LOM-related i-SMF reuse method

Abstract

An embodiment of the present disclosure provides a method. The method comprises the steps in which: due to UE mobility, a new AMF determines to maintain an existing I-SMF on the basis that the existing I-SMF is able to serve a UE at a new location thereof; and the new AMF transmits an SM context update request for a PDU session to the existing I-SMF, wherein the SM context update request indicates that LOM is not allowed.

Description

LOM-related I-SMF reuse method

[0001] This specification relates to mobile communication.

[0002] 3GPP (3rd generation partnership project) LTE (long-term evolution) is a technology designed to enable high-speed packet communication. Many methods have been proposed to achieve LTE goals, such as reducing costs for users and operators, improving service quality, expanding coverage, and increasing system capacity. As high-level requirements, 3GPP LTE demands reduced cost per bit, improved service availability, flexible use of frequency bands, a simple structure, open interfaces, and appropriate power consumption of terminals.

[0003] Work has begun at the ITU (International Telecommunication Union) and 3GPP to develop 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, satisfying both urgent market demands and the longer-term requirements presented by the ITU-R (ITU Radio Communication Sector) IMT (International Mobile Telecommunications)-2020 process. Furthermore, NR must be able to utilize any spectrum band up to at least 100 GHz so that it can be used for wireless communication even in the distant future.

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

[0005] When terminal mobility occurs, the new AMF decides to reuse the I-SMF for the LOM.

[0006] FIG. 1 shows an example of a communication system to which the implementation of the present specification is applied.

[0007] FIG. 2 shows an example of a wireless device to which the implementation of the present specification applies.

[0008] FIG. 3 shows an example of a UE to which the implementation of the present specification applies.

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

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

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

[0012] FIG. 8 shows an example of a structure in which an I-SMF and an SMF are used simultaneously to which the implementation of the present specification is applied.

[0013] FIGS. 9 and FIGS. 10 illustrate examples of an I-SMF function provision procedure according to the disclosure of the present specification.

[0014] FIGS. 11 and FIGS. 12 illustrate examples of I-SMF function change procedures according to the disclosure of the present specification.

[0015] FIG. 13 illustrates the procedure of a new AMF for the disclosure of the present specification.

[0016] FIG. 14 illustrates the procedure of the existing I-SMF for the disclosure of the present specification.

[0017] The following techniques, devices, and systems may 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 may be implemented through wireless technologies such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be implemented through 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 through 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) using E-UTRA.3GPP LTE uses OFDMA in the downlink (DL) and SC-FDMA in the uplink (UL). Evolutions of 3GPP LTE include LTE-A (advanced), LTE-A Pro, and / or 5G NR (new radio).

[0018] For convenience of explanation, the implementation of this specification is described primarily in relation to 3GPP-based wireless communication systems. However, the technical characteristics of this specification are not limited thereto. For example, the following detailed description is provided based on a mobile communication system corresponding to a 3GPP-based wireless communication system, but aspects of this specification that are not limited to 3GPP-based wireless communication systems may be applied to other mobile communication systems.

[0019] 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.

[0020] In this specification, "A or B" may mean "only A," "only B," or "both A and B." Alternatively, in this specification, "A or B" may be interpreted as "A and / or B." For example, in this specification, "A, B or C" may mean "only A," "only B," "only C," or "any combination of A, B and C."

[0021] A slash ( / ) or a comma used in this specification may mean "and / or." For example, "A / B" may mean "A and / or B." Accordingly, "A / B" may mean "only A," "only B," or "both A and B." For example, "A, B, C" may mean "A, B or C."

[0022] 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 as synonymous with "at least one of A and B."

[0023] Additionally, in this specification, "at least one of A, B and C" may mean "only A," "only B," "only C," or "any combination of A, B and C." Furthermore, "at least one of A, B or C" or "at least one of A, B and / or C" may mean "at least one of A, B and C."

[0024] Additionally, parentheses used in this specification may mean "for example." Specifically, when indicated as "control information (PDCCH)," "PDCCH" may be proposed as an example of "control information." In other words, "control information" in this specification is not limited to "PDCCH," and "PDCCH" may be proposed as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)," "PDCCH" may be proposed as an example of "control information."

[0025] Technical features described individually within a single drawing in this specification may be implemented individually or simultaneously.

[0026] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this specification may be applied to various fields where wireless communication and / or connectivity between devices (e.g., 5G) is required.

[0027] The present specification will be described in more detail below with reference to the drawings. In the following drawings and / or description, the same reference numerals may refer to the same or corresponding hardware blocks, software blocks, and / or function blocks unless otherwise indicated.

[0028] FIG. 1 shows an example of a communication system to which the implementation of the present specification is applied.

[0029] The 5G usage scenario shown in FIG. 1 is merely an example, and the technical features of this specification may be applied to other 5G usage scenarios not shown in FIG. 1.

[0030] The three main requirements categories for 5G are (1) enhanced mobile broadband (eMBB) category, (2) massive machine type communication (mMTC) category, and (3) ultra-reliable and low latency communications (URLLC) category.

[0031] Referring to FIG. 1, the 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 the network of the communication system (1), but the implementation of the present specification is not limited to a 5G system and may be applied to future communication systems beyond a 5G system.

[0032] The base station (200) and the network (300) can be implemented as wireless devices, and a specific wireless device can operate as a base station / network node in relation to another wireless device.

[0033] Wireless devices (100a to 100f) represent devices that perform communication using radio access technology (RAT) (e.g., 5G NR or LTE) and may also be referred to as communication / wireless / 5G devices. 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 with wireless communication capabilities, autonomous vehicles, and vehicles capable of performing communication between vehicles. 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 head-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., smartwatches 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.

[0034] 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 PDA (personal digital assistant), a PMP (portable multimedia player), a navigation system, a slate PC, a tablet PC, an ultrabook, a vehicle, a vehicle with autonomous driving capabilities, a connected car, a UAV, an AI module, a robot, an AR device, a VR device, an MR device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or financial device), a security device, a weather / environment device, a 5G service-related device, or a device related to the Fourth Industrial Revolution.

[0035] For example, a UAV can be an aircraft that is not on board and is navigated by radio control signals.

[0036] 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 a 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 a real world. For example, a holographic device may include a device for implementing a 360-degree stereoscopic image by recording and playing back stereoscopic information using the phenomenon of light interference that occurs when two laser lights called holograms meet.

[0037] For example, a public safety device may include an image relay device or an image device that can be worn on a user's body.

[0038] For example, MTC devices and IoT devices may be devices that do not require direct human intervention or operation. For instance, MTC devices and IoT devices may include smart meters, vending machines, thermometers, smart light bulbs, door locks, or various sensors.

[0039] For example, a medical device may be a device used for the purpose of diagnosing, treating, alleviating, curing, or preventing a disease. For example, a medical device may be a device used to diagnose, treat, alleviate, or correct 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, a (in vitro) diagnostic device, a hearing aid, or a surgical device.

[0040] For example, a security device may be a device installed to prevent potential risks and maintain safety. For example, a security device may be a camera, closed-circuit TV (CCTV), a recorder, or a black box.

[0041] 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 POS system.

[0042] For example, a weather / environment device may include a device for monitoring or predicting the weather / environment.

[0043] Wireless devices (100a to 100f) can be connected to a network (300) through a base station (200). AI technology may be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) through 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) may communicate with each other through the base station (200) / network (300), but they may 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., V2V (vehicle-to-vehicle) / V2X (vehicle-to-everything) communication). Also, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0044] Wireless communication / connections (150a, 150b, 150c) can be established between wireless devices (100a to 100f) and / or between wireless devices (100a to 100f) and base station (200) and / or between base station (200). Here, the wireless communication / connections can be established through various RATs (e.g., 5G NR), such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D (device-to-device) communication), and communication between base stations (150c) (e.g., relay, IAB (integrated access and backhaul)). Through the wireless communication / connections (150a, 150b, 150c), wireless devices (100a to 100f) and base station (200) can transmit / receive wireless signals to / from each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various proposals of the present specification, at least some of the following may be performed: a process for setting various configuration information for transmitting / receiving wireless signals, a process for various signal processing (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and a resource allocation process.

[0045] AI refers to the field of researching artificial intelligence or the methodologies to create it, while machine learning refers to the field of researching methodologies to define and solve various problems within the realm of artificial intelligence. Machine learning is also defined as an algorithm that improves performance on a task through continuous experience.

[0046] A robot can refer to a machine that automatically processes or operates given tasks based on its own capabilities. In particular, a robot equipped with the ability to perceive its environment, make independent judgments, and perform actions can be called an intelligent robot. Robots can be classified into industrial, medical, domestic, and military types depending on their purpose or field of use. Robots are equipped with drive units, including actuators or motors, to perform various physical movements, such as moving robot joints. Additionally, mobile robots include wheels, brakes, propellers, etc., in their drive units, enabling them to drive on the ground or fly in the air.

[0047] Autonomous driving refers to technology that drives itself, and an autonomous vehicle refers to a vehicle that drives without user intervention or with minimal user intervention. For example, autonomous driving can include technologies such as maintaining the driving lane, automatically adjusting speed like adaptive cruise control, driving automatically along a predetermined route, and automatically setting a route and driving once a destination is set. The term "vehicle" encompasses vehicles equipped solely with internal combustion engines, hybrid vehicles equipped with both internal combustion engines and electric motors, and electric vehicles equipped solely with electric motors; it can include not only automobiles but also trains and motorcycles. An autonomous vehicle can be viewed as a robot equipped with autonomous driving capabilities.

[0048] Augmented Reality is a collective term for VR, AR, and MR. VR technology provides real-world objects or backgrounds solely as CG images, AR technology provides virtual CG images superimposed on 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 technology in that it displays real-world and virtual objects together. However, there is a difference in that while virtual objects in AR technology are used to complement real-world objects, virtual and real objects in MR technology are used as equal entities.

[0049] NR supports multiple numerologies or subcarrier spacings (SCS) to support various 5G services. For example, when the SCS is 15 kHz, it supports a wide area in traditional cellular bands; when the SCS is 30 kHz / 60 kHz, it supports dense-urban areas, lower latency, and wider carrier bandwidth; and when the SCS is 60 kHz or higher, it supports a bandwidth greater than 24.25 GHz to overcome phase noise.

[0050] The NR frequency band can be defined by two types of frequency ranges (FR1, FR2). The numerical values ​​of the frequency ranges may change. For example, the two types of frequency ranges (FR1, FR2) may be as shown in Table 1 below. For convenience of explanation, among the frequency ranges used in the NR system, FR1 may mean "sub 6GHz range" and FR2 may mean "above 6GHz range" and may be referred to as millimeter wave (mmW).

[0051] Frequency Range Definition Frequency Range Subcarrier Spacing FR1 450 MHz - 6000 MHz 15, 30, 60 kHz FR2 24 250 MHz - 52600 MHz 60, 120, 240 kHz

[0052] As described above, the numerical value of the frequency range of the NR system may change. For example, FR1 may include a band of 410 MHz to 7125 MHz as shown in Table 2 below. That is, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher. For example, the frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or higher included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, for example, for communication for vehicles (e.g., autonomous driving).

[0053] Frequency Range Definition Frequency Range Subcarrier Spacing FR1 4 10 MHz - 7 125 MHz 15, 30, 60 kHz FR2 24 250 MHz - 5 2600 MHz 60, 120, 240 kHz

[0054] Here, the wireless communication technology implemented in the wireless device of this specification may include LTE, NR, and 6G, as well as narrowband IoT (NB-IoT) for low-power communication. For example, NB-IoT technology may be an example of low-power wide-area network (LPWAN) technology and may be implemented according to standards such as LTE Cat NB1 and / or LTE Cat NB2, but is not limited to the names mentioned above. Additionally, or generally, the wireless communication technology implemented in the wireless device of this specification may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be referred to by various names such as enhanced MTC (eMTC). For example, LTE-M technology may be implemented in 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 names mentioned above. Additionally or generally, wireless communication technology implemented in the wireless device of this specification may include at least one of ZigBee, Bluetooth, and / or LPWAN for low-power communication, and is not limited to the names mentioned above. For example, ZigBee technology may create personal area networks (PANs) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and may be referred to by various names.

[0055] FIG. 2 shows an example of a wireless device to which the implementation of the present specification applies.

[0056] 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 example / service. For example, {the first wireless device (100) and the second wireless device (200)} may correspond to at least one of {wireless devices (100a–100f) and base station (200)}, {wireless devices (100a–100f) and wireless devices (100a–100f)} and / or {base station (200) and base station (200)} of FIG. 1. The first wireless device (100) and / or the second wireless device (200) may be composed of various components, devices / parts and / or modules.

[0057] 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).

[0058] 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 generally, the memory (104) may be placed outside the processing chip (101).

[0059] The processor (102) can control the memory (104) and / or the transceiver (106) and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed herein. For example, the processor (102) may process information within the memory (104) to generate a first information / signal and transmit a wireless signal containing the first information / signal through the transceiver (106). The processor (102) may receive a wireless signal containing a second information / signal through the transceiver (106) and process the second information / signal to store the obtained information in the memory (104).

[0060] Memory (104) may be connected to the processor (102) so as to be operable. Memory (104) may store various types of information and / or instructions. Memory (104) may store firmware and / or software code (105) that implements code, instructions, and / or a set of instructions that perform the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this specification when executed by the processor (102). For example, firmware and / or software code (105) may implement instructions that perform the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this specification when executed by the processor (102). For example, firmware and / or software code (105) may control the processor (102) to perform one or more protocols. For example, firmware and / or software code (105) may control the processor (102) to perform one or more wireless interface protocol layers.

[0061] 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 a wireless signal through one or more antennas (108). Each transceiver (106) may include a transmitter and / or receiver. The transceiver (106) may be interchangeably used with an RF (radio frequency) unit. In this specification, the first wireless device (100) may represent a communication modem / circuit / chip.

[0062] 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).

[0063] 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 placed outside the processing chip (201).

[0064] The processor (202) can control the memory (204) and / or the transceiver (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed herein. For example, the processor (202) may process information within the memory (204) to generate a third information / signal and transmit a wireless signal containing the third information / signal through the transceiver (206). The processor (202) may receive a wireless signal containing a fourth information / signal through the transceiver (206) and process the fourth information / signal to store the obtained information in the memory (204).

[0065] Memory (204) may be connected to the processor (202) so as to be operable. Memory (204) may store various types of information and / or instructions. Memory (204) may store firmware and / or software code (205) that implements instruction code, instructions, and / or sets of instructions that perform descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this specification when executed by the processor (202). For example, firmware and / or software code (205) may implement instructions that perform descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this specification when executed by the processor (202). For example, firmware and / or software code (205) may control the processor (202) to perform one or more protocols. For example, firmware and / or software code (205) may control the processor (202) to perform one or more wireless interface protocol layers.

[0066] 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 transmit and / or receive a wireless signal through one or more antennas (208). Each transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be interchangeably used with an RF unit. In this specification, the second wireless device (200) may represent a communication modem / circuit / chip.

[0067] 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 PHY (physical) layer, a MAC (media access control) layer, a RLC (radio link control) layer, a PDCP (packet data convergence protocol) layer, a RRC (radio resource control) layer, and an SDAP (service data adaptation protocol) layer). One or more processors (102, 202) may generate one or more PDUs (protocol data units), one or more SDUs (service data units), messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this specification. One or more processors (102, 202) may generate a signal (e.g., baseband signal) including a PDU, SDU, message, control information, data, or information according to the description, function, procedure, proposal, method, and / or operation flowchart disclosed in this specification and provide it to one or more transceivers (106, 206). One or more processors (102, 202) may receive a signal (e.g., baseband signal) from one or more transceivers (106, 206) and may obtain a PDU, SDU, message, control information, data, or information according to the description, function, procedure, proposal, method, and / or operation flowchart disclosed in this specification.

[0068] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, and / or a microcomputer. 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 one or more processors (102, 202). For example, one or more processors (102, 202) may be composed of a set of communication control processors, application processors (APs), electronic control units (ECUs), central processing units (CPUs), graphic processing units (GPUs), and memory control processors.

[0069] One or more memories (104, 204) may be connected to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. One or more memories (104, 204) may consist of random access memory (RAM), dynamic RAM (DRAM), read-only memory (ROM), erasable programmable ROM (EPROM), flash memory, volatile memory, non-volatile memory, hard drives, registers, cache memory, computer read storage media, and / or combinations thereof. One or more memories (104, 204) may be located inside and / or outside of one or more processors (102, 202). Additionally, one or more memories (104, 204) may be connected to one or more processors (102, 202) through various technologies such as wired or wireless connections.

[0070] One or more transceivers (106, 206) may transmit user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this specification to one or more other devices. One or more transceivers (106, 206) may receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this specification from one or more other devices. For example, one or more transceivers (106, 206) may be connected to one or more processors (102, 202) and may transmit and receive wireless signals. For example, one or more processors (102, 202) may 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) can control one or more transceivers (106, 206) to receive user data, control information, wireless signals, etc. from one or more other devices.

[0071] One or more transceivers (106, 206) may be connected to one or more antennas (108, 208). Additionally and / or generally, 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 operation flowcharts disclosed herein through one or more antennas (108, 208). In this specification, one or more antennas (108, 208) may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports).

[0072] One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202). One or more transceivers (106, 206) can convert processed user data, control information, wireless signals / channels, etc. from baseband signals to RF band signals using one or more processors (102, 202). To this end, one or more transceivers (106, 206) may include (analog) oscillators and / or filters. For example, one or more transceivers (106, 206) can up-convert an OFDM baseband signal into an OFDM signal through 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) can receive an OFDM signal at a carrier frequency and down-convert the OFDM signal into an OFDM baseband signal through an (analog) oscillator and / or filter under the control of one or more processors (102, 202).

[0073] Although not illustrated in FIG. 2, the wireless device (100, 200) may 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., audio I / O port, video I / O port), a driving unit, and a computing unit. The additional components (140) may be connected to one or more processors (102, 202) through various technologies, such as wired or wireless connections.

[0074] In an implementation of this specification, the UE may operate as a transmitting device in the uplink (UL; uplink) and as a receiving device in the downlink (DL; downlink). In an implementation of this specification, the base station may operate as a receiving device in the UL and as a transmitting device in the DL. For technical convenience, it is generally assumed 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 to the first wireless device (100) may be configured to perform UE operations according to an implementation of this specification or to control a transceiver (106) to perform UE operations according to an implementation of this specification. A processor (202) connected to, mounted on, or released to the second wireless device (200) may be configured to perform base station operations according to an implementation of this specification or to control a transceiver (206) to perform base station operations according to an implementation of this specification.

[0075] In this specification, the base station may be referred to as Node B, eNode B, or gNB.

[0076] FIG. 3 shows an example of a UE to which the implementation of the present specification applies.

[0077] Referring to FIG. 3, the UE (100) can correspond to the first wireless device (100) of FIG. 2.

[0078] The UE (100) includes a processor (102), memory (104), 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).

[0079] The processor (102) may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operation 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 operation flowcharts disclosed herein. Layers of a wireless 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 processor, EXYNOS made by Samsung® TM Series processors, A Series processors made by Apple®, HELIO made by MediaTek® TM Series processors, ATOM made by Intel® TM It can be found in series processors or corresponding next-generation processors.

[0080] Memory (104) is coupled to the processor (102) so as to be operable and stores various information for operating the processor (102). Memory (104) may include ROM, RAM, flash memory, memory card, storage medium and / or other storage device. When the implementation is implemented in software, the technology described herein may be implemented using modules (e.g., procedures, functions, etc.) that perform the descriptions, functions, procedures, proposals, methods and / or operation flowcharts disclosed herein. Modules may be stored in memory (104) and executed by the processor (102). Memory (104) may be implemented within the processor (102) or outside the processor (102), in which case it may be communicatively coupled to the processor (102) through various methods known in the technology.

[0081] A transceiver (106) is coupled to operate with a processor (102) and transmits and / or receives a wireless signal. The transceiver (106) includes a transmitter and a receiver. The transceiver (106) may include a baseband circuit for processing a wireless frequency signal. The transceiver (106) controls one or more antennas (108) to transmit and / or receive a wireless signal.

[0082] 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).

[0083] The display (143) outputs the result 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).

[0084] A SIM card (145) is an integrated circuit for securely storing an International Mobile Subscriber Identity (IMSI) and associated keys, and is used to identify and authenticate a subscriber in a mobile device such as a mobile phone or computer. Additionally, contact information can be stored on many SIM cards.

[0085] 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).

[0086] Figure 4 is a structural diagram of a next-generation mobile communication network.

[0087] 5GC (5G Core) may include various components, and FIG. 5 includes some of them, such as 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).

[0088] The UE (100) is connected to the data network via the UPF (440) through the NG-RAN (Next Generation Radio Access Network) including the gNB (20).

[0089] The UE (100) can also receive data services through untrusted non-3GPP access, such as a WLAN (Wireless Local Area Network). To connect the non-3GPP access to the core network, an N3IWF (490) may be deployed.

[0090] The illustrated N3IWF (490) performs the function of managing interworking between non-3GPP access and 5G systems. When the UE (100) is connected to non-3GPP access (e.g., WiFi referred to as IEEE 801.11), the UE (100) can be connected to the 5G system through the N3IWF (490). The N3IWF (490) performs control signing with the AMF (410) and connects to the UPF (440) via the N3 interface for data transmission.

[0091] The illustrated AMF (410) can manage access and mobility in a 5G system. The AMF (410) can perform the function of managing Non-Access Stratum (NAS) security. The AMF (410) can perform the function of handling mobility in an idle state.

[0092] 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 communication.

[0093] 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 the data path between the gNB (20) and the SMF (420). Additionally, 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 the function of handling PDUs. For mobility within the NG-RAN (Next Generation Radio Access Network defined in 3GPP Release-15 or later), packets can be routed through the UPF. Additionally, the UPF (440) may also function as an anchor point for mobility with other 3GPP networks (RANs defined prior to 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.

[0094] The illustrated PCF (430) is a node that controls the operator's policy.

[0095] The illustrated AF (450) is a server for providing various services to the UE (100).

[0096] The illustrated UDM (460) is a type of server that manages subscriber information, such as the HSS (Home subscriber Server) of 4th generation mobile communication. The UDM (460) stores and manages the subscriber information in a Unified Data Repository (UDR).

[0097] The illustrated SMF (420) can perform the function of assigning the IP (Internet Protocol) address of the UE. Also, the SMF (420) can control the PDU (protocol data unit) session.

[0098] For reference, the reference numerals for AMF (410), SMF (420), PCF (430), UPF (440), AF (450), UDM (460), N3IWF (490), gNB (20), or UE (100) may be omitted below.

[0099] Fifth-generation mobile communication supports multiple numerologies or subcarrier spacings (SCS) to support various 5G services. For example, when the SCS is 15 kHz, it supports a wide area in traditional cellular bands; when the SCS is 30 kHz / 60 kHz, it supports dense-urban environments, lower latency, and wider carrier bandwidth; and when the SCS is 60 kHz or higher, it supports a bandwidth greater than 24.25 GHz to overcome phase noise.

[0100] FIG. 5 shows an example of a 5G system structure to which the implementation of the present specification is applied.

[0101] The 5G system (5GS) structure consists of the following network functions (NF).

[0102] - AUSF (Authentication Server Function)

[0103] - AMF (Access and Mobility Management Function)

[0104] - DN (Data Network), 예를 들어 운영자 서비스, 인터넷 접속 또는 타사 서비스

[0105] - USDF (Unstructured Data Storage Function)

[0106] - NEF (Network Exposure Function)

[0107] - I-NEF (Intermediate NEF)

[0108] - NRF (Network Repository Function)

[0109] - NSSF (Network Slice Selection Function)

[0110] - PCF (Policy Control Function)

[0111] - SMF (Session Management Function)

[0112] - UDM (Unified Data Management)

[0113] - UDR (Unified Data Repository)

[0114] - UPF (User Plane Function)

[0115] - UCMF (UE radio Capability Management Function)

[0116] - AF (Application Function)

[0117] - UE (User Equipment)

[0118] - (R)AN ((Radio) Access Network)

[0119] - 5G-EIR (5G-Equipment Identity Register)

[0120] - NWDAF (Network Data Analytics Function)

[0121] - CHF (CHarging Function)

[0122] In addition, the following network functions may be considered.

[0123] - N3IWF (Non-3GPP InterWorking Function)

[0124] - TNGF (Trusted Non-3GPP Gateway Function)

[0125] - W-AGF (Wireline Access Gateway Function)

[0126] Figure 5 shows the 5G system structure in a non-roaming case using a reference point representation showing how various network functions interact with each other.

[0127] In Fig. 5, for clarity of the point-to-point diagram, UDSF, NEF, and NRF are not described. However, all network functions shown can interact with UDSF, UDR, NEF, and NRF as needed.

[0128] 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.

[0129] The 5G system structure includes the following reference points.

[0130] - N1: Reference point between UE and AMF.

[0131] - N2: Reference point between (R)AN and AMF.

[0132] - N3: Reference point between (R)AN and UPF.

[0133] - N4: Reference point between SMF and UPF.

[0134] - N6: Reference point between the UPF and the data network.

[0135] - N9: Reference point between two UPFs.

[0136] The following reference points show the interactions that exist between the NF services of NF.

[0137] - N5: Reference point between PCF and AF.

[0138] - N7: Reference point between SMF and PCF.

[0139] - N8: Reference point between UDM and AMF.

[0140] - N10: Reference point between UDM and SMF.

[0141] - N11: Reference point between AMF and SMF.

[0142] - N12: Reference point between AMF and AUSF.

[0143] - N13: Reference point between UDM and AUSF.

[0144] - N14: Reference point between two AMFs.

[0145] - N15: Reference point between PCF and AMF for non-roaming scenarios, reference point between PCF and AMF of the visited network for roaming scenarios.

[0146] - N16: Reference point between two SMFs (in the case of roaming, between the SMF of the visited network and the SMF of the home network)

[0147] - N22: Reference point between AMF and NSSF.

[0148] In some cases, two NFs may need to be connected to each other to service the UE.

[0149] <PDU 세션 수립 절차>

[0150] The procedure for establishing a PDU session is described. Refer to Section 4.3.2 of 3GPP TS 23.502 V16.3.0 (2019-12).

[0151] FIGS. 6 and FIGS. 7 illustrate examples of PDU session establishment procedures to which the implementation of the present specification applies.

[0152] PDU session establishment may fall under the following:

[0153] - Procedure for establishing a PDU session initiated by the UE

[0154] - PDU session handover between 3GPP and non-3GPP initiated by the UE

[0155] - PDU session handover from EPS initiated by UE to 5GS.

[0156] - Procedure for establishing a PDU session triggered by the network

[0157] A PDU session may (a) be associated with a single access type at any given time, namely either a 3GPP access or a non-3GPP access, or (b) be associated with multiple access types simultaneously, namely one 3GPP access and one non-3GPP access. A PDU session associated with multiple access types is called a multi-access (MA) PDU session and may be requested by an access traffic steering, switching, splitting (ATSS) enabled UE.

[0158] Figures 6 and 7 specify a procedure for establishing a PDU session associated with a single connection type at a given time.

[0159] In the procedure shown in Figures 6 and 7, it is assumed that the AMF has already retrieved user subscription data from the UDM unless the UE is urgently registered, since the UE is already registered with the AMF.

[0160] First, the procedure of Fig. 6 will be explained.

[0161] (1) Step 1: To establish a new PDU session, the UE generates a new PDU session ID.

[0162] The UE initiates the PDU session establishment procedure requested by the UE by transmitting a NAS message containing a PDU session establishment request message within an N1 SM container. The PDU session establishment request message includes a PDU session ID, a requested PDU session type, a requested session and service continuity (SSC) mode, 5G SM capabilities, Protocol Configuration Options (PCO), an SM PDU DN Request Container, and a UE Integrity Protection Maximum Data Rate.

[0163] If the PDU session establishment is a request to establish a new PDU session, the request type indicates "Initial Request". If the request refers to an existing PDU session transitioning between a 3GPP connection and a non-3GPP connection, or a PDU session handover from an existing PDN (packet data network) connection in the EPC, the request type indicates "Existing PDU Session". If the PDU session establishment is a request to establish a PDU session for an emergency service, the request type indicates "Emergency Request". If the request refers to an existing PDU session for an emergency service transitioning between a 3GPP connection and a non-3GPP connection, or a PDU session handover from an existing PDN connection for an emergency service in the EPC, the request type indicates "Existing Emergency PDU Session".

[0164] The UE includes an S-NSSAI from the allowed NSSAI of the current connection type. If a Mapping of Allowed NSSAI is provided to the UE, the UE provides both the S-NSSAI of the visited VPLMN from the allowed NSSAI and the corresponding S-NSSAI of the HPLMN from the mapping of the allowed NSSAI.

[0165] (2) Step 2: The AMF selects an SMF. If the request type indicates an "initial request" or if the request is due to a handover from a non-3GPP connection provided by an EPS or another AMF, the AMF stores the connection type of the PDU session, as well as the association of the S-NSSAI(s), the DNN (data network name), the PDU session ID, and the SMF ID.

[0166] If the request type is "Initial Request" and the message also includes a previous PDU session ID representing an existing PDU session, the AMF selects an SMF and saves the new PDU session ID, S-NSAI(s), and the association of the selected SMF ID.

[0167] If the request type indicates an "existing PDU session," the AMF selects an SMF based on the SMF-ID received from the UDM. The AMF updates the connection type stored for the PDU session.

[0168] If the request type indicates an "existing PDU session" that refers to an existing PDU session moving between a 3GPP connection and a non-3GPP connection, and the serving PLMN S-NSSAI of the PDU session exists in the allowed NSSAI of the target connection type, the PDU session establishment procedure may be performed in the following cases.

[0169] - If the SMF ID corresponding to the PDU session ID and the AMF belong to the same PLMN;

[0170] - If the SMF ID corresponding to the PDU session ID belongs to the HPLMN;

[0171] Otherwise, the AMF rejects the request to establish a PDU session with an appropriate reason for rejection.

[0172] AMF rejects requests from urgently registered UEs where the request type does not indicate "Urgent Request" or "Existing Urgent PDU Session".

[0173] (3) Step 3: If the AMF is not associated with an SMF for a PDU session ID provided by the UE (e.g., when the request type indicates "initial request"), the AMF calls the Create SMContext request procedure (e.g., Nsmf_PDUSession_CreateSMContext Request). If the AMF is already associated with an SMF for a PDU session ID provided by the UE (e.g., when the request type indicates "existing PDU session"), the AMF calls the Update SMContext request procedure (e.g., Nsmf_PDUSession_UpdateSMContext Request).

[0174] The AMF transmits the S-NSSAI of the serving PLMN from the allowed NSSAI to the SMF. For a local breakout (LBO) roaming scenario, the AMF also transmits the corresponding S-NSSAI of the HPLMN from the mapping of the allowed NSSAI to the SMF.

[0175] The AMF ID is the UE's GUAMI and uniquely identifies the AMF serving the UE. The AMF transmits the PDU Session ID along with an N1 SM container containing the PDU session establishment request message received from the UE. The generic public subscription identifier (GPSI) is included if available in the AMF.

[0176] If a UE in a restricted service state is registered for emergency services without providing a SUPI, the AMF provides a PEI instead of a SUPI. If a UE in a restricted service state is registered for emergency services while providing a SUPI but is not authenticated, the AMF indicates that the SUPI is not authenticated. If the SMF does not receive a SUPI from a UE or if the AMF indicates that the SUPI is not authenticated, the UE is determined to be unauthenticated.

[0177] AMF can include a PCF ID in Nsmf_PDUSession_CreateSMContext. This PCFID identifies the H-PCF (home PCF) in the non-roaming case and the V-PCF (visited PCF) in the LBO roaming case.

[0178] (4) Step 4: If session management subscription data for S-NSSAI of the corresponding SUPI, DNN, HPLMN is unavailable, SMF can retrieve the session management subscription data from UDM and be notified when this subscription data is modified.

[0179] (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 in accordance with the request received in Step 3.

[0180] 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.

[0181] If the SMF decides not to accept the establishment of a PDU session, the SMF rejects the UE request via a NAS SM signal containing 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 that the SMF proceeds to step 20 below and the PDU session establishment procedure is stopped.

[0182] (6) Step 6: Optional secondary authentication / authorization may be performed.

[0183] (7a) Step 7a: When dynamic policy and charging control (PCC) is used in a PDU session, the SMF can perform PCF selection.

[0184] (7b) Step 7b: SMF can establish an SM policy association with PCF and obtain a basic PCC rule for the PDU session by performing the SM policy association establishment procedure.

[0185] (8) Step 8: SMF selects one or more UPFs.

[0186] (9) Step 9: SMF can provide information about the satisfied policy control request trigger conditions by performing the SM policy association modification procedure initiated by SMF.

[0187] (10) Step 10: If the request type indicates an “initial request,” the SMF may initiate an N4 Session Establishment procedure with the selected UPF. Otherwise, the SMF may initiate an N4 Session Modification procedure with the selected UPF.

[0188] In step 10a, SMF can send an N4 session establishment / modification request to UPF and provide packet detection, enforcement, and reporting rules installed in UPF for the PDU session. In step 10b, UPF can confirm by sending an N4 session establishment / modification response.

[0189] (11) Step 11: SMF sends an N1N2 message transfer message (e.g., Namf_Communication_N1N2 Message Transfer) to AMF.

[0190] The N1N2 message delivery message may include N2 SM information. The N2 SM information carries the following information that the AMF will transmit to the (R)AN.

[0191] - CN Tunnel Info: Corresponds to the core network address of the N3 tunnel corresponding to the PDU session;

[0192] - QFI (QoS flow ID) corresponding to one or more QoS (quality of service) profiles;

[0193] - PDU Session ID: Indicates to the UE the association between the RAN resource and the PDU session for the UE;

[0194] - S-NSSAI with a value for the serving PLMN (i.e., HPLMN S-NSSAI, or VPLMN S-NSSAI in the case of LBO roaming);

[0195] - User plane security enforcement information determined by SMF;

[0196] - Maximum data rate for UE integrity protection received in PDU session establishment request message: When integrity protection is indicated as "Preferred" or "Required" in user plane security enforcement information

[0197] - RSN (redundancy sequence number) parameter

[0198] The N1N2 message delivery message may include an N1 SM container. The N1 SM container includes a PDU session establishment acceptance message that the AMF will provide to the UE. The PDU session establishment acceptance message includes an S-NSSAI from an allowed NSASI. In the case of an LBO roaming scenario, the PDU session establishment acceptance message includes an S-NSSAI from an allowed NSSAI for the VPLMN, and also includes the corresponding S-NSSAI for the HPLMN from the mapping of the allowed NSSAI received by the SMF in step 3.

[0199] If necessary for QoS flows related to QoS rules and QoS profiles, multiple QoS rules, QoS flow levels, and QoS parameters may be included in the PDU session establishment acceptance message and N2 SM information within the N1 SM container.

[0200] If PDU session establishment fails between steps 5 and 11, the N1N2 message delivery message contains an N1 SM container containing a PDU session establishment rejection message, but does not contain N2 SM information. (R)AN sends a NAS message containing a PDU session establishment rejection message to the UE. In this case, steps 12-17 below are omitted.

[0201] (12) Step 12: The AMF sends a NAS message containing a PDU session ID destined for the UE, a message accepting the establishment of a PDU session, and N2 SM information received from the SMF to (R)AN within the N2 PDU session request message.

[0202] (13) Step 13: (R)AN can perform AN-specific signal exchanges with the UE regarding information received from the SMF. For example, in the case of NG-RAN, it can perform RRC connection reconfiguration with the UE to set up necessary NG-RAN resources in relation to the QoS rules for the PDU session request received by the UE in Step 12.

[0203] (R)AN forwards the NAS message (PDU session ID, N1 SM container (PDU session establishment acceptance message)) received in step 12 to the UE. (R)AN provides the NAS message to the UE only if the AN-specific signal exchange with the UE includes the addition of (R)AN resources related to the received N2 command.

[0204] If N2 SM information is not included in step 11, steps 14–16b and step 17 below are omitted.

[0205] Now, the procedure of Fig. 7 following the procedure of Fig. 6 is explained.

[0206] (14) Step 14: (R)AN sends an N2 PDU session response message to AMF. The N2 PDU session response message may include a PDU session ID, cause, N2 SM information (PDU session ID, AN tunnel information, list of accepted / rejected QFIs, user plane enforcement policy notifications), etc.

[0207] (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.

[0208] (16a) Step S16a: SMF initiates the N4 session modification procedure with UPF. SMF provides AN tunnel information and the corresponding forwarding rule to UPF.

[0209] (16b) Step S16b: UPF provides the N4 session modification response to SMF.

[0210] After this step, UPF can deliver the DL packet that may have been buffered for this PDU session to the UE.

[0211] (16c) Step 16c: If the SMF is not yet registered for this PDU session, the SMF can register with the UDM for the given PDU session.

[0212] (17) Step 17: SMF sends an update SM context response message (e.g., Nsmf_PDUSession_UpdateSMContext Response) to AMF.

[0213] After this step, AMF delivers the relevant events subscribed to by SMF.

[0214] (18) Step 18: At any time after Step 5, if the establishment of the PDU session fails during the procedure, the SMF may notify the AMF by calling Nsmf_PDUSession_SMContextStatusNotify (release). The SMF may also release the created N4 session, the assigned PDU session address (e.g., IP address), and, if possible, release the association with the PCF. In this case, Step 19 below is omitted.

[0215] (19) Step 19: For PDU session type IPv6 or IPv4v6, the SMF can generate an IPv6 Router Advertisement and send it to the UE.

[0216] (20) Step 20: SMF can perform SM policy association modifications initiated by SMF.

[0217] (21) Step 21: If the establishment of a PDU session fails after Step 4, and the SMF no longer processes the UE's PDU session, the SMF may unsubscribe from the modification of the session management subscription data.

[0218] Terminal Mobility and SMF Service Areas

[0219] 3GPP standard specifications describe ETSUN (Enhancing Topology of SMF and UPF in 5G Networks) support regarding terminal mobility and the service area of ​​SMFs. This content is described in Section 5.34 of TS 23.501 v19.2.1 and related service procedures are described in Section 4.23 of TS 23.502 v19.2.0. Depending on terminal mobility, if a terminal moves out of the service area of ​​an existing SMF (specifically, Anchor-SMF) selected during the PDU session establishment procedure, a separate SMF (specifically, Intermediate SMF (I-SMF)) may be selected / added to support connectivity.

[0220] If the UE is outside the SMF service area or the SMF is currently unable to provide a destination DNAI for routing traffic for local access to the DN, or if the UE is within the SMF service area and local offloading management (see Clause 6.10 and Clause 5.34.11 of TS 23.548 v19.4.0) is permitted, an I-SMF may be inserted between the SMF and the AMF. The I-SMF has an N11 interface with the AMF and an N16a interface with the SMF, and can control UPFs that the SMF cannot directly control. If necessary, SM context exchange and tunnel information transfer may be performed directly between the two SMFs without the intervention of the AMF.

[0221] Depending on the scenario, PDU sessions for non-roaming cases or local breakouts may be provided by a single SMF or by an SMF and an I-SMF. If PDU sessions are provided by both an SMF and an I-SMF, the SMF may be an NF instance having interfaces to PCF and CHF.

[0222] SMF can release or reject the PDU session if the DNN of the PDU session corresponds to LADN and I-SMF is inserted into the PDU session.

[0223] Note 1: This may mean that operators should plan LADN deployments so that the LADN service area must be within the SMF service area but does not cross the SMF service area.

[0224] Note 2: This may include cases where the UE is not in the SMF service area or moves out of the SMF service area and I-SMF is inserted into the PDU session (e.g., during PDU session setup, service request). If the PDU session is maintained via I-SMF, the SMF cannot enforce LADN service control. For example, notifications may not be delivered to the SMF during a service request.

[0225] Regardless of whether a deployment topology with a specific SMF service area is applied, if a PDU session is associated with SSC mode 2 or SSC mode 3, SMF can trigger a PDU session reset to the same DN.

[0226] Note 3: SSC Mode 2 or SSC Mode 3 may be used to optimize the SMF location for PDU sessions or, depending on the deployment environment, to ensure that the UE is always within the service area of ​​the SMF controlling the PDU session. In this case (where PDU session continuity via PLMN is not required), the procedures described in this clause may not be necessary.

[0227] Regarding the Local Offloading Management (LOM) function, an action of selecting / adding a separate SMF (specifically, an Intermediate SMF) to support Edge Computing has been proposed.

[0228] To resolve or prevent load concentration on the selected A-SMF (Anchor SMF) during PDU session establishment due to the increase in data that must be managed for terminal edge computing support and signaling for processing / decision / notification, a separate I-SMF can delegate edge computing support functions.

[0229] Unlike the I-SMF in the conventional ETSUN function, the above I-SMF can be supported regardless of the service area of ​​the SMF. For details on LOM support, refer to Section 6.10 (Support of the Local Offloading Management) of TS 23.548 v19.4.0 and Section 5.34.11 of TS 23.501 v19.2.1.

[0230] LOM support will be discussed later.

[0231] When deploying edge computing, 5GS can support local offloading management to reduce the impact of centrally deployed SMFs on edge computing-related information management.

[0232] In Distributed Anchor Point and multi-PDU session connection models, local offloading management can be supported using existing methods such as URSP and SSC modes.

[0233] In the Session Breakout connection model, local offloading management can be applied only to non-roaming PDU sessions. For the Session Breakout connection model, if the AMF determines that the UE is within the local offloading management service area and that local offloading management is permitted based on the SMF selection subscription data, the AMF may select / re-select an I-SMF to support local offloading management. This may include cases where the UE is within the SMF service area. For local offloading management, the I-SMF is responsible for edge computing processing and can support the following functions:

[0234] - EASDF configuration and DNS message processing instead of SMF

[0235] - I-SMF performs EASDF search and selection instead of SMF

[0236] - EDI Management and Search in NEF

[0237] Note 1: SMF can also be pre-configured with EDI.

[0238] - Receive local offloading information from PCF via SMF. This information may indicate IP ranges and / or FQDNs that can be routed to local parts of the DN.

[0239] Note 2: Even if I-SMF is inserted to support local offloading management, SM NAS messages can be terminated by SMF.

[0240] If an I-SMF is inserted for local offload management (for example, if the inserted I-SMF provides the SMF with a local offload allowance indicator), the SMF may not discover, select, or configure the EASDF. Additionally, the SMF may not perform DNS message processing for local offload traffic destined for the local part of the DN.

[0241] The UE may not know whether local offload management is applied to the PDU session.

[0242] In the LOM function, based on user subscriber information (e.g., SMF Selection Subscription Data), the LOM service area, and the terminal's location, the AMF can select a separate I-SMF for edge computing support.

[0243] In addition, depending on the mobility of the terminal, the AMF can determine the selection / deletion of the I-SMF based on the terminal location and the LOM Service Area.

[0244] UE mobility of PDU sessions supporting local offloading management will be described below.

[0245] For PDU sessions that support local offloading management, when mobility events such as handovers or AMF changes occur, mobility handling is executed in the same way as the corresponding mobility handling defined in Section 4.23 of TS 23.502 v19.2.0, but the following differences may exist:

[0246] i) If the UDM retrieves the Local Offloading Management Allowed indication as part of the SMF selection subscription data, the new AMF can determine the new I-SMF as follows:

[0247] - If a new UE location is included in the service area of ​​the SMF and the UE location is outside the local offloading management service area, the AMF can remove the existing I-SMF (if available).

[0248] - If a new UE location is included in the service area of ​​an SMF and the UE location is within the local offloading management service area, and an existing I-SMF cannot service the new UE location, the AMF may select a new I-SMF. If there is an older I-SMF that cannot support the new UE location, the AMF may also remove the older I-SMF.

[0249] - To support local offloading management, the selected I-SMF needs to support local offloading management, be able to serve new UE locations, and may support DNN and S-NSSAI associated with PDU sessions.

[0250] Note: The above procedure may also apply when a UE moves from an 'AMF not upgraded to operate according to the Local Offloading Management Support' indicator to an 'AMF upgraded to operate according to the Local Offloading Management Support' indicator.

[0251] ii) In the case of I-SMF insertion and relocation, the target I-SMF and SMF may interact as follows:

[0252] - The target I-SMF can send the newly selected EASDF IP address and the local offloading management allow indicator to the SMF.

[0253] - SMF can transmit the newly selected EASDF IP address to the UE via PCO.

[0254] iii) For I-SMF removal, SMF can be performed as follows:

[0255] - The SMF selects a new EASDF, and the SMF can transmit the selected new EASDF IP address to the UE via the PCO.

[0256] In the foregoing description, it is stated that if a terminal supported by LOM moves out of the LOM service area, the AMF releases / removes the I-SMF.

[0257] If the terminal's movement location is not included within the service area of ​​the anchor SMF (A-SMF), the existing I-SMF responsible for LOM support is released, and a separate I-SMF may be selected again according to ETSUN technology.

[0258] For example, the handover service procedure may involve the following steps.

[0259] i) LOM (Local Offloading Management) Support I-SMF Release Process:

[0260] - Request to create SM Context for A-SMF

[0261] - A-SMF Target I-UPF Selection and Configuration Procedure

[0262] - Old I-SMF Signaling and Resource Release Procedure

[0263] ii) ETSUN (Enhancing Topology of SMF and UPF in 5G Networks) Support I-SMF Selection Process:

[0264] - New I-SMF selection and SM Context request

[0265] - Selection and setup procedure for I-UPF, another target of the new I-SMF

[0266] - Tunnel setup procedure for A-SMF forwarding.

[0267] The aforementioned additional signaling and procedures may lead to increased handover times. Furthermore, frequent handovers caused by terminal movement can result in network performance degradation. Accordingly, it is necessary to reduce unnecessary signaling and procedures related to terminal mobility and to efficiently operate and control each SMF.

[0268] In addition, in the conventional N2-based handover service procedure (Step 2 of Section 4.23.7.3.2 of TS 23.502 v19.2.0), the target (new) AMF determines the selection of the I-SMF based on the location of the terminal and the area of ​​the SMF and I-SMF, but it is not possible to know whether the existing I-SMF was responsible for the LOM or ETSUN function.

[0269] Consequently, when the terminal's movement location falls within the service area of ​​the A-SMF, a problem arises where the target (new) AMF always disables the I-SMF, which was responsible for supporting the existing LOM (Local Offloading Management).

[0270] If the target (new) AMF can know the functional information previously handled by the existing I-MF, it can reduce unnecessary signaling and procedures associated with UE mobility scenarios and efficiently control the SMF.

[0271] To solve the above problems, a method is needed for the target (new) AMF to recognize the functions previously handled by the I-SMF (e.g., Local Offloading Management or Enhancing Topology of SMF and UPF in 5G Networks). In making the selection / deselection decision regarding the SMF(s) managing the PDU session, the target (new) AMF needs a method that comprehensively considers the service areas of the A-SMF and each I-SMF, in addition to the terminal's current location and LOM area (Local Offloading Management Area).

[0272] In this specification, such methods may be proposed.

[0273] FIG. 8 shows an example of a structure in which an I-SMF and an SMF are used simultaneously to which the implementation of the present specification is applied.

[0274] Figure 8 shows a structure using I-SMF in conventional ETSUN technology and LOM.

[0275] For convenience, the two SMFs managing a single PDU session may be referred to as I-SMF (Intermediate SMF) and A-SMF (Anchor-SMF).

[0276] Among the I-SMFs, the I-SMF responsible for the ETSUN (Enhancing Topology of SMF and UPF in 5G Networks) technology can be referred to as the ETSUN I-SMF.

[0277] Among the I-SMFs, the I-SMF responsible for the LOM (Local Offloading Management) function can be referred to as the LOM I-SMF.

[0278] The procedures and / or messages described in this specification may use conventional procedures / messages, extend conventional procedures / messages, or define and use new procedures / messages.

[0279] Depending on the purpose and needs of the method proposed in this specification, the procedures described below may be performed or used in combination or complementarily.

[0280] In this specification, the I-SMF responsible for the LOM (e.g., LOM I-SMF) may be an SMF controlled to support different functions / roles together with the A-SMF.

[0281] An I-SMF responsible for LOM (e.g., LOM I-SMF) can be described / defined as an I-SMF (Intermediate SMF) that performs other functions (e.g., functions / operations for providing edge computing to UEs) in addition to the operation of an I-SMF (e.g., ETSUN I-SMF) defined in the conventional ETSUN (Enhancing Topology of SMF and UPF in 5G Networks) technology.

[0282] I. I-SMF Function Information Management and Transmission Method

[0283] The following drawings are made to illustrate a specific example of the present specification. The names of specific devices or specific signals / messages / fields described in the drawings are presented as examples, and therefore the technical features of the present specification are not limited to the specific names used in the following drawings.

[0284] FIGS. 9 and FIGS. 10 illustrate examples of an I-SMF function provision procedure according to the disclosure of the present specification.

[0285] The procedure for establishing a PDP session may be applied according to the contents of Figures 6 and 7.

[0286] 1) Step 1

[0287] The terminal can send a PDU Session Establishment Request message to the S-AMF (source AMF) to create a PDU session.

[0288] 2) Step 2

[0289] In response to a terminal's request to establish a PDU session, the AMF (e.g., S-AMF) can check the LOM authorization status for each DNN / S-NSSAI in the subscriber information (e.g., SMF Selection Subscription data) via the UDM. For example, the AMF can check the LOM authorization status for each DNN / S-NSSAI in the subscriber information by interacting with the UDM.

[0290] Based on this, the AMF can select an I-SMF for LOM function support by considering the terminal's location and LOM service area. Additionally, the AMF can select an A-SMF.

[0291] Alternatively, if the DNN / S-NSSAI of the session to be established does not meet the LOM support conditions and the location of the terminal is not included in the service area of ​​the A-SMF, the AMF may select an I-SMF that supports the ETSUN (Enhancing Topology of SMF and UPF in 5G Networks) function according to the prior art.

[0292] Depending on the function of the selected I-SMF, the AMF can manage the I-SMF function information by inputting / storing it in the PDU Session Context within the UE Context.

[0293] For example, the AMF can store at least one of the following information within the UE Context:

[0294] - Information that can identify the case where AMF determines the LOM I-SMF as I-SMF

[0295] - Information to identify if AMF selected I-SMF to handle ETSUN functions rather than LOM

[0296] - Information indicating that I-SMF has been selected to support a specific feature

[0297] A PDU Session Context within a UE Context can contain 'ismfForLomInd' of type 'boolean'.

[0298] 'ismfForLomInd' can be displayed during an internal PLMN N2 handover if the relevant information is available.

[0299] If 'ismfForLomInd' is present, 'ismfForLomInd' can indicate whether I-SMF is used to support Local Offloading Management (LOM) as follows:

[0300] - true: I-SMF is selected to support LOM

[0301] - false: I-SMF is not selected for LOM

[0302] The new AMF can use this IE (ismfForLomInd) to identify the capabilities of I-SMF and take action based on supported capabilities and criteria. For example, the new AMF can switch between local offloading management in I-SMF's 5G networks and topology enhancements between SMF and UPF.

[0303] 3) Step 3

[0304] If the AMF selects the I-SMF for LOM support, the AMF (e.g., S-AMF) may send the Nsmf_PDUSession_CreateSMContext Request message to the I-SMF including a Local Offloading Management Allowed indication.

[0305] The AMF (e.g., S-AMF) can transmit information about the A-SMF selected in step 2 to the I-SMF.

[0306] 4-5) step 4-5

[0307] I-SMF can select I-UPF for local traffic steering.

[0308] I-SMF can establish an N4 session. For example, I-SMF can send an N4 session establishment request message to T-UPF.

[0309] 6-7) step 6-7

[0310] Based on the Local Offloading Management Allowed indication, I-SMF can recognize that it has been selected for edge computing support.

[0311] Based on this, I-SMF can select an EASDF (Edge Application Server Discovery Function) during the session establishment procedure to the terminal and perform the DNS context setup (creation) procedure. For example, I-SMF can send a DNS Context Create Request message to the selected EASDF.

[0312] 8-9) step 8-9

[0313] Based on the information received from the AMF, the I-SMF may send a PDU session creation request (PDUSession_Create Request) message to the A-SMF selected by the AMF in step 2. The PDU session creation request (e.g., PDUSession_Create Request) message may include information about the Local Offloading Management Allowed indication and / or the EASDF IP address (information obtained by the I-SMF through Steps 6-7).

[0314] I-SMF can send a PDU session creation request (e.g., PDUSession_Create Request) to A-SMF, including the Local Offloading Management Allowed indication received from AMF in Step 3 and the address information of EASDF obtained in Steps 6-7.

[0315] In addition, I-SMF can acquire / subscribe to EDI (EAS Deployment Information) information for edge computing support.

[0316] 10) Step 10

[0317] Depending on the movement of the terminal, an N2-based handover procedure may be performed.

[0318] In this procedure, the serving AMF serving the terminal can be changed from the existing S-AMF to the T-AMF (Target AMF) (or a new AMF).

[0319] According to the procedure, the existing S-AMF can select the T-AMF (Target AMF) (or a new AMF). Accordingly, the terminal's serving AMF can change from the S-AMF to the T-AMF.

[0320] 11) Step 11

[0321] S-AMF can transmit to T-AMF (or a new AMF) the function information of I-SMF (e.g., I-SMF selected in step 2) in the PDU Session Context within the UE Context.

[0322] At this time, the S-AMF can transmit information about the A-SMF to the T-AMF (or the new AMF).

[0323] S-AMF may send a Communication_CreateUEContext request message to T-AMF (or a new AMF). The Communication_CreateUEContext request message may include N2 information and / or UE context information. The UE context information may include I-SMF responsible feature information.

[0324] The above UE context information may include the following information:

[0325] - Whether the above UE's PDU session is allowed for LOM

[0326] 12) Step 12

[0327] The T-AMF (or new AMF) can determine whether to reuse the existing I-SMF or change its function based on the I-SMF function information received in Step 11.

[0328] For example, when S-AMF selects I-SMF (e.g., step 2) for LOM support and T-AMF (or new AMF) decides to continue supporting LOM (e.g., when the terminal is within the LOM service area set in T-AMF and LOM is allowed (Local Offloading Management allowed) in the terminal's subscription data), T-AMF (or new AMF) may decide to reuse the existing I-SMF.

[0329] If the S-AMF selects the I-SMF to support ETSUN, the T-AMF (or new AMF) can decide whether to select the new I-SMF or reuse the current I-SMF to support the terminal's LOM.

[0330] For example, the T-AMF (or new AMF) can check the capabilities of the I-SMF (e.g., whether it supports LOM functionality) through the NRF. If the I-SMF supports LOM, the T-AMF (or new AMF) can decide to reuse the I-SMF.

[0331] If the T-AMF (or new AMF) decides to reuse the I-SMF, the T-AMF (or new AMF) may send Nsmf_PDUSession_UpdateSMContext to the I-SMF along with a Local Offloading Management Allowed indication. Based on this, the I-SMF may create an EASDF context.

[0332] Additionally, I-SMF can send Nsmf_PDUSession_Update (including the generated EASDF context) to A-SMF along with a Local Offloading Management Allowed indication. Based on this, A-SMF can delete the existing EASDF context (e.g., existing DNS context) and send the EASDF information provided by I-SMF to the terminal.

[0333] Alternatively, if the T-AMF (or new AMF) decides to reuse the I-SMF (e.g., if the T-AMF decides to retain the existing I-SMF), the T-AMF (or new AMF) may send an Nsmf_PDUSession_UpdateSMContext request to the I-SMF without a Local Offloading Management Allowed indication.

[0334] Alternatively, if the T-AMF (or new AMF) decides to reuse the I-SMF (e.g., if the T-AMF decides to retain the existing I-SMF), the T-AMF (or new AMF) may send an Nsmf_PDUSession_UpdateSMContext request to the I-SMF, including information to disable LOM support (e.g., Local Offloading Management Not Allowed indication).

[0335] Alternatively, if the T-AMF (or new AMF) decides to reuse the I-SMF (e.g., if the T-AMF decides to retain the existing I-SMF), the T-AMF (or new AMF) may send an Nsmf_PDUSession_UpdateSMContext request to the I-SMF indicating information to disable LOM support (e.g., that local offloading management is disallowed). For example, the T-AMF (or new AMF) may send an Nsmf_PDUSession_UpdateSMContext request to the I-SMF containing an indication that local offloading management is disallowed.

[0336] Based on this, I-SMF can delete the DNS (Domain Name System) context from the EASDF (e.g., the EASDF in step 7). For example, I-SMF can request the EASDF to delete the DNS context.

[0337] If I-SMF receives an SM context update request (Nsmf_PDUSession_UpdateSMContext) from T-AMF (or a new AMF) without a Local Offloading Management Allowed indication, I-SMF may send a PDU session update request (Nsmf_PDUSession_Update Request) without the Local Offloading Management Allowed indication to the SMF (e.g., A-SMF).

[0338] Alternatively, if I-SMF receives an SM context update request (Nsmf_PDUSession_UpdateSMContext request) from T-AMF (or a new AMF) indicating that local offloading management is not allowed, I-SMF may send a PDU session update request (Nsmf_PDUSession_Update Request) to the SMF (e.g., A-SMF) indicating that local offloading management is not allowed.

[0339] Alternatively, if I-SMF receives an SM context update request (Nsmf_PDUSession_UpdateSMContext request) from T-AMF (or a new AMF) indicating that local offloading management is not allowed, I-SMF may send a PDU session update request (Nsmf_PDUSession_Update Request) to the SMF (e.g., A-SMF) without the local offloading management allowed indication.

[0340] II. I-SMF Function Determination and Control Method

[0341] As described in Section I, through the method in which the S-AMF stores / manages I-SMF function information and transmits it to the T-AMF (new AMF), the T-AMF (new AMF) can determine the I-SMF function and control responsible for the existing PDU session.

[0342] Alternatively, regardless of whether it receives information on the functions of the existing I-SMF responsible for or supported by the S-AMF, the T-AMF (new AMF) can verify SMF capability information (e.g., whether the I-SMF supports LOM) through interaction with the NRF. Based on this, the T-AMF (new AMF) can determine the functions and control of the existing I-SMF.

[0343] For example, when an I-SMF registers with the NRF, it can register its capability regarding LOM support. The T-AMF (new AMF) can verify SMF capability information (e.g., whether the I-SMF supports LOM) through interaction with the NRF. Based on this, the T-AMF (new AMF) can determine the existing I-SMF functions and controls.

[0344] For example, T-AMF (new AMF) can decide whether to reuse the existing I-SMF and maintain / change LOM / ETSUN function support by comprehensively considering the I-SMF function information (e.g., I-SMF function identification information) received in Step 11 of Section I, the current location of the terminal, the service area of ​​the existing I-SMF and A-SMF, and the LOM service area.

[0345] The following drawings are made to illustrate a specific example of the present specification. The names of specific devices or specific signals / messages / fields described in the drawings are presented as examples, and therefore the technical features of the present specification are not limited to the specific names used in the following drawings.

[0346] FIGS. 11 and FIGS. 12 illustrate examples of I-SMF function change procedures according to the disclosure of the present specification.

[0347] After the procedures of FIGS. 9 and 10 are performed, the procedures of FIGS. 11 and 12 described later may be performed.

[0348] 1) Step 1

[0349] T-AMF (New AMF) can receive information from S-AMF regarding the functions responsible for I-SMF. Alternatively, it can determine whether the existing I-SMF supports LOM based on SMF capability information via NRF.

[0350] 2) Step 2

[0351] Based on the existing I-SMF function identification information (I-SMF function information) received in Step 1, the terminal's current location, the service areas of the existing I-SMF and A-SMF, and the local offloading service area, the T-AMF (new AMF) can determine the reuse of the existing I-SMF and its functions (e.g., maintenance / change of LOM / ETSUN function support). The above decision can be made based on the SMF selection subscription data obtained by the existing I-SMF from the UDM.

[0352] For example, in the following case, T-AMF (new AMF) can decide to reuse the existing LOM I-SMF:

[0353] - If LOM is authorized for the DNN / S-NSSAI of the corresponding PDU session in the subscriber information

[0354] - If the existing I-SMF is selected for LOM support and currently supports terminal location

[0355] - When the terminal location is included within the LOM service area

[0356] - Cases where the existing I-SMF can serve a new terminal location

[0357] For example, in the following case, the T-AMF (new AMF) may change the function handled by the I-SMF:

[0358] - If the I-SMF no longer satisfies the LOM support conditions and the A-SMF does not support terminal location, the T-AMF (new AMF) can change the functions handled by the existing LOM I-SMF from LOM to ETSUN.

[0359] - If I-SMF is selected for ETSUN support but satisfies the LOM support conditions, T-AMF (new AMF) can change the functions handled by I-SMF to LOM.

[0360] 3) Step 3

[0361] Based on the decision regarding the reuse of I-SMF and functions (e.g., maintaining / changing LOM / ETSUN function support) in step 2, T-AMF (new AMF) can transmit control information to I-SMF.

[0362] For example, T-AMF (new AMF) can send a PDU session SM context update request message to I-SMF. The PDU session SM context update request message may include I-SMF responsible feature information based on the decision of step 2.

[0363] The information may be at least one of the following:

[0364] - Information requesting a change in the function of I-SMF

[0365] - Information on disabling LOM support

[0366] - Whether the terminal's location is included (or excluded) within the LOM service area

[0367] Based on the decision to reuse the I-SMF, the PDU session SM context update request message may not include an indication allowing local offloading management. Alternatively, based on the decision to reuse the I-SMF, the PDU session SM context update request message may indicate information disabling LOM support (e.g., that local offloading management is not allowed).

[0368] 4a-7a) step 4a-7a

[0369] If it is decided in Step 2 that the I-SMF function will be changed from LOM to ETSUN, steps 4a-7a may be performed.

[0370] If the T-AMF (new AMF) determines that the I-SMF function change is from LOM to ETSUN, the following action may be performed based on the information received in Step 3:

[0371] - I-SMF can delete the existing DNS context within EASDF and send edge computing support request information to A-SMF.

[0372] - A-SMF can generate EASDF selection and DNS context based on the request information of the above I-SMF.

[0373] 4b-7b) step 4b-7b

[0374] If it is decided in Step 2 that the I-SMF function will be changed from ETSUN to LOM, steps 4b-7b may be performed.

[0375] If the T-AMF (new AMF) determines the I-SMF function change as a LOM in ETSUN, the following actions may be performed based on the information received in Step 3:

[0376] - I-SMF can select the new EASDF.

[0377] - I-SMF can create a new DNS context within EASDF and send EASDF address information and LOM support notification information to A-SMF.

[0378] - A-SMF can release an existing DNS context.

[0379] Based on step 5a or step 6b, A-SMF can determine whether to create or release a DNS Context based on information from I-SMF.

[0380] If the A-SMF receives information from the I-SMF regarding whether the terminal location is included within the LOM service area, the A-SMF can decide to delete or create the DNS context.

[0381] For example, if the A-SMF receives information from the I-SMF that the terminal location is included within the LOM service area, the A-SMF may decide to delete the existing DNS context. Based on this, the A-SMF may request the EASDF to delete the DNS context.

[0382] For example, if the A-SMF receives information from the I-SMF that the terminal location is not included within the LOM service area, the A-SMF may decide to create a DNS context. Based on this, the A-SMF may request the EASDF to create a DNS context.

[0383] The information received from I-SMF in step 5a or step 6b may be information that explicitly requests the creation / deletion of a DNS context.

[0384] 8) Step 8

[0385] If a new EASDF and DNS context is selected / created according to step 5b or step 7b, an EASDF IP address may be provided to the terminal. For example, A-SMF may transmit information about the EASDF IP address to the terminal.

[0386] For example, if A-SMF receives a PDU session update request message from I-SMF that does not contain an indication allowing local offloading management (or if A-SMF receives a PDU session update request message from I-SMF indicating that local offloading management is not allowed), A-SMF may send a PCO to the terminal containing the IP address of an EASDF of its choice or the address of a central DNS server (e.g., DNS context information). If the DNS server address found by A-SMF is the same as the address previously provided by I-SMF, A-SMF may not include that DNS server address in the PCO.

[0387] III. Examples of Application of the Disclosure of the Present Specification

[0388] 1. Support for Local Offloading Management (LOM)

[0389] When deploying edge computing, 5GS can support local offloading management to reduce the impact of centrally deployed SMFs on edge computing-related information management.

[0390] In Distributed Anchor Point and multi-PDU session connection models, local offloading management can be supported using existing methods such as URSP and SSC modes.

[0391] In the Session Breakout connection model, local offloading management may be applied only to non-roaming PDU sessions. In the case of the Session Breakout connection model, if the AMF determines that the UE is within the local offloading management service area configured in the said AMF and that local offloading management is allowed in the SMF selection subscription data, the AMF may select / re-select / reuse an I-SMF to support local offloading management. This may include cases where the UE is within the SMF service area. For local offloading management, the I-SMF is responsible for edge computing processing and may support the following functions:

[0392] - EASDF configuration and DNS message processing instead of SMF

[0393] - I-SMF performs EASDF search and selection instead of SMF

[0394] - EDI Management and Search in NEF

[0395] Note 1: SMF can also be pre-configured with EDI.

[0396] - Receive local offloading information from PCF via SMF. This information may indicate IP ranges and / or FQDNs that can be routed to local parts of the DN.

[0397] Note 2: Even if I-SMF is inserted to support local offloading management, SM NAS messages can be terminated by SMF.

[0398] If an I-SMF is inserted for local offload management (for example, if the inserted I-SMF provides the SMF with a local offload allowance indicator), the SMF may not discover, select, or configure the EASDF. Additionally, the SMF may not perform DNS message processing for local offload traffic destined for the local part of the DN.

[0399] The UE may not know whether local offload management is applied to the PDU session.

[0400] 2. UE Mobility for PDU Sessions Supporting Local Offloading Management (LOM)

[0401] For PDU sessions that support local offloading management, when mobility events such as handovers or AMF changes occur, mobility handling is executed in the same way as the corresponding mobility handling defined in Section 4.23 of TS 23.502 v19.2.0, but the following differences may exist:

[0402] i) Based on the search for the Local Offloading Management Allowed indication as part of the SMF selection subscription data in the UDM, the new AMF can determine the I-SMF as follows:

[0403] - If a new UE location is included in the service area of ​​the SMF and the UE location is outside the local offloading management service area, the AMF can remove the existing I-SMF (if available).

[0404] - If the service area of ​​an SMF (e.g., A-SMF) does not include the new UE location and the UE location is outside the Local Offloading Management (LOM) service area, the AMF may remove the previous I-SMF if the previous I-SMF cannot service the new UE location. If the previous I-SMF can serve the new UE location and the UE is outside the Local Offloading Management service area, the AMF may retain the previous I-SMF and call the Nsmf_PDUSession_UpdateSMContext request without the Local Offloading Management allow indication. In this case, the previous I-SMF may also call the Nsmf_PDUSession_UpdateSMContext request to the SMF without the Local Offloading Management allow indication.

[0405] If I-SMF and SMF receive an Nsmf_PDUSession_UpdateSMContext request without an indication to allow local offloading management, I-SMF can drop the DNS context from the previous EASDF and SMF can create a DNS context by selecting a new EASDF.

[0406] - If the UE location is within the local offloading management service area, and the existing I-SMF cannot service the new UE location and cannot support LOM, the AMF can select a new I-SMF or change the existing I-SMF to a new SMT.

[0407] - To support local offloading management, the selected I-SMF needs to support local offloading management, be able to serve new UE locations, and may support DNN and S-NSSAI associated with PDU sessions.

[0408] - To support as defined above, the new AMF interacts with the NRF for SMF functionality to determine whether the previous I-SMF supports local offloading management.

[0409] Note: The above procedure may also apply when a UE moves from an 'AMF not upgraded to operate according to the Local Offloading Management Support' indicator to an 'AMF upgraded to operate according to the Local Offloading Management Support' indicator.

[0410] ii) In the case of I-SMF insertion and relocation, the target I-SMF and SMF may interact as follows:

[0411] - The target I-SMF can send the newly selected EASDF IP address and the local offloading management allow indicator to the SMF.

[0412] - SMF can transmit the newly selected EASDF IP address to the UE via PCO.

[0413] iii) For I-SMF removal, SMF can be performed as follows:

[0414] - The SMF selects a new EASDF, and the SMF can transmit the selected new EASDF IP address to the UE via the PCO.

[0415] iv) For I-SMF reuse cases where Local Offloading Management (LOM) is not applied, SMF and I-SMF can be performed as follows:

[0416] - Existing I-SMF can remove existing EASDF.

[0417] - The SMF selects a new EASDF, and the SMF can transmit the newly selected EASDF IP address to the UE via the PCO.

[0418] The I-SMF function information management and assigned function control / change methods described in the aforementioned Sections I and II can also be applied to handover procedures and session management service procedures that do not involve AMF changes depending on terminal mobility.

[0419] In this specification, the methods of Section I and / or Section II may be proposed for a control method for selecting / deselecting / reusing and determining / changing the function of an I-SMF responsible for a PDU session.

[0420] According to the disclosure of this specification, unnecessary SMF release and re-selection procedures and signaling can be reduced in service procedures based on terminal mobility.

[0421] The following actions (e.g., 1-1, 1-2, 1-3) may be performed in relation to Section I.

[0422] 1-1) In the terminal's PDU session establishment procedure, the AMF selects an I-SMF for supporting functions such as LOM or ETSUN and can store / manage / reference the I-SMF responsible function information in the PDU session related information within the UE context.

[0423] 1-2) Depending on the mobility of the terminal, the AMF can send I-SMF function information to the target AMF (new AMF) within the handover and session management procedure, and the target AMF can refer to this to change the PDU session and determine the I-SMF responsible function.

[0424] 1-3) Alternatively, the target AMF (new AMF) can identify the support functions, such as LOM of the I-SMF, based on the SMF's capability through interaction with the NRF. Based on this, the target AMF (new AMF) can determine the modification of the PDU session and the functions responsible for the I-SMF. To this end, when the SMF registers with the NRF, it can also register whether it has LOM capability.

[0425] In relation to Section II, the following operations (e.g., 2-1, 2-2, 2-3, 2-4) may be performed.

[0426] 2-1) The target AMF (new AMF) can decide to reuse the existing I-SMF and maintain / change the support for functions between LOM or ETSUN, rather than re-selecting the I-SMF (conventional technology), based on the I-SMF function identification information of Section I, the current location of the terminal, the service area of ​​the existing I-SMF and A-SMF, and the Local Offloading service area.

[0427] In the following cases, the target AMF (new AMF) can decide to reuse the existing LOM I-SMF:

[0428] - If LOM is authorized for the DNN / S-NSSAI of the corresponding PDU session in the subscriber information.

[0429] - When recognizing that an existing I-SMF has been selected for LOM support, and that the I-SMF supports the current terminal location

[0430] - When the terminal location is included within the LOM servic area

[0431] In addition, the target AMF (new AMF) may change the I-SMF responsible function depending on the following cases:

[0432] - If LOM support conditions are no longer met and A-SMF cannot support terminal location, reuse the existing I-SMF and change the responsible function from LOM to ETSUN.

[0433] - If the existing I-SMF is selected for ETSUN support but satisfies the LOM support conditions, the existing I-SMF is reused while changing the responsible functions to LOM.

[0434] 2-2) The AMF may send control information to the I-SMF in accordance with the decision in 2-1) above. The information may be information requesting a change in the function in charge of the I-SMF, or information notifying the release of a specific function supported by the SMF (e.g., Local Offloading Management), or information on whether the terminal location is included (or not included) within the LOM service area.

[0435] 2-3) I-SMF can determine EASDF selection and DNS Context creation / release based on the control information of 2-2) above, and send DNS Context creation / deletion request information to A-SMF.

[0436] 2-4) A-SMF can determine EASDF selection and DNS context creation / deletion based on DNS context creation / deletion request information from I-SMF of 2-3) above or whether it is included / excluded within the LOM service zone.

[0437] The following drawings are made to illustrate a specific example of the present specification. The names of specific devices or specific signals / messages / fields described in the drawings are presented as examples, and therefore the technical features of the present specification are not limited to the specific names used in the following drawings.

[0438] FIG. 13 illustrates the procedure of a new AMF for the disclosure of the present specification.

[0439] 1. Based on the fact that the existing I-SMF (Intermediate Session Management Function) can serve the new location of the UE (User Equipment) depending on the mobility of the UE, the new AMF (Access and Mobility Management Function) may decide to maintain the existing I-SMF.

[0440] 3. The new AMF can send a request to update the SM context of a PDU (protocol data unit) session to the existing I-SMF.

[0441] Based on the decision of the new AMF to maintain the existing I-SMF, the SM context update request may indicate that Local Offloading Management (LOM) is not allowed.

[0442] Based on the mobility of the above UE, the new AMF can receive UE context-related messages from the source AMF.

[0443] The above UE context-related message may include whether the PDU session is allowed for LOM (Local Offloading Management).

[0444] The step of deciding that the new AMF maintains the existing I-SMF can be performed based on the UE context.

[0445] The above new AMF can obtain SMF selection subscription data from UDM (Unified Data Management).

[0446] The step of deciding whether the new AMF maintains the existing I-SMF can be performed based on the SMF selection subscription data.

[0447] The above existing I-SMF may have performed the LOM function prior to the movement of the above UE.

[0448] Based on the fact that the above existing I-SMF does not currently satisfy the LOM support conditions, the above new AMF may decide to change the function of the above existing I-SMF from LOM to ETSUN (Enhancing Topology of SMF and UPF in 5G Networks).

[0449] Based on the decision of the new AMF to change the function of the existing I-SMF from LOM to ETSUN, the SM context update request may include information requesting to change the function of the existing I-SMF from LOM to ETSUN.

[0450] The above existing I-SMF may have performed the ETSUN function prior to the movement of the above UE.

[0451] Based on the fact that the above existing I-SMF currently satisfies the LOM support conditions, the above new AMF may decide to change the function of the above existing I-SMF from ETSUN to LOM.

[0452] Based on the decision of the new AMF to change the function of the existing I-SMF from ETSUN to LOM, the SM context update request may include information requesting to change the function of the existing I-SMF from LOM to ETSUN.

[0453] The following drawings are made to illustrate a specific example of the present specification. The names of specific devices or specific signals / messages / fields described in the drawings are presented as examples, and therefore the technical features of the present specification are not limited to the specific names used in the following drawings.

[0454] FIG. 14 illustrates the procedure of the existing I-SMF for the disclosure of the present specification.

[0455] 1. Based on the mobility of the UE, the existing I-SMF receives a request from the new AMF to update the SM context of the PDU session;

[0456] The above SM context update request may indicate that LOM (Local Offloading Management) is not allowed.

[0457] 2. Based on the above SM context update request, the existing I-SMF can delete the DNS (Domain Name System) context from the existing EASDF (Edge Application Server Discovery Function).

[0458] The existing I-SMF can send a request to update the PDU session to the A-SMF (Anchor SMF).

[0459] Based on the fact that the above SM context update request indicates that LOM is not allowed, the above update request of the above PDU session may not include an LOM allow indication.

[0460] The existing I-SMF can send a request to update the PDU session to the A-SMF (Anchor SMF).

[0461] Based on the fact that the above SM context update request indicates that LOM is not allowed, the above update request of the above PDU session may indicate that LOM is not allowed.

[0462] Before the above UE moves, the existing I-SMF can receive an SM context creation request message from the source AMF.

[0463] The above SM context creation request message may include an LOM allow indication.

[0464] Before the movement of the above UE, the existing I-SMF can select the existing EASDF.

[0465] Before the above UE moves, the existing I-SMF can send a DNS context creation request message to the existing EASDF.

[0466] The above existing I-SMF may have performed the LOM function prior to the movement of the above UE.

[0467] Based on the fact that the existing I-SMF does not currently satisfy the LOM support conditions, the SM context update request may include information requesting to change the function of the existing I-SMF from LOM to ETSUN.

[0468] The above existing I-SMF may have performed the ETSUN function prior to the movement of the above UE.

[0469] Based on the fact that the existing I-SMF currently satisfies the LOM support conditions, the SM context update request may include information requesting to change the function of the existing I-SMF from LOM to ETSUN.

[0470] Hereinafter, a device for performing communication according to some embodiments of the present specification will be described.

[0471] For example, the device may include a processor, a transceiver, and memory.

[0472] For example, the processor can be configured to be operablely coupled with memory and the processor.

[0473] The operation performed by the processor comprises: a step in which a new AMF (Access and Mobility Management Function) decides to maintain the existing I-SMF based on the fact that the existing I-SMF (Intermediate Session Management Function) can serve a new location of the UE (User Equipment) depending on the mobility of the UE (User Equipment); and a step in which the new AMF transmits a request for an SM context update of a PDU (protocol data unit) session to the existing I-SMF, and based on the new AMF's decision to maintain the existing I-SMF, the SM context update request may indicate that Local Offloading Management (LOM) is not allowed.

[0474] Hereinafter, a processor of a device for providing communication according to some embodiments of the present specification will be described.

[0475] The operation performed by the processor includes the step of a new AMF (Access and Mobility Management Function) deciding to maintain the existing I-SMF based on the fact that the existing I-SMF (Intermediate Session Management Function) can serve a new location of the UE (User Equipment) depending on the mobility of the UE; and the step of the new AMF sending a request for an SM context update of a PDU (protocol data unit) session to the existing I-SMF, and based on the new AMF deciding to maintain the existing I-SMF, the SM context update request may indicate that Local Offloading Management (LOM) is not allowed.

[0476] Hereinafter, a non-volatile computer-readable medium storing one or more instructions for providing mobile communication according to some embodiments of the present specification will be described.

[0477] According to some embodiments of the present disclosure, the technical features of the present disclosure may be directly implemented in hardware, software executed by a processor, or a combination of both. 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, 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.

[0478] In some examples, storage media are coupled to the processor so that the processor can read information from the storage media. Alternatively, the storage media can be integrated into the processor. The processor and storage media can reside in an ASIC. In other examples, the processor and storage media can reside as separate components.

[0479] Computer-readable media may include tangible and non-volatile computer-readable storage media.

[0480] For example, non-volatile computer-readable media may include RAM (Random Access Memory) such as SDRAM (Synchronization Dynamic Random Access Memory), ROM (Read-Only Memory), and NVRAM (Non-Volatile Random Access Memory); read-only memory (EEPROM); flash memory; magnetic or optical data storage media; or other media that can be used to store instructions or data structures. Non-volatile computer-readable media may also include combinations of the above.

[0481] Additionally, the method described herein may be realized at least partially by a computer-readable communication medium that transmits or transmits code in the form of instructions or data structures and can be accessed, read, and / or executed by a computer.

[0482] According to some embodiments of the present disclosure, a non-transient computer-readable medium stores one or more instructions thereon. The stored one or more instructions can be executed by a processor of a base station.

[0483] One or more stored commands include the step of a new AMF (Access and Mobility Management Function) deciding to maintain the existing I-SMF based on the fact that the existing I-SMF (Intermediate Session Management Function) can serve a new location of the UE depending on the mobility of the UE (User Equipment); and the step of the new AMF sending an SM context update request for a PDU (protocol data unit) session to the existing I-SMF, wherein, based on the new AMF deciding to maintain the existing I-SMF, the SM context update request may indicate that Local Offloading Management (LOM) is not allowed.

[0484] Hereinafter, a non-volatile computer-readable medium storing one or more instructions for providing mobile communication according to some embodiments of the present specification will be described.

[0485] This specification may have various effects.

[0486] For example, I-SMF can be reused through the procedure disclosed in this specification.

[0487] The effects obtainable through the specific examples of this specification are not limited to those listed above. For example, there may be various technical effects that a person with ordinary skill in the related art can understand or derive 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.

[0488] The claims described in this specification may be combined in various ways. For example, the technical features of the method claims in this specification may be combined to be implemented as a device, and the technical features of the device claims in this specification may be combined to be implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a device, and the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a method. Other implementations are within the scope of the following claims.

Claims

1. As a method, A step in which a new AMF (Access and Mobility Management Function) decides to maintain the existing I-SMF based on the fact that the existing I-SMF (Intermediate Session Management Function) can serve a new location of the UE (User Equipment) depending on the mobility of the UE (User Equipment); and The above new AMF includes the step of sending a request for an SM context update of a PDU (protocol data unit) session to the existing I-SMF, and A method indicating that the SM context update request is not allowed, based on the decision of the new AMF to maintain the existing I-SMF.

2. In Paragraph 1, Based on the mobility of the above UE, the new AMF further includes the step of receiving a UE context-related message from a source AMF, and The above UE context-related message includes whether the above PDU session is allowed for LOM, and The step of deciding that the new AMF maintains the existing I-SMF is performed based on the UE context.

3. In Paragraph 1, The above new AMF further includes the step of obtaining SMF selection subscription data from UDM (Unified Data Management), and The step of deciding that the new AMF will maintain the existing I-SMF is performed based on the SMF selection subscription data.

4. In any one of paragraphs 1 through 3, The above existing I-SMF is a method that performed the LOM function before the movement of the above UE.

5. In Paragraph 4, Based on the fact that the existing I-SMF does not currently satisfy the LOM support conditions, the new AMF further includes the step of deciding to change the function of the existing I-SMF from LOM to ETSUN (Enhancing Topology of SMF and UPF in 5G Networks), A method in which, based on the new AMF deciding to change the function of the existing I-SMF from LOM to ETSUN, the SM context update request includes information requesting to change the function of the existing I-SMF from LOM to ETSUN.

6. In any one of paragraphs 1 through 3, The above existing I-SMF performed the ETSUN function before the movement of the above UE, and Based on the fact that the existing I-SMF currently satisfies the LOM support conditions, the new AMF further includes the step of deciding to change the function of the existing I-SMF from ETSUN to LOM, and A method in which, based on the new AMF deciding to change the function of the existing I-SMF from ETSUN to LOM, the SM context update request includes information requesting to change the function of the existing I-SMF from LOM to ETSUN.

7. As a method, Based on the mobility of the UE, the existing I-SMF receives a request to update the SM context of a PDU session from a new AMF; The above SM context update request indicates that LOM (Local Offloading Management) is not allowed, and A method comprising the step of the existing I-SMF deleting the DNS (Domain Name System) context from the existing EASDF (Edge Application Server Discovery Function) based on the above SM context update request.

8. In Paragraph 7, The above existing I-SMF further includes the step of transmitting a request for an update of the PDU session to the A-SMF (Anchor SMF), and A method in which the update request of the PDU session does not include an LOM allowance indication, based on the fact that the above SM context update request indicates that LOM is not allowed.

9. In Paragraph 7, The above existing I-SMF further includes the step of transmitting a request for an update of the PDU session to the A-SMF, and A method in which the update request of the PDU session indicates that LOM is not allowed, based on the fact that the above SM context update request indicates that LOM is not allowed.

10. In any one of paragraphs 7 through 9, Before moving the above UE, the existing I-SMF further includes the step of receiving an SM context creation request message from the source AMF. The above SM context creation request message is a method that includes a LOM allow indication.

11. In any one of paragraphs 7 through 10, Before moving the above UE, the existing I-SMF selects the existing EASDF; and A method further comprising the step of, prior to the movement of the above UE, the existing I-SMF sending a DNS context creation request message to the existing EASDF.

12. In any one of paragraphs 7 through 11, The above existing I-SMF is a method that performed the LOM function before the movement of the above UE.

13. In Paragraph 12, A method in which, based on the fact that the existing I-SMF does not currently satisfy the LOM support conditions, the SM context update request includes information requesting to change the function of the existing I-SMF from LOM to ETSUN.

14. In any one of paragraphs 7 through 11, The above existing I-SMF performed the ETSUN function before the movement of the above UE, and A method in which, based on the existing I-SMF satisfying the current LOM support conditions, the SM context update request includes information requesting to change the function of the existing I-SMF from LOM to ETSUN.

15. As a new AMF performing communication, At least one transmitter / receiver; It includes at least one processor, The operation performed by the above at least one processor is a new AMF that is a method according to any one of claims 1 to 6.

16. Existing I-SMF performing communication, At least one transmitter / receiver; It includes at least one processor, The operation performed by the above at least one processor is an existing I-SMF, which is a method according to any one of claims 7 to 14.

17. As an apparatus in mobile communication, At least one processor; and It includes at least one memory that stores instructions and is operablely electrically connected to at least one processor, and A device in which the operation performed based on the execution of the above instruction by the at least one processor is a method according to any one of claims 1 to 6.

18. A non-volatile computer-readable storage medium that records instructions, A non-volatile computer-readable storage medium in which, when the above instructions are executed by one or more processors, the operation that causes the one or more processors to perform is a method according to any one of claims 1 to 6.

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