NAS timer setting method

Abstract

The present disclosure provides a method. The method comprises the steps in which: an SMF receives an establishment request for a PDU session for a UE from an AMF, wherein the establishment request includes a category for a satellite backhaul on the basis of the satellite backhaul being used for the UE; the SMF transmits an analysis request for the UE to an NWDAF; the SMF receives the result of UE analysis from the NWDAF on the basis of the analysis request, wherein the result of the analysis includes information about the satellite backhaul; the SMF determines, on the basis of the category for the satellite backhaul and result of the analysis, that an NAS timer used by the UE is to operate with a value extended from an existing value; and the SMF transmits the extended value to the UE on the basis of the determination.

Description

How to set NAS timer

[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] The network can set an extended NAS timer value based on the analysis and transmit it to the terminal.

[0006] Figure 1 illustrates an example of a communication system to which the implementation of this specification is applied.

[0007] Figure 2 illustrates an example of a wireless device to which the implementation of the present specification is applied.

[0008] Figure 3 shows an example of a UE to which the implementation of this specification is applied.

[0009] Figure 4 is a structural diagram of a next-generation mobile communications network.

[0010] Figure 5 shows an example of a 5G system structure to which the implementation of this specification is applied.

[0011] Figures 6 and 7 illustrate examples of a PDU session establishment procedure to which the implementation of the present specification applies.

[0012] Figure 8 shows an example of satellite arrangement.

[0013] Figure 9 shows an example of a backhaul.

[0014] FIG. 10 illustrates a first example of NAS timer setting according to the disclosure of this specification.

[0015] FIG. 11 illustrates a second example of NAS timer setting according to the disclosure of this specification.

[0016] FIG. 12 illustrates a third example of NAS timer setting according to the disclosure of this specification.

[0017] Figure 13 illustrates the SMF procedure for the disclosure of this specification.

[0018] Figure 14 illustrates the UE's procedure for disclosure of this specification.

[0019] The following techniques, devices, and systems can be applied to various wireless multiple access systems. Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and 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).

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

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

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

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

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

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

[0026] Additionally, parentheses used 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."

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

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

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

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

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

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

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

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

[0035] 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.

[0036] In this specification, wireless devices (100a to 100f) may be referred to as user equipment (UE). The UE may include, for example, a mobile phone, a smartphone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a slate PC, a tablet PC, an ultrabook, a vehicle, a vehicle with autonomous driving 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.

[0037] For example, a UAV may be an aircraft that is unmanned and navigated by radio control signals.

[0038] 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.

[0039] For example, a public safety device may include an image relay device or imaging device that can be worn on the user's body.

[0040] 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.

[0041] For example, a medical device may be a device used for the purpose of diagnosing, treating, mitigating, curing, or preventing a disease. For example, a medical device may be a device used for the purpose of diagnosing, treating, mitigating, 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.

[0042] 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), recorder, or black box.

[0043] 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.

[0044] For example, a weather / environment device may include a device that monitors or predicts the weather / environment.

[0045] 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).

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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).

[0053] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0054] 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 can be used for various purposes, such as for communications for vehicles (e.g., autonomous driving).

[0055] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0056] 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.

[0057] Figure 2 illustrates an example of a wireless device to which the implementation of the present specification is applied.

[0058] 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.

[0059] 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).

[0060] 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).

[0061] 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).

[0062] 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.

[0063] 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.

[0064] 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).

[0065] 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).

[0066] 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).

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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).

[0074] 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).

[0075] 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.

[0076] 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.

[0077] In this specification, a base station may be referred to as a Node B, an eNode B (eNB), or a gNB.

[0078] Figure 3 shows an example of a UE to which the implementation of this specification is applied.

[0079] Referring to FIG. 3, the UE (100) can correspond to the first wireless device (100) of FIG. 2.

[0080] 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).

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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).

[0085] 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).

[0086] 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.

[0087] 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).

[0088] Figure 4 is a structural diagram of a next-generation mobile communications network.

[0089] 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).

[0090] 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).

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] The illustrated PCF (430) is a node that controls the business operator's policy.

[0097] The illustrated AF (450) is a server for providing various services to the UE (100).

[0098] 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).

[0099] 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.

[0100] 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.

[0101] 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.

[0102] Figure 5 shows an example of a 5G system structure to which the implementation of this specification is applied.

[0103] The 5G system (5GS; 5G system) structure consists of the following network functions (NF; Network Function).

[0104] - AUSF (Authentication Server Function)

[0105] - AMF (Access and Mobility Management Function)

[0106] - DN (Data Network), 예를 들어 운영자 서비스, 인터넷 접속 또는 타사 서비스

[0107] - USDF (Unstructured Data Storage Function)

[0108] - NEF (Network Exposure Function)

[0109] - I-NEF (Intermediate NEF)

[0110] - NRF (Network Repository Function)

[0111] - NSSF (Network Slice Selection Function)

[0112] - PCF (Policy Control Function)

[0113] - SMF (Session Management Function)

[0114] - UDM (Unified Data Management)

[0115] - UDR (Unified Data Repository)

[0116] - UPF (User Plane Function)

[0117] - UCMF (UE radio Capability Management Function)

[0118] - AF (Application Function)

[0119] - UE (User Equipment)

[0120] - (R)AN ((Radio) Access Network)

[0121] - 5G-EIR (5G-Equipment Identity Register)

[0122] - NWDAF (Network Data Analytics Function)

[0123] - CHF (CHarging Function)

[0124] Additionally, the following network features may be considered:

[0125] - N3IWF (Non-3GPP InterWorking Function)

[0126] - TNGF (Trusted Non-3GPP Gateway Function)

[0127] - W-AGF (Wireline Access Gateway Function)

[0128] 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.

[0129] 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.

[0130] 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.

[0131] The 5G system architecture includes the following benchmarks:

[0132] - N1: Reference point between UE and AMF.

[0133] - N2: Reference point between (R)AN and AMF.

[0134] - N3: Reference point between (R)AN and UPF.

[0135] - N4: Reference point between SMF and UPF.

[0136] - N6: Reference point between UPF and data network.

[0137] - N9: Reference point between two UPFs.

[0138] The following benchmarks illustrate the interactions that exist between NF services in NF.

[0139] - N5: Reference point between PCF and AF.

[0140] - N7: Reference point between SMF and PCF.

[0141] - N8: Reference point between UDM and AMF.

[0142] - N10: Reference point between UDM and SMF.

[0143] - N11: Reference point between AMF and SMF.

[0144] - N12: Reference point between AMF and AUSF.

[0145] - N13: Reference point between UDM and AUSF.

[0146] - N14: Reference point between two AMFs.

[0147] - N15: Reference point between PCF and AMF for non-roaming scenarios, and reference point between PCF and AMF of visited network for roaming scenarios.

[0148] - N16: Reference point between two SMFs (in case of roaming, between the SMF of the visited network and the SMF of the home network)

[0149] - N22: Reference point between AMF and NSSF.

[0150] In some cases, two NFs may need to be interconnected to serve a UE.

[0151] <PDU 세션 수립 절차>

[0152] Describes the PDU session establishment procedure. See Section 4.3.2 of 3GPP TS 23.502 V16.3.0 (2019-12).

[0153] Figures 6 and 7 illustrate examples of a PDU session establishment procedure to which the implementation of the present specification applies.

[0154] Establishing a PDU session may involve:

[0155] - UE-initiated PDU session establishment procedure

[0156] - PDU session handover between 3GPP and non-3GPP initiated by UE

[0157] - PDU session handover from UE-initiated EPS to 5GS.

[0158] - Network-triggered PDU session establishment procedure

[0159] 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.

[0160] Figures 6 and 7 specify the procedure for establishing a PDU session associated with a single connection type at a given time.

[0161] In the procedures shown in Figures 6 and 7, 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.

[0162] First, the procedure of Fig. 6 is explained.

[0163] (1) Step 1: To establish a new PDU session, the UE generates a new PDU session ID.

[0164] 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.

[0165] 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."

[0166] 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.

[0167] (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.

[0168] 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.

[0169] 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.

[0170] 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:

[0171] - When the SMF ID and AMF corresponding to the PDU session ID belong to the same PLMN;

[0172] - If the SMF ID corresponding to the PDU session ID belongs to HPLMN;

[0173] Otherwise, AMF rejects the PDU session establishment request with an appropriate rejection cause.

[0174] AMF rejects requests from emergency-registered UEs whose request type does not indicate "Emergency Request" or "Existing Emergency PDU Session".

[0175] (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).

[0176] 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.

[0177] 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.

[0178] 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.

[0179] 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.

[0180] (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.

[0181] (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.

[0182] 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.

[0183] 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.

[0184] (6) Step 6: Optional secondary authentication / authorization may be performed.

[0185] (7a) Step 7a: When dynamic policy and charging control (PCC) is used in a PDU session, the SMF can perform PCF selection.

[0186] (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.

[0187] (8) Step 8: SMF selects one or more UPFs.

[0188] (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.

[0189] (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.

[0190] 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.

[0191] (11) Step 11: SMF sends an N1N2 message transfer message (e.g. Namf_Communication_N1N2 Message Transfer) to AMF.

[0192] 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:

[0193] - CN Tunnel Info: Corresponds to the core network address of the N3 tunnel corresponding to the PDU session;

[0194] - QFI (QoS flow ID) corresponding to one or more QoS (quality of service) profiles;

[0195] - PDU Session ID: Indicates to the UE the association between RAN resources and a PDU session for the UE;

[0196] - S-NSSAI with value for serving PLMN (i.e. HPLMN S-NSSAI, or VPLMN S-NSSAI in case of LBO roaming);

[0197] - User plane security enforcement information determined by SMF;

[0198] - 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.

[0199] - RSN (redundancy sequence number) parameter

[0200] 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.

[0201] 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.

[0202] 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.

[0203] (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.

[0204] (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.

[0205] (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.

[0206] If N2 SM information is not included in step 11, steps 14-16b and 17 below are omitted.

[0207] Now, the procedure of Fig. 7 following the procedure of Fig. 6 is described.

[0208] (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.

[0209] (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.

[0210] (16a) Step S16a: SMF initiates the N4 session modification procedure with UPF. SMF provides AN tunnel information and corresponding forwarding rules to UPF.

[0211] (16b) Step S16b: UPF provides an N4 session modification response to SMF.

[0212] After this step, the UPF can forward any DL packets that may have been buffered for this PDU session to the UE.

[0213] (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.

[0214] (17) Step 17: SMF sends an update SM context response message (e.g., Nsmf_PDUSession_UpdateSMContext Response) to AMF.

[0215] After this step, AMF forwards the relevant events to which SMF subscribes.

[0216] (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.

[0217] (19) Step 19: For PDU session type IPv6 or IPv4v6, SMF may generate and send an IPv6 Router Advertisement to the UE.

[0218] (20) Step 20: SMF can perform SM policy association modification initiated by SMF.

[0219] (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.

[0220] The NAS timer can be a 5GMM (5G Mobility Management) timer or a 5GSM (5G Session Management) timer.

[0221] The NAS timer can ensure that NAS messages are transmitted and received normally between terminals and the network (NW) in a 5G system. The NAS timer can operate on both the terminal and the network.

[0222] If the network fails to receive a NAS message sent by a terminal, the terminal may retransmit the NAS message to ensure reliable communication. This retransmission of NAS messages may be performed based on a NAS timer.

[0223] For example, a terminal may transmit a NAS message (e.g., a Registration Request) to the network. The terminal may wait for a response to the NAS message (e.g., registration approval or registration rejection).

[0224] A terminal can initiate a specific procedure (e.g., a registration procedure) via a NAS message (e.g., a registration request). When a terminal transmits a NAS message (e.g., a registration request) to the network, the terminal can start a NAS timer (e.g., a T3510 timer).

[0225] When the terminal receives a response to the NAS message from the network (e.g., registration approval or registration rejection), the terminal may stop the corresponding NAS timer (e.g., T3510 timer). Thereafter, the procedure according to the response may be performed.

[0226] If the terminal does not receive a response (e.g., registration approval or registration rejection) to the NAS message before the NAS timer (e.g., T3510 timer) expires, the terminal may retransmit the NAS message (e.g., registration request) or abort the corresponding procedure (e.g., registration procedure). The abort of the corresponding procedure (registration procedure) may be performed based on the number of retransmissions of the NAS message (e.g., registration request) by the terminal exceeding a predetermined number. This operation may be preset in the terminal.

[0227] NAS timer values ​​must be set appropriately.

[0228] If the NAS timer value is set to a long value, this process may take a long time.

[0229] Conversely, if the NAS timer value is set too short, triggers for the procedure may occur too frequently. Furthermore, unexpected behavior may occur due to procedure collisions between the terminal and the network.

[0230] Therefore, it is important that the NAS timer value is determined appropriately.

[0231] The NAS timer value can be determined based on the round trip time (RTT) between the terminal and the network, the NAS message size, the maximum retransmission number of the RAN, and the RAT type (e.g., terrestrial network, GEO satellite RAT type).

[0232] Specific NAS timer values ​​can be applied to the contents of TS24.501 v18.5.0 (5GMM NAS timer, 5GSM NAS timer).

[0233] When a terminal transmits NAS messages via a satellite NG-RAN, the NAS timer value may be determined based on information from a lower layer (e.g., RRC layer). When a terminal transmits NAS messages via a satellite NG-RAN, the NAS timer value may be determined based on the current satellite NG-RAN access RAT type.

[0234] For example, with respect to a specific NAS timer (T3510), if the terminal accesses via a GEO satellite NG-RAN type cell, the T3510 value may be 27 seconds. For normal access, the T3510 value may be 15 seconds.

[0235] If the terminal uses a satellite access network of the GEO access type, the GEO (Geosynchronous Earth Orbit) satellite (geostationary satellite) is generally 65768 km away from the ground, so the NAS timer value can be determined based on the RTT and number of retransmissions taking this into account.

[0236] When the RTT of the GEO satellite access type is 542 ms and the maximum number of retransmissions is 16, the calculated delay (delay without GNSS) is 10.02 sec.

[0237] The RTT of NG-RAN existing in the terrestrial network is considered to be almost zero compared to satellite networks.

[0238] Considering that the message is transmitted through more than one retransmission, RAN2 calculates the NAS message transport delay as shown in Table 3. Based on this, the NAS timer value can be determined.

[0239]

[0240] Until now, different NAS timer values ​​have been used based on the terminal's RAT type. That is, when a terminal accesses a GEO Satellite NG-RAN, the extended NAS timer value has been used.

[0241] Additionally, when a terminal transmits a message via satellite NG-RAN access, it is assumed that AMF, SMF, UPF, etc. are connected to the terrestrial core network, and therefore the NAS timer value used by the terminal is determined only based on satellite NG-RAN access.

[0242] However, in the case of the satellite backhaul currently discussed, UPF, etc. may exist on the satellite.

[0243] For example, the AMF and SMF for control to establish a connection may use the terrestrial core network, while the UPF may be onboard the satellite. In this case, the RTT between the AMF (or other network entity) and the UPF must be additionally considered for the connection. Since the N4 information IEs (PDR, FAR, QER, URR) are passed from the SMF to the UPF, additional RTT may be considered for these messages.

[0244] When a dynamic backhaul change is performed, different NAS timers may be used for different backhauls.

[0245] A conventional terrestrial network backhaul may be used, a satellite backhaul may be used, multiple satellite backhauls may be used, or different satellite backhauls may be used.

[0246] For example, a terminal can establish an initial connection using a geostationary satellite backhaul, and then perform a handover. After the handover, the terminal can utilize the terrestrial network backhaul or another satellite backhaul.

[0247] For example, after a PDU session is connected / established, a data network can be connected between the terminal, base station, and UPF. Then, data can be transmitted and received between the terminal and the network. After this, when a handover is performed, even if the AMF receives a handover command from the NG-RAN (base station), the AMF may not inform the terminal of a change in backhaul. In other words, even if the backhaul has changed, the AMF may not inform the terminal of this change.

[0248] Therefore, even if the backhaul changes to satellite backhaul due to handover, the NAS timer can be the value used in the core network existing in the existing terrestrial network.

[0249] That is, in some cases, a NAS timer may be required for satellite backhaul. If each satellite backhaul is used, a NAS timer considering each satellite backhaul may be required.

[0250] If dynamic backhaul changes occur, the NAS timer must be determined to take this into account.

[0251] Additionally, NAS timers must take satellite placement into account.

[0252] Figure 8 shows an example of satellite arrangement.

[0253] As shown in Fig. 8, an inter-satellite link (ISL) may exist between the terminal and the 5GC. In such a case, there has been no prior art regarding whether the NAS timer value would be determined taking the ISL into consideration.

[0254] As shown in Fig. 8, multi-hop satellites can be connected via ISL.

[0255] When a PDU session is established or modified, the SMF can establish a connection with the UPF via an N4 message. If the UPF is onboard the satellite, a dynamic NAS timer value can be used.

[0256] A method is needed to determine these dynamic NAS timer values.

[0257] Figure 9 shows an example of a backhaul.

[0258] Figure 9 shows an example of a conceptual backhaul.

[0259] Backhaul conceptually refers to the intermediate link operating between the core network and the network edge. In 5G systems, backhaul refers to the link passing between the base station (eNB or gNB) and the core network.

[0260] In 5G systems, the UPF, which handles data packet transmission, the AMF, which handles terminal mobility, and the SMF, which manages PDU sessions, can all function as backhaul. Currently, discussions are underway to integrate the UPF function into satellites rather than the existing terrestrial network via the 5GSAT_Ph2 WI. Furthermore, discussions are also underway to integrate AMF or SMF into satellites in addition to the UPF.

[0261] Additionally, AMF, SMF or UPF may be mounted on a satellite, but may also be located on the ground as before.

[0262] That is, the backhaul can be ground backhaul or satellite backhaul.

[0263] Satellites such as GEO and LEO can carry network entities such as AMF and SMF onboard. In this case, the AMF and SMF may be satellite backhaul.

[0264] Additionally, satellites such as GEO and LEO may be equipped with a UPF responsible for data transmission. In this case, the UPF may be a satellite backhaul.

[0265] Alternatively, communications can be performed via terrestrial backhaul. The terrestrial network's UPF can be the terrestrial backhaul.

[0266] Depending on how you set it up, it may determine which backhaul to use.

[0267] The backhaul of the terrestrial network and the backhaul of the satellite network can be selected statically, but the backhaul of the terrestrial network and the backhaul of the satellite network can also be selected dynamically.

[0268] For example, when using satellite network backhaul, network entities can be mounted on the satellite and used.

[0269] For example, when using a terrestrial network backhaul, the network entities of the terrestrial network can be used.

[0270] For example, if the serving AMF is mounted on a satellite (satellite network backhaul) and the target AMF is located on a terrestrial network (terrestrial network backhaul), the satellite network backhaul may be changed to the terrestrial network backhaul due to a handover, etc. In this way, the satellite network backhaul and the terrestrial network backhaul may be dynamically selected (dynamic backhaul).

[0271] In the PDU session establishment procedure of FIG. 6 and FIG. 7 (or 4.3.2.2 of TS23.502 V17.11.0), the terminal may transmit a session establishment request message to the AMF. At this time, the session establishment request message may include the RAT type and global RAN ID received from the NG-RAN.

[0272] The AMF can determine / recognize the satellite backhaul category based on local configuration. For example, the AMF can determine / recognize the satellite backhaul category based on the Global RAN Node IDs associated with the satellite backhaul.

[0273] The AMF can receive the cell ID on which the terminal camped from the base station (NG-RAN) through a registration procedure. Based on the received cell ID and global RAN node IDs, the AMF can determine / recognize the satellite backhaul category.

[0274] After the AMF selects the SMF, the AMF can transmit the satellite backhaul category and GEO satellite ID to the SMF.

[0275] Based on the locally configured mapping information based on the GEO satellite ID, local configuration, DNN, and S-NSSAI received from the AMF, the SMF can select a DNAI (Data network access identifier).

[0276] An operator can assign one or more DNAIs to each GEO satellite ID. Mapping information between DNAIs and GEO satellite IDs can be configured locally in the SMF. Based on this, the SMF can select a UPF associated with the DN (Data Network).

[0277] At this time, the SMF can select a satellite-onboard UPF. The SMF and UPF can then be connected via a satellite link. Satellite links can be slower than terrestrial network inter-entity links. Therefore, if the SMF selects a satellite-onboard UPF, the time it takes for the terminal to trigger the PDU session establishment process and receive session acceptance (or rejection) may be longer.

[0278] Since the N4 communication message that SMF transmits to UPF is large in size, the procedure that requires communication with the UPF mounted on the device may take longer.

[0279] The following cases may be used in this specification when satellite backhaul is used:

[0280] - If the base station serving the terminal is mounted on a satellite

[0281] - If the satellite has UPF for PDU sessions for terminals.

[0282] - If at least one node of the base station and network is mounted on the satellite.

[0283] When satellite backhaul is used, new satellites (satellite operators) can communicate via satellite without installing new base stations. Furthermore, when satellite backhaul (partial or complete core network onboard the satellite) is used, satellites can communicate via satellite backhaul even when frequent disputes prevent them from using the terrestrial core network.

[0284] If satellite backhaul is used for the terminal, the NAS timer of the terminal may be set to an extended value.

[0285] Therefore, if satellite backhaul is used (e.g., satellite-mounted UPF is selected), the NAS timer value can be set to a larger value than before.

[0286] For example, the NAS timer may be a T3580 timer that is started when the terminal sends a PDU session establishment request.

[0287] For example, the NAS timer may be a T3581 timer that is started when the terminal sends a PDU session modification request.

[0288] For example, the NAS timer may be a T3517 timer that is started when the terminal sends a service request.

[0289] However, these NAS timers can be used as fixed values. Furthermore, the SMF may know whether a satellite-mounted UPF is selected / used, but the terminal may not.

[0290] Therefore, there is a need for a method of determining whether to use the enhanced NAS timer and / or a method of causing a terminal to utilize an appropriate NAS timer.

[0291] NAS timers can have their timer values ​​set via OAM for each deployment option.

[0292] Alternatively, when a terminal attempts to establish a connection, NWDAF may transmit a NAS timer value to the terminal. Based on this, the terminal can set the NAS timer value.

[0293] Network entities such as OAM, NWDAF, etc. can set NAS timer values.

[0294] When GEO satellite backhaul is used via GEO satellite NG-RAN access, the NAS timer value may be set differently. In this case, the NAS timer value may be set longer than the conventional timer value.

[0295] When conventional backhaul (e.g., terrestrial network) is used over GEO satellite NG-RAN access, the NAS timer value may be set differently. In this case, the NAS timer value may be set longer than the conventional timer value.

[0296] When using satellite backhaul from a GEO satellite, the NAS timer value may be set differently. In this case, the NAS timer value may be set longer than the conventional timer value.

[0297] The NF (Network Function) (or network control node) (e.g. SMF, AMF) can determine whether the terminal is attempting to connect to a satellite NG-RAN cell using satellite backhaul.

[0298] The NF (Network Function) (or network control node) (e.g., SMF, AMF) can receive satellite NG-RAN cell information from a lower layer. Based on this information, the NF (Network Function) (e.g., SMF, AMF) can determine whether the terminal is attempting to connect to a satellite NG-RAN cell using satellite backhaul.

[0299] The NF (Network Function) (or Network Control Node) (e.g. SMF, AMF) can infer (or determine) whether satellite backhaul is used by receiving the Global RAN node ID from the satellite NG-RAN cell.

[0300] When a Network Function (NF) (or Network Control Node) (e.g., SMF, AMF) determines that satellite backhaul is to be used, the Network Function (NF) (e.g., SMF, AMF) may decide whether to use a timer value that is longer than the existing NAS timer value.

[0301] During the registration process, the AMF can receive the cell ID on which the terminal camped from the base station (NG-RAN). Based on the cell ID, the AMF can determine the global RAN node ID. Based on the global RAN node ID, the AMF can determine (or recognize) the satellite backhaul category for the terminal.

[0302] AMF can transmit the satellite backhaul category for the terminal to SMF.

[0303] When the AMF becomes aware of a change in the satellite backhaul category (e.g., a handover), the AMF may report the current (changed) satellite backhaul category to the SMF.

[0304] That is, the SMF can receive the terminal's current satellite backhaul category, GEO satellite ID, etc. from the AMF. Based on this, the SMF can decide whether to use a timer value that is longer than the existing NAS timer value.

[0305] If the SMF receives a changed satellite backhaul category from the AMF after it has already decided whether to use a timer value that is longer than the existing NAS timer value, the SMF can decide whether to use a new NAS timer and the new NAS timer value.

[0306] When a terminal attempts to connect to a satellite NG-RAN cell using satellite backhaul, the Network Function (NF) (e.g., SMF, AMF) can decide whether to use a timer value that is longer than the existing NAS timer value.

[0307] When a terminal attempts to connect to a satellite NG-RAN cell using satellite backhaul, the first network control node may determine whether to use a timer value that is longer than the existing NAS timer value. The first network control node may then transmit the determination and the timer value to a second network control node. The second network control node may then transmit the received timer value to the terminal.

[0308] The extended timer value can be determined (or calculated / set) by the network control node. Alternatively, the extended timer value can be determined (or calculated / set) by the NWDAF.

[0309] The extended timer value may be determined based on operator policy.

[0310] For 5GS mobility management via satellite NG-RAN cells, the terminal can apply NAS timer values ​​for access via satellite NG-RAN cells.

[0311] The applied NAS timer value may be determined based on the current satellite NG-RAN access RAT type determined based on information from lower layers.

[0312] The NAS timer value may be calculated when the NAS procedure starts. The NAS timer value may not be recalculated until the NAS procedure completes, restarts, or is aborted.

[0313] Access via a satellite NG-RAN cell by a terminal can be notified to the AMF by a lower layer. The AMF can then store this information. If the AMF, which supports access via a satellite NG-RAN cell, performs NAS signaling with the terminal via the satellite NG-RAN cell, the AMF can calculate the corresponding NAS timer value for access via the satellite NG-RAN cell.

[0314] When accessing a satellite NG-RAN cell with satellite backhaul, the AMF may calculate the corresponding NAS timer (e.g. T3517 timer) value for access via the satellite NG-RAN cell with satellite backhaul.

[0315] The applied NAS timer value may be determined based on the current satellite NG-RAN access RAT type with satellite backhaul, which is determined by operator policy and operator-specific data analysis information.

[0316] For 5GS session management via satellite NG-RAN cells, the terminal can determine the NAS timer value for access via the satellite NG-RAN cell.

[0317] The NAS timer value may be determined based on the current satellite NG-RAN access RAT type determined based on information from lower layers.

[0318] The AMF may instruct the use of an extended NAS timer for access via satellite NG-RAN cells. In this case, the SMF may calculate the extended NAS timer value for access via satellite NG-RAN cells.

[0319] When a terminal accesses a satellite NG-RAN cell with satellite backhaul, the SMF may calculate a NAS timer (e.g., T3580 timer) value for access via the satellite NG-RAN cell with satellite backhaul.

[0320] SMF can determine the extended NAS timer value to be used by the terminal.

[0321] SMF can determine the extended NAS timer value through another NF (e.g., NWDAF).

[0322] NWDAF can analyze the transmission time of PDU sessions transmitted over the satellite backhaul category. The analysis results can be transmitted to the SMF. Based on these results, the SMF can determine the extended NAS timer value.

[0323] Alternatively, the SMF can determine its own extended NAS timer value. The SMF can determine the NAS timer for each RAT type and satellite backhaul category.

[0324] SMF can notify AMF whether to use extended NAS timers.

[0325] SMF can notify AMF of extended NAS timer values.

[0326] AMF can notify the terminal whether to use extended NAS timer.

[0327] AMF can notify the terminal of an extended NAS timer value.

[0328] When the terminal receives an extended NAS timer value (and / or usage status), the terminal may update the existing NAS timer with the received extended NAS timer value.

[0329] When a terminal transmits a NAS message (e.g., PDU Session Establishment Request, PDU Session Modification Request, Service Request), the terminal may use an extended NAS timer that takes into account the satellite backhaul category. That is, based on the extended NAS timer value, the terminal may perform a NAS message retransmission (or abort the corresponding procedure) at a later time.

[0330] FIG. 10 illustrates a first example of NAS timer setting according to the disclosure of this specification.

[0331] (1) Step 1

[0332] A terminal can send a PDU session establishment request to AMF while it is registered.

[0333] (2) Step 2

[0334] AMF can send a PDU session establishment request to SMF.

[0335] AMF can receive NGAP messages from base stations (NG-RAN).

[0336] The NGAP message may include a global RAN node ID and a RAT type. The RAT type may include information about whether the base station (NG-RAN) is connected via a satellite backhaul. This allows the AMF to determine whether the base station is connected via a satellite backhaul (whether the terminal and / or base station uses a satellite backhaul).

[0337] AMF may include the satellite backhaul category in the PDU session establishment request to be sent to SMF.

[0338] For example, if the terminal and / or base station uses satellite backhaul, the AMF may include the satellite backhaul category in the PDU session establishment request. For example, the AMF may include GEO, MEO, LEO, OTHERSAT, DYNAMIC_GEO, DYNAMIC_MEO, DYNAMIC_LEO, DYNAMIC_OTHERSAT, etc. in the PDU session establishment request.

[0339] AMF may include the GEO satellite ID in the PDU session establishment request to be sent to SMF.

[0340] For example, if the base station accessed by the terminal is a GEO satellite, the AMF may include the corresponding GEO satellite ID in the PDU session establishment request.

[0341] (3) Step 3

[0342] The SMF may decide to use an extended NAS timer based on the received satellite backhaul category and / or GEO satellite ID.

[0343] The SMF can obtain information by interacting with the UDM. The information obtained from the UDM may include stored extended NAS timer values ​​and / or information about the satellite backhaul.

[0344] The SMF can obtain information through interaction with the NWDAF. The SMF can transmit information obtained from the NWDAF to the AMF.

[0345] Information obtained from NWDAF may include empirical statistics, NAS timer values ​​by backhaul category, 'extended NAS timer usage', etc.

[0346] Information obtained from NWDAF may be analysis information about the terminal.

[0347] NAS timer thresholds can be set for each deployment.

[0348] NWDAF can set NAS timer thresholds for each deployment based on the current NAS timer value and the value set in OAM.

[0349] The threshold of the NAS timer can be set for each backhaul type (e.g., GEO type, LEO type, etc.).

[0350] Based on the timestamp of the time when the terminal transmits the PDU session establishment request, the timestamp of the time when the SMF receives the message, and the timestamp of the time when the SMF sends the response message (PDU session acceptance / rejection), the NWDAF can calculate the time it takes the terminal to process the PDU session establishment related message.

[0351] If the time to transmit a NAS message is longer than a threshold, an extended NAS timer value may be used instead of the conventional NAS timer value.

[0352] That is, based on the information obtained from NWDAF, SMF can decide whether to use the extended NAS timer and can determine the extended NAS timer value.

[0353] If the NAS timer value obtained from NWDAF is higher than a set threshold, an extended NAS timer value can be determined.

[0354] Alternatively, AMF can determine the extended NAS timer value.

[0355] Based on information obtained from the satellite backhaul category, GEO satellite ID, and / or NWDAF, the SMF may determine that the terminal should use the extended NAS timer value instead of the existing value as the NAS timer.

[0356] Based on information obtained from the satellite backhaul category, GEO satellite ID, and / or NWDAF, the SMF can determine the extended NAS timer value.

[0357] Based on the SMF's decision that the terminal should use the extended NAS timer value instead of the existing value as the NAS timer, the SMF may transmit the extended NAS timer value to the terminal.

[0358] The SMF may select the UPF onboard the satellite during the session establishment process. Based on the SMF's selection of the UPF onboard the satellite, the SMF may determine that the terminal should use the extended NAS timer value instead of the existing value. The SMF may determine the extended NAS timer value based on information obtained from the satellite backhaul category, GEO satellite ID, and / or NWDAF. The information obtained from the NWDAF may include information regarding the UPF onboard the satellite.

[0359] (4) Step 4

[0360] Based on the information received from the SMF, the AMF can determine the NAS timer value. The AMF can determine whether to use the extended NAS timer and determine the extended NAS timer value.

[0361] If the operator policy has a defined NAS timer per satellite backhaul, the AMF can determine an extended NAS timer based on the defined NAS timer.

[0362] (5) Step 5

[0363] AMF may transmit an extended NAS timer value to the terminal. The extended ANS timer value may be determined by AMF or SMF.

[0364] AMF can transmit extended NAS timer values ​​to terminals for each satellite backhaul category.

[0365] The terminal can update the NAS timer value previously set to itself with the received value (extended NAS timer value).

[0366] The extended NAS timer value can be greater than the original NAS timer value.

[0367] Afterwards, when the terminal triggers a PDU session establishment procedure (or modification procedure, procedure by service request), the updated timer value may be used.

[0368] FIG. 11 illustrates a second example of NAS timer setting according to the disclosure of this specification.

[0369] (1) Step 1

[0370] A terminal can send a registration request to AMF.

[0371] The registration request may include information that the terminal supports the use of an extended NAS timer.

[0372] (2) Step 2

[0373] AMF can send a Uudm_UECM_Registration request to UDM.

[0374] AMF checks if there is a timer stored in UDM, and if not, it can retrieve the extended NAS timer value via NWDAF.

[0375] If there is no extended NAS timer value stored in the UDM, the UDM can obtain the extended NAS timer value from the NWDAF.

[0376] UDM can send extended NAS timer values ​​to AMF.

[0377] If a NAS timer value is stored in UDM, UDM can transmit that value to AMF.

[0378] If there is no NAS timer value stored in the UDM, the UDM can send the value obtained from the NWDAF to the AMF.

[0379] (3) Step 3

[0380] AMF can transmit extended NAS timer values ​​to terminals. AMF can transmit information to terminals that it is using extended NAS timers.

[0381] The terminal can update the NAS timer value previously set to itself with the received value (extended NAS timer value).

[0382] Afterwards, when the terminal triggers a PDU session establishment procedure (or modification procedure, procedure by service request), the updated timer value may be used.

[0383] FIG. 12 illustrates a third example of NAS timer setting according to the disclosure of this specification.

[0384] (1) Step 1

[0385] A terminal can send a registration request to AMF.

[0386] (2) Step 2

[0387] AMF can receive NGAP messages from base stations (NG-RAN).

[0388] The NGAP message may include a global RAN node ID and a RAT type. The RAT type may include information on whether the base station (NG-RAN) is connected via a satellite backhaul.

[0389] (3) Step 3

[0390] Based on the global RAN node ID and RAT type, the AMF can determine whether the base station is connected via satellite backhaul (whether the terminal and / or base station uses satellite backhaul).

[0391] Based on the global RAN node ID and RAT type, the AMF can determine the GEO satellite ID associated with the base station.

[0392] Based on the global RAN node ID and RAT type, AMF can determine the category of satellite backhaul.

[0393] (4) Step 4

[0394] AMF can send N2 messages to SMF.

[0395] The N2 message may include the satellite backhaul category and GEO satellite ID.

[0396] (5) Step 5

[0397] The decision to select a local PSA or PSA UPA may be made based on the DNAI corresponding to the GEO satellite ID and other factors.

[0398] SMF can decide whether to use the extended NAS timer. SMF can decide the value of the extended NAS timer.

[0399] (6) Step 6

[0400] SMF can send N2 messages to AMF.

[0401] The N2 message may include an indication of an extended NAS timer value and an extended NAS timer value.

[0402] (7) Step 7

[0403] AMF can send registration approval to the terminal.

[0404] The registration approval may include an indication of an extended NAS timer value and an extended NAS timer value.

[0405] (8) Step 8

[0406] The terminal can update the T3580 timer value with the extended NAS timer value received from AMF.

[0407] Afterwards, when the terminal triggers a PDU session establishment procedure (or modification procedure, procedure by service request), the updated timer value may be used.

[0408] The SMF may request the NWDAF to conduct an empirical analysis of a terminal that frequently transmits PDU session establishment requests. This may be a terminal operating in a deployment environment using satellite backhaul.

[0409] NWDAF can infer (or determine) the time taken to transmit a message by using the time stamp of the PDU session establishment request received, the satellite backhaul status, the satellite backhaul category, and the time stamp of the PDU session establishment rejection, PDU session establishment approval, or PDU session release message sent.

[0410] If the time taken for a message to be transmitted based on the aforementioned time information is greater than the NAS timer value currently used by the terminal or greater than a certain threshold, the NWDAF may notify the SMF of the analysis information. If the SMF receives the analysis information, the SMF may consider the terminal's NAS timer value setting to be invalid and may set a new NAS timer value using the maximum time taken for the message received from the NWDAF.

[0411] The SMF may request the NWDAF to conduct empirical analysis of a terminal that frequently transmits service requests. This may be a terminal operating in a deployment environment using satellite backhaul.

[0412] NWDAF can infer (or determine) the time taken to transmit a message by using the presence of satellite backhaul, satellite backhaul category, time stamp of receiving a service request, and time stamp of sending a service rejection, service approval, or PDU session release message.

[0413] If the time taken for a message to be transmitted based on the aforementioned time information is greater than the NAS timer value currently used by the terminal or greater than a certain threshold, the NWDAF may notify the AMF of the analysis information. If the AMF receives the analysis information, the AMF may consider the terminal's NAS timer value setting to be invalid and may set a new NAS timer value using the maximum time taken for the message received from the NWDAF.

[0414] 1. NAS Timer Analysis

[0415] (1) General

[0416] Extended NAS timer analysis can be used to:

[0417] - If the PDU session establishment procedure for one or more terminals deployed in the satellite backhaul is performed frequently (faster than the average value / threshold), the SMF can determine the timer value for 5GSM session management based on the more advanced NAS timer analysis.

[0418] - When service request procedures for one or more terminals deployed in the satellite backhaul are frequently performed, the AMF can determine the timer value for 5GSM session management based on more advanced NAS timer analysis.

[0419] A service consumer can be an NF (e.g., AMF, SMF).

[0420] Consumers of these analyses may indicate in their requests:

[0421] - Analysis ID = “enhanced NAS timer”.

[0422] - Analysis report target: All UEs

[0423] Terminals with extended NAS timers can be deployed in satellite backhaul.

[0424] (2) Input data

[0425] NWDAF, which supports data analysis for extended NAS timers, can collect timestamps for sending service request messages and timestamps for predicting the outcome of service requests. Based on the timestamp information, NWDAF can calculate the actual time for each message to be processed.

[0426] Table 4 shows the 5GC NF input data for the extended NAS timer.

[0427] Information Source Description Satellite backhaul category AMF or SMF satellite backhaul category can be used to classify which satellite uses which backhaul. Here are some examples of satellite backhaul categories:- GEO: indicates Geostationary satellite backhaul category (satellites in circular orbits 36,000 km above the equator are used as backhaul)- MEO: indicates Medium Earth Orbit satellite backhaul category (satellites primarily used for GPS, navigation, etc. and orbiting between 5,000 km and 20,000 km are used as backhaul)- LEO: indicates Low Earth Orbit satellite backhaul category (satellites primarily used for communications and orbiting between 500 km and 1,200 km are used as backhaul)- OTHERSAT: indicates other satellite backhaul category (satellites other than the above GEO, MEO, and LEO are used as backhaul)Dynamic backhaul is when the capabilities (latency and bandwidth) of the satellite backhaul may change over time due to the use of links between different satellites.The following are examples of dynamic backhaul: - DYNAMIC_GEO: indicates dynamic Geostationary satellite backhaul category - DYNAMIC_MEO: indicates dynamic medium earth orbit satellite backhaul category - DYNAMIC_LEO: indicates dynamic low orbit satellite backhaul category - DYNAMIC_OTHERSAT: indicates dynamic satellite backhaul category - NON_SATELLITE: indicates non satellite backhaul category (does not use backhaul). GEO Satellite ID AMF or SMF GEO Satellite ID Time stamp A time stamp associated with the collected information. Time stamp for sending Service Request AMF Time stamp when the AMF receives Service request for the UE. Time stamp for expecting result of Service Request AMF Time stamp when the AMF sends the result of the Service Request to the UE. sends results of Service request (eg(Service Accept, Service reject, PDU session release))Time stamp for sending PDU session establishment procedure (Time stamp when the SMF receives PDU session establishment request for the UE.)Time stamp for expecting result of PDU session establishment procedure (Time stamp when the SMF sends results of PDU session establishment request (e.g. PDU session establishment Accept, PDU session establishment reject, PDU session release)).

[0428] (3) Output data

[0429] NWDAF can provide both statistics and predictions about network performance.

[0430] Table 5 shows network performance statistics.

[0431] Information DescriptionSatellite Backhaul CategorySatellite backhaul category can be used to classify which satellite uses which backhaul. Here are some examples of satellite backhaul categories:- GEO: indicates Geostationary satellite backhaul category (satellites in circular orbits 36,000 km above the equator are used as backhaul)- MEO: indicates Medium Earth Orbit satellite backhaul category (satellites primarily used for GPS, navigation, etc. and orbiting between 5,000 km and 20,000 km are used as backhaul)- LEO: indicates Low Earth Orbit satellite backhaul category (satellites primarily used for communications and orbiting between 500 km and 1,200 km are used as backhaul)- OTHERSAT: indicates other satellite backhaul category (satellites other than the above GEO, MEO, and LEO are used as backhaul)Dynamic backhaul is when the capabilities (latency and bandwidth) of the satellite backhaul may change over time due to the use of links between different satellites. The following are examples of dynamic backhaul:- DYNAMIC_GEO: indicates dynamic Geostationary satellite backhaul category- DYNAMIC_MEO: indicates dynamic medium earth orbit satellite backhaul category- DYNAMIC_LEO: indicates dynamic low orbit satellite backhaul category- DYNAMIC_OTHERSAT: indicates dynamic satellite backhaul category- NON_SATELLITE: indicates non satellite backhaul category (does not use the above backhaul category).GEO Satellite ID GEO Satellite ID Calculated NAS Timer Calculated NAS Timer Indicator to use new NAS timer (NOTE) Indicate to use whether calculated NAS timer or original one NOTE: If the calculated NAS timer value is above than NAS timer currently used or threshold based on operator policy, the indicator to use new NAS timer is set to "TRUE".

[0432] (4) Trigger

[0433] The triggers for SMF to request or subscribe to NWDAF's analytics information are internal to SMF's logic and may include, for example:

[0434] - Locally detected events (e.g., frequent PDU session setup procedures of one or more UEs deployed with satellite backhaul)

[0435] Trigger conditions may vary depending on the operator and SMF implementation policies. When a trigger condition occurs, the SMF determines whether analysis information is needed and, if so, requests or subscribes to the NWDAF for analysis information.

[0436] When the SMF detects certain local events (e.g., frequent PDU session setup procedures of one or more UEs co-located with satellite backhaul), it can subscribe to extended NAS timer analysis of those UEs to determine enhanced NAS timer values.

[0437] The triggers for AMF to request or subscribe to analytics information from NWDAF are internal logic of AMF and may include, for example:

[0438] - Locally detected events (e.g., frequent service request procedures from one or more UEs deployed with satellite backhaul)

[0439] Trigger conditions may vary depending on the operator and AMF's implementation policies. When a trigger condition occurs, AMF determines whether analysis information is required and, if so, requests or subscribes to the NWDAF for analysis information.

[0440] AMF may subscribe to extended NAS timer analysis of UEs to determine extended NAS timer values ​​when certain local events (e.g., frequent service request procedures of one or more UEs deployed with satellite backhaul) are detected.

[0441] For terminals performing satellite access using satellite backhaul, the NAS timer may be newly determined.

[0442] SMF (or AMF) can obtain analysis information from the Network Data Analytics Function (NWDAF) node.

[0443] The above-mentioned acquired analysis information may include experience analysis information on transmission of a terminal using satellite backhaul.

[0444] Based on the above analysis information, the SMF (or AMF) can determine the NAS timer required during the procedure associated with the PDU session.

[0445] The above decision may be made based on satellite backhaul category information.

[0446] 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 / 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.

[0447] Figure 13 illustrates the SMF procedure for the disclosure of this specification.

[0448] 1. The SMF (Session Management Function) can receive a request to establish a PDU (Protocol Data Unit) session for a UE (User Equipment) from the AMF (Access and Mobility management Function).

[0449] Based on which satellite backhaul is used for the UE, the establishment request may include a category for satellite backhaul.

[0450] 2. The above SMF can send an analysis request for the UE to the NWDAF (Network Data Analytics Function).

[0451] 3. Based on the above analysis request, the SMF can receive analysis results for the UE from the NWDAF.

[0452] The above analysis results may include information about the satellite backhaul.

[0453] 4. Based on the category for the satellite backhaul and the analysis results, the SMF may determine that the NAS (Non-Access-Stratum) timer used by the UE operates at a value extended from the existing value.

[0454] 5. Based on the above decision, the SMF can transmit the extended value to the UE.

[0455] Based on the change in the category for the satellite backhaul for the UE, the SMF can receive the changed category for the satellite backhaul for the UE from the AMF.

[0456] The above decision can be made based on the changed satellite backhaul.

[0457] Based on the change in the category for the satellite backhaul for the UE after the above decision, the SMF can receive the changed category for the satellite backhaul for the UE from the AMF.

[0458] After the above decision, based on the change in category for the satellite backhaul for the UE, the SMF may send a new analysis request for the UE to the NWDAF.

[0459] Based on the new analysis request, the SMF can receive new analysis results for the UE from the NWDAF.

[0460] The new analysis results may include information about the changed satellite backhaul.

[0461] Based on the category for the changed satellite backhaul and the new analysis results, the SMF may determine that the NAS timer used by the UE operates with a new value.

[0462] Based on the above decision, the SMF can transmit the new value to the UE.

[0463] Based on the base station being a satellite for the UE, the establishment request may include the ID of the satellite.

[0464] The above decision can be made based on the ID of the satellite.

[0465] The above SMF can select a UPF (User Plane Function) onboard the satellite for the above PDU session.

[0466] The above analysis results may include information related to the UPF.

[0467] The above analysis results may include information about the extended value.

[0468] The above analysis results may include an indicator to use the extended value.

[0469] The base station for the above UE may be a satellite.

[0470] 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.

[0471] Figure 14 illustrates the UE's procedure for disclosure of this specification.

[0472] 1. The UE (User Equipment) can send a request to the network to establish a PDU (Protocol Data Unit) session.

[0473] Based on the satellite backhaul being used for the UE, the UE may receive a value that is longer than the existing value of the Non-Access-Stratum (NAS) timer.

[0474] 3. The UE can update the NAS timer to the extended value.

[0475] 4. The UE can send a NAS message to the network.

[0476] 5. Based on the UE transmitting the NAS message to the network, the UE can start the NAS timer.

[0477] 6. Based on the expiration of the NAS timer, the UE may retransmit the NAS message to the network or abort the procedure according to the NAS message.

[0478] Based on the change in the satellite backhaul for the UE, the UE can receive a new value of the NAS timer from the network.

[0479] The UE may update the NAS timer with the new value.

[0480] At least one node of the above network may be onboard a satellite.

[0481] The above NAS message may be a PDU session establishment request message.

[0482] The procedure according to the above NAS message may be a PDU session establishment procedure.

[0483] The above NAS message may be a PDU session modification request message.

[0484] The procedure according to the above NAS message may be a PDU session modification procedure.

[0485] The above NAS message may be a service request message.

[0486] The procedure according to the above NAS message may be a service request procedure.

[0487] Hereinafter, a device for performing communication according to some embodiments of the present specification will be described.

[0488] For example, a device may include a processor, a transceiver, and memory.

[0489] For example, a processor may be configured to be operatively coupled with memory and a processor.

[0490] The operations performed by the processor may include: a step of a UE (User Equipment) transmitting a request for establishing a Protocol Data Unit (PDU) session to a network; a step of the UE receiving a value of a Non-Access-Stratum (NAS) timer that is extended from a previous value based on the satellite backhaul being used for the UE; a step of the UE updating the NAS timer to the extended value; a step of the UE transmitting a NAS message to the network; a step of the UE starting the NAS timer based on the UE transmitting the NAS message to the network; and a step of the UE retransmitting the NAS message to the network or aborting a procedure according to the NAS message based on the NAS timer expiring.

[0491] Below, a processor of a device for providing communication according to some embodiments of the present specification is described.

[0492] The operations performed by the processor may include: a step of a UE (User Equipment) transmitting a request for establishing a PDU (Protocol Data Unit) session to a network; a step of the UE receiving a value of a NAS (Non-Access-Stratum) timer that is extended from a previous value based on the satellite backhaul being used for the UE; a step of the UE updating the NAS timer to the extended value; a step of the UE transmitting a NAS message to the network; a step of the UE starting the NAS timer based on the UE transmitting the NAS message to the network; and a step of the UE retransmitting the NAS message to the network or aborting a procedure according to the NAS message based on the NAS timer expiring.

[0493] 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.

[0494] 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.

[0495] 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.

[0496] Computer-readable media may include tangible and non-volatile computer-readable storage media.

[0497] 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.

[0498] 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.

[0499] 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.

[0500] The one or more stored commands may include: a step for a UE (User Equipment) to transmit a request for establishing a Protocol Data Unit (PDU) session to a network; a step for the UE to receive a value of a Non-Access-Stratum (NAS) timer that is extended from a previous value based on a satellite backhaul being used for the UE; a step for the UE to update the NAS timer with the extended value; a step for the UE to transmit a NAS message to the network; a step for the UE to start the NAS timer based on the UE transmitting the NAS message to the network; and a step for the UE to retransmit the NAS message to the network or to abort a procedure according to the NAS message based on the NAS timer expiring.

[0501] This specification may have various effects.

[0502] For example, if satellite backhaul is used, the terminal can use an extended NAS timer value.

[0503] 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.

[0504] 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 the SMF (Session Management Function) receives a request for establishing a PDU (Protocol Data Unit) session for a UE (User Equipment) from the AMF (Access and Mobility management Function); Based on the satellite backhaul being used for the UE, the establishment request includes a category for satellite backhaul, A step in which the SMF transmits an analysis request for the UE to the NWDAF (Network Data Analytics Function); Based on the above analysis request, the step of the SMF receiving the analysis result for the UE from the NWDAF; The above analysis results include information about the satellite backhaul, A step for determining, based on the category for the satellite backhaul and the analysis result, that the NAS (Non-Access-Stratum) timer used by the UE operates at a value extended from the existing value; A method comprising, based on the above determination, a step of the SMF transmitting the extended value to the UE.

2. In paragraph 1, Further comprising a step of the SMF receiving a changed category for the satellite backhaul for the UE from the AMF based on the changed category for the satellite backhaul for the UE; The above decision is made based on the changed satellite backhaul.

3. In paragraph 1, A step in which the SMF receives the changed category for the satellite backhaul for the UE from the AMF based on the change in the category for the satellite backhaul for the UE after the decision; A step in which the SMF transmits a new analysis request for the UE to the NWDAF based on a change in the category for the satellite backhaul for the UE after the above decision; Based on the new analysis request, the SMF receives a new analysis result for the UE from the NWDAF; The above new analysis results include information about the changed satellite backhaul, A step in which the SMF determines that the NAS timer used by the UE operates with a new value based on the category for the changed satellite backhaul and the new analysis result; A method further comprising the step of the SMF transmitting the new value to the UE based on the above determination.

4. In any one of the clauses 1 to 3, Based on the base station being a satellite for the UE, the establishment request includes the ID of the satellite, The above decision is performed based on the ID of the satellite.

5. In any one of paragraphs 1 to 4, The above SMF further includes a step of selecting a UPF (User Plane Function) onboard the satellite for the above PDU session, A method wherein the results of the above analysis include information related to the UPF.

6. In any one of paragraphs 1 to 5, A method wherein the results of the above analysis include information about the extended value.

7. In paragraph 6, A method wherein the result of the above analysis includes an indicator to use the extended value.

8. In any one of paragraphs 1 to 7, A method in which the base station for the above UE is a satellite.

9. As a method, A step in which a UE (User Equipment) transmits a request to establish a PDU (Protocol Data Unit) session to the network; A step in which the UE receives from the network a value that is longer than the existing value of a Non-Access-Stratum (NAS) timer, based on which a satellite backhaul is used for the UE; The step of the UE updating the NAS timer to the extended value; A step in which the UE transmits a NAS message to the network; A step in which the UE starts the NAS timer based on the UE transmitting the NAS message to the network; A method comprising the step of the UE retransmitting the NAS message to the network or aborting a procedure according to the NAS message based on the expiration of the NAS timer.

10. In paragraph 9, A step in which the UE receives a new value of the NAS timer from the network based on a change in the satellite backhaul for the UE; A method further comprising the step of the UE updating the NAS timer with the new value.

11. In paragraph 9 or 10, A method wherein at least one node of the above network is onboard a satellite.

12. In any one of the clauses 9 to 11, The above NAS message is a PDU session establishment request message, The procedure according to the above NAS message is a PDU session establishment procedure.

13. In any one of the clauses 9 to 11, The above NAS message is a PDU session modification request message, The procedure according to the above NAS message is a PDU session modification procedure.

14. In any one of the clauses 9 to 11, The above NAS message is a service request message, The procedure according to the above NAS message is a service request procedure.

15. As a SMF (Network Function), At least one transmitter and receiver; Contains at least one processor, The operation performed by the at least one processor is an SMF according to any one of claims 1 to 8.

16. As a UE (User Equipment), At least one transmitter and receiver; Contains at least one processor, A UE wherein the operation performed by at least one processor is a method according to any one of claims 9 to 14.

17. As an apparatus in mobile communication, at least one processor; and At least one memory storing instructions and being operably electrically connected to the at least one processor, A device wherein the operation performed based on the command being executed by at least one processor is a method according to any one of claims 9 to 14.

18. A non-volatile computer-readable storage medium that records commands, A non-volatile computer-readable storage medium, wherein the instructions, when executed by one or more processors, cause the one or more processors to perform a method according to any one of claims 9 to 14.

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