User equipment (UE) and mobility management apparatus

Abstract

To clarify the detailed behavior of a UE, a satellite and / or a network while clarifying a method for realizing a store and forward satellite operation.SOLUTION: In a mobile communications system, UE sends a first request message to a first satellite, initiates a mobility management procedure, and receives, from the first satellite, a first reject message that includes a first value of a Waittimer; Starting a Waittimer with a first value, controlling the first satellite identified by the first satelliteID not to retry sending the first request message while the Waittimer is running, and when the UE is powered off and then powered on again while the Waittimer is running, restarting the Waittimer with a difference between a first timer value and a second timer value, wherein the first timer value is a remaining time of the Waittimer timed out when the UE is powered off, and the second timer value is an elapsed time from power-off to power-on.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a UE (User Equipment) and a mobility management device. [Background technology]

[0002] The 3GPP (3rd Generation Partnership Project) is studying the system architecture of 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 to 3). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP TS 24.501 V18.7.0 (2024-07); 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 V18.7.0 (2024-07); 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 is expected to specify Store and Forward (S&F) satellite operation, but it does not disclose how this operation will be realized (see Non-Patent Document 4).

[0005] One aspect of the present invention has been made in consideration of the above circumstances, and aims to clarify how store and forward satellite operations are implemented and to clarify the detailed behavior of UEs, satellites, and / or networks. [Means for solving the problem]

[0006] A UE according to one embodiment of the present invention is a UE comprising a transceiver unit and a control unit, wherein the transceiver unit transmits a first request message to the first satellite, initiates an MM (Mobility Management) procedure, and receives a first rejection message from the first satellite, the first rejection message including a first value of a Wait timer; the control unit starts the Wait timer using the first value, and controls the UE not to retry transmitting the first request message to the first satellite identified by a first satellite ID while the Wait timer is running; and if the UE is powered off and then powered on again while the Wait timer is running, the control unit restarts the Wait timer using a value obtained by subtracting the second timer value from the first timer value if the first timer value is greater than the second timer value, wherein the first timer value is the remaining time of the Wait timer that timed out when the power was turned off, and the second timer value is the elapsed time from when the power was turned off to when the power was turned on. [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. [Figure 6] FIG. 1 is a diagram illustrating a detailed configuration of a mobile communication system (EPS / 5GS) using a satellite. [Figure 7] FIG. 10 is a diagram illustrating a registration procedure. [Figure 8] A diagram illustrating a deregistration procedure / detachment procedure initiated by the UE. [Figure 9] 10 is a diagram showing the relationship between timer values ​​when the UE is powered off and on while the Wait timer is running. FIG. 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] Furthermore, the core network_A may correspond to an EPC (Evolved Packet Core), which may include, 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 may correspond to a 5G Core Network (5GCN). For example, an Access and Mobility Management Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), a Policy Control Function (PCF), a Unified Data Management (UDM), etc. are arranged in the 5GCN. 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. Furthermore, the PDN may be expressed as a DN, and the DN may be expressed as a PDN. Furthermore, the PDN and the DN may be DNs that provide communication services to the UE, and are not limited to EPS DNs and 5GS PDNs.

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

[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] In this document, the management of information by each device may also mean storage.

[0035] [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.

[0036] 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.

[0037] [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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[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] [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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] The AMF has functions such as exchanging control messages with the RAN using the N2 interface, exchanging NAS messages with the UE using the N1 interface, encrypting and protecting the integrity of NAS messages, registration management (RM) functions, connection management (CM) functions, reachability management functions, mobility management functions for UEs, etc., transferring SM (Session Management) messages between the UE and the SMF, access authentication (Access Authorization) functions, security anchor functionality (SEA), security context management (SCM), a function to support the N2 interface for the N3IWF (Non-3GPP Interworking Function), a function to support sending and receiving NAS signals with the UE via the N3IWF, and a function to authenticate UEs connected via the N3IWF.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] Note that although the above explanation has been given using the example of AMF and / or MME, any NF having at least one function of AMF, such as a UE mobility management function, may be used, and AMF and / or MME may be interpreted as a mobility management device.

[0063] [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.

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

[0065] The network connection unit _B720 is a functional unit for the SMF to connect with the AMF, and / or UPF, and / or PCF, and / or UDM. In other words, the SMF can 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.

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

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

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

[0069] 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.

[0070] Although the above description has been given using the example of an SMF and / or PGW and / or PGW-C, any NF having at least one function of an SMF, such as a session management function, may be used, and the SMF and / or PGW and / or PGW-C may be interpreted as a session management device.

[0071] [2.5. UPF / PGW 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 read as PGW or PGW-U. 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. required for each operation of the UPF.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] Although the above description has been given using the example of UPF and / or PGW and / or PGW-U, any NF having at least one function of UPF is sufficient, and UPF and / or PGW and / or PGW-U may be interpreted as user plane function devices.

[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 MME during an MM procedure, or may be an NAS message (also referred to as an NAS MM message).

[0086] In addition, in 5GS, MM procedures (also referred to as procedures for MM (Mobility Management)) may include a registration procedure initiated by the UE, a de-registration procedure initiated by the UE or AMF (or the network), a generic UE configuration update procedure initiated by the AMF (or the network), a service request procedure initiated by the UE, a paging procedure initiated by the AMF (or the network), and a notification procedure initiated by the AMF (or the network).

[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 deregistration procedure initiated by the UE, the UE may send a deregistration request message to the AMF and receive a deregistration accept message sent from the AMF that received 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 when it allows the service request from the UE, or may send a service reject message when it does not allow the service 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 addition, in EPS, the MM procedures may include an Attach procedure initiated by the UE, a Tracking area updating procedure initiated by the UE, a Detach procedure initiated by the UE or MME (or the network), a Service Request procedure initiated by the UE, a Paging procedure initiated by the MME (or the network), and a Transport of NAS messages procedure initiated by the UE or MME (or the network).

[0095] In the attach procedure, the UE may send an Attach Request message to the MME and receive an Attach Accept message or an Attach Reject message from the MME upon receiving the Attach Request message. The MME may send an Attach Accept message if it accepts the Attach Request from the UE, or an Attach Reject message if it does not accept the Attach Request.

[0096] In addition, in the tracking area update procedure, the UE may send a tracking area update request message to the MME, and may receive an attach area update accept message or a tracking area update reject message from the MME that has received the request. Here, the MME may send a tracking area accept message if it accepts the tracking area update request from the UE, or may send a tracking area reject message if it does not accept the request.

[0097] In addition, in a detach procedure initiated by the UE, the UE may send a Detach Request message to the MME and receive a Detach Accept message sent from the MME that has received the Detach Request message.

[0098] In addition, in a detach procedure initiated by the MME (or the network), the MME may send a detach request message to the UE and receive a detach accept message sent from the UE that has received the detach request message.

[0099] 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).

[0100] Alternatively, the SM message may be a control message transmitted and received between the UE and the network in the SM procedure of EPS, or may be an NAS message (also referred to as an NAS SM message). Furthermore, the SM procedure (also referred to as a procedure for SM) in 5GS may include a UE-initiated PDU Session Establishment procedure, a UE- or SMF-initiated PDU Session Modification procedure, and a UE-requested PDU Session Release procedure.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] In addition, in the PDN connection 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 that has received 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] In addition, the 5GS (5G System) service may be a connection service provided using the core network_B190. Furthermore, the 5GS service may be a service different from the EPS service or may be a service similar to the EPS service.

[0115] In addition, non-5GS services may be services other than 5GS services, and may include EPS services and / or non-EPS services.

[0116] Furthermore, the PDN (Packet Data Network) type indicates the type of PDN connection, and can be IPv4, IPv6, IPv4v6, or non-IP. If IPv4 is specified, it indicates that data will be sent and received using IPv4. If IPv6 is specified, it indicates that data will be sent and received using IPv6. If IPv4v6 is specified, it indicates that data will be sent and received using either IPv4 or IPv6. If non-IP is specified, it indicates that communication will not be via IP, but via a communication method other than IP.

[0117] 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.

[0118] Furthermore, an MA PDU session may be a PDU session that provides PDU connectivity services using 3GPP access and / or non-3GPP access.

[0119] 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.

[0120] 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).

[0121] Furthermore, the PDU (Protocol Data Unit / Packet Data Unit) session type indicates the type of PDU session, and can be IPv4, IPv6, Ethernet, or Unstructured. If IPv4 is specified, it indicates that data will be transmitted and received using IPv4. If IPv6 is specified, it indicates that data will be transmitted and received using IPv6. If Ethernet is specified, it indicates that Ethernet frames will be transmitted and received. Furthermore, Ethernet may indicate that communication using IP is not performed. If Unstructured is specified, it indicates that data will be transmitted and received to an application server or the like in the DN using Point-to-Point (P2P) tunneling technology. As the P2P tunneling technology, for example, UDP / IP encapsulation technology may be used. In addition to the above, the PDU session type may also include IP. IP can be specified if the UE is capable of using both IPv4 and IPv6.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] The UE ID is information for identifying a UE. Specifically, for example, the UE ID may be a SUCI (Subscription Concealed Identifier), a SUPI (Subscription Permanent Identifier), a GUTI (Globally Unique Temporary Identifier), an IMEI (International Mobile Subscriber Identity), an IMEISV (IMEI Software Version), or a TMSI (Temporary Mobile Subscriber Identity). Alternatively, the UE ID may be other information set in an application or a network. Furthermore, the UE ID may be information for identifying a user.

[0127] Store and Forward (S&F) satellite operation (also referred to as S&F satellite operation mode) may refer to an operation mode in which a serving satellite provides communication services to a UE during a period and / or in a geographic area where the serving satellite is not simultaneously connected to a terrestrial network via a feeder link or an Inter-Satellite Link (ISL).

[0128] In the case of the uplink (also referred to as UL), "store" may mean storing UL information from the UE in the satellite, and "forward" may mean forwarding the stored UL information to the terrestrial network. In the case of the downlink (also referred to as DL), "store" may mean storing DL information from the terrestrial network in the satellite, and "forward" may mean forwarding the stored UL information to the UE. In this specification, the storage and forwarding satellite operations may be referred to as S&F, S&F function, S&F mode, or S&F operation mode. Supporting the S&F operation mode may also be referred to as supporting the first function.

[0129] Normal satellite operation (also referred to as normal satellite operation mode) may be an operation mode different from the S&F satellite operation mode. Normal satellite operation may be a mode with service link connectivity and feeder link connectivity. Normal satellite operation may also be a mode without the above-mentioned store and forward functions. Normal satellite operation may also be an operation mode in which a serving satellite provides communication services to a UE for a period and / or geographic area in which the serving satellite simultaneously connects to a terrestrial network via a feeder link or an inter-satellite link. Normal satellite operation may also be referred to as default satellite operation (also referred to as default satellite operation mode). In this specification, normal satellite operation may also be referred to as normal mode or normal operation mode.

[0130] A service link is a link, connection, or connectivity between a UE and a satellite. A service link being disconnected may refer to a state in which communication between the UE and the satellite is not possible or is not possible. In other words, a state in which the service link is disconnected may be expressed as a state in which the service link does not have connectivity and / or the service link is unavailable. Conversely, a state in which the service link is not disconnected and / or a state in which the service link is established and / or a state in which the service link is connected may be expressed as a state in which the service link has connectivity and / or a state in which the service link is available.

[0131] A feeder link is a link, connection, or connectivity between a satellite and a terrestrial network. A feeder link being disconnected may mean that communication between the satellite and the terrestrial network is no longer possible. In other words, a state in which a feeder link is disconnected may be expressed as a state in which there is no feeder link connectivity and / or a state in which the feeder link is unavailable. Conversely, a state in which a feeder link is not disconnected and / or a state in which the feeder link is established and / or a state in which the feeder link is connected may be expressed as a state in which there is feeder link connectivity and / or a state in which the feeder link is available.

[0132] A serving satellite may be a satellite that provides satellite connectivity to a UE (e.g., provides a serving cell). Depending on its orbit, a serving satellite may 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, while a UE without a serving satellite may not be able to communicate via the satellite. A serving satellite operating in S&F mode may have no feeder link connectivity.

[0133] 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.

[0134] Furthermore, the UE, and / or satellite, and / or NW may operate in S&F mode or in normal mode. When each device operates in S&F mode, it may be expressed as the S&F mode being active. When each device does not operate in S&F mode, it may be expressed as operating in normal mode.

[0135] Furthermore, only the UE, only the satellite, or only the NW may operate in the S&F mode and in the normal mode. For example, if only the satellite operates in the S&F mode and in the normal mode, components other than the satellite (in this case, the UE and NW) may not operate in either the S&F mode or the normal mode, and may behave in accordance with the mode in which the satellite operates. If only the UE operates in the S&F mode and in the normal mode, components other than the UE (in this case, the satellite and NW) may not operate in either the S&F mode or the normal mode, and may behave in accordance with the mode in which the UE operates. If only the NW operates in the S&F mode and in the normal mode, components other than the NW (in this case, the UE and satellite) may not operate in either the S&F mode or the normal mode, and may behave in accordance with the mode in which the NW operates.

[0136] For simplicity, the case where the UE, and / or satellite, and / or NW operates in S&F mode will be abbreviated as "operating in S&F mode (not operating in standard mode)", etc. For simplicity, the case where the UE, and / or satellite, and / or NW operates in normal mode will be abbreviated as "operating in normal mode (not operating in S&F mode)", etc.

[0137] In addition, the UE, and / or satellite, and / or NW may operate by switching between S&F mode and normal mode. For example, when the UE, and / or satellite, and / or NW is operating in normal mode, it may start a procedure and switch from normal mode to S&F mode while the procedure is being performed. In addition, when the UE, and / or satellite, and / or NW is operating in S&F mode, it may start a procedure and switch from S&F mode to normal mode while the procedure is being performed.

[0138] Next, a system configuration in which an access network and a portion of an MME and / or AMF are mounted on or installed on a satellite will be described with reference to Fig. 6. As shown in Fig. 6, in communications using a satellite, the functions of the MME and AMF may be divided between the satellite and the terrestrial network. In this case, the AMF and MME mounted on the satellite may be referred to as AMF-onboard 141 and MME-onboard 41, and the AMF and MME in the terrestrial network may be referred to as AMF-ground 142 and MME-ground 42.

[0139] The AMF-onboard 141 and the AMF-ground 142 may refer to one AMF 140, and the term "AMF 140" may refer to the AMF-onboard 141 and / or the AMF-ground 142. Similarly, the MME-onboard 41 and the MME-ground 42 may refer to one MME 40, and the term "MME 40" may refer to the MME-onboard 41 and / or the MME-ground 42.

[0140] Furthermore, the AMF-ground 142 and the MME-ground 42 may be AMFs and MMEs that are capable of normal connection via terrestrial base stations rather than via satellites. In other words, the AMF-ground 142 may be the AMF 140, and the MME-ground 42 may be the MME 40. In other words, the AMF-ground 142 and the MME-ground 42 may be functional units that are not distinguishable from conventional AMFs and MMEs.

[0141] The UE, the base station, the AMF, the SMF, and / or other core network devices or network functions may store information in advance and generate new information as needed. When information is transmitted and received between them, the receiving party may store the received information and perform operations based on the information.

[0142] The satellite ID may be information for identifying a satellite that is broadcast from an access network using a system information block (SIB). The SIB is a message transmitted in the RRC layer. Here, the SIB may be system information or broadcast information.

[0143] The first identification information is information indicating whether the UE supports the S&F operation mode. The first identification information may be information indicating that the UE supports the S&F operation mode.

[0144] The second identification information may be information indicating that the information transmitted by the UE is a retransmission of a request message that was rejected due to the S&F operation mode and / or a retry of transmitting the request message, or the second identification information may be information indicating whether the information transmitted by the UE is a retransmission of a request message that was rejected due to the S&F operation mode.

[0145] The second identification information is information indicating that the request message transmitted by the UE is a retransmission of a request message rejected due to S&F. When the UE receives a rejected request for S&F from the network and / or satellite, the UE may include the second identification information in the request message when retrying to transmit the request message after the Wait timer expires.

[0146] The second identification information may be information indicating that the request message rejected due to S&F and the request message sent together with and / or including the second identification information are the same information.

[0147] The tenth identification information may be information indicating that the procedure initiated by the UE when the request message is sent cannot be completed due to an S&F operation. The tenth identification information may be information indicating that the request indicated in the request message sent by the UE is rejected due to an S&F operation. The tenth identification information may be information indicating that the attach, TAU, or registration procedure can be retried for the same PLMN on the next satellite path. Furthermore, the tenth identification information may be information indicating that the information included in the UE's request message is stored in the MME or AMF in the satellite and forwarded to the terrestrial network after the feeder link is connected.

[0148] The tenth identification information may be a reason value, for example, an EMM cause for EPS or a 5GMM cause for 5GS.

[0149] The eleventh identification information may be information indicating a value of a Wait timer. The Wait timer may be information indicating a time period for the UE to wait before retrying the attach procedure, the TAU procedure, or the registration procedure with a satellite of the same PLMN. In other words, the UE may be controlled to prohibit and / or control and / or wait from transmitting a request message for the attach procedure, the TAU procedure, or the registration procedure with the current PLMN and / or satellite while the Wait timer is running.

[0150] The 11th identification information may be information indicating the upper limit and / or lower limit of the value of the Wait timer. Furthermore, the satellites targeted by the Wait timer indicated by the 11th identification information are not limited to these, and may be one or more satellites indicated by the 12th identification information described below. Note that the upper limit may mean the maximum value.

[0151] The twelfth identification information may be information indicating one or more satellites for which the UE can retry the attach, TAU, or registration procedure after the Wait timer expires. The twelfth identification information may be a list of satellite IDs and may be referred to as a list of satellite IDs. The twelfth identification information may include at least a satellite ID indicating the satellite that transmitted the twelfth identification information. The twelfth identification information may be information indicating satellites for which the UE is prohibited from retrying a registration procedure (e.g., an attach procedure, a TAU procedure, or a registration procedure) while the Wait timer is running.

[0152] [3. Description of procedures used in each embodiment] Next, procedures used in each embodiment will be described. The procedures used in each embodiment include a registration procedure and a network-initiated de-registration procedure. Each procedure will be described below.

[0153] In each embodiment, as shown in FIG. 2, the HSS and UDM, PCF and PCRF, SMF and PGW-C, and UPF and PGW-U are each configured as the same device (i.e., the same physical hardware, the same logical hardware, or the same software). However, the contents described in this embodiment are also applicable to cases where these are configured as different devices (i.e., different physical hardware, different logical hardware, or different software). For example, data may be transmitted and received directly between these devices, or data may be transmitted and received via the N26 interface between the AMF and MME, or data may be transmitted and received via the UE.

[0154] [3.1. Registration Procedure / Attach Procedure / Tracking Area Update Procedure (TAU Procedure)] First, a procedure for a UE to register and / or attach to a system (for example, 5GS or EPS) will be described with reference to Fig. 7. Hereinafter, this procedure refers to a procedure for a UE to register and / or attach to a system. For example, this procedure may be a registration procedure, an attach procedure, or a tracking area updating procedure (TAU), or may be some other procedure. The tracking area updating procedure is also called a TAU procedure.

[0155] The registration procedure is a procedure initiated by the UE to register with the access network _B and / or the core network _B and / or the DN. If the UE is not registered with the network, it can execute this procedure at any time, for example, when it is powered on. In other words, if the UE is in a non-registered state (5GMM-DEREGISTERED state), it can start this procedure at any time. Furthermore, each device (especially the UE and the AMF) can transition to a registered state (5GMM-REGISTED state) based on the completion of the registration procedure.

[0156] The attach procedure is a procedure initiated by the UE to register with the access network_A and / or the core network_A and / or the DN. If the UE is not registered with the network, it can execute this procedure at any time, for example, when it is powered on. In other words, if the UE is in the unregistered state (EMM-DEREGISTERED state), it can start this procedure at any time. Furthermore, each device (especially the UE and MME) can transition to the registered state (EMM-REGISTED state) based on the completion of the attach procedure.

[0157] Each registration state may be stored and / or managed by each device for each access. Specifically, each device may store and / or manage the registration state (registered state or unregistered state) for 3GPP access and the registration state for non-3GPP access independently.

[0158] Furthermore, the registration procedure and the TAU procedure may be procedures for updating the location registration information of the UE in the network, and / or for the UE to periodically notify the network of the status of the UE, and / or for updating certain parameters related to the UE in the network.

[0159] A UE may initiate the registration procedure when it moves across a registered TA (Tracking Area). In other words, a UE may initiate the registration procedure when it moves to a TA different from the TA indicated in its TA list (TAI list or registration area). Furthermore, a UE may initiate this procedure when a running backoff timer or other timer expires.

[0160] In 5GS, the procedure for a UE to transition from a state where it is not registered in the network to a state where it is registered may be referred to as an initial registration procedure or a registration procedure for initial registration, and the registration procedure performed when the UE is registered in the network may be referred to as a registration procedure for mobility and periodic registration update or a mobility and periodic registration procedure.

[0161] Furthermore, the registration procedures for mobility and periodic registration updates may be separate procedures: the registration procedure for mobility registration update and the registration procedure for periodic registration update.

[0162] On the other hand, in EPS, the procedure for a UE to transition from a state where it is not registered in the network to a state where it is registered may be referred to as an attach procedure, and the procedure for updating location information and / or UE registration information executed when the UE is registered in the network may be referred to as a normal or periodic tracking area updating procedure (TAU procedure).

[0163] Furthermore, if the TAU procedure is performed for mobility, the procedure may be referred to as a normal tracking area updating procedure, and if it is performed periodically, the procedure may be referred to as a periodic tracking area updating procedure.

[0164] 7, the base station device may be a base station device such as an eNB and / or a gNB, and may be a base station device installed on the ground or a base station device mounted on a satellite. The mobility management device may be an AMF 140 and / or an MME 40, and may be a mobility management device installed on the ground or a mobility management device mounted on a satellite, or may be configured by a combination of a mobility management device installed on the ground and a mobility management device mounted on a satellite.

[0165] The mobility management device-onboard may be AMF-onboard 141 and / or MME-onboard 41, which may be a mobility management device onboard a satellite. The mobility management device-ground may be AMF-ground 142 and / or MME-ground 42, which may be a mobility management device installed on the ground. The subscriber / authorization management device may be HSS 50 and / or UDM 150 and / or AUSF, which may be a network device installed on the ground for managing subscribers and / or authorizations.

[0166] Note that the term "mobility management device of a terrestrial network" may refer to a mobility management device and / or a mobility management device-onboard. The mobility management device may also include a mobility management device-onboard and / or a mobility management device-ground.

[0167] First, UE_A10 starts this procedure by sending a request message to the mobility management device (S600) (S602) (S604). For example, UE_A10 may start the registration procedure, attach procedure, or TAU procedure by sending a registration request message to AMF140, or an attach request message or tracking area update request message (TAU request message) to MME40.

[0168] Specifically, in 5GS, the UE transmits an RRC message including a registration request message to the 5G AN 120 (or gNB) (S600). Alternatively, in EPS, the UE transmits an RRC message including an attach request message or a TAU request message to the E-UTRAN 80 (or eNB) (S600). The 5G AN 120 (or gNB) and / or the E-UTRAN 80 (or eNB) may transmit or forward the received NAS message to the AMF 140 and / or the MME 40.

[0169] The registration request message is an NAS message transmitted and received over the N1 interface, while the attach request message and the TAU request message are NAS messages transmitted and received over the LTE-Uu interface and the S1-MME interface.

[0170] Furthermore, RRC messages may be control messages transmitted and received between a UE and an access network or a base station, and NAS messages are processed in the NAS layer, while RRC messages are processed in the RRC layer, which is a layer above the RRC layer.

[0171] Hereinafter, the registration request message, the attach request message, and the TAU request message are referred to as request messages. In other words, unless otherwise specified, the request message means the registration request message, the attach request message, and / or the TAU request message transmitted from the UE. Here, the UE_A10 can transmit the first identification information and / or the second identification information by including them in the request message and / or the RRC message.

[0172] UE_A10 may include UE capability information in the request message to notify the network of the capabilities supported by UE_A10. Here, the UE capability information may be a 5G MM capability IE for 5GS or a UE network capability IE for EPS. The first identification information may be information included in the 5G MM capability IE for 5GS and / or the UE network capability IE for EPS.

[0173] In other words, if the UE supports the first function, the UE may set information indicating that the UE supports the first function in the first identification information and transmit it.

[0174] If the request message to be sent is a retransmission of a request message that was rejected due to the S&F operation mode, UE_A10 may include the second identification information in the request message and send it. Alternatively, UE_A10 may set information indicating that the request message is a retransmission of a request message that was rejected due to the S&F operation mode in the second identification information and send it.

[0175] UE_A10 may transmit these identification information and / or IEs in a different control message, for example, a control message of a layer lower than the RRC layer (for example, a MAC layer, an RLC layer, or a PDCP layer). By transmitting these identification information, UE_A10 may indicate that UE_A10 supports each function, or may indicate a UE request, or may indicate both. Furthermore, when multiple identification information are transmitted and received, two or more of these identification information may be configured as one or more identification information. Furthermore, the information indicating support for each function and the information indicating a request for use of each function may be transmitted and received as the same identification information, or may be transmitted and received as different identification information.

[0176] UE_A10 may include other identification information in the request message and / or the RRC message containing the request message, for example, the UE ID and / or the PLMN ID.

[0177] Furthermore, UE_A10 may select and decide whether to send this identification information to the network based on the UE's capability information, and / or UE policy, and / or UE status, and / or user registration information, and / or context held by the UE, etc.

[0178] When the access network (5G AN120 (or gNB) or E-UTRAN (or eNB)) receives the RRC message including the request message, it selects a mobility management device (e.g., AMF, MME) to forward the request message (S602). Note that the access network can select the mobility management device based on one or more pieces of identification information included in the request message and / or the RRC message including the request message.

[0179] For example, the access network may select a mobility manager based on a PLMN ID. Specifically, the access network may select a mobility manager for a requested PLMN based on a PLMN ID indicating the PLMN requested by the UE.

[0180] Note that the method for selecting a mobility management device is not limited to this, and the access network may select a mobility management device based on other conditions. The access network extracts the request message from the received RRC message and transfers the request message to the selected mobility management device (S604). Note that the access network may transfer identification information that is not included in the request message but is included in the RRC message to the selected mobility management device together with the request message (S604).

[0181] Here, when this procedure is performed using a UE and / or a satellite and / or a NW having the capability to operate in S&F mode, the access network and / or base station device may be located on the satellite, and the mobility management device selected by the access network may be a mobility management device-onboard (e.g., MME-onboard 41 or AMF-onboard 141).

[0182] When the UE and / or satellite and / or NW operate in normal mode, the mobility management device-onboard may transmit information received from the UE via the access network to a mobility management device of a terrestrial network (S605). Specifically, for example, the MME-onboard 41 may transmit or forward information received from the UE via the E-UTRAN 80 (or eNB) to the MME-ground 142 or MME 140 of the terrestrial network. Similarly, the AMF-onboard 141 may transmit information received from the UE via the 5G AN 120 (or gNB) to the AMF-ground 142 or AMF 140 of the terrestrial network.

[0183] The mobility management device of the terrestrial network may determine and start an authentication procedure for the UE upon receiving a request message from the UE via the mobility management device-onboard and / or the access network (S606).

[0184] Specifically, when the AMF-ground 142 or the AMF 140 decides to start an authentication procedure for the UE, the AMF-ground 142 or the AMF 140 may select an AUSF based on the SUPI or SUCI of the UE, and may send the SUPI or SUCI of the UE to the selected AUSF to request the authentication procedure.

[0185] The AUSF may select a UDM, and the UDM may obtain authentication data. Once the UE is authenticated, the AUSF sends security related information about the UE to the AMF-ground 142 or AMF 140. Note that if the AUSF has received a SUCI from the AMF-ground 142 or AMF 140 during the authentication procedure, the AUSF may provide a SUPI to the AMF-ground 142 or AMF 140 only after the authentication is successful.

[0186] If the MME-ground 142 or the MME 140 decides to start an authentication procedure for the UE, the UE selects an HSS and obtains security information from the HSS. After successful authentication, all NAS messages are protected by NAS security.

[0187] After the authentication procedure is successful, if the mobility management device of the terrestrial network does not have the UE context, it may perform a procedure to obtain the UE context and / or the UE registration information from the subscriber management device (e.g., HSS50 or UDM150) (S608).

[0188] Specifically, AMF-ground 142 or AMF 140 may register to a UDM if the AMF has changed since the previous registration procedure, or if this registration procedure is an initial registration procedure or a registration procedure for emergency services, or if the UE includes in the request message a SUPI that does not reference a valid context in AMF-ground 142 or AMF 140, or if the UE registers to the same AMF as it is already registered to for non-3GPP access.

[0189] After successful registration to the UDM, if the AMF-ground 142 or the AMF 140 does not have the UE registration information and / or information contained in the UE registration information, the AMF-ground 142 or the AMF 140 may obtain the UE registration information and / or information contained in the UE registration information from the UDM.

[0190] Additionally, the MME-ground 142 or MME 140 may send an Update Location Request to the HSS if the MME has changed since the last detach, or if there is no valid registration context for the UE in the MME-ground 142 or MME 140, or if the UE has provided an IMSI or GUTI that does not reference a valid context in the MME-ground 142 or MME 140. The Update Location Request may include, for example, the MME ID and / or IMSI. The HSS may acknowledge the Update Location Request (also referred to as an Update Location message) by sending an Update Location Ack to the MME-ground 142 or MME 140, including the UE's IMSI and registration information.

[0191] If this procedure is performed via a satellite, and if the UE and / or satellite and / or NW are operating in normal mode and / or feeder link connectivity is available, the mobility management device of the terrestrial network may send and / or forward the UE authentication results and / or UE registration information obtained in S606 and S608 to the mobility management device-onboard (S609).

[0192] The mobility management device may decide whether to accept or reject a request from the UE based on the authentication procedure and / or the acquisition of UE registration information. Note that the information used to decide whether to accept or reject a request from the UE is not limited to the above, and the decision to accept or reject a request from the UE may be made based on one or more pieces of information acquired by the mobility management device of the terrestrial network during this procedure. Based on the decision to accept or reject the request from the UE, the mobility management device may generate a control message (acceptance message or rejection message) that is a response message to the request from the UE. Specifically, the mobility management device may generate an acceptance message if the request from the UE is to be accepted, and a rejection message if the request is to be rejected.

[0193] If this procedure is performed via a satellite, and if the UE and / or the satellite and / or the NW are operating in normal mode and / or feeder link connectivity is available, the mobility management device of the terrestrial network may send the generated control message to the mobility management device-onboard (S609).

[0194] If this procedure is performed via a satellite, and if the UE and / or satellite and / or NW operates in S&F mode and / or feeder link connectivity is unavailable, the mobility management device of the terrestrial network may store the UE authentication results and / or UE registration information obtained in S606 and S608, and transmit and / or forward them after feeder link connectivity becomes available (S609).

[0195] The mobility management device may send an RRC message including an accept message or a reject message to the UE (S610). The mobility management device may send an accept message if it accepts the request from the UE, or may send a reject message if it rejects the request.

[0196] The mobility management device-onboard may forward a control message received from the mobility management device-grand, or may generate a control message to be transmitted to the UE based on the control message and / or information received from the mobility management device-grand and transmit the generated control message to the UE. For example, the mobility management device-onboard may generate a new control message by adding information to the control message received from the mobility management device-grand, or may determine whether to accept a request from the UE based on the control message and / or information received from the mobility management device-grand and generate a control message.

[0197] The accept message may be a message indicating acceptance of a request message from the UE, such as a Registration accept message, an Attach accept message, or a Tracking area update accept message. The reject message may be a message indicating rejection of a request message from the UE, such as a Registration reject message, an Attach reject message, or a Tracking area update reject message.

[0198] When the mobility management device-onboard receives a request message from the UE in S604, if the UE and / or the satellite and / or the NW operates in the S&F mode, the mobility management device-onboard and / or each device in the network may reject the request from the UE without performing the procedures from S605 to S609. In this case, the mobility management device-onboard may send an RRC message including a rejection message to the UE (S610). In this case, the mobility management device-onboard may mean that it rejects the request from the UE because of the S&F mode.

[0199] When the mobility management device-onboard rejects a request from the UE because of the S&F mode, it may store information included in the request message from the UE, and after the feeder link becomes available for connection, execute S605 to S609, which it had not executed. In this case, the mobility management device-onboard may add information indicating that the mobility management device-onboard has already responded to the UE to the request message from the UE to be sent and / or forwarded to the mobility management device-grand, and send and / or forward the request message from the UE (S605). When the mobility management device-grand receives information indicating that the mobility management device-onboard has already responded to the request message from the UE, it may not decide whether to accept or reject the request indicated in the request message from the UE and / or may not send a control message to the mobility management device-onboard (S609).

[0200] The registration accept message and registration reject message are NAS messages transmitted and received over the N1 interface, while the attach accept message, attach reject message, TAU accept message, and TAU reject message are NAS messages transmitted and received over the LTE-Uu interface and the S1-MME interface.

[0201] When the mobility management device-onboard rejects a request from the UE for an S&F operation, the mobility management device-onboard may include at least one of the tenth to twelfth identification information in a rejection message or an RRC message containing the rejection message. The mobility management device-onboard may determine whether to send at least one of the tenth to twelfth identification information based on information received from the UE and / or the access network and / or the first identification information.

[0202] For example, when the mobility management device-onboard receives first identification information, which is information indicating that the UE supports the S&F operation mode, the mobility management device-onboard may transmit at least one of the tenth to twelfth identification information.

[0203] On the other hand, if the mobility management device-onboard receives first identification information that is information indicating that the UE does not support the S&F operation mode, or if it does not receive first identification information that is information indicating that the UE supports the S&F operation mode, it may not transmit identification information items 10 to 12. In this case, the mobility management device-onboard may include a cause value indicating Congestion (EMM cause or 5GMM cause) and a back-off timer value (T3346) in the rejection message or an RRC message containing the rejection message.

[0204] UE_A10 receives a control message and / or one or more pieces of information contained in the control message from the network. UE_A10 may recognize the received information based on receiving the control message and / or one or more pieces of information contained in the control message.

[0205] Specifically, a UE that receives the tenth identity may recognize that this procedure cannot be completed due to an S&F operation. A UE that receives the tenth identity may recognize that this procedure can be performed to retry the attach, TAU, or registration procedure for the same PLMN on the next satellite path. A UE that receives the tenth identity may recognize that the information included in the request message sent in this procedure is stored in the satellite's AMF or MME, and that the stored information will be forwarded to the terrestrial network when the feeder link becomes available. A UE that receives the tenth identity may store information about the satellite that is performing this procedure in the stored twelfth identity.

[0206] Upon receiving the eleventh identification information, the UE may execute a Wait timer using a value indicated in the eleventh identification information. The UE may associate a PLMN ID and / or a Satellite ID with the Wait timer, store and / or manage the Wait timer, and execute the Wait timer. Furthermore, the UE may stop and / or delete a running Wait timer based on the reception of the eleventh identification information.

[0207] The UE may control the UE so that, while the Wait timer is running, the UE does not retry transmitting the request message to the PLMN indicated by the PLMN ID associated with the Wait timer and / or the satellite indicated by the Satellite ID.

[0208] A UE that receives the 12th identification information may associate the value of the Wait timer indicated by the 11th identification information and / or the Wait timer using the value of the 11th identification information with a list of Satellite ID(s) consisting of one or more Satellite IDs indicated by the 12th identification information, and manage and / or store the list.

[0209] Furthermore, the mobility management device may select or determine the identification information to be included in the control message and / or the information to be notified based on each received identification information, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the AMF, etc.

[0210] In addition, the mobility management device may indicate that the UE's request has been accepted by sending a registration acceptance message based on the received identification information, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or context held by the AMF, etc., or may indicate that the UE's request has been rejected by sending a registration rejection message.

[0211] The UE receives a control message via the access network (S610). If the control message is an acceptance message, the UE can recognize that the request of the UE in the request message has been accepted and the contents of various identification information included in the acceptance message by receiving the acceptance message.

[0212] Alternatively, if the control message is a rejection message, the UE can recognize that the UE's request in the request message has been rejected and the contents of various identification information included in the rejection message by receiving the rejection message. Also, if the UE does not receive a control message within a predetermined period after sending the request message, the UE may recognize that the UE's request has been rejected.

[0213] If the control message is an accept message, the UE may further send a completion message to the AMF or MME via the access network as a response message to the accept message. Here, the completion message is an NAS message transmitted and received over the N1 interface, or the LTE-Uu interface and the S1-MME interface, and is transmitted and received between the UE and the access network in the form of an RRC message.

[0214] The completion message may be a registration completion message, an attach completion message, or a tracking area update completion message.

[0215] The mobility management device receives the completion message via the access network, and each device completes this procedure based on the transmission and reception of the control message and / or the completion message.

[0216] Each device may transition to or maintain each state based on the transmission and reception of a control message and / or information contained in the control message. Alternatively, the transition of each device to each state may be based on the transmission and reception of a completion message or the completion of this procedure. Transitioning to a certain state may mean the same as entering a certain state.

[0217] For example, each device may transition to or maintain a state in which the UE is registered in the network (RM_REGISTERED state or 5GMM-REGISTERED state) based on the transmission and reception of a registration accept message and / or a registration complete message, or may transition to or maintain a state in which the UE is not registered in the network on the access on which the registration reject message for the current PLMN was received (RM_DEREGISTERED state or 5GMM-DEREGISTERED state) or a state in which the UE is registered in the network based on the transmission and reception of a registration reject message and / or a cause value.

[0218] Alternatively, each device may transition to a state in which the UE is registered in the network (EMM_REGISTERED state) based on the sending and receiving of an attach accept message and / or an attach complete message, or may transition to or maintain a state in which the UE is not registered in the network (EMM_DEREGISTERED state) or a state in which the UE is registered in the network (EMM_REGISTERED state) on the access on which the attach reject message was received for the current PLMN based on the sending and receiving of an attach reject message and / or a cause value.

[0219] Alternatively, each device may transition to a state in which the UE is registered in the network (EMM_REGISTERED state) based on the transmission and reception of a TAU accept message and / or a TAU complete message, or may transition to or maintain a state in which the UE is not registered in the network (EMM_DEREGISTERED state) or a state in which the UE is registered in the network (EMM_REGISTERED state) on the access on which the Attach Reject message was received for the current PLMN based on the transmission and reception of a TAU reject message and / or a cause value.

[0220] Furthermore, if this procedure is a registration procedure other than initial registration, based on the sending and receiving of a registration rejection message and 10th identification information, each device may transition to or maintain a state in which the UE is not registered in the network (RM_DEREGISTERED state or 5GMM-DEREGISTERED state).

[0221] Alternatively, if this procedure is a registration procedure other than initial registration, and if a registration rejection message is sent or received or the registration procedure fails, and if the 10th identification information is sent or received, each device may transition to or maintain a state in which the UE is registered in the network (EMM_REGISTERED state).

[0222] Furthermore, if this procedure is an attach procedure, based on the sending and receiving of the attach rejection message and the 10th identification information, each device may transition to or maintain a state in which the UE is not registered in the network (EMM_DEREGISTERED state).

[0223] Furthermore, if this procedure is a TAU procedure, based on the sending and receiving of a TAU rejection message and 10th identification information, each device may transition to or maintain a state in which the UE is not registered in the network (EMM_DEREGISTERED state), or may transition to or maintain a state in which the UE is registered in the network (EMM_REGISTERED state).

[0224] Furthermore, each device may perform processing based on the information transmitted and received in this procedure based on the completion of this procedure. For example, if the device transmits or receives information indicating that some of the UE's requests were rejected, the device may recognize the reason why the UE's requests were rejected. Furthermore, each device may retry initiating the registration procedure, attach procedure, and / or TAU procedure based on the reason why the UE's requests were rejected, or may perform the registration procedure, attach procedure, and / or TAU procedure for the current satellite or another satellite, or the current PLMN or another PLMN.

[0225] Furthermore, the UE may store the identification information received with the accept and / or reject messages and may recognize the network's decision based on the completion of this procedure.

[0226] Furthermore, the UE may reset stored information, start a timer, or stop a running timer based on the completion of this procedure and / or information received in this procedure.

[0227] Specifically, for example, based on receiving at least one of the tenth and / or eleventh identification information, the UE may start counting a wait timer using the value of the wait timer indicated in the eleventh identification information. The wait timer may be stored and executed in association with a satellite ID indicating the current PLMN and / or satellite from which the UE has transmitted the request message.

[0228] In addition, when the UE receives the 12th identification information, the Wait timer may be further stored and executed in association with information (list of satellite IDs) indicating one or more satellites indicated by the 12th identification information.

[0229] In addition, when the information contained in the 11th identification information is neither 0 nor information indicating deactivate, the UE may start and / or execute counting the above-mentioned Wait timer and / or control using the Wait timer.

[0230] As a result of the above, each device may properly complete the registration procedure, the attach procedure, or the TAU procedure, and the stored information and / or the status may be updated and / or controlled based on the stored information.

[0231] 3.2. UE-initiated de-registration / detachment procedures Next, a procedure initiated by the UE for the UE to de-register and / or detach from a system (e.g., 5GS, EPS, etc.) will be described with reference to Fig. 8. Hereinafter, this procedure refers to a procedure for de-registering and / or detaching from a system. For example, this procedure may be a UE-initiated de-registration procedure, a UE-initiated detach procedure, or another procedure.

[0232] The deregistration procedure initiated by the UE is a procedure for the UE to initiate deregistration to the access network _B, and / or the core network _B, and / or the DN. If the UE is registered to the network, it can execute this procedure before powering off. In other words, if the UE is in a registered state (5GMM-REGISTERED state), it can start this procedure at any time. Furthermore, each device (especially the UE and the AMF) can transition to and / or enter a deregistered state (5GMM-DEREGISTEDED state) based on the completion of the deregistration procedure.

[0233] The detach procedure initiated by the UE is a procedure for the UE to initiate de-registration to access network_A, and / or core network_A, and / or DN. As long as the UE is registered to the network, it can execute this procedure at any time, for example, before powering off. In other words, the UE can start this procedure at any time as long as it is in the de-registered state (EMM-DEREGISTERED state). Furthermore, each device (especially the UE and MME) can transition to the de-registered state (EMM-DEREGISTED state) based on the completion of the detach procedure.

[0234] Each registration state may be stored and / or managed by each device for each access. Specifically, each device may store and / or manage the registration state (registered state or unregistered state) for 3GPP access and the registration state for non-3GPP access independently.

[0235] 8, the base station device may be a base station device such as an eNB and / or a gNB, the mobility management device may be an AMF 140 and / or an MME 40, the mobility management device-onboard may be an AMF-onboard 141 and / or an MME-onboard 41, the mobility management device-ground may be an AMF-ground 142 and / or an MME-ground 42, and the session management device may be an SMF 132 and / or an SGW 35 and / or a PGW and / or a PGW-C. Note that when referring to a mobility management device of a terrestrial network, this may mean the mobility management device and / or the mobility management device-onboard. Furthermore, the mobility management device may include the mobility management device-onboard and / or the mobility management device-ground.

[0236] First, UE_A10 starts this procedure by sending a request message to the mobility management device (S800). For example, UE_A10 may start a deregistration procedure initiated by the UE by sending a deregistration request message to AMF140, or may start a detachment procedure initiated by the UE by sending a detachment request message to MME40.

[0237] Specifically, in 5GS, the UE may send an RRC message including a deregistration request message to the 5G AN 120 (or gNB). Alternatively, in EPS, the UE may send an RRC message including a detach request message to the E-UTRAN 80 (or eNB). The 5G AN 120 (or gNB) and / or the E-UTRAN 80 (or eNB) may send or forward the received NAS message to the AMF 140 and / or the MME 40.

[0238] The unregistration request message is a NAS message transmitted and received over the N1 interface, whereas the detach request message is a NAS message transmitted and received using the LTE-Uu interface and the S1-MME interface.

[0239] Furthermore, RRC messages may be control messages transmitted and received between a UE and an access network or a base station, and NAS messages are processed in the NAS layer, while RRC messages are processed in the RRC layer, which is a layer above the RRC layer.

[0240] Hereinafter, the unregistration request message and the detachment request message will be referred to as a request message, that is, unless otherwise specified, the request message refers to the unregistration request message and / or the detachment request message sent from the UE.

[0241] UE_A10 may transmit information indicating whether this procedure is to be performed based on the UE being powered off in the request message. The information indicating whether this procedure is to be performed based on the UE being powered off may be information included in the Deregistration type IE and / or the Detach type IE.

[0242] UE_A10 may transmit information indicating the access type targeted by this procedure in the request message. Specifically, this information may indicate whether the access to be deregistered by this procedure is 3GPP access, non-3GPP access, or both. The information indicating the access type targeted by this procedure may be information included in the Deregistration type IE and / or Detach type IE.

[0243] UE_A10 may transmit these identification information and / or IEs in a control message other than these, for example, a control message of a layer lower than the RRC layer (for example, a MAC layer, an RLC layer, or a PDCP layer). UE_A10 may also indicate a UE request by transmitting these identification information. Furthermore, when multiple identification information are transmitted and received, two or more of these identification information may be configured as one or more identification information.

[0244] UE_A10 may include other identification information in the request message and / or the RRC message containing the request message, for example, the UE ID and / or the PLMN ID.

[0245] Here, when this procedure is performed using a UE and / or a satellite and / or a NW having the capability to operate in S&F mode, the access network and / or base station device may be located on the satellite, and the mobility management device to which the access network forwards the request message from the UE may be a mobility management device-onboard (e.g., MME-onboard 41 or AMF-onboard 141).

[0246] When the UE and / or satellite and / or NW operate in normal mode, the mobility management device-onboard may transmit information received from the UE via the access network to a mobility management device of a terrestrial network (S802). Specifically, for example, the MME-onboard 41 may transmit or forward information received from the UE via the E-UTRAN 80 (or eNB) to the MME-ground 142 or MME 140 of the terrestrial network. Similarly, the AMF-onboard 141 may transmit information received from the UE via the 5G AN 120 (or gNB) to the AMF-ground 142 or AMF 140 of the terrestrial network.

[0247] The mobility management device of the terrestrial network may transmit a session release request message to the session management device upon receiving the request message from the UE via the mobility management device-onboard and / or the access network (S804). The session management device that has received the session release request message may transmit a session release response message to the mobility management device of the terrestrial network (S806).

[0248] Specifically, when a PDU session is established on an access type for which deregistration has been requested by the UE, the AMF-ground 142 or the AMF 140 may transmit a PDU session release request message for each PDU session to the SMF 132. The SMF that has received the PDU session release request message may release the target PDU session and transmit a PDU session release response message to the AMF-ground 142 or the AMF 140 as a response message.

[0249] Furthermore, if the MME-ground 142 or MME 140 has an active PDN connection, it may send a Delete Session Request to the SGW for each PDN connection. Furthermore, the SGW may send a Delete Session Request to the PGW for each PDN connection. The PGW and / or SGW may send a Delete Session Response as a response message, and the MME-ground 142 or MME 140 may receive the Delete Session Response.

[0250] If this procedure is performed via a satellite, and if the UE and / or the satellite and / or the NW are operating in normal mode and / or feeder link connectivity is available, the mobility management device of the terrestrial network may recognize the release and / or deletion of the session based on the reception of S806 and may send a control message to the mobility management device-onboard in response to the request from the UE (S808). The control message may be an accept message, a deregistration accept message and / or a detach accept message, or any other accept message in response to the request from the UE.

[0251] If this procedure is performed via a satellite, and if the UE and / or satellite and / or NW operates in S&F mode and / or feeder link connectivity is unavailable, the mobility management device of the terrestrial network may recognize the release and / or deletion of the session based on receipt of S806, generate a control message in response to the request from the UE, store the control message in terrestrial memory, and transmit it after feeder link connectivity becomes available (S808).

[0252] The mobility management device may transmit an RRC message including an accept message to the UE (S810). The mobility management device-onboard may forward the control message received from the mobility management device-grand, or may generate a control message to be transmitted to the UE based on the control message and / or information received from the mobility management device-grand and transmit the control message to the UE. For example, the mobility management device-onboard may generate a new control message by adding information to the control message received from the mobility management device-grand, or may generate a control message based on the control message and / or information received from the mobility management device-grand. The control message may be an accept message, a deregistration accept message and / or a detach accept message, or any other accept message in response to a request from the UE.

[0253] When the mobility management device-onboard receives a request message from the UE in S800, if the UE and / or the satellite and / or the NW operates in the S&F mode, the mobility management device-onboard and / or each device in the network may accept the request from the UE without performing the procedures from S802 to S808. In this case, the mobility management device-onboard may send an RRC message including an acceptance message to the UE (S810).

[0254] The mobility management device-onboard skips S802 to S808 because it is in S&F mode, and if it accepts the request from the UE, it stores the information contained in the request message from the UE, and after the feeder link connection becomes possible, it executes S802, which it had not executed, while the feeder link is available, so that the mobility management device-onboard and / or each device in the network can execute S802 to S808.

[0255] In this case, the mobility management device-onboard may add information indicating that the mobility management device-onboard has already responded to the UE to the request message from the UE that is to be sent and / or forwarded to the mobility management device-grand, and transmit and / or forward the request message from the UE (S802).When the mobility management device-grand receives information indicating that the mobility management device-onboard has already responded to the UE to the request message from the UE, the mobility management device-grand may not transmit a control message to the mobility management device-onboard (S808).

[0256] The unregistration accept message is a NAS message sent and received over the N1 interface, while the detach accept message is a NAS message sent and received over the LTE-Uu interface and the S1-MME interface.

[0257] UE_A10 receives a control message and / or one or more pieces of information contained in the control message from the network. UE_A10 may recognize the received information based on receiving the control message and / or one or more pieces of information contained in the control message.

[0258] The UE receives a control message via the access network (S610). If the control message is an acceptance message, the UE can recognize that the UE's request in the request message has been accepted and the contents of various identification information included in the acceptance message by receiving the acceptance message. Furthermore, each device completes this procedure based on the transmission and reception of the control message and / or the completion message.

[0259] Each device may transition to or maintain each state based on the transmission and reception of a control message and / or information contained in the control message. Alternatively, the transition of each device to each state may be based on the transmission and reception of a completion message or the completion of this procedure. Transitioning to a certain state may mean the same as entering a certain state.

[0260] For example, each device may transition the UE to a state in which it is deregistered from the network (RM_DEREGISTERED state or 5GMM-DEREGISTERED state) based on sending or receiving a deregistration acceptance message.

[0261] Furthermore, the UE may store the identification information received with the acceptance message and may recognize the network's decision based on the completion of this procedure. Furthermore, the UE may reset the stored information, start a timer, or stop a running timer based on the completion of this procedure and / or the information received in this procedure.

[0262] Furthermore, each device may perform processing based on the information transmitted and received in this procedure and / or the information stored in each device upon completion of this procedure. For example, upon completion of this procedure, the UE may perform a PLMN search to find a PLMN to connect to.

[0263] As a result of the above, each device may properly complete the registration procedure, the attach procedure, or the TAU procedure, and the stored information and / or the status may be updated and / or controlled based on the stored information.

[0264] 4. Description of the embodiment An embodiment of the present invention may be a combination of one or more of the procedures described in Chapter 3. For example, in this embodiment, upon completion of the initial registration procedure described in Chapter 3.1, the UE may transition to the registered state, and then perform one or more registration procedures for mobility and periodic registration updates described in Chapter 3.1. Alternatively, upon completion of the attach procedure described in Chapter 3.1, the UE may transition to the registered state, and then perform one or more TAU procedures described in Chapter 3.1.

[0265] Further, for example, after the registration procedure and / or the attach procedure described in Section 3.1, the unregistration procedure and / or the detachment procedure described in Section 3.2 may be performed.

[0266] In addition, in an embodiment of the present invention, an SM procedure for sending and receiving SM messages may be performed based on the completion of the registration procedure described in Chapter 3.1.

[0267] The procedures used in the first to third embodiments may include the MM procedures described above.

[0268] In the embodiment of the present invention, as shown in FIG. 2, an example will be described in which the HSS and UDM, the PCF and PCRF, the SMF and PGW-C, and the UPF and PGW-U are configured as the same device / function (i.e., the same physical hardware, the same logical hardware, or the same software). However, the content described in this embodiment is also applicable to cases in which these are configured as different devices / functions (i.e., different physical hardware, different logical hardware, or different software). For example, data may be transmitted and received directly between these, or may be transmitted and received via the N26 interface between the AMF and MME, or may be transmitted and received via the UE.

[0269] Hereinafter, a satellite equipped with the functions of a base station device and / or a mobility management device may be simply referred to as a satellite, a base station device, or a mobility management device. Here, the base station device may be referred to as a base station, or may refer to a gNB, an eNB, an en-gNB, an ng-eNB, or an access point accommodated in non-3GPP access (for example, an access point such as that used in a wireless LAN). The MME may be MME-onboard and / or MME-ground, and the AMF may be AMF-onboard and / or AMF-ground.

[0270] Also, the UE, and / or the satellite, and / or the network may operate in S&F mode or in normal mode, i.e., the UE, and / or the satellite, and / or the network may support the functionality of operating in S&F mode.

[0271] Additionally, the UE and / or satellite and / or network may support the ability to connect the UE to a terrestrial core network via a satellite.

[0272] Specific examples of embodiments of the present invention will be described below.

[0273] 4.1 First embodiment First, a procedure used in the first embodiment will be described, which explains the behavior of each device when the power supply of the UE is turned off during execution of the Wait timer.

[0274] First, the first satellite may broadcast and / or transmit the Satellite ID of the first satellite to one or more UEs in the satellite's serving cell using an SIB, etc. The first satellite may further transmit the SIB including a Satellite PLMN ID, which is the PLMN of the first satellite, and PLMN ID(s) indicating the PLMNs of one or more terrestrial networks to which the first satellite can provide connectivity. Furthermore, the first satellite may transmit the SIB including information indicating that the S&F mode is active and / or that the satellite supports the S&F mode functionality.

[0275] A UE in an area where the first satellite can provide satellite connectivity may receive an SIB containing the above information from the first satellite. In other words, the UE may receive at least one of a Satellite ID, a Satellite PLMN ID, and one or more PLMN ID(s) from the first satellite.

[0276] Based on the reception from the first satellite, the UE transmits a first request message to the first satellite to attempt a satellite connection using the first satellite, and initiates an MM procedure.

[0277] Here, the first request message sent by the UE may be an attach request message, a tracking area update request message, and / or a registration request message. Furthermore, the MM procedure may be an attach procedure, a tracking area update procedure, and / or a registration procedure. The UE may send the request message together with a first PLMN ID indicating a first PLMN of the selected terrestrial network and / or a first satellite PLMN ID indicating a PLMN of a first satellite.

[0278] When the first satellite and / or each device onboard the first satellite operates in S&F mode, the first satellite and / or the mobility management device-onboard the first satellite receives the first request message transmitted by the UE. Note that the first satellite and / or each device onboard the first satellite operating in S&F mode may indicate that the first satellite has lost connectivity (feeder link) to the ground.

[0279] When the first satellite and / or each device onboard the first satellite operates in S&F mode, the first satellite and / or a mobility management device-onboard (e.g., MME-onboard or AMF-onboard) onboard the first satellite may transmit an RRC message including a first rejection message. The mobility management device-onboard may include at least one of identification information items 10 to 12 in the first rejection message or the RRC message including the first rejection message. Here, the first rejection message may be a registration rejection message, an attach rejection message, or a TAU rejection message.

[0280] The UE may receive the first rejection message and / or an RRC message including the first rejection message from the onboard mobility management device. In other words, the UE may receive the first rejection message from the first satellite.

[0281] When the UE receives the tenth identification information, the UE may start counting the first wait timer using the value indicated in the eleventh identification information. The UE may store and / or manage and execute the first wait timer in association with one or more PLMN ID(s) and / or Satellite ID(s).

[0282] If the value indicated by the eleventh identification information is the value of the Wait timer, the UE may set the value to the Wait timer and start the Wait timer. Alternatively, if the value indicated by the eleventh identification information includes the upper and / or lower limit values ​​of the Wait timer, the UE may set a random value to the Wait timer using one or more values ​​indicated by the eleventh identification information.

[0283] Specifically, when the value indicated by the eleventh identification information indicates the upper limit value of the wait timer, the UE may set the wait timer to a random value such that the value indicated by the eleventh identification information becomes the upper limit value, and start the wait timer. Alternatively, when the value indicated by the eleventh identification information indicates the lower limit value of the wait timer, the UE may set the wait timer to a random value such that the value indicated by the eleventh identification information becomes the lower limit value, and start the wait timer. Note that when the eleventh identification information includes both the upper limit value and the lower limit value of the wait timer, the UE may set the wait timer to a random value within the range between the upper limit value and the lower limit value indicated by the eleventh identification information, and start the wait timer.

[0284] If the value indicated in the 11th identification information is the value of the Wait timer, when the mobility management device-onboard sets the 11th identification information, it may take into consideration that multiple UEs do not simultaneously retry sending a request message, and may set the value set in the 11th identification information to be random.

[0285] The PLMN ID(s) associated with the first Wait timer may be a first PLMN ID of a terrestrial network and / or a first satellite PLMN ID indicating a PLMN of a satellite that the UE sent together with the first request message. The satellite ID(s) associated with the first Wait timer may be a Satellite ID that identifies the first satellite received by the UE in an SIB from the first satellite, or a first list of Satellite ID(s) consisting of one or more Satellite ID(s) indicated by the twelfth identification information.

[0286] For example, if the UE does not receive the twelfth identification information, the UE may associate the first Satellite ID that identifies the first satellite received in the SIB from the first satellite with the first Wait timer, and store and / or manage and execute the first Wait timer. On the other hand, if the UE receives the twelfth identification information, the UE may associate the first Wait timer with a first list of Satellite ID(s) that is made up of one or more Satellite ID(s) indicated in the twelfth identification information, and store and / or manage and execute the first Wait timer.

[0287] For example, when the UE receives the tenth identification information, it may store the first satellite ID that identifies the first satellite received in the SIB from the first satellite in the first wait timer, together with the twelfth identification information already stored in the UE.

[0288] The UE may control the UE so that it cannot transmit a request message to the PLMN(s) indicated by the associated PLMN ID(s) and retry initiating the MM procedure while the Wait timer is running. Similarly, the UE may control the UE so that it cannot transmit a request message to the satellite(s) indicated by the associated satellite ID(s) and retry initiating the MM procedure while the Wait timer is running.

[0289] Specifically, when the first Wait timer is associated with the first PLMN ID, the UE may be controlled not to transmit a request message to the PLMN indicated by the first PLMN ID and not to retry initiating the MM procedure. Similarly, when the first Wait timer is associated with the first Satellite ID, the UE may be controlled not to transmit a request message to the first satellite indicated by the first Satellite ID and not to retry initiating the MM procedure.

[0290] If the UE is powered off while a Wait timer is running, the UE may stop and / or keep one or more Wait timers. For example, the UE may keep one or more Wait timers in non-volatile memory. The UE may stop and / or delete the list if the USIM is removed.

[0291] Alternatively, if the UE is powered off while a Wait timer is running, the UE may stop and / or delete all Wait timers stored in the UE.

[0292] It should be noted that the UE may be powered on again after being powered off, in other words, the UE may be rebooted after being powered off.

[0293] The behavior when the UE power is restarted will be explained below. The first to third timer values ​​used in the following explanation will be explained using Figure 9. As shown in Figure 9, the first timer value is the remaining time of the Wait timer when the UE power is turned off, and the second timer value is the elapsed time from when the UE power is turned off until it is turned on. Furthermore, the third timer value is the value obtained by subtracting the second timer value from the first timer value.

[0294] When the UE is powered on after being powered off while the Wait timer is running, if there is no change in the USIM, the UE may take one of the following actions:

[0295] If the first timer value is greater than the second timer value, the UE may restart the Wait timer and / or restart the Wait timer using a third timer value. If the first timer value is lower than the second timer value, the UE may consider the running Wait timer to have expired and process it as if the Wait timer had expired, or may restart the Wait timer using the first timer value and not consider it to have expired.

[0296] Additionally, if the UE cannot determine the second timer value, the UE may restart counting the Wait timer with the first timer value and / or start the Wait timer.

[0297] When the UE restarts the Wait timer, this may mean that the UE resumes control to prohibit retransmission of the request message to the PLMN and / or one or more satellites associated with the Wait timer while the Wait timer is running.

[0298] As a result, when the UE is powered off while the Wait timer is running and then powered on again, the UE can execute and / or maintain control based on the running Wait timer.

[0299] Furthermore, the above may be applied to an NPN (SNPN and / or PNI-NPN). That is, the present embodiment may also be applied to an NPN by replacing PLMN with SNPN.

[0300] 4.2 Second embodiment Next, a procedure used in the second embodiment will be described, which describes the behavior of each device for transitioning to a non-registered state in order to search for another PLMN, based on receiving notification information indicating that the UE has lost feeder link connectivity from the first satellite.

[0301] First, the first satellite may broadcast and / or transmit the Satellite ID of the first satellite to one or more UEs in the satellite's serving cell using an SIB, etc. The first satellite may further transmit the SIB including a Satellite PLMN ID, which is the PLMN of the first satellite, and PLMN ID(s) indicating the PLMNs of one or more terrestrial networks to which the first satellite can provide connectivity. Furthermore, the first satellite may transmit the SIB including information indicating that the S&F mode is active and / or that the satellite supports the S&F mode functionality.

[0302] A UE in an area where the first satellite can provide satellite connectivity may receive an SIB containing the above information from the first satellite. In other words, the UE may receive at least one of a Satellite ID, a Satellite PLMN ID, and one or more PLMN ID(s) from the first satellite.

[0303] Based on receiving information from the first satellite indicating that the satellite's S&F mode is active, the UE may decide to search for and / or attempt to connect to other terrestrial PLMNs and / or satellites that it discovers.

[0304] Based on the determination, the UE may send a first request message to the first satellite to initiate a procedure for registration update (e.g., a registration procedure and / or a TAU procedure).

[0305] Here, the first request message sent by the UE may be a tracking area update request message and / or a registration request message. Furthermore, the MM procedure may be a tracking area update procedure and / or a registration procedure. The UE may send the request message together with a first PLMN ID and / or a first satellite PLMN ID indicating the PLMN of the first satellite.

[0306] When the first satellite operates in the S&F mode, the first satellite and / or a mobility management device-onboard (e.g., MME-onboard or AMF-onboard) mounted on the first satellite may transmit an RRC message including a first rejection message. The mobility management device-onboard may include at least one of the tenth to twelfth identities in the first rejection message or the RRC message including the first rejection message. Here, the first rejection message may be a registration rejection message, an attach rejection message, or a TAU rejection message.

[0307] The UE may receive the first rejection message and / or an RRC message including the first rejection message from the onboard mobility management device. In other words, the UE may receive the first rejection message from the first satellite.

[0308] When the UE receives the tenth identification information and / or the eleventh identification information, the UE may start counting the first wait timer using a value indicated in the eleventh identification information. The UE may store and / or manage, execute and / or start the first wait timer in association with one or more PLMN ID(s) and / or Satellite ID(s).

[0309] Alternatively, the UE may generate a second Wait timer based on searching for and / or attempting to connect to other terrestrial PLMNs and / or satellites discovered without performing a procedure for registration update, and may store and / or manage the second Wait timer in association with one or more PLMN ID(s) and / or Satellite ID(s), and start the second Wait timer.

[0310] The UE may control the UE so that it cannot transmit a request message to the PLMN(s) indicated by the associated PLMN ID(s) and retry initiating the MM procedure while the Wait timer is running. Similarly, the UE may control the UE so that it cannot transmit a request message to the satellite(s) indicated by the associated satellite ID(s) and retry initiating the MM procedure while the Wait timer is running.

[0311] Specifically, when the first and / or second wait timers are associated with a first PLMN ID, the UE may be controlled not to transmit a request message to the PLMN indicated by the first PLMN ID and not to retry initiating the MM procedure. Similarly, when the first and / or second wait timers are associated with a first satellite ID, the UE may be controlled not to transmit a request message to the first satellite indicated by the first satellite ID and not to retry initiating the MM procedure. That is, the wait timer may be generated based on information notified from a satellite and / or a mobility management device-onboard the satellite, or may be generated in a different way. For example, the UE may store a timer value for generating the second wait timer in advance, use that value to generate a random value, and set and / or start the second wait timer.

[0312] During the execution of the Wait timer, the UE may transmit a second request message for deregistration to the first satellite to initiate a procedure for deregistration (e.g., a deregistration procedure, a detachment procedure). Here, the second request message may be a message for requesting deregistration of the UE, and may be a deregistration request message and / or a detachment request message.

[0313] Upon receiving the second request message for deregistration, the mobility management device-onboard transmits an acceptance message to the UE. The UE may transition to the unregistered state by receiving the acceptance message from the mobility management device-onboard. Note that the Wait timer may not be stopped even when the UE transitions to the unregistered state, or the Wait timer may be stopped based on the UE becoming unregistered. The UE that has transitioned to the unregistered state may start searching for other terrestrial PLMNs and / or satellites.

[0314] Thus, each device may control and / or behave in a manner that allows a registered UE to search for other satellites and / or PLMNs if feeder link connectivity from a first satellite is lost.

[0315] The above may be applied to an NPN (SNPN and / or PNI-NPN). That is, the present embodiment may be applied to an NPN by replacing PLMN with SNPN.

[0316] [4.3 Third embodiment] Next, a procedure used in the third embodiment will be described, which explains the behavior of each device when a request message is retransmitted to a satellite and / or terrestrial PLMN after the Wait timer has expired.

[0317] Note that the behavior of each device from the time a message such as SIB is broadcast from the first satellite, the first request for S&F is rejected, and the time the Wait timer is executed may be the same as in the first embodiment, and detailed explanations will be omitted.

[0318] When the Wait timer expires, the UE starts retransmission of the request message and / or retry of transmission to the prohibited first satellite and / or PLMN. The following describes the case where the request message is retransmitted to the first satellite, but this may also be interpreted as the case where the UE connects to a terrestrial PLMN via a terrestrial base station.

[0319] After the Wait timer expires, the UE sends a second request message to the onboard mobility manager for the first satellite to reattempt satellite connection using the first satellite and / or to resubmit a request rejected due to S&F, thereby initiating a second MM procedure. The second request message may be the first request message including the second identification information. Alternatively, the UE may include the second identification information in an RRC message and send it to the onboard mobility manager together with the second request message.

[0320] Here, the second request message sent by the UE may be an attach request message, a tracking area update request message, and / or a registration request message. Furthermore, the MM procedure may be an attach procedure, a tracking area update procedure, and / or a registration procedure. The UE may send the request message together with a first PLMN ID indicating a first PLMN of the selected terrestrial network and / or a first satellite PLMN ID indicating a PLMN of the first satellite.

[0321] If the feeder link between the first satellite and the terrestrial network is available, the UE, and / or the base station, and / or the NW may operate in normal mode, and the mobility management device-onboard may forward the received second request message to the terrestrial mobility management device.

[0322] The mobility management device that receives the second identification information may recognize that the UE request is a retransmission of a rejected request message for S&F. Based on the reception of the second identification information, the mobility management device may decide whether to accept the UE request using the result of the authentication procedure and / or the procedure for acquiring UE registration information that is performed based on the first request message, without performing the authentication procedure and / or the procedure for acquiring UE registration information that is normally started by the second request message.

[0323] The mobility manager may send a control message to the UE based on the decision of whether to accept the UE's request, and the UE may recognize whether the UE's request has been accepted based on the control message received from the mobility manager.

[0324] As a result of the above, each device notifies the network that the MM procedure retried by the UE is a retry, allowing the network to use the results of the authentication procedure and / or the procedure for obtaining the UE's registration information performed by the first MM procedure.

[0325] The above may be applied to an NPN (SNPN and / or PNI-NPN). That is, the present embodiment may be applied to an NPN by replacing PLMN with SNPN.

[0326] 5. 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.

[0327] 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.

[0328] 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.

[0329] 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.

[0330] 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]

[0331] 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

1. A UE (User Equipment) including a transceiver unit and a control unit, The transmitting / receiving unit sending a first request message to the first satellite to initiate a Mobility Management (MM) procedure; receiving a first rejection message from a first satellite, the first rejection message including a first value of a Wait timer; The control unit starting a Wait timer using the first value; controlling not to retry transmission of the first request message to the first satellite identified by a first satellite ID while the Wait timer is running; If the UE is powered off and then powered on again while the Wait timer is running, and if the first timer value is greater than the second timer value, restart the Wait timer using a value obtained by subtracting the second timer value from the first timer value; where: the first timer value is the remaining time of the Wait timer that timed out when the power was turned off, The second timer value is the elapsed time from power-off to power-on. A UE characterized by:

2. A mobility management device mounted on a first satellite, the mobility management device comprising a transceiver unit and a control unit, when the first satellite has lost connectivity to the ground, The transceiver unit receives a first request message from a UE; the control unit sets the first value to be random; the transceiver unit transmits a first rejection message including the first value; where: The first value is a value of a Wait timer, and while the UE is executing the Wait timer, the UE is controlled not to retry transmitting the first request message to the first satellite. A mobility management device characterized by:

3. A UE comprising a transceiver unit and a controller, The transmitting / receiving unit sending a first request message to the first satellite to initiate a Mobility Management (MM) procedure; receiving a first rejection message from a first satellite, the first rejection message including a first value; The control unit Randomly setting a Wait timer using the first value and starting the Wait timer; and controlling not to retry transmission of the first request message to the first satellite identified by a first satellite ID while the wait timer is running. A UE characterized by:

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