[0012] As shown in FIG. 1, the mobile communication system 1 is described as being composed of UE_A10, access network_A80, core network_A90, PDN (Packet Data Network)_A5, access network_B120, core network_B190, and DN (Data Network)_A6.

[0013] Hereinafter, these devices / functions may be described with symbols omitted, such as UE, access network_A, core network_A, PDN, access network_B, core network_B, DN, etc.

[0014] Also, as shown in FIG. 2, devices / functions such as UE_A10, E-UTRAN80, MME40, SGW35, PGW-U30, PGW-C32, PCRF60, HSS50, 5G AN120, AMF140, UPF130, SMF132, PCF160, UDM150, N3IWF170, etc., and interfaces connecting these devices / functions to each other are described.

[0015] Hereinafter, these devices / functions may be described with symbols omitted, such as UE, E-UTRAN, MME, SGW, PGW-U, PGW-C, PCRF, HSS, 5G AN, AMF, UPF, SMF, PCF, UDM, N3IWF, etc.

[0016] Furthermore, the 4G system, EPS (Evolved Packet System), consists of access network_A and core network_A, but may also include UE and / or PDN. Similarly, the 5G system, 5GS (5G System), consists of UE, access network_B and core network_B, but may also include DN.

[0017] A UE is a device capable of connecting to network services via 3GPP access (also known as a 3GPP access network or 3GPP AN) and / or non-3GPP access (also known as a non-3GPP access network or non-3GPP AN). A UE may be a wireless communication terminal device such as a mobile phone or smartphone, and may be a terminal device capable of connecting to both EPS and 5GS. A UE may be equipped with a UICC (Universal Integrated Circuit Card) or an eUICC (Embedded UICC). A UE may also be referred to as a user device or a terminal device.

[0018] Furthermore, access network_A corresponds to E-UTRAN (Evolved Universal Terrestrial Radio Access Network) and / or a wireless LAN access network. E-UTRAN has one or more eNBs (evolved Node B)45. Note that in the following, eNB45 may be written simply as eNB. If there are multiple eNBs, each eNB is connected to the others, for example, by an X2 interface. Furthermore, the wireless LAN access network has one or more access points.

[0019] Furthermore, access network_B corresponds to the 5G access network (5G AN). The 5G AN consists of NG-RAN (NG Radio Access Network) and / or non-3GPP access networks. One or more gNBs (NR NodeBs)122 are located in the NG-RAN. Note that, below, gNB122 may be written with the symbol omitted, such as gNB. A gNB is a node that provides the NR (New Radio) user plane and control plane to the UE, and is a node that connects to the 5GCN via an NG interface (including the N2 interface or N3 interface). In other words, a gNB is a base station device newly designed for 5GS and has different functions from the base station device (eNB) used in the 4G system, EPS. Also, if there are multiple gNBs, each gNB is connected to the others, for example, by an Xn interface.

[0020] Furthermore, a non-3GPP access network may be an untrusted non-3GPP access network or a trusted non-3GPP access network. Here, an untrusted non-3GPP access network may be a non-3GPP access network that does not perform security management within the access network, such as a public Wi-Fi network. On the other hand, a trusted non-3GPP access network may be an access network defined by 3GPP and may be equipped with a TNAP (trusted non-3GPP access point) and a TNGF (trusted non-3GPP Gateway function).

[0021] Furthermore, in the following, E-UTRAN and NG-RAN may be referred to as 3GPP access. Similarly, wireless LAN access networks and non-3GPP AN may be referred to as non-3GPP access. Additionally, nodes located in access network_B may be collectively referred to as NG-RAN nodes.

[0022] Furthermore, in the following, access network_A and / or access network_B and / or the devices included in access network_A and / or the devices included in access network_B may be referred to as access network or access network device.

[0023] Furthermore, Core Network A corresponds to EPC (Evolved Packet Core). EPC is configured with, for example, MME (Mobility Management Entity), SGW (Serving Gateway), PGW (Packet Data Network Gateway)-U, PGW-C, PCRF (Policy and Charging Rules Function), HSS (Home Subscriber Server), etc.

[0024] Furthermore, Core Network B corresponds to 5GCN (5G Core Network). 5GCN includes, for example, AMF (Access and Mobility Management Function), UPF (User Plane Function), SMF (Session Management Function), PCF (Policy Control Function), and UDM (Unified Data Management). Here, 5GCN may also be expressed as 5GC.

[0025] Furthermore, in the following, Core Network A and / or Core Network B, the devices included in Core Network A and / or Core Network B may be referred to as the Core Network, Core Network devices, or devices within the Core Network.

[0026] The core network (Core Network A and / or Core Network B) may be an IP mobile communication network operated by a Mobile Network Operator (MNO) that connects the access network (Access Network A and / or Access Network B) to the PDN and / or DN; it may be a core network for a mobile network operator that operates and manages the mobile communication system 1; or it may be a core network for a virtual mobile communication operator or virtual mobile communication service provider such as an MVNO (Mobile Virtual Network Operator) or MVNE (Mobile Virtual Network Enabler).

[0027] Furthermore, although Figure 1 shows a case where the PDN and DN are the same, they may be different. The PDN may be a Data Network (DN) that provides communication services to the UE. The DN may be configured as a packet data service network, or it may be configured for each service. In addition, the PDN may include connected communication terminals. Therefore, connecting to the PDN may also mean connecting to communication terminals or server devices located in the PDN. Furthermore, sending and receiving user data with the PDN may also mean sending and receiving user data with communication terminals or server devices located in the PDN. Note that the PDN may be referred to as DN, and the DN may be referred to as PDN.

[0028] Furthermore, in the following, access network_A, core network_A, PDN, access network_B, core network_B, DN, and / or one or more devices included therein may be referred to as a network or network device. In other words, when a network and / or network device sends and receives messages and / or performs procedures, it means that access network_A, core network_A, PDN, access network_B, core network_B, DN, and / or one or more devices included therein send and receive messages and / or perform procedures.

[0029] Furthermore, the UE can connect to the access network. The UE can also connect to the core network via the access network. In addition, the UE can connect to the PDN or DN via the access network and the core network. That is, the UE can send and receive (communicate) user data with the PDN or DN. When sending and receiving user data, non-IP communication may be used in addition to IP (Internet Protocol) communication.

[0030] Here, IP communication refers to data communication using IP, where data is sent and received via IP packets. An IP packet consists of an IP header and a payload. The payload may include data sent and received by devices and functions included in EPS or devices and functions included in 5GS. Non-IP communication refers to data communication that does not use IP, where data is sent and received in a format different from the structure of an IP packet. For example, non-IP communication may be data communication realized by sending and receiving application data without an IP header, or it may be user data sent and received by the UE with other headers such as a MAC header or an Ethernet® frame header attached.

[0031] Furthermore, access network_A, core network_A, access network_B, core network_B, PDN_A, and DN_A may include devices not shown in Figure 2. For example, core network_A and / or core network_B may include an AUSF (Authentication Server Function) or an AAA (Authentication, authorization, and accounting) server (AAA-S).

[0032] Here, AUSF is a core network device equipped with authentication functions for 3GPP access and non-3GPP access. Specifically, it is a network function unit that receives authentication requests for 3GPP access and / or non-3GPP access from the UE and executes the authentication procedure.

[0033] Furthermore, the AAA server is a device equipped with authentication, authorization, and billing functions, which connects directly or indirectly to the AUSF via other network devices. The AAA server may be a network device within the core network. However, the AAA server may not be included in core network_A and / or core network_B, but may be included in PLMN. In other words, the AAA server may be a core network device or a device located outside the core network. For example, the AAA server may be a server device within PLMN managed by a third party.

[0034] Note that in Figure 2, for the sake of simplification, only one of each device / function is shown; however, multiple similar devices / functions may be configured in the mobile communication system 1. Specifically, the mobile communication system 1 may be configured with multiple devices / functions such as UE_A10, E-UTRAN80, MME40, SGW35, PGW-U30, PGW-C32, PCRF60, HSS50, 5G AN120, AMF140, UPF130, SMF132, PCF160, and / or UDM150.

[0035] UPF_A235 connects to DN, SMF, other UPFs, and access networks. UPF_A235 may also perform roles such as anchoring to intra-RAT mobility or inter-RAT mobility, packet routing and forwarding, UL CL (Uplink Classifier) ​​functionality supporting routing of multiple traffic flows to a single DN, branching point functionality supporting multi-homed PDU sessions, QoS processing for user planes, verification of uplink traffic, buffering of downlink packets, and triggering of downlink data notifications. Furthermore, UPF_A235 may also act as a relay device for transferring user data, serving as a gateway between the DN and the core network_B190. In addition, UPF_A235 may also act as a gateway for IP communication and / or non-IP communication. Moreover, UPF_A235 may have the functionality to forward IP communication and the functionality to convert between non-IP and IP communication. Furthermore, the multiple gateways that are deployed may also be gateways that connect the core network_B190 to a single DN. Note that UPF_A235 may have connectivity to other NFs and may connect to each device via other NFs.

[0036] Furthermore, a different UPF, UPF_C239 (also referred to as branching point or uplink classifier), may exist as a device or NF between UPF_A235 and the access network. If UPF_C239 exists, the PDU session between the UE and DN will be established via the access network, UPF_C239, and UPF_A235.

[0037] Furthermore, UPF130 may be the same device as UPF_A235. Note that UPF130 and UPF_A235 may be written with the symbols omitted, like UPF.

[0038] [2. Configuration of each device] Next, the configuration of each device (UE, and / or access network device, and / or core network device) used in each embodiment will be described with reference to a diagram. Each device may be configured as physical hardware, as logical (virtual) hardware configured on general-purpose hardware, or as software. Furthermore, at least some (including all) of the functions of each device may be configured as physical hardware, logical hardware, or software.

[0039] Furthermore, each memory unit (memory unit_A340, memory unit_A440, memory unit_B540, memory unit_A640, memory unit_B740) within each device / function described below is composed of, for example, semiconductor memory, SSD (Solid State Drive), HDD (Hard Disk Drive), etc. In addition, each memory unit can store not only the information originally set at the time of shipment, but also various information transmitted and received with devices / functions other than its own device / function (for example, UE, and / or access network devices, and / or core network devices, and / or PDN, and / or DN). In addition, each memory unit can store identification information, control information, flags, parameters, etc. contained in control messages transmitted and received within the various communication procedures described later. Furthermore, each memory unit may store this information for each UE. In addition, when interworking between 5GS and EPS occurs, each memory unit can store control messages and user data transmitted and received with devices / functions contained within 5GS and / or EPS. In this case, not only data transmitted and received via the N26 interface can be stored, but also data transmitted and received without using the N26 interface.

[0040] [2.1. UE Equipment Configuration] First, an example of the UE (User Equipment) configuration will be explained using Figure 3. The UE consists of a control unit_A300, an antenna 310, a transceiver_A320, and a storage unit_A340. The control unit_A300, transceiver_A320, and storage unit_A340 are connected via a bus. The transceiver_A320 is connected to the antenna 310.

[0041] The control unit_A300 is a functional unit that controls the operation and functions of the entire UE. The control unit_A300 realizes various processes in the UE by reading and executing various programs stored in the memory unit_A340 as needed.

[0042] The transceiver unit A320 is a functional unit for wireless communication with base station equipment (eNB or gNB) within the access network via an antenna. In other words, the UE can use the transceiver unit A320 to send and receive user data and / or control information between the access network equipment and / or core network equipment and / or PDN and / or DN.

[0043] Referring to Figure 2, the UE can communicate with the base station equipment (eNB) in E-UTRAN via the LTE-Uu interface using the transceiver unit A320. The UE can also communicate with the base station equipment (gNB) in 5G AN using the transceiver unit A320. Furthermore, the UE can send and receive NAS (Non-Access-Stratum) messages with the AMF via the N1 interface using the transceiver unit A320. However, since the N1 interface is logical, actual communication between the UE and the AMF takes place via the 5G AN.

[0044] Memory unit A340 is a functional unit for storing programs, user data, control information, etc., necessary for each operation of the UE.

[0045] [2.2. gNB System Configuration] Next, an example of the gNB's device configuration will be explained using Figure 4. The gNB consists of a control unit_B500, an antenna 510, a network connection unit_B520, a transceiver unit_B530, and a storage unit_B540. The control unit_B500, network connection unit_B520, transceiver unit_B530, and storage unit_B540 are connected via a bus. The transceiver unit_B530 is connected to the antenna 510.

[0046] The control unit B500 is a functional unit that controls the operation and functions of the entire gNB. The control unit B500 implements various processes in the gNB by reading and executing various programs stored in the memory unit B540 as needed.

[0047] The network connection unit B520 is a functional unit that allows the gNB to communicate with the AMF and / or UPF. In other words, the gNB can use the network connection unit B520 to send and receive user data and / or control information with the AMF and / or UPF.

[0048] The transceiver unit B530 is a functional unit for wireless communication with the UE via the antenna 510. In other words, the gNB can send and receive user data and / or control information to and from the UE using the transceiver unit B530.

[0049] Referring to Figure 2, the gNB within the 5G AN can communicate with the AMF via the N2 interface and with the UPF via the N3 interface by using the network connection unit B520. Furthermore, the gNB can communicate with the UE by using the transceiver unit B530.

[0050] Memory unit B540 is a functional unit for storing programs, user data, control information, etc., necessary for each operation of the gNB.

[0051] [2.3. AMF Equipment Configuration] Next, an example of the AMF's device configuration will be explained using Figure 5. The AMF consists of a control unit_B700, a network connection unit_B720, and a storage unit_B740. The control unit_B700, network connection unit_B720, and storage unit_B740 are connected via a bus. The AMF may be a node that handles the control plane.

[0052] The control unit B700 is a functional unit that controls the operation and functions of the entire AMF. The control unit B700 implements various processes in the AMF by reading and executing various programs stored in the memory unit B740 as needed.

[0053] The network connection unit_B720 is a functional unit that allows the AMF to connect to base station equipment (gNB), and / or SMF, and / or PCF, and / or UDM, and / or SCEF within the 5G AN. In other words, the AMF can use the network connection unit_B720 to send and receive user data and / or control information with base station equipment (gNB), and / or SMF, and / or PCF, and / or UDM, and / or SCEF within the 5G AN.

[0054] Referring to Figure 2, the AMF within 5GCN can communicate with the gNB via the N2 interface, the UDM via the N8 interface, the SMF via the N11 interface, and the PCF via the N15 interface, using the network connection unit _A620. Furthermore, the AMF can send and receive NAS messages with the UE via the N1 interface using the network connection unit _A620. However, since the N1 interface is logical, actual communication between the UE and the AMF takes place via the 5G AN. Additionally, if the AMF supports the N26 interface, it can communicate with the MME via the N26 interface using the network connection unit _A620.

[0055] Memory unit B740 is a functional unit for storing programs, user data, control information, etc., necessary for each operation of the AMF.

[0056] Furthermore, the AMF has functions such as exchanging control messages with the RAN using the N2 interface, exchanging NAS messages with the UE using the N1 interface, encrypting and protecting the integrity of NAS messages, registration management (RM) function, connection management (CM) function, reachability management function, mobility management function for UEs, etc., forwarding SM (Session Management) messages between the UE and the SMF, access authentication (Access Authentication, Access Authorization) function, security anchor function (SEA), security context management (SCM), support for the N2 interface to the N3IWF (Non-3GPP Interworking Function), support for sending and receiving NAS signals with the UE via the N3IWF, and authentication of UEs connected via the N3IWF.

[0057] Furthermore, registration management manages the RM state for each UE. The RM state may be synchronized between the UE and the AMF. There are two RM states: unregistered state (RM-DEREGISTERED state) and registered state (RM-REGISTERED state). In the RM-DEREGISTERED state, the UE is not registered with the network, so the UE context in the AMF does not have valid location or routing information for that UE, and therefore the AMF cannot reach the UE. In the RM-REGISTERED state, the UE is registered with the network, so the UE can receive services that require registration with the network. Note that the RM state may also be expressed as the 5GMM state. In this case, the RM-DEREGISTERED state may be expressed as the 5GMM-DEREGISTERED state, and the RM-REGISTERED state may be expressed as the 5GMM-REGISTERED state.

[0058] In other words, 5GMM-REGISTERED means that each device may have established a 5GMM context or a PDU session context. Furthermore, when each device is 5GMM-REGISTERED, UE_A10 may start sending and receiving user data and control messages, and may respond to paging. In addition, when each device is 5GMM-REGISTERED, UE_A10 may perform registration procedures other than the registration procedure for initial registration, and / or service request procedures.

[0059] Furthermore, 5GMM-DEREGISTERED may occur even if each device has not established a 5GMM context, or if the location information of UE_A10 is not known to the network, or if the network is unreachable to UE_A10. If each device is in a 5GMM-DEREGISTERED state, UE_A10 may initiate the registration procedure, or establish a 5GMM context by executing the registration procedure.

[0060] Furthermore, connection management manages the CM state for each UE. The CM state may be synchronized between the UE and the AMF. There are two CM states: disconnected state (CM-IDLE state) and connected state (CM-CONNECTED state). In the CM-IDLE state, the UE is in the RM-REGISTERED state but does not have a NAS signaling connection established with the AMF via the N1 interface. Also, in the CM-IDLE state, the UE does not have an N2 connection or an N3 connection. On the other hand, in the CM-CONNECTED state, the UE has a NAS signaling connection established with the AMF via the N1 interface. Also, in the CM-CONNECTED state, the UE may have an N2 connection and / or an N3 connection.

[0061] Furthermore, connection management may be handled separately for CM states in 3GPP access and CM states in non-3GPP access. In this case, the CM states in 3GPP access may include an unconnected state (CM-IDLE state over 3GPP access) and a connected state (CM-CONNECTED state over 3GPP access). Furthermore, the CM states in non-3GPP access may include an unconnected state (CM-IDLE state over non-3GPP access) and a connected state (CM-CONNECTED state over non-3GPP access). Note that the unconnected state may be expressed as idle mode, and the connected state may be expressed as connected mode.

[0062] Furthermore, the CM state may be expressed as 5GMM mode. In this case, the disconnected state may be expressed as 5GMM-IDLE mode, and the connected state may be expressed as 5GMM-CONNECTED mode. Additionally, the disconnected state in 3GPP access may be expressed as 5GMM-IDLE mode over 3GPP access, and the connected state in 3GPP access may be expressed as 5GMM-CONNECTED mode over 3GPP access. Furthermore, the disconnected state in non-3GPP access may be expressed as 5GMM-IDLE mode over non-3GPP access, and the connected state in non-3GPP access may be expressed as 5GMM-CONNECTED mode over non-3GPP access. Note that 5GMM-IDLE mode may also be expressed as idle mode, and 5GMM-CONNECTED mode may also be expressed as connected mode.

[0063] Furthermore, one or more AMFs may be placed within core network_B. Also, an AMF may be a Network Function (NF) that manages one or more Network Slice Instances (NSIs). Additionally, an AMF may be a Common Control Plane Network Function (CCNF) shared among multiple NSIs.

[0064] Furthermore, N3IWF is a device and / or function placed between the non-3GPP access and 5GCN when the UE connects to 5GS via non-3GPP access.

[0065] [2.4. SMF Equipment Configuration] Next, an example of the SMF device configuration will be explained using Figure 5. The SMF consists of a control unit_B700, a network connection unit_B720, and a storage unit_B740. The control unit_B700, network connection unit_B720, and storage unit_B740 are connected via a bus. The SMF may be a node that handles the control plane.

[0066] The control unit B700 is a functional unit that controls the operation and functions of the entire SMF. The control unit B700 implements various processes in the SMF by reading and executing various programs stored in the memory unit B740 as needed.

[0067] The network connection unit B720 is a functional unit for the SMF to connect with the AMF, and / or UPF, and / or PCF, and / or UDM. In other words, the SMF can use the network connection unit B720 to send and receive user data and / or control information with the AMF, and / or UPF, and / or PCF, and / or UDM.

[0068] Referring to Figure 2, the SMF within 5GCN can communicate with the AMF via the N11 interface, the UPF via the N4 interface, the PCF via the N7 interface, and the UDM via the N10 interface by using the network connection unit A620.

[0069] Memory unit B740 is a functional unit for storing programs, user data, control information, etc., necessary for each operation of the SMF.

[0070] SMF has functions such as session management (Session Management) including establishing, modifying, and releasing PDU sessions; IP address allocation and management for UEs; UPF selection and control; UPF configuration for routing traffic to appropriate destinations; sending and receiving the SM portion of NAS messages; Downlink Data Notification; providing AN-specific (AN-specific) SM information transmitted to ANs via the N2 interface through AMF; determining the SSC mode (Session and Service Continuity mode) for sessions; and roaming functionality.

[0071] [2.5. UPF Equipment Configuration] Next, an example of the UPF's configuration will be explained using Figure 5. The UPF consists of a control unit_B700, a network connection unit_B720, and a storage unit_B740. The control unit_B700, network connection unit_B720, and storage unit_B740 are connected via a bus. The UPF may be a node that handles the control plane.

[0072] The control unit B700 is a functional unit that controls the operation and functions of the entire UPF. The control unit B700 implements various processes in the UPF by reading and executing various programs stored in the memory unit B740 as needed.

[0073] The network connection unit B720 is a functional unit that allows the UPF to connect with base station equipment (gNB), and / or SMF, and / or DN within the 5G AN. In other words, the UPF can use the network connection unit B720 to send and receive user data and / or control information with base station equipment (gNB), and / or SMF, and / or DN within the 5G AN.

[0074] Referring to Figure 2, the UPF within 5GCN can communicate with the gNB via the N3 interface, the SMF via the N4 interface, the DN via the N6 interface, and other UPFs via the N9 interface by using the network connection unit A620.

[0075] Memory unit B740 is a functional unit for storing programs, user data, control information, etc., necessary for each operation of the UPF.

[0076] UPF has functions such as acting as an anchor point for intra-RAT mobility or inter-RAT mobility, acting as an external PDU session point for interconnecting to DNs (i.e., acting as a gateway between DNs and core network B to forward user data), routing and forwarding packets, an UL CL (Uplink Classifier) ​​function that supports routing multiple traffic flows to a single DN, a branching point function that supports multi-homed PDU sessions, a QoS (Quality of Service) processing function for the user plane, an uplink traffic verification function, downlink packet buffering, and a function to trigger downlink data notification.

[0077] Furthermore, the UPF may also be a gateway for IP communication and / or non-IP communication. The UPF may also have the function of forwarding IP communication, and may also have the function of converting non-IP communication to IP communication. In addition, multiple gateways may be gateways connecting the core network B to a single DN. The UPF may also have connectivity to other NFs, and may connect to each device via other NFs.

[0078] Furthermore, the user plane refers to user data transmitted and received between the UE and the network. The user plane may be transmitted and received using a PDN connection or a PDU session. In addition, in the case of EPS, the user plane may be transmitted and received using the LTE-Uu interface and / or the S1-U interface and / or the S5 interface and / or the S8 interface and / or the SGi interface. Furthermore, in the case of 5GS, the user plane may be transmitted and received via the interface between the UE and the NG RAN and / or the N3 interface and / or the N9 interface and / or the N6 interface. Hereinafter, the user plane may be referred to as U-Plane.

[0079] Furthermore, the control plane refers to the control messages transmitted and received for communication control of the UE, etc. The control plane may be transmitted and received using the NAS (Non-Access-Stratum) signaling connection between the UE and the MME. In addition, in the case of EPS, the control plane may be transmitted and received using the LTE-Uu interface and the S1-MME interface. In addition, in the case of 5GS, the control plane may be transmitted and received using the interface between the UE and the NG RAN and the N2 interface. Hereinafter, the control plane may be referred to as the control plane or the C-Plane.

[0080] Furthermore, the U-Plane (User Plane; UP) may also be a communication channel for sending and receiving user data, and may consist of multiple bearers. Furthermore, the C-Plane (Control Plane; CP) may also be a communication channel for sending and receiving control messages, and may consist of multiple bearers.

[0081] [2.6. Description of other devices and / or functions] Next, we will describe the other devices and / or functions.

[0082] First, "network" refers to at least a portion of Access Network B, Core Network B, and DN. Furthermore, one or more devices included in at least a portion of Access Network B, Core Network B, and DN may be referred to as a network or network device. In other words, when a network performs message transmission, reception, and / or processing, it may mean that devices within the network (network devices, and / or control devices) perform message transmission, reception, and / or processing. Conversely, when devices within the network perform message transmission, reception, and / or processing, it may mean that the network performs message transmission, reception, and / or processing. Also, "network" may be referred to as NW.

[0083] Furthermore, the network may refer to a PLMN (Public Land Mobile Network) or an NPN (Non-Public Network), as described later. Additionally, network selection may refer to PLMN selection or SNPN selection.

[0084] Next, NWDAF (Network Data Analytics Function) may be an NF that has the function of collecting data from NFs and application functions (also called AFs).

[0085] Next, a PCF (Policy Control Function) may be a Network Function (NF) that has the function of determining policies to control the behavior of the network.

[0086] Next, an NRF (Network Repository Function) may be an NF that has a service discovery function. An NRF may be an NF that, upon receiving a discovery request for another NF from one NF, provides information about the discovered NF.

[0087] Next, UDM (Unified Data Management) may be a NF that has functions such as authentication credential processing, user identification processing, access authentication, registration / mobility management, and subscription management.

[0088] Next, an SM (Session Management) message may be a NAS message used in the procedures for SM. An SM message may also be called a NAS (Non-Access-Stratum) SM message. An SM message may be a control message sent and received between UE_A10 and SMF_A230 via AMF_A240. Furthermore, SM messages may include PDU session establishment request messages, PDU session establishment accept messages, PDU session establishment reject messages, PDU session modification request messages, PDU session modification command messages, PDU session modification complete messages, PDU session modification command reject messages, PDU session modification reject messages, PDU session release request messages, PDU session release reject messages, PDU session release command messages, PDU session release complete messages, and the like.

[0089] Next, SM procedures (also called procedures for SMs) may include PDU session establishment procedures, PDU session modification procedures, and UE-requested PDU session release procedures. Each procedure may be initiated by the UE or by the network.

[0090] Next, an MM (Mobility management) message may be a NAS message used in the procedures for MM. An MM message may also be called a NAS MM message. An MM message may be a control message sent and received between UE_A10 and AMF_A240. Furthermore, an MM message may include registration request messages, registration accept messages, registration reject messages, de-registration request messages, de-registration accept messages, configuration update command messages, configuration update complete messages, service request messages, service accept messages, service reject messages, notification messages, notification response messages, etc.

[0091] Next, MM procedures (also referred to as procedures for MM) may include registration procedures, de-registration procedures, generic UE configuration update procedures, authentication / authorization procedures, service request procedures, paging procedures, and notification procedures. Each procedure may be initiated by the UE or by the network.

[0092] Next, the 5GS (5G System) service may be a connectivity service provided using the core network B190. Furthermore, the 5GS service may be a different service from the EPS service, or it may be a service similar to the EPS service.

[0093] Next, non-5GS services may be services other than 5GS services, and may include EPS services and / or non-EPS services.

[0094] Next, S1 mode is a mode in which UE_A10 is permitted to access EPC via E-UTRAN. In other words, S1 mode may be a mode in which messages are sent and received using the S1 interface. The S1 interface may consist of the S1-MME interface and the S1-U interface.

[0095] Next, N1 mode is a mode in which UE_A10 is permitted to access 5GC via the 5G access network. In other words, N1 mode may be a mode in which messages are sent and received using the N1 interface.

[0096] Next, the APN (Access Point Name) can be any identification information that identifies the core network and / or external networks such as PDNs. Furthermore, the APN can also be used as information to select gateways such as PGW_A30 / UPF_A235 to which the core network A_90 will be connected.

[0097] Next, the PDN (Packet Data Network) type indicates the type of PDN connection, and includes IPv4, IPv6, IPv4v6, and non-IP. If IPv4 is specified, it means that data will be sent and received using IPv4. If IPv6 is specified, it means that data will be sent and received using IPv6. If IPv4v6 is specified, it means that data will be sent and received using either IPv4 or IPv6. If non-IP is specified, it means that communication will be conducted using a communication method other than IP, rather than IP-based communication.

[0098] Next, a PDU (Protocol Data Unit) session can be defined as the relationship between a DN and an UE that provides PDU connectivity services, but it may also be connectivity established between the UE and an external gateway. In 5GS, the UE can send and receive user data to and from the DN using the PDU session by establishing a PDU session via access network_B and core network_B. Here, this external gateway may be UPF, SCEF, etc. The UE can use the PDU session to send and receive user data with devices such as application servers located on the DN. Furthermore, each device (UE, and / or access network device, and / or core network device) may manage by associating one or more pieces of identification information with each PDU session. These pieces of identification information may include one or more of the following: DNN, QoS rule, PDU session type, application identification information, NSI identification information, access network identification information, and SSC mode, or other information may be included. Furthermore, when multiple PDU sessions are established, the pieces of identification information associated with each PDU session may be the same or different.

[0099] Next, DNN (Data Network Name) may be identification information that identifies the core network and / or external networks such as DNs. Furthermore, DNN can also be used as information to select gateways such as PGW / UPFs that connect to the core network B190. Moreover, DNN may be equivalent to APN (Access Point Name).

[0100] Next, the PDU (Protocol Data Unit) session type indicates the type of PDU session, and includes IPv4, IPv6, Ethernet, and Unstructured. If IPv4 is specified, it indicates that data will be sent and received using IPv4. If IPv6 is specified, it indicates that data will be sent and received using IPv6. If Ethernet is specified, it indicates that Ethernet frames will be sent and received. Ethernet may also indicate that communication using IP will not be performed. If Unstructured is specified, it indicates that data will be sent and received to application servers, etc., on the DN using Point-to-Point (P2P) tunneling technology. As a P2P tunneling technology, for example, UDP / IP encapsulation technology may be used. In addition to the above, IP may also be included as a PDU session type. IP can be specified when the UE can use both IPv4 and IPv6.

[0101] Next, a PLMN (Public Land Mobile Network) is a communication network that provides mobile radio communication services. A PLMN is a network managed by a telecommunications operator, and the operator can be identified by the PLMN ID. A PLMN that matches the MCC (Mobile Country Code) and MNC (Mobile Network Code) of the UE's IMSI (International Mobile Subscription Identity) may be a Home PLMN (HPLMN). Furthermore, the UE may maintain an Equivalent PLMN list in the USIM to identify one or more EPLMNs (Equivalent PLMNs). A PLMN different from the HPLMN and / or EPLMN may be a Visited PLMN (VPLMN). A PLMN that has been successfully registered by the UE may be a Registered PLMN (RPLMN).

[0102] Next, PLMN selection may be a procedure for the UE to select a PLMN. Here, PLMN selection may be performed when the UE connects to a PLMN. Here, PLMN selection may be referred to as a PLMN selection process or a PLMN selection procedure.

[0103] Next, a tracking area is one or more ranges managed by the core network that can be represented by the location information of UE_A10. A tracking area may consist of multiple cells. Furthermore, a tracking area may be the range where control messages such as paging are broadcast, or the range where UE_A10 can move without handover procedures. Additionally, a tracking area may be a routing area, a location area, or something similar. Hereafter, a tracking area may also be a TA (Tracking Area). A tracking area may be identified by a TAI (Tracking Area Identity) consisting of a TAC (Tracking Area Code) and a PLMN.

[0104] Next, a registration area is a set of one or more TAs that the AMF assigns to the UE. Furthermore, while UE_A10 is moving within one or more TAs included in the registration area, it may move without sending or receiving signals for tracking area updates. In other words, a registration area may be a set of information indicating an area that UE_A10 can move to without performing the tracking area update procedure. A registration area may be identified by a TAI list consisting of one or more TAIs.

[0105] Next, a UE ID is information used to identify a UE (User Environment). For example, a UE ID may be SUCI, SUPI, IMSI, GUTI, 5G-GUTI, IMEI, IMEISV, TMSI, or 5G-S-TMSI. Alternatively, a UE ID may be other information configured within an application or network. Furthermore, a UE ID may be information used to identify a user.

[0106] PC5 is a reference point. PC5 may also be a reference point between ProSe-enabled UEs. Furthermore, PC5 may be a reference point for 5G ProSe Direct Discovery, 5G ProSe Direct Communication, and 5G ProSe UE-to-Network Relay.

[0107] A PC5 path may be a communication channel on PC5. A PC5 path may also be a communication channel between ProSe-compatible UEs. Furthermore, a PC5 path may be PC5 itself. A PC5 path may also be referred to as a PC5 interface.

[0108] Uu may be a wireless interface. Furthermore, Uu may be a wireless interface between a 5G AN and an UE.

[0109] A Uu path may be a communication channel on Uu. A Uu path may also be a communication channel between a 5G AN and a UE. Furthermore, a Uu path may be Uu itself. A Uu path may also be referred to as a Uu interface.

[0110] 5G ProSe (Proximity-based Services) are services provided by 5GS based on nearby UEs (Unified Entity). 5G ProSe may also be referred to simply as ProSe.

[0111] A 5G ProSe-enabled UE is a UE that supports 5G ProSe requirements and related procedures. A 5G ProSe-enabled UE may also be referred to simply as a ProSe-enabled UE.

[0112] A 5G ProSe Remote UE is a 5G ProSe-enabled UE that communicates with a DN via a 5G ProSe UE-to-Network Relay. A 5G ProSe Remote UE may also be referred to as a ProSe Remote UE or simply a Remote UE. Furthermore, a 5G ProSe Remote UE may be a 5G ProSe layer-2 Remote UE or a 5G ProSe layer-3 Remote UE.

[0113] A 5G ProSe layer-2 Remote UE is a 5G ProSe-enabled UE that communicates with a DN via a 5G ProSe layer-2 UE-to-network relay UE. Furthermore, a 5G ProSe layer-2 Remote UE may also be referred to as a layer-2 ProSe Remote UE, a layer-2 Remote UE, or a L2 Remote UE. Additionally, a 5G ProSe layer-2 Remote UE may simply be a 5G ProSe Remote UE.

[0114] A 5G ProSe layer-3 Remote UE is a 5G ProSe-enabled UE that communicates with a DN via a 5G ProSe layer-3 UE-to-network relay UE. Furthermore, a 5G ProSe layer-3 Remote UE may also be referred to as a layer-3 ProSe Remote UE, a layer-3 Remote UE, or a L3 Remote UE. Additionally, a 5G ProSe layer-3 Remote UE may simply be a 5G ProSe Remote UE.

[0115] A 5G ProSe UE-to-Network Relay may be a 5G ProSe-enabled UE that provides functionality to support network connectivity for a 5G ProSe Remote UE. Furthermore, a 5G ProSe UE-to-Network Relay may also be referred to as a 5G ProSe UE-to-Network Relay UE, ProSe UE-to-Network Relay UE, UE-to-Network Relay UE, UE-to-Network Relay UE, U2N Relay, or U2N Relay UE. Additionally, a 5G ProSe UE-to-Network Relay may be a 5G ProSe layer-2 UE-to-network relay or a 5G ProSe layer-3 UE-to-network relay.

[0116] Furthermore, 5G ProSe UE-to-Network Relay may be a function used by a 5G ProSe-enabled UE to discover other 5G ProSe-enabled UEs in its vicinity, based on direct wireless communication between two UEs using NR technology.

[0117] A 5G ProSe layer-2 UE-to-network relay may be a 5G ProSe-enabled UE that provides functionality to support network connectivity for a 5G ProSe layer-2 remote UE via the layer-2 protocol. A 5G ProSe layer-2 UE-to-Network Relay may also be referred to as a 5G ProSe layer-2 UE-to-Network Relay UE, ProSe layer-2 UE-to-Network Relay UE, or layer-2 UE-to-Network Relay UE, or layer-2 UE-to-Network Relay UE, or L2 U2N Relay, or L2 U2N Relay UE. Furthermore, a 5G ProSe layer-2 UE-to-Network Relay may be a 5G ProSe UE-to-network relay.

[0118] Furthermore, 5G ProSe layer-2 UE-to-network relay may be a function used by a 5G ProSe-enabled UE to support communication between a 5G ProSe layer-2 UE-to-network remote UE and a DN.

[0119] A 5G ProSe layer-3 UE-to-network relay may be a 5G ProSe-enabled UE that provides functionality to support network connectivity for a 5G ProSe layer-3 remote UE via the layer-3 protocol. A 5G ProSe layer-3 UE-to-Network Relay may also be referred to as a 5G ProSe layer-3 UE-to-Network Relay UE, ProSe layer-3 UE-to-Network Relay UE, or layer-3 UE-to-Network Relay UE, or layer-3 UE-to-Network Relay UE, or L3 U2N Relay, or L3 U2N Relay UE. Furthermore, a 5G ProSe layer-3 UE-to-Network Relay may also be a 5G ProSe UE-to-network relay.

[0120] Furthermore, 5G ProSe layer-3 UE-to-network relay may be a function used by a 5G ProSe-enabled UE to support communication between a 5G ProSe layer-3 UE-to-network remote UE and a DN.

[0121] ProSeP stands for 5G ProSe policy.

[0122] The initiating UE may be a UE used in communication between two UEs. The initiating UE may also send and receive messages with the target UE.

[0123] The target UE may be a UE used in communication between two UEs. The target UE may also send and receive messages with the initiating UE.

[0124] A relay emergency service may refer to an emergency service established between a Remote UE, a U2N Relay UE, and the network. Furthermore, a relay emergency service may refer to an emergency service using 5G ProSe. Additionally, a relay emergency service may refer to an emergency service using UE-to-Network Relaying. Finally, a relay emergency service may be described as an emergency service for UE-to-Network Relaying.

[0125] The Relay Service Code (RSC) may be a parameter that identifies the connectivity services that a 5G ProSe UE-to-Network Relay provides to a 5G ProSe Remote UE. The RSC may also be configured within the 5G ProSe UE-to-Network Relay for advertising purposes. Furthermore, the RSC may identify authorized users to whom the 5G ProSe UE-to-Network Relay provides services. The RSC may also be used to select relevant security policies and information.

[0126] Path switching may refer to a switch from a communication path between UEs using the Uu interface to a communication path between UEs using the PC5 interface.

[0127] [2.7. Description of Identification Information in This Embodiment] Next, the identification information transmitted, received, and / or stored and / or managed by each device in this embodiment will be described.

[0128] First, the first identification information is information indicating emergency registration. Furthermore, the first identification information may be a 5GS registration type information element (IE). Also, the first identification information may be information indicating emergency registration within the 5GS registration type information element. Furthermore, the first identification information may be information for carrying out registration procedures for emergency services.

[0129] Next, the second identification information may be information indicating registration for relay emergency services. Furthermore, the second identification information may be information within the 5GS registration type information element. Also, the second identification information may be information for carrying out the registration procedure for relay emergency services.

[0130] Furthermore, the second identification information may be a 5GS registration type information element. Furthermore, the second identification information may be an extended 5GS registration type information element.

[0131] Next, the third identification information may be information indicating a request for relay emergency service. Alternatively, the third identification information may be an indication for relay emergency service.

[0132] Next, the fourth identification information may be information indicating whether or not the UE supports relay emergency services. Alternatively, the fourth identification information may be information indicating that the UE supports relay emergency services. Alternatively, the fourth identification information may be information indicating that the UE does not support relay emergency services. Here, the UE may be a Remote UE or a U2N Relay UE. Also, the fourth identification information may be 5GMM capability or 5GSM capability. Also, the fourth identification information may be UE capability information.

[0133] Furthermore, the fourth identification information may be information indicating whether or not it supports operating as a U2N relay UE for emergency services. Furthermore, the fourth identification information may be information indicating that it supports operating as a U2N relay UE for emergency services. Furthermore, the fourth identification information may be information indicating that it does not support operating as a U2N relay UE for emergency services.

[0134] Furthermore, the fourth identification information may be information indicating whether or not it supports operating as a U2N relay UE for relay emergency services. Furthermore, the fourth identification information may be information indicating that it supports operating as a U2N relay UE for relay emergency services. Furthermore, the fourth identification information may be information indicating that it does not support operating as a U2N relay UE for relay emergency services.

[0135] Furthermore, the fourth identification information may be information indicating whether or not it supports operating as a Remote UE for emergency services. Furthermore, the fourth identification information may be information indicating that it supports operating as a Remote UE for emergency services. Furthermore, the fourth identification information may be information indicating that it does not support operating as a Remote UE for emergency services.

[0136] Furthermore, the fourth identification information may be information indicating whether or not it supports operating as a Remote UE for relay emergency services. Furthermore, the fourth identification information may be information indicating that it supports operating as a Remote UE for relay emergency services. Furthermore, the fourth identification information may be information indicating that it does not support operating as a Remote UE for relay emergency services.

[0137] Next, the tenth identifier may be a path selection policy. Alternatively, the tenth identifier may indicate a path preference. Alternatively, the tenth identifier may be a mapping to the path preference of a ProSe service. Alternatively, the tenth identifier may indicate PC5 preferred, Uu preferred, or no preference.

[0138] Furthermore, the UE may use the tenth identification to select the appropriate path. Alternatively, the UE may use the tenth identification to select the appropriate path for all or specific ProSe services.

[0139] In other words, the UE may use the 10th identifier to select either the PC5 path or the Uu path. Alternatively, the UE may use the 10th identifier to select either the PC5 path or the Uu path for all or specific ProSe services.

[0140] Furthermore, the tenth identification information may be a policy or parameter for 5G ProSe. Also, the tenth identification information may be a policy or parameter for 5G ProSe direct communication.

[0141] Next, the eleventh identifier may be a path switching policy. The eleventh identifier may also indicate which paths are permitted for path switching. The eleventh identifier may also be a mapping to the path switching permission for the ProSe service. The eleventh identifier may indicate PC5 permitted, or Uu permitted, or both PC5 and Uu permitted.

[0142] Specifically, if the 11th identification information indicates that PC5 is permitted, it may indicate that switching from a Uu path to a PC5 path is permitted, or that switching from a PC5 path to a Uu path is not permitted.

[0143] Furthermore, if the 11th identification information indicates Uu permitted, it may indicate that switching from a PC5 path to a Uu path is permitted, or that switching from Uu to a PC5 path is not permitted.

[0144] Furthermore, if the 11th identification information indicates both PC5 and Uu permitted, it may indicate that switching from a Uu path to a PC5 path, and switching from a Uu path to a PC5 path, is permitted.

[0145] Furthermore, the 11th identifier may indicate that path switching is not permitted. Also, if the 11th identifier indicates that path switching is not permitted, it may indicate that switching from the Uu path to the PC5 path, and switching from the Uu path to the PC5 path, is not permitted.

[0146] Furthermore, the UE may use the 11th identification to select the appropriate path. Alternatively, the UE may use the 11th identification to select the appropriate path for all or specific ProSe services.

[0147] In other words, the UE may use the 11th identification to select either the PC5 path or the Uu path. Alternatively, the UE may use the 11th identification to select either the PC5 path or the Uu path for all or specific ProSe services.

[0148] Furthermore, if the 11th identifier indicates PC5 permitted, the UE may use the 11th identifier to select the PC5 path. Furthermore, if the 11th identifier indicates Uu permitted, the UE may use the 11th identifier to select the Uu path. Furthermore, if the 11th identifier indicates both PC5 and Uu permitted, the UE may use the 10th identifier and / or the 11th identifier to select either the PC5 path or the Uu path.

[0149] Furthermore, if the 11th identifier indicates both PC5 and Uu permitted, the UE may recognize that path switching is possible. Also, if the 11th identifier indicates both PC5 and Uu permitted, the UE may recognize that path switching is possible for all or specific ProSe services.

[0150] Furthermore, the 11th identification information may be a policy or parameter for 5G ProSe. Furthermore, the 11th identification information may be a policy or parameter for 5G ProSe direct communication.

[0151] Next, the 12th identifier may be information indicating whether or not the network supports relay emergency services. Alternatively, the 12th identifier may be information indicating that the network supports relay emergency services. Alternatively, the 12th identifier may be information indicating that the network does not support relay emergency services. Alternatively, the 12th identifier may be 5GS network feature support. Alternatively, the 12th identifier may be extended 5GS network feature support. Here, the 5GS network feature support, or extended 5GS network feature support, may be set with information indicating whether or not it supports relay emergency services. Alternatively, the 12th identifier may be network capability information.

[0152] Next, the 13th identifier may be a reason value indicating that the network does not support relay emergency services. The 13th identifier may also be a 5GSM cause. The 13th identifier may also be a 5GSM cause value. The 13th identifier may also be a reason value indicating the reason for rejecting the UE's request.

[0153] Furthermore, the 13th identification information may be a reason value other than those mentioned above. For example, the 13th identification information may be #8 (operator determined barring), or #26 (insufficient resources), or #27 (missing or unknown DNN), or #28 (unknown PDU session type), or #29 (user authentication or authorization failed), or #31 (request rejected).#32 (unspecified), or #33 (requested service option not subscribed), or #35 (PTI already in use), or #38 (network failure), or #39 (reactivation requested), or #46 (out of LADN service area), or #50 (PDU session type IPv4 only allowed), or #51 (PDU session type IPv6 only allowed), or #54 (PDU session does not exist), or #57 (PDU session type IPv4v6 only allowed), or #58 (PDU session type Unstructured only allowed), or #61 (PDU session type Ethernet only allowed), or #67 (insufficient resources for specific slice and DNN), or #68 (not supported SSC mode), or #69 (insufficient resources for specific slice), or #70 (missing or unknown DNN in a slice), or #82 (maximum data rate per UE for user-plane) This may also be information indicating "integrity protection is too low," or #86 (UAS services not allowed), or #95-111 (protocol errors).

[0154] Next, the 20th identification information may be information indicating a request for relay emergency service. The 20th identification information may also be a reason value. Furthermore, the 20th identification information may be an RSC (Relay Service Code).

[0155] Next, the 21st identification information may be information indicating whether or not the Remote UE supports relay emergency services. Alternatively, the 21st identification information may be information indicating that the Remote UE supports relay emergency services. Alternatively, the 21st identification information may be information indicating that the Remote UE does not support relay emergency services. Alternatively, the 21st identification information may be UE capability information.

[0156] Next, the 30th identification information may be information indicating whether or not the UE supports relay emergency services. The 30th identification information may also be information indicating that the UE supports relay emergency services. The 30th identification information may also be information indicating that the UE does not support relay emergency services. Here, the UE may be a U2N Relay UE. The 30th identification information may also be an RSC. The 30th identification information may also be an RSC for emergency services. The 30th identification information may also be an RSC for relay emergency services.

[0157] Furthermore, the 30th identification information may indicate whether or not the network supports relay emergency services. Alternatively, the 30th identification information may indicate that the network supports relay emergency services. Furthermore, the 30th identification information may indicate that the network does not support relay emergency services.

[0158] Furthermore, the 30th identification information may be UE capability information or network capability information.

[0159] Next, the 31st identification information may be a reason value indicating that the U2N Relay UE and / or network does not support relay emergency services.

[0160] Furthermore, the 31st identification information may be a reason value other than those mentioned above. For example, the 31st identification information may be a reason value indicating #1 (direct communication to the target UE not allowed), or #3 (conflict of layer-2 ID for unicast communication is detected), or #5 (lack of resources for 5G ProSe direct link), or #13 (congestion situation), or #15 (security procedure failure of 5G ProSe UE-to-network relay), or #111 (protocol error, unspecified).

[0161] [3. Description of the procedures used in each embodiment] Next, the procedures used in each embodiment will be described.

[0162] In each embodiment, the explanation will be based on the example where the HSS and UDM, PCF and PCRF, SMF and PGW-C, and UPF and PGW-U are configured as the same device (i.e., the same physical hardware, the same logical hardware, or the same software), as shown in Figure 2. However, the contents described in this embodiment are also applicable when these are configured as different devices (i.e., different physical hardware, different logical hardware, or different software). For example, data may be transmitted and received directly between them, or data may be transmitted and received via the N26 interface between the AMF and MME, or data may be transmitted and received via the UE.

[0163] [3.1. Registration Procedure] First, the registration procedure will be explained using Figure 6. The registration procedure is a procedure in 5GS. In this chapter, "this procedure" refers to the registration procedure. The registration procedure is a procedure in which the UE takes the lead in registering with access network_B and / or core network_B and / or DN. If the UE is not registered with the network, it can execute this procedure at any time, for example, when the power is turned on. In other words, if the UE is in the unregistered state (RM-DEREGISTERED state), it can start this procedure at any time. In addition, each device (especially the UE and AMF) can transition to the registered state (RM-REGISTERED state) based on the completion of the registration procedure. Note that the registration state may be managed by each device for each access. Specifically, each device may independently manage the registration state for 3GPP access (registered state or unregistered state) and the registration state for non-3GPP access.

[0164] Furthermore, the registration procedure may be a registration procedure for initial registration. It may also be a registration procedure for mobility and periodic registration update. Furthermore, the registration procedure may be referred to simply as registration.

[0165] Furthermore, the registration procedure may also be a procedure for updating the location registration information of the UE in the network, and / or for the UE to periodically notify the network of the status of the UE, and / or for updating specific parameters related to the UE in the network.

[0166] Furthermore, the UE may perform the registration procedure after performing the SNPN selection or PLMN selection.

[0167] A UE may initiate the registration process when it moves across TAs. In other words, a UE may initiate the registration process when it moves to a TA different from the one indicated in its TA list. Furthermore, a UE may initiate the registration process when it is necessary to update the context of each device due to disconnection or invalidation of a PDU session. Furthermore, a UE may initiate the registration process when there is a change in the capability information and / or preferences related to the establishment of the UE's PDU session. Furthermore, a UE may initiate the registration process periodically. Furthermore, a UE may initiate the registration process based on the completion of the UE configuration update procedure. Note that a UE can perform the registration process at any time it chooses, not limited to these.

[0168] Furthermore, even if a UE is already registered, it may initiate the registration process periodically.

[0169] Furthermore, registration procedures performed based on UE mobility and registration procedures performed periodically may be referred to as registration procedures for mobility and registration renewal. In other words, registration procedures for mobility and registration renewal may be registration procedures performed based on UE mobility, or registration procedures performed periodically. Moreover, registration procedures for mobility and registration renewal may be registration procedures performed based on UE configuration updates. Furthermore, registration procedures for mobility and registration renewal may be registration procedures performed to establish a communication channel for sending and receiving user data. Furthermore, registration procedures for mobility and registration renewal may be registration procedures performed based on requests from the network. In other words, registration procedures for mobility and registration renewal may be registration procedures other than registration procedures for initial registration.

[0170] Next, we will explain each step of the registration procedure. Note that the registration procedure described below may be for initial registration or for mobility and registration renewal.

[0171] First, the UE initiates the registration process by sending a Registration request message to the AMF (S800)(S802)(S804). Specifically, the UE sends an RRC message containing the Registration request message to the 5G AN (or gNB) (S800). The Registration request message is a NAS message. The RRC message may be a control message sent and received between the UE and the 5G AN (or gNB). The NAS message is processed at the NAS layer, and the RRC message is processed at the RRC layer. The NAS layer is a higher layer than the RRC layer.

[0172] Here, the UE may include one or more of the first to fourth pieces of identification information in the registration request message and / or RRC message. More specifically, the UE may include one or more of the first to fourth pieces of identification information in the registration request message and / or RRC message, or it may include them in a different control message, for example, a control message at a lower layer than the RRC layer (e.g., MAC layer, RLC layer, PDCP layer).

[0173] Furthermore, by transmitting this identification information, the UE may indicate to the network that the UE supports each function, or indicate the UE's request. In addition, if multiple pieces of identification information are transmitted and received, two or more of these pieces of identification information may be combined into one or more pieces of identification information. Furthermore, the information indicating support for each function and the information indicating a request for the use of each function may be transmitted and received as the same piece of identification information, or as different pieces of identification information.

[0174] Furthermore, the UE may include one or more of the first to fourth types of identification information in the registration request message and send it, thereby indicating to the network what the identification information included in the registration request message represents.

[0175] Furthermore, the UE may select and decide whether to include one or more of the first to fourth types of identification information in the registration request message, based on subscriber information, and / or network status, and / or user registration information, and / or context held by the UE.

[0176] Furthermore, the UE may include identification information other than the first to fourth types of identification information in the registration request message.

[0177] When a 5G AN (or gNB) receives an RRC message containing a registration request message, it selects an AMF to forward the registration request message (S802). The 5G AN (or gNB) can select an AMF based on the information contained in the registration request message and / or RRC message. The 5G AN (or gNB) extracts the registration request message from the received RRC message and forwards it to the selected AMF (S804).

[0178] When the AMF receives a registration request message, it can perform a first conditional determination. This first conditional determination determines whether the network (or the AMF) will accept the UE's request. If the first conditional determination is true, the AMF initiates the procedure shown in Figure 6(A); if the first conditional determination is false, it initiates the procedure shown in Figure 6(B).

[0179] Furthermore, the first condition determination may be performed based on the receipt of a registration request message, and / or each piece of identification information contained in the registration request message, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or context held by AMF, etc. For example, if the network permits the UE's request, the first condition determination may be true, and if the network does not permit the UE's request, the first condition determination may be false. Also, if the network to which the UE is registered, and / or the devices within the network, support the function requested by the UE, the first condition determination may be true, and if they do not support the function requested by the UE, the first condition determination may be false. In addition, if the transmitted and received identification information is permitted, the first condition determination may be true, and if the transmitted and received identification information is not permitted, the first condition determination may be false. Furthermore, the conditions that determine the truth or falsity of the first condition determination are not limited to those described above.

[0180] First, let's explain the case where the first condition is true. In the procedure shown in Figure 6(A), the AMF sends a Registration accept message to the UE via the 5G AN (or gNB) as a response message to the registration request message (S806). The Registration accept message is a NAS message sent and received on the N1 interface, but it is included in the RRC message sent and received between the UE and the 5G AN (gNB).

[0181] The AMF may include one or more of the identification information from items 10 to 13 in the registration acceptance message. The AMF may also use these identification information to indicate that the network supports each function, or that the UE's request has been accepted. Furthermore, if multiple identification information is sent or received, two or more of these identification information may be combined into one or more identification information. The information indicating support for each function and the information indicating a request to use each function may be sent or received as the same identification information, or as different identification information.

[0182] Furthermore, AMF may indicate to the UE the content of one or more of the identification information from items 10 to 13 in the registration acceptance message. AMF may also indicate to the UE the content of the identification information by sending the registration acceptance message.

[0183] Furthermore, AMF may select and decide whether to include one or more of the identification information from items 10 to 13 in the registration acceptance message, based on each received identification information, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or context held by AMF.

[0184] Furthermore, AMF may include identification information other than the identification information specified in items 10 through 13 in the registration acceptance message.

[0185] Furthermore, the AMF may indicate that the UE's request has been accepted by sending a registration acceptance message based on the received identification information, and / or subscriber information, and / or network capability information, and / or operator policies, and / or network status, and / or user registration information, and / or context held by the AMF.

[0186] Furthermore, the AMF may include information in the registration acceptance message indicating that some of the UE's requests have been rejected, or may indicate the reason why some of the UE's requests have been rejected by sending information indicating that some of the UE's requests have been rejected. Furthermore, the UE may become aware of the reason why some of its requests have been rejected by receiving information indicating that some of the UE's requests have been rejected. The reason for rejection may also be information indicating that the content of the identification information received by the AMF is not permitted.

[0187] Next, the UE receives a registration acceptance message from the AMF via the 5G AN (gNB) (S806). The UE may also receive a registration acceptance message from the AMF that includes one or more of the identification information from the 10th to 13th identification information.

[0188] Here, upon receiving the registration acceptance message, the UE can recognize that its request in the registration request message has been accepted, and can also recognize the content of the various identification information contained in the registration acceptance message.

[0189] Next, the UE may or may not send a registration completion message to the AMF via the 5G AN(gNB) as a response message to the registration acceptance message (S808). Here, the registration completion message is a NAS message sent and received on the N1 interface, but it is included in the RRC message sent and received between the UE and the 5G AN(gNB).

[0190] Next, the AMF may or may not receive a registration completion message via the 5G AN (gNB) (S808).

[0191] Each device completes the procedure in Figure 6(A) based on the sending and receiving of registration acceptance messages and / or registration completion messages.

[0192] Furthermore, the UE may perform SNPN selection or PLMN selection based on the receipt of a registration acceptance message. The UE may also perform SNPN selection or PLMN selection based on the sending of a registration completion message.

[0193] Next, we will explain the case where the first condition determination is false. In the procedure shown in Figure 6(B), the AMF sends a registration rejection message to the UE via the 5G AN(gNB) as a response message to the registration request message (S810). Here, the registration rejection message is a NAS message that is sent and received on the N1 interface, but it is included in the RRC message and sent and received between the UE and the 5G AN(gNB).

[0194] Here, the AMF may include one or more of the identification information from the 10th to 13th items in the registration rejection message. Furthermore, by sending these identification information, the AMF may indicate that the UE's request has been rejected, or indicate the reason for the rejection.

[0195] Furthermore, AMF may indicate to the UE the content of the identification information included in the registration rejection message by including one or more of the identification information from the 10th to 13th identification information in the registration rejection message. AMF may also indicate to the UE the content of this identification information by sending the registration rejection message.

[0196] Furthermore, AMF may select and decide whether to include one or more of the identification information from the 10th to 13th categories in the registration rejection message, based on each received identification information, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or context held by AMF.

[0197] Furthermore, the AMF may indicate that the UE's request in the registration request message has been rejected by sending a registration rejection message. The AMF may also include information indicating the reason for the rejection in the registration rejection message, or may indicate the reason for the rejection by sending the reason for the rejection separately. Furthermore, the UE may recognize the reason for the rejection of its request by receiving information indicating the reason for the rejection of its request. The reason for the rejection may also be information indicating that the content of the identification information received by the AMF is not permitted.

[0198] Next, the UE receives a registration rejection message from the AMF via the 5G AN (gNB) (S810). The UE may also receive a registration rejection message from the AMF that includes one or more of the identification information from the 10th to 13th identification information. Upon receiving the registration rejection message, the UE can recognize that its request in the registration request message has been rejected, and can also recognize the content of the various identification information included in the registration rejection message.

[0199] Furthermore, if the UE receives a registration rejection message, it may perform SNPN selection or PLMN selection.

[0200] Furthermore, if a UE does not receive a registration rejection message after a predetermined period has elapsed since sending a registration request message, the UE may recognize that its request has been rejected.

[0201] Each device completes procedure (B) in this procedure based on the sending and receiving of registration rejection messages.

[0202] Furthermore, the procedure in Figure 6(B) may be initiated if the procedure in Figure 6(A) is canceled.

[0203] Each device completes the registration procedure based on the completion of either procedure (A) or (B) in Figure 6. Alternatively, each device may transition to the state where the UE is registered with the network (RM_REGISTERED state) based on the completion of procedure (A) in Figure 6. Furthermore, each device may maintain the state where the UE is not registered with the network (RM_DEREGISTERED state) or transition to the state where the UE is not registered with the network based on the completion of procedure (B) in Figure 6.

[0204] Furthermore, each device may perform processing based on the information sent and received during the registration process, upon completion of the registration procedure. For example, if it receives information indicating that some of the UE's requests were rejected, it may recognize the reason why the UE's requests were rejected. Furthermore, each device may perform the procedure again based on the reason why the UE's requests were rejected, or it may perform the registration procedure for core network_B or another cell.

[0205] Furthermore, based on the completion of the registration process, the UE may store the identification information received along with the registration acceptance message or registration rejection message, and may recognize the network's decision.

[0206] Furthermore, the UE may perform SNPN selection or PLMN selection based on the completion of the registration procedure.

[0207] [3.2. PDU Session Establishment Procedure] Next, the PDU session establishment procedure will be explained using Figure 7. Hereafter, the PDU session establishment procedure may be referred to as "this procedure." The PDU session establishment procedure may also be an SM procedure.

[0208] Note that this procedure may be performed after completing the registration procedure at least once.

[0209] Next, we will explain each step of the PDU session establishment procedure.

[0210] First, the UE sends a PDU session establishment request message to the SMF (S1200), (S1202), (S1204) to initiate the PDU session establishment procedure. The SMF then receives the PDU session establishment request message from the UE.

[0211] Specifically, the UE initiates the PDU session establishment procedure by sending a NAS message containing an N1 SM container with a PDU session establishment request message to the AMF via the access network (S1200). The NAS message is, for example, a message sent via the N1 interface and may be an uplink NAS transport (UL NAS TRANSPORT) message.

[0212] Here, the UE may include one or more of the identification information from the first to fourth in the PDU session establishment request message or NAS message.

[0213] Furthermore, by transmitting this identification information, the UE may indicate that it supports each function or indicate a request from the UE. In addition, if multiple pieces of identification information are transmitted and received, two or more of these pieces of identification information may be combined into one or more pieces of identification information. Furthermore, the information indicating support for each function and the information indicating a request for the use of each function may be transmitted and received with the same identification information or with different identification information.

[0214] Here, the UE may indicate the contents of each identification information to the network by sending a PDU session establishment request message or a NAS message.

[0215] Furthermore, the access network may be 3GPP access or non-3GPP access and may include base station equipment. That is, the UE may send NAS messages to the AMF via the base station equipment.

[0216] Furthermore, the UE may select and decide whether to include one or more of the first to fourth types of identification information in the PDU session establishment request message, based on subscriber information, and / or network status, and / or user registration information, and / or context held by the UE.

[0217] Furthermore, the UE may include identification information other than the first to fourth identification information in the PDU session establishment request message.

[0218] Next, when AMF receives a NAS message, it can recognize what the UE is requesting and / or the content of the information (message, container, information) contained in the NAS message.

[0219] Next, the AMF selects an SMF as the destination for at least some of the information (message, container, information) contained in the NAS message received from the UE (S1202). The AMF may also select the destination SMF based on the information (message, container, information) contained in the NAS message, and / or subscriber information, and / or network capability information, and / or UE policies, and / or operator policies, and / or network status, and / or user registration information, and / or context held by the AMF.

[0220] Next, the AMF sends at least a portion of the information (message, container, information) contained in the NAS message received from the UE to the selected SMF, for example via the N11 interface (S1204).

[0221] Next, when the SMF receives information (messages, containers, information) sent from the AMF, it can recognize what the UE is requesting and / or the content of the information (messages, containers, information) received from the AMF.

[0222] Furthermore, when SMF receives a PDU session establishment request message, it may perform the actions it would have taken upon receiving each piece of identification information contained in the PDU session establishment request message.

[0223] Here, the SMF may perform a second conditional determination. This second conditional determination may be for determining whether the network accepts the UE's request. If the SMF determines that the second conditional determination is true, it may initiate the procedure shown in Figure 7(A); if it determines that the second conditional determination is false, it may initiate the procedure shown in Figure 7(B).

[0224] Furthermore, the second condition determination may be performed by an NF other than the SMF. Such an NF may be, for example, an NSSF, NWDAF, PCF, or NRF. If an NF other than the SMF performs the second condition determination, the SMF may provide that NF with the information necessary to perform the second condition determination, specifically, at least a portion of the information received from the UE (S1206). If the NF determines the truth or falsity of the second condition determination based on the information received from the SMF, it may communicate to the SMF the result of the second condition determination (i.e., whether it is true or false). Based on the result of the second condition determination received from the NF, the SMF may determine the identification information and / or control message to be sent to the UE.

[0225] Furthermore, the second condition determination may be performed based on information received from AMF (messages, containers, information), and / or subscriber information, and / or network capability information, and / or UE policies, and / or operator policies, and / or network status, and / or user registration information, and / or context held by SMF.

[0226] For example, if the network permits the UE's request, the second condition may be judged as true, and if the network does not permit the UE's request, the second condition may be judged as false. Also, if the network to which the UE is connected, and / or the devices within the network, support the function requested by the UE, the second condition may be judged as true, and if they do not support the function requested by the UE, the second condition may be judged as false. Furthermore, if the transmitted and received identification information is permitted, the second condition may be judged as true, and if the transmitted and received identification information is not permitted, the second condition may be judged as false.

[0227] Furthermore, the conditions for determining the truth or falsity of the second condition are not limited to those mentioned above.

[0228] Next, we will explain each step of the procedure in Figure 7(A).

[0229] The SMF may select a UPF for the PDU session to be established and send an N4 session establishment request message to the selected UPF, for example, via the N4 interface (S1208). The N4 session establishment request message may include at least a portion of the PCC rules received from the PCF.

[0230] Here, the SMF may select one or more UPFs based on information received from the AMF (messages, containers, information), and / or information such as PCC rules received from the PCF, and / or subscriber information, and / or network capability information, and / or UE policies, and / or operator policies, and / or network status, and / or user registration information, and / or context held by the SMF. If multiple UPFs are selected, the SMF may send an N4 session establishment request message to each UPF. Here, it is assumed that a UPF has been selected.

[0231] Next, when the UPF receives an N4 session establishment request message (S1208), it can recognize the content of the information received from the SMF. Also, based on the receipt of the N4 session establishment request message, the UPF may send an N4 session establishment response message to the SMF, for example, via the N4 interface (S1210).

[0232] Next, when the SMF receives an N4 session establishment response message as a response message to the N4 session establishment request message, it can recognize the content of the information received from the UPF.

[0233] Next, based on the receipt of the PDU session establishment request message and / or the selection of the UPF and / or the receipt of the N4 session establishment response message, etc., the SMF sends a PDU session establishment accept message to the UE (S1212)(S1214)(S1216).

[0234] Specifically, based on the receipt of a PDU session establishment request message and / or selection of a UPF and / or receipt of an N4 session establishment response message, the SMF sends the N1 SM container, and / or N2 SM information, and / or PDU session ID to the AMF, for example, via the N11 interface (S1212). Here, the N1 SM container may contain a PDU session establishment acceptance message. Furthermore, the PDU session ID may be included in the PDU session establishment acceptance message.

[0235] Next, having received the N1 SM container and / or N2 SM information and / or PDU session ID, the AMF sends a NAS message to the UE via the access network (S1214)(S1216). Here, the NAS message is sent, for example, via the N1 interface. The NAS message may also be a downlink NAS transport (DL NAS TRANSPORT) message.

[0236] Specifically, when the AMF sends an N2 PDU session request message to the access network (S1214), the access network that receives the N2 PDU session request message sends a NAS message to the UE (S1216). Here, the N2 PDU session request message may include the NAS message and / or N2 SM information. The NAS message may also include the PDU session ID and / or N1 SM container.

[0237] Furthermore, the PDU session establishment acceptance message may be a response message to a PDU session establishment request. The PDU session establishment acceptance message may also indicate that the establishment of the PDU session has been accepted.

[0238] Here, the SMF and / or AMF may indicate that at least part of the UE's request in the PDU session establishment request message has been accepted by sending a PDU session establishment acceptance message and / or N1 SM container and / or PDU session ID and / or NAS message and / or N2 SM information and / or N2 PDU session request message.

[0239] Here, the SMF and / or AMF may include one or more of the identification information from the 10th to 13th identification information in the PDU session establishment acceptance message and / or N1 SM container and / or NAS message and / or N2 SM information and / or N2 PDU session request message.

[0240] Furthermore, by sending these identification information and / or a PDU session establishment acceptance message, the SMF may indicate that the network supports each function, that the UE's request has been accepted, that the request from the UE is not permitted, or a combination of these. In addition, if multiple pieces of identification information are sent and received, two or more of these pieces of identification information may be combined into one or more pieces of identification information. Furthermore, the information indicating support for each function and the information indicating a request to use each function may be sent and received as the same piece of identification information, or as different pieces of identification information.

[0241] Here, the network may indicate the contents of the above identification information to the UE by sending a PDU session establishment acceptance message.

[0242] Furthermore, the network may include identification information other than the identification information specified in items 10 through 13 in the PDU session establishment acceptance message.

[0243] Furthermore, the SMF and / or AMF may decide which identification information to include in the PDU session establishment acceptance message, and / or N1 SM container, and / or NAS message, and / or N2 SM information, and / or N2 PDU session request message, based on each received identification information, and / or subscriber information, and / or network capability information, and / or UE policy, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the SMF and / or AMF.

[0244] Next, the UE receives a PDU session establishment acceptance message and / or a NAS message from the SMF (S1212)(S1214)(S1216). When the UE receives the PDU session establishment acceptance message and / or a NAS message, for example via the N1 interface, it can recognize that the UE's request by the PDU session establishment request message has been accepted and / or the contents of the information (message, container, information) contained in the NAS message. If the UE receives one or more of the identification information from the 10th to 13, it may recognize the contents indicated by the received identification information.

[0245] Furthermore, the above behavior of the UE may be performed after receiving a PDU session establishment acceptance message. Also, the above behavior of the UE may be performed after receiving one or more of the identification information from the 10th to 13th identification information.

[0246] Furthermore, if the UE receives a PDU session establishment acceptance message and / or a NAS message, it may perform the actions it would have taken upon receiving each piece of identification information contained in the PDU session establishment acceptance message and / or NAS message.

[0247] Next, we will explain each step of the procedure in Figure 7(B).

[0248] First, the SMF sends a PDU session establishment reject message to the UE (S1218)(S1220)(S1222).

[0249] Specifically, based on the receipt of the PDU session establishment request message, the SMF sends the N1 SM container and / or the PDU session ID to the AMF, for example, via the N11 interface (S1218). Here, the N1 SM container may contain a PDU session establishment rejection message. Furthermore, the PDU session ID may be included in the PDU session establishment rejection message.

[0250] Next, the AMF, having received the N1 SM container and / or the PDU session ID, sends a NAS message to the UE via the access network (S1220)(S1222). Here, the NAS message is sent, for example, via the N1 interface. The NAS message may also be a downlink NAS transport (DL NAS TRANSPORT) message. The NAS message may also contain the PDU session ID and / or the N1 SM container.

[0251] Furthermore, the PDU session establishment rejection message may be a response message to a PDU session establishment request. Also, the PDU session establishment rejection message may indicate that the establishment of the PDU session has been rejected.

[0252] Here, the SMF and / or AMF may indicate that the UE's request in the PDU session establishment request message has been rejected by sending a PDU session establishment rejection message and / or an N1 SM container and / or a PDU session ID and / or a NAS message.

[0253] Furthermore, the SMF may indicate that the UE's request has been rejected by sending a PDU session establishment rejection message, or it may indicate that it has not permitted the request from the UE, or it may indicate a combination of these.

[0254] Here, the SMF and / or AMF may include one or more of the identification information from the 10th to 13th identification information in the PDU session establishment rejection message and / or N1 SM container and / or NAS message and / or N2 SM information and / or N2 PDU session request message.

[0255] Furthermore, the SMF and / or AMF may decide which identification information to include in the PDU session establishment rejection message, and / or N1 SM container, and / or NAS message, and / or N2 SM information, and / or N2 PDU session request message, based on each received identification information, and / or subscriber information, and / or network capability information, and / or UE policy, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the SMF and / or AMF.

[0256] Furthermore, the SMF and / or AMF may include information indicating that the UE's request has been rejected in the PDU session establishment rejection message and / or N1 SM container and / or NAS message and / or N2 SM information and / or N2 PDU session request message, or may indicate the reason for the rejection of the UE's request by sending information indicating that the UE's request has been rejected. Furthermore, the UE may recognize the reason for the rejection of its request by receiving information indicating that the UE's request has been rejected. The reason for rejection may be information indicating that the content indicated by the identification information received by the SMF and / or AMF is not permitted and / or is unavailable.

[0257] Next, when the UE receives a NAS message, for example via the N1 interface (S1222), it can recognize that the UE's request in the PDU session establishment request message has been rejected, and / or the content of the information contained in the NAS message (message, container, information). If the UE receives one or more of the identification information from the 10th to 13, it may recognize the content indicated by the received identification information.

[0258] Furthermore, the above behavior of the UE may be performed after receiving a PDU session establishment rejection message. Also, the above behavior of the UE may be performed after receiving one or more of the identification information from the 10th to 13th identification information.

[0259] Furthermore, if the UE receives a PDU session establishment rejection message and / or a NAS message, it may perform the actions it would have taken upon receiving each piece of identification information contained in the PDU session establishment rejection message and / or NAS message.

[0260] Each device may complete this procedure based on the sending and receiving of a PDU session establishment acceptance message. Alternatively, each device may establish a PDU session based on the completion of this procedure. At this point, each device may transition to a state where it can communicate with the DN using the established PDU session.

[0261] Furthermore, each device may complete this procedure based on the sending and receiving of a PDU session establishment rejection message. In this case, each device cannot establish a PDU session, and therefore cannot communicate with the DN if there are no already established PDU sessions.

[0262] Furthermore, each process performed by the UE based on the receipt of each piece of identification information as described above may be performed during or after this procedure, or after this procedure is completed, based on the completion of this procedure.

[0263] [3.3. Network Request UE Policy Management Procedures] Next, the Network-requested UE policy management procedure will be explained using Figure 8. Hereafter, the Network-requested UE policy management procedure may be referred to as "this procedure."

[0264] This procedure may be initiated upon completion of the registration procedure and / or the PDU session establishment procedure. It may also be initiated if the PCF wishes to update the UE policy.

[0265] Next, we will explain each step of this procedure.

[0266] First, the PCF sends a manage UE policy command message to the UE via the AMF (S1400). The PCF may also send a manage UE policy command message to the UE that includes one or more of the identification information from the 10th to 11th identification information.

[0267] Here, the PCF may indicate to the UE the content that each piece of identification information represents by transmitting one or more pieces of identification information from the 10th to 11th pieces of identification information.

[0268] Furthermore, the PCF may select and decide whether to include one or more of the identification information from the 10th to 11th categories in the management UE policy command message, based on the UE status and / or information received from other NFs.

[0269] Furthermore, the PCF may determine whether or not to send a management UE policy command message and / or identification information based on the status of the UE, and / or information received from the ProSe application server, and / or information received from other NFs.

[0270] Next, the UE receives a management UE policy command message from the PCF via the AMF. The UE may also receive a management UE policy command message from the PCF that includes one or more of the identification information from the 10th to 11th identification information.

[0271] Furthermore, based on the reception of a management UE policy command message, the UE may store the identification information received along with the management UE policy command message, or recognize a network decision. The UE may also recognize the content of the identification information received along with the management UE policy command message.

[0272] Furthermore, the above UE behavior may be performed after receiving a management UE policy command message. Also, the above UE behavior may be performed after receiving one or more of the identification information from the 10th to 11th identification information.

[0273] Furthermore, when a UE receives a management UE policy command message, it may perform the actions it would have taken upon receiving each piece of identification information contained in the management UE policy command message.

[0274] When a UE receives a management UE policy command message, it can perform a third conditional determination. This third conditional determination determines whether the UE will accept the network request. If the third conditional determination is true, the UE initiates the procedure shown in Figure 8(A); if the third conditional determination is false, it initiates the procedure shown in Figure 8(B).

[0275] Furthermore, the third condition determination may be performed based on the reception of a management UE policy command message, and / or the identification information contained in the management UE policy command message, and / or subscriber information, and / or UE capability information, and / or UE policy, and / or the state of the UE, and / or the context held by the UE, etc. For example, if the UE permits the network request, the third condition determination may be true, and if the UE does not permit the network request, the third condition determination may be false. Also, if the UE supports the functionality requested by the network, the third condition determination may be true, and if the UE does not support the functionality requested by the network, the third condition determination may be false. In addition, if the transmitted and received identification information is permitted, the third condition determination may be true, and if the transmitted and received identification information is not permitted, the third condition determination may be false. Furthermore, the conditions that determine the truth or falsity of the third condition determination are not limited to those described above.

[0276] First, let's explain the case where the third condition is true.

[0277] In the procedure of (A) in FIG. 8, the UE transmits a manage UE policy complete message to the PCF via the 5G AN (or gNB) and / or the AMF as a response message to the manage UE policy command message (S1402). Further, the UE may transmit a manage UE policy complete message including one or more pieces of identification information out of the first to fourth identification information to the PCF.

[0278] Here, the UE may indicate to the PCF the content indicated by each piece of identification information by transmitting one or more pieces of identification information out of the first to fourth identification information.

[0279] Note that the UE may select and determine whether to include one or more pieces of identification information out of the first to fourth identification information in the manage UE policy complete message based on the state of the UE and / or each received piece of identification information, etc.

[0280] Next, the PCF receives a manage UE policy complete message from the UE via the AMF. Further, the PCF may receive a manage UE policy complete message including one or more pieces of identification information out of the first to fourth identification information from the UE.

[0281] Furthermore, based on the reception of the manage UE policy complete message, the PCF may store the identification information received together with the manage UE policy complete message, or may recognize the decision of the UE. Also, based on the reception of the manage UE policy complete message, the PCF may recognize the content of the identification information received together with the manage UE policy complete message.

[0282] Note that the above behavior of the PCF may be performed after receiving the manage UE policy complete message.

[0283] Also, when the PCF receives a manage UE policy complete message, the PCF may perform the behavior at the time of receiving each piece of identification information included in the manage UE policy complete message.

[0284] Furthermore, the PCF may forward each piece of received identification information to another NF (e.g., a ProSe application server).

[0285] Each device may complete the procedure in Figure 8(A) based on the sending and receiving of a management UE policy command message and / or a management UE policy completion message.

[0286] Next, we will explain the case where the third condition is false.

[0287] In the procedure shown in Figure 8(B), the UE sends a manage UE policy command reject message to the PCF via the 5G AN (or gNB) and / or AMF as a response message to the managed UE policy command message (S1404). The UE may also send a manage UE policy command reject message to the PCF that includes one or more of the identification information from the first to fourth.

[0288] Here, the UE may transmit one or more of the first to fourth pieces of identification information to the PCF, thereby indicating the content of each piece of identification information.

[0289] Furthermore, the UE may select and decide whether to include one or more of the first to fourth pieces of identification information in the managed UE policy command rejection message, based on the UE status and / or each piece of identification information received.

[0290] Next, the PCF receives a management UE policy command rejection message from the UE via the AMF. The PCF may also receive a management UE policy command rejection message from the UE that includes one or more of the identification information from the first to fourth categories.

[0291] Furthermore, based on the receipt of a managed UE policy command rejection message, the PCF may store the identification information received along with the managed UE policy command rejection message, or recognize the UE's decision. The PCF may also recognize the content of the identification information received along with the managed UE policy command rejection message.

[0292] Furthermore, the above PCF behavior may be performed after receiving a management UE policy command rejection message.

[0293] Furthermore, if PCF receives a management UE policy command rejection message, it may perform the actions it would have taken upon receiving each piece of identification information contained in the management UE policy command rejection message.

[0294] Furthermore, the PCF may forward each piece of received identification information to another NF (e.g., a ProSe application server).

[0295] Each device may complete the procedure in Figure 8(B) based on the sending and receiving of a managed UE policy command message and / or a managed UE policy command rejection message.

[0296] Furthermore, each device may complete the network request UE policy management procedure based on the completion of the above-described process and / or the sending and receiving of a management UE policy command message and / or the sending and receiving of a management UE policy completion message and / or the sending and receiving of a management UE policy command rejection message.

[0297] Furthermore, each device may perform processing based on the identification information transmitted and received during this procedure, upon completion of this procedure.

[0298] Furthermore, based on the completion of the network request UE policy management procedure, the UE may add new UE policies, modify existing UE policies, or delete existing UE policies.

[0299] [3.4. UE requests the ProSeP to provide procedures] Next, the UE-requested ProSeP provisioning procedure will be described using FIG. 9. Hereinafter, the UE-requested ProSeP provisioning procedure may be referred to as this procedure.

[0300] This procedure may be started based on the completion of the registration procedure and / or the PDU session establishment procedure. Also, this procedure may be started when the UE requests a UE policy or a ProSe policy.

[0301] Next, each step of this procedure will be described.

[0302] First, the UE transmits a UE policy provisioning request message to the PCF via the AMF (S1600). Also, the UE may transmit a UE policy provisioning request message including one or more of the identification information from the first to the fourth to the PCF.

[0303] Here, the UE may show the content indicated by each identification information to the UE by transmitting one or more of the identification information from the first to the fourth.

[0304] In addition, the UE may select and determine whether to include one or more of the identification information from the first to the fourth in the UE policy provisioning request message based on the UE's state and / or each received identification information, etc.

[0305] Next, the PCF receives a UE policy provisioning request message from the UE via the AMF. Also, the PCF may receive a UE policy provisioning request message including one or more of the identification information from the first to the fourth from the UE.

[0306] Furthermore, based on the receipt of the UE policy request message, the PCF may store the identification information received along with the UE policy request message, or recognize the network decision. The PCF may also recognize the content of the identification information received along with the UE policy request message.

[0307] Furthermore, the above PCF behavior may be performed after receiving a UE policy command message. Also, the above PCF behavior may be performed after receiving one or more of the identification information from the first to fourth identification information.

[0308] Furthermore, when PCF receives a UE policy provision request message, it may perform the actions it would have taken upon receiving each piece of identification information contained in the UE policy provision request message.

[0309] When the PCF receives a UE policy provision request message, it can perform a fourth condition determination. The fourth condition determination determines whether the network will accept the UE's request. If the fourth condition determination is true, the PCF initiates procedure (A) in Figure 9; otherwise, it initiates procedure (B) in Figure 9.

[0310] Furthermore, the fourth condition determination may be performed based on the receipt of the UE policy provision request message, and / or each piece of identification information contained in the UE policy provision request message, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the PCF, etc. For example, if the network permits the UE's request, the fourth condition determination may be true, and if the network does not permit the UE's request, the fourth condition determination may be false. Also, if the network to which the UE is registered, and / or the devices within the network, support the function requested by the UE, the fourth condition determination may be true, and if they do not support the function requested by the UE, the fourth condition determination may be false. Furthermore, if the transmitted and received identification information is permitted, the fourth condition determination may be true, and if the transmitted and received identification information is not permitted, the fourth condition determination may be false. Furthermore, the conditions that determine the truth or falsity of the fourth condition determination are not limited to those described above.

[0311] First, let's explain the case where the fourth condition is true.

[0312] In the procedure shown in Figure 9(A), the PCF may perform the network request policy management procedure (S1602). Here, the network request policy management procedure may be the procedure described in Chapter 3.3 above.

[0313] Each device may complete the procedure in Figure 9(A) based on the sending and receiving of UE policy provision request messages and / or the completion of the network request policy management procedure.

[0314] Next, we will explain the case where the fourth condition is false.

[0315] In the procedure shown in Figure 9(B), the PCF sends a UE policy provisioning reject message to the UE via the 5G AN (or gNB) and / or AMF as a response message to the UE policy provisioning request message (S1604). The PCF may also send a UE policy provisioning reject message to the UE that includes one or more of the identification information from the 10th to 11th identification information.

[0316] Here, the PCF may transmit one or more of the identification information from the 10th to 11th identification information to the UE, thereby indicating the content of each identification information.

[0317] Furthermore, the PCF may select and decide whether to include one or more of the identification information from items 10 to 11 in the UE policy provision refusal message, based on the UE status and / or information received from other NFs.

[0318] Furthermore, the PCF may determine whether or not to send a UE policy refusal message and / or each piece of identification information based on the UE status and / or information received from the ProSe application server and / or information received from other NFs.

[0319] Next, the UE receives a UE policy provision refusal message from the PCF via the AMF. The UE may also receive a UE policy provision refusal message from the PCF that includes one or more of the identification information from the 10th to 11th identification information.

[0320] Furthermore, based on the receipt of a UE policy denial message, the UE may store the identification information received along with the UE policy denial message, or recognize the network decision. The UE may also recognize the content of the identification information received along with the UE policy denial message.

[0321] Furthermore, the above UE behavior may be performed after receiving a UE policy provision denial message.

[0322] Furthermore, if the UE receives a UE policy refusal message, it may perform the actions it would have taken upon receiving each piece of identification information contained in the UE policy refusal message.

[0323] Each device may complete the procedure in Figure 9(B) based on the sending and receiving of UE policy provision request messages and / or UE policy provision denial messages.

[0324] Furthermore, each device may complete this procedure based on the completion of the above-described process and / or the sending and receiving of UE policy provision request messages and / or the completion of the network request policy management procedure and / or the sending and receiving of UE policy provision refusal messages.

[0325] Furthermore, each device may perform processing based on the identification information transmitted and received during this procedure, upon completion of this procedure.

[0326] Furthermore, upon completion of this procedure, UE may add new UE policies, modify existing UE policies, or delete existing UE policies.

[0327] [3.5 Discovery Procedures] Next, the discovery procedure will be explained using Figure 10. Hereafter, the discovery procedure may be referred to as "this procedure."

[0328] This procedure may also be for 5G ProSe UE-to-Network Relay Discovery. Alternatively, this procedure may be for 5G ProSe UE-to-Network Relay Discovery using Model A.

[0329] This procedure may commence upon completion of the registration procedure and / or the PDU session establishment procedure. Alternatively, this procedure may commence before completion of the registration procedure and / or the PDU session establishment procedure.

[0330] Next, we will explain each step of this procedure.

[0331] First, the U2N Relay UE sends a UE-to-Network Relay Discovery Announcement message to the Remote UE (S1800). The U2N Relay UE may also send a UE-to-Network Relay Discovery Announcement message to the Remote UE that includes one or more of the identification information from items 30 to 31.

[0332] Furthermore, a U2N Relay UE may send UE-to-Network relay discovery announcement messages to multiple Remote UEs. In other words, a U2N Relay UE may broadcast UE-to-Network relay discovery announcement messages to multiple Remote UEs.

[0333] Here, the U2N Relay UE may transmit one or more of the identification information from the 30th to 31th identification information to the Remote UE, thereby indicating the content that each identification information represents.

[0334] Next, the Remote UE receives a UE-to-Network relay discovery announcement message from the U2N Relay UE. The Remote UE may also receive a UE-to-Network relay discovery announcement message from the U2N Relay UE that includes one or more of the identification information from items 30 to 31.

[0335] Furthermore, based on the reception of the UE-to-Network relay discovery announcement message, the Remote UE may store the identification information received along with the UE-to-Network relay discovery announcement message, or it may recognize the information of the U2N Relay UE. In addition, based on the reception of the UE-to-Network relay discovery announcement message, the Remote UE may recognize the content of the identification information received along with the UE-to-Network relay discovery announcement message.

[0336] Furthermore, the above behavior of the Remote UE may be performed after receiving the UE-to-Network relay discovery announcement message.

[0337] Furthermore, if the Remote UE receives a UE-to-Network relay discovery announcement message, it may perform the actions it would have taken upon receiving each piece of identification information contained in the UE-to-Network relay discovery announcement message.

[0338] Furthermore, the U2N Relay UE may send a Relay Discovery Additional Information message to the Remote UE (S1802). The U2N Relay UE may also send a Relay Discovery Additional Information message to the Remote UE that includes one or more identification pieces from the 30th to 31st identification pieces. Note that the Relay Discovery Additional Information message may or may not be sent.

[0339] Furthermore, the U2N Relay UE may send additional relay discovery information messages to multiple Remote UEs. In other words, the U2N Relay UE may broadcast additional relay discovery information messages to multiple Remote UEs.

[0340] Here, the U2N Relay UE may transmit one or more of the identification information from the 30th to 31th identification information to the Remote UE, thereby indicating the content that each identification information represents.

[0341] Next, the Remote UE may receive a relay discovery additional information message from the U2N Relay UE. The Remote UE may also receive a relay discovery additional information message from the U2N Relay UE that includes one or more identification pieces from the 30th to 31st identification pieces.

[0342] Furthermore, based on the reception of the relay discovery additional information message, the Remote UE may store the identification information received along with the relay discovery additional information message, or it may recognize the information of the U2N Relay UE. Also, based on the reception of the relay discovery additional information message, the Remote UE may recognize the content of the identification information received along with the relay discovery additional information message.

[0343] Furthermore, the above behavior of the Remote UE may be performed after receiving the relay discovery additional information message.

[0344] Furthermore, if the Remote UE receives a relay discovery additional information message, it may perform the actions it would have taken if it had received each piece of identification information included in the relay discovery additional information message.

[0345] Furthermore, each device may complete the discovery procedure based on the completion of the above-described process and / or the sending and receiving of a UE-to-Network relay discovery announcement message and / or the sending and receiving of a relay discovery additional information message.

[0346] Furthermore, each device may perform processing based on the identification information transmitted and received during this procedure, upon completion of this procedure.

[0347] [3.6 ProSe Direct Link Establishment Procedure] Next, the ProSe direct link establishment procedure will be explained using Figure 11. Hereafter, the ProSe direct link establishment procedure may be referred to as "this procedure."

[0348] Furthermore, this procedure may be performed after the registration procedure and / or PDU session establishment procedure has been performed at least once. Alternatively, this procedure may be performed during the registration procedure or the PDU session establishment procedure. Also, this procedure may be performed before the registration procedure or the PDU session establishment procedure is performed.

[0349] This procedure may be performed after service approval and provision have been carried out. Alternatively, this procedure may be carried out regardless of whether service approval and provision have been carried out.

[0350] Furthermore, in this procedure, there may be both an initiating UE and a target UE.

[0351] Furthermore, in this procedure, the initiating UE and the target UE may send and receive control messages on PC5.

[0352] Next, we will explain each step of this procedure.

[0353] First, the initiating UE sends a ProSe direct link establishment request message (S2000) to the target UE.

[0354] Here, the initiating UE may include one or more of the identification information from the 20th to 21th in the ProSe direct link establishment request message and send it.

[0355] Furthermore, the initiating UE may indicate that it supports each function or that it has a request by transmitting this identification information. In addition, if multiple pieces of identification information are transmitted and received, two or more of these pieces of identification information may be configured as one or more pieces of identification information. Furthermore, the information indicating support for each function and the information indicating a request to use each function may be transmitted and received with the same identification information or with different identification information.

[0356] Here, the initiating UE may indicate the content of each identifier to the target UE by sending a ProSe direct link establishment request message. Alternatively, the initiating UE may indicate the content of each identifier to the target UE by sending one or more of the identifiers from the 20th to 21st identifiers.

[0357] Furthermore, the initiating UE may select and decide whether to include one or more of the identification information from items 20 to 21 in the ProSe direct link establishment request message, based on subscriber information and / or network status and / or user registration information and / or context held by the UE.

[0358] The initiating UE may also request the establishment of a ProSe direct link by sending a ProSe direct link establishment request message. Alternatively, the initiating UE may request the establishment of a ProSe direct link by sending one or more identification pieces from the 20th to 21st identification pieces.

[0359] Next, the target UE receives a ProSe direct link establishment request message from the initiating UE. The target UE may also receive a ProSe direct link establishment request message from the initiating UE that includes one or more of the identification information from the 20th to 21st identification information.

[0360] When the target UE receives a ProSe direct link establishment request message, it may recognize what the initiating UE is requesting and / or the information contained in the ProSe direct link establishment request message (message, container, identification information).

[0361] Here, the target UE may perform a fifth conditional check. The fifth conditional check may be for determining whether the target UE accepts the request from the initiating UE. If the target UE determines that the fifth conditional check is true, it may start the procedure in Figure 11(A); if it determines that the fifth conditional check is false, it may start the procedure in Figure 11(B).

[0362] Furthermore, the fifth condition determination may be performed based on information received from the initiating UE (messages, containers, information), and / or subscriber information, and / or network capability information, and / or UE policies, and / or operator policies, and / or network status, and / or user registration information, and / or context held by the target UE.

[0363] For example, if the target UE permits the initiator UE's request, the fifth condition may be judged as true, and if the target UE does not permit the initiator UE's request, the fifth condition may be judged as false. Also, if the target UE supports the functionality requested by the initiator UE, the fifth condition may be judged as true, and if the target UE does not support the functionality requested by the initiator UE, the fifth condition may be judged as false. Furthermore, if the transmitted and received identification information is permitted, the fifth condition may be judged as true, and if the transmitted and received identification information is not permitted, the fifth condition may be judged as false.

[0364] Furthermore, the conditions for determining the truth or falsity of the fifth condition are not limited to those mentioned above.

[0365] Next, we will explain each step of the procedure in Figure 11(A).

[0366] Based on receiving the ProSe direct link establishment request message, the target UE sends a ProSe direct link establishment accept message to the initiating UE (S2002).

[0367] Furthermore, the ProSe direct link establishment acceptance message may be a response message to the ProSe direct link establishment request message. Also, the ProSe direct link establishment acceptance message may indicate that the ProSe direct link establishment request message has been accepted.

[0368] Here, the target UE may include one or more of the identification information from the 30th to 31st identification information in the ProSe direct link establishment acceptance message.

[0369] Here, the target UE may indicate that at least part of the initiating UE's request has been accepted by sending a ProSe direct link establishment acceptance message. Alternatively, the target UE may indicate that at least part of the initiating UE's request has been accepted by sending one or more of the identification information from the 30th to 31st identification information.

[0370] Furthermore, the target UE may indicate that it supports each function, that the initiator UE's request has been accepted, that it has not authorized the request from the initiator UE, or a combination of these, by sending this identification information and / or a ProSe direct link establishment acceptance message. In addition, if multiple pieces of identification information are sent and received, two or more of these pieces of identification information may be combined into one or more pieces of identification information. Furthermore, the information indicating support for each function and the information indicating a request to use each function may be sent and received as the same piece of identification information, or as different pieces of identification information.

[0371] Furthermore, the target UE may decide which identification information to include in the ProSe direct link establishment acceptance message based on each received identification information, and / or subscriber information, and / or network capability information, and / or UE policies, and / or operator policies, and / or network status, and / or user registration information, and / or context held by the target UE, etc.

[0372] Next, the initiating UE receives a ProSe direct link establishment acceptance message from the target UE.

[0373] When the initiating UE receives a ProSe direct link establishment acceptance message, it can recognize that the initiating UE's request has been accepted and / or the contents of the information (message, container, identification information) contained in the ProSe direct link establishment acceptance message.

[0374] Each device may complete the procedure in Figure 11(A) based on the sending and receiving of a ProSe direct link establishment request message and / or a ProSe direct link establishment acceptance message. Based on the completion of this procedure, each device may establish a ProSe direct link. At this time, each device may transition to a state in which communication using the ProSe direct link is possible.

[0375] Next, we will explain each step of the procedure in Figure 11(B).

[0376] First, based on receiving the ProSe direct link establishment request message, the target UE sends a ProSe direct link establishment reject message to the initiating UE (S2004).

[0377] Furthermore, the ProSe direct link establishment rejection message may be a response message to the ProSe direct link establishment request message. Also, the ProSe direct link establishment rejection message may indicate that the establishment of the ProSe direct link has been rejected.

[0378] Here, the target UE may indicate that the initiating UE's request has been rejected by sending a ProSe direct link establishment rejection message.

[0379] Furthermore, the target UE may indicate that the initiating UE's request has been rejected by sending a ProSe direct link establishment rejection message, or it may indicate that it has not permitted the request from the initiating UE, or it may indicate a combination of these.

[0380] Here, the target UE may include one or more of the identification information from the 30th to 31st identification information in the ProSe direct link establishment rejection message.

[0381] Furthermore, the target UE may decide which identification information to include in the ProSe direct link establishment rejection message based on each received identification information, and / or subscriber information, and / or network capability information, and / or UE policies, and / or operator policies, and / or network status, and / or user registration information, and / or context held by the target UE, etc.

[0382] Next, the initiating UE receives a ProSe direct link establishment rejection message. Upon receiving the ProSe direct link establishment rejection message, the initiating UE can recognize that its request has been rejected and / or the content of the information contained in the ProSe direct link establishment rejection message (message, container, identification information).

[0383] Each device may complete the procedure in Figure 11(B) based on the sending and receiving of a ProSe direct link establishment request message and / or a ProSe direct link establishment rejection message. At this time, each device does not need to be able to establish a ProSe direct link. Furthermore, each device may be in a state where it cannot communicate using the ProSe direct link.

[0384] Each device may complete this procedure based on the sending and receiving of a ProSe direct link establishment request message and / or a ProSe direct link establishment acceptance message and / or a ProSe direct link establishment rejection message.

[0385] Furthermore, the processes performed by the initiating UE and target UE based on the receipt of each piece of identification information as described above may be performed during or after this procedure, or after this procedure is completed based on its completion.

[0386] Upon completion of this procedure, the initiating UE and target UE that have established a ProSe direct link may begin exchanging information using the ProSe direct link.

[0387] [3.7 An example of 5G ProSe communication via U2N Relay] Next, an example of 5G ProSe communication via U2N Relay will be explained using Figure 12. Hereafter, this example of 5G ProSe communication via U2N Relay may be referred to as "this procedure."

[0388] This procedure may be performed after the registration procedure and / or the PDU session establishment procedure has been performed at least once. In other words, this procedure may be initiated based on the completion of the registration procedure and / or the PDU session establishment procedure.

[0389] Next, we will explain each step of this procedure.

[0390] First, the procedure for service authorization and provision may be performed between the U2N Relay UE and the network (S2200). Furthermore, the procedure for service authorization and provision may be performed between the Remote UE and the network (S2202).

[0391] Furthermore, each device may determine whether or not to perform the procedures for service authorization and provision based on the status of the UE, and / or the network status, and / or information received from other NFs.

[0392] Next, the U2N Relay UE may perform the PDU session establishment procedure (S2204). Here, the PDU session establishment procedure may be performed at the timing of S2204, or at the timings of S2210 and S2212 as described later in (B). In other words, the PDU session establishment procedure may be performed before the discovery procedure between the Remote UE and the U2N Relay UE is performed, or after the discovery procedure between the Remote UE and the U2N Relay UE is performed.

[0393] Furthermore, each device may decide whether or not to perform the PDU session establishment procedure based on the status of the UE and / or the network status and / or information received from other NFs.

[0394] Next, the discovery procedure is performed between the Remote UE and the U2N Relay UE (S2206).

[0395] Each device may decide whether or not to perform the discovery procedure based on the status of the UE, and / or the network status, and / or information received from other NFs.

[0396] Next, the ProSe direct link establishment procedure is performed between the Remote UE and the U2N Relay UE (S2208)(S2214). The ProSe direct link establishment procedure is shown in Figure 12(A).

[0397] Furthermore, each device may decide whether or not to perform the ProSe direct link establishment procedure based on the status of the UE and / or the network status and / or information received from other NFs.

[0398] Next, the PDU session establishment procedure is performed between the U2N Relay UE and the network (S2210)(S2212). The PDU session establishment procedure is shown in Figure 12(B). Here, the PDU session establishment procedure may be performed during the ProSe direct link establishment procedure. In other words, the U2N Relay UE may perform the PDU session establishment procedure before sending a ProSe direct link establishment acceptance message or a ProSe direct link establishment rejection message to the Remote UE.

[0399] Furthermore, each device may decide whether or not to perform the PDU session establishment procedure based on the status of the UE and / or the network status and / or information received from other NFs.

[0400] Below, we will discuss (A) and (B) in Figure 12 in more detail.

[0401] The Remote UE sends a ProSe direct link establishment request message (S2208) to the U2N Relay UE.

[0402] Here, the Remote UE may include one or more of the identification information from items 20 to 21 in the ProSe direct link establishment request message.

[0403] Furthermore, by transmitting this identification information, the Remote UE may indicate that it supports each function, or it may indicate a request from the Remote UE. In addition, if multiple pieces of identification information are sent and received, two or more of these pieces of identification information may be combined into one or more pieces of identification information. Furthermore, the information indicating support for each function and the information indicating a request to use each function may be sent and received with the same identification information, or they may be sent and received with different identification information.

[0404] Here, the Remote UE may indicate the contents of each identification information to the U2N Relay UE by sending a ProSe direct link establishment request message. Alternatively, the Remote UE may indicate the contents of each identification information to the U2N Relay UE by sending one or more of the identification information from the 20th to 21st identification information.

[0405] Furthermore, the Remote UE may select and decide whether to include one or more of the identification information from items 20 to 21 in the ProSe direct link establishment request message, based on subscriber information, and / or network status, and / or user registration information, and / or context held by the UE.

[0406] Furthermore, the Remote UE may request the establishment of a ProSe direct link by sending a ProSe direct link establishment request message. Alternatively, the Remote UE may request the establishment of a ProSe direct link by sending one or more identification information from the 20th to 21st identification information.

[0407] Next, the U2N Relay UE receives a ProSe direct link establishment request message from the Remote UE.

[0408] When the U2N Relay UE receives a ProSe direct link establishment request message, it may recognize what the Remote UE is requesting and / or the information contained in the ProSe direct link establishment request message (message, container, identification information).

[0409] Next, the U2N Relay UE sends a PDU session establishment request message to the network (S2210).

[0410] Here, the U2N Relay UE may include one or more of the identification information from the first to fourth in the PDU session establishment request message.

[0411] Furthermore, the U2N Relay UE may indicate that the Remote UE and / or U2N Relay UE support each function, or indicate a request from the Remote UE and / or U2N Relay UE, by transmitting this identification information. In addition, if multiple pieces of identification information are transmitted and received, two or more of these pieces of identification information may be configured as one or more pieces of identification information. Furthermore, the information indicating support for each function and the information indicating a request for use of each function may be transmitted and received with the same identification information, or they may be transmitted and received with different identification information.

[0412] Here, the U2N Relay UE may indicate the contents of each identifier to the network by sending a PDU session establishment request message. Alternatively, the U2N Relay UE may indicate the contents of each identifier to the network by sending one or more of the first to fourth identifiers.

[0413] Furthermore, the U2N Relay UE may select and decide whether to include one or more of the first to fourth types of identification information in the PDU session establishment request message, based on subscriber information, and / or network status, and / or user registration information, and / or context held by the UE, etc.

[0414] Next, the network receives a PDU session establishment request message from the U2N Relay UE.

[0415] When the network receives a PDU session establishment request message, it may recognize what the U2N Relay UE is requesting and / or the information contained in the PDU session establishment request message (message, container, identification information).

[0416] Next, the network sends either a PDU session establishment acceptance message or a PDU session establishment rejection message to the U2N Relay UE (S2212). The method for determining whether to send a PDU session establishment acceptance message or a PDU session establishment rejection message may be as described in the chapter on PDU session establishment procedures.

[0417] Furthermore, the PDU session establishment acceptance message may be a response message to the PDU session establishment request message. Also, the PDU session establishment acceptance message may indicate that the PDU session establishment request message has been accepted.

[0418] Furthermore, a PDU session establishment rejection message may be a response message to a PDU session establishment request message. Also, a PDU session establishment rejection message may indicate that the establishment of a PDU session has been rejected.

[0419] Here, the network may include one or more of the identification information from the 10th to 13th categories in the PDU session establishment acceptance message or the PDU session establishment rejection message.

[0420] Here, the network may indicate that at least part of the Remote UE and / or U2N Relay UE's request has been accepted by sending a PDU session establishment acceptance message. Alternatively, the network may indicate that at least part of the Remote UE and / or U2N Relay UE's request has been accepted by sending one or more of the identification information from the 10th to 13th identification information.

[0421] The network may also indicate that the request from the Remote UE and / or U2N Relay UE has been rejected by sending a PDU session establishment rejection message, or that it has not authorized the request from the Remote UE and / or U2N Relay UE, or a combination of these.

[0422] Furthermore, the network may indicate that it supports each function by sending these identification pieces and / or a PDU session establishment acceptance message. In addition, if multiple identification pieces are sent and received, two or more of these identification pieces may be configured as one or more identification pieces. Furthermore, the information indicating support for each function and the information indicating a request to use each function may be sent and received as the same identification piece, or as different identification pieces.

[0423] Furthermore, the network may decide which identification information to include in the PDU session establishment acceptance message or the PDU session establishment rejection message based on each received identification information, and / or subscriber information, and / or network capability information, and / or UE policy, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the U2N Relay UE, etc.

[0424] Next, the U2N Relay UE receives either a PDU session establishment acceptance message or a PDU session establishment rejection message from the network.

[0425] When the U2N Relay UE receives a PDU session establishment acceptance message, it can recognize that the requests of the Remote UE and / or the U2N Relay UE have been accepted, and / or the contents of the information (message, container, identification information) contained in the PDU session establishment acceptance message.

[0426] Furthermore, when the U2N Relay UE receives a PDU session establishment rejection message, it can recognize that its request has been rejected and / or the content of the information (message, container, identification information) contained in the PDU session establishment rejection message.

[0427] Each device may complete the procedure shown in Figure 12(B) based on the sending and receiving of a PDU session establishment acceptance message. Each device may establish a PDU session based on the completion of this procedure. At this point, each device may transition to a state where communication using the PDU session is possible.

[0428] Alternatively, each device may complete the procedure in Figure 12(B) based on the sending and receiving of a PDU session establishment rejection message. In this case, each device does not need to be able to establish a PDU session. Furthermore, each device may be in a state where it cannot communicate using the PDU session. In addition, each device does not need to perform the subsequent steps based on the sending and receiving of a PDU session establishment rejection message.

[0429] Next, the U2N Relay UE sends either a ProSe direct link establishment acceptance message or a ProSe direct link establishment rejection message to the Remote UE (S2214). The method for determining whether to send a ProSe direct link establishment acceptance message or a ProSe direct link establishment rejection message may be as described in the chapter on the ProSe direct link establishment procedure.

[0430] Furthermore, the ProSe direct link establishment acceptance message may be a response message to the ProSe direct link establishment request message. Also, the ProSe direct link establishment acceptance message may indicate that the ProSe direct link establishment request message has been accepted.

[0431] Furthermore, the ProSe direct link establishment rejection message may be a response message to the ProSe direct link establishment request message. Also, the ProSe direct link establishment rejection message may indicate that the establishment of the ProSe direct link has been rejected.

[0432] Here, the U2N Relay UE may include one or more of the identification information from items 30 to 31 in the ProSe direct link establishment acceptance message or the ProSe direct link establishment rejection message.

[0433] Here, the U2N Relay UE may indicate that at least part of the Remote UE's request has been accepted by sending a ProSe direct link establishment acceptance message. Alternatively, the U2N Relay UE may indicate that at least part of the Remote UE's request has been accepted by sending one or more of the identification information from the 30th to 31st identification information.

[0434] Furthermore, the U2N Relay UE may indicate that the Remote UE's request has been rejected by sending a ProSe direct link establishment rejection message, or it may indicate that it has not permitted the request from the Remote UE, or it may indicate a combination of these.

[0435] Furthermore, the U2N Relay UE may indicate that it supports each function, that the Remote UE's request has been accepted, that it has not authorized the request from the Remote UE, or a combination of these, by sending this identification information and / or a ProSe direct link establishment acceptance message. In addition, if multiple pieces of identification information are sent and received, two or more of these pieces of identification information may be configured as one or more pieces of identification information. Furthermore, the information indicating support for each function and the information indicating a request to use each function may be sent and received as the same piece of identification information, or as different pieces of identification information.

[0436] Furthermore, the U2N Relay UE may decide which identification information to include in the ProSe direct link establishment acceptance message or the ProSe direct link establishment rejection message based on the received identification information, and / or subscriber information, and / or network capability information, and / or UE policy, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the U2N Relay UE, etc.

[0437] Next, the Remote UE receives either a ProSe direct link establishment acceptance message or a ProSe direct link establishment rejection message from the U2N Relay UE.

[0438] When a Remote UE receives a ProSe direct link establishment acceptance message, it can recognize that the Remote UE's request has been accepted and / or the contents of the information (message, container, identification information) contained in the ProSe direct link establishment acceptance message.

[0439] Furthermore, when the Remote UE receives a ProSe direct link establishment rejection message, it can recognize that its request has been rejected and / or the content of the information (message, container, identification information) contained in the ProSe direct link establishment rejection message.

[0440] Each device may complete the procedure in Figure 12(A) based on the sending and receiving of a ProSe direct link establishment request message and / or a ProSe direct link establishment acceptance message. Based on the completion of this procedure, each device may establish a ProSe direct link. At this time, each device may transition to a state in which communication using the ProSe direct link is possible.

[0441] Alternatively, each device may complete the procedure in Figure 12(A) based on the sending and receiving of a ProSe direct link establishment request message and / or a ProSe direct link establishment rejection message. In this case, each device does not need to be able to establish a ProSe direct link. Furthermore, each device may be in a state where it cannot communicate using the ProSe direct link. In addition, each device does not need to perform the subsequent steps based on the sending and receiving of a ProSe direct link establishment rejection message.

[0442] Next, the ProSe direct link change procedure may be performed between the Remote UE and the U2N Relay UE (S2216).

[0443] Furthermore, each device may decide whether or not to perform the ProSe direct link change procedure based on the status of the UE and / or the network status and / or information received from other NFs.

[0444] Next, a PDU session change procedure may be performed between the U2N Relay UE and the network (S2218). Here, the PDU session change procedure may be performed during the ProSe direct link change procedure. In other words, the U2N Relay UE may perform the PDU session change procedure before sending a ProSe direct link change acceptance message or a ProSe direct link change rejection message to the Remote UE.

[0445] Furthermore, each device may decide whether or not to perform a PDU session modification procedure based on the status of the UE, and / or the network status, and / or information received from other NFs.

[0446] Next, the Remote UE reporting procedure may be performed between the U2N Relay UE and the network (S2220).

[0447] Furthermore, each device may decide whether or not to perform the Remote UE reporting procedure based on the status of the UE, and / or the network status, and / or information received from other NFs.

[0448] Furthermore, each device may complete this procedure based on the completion of the processes described above and / or the sending and receiving of each message.

[0449] Furthermore, each device may perform processing based on the identification information transmitted and received during this procedure, upon completion of this procedure.

[0450] Furthermore, based on the completion of this procedure, the Remote UE may communicate with the network via the U2N Relay UE.

[0451] [4. Embodiments] Next, each embodiment will be described.

[0452] [4.1. First Embodiment] First, the first embodiment will be described. In this chapter, the first embodiment may be referred to as this embodiment.

[0453] In this embodiment, a network request UE policy management procedure and / or a UE request ProSeP provision procedure may be performed.

[0454] In this embodiment, the first control message may be a management UE policy command message.

[0455] Furthermore, the behavior of the UE and the network upon receiving each control message may be the same as the behavior of the UE and the network in each of the procedures described above.

[0456] Furthermore, in this embodiment, the network may be an AMF, PCF, or ProSe application server.

[0457] The following describes each step of this embodiment.

[0458] First, the network may send a first control message to the UE. The network may also send a first control message to the UE that includes one or more of the identification information from the 10th to 11th identification information. The network may also send one or more of the identification information from the 10th to 11th identification information to the UE.

[0459] Here, the network may indicate to the UE what each identifier represents by transmitting one or more of the identifiers from the 10th to 11th identifiers.

[0460] Specifically, the network may indicate the UE's path preference to the UE by transmitting a tenth piece of identification information.

[0461] The network may also indicate to the UE which paths are permitted for path switching by transmitting an eleventh piece of identification information.

[0462] Furthermore, the network may select and decide whether to include one or more of the identification information from the 10th to 11th identification information in the first control message, based on the state of the UE and / or information received from other NFs, etc.

[0463] The network may also determine whether or not to transmit the first control message and / or each piece of identification information based on the status of the UE and / or information received from other NFs.

[0464] Next, the UE may receive a first control message from the network. The UE may also receive a first control message from the network that includes one or more of the identification information from the 10th to 11th identification information. The UE may also receive one or more of the identification information from the 10th to 11th identification information from the network.

[0465] Furthermore, based on the reception of the first control message, the UE may store the identification information received along with the first control message, or recognize the network decision. Also, based on the reception of the first control message, the UE may recognize the content of the identification information received along with the first control message.

[0466] Specifically, if the UE receives the tenth identifier, it may use the tenth identifier to select the appropriate path. Alternatively, if the UE receives the tenth identifier, it may use the tenth identifier to select the appropriate path for all or specific ProSe services.

[0467] In other words, if the UE receives the tenth identifier, it may use the tenth identifier to select either the PC5 path or the Uu path. Alternatively, if the UE receives the tenth identifier, it may use the tenth identifier to select either the PC5 path or the Uu path for all or specific ProSe services.

[0468] Furthermore, if the UE receives the tenth identification information, it may store the tenth identification information.

[0469] Furthermore, if the UE receives the 11th identification, it may use the 11th identification to select an appropriate path. Also, if the UE receives the 11th identification, it may use the 11th identification to select an appropriate path for all or specific ProSe services.

[0470] In other words, if the UE receives the 11th identification, it may use the 11th identification to select either the PC5 path or the Uu path. Alternatively, if the UE receives the 11th identification, it may use the 11th identification to select either the PC5 path or the Uu path for all or specific ProSe services.

[0471] Furthermore, if the UE receives the 11th identification information, it may store the 11th identification information.

[0472] Furthermore, if the UE receives an eleventh identifier indicating PC5 permitted, it may use the eleventh identifier to select the PC5 path. Also, if the UE receives an eleventh identifier indicating Uu permitted, it may use the eleventh identifier to select the Uu path. Furthermore, if the UE receives an eleventh identifier indicating both PC5 and Uu permitted, it may use the tenth identifier and / or the eleventh identifier to select either the PC5 path or the Uu path.

[0473] Furthermore, the UE may recognize that path switching is possible when it receives 11th identification information indicating both PC5 and Uu permitted. The UE may also recognize that path switching is possible for all or specific ProSe services when it receives 11th identification information indicating both PC5 and Uu permitted.

[0474] Furthermore, if the UE receives the 11th identification information, it may use the 11th identification information to select the appropriate path, regardless of the 10th identification information. In other words, if the UE receives the 11th identification information, it may use the 11th identification information to select either the PC5 path or the Uu path, regardless of the 10th identification information.

[0475] Furthermore, if the UE receives the tenth and eleventh identifiers, it may use the tenth and / or eleventh identifiers to select an appropriate path. Also, if the UE receives the eleventh identifier, it may use the tenth and / or eleventh identifiers to select an appropriate path for all or specific ProSe services.

[0476] In other words, if the UE receives the 10th and 11th identification information, it may use the 10th and / or 11th identification information to select either the PC5 path or the Uu path. Alternatively, if the UE receives the 11th identification information, it may use the 10th and / or 11th identification information to select either the PC5 path or the Uu path for all or specific ProSe services.

[0477] Here, if the tenth identifier indicates PC5 preferred and the eleventh identifier indicates Uu permitted, the UE may use the tenth identifier and / or the eleventh identifier to select the appropriate path. In other words, if the tenth identifier indicates PC5 preferred and the eleventh identifier indicates Uu permitted, the UE may use the tenth identifier and / or the eleventh identifier to select either the PC5 path or the Uu path.

[0478] Here, if the tenth identifier indicates PC5 preferred and the eleventh identifier indicates Uu permitted, the UE may prioritize either the tenth identifier or the eleventh identifier.

[0479] Here, if the tenth identifier indicates Uu preferred and the eleventh identifier indicates PC5 permitted, the UE may use the tenth identifier and / or the eleventh identifier to select the appropriate path. In other words, if the tenth identifier indicates Uu preferred and the eleventh identifier indicates PC5 permitted, the UE may use the tenth identifier and / or the eleventh identifier to select either the PC5 path or the Uu path.

[0480] Here, if the tenth identifier indicates Uu preferred and the eleventh identifier indicates PC5 permitted, the UE may prioritize either the tenth identifier or the eleventh identifier.

[0481] Furthermore, if the UE does not receive the 10th identifier and only receives the 11th identifier, it may recognize that the 10th identifier is of no preference and use the 11th identifier to select an appropriate path. In other words, if the UE does not receive the 10th identifier and only receives the 11th identifier, it may recognize that the 10th identifier is of no preference and use the 11th identifier to select either the PC5 path or the Uu path.

[0482] Furthermore, if the UE does not receive the 11th identification information and only receives the 10th identification information, it may recognize that path switching between the PC5 path and the Uu path is not permitted. In other words, if the UE does not receive the 11th identification information and only receives the 10th identification information, it does not need to perform the path switching procedure.

[0483] Furthermore, the above behavior of the UE may be performed after receiving the first control message. Also, the above behavior of the UE may be performed after receiving one or more of the identification information from the 10th to 11th identification information.

[0484] Furthermore, if the UE receives the first control message, it may perform the actions that would occur upon receiving each piece of identification information contained in the first control message.

[0485] [4.2. Second Embodiment] First, the second embodiment will be described. In this chapter, the second embodiment may be referred to as this embodiment.

[0486] In this embodiment, a registration procedure and / or a PDU session establishment procedure and / or a network request UE policy management procedure and / or a UE request ProSeP provision procedure and / or a discovery procedure and / or a ProSe direct link establishment procedure may be performed.

[0487] Furthermore, in this embodiment, the procedure for 5G ProSe communication via U2N Relay, as described in Chapter 3.7, may be implemented.

[0488] In this embodiment, the first control message may be a registration request message.

[0489] Furthermore, in this embodiment, the second control message may be a registration acceptance message.

[0490] Furthermore, in this embodiment, the third control message may be a ProSe direct link establishment request message.

[0491] Furthermore, in this embodiment, the fourth control message may be a PDU session establishment request message.

[0492] Furthermore, in this embodiment, the fifth control message may be a PDU session establishment acceptance message or a PDU session establishment rejection message.

[0493] Furthermore, in this embodiment, the sixth control message may be a ProSe direct link establishment acceptance message or a ProSe direct link establishment rejection message.

[0494] Furthermore, the behavior of the UE and the network upon receiving each control message may be the same as the behavior of the UE and the network in each of the procedures described above.

[0495] Furthermore, in this embodiment, the UE may be a Remote UE or a U2N Relay UE.

[0496] Furthermore, in this embodiment, the network may be an AMF, SMF, UPF, PCF, or ProSe application server.

[0497] The following describes each step of this embodiment.

[0498] First, the Remote UE and / or U2N Relay UE send a first control message to the network.

[0499] Here, the Remote UE and / or U2N Relay UE may include one or more of the identification information from the first to fourth in the first control message.

[0500] Furthermore, the Remote UE and / or U2N Relay UE may indicate that the U2N Relay UE supports each function, or indicate a request from the Remote UE and / or U2N Relay UE, by transmitting this identification information. In addition, if multiple pieces of identification information are transmitted and received, two or more of these pieces of identification information may be configured as one or more pieces of identification information. Furthermore, the information indicating support for each function and the information indicating a request for the use of each function may be transmitted and received with the same identification information, or they may be transmitted and received with different identification information.

[0501] Here, the Remote UE and / or U2N Relay UE may indicate the content of each identification information to the network by transmitting a first control message. Alternatively, the Remote UE and / or U2N Relay UE may indicate the content of each identification information to the network by transmitting one or more of the first to fourth identification information.

[0502] Specifically, a Remote UE and / or U2N Relay UE may indicate a 5GS registration type information element to the network by transmitting a first identification information, where the UE may indicate an emergency registration in the first identification information. In other words, the UE may indicate an emergency registration in the 5GS registration type information element to the network. The UE may also transmit the first identification information when performing a registration procedure for emergency services.

[0503] Furthermore, the Remote UE and / or U2N Relay UE may indicate to the network that they are registered for relay emergency services by transmitting a second identification information. The UE may also transmit a second identification information when performing the registration procedure for relay emergency services.

[0504] Furthermore, the Remote UE and / or U2N Relay UE may request relay emergency services from the network by transmitting a third identification information.

[0505] Furthermore, the Remote UE and / or U2N Relay UE may indicate whether or not they support relay emergency services by transmitting a fourth set of identification information.

[0506] Furthermore, the Remote UE and / or U2N Relay UE may select and decide whether to include one or more of the first to fourth pieces of identification information in the first control message, based on subscriber information, and / or network status, and / or user registration information, and / or context held by the UE, etc.

[0507] Next, the network receives a first control message from the Remote UE and / or U2N Relay UE. The network may also receive a first control message from the Remote UE and / or U2N Relay UE that includes one or more of the identification information from the first to fourth.

[0508] When the network receives the first control message, it may recognize what the Remote UE and / or U2N Relay UE are requesting, and / or the contents of the information contained in the first control message (message, container, identification information).

[0509] Specifically, when the network receives the first identification information, it may recognize that the UE is indicating registration for emergency services.

[0510] Furthermore, if the network receives the second identification information, it may recognize that the UE is registering for relay emergency services.

[0511] Furthermore, upon receiving the fourth identification information, the network may determine whether the Remote UE and / or U2N Relay UE support relay emergency services. If the fourth identification information indicates that the Remote UE and / or U2N Relay UE support relay emergency services, the network may perform the PDU session establishment procedure for relay emergency services. If the fourth identification information indicates that the Remote UE and / or U2N Relay UE do not support relay emergency services, the network does not need to perform the PDU session establishment procedure for relay emergency services.

[0512] Next, the network sends a second control message to the Remote UE and / or U2N Relay UE.

[0513] Here, the network may include one or more of the identification information from the 10th to 13th in the second control message.

[0514] Here, the network may indicate that at least part of the request from the Remote UE and / or U2N Relay UE has been accepted by sending a second control message. Alternatively, the network may indicate that at least part of the request from the Remote UE and / or U2N Relay UE has been accepted by sending one or more of the identification information from the 10th to 13th identification information.

[0515] Specifically, the network may indicate whether or not it supports relay emergency services by transmitting a 12th piece of identification information.

[0516] Furthermore, the network may indicate that it supports or does not support each function by transmitting these identification pieces and / or a second control message. In addition, if multiple identification pieces are transmitted and received, two or more of these identification pieces may be configured as one or more identification pieces. Furthermore, the information indicating support for each function and the information indicating a request to use each function may be transmitted and received as the same identification piece, or as different identification pieces.

[0517] Furthermore, the network may decide which identification information to include in the second control message based on each received identification information, and / or subscriber information, and / or network capability information, and / or UE policies, and / or operator policies, and / or network status, and / or user registration information, and / or context held by the UE, etc.

[0518] Next, the Remote UE and / or U2N Relay UE receive a second control message from the network. The Remote UE and / or U2N Relay UE may also receive a second control message from the network that includes one or more of the identification information from the 10th to 13th identification information.

[0519] When the Remote UE and / or U2N Relay UE receive the second control message, they can recognize that their request has been accepted and / or the contents of the information (message, container, identification information) contained in the second control message.

[0520] Specifically, when the UE receives the 12th identification information, it may recognize whether the network supports relay emergency services. Furthermore, when the UE receives the 12th identification information, it may recognize whether the network supports relay emergency services. Also, when the UE receives the 12th identification information, it may recognize whether the network does not support relay emergency services.

[0521] Next, the discovery procedure may be performed between the Remote UE and the U2N Relay UE.

[0522] Each device may decide whether or not to perform the discovery procedure based on the status of the UE, and / or the network status, and / or information received from other NFs.

[0523] Specifically, the U2N Relay UE may send a UE-to-Network relay discovery announcement message to the Remote UE. The U2N Relay UE may also send a UE-to-Network relay discovery announcement message to the Remote UE that includes one or more of the identification information from items 30 to 31.

[0524] Furthermore, a U2N Relay UE may send UE-to-Network relay discovery announcement messages to multiple Remote UEs. In other words, a U2N Relay UE may broadcast UE-to-Network relay discovery announcement messages to multiple Remote UEs.

[0525] Here, the U2N Relay UE may transmit one or more of the identification information from the 30th to 31th identification information to the Remote UE, thereby indicating the content that each identification information represents.

[0526] Specifically, the U2N Relay UE may indicate whether it supports relay emergency services by transmitting the 30th identification information. The U2N Relay UE may also indicate whether the network supports relay emergency services by transmitting the 30th identification information to the Remote UE.

[0527] Furthermore, if the U2N Relay UE does not support relay emergency services, the U2N Relay UE does not need to transmit the 30th identification information. Furthermore, if the U2N Relay UE does not support relay emergency services, the U2N Relay UE may transmit the 30th identification information indicating that the U2N Relay UE does not support relay emergency services. Furthermore, if the U2N Relay UE does not support relay emergency services, the U2N Relay UE may decide whether or not to transmit the 30th identification information.

[0528] Furthermore, if the 12th identification indicates that the network does not support relay emergency services, the U2N Relay UE does not need to transmit the 30th identification. In other words, if the network does not support relay emergency services, the U2N Relay UE does not need to transmit the 30th identification. Furthermore, if the 12th identification indicates that the network does not support relay emergency services, the U2N Relay UE may transmit the 30th identification indicating that the network does not support relay emergency services. In other words, if the network does not support relay emergency services, the U2N Relay UE may transmit the 30th identification indicating that the network does not support relay emergency services.

[0529] Next, the Remote UE may receive a UE-to-Network relay discovery announcement message from the U2N Relay UE. The Remote UE may also receive a UE-to-Network relay discovery announcement message from the U2N Relay UE that includes one or more of the identification information from items 30 to 31.

[0530] Furthermore, based on the reception of the UE-to-Network relay discovery announcement message, the Remote UE may store the identification information received along with the UE-to-Network relay discovery announcement message, or it may recognize the information of the U2N Relay UE. In addition, based on the reception of the UE-to-Network relay discovery announcement message, the Remote UE may recognize the content of the identification information received along with the UE-to-Network relay discovery announcement message.

[0531] Specifically, when the Remote UE receives the 30th identification information, it may recognize whether the U2N Relay UE or the network supports relay emergency services. Furthermore, when the Remote UE receives the 30th identification information, it may recognize whether the U2N Relay UE or the network supports relay emergency services. Also, when the Remote UE receives the 30th identification information, it may recognize whether the U2N Relay UE or the network does not support relay emergency services.

[0532] Furthermore, the above behavior of the Remote UE may be performed after receiving the UE-to-Network relay discovery announcement message.

[0533] Furthermore, if the Remote UE receives a UE-to-Network relay discovery announcement message, it may perform the actions it would have taken upon receiving each piece of identification information contained in the UE-to-Network relay discovery announcement message.

[0534] Furthermore, the U2N Relay UE may send an additional relay discovery information message to the Remote UE. The U2N Relay UE may also send an additional relay discovery information message to the Remote UE that includes one or more identification pieces from the 30th to 31st identification pieces. Note that the additional relay discovery information message may or may not be sent.

[0535] Furthermore, the U2N Relay UE may send additional relay discovery information messages to multiple Remote UEs. In other words, the U2N Relay UE may broadcast additional relay discovery information messages to multiple Remote UEs.

[0536] Here, the U2N Relay UE may transmit one or more of the identification information from the 30th to 31th identification information to the Remote UE, thereby indicating the content that each identification information represents.

[0537] Specifically, the U2N Relay UE may indicate whether it supports relay emergency services by transmitting the 30th identification information. The U2N Relay UE may also indicate whether the network supports relay emergency services by transmitting the 30th identification information to the Remote UE.

[0538] Furthermore, if the U2N Relay UE does not support relay emergency services, the U2N Relay UE does not need to transmit the 30th identification information. Furthermore, if the U2N Relay UE does not support relay emergency services, the U2N Relay UE may transmit the 30th identification information indicating that the U2N Relay UE does not support relay emergency services. Furthermore, if the U2N Relay UE does not support relay emergency services, the U2N Relay UE may decide whether or not to transmit the 30th identification information.

[0539] Furthermore, if the 12th identification indicates that the network does not support relay emergency services, the U2N Relay UE does not need to transmit the 30th identification. In other words, if the network does not support relay emergency services, the U2N Relay UE does not need to transmit the 30th identification. Furthermore, if the 12th identification indicates that the network does not support relay emergency services, the U2N Relay UE may transmit the 30th identification indicating that the network does not support relay emergency services. In other words, if the network does not support relay emergency services, the U2N Relay UE may transmit the 30th identification indicating that the network does not support relay emergency services.

[0540] Next, the Remote UE may receive a relay discovery additional information message from the U2N Relay UE. The Remote UE may also receive a relay discovery additional information message from the U2N Relay UE that includes one or more identification pieces from the 30th to 31st identification pieces.

[0541] Furthermore, based on the reception of the relay discovery additional information message, the Remote UE may store the identification information received along with the relay discovery additional information message, or it may recognize the information of the U2N Relay UE. Also, based on the reception of the relay discovery additional information message, the Remote UE may recognize the content of the identification information received along with the relay discovery additional information message.

[0542] Specifically, when the Remote UE receives the 30th identification information, it may recognize whether the U2N Relay UE or the network supports relay emergency services. Furthermore, when the Remote UE receives the 30th identification information, it may recognize whether the U2N Relay UE or the network supports relay emergency services. Also, when the Remote UE receives the 30th identification information, it may recognize whether the U2N Relay UE or the network does not support relay emergency services.

[0543] Furthermore, the above behavior of the Remote UE may be performed after receiving the relay discovery additional information message.

[0544] Furthermore, if the Remote UE receives a relay discovery additional information message, it may perform the actions it would have taken if it had received each piece of identification information included in the relay discovery additional information message.

[0545] Next, the Remote UE sends a third control message to the U2N Relay UE.

[0546] Here, the Remote UE may include one or more of the identification information from the 20th to 21th in the third control message and send it.

[0547] Furthermore, by transmitting this identification information, the Remote UE may indicate that it supports each function, or it may indicate a request from the Remote UE. In addition, if multiple pieces of identification information are sent and received, two or more of these pieces of identification information may be combined into one or more pieces of identification information. Furthermore, the information indicating support for each function and the information indicating a request to use each function may be sent and received with the same identification information, or they may be sent and received with different identification information.

[0548] Here, the Remote UE may indicate the content of each identification information to the U2N Relay UE by sending a third control message. Alternatively, the Remote UE may indicate the content of each identification information to the U2N Relay UE by sending one or more of the identification information from the 20th to 21st identification information.

[0549] Specifically, the Remote UE may request relay emergency services from the U2N Relay UE and / or network by transmitting the 20th identification information.

[0550] Furthermore, the Remote UE may indicate to the U2N Relay UE and / or network whether or not it supports relay emergency services by transmitting the 21st identification information.

[0551] Furthermore, if the Remote UE receives a 30th identification indicating that the U2N Relay UE and / or network does not support relay emergency services, it does not need to send a third control message. In other words, if the U2N Relay UE and / or network does not support relay emergency services, the Remote UE does not need to send a third control message.

[0552] Furthermore, if Remote UE receives identification number 12 indicating that the network does not support relay emergency services, it does not need to send a third control message even if it receives identification number 30.

[0553] Furthermore, if the Remote UE receives a 30th identification indicating that the U2N Relay UE and / or network does not support relay emergency services, it does not need to send the 20th and 21st identifications. In other words, if the U2N Relay UE and / or network does not support relay emergency services, the Remote UE does not need to request relay emergency services.

[0554] Furthermore, the Remote UE may select and decide whether to include one or more of the identification information from items 20 to 21 in the third control message, based on subscriber information, and / or network status, and / or user registration information, and / or context held by the UE.

[0555] Next, the U2N Relay UE receives a third control message from the Remote UE. The U2N Relay UE may also receive a third control message from the Remote UE that includes one or more of the identification information from the 20th to 21st identification information.

[0556] When the U2N Relay UE receives a third control message, it may recognize what the Remote UE is requesting and / or the information contained in the third control message (message, container, identification information).

[0557] Specifically, when the U2N Relay UE receives the 20th identification information, it may recognize that the Remote UE is requesting relay emergency service.

[0558] Furthermore, when the U2N Relay UE receives the 21st identification information, it may recognize whether the Remote UE supports relay emergency services.

[0559] Next, the U2N Relay UE sends a fourth control message to the network.

[0560] Here, the U2N Relay UE may include one or more of the identification information from the first to fourth in the fourth control message and send it.

[0561] Furthermore, the U2N Relay UE may indicate that the Remote UE and / or U2N Relay UE support each function, or indicate a request from the Remote UE and / or U2N Relay UE, by transmitting this identification information. In addition, if multiple pieces of identification information are transmitted and received, two or more of these pieces of identification information may be configured as one or more pieces of identification information. Furthermore, the information indicating support for each function and the information indicating a request for use of each function may be transmitted and received with the same identification information, or they may be transmitted and received with different identification information.

[0562] Here, the U2N Relay UE may indicate the content of each identification information to the network by sending a fourth control message. Alternatively, the U2N Relay UE may indicate the content of each identification information to the network by sending one or more of the first to fourth identification information.

[0563] Specifically, a U2N Relay UE may request relay emergency service by transmitting a third identification piece of information.

[0564] Furthermore, the U2N Relay UE may indicate whether the Remote UE and / or U2N Relay UE support relay emergency services by transmitting a fourth set of identification information.

[0565] Furthermore, the U2N Relay UE may transmit a fourth control message based on the reception of the 20th and / or 21st identification information. The U2N Relay UE may also decide whether or not to transmit a fourth control message based on the reception of the 20th and / or 21st identification information.

[0566] Furthermore, if the 12th identification information indicates that the network does not support relay emergency services, the U2N Relay UE does not need to send the 4th control message. In other words, if the network does not support relay emergency services, the U2N Relay UE does not need to send the 4th control message.

[0567] Furthermore, the U2N Relay UE may select and decide whether to include one or more of the first to fourth types of identification information in the fourth control message, based on subscriber information and / or network status and / or user registration information and / or context held by the UE.

[0568] Next, the network receives a fourth control message from the U2N Relay UE. The network may also receive a fourth control message from the U2N Relay UE that includes one or more of the identification information from the first to fourth.

[0569] When the network receives the fourth control message, it may recognize what the U2N Relay UE is requesting and / or the information contained in the fourth control message (message, container, identification information).

[0570] Specifically, the network may recognize that a relay emergency service is being requested when it receives third identification information.

[0571] Furthermore, upon receiving the fourth identification information, the network may determine whether the Remote UE and / or U2N Relay UE support relay emergency services.

[0572] Next, the network sends a fifth control message to the U2N Relay UE.

[0573] Here, the network may include one or more of the identification information from the tenth to thirteenth in the fifth control message.

[0574] Here, the network may indicate that at least part of the Remote UE and / or U2N Relay UE request has been accepted by sending a fifth control message. Alternatively, the network may indicate that at least part of the Remote UE and / or U2N Relay UE request has been accepted by sending one or more of the identification information from the tenth to thirteenth sets of identification information.

[0575] The network may also send a fifth control message indicating that the request from the Remote UE and / or U2N Relay UE has been rejected, that it has not authorized the request from the Remote UE and / or U2N Relay UE, or a combination of these.

[0576] Specifically, the network may indicate that it does not support relay emergency services by transmitting a 13th piece of identification information.

[0577] Furthermore, if the network indicated in the 12th identification that it does not support relay emergency services, the network may transmit the 13th identification. In other words, if the network indicated that it does not support relay emergency services, the network may transmit the 13th identification.

[0578] Furthermore, the network may indicate that it supports each function by transmitting these identification pieces and / or a fifth control message. In addition, if multiple identification pieces are transmitted and received, two or more of these identification pieces may be configured as one or more identification pieces. Furthermore, the information indicating support for each function and the information indicating a request to use each function may be transmitted and received as the same identification piece, or as different identification pieces.

[0579] Furthermore, the network may decide which identification information to include in the fifth control message based on each received identification information, and / or subscriber information, and / or network capability information, and / or UE policy, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the U2N Relay UE, etc.

[0580] Next, the U2N Relay UE receives a fifth control message from the network. The U2N Relay UE may also receive a fifth control message from the network that includes one or more of the identification information from the tenth to thirteenth identification information.

[0581] When the U2N Relay UE receives the fifth control PDU session establishment acceptance message, it can recognize the contents of the information (message, container, identification information) contained in the fifth control message.

[0582] Specifically, if the U2N Relay UE receives the 13th identification information, it may recognize that the network does not support relay emergency services.

[0583] Next, the U2N Relay UE sends a sixth control message to the Remote UE.

[0584] Here, the U2N Relay UE may include one or more of the identification information from the 30th to 31th in the sixth control message.

[0585] Here, the U2N Relay UE may indicate that at least part of the Remote UE's request has been accepted by sending a sixth control message. Alternatively, the U2N Relay UE may indicate that at least part of the Remote UE's request has been accepted by sending one or more of the identification information from the 30th to 31st identification information.

[0586] Specifically, the U2N Relay UE may indicate that the U2N Relay UE and / or the network does not support relay emergency services by transmitting the 31st identification information.

[0587] Furthermore, if the U2N Relay UE receives the 13th identification information, it may transmit the 31st identification information. In other words, if the U2N Relay UE or the network does not support relay emergency services, the U2N Relay UE may transmit the 31st identification information. Also, if the U2N Relay UE or the network does not support relay emergency services, the U2N Relay UE may transmit the 6th control message.

[0588] Furthermore, if the U2N Relay UE or the network does not support relay emergency services, the U2N Relay UE may send the sixth control message without sending or receiving the fourth and / or fifth control messages.

[0589] Furthermore, the U2N Relay UE may send a sixth control message to indicate that the Remote UE's request has been rejected, that it has not authorized the request from the Remote UE, or a combination of these.

[0590] Furthermore, by transmitting this identification information and / or the sixth control message, the U2N Relay UE may indicate that it supports each function, that the Remote UE's request has been accepted, that it has not authorized the request from the Remote UE, or a combination of these. In addition, if multiple pieces of identification information are transmitted and received, two or more of these pieces of identification information may be configured as one or more pieces of identification information. Furthermore, the information indicating support for each function and the information indicating a request to use each function may be transmitted and received as the same piece of identification information, or as different pieces of identification information.

[0591] Furthermore, the U2N Relay UE may decide which identification information to include in the sixth control message based on each received identification information, and / or subscriber information, and / or network capability information, and / or UE policy, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the U2N Relay UE, etc.

[0592] Next, the Remote UE receives a sixth control message from the U2N Relay UE. The Remote UE may also receive a sixth control message from the U2N Relay UE that includes one or more of the identification information from the 30th to 31st identification information.

[0593] When the Remote UE receives the sixth control message, it can recognize the contents of the information (message, container, identification information) contained in the sixth control message.

[0594] Specifically, if the Remote UE receives the 31st identification information, it may recognize that the U2N Relay UE and / or network does not support relay emergency services.

[0595] Furthermore, each device may complete this embodiment based on the completion of the above-described processes and / or the sending and receiving of each message.

[0596] Furthermore, each device may perform processing based on the identification information transmitted and received in this embodiment, upon completion of this embodiment.

[0597] Furthermore, based on the completion of this embodiment, the Remote UE may communicate with the network via the U2N Relay UE.

[0598] [5. Variant] A program that operates in a device according to one aspect of the present invention may be a program that controls a Central Processing Unit (CPU), etc., to make the computer function in order to realize the functions of an embodiment according to one aspect of the present invention. The program or the information handled by the program is temporarily stored in volatile memory such as Random Access Memory (RAM), non-volatile memory such as flash memory, a Hard Disk Drive (HDD), or other storage device system.

[0599] Furthermore, a program for realizing the functions of an embodiment relating to one aspect of the present invention may be recorded on a computer-readable recording medium. This can also be realized by loading the program recorded on this recording medium into a computer system and executing it. The term "computer system" here refers to a computer system built into a device, and includes hardware such as an operating system and peripheral devices. The term "computer-readable recording medium" may be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a medium that dynamically holds a program for a short period of time, or any other computer-readable recording medium.

[0600] Furthermore, each functional block or feature of the apparatus used in the embodiments described above may be implemented or executed by an electrical circuit, such as an integrated circuit or a combination of integrated circuits. An electrical circuit designed to perform the functions described herein may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or a combination thereof. The general-purpose processor may be a microprocessor, a conventional processor, controller, microcontroller, or state machine. The aforementioned electrical circuit may consist of digital circuits or analog circuits. Also, if advances in semiconductor technology lead to the emergence of integrated circuit technologies that replace current integrated circuits, one or more aspects of the present invention may use new integrated circuits based on such technologies.

[0601] It should be noted that the present invention is not limited to the embodiments described above. Although one example of a device is described in the embodiments, the present invention is not limited thereto and can be applied to stationary or non-movable electronic devices installed indoors or outdoors, such as terminal devices or communication devices for AV equipment, kitchen equipment, cleaning and washing machines, air conditioning equipment, office equipment, vending machines, and other household appliances.

[0602] While embodiments of this invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and design modifications and the like that do not depart from the gist of this invention are also included. Furthermore, the present invention can be modified in various ways within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this invention. In addition, configurations in which elements described in each of the above embodiments that produce similar effects are substituted for each other are also included. [Explanation of Symbols]

[0603] 1. Mobile communication systems 10 UE_A 30 PGW-U 32 PGW-C 35 SGW 40 MME 45 eNB 50 HSS 60 PCRF 80 Access Network_A(E-UTRAN) 90 Core Network_A 120 Access Network_B(5G AN) 122 gNB 130 UPF 132 SMF 140 AMF 150 UDM 160 PCF 190 Core Network_B 235 UPF_A 239 UPF_C

Claims

1. User Equipment (UE), The aforementioned UE operates as a Remote UE, The aforementioned UE comprises a transmitting / receiving unit and a control unit, The transmitting / receiving unit sends a registration request message containing the first identification information to the network. The first identification information is information indicating that the UE supports emergency services using relays, The aforementioned transmitting and receiving unit receives a registration acceptance message containing second identification information from the network. The second identification information is information indicating that the network does not support emergency services using relays. Based on the second identification information, the control unit recognizes that the network does not support emergency services using relays. Even if the aforementioned transmitting / receiving unit receives a Relay Service Code (RSC) for emergency service from the Layer-3 UE-to-Network Relay UE, it will not send a ProSe direct link establishment request message. A UE characterized by the following:

2. The transmitting / receiving unit receives a UE-to-Network Relay discovery additional information message containing third identification information from the Layer-3 UE-to-Network Relay UE. The third identification information is the Relay Service Code (RSC) for emergency services, Based on the third identification information, the control unit recognizes that the Layer-3 UE-to-Network Relay UE does not support emergency services using relays. The aforementioned transmitting / receiving unit does not send a ProSe direct link establishment request message. The UE according to feature 1.

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