Xn setting method of mwab

Abstract

A method is provided in one embodiment of the present disclosure. The method comprises steps in which: a UE of a specific MWAB transmits a registration request message to a network; the UE of the specific MWAB receives a registration approval message from the network; the UE of the specific MWAB transmits an establishment request message of a PDU session to the network; the UE of the specific MWAB receives an approval message of the PDU session from the network; and a gNB of the specific MWAB performs an Xn connection establishment procedure with a first base station through the PDU session, wherein the step of performing the Xn connection establishment procedure comprises a step in which the gNB of the specific MWAB transmits mobility information of the specific MWAB to the first base station.

Description

How to set up XN in MWAB

[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 in a timely manner, meeting both urgent market needs and the longer-term requirements outlined by the ITU-R (ITU radio communication sector) International Mobile Telecommunications (IMT)-2020 process. NR must also be able to utilize any spectrum band up to at least 100 GHz, ensuring that it remains available for wireless communications well into the future.

[0004] NR aims to be a single technology framework that addresses all deployment scenarios, usage scenarios, and requirements, including enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable and low latency communications (URLLC). NR must be inherently forward-compatible.

[0005] How to set Xn of MWAB is required.

[0006] MWAB transmits its mobility information to the opposing base station during the Xn setup procedure.

[0007] Figure 1 illustrates an example of a communication system to which the implementation of this specification is applied.

[0008] Figure 2 illustrates an example of a wireless device to which the implementation of the present specification is applied.

[0009] Figure 3 shows an example of a UE to which the implementation of this specification is applied.

[0010] Figure 4 is a structural diagram of a next-generation mobile communications network.

[0011] Figure 5 shows an example of a 5G system structure to which the implementation of this specification is applied.

[0012] Figures 6 and 7 illustrate examples of registration procedures to which the implementation of the present specification applies.

[0013] Figures 8 and 9 illustrate examples of a PDU session establishment procedure to which the implementation of the present specification applies.

[0014] Figure 10 shows an example of the architecture of MWAB.

[0015] Figure 11 shows an example of the architecture in a non-roaming scenario of MWAB.

[0016] Figure 12 shows an example of the architecture in a roaming scenario of MWAB.

[0017] Figure 13 shows an example of a successful Xn setup operation.

[0018] Figure 14 shows an example of a failure of the Xn setup operation.

[0019] Fig. 15 shows an example of Xn settings according to the first embodiment of the present specification.

[0020] Fig. 16 shows an example of Xn settings according to the second embodiment of the present specification.

[0021] Figure 17 illustrates the procedure of the AMF of HPLMN for the disclosure of this specification.

[0022] Figure 18 illustrates the procedure of a base station for the disclosure of this specification.

[0023] Figure 19 illustrates the procedure of a base station for the disclosure of this specification.

[0024] 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 multicarrier frequency division multiple access (MC-FDMA) systems. CDMA can be implemented via wireless technologies such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA can be implemented via 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 E-UTRA (evolved UTRA). UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long-term evolution) is part of E-UMTS (evolved UMTS) that uses 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).

[0025] 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.

[0026] 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.

[0027] 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."

[0028] 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."

[0029] 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.”

[0030] 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”.

[0031] 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."

[0032] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0033] 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).

[0034] 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.

[0035] Figure 1 illustrates an example of a communication system to which the implementation of this specification is applied.

[0036] 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.

[0037] 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).

[0038] 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.

[0039] 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.

[0040] Wireless devices (100a to 100f) refer to 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. Wireless devices (100a to 100f) may include, but are not limited to, robots (100a), vehicles (100b-1 and 100b-2), extended reality (XR) devices (100c), portable devices (100d), home appliances (100e), IoT devices (100f), and artificial intelligence (AI) devices / servers (400). For example, vehicles may include vehicles having wireless communication capabilities, autonomous vehicles, and vehicles capable of performing vehicle-to-vehicle communication. Vehicles may include unmanned aerial vehicles (UAVs) (e.g., drones). XR devices may include AR / VR / mixed reality (MR) devices, and may be implemented in the form of head-mounted devices (HMDs) and heads-up displays (HUDs) 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.

[0041] 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 functions, a connected car, a UAV, an AI module, a robot, an AR device, a VR device, an MR device, a holographic 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.

[0042] For example, a UAV may be an aircraft that is unmanned and navigated by radio control signals.

[0043] For example, a VR device may include a device for implementing objects or backgrounds in a virtual environment. For example, an AR device may include a device that implements objects or backgrounds in a virtual world by connecting them to objects or backgrounds in the real world. For example, an MR device may include a device that implements objects or backgrounds in a virtual world by merging them with objects or backgrounds in the real world. For example, a holographic device may include a device that implements 360-degree stereoscopic images by recording and reproducing three-dimensional information using the light interference phenomenon that occurs when two laser lights, called holograms, meet.

[0044] For example, a public safety device may include an image relay device or imaging device that can be worn on the user's body.

[0045] For example, MTC devices and IoT devices may be devices that do not require direct human intervention or manipulation. Examples include smart meters, vending machines, thermometers, smart light bulbs, door locks, or various sensors.

[0046] For example, a medical device may be a device used for the purpose of diagnosing, treating, alleviating, curing, or preventing a disease. For example, a medical device may be a device used for diagnosing, treating, alleviating, or correcting an injury or damage. For example, a medical device may be a device used for the purpose of examining, replacing, or modifying a structure or function. For example, a medical device may be a device used for the purpose of regulating pregnancy. For example, a medical device may include a therapeutic device, a driving device, an (in vitro) diagnostic device, a hearing aid, or a surgical device.

[0047] For example, a security device may be a device installed to prevent potential hazards and maintain safety. For example, a security device may be a camera, closed-circuit television (CCTV), a recorder, or a black box.

[0048] For example, a fintech device may be a device capable of providing financial services, such as mobile payments. For example, a fintech device may include a payment device or a point-of-sale system.

[0049] For example, a weather / environment device may include a device that monitors or predicts the weather / environment.

[0050] 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).

[0051] 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, device-to-device (D2D) communication), and base station-to-base station communication (150c) (e.g., relay, integrated access and backhaul (IAB)). 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.

[0052] AI is the study of artificial intelligence or the methodologies for creating it, while machine learning (ML) defines various problems in the field of AI and studies the methodologies for solving them. Machine learning is also defined as an algorithm that improves performance on a task through consistent experience.

[0053] A robot can be defined as a machine that automatically processes or operates a given task based on its own capabilities. Specifically, a robot capable of perceiving its environment, making decisions, and performing actions on its own can be called an intelligent robot. Robots can be categorized into industrial, medical, household, and military applications based on their intended use or field. Robots are equipped with a drive unit, including an actuator or motor, enabling them to perform various physical actions, such as moving robot joints. Furthermore, mobile robots include wheels, brakes, and propellers in their drive unit, enabling them to drive on the ground or fly in the air.

[0054] Autonomous driving refers to the technology of driving on one's own, while autonomous vehicles refer to vehicles that drive without, or with minimal, user intervention. For example, autonomous driving can include technologies such as lane keeping, automatic speed control like adaptive cruise control, autonomous driving along a set route, and autonomous driving based on a set destination. Vehicles encompass all types of vehicles: those with internal combustion engines, hybrid vehicles with both internal combustion engines and electric motors, and electric vehicles with only electric motors. These vehicles can include not only cars but also trains and motorcycles. Autonomous vehicles can be viewed as robots with autonomous driving capabilities.

[0055] Extended reality is a general term for VR, AR, and MR. VR technology provides real-world objects and backgrounds as CG images only, AR technology provides virtual CG images over images of real objects, and MR technology is a CG technology that mixes and combines virtual objects with the real world. MR technology is similar to AR in that it displays real and virtual objects together. However, there is a difference: while AR uses virtual objects to complement real objects, MR uses virtual and real objects equally.

[0056] NR supports multiple numerologies, or subcarrier spacing (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.

[0057] 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 NR systems, FR1 can mean the "sub-6GHz range," and FR2 can mean the "above 6GHz range," which can be referred to as millimeter wave (mmW).

[0058] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0059] 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).

[0060] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0061] 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 PAN (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.

[0062] Figure 2 illustrates an example of a wireless device to which the implementation of the present specification is applied.

[0063] 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.

[0064] 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).

[0065] 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).

[0066] 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).

[0067] 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.

[0068] 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.

[0069] 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).

[0070] 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).

[0071] 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).

[0072] 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 instruction codes, commands 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0077] 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.

[0078] 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 specification, one or more antennas (108, 208) may be multiple physical antennas or multiple logical antennas (e.g., antenna ports).

[0079] 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).

[0080] 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.

[0081] In the implementation of the present specification, a UE can operate as a transmitter in the uplink (UL) and as a receiver in the downlink (DL). In the implementation of the present 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 the present specification or to control a transceiver (106) to perform UE operations according to the implementation of the present 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 the present specification or to control a transceiver (206) to perform base station operations according to the implementation of the present specification.

[0082] In this specification, a base station may be referred to as a Node B, an eNode B (eNB), or a gNB.

[0083] Figure 3 shows an example of a UE to which the implementation of this specification is applied.

[0084] Referring to FIG. 3, the UE (100) can correspond to the first wireless device (100) of FIG. 2.

[0085] 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).

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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).

[0090] 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).

[0091] 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.

[0092] 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).

[0093] Figure 4 is a structural diagram of a next-generation mobile communications network.

[0094] 5GC (5G Core) may include various components, and in FIG. 5, some of them include AMF (Access and Mobility Management Function) (410), SMF (Session Management Function) (420), PCF (Policy Control Function) (430), UPF (User Plane Function) (440), AF (Application Function) (450), UDM (Unified Data Management) (460), and N3IWF (Non-3GPP (3rd Generation Partnership Project) Inter Working Function) (490).

[0095] The UE (100) is connected to a data network via UPF (440) through a Next Generation Radio Access Network (NG-RAN) including a gNB (20).

[0096] The UE (100) can also receive data services via untrusted non-3GPP access, such as a Wireless Local Area Network (WLAN). To connect the non-3GPP access to the core network, an N3IWF (490) may be deployed.

[0097] The illustrated N3IWF (490) performs the function of managing interworking between non-3GPP access and 5G system. When UE (100) is connected to non-3GPP access (e.g., WiFi, referred to as IEEE 801.11), UE (100) can be connected to 5G system through N3IWF (490). N3IWF (490) performs control signaling with AMF (410) and is connected to UPF (440) through N3 interface for data transmission.

[0098] The illustrated AMF (410) can manage access and mobility in a 5G system. The AMF (410) can perform functions to manage Non-Access Stratum (NAS) security. The AMF (410) can perform functions to handle mobility in the idle state.

[0099] The illustrated UPF (440) is a type of gateway through which user data is transmitted and received. The UPF node (440) can perform all or part of the user plane functions of the S-GW (Serving Gateway) and P-GW (Packet Data Network Gateway) of 4th generation mobile communications.

[0100] The UPF (440) acts as a boundary point between the next generation radio access network (NG-RAN) and the core network, and is an element that maintains a data path between the gNB (20) and the SMF (420). In addition, when the UE (100) moves across the area served by the gNB (20), the UPF (440) acts as a mobility anchor point. The UPF (440) can perform a function of handling PDUs. For mobility within the NG-RAN (Next Generation-Radio Access Network defined after 3GPP Release-15), the UPF can route packets. Additionally, the UPF (440) may also function as an anchor point for mobility with other 3GPP networks (RANs defined before 3GPP Release-15, e.g., UTRAN, E-UTRAN (Evolved-UMTS (Universal Mobile Telecommunications System) Terrestrial Radio Access Network)) or GERAN (GSM (Global System for Mobile Communication) / EDGE (Enhanced Data rates for Global Evolution) Radio Access Network). The UPF (440) may correspond to a termination point of a data interface toward a data network.

[0101] The illustrated PCF (430) is a node that controls the business operator's policy.

[0102] The illustrated AF (450) is a server for providing various services to the UE (100).

[0103] The illustrated UDM (460) is a type of server that manages subscriber information, such as the HSS (Home Subscriber Server) of 4th generation mobile communications. The UDM (460) stores and manages the subscriber information in a Unified Data Repository (UDR).

[0104] The illustrated SMF (420) can perform the function of allocating an IP (Internet Protocol) address of the UE. In addition, the SMF (420) can control a PDU (protocol data unit) session.

[0105] For reference, the drawing symbols for AMF (410), SMF (420), PCF (430), UPF (440), AF (450), UDM (460), N3IWF (490), gNB (20), or UE (100) may be omitted below.

[0106] 5G mobile communications support multiple numerologies, or subcarrier spacing (SCS), to support diverse 5G services. For example, a 15 kHz SCS supports wide areas in traditional cellular bands. A 30 kHz / 60 kHz SCS supports dense urban environments, lower latency, and wider carrier bandwidth. An SCS of 60 kHz or higher supports bandwidths greater than 24.25 GHz to overcome phase noise.

[0107] Figure 5 shows an example of a 5G system structure to which the implementation of this specification is applied.

[0108] The 5G system (5GS; 5G system) structure consists of the following network functions (NF; Network Function).

[0109] - AUSF (Authentication Server Function)

[0110] - AMF (Access and Mobility Management Function)

[0111] - DN (Data Network), 예를 들어 운영자 서비스, 인터넷 접속 또는 타사 서비스

[0112] - USDF (Unstructured Data Storage Function)

[0113] - NEF (Network Exposure Function)

[0114] - I-NEF (Intermediate NEF)

[0115] - NRF (Network Repository Function)

[0116] - NSSF (Network Slice Selection Function)

[0117] - PCF (Policy Control Function)

[0118] - SMF (Session Management Function)

[0119] - UDM (Unified Data Management)

[0120] - UDR (Unified Data Repository)

[0121] - UPF (User Plane Function)

[0122] - UCMF (UE radio Capability Management Function)

[0123] - AF (Application Function)

[0124] - UE (User Equipment)

[0125] - (R)AN ((Radio) Access Network)

[0126] - 5G-EIR (5G-Equipment Identity Register)

[0127] - NWDAF (Network Data Analytics Function)

[0128] - CHF (CHarging Function)

[0129] Additionally, the following network features may be considered:

[0130] - N3IWF (Non-3GPP InterWorking Function)

[0131] - TNGF (Trusted Non-3GPP Gateway Function)

[0132] - W-AGF (Wireline Access Gateway Function)

[0133] Figure 5 illustrates the 5G system architecture for a non-roaming case using a reference point representation showing how various network functions interact with each other.

[0134] For clarity of the point-to-point diagram in Figure 5, UDSF, NEF, and NRF are not illustrated. However, all network functions shown can interact with UDSF, UDR, NEF, and NRF as needed.

[0135] 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.

[0136] The 5G system architecture includes the following benchmarks:

[0137] - N1: Reference point between UE and AMF.

[0138] - N2: Reference point between (R)AN and AMF.

[0139] - N3: Reference point between (R)AN and UPF.

[0140] - N4: Reference point between SMF and UPF.

[0141] - N6: Reference point between UPF and data network.

[0142] - N9: Reference point between two UPFs.

[0143] The following benchmarks illustrate the interactions that exist between NF services in NF.

[0144] - N5: Reference point between PCF and AF.

[0145] - N7: Reference point between SMF and PCF.

[0146] - N8: Reference point between UDM and AMF.

[0147] - N10: Reference point between UDM and SMF.

[0148] - N11: Reference point between AMF and SMF.

[0149] - N12: Reference point between AMF and AUSF.

[0150] - N13: Reference point between UDM and AUSF.

[0151] - N14: Reference point between two AMFs.

[0152] - N15: Reference point between PCF and AMF for non-roaming scenarios, and reference point between PCF and AMF of visited network for roaming scenarios.

[0153] - N16: Reference point between two SMFs (in case of roaming, between the SMF of the visited network and the SMF of the home network)

[0154] - N22: Reference point between AMF and NSSF.

[0155] In some cases, two NFs may need to be interconnected to serve a UE.

[0156] <Registration Procedure>

[0157] Describes the registration procedure. See section 4.2.2.2 of 3GPP TS 23.502 V16.3.0 (2019-12).

[0158] Figures 6 and 7 illustrate examples of registration procedures to which the implementation of the present specification applies.

[0159] 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:

[0160] - Initial registration for 5GS; or

[0161] - mobility registration update; or

[0162] - Periodic registration update; or

[0163] - Emergency registration

[0164] The general registration procedures of Figures 6 and 7 apply to all registration procedures described above, but periodic registration updates do not need to include all parameters used in other registration procedures.

[0165] The general registration procedures of Figures 6 and 7 can also be used when registering for a 3GPP connection when the UE is already registered for a non-3GPP connection, and vice versa. Registering for a 3GPP connection when the UE is already registered for a non-3GPP connection scenario may require an AMF change.

[0166] First, the procedure of Fig. 6 is described.

[0167] (1) Step 1: The UE transmits a Registration Request message to the (R)AN. The Registration Request message corresponds to an AN message.

[0168] 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.

[0169] A registration request message may include a registration type. The registration type indicates whether the UE wants to perform an initial registration (i.e., the UE is in RM-DEREGISTERED state), or a mobility registration update (i.e., the UE is in RM-REGISTERED state and the registration procedure is initiated because the UE moves, or the UE wants to update its capabilities or protocol parameters, or because the UE requests a change in the set of network slices it is allowed to use), or a periodic registration update (i.e., the UE is in RM-REGISTERED state and the registration procedure is initiated because the periodic registration update timer has expired), or an emergency registration (i.e., the UE is in restricted service state).

[0170] When a UE performs initial registration, the UE indicates its UE ID in the registration request message, listed in decreasing priority order.

[0171] i) If the UE has a valid evolved packet system (EPS) globally unique temporary identifier (GUTI), 5G-GUTI mapped from the EPS GUTI;

[0172] ii) Native 5G-GUTI (if available) allocated by the PLMN in which the UE is attempting to register;

[0173] iii) Native 5G-GUTI allocated by a PLMN equivalent to the PLMN in which the UE is attempting to register;

[0174] iv) Native 5G-GUTI allocated by another PLMN (if available);

[0175] v) Otherwise, the UE includes a subscriber concealed identifier (SUCI) in the registration request message.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] 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.

[0180] (2) Step 2: (R)AN selects AMF.

[0181] 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.

[0182] When the UE is in CM-CONNECTED state, (R)AN can forward a registration request message to AMF based on the UE's N2 connection.

[0183] 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.

[0184] (3) Step 3: (R)AN sends a registration request message to the new AMF. The registration request message corresponds to the N2 message.

[0185] 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.

[0186] 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.

[0187] If the registration type indicated by the UE is periodic registration update, steps 4-19 described below may be omitted.

[0188] (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.

[0189] (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.

[0190] (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.

[0191] (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).

[0192] (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.

[0193] (9) Step 9: Authentication / security can be established by UE, new AMF, AUSF and / or UDM.

[0194] (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.

[0195] (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.

[0196] (12) Step 12: Optionally, the new AMF can initiate ME ID checking by calling the N5g-eir_EquipmentIdentityCheck_Get service operation.

[0197] Now, the procedure of Fig. 7 following the procedure of Fig. 6 is described.

[0198] (13) Step 13: If step 14 below is performed, the new AMF can select a UDM based on SUPI, and the UDM can select a UDR instance.

[0199] (14) Step 14: New AMFs can be registered with UDM.

[0200] (15) Step 15: New AMF can select PCF.

[0201] (16) Step 16: The new AMF may optionally perform AM policy association establishment / modification.

[0202] (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.

[0203] (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.

[0204] (19) Step 19: N3IWF / TNGF / W-AGF may send a UE context modification response to the new AMF.

[0205] (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.

[0206] (21) Step 21: The new AMF sends a Registration Accept message to the UE.

[0207] 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.

[0208] 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.

[0209] Additionally, optionally, the new AMF performs UE policy association establishment.

[0210] (22) Step 22: If the UE successfully updates itself, it can send a Registration Complete message to the new AMF.

[0211] The UE may send a registration complete message to the new AMF to confirm that a new 5G-GUTI has been allocated.

[0212] (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.

[0213] (24) Step 24: AMF can perform information updates on UDM.

[0214] (25) Step 25: The UE may execute a network slice-specific authentication and authorization (NSSAA) procedure.

[0215] <PDU 세션 수립 절차>

[0216] Describes the PDU session establishment procedure. See Section 4.3.2 of 3GPP TS 23.502 V16.3.0 (2019-12).

[0217] Figures 8 and 9 illustrate examples of a PDU session establishment procedure to which the implementation of the present specification applies.

[0218] Establishing a PDU session may involve:

[0219] - UE-initiated PDU session establishment procedure

[0220] - PDU session handover between 3GPP and non-3GPP initiated by UE

[0221] - PDU session handover from UE-initiated EPS to 5GS.

[0222] - Network-triggered PDU session establishment procedure

[0223] A PDU session may be associated with either (a) a single connection type at a given time, i.e., either a 3GPP connection or a non-3GPP connection, or (b) multiple connection types simultaneously, i.e., one 3GPP connection and one non-3GPP connection. A PDU session associated with multiple connection types is called a multi-access (MA) PDU session and may be requested by an access traffic steering, switching, splitting (ATSS) capable UE.

[0224] Figures 8 and 9 specify the procedure for establishing a PDU session associated with a single connection type at a given time.

[0225] In the procedures shown in Figures 8 and 9, it is assumed that the UE is already registered with the AMF, so unless the UE is emergency registered, the AMF has already retrieved the user subscription data from the UDM.

[0226] First, the procedure of Fig. 8 is explained.

[0227] (1) Step 1: To establish a new PDU session, the UE generates a new PDU session ID.

[0228] The UE initiates the PDU session establishment procedure requested by the UE by sending an NAS message containing a PDU session establishment request message within the N1 SM container. The PDU session establishment request message includes the PDU session ID, the requested PDU session type, the requested session and service continuity (SSC) mode, 5G SM capabilities, Protocol Configuration Options (PCO), the SM PDU DN Request Container, and the UE Integrity Protection Maximum Data Rate.

[0229] If the PDU session establishment is a request to establish a new PDU session, the request type is "Initial Request." If the request refers to an existing PDU session switching between a 3GPP connection and a non-3GPP connection, or a PDU session handover from an existing packet data network (PDN) connection in the EPC, the request type is "Existing PDU Session." If the PDU session establishment is a request to establish a PDU session for emergency services, the request type is "Emergency Request." If the request refers to an existing PDU session for emergency services switching between a 3GPP connection and a non-3GPP connection, or a PDU session handover from an existing PDN connection for emergency services in the EPC, the request type is "Existing Emergency PDU Session."

[0230] The UE includes the S-NSSAI from the allowed NSSAI of the current connection type. If a mapping of allowed NSSAIs (Mapping of Allowed NSSAIs) is provided to the UE, the UE provides both the S-NSSAI of the VPLMN (visited VPLMN) from the allowed NSSAIs and the corresponding S-NSSAI of the HPLMN from the mapping of allowed NSSAIs.

[0231] (2) Step 2: AMF selects an SMF. If the request type indicates "Initial Request" or the request is due to a handover from an EPS or other non-3GPP connection provided by an AMF, AMF stores the connection type of the PDU session as well as the association of S-NSSAI(s), data network name (DNN), PDU session ID, and SMF ID.

[0232] If the request type is "Initial Request" and the message also contains a previous PDU Session ID representing an existing PDU Session, AMF selects an SMF and stores the association of the new PDU Session ID, S-NSAI(s), and the selected SMF ID.

[0233] If the request type indicates "Existing PDU Session," AMF selects an SMF based on the SMF-ID received from the UDM. AMF updates the stored connection type for the PDU session.

[0234] If the request type indicates "Existing PDU Session", which refers to an existing PDU session moving between a 3GPP connection and a non-3GPP connection, and if the serving PLMN S-NSSAI of the PDU session is in the allowed NSSAI of the target connection type, the PDU session establishment procedure may be performed in the following cases:

[0235] - When the SMF ID and AMF corresponding to the PDU session ID belong to the same PLMN;

[0236] - If the SMF ID corresponding to the PDU session ID belongs to HPLMN;

[0237] Otherwise, AMF rejects the PDU session establishment request with an appropriate rejection cause.

[0238] AMF rejects requests from emergency-registered UEs whose request type does not indicate "Emergency Request" or "Existing Emergency PDU Session".

[0239] (3) Step 3: If the AMF is not associated with an SMF for the PDU session ID provided by the UE (e.g., when the request type indicates "Initial Request"), the AMF invokes the Create SM Context request procedure (e.g., Nsmf_PDUSession_CreateSMContext Request). If the AMF is already associated with an SMF for the PDU session ID provided by the UE (e.g., when the request type indicates "Existing PDU Session"), the AMF invokes the Update SM Context request procedure (e.g., Nsmf_PDUSession_UpdateSMContext Request).

[0240] The AMF transmits the S-NSSAI of the serving PLMN to the SMF from the allowed NSSAI. For a roaming scenario of local breakout (LBO), the AMF also transmits the corresponding S-NSSAI of the HPLMN to the SMF from the mapping of the allowed NSSAI.

[0241] The AMF ID is the UE's GUAMI, which uniquely identifies the AMF serving the UE. The AMF passes the PDU session ID along with the N1 SM container containing the PDU session establishment request message received from the UE. The GPSI (generic public subscription identifier) ​​is included if available to the AMF.

[0242] If a UE in limited service state is registered for emergency services without providing SUPI, the AMF provides PEI instead of SUPI. If a UE in limited service state is registered for emergency services while providing SUPI but is not authenticated, the AMF indicates that the SUPI is not authenticated. If the SMF does not receive a SUPI for the UE or if the AMF indicates that the SUPI is not authenticated, the UE is considered unauthenticated.

[0243] AMF can include a PCF ID in Nsmf_PDUSession_CreateSMContext. This PCFID identifies the home PCF (H-PCF) in non-roaming cases and the visited PCF (V-PCF) in LBO roaming cases.

[0244] (4) Step 4: If the session management subscription data for the S-NSSAI of the corresponding SUPI, DNN, or HPLMN is not available, the SMF can retrieve the session management subscription data from the UDM and be notified when the subscription data is modified.

[0245] (5) Step 5: SMF sends a create SM context response message (e.g., Nsmf_PDUSession_CreateSMContext Response) or an update SM context response message (e.g., Nsmf_PDUSession_UpdateSMContext Response) to AMF according to the request received in step 3.

[0246] If SMF receives the Nsmf_PDUSession_CreateSMContext Request in step 3 and can process the PDU session establishment request, SMF creates an SM context and responds to AMF by providing the SM context ID.

[0247] If the SMF decides not to accept the PDU session establishment, the SMF rejects the UE request by sending a NAS SM signal including the relevant SM rejection cause by responding to the AMF with an Nsmf_PDUSession_CreateSMContext Response. The SMF also indicates to the AMF that the PDU session ID is considered released and the SMF proceeds to step 20 below, aborting the PDU session establishment procedure.

[0248] (6) Step 6: Optional secondary authentication / authorization may be performed.

[0249] (7a) Step 7a: When dynamic policy and charging control (PCC) is used in a PDU session, the SMF can perform PCF selection.

[0250] (7b) Step 7b: SMF performs the SM policy association establishment procedure to establish a PCF and SM policy association, and obtains the basic PCC rules for the PDU session.

[0251] (8) Step 8: SMF selects one or more UPFs.

[0252] (9) Step 9: The SMF may provide information about the satisfied policy control request trigger conditions by performing the SM policy association modification procedure initiated by the SMF.

[0253] (10) Step 10: If the request type indicates an "Initial Request," the SMF may initiate the N4 Session Establishment procedure with the selected UPF. Otherwise, the SMF may initiate the N4 Session Modification procedure with the selected UPF.

[0254] In step 10a, the SMF can send an N4 session establishment / modification request to the UPF, providing packet detection, enforcement, and reporting rules to be installed in the UPF for the PDU session. In step 10b, the UPF can confirm by sending an N4 session establishment / modification response.

[0255] (11) Step 11: SMF sends an N1N2 message transfer message (e.g. Namf_Communication_N1N2 Message Transfer) to AMF.

[0256] The N1N2 Message Forwarding message may contain N2 SM information. The N2 SM information carries the following information that the AMF will forward to the (R)AN:

[0257] - CN Tunnel Info: Corresponds to the core network address of the N3 tunnel corresponding to the PDU session;

[0258] - QFI (QoS flow ID) corresponding to one or more QoS (quality of service) profiles;

[0259] - PDU Session ID: Indicates to the UE the association between RAN resources and a PDU session for the UE;

[0260] - S-NSSAI with value for serving PLMN (i.e. HPLMN S-NSSAI, or VPLMN S-NSSAI in case of LBO roaming);

[0261] - User plane security enforcement information determined by SMF;

[0262] - UE integrity protection maximum data rate received in PDU Session Establishment Request message: if integrity protection is indicated as "Preferred" or "Required" in the user plane security enforcement information.

[0263] - RSN (redundancy sequence number) parameter

[0264] The N1N2 message transfer message may include an N1 SM container. The N1 SM container includes a PDU Session Establishment Accept message that the AMF will provide to the UE. The PDU Session Establishment Accept message includes the S-NSSAI from the allowed NSSAI. For the LBO roaming scenario, the PDU Session Establishment Accept message includes the S-NSSAI from the allowed NSSAI for the VPLMN, and also includes the corresponding S-NSSAI of the HPLMN from the mapping of the allowed NSSAI received by the SMF in step 3.

[0265] Multiple QoS rules, QoS flow levels, and QoS parameters may be included in the PDU session establishment accept message and N2 SM information within the N1 SM container, if required, for QoS flows associated with QoS rules and QoS profiles.

[0266] If the PDU session establishment fails between steps 5 and 11, the N1N2 message forwarding message contains an N1 SM container containing a PDU session establishment rejection message, but does not contain N2 SM information. The (R)AN sends an NAS message containing a PDU session establishment rejection message to the UE. In this case, steps 12-17 below are omitted.

[0267] (12) Step 12: AMF sends a NAS message containing the PDU Session ID and PDU Session Establishment Accept message destined for the UE and the N2 SM information received from SMF to (R)AN within an N2 PDU Session Request message.

[0268] (13) Step 13: The (R)AN may perform AN-specific signaling exchanges with the UE related to the information received from the SMF. For example, in the case of the NG-RAN, the UE may perform an RRC connection reconfiguration with the UE to set up the necessary NG-RAN resources related to the QoS rules for the PDU session request received in step 12.

[0269] (R)AN forwards the NAS message (PDU Session ID, N1 SM container (PDU Session Establishment Accept message)) received in step 12 to the UE. (R)AN provides the NAS message to the UE only if the AN-specific signaling exchange with the UE includes (R)AN resource additions related to the received N2 command.

[0270] If N2 SM information is not included in step 11, steps 14-16b and 17 below are omitted.

[0271] Now, the procedure of Fig. 9 following the procedure of Fig. 8 is described.

[0272] (14) Step 14: (R)AN sends an N2 PDU Session Response message to AMF. The N2 PDU Session Response message may include PDU Session ID, cause, N2 SM information (PDU Session ID, AN tunnel information, accepted / rejected QFI list, user plane enforcement policy notification), etc.

[0273] (15) Step 15: AMF sends an update SM context request message (e.g., Nsmf_PDUSession_UpdateSMContext Request) to SMF. AMF forwards the N2 SM information received from (R)AN to SMF.

[0274] (16a) Step S16a: SMF initiates the N4 session modification procedure with UPF. SMF provides AN tunnel information and corresponding forwarding rules to UPF.

[0275] (16b) Step S16b: UPF provides an N4 session modification response to SMF.

[0276] After this step, the UPF can forward any DL packets that may have been buffered for this PDU session to the UE.

[0277] (16c) Step 16c: If the SMF is not yet registered for this PDU session, the SMF may register with the UDM for the given PDU session.

[0278] (17) Step 17: SMF sends an update SM context response message (e.g., Nsmf_PDUSession_UpdateSMContext Response) to AMF.

[0279] After this step, AMF forwards the relevant events to which SMF subscribes.

[0280] (18) Step 18: At any time during the procedure after Step 5, if the PDU session establishment is not successful, the SMF can notify the AMF by calling Nsmf_PDUSession_SMContextStatusNotify (release). The SMF can also release the created N4 session, the PDU session address (e.g., IP address) if assigned, and possibly the association with the PCF. In this case, Step 19 below is omitted.

[0281] (19) Step 19: For PDU session type IPv6 or IPv4v6, SMF may generate and send an IPv6 Router Advertisement to the UE.

[0282] (20) Step 20: SMF can perform SM policy association modification initiated by SMF.

[0283] (21) Step 21: If the PDU session establishment fails after step 4, the SMF may unsubscribe from modifications to the session management subscription data if the SMF no longer processes the UE's PDU session.

[0284] <MWAB (Mobile gNB with wireless access backhauling)>

[0285] Figure 10 shows an example of the architecture of MWAB.

[0286] MNO2 (mobile network operator2) can provide wireless access and transmission between MWAB (vehicle relay in Fig. 10) and MNO1.

[0287] MNO1 may decide to tunnel MNO1 traffic to MWAB, leveraging the 5G wireless (and transport) connectivity provided by MNO2.

[0288] The MNO2 connection between MWAB and MNO1 can be used to carry relay traffic between MWAB and MNO1 5GC.

[0289] (1) Service Flow

[0290] Step 1. MWAB can be provisioned and configured to register with MNO2 and establish the required PDU sessions using specific quality of service and policies (as negotiated for MNO1 traffic and subscribers).

[0291] Step 2. MWAB can be provisioned and configured to connect to the MNO1 network for communication between users of MNO1 and the MNO1 network.

[0292] Step 3. MN01 subscribers / UEs can camp on the MWAB broadcasting the MNO1 PLMN ID. MN01 subscribers / UEs can then register and connect to the MNO1 network.

[0293] Step 4. All traffic generated by MNO1 UE through MWAB can be tunneled through MNO2 5G connection of configured relay.

[0294] (2) Architecture

[0295] In the MWAB architecture, the MWAB (Mobile gNB with wireless access backhauling) (or VMR, mobile base station) can be a relay belonging to MNO1. The MWAB connects to the base station and 5GC of MNO2 to create a PDU session, and connects the N2 / N3 interface to the 5GC of MNO1 through the created PDU session, so that the MWAB can directly operate as a base station.

[0296] MWAB can also operate as a base station by connecting to MNO1's base station and 5GC to create a PDU session and connecting the N2 / N3 interface to MNO1's 5GC through the created PDU session. In this specification, the base station that MWAB connects to connect the N2 / N3 interface to the 5GC can be referred to as an underlay base station.

[0297] Looking at the MWAB (Vehicle Relay) architecture, MWAB (Vehicle Relay) is a relay belonging to MNO1. In a roaming situation, it connects to the base station and 5GC of MNO2 to create a PDU session, and connects the N2 / N3 interface to the 5GC of MNO1 through the created PDU session, so that MWAB (Vehicle Relay) can operate directly as a base station.

[0298] The MWAB belonging to the above MNO1 can connect to the base station and 5GC of MNO2 to create a PDU session, and connect the N2 / N3 interface to the 5GC of MNO2 through the created PDU session, so that the MWAB can operate directly as a base station. In addition, when the MWAB (Vehicle Relay) is non-roaming, it can connect to the base station and 5GC of MNO1 to create a PDU session, and connect the N2 / N3 interface to the 5GC of MNO1 through the created PDU session, so that it can operate as a base station. In this specification, the base station that the MWAB (Vehicle Relay) connects to connect the N2 / N3 interface to the 5GC is referred to as an underlay base station.

[0299] Figure 11 shows an example of the architecture in a non-roaming scenario of MWAB.

[0300] Figure 12 shows an example of the architecture in a roaming scenario of MWAB.

[0301] MWAB (Mobile gNB with wireless access backhauling) may include an MWAB-UE that performs the function of a terminal and an MWAB-gNB that performs the function of a base station.

[0302] MWAB (Mobile gNB with wireless access backhauling) may mean Vehicle Relay (or Mobile Base Station).

[0303] The bold line between MWAB-UE and 5GC may represent PDU Session(s) for tunneling N2 / N3 interfaces of MWAB-gNB.

[0304] The dotted line between the MWAB-gNB and the 5GC may represent the N2 / N3 interfaces of the MWAB-gNB tunneled through PDU Session(s).

[0305] MWAB can connect to other base stations(es) via Xn interface.

[0306] The base station to which the MWAB connects the Xn interface may be an MWAB or a non-MWAB base station (e.g., a conventional base station, typically a stationary base station or a fixed base station).

[0307] A method is needed to manage / support the Xn interface connection of MWAB with mobility compared to the Xn interface connection between existing base stations.

[0308] <Xn 설정>

[0309] The purpose of the Xn setup procedure may be to exchange application-level configuration data required for two NG-RAN nodes to interoperate properly over the Xn-C interface.

[0310] If Xn-C signaling is shared across multiple Xn-C interface instances, one Xn setup procedure may be executed per Xn-C interface instance to be configured. For example, multiple Xn setup procedures may be executed over the same TNL connection after that TNL connection is brought up.

[0311] This procedure may use signals that are not associated with the UE.

[0312] Figure 13 shows an example of a successful Xn setup operation.

[0313] NG-RAN node 1 can initiate the procedure by sending an XN SETUP REQUEST message to candidate NG-RAN node 2.

[0314] Candidate NG-RAN Node 2 may respond with an XN SETUP RESPONSE message.

[0315] The AMF Region Information IE in the XN SETUP REQUEST message may contain a full list of global AMF Region IDs to which NG-RAN node1 belongs. The AMF Region Information IE in the XN SETUP RESPONSE message may contain a full list of global AMF Region IDs to which NG-RAN node2 belongs.

[0316] Figure 14 shows an example of a failure of the Xn setup operation.

[0317] If the candidate NG-RAN Node2 cannot accept the setup, it may respond with an XN SETUP FAILURE message with an appropriate cause value.

[0318] If the XN SETUP FAILURE message contains a Time To Wait IE, the initiating NG-RAN node1 waits at least the specified time before restarting the Xn setup procedure for the same NG-RAN node2.

[0319] The XN SETUP REQUEST message of FIGS. 13 and 14 may include:

[0320] - Message Type

[0321] - Global NG-RAN Node ID

[0322] - TAI Support List

[0323] - AMF Region Information

[0324] - List of Served Cells NR

[0325] - List of Served Cells E-UTRA

[0326] - Interface Instance Indication

[0327] - TNL Configuration Info

[0328] - Partial List Indicator NR

[0329] - Cell and Capacity Assistance Information NR

[0330] - Partial List Indicator E-UTRA

[0331] - Cell and Capacity Assistance Information E-UTRA

[0332] - Local NG-RAN Node Identifier

[0333] - Neighbor NG-RAN Node List

[0334] The XN SETUP RESPONSE message may include a List of Served Cells NR, a List of Served Cells E-UTRA, and / or a Neighbor NG-RAN Node List.

[0335] In this specification, UE (User Equipment) and terminal are used interchangeably.

[0336] In this specification, the terms Subscriber and User are used interchangeably.

[0337] In this specification, NG-RAN, RAN, base station, NR base station, LTE base station, gNB, eNB, ng-eNB, etc. are used interchangeably to describe.

[0338] In this specification, MWAB (or mWAB or MgWAB) (Mobile gNB with wireless access backhauling) and Vehicle Relay, Vehicle-Mounted Relay (VMR), Relay, Mobile Relay, MBSR (Mobile Base Station Relay), eMBSR (enhanced MBSR), mobile base station, gNB of MWAB, etc. are used interchangeably to describe them.

[0339] In this specification, the underlay base station of MWAB, the base station that MWAB connects to connect the N2 / N3 interface to 5GC, the base station of MWAB-UE, the base station that serves MWAB-UE, and the base station that MWAB-UE connects to are used interchangeably to describe.

[0340] In this specification, the underlay core network of MWAB, 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, and the core network to which MWAB-UE connects / registers are used interchangeably to describe.

[0341] In this specification, the underlay network may be interpreted as including one or more of an underlay base station and an underlay core network.

[0342] In this specification, the terms MWAB base station, MWAB base station part, MWAB-gNB, MWAB base station, MWAB base station part, MWAB RAN, MWAB NG-RAN, etc. are used interchangeably to describe.

[0343] In this specification, the N2 interface is described interchangeably with the NG-C interface, the NGAP (NG Application Protocol) interface, and the N2 tunnel, and the N3 interface is described interchangeably with the NG-U interface and the N3 tunnel.

[0344] In this specification, the Xn interface is described interchangeably with the connection between base stations.

[0345] In this specification, Xn setup, Xn interface connection, connection with other base stations (setup), connection between base stations (setup), etc. are used interchangeably to describe them.

[0346] MWABs can be mounted on a variety of vehicles, including ground 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 an aerial vehicle, they may be referred to as Aerial MWABs or Aerial Vehicle Relays (AVRs). Furthermore, MWABs do not necessarily need to be mobile; they can also function as base stations while stationary.

[0347] A MWAB can serve not only UEs within the vehicle / MWAB, but also UEs around it.

[0348] MWAB can use various RATs to serve UEs (e.g., NR, LTE, 6G RAT, etc.).

[0349] A MWAB may include a UE or a Mobile Terminal (MT) part. This may be interpreted as the MWAB including a UE part / operation / functionality or a Mobile Terminal (MT) part / operation / functionality. This may be referred to as the UE of MBWAB, MWAB-UE, or MWAB-MT.

[0350] The method proposed in this specification may be composed of a combination of one or more of the operations / configurations / steps described below, and the proposed methods may be performed or used in combination or complementary manner.

[0351] The method proposed in this specification can be applied to both cases where an MWAB is connected to a PLMN to provide services and cases where it is connected to an NPN to provide services. When an MWAB is connected to an NPN to provide services, the PLMN ID in this specification can be interpreted by replacing it with NPN identification information. In particular, when an MWAB is connected to an SNPN to provide services, the PLMN ID in this specification can be interpreted by replacing it with SNPN identification information (PLMN ID and NID identifying an SNPN).

[0352] The operations and contents described herein as being performed by an MWAB-UE or an MWAB base station (e.g., an MWAB-gNB) may be interpreted as operations and contents performed by the MWAB. Alternatively, the operations and contents performed by the MWAB may be specifically performed by the MWAB-UE or the MWAB base station.

[0353] In this specification, the definition / operation of conventional IAB-based VMR (MBSR), registration procedure, PDU session-related procedure, UCU (UE Configuration Update) procedure, etc. refer to TS 23.501 v18.4.0, TS 23.502 v18.4.0, etc., and Xn-related operation / procedure / message, including Xn configuration procedure, can refer to TS 38.423 v18.0.0. This specification mainly describes the proposed matters.

[0354] I. Providing mobility-related information of MWAB when performing Xn setup between MWAB and other base stations.

[0355] An MWAB can establish an Xn interface connection with another base station. The other base station may be an MWAB or a non-MWAB base station (e.g., a conventional base station, typically a stationary base station or a fixed base station). The other base station may be a base station located around the MWAB or a base station capable of Xn connection.

[0356] Performing Xn configuration (connecting Xn interface) of MWAB and other base stations may be performed after NG configuration of MWAB, may be performed in parallel, or may be performed before NG configuration.

[0357] 1. First Example

[0358] 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.

[0359] Fig. 15 shows an example of Xn settings according to the first embodiment of the present specification.

[0360] MWAB can initiate Xn setup.

[0361] MWAB can be either non-roaming or roaming. Figure 15 illustrates a PLMN (HPLMN or VPLMN in Figure 15) as the underlay network. However, the underlay network can also be an NPN, not a PLMN. This applies throughout this specification.

[0362] 1) Step 1

[0363] The MWAB-UE may send a Registration Request message to the AMF to perform registration. The AMF may be an AMF of the underlay core network.

[0364] The MWAB-UE may transmit an RRC message and / or a registration request message to the base station. The base station may transmit the RRC message and / or the registration request message to the AMF.

[0365] The MWAB-UE may include information indicating that it wishes to perform MWAB operation in the RRC message and / or registration request message. Based on this, the base station that receives the RRC message and / or registration request message from the MWAB-UE may select an AMF that supports MWAB. In addition, the MWAB-UE may transmit information about neighboring base stations that require the Xn interface (e.g., gNB ID, cell ID) to the base station (or AMF).

[0366] The AMF can obtain subscriber information of the MWAB-UE from the UDM. The UDM may be a UDM of the network to which the MWAB-UE has subscribed. If the MWAB is roaming, the UDM may be a UDM of the overlay core network. If the MWAB is roaming and connects the N2 / N3 interface to a roaming network, the UDM may be a UDM of the network to which the MWAB-UE has subscribed.

[0367] The subscriber information may include information (e.g., DNN, S-NSSAI, etc.) for establishing a PDU session for the MWAB to use on the Xn interface with another NG-RAN. Additionally, the PDU session may be for the N2 / N3 interface of the MWAB-gNB.

[0368] The above subscriber information may include information about whether the MWAB can establish an Xn connection with another base station (or whether the establishment is permitted / instructed to be established).

[0369] The above subscriber information may be information that allows the MWAB to establish an Xn connection only when it is not roaming. Alternatively, the subscriber information may be information that allows the MWAB to establish an Xn connection regardless of whether it is roaming. Alternatively, the subscriber information may be information about whether an Xn connection is established for each PLMN to which the MWAB-UE connects / registers.

[0370] The above subscriber information may include information (e.g. DNN, S-NSSAI, etc.) for MWAB to establish a PDU session for use in NG setup.

[0371] Information for establishing a PDU session for use on the Xn interface may be set in AMF.

[0372] Information for MWAB to establish a PDU session for use in NG configuration may be set in AMF.

[0373] Information about whether an MWAB can establish Xn connections with other base stations (or is allowed / instructed to do so) may be set in the AMF.

[0374] The information for establishing a PDU session for use on the Xn interface may be different from, or may be the same as, the information for establishing a PDU session for use by MWAB in NG configuration, or may be partially the same.

[0375] Additionally, AMF may have different information (e.g. DNN, S-NSSAI) set for establishing PDU sessions for Xn interfaces for each target base station of the Xn interface. AMF can decide which information to inform MWAB-UE based on the base station information requested by MWAB-UE.

[0376] 2) Step 2

[0377] AMF can send a registration approval message to MWAB-UE.

[0378] The above registration approval message may contain information (either intact or in a modified form) for MWAB to establish a PDU session for use in NG setup.

[0379] The above registration approval message may contain information (either verbatim or in a modified form) about whether the MWAB can establish an Xn connection with another base station (or whether establishment is permitted / instructed to do so).

[0380] This information may be provided separately to MWAB-UEs depending on each base station.

[0381] During the registration process of MWAB-UE, AMF may perform authorization to allow MWAB operation based on subscriber information, local configuration, operator policy, and messages / information received in step 1.

[0382] If MWAB operation is allowed / authorized, AMF may provide the MWAB with information to establish a PDU session for use on the Xn interface.

[0383] 3) Step 3

[0384] MWAB-UE can establish PDU sessions to be used for Xn setup (or Xn interface connection).

[0385] At this time, the parameters used by MWAB-UE can utilize values ​​received from AMF (e.g., values ​​received through a registration approval message).

[0386] Alternatively, the MWAB-UE can determine parameters based on its URSP rules, local settings, etc. The MWAB-UE can use the determined parameters to establish a PDU session to be used for Xn configuration (or Xn interface connection).

[0387] The PDU session establishment procedure may be performed based on whether the MWAB operation is permitted (authorized). For example, in the registration procedure of an MWAB-UE, if the MWAB-UE receives information from the AMF that the MWAB operation is authorized, the MWAB-UE may establish a PDU session to be used for Xn setup (or Xn interface connection).

[0388] The PDU session establishment procedure may be performed based on whether the MWAB is allowed / instructed to establish an Xn connection with other base stations (which may be provided by the AMF or configured in the MWAB). For example, if the MWAB-UE receives information from the AMF during the registration procedure that the MWAB is allowed to establish an Xn connection with other base stations or if the MWAB is configured with information that the MWAB is allowed to establish an Xn connection with other base stations, the MWAB-UE may establish a PDU session to be used for Xn establishment (or Xn interface connection).

[0389] After MWAB successfully performs / completes configuration setup / update with OAM server, MWAB-UE can establish PDU session to be used for Xn setup (or Xn interface connection).

[0390] MWAB can receive configuration information required for MWAB operation through the OAM server. For example, it can receive TA information and cell information that MWAB should use.

[0391] Additionally, the MWAB can receive information necessary for the MWAB to perform Xn interface connection with surrounding base stations through the OAM server (e.g., global NG-RAN Node ID information and / or TNL address of base stations located around a specific location, etc.).

[0392] Information received by MWAB from OAM server may include information about PDU sessions required for Xn interface connection (e.g. DNN, S-NSSAI).

[0393] MWAB can transmit its location information and information about surrounding base stations to the OAM server. Based on this, the OAM server can transmit the aforementioned information to MWAB.

[0394] A PDU session can be a Local Breakout PDU session or a Home Routed PDU session.

[0395] The PDU sessions for the Xn interface may also be used for the NG interfaces (N2 and / or N3). Alternatively, the PDU sessions for the NG interfaces (N2 and / or N3) may also be used for the Xn interface. This can be applied throughout this specification.

[0396] 4) Step 4

[0397] If the MWAB-gNB learns the RAN node ID of the NG-RAN (e.g., via the ANR function), but does not have a Transport Network Layer (TNL) address for SCTP connectivity, the MWAB-gNB may use the AMF to which the MWAB-gNB is connected to determine the TNL address of the NG-RAN.

[0398] For example, the MWAB-gNB may send an Uplink RAN ​​Configuration Transfer message to the AMF to request the TNL address of the NG-RAN from the AMF. Based on this, the AMF may send a Downlink RAN ​​Configuration Transfer message to the NG-RAN to relay the request from the MWAB-gNB. Upon receiving this, the NG-RAN may respond with an Uplink RAN ​​Configuration Transfer message to the AMF, including one or more TNL addresses to be used for SCTP connectivity with the MWAB-gNB. The AMF may then send a Downlink Configuration Transfer message to the MWAB-gNB to relay the response from the NG-RAN.

[0399] The MWAB may decide to perform Xn configuration with another base station. This decision may be based on one or more of the following information:

[0400] - Information provided by UE (e.g. measurement reports, etc.)

[0401] - Information provided by MWAB from surrounding base stations

[0402] - Information provided by the OAM server

[0403] - Information provided from the core network

[0404] - Information set in MWAB

[0405] - Information provided by the MWAB-UE part (e.g., information indicating that MWAB operation is permitted / authorized)

[0406] - Information indicating that a PDU session required for Xn configuration has been established.

[0407] - Information indicating that Xn settings can be initiated, etc.

[0408] This can be applied throughout this specification.

[0409] Based on the above decision, the Xn setup procedure can be performed. If the Xn setup is successful (if the Xn connection is established), steps 5a and 6a described below can be performed. Alternatively, if the Xn setup fails, steps 5b and 6b described below can be performed.

[0410] 5a) step 5a

[0411] MWAB-gNB can send Xn Setup Request message to other NG-RAN via PDU session for Xn interface.

[0412] The MWAB-gNB may include mobility-related information (explicit, implicit, or implicit) of the MWAB in the Xn Setup Request message.

[0413] Mobility-related information for an MWAB may consist of one or more of the following information, which may be explicit, implicit, or implicit. Mobility-related information for an MWAB may also be interpreted as mobility status information, etc.:

[0414] - i) Information that it operates as MWAB: This can be interpreted as information indicating that it is a mobile base station. In addition, the MWAB-gNB can transmit its own base station ID information and a list of served cells (cells served by the MWAB-gNB) belonging to the MWAB-gNB to the surrounding NG-RAN. If another MWAB-UE belongs to the NG-RAN that received this, the NG-RAN may not designate the served cell belonging to the MWAB-gNB as a target cell when performing a handover for the MWAB-UE. This can prevent another MWAB-UE from being connected to the served cell of the MWAB-gNB (for example, can prevent the MWAB from being connected in multi-hop).

[0415] - ii) Whether the MWAB is mobile: Even if this information is not included, if the information in iii) and / or iv) is included, the MWAB can be considered mobile. Alternatively, the information in iii) can be used to indicate this. For example, if the information in iv) includes 0 km / h, it can be considered non-mobile.

[0416] - iii) Information related to the direction of movement of MWAB: This can be in various forms, such as east, west, south, north, southeast, northwest, etc., or it can be information on the coordinates of the destination of movement (final, intermediate, or destination to be reached / arrived at by a certain time, etc.).

[0417] - iv) Information related to the movement speed of MWAB: This can be actual speed information, or it can be expressed as information such as high / medium / low depending on the speed.

[0418] - v) Location information of MWAB: This may be information indicating the location of MWAB in coordinates, serving cell information of MWAB-UE, tracking area information of MWAB-UE, serving base station information of MWAB-UE, etc.

[0419] The Xn Setup Request message may be an extension of the existing one, or it may be a newly defined message instead.

[0420] 6a) step 6a

[0421] Based on the Xn Setup Request message (and the information contained in that message), the NG-RAN can decide whether to accept the Xn Setup Request.

[0422] If the NG-RAN is an MWAB, the NG-RAN can determine whether to accept the Xn setup request based on its own mobility-related information and the mobility-related information of the MWAB that transmitted the Xn setup request.

[0423] For example, if the MWAB that sent the Xn setup request and the NG-RAN (if it is an MWAB) that received it have similar or identical mobility (or if the match between their mobility-related information meets some criteria, e.g., moving in the same direction), the NG-RAN may decide to accept the Xn setup request.

[0424] For example, if the MWAB that sent the Xn setup request and the NG-RAN (if it is an MWAB) that received it have different mobilities (or if the match between their mobility-related information does not meet some criteria, for example, if they are moving in opposite directions), the NG-RAN may decide to reject the Xn setup request.

[0425] The decision on whether to accept an Xn setup request may additionally be made based on the following information:

[0426] - Whether the MWAB that requested Xn settings is roaming, and if roaming, the network to which the NG interface is connected (whether connected to the Home network or the Visited network, etc.)

[0427] - If the NG-RAN that received the above Xn setup request is MWAB, whether it is roaming or not, and if roaming, the network to which the NG interface is connected (whether connected to the home network or the visited network, etc.),

[0428] - Information such as distance from MWAB that requested Xn setting

[0429] This information may be included explicitly, implicitly, or implicitly in the Xn setup request message.

[0430] It may be determined that the Xn request is accepted. In this case, the NG-RAN may send a response / acceptance message (e.g., an Xn Setup Response message) to the MWAB-gNB for the Xn setup request. This may enable the Xn connection to be established.

[0431] If the NG-RAN that received the step 5a message (the NG-RAN that performs the Xn setup) is MWAB, the NG-RAN may explicitly, implicitly, or implicitly include the mobility-related information described in step 5a) in the response / acceptance message.

[0432] The Xn Setup Response message may be an extension of the existing one, or may be a newly defined message instead. This may be applied throughout this specification.

[0433] 5b) step 5b

[0434] The contents of step 5a described above can be applied.

[0435] 6b) step 6b

[0436] The contents of step 6a described above can be applied.

[0437] It may be determined that the Xn request is rejected. In this case, the NG-RAN may send a response / rejection message (e.g., an Xn Setup Failure message) to the MWAB-gNB for the Xn setup request.

[0438] The above response / rejection message may include information about the reason for the rejection.

[0439] If the NG-RAN that received the step 5b message (the target NG-RAN that performs the above Xn configuration) is MWAB, the NG-RAN may explicitly, implicitly, or implicitly include the mobility-related information described in step 5a) in the response / rejection message.

[0440] An MWAB that receives the above response / rejection message (Xn Setup Failure message) may not retry Xn setup to the NG-RAN until certain conditions (e.g., a certain time and / or location, etc.) are satisfied based on the information about the rejection reason included in the message.

[0441] For example, the above response / rejection message (Xn Setup Failure message) may include information about a certain period of time (or a specific point in time). Based on this, the MWAB may not perform Xn setup (e.g., transmit an Xn Setup Request message) to the NG-RAN during the certain period of time (or until a specific point in time).

[0442] The Xn Setup Failure message may be an extension of the existing one, or may be a newly defined message instead. This may be applied throughout this specification.

[0443] After or before the aforementioned Xn setup procedure, the MWAB-gNB may perform MWAB operations (e.g., broadcasting system information, etc.). The MWAB operation may be interpreted as starting to operate as a base station serving UEs.

[0444] 2. Second Example

[0445] 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.

[0446] Fig. 16 shows an example of Xn settings according to the second embodiment of the present specification.

[0447] MWAB can be either non-roaming or roaming. Figure 16 illustrates a PLMN (HPLMN or VPLMN in Figure 16) as the underlay network. However, the underlay network can also be an NPN, not a PLMN. This applies throughout this specification.

[0448] 1-3) Step 1 to Step 3

[0449] The contents of step 1 to step 3 of Fig. 15 can be applied.

[0450] 4) Step 4.

[0451] If the NG-RAN learns the RAN Node ID of the MWAB-gNB (e.g., via the ANR function), but does not have a TNL address for SCTP connectivity, the NG-RAN may use the AMF to which the NG-RAN is connected to determine the TNL address of the MWAB-gNB.

[0452] For example, the NG-RAN may send an Uplink RAN ​​Configuration Transfer message to the AMF to request the TNL address of the MWAB-gNB. Based on this, the AMF may send a Downlink RAN ​​Configuration Transfer message to the MWAB-gNB to relay the request from the NG-RAN. The MWAB-gNB, upon receiving this, may respond to the AMF with an Uplink RAN ​​Configuration Transfer message containing one or more TNL addresses to be used for SCTP connectivity with the NG-RAN. The AMF may then send a Downlink Configuration Transfer message to the NG-RAN to relay the response from the MWAB-gNB.

[0453] The NG-RAN may decide to perform Xn configuration with another base station (e.g., the MWAB-gNB). This decision may be based on at least one of the following information:

[0454] - Information provided by UE (e.g. measurement reports, etc.)

[0455] - Information provided by NG-RAN from surrounding base stations

[0456] - Information provided by the OAM server

[0457] - Information provided from the core network

[0458] - Information set in NG-RAN, etc.

[0459] This can be applied throughout this specification.

[0460] Based on the above decision, the Xn setup procedure can be performed. If the Xn setup is successful, steps 5a and 6a described below can be performed. Alternatively, if the Xn setup fails, steps 5b and 6b described below can be performed.

[0461] 5a) Step 5a

[0462] NG-RAN can send Xn Setup Request message to another NG-RAN (e.g. MWAB-gNB) via PDU session to be used on Xn interface.

[0463] If the NG-RAN is an MWAB, the NG-RAN may include mobility-related information (explicit, implicit, or implicit) of the MWAB in the Xn Setup Request message. The mobility-related information of the MWAB may be one or more of the information from i to v in step 5a of FIG. 15.

[0464] 6a) step 6a

[0465] Based on the Xn setup request message (and the information contained in that message), MWAB can decide whether to accept the Xn setup request.

[0466] The above MWAB can decide whether to accept the Xn setup request based on its own mobility-related information and the mobility-related information of the MWAB that sent the Xn setup request (if the NG-RAN that sent the Xn setup request is an MWAB).

[0467] For example, if the NG-RAN (if MWAB) that sent the Xn setup request and the MWAB that received it have similar or identical mobility (or if the match between the mobility-related information meets some criteria, e.g., moving in the same direction), the MWAB may decide to accept the Xn setup request.

[0468] For example, if the NG-RAN (if MWAB) that sent the Xn setup request and the MWAB that received it have different mobilities (or if the match between the mobility-related information does not meet some criteria, for example, if they are moving in opposite directions), the MWAB may decide to reject the Xn setup request.

[0469] The decision on whether to accept an Xn setup request may additionally be made based on the following information:

[0470] - If the NG-RAN requesting Xn settings is MWAB, whether the NG-RAN is roaming, and if roaming, the network to which the NG interface is connected (whether connected to the home network or the visited network, etc.)

[0471] - Whether the MWAB that received the above Xn setup request is roaming, and if roaming, the network to which the NG interface is connected (whether connected to the Home network or the Visited network, etc.),

[0472] - Information such as distance from NG-RAN that requested Xn settings

[0473] This information may be included explicitly, implicitly, or implicitly in the Xn setup request message.

[0474] It may be determined that the Xn request is accepted. In this case, the MWAB-gNB may transmit a response / acceptance message (e.g., an Xn Setup Response message) for the Xn setup request to the NG-RAN. The MWAB-gNB may explicitly, implicitly, or implicitly include mobility-related information in the response / acceptance message. The mobility-related information may be one or more of the information from i to v of step 5a of FIG. 15.

[0475] The Xn Setup Response message may be an extension of the existing one, or may be a newly defined message instead. This may be applied throughout this specification.

[0476] 5b) step 5b

[0477] The contents of step 5a described above can be applied.

[0478] 6b) step 6b

[0479] The contents of step 6a described above can be applied.

[0480] It may be determined that the Xn request is rejected. In this case, the MWAB-gNB may send a response / rejection message (e.g., an Xn Setup Failure message) to the NG-RAN for the Xn setup request.

[0481] The above response / rejection message may include information about the reason for the rejection.

[0482] The above MWAB-gNB may explicitly, implicitly, or implicitly include the mobility-related information described in step 5a) in the above response / rejection message.

[0483] The NG-RAN, which has received the above response / rejection message (Xn Setup Failure message), may not retry Xn setup to the MWAB-gNB until certain conditions (e.g., a certain time and / or location, etc.) are satisfied, based on the information about the rejection reason included in the message.

[0484] For example, the above response / rejection message (Xn Setup Failure message) may include information about a certain period of time (or a specific point in time). Based on this, the NG-RAN may not perform Xn setup (e.g., transmit an Xn Setup Request message) to the MWAB-gNB during the certain period of time (or until a specific point in time).

[0485] The Xn Setup Failure message may be an extension of the existing one, or may be a newly defined message instead. This may be applied throughout this specification.

[0486] After or before the aforementioned Xn setup procedure, the MWAB-gNB may perform MWAB operations (e.g., broadcasting system information, etc.). The MWAB operation may be interpreted as starting to operate as a base station serving UEs.

[0487] After the MWAB establishes an Xn connection with another base station (the Xn connection may be established via the first or second embodiment), if any mobility-related information changes (e.g., direction of movement, speed, etc. change), the MWAB may notify the base station with which it has established the Xn connection of the changed information. This operation may be performed via an extension of the existing NG-RAN Node Configuration Update procedure message, or via a newly defined procedure / message.

[0488] As described above, after the MWAB notifies the base station (the base station that performed the MWAB and Xn setup) of a change in mobility-related information, the Xn connection between the MWAB and the base station may be maintained or released / removed.

[0489] For example, after the MWAB notifies the base station (the base station that performed the MWAB and Xn setup) of a change in mobility-related information, the MWAB (or the base station) can release / remove (or continue to maintain) the Xn connection.

[0490] The reason why the Xn connection is released / removed may be the same as the reason why the Xn setup request is rejected in the first embodiment (or the second embodiment).

[0491] For example, when Xn is established, the mobility between the two base stations is similar or the same, so the Xn connection is established. However, if the mobility changes and the mobility becomes different, the Xn connection may be released / removed. This can be applied throughout this specification.

[0492] After MWAB establishes an Xn connection with another base station (the Xn connection may be established via the first embodiment or the second embodiment), if mobility-related information changes (e.g., direction of movement, speed, etc. change), MWAB may release / remove the Xn connection without notifying the other base stations of the change in mobility-related information. MWAB may notify the other base stations of the change in mobility-related information while releasing / removing the Xn connection.

[0493] The above-mentioned action of releasing / removing the Xn connection may be performed via the existing Xn Removal Request / Response message (or an extended corresponding message) or via a newly defined procedure / message.

[0494] When performing the release / removal of the Xn connection of the aforementioned MWAB (or base station), the MWAB (or base station) can inform the other base station of the reason for the release / removal.

[0495] Alternatively, the TNL association used for the Xn connection may be released / removed through SCTP SHUTDOWN, thereby performing the release / removal of the Xn connection. For example, MWAB may perform SCTP SHUTDOWN to release / remove the TNL association used for the Xn connection. Based on this, the release / removal of the Xn connection may be performed.

[0496] Unlike the above, instead of performing the Xn release / removal procedure, the MWAB may implicitly / locally release / remove the Xn. And, the MWAB may cause the base station that has established the Xn connection to implicitly / locally release / remove the Xn connection established with the MWAB.

[0497] For example, the MWAB may implicitly / locally release / remove the Xn connection by not performing or responding to a liveness check with the counterpart base station with which it has established an Xn connection, and may cause the counterpart base station to implicitly / locally release / remove the Xn connection established with the MWAB.

[0498] In this specification, the description is mainly focused on the case where all base stations establishing Xn connections are MWAB, but it can also be applied to cases where the base stations attempting to establish MWAB and Xn connections are non-MWAB base stations.

[0499] II. MWAB provides mobility-related information to the UE, and the UE considers this and decides whether to report the MWAB to another base station (e.g., serving base station).

[0500] MWAB can provide mobility-related information to UEs (e.g., when broadcasting system information).

[0501] The above mobility-related information may be one or more of the information from i to v in step 5a of FIG. 15.

[0502] The above mobility-related information may be interpreted as mobility-related information of the cell(s) operated by the MWAB (or constituting the MWAB or belonging to the MWAB).

[0503] When a UE receives mobility-related information of a specific neighboring cell (e.g., a surrounding MWAB), the UE may utilize the mobility-related information of the specific neighboring cell when reporting information about the neighboring cell to the serving base station.

[0504] For example, if a UE receives mobility-related information of a specific neighboring cell (e.g., a surrounding MWAB), when the UE reports information about the neighboring cell to the serving base station, the UE may determine whether to report the specific neighboring cell to the serving base station based on the mobility-related information of the specific neighboring cell.

[0505] The above decision may be based on instructions from the serving base station. Alternatively, the decision may be based on configuration or implementation.

[0506] For example, if a UE receives mobility-related information about a specific neighboring cell (e.g., a surrounding MWAB), the UE may determine that the MWAB is moving in a similar or identical direction to itself based on the mobility-related information about the specific neighboring cell. In this case, the UE may report information about the specific neighboring cell to the serving base station.

[0507] For example, if a UE receives mobility-related information about a specific neighboring cell (e.g., a surrounding MWAB), the UE may determine that the MWAB is moving in the opposite direction from itself based on the mobility-related information about the specific neighboring cell. In this case, the UE may not report information about the specific neighboring cell to the serving base station when reporting information about the neighboring cell.

[0508] When the serving base station of the UE is a specific MWAB, the specific MWAB may instruct (or provide a policy) to report neighboring cells that have similar or identical mobility to the specific MWAB (the serving base station of the UE) (or when a match between mobility-related information satisfies some criterion, for example, moving in the same direction) when instructing the UE to perform a measurement report.

[0509] III. Processing / management related to Xn interface when MWAB becomes not authorized (or out of service)

[0510] A MWAB (Vehicle Relay) can be authorized to operate as a MWAB (Vehicle Relay) and then become unauthorized. Examples of situations where the status of a MWAB (Vehicle Relay) may change (e.g., from authorized to unauthorized, or vice versa) include the following:

[0511] - Change subscriber information

[0512] - Change the location of MWAB (Vehicle Relay)

[0513] - The passage of time

[0514] - Changes to operator policy, etc.

[0515] - Various other reasons

[0516] A MWAB (Vehicle Relay) that was authorized to operate as a MWAB (Vehicle Relay) and then became not authorized can be interpreted as one of the following examples (as one of the causes of the following states):

[0517] - MWAB (Vehicle Relay) becomes unavailable for service provision

[0518] - MWAB (Vehicle Relay) becomes 'out of service'

[0519] - The base station part of MWAB (Vehicle Relay) becomes 'out of service'

[0520] - Unable to perform MWAB (Vehicle Relay) operation

[0521] These matters may be applied throughout this specification.

[0522] When an MWAB is put into the MWAB not authorized (or out of service) state (it is determined that the MWAB cannot operate as a MWAB), if there are already configured / connected Xn interfaces, one or more of the following actions may be taken (or decided to be taken):

[0523] - i. Maintain the Xn interface

[0524] - ii. Remove / release the Xn interface. To do this, perform the Xn release / remove procedure with the opposing base station that established the Xn interface.

[0525] - iii. Suspend / deactivate the Xn interface. To do this, perform the Xn suspend / deactivate procedure with the opposing base station that has established the Xn interface.

[0526] - iv. Notify the opposing base station with Xn interface that the base station operation has been stopped.

[0527] - v. Notifies the peer base station with Xn interface that it is in a not authorized (or out of service) state.

[0528] - Request the opposing base station with vi. Xn interface to stop NG-RAN node configuration update.

[0529] Depending on the type of base station that has established the Xn interface, different actions may be performed.

[0530] For example, if the opposing base station is MWAB, ii is performed, and if the opposing base station is not MWAB, i is performed and additionally iv and / or v may be performed.

[0531] The above-mentioned ii to vi can be performed in a combined form.

[0532] The above-mentioned ii to vi may be performed in a form in which the purpose or information of another procedure is provided while performing one procedure (e.g., the purpose / information of iv is provided while performing procedure iii).

[0533] For the above-mentioned ii to vi, the conventional Xn message may be extended and used, or a new Xn message may be defined and used.

[0534] When an MWAB is in the MWAB not authorized (or out of service) state (the MWAB is determined to be incapable of operating as a MWAB), if there are PDU sessions for the Xn interface, it may (or decide to) perform one or more of the following actions:

[0535] - Maintain PDU sessions for Xn interfaces

[0536] - Release the PDU session for the Xn interface

[0537] - Suspend / deactivate PDU sessions for Xn interfaces.

[0538] Conventional PDU session related procedures may be used (either as is or extended) to release a PDU session for the aforementioned Xn interface and / or to suspend / deactivate a PDU session for the Xn interface, or new PDU session related procedures may be defined and used.

[0539] MWAB can utilize various information (e.g., local configuration, information provided / instructed from the network, mobility-related information of MWAB (one or more of the information from i to v in step 5a of FIG. 15), current time, information about the counterpart base station that has established the Xn interface, etc.) to determine the processing / management tasks related to the Xn interface (e.g., Xn interface-related operations, PDU session-related operations for the Xn interface).

[0540] As the MWAB becomes MWAB not authorized (or out of service) (as it is determined that the MWAB cannot operate as a MWAB), the MWAB may handover or redirect the UE(s) it was serving to another base station.

[0541] After performing a handover or redirection of the UE(s) served by the MWAB to another base station, the MWAB may perform the aforementioned Xn interface-related processing / management tasks (e.g., i to vi operations).

[0542] In case it is decided to perform i (maintain the Xn interface), iv (notify the counterpart base station with the Xn interface to stop base station operation), v (notify the counterpart base station with the Xn interface that it has become not authorized (or out of service) state), vi (request the counterpart base station with the Xn interface to stop NG-RAN node configuration update) or maintain the PDU session for the Xn interface, the MWAB may perform cleanup work (e.g., handover or redirect) of the UE(s) it was serving and processing / management work related to the Xn interface (e.g., operations i to vi described above, the work of deciding to maintain the PDU session for the Xn interface) in parallel. Alternatively, the processing / management work related to the Xn interface may be performed first.

[0543] According to the disclosure of this specification, Xn connections between MWABs and other base stations can be established and managed efficiently, taking into account the mobility of MWABs. In addition, seamless services can be provided to terminals through handover operations between base stations, etc.

[0544] The following actions can be performed:

[0545] - MWAB may decide to perform Xn configuration with another base station.

[0546] - MWAB-gNB can send Xn setup request message to another NG-RAN via PDU session to be used for Xn interface. At this time, MWAB-gNB can include mobility related information of MWAB explicitly, implicitly, or implicitly in said message.

[0547] - The NG-RAN that receives the Xn setup request can decide whether to accept the Xn setup request based on the request message and the information included in the request message. In particular, when deciding whether to accept, if the NG-RAN is an MWAB, its own mobility-related information and the mobility-related information of the MWAB that transmitted the Xn setup request can be used.

[0548] - The NG-RAN that receives the Xn setup request can send a response (accept or reject) message to the MWAB-gNB for the Xn setup request.

[0549] 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.

[0550] Figure 17 illustrates the procedure of the AMF of HPLMN for the disclosure of this specification.

[0551] 1. A UE (User Equipment) of a specific MWAB (Mobile gNB with wireless access backhauling) can send a registration request message to the network.

[0552] 2. The UE of the above specific MWAB can receive a registration approval message from the network.

[0553] 3. The UE of the above specific MWAB can send a PDU (Protocol Data Unit) session establishment request message to the network.

[0554] 4. The UE of the above specific MWAB can receive an acknowledgment message of the PDU session from the network.

[0555] 5. The gNB (gNodeB) of the above specific MWAB can perform an Xn connection establishment procedure with the first base station through the PDU session.

[0556] The step of performing the above Xn connection establishment procedure may include: a step of the gNB of the specific MWAB transmitting mobility information of the specific MWAB to the first base station.

[0557] The steps for performing the above Xn connection establishment procedure are:

[0558] - It may include a step of a gNB of a specific MWAB transmitting an Xn setup request message to the first base station. The Xn setup request message may include mobility information of the specific MWAB.

[0559] - Based on the Xn setup request message, the gNB of the specific MWAB may include a step of receiving an Xn setup response message from the first base station that accepts the Xn setup request message.

[0560] The steps for performing the above Xn connection establishment procedure are:

[0561] - It may include a step of a gNB of a specific MWAB transmitting an Xn setup request message to the first base station. The Xn setup request message may include mobility information of the specific MWAB.

[0562] - It may include a step of receiving an Xn setup response message from the first base station, wherein the gNB of the specific MWAB accepts the Xn setup request message, based on i) that the first base station corresponds to an MWAB and ii) that the mobility of the first base station and the mobility of the specific MWAB are similar.

[0563] Based on the first base station corresponding to MWAB, the Xn setup response message may include mobility information of the first base station.

[0564] The steps for performing the above Xn connection establishment procedure are:

[0565] - It may include a step of the gNB of a specific MWAB transmitting an Xn setup request message to the first base station.

[0566] The above Xn setup request message may include mobility information of the specific MWAB.

[0567] - Based on the Xn setup request message, the gNB of the specific MWAB may include a step of receiving an Xn setup failure message rejecting the Xn setup request message from the first base station.

[0568] The steps for performing the above Xn connection establishment procedure are:

[0569] - It may include a step of a gNB of a specific MWAB transmitting an Xn setup request message to the first base station. The Xn setup request message may include mobility information of the specific MWAB.

[0570] - It may include a step of receiving an Xn setup failure message from the gNB of the specific MWAB rejecting the Xn setup request message from the first base station based on i) that the first base station corresponds to an MWAB and ii) that the mobility of the first base station and the mobility of the specific MWAB are not similar.

[0571] Based on the first base station corresponding to MWAB, the Xn setup failure message may include mobility information of the first base station.

[0572] Based on the above Xn setup failure message, the specific MWAB can send a new Xn setup request message to the first base station.

[0573] Based on the above Xn setup failure message, the specific MWAB may skip transmitting a new Xn setup request message to the first base station for a certain period of time.

[0574] Based on the above Xn setup failure message, the specific MWAB may receive the Xn setup failure message from the first base station and transmit a new Xn setup request message after a certain period of time.

[0575] The above Xn setup request message may include i) whether the specific MWAB is roaming or ii) network information that the NG interface is connected to based on the roaming of the specific MWAB.

[0576] The steps for performing the above Xn connection establishment procedure are:

[0577] - A step may be included in which a gNB of a specific MWAB receives an Xn setup request message from the first base station.

[0578] - Based on the Xn setup request message, the step may include determining whether the gNB of the specific MWAB approves the Xn setup with the first base station.

[0579] - Based on the gNB of the specific MWAB deciding to accept the Xn configuration, the step of the gNB of the specific MWAB transmitting an Xn configuration response message accepting the Xn configuration request message to the first base station may be included. The Xn configuration response message includes mobility information of the specific MWAB,

[0580] - A step may include a step of the gNB of the specific MWAB transmitting an Xn setup failure message to the first base station, wherein the Xn setup failure message does not accept the Xn setup request message based on the gNB of the specific MWAB deciding not to accept the Xn setup. The Xn setup failure message may include mobility information of the specific MWAB.

[0581] Based on the first base station corresponding to MWAB, the Xn setup request message may include mobility information of the first base station.

[0582] i) Based on the fact that the first base station corresponds to an MWAB and ii) that the mobility of the first base station and the mobility of the specific MWAB are similar, the step of determining whether the gNB of the specific MWAB approves or not may include: determining that the gNB of the specific MWAB approves the Xn configuration.

[0583] i) Based on the fact that the first base station corresponds to an MWAB and ii) that the mobility of the first base station and the mobility of the specific MWAB are not similar, the step of determining whether the gNB of the specific MWAB approves or disapproves may include: determining that the gNB of the specific MWAB does not approve the Xn configuration.

[0584] Based on the first base station corresponding to MWAB, the Xn setup request message may include i) whether the first base station is roaming or ii) network information that connects the NG interface based on the first base station having roamed.

[0585] The step of determining whether the gNB of the specific MWAB approves or not may be performed based on at least one of: i) whether the first base station is roaming, ii) network information that connects the NG interface based on the roaming of the first base station, and iii) the distance between the first base station and the specific MWAB.

[0586] The mobility information of the specific MWAB may include information that the specific MWAB is moving.

[0587] The mobility information of the first base station may include information that the first base station is moving.

[0588] The mobility information of the specific MWAB may include at least one of information on whether the specific MWAB operates as an MWAB, whether the specific MWAB is mobile, a moving direction, a moving speed, and a location.

[0589] The mobility information of the first base station may include at least one of information on whether the first MWAB operates as an MWAB, whether the first base station is mobile, a moving direction, a moving speed, and location information.

[0590] 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.

[0591] Figure 18 illustrates the procedure of a base station for the disclosure of this specification.

[0592] 1. The base station can receive an Xn setup request message from a gNB (gNodeB) of a specific MWAB (Mobile gNB with wireless access backhauling).

[0593] The above Xn setup request message may include mobility information of the specific MWAB.

[0594] 2. Based on the Xn setup request message, the base station can determine whether to accept the Xn setup with the specific MWAB.

[0595] 3-1. Based on the base station's decision to accept the Xn setting, the base station may transmit an Xn setting response message accepting the Xn setting request message to the gNB of the specific MWAB.

[0596] 3-2. Based on the base station's decision not to accept the Xn configuration, the step of transmitting an Xn configuration response message rejecting the Xn configuration request message to the gNB of the specific MWAB may be included.

[0597] The above Xn setup request message may include i) whether the specific MWAB is roaming or ii) network information that the NG interface is connected to based on the roaming of the specific MWAB.

[0598] 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.

[0599] Figure 19 shows the procedure of the base station for the disclosure of this specification.

[0600] 1. An Xn setup request message can be sent to the gNB (gNodeB) of this specific MWAB (Mobile gNB with wireless access backhauling).

[0601] 2-1. Based on the Xn setup request message and the Xn setup request message being accepted, the base station can receive an Xn setup response message from a gNB of a specific MWAB.

[0602] The above Xn setup response message may include mobility information of the specific MWAB.

[0603] 2-2. Based on the Xn setup request message and the Xn setup request message not being accepted, the base station may receive an Xn setup failure message from the gNB of a specific MWAB.

[0604] The above Xn setup failure message may include mobility information of the specific MWAB.

[0605] Hereinafter, a device for performing communication according to some embodiments of the present specification will be described.

[0606] For example, a device may include a processor, a transceiver, and memory.

[0607] For example, a processor may be configured to be operatively coupled with memory and a processor.

[0608] The operations performed by the processor include: a step for a UE of a specific MWAB to transmit a registration request message to a network; a step for a UE of the specific MWAB to receive a registration acceptance message from the network; a step for a UE of the specific MWAB to transmit a PDU session establishment request message to the network; a step for a UE of the specific MWAB to receive an acceptance message of the PDU session from the network; a step for a gNB of the specific MWAB to perform an Xn connection establishment procedure with a first base station through the PDU session, and the step for performing the Xn connection establishment procedure may include a step for a gNB of the specific MWAB to transmit mobility information of the specific MWAB to the first base station.

[0609] Below, a processor of a device for providing communication according to some embodiments of the present specification is described.

[0610] The method comprises: a step in which a UE of a specific MWAB, which is performed by the processor, transmits a registration request message to a network; a step in which the UE of the specific MWAB receives a registration approval message from the network; a step in which the UE of the specific MWAB transmits a PDU session establishment request message to the network; a step in which the UE of the specific MWAB receives an approval message of the PDU session from the network; and a step in which a gNB of the specific MWAB performs an Xn connection establishment procedure with a first base station through the PDU session, wherein the step in which the gNB of the specific MWAB performs an Xn connection establishment procedure may include a step in which the gNB of the specific MWAB transmits mobility information of the specific MWAB to the first base station.

[0611] Hereinafter, a non-volatile computer-readable medium storing one or more commands for providing mobile communication according to some embodiments of the present specification is described.

[0612] According to some embodiments of the present disclosure, the technical features of the present disclosure may be implemented directly in hardware, software executed by a processor, or a combination of the two. For example, a method performed by a wireless device in wireless communication may be implemented in hardware, software, firmware, or any combination thereof. For example, the software may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or other storage media.

[0613] Some examples of storage media are coupled to the processor, allowing the processor to read information from the storage media. Alternatively, the storage media may be integrated into the processor. The processor and storage media may reside in an ASIC. In other examples, the processor and storage media may reside as separate components.

[0614] Computer-readable media may include tangible and non-volatile computer-readable storage media.

[0615] For example, nonvolatile computer-readable media may include random access memory (RAM), such as synchronized dynamic random access memory (SDRAM), read-only memory (ROM), non-volatile random access memory (NVRAM), read-only memory (EEPROM), flash memory, magnetic or optical data storage media, or any other media that can be used to store instructions or data structures. Nonvolatile computer-readable media may also include combinations of the above.

[0616] Additionally, the methods described herein can be realized at least in part by a computer-readable communication medium that carries or transmits code in the form of instructions or data structures and that can be accessed, read, and / or executed by a computer.

[0617] According to some embodiments of the present disclosure, a non-transitory computer-readable medium has one or more instructions stored thereon. The one or more stored instructions can be executed by a processor of a base station.

[0618] The one or more stored commands include: a step for a UE of a specific MWAB to transmit a registration request message to a network; a step for the UE of the specific MWAB to receive a registration acknowledgement message from the network; a step for the UE of the specific MWAB to transmit a PDU session establishment request message to the network; a step for the UE of the specific MWAB to receive an acknowledgement message of the PDU session from the network; and a step for a gNB of the specific MWAB to perform an Xn connection establishment procedure with a first base station through the PDU session, wherein the step for performing the Xn connection establishment procedure may include a step for the gNB of the specific MWAB to transmit mobility information of the specific MWAB to the first base station.

[0619] Hereinafter, a non-volatile computer-readable medium storing one or more commands for providing mobile communication according to some embodiments of the present specification is described.

[0620] This specification may have various effects.

[0621] For example, through the procedure disclosed in this specification, efficient communication is enabled by setting up the Xn interface while taking mobility into consideration.

[0622] The effects that can be achieved through 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.

[0623] 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. As a method, A step in which a UE (User Equipment) of a specific MWAB (Mobile gNB with wireless access backhauling) transmits a registration request message to the network; A step in which a UE of the specific MWAB receives a registration approval message from the network; A step in which the UE of the specific MWAB transmits a PDU (Protocol Data Unit) session establishment request message to the network; A step in which the UE of the specific MWAB receives an acknowledgment message of the PDU session from the network; The step of the gNB (gNodeB) of the above specific MWAB performing an Xn connection establishment procedure with the first base station through the PDU session is included, A method wherein the step of performing the above Xn connection establishment procedure comprises: a step of the gNB of the specific MWAB transmitting mobility information of the specific MWAB to the first base station.

2. In paragraph 1, The steps for performing the above Xn connection establishment procedure are: A step in which the gNB of the specific MWAB transmits an Xn setup request message to the first base station; The above Xn setup request message includes mobility information of the specific MWAB, A method comprising the step of: receiving, by the gNB of the specific MWAB, an Xn setup response message acknowledging the Xn setup request message from the first base station, based on the Xn setup request message.

3. In paragraph 1, The steps for performing the above Xn connection establishment procedure are: A step in which the gNB of the specific MWAB transmits an Xn setup request message to the first base station; The above Xn setup request message includes mobility information of the specific MWAB, A method comprising the step of: i) receiving, by a gNB of the specific MWAB, an Xn setup response message accepting the Xn setup request message from the first base station, based on the fact that the first base station corresponds to an MWAB and ii) that the mobility of the first base station and the mobility of the specific MWAB are similar.

4. In paragraph 3, A method wherein the Xn setup response message includes mobility information of the first base station, based on the first base station corresponding to the MWAB.

5. In paragraph 1, The steps for performing the above Xn connection establishment procedure are: A step in which the gNB of the specific MWAB transmits an Xn setup request message to the first base station; The above Xn setup request message includes mobility information of the specific MWAB, A method comprising the step of: receiving, by the gNB of the specific MWAB, an Xn setup failure message rejecting the Xn setup request message from the first base station based on the Xn setup request message.

6. In paragraph 1, The steps for performing the above Xn connection establishment procedure are: A step in which the gNB of the specific MWAB transmits an Xn setup request message to the first base station; The above Xn setup request message includes mobility information of the specific MWAB, A method comprising the step of: i) receiving, by a gNB of the specific MWAB, an Xn setup failure message rejecting the Xn setup request message from the first base station based on the fact that the first base station corresponds to an MWAB and ii) that the mobility of the first base station and the mobility of the specific MWAB are not similar.

7. In paragraph 6, A method wherein the Xn setup failure message includes mobility information of the first base station, based on the first base station corresponding to MWAB.

8. In paragraph 5 or 6, Based on the above Xn setup failure message, the specific MWAB further includes a step of transmitting a new Xn setup request message to the first base station, A method in which, based on the above Xn setup failure message, the specific MWAB skips transmitting a new Xn setup request message to the first base station for a certain period of time.

9. In paragraph 5 or 6, Based on the above Xn setup failure message, the specific MWAB further includes a step of receiving the Xn setup failure message to the first base station and transmitting a new Xn setup request message after a certain period of time, 10. In clauses 2 to 9, A method wherein the above Xn setup request message includes i) information on whether the specific MWAB is roaming or ii) information on the network that connected the NG interface based on the roaming of the specific MWAB.

11. In paragraph 1, The steps for performing the above Xn connection establishment procedure are: A step in which the gNB of the specific MWAB receives an Xn setup request message from the first base station; A step of determining whether the gNB of the specific MWAB approves the Xn setup with the first base station based on the Xn setup request message; A step of the gNB of the specific MWAB transmitting an Xn setup response message to the first base station, wherein the Xn setup response message acknowledges the Xn setup request message based on the gNB of the specific MWAB deciding to accept the Xn setup; The above Xn setup response message includes mobility information of the specific MWAB, A step of the gNB of the specific MWAB transmitting an Xn setup failure message to the first base station, wherein the gNB of the specific MWAB determines not to accept the Xn setup request message, based on the gNB of the specific MWAB deciding not to accept the Xn setup, A method wherein the above Xn setup failure message includes mobility information of the specific MWAB.

12. In paragraph 11, Based on the above first base station corresponding to MWAB, the Xn setup request message includes mobility information of the first base station, i) based on the first base station corresponding to the MWAB and ii) the mobility of the first base station and the mobility of the specific MWAB being similar, the step of determining whether the gNB of the specific MWAB accepts or rejects the Xn configuration is: determining that the gNB of the specific MWAB accepts the Xn configuration; i) based on the first base station corresponding to the MWAB and ii) the mobility of the first base station and the mobility of the specific MWAB are not similar, the step of determining whether the gNB of the specific MWAB accepts or rejects the Xn configuration is: a method of determining that the gNB of the specific MWAB does not accept the Xn configuration.

13. In paragraph 12, Based on the first base station corresponding to MWAB, the Xn setup request message includes i) whether the first base station is roaming or ii) network information that connects the NG interface based on the first base station roaming, A method according to claim 1, wherein the step of determining whether the gNB of the specific MWAB accepts or rejects the specific MWAB is performed based on at least one of: i) whether the first base station is roaming, ii) network information connecting the NG interface based on the roaming of the first base station, and iii) the distance between the first base station and the specific MWAB.

14. In any one of paragraphs 1 to 13, The mobility information of the above specific MWAB includes information that the above specific MWAB moves, A method wherein the mobility information of the first base station includes information that the first base station is moving.

15. In any one of paragraphs 1 to 14, The mobility information of the specific MWAB includes at least one of information on whether the specific MWAB operates as a MWAB, whether the specific MWAB is mobile, a moving direction, a moving speed, and a location. A method in which the mobility information of the first base station includes at least one of information that the first MWAB operates as a MWAB, whether the first base station is mobile, a moving direction, a moving speed, and location information.

16. As a method, A step in which a base station receives an Xn setup request message from a gNB (gNodeB) of a specific MWAB (Mobile gNB with wireless access backhauling); The above Xn setup request message includes mobility information of the specific MWAB, A step of determining whether the base station approves Xn setup with the specific MWAB based on the Xn setup request message; A step of the base station transmitting an Xn setup response message acknowledging the Xn setup request message to the gNB of the specific MWAB based on the base station's decision to accept the Xn setup; A method comprising the step of the base station sending an Xn setup failure message to the gNB of the specific MWAB, rejecting the Xn setup request message based on the base station deciding not to accept the Xn setup.

17. In paragraph 16, A method wherein the above Xn setup request message includes i) information on whether the specific MWAB is roaming or ii) information on the network that connected the NG interface based on the roaming of the specific MWAB.

18. As a method, A step in which a base station transmits an Xn setup request message to a gNB (gNodeB) of a specific MWAB (Mobile gNB with wireless access backhauling); A step of the base station receiving an Xn setup response message from a gNB of a specific MWAB based on the Xn setup request message and the Xn setup request message being accepted; The above Xn setup response message includes mobility information of the specific MWAB, A step of the base station receiving an Xn setup failure message from a gNB of a specific MWAB based on the Xn setup request message and the Xn setup request message being not accepted; A method wherein the above Xn setup failure message includes mobility information of the specific MWAB.

19. As a specific MWAB (Mobile gNB with wireless access backhauling) performing communication, At least one transmitter and receiver; comprising at least one processor, A specific MWAB wherein the operations performed by said at least one processor are a method according to any one of claims 1 to 15.

20. As a base station performing communications, At least one transmitter and receiver; comprising at least one processor, A UE wherein the operation performed by at least one processor is a method according to any one of claims 16 to 18.

21. As an apparatus in mobile communication, at least one processor; and At least one memory storing instructions and being operably electrically connected to said at least one processor, A device wherein an operation performed based on the above command being executed by the at least one processor is a method according to any one of claims 1 to 15.

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