Communication based on mobile base station

Abstract

The present disclosure provides a method. The method may comprise the steps of: receiving information related to a backhaul network from a base station of a mobile base station; and transmitting a NAS message to a network entity related to mobility via the base station of the mobile base station.

Description

Communication based on mobile base stations

[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. Furthermore, NR must be able to utilize any spectrum band up to at least 130 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] Methods for providing services to UEs based on the connection between the UE and the mobile base station are being discussed. For example, the mobile base station may be referred to as a Mobile gNB with wireless access backhauling (MWAB). However, conventional technology has a problem in that communication based on the connection between the UE and the mobile base station is not effectively provided, depending on the type of network to which the UE of the mobile base station is connected to the backhaul network.

[0006] In one aspect, a method is provided. The method may include the steps of: receiving information related to a backhaul network from a base station of a mobile base station; and transmitting an NAS message to a network entity related to mobility via the base station of the mobile base station.

[0007] In another aspect, a device implementing the above method is provided.

[0008] In one aspect, a method is provided. The method may include: a network entity receiving a first NAS message from a UE; and a network entity transmitting a second NAS message to the UE.

[0009] In another aspect, a device implementing the above 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 is an example of a non-roaming mobile base station architecture to which the implementation of this specification is applied.

[0016] Figure 8 is an example of an architecture in which both the backhaul network of a mobile base station to which the implementation of this specification is applied and the serving network of the UE are home networks.

[0017] Figure 9 is an example of an architecture in which the backhaul network of a mobile base station to which the implementation of the present specification is applied is a visited network and the serving network of the UE is a home network.

[0018] FIG. 10 is a first example of an architecture in which a UE of a mobile base station to which the implementation of the present specification is applied is connected to a backhaul network via an NTN.

[0019] FIG. 11 is a second example of an architecture in which a UE of a mobile base station to which the implementation of the present specification is applied is connected to a backhaul network via an NTN.

[0020] Figure 12 is an example of a procedure to which the implementation of this specification is applied.

[0021] FIG. 13 illustrates an example of a procedure performed according to one embodiment of the disclosure of the present specification.

[0022] 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).

[0023] 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. However, aspects of this specification that are not limited to a 3GPP-based wireless communication system can be applied to other mobile communication systems.

[0024] 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.

[0025] 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."

[0026] 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."

[0027] 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.”

[0028] 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”.

[0029] Additionally, parentheses used herein 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 (i.e., PDCCH)", "PDCCH" may be proposed as an example of "control information."

[0030] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0031] 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).

[0032] 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.

[0033] Figure 1 illustrates an example of a communication system to which the implementation of this specification is applied.

[0034] 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.

[0035] 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).

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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).

[0041] 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, at least some of the 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 based on various proposals of the present specification.

[0042] 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.

[0043] 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).

[0044] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0045] 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. That is, FR1 may include frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 may include unlicensed bands. Unlicensed bands may be used for various purposes, such as for communications for vehicles (e.g., autonomous driving).

[0046] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0047] 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.

[0048] Figure 2 illustrates an example of a wireless device to which the implementation of the present specification is applied.

[0049] 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.

[0050] 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).

[0051] 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).

[0052] 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).

[0053] 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.

[0054] 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.

[0055] 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).

[0056] 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).

[0057] 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).

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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).

[0064] 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).

[0065] 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.

[0066] 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.

[0067] In this specification, a base station may be referred to as a Node B, an eNode B (eNB), or a gNB.

[0068] Figure 3 shows an example of a UE to which the implementation of this specification is applied.

[0069] Referring to FIG. 3, the UE (100) can correspond to the first wireless device (100) of FIG. 2.

[0070] 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).

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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).

[0075] 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).

[0076] 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.

[0077] 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).

[0078] Figure 4 shows an example of a 5G system structure to which the implementation of this specification is applied.

[0079] The 5G system (5GS; 5G system) structure consists of the following network functions (NF; Network Function).

[0080] - AUSF (Authentication Server Function)

[0081] -AMF (Access and Mobility Management Function)

[0082] - DN (Data Network), for example, operator services, Internet access, or third-party services.

[0083] - USDF (Unstructured Data Storage Function)

[0084] - NEF (Network Exposure Function)

[0085] - I-NEF (Intermediate NEF)

[0086] - NRF (Network Repository Function)

[0087] - NSSF (Network Slice Selection Function)

[0088] - PCF (Policy Control Function)

[0089] - SMF (Session Management Function)

[0090] - UDM (Unified Data Management)

[0091] - UDR (Unified Data Repository)

[0092] - UPF (User Plane Function)

[0093] - UCMF (UE radio Capability Management Function)

[0094] - AF (Application Function)

[0095] - UE (User Equipment)

[0096] - (R)AN ((Radio) Access Network)

[0097] - 5G-EIR (5G-Equipment Identity Register)

[0098] - NWDAF (Network Data Analytics Function)

[0099] - CHF (CHarging Function)

[0100] 또한, 다음과 같은 네트워크 기능이 고려될 수 있다.

[0101] - N3IWF (Non-3GPP InterWorking Function)

[0102] - TNGF (Trusted Non-3GPP Gateway Function)

[0103] - W-AGF (Wireline Access Gateway Function)

[0104] 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.

[0105] 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.

[0106] 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.

[0107] The 5G system architecture includes the following benchmarks:

[0108] - N1: Reference point between UE and AMF.

[0109] - N2: Reference point between (R)AN and AMF.

[0110] - N3: Reference point between (R)AN and UPF.

[0111] - N4: Reference point between SMF and UPF.

[0112] - N6: Reference point between UPF and data network.

[0113] - N9: Reference point between two UPFs.

[0114] The following benchmarks illustrate the interactions that exist between NF services in NF.

[0115] - N5: Reference point between PCF and AF.

[0116] - N7: Reference point between SMF and PCF.

[0117] - N8: Reference point between UDM and AMF.

[0118] - N10: Reference point between UDM and SMF.

[0119] - N11: Reference point between AMF and SMF.

[0120] - N12: Reference point between AMF and AUSF.

[0121] - N13: Reference point between UDM and AUSF.

[0122] - N14: Reference point between two AMFs.

[0123] - N15: Reference point between PCF and AMF for non-roaming scenarios, and reference point between PCF and AMF of visited network for roaming scenarios.

[0124] - N16: Reference point between two SMFs (in case of roaming, between the SMF of the visited network and the SMF of the home network)

[0125] - N22: Reference point between AMF and NSSF.

[0126] In some cases, two NFs may need to be interconnected to serve a UE.

[0127] Describes the registration procedure. See section 4.2.2.2 of 3GPP TS 23.502 V16.3.0 (2019-12).

[0128] Figures 5 and 6 illustrate examples of registration procedures to which the implementation of the present specification applies.

[0129] 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:

[0130] - Initial registration for 5GS; or

[0131] - mobility registration update; or

[0132] - Periodic registration update; or

[0133] - Emergency registration

[0134] 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.

[0135] 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.

[0136] First, the procedure of Fig. 5 is described.

[0137] (1) Step 1: The UE transmits a Registration Request message to the (R)AN. The Registration Request message corresponds to an AN message.

[0138] 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.

[0139] 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).

[0140] When a UE performs initial registration, the UE indicates its UE ID in the registration request message, listed in decreasing priority order.

[0141] i) If the UE has a valid evolved packet system (EPS) globally unique temporary identifier (GUTI), 5G-GUTI mapped from the EPS GUTI;

[0142] ii) Native 5G-GUTI (if available) allocated by the PLMN in which the UE is attempting to register;

[0143] iii) Native 5G-GUTI allocated by a PLMN equivalent to the PLMN in which the UE is attempting to register;

[0144] iv) Native 5G-GUTI allocated by another PLMN (if available);

[0145] v) Otherwise, the UE includes a subscriber concealed identifier (SUCI) in the registration request message.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] (2) Step 2: (R)AN selects AMF.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] (3) Step 3: (R)AN sends a registration request message to the new AMF. The registration request message corresponds to the N2 message.

[0155] 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.

[0156] 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.

[0157] If the registration type indicated by the UE is periodic registration update, steps 4-19 described below may be omitted.

[0158] (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.

[0159] (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.

[0160] (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.

[0161] (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).

[0162] (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.

[0163] (9) Step 9: Authentication / security can be established by UE, new AMF, AUSF and / or UDM.

[0164] (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.

[0165] (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.

[0166] (12) Step 12: Optionally, the new AMF can initiate ME ID checking by calling the N5g-eir_EquipmentIdentityCheck_Get service operation.

[0167] Now, the procedure of Fig. 6 following the procedure of Fig. 5 is described.

[0168] (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.

[0169] (14) Step 14: New AMFs can be registered with UDM.

[0170] (15) Step 15: New AMF can select PCF.

[0171] (16) Step 16: The new AMF may optionally perform AM policy association establishment / modification.

[0172] (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.

[0173] (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.

[0174] (19) Step 19: N3IWF / TNGF / W-AGF may send a UE context modification response to the new AMF.

[0175] (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.

[0176] (21) Step 21: The new AMF sends a Registration Accept message to the UE.

[0177] 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.

[0178] 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.

[0179] Additionally, optionally, the new AMF performs UE policy association establishment.

[0180] (22) Step 22: If the UE successfully updates itself, it can send a Registration Complete message to the new AMF.

[0181] The UE may send a registration complete message to the new AMF to confirm that a new 5G-GUTI has been allocated.

[0182] (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.

[0183] (24) Step 24: AMF can perform information updates on UDM.

[0184] (25) Step 25: The UE may execute a network slice-specific authentication and authorization (NSSAA) procedure.

[0185] A method of providing services to UEs based on the connection between UEs and mobile base stations is being discussed.

[0186] For example, a mobile base station (GBS) may also be referred to as a mobile gNB with wireless access backhaul (MWAB). However, this is merely an example, and the scope of the disclosure herein is not limited by the term "MWAB." Any description of a GBS or MWAB in the disclosure herein may be interpreted as a description of any entity that acts as a base station for other UEs and provides them with access to the network.

[0187] For reference, the descriptions of MWABs in the disclosure of this specification may be interpreted as descriptions of mobile base stations. For example, the operations of MWABs may be interpreted as the operations of mobile base stations. Furthermore, MWABs are examples of mobile base stations, and the operations performed by MWABs may be operations performed by mobile base stations.

[0188] Regarding mobile base stations, reference may be made to TR 23.700-06. Below, with reference to TR 23.700-06, terms related to mobile base stations, architectural assumptions, and examples of architectural requirements are explained.

[0189] Mobile base station (e.g., mobile gNB with wireless access backhaul (MWAB): A mobile base station acts as a gNB for other UEs and can provide them with access to the network (e.g., a 5G network). For example, a mobile gNB can provide a NR access link to the UE. For example, a mobile gNB can wirelessly connect to the 5GC using NR by providing IP connectivity via a PDU (e.g., Protocol Data Unit) session established via an NG-RAN cell where the mobile gNB (e.g., mobile gNB) can camp. The PDU session is provided by a terrestrial network (TN) or a non-terrestrial network (NTN). Such a mobile gNB (e.g., mobile gNB) can be mounted on a moving vehicle and can serve UEs located inside or outside the vehicle (or entering or exiting the vehicle).

[0190] MWAB stands for Mobile gNB with wireless access backhauling. MWAB-gNB is the gNB component of MWAB. MWAB-UE is the UE component of MWAB. NTN stands for Non-Terrestrial Network. TN stands for Terrestrial Network.

[0191] An example of an architectural assumption related to a mobile base station is described.

[0192] An MWAB may include a gNB component (MWAB-gNB) and a UE component (MWAB-UE).

[0193] MWAB-gNB is based on the gNB functionality specified in TS 38.300 V18.0.0 and TS 38.401 V18.0.0.

[0194] N2 / N3 and Operations, Administration and Maintenance (OAM) access of MWAB-gNB can be provided via IP connectivity provided by PDU session(s) of MWAB-UE.

[0195] An MWAB-UE may have a single NR Uu hop to the NG-RAN (e.g., an MWAB-UE may access a gNB via an NR Uu interface that may use TN technology or NTN technology).

[0196] MWAB can serve UEs located inside or outside a vehicle equipped with a relay.

[0197] NR Uu can be used for the radio link between the MWAB-gNB and the served UE. The NR Uu radio link between the MWAB-gNB and the served UE may not use NTN technology.

[0198] The LCS framework defined in TS 23.273 V18.4.0 can be used to provide location services to UEs served.

[0199] A mobile base station (e.g., MWAB) may be connected to a NG-RAN of a PLMN or to a NG-RAN of a SNPN.

[0200] The MWAB-gNB may broadcast a PLMN ID different from the PLMN ID of the PLMN to which the MWAB-UE is connected.

[0201] The serving PLMN of the UE may be the PLMN on which the MWAB-gNB is camped or the PLMN broadcast by the connected MWAB-gNB. The PLMN ID of the serving PLMND may be different from the PLMN ID of the PLMN serving the MWAB-UE.

[0202] MWAB-UE can support emergency services.

[0203] Referring to the example of Fig. 7, an example of a mobile base station architecture in a non-roaming scenario is described.

[0204] 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.

[0205] Figure 7 is an example of a non-roaming mobile base station architecture to which the implementation of this specification is applied.

[0206] Although the example in Figure 7 illustrates an example of a mobile base station architecture for a non-roaming scenario, the mobile base station operation can support roaming scenarios as well as non-roaming scenarios.

[0207] For example, the example in FIG. 7 is an example of a non-roaming MWAB architecture for 5GS.

[0208] Referring to the example of FIG. 7, a backhaul PDU session is illustrated for tunneling the N2 interface and / or N3 interface (e.g., the N2 / N3 interface) of the MWAB-gNB. Also illustrated is an N2 / N3 interface (e.g., the N2 / N3 interface of the MWAB-gNB) tunneled via the backhaul PDU session.

[0209] For example, the MWAB-UE can establish a PDU session to provide the N2 / N3 interface to the MWAB-gNB. For the PDU session establishment procedure, 3GPP TS 23.502 V18.4.0 S 4.3.2 can be referenced. The MWAB-UE can establish a BH PDU session with a core network (e.g., BH-5GC) via a base station (e.g., BH-gNB). The MWAB-UE can provide information related to the BH PDU session to the MWAB-gNB. The MWAB-gNB can be connected to a core network serving the UE (e.g., 5GC serving UE) based on the N2 interface and / or N3 interface through which the BH PDU session is tunneled.

[0210] Describes an example of the architectural requirements related to a mobile base station.

[0211] MWAB can provide services to legacy UE(s) connected via MWAB.

[0212] End-to-end service continuity for UEs served by MWAB can be supported during MWAB movement.

[0213] It can help mobile network operators configure, provision, and control the operation of MWAB.

[0214] When a UE accesses 5GS via MWAB, regulatory requirements (e.g., emergency services, priority services support) can be supported.

[0215] Roaming of MWAB-UEs from HPLMN to VPLMN may be supported.

[0216] FIGS. 8 and 9 are examples illustrating architectures including 5G Core Network Functions based on the MWAB architecture of FIG. 7.

[0217] 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.

[0218] Figure 8 is an example of an architecture in which both the backhaul network of a mobile base station to which the implementation of this specification is applied and the serving network of the UE are home networks.

[0219] The example in Fig. 8 is an example of an architecture in which both the backhaul network of MWAB and the serving network of the UE are home networks.

[0220] In the architecture according to the example of Fig. 8, an MWAB (e.g., MWAB-UE) can connect to a base station and 5GC of the home network and create a PDU session. Through the created PDU session, the MWAB can connect the N2 / N3 interfaces to the 5GC of the home network and operate as a base station.

[0221] The example of FIG. 8 illustrates a scenario where both the Backhaul (BH) network of the MWAB and the serving network of the UE are the Home network of the MWAB. The example of FIG. 8 illustrates the 5G Core Network Functions for the MWAB-UE (e.g., BH AMF, BH SMF, BH UPF, UDM (MWAB-UE)) and the 5G Core Network Functions for the UE served by the MWAB-gNB (e.g., AMF, SMF, UPF, UDM) as different NFs. However, this is merely an example, and some or all of the 5G Core Network Functions for the MWAB-UE and the 5G Core Network Functions for the UE served by the MWAB-gNB illustrated in the example of FIG. 8 may be the same NF. For example, the BH AMF and the AMF may be the same AMF, and / or the UDM (MWAB-UE) and the UDM may be the same UDM.

[0222] 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.

[0223] Figure 9 is an example of an architecture in which the backhaul network of a mobile base station to which the implementation of the present specification is applied is a visited network and the serving network of the UE is a home network.

[0224] Figure 9 is an example of an architecture in which the backhaul network of MWAB is a visited network and the serving network of the UE is a home network.

[0225] In the architecture according to the example of Fig. 9, an MWAB (e.g., MWAB-UE) can connect to a base station and 5GC of a visited network to create a PDU session. The MWAB (e.g., MWAB-gNB) can operate as a base station by connecting N2 / N3 interfaces to a 5GC of a home network through the created PDU session.

[0226] The example in Figure 9 illustrates a scenario where the MWAB's Backhaul (BH) network is the Visited network (i.e., the roaming network) and the UE's serving network is the MWAB's Home network. In Figure 9, the UDM for the MWAB-UE (e.g., UDM (MWAB-UE)) and the UDM for the UE served by the MWAB-gNB are depicted as different NFs. However, this is merely an example, and UDM (MWAB-UE) and UDM may be the same UDM.

[0227] In the examples of FIGS. 8 and 9, a gNB (e.g., an NR base station) is depicted as the backhaul base station, but this is merely an example. For example, the backhaul base station may be a base station / RAN that supports a Radio Access Technology (RAT) other than NR.

[0228] According to the structural architecture assumptions described above, MWAB-UEs can access / connect to the backhaul network not only via the Terrestrial network (TN) but also via the Non-Terrestrial Network (NTN). For example, MWAB-UEs can have a single NR Uu hop to the NG-RAN (e.g., MWAB-UEs can access gNBs via an NR Uu interface that can use either TN or NTN technology).

[0229] Below, with reference to examples of FIGS. 10 and 11, the architecture in the case where the MWAB-UE connects / connects to the Backhaul network via NTN is described.

[0230] 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.

[0231] FIG. 10 is a first example of an architecture in which a UE of a mobile base station to which the implementation of the present specification is applied is connected to a backhaul network via an NTN.

[0232] Figure 10 is an example of an architecture in which both the MWAB backhaul network and the UE's serving network are home networks. In the example of Figure 10, the MWAB-UE can be connected to the BH network via an NTN.

[0233] 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.

[0234] FIG. 11 is a second example of an architecture in which a UE of a mobile base station to which the implementation of the present specification is applied is connected to a backhaul network via an NTN.

[0235] Figure 11 is an example of an architecture in which the MWAB's backhaul network is a visited network and the UE's serving network is a home network. In the example of Figure 11, the MWAB-UE can be connected to the BH network via an NTN.

[0236] For reference, although a Gateway (or NTN Gateway) is not shown between a Satellite and a BH-gNB in ​​FIGS. 10 and 11, this is merely an example and the scope of the disclosure of the present specification is not limited by the examples in FIGS. 10 and 11. For example, a Gateway (or NTN Gateway) may exist between a Satellite and a BH-gNB.

[0237] Fig. 10 illustrates a scenario in which an MWAB-UE connects / connects to a BH-gNB via an NTN, in contrast to Fig. 8. Fig. 11 illustrates a scenario in which an MWAB-UE connects / connects to a BH-gNB via an NTN, in contrast to Fig. 9.

[0238] Regarding satellite access, the RAT type of TS 29.571 V18.4.0 includes the satellite access type.

[0239] Enumeration Value Description "NR" New Radio "EUTRA" (WB) Evolved Universal Terrestrial Radio Access "WLAN" Untrusted Wireless LAN (IEEE 802.11) access "VIRTUAL" Virtual (see NOTE 1) "NBIOT" NB IoT "WIRELINE" Wireline access "WIRELINE_CABLE" Wireline Cable access "WIRELINE_BBF" Wireline BBF access "LTE-M" LTE-M (see NOTE 2) "NR_U" New Radio in unlicensed bands "EUTRA_U" (WB) Evolved Universal Terrestrial Radio Access in unlicensed bands "TRUSTED_N3GA" Trusted Non-3GPP access "TRUSTED_WLAN" Trusted Wireless LAN (IEEE 802.11) access "UTRA" UMTS Terrestrial Radio Access "GERA" GSM EDGE Radio Access Network"NR_LEO"NR (LEO) satellite access type)"NR_MEO"NR (MEO) satellite access type)"NR_GEO"NR (GEO) satellite access type)"NR_OTHER_SAT"NR (OTHERSAT) satellite access type)"NR_REDCAP"NR RedCap access type (see NOTE 3)NOTE 1: Virtual may be used if the N3IWF does not know the access technology for the untrusted non-3GPP access.NOTE 2: This RAT type value is only used in the core network. It is only used if a Category M UE using E-UTRA has provided a Category M indication to the NG-RAN.NOTE 3: This RAT type value is used only in the core network. This RAT type value can only be used for UEs using NR with reduced radio capabilities provided to the NG-RAN.

[0240] Looking at the RAT types included in the examples in Table 3, various satellite access types can be included.

[0241] In relation to Table 3, TS 29.571 V18.4.0 Table 5.4.3.2-1: Enumeration RatType may be referenced.

[0242] In the examples in Table 3, LEO can stand for Low Earth orbit, MEO for Medium Earth orbit, and GEO for Geostationary equatorial orbit. OTHERSAT can stand for any satellite access type other than LEO, MEO, or GEO.

[0243] According to TS 24.501 V18.5.0, a timer may be used when NAS operations / procedures are performed between the UE and the Core Network.

[0244] For reference, in the disclosure of this specification, NAS operations / procedures may include NAS-related procedures and / or NAS-related message transmission, and / or NAS-related message reception.

[0245] Below, examples of representative MM (Mobility Management) operations, MM procedures, and / or MM-related timers are described.

[0246] Describes an example of initial registration initiation. TS 24.501 V18.5.0 S5.5.1.2 Registration procedure for initial registration may be referenced.

[0247] Describes an example of the registration process for initial registration.

[0248] For example, a UE may send a registration request message to the AMF. The UE may send the registration request message and start a timer based on T3510. The AMF may send a registration acceptance message to the UE. Once the AMF sends the registration acceptance message to the UE, the UE may stop the timer based on T3510.

[0249] For another example, the UE may send a registration request message to the AMF. The UE may send the registration request message and start a timer based on T3510. The AMF may send a registration accept message to the UE. When the AMF sends the registration accept message to the UE, the AMF may start a timer based on T3550. When the AMF sends the registration accept message to the UE, the UE may stop the timer based on T3510. The UE may send a registration complete message to the AMF. When the AMF receives the registration complete message, the AMF may stop the timer based on T3550.

[0250] For another example, a UE may send a registration request message to the AMF. The UE may send the registration request message and start a timer based on T3510. The AMF may send a registration rejection message to the UE. If the AMF sends the registration rejection message to the UE, the UE may stop the timer based on T3510.

[0251] Describes examples of abnormal cases in the UE. TS 24.501 V18.5.0 5.5.1.2.7 Abnormal cases in the UE may be referenced.

[0252] A timeout on T3510 can be identified as an abnormal case.

[0253] In the event of a T3510 timeout (e.g., T3510 expires), the UE may perform the following actions. For example, the UE may abort the initial registration procedure if the initial registration request is not for emergency services or is not for initiating a PDU session for emergency services with the request type set to "existing emergency PDU session." In this case, the NAS signaling connection, if any, may be released locally.

[0254] If Timer T3510 is still running, it can be stopped.

[0255] If the registration procedure is not an initial registration for emergency services, nor is it for establishing an emergency PDU session where the registration type is not set to "Emergency Registration", the registration attempt counter may be incremented unless it is already set to 5.

[0256] If the registration attempt counter is less than 5:

[0257] - If the initial registration request is not for emergency services, timer T3511 may be started, and the status may change to 5GMM-DEREGISTERED.ATTEMPTING-REGISTRATION. When timer T3511 expires, the initial registration process may be restarted if still required.

[0258] If the registration attempt counter is equal to 5, the following actions can be performed:

[0259] - The UE shall delete the TAI list and the last visited registered TAI, and if the value of the timer indicated by the network is not 0, the UE shall start timer T3502 and set the 5GS update status to 5U2 NOT UPDATED. If the UE is not registered or has never been registered to the same PLMN over 3GPP access and non-3GPP access, the UE may additionally delete the 5G-GUTI, ngKSI and equivalent PLMN list (if any) or equivalent SNPN list (if any). The status shall be changed to 5GMM-DEREGISTERED.ATTEMPTING-REGISTRATION or optionally to 5GMM-DEREGISTERED.PLMN-SEARCH to perform PLMN selection, SNPN selection or SNPN selection for onboarding services as per 3GPP TS 23.122 V18.5.0.

[0260] - If the value of T3502 indicated in the network is 0, the UE may perform the action defined for the expiration of the T3502 timer.

[0261] - If the procedure is performed via 3GPP access and the UE is operating in single registration mode:

[0262] - In case of abnormality where EPS attach procedure fails and connection attempt counter is equal to 5, UE can additionally process EMM parameters, EPS update status, EMM status, 4G-GUTI, TAI list, last visited registered TAI, equivalent PLMN list and eKSI as specified in 3GPP TS 24.301 V18.5.0.

[0263] - The UE can select an E-UTRAN radio access technology and perform appropriate EMM-related procedures. Additionally, the UE can disable N1 mode functionality as specified in TS 24.501 V18.5.0 S4.9.

[0264] Describes examples of abnormal cases on the network side. TS 24.501 V18.5.0 5.5.1.2.8 Abnormal cases on the network side can be referenced.

[0265] A timeout on the T3550 can be identified as an abnormal case.

[0266] In case of a T3550 timeout (e.g., when T3550 expires), the following actions can be performed:

[0267] When Timer T3550 expires for the first time, AMF may resend the REGISTRATION ACCEPT message, reset and restart Timer T3550.

[0268] This retransmission is repeated four times. For example, when timer T3550 expires for the fifth time, the initial registration procedure is aborted and the AMF may enter state 5GMM-REGISTERED. If a new 5G-GUTI is allocated in the REGISTRATION ACCEPT message, the AMF may consider both the old 5G-GUTI and the new 5G-GUTI as valid until the old 5G-GUTI is deemed invalid by the AMF or by a 5GMM context that is marked as deregistered by the AMF. If the old 5G-GUTI was allocated by an AMF other than the current AMF, the current AMF does not need to maintain the old 5G-GUTI.

[0269] Below, examples of SM (Session Management) operations, SM (Session Management) procedures, and / or related timers are described. An example of a UE-requested PDU session establishment procedure is described. TS 24.501 V18.5.0 6.4.1 UE-requested PDU session establishment procedure may be referenced.

[0270] Describes an example of how a PDU session establishment procedure requested by a UE is initiated.

[0271] The UE may send a PDU Session Establishment Request message to the SMF. The UE may send the PDU Session Establishment Request message and start timer T3580.

[0272] In this case, for example, the SMF may send a PDU Session Establishment Accept message to the UE. The UE may stop timer T3580.

[0273] For another example, the SMF may send a PDU Session Establishment Reject message to the UE. The UE may stop timer T3580.

[0274] Describes an example of an abnormal case in UE.

[0275] A T3580 timeout can be identified as an abnormal event. In the event of a T3580 timeout (e.g., when T3580 expires), the following actions can be taken:

[0276] The UE may perform the following actions when timer T3580 first expires:

[0277] - When a PDU Session Establishment Request message is sent with a request type set to "Initial Emergency Request" or "Existing Emergency PDU Session", the UE may do one of the following:

[0278] a) the UE notifies the upper layer of the procedure failure; or

[0279] b) If not already deregistered, the UE may deregister locally and attempt initial registration for emergency services.

[0280] When a UE sends a PDU SESSION ESTABLISHMENT REQUEST message to perform a handover of an existing emergency PDU session between 3GPP access and non-3GPP access, the UE may consider that the emergency PDU session is associated with the source access type.

[0281] - Otherwise, the UE retransmits the PDU Session Establishment Request message and the PDU session information transmitted with the initial transmission of the PDU Session Establishment Request message, and may reset and start timer T3580 if necessary. This retransmission may be repeated up to four times. For example, upon the fifth expiration of timer T3580, the UE may abort the procedure, release the allocated PTI, and enter PROCEDURE TRANSACTION INACTIVE state. If the UE transmits the PDU SESSION ESTABLISHMENT REQUEST message to perform a handover of an existing non-emergency PDU session between 3GPP access and non-3GPP access, the UE may consider that PDU session to be associated with the source access type.

[0282] Describes an example of a UE-requested PDU session modification procedure. TS 24.501 V18.5.0 6.4.2 UE-requested PDU session modification procedure may be referenced.

[0283] The UE may send a PDU Session Modification Request message to the SMF. The UE may start timer T3581.

[0284] In this case, for example, the SMF and the UE may perform a PDU session modification procedure requested by the network. Then, the UE may stop timer T3581.

[0285] For another example, the SMF may send a PDU Session Modification Reject message to the UE, which may then stop timer T3581.

[0286] Describes an example of an abnormal case in UE.

[0287] The expiration of timer T3581 may be identified as an abnormal event. When timer T3581 expires, the UE may perform the following actions:

[0288] Upon the first expiration of timer T3581, the UE retransmits the PDU session information and PDU SESSION MODIFICATION REQUEST message transmitted with the initial transmission of that message, and the UE may reset and start timer T3581. This retransmission may be repeated four times. For example, upon the fifth expiration of timer T3581, the UE may abort the procedure and release the allocated PTI.

[0289] Describes an example of a network-requested PDU session modification procedure. TS 24.501 V18.5.0 6.3.2 Network-requested PDU session modification procedure can be referenced.

[0290] The SMF may send a PDU Session Modification Command message to the UE. The SMF may start timer T3591.

[0291] In this case, for example, the UE may send a PDU Session Modification Complete message to the SMF. Then, the SMF may stop timer T3591.

[0292] For another example, the UE may send a PDU Session Modification Command Reject message to the SMF. The SMF may then stop timer T3591.

[0293] An example of an abnormal case on the network side is described. The expiration of timer T3591 can be identified as an abnormal case. In this case, the network can behave as follows:

[0294] When timer T3591 expires for the first time, the SMF may retransmit the PDU Session Modification Command message, reset timer T3591, and restart the process. This retransmission may be repeated up to four times. For example, when timer T3591 expires for the fifth time, the SMF may abort the process and enter the PDU Session Active state.

[0295] The SMF may continue to use the previous PDU session configuration or initiate a PDU session release procedure requested by the network. If the SMF decides to continue using the previous PDU session configuration, it may perform the following actions:

[0296] i) If the PDU SESSION MODIFICATION COMMAND message contains an approved Quality of Service (QoS) rule IE, the SMF may mark the PDU session as requiring that the corresponding approved QoS rule be synchronized with the UE; and

[0297] ii) If the PDU SESSION MODIFICATION COMMAND message contains an approved QoS flow description IE, the SMF may mark the corresponding approved QoS flow description of the PDU session to be synchronized with the UE.

[0298] Referring to the timers defined in TS 24.501 V18.5.0, when the UE connects to the network via a satellite NG-RAN cell (e.g., when the UE connects to the network via an NTN), a longer timer value can be used compared to the other cases. This longer timer value takes into account the delay time when the UE and the network exchange NAS messages via the satellite / NTN.

[0299] Below, examples of timer values ​​for access via a satellite NG-RAN cell are described, among timers related to 5GS mobility management and / or timers related to 5GS session management.

[0300] Describes examples of timers related to mobility management. TS 24.501 V18.5.0 10.2 Timers of 5GS mobility management can be referenced.

[0301] Timer numberTimer valueStatusReason for startingNormal interruptionExpiresT351015sIn WB-N1 / CE mode, 85sFor access via a satellite NG-RAN cell, 27s5GMM-REGISTERED-INITIATEDRegistration request message is sentIf a registration acceptance message is received or a registration rejection message is receivedIf timer T3510 expires during the registration procedure for initial registration, start timer T3511 or timer T3502 as described in TS 24.501 V18.5.0 S5.5.1.2.7.If T3510 expires during the registration procedure for mobility and periodic registration update, start T3511 or T3502 as described in TS 24.501 V18.5.0 S5.5.1.3.7.

[0302] Table 4 shows examples of timers related to 5GS mobility management on the UE side. TS 24.501 V18.5.0 Table 10.2.1: Timers of 5GS mobility management - UE side can be referenced.

[0303] For timer T3510, in satellite NG-RAN access, a value of 27 seconds can be selected for access via satellite NG-RAN cell when the satellite NG-RAN RAT type is NR (MEO) or NR (GEO).

[0304] For reference, although not included in Table 4, TS 24.501 V18.5.0 Table 10.2.1: Timers of 5GS mobility management - UE side may include T3502, T3510, T3516, T3517, T3519, T3520, T3521, T3525, and / or T3540. These timer values ​​may also be selected for access via satellite NG-RAN cells when the satellite NG-RAN RAT type is NR (MEO) or NR (GEO).

[0305] Timer number Timer value Status Reason for start Normal interruption Expires T35506 For WB-N1 / CE mode, 18s For access via satellite NG-RAN cell, 11s 5GMM-COMMON-PROCEDURE-INITIATED Transmission of registration acceptance message If registration completion message is received Retransmission of registration acceptance message

[0306] Table 5 provides examples of timers related to 5GS mobility management on the AMF side. TS 24.501 V18.5.0 Table 10.2.2: Timers of 5GS mobility management - AMF side can be referenced.

[0307] For timer T3550, in satellite NG-RAN access, a value of 11 seconds can be selected for access via satellite NG-RAN cell when the satellite NG-RAN RAT type is NR (MEO) or NR (GEO).

[0308] For reference, although not included in Table 5, TS 24.501 V18.5.0 Table 10.2.2 may include T3502, T3513, T3522, T3550, T3555, T3560, T3565, T3570, and / or T3575. These timer values ​​may also be selected for access via satellite NG-RAN cells when the satellite NG-RAN RAT type is NR(MEO) or NR(GEO).

[0309] Describes examples of timers related to 5GS session management. TS 24.501 V18.5.0 S10.3 Timers of 5GS session management can be referenced.

[0310] Timer numberTimer valueStatusReason for startNormal interruptionExpires (e.g., for the first, second, third, and / or fourth time)T358016For WB-N1 / CE mode, 24sFor access via satellite NG-RAN cell, 21sPDU SESSION ACTIVE PENDINGTransmission of PDU Session Establishment Request messageWhen a PDU Session Establishment Accept message is received, orWhen a PDU Session Establishment Reject message is received, orWhen a DL NAS Transmit message containing a PDU Session Establishment Request message is received with 5GMM cause #22, #28, #65, #67, #69, #90, #91, or #92Retransmission of PDU Session Establishment Request messageT358116For WB-N1 / CE mode, 24sFor access via satellite NG-RAN cell, 21sPDU SESSION MODIFICATION PENDINGPDU Session Modification Retransmission of a PDU Session Modification Request message if a PDU Session Modification Command message is received with the same PTI, or if a PDU Session Modification Reject message is received, or if a DL NAS Transmit message containing a PDU Session Modification Request message is received with 5GMM cause #22, #28, #67, #69, or #90.

[0311] Table 6 shows examples of timers related to 5GS session management on the UE side. TS 24.501 V18.5.0 Table 10.3.1: Timers of 5GS session management - UE side can be referenced.

[0312] For timers T3580 and T3581, in satellite NG-RAN access, a value of 21 seconds can be selected for access via satellite NG-RAN cells when the satellite NG-RAN RAT type is NR (MEO) or NR (GEO).

[0313] For reference, although not included in Table 6, TS 24.501 V18.5.0 Table 10.2.2 may further include T3582 and / or T3586. These timer values ​​may also be selected for access via satellite NG-RAN cells when the satellite NG-RAN RAT type is NR (MEO) or NR (GEO).

[0314] Timer numberTimer valueStatusReason for startNormal interruptionExpiration (e.g., first, second, third, and / or fourth time)T359116sFor WB-N1 / CE mode, 24sFor access via satellite NG-RAN cell, 22sPDU SESSION MODIFICATION PENDINGTransmission of PDU Session Modification Command messageWhen PDU Session Modification Complete message is received, orPDU Session Modification Command Reject message is receivedRetransmission of PDU Session Modification Command message

[0315] Table 7 provides examples of timers related to 5GS session management on the SMF side. TS 24.501 V18.5.0 Table 10.3.2: Timers of 5GS session management - SMF side can be referenced.

[0316] For timer T3591, in satellite NG-RAN access, a value of 22 seconds can be selected for access via satellite NG-RAN cell when the satellite NG-RAN RAT type is NR (MEO) or NR (GEO).

[0317] For reference, although not included in Table 7, TS 24.501 V18.5.0 Table 10.3.2 may further include T3590, T3591, T3592, and / or T3594. These timer values ​​may also be selected for access via satellite NG-RAN cells when the satellite NG-RAN RAT type is NR(MEO) or NR(GEO).

[0318] A UE of a mobile base station (e.g., MWAB-UE) may connect / access to a network via NTN. In this case, when NAS operations and / or procedures are performed for the UE of the mobile base station (e.g., MWAB-UE), a longer timer value may be used, as in the example described above. In this case, there is a problem in that, according to the prior art, a timer value of a normal length (e.g., a timer value that does not consider NTN, or a timer value that considers TN) is used for a UE that connects / accesses to a network via the mobile base station (e.g., MWAB), i.e., a UE that is served by the mobile base station (e.g., MWAB). Accordingly, in the prior art, when NAS operations and / or procedures are performed between the UE and the network, unnecessary retries or failures occur due to the timer value that does not consider the connection via NTN.

[0319] In this specification, UE (User Equipment) and terminal may be used as terms with the same meaning.

[0320] In this specification, the terms “Subscriber” and “User” may be used interchangeably.

[0321] In this specification, NG-RAN, RAN, base station, NR base station, LTE base station, gNB, eNB, ng-eNB, etc. may be used as terms with the same meaning.

[0322] In this specification, Mobile gNB with wireless access backhauling (MWAB or mWAB or MgWAB), mobile RAN, Vehicle Relay, Vehicle-Mounted Relay (VMR), Relay, Mobile Relay, MBSR (Mobile Base Station Relay), eMBSR (enhanced MBSR), mobile base station, etc. may be used as terms with the same meaning.

[0323] In this specification, underlay network and Backhaul (BH) network may be used as terms with the same meaning.

[0324] In this specification, the Backhaul (BH) base station of a mobile base station (e.g., MWAB), the underlay base station of the MWAB and the base station to which the MWAB connects to connect the N2 / N3 interfaces to 5GC, the base station of the MWAB-UE, the base station serving the MWAB-UE, the base station to which the MWAB-UE connects, etc. may be used as terms with the same meaning.

[0325] In this specification, the Backhaul (BH) underlay Core Network of MWAB, the underlay Core Network of MWAB and the Core Network to which MWAB connects / registers to connect N2 / N3 interfaces to 5GC, the Core Network of MWAB-UE, the Core Network serving MWAB-UE, the Core Network to which MWAB-UE connects / registers, etc. may be used as terms with the same meaning.

[0326] In this specification, Backhaul (BH) network may be interpreted as including one or more of a Backhaul (BH) base station and / or a Backhaul (BH) Core Network.

[0327] In this specification, an underlay network may be interpreted as including one or more of an underlay base station and / or an underlay Core Network.

[0328] In this specification, terms such as MWAB base station, MWAB base station part, MWAB-gNB, MWAB base station, MWAB base station part, MWAB RAN, MWAB NG-RAN, etc. may be used as terms with the same meaning.

[0329] In this specification, N2 interface may be used as a term with the same meaning as NG-C interface, NGAP (NG Application Protocol) interface, N2 tunnel, interface for control plane between base station and core network, etc. N3 interface may be used as a term with the same meaning as NG-U interface, N3 tunnel, interface for user plane between base station and core network, etc.

[0330] In this specification, PDU Session for N2 interface, PDU Session for N2 interface, N2 PDU Session, Backhaul (BH) N2 PDU Session, N2 Backhaul (BH) PDU Session, Backhaul (BH) PDU Session, etc. may be used as terms with the same meaning.

[0331] In this specification, PDU Session for N3 interface, PDU Session for N3 interface, N3 PDU Session, Backhaul (BH) N3 PDU Session, N3 Backhaul (BH) PDU Session, Backhaul (BH) PDU Session, etc. may be used as terms with the same meaning.

[0332] In this specification, NTN, satellite, satellite network, satellite communication network, etc. may be used as terms with the same meaning.

[0333] In this specification, network connection / access via NTN, network connection / access via satellite, connection / access via satellite NG-RAN cell, satellite NG-RAN access, satellite RAN access, connection / access via satellite cell, connection / access via NTN cell, connection / access via NTN-based NG-RAN, connection / access via NTN-based RAN, connection / access via NTN-based cell, satellite access, NTN access, etc. may be used as terms with the same meaning.

[0334] In this specification, NTN-based NG-RAN may refer to a transparent payload-based satellite and / or a regenerative-based satellite.

[0335] In this specification, TN NG-RAN cell, NG-RAN cell, non-satellite cell, etc. may be used as terms with the same meaning.

[0336] Mobile base stations (e.g., MWABs) can be mounted on various types of vehicles, including land vehicles (e.g., cars, trains), sea or river vehicles (e.g., ships, boats), aerial vehicles (e.g., airplanes, helicopters, drones), and satellites. When mounted on a mobile vehicle in the air, the mobile base station may be referred to as an Aerial MWAB or Aerial Vehicle Relay (AVR). Furthermore, mobile base stations (e.g., MWABs) do not necessarily have to be mobile; they can also function as base stations while stationary.

[0337] A mobile base station (e.g., MWAB) can serve not only UEs within the vehicle / MWAB but also UEs in the surrounding area.

[0338] A mobile base station (e.g., MWAB) can use various Radio Access Technology (RAT) to serve UEs (e.g., NR, LTE, 6G RAT, etc.).

[0339] A mobile base station (e.g., MWAB) may include a UE portion or a Mobile Terminal (MT) portion. This may be interpreted as MWAB including a UE portion / operation / functionality or a Mobile Terminal (MT) portion / operation / functionality. The UE portion or MT portion of a mobile base station may be referred to as MWAB-UE or MWAB-MT.

[0340] The methods proposed in the various examples of the disclosure of this specification may be composed of a combination of one or more of the following operations / compositions / steps, and the proposed methods may be performed or used in combination or complementary manner.

[0341] The method proposed in this specification can be applied to both cases where a mobile base station (e.g., MWAB) is connected to a PLMN to provide a service and cases where a mobile base station (e.g., MWAB) is connected to an NPN to provide a service. When a mobile base station (e.g., MWAB) is connected to an NPN to provide a service, the PLMN ID disclosed in this specification can be interpreted as NPN identification information. When a mobile base station (e.g., MWAB) is connected to an SNPN to provide a service, the PLMN ID disclosed in this specification can be interpreted by replacing it with SNPN identification information (PLMN ID and NID identifying an SNPN).

[0342] The operations and contents described in this specification as being performed by a UE of a mobile base station (e.g., MWAB-UE) or a base station of a mobile base station (e.g., MWAB-base station) may be interpreted as operations and contents performed by a mobile base station (e.g., MWAB).

[0343] In the disclosure of this specification, operations performed by a mobile base station (e.g., MWAB) and / or contents related to the mobile base station (e.g., MWAB) may be specifically interpreted as operations performed by a UE of the mobile base station (e.g., MWAB-UE) or a base station of the mobile base station (e.g., MWAB-base station) and / or contents related to a UE of the mobile base station (e.g., MWAB-UE) or a base station of the mobile base station (e.g., MWAB-base station).

[0344] In the disclosure of this specification, the terms "timer to be used during NAS operation / procedure", "timer for NAS operation and / or NAS procedure" may be used as terms having the same meaning. The timer to be used during NAS operation / procedure may refer to an MM-related timer and / or an SM-related timer.

[0345] In this specification, PDU (Protocol Data Unit, or Packet Data Unit) Session related operations, procedures, timers, and / or messages and Session Management (SM) related operations, procedures, timers, and / or messages may be used interchangeably.

[0346] In this specification, with respect to conventional MM-related operations, procedures, timers, and / or messages, and SM-related operations, procedures, timers, and / or messages, reference may be made to TS 23.501 V18.0.0, TS 23.502 V18.4.0, TS 24.501 V18.5.0, TS 38.413 V18.0.0, etc. Hereinafter, descriptions related to conventional technologies will be omitted, and various examples of the disclosure of this specification will be described with a focus on matters proposed in this specification.

[0347] The method proposed in this specification may be applicable only to a specific type of satellite (e.g., long-delay satellites such as MEO (Medium Earth Orbit) and GEO (Geosynchronous Orbit)) or may be applicable to all satellites. For example, if the method proposed in this specification is applicable only to a specific type of satellite, even if a mobile base station (e.g., MWAB) connects / accesses to the network through a type of satellite to which the method proposed in this specification does not apply, the mobile base station (e.g., MWAB) may be regarded / assumed to be connected / accessed through a TN.

[0348] According to one embodiment of the disclosure of the present specification, when the backhaul network of a mobile base station (e.g., MWAB) is an NTN, when NAS operation and / or NAS procedure are performed for a UE served through the mobile base station (e.g., MWAB), NTN-related timer(s) may be used.

[0349] The fact that the backhaul network of a mobile base station (e.g., MWAB) is an NTN may mean that the network to which the UE of the mobile base station (e.g., MWAB-UE) is connected / accessed is an NTN, or that the cell to which the UE of the mobile base station (e.g., MWAB-UE) is connected / accessed is an NTN cell. Examples of such scenarios / architectures can be found in FIGS. 10 and 11.

[0350] A UE served through a mobile base station (e.g., MWAB) can be interpreted as a UE served by the MWAB's base station (e.g., MWAB-base station), a UE connected / accessed to the network through the mobile base station (e.g., MWAB).

[0351] NTN-related timer(s) can be interpreted as meanings of the following examples. For example, NTN-related timer(s) can be interpreted as timer(s) that take into account the delay required to transmit NAS messages via NTN. NTN-related timer(s) can be interpreted as timer(s) used / applied during NAS operations / procedures in case of satellite NG-RAN access. NTN-related timer(s) can be interpreted as timer(s) that are designated / set longer than the timer(s) used / applied during normal NAS operations / procedures. NTN-related timer(s) can be interpreted as timer(s) used / applied during NAS operations / procedures via NTN cells. NTN-related timer(s) can be interpreted as timer(s) used / applied during NAS operations / procedures via cells other than TN cells. NTN-related timer(s) can be interpreted as timer(s) for cases where MWAB accesses via satellite NG-RAN cells. NTN related timers can be interpreted as timers(s) that are designated / set longer than the timers(s) that only consider the UE receiving services through the MWAB. NTN related timers can be interpreted as timers(s) that are designated / set longer than the timers(s) used when the UE receives services through the MWAB connected / accessed to the network through the TN cell. NTN related timers can be interpreted as timers(s) that consider both the UE receiving services through the MWAB and passing through the NTN. NTN related timers can be interpreted as timers(s) that are designated / set longer than the timers(s) used when the UE does not receive services through the MWAB.

[0352] In one embodiment of the disclosure of the present specification, with respect to NTN-related timer(s), NTN-related timers may be defined and used separately. Alternatively, with respect to NTN-related timer(s), conventional timers may be used, but timer values ​​may be used differently.

[0353] NTN related timer(s) may also be called delay-considering timer(s), extended timer(s), longer timer(s), etc.

[0354] For example, in the disclosure of this specification, an NTN-related timer (or, NTN-related timer(s)) may be referred to or interpreted as a Timer For access via MWAB connected to satellite. However, this name or interpretation is only an example, and the scope of the disclosure of this specification is not limited thereto. For example, the scope of the name or interpretation of a timer in the disclosure of this specification may include a name or interpretation indicating a timer related to a mobile base station and / or a satellite. For example, an NTN-related timer (or, NTN-related timer(s)) may include various names or interpretations such as a satellite-related timer, a timer related to a mobile base station connected to a satellite, a timer used / selected when connected via a satellite base station cell, a timer used / selected when connected to a satellite, etc.

[0355] The NTN-related timer(s) may be one or more of the MM NAS operation-related timer(s) and / or SM NAS operation-related timer(s). In addition, when the NTN-related timer(s) are MM NAS operation-related timer(s), the NTN-related timer(s) may be timer(s) related to some MM NAS operations, not all MM NAS operations. When the NTN-related timers(s) are SM NAS operation-related timer(s), the NTN-related timers(s) may be timer(s) related to some SM NAS operations, not all SM NAS operations.

[0356] NTN related timer(s) may be timer(s) used by one or more entities among UE, AMF, and / or SMF. Referring to TS 24.501 V18.5.0, each entity has timers that are used / applied according to NAS operations / procedures. For example, with respect to NTN related timer(s), it can be assumed that each entity has NTN related timer(s) that are used / applied according to NAS operations / procedures.

[0357] In some implementations, NTN-related timer(s) may be configured in the UE, AMF, and / or SMF, respectively. The UE, AMF, and / or SMF may also obtain timer values ​​associated with the NTN-related timer(s) from other entities (e.g., a base station of a mobile base station, the UE, AMF, SMF, etc.).

[0358] According to one embodiment of the disclosure of the present specification, a base station (e.g., MWAB-gNB) of a mobile base station may provide network-related information (e.g., information related to a backhaul network) to a UE and / or a serving core network of the UE.

[0359] For example, the serving core network of the UE may be the serving AMF of the UE or the serving SMF of the UE.

[0360] For example, the MWAB-gNB may provide backhaul network related information to the UE and / or the UE's serving core network (e.g., AMF, SMF, etc.) based on the base station / MWAB operation being authorized to be performed (or based on the mobile base station performing base station operation).

[0361] In some implementations, information related to a network (e.g., information related to a backhaul network) may include one or more of the following information. The information may be explicit, implicit, implicit, or a combination of one or more of the following:

[0362] a) Information regarding whether the MWAB is connected and / or accessed via a satellite NG-RAN cell:

[0363] - When the MWAB connects / accesses via a satellite NG-RAN cell, the MWAB may provide this information to the UE and / or the UE's serving core network. Alternatively, information regarding whether the MWAB connects / accesses via a satellite NG-RAN cell may indicate whether the MWAB connects / accesses via a satellite NG-RAN cell or via a TN NG-RAN cell.

[0364] b) Information regarding whether the backhaul network (or backhaul cell) is an NTN (or NTN cell):

[0365] - Only when the Backhaul network (or Backhaul cell) of the MWAB is an NTN (or NTN cell), the MWAB may provide this information to the UE and / or the UE's serving core network. Alternatively, the information regarding whether the Backhaul network (or Backhaul cell) is an NTN (or NTN cell) may indicate whether the Backhaul network (or Backhaul cell) of the MWAB is an NTN (or NTN cell) or a TN (or TN cell).

[0366] c) Information regarding whether the RAT (or access type) to which the MWAB is connected, connected to, and / or in use is satellite / NTN:

[0367] - The MWAB may provide this information to the UE and / or the UE's serving core network only when the RAT (or access type) to which the MWAB is connected / connected / using is satellite / NTN. Alternatively, the information regarding whether the RAT (or access type) to which the MWAB is connected, connected, and / or using is satellite / NTN may also indicate whether the RAT (or access type) to which the MWAB is connected / connected / using is satellite / NTN or TN. This information may be expressed as the type of satellite, such as MEO, GEO, NR_MEO, NR_GEO, etc., in case of connection / access via satellite / NTN. The type of the satellite may be explicitly indicated or implicitly indicated (e.g., through orbital information of the satellite).

[0368] d) Information indicating whether a timer value should be used for access via satellite NG-RAN cell during NAS operation / procedure:

[0369] - In relation to NAS operation / procedure, if a timer value applicable in case of satellite NG-RAN access should be used (or if MWAB is connected / accessed via satellite NG-RAN cell), MWAB may provide this information to UE and / or UE's serving core network. For example, this information may indicate whether the timer value for satellite NG-RAN access should be used in NAS operation / procedure (e.g. 27s for T3510, 22s for T3591). This information may indicate whether the timer value for satellite NG-RAN access does not need to be used (in this case, the configured / specified timer value can be used without considering the delay due to NAS message exchange via NTN - for example 15s for T3510, 16s for T3591).

[0370] e) Information indicating whether the timer value should be used for cases where MWAB accesses a satellite NG-RAN cell during NAS operation / procedure:

[0371] - In relation to NAS operation / procedure, timer values ​​may be defined / set for cases where MWAB accesses via satellite NG-RAN cell (for example, timers for UE may be set to UE, timers for AMF may be set to AMF, and timers for SMF may be set to SMF). The above timer values ​​may be timer values ​​set / specified considering the delay in exchanging NAS messages via NTN. The above timer values ​​may also be set / specified to be the same as the timer values ​​for access via satellite NG-RAN cell during NAS operation / procedure (for example, 27s for T3510, 22s for T3591).

[0372] - If the timer value for the case where the MWAB accesses via satellite NG-RAN cell during NAS operation / procedure should be used (or the MWAB is connected / attached via satellite NG-RAN cell), the MWAB may provide this information to the UE and / or the UE's serving core network. Alternatively, this information may indicate whether the timer value for the case where the MWAB accesses via satellite NG-RAN cell during NAS operation / procedure should be used, or whether the timer value for the case where the MWAB accesses via satellite NG-RAN cell is not to be used (this may mean a timer value set / specified without considering the delay due to NAS message exchange via NTN - for example, 15s for T3510, 16s for T3591).

[0373] f) NTN-related timer values ​​to be used during NAS operations / procedures:

[0374] - The above timer values ​​may be timer values ​​set / specified taking into account delay when exchanging NAS messages via NTN.

[0375] g) Information regarding the number of retries for NAS operations / procedures (whether the number of NAS operation / procedure retries should be increased compared to the previous number):

[0376] - If the number of NAS operation / procedure retries should be increased compared to the previous number, the MWAB may provide this information to the UE and / or the UE's serving core network. Alternatively, this information may indicate whether the number of NAS operation / procedure retries should be increased compared to the previous number or should be operated at the previous number. The number of NAS operation / procedure retries may be provided together with this information. The number of NAS operation / procedure retries increased compared to the previous number may be applied instead of using NTN-related timer(s) (which are the timers described in d), e), and f) above) during the NAS operation / procedure, or may be applied simultaneously with the use of NTN-related timer(s).

[0377] In the case of the above e) and f), it can be interpreted that the timers are defined separately from the existing timers and values ​​are specified / set for each.

[0378] In the above a) to f), the mobile base station (e.g., MWAB) may mean MWAB-gNB, MWAB-UE, base station, cell, mobile cell, Rel-19 mobile cell, MWAB cell, NG-RAN, gNB, mobile gNB, etc., or may be interpreted as a collective term for these terms.

[0379] When the MWAB is connected / accessed via a satellite NG-RAN cell, the MWAB may provide network-related information (e.g., information related to the backhaul network) to the UE and / or the UE's serving core network. In this case, when the MWAB is connected / accessed via the satellite NG-RAN cell and then moves to a TN NG-RAN cell and connects / accesses to the TN NG-RAN cell, the MWAB may stop providing information related to the backhaul network. By stopping the MWAB from providing information related to the backhaul network, the MWAB may notify the UE and / or the UE's serving core network that it is no longer connected / accessed via the satellite NG-RAN cell.

[0380] In some implementations, the MWAB may recognize / determine that it is connected / attached via a satellite NG-RAN cell based on one or more of the methods below. The following also describes how the MWAB obtains / determines backhaul network-related information. The methods below may be used in combination. Furthermore, backhaul network-related information may be determined by various methods and combinations of methods, such that some of the backhaul network-related information may be obtained / determined by method A) and / or other portions may be obtained / determined by method B).

[0381] A) The MWAB-UE may recognize and / or determine that the MWAB-UE is connected / accessed via a satellite NG-RAN cell (i.e., an NTN cell). The MWAB-UE may provide information related to the connection / access via a satellite NG-RAN cell (i.e., an NTN cell) to the MWAB-gNB. For example, the MWAB-UE may provide information related to the backhaul network (e.g., at least one of a to g) to the MWAB-gNB. For example, the timer value of e) and / or the timer value of f) may be set in the MWAB-UE, or the MWAB-UE may receive the timer value of e) and / or the timer value of f) from a network (e.g., AMF, PCF, etc.).

[0382] A base station (e.g., BH-gNB) of a backhaul network can transmit system information to the MWAB-UE. Based on the system information transmitted by the BH-gNB, the MWAB-UE can determine whether the MWAB-UE is connected / accessed to an NTN cell. For example, the system information may be SIB1 and / or SIB19. For example, in the case of SIB1, if SIB1 includes cellBarredNTN, the MWAB-UE can determine that the cell it is connected / accessed to is an NTN cell. The cellBarredNTN may be included in SIB1 to inform the UE whether the cell providing this information allows the UE to connect to the NTN. In addition, the MWAB-UE can obtain detailed information related to the NTN (e.g., NTN ephemeris, etc.) based on SIB19.

[0383] Based on the MWAB-UE being authorized by the network, the MWAB-gNB can be provided with information related to the MWAB-UE connecting / accessing via a satellite NG-RAN cell (i.e., NTN cell).

[0384] B) The MWAB-gNB may receive (or be provided with) information from the OAM server regarding whether the MWAB is connected / accessed via a satellite NG-RAN cell (i.e., NTN cell). The OAM server may determine whether the MWAB is connected / accessed via a satellite NG-RAN cell (i.e., NTN cell) based on the location information of the MWAB. For example, the OAM server may provide the MWAB-gNB with information regarding the aforementioned backhaul network.

[0385] C) The MWAB can determine whether the MWAB is connected / accessed via a satellite NG-RAN cell (i.e., an NTN cell) based on the MWAB's location. To this end, a mapping and / or configuration may exist for determining whether the MWAB is an NTN cell or not based on the MWAB's location. For example, a mapping and / or configuration may exist for determining whether a certain area (e.g., an area based on coordinate information) is associated with an NTN cell or not. Information related to the backhaul network may also be configured in the MWAB-gNB or the MWAB.

[0386] D) The MWAB can determine whether the MWAB is connected / accessed via a satellite NG-RAN cell (e.g., an NTN cell) based on the global RAN Node ID and / or cell Id and / or TAI to which the MWAB is connected. For example, the MWAB can receive global RAN Node ID and / or cell Id and / or TAI list information on which the satellite NG-RAN cell is used from the OAM server. The MWAB can determine whether the MWAB is connected / accessed via a satellite NG-RAN cell (e.g., an NTN cell) based on the global RAN Node ID and / or cell Id and / or TAI list information on which the satellite NG-RAN cell is used received from the OAM server and the global RAN Node ID and / or cell Id and / or TAI to which the MWAB is connected. Alternatively, the global RAN Node ID and / or cell Id and / or TAI list information on which the satellite NG-RAN cell is used may be preconfigured in the MWAB.

[0387] In the above A), B), C), and D), the information indicating that the MWAB-UE (or MWAB) is connected / accessed via a satellite NG-RAN cell (e.g., NTN cell) may be interpreted as information corresponding to a) among the information related to the backhaul network.

[0388] Below, an example of a procedure to which the implementation of the present specification is applied is described with reference to FIG. 12.

[0389] 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.

[0390] Figure 12 is an example of a procedure to which the implementation of this specification is applied.

[0391] MWAB can be in a non-roaming or roaming state.

[0392] In the example of FIG. 12, the backhaul network may include a base station (e.g., BH-gNB), a network entity related to mobility (e.g., BH AMF), a network entity related to sessions (e.g., BH SMF), and a network entity related to the user plane (e.g., BH UPF).

[0393] The serving network of the UE may be a network serving a UE served by the MWAB (e.g., the leftmost UE in FIG. 12). The serving network of the UE may include network entities related to mobility (e.g., AMF) and network entities related to sessions (e.g., SMF).

[0394] Although Figure 12 illustrates a PLMN (e.g., a backhaul network or a serving network of a UE), this is merely an example. HPLMN (e.g., a home network) and / or VPLMN (e.g., a visited network) may also be NPNs. This can be applied throughout this specification.

[0395] 1. The MWAB-UE can register with the network. For example, the MWAB-UE can perform the registration procedure according to the examples in FIGS. 5 and 6 . In FIG. 12 , it is assumed that the MWAB-UE connects / accesses to the network via an NTN cell. (See, for example, the architectures in FIGS. 10 and 11 .)

[0396] Although not illustrated in Figure 12, the MWAB-UE may form (or create) Backhaul PDU Session(s) with the BH SMF. The MWAB-UE may establish some or all of the BH PDU Session(s) before step 2, and / or in parallel with step 2, and / or after step 2.

[0397] MWAB-gNB can perform NG Setup (i.e., N2 Setup) process to AMF using Backhaul PDU Session(s). At this time, MWAB-gNB can transmit NG Setup Request message containing information related to Backhaul network to AMF.

[0398] For example, information related to the backhaul network transmitted by the MWAB-gNB may include the cell id, TAI information, and / or RAT information of the MWAB-UE. Information such as the cell id, TAI information, and / or RAT information of the MWAB-UE may also be included in the form of the User Location Information of the MWAB-UE or an extended form of the User Location Information form.

[0399] For another example, information related to the backhaul network transmitted by the MWAB-gNB may include one or more pieces of information related to the satellite access type according to the example in Table 3.

[0400] For another example, information related to the backhaul network transmitted by the MWAB-gNB may include one or more of the information a) to g) described above.

[0401] If there is a change in information related to the backhaul network after NG Setup is completed, MWAB may provide updated information by sending a RAN Configuration Update message to AMF.

[0402] 2. The MWAB-UE can provide network-related information to the MWAB-gNB. For example, the network-related information may be information related to the backhaul network.

[0403] For example, an MWAB-UE may recognize / determine that the MWAB is connected / accessed via a satellite NG-RAN cell. The MWAB-UE may obtain and / or determine network-related information (e.g., information related to the backhaul network).

[0404] For example, based on one or more of methods A), B), C), and / or D), the MWAB can recognize / determine that the MWAB is connected / accessed via a satellite NG-RAN cell, and can obtain / determine information related to the backhaul network.

[0405] When the method A) described above is used, the message of step 2 of FIG. 12 may be transmitted. The message of step 2 (e.g., the message transmitted by the MWAB-UE to the MWAB-gNB) may be transmitted in response to a request from the MWAB-gNB. Alternatively, the message of step 2 (e.g., the message transmitted by the MWAB-UE to the MWAB-gNB) may be in the form of a notification / information message indicating that the MWAB-UE has completed registration with the network and / or establishment of a BH PDU Session.

[0406] 3. The MWAB can transmit network-related information to the UE. For example, the network-related information may be information related to the backhaul network.

[0407] i) For example, the MWAB-gNB may transmit information related to the backhaul network to the UE. The information related to the backhaul network may include at least one of a) to g). For example, the MWAB-gNB may transmit information related to the backhaul network to the UE using system information and / or dedicated signaling.

[0408] 4. The UE can send a Registration Request message to perform registration with the network.

[0409] NAS operations / procedures may include registration procedures, and / or PDU session establishment procedures. The UE may decide whether to use and / or apply NTN-related timers for NAS operations / procedures.

[0410] For example, the UE's decision whether to use and / or apply a NTN-related timer may be interpreted as the UE determining whether the backhaul / underlay network (e.g., the network involved in the backhaul PDU session of the MWAB-UE) passes through the NTN. The UE may make this decision based on information related to the backhaul network, etc. The UE may decide whether to use and / or apply a NTN-related timer for an NAS operation / procedure. In this case, the UE may initiate a NTN-related timer related to a registration operation / procedure (or a NTN-related timer related to initiating a registration operation / procedure, or a NTN-related timer upon transmitting a Registration Request message) (e.g., extended T3510).

[0411] For reference, as explained above, in the disclosure of this specification, the NTN-related timer (or NTN-related timer(s)) may also be referred to as a timer(s) considering delay, an extended timer(s), a longer timer(s), or a Timer For access via MWAB connected to satellite. However, these names are merely examples, and the scope of the disclosure of this specification is not limited thereto.

[0412] ii) The UE may also include information related to the Backhaul network in the Registration Request message.

[0413] iii) When the MWAB-gNB transmits a Registration Request message to the AMF, it may also transmit an N2 message containing information related to the backhaul network to the AMF. Information related to the backhaul network may be transmitted in the form of additional ULI information, or a new IE / parameter may be defined and transmitted.

[0414] 5. AMF can send a Registration Accept message to the UE.

[0415] When the UE receives the Registration Accept message, it can stop the timer (e.g., extended T3510) started in step 4.

[0416] The AMF may determine whether to use / apply NTN-related timers for NAS operations / procedures for the UE. The AMF's determination of whether to use / apply NTN-related timers can be interpreted as the AMF determining whether the backhaul / underlay network for the UE passes through the NTN. The AMF may make this determination based on information related to the backhaul network, etc. The AMF may decide to use / apply NTN-related timers. In this case, the AMF may use / apply NTN-related timers when it needs to use timers for NAS operations / procedures with the UE.

[0417] For example, although not shown in Fig. 12, the AMF may need to receive a Registration Complete message from the UE. If the AMF decides to use / apply an NTN-related timer for NAS operation / procedure, it may start an NTN-related timer related to the registration operation / procedure (or an NTN-related timer related to sending a Registration Accept message or an NTN-related timer related to waiting for a Registration Complete message) (e.g., extended T3550). Afterwards, when the AMF receives a Registration Complete message from the UE, it may stop the timer it started (e.g., extended T3550).

[0418] iv) The AMF may include information related to the backhaul network received from the MWAB-gNB in ​​the Registration Accept message. For example, the AMF may send the Registration Accept message containing information related to the backhaul network to the UE. The UE may not have received information related to the backhaul network from the MWAB. In this case, the UE may use a TN-related timer (e.g., a timer other than the NTN-related timer) (e.g., T3510 with 15 s) instead of the NTN-related timer in step 4. After the UE receives information related to the backhaul network from the AMF, the UE may use the NTN-related timer(s).

[0419] 6. The UE can send a PDU session establishment request message.

[0420] For example, the UE may send a PDU Session Establishment Request message to the AMF to form (or establish or create) a PDU Session.

[0421] In this case, the UE may decide whether to use / apply NTN-related timers for NAS operations / procedures. The UE's decision to use / apply NTN-related timers may be interpreted as the UE determining whether the backhaul / underlay network passes through NTN. The UE may make this decision based on backhaul network-related information, etc. If the UE decides to use / apply NTN-related timers for NAS operations / procedures, it may initiate NTN-related timers related to PDU Session establishment operations / procedures (or NTN-related timers based on initiating PDU Session establishment operations / procedures, or NTN-related timers based on transmitting a PDU Session Establishment Request message) (e.g., extended T3580).

[0422] v) The UE may also include information related to the Backhaul network in the PDU Session Establishment Request message.

[0423] vi) The UE may include information related to the backhaul network in the MM NAS message including the PDU Session Establishment Request message.

[0424] vii) When the MWAB-gNB transmits a PDU Session Establishment Request message to the AMF, it may include information related to the backhaul network in the N2 message. Information related to the backhaul network may be transmitted in the form of additional ULI information or a new IE / parameter may be defined and transmitted.

[0425] 7. AMF can send a PDU Session Establishment Request message to SMF.

[0426] viii) When the AMF transmits a PDU Session Establishment Request message to the SMF, it may transmit information related to the backhaul network to the SMF. This information related to the backhaul network may be what the AMF obtained in step 1, and / or what the AMF obtained in step 4, and / or what the AMF obtained in step 6. When the AMF performs the operation of transmitting the information related to the backhaul network to the SMF, the operation of reporting the conventional backhaul category change may be reused, or it may be interpreted that separate indication / information (e.g., underlay network category change) is transmitted.

[0427] 8. SMF can respond to AMF.

[0428] The SMF may determine whether to use / apply NTN-related timers for NAS operations / procedures for the UE. The SMF's determination of whether to use / apply NTN-related timers can be interpreted as the SMF determining whether the backhaul / underlay network for the UE passes through the NTN. The SMF may make this determination based on backhaul network-related information, etc. The SMF may decide to use / apply NTN-related timers. In this case, if the SMF uses timers for NAS operations / procedures with the UE, the SMF may use / apply NTN-related timers.

[0429] Additionally, the SMF can also transmit a backhaul category change (or underlay network category change) to the PCF. This action can be based on the existing "Satellite backhaul category change" PCRT, or a new PCRT (e.g., "Underlay network category change") can be defined and used. The PCF can consider these events when determining QoS for the terminal.

[0430] 9. SMF can forward a message to AMF. For example, the message can be a message for N1N2 message transfer (e.g., Namf_Communication_N1N2MessageTransfer).

[0431] For example, the SMF may send a message to the AMF containing a PDU Session Establishment Accept message and N2 SM information for creating PDU Session related resources at the base station.

[0432] 10. AMF may send a PDU Session Establishment Acceptance message to the UE.

[0433] For example, the AMF may send an N2 message containing a message received from the SMF (e.g., a PDU Session Establishment Accept message) to the MWAB-gNB. The MWAB-gNB may then send a PDU Session Establishment Accept message to the UE.

[0434] When the UE receives the PDU Session Establishment Accept message, the UE may stop any timer (e.g., NTN related timer(s)) (e.g., extended T3580) that it started in step 6.

[0435] In the description referring to FIG. 12, at least one of the operations described in i) to viii) may be performed. For example, all of the operations in i) to viii) may be performed, only one of the operations in i) to viii) may be performed, or two or more of the operations in i) to viii) may be performed in combination.

[0436] For example, among the operations described in i) to viii), which operation to perform may be determined based on the operator's deployment, implementation, operator's policies / settings, etc. However, these operations can ultimately be understood as operations performed to enable the UE, and / or the AMF, and / or the SMF to obtain information related to the backhaul network.

[0437] For example, i), ii), and v) may be performed so that at least one of the UE, the AMF, and / or the SMF may obtain information related to the backhaul network. For another example, i), iii), vii), and viii) may be performed so that at least one of the UE, the AMF, and / or the SMF may obtain information related to the backhaul network.

[0438] The MWAB may connect / access through an NTN cell and then move to a TN cell to connect / access. Alternatively, the MWAB may connect / access through a TN cell and then move to an NTN cell to connect / access. In at least one of these two cases, the MWAB-UE may provide the MWAB-gNB with information related to the change of the cell to which the MWAB is connected (the change between the NTN cell and the TN cell). The MWAB-gNB may also provide the UE, the AMF, and the SMF with information related to the change of the cell to which the MWAB is connected (the change between the NTN cell and the TN cell). The mobile base station may explicitly or implicitly notify information related to such changes in various ways, such as by providing information related to the backhaul network, and / or by providing and then stopping information related to the backhaul network, and / or by not providing and then providing information related to the backhaul network.

[0439] In some implementations, the UE may be aware of and / or determine a change between an NTN cell and a TN cell in the underlay network (and / or backhaul network). In this case, the UE may notify the AMF of the change between an NTN cell and a TN cell in the underlay network (and / or backhaul network).

[0440] In some implementations, the AMF may be aware of and / or determine a change between an NTN cell and a TN cell in the underlay network (and / or backhaul network). In this case, the AMF may notify the UE and / or SMF of the change between an NTN cell and a TN cell in the underlay network (and / or backhaul network).

[0441] According to one embodiment of the disclosure of the present specification, the UE, and / or the AMF, and / or the SMF may determine whether to use NTN related timer(s) based on information related to the network (e.g., information related to the Backhaul network).

[0442] For reference, in the example of FIG. 12, the Registration operation / procedure and the PDU Session Establishment operation / procedure are illustrated and described as NAS operations / procedures. However, the scope of the disclosure of this specification is not limited to the Registration operation / procedure and the PDU Session Establishment operation / procedure. It can be understood that the contents described with reference to the example of FIG. 12 also apply to other NAS operations / procedures.

[0443] 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.

[0444] FIG. 13 illustrates an example of a procedure performed according to one embodiment of the disclosure of the present specification.

[0445] For reference, the procedure illustrated in FIG. 13 is merely an example, and the scope of the disclosure of this specification is not limited by the example in FIG. 13.

[0446] For example, with respect to the example of FIG. 13, the operations described in the examples of FIGS. 1 to 12 may also be applied. For example, even if operations, contents, etc. are not directly described in the example of FIG. 12, operations, contents, etc. described in various examples of the disclosure of this specification may be applied.

[0447] According to the example of Fig. 13, a mobile base station may include a UE and a base station. The UE included in the mobile base station of Fig. 13 may also perform a relay role, allowing the mobile base station to provide services as a mobile base station to the UEs it serves.

[0448] In the example of FIG. 13, the UE of the mobile base station (e.g., a UE included in the mobile base station) and the base station (e.g., a base station included in the mobile base station) may be referred to as MWAB-UE and MWAB-gNB, respectively.

[0449] In the example of Figure 13, the network entity may be, for example, a network entity related to mobility. For example, the network entity managing mobility may be AMF.

[0450] In the example of Figure 13, the network entity may be, for example, a network entity involved in a session. For example, the network entity managing the session may be an SMF.

[0451] For reference, before step (S1301) is performed, the mobile base station (e.g., the UE of the mobile base station) can establish a backhaul PDU session to support the mobile base station operation.

[0452] In step (S1301), the mobile base station (e.g., the base station of the mobile base station) can transmit network-related information to the UE.

[0453] For example, information related to a network may be information related to a backhaul network.

[0454] In step (S1302), the UE may transmit a NAS message to a network entity. For example, the UE may transmit the NAS message to the network entity via a base station of a mobile base station.

[0455] After the NAS message is transmitted, a timer for access via a mobile base station connected to the satellite may be initiated based on information related to the backhaul network. This timer may be an NTN-related timer described in various examples of the disclosure herein.

[0456] For example, information related to a backhaul network may include one or more of the information a) to g) of the disclosure of this specification.

[0457] In some implementations, the information related to the backhaul network may include one or more of: information related to whether the mobile base station is connected to the network via a satellite cell; information related to whether the backhaul network is a network based on a Non Terrestrial Network (NTN); information related to whether the timer should be used for an operation related to NAS; a timer value related to the NTN for an operation related to NAS; and / or information related to the number of retries of an operation related to NAS.

[0458] In some implementations, the NAS message may also include information related to the backhaul network of the mobile base station.

[0459] In some implementations, information related to the backhaul network may be transmitted by the base station of the mobile base station to the network entity related to the mobility.

[0460] The backhaul network may be a network related to a backhaul PDU session established by the UE of the mobile base station.

[0461] In some implementations, the UE may receive a response message to the NAS message. Based on the reception of the response message, the timer may be stopped.

[0462] In some implementations, the network entity may also send a second NAS message to the UE.

[0463] For example, after the second NAS message is transmitted, based on information related to the backhaul network of the mobile base station serving the UE, the network entity may initiate a timer for access via the mobile base station connected to satellite.

[0464] In some implementations, the UE may also send a response message to the second NAS message to the network entity. In this case, a timer initiated by the network entity may be stopped based on the reception of the response message.

[0465] In some implementations, based on the network entity being a network entity related to mobility, the NAS message of step (S1302) may be a registration request message and the second NAS message may be a registration acceptance message.

[0466] In some implementations, based on the network entity being a network entity involved in the session, the second NAS message may be a PDU Session Modification Command message.

[0467] In some implementations, a network entity may obtain information related to the backhaul network.

[0468] For example, information related to the backhaul network may be obtained based on an NAS message received from the UE. For example, the NAS message may include information related to the backhaul network.

[0469] For example, information related to the backhaul network may be obtained based on an NG setup request message or a RAN Configuration Update message received from the mobile base station. For example, the mobile base station may transmit an NG setup request message or a RAN Configuration Update message containing information related to the backhaul network to a network entity.

[0470] For example, based on the network entity being a network entity involved in a session, information related to the backhaul network may be obtained from the network entity involved in mobility. For example, when the network entity involved in mobility transmits a PDU session establishment request message to the network entity involved in the session, information related to the backhaul network may also be transmitted to the network entity involved in the session.

[0471] In some implementations, if the backhaul network of the MWAB is an NTN, NAS operations and / or procedures may be performed for UEs served through this MWAB. In this case, the UE, AMF, and SMF may utilize NTN-related timer(s).

[0472] In some implementations, the backhaul network of an MWAB may be changed from an NTN to a TN. In this case, NAS operations and / or procedures for UEs served through this MWAB may be performed. In this case, the UE, AMF, and SMF may not use NTN-related timers(s). Not using NTN-related timers may be interpreted as using normal / TN-related timers(s). Alternatively, not using NTN-related timers may be interpreted as using timers(s) that take into account the case where the MWAB is connected / accessed through a TN cell.

[0473] This specification may have various effects.

[0474] Methods for effectively managing mobile base stations can be supported.

[0475] For example, communication based on a connection between a UE and a mobile base station can be effectively supported.

[0476] For example, when an MWAB connects / accesses to a network via an NTN, communication and / or services can be effectively provided to a UE connected / accessed to the network via such MWAB. For example, a UE receiving (served by) a service from such MWAB can use a timer value that takes NTN into account. For example, when such a UE performs an NAS operation and / or procedure, unnecessary retries / failures of NAS operation / procedure / message transmission can be minimized by the UE using a timer value that takes NTN into account.

[0477] 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.

[0478] For reference, the operation of the terminal (e.g., UE, UE of mobile base station, MWAB-UE) described in this specification can be implemented by the devices of FIGS. 1 to 3 described above. For example, the terminal can be the first device (100) or the second device (200) of FIG. 2. For example, the operation of the terminal (e.g., UE) described in this specification can be processed by one or more processors (102 or 202). The operation of the terminal described in this specification can 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 (105 or 206), and execute instructions / programs stored in one or more memories (104 or 204) to perform operations of a terminal (e.g., UE) described in the disclosure of this specification.

[0479] 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 (e.g., UE) described in the disclosure of this specification.

[0480] For reference, the operation of a network node (e.g., AMF, SMF, UPF, PCF, V-UPF, UDM, etc.) or a base station (e.g., mobile base station, MWAB, MWAB-gNB, NG-RAN, gNB, BH-gNB, BH-5GC, BH AMF, BH UPF, BH SMF, etc.) described in this specification may be implemented by the devices of FIGS. 1 to 3 described below. For example, the network node or base station may be the first device (100) or the second device (200) of FIG. 2. For example, the operation of a network node or base station described in this specification may be processed by one or more processors (102 or 202). The operation of a 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.

[0481] 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.

[0482] Although the preferred embodiments have been described above by way of example, the disclosure of this specification is not limited to these specific embodiments, and may be modified, changed, or improved in various forms within the scope of the spirit and claims of this specification.

[0483] 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.

[0484] 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 information related to a backhaul network from a base station of a mobile base station; and Comprising a step of transmitting a Non Access Stratum (NAS) message to a network entity related to mobility via a base station of the mobile base station, A method in which, after the above NAS message is transmitted, a timer for access via a mobile base station connected to satellite is started based on information related to the backhaul network.

2. In paragraph 1, Information related to the above backhaul network: Information regarding whether the above mobile base station is connected to the network via a satellite cell; Information regarding whether the above backhaul network is a network based on a Non Terrestrial Network (NTN); Information regarding whether the above timer should be used for NAS-related operations; A timer value related to NTN for an operation related to the above NAS; and / or A method comprising one or more pieces of information related to the number of retries of an operation related to the NAS.

3. In paragraph 1 or 2, A method wherein the NAS message includes information related to the backhaul network of the mobile base station.

4. In paragraph 1 or 2, A method in which information related to the backhaul network is transmitted to a network entity related to the mobility by a base station of the mobile base station, 5. In any one of paragraphs 1 to 4, The above backhaul network is a method in which a network is related to a backhaul Protocol Data Unit (PDU) session established by a User Equipment (UE) of the mobile base station.

6. In any one of paragraphs 1 to 5, Further comprising the step of receiving a response message to the NAS message, A method wherein the timer is stopped based on the reception of the above response message.

7. At least one transmitter / receiver; at least one processor; and comprising one or more memories capable of storing instructions and being operable to the one or more processors; A device wherein at least one processor is adapted to perform a method according to any one of claims 1 to 6.

8. At least one processor; and At least one memory storing instructions and being operably electrically connected to the at least one processor, An apparatus, wherein at least one processor is adapted to perform a method according to any one of claims 1 to 6.

9. A non-transitory computer-readable medium (CRM) that records commands, The above instructions, when executed by one or more processors, cause the one or more processors to perform a method according to any one of claims 1 to 6. CRM.

10. A step in which a network entity receives a first Non Access Stratum (NAS) message from a User Equipment (UE); and The network entity comprises a step of transmitting a second NAS message to the UE, A method in which, after the second NAS message is transmitted, a timer for access via a mobile base station connected to satellite is started based on information related to the backhaul network of the mobile base station serving the UE.

11. In paragraph 10, Information related to the above backhaul network: Information regarding whether the above mobile base station is connected to the network via a satellite cell; Information regarding whether the above backhaul network is a network based on a Non Terrestrial Network (NTN); Information regarding whether the above timer should be used for NAS-related operations; A timer value related to NTN for an operation related to the above NAS; and / or A method comprising one or more pieces of information related to the number of retries of an operation related to the NAS.

12. In paragraph 10 or 11, Based on the above network entity being a network entity related to mobility, the first NAS message is a registration request message, The method wherein the second NAS message is a registration acceptance message.

13. In any one of paragraphs 10 to 12, A method wherein the first NAS message is a Protocol Data Unit (PDU) session modification request message and the second NAS message is a PDU session modification command message, based on the network entity being a network entity related to a session.

14. In any one of paragraphs 10 to 13, A method in which information related to the above backhaul network is obtained from the UE or the mobile base station.

15. In any one of paragraphs 10 to 14, A method, wherein the network entity further comprises a step of obtaining information related to the backhaul network.

16. In paragraph 15, A method in which information related to the above backhaul network is obtained based on the first NAS message.

17. In paragraph 15, A method in which information related to the above backhaul network is obtained based on an NG setup request message or a RAN Configuration Update message received from the mobile base station.

18. In paragraph 15, A method in which information related to the backhaul network is obtained from a network entity related to mobility, based on the network entity being a network entity related to a session.

19. In any one of paragraphs 10 to 14, Further comprising the step of receiving a response message to the second NAS message from the UE, A method wherein the timer is stopped based on the reception of the above response message.

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; A device wherein at least one processor is adapted to perform a method according to any one of claims 10 to 19.

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