UE(user equipment)

Abstract

The detailed behavior of the UE, and / or the detailed behavior of the satellite, and / or the detailed behavior of the network with respect to the store and forward satellite operation is clarified.SOLUTION: A UE capable of communicating with base stations and a satellite equipped with an MME-ground transmits, in a TAU procedure, a TAU request message including UE capability information indicating that the UE supports an S & F mode, receives an attach reject message including a cause value indicating that the TAU procedure cannot be completed due to an S & F operation, resets a TAU attempt counter based on the cause value, and sets an EPS update status to EU2 or EU3.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] The 3GPP (3rd Generation Partnership Project) is studying the system architectures of the EPS (Evolved Packet System), a fourth-generation (4G) mobile communication system, and the 5GS (5G System), a fifth-generation (5G) mobile communication system, and is discussing how to support new procedures and new functions (see Non-Patent Documents 1 and 2). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP TS 24.501 V18.6.0 (2024-03); 3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3; (Release 18) [Non-patent document 2] 3GPP TS 24.301 V18.6.0 (2024-03); 3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage 3; (Release 18) [Non-patent document 3] 3GPP TR 23.700-29 V19.0.0 (2024-06); 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Study on integration of satellite components in the 5G architecture; Phase 3 (Release 19) Summary of the Invention [Problem to be solved by the invention]

[0004] Release 19 considers Store and Forward (S&F) satellite operation (see Non-Patent Document 3). However, the details of UE behavior, satellite behavior, and network behavior are still to be fully considered.

[0005] One aspect of the present invention has been made in view of the above circumstances, and aims to clarify detailed UE behavior, and / or detailed satellite behavior, and / or detailed network behavior regarding store and forward satellite operations. [Means for solving the problem]

[0006] a tracking area update request message including UE capability information indicating that the tracking area update procedure is supported in S&F mode; the tracking area update rejection message includes a reason value, a waiting time value, and / or a list of satellite identifiers; the rejection reason value indicates that the tracking area update procedure cannot be completed due to S&F operation; the waiting time value indicates a waiting time value for the UE to wait before retrying the tracking area update procedure for a current or a different satellite belonging to the same or a different PLMN; and the list of satellite identifiers includes one or more identifiers of satellites for which the UE will retry the tracking area update procedure after the waiting time has expired; and the control unit resets a tracking area update attempt counter based on the reason value and sets an EPS update state to EU2 or EU3. [Effects of the Invention]

[0007] According to one aspect of the present invention, it is possible to clarify how store and forward satellite operations are implemented, and to clarify the detailed behavior of the UE, and / or satellite, and / or network. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an outline of a mobile communication system (EPS / 5GS). [Figure 2] FIG. 1 is a diagram illustrating the detailed configuration of a mobile communication system (EPS / 5GS). [Figure 3] FIG. 1 is a diagram illustrating the device configuration of a UE. [Figure 4] FIG. 2 is a diagram illustrating the configuration of an access network device. [Figure 5]FIG. 2 is a diagram illustrating the configuration of a core network device. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a best mode for carrying out one aspect of the present invention will be described with reference to the drawings. In this embodiment, an embodiment of a mobile communication system to which one aspect of the present invention is applied will be described as an example.

[0010] [1. System Overview] First, FIG. 1 is a diagram for explaining an outline of a mobile communication system 1 used in each embodiment, and FIG. 2 is a diagram for explaining a detailed configuration of the mobile communication system 1. As shown in FIG.

[0011] FIG. 1 shows that the mobile communication system 1 is composed of UE_A10, access network _A80, core network _A90, PDN (Packet Data Network) _A5, access network _B120, core network _B190, and DN (Data Network) _A6.

[0012] In the following, these devices and functions may be referred to by abbreviating the symbols, such as UE, access network_A, core network_A, PDN, access network_B, core network_B, DN, etc.

[0013] Figure 2 also shows devices and functions such as UE_A10, E-UTRAN80, MME40, SGW35, PGW-U30, PGW-C32, PCRF60, HSS50, 5G AN120, AMF140, UPF130, SMF132, PCF160, UDM150, and N3IWF170, as well as interfaces that connect these devices and functions to each other.

[0014] In the following, these devices and functions may be referred to by abbreviated symbols such as UE, E-UTRAN, MME, SGW, PGW-U, PGW-C, PCRF, HSS, 5G AN, AMF, UPF, SMF, PCF, UDM, N3IWF, etc.

[0015] The 4G system EPS (Evolved Packet System) includes an access network A and a core network A, but may further include a UE and / or a PDN. The 5G system 5GS (5G System) includes a UE, an access network B, and a core network B, but may further include a DN.

[0016] A UE is a device that can connect to a network service via 3GPP access (also referred to as a 3GPP access network, or 3GPP AN) and / or non-3GPP access (also referred to as a non-3GPP access network, or non-3GPP AN). A UE may be a terminal device capable of wireless communication, such as a mobile phone or a smartphone, or may be a terminal device that can connect to EPS and / or 5GS. A UE may include a UICC (Universal Integrated Circuit Card) or an eUICC (Embedded UICC). Note that a UE may also be referred to as a user device or a terminal device.

[0017] Furthermore, access network_A corresponds to an E-UTRAN (Evolved Universal Terrestrial Radio Access Network) and / or a wireless LAN access network. One or more eNBs (evolved Node Bs) 45 are deployed in the E-UTRAN. Note that, hereinafter, the eNB 45 may be referred to by abbreviating the symbol eNB. If there are multiple eNBs, the eNBs are connected to each other, for example, via an X2 interface. Furthermore, one or more access points are deployed in the wireless LAN access network.

[0018] Furthermore, access network_B corresponds to a 5G access network (5G AN). The 5G AN is composed of an NG-RAN (NG Radio Access Network) and / or a non-3GPP access network. One or more gNBs (NR NodeBs) 122 are deployed in the NG-RAN. Note that, hereinafter, the symbol for gNB 122 may be abbreviated, such as gNB. The gNB is a node that provides the NR (New Radio) user plane and control plane to UEs, and is a node that connects to the 5GCN via an NG interface (including an N2 interface or an N3 interface). In other words, the gNB is a base station device newly designed for 5GS, and has different functions from the base station device (eNB) designed for the 4G system EPS. Furthermore, when there are multiple gNBs, the gNBs are connected to each other, for example, via an Xn interface.

[0019] Furthermore, the non-3GPP access network may include an untrusted non-3GPP access network and a trusted non-3GPP access network. Here, the untrusted non-3GPP access network may be a non-3GPP access network that does not perform security management within the access network, such as a public wireless LAN. On the other hand, the trusted non-3GPP access network may be an access network specified by 3GPP, and may include a trusted non-3GPP access point (TNAP) and a trusted non-3GPP gateway function (TNGF).

[0020] In the following, E-UTRAN and NG-RAN may be referred to as 3GPP access. Also, wireless LAN access networks and non-3GPP AN may be referred to as non-3GPP access. Also, nodes located in access network_B may be collectively referred to as NG-RAN nodes.

[0021] In addition, in the following, access network _A, access network _B, and devices included in access network _A, and devices included in access network _B may be referred to as access networks, or access network devices, or devices within the access network.

[0022] The core network_A corresponds to an EPC (Evolved Packet Core), which includes, for example, an MME (Mobility Management Entity), an SGW (Serving Gateway), a PGW (Packet Data Network Gateway)-U, a PGW-C, a PCRF (Policy and Charging Rules Function), and an HSS (Home Subscriber Server).

[0023] Furthermore, the core network_B corresponds to a 5G Core Network (5GCN). In the 5GCN, for example, an Access and Mobility Management Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), a Policy Control Function (PCF), a Unified Data Management (UDM), etc. are arranged. Here, the 5GCN may be expressed as a 5GC.

[0024] In addition, in the following, core network _A, core network _B, and devices included in core network _A, and devices included in core network _B may be referred to as core networks, or core network devices, or devices within the core network.

[0025] The core network (core network _A and / or core network _B) may be an IP mobile communication network operated by a mobile network operator (MNO) that connects the access network (access network _A and / or access network _B) to the PDN and / or DN, or it may be a core network for a mobile network operator that operates and manages the mobile communication system 1, or it may be a core network for a virtual mobile communication operator or virtual mobile communication service provider such as an MVNO (Mobile Virtual Network Operator) or MVNE (Mobile Virtual Network Enabler).

[0026] Also, while FIG. 1 illustrates a case where the PDN and the DN are the same, they may be different. The PDN may be a DN (Data Network) that provides communication services to the UE. The DN may be configured as a packet data service network, or may be configured for each service. Furthermore, the PDN may include a connected communication terminal. Therefore, connecting to the PDN may mean connecting to a communication terminal or a server device located in the PDN. Furthermore, transmitting and receiving user data to and from the PDN may mean transmitting and receiving user data to and from a communication terminal or a server device located in the PDN. The PDN may be expressed as the DN, and the DN may be expressed as the PDN.

[0027] In addition, hereinafter, at least a portion of the access network _A, core network _A, PDN, access network _B, core network _B, and DN, and / or one or more devices included therein may be referred to as a network (also referred to as NW) or network device. In other words, when a network and / or network device sends and receives messages and / or performs procedures, it means that at least a portion of the access network _A, core network _A, PDN, access network _B, core network _B, and DN, and / or one or more devices included therein send and receive messages and / or perform procedures.

[0028] The UE can also be connected to an access network. The UE can also be connected to a core network via the access network. The UE can also be connected to a PDN or DN via the access network and the core network. That is, the UE can transmit and receive (communicate) user data with the PDN or DN. When transmitting and receiving user data, not only IP (Internet Protocol) communication but also non-IP communication may be used.

[0029] Here, IP communication refers to data communication using IP, and data is transmitted and received using IP packets. An IP packet consists of an IP header and a payload. The payload may include data transmitted and received by devices and functions included in EPS or devices and functions included in 5GS. Non-IP communication refers to data communication that does not use IP, and data is transmitted and received in a format different from the IP packet structure. For example, non-IP communication may be data communication achieved by transmitting and receiving application data without an IP header, or may be user data transmitted and received by a UE with a different header, such as a MAC header or an Ethernet (registered trademark) frame header, added.

[0030] In addition, access network _A, core network _A, access network _B, core network _B, PDN_A, and DN_A may be configured with devices not shown in Fig. 2. For example, core network _A and / or core network _B may include an AUSF (Authentication Server Function) and an AAA (Authentication, authorization, and accounting) server (AAA-S).

[0031] Here, the AUSF is a core network device having an authentication function for 3GPP access and non-3GPP access, specifically, a network function unit that receives an authentication request for 3GPP access and / or non-3GPP access from a UE and executes the authentication procedure.

[0032] The AAA server is a device that has authentication, authorization, and accounting functions and is connected to the AUSF directly or indirectly via another network device. The AAA server may be a network device within the core network. The AAA server may not be included in the core network _A and / or core network _B, but may be included in the PLMN. In other words, the AAA server may be a core network device or a device outside the core network. For example, the AAA server may be a server device within the PLMN managed by a third party.

[0033] 2, for the sake of simplicity, each device and function is shown one by one, but multiple similar devices and functions may be configured in the mobile communication system 1. Specifically, the mobile communication system 1 may be configured with multiple devices and functions such as UE_A10, E-UTRAN80, MME40, SGW35, PGW-U30, PGW-C32, PCRF60, HSS50, 5G AN120, AMF140, UPF130, SMF132, PCF160, and / or UDM150.

[0034] [2. Configuration of each device] Next, the configuration of each device (UE, and / or access network device, and / or core network device) used in each embodiment will be described with reference to the drawings. Each device may be configured as physical hardware, as logical (virtual) hardware configured on general-purpose hardware, or as software. Furthermore, at least a part (including all) of the functions of each device may be configured as physical hardware, logical hardware, or software.

[0035] Note that each memory unit (memory unit_A340, memory unit_B540, memory unit_B740) in each device / function mentioned below is configured with, for example, a semiconductor memory, a solid state drive (SSD), a hard disk drive (HDD), etc. Each memory unit can store not only information originally configured at the time of shipment, but also various information transmitted and received between the device / function and itself (e.g., UE, and / or access network device, and / or core network device, and / or PDN, and / or DN). Each memory unit can also store identification information, control information, flags, parameters, etc. contained in control messages transmitted and received in various communication procedures described below. Each memory unit may also store this information for each UE. Furthermore, when interworking between 5GS and EPS is performed, each memory unit can store control messages and user data transmitted and received between the device / function included in 5GS and / or EPS. In this case, not only those transmitted and received via the N26 interface but also those transmitted and received without via the N26 interface can be stored.

[0036] [2.1. UE Device Configuration] First, an example of the device configuration of UE (User Equipment) will be explained using Figure 3. The UE is composed of a control unit _A300, an antenna 310, a transceiver unit _A320, and a memory unit _A340. The control unit _A300, the transceiver unit _A320, and the memory unit _A340 are connected via a bus. The transceiver unit _A320 is connected to the antenna 310.

[0037] The control unit _A300 is a functional unit that controls the operation and functions of the entire UE. The control unit _A300 realizes various processing in the UE by reading and executing various programs stored in the memory unit _A340 as necessary.

[0038] The transceiver unit _A320 is a functional unit for wireless communication with a base station device (eNB or gNB) in the access network via an antenna. That is, the UE can use the transceiver unit _A320 to transmit and receive user data and / or control information between an access network device, and / or a core network device, and / or a PDN, and / or a DN.

[0039] Explaining in detail with reference to Figure 2, the UE can communicate with a base station device (eNB) in the E-UTRAN via the LTE-Uu interface by using the transceiver unit _A320. The UE can also communicate with a base station device (gNB) in the 5G AN by using the transceiver unit _A320. The UE can also transmit and receive AMF and NAS (Non-Access-Stratum) messages via the N1 interface by using the transceiver unit _A320. However, since the N1 interface is logical, in reality, communication between the UE and the AMF is performed via the 5G AN.

[0040] The memory unit _A340 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the UE. The memory unit _340 may also have the function of storing control information transmitted and received between an access network device, a core network device, and a DN.

[0041] The UE may also be capable of communicating with a satellite equipped with base station device functionality and / or at least some AMF and / or MME functionality.

[0042] [2.2. Base station equipment configuration] Next, an example of the device configuration of a base station device will be described using Figure 4. The base station device may be a gNB, or an eNB, or an en-gNB, or an ng-eNB. Here, the base station device will be described using a gNB as an example. That is, in the following description, gNB may be read as eNB, or an en-gNB, or an ng-eNB. The gNB is composed of a control unit _B500, an antenna 510, a network connection unit _B520, a transceiver unit _B530, and a memory unit _B540. The control unit _B500, the network connection unit _B520, the transceiver unit _B530, and the memory unit _B540 are connected via a bus. The transceiver unit _B530 is connected to the antenna 510.

[0043] The control unit _B500 is a functional unit that controls the operation and functions of the entire gNB. The control unit _B500 realizes various processes in the gNB by reading and executing various programs stored in the memory unit _B540 as necessary.

[0044] The network connection unit _B520 is a functional unit for the gNB to communicate with the AMF and / or UPF. That is, the gNB can send and receive user data and / or control information between the AMF and / or UPF using the network connection unit _B520.

[0045] The transceiver unit _B530 is a functional unit for wireless communication with the UE via the antenna 510. That is, the gNB can transmit and receive user data and / or control information to and from the UE using the transceiver unit _B530.

[0046] 2, a gNB in ​​a 5G AN can communicate with an AMF via an N2 interface by using a network connection unit _B 520, and can communicate with a UPF via an N3 interface, and can communicate with a UE by using a transceiver unit _B 530.

[0047] The memory unit _B540 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the gNB. The memory unit _540 may also have the function of storing control information transmitted and received between the UE, other access network devices (base station devices), core network devices, and DNs.

[0048] The satellite may also have the functionality of a base station device.

[0049] Furthermore, in this specification, a satellite equipped with at least the functions of a base station device may be simply referred to as a satellite or a base station device. Here, the base station device may be referred to as a base station, or may refer to a gNB, eNB, en-gNB, ng-eNB, or an access point accommodated in non-3GPP access (for example, an access point similar to that used in a wireless LAN).

[0050] [2.3. AMF / MME Device Configuration] Next, we will explain example device configurations of AMF and MME, which are core network devices or part of core network functions. Here, we will explain an example device configuration of AMF using Figure 5. Here, we will explain using the AMF as an example, but it may also be read as MME. The AMF is composed of a control unit _B700, a network connection unit _B720, and a memory unit _B740. The control unit _B700, the network connection unit _B720, and the memory unit _B740 are connected via a bus. The AMF may be a node that handles the control plane.

[0051] The control unit _B700 is a functional unit that controls the operation and functions of the entire AMF. The control unit _B700 realizes various processing in the AMF by reading and executing various programs stored in the memory unit _B740 as necessary.

[0052] The network connection unit _B720 is a functional unit for the AMF to connect to a base station device (gNB), and / or SMF, and / or PCF, and / or UDM, and / or SCEF, and / or NSACF in a 5G AN. In other words, the AMF can use the network connection unit _B720 to send and receive user data and / or control information between a base station device (gNB), and / or SMF, and / or PCF, and / or UDM, and / or SCEF in a 5G AN.

[0053] Explaining in detail with reference to FIG. 2, the AMF in the 5GCN can communicate with a gNB via the N2 interface by using the network connection unit _A620, can communicate with a UDM via the N8 interface, can communicate with an SMF via the N11 interface, and can communicate with a PCF via the N15 interface. The AMF can also send and receive NAS messages with a UE via the N1 interface by using the network connection unit _A620. However, since the N1 interface is logical, communication between the UE and the AMF is actually performed via a 5G AN. Furthermore, if the AMF supports the N26 interface, it can communicate with an MME via the N26 interface by using the network connection unit _A620.

[0054] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. required for each operation of the AMF. The memory unit _740 may also have the function of storing control information transmitted and received between the UE, access network devices, other core network devices, and DN.

[0055] The AMF has functions such as exchanging control messages with the RAN using the N2 interface, exchanging NAS messages with the UE using the N1 interface, encrypting and protecting the integrity of NAS messages, registration management (RM) functions, connection management (CM) functions, reachability management functions, mobility management functions for UEs, etc., transferring SM (Session Management) messages between the UE and the SMF, access authentication (Access Authorization) functions, security anchor functionality (SEA), security context management (SCM), supporting the N2 interface for the N3IWF (Non-3GPP Interworking Function), supporting the transmission and reception of NAS signals with the UE via the N3IWF, and authenticating the UE connected via the N3IWF.

[0056] In addition, registration management manages the RM state for each UE. The RM state may be synchronized between the UE and the AMF. The RM state includes an unregistered state (RM-DEREGISTERED state) and a registered state (RM-REGISTERED state). In the RM-DEREGISTERED state, the UE is not registered with the network, and therefore the UE context in the AMF does not have valid location information or routing information for the UE, and therefore the AMF cannot reach the UE. In the RM-REGISTERED state, the UE is registered with the network, and therefore the UE can receive services that require registration with the network. Note that the RM state may also be expressed as a 5GMM state. In this case, the RM-DEREGISTERED state may be expressed as a 5GMM-DEREGISTERED state, and the RM-REGISTERED state may be expressed as a 5GMM-REGISTERED state.

[0057] In other words, 5GMM-REGISTERED may be a state in which each device has established a 5GMM context or a PDU session context. When each device is 5GMM-REGISTERED, UE_A10 may start transmitting and receiving user data and control messages, or may respond to paging. Furthermore, when each device is 5GMM-REGISTERED, UE_A10 may perform registration procedures other than the registration procedure for initial registration, and / or service request procedures.

[0058] Furthermore, 5GMM-DEREGISTERED may be a state in which each device has not established a 5GMM context, a state in which UE_A10's location information is not known to the network, or a state in which UE_A10 is unreachable from the network. Note that when each device is 5GMM-DEREGISTERED, UE_A10 may initiate a registration procedure or may establish a 5GMM context by performing the registration procedure.

[0059] In addition, connection management manages the CM state for each UE. The CM state may be synchronized between the UE and the AMF. The CM state includes a non-connected state (CM-IDLE state) and a connected state (CM-CONNECTED state). In the CM-IDLE state, the UE is in the RM-REGISTERED state but does not have a NAS signaling connection established with the AMF via the N1 interface. In the CM-IDLE state, the UE does not have an N2 interface connection or an N3 interface connection. On the other hand, in the CM-CONNECTED state, the UE has a NAS signaling connection established with the AMF via the N1 interface. In the CM-CONNECTED state, the UE may have an N2 interface connection and / or an N3 interface connection.

[0060] Furthermore, in connection management, the CM state in 3GPP access and the CM state in non-3GPP access may be managed separately. In this case, the CM state in 3GPP access may include a non-connected state in 3GPP access (CM-IDLE state over 3GPP access) and a connected state in 3GPP access (CM-CONNECTED state over 3GPP access). Furthermore, the CM state in non-3GPP access may include a non-connected state in non-3GPP access (CM-IDLE state over non-3GPP access) and a connected state in non-3GPP access (CM-CONNECTED state over non-3GPP access). Note that the non-connected state may be expressed as an idle mode, and the connected state mode may be expressed as a connected mode.

[0061] The CM state may be expressed as a 5GMM mode. In this case, the unconnected state may be expressed as a 5GMM-IDLE mode, and the connected state may be expressed as a 5GMM-CONNECTED mode. Furthermore, the unconnected state in 3GPP access may be expressed as a 5GMM-IDLE mode over 3GPP access, and the connected state in 3GPP access may be expressed as a 5GMM-CONNECTED mode over 3GPP access. Furthermore, the unconnected state in non-3GPP access may be expressed as 5GMM unconnected mode in non-3GPP access (5GMM-IDLE mode over non-3GPP access), and the connected state in non-3GPP access may be expressed as 5GMM connected mode in non-3GPP access (5GMM-CONNECTED mode over non-3GPP access). Note that the 5GMM unconnected mode may be expressed as idle mode, and the 5GMM connected mode may be expressed as connected mode.

[0062] In addition, one or more AMFs may be placed in the core network_B. In addition, the AMF may be a Network Function (NF) that manages one or more Network Slice Instances (NSIs). In addition, the AMF may be a Common Control Plane Network Function (CCNF) shared among multiple NSIs.

[0063] In addition, the N3IWF is a device and / or function located between the non-3GPP access and the 5GCN when the UE connects to the 5GS via the non-3GPP access.

[0064] Furthermore, the satellite may have at least some of the MME functionality.

[0065] [2.4. SMF / PGW Device Configuration] Next, an example of the device configuration of an SMF, which is part of a core network device or core network function, will be explained using Figure 5. Here, we will use the SMF as an example, but it may also be interpreted as a PGW or PGW-C. The SMF is composed of a control unit _B700, a network connection unit _B720, and a memory unit _B740. The control unit _B700, the network connection unit _B720, and the memory unit _B740 are connected via a bus. The SMF may be a node that handles the control plane.

[0066] The control unit _B700 is a functional unit that controls the operation and functions of the entire SMF.The control unit _B700 realizes various processing in the SMF by reading and executing various programs stored in the memory unit _B740 as 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 between the AMF, and / or UPF, and / or PCF, and / or UDM, and / or NSACF.

[0068] Explaining in more detail with reference to Figure 2, the SMF in the 5GCN can communicate with the AMF via the N11 interface, with the UPF via the N4 interface, with the PCF via the N7 interface, and with the UDM via the N10 interface by using the network connection unit _A620.

[0069] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. required for each operation of the SMF.

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

[0071] In addition, the memory unit _740 may have the function of storing control information transmitted and received between the UE, access network devices, other core network devices, and DN.

[0072] [2.5. UPF / PGW / SGW Device Configuration] Next, an example of the device configuration of the UPF, which is one of the core network devices or core network functions, will be explained using Figure 5. Here, we will use the UPF as an example, but it may also be interpreted as PGW, PGW-U, or SGW. The PGW may combine the functions of both PGW-C and PGW-U. The UPF is composed of a control unit _B700, a network connection unit _B720, and a memory unit _B740. The control unit _B700, the network connection unit _B720, and the memory unit _B740 are connected via a bus. The UPF may be a node that handles the control plane.

[0073] The control unit _B700 is a functional unit that controls the operation and functions of the entire UPF. The control unit _B700 realizes various processes in the UPF by reading and executing various programs stored in the memory unit _B740 as needed.

[0074] The network connection unit _B720 is a functional unit for the UPF to connect to a base station device (gNB), and / or SMF, and / or DN within the 5G AN. In other words, the UPF can use the network connection unit _B720 to transmit and receive user data and / or control information between the base station device (gNB), and / or SMF, and / or DN within the 5G AN.

[0075] Explaining in more detail with reference to Figure 2, a UPF in a 5GCN can communicate with a gNB via the N3 interface, with an SMF via the N4 interface, with a DN via the N6 interface, and with other UPFs via the N9 interface by using the network connection unit _A620.

[0076] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. required for each operation of the UPF.

[0077] The UPF has functions such as an anchor point for intra-RAT mobility or inter-RAT mobility, an external PDU session point for interconnecting to DNs (i.e., a gateway between DNs and core network_B that forwards user data), packet routing and forwarding, an UL CL (Uplink Classifier) ​​function that supports routing of multiple traffic flows to one DN, a branching point function that supports multi-homed PDU sessions, a QoS (Quality of Service) processing function for the user plane, an uplink traffic verification function, downlink packet buffering, and a function to trigger downlink data notifications.

[0078] The UPF may also be a gateway for IP communication and / or non-IP communication. The UPF may also have a function for forwarding IP communication and a function for converting non-IP communication and IP communication. Furthermore, multiple gateways may be gateways that connect the core network_B to a single DN. The UPF may also have connectivity with other NFs and may be connected to each device via other NFs.

[0079] In addition, the memory unit _740 may have the function of storing control information transmitted and received between the UE, access network devices, other core network devices, and DN.

[0080] [2.6. Description of other devices and / or functions and identification information in this embodiment] Next, other devices and / or functions and identification information will be described.

[0081] A network refers to at least a portion of an access network _B, a core network _B, and a DN. Furthermore, one or more devices included in at least a portion of an access network _B, a core network _B, and a DN may be referred to as a network or a network device. In other words, when a network transmits, receives, and / or processes messages, it may mean that devices within the network (network devices and / or control devices) transmit, receive, receive, and / or process messages. Conversely, when a device within the network transmits, receives, receives, and / or processes messages, it may mean that the network transmits, receives, receives, and / or processes messages.

[0082] The user plane (also referred to as UP) refers to user data transmitted and received between a UE and a network. The UP may be a communication path for transmitting and receiving user data and may be composed of multiple bearers. The UP may be transmitted and received using a PDN connection in the case of 4G, or a PDU session in the case of 5G. In the case of EPS, the UP 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. In the case of 5GS, the UP 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. The UP may also be expressed as the U-Plane.

[0083] Furthermore, a control plane (also referred to as CP) refers to a control message transmitted and received to control communication of a UE, etc. The CP may be a communication path for transmitting and receiving control messages, and may be composed of multiple bearers. The CP may be transmitted and received using a NAS (Non-Access-Stratum) signaling connection between the UE and the MME. The CP may be transmitted and received using a NAS (Non-Access-Stratum) signaling connection between the UE and the AMF. In the case of EPS, the CP may be transmitted and received using the LTE-Uu interface and the S1-MME interface. In the case of 5GS, the CP may be transmitted and received using the interface between the UE and the NG RAN and the N2 interface. The CP may be expressed as a control plane or a C-Plane.

[0084] Furthermore, the U-Plane (User Plane; UP) may be a communication path for transmitting and receiving user data and may be composed of multiple bearers. Furthermore, the C-Plane (Control Plane; CP) may be a communication path for transmitting and receiving control messages and may be composed of multiple bearers.

[0085] In addition, an MM (Mobility Management) message may be a control message transmitted and received between a UE and an AMF or an MME during an MM procedure, or may be an NAS message (also referred to as an NAS MM message).

[0086] The MM procedure (also referred to as a procedure for MM) may include a UE-initiated registration procedure, a UE- or AMF- (or network-) initiated de-registration procedure, an AMF- (or network-) initiated generic UE configuration update procedure, a UE-initiated service request procedure, an AMF- (or network-) initiated paging procedure, and an AMF- (or network-) initiated notification procedure. The MM procedure may also include a UE-initiated attach procedure, a UE- or MME- (or network-) initiated detach procedure, a UE-initiated tracking area updating procedure (also referred to as a TAU procedure), a UE-initiated service request procedure, and an MME- (or network-) initiated paging procedure.

[0087] In this case, in the registration procedure, the UE may send a Registration Request message to the AMF and receive a Registration Accept message or a Registration Reject message from the AMF that has received the Registration Request message. Here, the AMF may send a Registration Accept message if it approves the registration request from the UE, or may send a Registration Reject message if it does not approve the registration request.

[0088] In addition, in a de-registration procedure initiated by the UE, the UE may send a de-registration request message to the AMF and receive a de-registration accept message sent from the AMF that receives the message.

[0089] In addition, in a deregistration procedure initiated by the AMF (or network), the AMF may send a deregistration request message to the UE and receive a deregistration acceptance message sent from the UE that receives the message.

[0090] In addition, in the generic UE configuration update procedure, the AMF may send a configuration update command message to the UE and receive a configuration update complete message sent from the UE that receives the message.

[0091] In addition, in the service request procedure, the UE may send a service request message or a control plane service request message to the AMF, and may receive a service accept message or a service reject message from the AMF that has received the message. Here, the AMF may send a service accept message if it allows the request from the UE, or may send a service reject message if it does not allow the request.

[0092] In addition, in the paging procedure, the AMF sends a paging request (Request Paging) to the base station, and the base station that receives this sends a paging message to the UE, and the UE that receives this sends a service request message, or a CP service request message, or a registration request message to the AMF, which the AMF may receive.

[0093] In addition, in the notification procedure, the AMF may send a notification message to the UE and receive a notification response message, or a service request message, or a CP service request message, or a registration request message sent from the UE that received the notification message.

[0094] In the attach procedure, the UE may transmit an Attach Request message and receive an Attach Accept message or an Attach Reject message from the MME that has received the Attach Request message. Here, the MME may transmit an Attach Accept message if it accepts the request from the UE, or may transmit an Attach Reject message if it does not accept the request. In addition, when the UE receives the Attach Accept message, the UE may transmit an Attach Complete message, which the MME may receive.

[0095] In addition, in a detach procedure initiated by the UE, the UE may transmit a Detach Request message and receive a Detach Accept message transmitted from the MME that has received the Detach Request message.

[0096] In addition, in a detach procedure initiated by the MME (or the network), the MME may send a Detach Request message and receive a Detach Accept message sent from the UE that has received the Detach Request message.

[0097] In the tracking area update procedure, the UE may transmit a Tracking Area Update (also referred to as TAU) Request message and may receive a Tracking Area Update Accept message or a Tracking Area Update Reject message transmitted from the UE upon receiving the message. Here, the MME may transmit a Tracking Area Update Accept message if it accepts the request from the UE, or may transmit a Tracking Area Update Reject message if it does not accept the request. Furthermore, when the UE receives the Tracking Area Update Accept message, the UE may transmit a Tracking Area Update Complete message, which the MME may receive.

[0098] In addition, in the service request procedure, the UE may send a Service Request message, a Control Plane Service Request message, or an Extended Service Request message to the MME, and may receive a Service Accept message or a Service Reject message from the MME that has received the message. Here, the MME may send a Service Accept message if it approves the request from the UE, or may send a Service Reject message if it does not approve the request.

[0099] In addition, in the paging procedure, the MME transmits a paging request (Request Paging) message to the base station, and the base station, upon receiving the paging message, transmits a paging message to the UE, and the UE, upon receiving the paging message, transmits a service request message, a CP service request message, or an extended service request message to the MME, which the MME may receive.

[0100] In addition, an SM (Session Management) message (also referred to as a NAS (Non-Access-Stratum) SM message) may be a control message transmitted and received between a UE and an SMF via an AMF during an SM procedure, or may be an NAS message (also referred to as a NAS SM message).

[0101] In addition, the SM procedure (also referred to as the procedure for SM) may include a UE-initiated PDU Session Establishment procedure, a UE- or SMF- (or network-) initiated PDU Session Modification procedure, and a UE-requested PDU Session Release procedure initiated by the UE or SMF- (or network-) initiated PDU Session Release procedure. The SM procedure may also include a UE initiated PDN connectivity procedure, a UE initiated PDN disconnectivity procedure, a UE initiated bearer resource allocation procedure, a UE initiated bearer resource modification procedure, a NW initiated Default EPS bearer context activation procedure, a NW initiated Dedicated EPS bearer context activation procedure, a NW initiated EPS bearer context modification procedure, and a NW initiated EPS bearer context deactivation procedure.

[0102] In the PDU session establishment procedure, the UE may send a PDU Session Establishment Request message to the SMF and receive a PDU Session Establishment Accept message or a PDU Session Establishment Reject message from the SMF that has received the PDU Session Establishment Request message. The SMF may send a PDU Session Establishment Accept message if it accepts the PDU session establishment request from the UE, or may send a PDU Session Establishment Reject message if it does not accept the PDU session establishment request.

[0103] In addition, in the UE-initiated PDU session modification procedure, the UE transmits a PDU Session Modification Request message to the SMF, and upon receiving the PDU Session Modification Request message, the SMF either executes the SMF-initiated PDU session modification procedure or transmits a PDU Session Modification Reject message to the UE, which the UE receives. Here, the SMF may execute the SMF-initiated PDU session modification procedure if it accepts the PDU session modification request from the UE, or transmit a PDU Session Modification Reject message if it rejects the request.

[0104] In addition, in a PDU session modification procedure initiated by the SMF (or the network), the SMF may send a PDU Session Modification Command message to the UE and receive a PDU Session Modification Complete message or a PDU Session Modification Command Reject message from the UE that has received the PDU Session Modification Command. Here, the UE may send a PDU Session Modification Complete message if it accepts the PDU session modification instruction from the SMF, or may send a PDU Session Modification Command Reject message if it does not accept it.

[0105] In addition, in the UE-initiated PDU session release procedure, the UE transmits a PDU Session Release Request message to the SMF, and upon receiving the PDU Session Release Request message, the SMF either executes the SMF-initiated PDU session release procedure or transmits a PDU Session Release Reject message to the UE, which the UE receives. Here, the SMF may execute the SMF-initiated PDU session release procedure if it accepts the PDU session release request from the UE, or may transmit a PDU Session Release Reject message if it rejects the request.

[0106] In addition, in a PDU session release procedure initiated by the SMF (or the network), the SMF may send a PDU Session Release Command message to the UE and receive a PDU Session Release Complete message from the UE that has received the PDU Session Release Command message.

[0107] In the PDN connectivity procedure, the UE may send a PDN Connectivity Request message to the MME and may receive an Activate Default EPS Bearer Context Request message or a PDN Connectivity Reject message from the MME upon receiving the PDN Connectivity Request message. Here, the MME may send an Activate Default EPS Bearer Context Request message if it approves the request from the UE, or may send a PDN Connectivity Reject message if it does not approve the request.

[0108] In the PDN disconnection procedure, the UE may send a PDN Disconnect Request message to the MME and may receive a Deactivate EPS Bearer Context Request message or a PDN Disconnect Reject message from the MME upon receiving the PDN Disconnect Request message. Here, the MME may send a Deactivate EPS Bearer Context Request message if it approves the request from the UE, or may send a PDN Disconnect Reject message if it does not approve the request.

[0109] In the bearer resource allocation procedure, the UE may send a Bearer Resource Allocation Request message to the MME, and may receive an Activate Dedicated EPS Bearer Context Request message, a Modify EPS Bearer Context Request message, or a Bearer Resource Allocation Reject message from the MME upon receiving the message. Here, the MME may send an Activate Dedicated EPS Bearer Context Request message or a Modify EPS Bearer Context Request message if it approves the request from the UE, or may send a Bearer Resource Allocation Reject message if it does not approve the request.

[0110] In the bearer resource modification procedure, the UE may send a Bearer Resource Modification Request message to the MME, and may receive an Activate Dedicated EPS Bearer Context Request message, a Modify EPS Bearer Context Request message, a Deactivate EPS Bearer Context Request message, or a Bearer Resource Modification Reject message from the MME upon receiving the message. Here, the MME may send an Activate Dedicated EPS Bearer Context Request message, a Modify EPS Bearer Context Request message, or a Deactivate EPS Bearer Context Request message if it approves the request from the UE, or may send a Bearer Resource Modification Reject message if it does not approve the request.

[0111] In the default EPS bearer context activation procedure, the MME may send an Activate Default EPS Bearer Context Request message to the UE, and may receive an Activate Default EPS Bearer Context Accept message or an Activate Default EPS Bearer Context Reject message from the UE that has received the request. Here, the UE may send an Activate Default EPS Bearer Context Accept message if it accepts the request from the MME, or may send an Activate Default EPS Bearer Context Reject message if it does not accept the request.

[0112] In the dedicated EPS bearer context activation procedure, the MME may send an Activate Dedicated EPS Bearer Context Request message to the UE, and may receive an Activate Dedicated EPS Bearer Context Accept message or an Activate Dedicated EPS Bearer Context Reject message from the UE upon receiving the request. Here, the UE may send an Activate Dedicated EPS Bearer Context Accept message if it accepts the request from the MME, or may send an Activate Dedicated EPS Bearer Context Reject message if it does not accept the request.

[0113] In the EPS bearer context modification procedure, the MME may send a Modify EPS Bearer Context Request message to the UE, and may receive a Modify EPS Bearer Context Accept message or a Modify EPS Bearer Context Reject message from the UE that has received the message. Here, the UE may send a Modify EPS Bearer Context Accept message if it accepts the request from the MME, or may send a Modify EPS Bearer Context Reject message if it does not accept the request.

[0114] In addition, in the EPS bearer context deactivation procedure, the MME may send a Deactivate EPS Bearer Context Request message to the UE and receive a Deactivate EPS Bearer Context Accept message from the UE that has received the message.

[0115] In addition, the 5GS (5G System) service may be a connection service provided using the core network _B 190. Furthermore, the 5GS service may be a service different from the EPS service or may be a service similar to the EPS service.

[0116] In addition, non-5GS services may be services other than 5GS services, and may include EPS services and / or non-EPS services.

[0117] Furthermore, 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 indicates that data will be sent and received using IPv4. If IPv6 is specified, it indicates that data will be sent and received using IPv6. If IPv4v6 is specified, it indicates that data will be sent and received using IPv4 or IPv6. If non-IP is specified, it indicates that communication will not be via IP, but via a communication method other than IP.

[0118] Furthermore, a PDU (Protocol Data Unit) session can be defined as an association between a DN that provides a PDU connectivity service and a UE, but may also be connectivity established between a UE and an external gateway. In 5GS, a UE can transmit and receive user data to and from a DN by establishing a PDU session via an access network _B and a core network _B. Here, this external gateway may be a UPF, SCEF, or the like. The UE can transmit and receive user data to and from a device such as an application server located in the DN using the PDU session.

[0119] Furthermore, an MA PDU session may be a PDU session that provides PDU connectivity services using 3GPP access and / or non-3GPP access.

[0120] Each device (UE, and / or access network device, and / or core network device) may associate one or more pieces of identification information with a PDU session and manage them. These pieces of identification information may include one or more of the DNN, QoS rule, PDU session type, application identification information, NSI identification information, and access network identification information, or may further include other information. Furthermore, when multiple PDU sessions are established, the identification information associated with the PDU sessions may be the same or different.

[0121] Furthermore, the DNN (Data Network Name) may be identification information for identifying a core network and / or an external network such as a DN. Furthermore, the DNN can also be used as information for selecting a gateway such as PGW_A30 / UPF_A235 that connects the core network B190. Furthermore, the DNN may be equivalent to an APN (Access Point Name).

[0122] Furthermore, the PDU (Protocol Data Unit / Packet Data Unit) session type indicates the type of PDU session, and can be IPv4, IPv6, Ethernet, or Unstructured. If IPv4 is specified, it indicates that data is transmitted and received using IPv4. If IPv6 is specified, it indicates that data is transmitted and received using IPv6. If Ethernet is specified, it indicates that Ethernet frames are transmitted and received. Furthermore, Ethernet may indicate that communication using IP is not performed. If Unstructured is specified, it indicates that data is transmitted and received to an application server or the like in a DN using Point-to-Point (P2P) tunneling technology. As the P2P tunneling technology, for example, UDP / IP encapsulation technology may be used. In addition to the above, the PDU session type may also include IP. IP can be specified if the UE can use both IPv4 and IPv6.

[0123] Furthermore, a PDN connection can be defined as an association between a PDN represented by an APN and a UE, but may also be connectivity established between a UE and an external gateway. By establishing a PDN connection via an access network _A and a core network _A in the EPS, the UE can transmit and receive user data to and from the PDN using the PDN connection. Here, this external gateway may be a PGW, SCEF, etc. The UE can transmit and receive user data to and from devices such as an application server located in the PDN using the PDN connection.

[0124] A PLMN (Public Land Mobile Network) is a communication network that provides mobile radio communication services. A PLMN is a network managed by an operator, which is a communications carrier, and the operator can be identified by a PLMN ID. A PLMN that matches the MCC (Mobile Country Code) and MNC (Mobile Network Code) of a UE's IMSI (International Mobile Subscriber Identity) may be a Home PLMN (HPLMN). Furthermore, the UE may store an Equivalent HPLMN list in its USIM to identify one or more Equivalent HPLMNs (EPLMNs). A PLMN different from the HPLMN and / or EPLMN may be a Visited PLMN (VPLMN). A PLMN to which a UE has successfully registered may be a Registered PLMN (RPLMN). Note that a service provided by a PLMN may be referred to as a PLMN service, and a service provided by an SNPN may be referred to as an SNPN service.

[0125] A tracking area is a single or multiple ranges managed by the core network that can be represented by the location information of UE_A10. A tracking area may be composed of multiple cells. Furthermore, a tracking area may be an area in which control messages such as paging are broadcast, or an area in which UE_A10 can move without performing a handover procedure. Furthermore, a tracking area (also referred to as a Tracking Area, TA) may be a routing area, a location area, or anything similar. A tracking area may be identified by a Tracking Area Identity (TAI) consisting of a Tracking Area Code (TAC) and a PLMN.

[0126] A registration area (also referred to as a registration area) is a set of one or more TAs assigned to a UE by the AMF. Note that while UE_A10 is moving within one or more TAs included in the registration area, it may be able to move without sending or receiving signals for tracking area update. In other words, a registration area may be a group of information indicating areas in which UE_A10 can move without performing a tracking area update procedure. A registration area may be identified by a TAI list consisting of one or more TAIs.

[0127] The UE ID is information for identifying a UE. Specifically, for example, the UE ID may be a Subscription Concealed Identifier (SUCI), a Subscription Permanent Identifier (SUPI), a Globally Unique Temporary Identifier (GUTI), an International Mobile Subscriber Identity (IMEI), an IMEISV (IMEI Software Version), or a Temporary Mobile Subscriber Identity (TMSI). Alternatively, the UE ID may be other information set in an application or a network. Furthermore, the UE ID may be information for identifying a user.

[0128] Also, a UE in single registration mode has only one active MM state. That is, a UE in single registration mode can only be active in either the RM state (5GMM state) in 5GC or the EMM state in EPC. Also, a UE in single registration mode is in 5GC NAS mode when connecting to 5GC, and is in EPC NAS mode when connecting to EPC. Also, since a UE in single registration mode can only be registered to either 5GC or EPC, when moving between EPC and 5GC, it is necessary to map EPS-GUTI (also referred to as 4G-GUTI) and 5G-GUTI.

[0129] In addition, a UE in dual registration mode may be able to independently register with 5GC and EPC. A UE in dual registration mode can independently maintain 5G-GUTI and EPS-GUTI (also referred to as 4G-GUTI).

[0130] An attach attempt counter may be a counter used in a UE and / or a satellite and / or a network to limit the number of attach attempts (i.e., the number of times an attach procedure is performed). The initial value of the attach attempt counter may be 0. The maximum value of the attach attempt counter may be 5 or a different value. The value of the attach attempt counter may be incremented (i.e., increased by 1) each time an attach procedure is performed and an attach reject message is received. The value of the attach attempt counter may be incremented if it is not set to the maximum value. The value of the attach attempt counter may be reset when the UE is powered on or when a USIM is inserted, when the attach procedure is successfully completed, when the attach procedure is rejected with a predefined cause value (i.e., when the UE receives an attach reject message with a predefined cause value), when a network-initiated detach procedure is completed with a predefined cause value (i.e., when the UE receives a detach request message with a predefined cause value), or when a new PLMN is selected. Here, resetting the value of the attach attempt counter may mean resetting the value to an initial value. In this specification, the value of the attach attempt counter may be simply referred to as an attach attempt counter. In this specification, the attach attempt counter may be simply referred to as a first UE implementation specific attempt counter.

[0131] A tracking area updating attempt counter may be a counter used in a UE, a satellite, and / or a network to limit the number of tracking area update attempts (i.e., the number of times a tracking area update procedure is performed). In this specification, the tracking area update attempt counter may also be referred to as a TAU attempt counter. The initial value of the TAU attempt counter may be 0. The maximum value of the TAU attempt counter may be 5 or a different value. The value of the TAU attempt counter may be incremented (i.e., increased by 1) each time a TAU procedure is performed and a TAU rejection message is received. The value of the TAU attempt counter may be incremented if it is not set to the maximum value. The value of the TAU attempt counter may be reset when the TAU procedure is successfully completed, when the TAU procedure is rejected with a predetermined cause value (in other words, when the UE receives a TAU rejection message including a predetermined cause value), or when a new PLMN is selected. Here, resetting the value of the TAU attempt counter may mean resetting the value to its initial value. In this specification, the value of the TAU attempt counter may be simply referred to as the TAU attempt counter, and in this specification, the TAU attempt counter may be referred to as a second UE implementation specific attempt counter.

[0132] Furthermore, a service request attempt counter may be a counter used in a UE, a satellite, and / or a network to limit the number of service request attempts (i.e., the number of times a service request procedure is executed). The initial value of the TAU attempt counter may be 0. The maximum value of the service request attempt counter may be 5 or a different value. The value of the service request attempt counter may be incremented (i.e., increased by 1) each time a service request procedure is executed and a service rejection message is received. The value of the service request attempt counter may be incremented if it is not set to the maximum value. The value of the service request attempt counter may be reset when the service request procedure is successfully completed, when the service request procedure is rejected with a predetermined cause value (in other words, when the UE receives a service rejection message including a predetermined cause value), or when the UE transitions to an EMM-DEREGISTERED state. Here, resetting the value of the service request attempt counter may mean resetting the value to its initial value. In this specification, the value of the service request attempt counter may be simply referred to as the service request attempt counter. In addition, the service request attempt counter may be referred to herein as a third UE implementation specific attempt counter.

[0133] A registration attempt counter may be a counter used in a UE, a satellite, and / or a network to limit the number of registration attempts (i.e., the number of times a registration procedure is performed). The initial value of the registration attempt counter may be 0. The maximum value of the registration attempt counter may be 5 or a different value. The value of the registration attempt counter may be incremented (i.e., increased by 1) each time a registration procedure is performed and a registration reject message is received. The value of the registration attempt counter may be incremented if it is not set to the maximum value. The value of the registration attempt counter may be reset when the UE is powered on or a USIM is inserted, when the registration procedure is successfully completed, when the registration procedure is rejected with a predetermined cause value (i.e., when the UE receives a registration reject message with a predetermined cause value), when a network-initiated de-registration procedure is completed with a predetermined cause value (i.e., when the UE receives a de-registration request message with a predetermined cause value), or when a new PLMN is selected. Here, resetting the value of the registration attempt counter may mean resetting the value to its initial value. In addition, in this specification, the value of the registration attempt counter may be simply referred to as the registration attempt counter. In addition, in this specification, the registration attempt counter may be simply referred to as a fourth UE implementation specific attempt counter. In addition, in this specification, the first UE implementation specific attempt counter, the second UE implementation specific attempt counter, the third UE implementation specific attempt counter, and the fourth UE implementation specific attempt counter may be simply referred to as UE implementation specific attempt counters.

[0134] Furthermore, the EPS update status (also referred to as EPS update (EU) status) may indicate the status of the UE in EPS. The EPS update status may be stored in a non-volatile memory in the USIM or ME. The EPS update status may be updated after performing an attach procedure, a TAU procedure, a detach procedure, a service request procedure, or a paging procedure. The EPS update status may also be updated when the back-off timer (T3346) of the NAS-level mobility management congestion control is changed to a TAI that is not in the TAI list during operation.

[0135] Additionally, the EPS update states may include EU1, EU2, and EU3, where EU1 may be referred to as "EU1: UPDATED," EU2 may be referred to as "EU2: NOT UPDATED," and EU3 may be referred to as "EU3: ROAMING NOT ALLOWED."

[0136] EU1 may also indicate that the last attach or attach procedure attempt was successful, or that the last TAU ​​or TAU procedure attempt was successful.

[0137] EU2 may also indicate that the last attach or attempted attach procedure failed procedurally. For example, this may occur when the UE receives an attach rejection message from the MME, or when the UE does not receive a response message (attach accept message or attach rejection message) from the MME. EU2 may also indicate that the last TAU ​​or attempted TAU procedure failed procedurally. For example, this may occur when the UE receives a TAU rejection message from the MME, or when the UE does not receive a response message (TAU accept message or TAU rejection message) from the MME. EU2 may also indicate that the last service request or attempted service request procedure failed procedurally. For example, this may occur when the UE receives a service rejection message from the MME, or when the UE does not receive a response message (service accept message or service rejection message) from the MME.

[0138] The EU3 may also indicate that the last attach or attach procedure attempt was successful but the answer or response from the MME was negative due to roaming or subscription restrictions.The EU3 may also indicate that the last TAU ​​or TAU procedure attempt was successful but the answer or response from the MME was negative due to roaming or subscription restrictions.The EU3 may also indicate that the last service request or service request procedure attempt was successful but the answer or response from the MME was negative due to roaming or subscription restrictions.

[0139] Furthermore, the 5GS update status (also referred to as 5U) may indicate the status of the UE in 5GS. The 5GS update status may be stored in non-volatile memory in the USIM or ME. The 5GS update status may be updated after performing a registration procedure, a network initiated de-registration procedure, a service request procedure, a paging procedure, etc. The 5GS update status may also be updated when the back-off timer (T3346) of the NAS level mobility management congestion control is changed to a TAI that does not belong to the current registration area while in operation.

[0140] The 5GS update states may include 5U1, 5U2, and 5U3, where 5U1 may be referred to as "5U1: UPDATED," 5U2 may be referred to as "5U2: NOT UPDATED," and 5U3 may be referred to as "5U3: ROAMING NOT ALLOWED."

[0141] 5U1 may also indicate that the last registration or registration procedure attempt was successful.

[0142] 5U2 may also indicate that the last registration or registration procedure attempt has procedurally failed. For example, this may occur when the UE receives a registration rejection message from the AMF, or when the UE does not receive a response message (a registration accept message or a registration rejection message) from the AMF. 5U2 may also indicate that the last service request or service request procedure attempt has procedurally failed. For example, this may occur when the UE receives a service rejection message from the AMF, or when the UE does not receive a response message (a service accept message or a service rejection message) from the AMF.

[0143] 5U3 may also indicate that the last registration or registration procedure attempt was performed correctly, but the answer or response from the AMF was negative due to roaming or subscription restrictions. 5U3 may also indicate that the last service request or service request procedure attempt was performed correctly, but the answer or response from the AMF was negative due to roaming or subscription restrictions.

[0144] The GUTI is a UE identifier used in EPS and is intended to prevent the permanent identifiers of the UE or user from being revealed. The GUTI consists of a Globally Unique MME Identifier (GUMMEI), which uniquely identifies the MME that assigned the GUTI, and a Temporary Mobile Subscriber Identity (M-TMSI), which uniquely identifies the UE within that MME. The GUMMEI consists of a Mobile Country Code (MCC), a Mobile Network Code (MNC), and an MME identifier. The MME identifier consists of a 16-bit MME Group ID and an 8-bit MME Code. The M-TMSI is 32 bits long.

[0145] 5G-GUTI is a UE identifier used in 5GS, and is intended to prevent the permanent identifiers of the UE or user from being revealed. 5G-GUTI consists of GUAMI, an identifier that uniquely identifies the AMF to which 5G-GUTI is assigned, and 5G-TMSI, an identifier that uniquely identifies the UE within that AMF. GUAMI consists of MCC, MNC, and AMF identifier (AMF Identifier). The AMF Identifier consists of an 8-bit AMF Region ID, a 10-bit AMF Set ID, and a 6-bit AMF Pointer. The 5G-TMSI is 32 bits long.

[0146] The last visited registered TAI (Tracking Area Identity) may be a TAI included in a TAI list or registration area registered by the UE in the network, and may be an identifier that identifies the TA last visited by the UE. If the cell is a satellite cell or a satellite NG-RAN cell that broadcasts multiple TAIs, the last visited registered TAI may be a TAI included in a TAI list or registration area registered by the UE in the network, and may be the TAI last selected by the UE as the current TA.

[0147] Furthermore, the service link may be a wireless link between the UE and the NTN payload. The feeder link may be a wireless link between the NTN gateway and the NTN payload. The NTN gateway may be an earth station located on the Earth's surface that provides connectivity to the NTN payload using a feeder link. The NTN payload may be a network node mounted on a satellite or a high altitude platform station (HAPS) that provides connectivity between the service link and the feeder link. In this specification, the NTN payload may refer to a satellite, and the NTN payload may also be referred to as a satellite.

[0148] Store and forward (S&F) satellite operation may refer to an operation or mode of operation in which a serving satellite provides communication services to a UE during a period and / or geographic area where the serving satellite is not simultaneously connected to a terrestrial network via a feeder link or an inter-satellite link (ISL). Store and forward satellite operation may also refer to an operation or mode of operation without either a service link, which is connectivity between the UE and the satellite, or a feeder link, which is connectivity between the satellite and the network. In other words, store and forward satellite operation may refer to an operation or mode of operation in which the UE and / or satellite and / or network have service link connectivity but no feeder link connectivity. Store and forward satellite operation may also refer to an operation or mode of operation in which the UE and / or satellite and / or network have feeder link connectivity but no service link connectivity.

[0149] Also, in the case of store and forward satellite operations, in the case of uplink (also referred to as UL), store may mean storing UL information from the UE in a storage medium onboard the satellite, and forward may mean forwarding the stored UL information to the terrestrial network.

[0150] Also, in the case of store and forward satellite operations, in the case of downlink (DL), store may mean storing DL information from the terrestrial network in a storage medium mounted on the satellite, and forward may mean forwarding the stored DL information to the UE.

[0151] Store and forward satellite operation may also be referred to herein as S&F, S&F operation, S&F mode, S&F operating mode, S&F satellite operation, S&F satellite operating mode, and the like.

[0152] Normal satellite operation may be an operation or mode of operation different from S&F satellite operation. Normal satellite operation may also be an operation or mode of operation with service link connectivity and feeder link connectivity. Normal satellite operation may also be an operation or mode of operation without the above-described store and forward. Normal satellite operation may also be an operation or mode of operation in which a serving satellite provides communication services to a UE during a period and / or geographic area while simultaneously connecting to a terrestrial network via a feeder link or an inter-satellite link. Normal satellite operation may also be referred to herein as normal operation, normal mode, normal operating mode, normal satellite operating mode, normal operating function, default satellite operation, or default satellite operating mode.

[0153] A serving satellite may be a satellite that provides a satellite connection to a UE. A serving satellite may be, for example, a satellite that provides a serving cell. Depending on the satellite's orbit, a serving satellite may be able to cover a geographic area for a limited period of time. In other words, a UE with a serving satellite may be able to communicate via the satellite, and a UE without a serving satellite may not be able to communicate via the satellite. A serving satellite operating in S&F mode may not have feeder link connectivity.

[0154] UE-Satellite-UE Communication may also refer to communication between UEs within range of one or more serving satellites, or may refer to communication between UEs using a satellite connection such that user traffic (also referred to as user data) does not pass through a terrestrial segment (e.g., including a core network).

[0155] The UE, and / or base station, and / or NW (for example, MME, or SGW, or PGW, or AMF, or SMF, or UPF, etc., the same applies below) may store information in advance and generate new information as needed. Furthermore, when such information is transmitted and received between them, the receiving party may store the received information and perform operations based on that information.

[0156] Furthermore, the UE, and / or the satellite, and / or the NW may operate in the S&F mode or in the normal mode.

[0157] In addition, for simplicity, the case where the UE, and / or satellite, and / or NW operates in S&F mode may be abbreviated as operating in S&F mode (not operating in normal mode), etc.

[0158] In addition, for simplicity, the case where the UE, and / or satellite, and / or NW operates in normal mode may be abbreviated as operating in normal mode (not operating in S&F mode), etc.

[0159] Also, in this specification, a satellite may include a base station device, and may further include an MME and / or an AMF. An MME onboard a satellite may be referred to as an MME-onboard, and an MME located on the ground may be referred to as an MME-ground. In other words, the MME function may be divided into an MME-onboard and an MME-ground. An AMF onboard a satellite may be referred to as an AMF-onboard, and an AMF located on the ground may be referred to as an AMF-ground. In other words, the AMF function may be divided into an AMF-onboard and an AMF-ground.

[0160] Furthermore, the MME-onboard may be an MME having at least some or all of the MME functions. The MME-ground may be an MME having at least some or all of the MME functions. The functions of the MME-onboard and the MME-ground may be configured to overlap with each other. The functions of the MME-onboard and the MME-ground may be configured not to overlap with each other. For example, the MME-onboard may have only some of the MME functions, and the MME-ground may have only MME functions that the MME-onboard does not have, or the MME-onboard and the MME-ground may be configured to have the functions of a single MME.

[0161] Furthermore, the AMF-onboard may be an AMF having at least some or all of the AMF functions. The AMF-ground may be an AMF having at least some or all of the AMF functions. The functions of the AMF-onboard and the functions of the AMF-ground may be configured to overlap with each other. The functions of the AMF-onboard and the functions of the AMF-ground may be configured not to overlap with each other. For example, the AMF-onboard may have only some of the AMF functions, and the AMF-ground may have only AMF functions that the AMF-onboard does not have, or the AMF-onboard and the AMF-ground may be configured to have the functions of one AMF.

[0162] The first identification information may also be UE capability information indicating whether the UE supports the S&F mode. For example, if the UE supports the S&F mode, the first identification information may indicate that the UE supports the S&F mode, or if the UE does not support the S&F mode, the first identification information may indicate that the UE does not support the S&F mode.

[0163] The eleventh identification information may also indicate that the MM procedure or SM procedure cannot be completed due to the S&F operation, and / or that the MM procedure or SM procedure can be retried for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM procedure or SM procedure can be attempted for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM message or SM message can be retransmitted for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM message or SM message can be sent for the same or a different satellite belonging to the same or a different PLMN, and / or that information included in the MM message or SM message is stored in the MME-onboard and / or AMF-onboard, and / or that the network becomes available after connection with a terrestrial network, where the terrestrial network may refer to an MME-ground, AMF-ground, or core network located on the ground. Furthermore, the eleventh identification information may be indicated as a cause value, and may be indicated as an EMM (EPS Mobility Management) cause value, an ESM (EPS Session Management) cause value, a 5GMM (5GS Mobility Management) cause value, or a 5GSM (5GS Session Management) cause value. For example, the eleventh identification information may be an EMM cause value or a 5GMM cause value indicating that an MM procedure cannot be completed due to an S&F operation. For example, the eleventh identification information may be an ESM cause value or a 5GSM cause value indicating that an SM procedure cannot be completed due to an S&F operation.

[0164] The twelfth identification information may also indicate a waiting time or timer value. The twelfth identification information may also indicate a waiting time or timer value that the UE waits before attempting or retrying an MM procedure or SM procedure for a current or different satellite belonging to the same or a different PLMN, and / or a waiting time or timer value that the UE waits before transmitting or retransmitting an MM message or SM message. The twelfth identification information may also apply only to satellites belonging to the same PLMN, only to satellites belonging to different PLMNs, or only to satellites belonging to all PLMNs. If the twelfth identification information is provided for satellites belonging to all PLMNs or only applies to satellites belonging to the same PLMN, the twelfth identification information does not need to include a PLMN ID in addition to the waiting time or timer value. If the twelfth identification information is applied to satellites belonging to some different PLMNs but not to all PLMNs, the twelfth identification information may also include one or more PLMN IDs in addition to the waiting time or timer value.

[0165] Furthermore, the 13th identification information may be an identifier for identifying a satellite (also referred to as a satellite ID). Alternatively, the 13th identification information may be a list of satellite IDs including one or more satellite IDs. Alternatively, the 13th identification information may be a satellite ID or a list of satellite IDs for which an MM procedure or an SM procedure is attempted or retried after the waiting time or timer value indicated by the 12th identification information, set and started in the UE, expires. Alternatively, the satellite ID or the satellite ID included in the list of satellite IDs included in the 13th identification information may be a satellite ID included in system information broadcast by a base station device. This base station device may be a base station device mounted on a satellite, or may be a base station device located on the ground (not mounted on a satellite). In the case of EPS, this system information may refer to SIBs (System Information Blocks) 31, 32, and 33, or may refer to other SIBs. In the case of 5GS, this system information may refer to SIBs 19 and 25, or may refer to other SIBs.

[0166] 3. First Embodiment 3.1. UE, satellite, and network behavior during normal operation First, the behavior of the UE, satellite, and network during normal operation will be described. As described above, during normal operation, both the service link and the feeder link have connectivity. Therefore, for example, when a UE initiates an MM procedure or SM procedure, the UE transmits an MM message or SM message to the satellite, which receives it. The satellite then transmits the received MM message or SM message to a terrestrial core network or a network function or network device within the core network, which can receive it. The core network, network function, or network device then transmits an MM message or SM message, which is a response message to the received MM message or SM message, to the satellite, which receives it. The satellite then transmits the response MM message or SM message to the UE, which can receive it. Note that the MM message or SM message, which is a response message transmitted from the network, does not need to include the 11th to 13th identification information. The MM message or SM message transmitted from the UE may include the first identification information.

[0167] Furthermore, in normal operation, MME-onboard may or may not be used. For example, a satellite or a base station device disposed on a satellite that receives an MM message or SM message from a UE may transmit the MM message or SM message to an MME or MME-ground without selecting MME-onboard (i.e., not via MME-onboard).

[0168] In addition, a satellite or a base station device located on a satellite that receives an MM message or SM message from a UE may select MME-onboard (i.e., via MME-onboard) and transmit the MM message or SM message to MME-ground.

[0169] Furthermore, when the MME or MME-ground transmits a response message to a satellite in response to an MM message or SM message received from the UE, the response message may be received by a base station device located on the satellite (i.e., not via the MME-onboard), and the base station device may transmit the response message to the UE.

[0170] In addition, when the MME or MME-ground transmits a response message to the satellite in response to the MM message or SM message received from the UE, if the MME-onboard located on the satellite receives the response message, the MME or MME-ground may transmit the response message to the UE via the base station device located on the satellite.

[0171] It should be noted that each of the following procedures may be executed one or more times, and after a procedure is executed, the same or a different procedure may be executed repeatedly.

[0172] [3.1.1] Behavior when sending and receiving system information If the network supports S&F operation because both the service link and the feeder link are available, the satellite or the base station on the satellite may transmit control information to the UE indicating that S&F satellite operation is not applied and / or that S&F operation is supported, and this control information may be broadcast in the system information.

[0173] By receiving this control information, the UE may recognize that the network supports S&F operation and / or that S&F satellite operation is not applied and / or that normal operation is applied.

[0174] [3.1.2] Behavior during execution of MM or SM procedures The following describes the behavior of the UE, satellite, and network during normal operation for the attach procedure in EPS, the TAU procedure in EPS, the service request procedure in EPS, the registration procedure in 5GS, and the service request procedure in 5GS.

[0175] [3.1.2.1] Behavior of the attach procedure in EPS In an attach procedure in EPS, a UE transmits an attach request message to a satellite, the message including first identification information indicating that the UE supports the S&F mode. The satellite, a base station device, or an MME (MME-onboard) mounted on the satellite may receive the message. Here, the satellite or the base station device located on the satellite may transmit the attach request message to a terrestrial MME or MME-ground without selecting an MME-onboard (i.e., not via an MME-onboard). Alternatively, the satellite or the base station device located on the satellite may select an MME-onboard and transmit the attach request message to the MME-onboard, and the MME-onboard that receives the attach request message may transmit the attach request message to the MME-ground. Then, the terrestrial MME or MME-ground that receives the attach request message may transmit an attach accept message or an attach reject message to the satellite as a response message to the attach request message. When the base station device located on the satellite receives the transmitted control message without going through an MME-onboard, the base station device may transmit the control message to the UE. Furthermore, when the MME-onboard receives the transmitted control message in the satellite, the MME-onboard may transmit the control message to the base station, which may then transmit the control message to the UE. The UE may then receive the control message from the base station.

[0176] If an attach accept message is sent or received, the UE may be able to attach to the EPC for packet services in the EPS. That is, the UE may be able to attach to the EPC and perform location registration. If an attach reject message is sent or received, the UE may not be able to attach to the EPC for packet services in the EPS.

[0177] [3.1.2.2] Behavior of EPS when TAU procedure is executed In a TAU procedure in EPS, a UE transmits a TAU request message to a satellite, the message including first identification information indicating that the UE supports the S&F mode. The TAU request message may be received by the satellite, a base station device, or an MME (MME-onboard) mounted on the satellite. Here, the satellite or the base station device located on the satellite may transmit the TAU request message to a terrestrial MME or MME-ground without selecting an MME-onboard (i.e., not via an MME-onboard). Alternatively, the satellite or the base station device located on the satellite may select an MME-onboard and transmit the TAU request message to the MME-onboard. The MME-onboard that receives the TAU request message may then transmit a TAU acceptance message or a TAU rejection message to the satellite as a response message to the TAU request message. When the base station device located on the satellite receives the transmitted control message without via an MME-onboard, the base station device may transmit the control message to the UE. Furthermore, when the MME-onboard receives the control message in the satellite that received the control message, the MME-onboard may transmit the control message to the base station device, and the base station device may transmit the control message to the UE. Then, the UE may receive the control message from the base station device.

[0178] If a TAU accept message is sent or received, the location registration of the UE's TA may be updated, whereas if a TAU reject message is sent or received, the location registration of the UE's TA may not be updated.

[0179] [3.1.2.3] Behavior during execution of service request procedures in EPS In a service request procedure in EPS, a UE transmits a service request message to a satellite, the service request message including first identification information indicating that the UE supports the S&F mode. The satellite, a base station device, or an MME (MME-onboard) mounted on the satellite may receive the message. Here, the satellite or the base station device located on the satellite may transmit the service request message to a terrestrial MME or MME-ground without selecting an MME-onboard (i.e., not via an MME-onboard). Alternatively, the satellite or the base station device located on the satellite may select an MME-onboard and transmit a service request message to the MME-onboard, and the MME-onboard that receives the service request message may transmit a service request message to the MME-ground. Then, the terrestrial MME or MME-ground that receives the service request message may transmit a service accept message or a service reject message to the satellite as a response message to the service request message. When the base station device located on the satellite receives the transmitted control message without via an MME-onboard, the base station device may transmit the control message to the UE. Furthermore, when the MME-onboard receives the transmitted control message in the satellite, the MME-onboard may transmit the control message to the base station, which may then transmit the control message to the UE. The UE may then receive the control message from the base station.

[0180] If a service accept message is sent or received, the UE may transition its EMM mode from EMM-IDLE to EMM-CONNECTED. If a service reject message is sent or received, the UE may not transition its EMM mode from EMM-IDLE to EMM-CONNECTED.

[0181] [3.1.2.4] Behavior when performing registration procedures on 5GS In a 5GS registration procedure, a UE may transmit a registration request message to a satellite, the registration request message including first identification information indicating that the UE supports the S&F mode, and the satellite, a base station device, or an AMF (AMF-onboard) mounted on the satellite may receive the message. Here, the satellite or a base station device deployed on the satellite may transmit the registration request message to the terrestrial AMF or AMF-ground without selecting AMF-onboard (i.e., not via AMF-onboard). Alternatively, the satellite or a base station device deployed on the satellite may select AMF-onboard and transmit the registration request message to AMF-onboard, and the AMF-onboard that receives the registration request message may transmit the registration request message to the AMF-ground. Then, the terrestrial AMF or AMF-ground that receives the registration request message may transmit a registration accept message or a registration reject message to the satellite as a response message to the registration request message. When the base station device deployed on the satellite receives the transmitted control message without via AMF-onboard, the base station device may transmit the control message to the UE. Furthermore, when the satellite that receives the transmitted control message receives the AMF-onboard, it may transmit the control message to the base station device, and the base station device may transmit the control message to the UE. Then, the UE may receive the control message from the base station device.

[0182] If a registration accept message is sent or received, the UE may be registered with the network, whereas if a registration reject message is sent or received, the UE may not be registered with the network.

[0183] [3.1.2.5] Behavior when executing a service request procedure in 5GS In a service request procedure in 5GS, a UE transmits a service request message to a satellite, the service request message including first identification information indicating that the UE supports the S&F mode, and the satellite, a base station device, or an AMF (AMF-onboard) mounted on the satellite may receive the message. Here, the satellite or a base station device located on the satellite may transmit the service request message to an AMF or AMF-ground located on the ground without selecting AMF-onboard (i.e., not via AMF-onboard). Alternatively, the satellite or a base station device located on the satellite may select AMF-onboard and transmit a service request message to AMF-onboard, and the AMF-onboard that receives the service request message may transmit a service request message to the AMF-ground. Then, the AMF or AMF-ground located on the ground that receives the service request message may transmit a service accept message or a service reject message to the satellite as a response message to the service request message. When the base station device located on the satellite receives the transmitted control message without via AMF-onboard, the base station device may transmit the control message to the UE. Furthermore, when the satellite that receives the transmitted control message receives the AMF-onboard, it may transmit the control message to the base station device, and the base station device may transmit the control message to the UE. Then, the UE may receive the control message from the base station device.

[0184] If a service acceptance message is received or transmitted, the UE may transition the 5GMM mode from 5GMM-IDLE to 5GMM-CONNECTED. If a service rejection message is received or transmitted, the UE may not transition the 5GMM mode from 5GMM-IDLE to 5GMM-CONNECTED.

[0185] [3.2. UE, satellite, and network behavior during S&F operation] Next, the behavior of the UE, satellite, and network in S&F operation will be described. In S&F operation, there is no connectivity of either the service link or the feeder link, so the UE, satellite, and network cannot behave as in normal operation as described above.

[0186] It should be noted that each of the following procedures may be executed one or more times, and after a procedure is executed, the same or a different procedure may be executed repeatedly.

[0187] [3.2.1] Behavior when sending and receiving system information When the feeder link is unavailable and the network supports S&F operation, the satellite or the base station on the satellite may transmit control information indicating whether S&F satellite operation is applied and / or that S&F satellite operation is applied and / or that S&F operation is supported to the UE, and at this time, this control information may be broadcasted by being included in system information.

[0188] By receiving this control information, the UE may know that the feeder link is unavailable, and / or that the network supports S&F operation, and / or whether S&F satellite operation is applied, and / or that S&F satellite operation is applied, and / or that normal operation is not applied.

[0189] [3.2.2] Behavior during execution of MM or SM procedures Next, in the MM procedure or SM procedure, the UE may transmit the first identification information to the satellite. In this case, if the satellite cannot complete the MM procedure or SM procedure due to S&F operation (e.g., due to lack of feeder link connectivity), it may transmit an MM message or SM message to the UE that includes at least one of the 11th to 13th identification information. The behavior of the UE, satellite, and network in S&F operation will be described below for the attach procedure in EPS, the TAU procedure in EPS, the service request procedure in EPS, the registration procedure in 5GS, and the service request procedure in 5GS.

[0190] [3.2.2.1] Behavior of the attach procedure in EPS In an attach procedure in EPS, the UE transmits an attach request message including first identification information indicating that the UE supports the S&F mode, and if the satellite or MME (MME-onboard) receiving the message cannot complete the procedure due to the S&F operation, it transmits an attach rejection message including at least one of the eleventh to thirteenth identification information to the UE, and the UE receives the message and stores the received eleventh to thirteenth identification information. Note that if the UE supports the S&F mode, the UE may set the first identification information to indicate that the UE supports the S&F mode.

[0191] Based on receiving the 11th identification information, the UE may recognize that the MM procedure (attach procedure) cannot be completed due to the S&F operation, and / or that the MM procedure (attach procedure) can be retried for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM procedure can be attempted for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM message (attach request message) can be resent for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM message can be sent for the same or a different satellite belonging to the same or a different PLMN, and / or that the information contained in the MM message (attach request message) is stored in the MME-onboard, and / or that the network will be available after connection with the terrestrial network.

[0192] Furthermore, upon receiving the twelfth identification, the UE may start a timer set to a waiting time or timer value indicated by the received twelfth identification. While this timer is running, the UE may not attempt an MM procedure or retry the attach procedure with the current or different satellites belonging to the same or a different PLMN. Furthermore, if this timer expires, the UE may retry an MM procedure or retry the attach procedure with those satellites, which may be one or more satellites indicated by one or more satellite identifiers included in the system information and / or the thirteenth identification.

[0193] Furthermore, if the twelfth identification information includes one or more PLMN IDs, the UE may not attempt an MM procedure or retry an attach procedure for one or more current or different satellites belonging to one or more PLMNs indicated by the one or more PLMN IDs while this timer is running. In this case, if this timer expires, the UE may be able to retry an MM procedure or retry an attach procedure for those satellites.

[0194] Furthermore, if the 12th identification information does not include a PLMN ID, the UE may not attempt an MM procedure or retry the attach procedure for one or more current or different satellites belonging to the same (current) PLMN or all PLMNs while this timer is running. In this case, if this timer expires, the UE may be able to retry an MM procedure or retry the attach procedure for those satellites.

[0195] Also, if the UE receives system information including a satellite identifier, the satellite may be the satellite indicated by the satellite identifier included in the system information.

[0196] In addition, if the UE receives system information including a satellite identifier but does not receive the 13th identification information, the satellite may be the satellite indicated by the satellite identifier included in the system information.

[0197] Furthermore, when the UE receives the thirteenth identification information, the satellite may be the satellite indicated by the satellite identifier included in the thirteenth identification information.

[0198] Furthermore, if the UE has not received system information including a satellite identifier and has received 13th identification information, the satellite may be the satellite indicated by the satellite identifier included in the 13th identification information.

[0199] Furthermore, when the UE receives system information including a satellite identifier and receives thirteenth identification information, the satellite may be a satellite indicated by a satellite identifier included in both the system information and the thirteenth identification information. In this case, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information. Furthermore, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information. Furthermore, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information.

[0200] Furthermore, when the UE receives system information including a satellite identifier and also receives thirteenth identification information, the satellite may be a satellite indicated by a satellite identifier included in either the system information or the thirteenth identification information. In this case, the satellite does not have to be a satellite indicated by a satellite identifier not included in either the system information or the thirteenth identification information.

[0201] The UE may also reset the attach attempt counter, set the EPS update state to EU2 or EU3, delete all GUTIs, delete the last visited registered TAI, and delete the equivalent PLMN list.

[0202] If the UE does not support the S&F mode, the first identification information may indicate that the UE does not support the S&F mode. In this case, the satellite or MME (onboard) may not include at least one of the eleventh to thirteenth identification information in the attach reject message, and may include in the attach reject message a cause value indicating EPS services not allowed, EPS services and non-EPS services not allowed, implicitly detached, PLMN not allowed, Tracking Area not allowed, EPS services not allowed in this PLMN, No Suitable Cells In Tracking Area, severe network failure, or PLMN not allowed to operate at the present UE location. Furthermore, a UE that does not support S&F mode may recognize that the attach procedure has been rejected and / or that the attach procedure via the satellite has been rejected and / or that it is unable to connect to the satellite by receiving an attach rejection message that includes such a cause value.

[0203] [3.2.2.2] Behavior of EPS when TAU procedure is executed In a TAU procedure in the EPS, the UE transmits a TAU request message including first identification information indicating that the UE supports the S&F mode, and if the satellite or MME (MME-onboard) that receives the message cannot complete the procedure due to the S&F operation, it transmits a TAU rejection message including at least one of the eleventh to thirteenth identification information to the UE, and the UE receives the message and stores the received eleventh to thirteenth identification information. Note that if the UE supports the S&F mode, the UE may set the first identification information to indicate that the UE supports the S&F mode.

[0204] Based on receiving the 11th identification information, the UE may recognize that the MM procedure (TAU procedure) cannot be completed due to the S&F operation, and / or that the MM procedure (TAU procedure) can be retried for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM procedure can be attempted for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM message (TAU request message) can be resent for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM message can be sent for the same or a different satellite belonging to the same or a different PLMN, and / or that the information contained in the MM message (TAU request message) is stored in the MME-onboard, and / or that the network will be available after connection with the terrestrial network.

[0205] Furthermore, upon receiving the 12th identification, the UE may start a timer set to a waiting time or timer value indicated by the received 12th identification. While this timer is running, the UE may not attempt an MM procedure or retry a TAU procedure with the current or different satellites belonging to the same or a different PLMN. Furthermore, if this timer expires, the UE may retry an MM procedure or TAU procedure with those satellites, which may be one or more satellites indicated by one or more satellite identifiers included in the system information and / or the 13th identification.

[0206] Furthermore, if the twelfth identification information includes one or more PLMN IDs, the UE may not attempt an MM procedure or retry a TAU procedure for one or more current or different satellites belonging to one or more PLMNs indicated by the one or more PLMN IDs while this timer is running. In this case, if this timer expires, the UE may be able to attempt an MM procedure or retry a TAU procedure for those satellites.

[0207] Furthermore, if the 12th identification information does not include a PLMN ID, the UE may not attempt an MM procedure or retry a TAU procedure for one or more current or different satellites belonging to the same (current) PLMN or all PLMNs while this timer is running. In this case, if this timer expires, the UE may be able to retry an MM procedure or a TAU procedure for those satellites.

[0208] Also, if the UE receives system information including a satellite identifier, the satellite may be the satellite indicated by the satellite identifier included in the system information.

[0209] In addition, if the UE receives system information including a satellite identifier but does not receive the 13th identification information, the satellite may be the satellite indicated by the satellite identifier included in the system information.

[0210] Furthermore, when the UE receives the thirteenth identification information, the satellite may be the satellite indicated by the satellite identifier included in the thirteenth identification information.

[0211] Furthermore, if the UE has not received system information including a satellite identifier and has received 13th identification information, the satellite may be the satellite indicated by the satellite identifier included in the 13th identification information.

[0212] Furthermore, when the UE receives system information including a satellite identifier and receives thirteenth identification information, the satellite may be a satellite indicated by a satellite identifier included in both the system information and the thirteenth identification information. In this case, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information. Furthermore, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information. Furthermore, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information.

[0213] Furthermore, when the UE receives system information including a satellite identifier and also receives thirteenth identification information, the satellite may be a satellite indicated by a satellite identifier included in either the system information or the thirteenth identification information. In this case, the satellite does not have to be a satellite indicated by a satellite identifier not included in either the system information or the thirteenth identification information.

[0214] The UE may also reset the TAU attempt counter, set the EPS update state to EU2 or EU3, delete all GUTIs, delete the last visited registered TAI, and delete the equivalent PLMN list.

[0215] If the UE does not support the S&F mode, the first identification information may indicate that the UE does not support the S&F mode. In this case, the satellite or MME (onboard) may not include at least one of the eleventh to thirteenth identification information in the TAU rejection message, and may include in the TAU rejection message a cause value indicating EPS services not allowed, EPS services and non-EPS services not allowed, implicitly detached, PLMN not allowed, Tracking Area not allowed, EPS services not allowed in this PLMN, No Suitable Cells In Tracking Area, severe network failure, or PLMN not allowed to operate at the present UE location. In addition, a UE that does not support S&F mode may recognize that the TAU procedure has been rejected and / or that the TAU procedure via the satellite has been rejected and / or that it is unable to connect to the satellite by receiving a TAU rejection message containing such a cause value.

[0216] [3.2.2.3] Behavior during execution of service request procedures in EPS Furthermore, in a service request procedure in the EPS, the UE may transmit a service request message including first identification information indicating that the UE supports the S&F mode, and if the satellite or MME (MME-onboard) receiving the message is unable to complete the procedure due to the S&F operation, it may transmit a service refusal message including at least one of the eleventh to thirteenth identification information to the UE, and the UE may receive the message and store the received eleventh to thirteenth identification information. Note that if the UE supports the S&F mode, the UE may set the first identification information to indicate that the UE supports the S&F mode.

[0217] Based on receiving the 11th identification information, the UE may recognize that the MM procedure (service request procedure) cannot be completed due to an S&F operation, and / or that the MM procedure (service request procedure) can be retried for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM procedure can be attempted for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM message (service request message) can be retransmitted for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM message can be sent for the same or a different satellite belonging to the same or a different PLMN, and / or that the information contained in the MM message (service request message) is stored in the MME-onboard, and / or that the network will be available after connection with the terrestrial network.

[0218] Furthermore, upon receiving the 12th identification, the UE may start a timer set to a waiting time or timer value indicated by the received 12th identification. While this timer is running, the UE may not attempt an MM procedure or retry a service request procedure with the current or different satellites belonging to the same or a different PLMN. Furthermore, if this timer expires, the UE may retry an MM procedure or retry a service request procedure with those satellites, which may be one or more satellites indicated by one or more satellite identifiers included in the system information and / or the 13th identification.

[0219] Furthermore, if the twelfth identification information includes one or more PLMN IDs, the UE may not attempt to perform an MM procedure or retry a service request procedure for one or more current or different satellites belonging to one or more PLMNs indicated by the one or more PLMN IDs while this timer is running. In this case, if this timer expires, the UE may be able to retry an MM procedure or service request procedure for those satellites.

[0220] Furthermore, if the 12th identification information does not include a PLMN ID, the UE may not attempt to perform an MM procedure or retry a service request procedure for one or more current or different satellites belonging to the same (current) PLMN or all PLMNs while this timer is running. In this case, if this timer expires, the UE may be able to retry an MM procedure or service request procedure for those satellites.

[0221] Also, if the UE receives system information including a satellite identifier, the satellite may be the satellite indicated by the satellite identifier included in the system information.

[0222] In addition, if the UE receives system information including a satellite identifier but does not receive the 13th identification information, the satellite may be the satellite indicated by the satellite identifier included in the system information.

[0223] Furthermore, when the UE receives the thirteenth identification information, the satellite may be the satellite indicated by the satellite identifier included in the thirteenth identification information.

[0224] Furthermore, if the UE has not received system information including a satellite identifier and has received 13th identification information, the satellite may be the satellite indicated by the satellite identifier included in the 13th identification information.

[0225] Furthermore, when the UE receives system information including a satellite identifier and receives thirteenth identification information, the satellite may be a satellite indicated by a satellite identifier included in both the system information and the thirteenth identification information. In this case, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information. Furthermore, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information. Furthermore, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information.

[0226] Furthermore, when the UE receives system information including a satellite identifier and also receives thirteenth identification information, the satellite may be a satellite indicated by a satellite identifier included in either the system information or the thirteenth identification information. In this case, the satellite does not have to be a satellite indicated by a satellite identifier not included in either the system information or the thirteenth identification information.

[0227] The UE may also reset the service request attempt counter, set the EPS update state to EU2 or EU3, delete the GUTI, delete the last visited registered TAI, and delete the equivalent PLMN list.

[0228] If the UE does not support the S&F mode, the first identification information may indicate that the UE does not support the S&F mode. In this case, the satellite or MME (onboard) may not include at least one of the eleventh to thirteenth identification information in the service rejection message, and may include in the service rejection message a cause value indicating EPS services not allowed, EPS services and non-EPS services not allowed, implicitly detached, PLMN not allowed, Tracking Area not allowed, EPS services not allowed in this PLMN, No Suitable Cells In Tracking Area, severe network failure, or PLMN not allowed to operate at the present UE location. Furthermore, a UE that does not support S&F mode may recognize that the service request procedure has been rejected and / or that the service request procedure via the satellite has been rejected and / or that it is unable to connect to the satellite by receiving a service rejection message containing such a cause value.

[0229] [3.2.2.4] Behavior when performing registration procedures on 5GS Furthermore, in a registration procedure in 5GS, the UE may transmit a registration request message including first identification information indicating that the UE supports the S&F mode, and if the satellite or AMF (AMF-onboard) that receives this cannot complete the procedure due to the S&F operation, it may transmit a registration rejection message including at least one of the 11th to 13th identification information to the UE, and the UE may receive this and store the received 11th to 13th identification information. Note that if the UE supports the S&F mode, the UE may set the first identification information to indicate that the UE supports the S&F mode.

[0230] Based on receiving the 11th identification information, the UE may recognize that the MM procedure (registration procedure) cannot be completed due to S&F operation, and / or that the MM procedure (registration procedure) can be retried for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM procedure can be attempted for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM message (registration request message) can be resent for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM message can be sent for the same or a different satellite belonging to the same or a different PLMN, and / or that the information contained in the MM message (registration request message) is stored in the AMF-onboard, and / or that the network will be available after connection with the terrestrial network.

[0231] Furthermore, upon receiving the twelfth identification, the UE may start a timer set to a waiting time or timer value indicated by the received twelfth identification. While this timer is running, the UE may not attempt an MM procedure or retry the registration procedure with the current or different satellites belonging to the same or a different PLMN. Furthermore, if this timer expires, the UE may retry the MM procedure or retry the registration procedure with those satellites, which may be one or more satellites indicated by one or more satellite identifiers included in the system information and / or the thirteenth identification.

[0232] Furthermore, if the twelfth identification information includes one or more PLMN IDs, the UE may not attempt an MM procedure or retry a registration procedure for one or more current or different satellites belonging to one or more PLMNs indicated by the one or more PLMN IDs while this timer is running. In this case, if this timer expires, the UE may be able to retry an MM procedure or registration procedure for those satellites.

[0233] Furthermore, if the 12th identification information does not include a PLMN ID, the UE may not attempt an MM procedure or retry a registration procedure for one or more current or different satellites belonging to the same (current) PLMN or all PLMNs while this timer is running. In this case, if this timer expires, the UE may be able to retry an MM procedure or registration procedure for those satellites.

[0234] Also, if the UE receives system information including a satellite identifier, the satellite may be the satellite indicated by the satellite identifier included in the system information.

[0235] In addition, if the UE receives system information including a satellite identifier but does not receive the 13th identification information, the satellite may be the satellite indicated by the satellite identifier included in the system information.

[0236] Furthermore, when the UE receives the thirteenth identification information, the satellite may be the satellite indicated by the satellite identifier included in the thirteenth identification information.

[0237] Furthermore, if the UE has not received system information including a satellite identifier and has received 13th identification information, the satellite may be the satellite indicated by the satellite identifier included in the 13th identification information.

[0238] Furthermore, when the UE receives system information including a satellite identifier and receives thirteenth identification information, the satellite may be a satellite indicated by a satellite identifier included in both the system information and the thirteenth identification information. In this case, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information. Furthermore, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information. Furthermore, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information.

[0239] Furthermore, when the UE receives system information including a satellite identifier and also receives thirteenth identification information, the satellite may be a satellite indicated by a satellite identifier included in either the system information or the thirteenth identification information. In this case, the satellite does not have to be a satellite indicated by a satellite identifier not included in either the system information or the thirteenth identification information.

[0240] The UE may also reset the registration attempt counter, set the 5GS update state to 5U2 or 5U3, delete all 5G-GUTIs, delete the last visited registered TAI, and delete the equivalent PLMN list.

[0241] If the UE does not support the S&F mode, the first identification information may indicate that the UE does not support the S&F mode. In this case, the satellite or the AMF (AMF-onboard) may not include at least one of the eleventh to thirteenth identification information in the attach rejection message, and may include in the attach rejection message a cause value indicating "5GS services not allowed," "implicitly de-registered," "PLMN not allowed," "Tracking Area not allowed," "No Suitable Cells in a Tracking Area," "No network slices available," or "PLMN not allowed to operate at the present UE location." Furthermore, by receiving a registration rejection message including such a cause value, a UE that does not support the S&F mode may recognize that the registration procedure has been rejected and / or that the registration procedure via the satellite has been rejected and / or that it cannot connect to the satellite.

[0242] [3.2.2.5] Behavior when executing a service request procedure in 5GS Furthermore, in a service request procedure in 5GS, the UE may transmit a service request message including first identification information indicating that the UE supports the S&F mode, and if the satellite or AMF (AMF-onboard) that receives this cannot complete the procedure due to the S&F operation, it may transmit a service refusal message including at least one of the 11th to 13th identification information to the UE, and the UE may receive this and store the received 11th to 13th identification information. Note that if the UE supports the S&F mode, the UE may set the first identification information to indicate that the UE supports the S&F mode.

[0243] Based on receiving the 11th identification information, the UE may recognize that the MM procedure (service request procedure) cannot be completed due to S&F operation, and / or that the MM procedure (service request procedure) can be retried for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM procedure can be attempted for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM message (service request message) can be retransmitted for the same or a different satellite belonging to the same or a different PLMN, and / or that the MM message can be sent for the same or a different satellite belonging to the same or a different PLMN, and / or that the information contained in the MM message (service request message) is stored in the AMF-onboard, and / or that the network will be available after connection with the terrestrial network.

[0244] Furthermore, upon receiving the 12th identification, the UE may start a timer set to a waiting time or timer value indicated by the received 12th identification. While this timer is running, the UE may not attempt an MM procedure or retry a service request procedure with the current or different satellites belonging to the same or a different PLMN. Furthermore, if this timer expires, the UE may retry an MM procedure or retry a service request procedure with those satellites, which may be one or more satellites indicated by one or more satellite identifiers included in the system information and / or the 13th identification.

[0245] Furthermore, if the twelfth identification information includes one or more PLMN IDs, the UE may not attempt to perform an MM procedure or retry a service request procedure for one or more current or different satellites belonging to one or more PLMNs indicated by the one or more PLMN IDs while this timer is running. In this case, if this timer expires, the UE may be able to retry an MM procedure or service request procedure for those satellites.

[0246] Furthermore, if the 12th identification information does not include a PLMN ID, the UE may not attempt to perform an MM procedure or retry a service request procedure for one or more current or different satellites belonging to the same (current) PLMN or all PLMNs while this timer is running. In this case, if this timer expires, the UE may be able to retry an MM procedure or service request procedure for those satellites.

[0247] Also, if the UE receives system information including a satellite identifier, the satellite may be the satellite indicated by the satellite identifier included in the system information.

[0248] In addition, if the UE receives system information including a satellite identifier but does not receive the 13th identification information, the satellite may be the satellite indicated by the satellite identifier included in the system information.

[0249] Furthermore, when the UE receives the thirteenth identification information, the satellite may be the satellite indicated by the satellite identifier included in the thirteenth identification information.

[0250] Furthermore, if the UE has not received system information including a satellite identifier and has received 13th identification information, the satellite may be the satellite indicated by the satellite identifier included in the 13th identification information.

[0251] Furthermore, when the UE receives system information including a satellite identifier and receives thirteenth identification information, the satellite may be a satellite indicated by a satellite identifier included in both the system information and the thirteenth identification information. In this case, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information. Furthermore, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information. Furthermore, the satellite may not be a satellite indicated by a satellite identifier included in the system information but not in the thirteenth identification information.

[0252] Furthermore, when the UE receives system information including a satellite identifier and also receives thirteenth identification information, the satellite may be a satellite indicated by a satellite identifier included in either the system information or the thirteenth identification information. In this case, the satellite does not have to be a satellite indicated by a satellite identifier not included in either the system information or the thirteenth identification information.

[0253] The UE may also reset the service request attempt counter, set the 5GS update state to 5U2 or 5U3, delete all 5G-GUTIs, delete the last visited registered TAI, and delete the equivalent PLMN list.

[0254] If the UE does not support the S&F mode, the first identification information may indicate that the UE does not support the S&F mode. In this case, the satellite or AMF (AMF-onboard) may not include at least one of the eleventh to thirteenth identification information in the service rejection message, and may include in the service rejection message a cause value indicating 5GS services not allowed, implicitly deregistered, PLMN not allowed, Tracking Area not allowed, no suitable cells in the tracking area, no network slices available, or PLMN not allowed to operate at the present UE location. Furthermore, by receiving a service rejection message including such a cause value, a UE that does not support the S&F mode may recognize that the service request procedure has been rejected and / or that the service request procedure via the satellite has been rejected and / or that it cannot connect to the satellite.

[0255] [3.2.2.6] Other behavior Also, when the service link is available and the feeder link is unavailable, mobile originated (MO) data may be stored in the MME-onboard and may be forwarded to the ground when the feeder link becomes available. Also, when the feeder link is unavailable, mobile terminated (MT) data may be stored in the MME-ground and may be forwarded to the MME-onboard when the feeder link becomes available. Also, when the feeder link is available and the service link is unavailable, MT data may be stored in the MME-onboard and may be forwarded to the UE when the service link becomes available. Also, all types of data traffic may be supported and may be forwarded using procedures defined in EPS.

[0256] Also, when the service link is available and the feeder link is unavailable, mobile originated (MO) data may be stored in AMF-onboard and may be forwarded to the ground when the feeder link becomes available. Also, when the feeder link is unavailable, mobile terminated (MT) data may be stored in AMF-ground and may be forwarded to AMF-onboard when the feeder link becomes available. Also, when the feeder link is available and the service link is unavailable, MT data may be stored in AMF-onboard and may be forwarded to the UE when the service link becomes available. Also, all types of data traffic may be supported and may be forwarded using procedures defined in EPS.

[0257] Also, when operating in S&F operation, the UE may be able to receive a configuration update command. In other words, in a registration procedure in 5GS, the UE transmits a registration request message including first identification information, and if the satellite or AMF (AMF-onboard) that receives this message cannot complete the procedure due to S&F operation, it may transmit a registration rejection message including at least one of the eleventh to thirteenth identification information to the UE, which the UE may receive and store. Thereafter, the satellite or AMF (AMF-onboard) may transmit a configuration update command to the UE including at least one of the updated eleventh to thirteenth identification information, which the UE may receive and store, updating the stored eleventh to thirteenth identification information.

[0258] 4. Variations A program running on an apparatus according to one aspect of the present invention may be a program that controls a central processing unit (CPU) or the like to cause a computer to function so as to realize the functions of an embodiment according to the present invention. The program or information handled by the program is temporarily stored in a volatile memory such as a random access memory (RAM), a non-volatile memory such as a flash memory, a hard disk drive (HDD), or another storage device system.

[0259] A program for implementing the functions of an embodiment according to one aspect of the present invention may be recorded on a computer-readable recording medium. The program may be read into a computer system and executed. The term "computer system" as used herein refers to a computer system built into a device, including hardware such as an operating system and peripheral devices. The term "computer-readable recording medium" may also refer to a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a medium that dynamically stores a program for a short period of time, or any other computer-readable recording medium.

[0260] Additionally, each functional block or feature of the device used in the above-described embodiments may be implemented or performed by an electrical circuit, such as an integrated circuit or multiple integrated circuits. The electrical circuit designed to perform the functions described herein may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or a combination thereof. The general-purpose processor may be a microprocessor, or a conventional processor, controller, microcontroller, or state machine. The electrical circuit may be composed of digital circuits or analog circuits. Furthermore, as advances in semiconductor technology emerge, one or more aspects of the present invention may utilize new integrated circuits based on that technology.

[0261] The present invention is not limited to the above-described embodiment. Although one example of a device has been described in the embodiment, one aspect of the present invention is not limited to this and can be applied to terminal devices or communication devices of stationary or non-movable electronic devices installed indoors or outdoors, such as AV equipment, kitchen equipment, cleaning / washing equipment, air conditioning equipment, office equipment, vending machines, and other household appliances.

[0262] Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like are also included within the scope of the gist of the present invention. Furthermore, various modifications of one aspect of the present invention are possible within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, configurations in which elements described in the above embodiments are substituted with elements that achieve the same effect are also included. [Explanation of symbols]

[0263] 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 90 Core Network_A 120 Access Network_B 122 gNB 130 UPF 132 SMF 140 AMF 150 UDM 160 PCF 170 N3IWF 190 Core Network_B

Claims

[Claim 1] A UE comprising a transceiver unit and a controller, The UE is capable of communicating with a base station and a satellite carrying an MME-ground; The transmitting and receiving unit, in a tracking area update procedure, sending a tracking area update request message to the satellite; receiving a tracking area update rejection message from the satellite; the tracking area update request message includes UE capability information indicating that the UE supports an S&F mode; the tracking area update rejection message includes a reason value, a waiting time value, and / or a list of satellite identifiers; The rejection reason value indicates that the tracking area update procedure cannot be completed due to an S&F operation; the waiting time value indicates a waiting time value that the UE waits before retrying the tracking area update procedure for the current or a different satellite belonging to the same or a different PLMN; the list of satellite identifiers includes one or more identifiers of satellites for which the UE will retry the tracking area update procedure after the waiting time has expired; The control unit, based on the reason value, Reset the tracking area update attempt counter, Set the EPS update state to EU2 or EU3, A UE characterized by:

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