User equipment (UE)

Abstract

The present invention provides: a means for transmitting and receiving information for appropriately operating a timer based on a time offset of an overload control between a UE and a network after an unusable period during which the UE is out of service due to non-continuous coverage of NR satellite access; and a method for executing appropriate processing based on said information.

Description

UE (User Equipment)

[0001] The present invention relates to UE (User Equipment). This application claims priority to Japanese Patent Application No. 2023-114181, filed on July 12, 2023, the contents of which are incorporated herein by reference.

[0002] The 3GPP (3rd Generation Partnership Project: registered trademark) is studying the system architecture of the 5G System (5GS), a fifth-generation (5G) mobile communication system, and is discussing how to support new procedures and new functions (see Non-Patent Documents 1 to 4). Release 18 of the 5G standard is studying the architecture, communication and control procedures, etc. for 5G communications via satellites (also simply referred to as "satellites") (see Non-Patent Document 4).

[0003] 3GPP TS 23.501 V18.2.2 (2023-07); 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; System architecture for the 5G System (5GS); Stage 2 (Release 18)3GPP TS 23.502 V18.2.0 (2023-06); 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Procedures for the 5G System (5GS); Stage 2 (Release 18)3GPP TS 24.501 V18.3.0 (2023-06); 3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3; 23.700-28 V18.1.0 (2023-03); 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Study on Integration of satellite components in the 5G architecture; Phase 2 (Release 18)

[0004] In the 5G System (5GS), a new core network called 5G Core Network (5GCN) is being considered to provide a wide variety of services. In addition, an architecture for 5G communication via satellites (also simply called "satellites") is being considered.

[0005] Currently, in such communication architectures that use satellites as a wireless technology (radio access technology) connecting user equipment (UE) and core networks, studies are underway to extend the existing procedures, messages, or parameters to take into account the characteristics of wireless connections via satellite.

[0006] On the other hand, the information required to perform control using time offsets to avoid overload caused by a large number of UEs simultaneously returning to the coverage area of ​​NR (New Radio) satellite access after an unavailable period in which the UE is out of range due to discontinuous coverage via NR satellite access, the transmission and reception of this information, and the behavior and processing of the UE and each device involved in overload control are not clear.

[0007] This embodiment has been made in consideration of the above circumstances, and its purpose is to provide a means for transmitting and receiving information between a UE and a network that is necessary for the UE to appropriately execute a timer based on a time offset for overload control after a period in which the UE is unavailable due to discontinuous coverage of NR satellite access, and a method for executing appropriate processing based on the information.

[0008] The UE (User Equipment) of this embodiment is a UE having a transceiver unit, a control unit, and a memory unit, wherein the transceiver unit receives a first timer value, and / or a first type, and / or a maximum waiting time from a network (NW), the first timer value is a timer value indicating the duration of an Unavailability Period, the first type is a type indicating that the Unavailability Period is not dependent on discontinuous coverage provided by NR (New Radio) satellite access, the control unit stores the first timer value and the first type in association with each other in the memory unit, the control unit does not set and / or start a second timer after expiration of a timer based on the first timer value associated with the first type stored in the memory unit, and the second timer is a timer whose timer value is a period determined by the UE based on the maximum waiting time. The UE (User Equipment) of this embodiment is a UE having a transceiver unit, a control unit, and a memory unit, wherein the memory unit stores a first timer and a second timer, the first timer is a timer whose timer value is an unavailability period associated with a type indicating that the unavailability period is not due to discontinuous coverage provided by NR (New Radio) satellite access, the second timer is a timer whose timer value is an unavailability period associated with a type indicating that the unavailability period is due to discontinuous coverage provided by the NR satellite access, the transceiver unit receives first control information from a network, the first control information is information indicating the first or second timer value and / or type, and the control unit executes the timers based on the first control information.The UE (User Equipment) of this embodiment is a UE having a transceiver unit, a control unit, and a memory unit, and the memory unit stores a first timer value and a first type in association with each other, the first timer value is a timer value indicating the duration of an unavailability period, the first type is a type indicating that the unavailability period is not due to discontinuous coverage provided by NR (New Radio) satellite access, the memory unit further stores a waiting time, the waiting time is a value determined by the control unit based on a maximum waiting time received by the transceiver unit from a network, and the control unit executes a PLMN (Public Land Mobile Network) selection procedure when the timer based on the first timer value expires and the timer based on the unavailability period due to discontinuous coverage provided by NR satellite access is running.

[0009] According to this embodiment, in overload control performed after an unavailable period due to discontinuous coverage of NR satellite access, a means for transmitting and receiving information required for the UE to properly execute a timer based on a time offset between the UE and the network, and a method for the UE and the network to perform appropriate processing based on the information are provided.

[0010] FIG. 1 is a diagram illustrating an overview of a mobile communication system (EPS / 5GS). FIG. 2 is a diagram illustrating a detailed configuration of a mobile communication system (EPS / 5GS). FIG. 3 is a diagram illustrating the device configuration of a UE. FIG. 4 is a diagram illustrating the configuration of an access network device (gNB) in 5GS. FIG. 5 is a diagram illustrating the configuration of a core network device (AMF / SMF / UPF) in 5GS. FIG. 6 is a diagram illustrating a registration procedure.

[0011] Hereinafter, the best mode for carrying out the present embodiment will be described with reference to the drawings. In this embodiment, as an example, an embodiment of a mobile communication system to which the present embodiment is applied will be described.

[0012] [1. System Overview] First, FIG. 1 is a diagram for explaining an overview 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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, and may be a terminal device that can connect to both EPS and 5GS. A UE may include a UICC (Universal Integrated Circuit Card) or an eUICC (Embedded UICC). Note that a UE may be referred to as a user device or a terminal device.

[0019] 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.

[0020] 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 Node Bs) 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 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) used in the 4G system EPS. Furthermore, when there are multiple gNBs, the gNBs are connected to each other, for example, via an Xn interface.

[0021] Furthermore, the non-3GPP access network may be an untrusted non-3GPP access network or a trusted non-3GPP access network. Here, the untrusted non-3GPP access network may be a non-3GPP access network that does not perform security management within the access network, such as a public wireless LAN. On the other hand, the trusted non-3GPP access network may be an access network specified by 3GPP, and may include a trusted non-3GPP access point (TNAP) and a trusted non-3GPP gateway function (TNGF).

[0022] 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.

[0023] Furthermore, in the following, access network _A, and / or access network _B, and / or devices included in access network _A, and / or devices included in access network _B may be referred to as access networks or access network devices.

[0024] The core network_A corresponds to an EPC (Evolved Packet Core), which includes, for example, an MME (Mobility Management Entity), an SGW (Serving Gateway), a PGW (Packet Data Network Gateway)-U, a PGW-C, a PCRF (Policy and Charging Rules Function), and an HSS (Home Subscriber Server).

[0025] Furthermore, the core network_B corresponds to a 5G Core Network (5GCN). In the 5GCN, for example, an Access and Mobility Management Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), a Policy Control Function (PCF), a Unified Data Management (UDM), etc. are arranged. Here, the 5GCN may be expressed as a 5GC.

[0026] In addition, in the following, core network _A and / or core network _B, devices included in core network _A, and / or devices included in core network _B may be referred to as core networks, core network devices, or devices within the core network.

[0027] 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).

[0028] Also, while FIG. 1 illustrates a case where the PDN and the DN are the same, they may be different. The PDN may be a DN (Data Network) that provides communication services to the UE. The DN may be configured as a packet data service network, or may be configured for each service. Furthermore, the PDN may include a connected communication terminal. Therefore, connecting to the PDN may mean connecting to a communication terminal or a server device located in the PDN. Furthermore, transmitting and receiving user data to and from the PDN may mean transmitting and receiving user data to and from a communication terminal or a server device located in the PDN. The PDN may be referred to as the DN, and the DN may be referred to as the PDN.

[0029] 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.

[0030] The UE can also connect to an access network. The UE can also connect to a core network via the access network. The UE can also connect to a PDN or DN via the access network and the core network. That is, the UE can transmit and receive (communicate) user data with the PDN or DN. When transmitting and receiving user data, not only IP (Internet Protocol) communication but also non-IP communication can be used.

[0031] 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 portion. The payload portion 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 it 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.

[0032] 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).

[0033] 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.

[0034] 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.

[0035] 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.

[0036] The UPF_A235 is connected to the DN, the SMF, other UPFs, and the access network. The UPF_A235 may perform functions such as anchoring for intra-RAT or inter-RAT mobility, packet routing and forwarding, an UL CL (Uplink Classifier) ​​function that supports routing of multiple traffic flows for one DN, a branching point function that supports multi-homed PDU sessions, QoS processing for the user plane, verification of uplink traffic, buffering of downlink packets, and a trigger function for downlink data notification. The UPF_A235 may also be a relay device that forwards user data as a gateway between the DN and the core network_B190. The UPF_A235 may also be a gateway for IP communication and / or non-IP communication. The UPF_A235 may also have the function of forwarding IP communication and the function of converting non-IP communication to IP communication. Furthermore, multiple gateways may be gateways that connect the core network _B190 to a single DN. Note that UPF_A235 may have connectivity with other NFs and may be connected to each device via other NFs.

[0037] Between UPF_A235 and the access network, UPF_C239 (also called a branching point or uplink classifier), which is a UPF different from UPF_A235, may exist as a device or NF. When UPF_C239 exists, a PDU session between the UE and the DN will be established via the access network, UPF_C239, and UPF_A235.

[0038] Furthermore, the UPF 130 may be the same device as the UPF_A 235. Note that the UPF 130 and the UPF_A 235 may be written with the symbols omitted, such as UPF.

[0039] [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.

[0040] Note that each memory unit (memory unit_A340, memory unit_A440, memory unit_B540, memory unit_A640, 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. Furthermore, each memory unit can store not only information originally set at the time of shipment, but also various information transmitted and received between devices / functions other than the device / function itself (e.g., UE, and / or access network device, and / or core network device, and / or PDN, and / or DN). Furthermore, each memory unit can store identification information, control information, flags, parameters, etc. included in control messages transmitted and received in various communication procedures described below. Furthermore, each memory unit may 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 5GS and / or devices / functions included in EPS. At this time, not only those transmitted and received via the N26 interface but also those transmitted and received without going through the N26 interface can be stored.

[0041] [2.1. Device configuration of UE] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] The memory unit _A340 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the UE.

[0046] [2.2. gNB Device Configuration] Next, an example of the gNB device configuration will be described using Figure 4. The gNB is composed of a control unit _B500, an antenna 510, a network connection unit _B520, a transceiver unit _B530, and a memory unit _B540. The control unit _B500, the network connection unit _B520, the transceiver unit _B530, and the memory unit _B540 are connected via a bus. The transceiver unit _B530 is connected to the antenna 510.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] The memory unit _B540 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the gNB.

[0052] [2.3. AMF Device Configuration] Next, an example of the AMF device configuration will be explained using Figure 5. The AMF is composed of a control unit _B700, a network connection unit _B720, and a memory unit _B740. The control unit _B700, the network connection unit _B720, and the memory unit _B740 are connected via a bus. The AMF may be a node that handles the control plane. The AMF may also be a network device. In other words, for example, in this specification, a network device may mean an AMF.

[0053] 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 needed.

[0054] 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 in a 5G AN. That is, the AMF can use the network connection unit _B720 to transmit and receive user data and / or control information between a base station device (gNB), and / or SMF, and / or PCF, and / or UDM, and / or SCEF in a 5G AN. In other words, for example, the network connection unit may be a transceiver unit.

[0055] 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.

[0056] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. necessary for each operation of the AMF.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] [2.4. SMF Device Configuration] Next, an example of the SMF device configuration will be explained using Figure 5. The SMF is composed of a control unit _B700, a network connection unit _B720, and a memory unit _B740. The control unit _B700, the network connection unit _B720, and the memory unit _B740 are connected via a bus. The SMF may be a node that handles the control plane.

[0067] 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.

[0068] 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 send and receive user data and / or control information between the AMF, and / or UPF, and / or PCF, and / or UDM using the network connection unit _B720.

[0069] 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.

[0070] The memory unit _B740 is a functional unit for storing programs, user data, control information, etc. required for each operation of the SMF.

[0071] 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.

[0072] [2.5. UPF Device Configuration] Next, an example of the UPF device configuration will be explained using Figure 5. The UPF is composed of a control unit _B700, a network connection unit _B720, and a memory unit _B740. The control unit _B700, the network connection unit _B720, and the memory unit _B740 are connected via a bus. The UPF may be a node that handles the control plane.

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

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

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

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

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

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

[0079] The user plane refers to user data transmitted and received between a UE and a network. The user plane may be transmitted and received using a PDN connection or a PDU session. Furthermore, in the case of EPS, the user plane may be transmitted and received using the LTE-Uu interface, and / or the S1-U interface, and / or the S5 interface, and / or the S8 interface, and / or the SGi interface. Furthermore, in the case of 5GS, the user plane may be transmitted and received via the interface between the UE and the NG RAN, and / or the N3 interface, and / or the N9 interface, and / or the N6 interface. Hereinafter, the user plane may be referred to as the U-Plane.

[0080] Furthermore, the control plane refers to control messages transmitted and received to control UE communications, etc. The control plane may be transmitted and received using a Non-Access-Stratum (NAS) signaling connection between the UE and the MME. Furthermore, in the case of EPS, the control plane may be transmitted and received using the LTE-Uu interface and the S1-MME interface. Furthermore, in the case of 5GS, the control plane may be transmitted and received using the interface between the UE and the NG RAN and the N2 interface. Hereinafter, the control plane may be referred to as the control plane or the C-Plane.

[0081] 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.

[0082] [2.6. Description of Other Devices and / or Functions] Next, other devices and / or functions will be described.

[0083] The PCF has a function to provide policy rules.

[0084] The UDM also has functions such as authentication credential processing, user identification processing, access authentication, registration / mobility management, and subscription management.

[0085] The PCRF is connected to the PGW and / or PDN and has a function of managing QoS for data delivery. For example, it manages the QoS of the communication path between the UE_A10 and the PDN. Furthermore, the PCRF may be a device that creates and / or manages PCC (Policy and Charging Control) rules and / or routing rules used by each device when transmitting and receiving user data.

[0086] The HSS is connected to the MME and / or SCEF and has a function of managing subscriber information. The subscriber information of the HSS is referred to, for example, when controlling access to the MME. Furthermore, the HSS may be connected to a location management device different from the MME.

[0087] [3. Explanation of Terms and Identification Information Used in Each Embodiment] Next, terms and identification information used in each embodiment will be explained in advance.

[0088] [3.1. Explanation of Terms Used in Each Embodiment] Next, highly specialized terms used in each embodiment and identification information used in procedures will be explained.

[0089] 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.

[0090] An SM (Session Management) message (also referred to as an NAS (Non-Access-Stratum) SM message) may be an NAS message used in procedures for SM, and may be a control message sent and received between UE_A10 and SMF_A230 via AMF_A240. Furthermore, the SM message may include a PDU session establishment request message, a PDU session establishment accept message, a PDU session establishment reject message, a PDU session modification request message, a PDU session modification command message, a PDU session modification complete message, a PDU session modification command reject message, a PDU session modification reject message, a PDU session release request message, a PDU session release reject message, a PDU session release command message, a PDU session release complete message, etc. Furthermore, the procedure for SM or the SM procedure may include a PDU session establishment procedure, a PDU session modification procedure, and a UE-requested PDU session release procedure.Each procedure may be initiated from the UE or from the NW.

[0091] An MM (Mobility management) message (also referred to as an NAS MM message) may be an NAS message used in procedures for MM, and may be a control message transmitted and received between UE_A10 and AMF_A240. Furthermore, the MM message may include a registration request message, a registration accept message, a registration reject message, a de-registration request message, a de-registration accept message, a configuration update command message, a configuration update complete message, a service request message, a service accept message, a service reject message, a notification message, a notification response message, etc. Furthermore, the procedures for MM or MM procedures may include a registration procedure, a de-registration procedure, a generic UE configuration update procedure (also simply referred to as a UE configuration update procedure), an authentication and / or authorization procedure, a service request procedure, a paging procedure, and a notification procedure.

[0092] The 5GS (5G System) service is a connection service provided using the core network _B190. Furthermore, the 5GS service may be a service different from the EPS service or a service similar to the EPS service.

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

[0094] 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.

[0095] A PDU (Protocol Data Unit / Packet Data Unit) session can be defined as an association between a DN that provides PDU connectivity services and a UE, but it 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. Note that each device (UE, and / or access network device, and / or core network device) may manage one or more pieces of identification information associated with a PDU session. Note that this identification information may include one or more of a DNN, a QoS rule, a PDU session type, an application identification information, an NSI identification information, an access network identification information, and an SSC mode, or may further include other information. Furthermore, when multiple PDU sessions are established, the identification information associated with each PDU session may be the same or different.

[0096] 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 a PGW / UPF that connects the core network B190. Furthermore, the DNN may be equivalent to an APN (Access Point Name).

[0097] 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 sent and received using IPv4. If IPv6 is specified, it indicates that data will be sent and received using IPv6. If Ethernet is specified, it indicates that Ethernet frames will be sent and received. Ethernet may also indicate that communication using IP is not performed. If Unstructured is specified, it indicates that data will be sent 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.

[0098] 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 communication service provider, 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, a UE may store an Equivalent HPLMN list (also referred to as equivalent HPLMN) in its USIM to identify one or more EPLMNs (Equivalent HPLMNs). 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).

[0099] 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. Note that 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 may be a routing area, a location area, or anything similar. Hereinafter, a tracking area may be a TA (Tracking Area). A tracking area may be identified by a TAI (Tracking Area Identity) consisting of a TAC (Tracking area code) and a PLMN.

[0100] A registration area is a collection 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.

[0101] The Current TAI is the TAI broadcast by the selected PLMN in the cell where the UE is located or camped, or if the cell is a satellite NG-RAN cell that broadcasts multiple Tracking Area Codes (TACs) in the selected PLMN, the UE NAS layer may select the current TAI from multiple Tracking Area Codes (TACs) in the selected PLMN.

[0102] The Lists of 5GS forbidden tracking areas may be a list of 5GS forbidden tracking areas for roaming and / or a list of 5GS forbidden tracking areas for regional provision of service stored by a UE not operating in an SNPN access operation mode. In other words, a UE not operating in an SNPN access operation mode must store a list of 5GS forbidden tracking areas for roaming and / or a list of 5GS forbidden tracking areas for regional service provision. Furthermore, the UE must search for a suitable cell within the same PLMN that belongs to a TA that is not included in the list of 5GS forbidden tracking areas.

[0103] Furthermore, a UE is not permitted to request 5GS services other than emergency services if it is located in a cell of a TA that belongs to the list of 5GS forbidden tracking areas for regional provision of service.

[0104] The UE may also store the forbidden tracking area ID (TAI) in a list of 5GS forbidden tracking areas for regional service provision to prevent repeated attempts to access cells in the forbidden tracking area. Furthermore, the list of 5GS forbidden tracking areas for regional service provision may be deleted when the UE is powered off, when the SIM is removed, or periodically (for a period ranging from 12 to 24 hours).

[0105] In addition, the information indicating the 5GS forbidden tracking areas for roaming may be included in an information element (IE) containing one or more forbidden TAI(s) for the list of "5GS forbidden tracking areas for roaming" included in a message sent by the network, and transmitted to the UE.

[0106] In addition, the 5GS forbidden tracking areas for regional provision of service may be included in an information element (IE) containing one or more forbidden TAIs for the list of "5GS forbidden tracking areas for regional provision of service" (5GS forbidden tracking areas for roaming) included in a message sent by the network and transmitted to the UE.

[0107] The UE ID is information for identifying a UE. 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.

[0108] An NTN (Non-terrestrial network) may be an NG-RAN consisting of multiple gNBs, which provides non-terrestrial NR access to UEs via NTN payloads and NTN gateways mounted on NTN transmission means such as satellites, aircraft, etc. installed in space or the air.

[0109] Here, the NTN payload is a network node mounted on a satellite or a high-altitude platform station and providing a connection function between a service link and a feeder link. Furthermore, the NTN payload may be a TNL (Transport Network Layer) node.

[0110] An NTN Gateway is an earth station installed on the Earth's surface that provides connectivity to the NTN payload using a feeder link, and may also be a TNL (Transport Network Layer) node.

[0111] In other words, for example, a "NR connection via satellite" (NR satellite access) by a UE may be an NR connection via a satellite (also simply referred to herein as a satellite) carrying an NTN payload and a gNB configured as an NTN gateway. Furthermore, the UE may perform procedures for registering with the network and / or establishing a PDU session via the NR connection, and may further perform communication using the established PDU session after completion of these procedures.

[0112] Herein, communication via an NTN is also referred to as communication via NR satellite access, or communication via an NTN, NTN communication, satellite communication, etc. Also, an NR connection via an NTN is also referred to as NR satellite access, or connection or access via a satellite, or satellite access, satellite radio access, etc.

[0113] A TN (terrestrial network) may provide terrestrial radio access to UEs through an access network configured with base stations and the like installed on the ground. In contrast to an NTN, which is a non-terrestrial network using satellites, a TN may be a terrestrial network. Furthermore, an access network installed and configured on the ground may be, for example, an NG-RAN configured with multiple gNBs, or an E-UTRAN configured with multiple eNBs, but is not limited to these.

[0114] Herein, communication via a TN is also referred to as communication via NR terrestrial access, or communication via a TN, TN communication, or non-satellite communication, etc. Also, NR connection via a TN is also referred to as NR terrestrial access, or connection or access via a non-satellite, or non-satellite access, etc.

[0115] The satellite NG-RAN Radio Access Technology (RAT) type may be information used to identify or distinguish different types of satellite NG-RAN access. The satellite NG-RAN RAT type may include, for example, "NR (LEO)," "NR (MEO)," "NR (GEO)," and "NR (OTHERSAT)." Here, "LEO" refers to a low earth orbit satellite, "MEO" refers to a medium earth orbit satellite, "GEO" refers to a geostationary earth orbit satellite, and "OTHERSAT" refers to other satellites.

[0116] Here, the access technology may be associated with a PLMN or SNPN. Further, a PLMN or SNPN may be capable of supporting multiple access technologies. Here, the UE may use the access technology information to determine the type of wireless carrier when selecting a particular PLMN or SNPN.

[0117] The AMF may also determine the RAT type of NR satellite access, and if the UE is accessing NR using satellite access, an indication of the NR satellite access type may be provided on the N2 interface. Furthermore, for the serving PLMN to implement efficient mobility restrictions for NR access, the TA in which cells of each NR satellite RAT type are deployed must be different from the TAs of other different satellite RAT types and the TAs of terrestrial access RAT types. Furthermore, the AMF may initiate UE deregistration when it receives an N2 UE Context Release Request with a cause value indicating that the UE is not in the PLMN serving area.

[0118] Herein, communication via an NTN is also referred to as communication via NR satellite access, or communication via satellite access, or 5GSAT communication, or NTN communication, etc. Also, an NR connection via a satellite (i.e., an NTN) is also referred to as NR satellite access, or connection or access via a satellite, or satellite access, etc. Also, NR satellite access may be 3GPP access.

[0119] The NR satellite access coverage provided by a satellite or satellite constellation may be discontinuous, also referred to as discontinuous network coverage, discontinuous coverage, or NR satellite access discontinuous coverage. Here, discontinuous coverage may result, for example, from the satellite or satellite constellation moving over time relative to a particular location on Earth, resulting in discontinuities in the coverage that the satellite or satellite constellation can provide.

[0120] Furthermore, a UE connected to a network via NR satellite access providing such discontinuous coverage is expected to move back and forth between coverage and out-of-service areas over time. Therefore, each device of the UE and / or the network may support some or all of one or more functions, including controls, parameters, or procedures, for supporting the discontinuous network coverage provided by NR satellite access. Note that, here, "in-service" may refer to a coverage (area) where the UE can communicate with a satellite, or a coverage (area) where the UE can communicate via a satellite. Furthermore, "out-of-service" may refer to a coverage (area) where the UE cannot communicate with a satellite, or a coverage (area) where the UE cannot communicate via a satellite.

[0121] More specifically, the one or more features including controls, parameters, or procedures for supporting discontinuous network coverage provided by NR satellite access may include satellite coverage availability information, and / or a mobility pattern, and / or an unavailability period, and / or unavailability period support, and / or a type of unavailability period, and / or an unavailability period duration, and / or a start of an unavailability period, and / or overload control in the discontinuous coverage provided by NR satellite access, and / or a maximum waiting time for overload control in the discontinuous coverage, and / or a discontinuous coverage wait timer value for overload control in the discontinuous coverage. The information may include a back-off timer in discontinuous coverage provided by the NR satellite access, a back-off timer in discontinuous coverage provided by the NR satellite access, and / or timer offset information in discontinuous coverage provided by the NR satellite access, and / or a maximum time offset or a discontinuous coverage maximum NAS signaling wait time. These are described below.

[0122] Satellite coverage availability information may be location and time information related to the expected coverage availability of a satellite or satellite constellation that provides discontinuous coverage, where a UE may use the satellite coverage availability information for satellite access to support discontinuous coverage operation. The satellite coverage availability information may be provided to the UE from an external server via a PDU session or Short Message Service (SMS).

[0123] The AMF may also use satellite coverage availability information to support satellite access by UEs operating in discontinuous coverage. Furthermore, satellite coverage availability information may be provided to the AMF from O&M (Operation and Maintenance). Here, the satellite coverage availability information provided to the AMF may describe when and where satellite reception is available in a certain area. Furthermore, the satellite coverage availability information is not UE-specific, and the AMF may be applicable to any UE in the affected area. In other words, the satellite coverage availability information may be information about a location or time when satellite access provided by a satellite or a group of satellites (satellite constellations) is expected to be available for use by a UE. That is, the satellite coverage availability information may indicate whether a UE is expected to be in or out of coverage at the location and time indicated by the information.

[0124] The satellite coverage availability information may include, for example, information indicating the time and location at which each satellite is expected to be able to provide NR satellite access to terrestrial UEs. Alternatively, the satellite coverage availability information may include information indicating the time and location at which each satellite is able to provide NR satellite access to terrestrial UEs, and the time and location at which each satellite is unable to provide NR satellite access to terrestrial UEs. Note that terrestrial UEs do not necessarily refer to UEs that are strictly adjacent to the Earth's surface, but also include UEs that are not adjacent to the Earth's surface.

[0125] An unavailability period may be a period or time during which a UE is out of coverage (i.e., out of service) or is expected or assumed to be out of coverage in NR satellite access discontinuous coverage. Furthermore, the unavailability period may be synonymous with a UE out-of-coverage period, an unreachable period, or an unreachability period. Here, the unavailability period may include an unavailability period due to NR satellite access discontinuous coverage and an unavailability period not due to NR satellite access discontinuous coverage. Furthermore, the unavailability period may be interpreted as an unavailability period due to NR satellite access discontinuous coverage and / or an unavailability period not due to NR satellite access discontinuous coverage. The unavailability period may also be interpreted as an unavailability period duration.

[0126] In addition, an unavailability period that is not due to NR satellite access discontinuous coverage is a period during which the network (i.e., 5GS) becomes unavailable, for example, for several minutes, due to a specific event being performed by the UE at any time, such as an update of the OS being executed, an update of the modem firmware, or a silent reset of the modem.

[0127] Here, the UE may become unable to use application functions without prior notification from the NW and / or UE due to an unavailability period not dependent on discontinuous NR satellite access coverage, which may affect the operation of the application server and / or network that depends on the availability of the UE during that period. Therefore, the UE needs to adjust the unavailability period not dependent on discontinuous NR satellite access coverage between the network and / or application function. Note that the UE and / or network may transmit and receive information regarding the unavailability period to adjust the unavailability period not dependent on discontinuous NR satellite access coverage. Details will be described later.

[0128] Here, the unavailability period that is not dependent on discontinuous NR satellite access coverage may also be referred to as a conventional function related to the unavailability period. Note that in this specification, the conventional function related to the unavailability period may also be referred to as "support for an unavailability period that is not dependent on discontinuous NR satellite access coverage" to distinguish it from "support for an unavailability period due to discontinuous NR satellite access coverage" described later.

[0129] In addition, an unavailability period due to discontinuous NR satellite access coverage is a period during which a UE connected to an NR satellite access that provides discontinuous coverage is out of the range of the NR satellite access and is unable to use the network (i.e., 5GS) for, for example, several minutes.

[0130] Here, by considering, for example, ephemeris information and UE location information as information related to satellite orbits, it is possible to predict in advance whether NR satellite access can provide connectivity to a UE at a specific location on the Earth. That is, the UE and / or NW may be able to predict in advance the unavailability period due to discontinuous coverage of the NR satellite access from the ephemeris information and the UE location information. Note that the UE may receive the ephemeris information as broadcast information from the NR satellite access and / or as a control message or user data from the network.

[0131] Here, in an unavailability period not due to discontinuous NR satellite access coverage, it is assumed that this behavior is due to a specific small number of UEs, and after the period, the UEs can reconnect to the network and / or resume communication. On the other hand, in an unavailability period due to discontinuous NR satellite access coverage, it is assumed that excessive network unavailability may occur due to reconnection when a large number of UEs accommodated in the coverage of a cell provided by the NR satellite access return to the coverage provided by the NR satellite access after being unavailable for the period. For this reason, overload control is required that takes into account the load caused by a large number of UEs reconnecting to the network via the NR satellite access, which is assumed after the unavailability period due to discontinuous NR satellite access coverage. Overload control will be described later. In this way, the parameters, judgments, behaviors, etc. considered by the UE and / or the NW may differ depending on whether the unavailability period is due to discontinuous NR satellite access coverage.

[0132] In order to realize such an unavailability period function, information indicating the type of unavailability period, the duration of the unavailability period, and / or the start of the unavailability period is required to determine whether the unavailability period is due to discontinuous NR satellite access coverage. This information is described below.

[0133] Unavailability period support may be capability information indicating support for a function for using an unavailable period. More specifically, in a registration procedure, a UE that supports the unavailable period function may indicate Unavailability period support as part of capability information (5GMM Core Network Capability or 5GMM capability) in a registration request message for initial registration or every mobility registration (mobility registration or mobility registration update).

[0134] Note that support for unavailable periods may include support for unavailability periods using discontinuous NR satellite access coverage and support for unavailability periods not using discontinuous NR satellite access coverage. Specific details of the operation will be described later.

[0135] The information may indicate the type of unavailability period, whether the unavailability period is due to non-contiguous NR satellite access coverage, and / or whether the unavailability period is due to non-contiguous NR satellite access coverage. In other words, for example, the type of unavailability period may indicate that the unavailability period is due to non-contiguous NR satellite access coverage.

[0136] The unavailability period duration may be information indicating the duration of the unavailability period. Furthermore, a timer may be executed using the unavailability period duration as a timer value. Here, the unavailability period duration may be information associated with the type of the unavailability period, and the UE and / or NW may transmit or store the unavailability period duration in association with the type of the unavailability period.

[0137] The start of the unavailability period may be information indicating a timing or time that specifies the start of the unavailability period. More specifically, for example, the start of the unavailability period may be information indicating a timing or time at which an unavailability period due to discontinuous NR satellite access coverage starts. Note that the start of the unavailability period may be information that is not used in an unavailability period that is not due to discontinuous NR satellite access coverage, or may be information that is used. Furthermore, the start of the unavailability period may be received and stored by the UE by broadcast information from the NR satellite access and / or a message from the NW. Furthermore, the start of the unavailability period may be information that is associated with the type of unavailability period, or may not be associated with the type of unavailability period.

[0138] Here, the UE out-of-coverage period may be determined based on satellite coverage information and a UE mobility pattern. The UE out-of-coverage period may be synonymous with the unavailability period, and the UE out-of-coverage period described in this specification may be read as the unavailability period. Furthermore, the UE out-of-coverage period may be determined by the UE, or by the network or each network device. More specifically, for example, the UE may transmit the determined UE out-of-coverage period to the network, and the network or each network device may receive and store it.

[0139] In addition, for example, the network or any network device (e.g., AMF) may transmit the determined UE out-of-service period to the UE, the network, or another network device, and the UE, the network, or another network device may receive and store the determined UE out-of-service period. The UE out-of-service period is also referred to as a period during which the UE is out of service.

[0140] Here, the UE out-of-service period may be a period during which the UE is out of service, or may be a timer or timer value corresponding to the period during which the UE is out of service. Furthermore, the UE out-of-service period may be an unreachability period, or may be a period indicated by the unreachability period or a corresponding timer or timer value. Furthermore, for example, the unreachability period may be a timer or timer value included in the "Unreachability period duration IE." Furthermore, if the UE out-of-service period is a timer or timer value corresponding to the period during which the UE is out of service, the timer may be started when the UE transitions to an out-of-service state or an idle state (idle mode).

[0141] Furthermore, for example, the UE may use an existing timer or timer value corresponding to the UE out-of-coverage period, or may use a new timer different from the existing timer. More specifically, for example, the UE out-of-coverage period may be a timer or timer value included in a "UE out-of-coverage period duration information element (IE)." Furthermore, the "UE out-of-coverage period duration IE" may be an existing timer or timer value (e.g., GPRS Timer 3 IE), or may be information indicating a new timer or a new timer value for 5GSAT communication. Note that, for example, if the UE out-of-coverage period is an unreachability period, a timer or timer value indicating a period corresponding to the UE out-of-coverage period may be included in the "UE out-of-coverage period duration IE" and / or the "Unreachability period duration IE."

[0142] Furthermore, when the UE determines the UE out-of-service period, it may be based on satellite coverage availability information and a UE mobility pattern provided by the network, or on satellite coverage availability information and a UE mobility pattern maintained by the UE. For example, the UE may determine the UE out-of-service period based on satellite coverage availability information provided by the network and a UE mobility pattern provided by the network. Alternatively, for example, the UE may determine the UE out-of-service period based on satellite coverage availability information provided by the network and a UE mobility pattern maintained by the UE. Alternatively, for example, the UE may determine the UE out-of-service period based on, but not limited to, satellite coverage availability information maintained by the UE and a UE mobility pattern maintained by the UE.

[0143] Furthermore, for example, if the UE can determine the UE out-of-coverage period and decides to remain out of service for the period indicated by the UE out-of-coverage period, it may perform a Mobility Registration Update procedure before the start of the unreachability period. Furthermore, the UE may request a Mobile Initiated Connection Only (MICO) mode parameter, extended DRX (eDRX) parameter in CM-IDLE, or other NAS timer using a related procedure that takes into account the UE out-of-coverage period, and in this case, if the UE requests the use of MICO mode or eDRX, the UE out-of-coverage period may not be included. Alternatively, the UE may notify the network of the UE out-of-coverage period when it intends to leave satellite coverage, and may perform a Mobility Registration Update procedure when it returns to coverage via any access type.

[0144] The AMF may adjust the mobile reachable timer and / or the implicit unregistration timer so that the AMF does not implicitly deregister the UE during the UE's unavailability period.

[0145] Overload control in discontinuous coverage provided by NR satellite access is a control and / or function for avoiding excessive signal load on the network when a large number of UEs return from outside the coverage area of ​​the NR satellite access. Furthermore, overload control in discontinuous coverage may be control using a maximum waiting time, a Disco wait range, and / or a maximum time offset or a discontinuous coverage maximum NAS signaling wait time. Furthermore, the maximum waiting time may be a time determined by the AMF until a UE that has returned to the coverage area of ​​the satellite access is permitted to start NAS signaling with the network. In other words, for overload control, the AMF may determine the maximum waiting time until a UE is permitted to start NAS signaling with the network. Here, the maximum waiting time may be, for example, Disco wait range, and / or Maximum Time Offset, or Discontinuous coverage maximum NAS signaling wait time, and in this specification, unless otherwise specified, these may be synonymous.

[0146] More specifically, for example, in overload control in discontinuous coverage using a maximum latency, the AMF first determines a maximum latency based on network configuration, a prioritized user, or a prioritized service, and transmits the maximum latency to the UE during the registration procedure or the UE configuration update procedure. Next, if the UE that receives the maximum latency has already received a maximum latency for the same RAT type and PLMN, the UE may replace the stored or saved maximum latency. Furthermore, the UE that receives the maximum latency may select a random value as an upper limit for the maximum latency to determine a discontinuous coverage wait timer value. In other words, for example, if the UE has stored or saved a discontinuous coverage maximum NAS signaling latency for each PLMN and / or satellite NG-RAN RAT type, the UE may update the value to the latest value when it receives a discontinuous coverage maximum NAS signaling latency for the same PLMN and / or satellite NG-RAN RAT type combination.

[0147] Wherein, the discontinuous coverage waiting timer may be a timer that restricts the UE from connecting to the network via the satellite access, and the UE may execute the discontinuous coverage waiting timer based on a discontinuous coverage waiting timer value determined by the UE.

[0148] In addition, when a UE returns to NR satellite access coverage from outside the coverage area with the same RAT (Radio Access Technology) type and PLMN, it starts a discontinuous coverage wait timer. A UE running the discontinuous coverage wait timer must not start NAS signaling for that RAT type and PLMN. Through the above procedures and processes, multiple UEs returning to coverage area each run a discontinuous coverage wait timer with a different random value, thereby controlling and reducing excessive signal load on the network.

[0149] Here, the maximum waiting time determined by the AMF may be included in an MM message transmitted and received during an MM (Mobility Management) procedure and transmitted to the UE. More specifically, for example, the MM procedure in which the AMF transmits the maximum waiting time to the UE may be a registration procedure or a UE configuration update procedure. Furthermore, for example, the MM message in which the AMF includes the maximum waiting time may be, for example, a registration accept message, a registration reject message, or a configuration update command message. In other words, the maximum waiting time may be included in an MM message and transmitted from the AMF to the UE in an MM procedure such as a registration procedure or a UE configuration update procedure.

[0150] Also, if the UE has stored a discontinuous coverage maximum NAS signal latency due to discontinuous coverage, when it goes out of coverage (i.e., out of range) of NR satellite access and then returns to coverage (i.e., in range), the UE sets the discontinuous coverage maximum NAS signal latency value to a random value up to the discontinuous coverage maximum NAS signal latency stored for this PLMN and satellite NG-RAN RAT type and starts this timer. While the discontinuous coverage maximum NAS signal latency timer is running, the UE must not initiate NAS signals on that satellite NG-RAN RAT type and PLMN.

[0151] Furthermore, if the UE receives a paging message and there is an emergency service pending, or if the UE enters a TAI outside the registration area, the UE may stop the timer based on the non-contiguous coverage maximum NAS signaling latency and start NAS signaling.

[0152] Also, a UE, a network, or each device that uses a function related to maximum latency may support maximum latency. In other words, if a UE, a network, or each device supports maximum latency, for example, an AMF may have the capability to determine the maximum latency, or the UE may have the capability to select or determine a discontinuous coverage latency timer from the received maximum latency. In other words, a UE, a network, or each device that supports communication via NR satellite access may support maximum latency as a function for discontinuous coverage.

[0153] The back-off timer in discontinuous coverage provided by NR satellite access may be a timer provided by the AMF to the UE to prevent the initiation of Mobile Originated (MO) data transmission or signaling before the UE is about to go out of coverage.

[0154] In other words, the back-off timer for the discontinuous satellite coverage provided by the AMF to the UE may be started to end when the UE is in range based on the satellite coverage availability information (i.e., the coverage period of the NR satellite access), and while the timer is running, the UE may be prohibited from starting MO data transmission or signaling. Also, if the UE is still in the same satellite communication area after the timer expires, it may start MO data transmission or signaling, or if it finds a cell of another TN or NTN, it may stop the timer and register through a new access network and send MO data.

[0155] The AMF that provided the back-off timer to the UE may initiate the AN release procedure. Furthermore, the back-off timer in the discontinuous satellite coverage may use an existing timer or may be defined and used as a new timer.

[0156] The timer offset information in NR satellite access providing discontinuous coverage may be information indicating a timer offset value that is associated with a timer that runs while the UE is in coverage or a timer that runs while the UE is out of coverage, and that takes into account the coverage that the UE or the network recognizes based on satellite coverage availability information and a physical coverage gap due to UE movement, satellite orbit, etc. In this specification, the timer offset information in NR satellite access providing discontinuous coverage may also be referred to as timer offset information indicating a time or period, timer offset information, timer offset, offset information, or simply offset, etc.

[0157] Here, the offset information may be information or parameters preconfigured in the UE, determined by the UE, or determined by the network. More specifically, for example, the offset information may be information or parameters preconfigured in the UE. Alternatively, the offset information may be information or parameters determined by the network, transmitted to the UE, and stored by the received UE. Alternatively, the offset information may be information or parameters determined by the UE, transmitted to the network, and stored by the network or each device.

[0158] Furthermore, the timer offset information may be associated with one or more timers. That is, the same number of timer offset information may be associated with one or more timers, or one offset information may be associated with one or more timers. Here, the timer associated with the offset information may be information associated with a period or timer indicating a time during which the UE is in coverage corresponding to the satellite coverage availability information and / or a UE out-of-coverage period. More specifically, for example, the offset information may be an offset value of a timer used to specify a time to advance or delay the start or end of a timer corresponding to a period during which the UE is out of coverage or in coverage, taking into account discontinuous coverage in NR satellite access. In other words, for example, if the offset information indicates that the expiration time of a timer corresponding to a UE out-of-coverage period should be extended, the UE may start the timer based on a value obtained by adding the value of the offset information to the timer value.

[0159] In addition, a UE connected to a network via a TN or NTN and in a registered state (RM-REGISTERED state) may perform a Mobility Registration Update procedure if the current TAI of the serving cell is not included in the list of TAIs that the UE received from the network, in order to maintain the registration and enable the AMF to page the UE. Note that in this specification, the Mobility Registration Update procedure is also simply referred to as Mobility Registration Update.

[0160] Furthermore, if the UE is connected to the network, particularly via an NTN (i.e., NR satellite access), in addition to the above conditions for performing the mobility registration update procedure when connecting to the network via a TN or NTN, the following conditions shall be taken into account:

[0161] First, a moving radio cell for NR satellite access may be able to indicate support for one or more TACs per PLMN. Here, a UE registered in a PLMN can access a radio cell as long as at least one supported TAC of the RPLMN or an equivalent RPLMN is part of the UE registration area, and does not need to perform a mobility registration update procedure. Also, a UE must perform a mobility registration update procedure when accessing a radio cell in which none of the TACs supported by the RPLMN or an equivalent RPLMN is part of the UE registration area.

[0162] Furthermore, when the UE indicates the last accessed TAI in a mobility registration update, it may be able to indicate a TAI that is supported in the radio cell of the RPLMN or equivalent RPLMN that the UE last accessed before the registration update and is part of the UE registration area.

[0163] [3.2. Description of Identification Information in Each Embodiment] In this embodiment, the first identification information is capability information of the UE. The first identification information may be a 5GMM capability, a 5GMM capability information element (IE), or information included as part of the 5GMM capability. Furthermore, the first identification information may be capability information of the UE indicating whether or not the UE supports an unavailability period taking into account NR satellite access discontinuous coverage.

[0164] Here, support for an unavailability period may include support for an unavailability period due to discontinuous NR satellite access coverage indicated by the first identification information, and / or support for an unavailability period not depending on discontinuous NR satellite access coverage. Furthermore, support for an unavailability period due to discontinuous NR satellite access coverage indicated by the first identification information may indicate that it is possible to control an out-of-range period in discontinuous coverage during NR satellite access connection using a conventional function related to an unavailability period (see Non-Patent Document 3). In this specification, the conventional function related to an unavailability period may be referred to as "support for an unavailability period not depending on discontinuous NR satellite access coverage" to distinguish it from "support for an unavailability period due to discontinuous NR satellite access coverage."

[0165] Furthermore, the first identification information may have multiple forms, and these forms are referred to herein as first identification information #1, and / or first identification information #2, and / or first identification information #3. Each form of the first identification information is described below.

[0166] First, the first identification information #1 may be capability information indicating whether the UE supports an unavailability period due to discontinuous NR satellite access coverage. Here, the first identification information #1 may be information different from information indicating support for an unavailability period not depending on discontinuous NR satellite access coverage. In other words, the information indicating unavailability period support may include information indicating support for an unavailability period not depending on discontinuous NR satellite access coverage by the first identification information #1 and information indicating support for an unavailability period not depending on discontinuous NR satellite access coverage.

[0167] Furthermore, the UE may indicate that it supports the unavailability period due to discontinuous NR satellite access coverage by including the first identification information #1 in a message and transmitting the message to the network (NW). Also, for example, when the UE indicates to the NW that it supports both the unavailability period due to discontinuous NR satellite access coverage and the unavailability period not depending on discontinuous NR satellite access coverage, the UE may transmit the first identification information #1 and information indicating support of the unavailability period not depending on discontinuous NR satellite access coverage in a message to the NW.

[0168] In addition, unavailability period support that is not based on NR satellite access non-contiguous coverage may be indicated as an UN-PER bit in the 5GMM capability IE, and the first identification information #1 may be indicated as information different from the UN-PER bit in the 5GMM capability IE.

[0169] Furthermore, the first identification information #2 may be capability information indicating whether the UE supports an unavailability period.

[0170] Here, for example, the first identification information #2 may be capability information indicating that the UE supports either an unavailability period due to NR satellite access discontinuous coverage or an unavailability period not due to NR satellite access discontinuous coverage.

[0171] Alternatively, for example, the first identification information #2 may be capability information indicating that the UE supports an unavailability period due to discontinuous NR satellite access coverage. In this case, for example, the UE may indicate to the network that it supports an unavailability period due to discontinuous NR satellite access coverage by transmitting a message including the first identification information #2 together with third identification information indicating a type of unavailability period due to discontinuous NR satellite access coverage. Furthermore, in this case, the network receiving from the UE a message including the first identification information #2 together with the third identification information indicating a type of unavailability period due to discontinuous NR satellite access coverage may recognize that the UE supports an unavailability period due to discontinuous NR satellite access coverage.

[0172] Conversely, for example, if a UE that includes first identification information #2 in a message does not include third identification information indicating a type of unavailability period due to NR satellite access discontinuous coverage in the message, or includes third identification information indicating a type of unavailability period not due to NR satellite access discontinuous coverage, the UE may indicate to the NW that it supports unavailability periods not due to NR satellite access discontinuous coverage. In this case, the NW that receives the message may recognize that the UE supports unavailability periods not due to NR satellite access discontinuous coverage.

[0173] For example, if the UE supports an unavailability period due to discontinuous NR satellite access coverage, the first identification information #2 may be set to indicate that the unavailability period is supported. For example, if the UE supports an unavailability period not due to discontinuous NR satellite access coverage, the first identification information #2 may be set to indicate that the unavailability period is supported.

[0174] In addition, the first identification information #2 may be indicated using the UN-PER bit in the 5GMM capability IE.

[0175] Furthermore, the first identification information #3 may be capability information indicating that the UE supports an unavailability period due to NR satellite access non-contiguous coverage and / or supports an unavailability period not due to NR satellite access non-contiguous coverage.

[0176] In other words, for example, the first identification information #3 may be capability information indicating that neither support of an unavailability period due to discontinuous NR satellite access coverage nor support of an unavailability period not due to discontinuous NR satellite access coverage is supported. Alternatively, for example, the first identification information #3 may be capability information indicating that only support of an unavailability period due to discontinuous NR satellite access coverage is supported. Alternatively, for example, the first identification information #3 may be capability information indicating that only support of an unavailability period not due to discontinuous NR satellite access coverage is supported. Alternatively, for example, the first identification information #3 may be capability information indicating that both support of an unavailability period due to discontinuous NR satellite access coverage and support of an unavailability period not due to discontinuous NR satellite access coverage are supported.

[0177] More specifically, for example, when a UE indicates that it supports an unavailability period due to discontinuous NR satellite access coverage, the UE may include first identification information #3 indicating that it supports the unavailability period due to discontinuous NR satellite access coverage in a message and transmit the message to the NW. In this case, the NW that receives the first identification information #3 may recognize that the UE supports the unavailability period due to discontinuous NR satellite access coverage.

[0178] In this specification, the term "first identification information" may refer to any of first identification information #1, first periodic information #2, or first identification information #3. Furthermore, unless otherwise specified, the term "first identification information" may indicate that the UE supports NR satellite access discontinuous coverage.

[0179] In other words, in this specification, when simply referring to first identification information, it may be any form indicated by the description of the first identification information. More specifically, for example, when referring to "first identification information indicating that the UE supports an unavailability period due to discontinuous NR satellite access coverage," it may be first identification information #1 indicating that the UE supports an unavailability period due to discontinuous NR satellite access coverage, first identification information #2 indicating that the UE supports an unavailability period due to discontinuous NR satellite access coverage, or first identification information #3 indicating that at least the UE supports an unavailability period due to discontinuous NR satellite access coverage.

[0180] Further details of the behavior of the UE and NW based on the first identification information are also described in Chapter 4 and / or Chapter 5.

[0181] The second identification information in this embodiment is capability information of a network (NW). The second identification information may be included as part of 5GS network feature support, a 5GS network feature support IE, or 5GS network feature support. The second identification information may also be capability information of a NW indicating whether or not an unavailability period is supported in consideration of NR satellite access discontinuous coverage.

[0182] Here, the support of the unavailability period may include support of the unavailability period due to discontinuous NR satellite access coverage indicated by the second identification information, and / or support of the unavailability period not due to discontinuous NR satellite access coverage. Furthermore, the support of the unavailability period due to discontinuous NR satellite access coverage indicated by the second identification information may indicate that it is possible to control the out-of-range period in discontinuous coverage during NR satellite access connection using a conventional function related to the unavailability period (see Non-Patent Document 3).

[0183] Furthermore, the second identification information may have multiple forms, and these forms are referred to herein as second identification information #1, and / or second identification information #2, and / or second identification information #3. Each form of the second identification information is described below.

[0184] First, the second identification information #1 may be capability information indicating whether the NW supports an unavailability period due to discontinuous NR satellite access coverage. Here, the second identification information #1 may be information different from information indicating support of an unavailability period not depending on discontinuous NR satellite access coverage. In other words, the information indicating unavailability period support may include information indicating support of an unavailability period not depending on discontinuous NR satellite access coverage by the second identification information #1 and information indicating support of an unavailability period not depending on discontinuous NR satellite access coverage.

[0185] Furthermore, the UE may indicate that it supports the unavailability period due to discontinuous NR satellite access coverage by including the second identification information #1 in a message and transmitting the message to the UE. Furthermore, for example, when the NW indicates to the UE that it supports both the unavailability period due to discontinuous NR satellite access coverage and the unavailability period not depending on discontinuous NR satellite access coverage, the NW may transmit the second identification information #1 and information indicating support for the unavailability period not depending on discontinuous NR satellite access coverage to the UE by including the second identification information #1 in a message.

[0186] In addition, unavailability period support that is not based on NR satellite access non-contiguous coverage may be indicated as an UN-PER bit in the 5GS network feature support IE, and the first identification information #1 may be indicated as information different from the UN-PER bit in the 5GS network feature support IE.

[0187] Also, the second identification information #2 may be capability information indicating whether the NW supports an unavailability period.

[0188] Here, for example, the second identification information #2 may be capability information indicating that the NW either supports an unavailability period due to NR satellite access non-contiguous coverage or supports an unavailability period without NR satellite access non-contiguous coverage.

[0189] Alternatively, for example, the second identification information #2 may be capability information indicating that the network supports an unavailability period due to discontinuous NR satellite access coverage. In this case, for example, the UE may indicate to the UE that it supports an unavailability period due to discontinuous NR satellite access coverage by transmitting a message including the second identification information #2 together with third identification information indicating a type of unavailability period due to discontinuous NR satellite access coverage. Furthermore, in this case, the UE may recognize that the network supports an unavailability period due to discontinuous NR satellite access coverage by transmitting a message including the second identification information #2 together with third identification information indicating a type of unavailability period due to discontinuous NR satellite access coverage from the UE.

[0190] Conversely, for example, if a network that includes second identification information #2 in a message does not include third identification information indicating a type of unavailability period due to NR satellite access discontinuous coverage in the message, or includes third identification information indicating a type of unavailability period not due to NR satellite access discontinuous coverage, the network may indicate to the UE that it supports unavailability periods not due to NR satellite access discontinuous coverage. In this case, a UE that receives the message may recognize that the network supports unavailability periods not due to NR satellite access discontinuous coverage.

[0191] Also, for example, if the NW supports an unavailability period due to discontinuous NR satellite access coverage, the second identification information #2 may be set to indicate that the unavailability period is supported. Also, for example, if the NW supports an unavailability period that is not due to discontinuous NR satellite access coverage, the second identification information #2 may be set to indicate that the unavailability period is supported.

[0192] In addition, the second identification information #2 may be indicated using the UN-PER bit in the 5GS network feature support IE.

[0193] Furthermore, the second identification information #3 may be capability information indicating that the NW supports an unavailability period due to non-contiguous NR satellite access coverage and / or supports an unavailability period not due to non-contiguous NR satellite access coverage.

[0194] In other words, for example, the second identification information #3 may be capability information indicating that neither an unavailability period due to discontinuous NR satellite access coverage nor an unavailability period not due to discontinuous NR satellite access coverage is supported. Alternatively, for example, the second identification information #3 may be capability information indicating that only support for an unavailability period due to discontinuous NR satellite access coverage is supported. Alternatively, for example, the second identification information #3 may be capability information indicating that only support for an unavailability period not due to discontinuous NR satellite access coverage is supported. Alternatively, for example, the second identification information #3 may be capability information indicating that both support for an unavailability period due to discontinuous NR satellite access coverage and support for an unavailability period not due to discontinuous NR satellite access coverage are supported.

[0195] More specifically, for example, when a network indicates that it supports an unavailability period due to discontinuous NR satellite access coverage, the network may include second identification information #3 indicating that it supports the unavailability period due to discontinuous NR satellite access coverage in a message and transmit the message to the UE. In this case, the UE that receives the second identification information #3 may recognize that the network supports the unavailability period due to discontinuous NR satellite access coverage.

[0196] In this specification, simply referring to the second identification information may refer to any of the second identification information #1, the second period information #2, or the second identification information #3. Furthermore, simply referring to the second identification information may indicate that the NW supports NR satellite access non-contiguous coverage, unless otherwise specified.

[0197] In other words, in this specification, when simply referring to second identification information, it may be any form indicated by the description of the second identification information. More specifically, for example, when referring to "second identification information indicating that the UE supports an unavailability period due to discontinuous NR satellite access coverage," it may be second identification information #1 indicating that the UE supports an unavailability period due to discontinuous NR satellite access coverage, second identification information #2 indicating that the UE supports an unavailability period due to discontinuous NR satellite access coverage, or second identification information #3 indicating that at least the UE supports an unavailability period due to discontinuous NR satellite access coverage.

[0198] Further details of the behavior of the UE and NW based on the second identification information are also described in Chapter 4 and / or Chapter 5.

[0199] The third identification information in this embodiment is information indicating the type of unavailability period. The type of unavailability period indicated by the third identification information may be a type indicating an unavailability period due to discontinuous NR satellite access coverage, or a type indicating an unavailability period not due to discontinuous NR satellite access coverage. Here, the type indicated by the third identification information may be information indicating the type of unavailability period duration and / or start of unavailability period included in a message transmitted together with the third identification information.

[0200] In other words, for example, the third identification information may indicate the type of the unavailability period or the unavailability period duration by being included in a message and transmitted together with the unavailability period duration. Furthermore, a UE or NW that receives the third identification information, the unavailability period duration, and the start of the unavailability period may recognize that the unavailability period and the start of the unavailability period are of the type indicated by the third identification information, and may store the unavailability period in association with the type indicated by the third identification information.

[0201] More specifically, for example, a UE or a NW that receives the third identification information indicating the type of the unavailability period due to discontinuous NR satellite access coverage, the unavailability period duration, and / or the start of the unavailability period may store the received unavailability period duration and / or the start of the unavailability period in association with the type of the unavailability period due to discontinuous NR satellite access coverage. Furthermore, the UE or the NW may execute a timer based on the unavailability period duration as the unavailability period due to discontinuous NR satellite access coverage based on the start of the unavailability period.

[0202] The third identification information may have multiple forms, and in this specification these forms are referred to as third identification information #1, and / or third identification information #2, and / or third identification information #3. Each form of the third identification information is described below.

[0203] First, the third identification information #1 may be identification information indicating the type of unavailability period due to discontinuous NR satellite access coverage, i.e., the unavailability period duration and / or start of unavailability period transmitted together with the third identification information #1 may indicate the type of unavailability period due to discontinuous NR satellite access coverage.

[0204] In other words, for example, if a UE or NW transmits an unavailability period duration and / or a start of an unavailability period without including third identification information #1 in a message, these may indicate that the unavailability period is a type that is not based on NR satellite access discontinuous coverage. Furthermore, a UE or NW receiving the message may recognize the unavailability period duration and / or the start of an unavailability period as a type of unavailability period that is not based on NR satellite access discontinuous coverage and store the unavailability period duration and / or the start of an unavailability period in association with the type.

[0205] Here, the UE and / or NW may indicate whether the type of unavailability period is due to discontinuous NR satellite access coverage by including or not including third identification information #1 in the message. Alternatively, the UE and / or NW may indicate whether the type of unavailability period is due to discontinuous NR satellite access coverage by using third identification information #1 together with third identification information #2 described later, and details of this case will be described later.

[0206] Furthermore, the third identification information #2 may be identification information indicating a type of unavailability period that is not due to non-contiguous NR satellite access coverage, i.e., the unavailability period duration and / or start of unavailability period transmitted together with the third identification information #2 may indicate a type of unavailability period that is not due to non-contiguous NR satellite access coverage.

[0207] The third identification information #2 may be identification information used based on the above-mentioned third identification information #1. In other words, for example, when indicating a type of unavailability period due to NR satellite access discontinuous coverage, the UE or NW may include the third identification information #1 in a message together with the unavailability period duration and / or start of the unavailability period. Alternatively, for example, when indicating a type of unavailability period not due to NR satellite access discontinuous coverage, the UE or NW may include the third identification information #2 in a message together with the unavailability period duration and / or start of the unavailability period.

[0208] Furthermore, the third identification information #3 may be identification information indicating the type of unavailability period due to discontinuous NR satellite access coverage and / or the type of unavailability period not due to discontinuous NR satellite access coverage, where the unavailability period duration and / or the start of the unavailability period may be the type indicated by the third identification information #3.

[0209] In other words, for example, the third identification information #3 may be identification information indicating only the type of unavailability period due to NR satellite access discontinuous coverage. Or, the third identification information #3 may be identification information indicating only the type of unavailability period not due to NR satellite access discontinuous coverage. Or, the third identification information #3 may be identification information indicating both the type of unavailability period due to NR satellite access discontinuous coverage and the type of unavailability period not due to NR satellite access discontinuous coverage. Or, the third identification information #3 may be identification information indicating neither the type of unavailability period due to NR satellite access discontinuous coverage nor the type of unavailability period not due to NR satellite access discontinuous coverage.

[0210] In addition, when the third identification information is in the form of third identification information #3, the unavailability period duration and / or the start of the unavailability period may be in, for example, a list format that can store information of the corresponding type. In other words, for example, when the third identification information #3 indicates both the type of unavailability period due to NR satellite access discontinuous coverage and the type of unavailability period not due to NR satellite access discontinuous coverage, the unavailability period duration and / or the start of the unavailability period may be transmitted as information in a format corresponding to each type.

[0211] In this specification, simply referring to the third identification information may refer to any one of the third identification information #1, the third identification information #1 and / or the third identification information #2, or the third identification information #3. Furthermore, simply referring to the third identification information may refer to a type indicating an unavailability period due to discontinuous NR satellite access coverage, unless otherwise specified.

[0212] Further details of the UE and network behavior based on the third identity information are also provided in Chapter 4 and / or Chapter 5.

[0213] Details of the behavior of the UE and the network based on one or a combination of the above first to third identification information are not limited to those described in this chapter, but are also described in Chapter 4 and / or Chapter 5.

[0214] [4. Description of Procedures Used in Each Embodiment] Next, procedures used in each embodiment will be described. Here, the procedures used in each embodiment may include a registration procedure.

[0215] 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.

[0216] The registration procedure is explained in detail below.

[0217] [4.1. Registration Procedure] First, the registration procedure will be explained using Figure 6. The registration procedure is a procedure in 5GS. Hereinafter, in this section, this procedure refers to the registration procedure. 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 powered on. In other words, if the UE is in the deregistered state (RM-DEREGISTERED state), it can start this procedure at any time. Furthermore, each device (especially the UE and AMF) can transition to the registered state (RM-REGISTERED state) based on the completion of the registration procedure.

[0218] The registration procedure may be an initial registration initiated by the UE, or a mobility and periodic registration update, or a mobility registration update procedure. Here, the mobility registration update procedure may also be referred to as a registration procedure for mobility update. These registration procedures may also be MM procedures.

[0219] Furthermore, the registration procedure may be a procedure for updating the location registration information of the UE in the network, and / or for the UE to periodically notify the network of the status of the UE, and / or for updating certain parameters related to the UE in the network, or may be a mobility registration update procedure performed after the completion of the initial registration procedure and the expiration of the unavailability period to resume normal service.

[0220] This procedure may also be a procedure for registration by a UE via NR satellite access. Furthermore, the PDU session established after completion of this procedure may be a PDU session via the satellite NG-RAN or NR satellite access. In other words, for example, a PDU session established by a PDU session establishment procedure performed after completion of the registration procedure via NR satellite access may be a PDU session via NR satellite access. Alternatively, for example, a PDU session via NR satellite access may be established based on completion of this procedure.

[0221] A UE may initiate a registration procedure when performing mobility across TAs. More specifically, a UE may initiate a Mobility Registration Update procedure to re-register when it moves to a TA different from the TA indicated in the TA list it holds. Furthermore, a UE may initiate this procedure when a running timer expires. Furthermore, a UE may initiate a registration procedure when a context update for each device is required due to a PDU session disconnection or invalidation. Furthermore, a UE may initiate a registration procedure when a change occurs in the capability information and / or preferences related to the establishment of a PDU session. Furthermore, a UE may initiate a registration procedure periodically. Furthermore, a UE may initiate a registration procedure based on the completion of a UE Configuration Update procedure. However, the UE may perform the registration procedure at any timing, not limited to these.

[0222] Furthermore, even when the UE is in a registered state, the UE may periodically initiate the registration procedure. In other words, the UE may initiate the registration procedure based on the expiration of a timer. In other words, the registration procedure performed periodically may be a periodic registration update procedure.

[0223] Note that a registration procedure performed based on the mobility of the UE and a registration procedure performed periodically may be referred to as a registration procedure for mobility and registration update. In other words, the registration procedure for mobility and registration update may be a registration procedure performed based on the mobility of the UE, or may be a registration procedure performed periodically. Furthermore, the registration procedure for mobility and registration update may be a registration procedure performed based on a configuration update of the UE. Furthermore, the registration procedure for mobility and registration update may be a registration procedure performed to establish a communication path for transmitting and receiving user data. Furthermore, the registration procedure for mobility and registration update may be a registration procedure performed based on a request from the network. Furthermore, in other words, the registration procedure for mobility and registration update may be a registration procedure other than the initial registration procedure. Hereinafter, the registration procedure for mobility and registration update may be referred to as the main procedure.

[0224] Next, each step of the registration procedure will be described. Note that the registration procedure described below may be an initial registration procedure or a registration procedure for mobility and registration renewal.

[0225] First, the UE starts the registration procedure by sending a registration request message to the AMF (S600) (S602) (S604). Specifically, the UE sends an RRC message including a registration request message to the 5G AN (or gNB) (S600). The registration request message is a NAS message. The RRC message may be a control message transmitted and received between the UE and the 5G AN (or gNB). The NAS message is processed in the NAS layer, and the RRC message is processed in the RRC layer. The NAS layer is a layer higher than the RRC layer.

[0226] Here, the UE may transmit the first identification information, the third identification information, the unavailability period duration, and / or the start of the unavailability period in the registration request message.

[0227] Furthermore, when multiple pieces of identification information are transmitted and received, two or more of these pieces of identification information may be configured as one or more pieces of identification information. Note that the information indicating support for each function and the information indicating a request for use of the function may be transmitted and received as the same identification information, or may be transmitted and received as different identification information.

[0228] The UE may also initiate the PDU session establishment procedure during the registration procedure by sending an SM message included in or together with a registration request message, where the SM message may be a PDU session establishment request message.

[0229] When a 5G AN (or gNB) receives an RRC message including a registration request message, it selects an AMF to which to forward the registration request message (S602). Note that the 5G AN (or gNB) can select an AMF based on information included in the registration request message and / or the RRC message. The 5G AN (or gNB) extracts the registration request message from the received RRC message and forwards the registration request message to the selected AMF (S604).

[0230] The AMF that receives the registration request message from the UE may recognize and store the meaning of the identification information included in the registration request message.

[0231] When the AMF receives the registration request message, the AMF can perform a first condition determination. The first condition determination is for determining whether the network (or the AMF) accepts the UE's request. If the first condition determination is true, the AMF starts the procedure of (A) in Figure 6, while if the first condition determination is false, the AMF starts the procedure of (B) in Figure 6.

[0232] The first condition determination may be performed based on the reception of a registration request message, and / or each identification information included in the registration request message, and / or subscriber information, and / or network capability information, and / or operator policy, and / or network status, and / or user registration information, and / or a context held by the AMF, etc. For example, if the network permits the UE's request, the first condition determination may be true, and if the network does not permit the UE's request, the first condition determination may be false. Furthermore, if the network to which the UE is registered and / or a device within the network supports a function requested by the UE, the first condition determination may be true, and if the function requested by the UE is not supported, the first condition determination may be false. Furthermore, if the identification information to be transmitted and received is permitted, the first condition determination may be true, and if the identification information to be transmitted and received is not permitted, the first condition determination may be false. The conditions for determining whether the first condition determination is true or false do not have to be limited to the above-described conditions.

[0233] First, we will explain the case where the first condition determination is true. In the procedure of (A) in Figure 6, the AMF can first execute the fourth condition determination. The fourth condition determination is for determining whether the AMF transmits and receives SM messages to and from the SMF.

[0234] Furthermore, the fourth condition determination may be performed based on whether the AMF has received an SM message. Furthermore, the fourth condition determination may be performed based on whether an SM message is included in the registration request message. For example, if the AMF has received an SM message and / or if the registration request message includes an SM message, the fourth condition determination may be true, and if the AMF has not received an SM message and / or if the registration request message does not include an SM message, the fourth condition determination may be false. Furthermore, the conditions that determine the truth or falsity of the fourth condition determination do not have to be limited to the conditions described above.

[0235] Next, the AMF transmits a registration accept message to the UE via the 5G AN (or gNB) as a response message to the registration request message based on the reception of the registration request message and / or the completion of the transmission and reception of an SM message with the SMF (S608). For example, if the fourth condition determination is false, the AMF may transmit the registration accept message based on the reception of the registration request message from the UE. Also, if the fourth condition determination is true, the AMF may transmit the registration accept message based on the completion of the transmission and reception of an SM message with the SMF. Note that the registration accept message is a NAS message transmitted and received on the N1 interface, but is transmitted and received between the UE and the 5G AN (gNB) included in an RRC message.

[0236] The AMF may send the registration acceptance message including the second identification information and / or the third identification information, and / or the unavailability period duration, and / or the start of the unavailability period.

[0237] Furthermore, when multiple pieces of identification information are transmitted and received, two or more of these pieces of identification information may be configured as one or more pieces of identification information. Note that the information indicating support for each function and the information indicating a request for use of the function may be transmitted and received as the same identification information, or may be transmitted and received as different identification information.

[0238] Furthermore, the AMF may select and decide whether to include the second identification information and / or the third identification information, and / or the unavailability period duration, and / or the start of the unavailability period in the registration acceptance message based on each identification information received by the AMF from the UE or each device, 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.

[0239] Furthermore, the AMF can include and transmit an SM message in a registration accept message, or can transmit an SM message together with the registration accept message. However, this transmission method may be performed when the SM message is included in the registration request message and the fourth condition determination is true. Also, this transmission method may be performed when the SM message is included together with the registration request message and the fourth condition determination is true. By performing such a transmission method, the AMF can indicate that the procedure for SM has been accepted in the registration procedure. Here, the SM message may be a PDU session establishment request message or a PDU session establishment accept message.

[0240] The AMF may also indicate that the UE's request has been accepted by sending a registration acceptance message based on the received identification information, and / or subscription 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.

[0241] Furthermore, the AMF may include information indicating that some of the UE's requests have been rejected in the registration acceptance message and send it, or may indicate the reason why some of the UE's requests have been rejected by sending the information indicating that some of the UE's requests have been rejected. Furthermore, the UE may recognize the reason why some of the UE's requests have been rejected by receiving the information indicating that some of the UE's requests have been rejected. Note that the reason for the rejection may be information indicating that the content indicated by the identification information received by the AMF is not permitted.

[0242] The UE receives a registration acceptance message from the AMF via the 5G AN (gNB) (S608). By receiving the registration acceptance message, the UE can recognize that the UE's request via the registration request message has been accepted and the contents of various identification information included in the registration acceptance message.

[0243] Here, a UE that receives a registration acceptance message from the AMF may recognize and store what the received second identification information and / or third identification information, and / or unavailability period duration, and / or start of unavailability period indicate.

[0244] Furthermore, the UE may send a registration completion message to the AMF via the 5G AN (gNB) as a response message to the registration acceptance message (S610). Here, the registration completion message is an NAS message transmitted and received on the N1 interface, but is included in an RRC message and transmitted and received between the UE and the 5G AN (gNB).

[0245] The AMF receives a registration completion message via the 5G AN (gNB) (S610). In addition, each device completes the procedure of (A) in FIG. 6 based on the transmission and reception of the registration acceptance message and / or the registration completion message.

[0246] Next, a case where the first condition determination is false will be described. In the procedure of (B) of Fig. 6, the AMF transmits a registration reject message to the UE via the 5G AN (gNB) as a response message to the registration request message (S612). Here, the registration reject message is an NAS message transmitted and received on the N1 interface, but is transmitted and received between the UE and the 5G AN (gNB) as an RRC message.

[0247] Furthermore, the AMF may indicate that the UE's request via the registration request message has been rejected by sending a registration rejection message. Furthermore, the AMF may include information indicating the reason for the rejection in the registration rejection message and send it, or may indicate the reason for the rejection by sending the reason for the rejection. Furthermore, the UE may recognize the reason for the rejection of the UE's request by receiving information indicating the reason for the rejection of the UE's request. Note that the reason for the rejection may be information indicating that the content indicated by the identification information received by the AMF is not permitted.

[0248] The UE receives a registration rejection message from the AMF via the 5G AN (gNB) (S612). By receiving the registration rejection message, the UE can recognize that the UE's request via the registration request message has been rejected and the contents of the various identification information included in the registration rejection message. Furthermore, if the UE does not receive a registration rejection message even after a predetermined period has elapsed since sending the registration request message, the UE may recognize that the UE's request has been rejected. Each device completes the procedure (B) in this procedure based on the transmission and reception of the registration rejection message.

[0249] The procedure in FIG. 6(B) may be started when the procedure in FIG. 6(A) is stopped.

[0250] Each device completes the registration procedure based on the completion of the procedure of (A) or (B) in Figure 6. Note that each device may transition to a state in which the UE is registered in the network (RM-REGISTERED state) based on the completion of the procedure of (A) in Figure 6, or may maintain a state in which the UE is not registered in the network (RM-DEREGISTERED state) or transition to a state in which the UE is not registered in the network based on the completion of the procedure of (B) in Figure 6. Furthermore, the transition of each device to each state may be based on the completion of the registration procedure or the establishment of a PDU session.

[0251] The UE may also complete the registration procedure based on receiving a registration accept message or a registration reject message.

[0252] Furthermore, each device may perform processing based on the information transmitted and received during the registration procedure based on the completion of the registration procedure. For example, if the device transmits or receives information indicating that some of the UE's requests have been rejected, the device may recognize the reason why the UE's requests have been rejected. Furthermore, each device may perform this procedure again based on the reason why the UE's requests have been rejected, or may perform the registration procedure for the core network_B or another cell.

[0253] Furthermore, the UE may store the identification information received with the registration accept message and / or the registration reject message and may recognize the network's decision based on the completion of the registration procedure.

[0254] The UE may recognize the content of the above identification information by receiving a registration acceptance message or a registration rejection message.

[0255] The behavior to be performed when each piece of identification information is received may be performed based on the received identification information.

[0256] [5. Embodiments] Next, each embodiment of this example will be described. Note that each embodiment described in this chapter is based on the definitions of terms and various identification information explained in Chapter 3, and the procedures explained in Chapter 4.

[0257] Furthermore, each embodiment may be an embodiment that starts in a state where the UE has connected to the network via NR satellite access and has completed registration.

[0258] Furthermore, unless otherwise specified, the embodiments in this example are not limited to being implemented individually and independently as each embodiment described in each section of this chapter, but may be implemented as a combination of one or more embodiments described in each section, or one or more embodiments described in each section may be implemented in any order.

[0259] Furthermore, the UE in each embodiment may be provided with and store a maximum time offset or a discontinuous coverage maximum NAS signaling wait time from the network. Here, the maximum time offset and the discontinuous coverage maximum NAS signaling wait time may be the same. Furthermore, the maximum time offset or the discontinuous coverage maximum NAS signaling wait time may be determined by the AMF. More specifically, for example, the AMF may determine a time or a timer value corresponding to the maximum time offset or the discontinuous coverage maximum NAS signaling wait time.

[0260] More specifically, for example, the AMF may provide a Maximum Time Offset or a Discontinuous Coverage Maximum NAS Signaling Wait Time to the UE by including the Maximum Time Offset or the Discontinuous Coverage Maximum NAS Signaling Wait Time in a Registration Accept message transmitted and received during a UE-initiated registration procedure for initial or mobility update, and / or in a Configuration Update Command message transmitted and received during a NW-initiated UE Configuration Update (UE Configuration Update or Generic UE Configuration Update) procedure. Furthermore, the UE may store the received Maximum Time Offset or the Discontinuous Coverage Maximum NAS Signaling Wait Time. Furthermore, when the UE receives a new and latest Maximum Time Offset or the Discontinuous Coverage Maximum NAS Signaling Wait Time, the UE may replace the previously received and / or stored Maximum Time Offset or the Discontinuous Coverage Maximum NAS Signaling Wait Time with the latest value.

[0261] Furthermore, a UE that has received and stored the Maximum Time Offset or the Discontinuous coverage maximum NAS signaling wait time may set a random value whose maximum value is the Maximum Time Offset or the Discontinuous coverage maximum NAS signaling wait time.

[0262] Additionally, due to discontinuous coverage provided by NR satellite access, a UE that returns to coverage after being out of range may start a timer set to a random value up to the value of the discontinuous coverage maximum NAS signaling latency for that PLMN and satellite NG-RAN RAT type.

[0263] Additionally, the UE in each embodiment may receive and store the discontinuous coverage maximum NAS signaling latency from the network before the start of the unavailability period.

[0264] In addition, unless otherwise specified, the UE and NW in each embodiment may support an unavailability period due to NR satellite access discontinuous coverage and an unavailability period due to NR satellite access discontinuous coverage.

[0265] In addition, the unavailability period may be interpreted as an unavailability period due to non-contiguous NR satellite access coverage and / or an unavailability period not due to non-contiguous NR satellite access coverage.

[0266] Each embodiment of this example will be described below.

[0267] [5.1. First embodiment] A first embodiment of this example will be described. Hereinafter, in this section, the first embodiment will also be referred to as this embodiment.

[0268] In this embodiment, the UE may transmit a registration request message including the first identity and / or the third identity (e.g., the third identity #2 or #3), and / or the unavailability period duration and / or the start of the unavailability period to the network in the registration procedure for initial or registration renewal. Furthermore, upon receiving this registration request message, the network may transmit a registration accept message including the second identity and the third identity (e.g., the third identity #2 or #3), and the unavailability period duration and / or the start of the unavailability period and / or the discontinuous coverage maximum NAS signaling wait time to the UE, and the UE may receive this message.

[0269] The UE may also receive the discontinuous coverage maximum NAS signaling latency from the network in a Configuration Update Command message in a UE Configuration Update procedure.

[0270] More specifically, in this embodiment, when a UE receives from the network third identification information #2 or #3 indicating that the value of the unavailability period duration and / or the unavailability period is a type that does not depend on discontinuous coverage provided by NR satellite access, the UE may simply store the unavailability period duration and / or the start of the unavailability period and the type of unavailability period indicated by the third identification information #2 or #3, or may store them in association with each other. Here, based on the unavailability period duration and / or the start of the unavailability period received together with the type that does not depend on discontinuous coverage provided by NR satellite access, the UE may start or run a timer based on the unavailability period that does not depend on discontinuous coverage provided by NR satellite access. Then, when the timer expires or has completed running, the UE may not determine a timer value based on the received discontinuous coverage maximum NAS signaling waiting time, and may not set or start a timer value based on the discontinuous coverage maximum NAS signaling waiting time.

[0271] Here, the UE and NW of this embodiment may support an unavailability period not depending on discontinuous NR satellite access coverage and an unavailability period due to discontinuous NR satellite access coverage. Alternatively, the UE and NW of this embodiment may support an unavailability period not depending on discontinuous NR satellite access coverage, but may not support an unavailability period due to discontinuous NR satellite access coverage.

[0272] In addition, the UE may determine, store, and / or set a timer value based on the received discontinuous coverage maximum NAS signaling latency time when receiving the received discontinuous coverage maximum NAS signaling latency time.

[0273] Alternatively, the UE may not determine, store, and / or set a timer value based on the discontinuous coverage maximum NAS signaling latency upon receiving the discontinuous coverage maximum NAS signaling latency, and may determine, store, and / or set a timer value based on the discontinuous coverage maximum NAS signaling latency after the unavailability period has elapsed.

[0274] Here, these actions may be based on UE and / or NW capability information, or may be determined by the content of information provided and / or stored by the UE and / or NW.

[0275] As described above, the UE of this embodiment receives, from the network, for example, a timer value indicating the duration of an unavailability period, and / or third identification information indicating that the unavailability period is a type that does not rely on discontinuous coverage provided by NR satellite access, and / or a discontinuous coverage maximum NAS signaling wait time. The UE stores the received timer value indicating the duration of the unavailability period in association with the type indicating that the unavailability period is not a type that does not rely on discontinuous coverage provided by NR satellite access indicated by the third identification information. The UE starts or runs a timer based on the timer value indicating the duration of an unavailability period that does not rely on discontinuous coverage provided by NR satellite access, and after the timer expires, sets and / or does not start a timer based on the discontinuous coverage maximum NAS signaling wait time.

[0276] Here, the discontinuous coverage maximum NAS signaling latency may be the maximum value of a period or timer indicating the discontinuous coverage maximum NAS signaling latency received by the UE from the network. Furthermore, the UE of this embodiment may determine and store a timer value based on, for example, the discontinuous coverage maximum NAS signaling latency received from the network. That is, the timer based on the discontinuous coverage maximum NAS signaling latency may be a timer whose timer value is a period determined by the UE based on the discontinuous coverage maximum NAS signaling latency. When a timer based on a timer value indicating the duration of an unavailability period not dependent on discontinuous coverage provided by NR satellite access expires, the UE may not execute the timer based on the timer value determined based on the discontinuous coverage maximum NAS signaling latency, regardless of whether the UE has stored the timer value determined based on the discontinuous coverage maximum NAS signaling latency.

[0277] Alternatively, the UE of this embodiment may not need to determine, set, and / or start a timer value based on a discontinuous coverage maximum NAS signaling latency, for example, when a timer based on a timer value indicating the duration of an Unavailability Period that is not dependent on discontinuous coverage provided by NR satellite access expires.

[0278] Furthermore, if the unavailability period (or unavailability period duration) and / or start of unavailability period received from the network is not based on discontinuous coverage provided by NR satellite access, the UE may start a timer using the unavailability period (or unavailability period duration) and / or start of unavailability period that is not based on discontinuous coverage provided by NR satellite access. However, after the timer expires (i.e., after the unavailability period (or unavailability period duration) that is not based on discontinuous coverage provided by NR satellite access has elapsed), the UE may not set a timer value based on the discontinuous coverage maximum NAS signaling latency that applies to the unavailability period (or unavailability period duration) related to the discontinuous coverage provided by NR satellite access, and may not start a timer using that timer value.

[0279] Furthermore, if the unavailability period (or unavailability period duration) and / or start of unavailability period received from the network is not based on discontinuous coverage provided by NR satellite access, the UE may start a timer using the unavailability period (or unavailability period duration) and / or start of unavailability period that is not based on discontinuous coverage provided by NR satellite access. However, if the UE is within the unavailability period (or unavailability period duration) related to the discontinuous coverage provided by NR satellite access when the timer expires (i.e., when the unavailability period (or unavailability period duration) that is not based on discontinuous coverage provided by NR satellite access has elapsed), the UE may set a timer value based on the discontinuous coverage maximum NAS signaling waiting time after the unavailability period (or unavailability period duration) has elapsed, or may start a timer using that timer value.

[0280] Furthermore, if the unavailability period (or unavailability period duration) and / or start of unavailability period received from the network is not based on discontinuous coverage provided by NR satellite access, the UE may start a timer using the unavailability period (or unavailability period duration) and / or start of unavailability period that is not based on discontinuous coverage provided by NR satellite access. However, when the timer expires (i.e., when the unavailability period (or unavailability period duration) that is not based on discontinuous coverage provided by NR satellite access has passed), if the unavailability period (or unavailability period duration) related to the discontinuous coverage provided by NR satellite access has passed, the UE may not set a timer value based on the discontinuous coverage maximum NAS signaling latency or may not start a timer using that timer value.

[0281] Furthermore, if the unavailability period (or unavailability period duration) and / or start of unavailability period received from the network is not due to discontinuous coverage provided by NR satellite access, the UE may start a timer using the unavailability period (or unavailability period duration) and / or start of unavailability period not due to discontinuous coverage provided by NR satellite access, but may stop the timer if the unavailability period (or unavailability period duration) related to the discontinuous coverage provided by NR satellite access starts before the timer expires (i.e., before the unavailability period (or unavailability period duration) not due to discontinuous coverage provided by NR satellite access has elapsed).

[0282] Furthermore, if the unavailability period (or unavailability period duration) and / or start of unavailability period received from the network is due to discontinuous coverage provided by NR satellite access, the UE may start a timer using a timer value set based on the discontinuous coverage maximum NAS signaling latency, but may stop the timer if an unavailability period (or unavailability period duration) not due to discontinuous coverage provided by NR satellite access starts before the timer expires.

[0283] [5.2. Second embodiment] A second embodiment of this example will be described. In this section, the second embodiment will also be referred to as this embodiment.

[0284] This embodiment may be the case where the UE and NW support both an unavailability period without NR satellite access discontinuous coverage and an unavailability period with NR satellite access discontinuous coverage.

[0285] Furthermore, if the UE stores a timer associated with an unavailability period that is not due to NR satellite access discontinuous coverage and a timer associated with an unavailability period due to NR satellite access discontinuous coverage, the UE may recognize which of the stored timers to execute based on control information transmitted from the NW, and start or execute the timer.

[0286] Here, the control information that the UE receives from the NW may be information indicating either or both of a timer associated with an unavailability period not due to discontinuous NR satellite access coverage and / or a timer associated with an unavailability period due to discontinuous NR satellite access coverage. Furthermore, the UE that receives the control information may recognize the content indicated by the control information and start or execute the timer indicated by the control information.

[0287] More specifically, for example, when the control information received by the UE from the NW includes information indicating a timer associated with an unavailability period not depending on NR satellite access discontinuous coverage, the UE may recognize that the stored timer associated with the unavailability period not depending on NR satellite access discontinuous coverage is to be executed, and may further start or execute the timer. Note that here, the control information received by the UE from the NW indicating the timer associated with the unavailability period not depending on NR satellite access discontinuous coverage and / or the timer associated with the unavailability period due to NR satellite access discontinuous coverage may be included in a registration accept message and / or a UE configuration command message received by the UE from the AMF, or may be included in an MM message sent by the NW to the UE, but is not limited to these.

[0288] Alternatively, for example, if the control information received by the UE from the NW includes information indicating a timer associated with an unavailability period due to NR satellite access discontinuous coverage, the UE may recognize that it should execute the timer associated with the unavailability period due to NR satellite access discontinuous coverage that it has stored, and may further start or execute the timer.

[0289] If the timer executed by the UE is a timer associated with the unavailability period due to discontinuous coverage of NR satellite access, after the timer expires, the UE may further execute a timer based on the discontinuous coverage maximum NAS signaling latency, where the behavior of the timer based on the discontinuous coverage maximum NAS signaling latency may be the behavior described in the fourth embodiment.

[0290] Here, for example, the NW may determine the control information to be transmitted to the UE by taking into consideration the larger timer value from the timer associated with the unavailability period not due to discontinuous NR satellite access coverage and the timer associated with the unavailability period due to discontinuous NR satellite access coverage. For example, the NW may select and determine the timer with the larger timer value.

[0291] Alternatively, for example, the control information that the NW transmits to the UE may be determined by selecting a timer with a later expiration time from among the timers associated with an unavailability period that is not due to NR satellite access discontinuous coverage and the timers associated with an unavailability period that is due to NR satellite access discontinuous coverage.

[0292] Alternatively, for example, the control information transmitted by the NW to the UE may select and determine a timer value from a timer associated with an unavailability period not due to NR satellite access discontinuous coverage and a timer associated with an unavailability period due to NR satellite access discontinuous coverage based on a UE policy and / or a network policy.

[0293] Note that storing a timer may mean storing a timer value in association with each timer.

[0294] The UE of this embodiment stores, for example, a timer associated with an unavailability period not dependent on discontinuous NR satellite access coverage and a timer associated with an unavailability period due to discontinuous NR satellite access coverage. Furthermore, the UE that stores these timers may recognize and / or determine which of the timers stored in the UE to execute and start or execute, based on control information received from the network. Here, the control information received by the UE from the network may be information indicating either or both of the timer associated with the unavailability period not dependent on discontinuous NR satellite access coverage and / or the timer associated with the unavailability period due to discontinuous NR satellite access coverage. Furthermore, the UE that receives the control information may recognize the content indicated by the control information and start or execute the timer indicated by the control information.

[0295] [5.3. Third embodiment] A third embodiment of this example will be described. In this section, the third embodiment will also be referred to as this embodiment.

[0296] The UE of this embodiment may store a timer value determined based on a timer based on a discontinuous coverage maximum NAS signaling latency in addition to a timer associated with an unavailability period not due to NR satellite access discontinuous coverage and / or a timer associated with an unavailability period due to NR satellite access discontinuous coverage, and may further start or execute a timer associated with an unavailability period not due to NR satellite access discontinuous coverage.

[0297] Subsequently, if the UE is out of range due to an unavailability period due to discontinuous coverage of the NR satellite access when the timer expires, the UE may perform a PLMN selection procedure and / or RAT selection.

[0298] Alternatively, if a timer associated with an unavailability period due to discontinuous coverage of the NR satellite access has not expired when the timer expires, the UE may perform a PLMN selection procedure and / or RAT selection, where the UE may be out of range of the NR satellite access when the timer expires and a timer associated with an unavailability period due to discontinuous coverage of the NR satellite access has not expired when the timer expires.

[0299] Alternatively, the UE of this embodiment may store, for example, a timer associated with an unavailability period not due to NR satellite access discontinuous coverage. Furthermore, the UE may store a timer value determined by the UE based on a timer based on a discontinuous coverage maximum NAS signaling latency. If the timer associated with an unavailability period due to discontinuous satellite access coverage is still running after the stored timer associated with the unavailability period not due to NR satellite access discontinuous coverage expires, the UE may perform a PLMN selection procedure. The PLMN selection procedure may select different PLMN / access technology combinations for the UE to attempt registration. For example, the UE may select a PLMN / access technology combination from a list of PLMN IDs and access technologies stored in the UE, taking into account the PLMN and / or access technology. Here, access technology may be interpreted as radio access technology, radio access, or access network. Furthermore, the access technology may include wireless access via TN or wireless access via NTN.

[0300] [5.4. Fourth Embodiment] A fourth embodiment of this example will be described. In this section, the fourth embodiment will also be referred to as the present embodiment. This embodiment relates to timer processing based on discontinuous coverage maximum NAS signaling latency. This embodiment may also be the behavior performed by the UE and / or NW in each of the first to third embodiments.

[0301] This embodiment may be the case where the UE and / or NW supports both an unavailability period due to NR satellite access discontinuous coverage and an unavailability period not due to NR satellite access discontinuous coverage.

[0302] Furthermore, the UE and / or NW may receive and store both the unavailability period not depending on NR satellite access discontinuous coverage and the unavailability period duration depending on NR satellite access discontinuous coverage in the registration procedure and / or the UE configuration update procedure. Here, the unavailability period not depending on NR satellite access discontinuous coverage may be stored in association with the type not depending on NR satellite access discontinuous coverage indicated by the third identification information transmitted and received together with the unavailability period.

[0303] In this embodiment, when an unavailability period due to NR satellite access discontinuous coverage ends during the execution of an unavailability period not due to NR satellite access discontinuous coverage that starts at any timing, the UE may determine, set, and execute a timer value based on the discontinuous coverage maximum NAS signaling waiting time, or may not execute these.

[0304] More specifically, for example, when the UE and the NW both support at least an unavailability period due to NR satellite access discontinuous coverage, and when the UE receives third identification information indicating the type of the unavailability period due to NR satellite access discontinuous coverage and the unavailability period duration from the network, the UE may determine, store, or set a timer value based on the discontinuous coverage maximum NAS signaling waiting time at the timing of receiving the timer based on the discontinuous coverage maximum NAS signaling waiting time.

[0305] Alternatively, for example, if the UE and the NW support at least an unavailability period due to NR satellite access discontinuous coverage, and if the UE has received third identification information indicating the type of the unavailability period due to NR satellite access discontinuous coverage and the unavailability period duration from the network, after receiving the timer based on the discontinuous coverage maximum NAS signaling latency, the UE may determine, store, or set a timer value based on the discontinuous coverage maximum NAS signaling latency after the unavailability period ends.

[0306] Alternatively, for example, if the UE and the NW support at least an unavailability period due to NR satellite access discontinuous coverage and if the UE has not received third identification information indicating the type of unavailability period due to NR satellite access discontinuous coverage and the unavailability period duration from the network, the UE may not determine, store, set, and / or start the timer value based on the discontinuous coverage maximum NAS signaling latency after receiving the timer based on the discontinuous coverage maximum NAS signaling latency.

[0307] [6. Modifications] The program that runs on the device according to this embodiment 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 the embodiment according to this embodiment. The program or information handled by the program is temporarily stored in a volatile memory such as a random access memory (RAM), a non-volatile memory such as a flash memory, a hard disk drive (HDD), or other storage device system.

[0308] A program for realizing the functions of the embodiments according to 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.

[0309] 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 embodiments may utilize new integrated circuit technologies that replace current integrated circuits.

[0310] It should be noted that this example is not limited to the above-described embodiment. In the embodiment, one example of a device is described, but this example is not limited to this and can be applied to terminal devices or communication devices such as stationary or non-movable electronic devices installed indoors or outdoors, for example, AV equipment, kitchen equipment, cleaning / washing equipment, air conditioning equipment, office equipment, vending machines, and other household appliances.

[0311] Although the embodiment of this example has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications within the scope of this example are also included. Furthermore, various modifications of this example 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 this example. Furthermore, configurations in which elements described in each of the above embodiments are substituted with elements that achieve the same effect are also included.

[0312] This embodiment can be used in, for example, a communication system, a communication device (for example, a mobile phone device, a base station device, a wireless LAN device, or a sensor device), an integrated circuit (for example, a communication chip), or a program.

[0313] 1 Mobile communication system 10 UE_A 30 PGW-U 32 PGW-C 35 SGW 40 MME 45 eNB 50 HSS 60 PCRF 80 Access network_A (E-UTRAN) 90 Core network_A 120 Access network_B (5G AN) 122 gNB 130 UPF 132 SMF 140 AMF 150 UDM 160 PCF 190 Core network_B 235 UPF_A 239 UPF_C

Claims

1. A UE (User Equipment) comprising a transceiver unit, a control unit, and a memory unit, wherein the transceiver unit receives a first timer value, and / or a first type, and / or a maximum waiting time from a network (NW), the first timer value is a timer value indicating a duration of an Unavailability Period, and the first type is a type indicating that the Unavailability Period is not dependent on discontinuous coverage provided by NR (New Radio) satellite access, the control unit stores the first timer value and the first type in association with each other in the memory unit, the control unit does not set and / or start a second timer after expiration of a timer based on the first timer value associated with the first type stored in the memory unit, and the second timer is a timer whose timer value is a period determined by the UE based on the maximum waiting time.

2. The UE of claim 1, wherein, when an unavailability period due to discontinuous coverage provided by the NR satellite access has expired at the time when the timer based on the second timer value expires, the control unit does not determine and / or set the timer value of the second timer and does not start the second timer.

3. A UE (User Equipment) comprising a transceiver unit, a control unit, and a memory unit, wherein the memory unit stores a first timer and a second timer, the first timer is a timer whose timer value is an availability period associated with a type indicating that the unavailability period is not due to discontinuous coverage provided by NR (New Radio) satellite access, and the second timer is a timer whose timer value is an availability period associated with a type indicating that the unavailability period is due to discontinuous coverage provided by the NR satellite access, the transceiver unit receives first control information from a network, the first control information is information indicating the first or second timer value and / or type, and the control unit executes the timer based on the first control information.

4. A UE (User Equipment) comprising a transceiver, a control unit, and a memory unit, wherein the memory unit stores a first timer value in association with a first type, the first timer value being a timer value indicating the duration of an unavailability period, the first type being a type indicating that the unavailability period is not due to discontinuous coverage provided by NR (New Radio) satellite access, the memory unit further stores a waiting time, the waiting time being a value determined by the control unit based on a maximum waiting time received by the transceiver from a network, and the control unit executes a PLMN (Public Land Mobile Network) selection procedure when a timer based on an unavailability period due to discontinuous coverage provided by NR satellite access is running at the time when the timer based on the first timer value expires.

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