Satellite communication

Abstract

The present disclosure provides a method. The method may comprise the steps of: receiving system information from a base station included in a satellite; transmitting a first request message for accessing the satellite to a network entity related to mobility; and receiving a rejection message from the network entity.

Description

satellite communications

[0001] This specification relates to mobile communications.

[0002] 3GPP (3rd Generation Partnership Project) LTE (Long-Term Evolution) is a technology designed to enable high-speed packet communications. Numerous approaches have been proposed to achieve LTE's goals of reducing costs for users and operators, improving service quality, expanding coverage, and increasing system capacity. 3GPP LTE's high-level requirements include reduced cost per bit, improved service availability, flexible use of frequency bands, a simple architecture, open interfaces, and adequate power consumption for terminals.

[0003] The International Telecommunication Union (ITU) and 3GPP have begun work on developing requirements and specifications for New Radio (NR) systems. 3GPP must identify and develop the technical components necessary to successfully standardize NR, meeting both urgent market needs and the longer-term requirements outlined by the ITU Radio communication sector (ITU-R) International Mobile Telecommunications (IMT)-2020 process. NR must also be able to utilize any spectrum band up to at least 100 GHz, ensuring that it remains available for wireless communications well into the future.

[0004] NR aims to be a single technology framework that addresses all deployment scenarios, usage scenarios, and requirements, including enhanced Mobile Broadband (eMBB), massive Machine Type Communications (mMTC), and Ultra-Reliable and Low Latency Communications (URLLC). NR must be inherently forward-compatible.

[0005] Communication between terminals and satellites can be supported. However, conventional technology suffers from inefficient communication due to the lack of consideration for satellite operation and / or structure.

[0006] According to one embodiment of the present disclosure, a method is provided. The method may include: receiving system information from a base station included in a satellite; transmitting a first request message for accessing the satellite to a network entity associated with mobility; and receiving a rejection message from the network entity.

[0007] According to one embodiment, a device implementing the method is provided.

[0008] According to one embodiment of the present disclosure, a method is provided. The method may include receiving a first request message for accessing a satellite from a User Equipment (UE); and transmitting a rejection message to the UE.

[0009] According to one embodiment, a device implementing the method is provided.

[0010] Figure 1 illustrates an example of a communication system to which the implementation of this specification is applied.

[0011] Figure 2 illustrates an example of a wireless device to which the implementation of the present specification is applied.

[0012] Figure 3 shows an example of a UE to which the implementation of this specification is applied.

[0013] Figure 4 shows an example of a 5G system structure to which the implementation of this specification is applied.

[0014] Figures 5 and 6 illustrate examples of registration procedures to which the implementation of the present specification applies.

[0015] Figure 7 shows an example of an NTN structure.

[0016] FIG. 8 is a first example of a procedure according to one embodiment of the disclosure of the present specification.

[0017] FIG. 9 is a second example of a procedure according to one embodiment of the disclosure of the present specification.

[0018] FIG. 10 illustrates an example of operations according to one embodiment of the disclosure of the present specification.

[0019] The following techniques, devices, and systems can be applied to various wireless multiple access systems. Examples of multiple access systems include Code Division Multiple Access (CDMA) systems, Frequency Division Multiple Access (FDMA) systems, Time Division Multiple Access (TDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, and Multi-Carrier Frequency Division Multiple Access (MC-FDMA) systems. CDMA can be implemented using wireless technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented using wireless technologies such as Global System for Mobile communications (GSM), General Packet Radio Service (GPRS), or Enhanced Data rates for GSM Evolution (EDGE). OFDMA can be implemented using wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or Evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP (3rd Generation Partnership Project) Long-Term Evolution (LTE) is part of E-UMTS (Evolved UMTS) that utilizes E-UTRA.3GPP LTE uses OFDMA in the downlink (DL) and SC-FDMA in the uplink (UL). Evolution of 3GPP LTE includes LTE-A (Advanced), LTE-A Pro, and / or 5G NR (New Radio).

[0020] For convenience of explanation, the implementation of this specification is primarily described in relation to a 3GPP-based wireless communication system. However, the technical features of this specification are not limited thereto. For example, the following detailed description is provided based on a mobile communication system corresponding to a 3GPP-based wireless communication system, but aspects of this specification that are not limited to a 3GPP-based wireless communication system can be applied to other mobile communication systems.

[0021] For terms and technologies used in this specification that are not specifically described, reference may be made to wireless communication standard documents published prior to this specification.

[0022] As used herein, "A or B" can mean "only A," "only B," or "both A and B." Alternatively, as used herein, "A or B" can be interpreted as "A and / or B." For example, as used herein, "A, B or C" can mean "only A," "only B," "only C," or "any combination of A, B and C."

[0023] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0024] In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted identically to “at least one of A and B.”

[0025] Additionally, in this specification, “at least one of A, B and C” can mean “only A”, “only B”, “only C”, or “any combination of A, B and C”. Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C”.

[0026] Additionally, parentheses used in this specification may mean "for example." Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information." In other words, "control information" in this specification is not limited to "PDCCH," and "PDCCH" may be proposed as an example of "control information." Furthermore, even when indicated as "control information (e.g., PDCCH)", "PDCCH" may be proposed as an example of "control information."

[0027] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0028] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein may be applied to various fields requiring wireless communication and / or connectivity between devices (e.g., 5G).

[0029] Hereinafter, the present specification will be described in more detail with reference to the drawings. In the following drawings and / or description, the same reference numbers may refer to the same or corresponding hardware blocks, software blocks, and / or functional blocks, unless otherwise indicated.

[0030] Figure 1 illustrates an example of a communication system to which the implementation of this specification is applied.

[0031] The 5G usage scenario shown in FIG. 1 is only an example, and the technical features of this specification can be applied to other 5G usage scenarios not shown in FIG. 1.

[0032] The three main requirement categories for 5G are (1) enhanced mobile broadband (eMBB), (2) massive machine type communication (mMTC), and (3) ultra-reliable and low latency communications (URLLC).

[0033] Referring to FIG. 1, a communication system (1) includes wireless devices (100a to 100f), a base station (BS; 200), and a network (300). FIG. 1 illustrates a 5G network as an example of a network of the communication system (1), but the implementation of the present disclosure is not limited to a 5G system and can be applied to future communication systems beyond the 5G system.

[0034] The base station (200) and the network (300) may be implemented as wireless devices, and a particular wireless device may operate as a base station / network node in relation to other wireless devices.

[0035] The wireless devices (100a to 100f) represent devices that perform communication using Radio Access Technology (RAT) (e.g., 5G NR or LTE) and may also be referred to as communication / wireless / 5G devices. The wireless devices (100a to 100f) may include, but are not limited to, a robot (100a), a vehicle (100b-1 and 100b-2), an extended reality (XR) device (100c), a portable device (100d), a home appliance (100e), an Internet-of-Things (IoT) device (100f), and an artificial intelligence (AI) device / server (400). For example, the vehicles may include vehicles having wireless communication capabilities, autonomous vehicles, and vehicles capable of performing vehicle-to-vehicle communication. The vehicles may include unmanned aerial vehicles (UAVs) (e.g., drones). XR devices may include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and may be implemented in the form of HMD (Head-Mounted Device) and HUD (Head-Up Display) mounted on vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signs, vehicles, robots, etc. Portable devices may include smartphones, smart pads, wearable devices (e.g., smart watches or smart glasses), and computers (e.g., laptops). Home appliances may include TVs, refrigerators, and washing machines. IoT devices may include sensors and smart meters.

[0036] In this specification, wireless devices (100a to 100f) may be referred to as user equipment (UE). The UE may include, for example, a mobile phone, a smartphone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a slate PC, a tablet PC, an ultrabook, a vehicle, a vehicle with autonomous driving function, a connected car, a UAV, an AI module, a robot, an AR device, a VR device, an MR device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a weather / environmental device, a 5G service-related device, or a 4th industrial revolution-related device.

[0037] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). AI technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, and a network after 5G. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station (200) / network (300). For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). Additionally, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0038] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a to 100f) and / or between wireless devices (100a to 100f) and a base station (200) and / or between base stations (200). Here, the wireless communication / connection can be established through various RATs (e.g., 5G NR), such as uplink / downlink communication (150a), sidelink communication (150b) (or, D2D (Device-To-Device) communication), and base station-to-base station communication (150c) (e.g., relay, IAB (Integrated Access and Backhaul)). Through the wireless communication / connection (150a, 150b, 150c), the wireless devices (100a to 100f) and the base station (200) can transmit / receive wireless signals to / from each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various proposals of this specification, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed.

[0039] NR supports multiple numerologies, or subcarrier spacings (SCS), to support diverse 5G services. For example, an SCS of 15 kHz supports wide areas in traditional cellular bands; an SCS of 30 kHz / 60 kHz supports dense urban areas, lower latency, and wider carrier bandwidth; and an SCS of 60 kHz or higher supports bandwidths greater than 24.25 GHz to overcome phase noise.

[0040] The NR frequency band can be defined by two types of frequency ranges (FR1 and FR2). The numerical values ​​of the frequency ranges can be changed. For example, the two types of frequency ranges (FR1 and FR2) can be as shown in Table 1 below. For convenience of explanation, among the frequency ranges used in the NR system, FR1 can mean the "sub 6 GHz range," and FR2 can mean the "above 6 GHz range," which can be called millimeter wave (mmW).

[0041] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0042] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a band from 410 MHz to 7125 MHz, as shown in Table 2 below. For example, FR1 may include a frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, such as for communications for vehicles (e.g., autonomous driving).

[0043] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0044] Here, the wireless communication technology implemented in the wireless device of the present specification may include not only LTE, NR, and 6G, but also Narrowband IoT (NB-IoT) for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented with standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device of the present specification may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be called by various names such as eMTC (enhanced MTC). For example, LTE-M technology can be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (Non-Bandwidth Limited), 5) LTE-MTC, 6) LTE MTC, and / or 7) LTE M, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device of the present specification can include at least one of ZigBee, Bluetooth, and / or LPWAN considering low-power communication, and is not limited to the above-described names. For example, ZigBee technology can create PANs (Personal Area Networks) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

[0045] Figure 2 illustrates an example of a wireless device to which the implementation of the present specification is applied.

[0046] In FIG. 2, the first wireless device (100) and / or the second wireless device (200) may be implemented in various forms depending on the use case / service. For example, {the first wireless device (100) and the second wireless device (200)} may correspond to at least one of {the wireless devices (100a to 100f) and the base station (200)}, {the wireless devices (100a to 100f) and the wireless devices (100a to 100f)}, and / or {the base station (200) and the base station (200)} of FIG. 1. The first wireless device (100) and / or the second wireless device (200) may be configured by various components, devices / parts, and / or modules.

[0047] The first wireless device (100) may include at least one transceiver, such as a transceiver (106), at least one processing chip, such as a processing chip (101), and / or one or more antennas (108).

[0048] The processing chip (101) may include at least one processor, such as a processor (102), and at least one memory, such as a memory (104). Additionally and / or alternatively, the memory (104) may be located external to the processing chip (101).

[0049] The processor (102) may control the memory (104) and / or the transceiver (106) and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein. For example, the processor (102) may process information in the memory (104) to generate first information / signal and transmit a wireless signal including the first information / signal via the transceiver (106). The processor (102) may receive a wireless signal including second information / signal via the transceiver (106) and store information obtained by processing the second information / signal in the memory (104).

[0050] A memory (104) may be operatively connected to the processor (102). The memory (104) may store various types of information and / or instructions. The memory (104) may store firmware and / or software code (105) that implements code, instructions and / or sets of instructions that, when executed by the processor (102), perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. For example, the firmware and / or software code (105) may implement instructions that, when executed by the processor (102), perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. For example, the firmware and / or software code (105) may control the processor (102) to perform one or more protocols. For example, the firmware and / or software code (105) may control the processor (102) to perform one or more air interface protocol layers.

[0051] Here, the processor (102) and memory (104) may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). A transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). Each transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present specification, the first wireless device (100) may represent a communication modem / circuit / chip.

[0052] The second wireless device (200) may include at least one transceiver, such as a transceiver (206), at least one processing chip, such as a processing chip (201), and / or one or more antennas (208).

[0053] The processing chip (201) may include at least one processor, such as a processor (202), and at least one memory, such as a memory (204). Additionally and / or alternatively, the memory (204) may be located external to the processing chip (201).

[0054] The processor (202) may control the memory (204) and / or the transceiver (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein. For example, the processor (202) may process information in the memory (204) to generate third information / signal and transmit a wireless signal including the third information / signal via the transceiver (206). The processor (202) may receive a wireless signal including fourth information / signal via the transceiver (206) and store information obtained by processing the fourth information / signal in the memory (204).

[0055] A memory (204) may be operatively connected to the processor (202). The memory (204) may store various types of information and / or instructions. The memory (204) may store firmware and / or software code (205) that implements code, instructions and / or sets of instructions that, when executed by the processor (202), perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. For example, the firmware and / or software code (205) may implement instructions that, when executed by the processor (202), perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. For example, the firmware and / or software code (205) may control the processor (202) to perform one or more protocols. For example, the firmware and / or software code (205) may control the processor (202) to perform one or more air interface protocol layers.

[0056] Here, the processor (202) and memory (204) may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). A transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). Each transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with the RF unit. In the present specification, the second wireless device (200) may represent a communication modem / circuit / chip.

[0057] Hereinafter, hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as a physical (PHY) layer, a Media Access Control (MAC) layer, a Radio Link Control (RLC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Resource Control (RRC) layer, and a Service Data Adaptation Protocol (SDAP) layer). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs), one or more Service Data Units (SDUs), messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0058] The one or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, and / or a microcomputer. The one or more processors (102, 202) may be implemented by hardware, firmware, software, and / or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), and / or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or more processors (102, 202). For example, the one or more processors (102, 202) may be configured by a set of a communication control processor, an Application Processor (AP), an Electronic Control Unit (ECU), a Central Processing Unit (CPU), a Graphic Processing Unit (GPU), and a Memory Control Processor. One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions and / or commands. The one or more memories (104, 204) may be configured as random access memory (RAM), dynamic RAM (DRAM), read-only memory (ROM), erasable programmable ROM (EPROM), flash memory, volatile memory, nonvolatile memory, hard drive, register, cache memory, computer readable storage media and / or combinations thereof.One or more memories (104, 204) may be located internally and / or externally to one or more processors (102, 202). Additionally, one or more memories (104, 204) may be connected to one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0059] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., referred to in the descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed herein to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., referred to in the descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed herein from one or more other devices. For example, one or more transceivers (106, 206) can be coupled to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, wireless signals, etc., to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, wireless signals, etc. from one or more other devices.

[0060] One or more transceivers (106, 206) may be coupled to one or more antennas (108, 208). Additionally and / or alternatively, one or more transceivers (106, 206) may include one or more antennas (108, 208). One or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein via one or more antennas (108, 208). In the present disclosure, one or more antennas (108, 208) may be multiple physical antennas or multiple logical antennas (e.g., antenna ports).

[0061] One or more transceivers (106, 206) may convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202). One or more transceivers (106, 206) may convert processed user data, control information, wireless signals / channels, etc. from baseband signals to RF band signals using one or more processors (102, 202). For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or a filter. For example, one or more transceivers (106, 206) may up-convert an OFDM baseband signal to an OFDM signal via an (analog) oscillator and / or filter under the control of one or more processors (102, 202) and transmit the up-converted OFDM signal at a carrier frequency. One or more transceivers (106, 206) may receive an OFDM signal at a carrier frequency and down-convert the OFDM signal to an OFDM baseband signal via an (analog) oscillator and / or filter under the control of one or more processors (102, 202).

[0062] Although not illustrated in FIG. 2, the wireless device (100, 200) may further include additional components. The additional components (140) may be configured in various ways depending on the type of the wireless device (100, 200). For example, the additional components (140) may include at least one of a power unit / battery, an input / output (I / O) device (e.g., an audio I / O port, a video I / O port), a driving device, and a computing device. The additional components (140) may be connected to one or more processors (102, 202) via various technologies, such as a wired or wireless connection.

[0063] In the implementation of this specification, a UE can operate as a transmitter in the uplink and as a receiver in the downlink. In the implementation of this specification, a base station can operate as a receiver in the UL and as a transmitter in the DL. For the sake of convenience of description, it is mainly assumed below that the first wireless device (100) operates as a UE and the second wireless device (200) operates as a base station. For example, a processor (102) connected to, mounted on, or released in the first wireless device (100) can be configured to perform UE operations according to the implementation of this specification or to control a transceiver (106) to perform UE operations according to the implementation of this specification. A processor (202) connected to, mounted on, or released in the second wireless device (200) can be configured to perform base station operations according to the implementation of this specification or to control a transceiver (206) to perform base station operations according to the implementation of this specification.

[0064] In this specification, a base station may be referred to as a Node B, an eNode B (eNB), or a gNB.

[0065] Figure 3 shows an example of a UE to which the implementation of this specification is applied.

[0066] Referring to FIG. 3, the UE (100) can correspond to the first wireless device (100) of FIG. 2.

[0067] The UE (100) includes a processor (102), memory (104), a transceiver (106), one or more antennas (108), a power management module (141), a battery (142), a display (143), a keypad (144), a SIM (Subscriber Identification Module) card (145), a speaker (146), and a microphone (147).

[0068] The processor (102) may be configured to implement the descriptions, functions, procedures, proposals, methods and / or flowcharts disclosed herein. The processor (102) may be configured to control one or more other components of the UE (100) to implement the descriptions, functions, procedures, proposals, methods and / or flowcharts disclosed herein. A layer of a radio interface protocol may be implemented in the processor (102). The processor (102) may include an ASIC, other chipsets, logic circuits and / or data processing devices. The processor (102) may be an application processor. The processor (102) may include at least one of a DSP, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and a modem (modulator and demodulator). An example of the processor (102) is the SNAPDRAGON manufactured by Qualcomm®. TM Series processors, EXYNOS made by Samsung® TM Series processors, A-series processors made by Apple®, HELIO made by MediaTek® TM ATOM series processors made by Intel® TM It can be found in the series processors or the corresponding next-generation processors.

[0069] Memory (104) is operatively coupled to the processor (102) and stores various information for operating the processor (102). Memory (104) may include ROM, RAM, flash memory, memory cards, storage media, and / or other storage devices. When the implementation is implemented in software, the techniques described herein may be implemented using modules (e.g., procedures, functions, etc.) that perform the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed herein. The modules may be stored in memory (104) and executed by the processor (102). Memory (104) may be implemented within the processor (102) or external to the processor (102), in which case it may be communicatively coupled to the processor (102) via various methods known in the art.

[0070] A transceiver (106) is operably coupled to the processor (102) and transmits and / or receives a radio signal. The transceiver (106) includes a transmitter and a receiver. The transceiver (106) may include a baseband circuit for processing a radio frequency signal. The transceiver (106) controls one or more antennas (108) to transmit and / or receive a radio signal.

[0071] The power management module (141) manages the power of the processor (102) and / or the transceiver (106). The battery (142) supplies power to the power management module (141).

[0072] The display (143) outputs the results processed by the processor (102). The keypad (144) receives input to be used by the processor (102). The keypad (144) can be displayed on the display (143).

[0073] A SIM card (145) is an integrated circuit that securely stores an International Mobile Subscriber Identity (IMSI) and associated keys, and is used to identify and authenticate subscribers in mobile devices such as mobile phones and computers. Additionally, many SIM cards can store contact information.

[0074] The speaker (146) outputs sound-related results processed by the processor (102). The microphone (147) receives sound-related input to be used by the processor (102).

[0075] Figure 4 shows an example of a 5G system structure to which the implementation of this specification is applied.

[0076] The 5G system (5GS; 5G system) structure consists of the following network functions (NF; Network Function).

[0077] - AUSF (Authentication Server Function)

[0078] -AMF (Access and Mobility Management Function)

[0079] - DN (Data Network), for example, operator services, Internet access, or third-party services

[0080] - USDF (Unstructured Data Storage Function)

[0081] - NEF (Network Exposure Function)

[0082] - I-NEF (Intermediate NEF)

[0083] - NRF (Network Repository Function)

[0084] - NSSF (Network Slice Selection Function)

[0085] - PCF (Policy Control Function)

[0086] - SMF (Session Management Function)

[0087] - UDM (Unified Data Management)

[0088] - UDR (Unified Data Repository)

[0089] - UPF (User Plane Function)

[0090] - UCMF (UE radio Capability Management Function)

[0091] - AF (Application Function)

[0092] - UE (User Equipment)

[0093] - (R)AN ((Radio) Access Network)

[0094] - 5G-EIR (5G-Equipment Identity Register)

[0095] - NWDAF (Network Data Analytics Function)

[0096] - CHF (CHarging Function)

[0097] 또한, 다음과 같은 네트워크 기능이 고려될 수 있다.

[0098] - N3IWF (Non-3GPP InterWorking Function)

[0099] - TNGF (Trusted Non-3GPP Gateway Function)

[0100] - W-AGF (Wireline Access Gateway Function)

[0101] Figure 4 illustrates the 5G system architecture for a non-roaming case using a reference point representation showing how various network functions interact with each other.

[0102] For clarity of the point-to-point diagram in Figure 4, UDSF, NEF, and NRF are not illustrated. However, all network functions shown can interact with UDSF, UDR, NEF, and NRF as needed.

[0103] For clarity, the connection between UDR and other NFs (e.g., PCF) is not shown in Fig. 4. For clarity, the connection between NWDAF and other NFs (e.g., PCF) is not shown in Fig. 4.

[0104] The 5G system architecture includes the following benchmarks:

[0105] - N1: Reference point between UE and AMF.

[0106] - N2: Reference point between (R)AN and AMF.

[0107] - N3: Reference point between (R)AN and UPF.

[0108] - N4: Reference point between SMF and UPF.

[0109] - N6: Reference point between UPF and data network.

[0110] - N9: Reference point between two UPFs.

[0111] The following benchmarks illustrate the interactions that exist between NF services in NF.

[0112] - N5: Reference point between PCF and AF.

[0113] - N7: Reference point between SMF and PCF.

[0114] - N8: Reference point between UDM and AMF.

[0115] - N10: Reference point between UDM and SMF.

[0116] - N11: Reference point between AMF and SMF.

[0117] - N12: Reference point between AMF and AUSF.

[0118] - N13: Reference point between UDM and AUSF.

[0119] - N14: Reference point between two AMFs.

[0120] - N15: Reference point between PCF and AMF for non-roaming scenarios, and reference point between PCF and AMF of visited network for roaming scenarios.

[0121] - N16: Reference point between two SMFs (in case of roaming, between the SMF of the visited network and the SMF of the home network)

[0122] - N22: Reference point between AMF and NSSF.

[0123] In some cases, two NFs may need to be interconnected to serve a UE.

[0124] Describes the registration procedure. See section 4.2.2.2 of 3GPP TS 23.502 V16.3.0 (2019-12).

[0125] Figures 5 and 6 illustrate examples of registration procedures to which the implementation of the present specification applies.

[0126] A UE must register with the network to receive services, enable mobility tracking, and enable reachability. The UE initiates the registration process using one of the following registration types:

[0127] - Initial registration for 5GS; or

[0128] - mobility registration update; or

[0129] - Periodic registration update; or

[0130] - Emergency registration

[0131] The general registration procedures of Figures 5 and 6 apply to all registration procedures described above, but periodic registration updates do not need to include all parameters used in other registration procedures.

[0132] The general registration procedures of Figures 5 and 6 can also be used to register a UE for a 3GPP connection when it is already registered for a non-3GPP connection, and vice versa. Registering a UE for a 3GPP connection when it is already registered for a non-3GPP connection scenario may require an AMF change.

[0133] First, the procedure of Fig. 5 is described.

[0134] (1) Step 1: The UE transmits a Registration Request message to the (R)AN. The Registration Request message corresponds to an AN message.

[0135] The registration request message may include AN parameters. For NG-RAN, the AN parameters include, for example, the 5G SAE temporary mobile subscriber identity (5G-S-TMSI) or globally unique AMF ID (GUAMI), the selected public land mobile network (PLMN) ID (or PLMN ID and network identifier (NID)), and the requested network slice selection assistance information (NSSAI). The AN parameters also include an establishment cause. The establishment cause provides the reason for requesting establishment of an RRC connection. Whether and how the UE includes the requested NSSAI as part of the AN parameters depends on the value of the access stratum connection establishment NSSAI inclusion mode parameter.

[0136] A registration request message may include a registration type. The registration type indicates whether the UE wants to perform an initial registration (e.g., the UE is in RM-DEREGISTERED state), or a mobility registration update (e.g., the UE is in RM-REGISTERED state and initiates a registration procedure because the UE moves, or the UE wants to update capabilities or protocol parameters, or requests a change in the set of network slices the UE is allowed to use), or a periodic registration update (e.g., the UE is in RM-REGISTERED state and initiates a registration procedure because a periodic registration update timer expires), or an emergency registration (e.g., the UE is in a restricted service state).

[0137] When a UE performs initial registration, the UE indicates its UE ID in the registration request message, listed in decreasing priority order.

[0138] i) If the UE has a valid evolved packet system (EPS) globally unique temporary identifier (GUTI), 5G-GUTI mapped from the EPS GUTI;

[0139] ii) Native 5G-GUTI (if available) allocated by the PLMN in which the UE is attempting to register;

[0140] iii) Native 5G-GUTI allocated by a PLMN equivalent to the PLMN in which the UE is attempting to register;

[0141] iv) Native 5G-GUTI allocated by another PLMN (if available);

[0142] v) Otherwise, the UE includes a subscriber concealed identifier (SUCI) in the registration request message.

[0143] If a UE performing initial registration has both a valid EPS GUTI and a native 5G-GUTI, the UE also indicates the native 5G-GUTI as an additional GUTI. If more than one native 5G-GUTI is available, the UE selects a 5G-GUTI from items (ii)-(iv) in decreasing priority order in the list above.

[0144] When the UE performs initial registration with native 5G-GUTI, the UE indicates the relevant GUAMI information in the AN parameters. When the UE performs initial registration with SUCI, the UE does not indicate the GUAMI information in the AN parameters.

[0145] For emergency registration, if the UE does not have a valid 5G-GUTI, the SUCI is included. If the UE does not have a subscriber permanent identifier (SUPI) and does not have a valid 5G-GUTI, the PEI (Permanent Equipment Identifier) ​​is included. Otherwise, the 5G-GUTI is included, indicating the last serving AMF.

[0146] The registration request message may also include security parameters, PDU session status, etc. Security parameters are used for authentication and integrity protection. The PDU session status indicates a previously established PDU session in the UE. When the UE is connected to two AMFs belonging to different PLMNs via a 3GPP connection and a non-3GPP connection, the PDU session status indicates the PDU session currently established in the PLMN in the UE.

[0147] (2) Step 2: (R)AN selects AMF.

[0148] If 5G-S-TMSI or GUAMI is not included, or if 5G-S-TMSI or GUAMI does not indicate a valid AMF, the (R)AN selects an AMF based on the (R)AT and the requested NSSAI, if available.

[0149] When the UE is in CM-CONNECTED state, (R)AN can forward a registration request message to AMF based on the N2 connection of the UE.

[0150] If the (R)AN cannot select an appropriate AMF, the (R)AN performs AMF selection by forwarding a registration request message to the AMF configured in the (R)AN.

[0151] (3) Step 3: (R)AN sends a registration request message to the new AMF. The registration request message corresponds to the N2 message.

[0152] The registration request message may contain all of the information and / or part of the information contained in the registration request message received from the UE described in step 1.

[0153] The registration request message may include an N2 parameter. When NG-RAN is used, the N2 parameter includes the selected PLMN ID (or PLMN ID and NID), location information and cell ID related to the cell where the UE is camping, and a UE context request indicating that a UE context including security information should be established in the NG-RAN. When NG-RAN is used, the N2 parameter also includes an establishment cause.

[0154] If the registration type indicated by the UE is periodic registration update, steps 4-19 described below may be omitted.

[0155] (4) Step 4: If the UE's 5G-GUTI is included in the registration request message and the serving AMF has changed since the last registration procedure, the new AMF may invoke the Namf_Communication_UEContextTransfer service operation to the previous AMF, including the full registration request non-access stratum (NAS) message to request the UE's SUPI and UE context.

[0156] (5) Step 5: The old AMF can respond to the new AMF for the Namf_Communication_UEContextTransfer call including the UE's SUPI and UE context.

[0157] (6) Step 6: If SUCI is not provided by the UE or not retrieved from the previous AMF, the new AMF may initiate an ID request procedure by sending an Identity Request message to request SUCI from the UE.

[0158] (7) Step 7: The UE may respond with an Identity Response message including the SUCI. The UE derives the SUCI using the provided public key of the home PLMN (HPLMN).

[0159] (8) Step 8: The new AMF may decide to initiate UE authentication by calling the AUSF. In this case, the new AMF selects the AUSF based on SUPI or SUCI.

[0160] (9) Step 9: Authentication / security can be established by UE, new AMF, AUSF and / or UDM.

[0161] (10) Step 10: If the AMF has changed, the new AMF may call the Namf_Communication_RegistrationCompleteNotify service operation to notify the old AMF that the UE registration with the new AMF is complete. If the authentication / security procedure fails, the registration is rejected and the new AMF may call the Namf_Communication_RegistrationCompleteNotify service operation with a reject indication reason code to the old AMF. The old AMF may continue as if the UE context transfer service operation was not received.

[0162] (11) Step 11: If the PEI was not provided by the UE or was not retrieved from the previous AMF, the new AMF may initiate the ID request procedure by sending an Identity Request message to the UE to retrieve the PEI. The PEI is transmitted encrypted, except when the UE performs emergency registration and cannot be authenticated.

[0163] (12) Step 12: Optionally, the new AMF can initiate ME ID checking by calling the N5g-eir_EquipmentIdentityCheck_Get service operation.

[0164] Now, the procedure of Fig. 6 following the procedure of Fig. 5 is described.

[0165] (13) Step 13: When step 14 below is performed, the new AMF can select a UDM based on SUPI, and the UDM can select a UDR instance.

[0166] (14) Step 14: New AMFs can be registered with UDM.

[0167] (15) Step 15: New AMF can select PCF.

[0168] (16) Step 16: The new AMF may optionally perform AM policy association establishment / modification.

[0169] (17) Step 17: The new AMF can send update / release SM context messages (e.g., Nsmf_PDUSession_UpdateSMContext and / or Nsmf_PDUSession_ReleaseSMContext) to the SMF.

[0170] (18) Step 18: If the new AMF and the old AMF are in the same PLMN, the new AMF may send a UE context modification request to the N3IWF / TNGF / W-AGF.

[0171] (19) Step 19: N3IWF / TNGF / W-AGF may send a UE context modification response to the new AMF.

[0172] (20) Step 20: After the new AMF receives the response message from N3IWF / TNGF / W-AGF in step 19, the new AMF can register with UDM.

[0173] (21) Step 21: The new AMF sends a Registration Accept message to the UE.

[0174] The new AMF sends the UE a Registration Accept message indicating that the registration request has been accepted. If the new AMF allocates a new 5G-GUTI, it includes the 5G-GUTI. If the UE is already in the RM-REGISTERED state through another connection to the same PLMN, the UE uses the 5G-GUTI received in the Registration Accept message for both registrations. If the Registration Accept message does not include a 5G-GUTI, the UE uses the 5G-GUTI assigned to the existing registration for the new registration. If the new AMF allocates a new registration area, it sends the registration area to the UE in the Registration Accept message. If the Registration Accept message does not include a registration area, the UE considers the previous registration area to be valid. Mobility Restrictions are included if mobility restrictions apply to the UE and the registration type is not emergency registration. The new AMF indicates the PDU sessions established for the UE in the PDU Session State. The UE locally removes internal resources associated with PDU sessions that are not marked as established in the received PDU Session State. When a UE is connected to two AMFs belonging to different PLMNs via a 3GPP connection and a non-3GPP connection, the UE locally removes internal resources associated with PDU sessions in the current PLMN that are not marked as established in the received PDU session status. If PDU session status information is present in the Registration Accept message, the new AMF indicates the PDU session status to the UE.

[0175] The Allowed NSSAI provided in the Registration Accept message is valid for the registration area and applies to all PLMNs that have a tracking area included in the registration area. The Mapping of Allowed NSSAIs maps HPLMN S-NSSAIs to each S-NSSAI of the Allowed NSSAIs. The Mapping of Configured NSSAIs maps HPLMN S-NSSAIs to each S-NSSAI of the Configured NSSAI for the serving PLMN.

[0176] Additionally, optionally, the new AMF performs UE policy association establishment.

[0177] (22) Step 22: If the UE successfully updates itself, it can send a Registration Complete message to the new AMF.

[0178] The UE may send a registration complete message to the new AMF to confirm that a new 5G-GUTI has been allocated.

[0179] (23) Step 23: In case of registration via 3GPP connection, if the new AMF does not release the signaling connection, the new AMF may send RRC Inactive Assistance information to the NG-RAN. In case of registration via non-3GPP connection, if the UE is in CM-CONTENED state on the 3GPP connection, the new AMF may send RRC Inactive Assistance information to the NG-RAN.

[0180] (24) Step 24: AMF can perform information updates on UDM.

[0181] (25) Step 25: The UE may execute a network slice-specific authentication and authorization (NSSAA) procedure.

[0182] An example of Non-Terrestrial Networks (NTN) is described. For a detailed description of NTN, in addition to what is described in the disclosure of this specification, refer to 3GPP TS 38.300 V18.1.0 S16.14.

[0183] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals, messages, and fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0184] Figure 7 shows an example of an NTN structure.

[0185] Figure 7 illustrates an example of an NTN providing NTN NR access to a UE via an NTN payload and an NTN gateway. Referring to the example of Figure 7, a service link between the NTN payload and the UE and a feeder link between the NTN gateway and the NTN payload are illustrated.

[0186] The NTN payload can receive radio protocols from the UE (via the service link). The NTN payload can transparently forward radio protocols to the NTN gateway (via the feeder link) or vice versa. The NTN payload supports the following connections:

[0187] - NTN gateway can serve multiple NTN payloads;

[0188] - A single NTN payload can be served by multiple NTN gateways.

[0189] For NTN, in addition to the network identifiers described in clause 8.2 of 3GPP TS 38.300 V18.1.0, the following may apply:

[0190] - Tracking areas correspond to fixed geographical areas. Each mapping can be configured in the RAN;

[0191] - Mapped cell ID.

[0192] Three types of service links can be supported:

[0193] - Earth-fixed: may be provided by beam(s) that continuously cover the same geographic area at all times (e.g., in the case of GSO satellites);

[0194] - Quasi-Earth-fixed: may be provided as a beam that covers one geographic area for a limited period of time and another geographic area for a different period of time (e.g., for NGSO satellites that produce steerable beams);

[0195] - Earth-moving: The coverage area may be provided by a beam sliding over the Earth's surface (e.g., for NGSO satellites producing fixed or unsteered beams).

[0196] For example, a gNB using an NGSO satellite can provide a quasi-Earth-fixed service link or an Earth-moving service link. A gNB based on a GSO satellite can provide an Earth-fixed service link or a quasi-Earth-fixed service link.

[0197] In NTN, distance means Euclidean distance.

[0198] Satellites (or UAS platforms) can implement transparent or regenerative (including onboard processing) payloads. Satellites (or UAS platforms) can generate beams. For example, satellites typically generate multiple beams for a given service area, depending on their field of view. The geographic area over which the beams reach the ground, called the footprint, is typically elliptical.

[0199] - Transparent payload: A transparent payload can support radio frequency filtering, frequency conversion, and amplification. Therefore, the waveform signal repeated by the payload remains unchanged.

[0200] - Regenerative payload: Regenerative payloads can support radio frequency filtering, frequency conversion and amplification, demodulation / decoding, switching and / or routing, and coding / modulation. This is essentially equivalent to embedding all or part of a base station function (e.g., gNB) on a satellite (or UAS platform).

[0201] Measures to support satellite communications are being discussed. For example, research on the integration of satellite components in the 5G architecture (3GPP SP-231199) has been discussed.

[0202] A solution is needed to support satellite store-and-forward operations. Store-and-forward operations allow a satellite relaying data to temporarily store the information it receives and then forward it to the next destination at an appropriate time.

[0203] For reference, various examples disclosed in this specification exemplify EPS network nodes for core network network nodes, but these are merely examples. The descriptions of network nodes in this specification can also be applied to 5G, 6G, or later generations of mobile communications. For example, operations related to MME can be applied to network nodes related to mobility (e.g., AMF in 5G).

[0204] To support Store and Forward satellite operations, the following examples may be applied:

[0205] Depending on the operator's deployment, it may be decided whether to have a full CN onboard the satellite, including a base station (e.g., eNB or gNB), or to use a split MME architecture, including a base station (e.g., eNB or gNB).

[0206] The following options can be applied to support store-and-forward operations in a split MME architecture, based on the following principles:

[0207] 1) In a split Mobility Management Entity (MME) architecture, the Home Subscriber Server (HSS) is on the ground.

[0208] 2) The MME function can be divided into two parts: MME-onboard, which can be the MME part mounted on the satellite; MME-ground, which can be the MME part located in the terrestrial network with interfaces outside the scope of 3GPP and MME-onboard.

[0209] 3) Mobile Originated (MO) data can be stored in the MME onboard when the service link is available and the feeder link is unavailable. When the feeder link becomes available, the MO data can be transmitted to the ground. Mobile Terminated (MT) data is stored in the MME ground or S-GW when the feeder link is unavailable, and can be transmitted to the MME onboard when the feeder link becomes available. MT data is stored in the MME onboard when the feeder link is available and the service link is unavailable, and can be transmitted to the UE when the service link becomes available. All types of data traffic (e.g., IP, etc.) can be supported and transmitted using the existing user plane and control plane procedures defined in the EPS.

[0210] For reference, a service link refers to the communication link between a terminal and a satellite. A feeder link refers to the communication link between a satellite and a ground gateway (or NTN gateway).

[0211] 4) For MO SMS, upon receiving MO SMS, MME onboard stores MO-SMS and immediately sends a delivery report (e.g., RP-ACK) to UE, so that MO-SMS can be processed as if it has already been successfully delivered to Service Center (SC).

[0212] Additionally, the following may apply:

[0213] 1) If a feeder link is not available and the network supports S&F operation, the network may inform the UE(s) whether S&F satellite operation is applicable (e.g., the base station may broadcast support of S&F operation as part of the system information).

[0214] 2) When the UE initiates a procedure to access the network (e.g., Attach procedure, TAU procedure, Registration procedure, etc.), the UE may notify the MME of its support for S&F mode according to the conventional NAS function. If these procedures cannot be completed due to the S&F operation, the MME may send an Attach Reject message or a TAU Reject message to the UE. The Attach Reject message or TAU Reject message may include the following:

[0215] a) The attach procedure or TAU procedure could not be completed due to the S&F operation and new information may be included indicating that the UE may reattempt the attach or TAU on this PLMN in the next satellite pass. This information indicates to the UE that the information contained in the attach request message or TAU request message is stored in the MME and will be available to the UE after interaction with the terrestrial network.

[0216] b) A wait timer may be included. The wait timer may indicate to the UE how long it must wait before retrying the Attach / TAU procedure on the current or another satellite of the same PLMN.

[0217] c) Optionally, a list of satellite IDs for which the UE can retry the Attach / TAU procedure after the wait timer expires may be included. The satellite IDs may be based on SIB information broadcast by the base station.

[0218] 3) How the UE processes the information in 2) depends on the UE implementation. While the waiting timer is running, the UE can search for other terrestrial or satellite PLMNs to receive normal service.

[0219] 4) The MME may indicate a “Request Time” to the HSS, and the HSS may verify that no other (e.g., terrestrial) MME has sent an update location request since the “Request Time”, and may retrieve authentication vectors and other details from the HSS according to the current authentication and security procedures. The MME may trigger a location update to the HSS, and the MME may receive an Update Location ACK. For example, all subscriber details are retrieved from the MME-ground. The Update Location Request may include an indication that this location update is provisional. For example, the HSS may not consider the UE registered until it receives the final Location Update Request.

[0220] 5) When the waiting timer given to the UE in step 2) expires, if the UE has not successfully attached to another PLMN and finds a cell that has transmitted a valid satellite ID to retry the attachment procedure, the UE retransmits an attach request message or a TAU request message.

[0221] 6) During the Attach procedure or TAU procedure with the UE, the MME may provide the UE with a list of satellite IDs with which the UE can exchange signals and data, and a wait timer. The wait timer may be a timer that informs the UE of the time it must wait before attempting to exchange signals and data with the corresponding satellite.

[0222] 7) The MME may send the UE an NAS message (e.g., an Attach Accept message, a TAU Accept message, or a Service Accept message) containing the expected delivery time. How the UE uses this information is dependent on the UE implementation.

[0223] 8) The core network can indicate to external SCS / AS whether the UE is registered in S&F mode and the expected delivery time.

[0224] The following description can be applied to support store-and-forward operations by carrying a full CN on a satellite:

[0225] - The entire CN, including eNB, MME, SGW, PGW, HSS, E-SMLC, SMSC, etc., can be mounted on each satellite. Proxies can be deployed on the satellite and ground to support application traffic, including MT traffic, MO traffic, SMS, etc.

[0226] - The implementation of the proxy and the interface between the proxy may be outside the scope of 3GPP.

[0227] - As needed and according to the monitoring list, the UE can transmit data (e.g. SMS, MO and MT data, etc.) to each satellite, or attach or detach from each satellite.

[0228] For MT traffic, the UE attaches to a satellite to allow transmission of MO traffic from a user or an application on the UE. Depending on the implementation, the UE may first wait for an indication of pending MT traffic from the user or application on the UE, or it may wait until the MT traffic is expected to arrive before performing the attach.

[0229] - Depending on the deployment and implementation, the satellite's HSS may be populated with subscriber data for the UE that has access to the satellite or for all UEs that have access to the satellite.

[0230] - Depending on the deployment, the UE may have an enhanced USIM for IOPS or a USIM dedicated to the satellite network.

[0231] The following explanations may apply:

[0232] - Storage and forwarding can be supported in EPS, 5GS, etc.

[0233] - Optionally, the MME may provide the UE with a S&F monitoring list of satellite IDs during the attach / TAU procedure. The UE can exchange MO / MT data / signals with the CN using the satellites in the S&F monitoring list. The CN can determine the S&F monitoring list.

[0234] - The UE may be aware that the satellite supports S&F mode.

[0235] - If the current satellite cannot support the UE, the UE may be rejected. The attach rejection message may include a timer indicating the time the UE must wait before retrying, and a list of S&F monitoring points from which the UE can attempt to reattach.

[0236] To support the Store and Forward operation of satellites, operators can choose to deploy either a Split MME architecture, which mounts eNB and MME on the satellite, or a Full CN architecture, which mounts all Core Network Functions, including eNB, on the satellite.

[0237] However, this structure is a network deployment option. Terminals may require different behavior depending on each network deployment.

[0238] For example, in the case of Full CN architecture, the UE may attach (or register) to each satellite whenever it is connected to it, and detach (or deregister) whenever it leaves the satellite coverage. In addition, if the UE leaves the satellite coverage before detach (or deregister), a local detach (or deregister) may be required for the UE and the network. Therefore, rather than monitoring the satellite paging to receive MT data, the UE may attach (or register) to the satellite corresponding to the monitoring list each time. Alternatively, if the UE or the user's application notifies that there is MT data to be received, and the UE may know the time when the MT data traffic occurs, the UE may attach (or register) at that time and receive the MT data.

[0239] For another example, in the case of Split MME, the UE may not detach even if it leaves the satellite's coverage area. If MO data transmission is required, the UE may attempt to transmit MO data via NAS messages such as Service Request. The UE may also monitor paging from the satellite's base station to receive MT data.

[0240] Additionally, since satellites with a Full CN structure do not support roaming, the terminal may not connect / attach to the network for satellites with a Full CN in the roaming area.

[0241] As described above, terminal and network behavior can vary depending on deployment options related to the satellite's structure. However, prior technology failed to consider the satellite's structure at all, making efficient communication impossible.

[0242] For example, using different terminals for each deployment option is inefficient. Furthermore, according to conventional technology, the UE must perform an Attach (or Register) operation each time in a Split MME architecture, or perform a TAU and then receive a reject in a Full CN architecture. This can result in unnecessary signaling. To reduce this unnecessary signaling and support efficient communication, a method is needed that allows the terminal to operate by distinguishing between the satellite's S&F architecture.

[0243] In various examples disclosed in this specification, methods are described for a UE to support both Split MME and Full CN architectures. Examples of UEs supporting differentiation of a satellite's S&F architecture are described.

[0244] The method for distinguishing the store and forward structure of a satellite base station by a terminal proposed in the disclosure of this specification may be composed of a combination of one or more of the following operations / configurations / steps.

[0245] For the procedures and / or messages described below, existing procedures / messages may be used, existing procedures / messages may be extended and used, or new procedures / messages may be defined and used.

[0246] In various examples of the disclosure of this specification, the terms Satellite and satellite are used interchangeably.

[0247] In various examples of the disclosure of this specification, UE (User Equipment) and terminal are used interchangeably.

[0248] In various examples of the disclosure of this specification, descriptions that are identical to those of the prior art are omitted, and descriptions are focused on the contents proposed in the disclosure of this specification.

[0249] This specification assumes a structure in which NG-RAN is mounted on a satellite.

[0250] In this specification, the satellite is assumed to be a Low Earth Orbit (LEO) or Medium Earth Orbit (MEO) satellite.

[0251] In this specification, the Full CN structure can be interpreted as the Full MME structure (or the Full AMF structure).

[0252] Although this specification focuses on the components and interfaces of EPS, it can be equally applied to 5GS or 6G systems. For example, the description related to MME can be applied to AMF. The description related to eNB can be applied to NG-RAN (gNB). The description related to HSS can be applied to UDM. The description related to Attach can be applied to Registration. The description related to TAU can be applied to Mobility Registration. The description related to ECM-IDLE can be applied to CM-IDLE. The description related to ECM-CONNECTED can be applied to CM-CONNECTED. The description related to S1 Release can be applied to AN Release.

[0253] Split MME and Full CN architectures have base stations (e.g., eNB, gNB, etc.) in common.

[0254] For example, Split MME may be a structure in which an onboard-MME (or onboard-AMF) is mounted on a satellite in addition to a base station (e.g., eNB, gNB, etc.) and connected to a ground-MME on the ground. Full CN may be a structure in which all CNs (or 5G core network), such as MME, SGW, PGW, HSS, E-SMLC, SMSC, etc., are mounted on a base station (e.g., eNB, gNB, etc.).

[0255] Base stations (e.g., eNBs, gNBs, etc.) onboard a satellite can fundamentally inform the UE whether they support Store and Forward (S&F). It is assumed that all S&F-supporting satellites within the same PLMN have the same S&F architecture.

[0256] The disclosure of this specification describes various examples for distinguishing the architecture of a satellite (Split MME or Full CN structure) that supports S&F by a terminal. For example, the first example of the disclosure of this specification (e.g., [1] a method in which a base station of a satellite notifies via SIB), the second example of the disclosure of this specification (e.g., [2] a method in which a satellite gives an indication during an Attach / TAU process), and the third example of the disclosure of this specification (e.g., [3] a method in which a terminal can implicitly know) can be proposed. According to the disclosure of this specification, a terminal can support different operations depending on the architecture of the network.

[0257] 1. First example of disclosure of this specification

[0258] A first example of the disclosure of this specification is that a base station (e.g., eNB, gNB, etc.) of a satellite can inform a UE of the structure of the satellite via SIB.

[0259] For example, a base station (e.g., eNB, gNB, etc.) mounted on a Satellite that supports S&F operation can inform the UE whether it is a base station (e.g., eNB, gNB, etc.) that supports Store and Forward (S&F).

[0260] A structure for S&F operations of a satellite equipped with a base station (e.g., eNB, gNB, etc.) can be configured on the satellite. The base station can additionally broadcast SIB information to the terminal, including information on whether the current satellite is in a Split MME or Full CN configuration. For example, a new IE indicating the satellite's S&F structure can be added to the SIB message. Based on this broadcast information, the terminal can understand the satellite's structure before performing Attach / TAU operations, etc., to the satellite.

[0261] Instead of providing information related to the Split MME / Full CN structure using information related to S&F support and information related to whether the base station supports Split MME S&F, the base station may provide information to the UE on whether the base station supports Split MME S&F and whether the base station supports Full CN S&F.

[0262] The base station can transmit information indicating a Split MME to the UE in the following format. However, the following format is only an example and may be transmitted in other formats:

[0263] - Information indicating that inter-satellite mobility is supported;

[0264] - Information indicating that TAU ​​must be performed when the UE accesses a satellite cell belonging to the same PLMN; and / or

[0265] - Information indicating that detach is not required after data transmission.

[0266] The base station can transmit information indicating the Full CN in the following formats. However, the following formats are only examples and can be transmitted in other formats:

[0267] - Information indicating that inter-satellite mobility is not supported;

[0268] - Information indicating that an attach must be performed when the UE accesses a satellite cell belonging to the same PLMN; and / or

[0269] - Information indicating that detach is required after data transmission.

[0270] Based on the indication / information about the above satellite structure, the UE may determine whether to access / attach to the network via the satellite when roaming. For example, if the satellite structure is Split MME, the UE may decide to access / attach to the network. If it is Full CN, the UE may decide not to access / attach to the network.

[0271] Based on the indication / information about the above satellite structure, the terminal can determine the Preferred Network Behavior when connecting / attaching to the network. For example, in case of Split MME, since general User Plane data transfer is not supported but general CIoT optimization is not supported, the terminal can indicate that only Control Plane CIoT EPS Optimization is supported and S1-U data transfer is not supported. In case of Full CN, the terminal can indicate that it supports Control Plane CIoT EPS Optimization, User Plane CIoT EPS Optimization, and S1-U data transfer. In case of Full CN, the terminal can receive services using general PDN Connection without indicating Control Plane CIoT EPS Optimization and User Plane CIoT EPS Optimization.

[0272] 2. Second example of disclosure of this specification

[0273] According to the second example of the disclosure of this specification, the satellite can transmit an indication to the UE during the Attach process or the TAU process.

[0274] For example, when a terminal performs an Attach procedure or a TAU procedure on a satellite that supports S&F operation, the terminal can transmit information related to whether the terminal supports S&F mode operation to the satellite.

[0275] Network entities related to mobility (e.g., MME, AMF, etc.) can receive information from the UE regarding whether S&F mode operation is supported. The MME (or AMF) can include additional information indicating the S&F architecture in the response message (e.g., Attach Reject message, TAU Reject message, Registration Reject message, or Attach Accept message, TAU Accept message, Registration Accept message, etc.). Through this, the network entities related to mobility (e.g., MME, AMF, etc.) can inform the UE whether the current satellite is in a Split MME architecture or a Full CN architecture.

[0276] For indication / information on the above satellite structure, reference may be made to the contents of the first example of the disclosure of the present specification.

[0277] For example, the MME (or AMF) may inform the UE of information related to the Split MME / Full CN structure using information related to S&F support separately from information related to S&F support. Alternatively, the MME (or AMF) may separately inform the UE of whether it supports Split MME S&F and whether it supports Full CN S&F.

[0278] The MME (or AMF) may transmit information indicating a Split MME to the UE in the following format. However, the format below is only an example and may be transmitted in other formats:

[0279] - Information indicating that inter-satellite mobility is supported;

[0280] - Information indicating that TAU ​​must be performed when the UE accesses a satellite cell belonging to the same PLMN; and / or

[0281] - Information indicating that detach is not required after data transmission.

[0282] The MME (or AMF) can transmit information indicating a Full CN in the following formats. However, the formats below are only examples and can be transmitted in other formats as well:

[0283] - Information indicating that inter-satellite mobility is not supported;

[0284] - Information indicating that an attach must be performed when the UE accesses a satellite cell belonging to the same PLMN; and / or

[0285] - Information indicating that detach is required after data transmission.

[0286] Based on the indication / information about the above satellite structure, the UE may determine whether to access / attach to the network via the satellite when roaming. For example, if the satellite structure is Split MME, the UE may decide to access / attach to the network. If it is Full CN, the UE may decide not to access / attach to the network.

[0287] Based on the indication / information about the above satellite structure, the terminal can determine the Preferred Network Behavior when connecting / attaching to the network. For example, in case of Split MME, since general User Plane data transfer is not supported but CIoT optimization is not supported, the terminal can indicate that only Control Plane CIoT EPS Optimization is supported and S1-U data transfer is not supported. In case of Full CN, the terminal can indicate that Control Plane CIoT EPS Optimization, User Plane CIoT EPS Optimization, and S1-U data transfer are all supported. In case of Full CN, the terminal can also receive services using general PDN Connection without indicating Control Plane CIoT EPS Optimization and User Plane CIoT EPS Optimization.

[0288] In case of Split AMF of 5GS, since general User Plane data transfer is not supported but CIoT optimization, the terminal can indicate that it supports only Control Plane CIoT 5GS Optimization and does not support N3 data transfer. In case of Full CN, the terminal can indicate that it supports Control Plane CIoT EPS Optimization, User Plane CIoT EPS Optimization, and N3 data transfer. In case of Full CN, the terminal can also receive services using general PDN Connection without indicating Control Plane CIoT 5GS Optimization and User Plane CIoT 5GS Optimization.

[0289] 3. Third example of disclosure of this specification

[0290] A third example of the disclosure of this specification may include an example of a method by which a terminal can implicitly know the structure of a satellite.

[0291] In the case of a Split MME, when a UE initially sends an Attach Request message, the MME (or AMF) may send a reject message to the UE because there is no authentication data. In this case, the UE may receive information from the MME (or AMF) indicating that the UE cannot complete the attach or TAU procedure due to the S&F operation. Since this message (or information) is not transmitted by satellites equipped with a Full CN, the UE can determine based on this information that the current satellite is a Split MME-structured satellite that supports S&F operations.

[0292] When a UE performs an Initial Attach in S&F mode to a satellite of a specific PLMN, the UE may receive a reject message. In this case, if the reject message does not include information indicating that the UE cannot complete the attach or TAU procedure due to the S&F operation, the UE can determine that the satellite transmitting the reject message is a satellite equipped with a Full CN in the corresponding PLMN. Alternatively, if the UE does not receive an Attach reject message and the Attach procedure succeeds, the UE can determine that the satellite to which it transmitted the attach request message is a satellite equipped with a Full CN in the corresponding PLMN.

[0293] Note that even for a satellite with a Split MME architecture, if the satellite has the UE context of the terminal, there may be cases where the satellite transmits an accept message to the terminal instead of a reject message. However, in this case, the terminal may store that the satellite in the PLMN is a Split MME structure based on the reject message received during the previous initial attach process. Therefore, even in this case, the terminal can recognize that the satellite is a Split MME structure and operate.

[0294] Alternatively, the MME can be configured to always perform authentication when performing an attach procedure with a UE. Accordingly, even if the MME has the UE context, the MME can send a reject message for the initial attach to the UE, indicating that the attach or TAU procedure cannot be completed due to the S&F operation.

[0295] In the second and / or third examples of the disclosure of the present specification, the UE may receive an Attach reject message (or a Registration Reject message). In this case, the UE may determine, based on the satellite structure information, whether to access / attach to the network via the PLMN of the satellite when the UE is roaming. For example, if the satellite structure is a Split MME, the UE may decide to access / attach to the PLMN, and if it is a Full CN, the UE may decide not to access / attach to the PLMN.

[0296] 4. Fourth example of disclosure of this specification

[0297] According to the fourth example of the disclosure of this specification, the structure of the satellite may be preset in the USIM and / or the terminal.

[0298] The terminal's USIM or the terminal itself may be configured with a satellite-supported architecture. This configuration may be configured for each satellite ID and / or PLMN. Even if the terminal has preset information, it may recognize a different satellite-supported architecture through other means. In this case, the terminal's preset information is not used, and the terminal operates using its own chosen architecture.

[0299] 5. Fifth example of disclosure of this specification

[0300] In the fifth example of the disclosure of this specification, an example of handling GUTI is described.

[0301] According to the prior art, when a UE performs an attach / TAU operation on a network, it transmits the GUTI information previously received from the network to the network. For example, the GUTI information may be included in an attach request message or a TAU request message. Based on this information, the MME locates the old MME and retrieves the UE context. However, if the MME is located on a satellite, the MME may not be able to retrieve the UE context from another satellite. Therefore, if the UE recognizes this situation, it may not include the GUTI information.

[0302] For example, in the case of a Full CN structure, the satellite cannot obtain the UE context because there is no interface between satellites. Therefore, if the terminal determines that it is a Full CN structure, it can perform Attach / TAU and include only the GUTI information received from the same satellite in the Attach request message / TAU request message. To this end, the terminal can store the satellite ID of the satellite that received Attach accept and TAU accept when storing the GUTI, and determine whether to include the GUTI information based on this.

[0303] Additionally, in the case of a Split MME architecture, the MME may not be able to obtain the UE context due to the lack of a feeder link from the satellite to the ground or an inter-satellite link between satellites. Therefore, if the UE determines that the MME architecture is a Split MME architecture, it can include the GUTI only when transmitting a message to a satellite included in the Satellite ID list received from the previous satellite during Attach / TAU.

[0304] Additionally, the MME included in the satellite can determine whether it can retrieve the UE context based on the MME information included in the GUTI when the terminal transmits the GUTI. If the MME containing the UE context is on a different satellite or in a different MME group, the MME included in the satellite may not attempt to retrieve the UE context. To this end, information on the MME mounted on the satellite and information on the MME group that can retrieve the UE context can be set in the satellite's MME.

[0305] The terminal can receive satellite ID list information from the MME through a response message (e.g., Attach reject message, TAU reject message, Registration reject message, TAU accept message, Attach accept message, Registration accept message, etc.). The terminal can store that all satellites with the received satellite ID have the same structure. For example, based on the examples suggested above, the terminal can identify the structure of a specific satellite and apply the corresponding information to other satellites in the satellite ID list.

[0306] Figure 8 below illustrates a first example of a procedure when applying one or more of the methods of the first to fifth examples of the disclosure of the present specification proposed above. In the example of Figure 8, the satellite is shown in a (Split MME) structure including an eNB and an MME onboard, as well as a Full CN structure including all other CNs including the eNB and the MME.

[0307] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals, messages, and fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0308] FIG. 8 is a first example of a procedure according to one embodiment of the disclosure of the present specification.

[0309] The example in Fig. 8 shows an example of an attach procedure based on a split MME structure or a full CN structure in EPS.

[0310] For reference, in the example of FIG. 8, in the case of the split MME structure, the satellite may not include "Other CNs" shown in dotted lines. The CNs shown in dotted lines on the right side of the drawing may be located on the ground. In the case of the full CN structure, the satellite includes "Other CNs" shown in dotted lines, and the CNs shown in dotted lines on the right side of the drawing are also located on the ground. The descriptions of the split MME structure and the full CN structure can be equally applied to the split AMF structure and the full CN structure of FIG. 9.

[0311] For reference, in the example of FIG. 8, each of [1], [2], and [3] may correspond to the contents described in the first to third examples of the disclosure of the present specification. In the example of FIG. 8, although [1], [2], and [3] are all illustrated, this is merely an example for explanation, and one or more of [1], [2], and / or [3] may be applied.

[0312] 1. A satellite supporting S&F operation can transmit a SIB. For example, a base station of the satellite can transmit a SIB. The SIB can include information indicating that the satellite supports S&F operation. If the first example of the disclosure of this specification is applicable, the SIB can additionally include information about the S&F structure currently supported by the satellite (Split MME or Full CN) along with the information indicating that the satellite supports S&F operation. A terminal receiving this information can store information about the S&F structure of the satellite of the corresponding PLMN.

[0313] When a UE is roaming, it may determine whether to connect / attach to a network via the satellite based on indications / information about the satellite structure. For example, if the satellite structure is Split MME, the UE may decide to connect / attach to the network, and if it is Full CN, the UE may decide not to connect / attach.

[0314] The terminal can determine the Preferred Network Behavior at the time of Attach in Step 2 based on the indication / information about the above satellite structure.

[0315] 2. The terminal can send an attach request message.

[0316] For example, a terminal attempts to attach to a satellite for S&F operation. The Attach request message may include an indication that the terminal supports S&F Mode or an indication requesting S&F operation.

[0317] 3. In the case of Split MME, if the MME-onboard of the satellite does not have the UE context of the current UE, an Attach Reject message may be transmitted to the UE. If the second example of the disclosure of the present specification is applied, the Attach Reject message may include S&F structure information of the current satellite. For example, the satellite (e.g., the MME of the satellite) may also transmit to the UE a list of waiting times and satellite IDs. For example, the satellite (e.g., the MME of the satellite) may transmit to the UE an Attach Reject message including a list of waiting times and satellite IDs. Here, the waiting time may indicate the time that the UE must wait before retrying the Attach / TAU procedure on the current satellite or another satellite of the same PLMN. The list of satellite IDs may indicate a list of satellite IDs for which the UE can retry the Attach / TAU procedure after the waiting time expires. The UE may know that the satellites included in the list of satellite IDs also have the same S&F structure.

[0318] Even in the case of a full CN structure, if the satellite's MME cannot currently support the terminal for a specific reason, the satellite's MME can transmit a list of wait times and satellite IDs to the terminal along with an Attach reject message.

[0319] When the third example of the disclosure of this specification applies, the UE may receive information along with a reject message indicating that the UE cannot complete the attach or TAU procedure due to the S&F operation. In this case, the UE may know that the satellite is in a Split MME configuration. In the absence of such information, the UE may know that the satellite is in a Full CN configuration.

[0320] Based on Step 1 and / or Step 3, the terminal can know the S&F structure (Split MME or Full CN) of the current satellite and the satellites to which it will attempt to attach after the wait time.

[0321] If the UE is roaming, the UE may determine whether to additionally access / attach to the network through the PLMN of the satellite in step 6 based on the satellite structure information after receiving the reject message. For example, if the satellite structure is Split MME, the UE may decide to access / attach to the PLMN, and if it is Full CN, the UE may decide not to access / attach to the PLMN.

[0322] As the satellite moves, it may leave the terminal's coverage area and the Feeder Link may be disconnected.

[0323] 4. In a split MME architecture, the satellite's MME-onboard requests the ground MME-ground for the UE's authentication data. The ground network node (e.g., MME-ground) can then select the satellite to which the UE will connect next and forward the UE's authentication data to that satellite.

[0324] In the case of a full CN structure, the satellite may also perform a process of synchronizing subscriber information with the ground-based HSS.

[0325] 5. A satellite can transmit a SIB. For example, a base station on a satellite can transmit a SIB. The SIB can include information indicating that it supports S&F operations. If the first example of the disclosure of this specification applies, the SIB can additionally include information about the S&F structure currently supported by the satellite (Split MME or Full CN) along with the information indicating that it supports S&F operations.

[0326] The terminal identifies satellites that support S&F operations based on the satellite's SIB. If the terminal receives a list of satellite IDs in Step 3, it may additionally verify in Step 5 whether the satellite transmitting the SIB is included in the list.

[0327] 6. If the terminal receives an Attach reject in Step 3, a timer based on the wait time received together may be started. When the wait time-based timer expires and the terminal discovers a satellite matching the satellite ID list received together, the terminal may attempt to attach to that satellite. Note that the satellite receiving the Attach request in Step 2 may be the same satellite as the satellite in Step 2 or a different satellite.

[0328] For reference, MME-ground can synchronize UE authentication data with MME-onboards on multiple satellites. The UE can connect to one of the MME-onboards that contains the synchronized authentication data.

[0329] 7. For Full CN, the MME can perform terminal authentication via the satellite's HSS. Step 7 may be omitted for a split MME architecture.

[0330] 8. For example, the satellite's MME may transmit an Attach Accept message. For example, the MME may complete terminal authentication and transmit an Attach Accept message to the terminal. If the second example of the disclosure of this specification applies, the Attach Accept message may include the current satellite network's S&F structure.

[0331] In the case where the third example of the disclosure of this specification applies, the Initial Attach in S&F mode may be accepted directly without an Attach rejection process (e.g., step 3). In this case, the terminal can recognize that the satellite is in a Full CN configuration.

[0332] Based on one or more of the examples described in Examples 1 to 5 of the disclosure of this specification, the terminal can be aware of the S&F structure (Split MME or Full CN) of the satellite in the currently attached PLMN. In situations such as the following examples, the terminal can perform operations based on the S&F structure of the satellite.

[0333] - If you leave the satellite's coverage area, the following actions may be taken:

[0334] i) In the case of a Split MME architecture, the following actions may be performed: The UE may not trigger the detach procedure even if it knows that it will go out of satellite coverage. The MME may initiate the S1 Release Procedure before the satellite goes out of the UE's coverage. Accordingly, the UE may enter the ECM-IDLE state or the RRC Connection Suspend state (e.g., see TS 23.401 V18.5.0 clause 5.3.4A). The UE may maintain the ECM-IDLE state or the RRC Connection Suspend state without performing a local detach even when it goes out of satellite coverage.

[0335] ii) For a Full CN architecture, the following examples may be performed: If the terminal detects that it is about to leave satellite coverage, it can trigger a detach procedure. If the terminal leaves satellite coverage before triggering / completing the detach procedure, it can perform a local detach. Alternatively, the terminal can perform detach after data transmission is completed following attach.

[0336] - For MT Data reception operations, the following description may apply:

[0337] i) In the case of a Split MME structure, the following example may be performed. The terminal may monitor paging from all satellites in the ECM-IDLE state, or, if a list of satellite IDs is received from the network, monitor paging only for the satellites in the list.

[0338] ii) In the case of a Full CN structure, the following examples can be performed:

[0339] (ii-1) When the terminal is in a detached state, it may attempt to attach to all satellites, or, if it has received a list of satellite IDs from the network, it may attempt to attach to each satellite in the list whenever it finds it, and receive MT Data if available.

[0340] (ii-2) The terminal may receive an indication from a user or application indicating that MT data reception is required, or may be aware of the time when MT data traffic occurs. Upon receiving this indication, or during the time when MT data traffic occurs, the terminal can attach to a satellite to receive MT data. If a list of satellite IDs is received from the network, attachments can only be attempted for satellites within that list.

[0341] Figure 9 below illustrates a first example of a procedure when applying one or more of the methods of the first to fifth examples of the disclosure of the present specification proposed above. In the example of Figure 9, the satellite is shown in a (Split AMF) structure including a gNB and an AMF onboard, as well as a Full CN structure including all other CNs including the gNB and the AMF.

[0342] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals, messages, and fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0343] FIG. 9 is a second example of a procedure according to one embodiment of the disclosure of the present specification.

[0344] The example in Fig. 9 shows an example of a registration procedure based on a split AMF structure or a full CN structure in 5GS.

[0345] 1. A satellite supporting S&F operation can transmit a SIB. For example, a base station (e.g., NG-RAN) of the satellite can transmit a SIB. The SIB can include information indicating that the satellite supports S&F operation. If the first example of the disclosure of this specification is applied, the SIB can additionally include information about the S&F structure currently supported by the satellite (Split AMF or Full CN) along with the information indicating that the satellite supports S&F operation. A terminal receiving this information can store information about the S&F structure of the satellite of the corresponding PLMN.

[0346] When a UE is roaming, it may determine whether to access / register with a network via the satellite based on indications / information about the satellite structure. For example, if the satellite structure is Split AMF, the UE may decide to access / register with the network, and if it is Full CN, the UE may decide not to access / register.

[0347] The terminal can determine the Preferred Network Behavior when transmitting the registration request message in Step 2 based on the indication / information about the above satellite structure.

[0348] 2. The terminal can send a registration request message.

[0349] For example, a terminal attempts to register with a satellite for S&F operations (e.g., Initial registration or Mobility Registration). The registration request message may include an indication that the terminal supports S&F mode or an indication requesting S&F operations.

[0350] 3. The satellite's AMF may also send a registration rejection message to the terminal.

[0351] For example, in the case of Split AMF, if the AMF-onboard of the satellite does not have the UE context of the current UE, the AMF-onboard of the satellite may transmit a Registration Reject message. If the second example of the disclosure of the present specification is applied, the Registration Reject message may include the S&F structure information of the current satellite. For example, the satellite (e.g., the AMF of the satellite) may also transmit to the UE a list of waiting times and satellite IDs. For example, the satellite (e.g., the AMF of the satellite) may transmit to the UE an Attach Reject message including a list of waiting times and satellite IDs. Here, the waiting time may indicate the time that the UE must wait before retrying the registration procedure on the current satellite or another satellite of the same PLMN. The list of satellite IDs may indicate a list of satellite IDs for which the UE can retry the registration procedure after the waiting time expires. The UE may know that the satellites included in the list of satellite IDs also have the same S&F structure.

[0352] Even in the case of a full CN structure, if the satellite's AMF cannot currently support the terminal for a specific reason, the satellite's AMF can send a list of wait times and satellite IDs to the terminal along with a Registration reject message.

[0353] When the third example of the disclosure of this specification applies, the terminal may receive information along with a reject message indicating that the UE cannot complete the registration procedure due to the S&F operation. In this case, the terminal may determine that the satellite has a Split AMF configuration. In the absence of this information, the terminal may determine that the satellite has a Full CN configuration.

[0354] Based on Step 1 and / or Step 3, the terminal can know the S&F structure (Split AMF or Full CN) of the current satellite and the satellites to be registered after the wait time.

[0355] If the UE is roaming, the UE may determine whether to additionally access / register with the network through the PLMN of the satellite in step 6 based on the satellite structure information after receiving the reject message. For example, if the satellite structure is Split AMF, the UE may decide to access / register with the PLMN, and if it is Full CN, the UE may decide not to access / register with the PLMN.

[0356] As the satellite moves, it may leave the terminal's coverage area and the Feeder Link may be disconnected.

[0357] 4. In a Split AMF architecture, the satellite's AMF-onboard requests the terminal's authentication data from the ground's AMF-ground. The ground network node (e.g., MME AMF ground) can then select the satellite to which the UE will connect next and forward the terminal's authentication data to that satellite.

[0358] In the case of a full CN structure, a process of synchronizing the terrestrial UDM and subscriber information can also be performed.

[0359] 5. A satellite may transmit a SIB. For example, a base station on the satellite may transmit a SIB. The SIB may include information indicating that it supports S&F operations. If the first example of the disclosure of this specification applies, the SIB may additionally include information about the S&F structure currently supported by the satellite (Split AMF or Full CN) in addition to the information indicating that it supports S&F operations.

[0360] The terminal identifies satellites that support S&F operations based on the satellite's SIB. If the terminal receives a list of satellite IDs in Step 3, it may additionally verify in Step 5 whether the satellite transmitting the SIB is included in the list.

[0361] 6. If the terminal receives a registration reject in step 3, it can start a timer based on the wait time received together. When the wait time-based timer expires and the terminal discovers a satellite corresponding to the satellite ID list received together, the terminal can attempt to register with that satellite.

[0362] 7. For Full CN, AMF performs terminal authentication via the satellite's UDM. Step 7 may be omitted for a split AMF architecture.

[0363] 8. For example, the satellite's AMF may transmit a registration acceptance message. For example, the AMF may complete terminal authentication and transmit a registration acceptance message to the terminal. If the second example of the disclosure of this specification applies, the registration acceptance message may include the current satellite network's S&F structure.

[0364] If the third example of the disclosure of this specification applies, the initial registration in S&F mode may be accepted immediately without a registration rejection process (e.g., step 3). In this case, the terminal can recognize that the satellite is in a Full CN configuration.

[0365] Based on one or more of the examples described in Examples 1 through 5 of the disclosure of this specification, the terminal can learn the S&F structure (Split AMF or Full CN) of the satellite in the currently registered PLMN. In situations such as the following examples, the terminal can perform operations based on the S&F structure of the satellite.

[0366] - If you leave the satellite's coverage area, the following actions may be taken:

[0367] i) In case of Split AMF structure, the following actions may be performed: The UE may not trigger the deregistration procedure even if it knows that it will go out of satellite coverage. The AMF may trigger the AN Release Procedure before the satellite goes out of the UE's coverage. Accordingly, the UE may be in CM-IDLE state or CM-CONNECTED with RRC inactive state (see TS 23.502 V18.5.0 clause 4.8.1.1a). The UE may maintain CM-IDLE state or CM-CONNECTED with RRC inactive state without performing local deregistration even when it goes out of satellite coverage.

[0368] ii) For a Full CN architecture, the following examples may be performed: If the terminal knows it will leave satellite coverage, it can trigger a deregistration procedure. If the terminal leaves satellite coverage before triggering / completing the deregistration procedure, it can perform a local deregistration. Alternatively, the terminal can perform deregistration after data transmission is completed following registration.

[0369] - For MT Data reception operations, the following description may apply:

[0370] i) In the case of Split AMF structure, the following example operations can be performed. The terminal can monitor paging from all satellites in CM-IDLE state, or, if a list of satellite IDs is received from the network, monitor paging only for satellites within the list.

[0371] ii) In the case of a Full CN structure, the following examples can be performed:

[0372] (ii-1) When the terminal is in a deregistrated state, it may attempt registration for all satellites, or, if it receives a list of satellite IDs from the network, it may attempt registration whenever it discovers satellites within the list, and receive MT Data if available.

[0373] (ii-2) The terminal may receive an indication from a user or application indicating the need for MT data reception, or may be aware of the time at which MT data traffic occurs. Upon receiving this indication, or during the time at which MT data traffic occurs, the terminal may register with a satellite to receive MT data. If a list of satellite IDs is received from the network, registration may only be attempted for satellites within that list.

[0374] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals, messages, and fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0375] FIG. 10 illustrates an example of operations according to one embodiment of the disclosure of the present specification.

[0376] For reference, the procedure illustrated in FIG. 10 is merely an example, and the scope of the disclosure of this specification is not limited by the example in FIG. 10.

[0377] For example, with respect to the example of FIG. 10, the operations described in the examples of FIGS. 1 to 9 may also be applied. For example, even if operations, contents, etc. are not directly described in the example of FIG. 10, operations, contents, etc. described in various examples of the disclosure of this specification may be applied.

[0378] In step (S1001), the UE can receive system information from a base station included in the satellite.

[0379] For example, the system information may include information that the satellite supports store and forward operations.

[0380] In step (S1002), the UE may transmit a request message to a network entity related to mobility.

[0381] For example, both network entities and base stations may be included in a satellite.

[0382] For example, the request message may include information that the UE supports Store and Forward operation.

[0383] In step (S1003), the first network entity may transmit a rejection message to the UE. In claim 15 or 16,

[0384] For example, based on the network entity not having the UE context of the UE, the network entity may send a reject message.

[0385] For example, a rejection message may contain information related to the structure of the satellite.

[0386] For example, information related to the structure of the satellite may include information that the entire core network is a Full Core Network (CN) structure included in the satellite, or that the satellite is a split structure including a part of the core network.

[0387] For example, if the UE is roaming, it may decide whether to transmit a second request message to access that satellite or another satellite based on information related to the structure of that satellite.

[0388] For example, based on the fact that the satellite has a split structure, the UE may transmit a second request message. For example, based on the fact that the satellite has a full CN structure, the UE may not transmit a second request message.

[0389] For example, the rejection message may include a wait time and a list of satellite IDs. Based on the expiration of the wait time, the UE may send a second request message to one or more satellites included in the list of satellite IDs.

[0390] For example, if the UE leaves the satellite's coverage area, the UE may determine whether to release access associated with the satellite based on the satellite's architecture. For example, if the UE leaves the satellite's coverage area, the UE may determine whether to perform detachment or deregistration based on the satellite's architecture.

[0391] For example, based on the fact that the satellite structure is a split structure, the UE can monitor paging for one or more satellites included in the satellite ID list.

[0392] For example, the rejection message may include information that the access cannot be completed due to a store-and-forward operation.

[0393] For example, based on the network entity not having the UE context of the UE, the network entity may send a reject message to the UE.

[0394] According to one embodiment of the disclosure of this specification, a terminal may be supported to distinguish between the architecture of a satellite supporting S&F (e.g., Split MME, Split AMF, or Full CN). The terminal may be supported to perform different operations depending on the network architecture. Reference may be made to Examples 1 to 5 of the disclosure of this specification and the examples of FIGS. 8 to 10.

[0395] This specification may have various effects.

[0396] For example, effective communication can be supported based on a network structure that supports S&F operations.

[0397] For example, the UE can know whether the network supporting S&F operation is operating in a Split MME structure (or Split AMF structure) or a Full CN structure.

[0398] For example, depending on the network structure, the UE can perform attach and detach (or registration and deregistration) for each satellite supporting S&F in the case of Full CN, or perform an attach operation (or registration operation) for receiving MT data.

[0399] For example, if a UE leaves satellite coverage, the UE can perform local detach (or local deregistration). For example, in the case of a Split MME (or Split AMF) architecture, the UE can perform S&F operations via satellites by monitoring satellites without performing a detach operation even if it leaves satellite coverage.

[0400] For example, in the case of a Split MME architecture (or a Split AMF architecture), the UE may not perform the attach operation (or registration operation) every time, or perform the TAU (or registration procedure) and then receive a rejection in the Full CN architecture. Accordingly, for satellites with a Full CN architecture, if the UE is roaming, it can decide not to attach, thereby reducing unnecessary signaling and operating efficiently. In addition, the Preferred Network Behavior can be set differently depending on the satellite architecture.

[0401] The effects that can be achieved through the specific examples of this specification are not limited to the effects listed above. For example, a person with ordinary skill in the relevant technical field may understand or derive various technical effects from this specification. Accordingly, the specific effects of this specification are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of this specification.

[0402] For reference, the operation of the terminal (e.g., UE) described in this specification may be implemented by the devices of FIGS. 1 to 3 described above. For example, the terminal may be the first device (100) or the second device (200) of FIG. 2. For example, the operation of the terminal described in this specification may be processed by one or more processors (102 or 202). The operation of the terminal described in this specification may be stored in one or more memories (104 or 204) in the form of instructions / programs (e.g., instructions, executable codes) executable by one or more processors (102 or 202). The one or more processors (102 or 202) may control one or more memories (104 or 204) and one or more transceivers (105 or 206), and execute the instructions / programs stored in one or more memories (104 or 204) to perform the operation of the terminal (e.g., UE) described in the disclosure of this specification.

[0403] Additionally, the commands for performing the operations of the terminal described in the disclosure of this specification may be stored in a non-volatile computer-readable storage medium. The storage medium may be included in one or more memories (104 or 204). In addition, the commands recorded in the storage medium may be executed by one or more processors (102 or 202) to perform the operations of the terminal described in the disclosure of this specification.

[0404] For reference, the operation of a network node (e.g., AMF, SMF, PCF, UDM, MME, etc.) or a base station (e.g., NG-RAN, gNB, RAN, eNB, (R)AN, etc.) described in this specification may be implemented by the devices of FIGS. 1 to 3 described below. For example, the network node or the base station may be the first device (100) or the second device (200) of FIG. 2. For example, the operation of the network node or the base station described in this specification may be processed by one or more processors (102 or 202). The operation of the terminal described in this specification may be stored in one or more memories (104 or 204) in the form of instructions / programs (e.g., instructions, executable codes) executable by one or more processors (102 or 202). One or more processors (102 or 202) may control one or more memories (104 or 204) and one or more transceivers (106 or 206), and execute instructions / programs stored in one or more memories (104 or 204) to perform operations of a network node or base station as described in the disclosure of this specification.

[0405] Additionally, the instructions for performing the operations of the network node or base station described in the disclosure of this specification may be stored in a non-volatile (or non-transitory) computer-readable storage medium having the instructions recorded thereon. The storage medium may be included in one or more memories (104 or 204). In addition, the instructions recorded in the storage medium may be executed by one or more processors (102 or 202) to perform the operations of the network node or base station described in the disclosure of this specification.

[0406] Although the preferred embodiments have been described above by way of example, the disclosure of this specification is not limited to such specific embodiments, and may be modified, changed, or improved in various forms within the scope described in the spirit and claims of this specification.

[0407] In the exemplary system described above, the methods are described based on a flowchart as a series of steps or blocks. However, the order of the steps described is not limited, and some steps may occur in a different order or simultaneously with other steps described above. Furthermore, those skilled in the art will understand that the steps depicted in the flowchart are not exclusive, and other steps may be included, or one or more steps in the flowchart may be deleted without affecting the scope of the invention.

[0408] The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined to implement a device, and the technical features of the device claims of this specification may be combined to implement a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined to implement a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined to implement a method. Other implementations are within the scope of the claims.

Claims

1. A step of receiving system information from a base station included in a satellite; a step of transmitting a first request message for accessing the satellite to a network entity related to mobility; and comprising the step of receiving a rejection message from the network entity; The above network entity is included in the above satellite, and A method characterized in that the rejection message includes information related to the structure of the satellite.

2. In paragraph 1, The above system information includes information that the satellite supports store and forward operation, 3. In paragraph 1 or 2, A method characterized in that the above request message includes information that the User Equipment (UE) supports a store and forward operation.

4. In any one of paragraphs 1 to 3, A method characterized in that information related to the structure of the satellite includes information that the entire core network is a Full Core Network (CN) structure included in the satellite or that the satellite is a split structure including a part of the core network.

5. In any one of paragraphs 1 to 3, The above rejection message contains information that the above access cannot be completed due to a store-and-forward operation, A method characterized in that it is recognized that the above satellite has a split structure.

6. In any one of paragraphs 1 to 5, A method further comprising the step of determining whether to transmit a second request message for accessing the satellite or another satellite based on information related to the structure of the satellite, when the UE is roaming.

7. In paragraph 6, Based on the fact that the structure of the above satellite is a split structure, the second request message is transmitted, and A method characterized in that the second request message is not transmitted based on the structure of the satellite being a full CN structure.

8. In any one of paragraphs 1 to 7, The above rejection message includes a waiting time and a list of satellite IDs, A method further comprising the step of transmitting a second request message to one or more satellites included in the satellite ID list based on the expiration of the waiting time.

9. In any one of paragraphs 1 to 8, A method further comprising a step of determining whether to perform detach or deregister based on the structure of the satellite when the UE goes out of the coverage of the satellite.

10. In any one of paragraphs 1 to 9, A method further comprising a step of monitoring paging for one or more satellites included in the satellite ID list based on the structure of the satellite being a split structure.

11. In any one of paragraphs 1 to 10, A method characterized in that the rejection message is received based on the network entity not having a UE context of the User Equipment (UE).

12. One or more transmitters and receivers; one or more processors; and comprising one or more memories capable of storing instructions and being operable to the one or more processors; The actions performed based on the above instructions being executed by the one or more processors are: A device according to any one of claims 1 to 11.

13. In an apparatus of a communication system, the apparatus: One or more transmitters and receivers; one or more processors; and comprising one or more memories capable of storing instructions and being operable to the one or more processors; A device wherein the operation performed based on the command being executed by the one or more processors is a method according to any one of claims 1 to 11.

14. A non-transitory computer readable medium (CRM) storing instructions, wherein an operation performed based on the instructions being executed by one or more processors is a method according to any one of claims 1 to 11.

15. A step of receiving a first request message for accessing a satellite from a User Equipment (UE); and comprising the step of transmitting a rejection message to the UE; The above rejection message is transmitted by the network entity involved in mobility, The above network entity is included in the above satellite, and A method characterized in that the rejection message includes information related to the structure of the satellite.

16. In paragraph 15, A method characterized in that the above request message includes information that the User Equipment (UE) supports a store and forward operation.

17. In paragraph 15 or 16, A method characterized in that the rejection message is transmitted based on the network entity not having the UE context of the UE.

18. In any one of paragraphs 15 to 17, A method characterized in that information related to the structure of the satellite includes information that the entire core network is a Full Core Network (CN) structure included in the satellite or that the satellite is a split structure including a part of the core network.

19. In any one of paragraphs 15 to 18, A method characterized in that, based on the structure of the satellite being a full CN structure, information related to the structure of the satellite includes information that the rejection message cannot complete the access due to a store-and-forward operation.

20. One or more transmitters and receivers; one or more processors; and comprising one or more memories capable of storing instructions and being operable to the one or more processors; The actions performed based on the above instructions being executed by the one or more processors are: A device according to any one of claims 15 to 19.

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