Method for allocating EBI for dual 3GPP access

Abstract

One disclosure in the present specification provides a method by which an AAnF communicates. The method comprises the steps of: receiving a registration request from a UE through a first 3GPP access; receiving an establishment request for a PDU session through the first 3GPP access from the UE; transmitting an SM context request to an SMF on the basis of the establishment request message; receiving, from the SMF, a request for allocation of an EBI for a first QoS flow related to the PDU session; allocating a first EBI for the QoS flow on the basis of the allocation request; and transmitting information on the first EBI to a UDM.

Description

EBI Allocation Method for Dual 3GPP Access

[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] A method is needed to address the issue of same EBI being allocated when a terminal has two different serving AMFs due to dual 3GPP access.

[0006] The AMF that first allocates an EBI transmits the allocated EBI to the AMF that allocates the next EBI via UDM.

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

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

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

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

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

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

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

[0014] Figure 10 shows an example of a flowchart according to the first embodiment of the present specification.

[0015] Fig. 11 shows an example of a flowchart according to the fourth embodiment of the present specification.

[0016] FIG. 12 illustrates an example of an EPS bearer context state information element according to an embodiment of the present specification.

[0017] Figure 13 illustrates the AMF's procedure for the disclosure of this specification.

[0018] Figure 14 illustrates the UDM procedure for the disclosure of this specification.

[0019] Figure 15 illustrates the UE's procedure for disclosure of this specification.

[0020] 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).

[0021] 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.

[0022] 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.

[0023] 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."

[0024] 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."

[0025] 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.”

[0026] 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”.

[0027] 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."

[0028] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0029] 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).

[0030] 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.

[0031] Figure 1 illustrates an example of a communication system to which the implementation of this specification is applied.

[0032] 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.

[0033] 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).

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] For example, a UAV may be an aircraft that is unmanned and navigated by radio control signals.

[0039] 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.

[0040] For example, a public safety device may include an image relay device or imaging device that can be worn on the user's body.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] For example, a weather / environment device may include a device that monitors or predicts the weather / environment.

[0046] 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).

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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).

[0054] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0055] 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).

[0056] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0057] 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.

[0058] Figure 2 illustrates an example of a wireless device to which the implementation of the present specification is applied.

[0059] 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.

[0060] 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).

[0061] 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).

[0062] 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).

[0063] 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.

[0064] 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.

[0065] 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).

[0066] 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).

[0067] 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).

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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).

[0075] 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).

[0076] 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.

[0077] 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.

[0078] In this specification, a base station may be referred to as a Node B, an eNode B (eNB), or a gNB.

[0079] Figure 3 shows an example of a UE to which the implementation of this specification is applied.

[0080] Referring to FIG. 3, the UE (100) can correspond to the first wireless device (100) of FIG. 2.

[0081] 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).

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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).

[0086] 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).

[0087] 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.

[0088] 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).

[0089] Figure 4 is a structural diagram of a next-generation mobile communications network.

[0090] 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).

[0091] 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).

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] The illustrated PCF (430) is a node that controls the business operator's policy.

[0098] The illustrated AF (450) is a server for providing various services to the UE (100).

[0099] 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).

[0100] 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.

[0101] 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.

[0102] 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.

[0103] Figure 5 shows an example of a 5G system structure to which the implementation of this specification is applied.

[0104] The 5G system (5GS; 5G system) structure consists of the following network functions (NF; Network Function).

[0105] - AUSF (Authentication Server Function)

[0106] - AMF (Access and Mobility Management Function)

[0107] - DN (Data Network), 예를 들어 운영자 서비스, 인터넷 접속 또는 타사 서비스

[0108] - USDF (Unstructured Data Storage Function)

[0109] - NEF (Network Exposure Function)

[0110] - I-NEF (Intermediate NEF)

[0111] - NRF (Network Repository Function)

[0112] - NSSF (Network Slice Selection Function)

[0113] - PCF (Policy Control Function)

[0114] - SMF (Session Management Function)

[0115] - UDM (Unified Data Management)

[0116] - UDR (Unified Data Repository)

[0117] - UPF (User Plane Function)

[0118] - UCMF (UE radio Capability Management Function)

[0119] - AF (Application Function)

[0120] - UE (User Equipment)

[0121] - (R)AN ((Radio) Access Network)

[0122] - 5G-EIR (5G-Equipment Identity Register)

[0123] - NWDAF (Network Data Analytics Function)

[0124] - CHF (CHarging Function)

[0125] Additionally, the following network features may be considered:

[0126] - N3IWF (Non-3GPP InterWorking Function)

[0127] - TNGF (Trusted Non-3GPP Gateway Function)

[0128] - W-AGF (Wireline Access Gateway Function)

[0129] 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.

[0130] In Figure 5, for clarity of the point-to-point diagram, UDSF, NEF, and NRF are not illustrated. However, all network functions shown can interact with UDSF, UDR, NEF, and NRF as needed.

[0131] 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.

[0132] The 5G system architecture includes the following benchmarks:

[0133] - N1: Reference point between UE and AMF.

[0134] - N2: Reference point between (R)AN and AMF.

[0135] - N3: Reference point between (R)AN and UPF.

[0136] - N4: Reference point between SMF and UPF.

[0137] - N6: Reference point between UPF and data network.

[0138] - N9: Reference point between two UPFs.

[0139] The following benchmarks illustrate the interactions that exist between NF services in NF.

[0140] - N5: Reference point between PCF and AF.

[0141] - N7: Reference point between SMF and PCF.

[0142] - N8: Reference point between UDM and AMF.

[0143] - N10: Reference point between UDM and SMF.

[0144] - N11: Reference point between AMF and SMF.

[0145] - N12: Reference point between AMF and AUSF.

[0146] - N13: Reference point between UDM and AUSF.

[0147] - N14: Reference point between two AMFs.

[0148] - N15: Reference point between PCF and AMF for non-roaming scenarios, and reference point between PCF and AMF of visited network for roaming scenarios.

[0149] - N16: Reference point between two SMFs (in case of roaming, between the SMF of the visited network and the SMF of the home network)

[0150] - N22: Reference point between AMF and NSSF.

[0151] In some cases, two NFs may need to be interconnected to serve a UE.

[0152] <Registration Procedure>

[0153] Describes the registration procedure. See section 4.2.2.2 of 3GPP TS 23.502 V16.3.0 (2019-12).

[0154] Figures 6 and 7 illustrate examples of registration procedures to which the implementation of the present specification applies.

[0155] A UE must register with the network to receive services, enable mobility tracking, and enable reachability. The UE initiates the registration process using one of the following registration types:

[0156] - Initial registration for 5GS; or

[0157] - mobility registration update; or

[0158] - Periodic registration update; or

[0159] - Emergency registration

[0160] The general registration procedures of Figures 6 and 7 apply to all registration procedures described above, but periodic registration updates do not need to include all parameters used in other registration procedures.

[0161] The general registration procedures of Figures 6 and 7 can also be used when registering for a 3GPP connection when the UE is already registered for a non-3GPP connection, and vice versa. Registering for a 3GPP connection when the UE is already registered for a non-3GPP connection scenario may require an AMF change.

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

[0163] (1) Step 1: The UE transmits a Registration Request message to the (R)AN. The Registration Request message corresponds to an AN message.

[0164] The registration request message may include AN parameters. For NG-RAN, the AN parameters include, for example, the 5G SAE temporary mobile subscriber identity (5G-S-TMSI) or globally unique AMF ID (GUAMI), the selected public land mobile network (PLMN) ID (or PLMN ID and network identifier (NID)), and the requested network slice selection assistance information (NSSAI). The AN parameters also include an establishment cause. The establishment cause provides the reason for requesting establishment of an RRC connection. Whether and how the UE includes the requested NSSAI as part of the AN parameters depends on the value of the access stratum connection establishment NSSAI inclusion mode parameter.

[0165] A registration request message may include a registration type. The registration type indicates whether the UE wants to perform an initial registration (i.e., the UE is in RM-DEREGISTERED state), or a mobility registration update (i.e., the UE is in RM-REGISTERED state and the registration procedure is initiated because the UE moves, or the UE wants to update its capabilities or protocol parameters, or because the UE requests a change in the set of network slices it is allowed to use), or a periodic registration update (i.e., the UE is in RM-REGISTERED state and the registration procedure is initiated because the periodic registration update timer has expired), or an emergency registration (i.e., the UE is in restricted service state).

[0166] When a UE performs initial registration, the UE indicates its UE ID in the registration request message, listed in decreasing priority order.

[0167] i) If the UE has a valid evolved packet system (EPS) globally unique temporary identifier (GUTI), 5G-GUTI mapped from the EPS GUTI;

[0168] ii) Native 5G-GUTI (if available) allocated by the PLMN in which the UE is attempting to register;

[0169] iii) Native 5G-GUTI allocated by a PLMN equivalent to the PLMN in which the UE is attempting to register;

[0170] iv) Native 5G-GUTI allocated by another PLMN (if available);

[0171] v) Otherwise, the UE includes a subscriber concealed identifier (SUCI) in the registration request message.

[0172] If a UE performing initial registration has both a valid EPS GUTI and a native 5G-GUTI, the UE also indicates the native 5G-GUTI as an additional GUTI. If more than one native 5G-GUTI is available, the UE selects a 5G-GUTI from items (ii)-(iv) in decreasing priority order in the list above.

[0173] When the UE performs initial registration with native 5G-GUTI, the UE indicates the relevant GUAMI information in the AN parameters. When the UE performs initial registration with SUCI, the UE does not indicate the GUAMI information in the AN parameters.

[0174] For emergency registration, if the UE does not have a valid 5G-GUTI, the SUCI is included. If the UE does not have a subscriber permanent identifier (SUPI) and does not have a valid 5G-GUTI, the PEI (Permanent Equipment Identifier) ​​is included. Otherwise, the 5G-GUTI is included, indicating the last serving AMF.

[0175] The registration request message may also include security parameters, PDU session status, etc. Security parameters are used for authentication and integrity protection. The PDU session status indicates a previously established PDU session in the UE. When the UE is connected to two AMFs belonging to different PLMNs via a 3GPP connection and a non-3GPP connection, the PDU session status indicates the PDU session currently established in the PLMN in the UE.

[0176] (2) Step 2: (R)AN selects AMF.

[0177] If 5G-S-TMSI or GUAMI is not included, or if 5G-S-TMSI or GUAMI does not indicate a valid AMF, the (R)AN selects an AMF based on the (R)AT and the requested NSSAI, if available.

[0178] When the UE is in CM-CONNECTED state, (R)AN can forward a registration request message to AMF based on the UE's N2 connection.

[0179] If the (R)AN cannot select an appropriate AMF, the (R)AN performs AMF selection by forwarding a registration request message to the AMF configured in the (R)AN.

[0180] (3) Step 3: (R)AN sends a registration request message to the new AMF. The registration request message corresponds to the N2 message.

[0181] The registration request message may contain all of the information and / or part of the information contained in the registration request message received from the UE described in step 1.

[0182] The registration request message may include an N2 parameter. When NG-RAN is used, the N2 parameter includes the selected PLMN ID (or PLMN ID and NID), location information and cell ID related to the cell where the UE is camping, and a UE context request indicating that a UE context including security information should be established in the NG-RAN. When NG-RAN is used, the N2 parameter also includes an establishment cause.

[0183] If the registration type indicated by the UE is periodic registration update, steps 4-19 described below may be omitted.

[0184] (4) Step 4: If the UE's 5G-GUTI is included in the registration request message and the serving AMF has changed since the last registration procedure, the new AMF may invoke the Namf_Communication_UEContextTransfer service operation to the previous AMF, including the full registration request non-access stratum (NAS) message to request the UE's SUPI and UE context.

[0185] (5) Step 5: The old AMF can respond to the new AMF for the Namf_Communication_UEContextTransfer call including the UE's SUPI and UE context.

[0186] (6) Step 6: If SUCI is not provided by the UE or not retrieved from the previous AMF, the new AMF may initiate an ID request procedure by sending an Identity Request message to request SUCI from the UE.

[0187] (7) Step 7: The UE may respond with an Identity Response message including the SUCI. The UE derives the SUCI using the provided public key of the home PLMN (HPLMN).

[0188] (8) Step 8: The new AMF may decide to initiate UE authentication by calling the AUSF. In this case, the new AMF selects the AUSF based on SUPI or SUCI.

[0189] (9) Step 9: Authentication / security can be established by UE, new AMF, AUSF and / or UDM.

[0190] (10) Step 10: If the AMF has changed, the new AMF may call the Namf_Communication_RegistrationCompleteNotify service operation to notify the old AMF that the UE registration with the new AMF is complete. If the authentication / security procedure fails, the registration is rejected and the new AMF may call the Namf_Communication_RegistrationCompleteNotify service operation with a reject indication reason code to the old AMF. The old AMF may continue as if the UE context transfer service operation was not received.

[0191] (11) Step 11: If the PEI was not provided by the UE or was not retrieved from the previous AMF, the new AMF may initiate the ID request procedure by sending an Identity Request message to the UE to retrieve the PEI. The PEI is transmitted encrypted, except when the UE performs emergency registration and cannot be authenticated.

[0192] (12) Step 12: Optionally, the new AMF can initiate ME ID checking by calling the N5g-eir_EquipmentIdentityCheck_Get service operation.

[0193] Now, the procedure of Fig. 7 following the procedure of Fig. 6 is described.

[0194] (13) Step 13: If step 14 below is performed, the new AMF can select a UDM based on SUPI, and the UDM can select a UDR instance.

[0195] (14) Step 14: New AMFs can be registered with UDM.

[0196] (15) Step 15: New AMF can select PCF.

[0197] (16) Step 16: The new AMF can optionally perform AM policy association establishment / modification.

[0198] (17) Step 17: The new AMF can send update / release SM context messages (e.g., Nsmf_PDUSession_UpdateSMContext and / or Nsmf_PDUSession_ReleaseSMContext) to the SMF.

[0199] (18) Step 18: If the new AMF and the old AMF are in the same PLMN, the new AMF may send a UE context modification request to the N3IWF / TNGF / W-AGF.

[0200] (19) Step 19: N3IWF / TNGF / W-AGF may send a UE context modification response to the new AMF.

[0201] (20) Step 20: After the new AMF receives the response message from N3IWF / TNGF / W-AGF in step 19, the new AMF can register with UDM.

[0202] (21) Step 21: The new AMF sends a Registration Accept message to the UE.

[0203] The new AMF sends the UE a Registration Accept message indicating that the registration request has been accepted. If the new AMF allocates a new 5G-GUTI, it includes the 5G-GUTI. If the UE is already in the RM-REGISTERED state through another connection to the same PLMN, the UE uses the 5G-GUTI received in the Registration Accept message for both registrations. If the Registration Accept message does not include a 5G-GUTI, the UE uses the 5G-GUTI assigned to the existing registration for the new registration. If the new AMF allocates a new registration area, it sends the registration area to the UE in the Registration Accept message. If the Registration Accept message does not include a registration area, the UE considers the previous registration area to be valid. Mobility Restrictions are included if mobility restrictions apply to the UE and the registration type is not emergency registration. The new AMF indicates the PDU sessions established for the UE in the PDU Session State. The UE locally removes internal resources associated with PDU sessions that are not marked as established in the received PDU Session State. When a UE is connected to two AMFs belonging to different PLMNs via a 3GPP connection and a non-3GPP connection, the UE locally removes internal resources associated with PDU sessions in the current PLMN that are not marked as established in the received PDU session status. If PDU session status information is present in the Registration Accept message, the new AMF indicates the PDU session status to the UE.

[0204] The Allowed NSSAI provided in the Registration Accept message is valid for the registration area and applies to all PLMNs that have a tracking area included in the registration area. The Mapping of Allowed NSSAIs maps HPLMN S-NSSAIs to each S-NSSAI of the Allowed NSSAIs. The Mapping of Configured NSSAIs maps HPLMN S-NSSAIs to each S-NSSAI of the Configured NSSAI for the serving PLMN.

[0205] Additionally, optionally, the new AMF performs UE policy association establishment.

[0206] (22) Step 22: If the UE successfully updates itself, it can send a Registration Complete message to the new AMF.

[0207] The UE may send a registration complete message to the new AMF to confirm that a new 5G-GUTI has been allocated.

[0208] (23) Step 23: In case of registration via 3GPP connection, if the new AMF does not release the signaling connection, the new AMF may send RRC Inactive Assistance information to the NG-RAN. In case of registration via non-3GPP connection, if the UE is in CM-CONTENED state on the 3GPP connection, the new AMF may send RRC Inactive Assistance information to the NG-RAN.

[0209] (24) Step 24: AMF can perform information updates on UDM.

[0210] (25) Step 25: The UE may execute a network slice-specific authentication and authorization (NSSAA) procedure.

[0211] <PDU 세션 수립 절차>

[0212] Describes the PDU session establishment procedure. See Section 4.3.2 of 3GPP TS 23.502 V16.3.0 (2019-12).

[0213] Figures 8 and 9 illustrate examples of a PDU session establishment procedure to which the implementation of the present specification applies.

[0214] Establishing a PDU session may involve:

[0215] - UE-initiated PDU session establishment procedure

[0216] - PDU session handover between 3GPP and non-3GPP initiated by UE

[0217] - PDU session handover from UE-initiated EPS to 5GS.

[0218] - Network-triggered PDU session establishment procedure

[0219] 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.

[0220] Figures 8 and 9 specify the procedure for establishing a PDU session associated with a single connection type at a given time.

[0221] In the procedures shown in Figures 8 and 9, it is assumed that the UE is already registered with the AMF, so unless the UE is emergency registered, the AMF has already retrieved the user subscription data from the UDM.

[0222] First, the procedure of Fig. 8 is explained.

[0223] (1) Step 1: To establish a new PDU session, the UE generates a new PDU session ID.

[0224] 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.

[0225] 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."

[0226] 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.

[0227] (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.

[0228] 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.

[0229] 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.

[0230] 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:

[0231] - When the SMF ID and AMF corresponding to the PDU session ID belong to the same PLMN;

[0232] - If the SMF ID corresponding to the PDU session ID belongs to HPLMN;

[0233] Otherwise, AMF rejects the PDU session establishment request with an appropriate rejection cause.

[0234] AMF rejects requests from emergency-registered UEs whose request type does not indicate "Emergency Request" or "Existing Emergency PDU Session".

[0235] (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).

[0236] 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.

[0237] 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.

[0238] 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.

[0239] 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.

[0240] (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.

[0241] (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.

[0242] 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.

[0243] 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.

[0244] (6) Step 6: Optional secondary authentication / authorization may be performed.

[0245] (7a) Step 7a: When dynamic policy and charging control (PCC) is used in a PDU session, the SMF can perform PCF selection.

[0246] (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.

[0247] (8) Step 8: SMF selects one or more UPFs.

[0248] (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.

[0249] (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.

[0250] 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.

[0251] (11) Step 11: SMF sends an N1N2 message transfer message (e.g. Namf_Communication_N1N2 Message Transfer) to AMF.

[0252] 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:

[0253] - CN Tunnel Info: Corresponds to the core network address of the N3 tunnel corresponding to the PDU session;

[0254] - QFI (QoS flow ID) corresponding to one or more QoS (quality of service) profiles;

[0255] - PDU Session ID: Indicates to the UE the association between RAN resources and a PDU session for the UE;

[0256] - S-NSSAI with value for serving PLMN (i.e. HPLMN S-NSSAI, or VPLMN S-NSSAI in case of LBO roaming);

[0257] - User plane security enforcement information determined by SMF;

[0258] - 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.

[0259] - RSN (redundancy sequence number) parameter

[0260] 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.

[0261] 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.

[0262] 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.

[0263] (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.

[0264] (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.

[0265] (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.

[0266] If N2 SM information is not included in step 11, steps 14-16b and 17 below are omitted.

[0267] Now, the procedure of Fig. 9 following the procedure of Fig. 8 is described.

[0268] (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.

[0269] (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.

[0270] (16a) Step S16a: SMF initiates the N4 session modification procedure with UPF. SMF provides AN tunnel information and corresponding forwarding rules to UPF.

[0271] (16b) Step S16b: UPF provides an N4 session modification response to SMF.

[0272] After this step, the UPF can forward any DL packets that may have been buffered for this PDU session to the UE.

[0273] (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.

[0274] (17) Step 17: SMF sends an update SM context response message (e.g., Nsmf_PDUSession_UpdateSMContext Response) to AMF.

[0275] After this step, AMF forwards the relevant events to which SMF subscribes.

[0276] (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.

[0277] (19) Step 19: For PDU session type IPv6 or IPv4v6, SMF may generate and send an IPv6 Router Advertisement to the UE.

[0278] (20) Step 20: SMF can perform SM policy association modification initiated by SMF.

[0279] (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.

[0280] Dual 3GPP access

[0281] 1. Dual 5G satellite access

[0282] This use case describes a scenario where an autonomous ship is remotely controlled from shore. The ship has UEs served by two satellite RANs (GEO and LEO) belonging to the same PLMN managed by a 5G satellite operator. The ship's UEs have a single PLMN subscription.

[0283] Dual 5G satellite access will be deployed to accommodate the massive data traffic for remote control operations. To improve the performance of autonomous ship operations, delay-sensitive applications (e.g., remote control operations, collision / accident prevention, emergency management, etc.) will utilize LEO satellite links, which have lower UE-to-ground propagation delays than GEO satellite links (up to 30 ms for LEO vs. up to 280 ms for GEO). Other delay-sensitive applications (e.g., sensor data monitoring, video surveillance, etc.) can utilize GEO satellite links or aggregate traffic across both accesses.

[0284] 2. NTN-based dual 3GPP access

[0285] By integrating two 3GPP access links simultaneously, one of which is a non-terrestrial network, the following 5G services can be provided, which is particularly useful in isolated areas where bandwidth is limited or access links are unreliable:

[0286] - Expanded mobile broadband

[0287] - Very stable service communication

[0288] Several service scenarios (e.g., residential users in remote areas, users on vehicles, high-speed trains, ships, or airplanes) may benefit from combining terrestrial and non-terrestrial access, or from combining two types of non-terrestrial access (e.g., based on GSO and NGSO), to meet target service performance in terms of data rate and / or reliability.

[0289] In areas where service is unavailable, the bandwidth provided by terrestrial-based access (e.g., NR or LTE) may be limited at the cell edge. Adding NTN-based NG-RAN can help achieve the desired perceived data rates.

[0290] In some scenarios, such as on high-speed trains, the service area may not be completely uniform along the track, and multiple connections, including NTN-based NG-RAN, can provide the desired reliability.

[0291] Therefore, UEs can be connected and serviced simultaneously in the following ways:

[0292] - One NTN-based 3GPP access and one terrestrial-based 3GPP access

[0293] - One NTN-based 3GPP access (NGSO) and another NTN-based 3GPP access (GSO).

[0294] - One NTN-based 3GPP access (NGSO) via two different satellites in the same constellation

[0295] Dual access bonding can occur on the uplink, downlink, or both.

[0296] The same or different gNBs can serve NR cells via terrestrial access networks and satellite access networks (e.g., transparent payloads carried on satellites).

[0297] NTN-based NG-RAN can refer to transparent payload satellites as well as regenerative payload satellites equipped with, for example, some gNB functionality.

[0298] 3. Inter-PLMN or PLMN-SNPN

[0299] This example scenario depicts a stadium with an ad hoc / in-stadium 5G NR deployment (high capacity) from one SNPN or PLMN network (MNO-A) and 5G NR coverage from another PLMN outside the stadium (MNO-B). There is no network sharing between the two 5G networks.

[0300] The above example can be similarly applied to other local business locations such as campuses, companies, shopping malls, and factories.

[0301] MNO-B has a business and roaming partnership with MNO-A, including an agreement to lease additional capacity to provide ultra-broadband experiences to some of MNO-B's "golden" customers. The agreement between MNO-A and B includes the ability for MNO-B users' data traffic to utilize additional NR connectivity links in PLMN-A, enabling them to connect at higher data rates (including anchoring and aggregation to the HPLMN's CN). This capability is assumed to be supported by both PLMN's CNs and the UEs (of the golden MNO-B users). It involves a set of traffic policies and conditions negotiated by the MNOs, which the HPLMN controls and can provision (to UEs and CN entities).

[0302] A UE can receive services through two 3GPP accesses (or 3GPP access links).

[0303] Two 3GPP accesses may be connected to one Core Network (CN), or two 3GPP accesses may be connected to two CNs.

[0304] A CN can be a Public Land Mobile Network (PLMN) or a Non-Public Network (NPN).

[0305] For some services, a PDU session created by a terminal can be established via two 3GPP accesses. In this case, the PDU session may be a Multi-Access (MA) PDU session. Previously, an MA PDU session referred to a session via both a 3GPP access and a non-3GPP access, but the concept has now been expanded to include a session via two 3GPP accesses.

[0306] For some services, traffic can be steered, switched, and split across PDU sessions with two accesses.

[0307] Alternatively, for some services, a PDU session may be established over one 3GPP access and traffic may be transmitted over that session.

[0308] For dual access (or dual steer), a terminal may have a single subscription.

[0309] In this case, conventionally, the terminal performed registration with only one core network for 3GPP access.

[0310] However, to receive services through two 3GPP accesses, a terminal can separately register for two 3GPP accesses for one 5G core network.

[0311] Alternatively, to receive services through two 3GPP accesses, the terminal may separately register with 3GPP access for each of the two 5G core networks.

[0312] If a terminal is registered to two 5G core networks, decisions may need to be made regarding which core network to establish a PCU session for each service and which core network to transmit traffic to.

[0313] A terminal can simultaneously register with one core network (PLMN or SNPN) using two 3GPP RATs (Radio Access Technology).

[0314] Alternatively, a terminal can simultaneously register with two different core networks using two 3GPP RATs (Radio Access Technology). In this case, the PDU session establishment procedure can be performed for each different core network.

[0315] The other core networks may both be PLMNs. Alternatively, the other core networks may both be SNPNs. Alternatively, one of the other core networks may be a PLMN and the other may be an SNPN. The 3GPP RAT may support various forms, such as NR+NR, NR+E-UTRA, TN-NTN, and NTN-NTN.

[0316] 5GS supports EPC interworking using the N26 interface.

[0317] For EPC interworking, during the PDU session establishment process, the 5G core network can assign an EPS bearer ID (EBI) to the QoS flow when generating QoS. Specifically, an EBI can be allocated when the SMF+PGW-C requests EBI allocation from the AMF.

[0318] That is, the 5G core network can allocate EBI for interworking from 5GS to EPC during the PDU session establishment process.

[0319] When two PDU sessions are created, each session can be managed by a different SMF+PGW-C. Therefore, performing EBI allocation in SMF+PGW-C can result in the same EBI being allocated to different QoS flows. For this reason, AMF is responsible for allocating EBI.

[0320] When a terminal registers via dual access (dual 3GPP access), the terminal may have two serving AMFs. In this case, different AMFs will each allocate EBIs. However, problems may arise if the allocated EBIs are identical.

[0321] Since dual 3GPP registration is not supported in EPS, a way to prevent this situation from occurring is needed.

[0322] If EBI is insufficient, AMF must revoke EBI based on ARP, S-NSSAI, local policy, etc., but if AMF is different, this may not be possible.

[0323] The following description may be a method for supporting EPC linkage in the case of dual 3GPP registration.

[0324] A method for supporting registration in dual 3GPP access may consist of a combination of one or more of the actions / configurations / steps described below.

[0325] In this specification, UE (User Equipment) and terminal are used interchangeably.

[0326] In this specification, the terms Subscriber and User are used interchangeably.

[0327] In this specification, AF (Application Function) and AS (Application Server) are used interchangeably.

[0328] The service operations used in this specification are examples and other similar service operations can be used or new service operations can be defined and used.

[0329] The methods presented below may be performed or used in combination or complementary manner.

[0330] I. First embodiment - How to store EBI in another NF (e.g. UDM, V-PCF, new NF)

[0331] When AMF allocates an EBI, AMF may store information about the allocated EBI in another NF. The information about the EBI may include one or more of PDU session type / characteristics (e.g., single access PDU Session, MA PDU Session, dual 3GPP access MA PDU Session, etc.), PDU session ID, QoS flow information (e.g., QFI), EBI and related ARP information, etc.

[0332] EBI information stored in other NFs can be transferred to other AMFs. Since each AMF has information about the assigned EBIs, the second AMF to allocate an EBI can assign an unassigned EBI value. This prevents the problem of identical EBIs being allocated.

[0333] If an AMF needs to allocate an EBI but there are no EBIs to allocate, the AMF may request EBI revocation to another AMF through another NF.

[0334] Figure 10 shows an example of a flowchart according to the first embodiment of the present specification.

[0335] Step 1. The terminal can register with network 1 using the first 3GPP access. The registration process can be applied as shown in Figure 6-7.

[0336] The terminal can send a registration request message to network 1.

[0337] The registration request transmitted by the terminal to network 1 may include information about an EBI already allocated to the UE. The information about the already allocated EBI may be transmitted to the AMF. In step 5, described below, the AMF may allocate an EBI that does not overlap with an already allocated EBI based on the information about the already allocated EBI.

[0338] The registration request message may include information that the terminal performs dual registration (or dual 3GPP access).

[0339] The registration request message may include information about the capability of the terminal to perform dual registration (or dual 3GPP access).

[0340] During the registration process, based on subscriber information from UDM, operator policy, network capability, etc., AMF can send information to the terminal on whether dual registration (or dual 3GPP access) is allowed.

[0341] Based on the above dual registration (or dual 3GPP access) being allowed, steps 2 and 9 described below can be performed.

[0342] Step 2. The terminal can register with Network 2 using the second 3GPP access. The registration process can be applied as shown in Figure 6-7. The terminal can send a registration request to Network 2.

[0343] The registration request may include a subscription identifier (e.g., SUPI / SUCI). The AMF of Network 2 may select / determine / detect a UDM based on the subscription identifier included in the registration request and receive subscriber information including EBI information from the UDM (step 8).

[0344] Network 1 may be an HPLMN and network 2 may be a VPLMN.

[0345] Step 3. The terminal can request PDU session establishment with Network 1 using the first 3GPP access. The PDU session establishment process can be applied as shown in Figure 8-9.

[0346] The PDU session establishment request transmitted by the terminal to network 1 may include information about an EBI already allocated to the UE. The information about the already allocated EBI may be transmitted to the AMF. In step 5 described below, the AMF may allocate an EBI that does not overlap with an already allocated EBI based on the information about the already allocated EBI.

[0347] Step 4. The SMF may determine that an EBI allocation is necessary. In this case, the SMF may request EBI allocation from the AMF (AMF 1). The EBI may be for the PDU session in step 3.

[0348] Step 5. AMF can perform EBI allocation. AMF can store the allocated EBI information in the UDM of Network 1 using the Nudm_UECM_Update service (or another new service may be used).

[0349] The allocated EBI may be for a QoS flow associated with the PDU session in step 3.

[0350] The AMF may receive subscriber information from the UDM, including information about previously allocated EBIs. In Step 5, the AMF may allocate an EBI different from the previously allocated EBI.

[0351] The above-mentioned allocated EBI information can be stored in the UDM in the form of subscription data. Meanwhile, AMF 2 can perform an event subscription for changes in subscriber information in the UDM during the registration process.

[0352] Accordingly, when the allocated EBI information is stored as subscriber information, UDM can transmit the stored EBI information to AMF 2 according to the event subscription performed by AMF 2 (step 8 described below).

[0353] If necessary (if AMF needs to allocate an EBI but there is no EBI to allocate), AMF can perform a revocation of an existing EBI.

[0354] If revocation is required for an EBI allocated by another AMF, the AMF can request revocation to the other AMF via UDM.

[0355] A request for revocation can be made by AMF to UDM at the same time as EBI allocation information, or EBI allocation can be performed after completing the revocation request and receiving a response to it.

[0356] The AMF can receive subscriber information for a terminal from the UDM through the 14 steps described in Figure 7. The subscriber information may include information about an EBI already allocated to the terminal. Based on the information about the already allocated EBI, the AMF can allocate an EBI to the terminal that does not overlap with an EBI already allocated.

[0357] Step 5 can be performed after step 6 or in conjunction with it.

[0358] Step 6. AMF can transmit the assigned EBI information to SMF.

[0359] Step 7. The SMF can send a PDU session establishment acknowledgement (informing the terminal that the PDU session has been successfully established) to the terminal. At this time, the SMF can send the terminal the allocated EBI information (information about the EBI allocated by AMF 1).

[0360] Step 8. UDM can transmit the EBI information updated by step 5 to another AMF (AMF 2).

[0361] The UDM may determine that EPC interworking is not necessary for other 3GPP accesses. In this case, regardless of the EBI information actually allocated in AMF 1, the UDM can notify AMF 2 that all EBIs have been allocated. At this time, the UDM can set the ARP (Allocation and Retention Priority) of all allocated EBIs to the highest value to prevent AMF 2 from requesting revocation for the already allocated EBIs. This prevents the UE's second 3GPP access from being handed over to the EPC.

[0362] EBIs can be allocated per QoS flow. ARP can indicate the importance of a QoS flow. If an EBI allocation is required for a high QoS flow with no more EBIs remaining, ARP can revoke the EBI for a low QoS flow, allowing EBI allocation to be performed for the high QoS flow with ARP.

[0363] Step 9. The terminal can request the establishment of a PDU session with Network 2 using the second 3GPP access. The PDU session establishment process can be applied as shown in Figure 8-9.

[0364] Step 10. The SMF may determine that an EBI allocation is necessary. In this case, the SMF may request an EBI allocation from the AMF (AMF 2).

[0365] Step 11. Based on the EBI information received in Step 8, AMF (AMF 2) can allocate an EBI different from the previously allocated EBI (the EBI allocated by AMF 1).

[0366] Other allocated EBIs may be for QoS flows associated with the PDU session in step 9.

[0367] AMF can store the allocated EBI information in the form of subscription data in the UDM of Network 1 using the Nudm_UECM_Update service (or a newer service may be used).

[0368] If necessary, AMF may perform revocation of existing EBIs.

[0369] If revocation is required for an EBI allocated by another AMF, the AMF can request revocation to the other AMF via UDM.

[0370] A request for revocation can be made by AMF to UDM at the same time as EBI allocation information, or EBI allocation can be performed after completing the revocation request and receiving a response to it.

[0371] Step 5 can be performed after step 6 or in conjunction with it.

[0372] Step 12. AMF can transmit the assigned EBI information to SMF.

[0373] Step 13. The SMF can send a PDU session establishment acknowledgement (informing the terminal that the PDU session has been successfully established) to the terminal. At this time, the SMF can send the terminal the allocated EBI information (information about the EBI allocated by AMF 2).

[0374] II. Second embodiment - A method to prevent a subscription from being passed to the EPC through a core network type restriction when the UDM sends a subscription to the AMF.

[0375] When UDM sends subscriber information to the serving AMF of the terminal's 3GPP access, UDM can impose different core network type restrictions on each AMF.

[0376] A UDM can transmit information that EPC is not available to one AMF, and a UDM can transmit information that EPC is available to another AMF.

[0377] In this case, only the AMF that has received information that the EPC is available can allocate the EBI.

[0378] Since the UDM informs only one AMF that the EPC is available, EBI allocation can be performed only by one AMF, avoiding the EBI duplicate allocation problem.

[0379] When performing Nudm_UECM_Registration, AMF can transmit information such as RAT type information and AMF's GUAMI to UDM. This operation can be performed in step 14 of Fig. 7.

[0380] Based on the above RAT type information, AMF's GUAMI, etc., UDM can decide whether to notify that EPC is not available for a specific AMF.

[0381] AMF can additionally inform UDM whether the terminal supports dual registration and whether the terminal is performing dual registration. Based on this, UDM can set core network type restrictions.

[0382] The network can provide terminals with information to enable them to use specific RATs / networks for specific services. This can prevent interruptions in services requiring EPC connectivity.

[0383] Information for enabling the above-mentioned specific service to use a specific RAT / network can be updated in the URSP rules and provided to the terminal in the form of preferred RAT type (e.g., NR(LEO), NR(GEO), E-UTRA, etc.)), preferred network (PLMN ID, SNPN ID, etc.) information, etc.

[0384] III. Third embodiment - Method for sending Nudm_UECM_DeregistrationNotification to all AMFs when UDM receives Update Location Request / Nudm_UECM_AMFDeregistration Request from MME / HSS

[0385] When the UE transitions to the EPC and performs TAU, the MME can send an Update Location Request to the HSS / UDM. At this time, the UDM can send a Nudm_UECM_DeregistrationNotification message to the two serving AMFs that served the UE prior to interworking.

[0386] Then, AMF can clear the terminal's context according to conventional procedures. During this process, connections of terminals connected through other 3GPP access points are naturally released, and all related sessions can be terminated.

[0387] According to the prior art, when the AMF receives Nudm_UECM_DeregistrationNotification from the UDM, the AMF performs an AN release to the base station (NG-RAN) and notifies it of a "cause value that indicates that the UE has already locally released the NG-RAN's RRC Connection." Then, the base station can perform a local release with the terminal. A local release may mean that the base station clears the context of the terminal without signaling between the terminal and the RRC.

[0388] To prevent such local release, if the UE was in dual 3GPP access registration state and the MME did not receive the UE context, the AMF may notify the NG-RAN of a normal release instead of the "cause value that indicates that the UE has already locally released the NG-RAN's RRC Connection" when performing the AN Release procedure. This allows a normal RRC connection release to be performed.

[0389] When a terminal is dual 3GPP registered and moves from one 3GPP access to EPC, after the EPC linking procedure is performed, the terminal can request local release or RRC connection release for the 5GC connection in the other 3GPP access.

[0390] If the network supports the MUSIM Connection Release feature, the terminal can request connection release from AMF through NAS signaling.

[0391] IV. Embodiment 4 - How a Terminal Allocates EBI

[0392] According to the fourth embodiment, the terminal can allocate EBI without AMF allocating EBI.

[0393] During the process of establishing a PDU session or creating a QoS flow (PDU Session Modification), the terminal can notify the SMF of its capability to indicate that EBI allocation is possible.

[0394] Based on the capabilities of the terminal, the SMF can request EBI allocation from the terminal.

[0395] SMF can directly request EBI allocation from terminals for specific QoS flows.

[0396] A terminal can determine EBI allocation. For example, a terminal can allocate an EBI for the default QoS flow of a PDU session used for a specific service (e.g., a telephone service) and transmit it to the SMF. For example, a terminal can allocate an EBI and notify the SMF in a PDU session establishment request message.

[0397] For example, the UE-PCF (PCF for a UE) can transmit information to the terminal notifying that EBI allocation is required for a specific DNN / S-NSSAI in the URSP rule. To this end, the terminal can transmit capability information to the UE-PCF notifying that the terminal supports EBI allocation in the UE PCF container. The UE-PCF (PCF for a UE) can be an NF that creates URSP rules and transmits them to the terminal.

[0398] For example, after the SMF sends a PDU session establishment approval to the terminal, the SMF can request the terminal to allocate an EBI through a PDU Session Modification Command. The terminal can then allocate an EBI and transmit the allocated EBI information to the SMF through a PDU Session Modification Complete.

[0399] When generating EBIs, a terminal must allocate them without duplication and, if necessary, may perform EBI revocation. To perform EBI revocation, the terminal can notify the SMF of the revocation information. When an EBI is allocated or revocation by a terminal, the SMF can notify the AMF.

[0400] 1. Example 1 of the 4th embodiment

[0401] Fig. 11 shows an example of a flowchart according to the fourth embodiment of the present specification.

[0402] Step 1. The terminal can register with network 1 using the first 3GPP access. The registration process can be applied as shown in Figure 6-7.

[0403] Step 2. The terminal can register with network 2 using the second 3GPP access. The registration process can be applied as shown in Figure 6-7.

[0404] Step 3. The terminal can request PDU session establishment to network 1 using the first 3GPP access. The PDU session establishment process can be applied as shown in Figures 8-9.

[0405] The terminal can transmit capability information indicating that the terminal supports EBI allocation to the SMF through the PDU session establishment request.

[0406] Alternatively, the terminal can transmit dual registration capability information to the AMF through a registration request in step 1. The AMF can then store the dual registration capability information. Afterwards, upon receiving a PDU session establishment request from the terminal, the AMF can transmit the dual registration capability information to the SMF in a PDU session establishment message.

[0407] Based on the dual registration capability information, the SMF can determine that the terminal is capable of EBI allocation.

[0408] Step 4. SMF can send a PDU Session Establishment Accept message to the terminal.

[0409] The PDU Session Establishment Accept message may include the capability to support EBI allocation and an indication of whether EBI allocation is required.

[0410] Step 5. The SMF may send a PDU Session Modification Command message to the terminal. The PDU Session Modification Command message may include a QoS flow list required for EBI allocation and a request for EBI allocation.

[0411] Step 6. The terminal can perform EBI allocation for QoS flows requested by the SMF. The terminal can send a PDU Session Modification Complete message containing information about the allocated EBI to the SMF.

[0412] When a terminal allocates an EBI, it can store the allocated EBI. Then, when allocating an EBI in step 12 described below, the terminal can allocate an EBI that avoids the stored EBI. This prevents the problem of duplicate EBI allocation.

[0413] If necessary, the terminal can perform EBI revocation. To perform EBI revocation, the terminal can notify another SMF (SMF 2) or the same SMF (SMF 1) of the EBI revocation via a PDU Session Modification Request message. Upon receiving this, the SMF can notify the AMF of the EBI revocation.

[0414] Steps 7-8. SMF can transmit assigned EBI information to AMF via Namf_Communication_EBIAssignment Request. Alternatively, EBI information can be transmitted via a newly defined service.

[0415] Step 9. The terminal can request PDU session establishment to network 2 using the second 3GPP access. The PDU session establishment process can be applied as shown in Figure 8-9.

[0416] The terminal can transmit capability information indicating that the terminal supports EBI allocation to the SMF through the PDU session establishment request.

[0417] Alternatively, the terminal can transmit dual registration capability information to the AMF through a registration request in step 2. The AMF can then store the dual registration capability information. Afterwards, upon receiving a PDU session establishment request from the terminal, the AMF can transmit the dual registration capability information to the SMF in a PDU session establishment message.

[0418] Based on the dual registration capability information, the SMF can determine that the terminal is capable of EBI allocation.

[0419] Step 10. The SMF can send a PDU Session Establishment Accept message to the terminal.

[0420] The PDU Session Establishment Accept message may include the capability to support EBI allocation and an indication of whether EBI allocation is required.

[0421] Step 11. The SMF may send a PDU Session Modification Command message to the terminal. The PDU Session Modification Command message may include a QoS flow list required for EBI allocation and a request for EBI allocation.

[0422] Step 12. The terminal can perform EBI allocation for QoS flows requested by the SMF. The terminal can send a PDU Session Modification Complete message containing information about the allocated EBI to the SMF.

[0423] When the terminal allocates an EBI, based on the EBI saved in step 6, the terminal can allocate an EBI different from the EBI allocated in step 6. The terminal can store the newly allocated EBI information.

[0424] If necessary, the terminal can perform EBI revocation. To perform EBI revocation, the terminal can notify another SMF (SMF 2) or the same SMF (SMF 1) of the EBI revocation via a PDU Session Modification Request message. Upon receiving this, the SMF can notify the AMF of the EBI revocation.

[0425] Steps 13-14. The SMF can transmit the assigned EBI information to the AMF via the Namf_Communication_EBIAssignment Request. Alternatively, the EBI information can be transmitted via a newly defined service.

[0426] 2. Second example of the fourth embodiment

[0427] If the terminal announces that it has EBI allocation capability, the UE-PCF can include information indicating the need for EBI allocation in the URSP rule. That is, the RSD of the URSP rule can include information on whether EBI allocation is required.

[0428] URSP rules containing the above-described information can be transmitted to the terminal.

[0429] Based on the URSP rules, the terminal can transmit the allocated EBI information to the network in the PDU session establishment request message.

[0430] A URSP rule (UE Route Selection Policy Rule) may contain a list of Route Selection Descriptors (RSDs).

[0431] The list of RSDs may include multiple RSDs. One of the multiple RSDs may be an RSD of an EBI Allocation.

[0432] The RSD of the aforementioned EBI Allocation can indicate whether the terminal needs to allocate EBI for the default QoS flow of the PDU session. The RSD indicating the need for EBI Allocation may be optional. That is, the RSD of EBI Allocation may not be mandatory in the URSP rule.

[0433] V. Embodiment 5 - When EBI allocation is performed, a method for notifying EBI information while performing registration with AMF by a terminal

[0434] The terminal can receive allocated EBI information from the SMF. The allocated EBI information (Mapped EPS bearer context information) can be transmitted to the terminal through procedures such as PDU Session Establishment Accept and PDU Session Modification Command. In this case, if there is a change in the allocated EBI, the terminal can transmit the EBI allocation information to the AMF of another 3GPP access.

[0435] The terminal can send the assigned EBI information to the AMF by including it in a Registration Request message.

[0436] When a terminal moves from EPS to 5GS and performs registration and has a locally released EPS bearer, the terminal can send EBI information to AMF in a Registration Request message.

[0437] The EPS bearer context status information element may indicate the status of each EPS bearer context identified by the EPS bearer identity.

[0438] The EPS bearer context status information element may be a type 4 information element of 4 octets in length.

[0439] FIG. 12 illustrates an example of an EPS bearer context state information element according to an embodiment of the present specification.

[0440] EBI(x) can be coded as follows:

[0441] - EBI(0): Bit 1 of octet 3 is spare and is coded as 0.

[0442] - EBI(1) - EBI(15): 0 indicates that the ESM state of the corresponding EPS bearer context is BEARER CONTEXT-INACTIVE. 1 indicates that the ESM state of the corresponding EPS bearer context is not BEARER CONTEXT-INACTIVE.

[0443] AMF can store EBI information currently assigned to a terminal in the UE context. Alternatively, AMF can update EBI information previously assigned to a terminal.

[0444] When an EBI allocation change occurs for a terminal, the terminal may transmit EBP bearer information while sending a registration request message to the AMF of another 3GPP access that is not associated with the particular PDU session.

[0445] When a terminal receives changed mapped EPS bearer context information for a specific PDU session (i.e., when the mapped EPS bearer context contains information for newly allocating an EBI or releasing an existing allocated EBI), the AMF may transmit EBP bearer information while sending a registration request message to the AMF of another 3GPP access that is not associated with the specific PDU session.

[0446] Then, duplicate EPS bearer allocation can be prevented because different AMFs can know the EBI information allocated to the terminal.

[0447] If EBI allocations occur almost simultaneously by different SMFs (i.e., by different AMFs), duplicate EBI allocations may occur before the UE notifies the changed EBI information. In this case, the UE can request a reallocation or notify the SMF of the duplicate EBI by sending a PDU Session Modification Request message or a PDU Session Modification Complete message. The SMF can then request a reallocation from the AMF.

[0448] Alternatively, a terminal can only sequentially create one PDU session at a time. If the terminal receives multiple PDU Session Modification Command messages simultaneously, it can process only one and temporarily reject the rest. After this, the SMF can then perform the PDU Session Modification procedure again.

[0449] For this purpose, new causes such as those that indicate that EBI is duplicated can be defined.

[0450] VI. Embodiment 6 - EBI Allocation Method for MA PDU Session Using Dual 3GPP Access

[0451] For MA PDU sessions using 3GPP access and non-3GPP access, EBI allocation is done only for 3GPP access.

[0452] However, for MA PDU sessions utilizing dual 3GPP access, EBI allocation may need to be performed for both 3GPP accesses.

[0453] For MA PDU sessions utilizing dual 3GPP accesses, the same EBI must be allocated to both 3GPP accesses, as they are identical PDU sessions. However, since the serving AMFs of each access are different, the same EBI may not be allocated.

[0454] To address this, when an SMF in a dual 3GPP access MA PDU session requests an EBI allocation to the AMF of one 3GPP access and is allocated an EBI, the SMF can then send information about the allocated EBI to the AMF of the other 3GPP access.

[0455] Alternatively, the EBI information for that MA PDU session can be passed to another AMF via another NF, as used in the first embodiment.

[0456] If, as in the fifth embodiment, a terminal notifies EBI information to another AMF, the terminal may not simply notify the activated EBI, but may also notify information related to the EBI (PDU session type / characteristics (e.g., single access PDU session, MA PDU session, dual 3GPP access MA PDU session, etc.), PDU session ID, QoS flow information (e.g., QFI)).

[0457] EPC linkage is also supported for terminals registered using dual 3GPP access, so that terminals can use the service without interruption.

[0458] The following actions can be performed:

[0459] - When AMF allocates EBI, it can store it in another NF (e.g. UDM, V-PCF, new NF) and the stored information can be transmitted to another AMF.

[0460] - If UDM recognizes dual registration, it can impose core network restrictions to prevent one AMF from using EPC and the other AMF from using EPC.

[0461] - When UDM receives Update Location Request / Numd_UECM_AMFDeregistration Request from MME / HSS, it can send Nudm_UECM_DeregistrationNotification to both 3GPP Access Serving AMFs.

[0462] - The terminal can directly allocate EBI and notify it to SMF, and SMF can transmit EBI information to AMF.

[0463] - When an EBI allocation occurs, the terminal can perform registration with AMF to notify EBI information.

[0464] 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.

[0465] Figure 13 illustrates the AMF's procedure for the disclosure of this specification.

[0466] 1. AMF can receive registration requests from UE (User Equipment) through the first 3GPP (3rd Generation Partnership Project) access.

[0467] 2. AMF can receive an establishment request for a PDU (Packet Data Unit) session from the UE via the first 3GPP access.

[0468] 3. Based on the above establishment request message, AMF can send an SM context request to SMF (Session Management Function).

[0469] 4. The AMF may receive a request for allocation of an EPS bearer ID (EBI) for the first QoS (Quality of Service) flow related to the PDU session from the SMF.

[0470] The above QoS flow may be related to the 3GPP access.

[0471] 5. Based on the above allocation request, AMF can allocate the first EBI for the QoS flow.

[0472] 6. AMF can transmit information about the above first EBI to UDM (Unified Data Management).

[0473] The information about the first EBI may include at least one of an ID of the PDU session, information about the first QoS flow, and Allocation and Retention Priority (ARP).

[0474] The information about the first EBI may include information indicating whether the PDU session is a session via single access, a MA (Multi-Access) PDU session, or an MA PDU session via dual 3GPP access.

[0475] AMF can receive subscriber information of the UE from the UDM.

[0476] The above subscriber information may include EBI information already allocated to the UE.

[0477] The step of allocating the first EBI may include: the AMF allocating the first EBI that does not overlap with the already allocated EBI.

[0478] The above registration request may include information about an EBI already allocated to the UE.

[0479] The step of allocating the first EBI may include: AMF allocating the first EBI that does not overlap with an already allocated EBI.

[0480] The above establishment request may include information about EBIs already allocated to the UE.

[0481] The step of allocating the first EBI may include: AMF allocating the first EBI that does not overlap with an already allocated EBI.

[0482] Based on the above allocation request, the AMF may send an EBI revocation request to the UDM based on the fact that the AMF has no EBI to allocate.

[0483] The above registration request may include information about the capability of the UE for dual 3GPP access.

[0484] Based on the information about the capability for the dual 3GPP access, the AMF can send information to the UE about whether the dual 3GPP access is allowed.

[0485] The above dual 3GPP access may include the first 3GPP access.

[0486] The step of transmitting information about the first EBI to the UDM may be performed based on information about the capability for the dual 3GPP access.

[0487] 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.

[0488] Figure 14 illustrates the UDM procedure for the disclosure of this specification.

[0489] 1. The UDM can receive information about the first EBI (EPS bearer ID) allocated from the first AMF (Access Mobility Function).

[0490] The above first AMF may be a serving AMF for the first 3GPP (3rd Generation Partnership Project) access of a UE (User Equipment).

[0491] The above first EBI may be for a Quality of Service (QoS) flow related to a Packet Data Unit (PDU) session for the UE.

[0492] The above QoS flow may be related to a Packet Data Unit (PDU) session for the UE and the first 3GPP.

[0493] 2. The UDM can transmit information about the first EBI to the second AMF.

[0494] The second AMF may be a serving AMF for the second 3GPP access of the UE.

[0495] 3. The UDM can receive information about the second EBI allocated from the second AMF.

[0496] Based on transmitting information about the first EBI to the second AMF, the first EBI may be different from the second EBI.

[0497] Information about the allocated EBI may include at least one of an ID of the PDU session, QoS flow information, and Allocation and Retention Priority (ARP).

[0498] The information about the first EBI may include information indicating whether the PDU session is a session via single access, a MA (Multi-Access) PDU session, or an MA PDU session via dual 3GPP access.

[0499] Based on the fact that the first AMF has no EBI to allocate, the UDM can receive an EBI revocation request from the first AMF.

[0500] The UDM can transmit the EBI revocation to the second AMF.

[0501] 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.

[0502] Figure 15 illustrates the UE's procedure for disclosure of this specification.

[0503] 1. The UE may send a first registration request to the first AMF (Access Mobility Function) via the first 3GPP (3rd Generation Partnership Project) access.

[0504] The above first registration request may include information about the capability of the UE for dual 3GPP access.

[0505] 2. Based on the information about the capability for the dual 3GPP access, the UE can receive information from the first AMF about whether the dual 3GPP access is allowed.

[0506] 3. The UE may send an establishment request for a first PDU (Packet Data Unit) session to the first AMF via the first 3GPP access.

[0507] 4. The UE may receive information about a first EBI (EPS bearer ID) for a first QoS (Quality of Service) flow related to the first PDU session from a first SMF (Session Management Function).

[0508] 5. Based on the above dual 3GPP access being allowed, the UE can send a second registration request to the second AMF via the second 3GPP access.

[0509] 6. The UE may send a forest request for a second PDU session to the second AMF via the second 3GPP access.

[0510] 7. The UE may receive information about a second EBI for a second QoS flow associated with the second PDU session from the second SMF.

[0511] The above dual 3GPP access may include the first 3GPP access and the second 3GPP access.

[0512] The above first EBI may be different from the above second EBI.

[0513] Hereinafter, a device for performing communication according to some embodiments of the present specification will be described.

[0514] For example, a device may include a processor, a transceiver, and memory.

[0515] For example, a processor may be configured to be operatively coupled with memory and a processor.

[0516] The operations performed by the processor include: transmitting a first registration request to a first AMF (Access Mobility Function) via a first 3GPP (3rd Generation Partnership Project) access; wherein the first registration request includes information about a capability of the UE for dual 3GPP access, and based on the information about the capability of the UE for dual 3GPP access, receiving information from the first AMF as to whether the dual 3GPP access is allowed; transmitting an establishment request for a first PDU (Packet Data Unit) session to the first AMF via the first 3GPP access; receiving information about a first EBI (EPS bearer ID) for a first QoS (Quality of Service) flow related to the first PDU session from a first SMF (Session Management Function); and transmitting a second registration request to a second AMF via a second 3GPP access based on the dual 3GPP access being allowed. A step of transmitting a forest request for a second PDU session to the second AMF via the second 3GPP access; and a step of receiving information about a second EBI for a second QoS flow related to the second PDU session from the second SMF, wherein the dual 3GPP access includes the first 3GPP access and the second 3GPP access, and the first EBI may be different from the second EBI.

[0517] Below, a processor of a device for providing communication according to some embodiments of the present specification is described.

[0518] The operations performed by the processor include: transmitting a first registration request to a first AMF (Access Mobility Function) via a first 3GPP (3rd Generation Partnership Project) access; wherein the first registration request includes information about a capability of the UE for dual 3GPP access, and based on the information about the capability of the UE for dual 3GPP access, receiving information from the first AMF as to whether the dual 3GPP access is allowed; transmitting an establishment request for a first PDU (Packet Data Unit) session to the first AMF via the first 3GPP access; receiving information about a first EBI (EPS bearer ID) for a first QoS (Quality of Service) flow related to the first PDU session from a first SMF (Session Management Function); and transmitting a second registration request to a second AMF via a second 3GPP access based on the dual 3GPP access being allowed. A step of transmitting a forest request for a second PDU session to the second AMF via the second 3GPP access; and a step of receiving information about a second EBI for a second QoS flow related to the second PDU session from the second SMF, wherein the dual 3GPP access includes the first 3GPP access and the second 3GPP access, and the first EBI may be different from the second EBI.

[0519] 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.

[0520] 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.

[0521] 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.

[0522] Computer-readable media may include tangible and non-volatile computer-readable storage media.

[0523] 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.

[0524] 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.

[0525] 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.

[0526] The stored one or more commands comprise: transmitting a first registration request to a first Access Mobility Function (AMF) via a first 3rd Generation Partnership Project (3GPP) access; wherein the first registration request includes information about a capability of the UE for dual 3GPP access, and based on the information about the capability of the UE for dual 3GPP access, receiving information from the first AMF as to whether the dual 3GPP access is allowed; transmitting an establishment request for a first Packet Data Unit (PDU) session to the first AMF via the first 3GPP access; receiving information about a first EPS bearer ID (EBI) for a first Quality of Service (QoS) flow associated with the first PDU session from a first Session Management Function (SMF); and transmitting a second registration request to a second AMF via a second 3GPP access based on the dual 3GPP access being allowed. A step of transmitting a forest request for a second PDU session to the second AMF via the second 3GPP access; and a step of receiving information about a second EBI for a second QoS flow related to the second PDU session from the second SMF, wherein the dual 3GPP access includes the first 3GPP access and the second 3GPP access, and the first EBI may be different from the second EBI.

[0527] This specification may have various effects.

[0528] For example, the problem of assigning the same EBI can be prevented through the procedure disclosed in this specification.

[0529] 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.

[0530] 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. AMF (Access Mobility Function) is a method for performing communication. A step of receiving a registration request from a UE (User Equipment) via the first 3GPP (3rd Generation Partnership Project) access; A step of receiving an establishment request for a PDU (Packet Data Unit) session through the first 3GPP access from the UE; A step of transmitting an SM context request to an SMF (Session Management Function) based on the above establishment request message; A step of receiving a request for allocation of an EPS bearer ID (EBI) for a first QoS (Quality of Service) flow related to the PDU session from the SMF; The above QoS flow is related to the 3GPP access, A step of allocating a first EBI for the QoS flow based on the allocation request; A method comprising the step of transmitting information about the first EBI to a Unified Data Management (UDM).

2. In paragraph 1, A method wherein the information about the first EBI includes at least one of an ID of the PDU session, information about the first QoS flow, and Allocation and Retention Priority (ARP).

3. In paragraph 1 or 2, A method wherein the information for the first EBI includes information indicating whether the PDU session is a session via single access, a MA (Multi-Access) PDU session, or an MA PDU session via dual 3GPP access.

4. In any one of the clauses 1 to 3, Further comprising a step of receiving subscriber information of the UE from the UDM, The above subscriber information includes EBI information already allocated to the UE, The step of allocating the first EBI comprises: a method in which the AMF allocates the first EBI that does not overlap with the already allocated EBI.

5. In any one of paragraphs 1 to 4, The above registration request includes information about the EBI already allocated to the UE, The step of allocating the first EBI comprises: a method in which the AMF allocates the first EBI that does not overlap with the already allocated EBI.

6. In any one of paragraphs 1 to 4, The above establishment request includes information about the EBI already allocated to the UE, The step of allocating the first EBI comprises: a method in which the AMF allocates the first EBI that does not overlap with the already allocated EBI.

7. In any one of paragraphs 1 to 6, A method further comprising the step of transmitting an EBI revocation request to the UDM based on the allocation request and the AMF having no EBI to allocate.

8. In any one of paragraphs 1 to 6, The above registration request includes information about the capability of the UE for dual 3GPP access, Further comprising a step of transmitting information to the UE as to whether the dual 3GPP access is allowed based on the information about the capability for the dual 3GPP access, The above dual 3GPP access includes the first 3GPP access, The step of transmitting information about the first EBI to the UDM is performed based on information about the capability for the dual 3GPP access. 9.UDM (Unified Data Management) is a method for performing communication. A step of receiving information about a first EBI (EPS bearer ID) allocated from a first AMF (Access Mobility Function); The above first AMF is a serving AMF for the first 3GPP (3rd Generation Partnership Project) access of the UE (User Equipment), The above first EBI is for a QoS (Quality of Service) flow related to a PDU (Packet Data Unit) session for the UE, The above QoS flow is related to a PDU (Packet Data Unit) session for the UE and the first 3GPP, A step of transmitting information about the first EBI to the second AMF; The above second AMF is a serving AMF for the second 3GPP access of the UE, comprising a step of receiving information about a second EBI allocated from the second AMF; A method wherein the first EBI is different from the second EBI based on transmitting information about the first EBI to the second AMF.

10. In paragraph 9, A method in which information about the allocated EBI includes at least one of an ID of the PDU session, QoS flow information, and ARP (Allocation and Retention Priority).

11. In paragraph 9 or 10, A method wherein the information for the first EBI includes information indicating whether the PDU session is a session via single access, a MA (Multi-Access) PDU session, or an MA PDU session via dual 3GPP access.

12. In any one of the clauses 9 to 11, A step of receiving an EBI revocation request from the first AMF based on the first AMF having no EBI to allocate; A method further comprising the step of transmitting the EBI revocation to the second AMF.

13. A method for UE (User Equipment) to perform communication, A step of transmitting a first registration request to a first AMF (Access Mobility Function) via a first 3GPP (3rd Generation Partnership Project) access; The above first registration request includes information about the capability of the UE for dual 3GPP access, A step of receiving information from the first AMF as to whether the dual 3GPP access is allowed based on information about the capability for the dual 3GPP access; A step of transmitting an establishment request for a first PDU (Packet Data Unit) session to the first AMF via the first 3GPP access; A step of receiving information about a first EBI (EPS bearer ID) for a first QoS (Quality of Service) flow related to the first PDU session from a first SMF (Session Management Function); A step of transmitting a second registration request to a second AMF via a second 3GPP access based on the above dual 3GPP access being allowed; A step of transmitting a forest request for a second PDU session to the second AMF via the second 3GPP access; comprising the step of receiving information about a second EBI for a second QoS flow related to the second PDU session from a second SMF; The above dual 3GPP access includes the first 3GPP access and the second 3GPP access, A method wherein the first EBI is different from the second EBI.

14. As an AMF (Access Mobility Function) that performs communication, Transmitter and receiver; Contains a processor, The operation performed by the above processor is an AMF method according to any one of claims 1 to 8.

15. As a UDM (Unified Data Management) that performs communication, Transmitter and receiver; Contains a processor, The operation performed by the above processor is a UDM method according to any one of claims 9 to 12.

16. As a UE (User Equipment) performing communication, Transmitter and receiver; Contains a processor, The operation performed by the above processor is a UE method according to claim 13.

Images