Edge computing support

Abstract

One disclosure of the present specification provides a method. The method may comprise the steps of: transmitting, to a NRF, a NF discovery request message including information for querying information providable by an AF; receiving a NF discovery response message from the NRF; receiving an event notification message from a NEF; and transmitting a request message requesting for EAS rediscovery to a SMF serving a UE.

Description

Edge computing support

[0001] This specification relates to mobile communications.

[0002] 3GPP (3rd Generation Partnership Project) LTE (Long-Term Evolution) is a technology designed to enable high-speed packet communications. Numerous approaches have been proposed to achieve LTE's goals of reducing costs for users and operators, improving service quality, expanding coverage, and increasing system capacity. 3GPP LTE's high-level requirements include reduced cost per bit, improved service availability, flexible use of frequency bands, a simple architecture, open interfaces, and adequate power consumption for terminals.

[0003] The International Telecommunication Union (ITU) and 3GPP have begun work on developing requirements and specifications for New Radio (NR) systems. 3GPP must identify and develop the technical components necessary to successfully standardize NR, meeting both urgent market needs and the longer-term requirements outlined by the ITU Radio communication sector (ITU-R) International Mobile Telecommunications (IMT)-2020 process. NR must also be able to utilize any spectrum band up to at least 100 GHz, ensuring that it remains available for wireless communications well into the future.

[0004] NR aims to be a single technology framework that addresses all deployment scenarios, usage scenarios, and requirements, including enhanced Mobile Broadband (eMBB), massive Machine Type Communications (mMTC), and Ultra-Reliable and Low Latency Communications (URLLC). NR must be inherently forward-compatible.

[0005] Edge computing services can be supported for terminals. However, previously, edge computing services had to be provided using only static information provided by AF on the network. This presents a problem: edge computing services cannot be effectively supported when the network environment, such as EAS load conditions, changes dynamically.

[0006] According to one embodiment of the present disclosure, a method is provided. The method may include the steps of transmitting an NF discovery request message to an NRF, the NF discovery request message including information querying information that an AF can provide; receiving an NF discovery response message from the NRF; receiving an event notification message from the NEF; and transmitting a request message requesting EAS re-discovery to an SMF serving the UE.

[0007] According to one embodiment, a device implementing the method is provided.

[0008] According to one embodiment of the present disclosure, a method is provided. The method may include the steps of: receiving a PDU session establishment request message from a UE; transmitting a PDU session establishment acceptance message to the UE; receiving a request message requesting EAS re-discovery from an EASDF; and transmitting a PDU session modification command message including information requesting the EAS re-discovery to the UE.

[0009] According to one embodiment, a device implementing the method is provided.

[0010] According to one embodiment of the present disclosure, a method is provided. The method may include the steps of: transmitting a PDU session establishment request message to an SMF; receiving a PDU session establishment acceptance message from the SMF; and receiving a PDU session modification command message from the SMF, the PDU session establishment request message including information requesting EAS re-discovery.

[0011] According to one embodiment, a device implementing the method is provided.

[0012] Figure 1 illustrates an example of a communication system to which the implementation of this specification is applied.

[0013] Figure 2 illustrates an example of a wireless device to which the implementation of the present specification is applied.

[0014] Figure 3 shows an example of a UE to which the implementation of this specification is applied.

[0015] Figure 4 shows an example of a 5G system structure to which the implementation of this specification is applied.

[0016] Figures 5 and 6 illustrate examples of a PDU session establishment procedure to which the implementation of the present specification applies.

[0017] FIG. 7a and FIG. 7b are examples of an EAS search procedure based on EASDF according to one embodiment of the disclosure of the present specification.

[0018] FIG. 8 illustrates an example of an EAS discovery procedure based on a local DNS server / resolver according to one embodiment of the disclosure of the present specification.

[0019] FIG. 9a and FIG. 9b illustrate examples of an EAS re-search procedure according to one embodiment of the disclosure of the present specification.

[0020] FIG. 10 illustrates an example of operations according to one embodiment of the disclosure of the present specification.

[0021] The following techniques, devices, and systems can be applied to various wireless multiple access systems. Examples of multiple access systems include Code Division Multiple Access (CDMA) systems, Frequency Division Multiple Access (FDMA) systems, Time Division Multiple Access (TDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, and Multi-Carrier Frequency Division Multiple Access (MC-FDMA) systems. CDMA can be implemented using wireless technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented using wireless technologies such as Global System for Mobile communications (GSM), General Packet Radio Service (GPRS), or Enhanced Data rates for GSM Evolution (EDGE). OFDMA can be implemented using wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or Evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP (3rd Generation Partnership Project) Long-Term Evolution (LTE) is part of E-UMTS (Evolved UMTS) that utilizes E-UTRA.3GPP LTE uses OFDMA in the downlink (DL) and SC-FDMA in the uplink (UL). Evolution of 3GPP LTE includes LTE-A (Advanced), LTE-A Pro, and / or 5G NR (New Radio).

[0022] For convenience of explanation, the implementation of this specification is primarily described in relation to a 3GPP-based wireless communication system. However, the technical features of this specification are not limited thereto. For example, the following detailed description is provided based on a mobile communication system corresponding to a 3GPP-based wireless communication system, but aspects of this specification that are not limited to a 3GPP-based wireless communication system can be applied to other mobile communication systems.

[0023] 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.

[0024] As used herein, "A or B" can mean "only A," "only B," or "both A and B." Alternatively, as used herein, "A or B" can be interpreted as "A and / or B." For example, as used herein, "A, B or C" can mean "only A," "only B," "only C," or "any combination of A, B and C."

[0025] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0026] In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted identically to “at least one of A and B.”

[0027] Additionally, in this specification, “at least one of A, B and C” can mean “only A”, “only B”, “only C”, or “any combination of A, B and C”. Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C”.

[0028] Additionally, parentheses used herein may mean "for example." Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information." In other words, "control information" in this specification is not limited to "PDCCH," and "PDCCH" may be proposed as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)", "PDCCH" may be proposed as an example of "control information."

[0029] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0030] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein may be applied to various fields requiring wireless communication and / or connectivity between devices (e.g., 5G).

[0031] Hereinafter, the present specification will be described in more detail with reference to the drawings. In the following drawings and / or description, the same reference numbers may refer to the same or corresponding hardware blocks, software blocks, and / or functional blocks, unless otherwise indicated.

[0032] Figure 1 illustrates an example of a communication system to which the implementation of this specification is applied.

[0033] The 5G usage scenario shown in FIG. 1 is only an example, and the technical features of this specification can be applied to other 5G usage scenarios not shown in FIG. 1.

[0034] The three main requirement categories for 5G are (1) enhanced mobile broadband (eMBB), (2) massive machine type communication (mMTC), and (3) ultra-reliable and low latency communications (URLLC).

[0035] Referring to FIG. 1, a communication system (1) includes wireless devices (100a to 100f), a base station (BS; 200), and a network (300). FIG. 1 illustrates a 5G network as an example of a network of the communication system (1), but the implementation of the present disclosure is not limited to a 5G system and can be applied to future communication systems beyond the 5G system.

[0036] The base station (200) and the network (300) may be implemented as wireless devices, and a particular wireless device may operate as a base station / network node in relation to other wireless devices.

[0037] The wireless devices (100a to 100f) represent devices that perform communication using Radio Access Technology (RAT) (e.g., 5G NR or LTE) and may also be referred to as communication / wireless / 5G devices. The wireless devices (100a to 100f) may include, but are not limited to, a robot (100a), a vehicle (100b-1 and 100b-2), an extended reality (XR) device (100c), a portable device (100d), a home appliance (100e), an Internet-of-Things (IoT) device (100f), and an artificial intelligence (AI) device / server (400). For example, the vehicles may include vehicles having wireless communication capabilities, autonomous vehicles, and vehicles capable of performing vehicle-to-vehicle communication. The vehicles may include unmanned aerial vehicles (UAVs) (e.g., drones). XR devices may include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and may be implemented in the form of HMD (Head-Mounted Device) and HUD (Head-Up Display) mounted on vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signs, vehicles, robots, etc. Portable devices may include smartphones, smart pads, wearable devices (e.g., smart watches or smart glasses), and computers (e.g., laptops). Home appliances may include TVs, refrigerators, and washing machines. IoT devices may include sensors and smart meters.

[0038] In this specification, wireless devices (100a to 100f) may be referred to as user equipment (UE). The UE may include, for example, a mobile phone, a smartphone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a slate PC, a tablet PC, an ultrabook, a vehicle, a vehicle with autonomous driving function, a connected car, a UAV, an AI module, a robot, an AR device, a VR device, an MR device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a fintech device (or a financial device), a security device, a weather / environmental device, a 5G service-related device, or a 4th industrial revolution-related device.

[0039] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). AI technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, and a network after 5G. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station (200) / network (300). For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). Additionally, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0040] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a to 100f) and / or between wireless devices (100a to 100f) and a base station (200) and / or between base stations (200). Here, the wireless communication / connection can be established through various RATs (e.g., 5G NR), such as uplink / downlink communication (150a), sidelink communication (150b) (or, D2D (Device-To-Device) communication), and base station-to-base station communication (150c) (e.g., relay, IAB (Integrated Access and Backhaul)). Through the wireless communication / connection (150a, 150b, 150c), the wireless devices (100a to 100f) and the base station (200) can transmit / receive wireless signals to / from each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various proposals of this specification, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed.

[0041] NR supports multiple numerologies, or subcarrier spacings (SCS), to support diverse 5G services. For example, an SCS of 15 kHz supports wide areas in traditional cellular bands; an SCS of 30 kHz / 60 kHz supports dense urban areas, lower latency, and wider carrier bandwidth; and an SCS of 60 kHz or higher supports bandwidths greater than 24.25 GHz to overcome phase noise.

[0042] The NR frequency band can be defined by two types of frequency ranges (FR1 and FR2). The numerical values ​​of the frequency ranges can be changed. For example, the two types of frequency ranges (FR1 and FR2) can be as shown in Table 1 below. For convenience of explanation, among the frequency ranges used in the NR system, FR1 can mean the "sub 6 GHz range," and FR2 can mean the "above 6 GHz range," which can be called millimeter wave (mmW).

[0043] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0044] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a band from 410 MHz to 7125 MHz, as shown in Table 2 below. That is, FR1 may include frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 may include unlicensed bands. Unlicensed bands can be used for various purposes, such as for communications for vehicles (e.g., autonomous driving).

[0045] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0046] Here, the wireless communication technology implemented in the wireless device of the present specification may include not only LTE, NR, and 6G, but also Narrowband IoT (NB-IoT) for low-power communication. For example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology and may be implemented with standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device of the present specification may perform communication based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and may be called by various names such as eMTC (enhanced MTC). For example, LTE-M technology can be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (Non-Bandwidth Limited), 5) LTE-MTC, 6) LTE MTC, and / or 7) LTE M, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device of the present specification can include at least one of ZigBee, Bluetooth, and / or LPWAN considering low-power communication, and is not limited to the above-described names. For example, ZigBee technology can create PANs (Personal Area Networks) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

[0047] Figure 2 illustrates an example of a wireless device to which the implementation of the present specification is applied.

[0048] In FIG. 2, the first wireless device (100) and / or the second wireless device (200) may be implemented in various forms depending on the use case / service. For example, {the first wireless device (100) and the second wireless device (200)} may correspond to at least one of {the wireless devices (100a to 100f) and the base station (200)}, {the wireless devices (100a to 100f) and the wireless devices (100a to 100f)}, and / or {the base station (200) and the base station (200)} of FIG. 1. The first wireless device (100) and / or the second wireless device (200) may be configured by various components, devices / parts, and / or modules.

[0049] 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).

[0050] The processing chip (101) may include at least one processor, such as a processor (102), and at least one memory, such as a memory (104). Additionally and / or alternatively, the memory (104) may be located external to the processing chip (101).

[0051] The processor (102) may control the memory (104) and / or the transceiver (106) and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein. For example, the processor (102) may process information in the memory (104) to generate first information / signal and transmit a wireless signal including the first information / signal via the transceiver (106). The processor (102) may receive a wireless signal including second information / signal via the transceiver (106) and store information obtained by processing the second information / signal in the memory (104).

[0052] A memory (104) may be operatively connected to the processor (102). The memory (104) may store various types of information and / or instructions. The memory (104) may store firmware and / or software code (105) that implements code, instructions and / or sets of instructions that, when executed by the processor (102), perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. For example, the firmware and / or software code (105) may implement instructions that, when executed by the processor (102), perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. For example, the firmware and / or software code (105) may control the processor (102) to perform one or more protocols. For example, the firmware and / or software code (105) may control the processor (102) to perform one or more air interface protocol layers.

[0053] Here, the processor (102) and memory (104) may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). A transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). Each transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present specification, the first wireless device (100) may represent a communication modem / circuit / chip.

[0054] 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).

[0055] The processing chip (201) may include at least one processor, such as a processor (202), and at least one memory, such as a memory (204). Additionally and / or alternatively, the memory (204) may be located external to the processing chip (201).

[0056] The processor (202) may control the memory (204) and / or the transceiver (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein. For example, the processor (202) may process information in the memory (204) to generate third information / signal and transmit a wireless signal including the third information / signal via the transceiver (206). The processor (202) may receive a wireless signal including fourth information / signal via the transceiver (206) and store information obtained by processing the fourth information / signal in the memory (204).

[0057] A memory (204) may be operatively connected to the processor (202). The memory (204) may store various types of information and / or instructions. The memory (204) may store firmware and / or software code (205) that implements code, instructions and / or sets of instructions that, when executed by the processor (202), perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. For example, the firmware and / or software code (205) may implement instructions that, when executed by the processor (202), perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. For example, the firmware and / or software code (205) may control the processor (202) to perform one or more protocols. For example, the firmware and / or software code (205) may control the processor (202) to perform one or more air interface protocol layers.

[0058] Here, the processor (202) and memory (204) may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). A transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). Each transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with the RF unit. In the present specification, the second wireless device (200) may represent a communication modem / circuit / chip.

[0059] Hereinafter, hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as a physical (PHY) layer, a Media Access Control (MAC) layer, a Radio Link Control (RLC) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Resource Control (RRC) layer, and a Service Data Adaptation Protocol (SDAP) layer). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs), one or more Service Data Units (SDUs), messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0060] The one or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, and / or a microcomputer. The one or more processors (102, 202) may be implemented by hardware, firmware, software, and / or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), and / or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or more processors (102, 202). For example, the one or more processors (102, 202) may be configured by a set of a communication control processor, an Application Processor (AP), an Electronic Control Unit (ECU), a Central Processing Unit (CPU), a Graphic Processing Unit (GPU), and a Memory Control Processor. One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions and / or commands. The one or more memories (104, 204) may be configured as random access memory (RAM), dynamic RAM (DRAM), read-only memory (ROM), erasable programmable ROM (EPROM), flash memory, volatile memory, nonvolatile memory, hard drive, register, cache memory, computer readable storage media and / or combinations thereof.One or more memories (104, 204) may be located internally and / or externally to one or more processors (102, 202). Additionally, one or more memories (104, 204) may be connected to one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0061] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., referred to in the descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed herein to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., referred to in the descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed herein from one or more other devices. For example, one or more transceivers (106, 206) can be coupled to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, wireless signals, etc., to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, wireless signals, etc. from one or more other devices.

[0062] One or more transceivers (106, 206) may be coupled to one or more antennas (108, 208). Additionally and / or alternatively, one or more transceivers (106, 206) may include one or more antennas (108, 208). One or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein via one or more antennas (108, 208). In the present disclosure, one or more antennas (108, 208) may be multiple physical antennas or multiple logical antennas (e.g., antenna ports).

[0063] One or more transceivers (106, 206) may convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202). One or more transceivers (106, 206) may convert processed user data, control information, wireless signals / channels, etc. from baseband signals to RF band signals using one or more processors (102, 202). For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or a filter. For example, one or more transceivers (106, 206) may up-convert an OFDM baseband signal to an OFDM signal via an (analog) oscillator and / or filter under the control of one or more processors (102, 202) and transmit the up-converted OFDM signal at a carrier frequency. One or more transceivers (106, 206) may receive an OFDM signal at a carrier frequency and down-convert the OFDM signal to an OFDM baseband signal via an (analog) oscillator and / or filter under the control of one or more processors (102, 202).

[0064] Although not illustrated in FIG. 2, the wireless device (100, 200) may further include additional components. The additional components (140) may be configured in various ways depending on the type of the wireless device (100, 200). For example, the additional components (140) may include at least one of a power unit / battery, an input / output (I / O) device (e.g., an audio I / O port, a video I / O port), a driving device, and a computing device. The additional components (140) may be connected to one or more processors (102, 202) via various technologies, such as a wired or wireless connection.

[0065] In the implementation of this specification, a UE can operate as a transmitter in the uplink and as a receiver in the downlink. In the implementation of this specification, a base station can operate as a receiver in the UL and as a transmitter in the DL. For the sake of convenience of description, it is mainly assumed below that the first wireless device (100) operates as a UE and the second wireless device (200) operates as a base station. For example, a processor (102) connected to, mounted on, or released in the first wireless device (100) can be configured to perform UE operations according to the implementation of this specification or to control a transceiver (106) to perform UE operations according to the implementation of this specification. A processor (202) connected to, mounted on, or released in the second wireless device (200) can be configured to perform base station operations according to the implementation of this specification or to control a transceiver (206) to perform base station operations according to the implementation of this specification.

[0066] In this specification, a base station may be referred to as a Node B, an eNode B (eNB), or a gNB.

[0067] Figure 3 shows an example of a UE to which the implementation of this specification is applied.

[0068] Referring to FIG. 3, the UE (100) can correspond to the first wireless device (100) of FIG. 2.

[0069] The UE (100) includes a processor (102), memory (104), a transceiver (106), one or more antennas (108), a power management module (141), a battery (142), a display (143), a keypad (144), a SIM (Subscriber Identification Module) card (145), a speaker (146), and a microphone (147).

[0070] The processor (102) may be configured to implement the descriptions, functions, procedures, proposals, methods and / or flowcharts disclosed herein. The processor (102) may be configured to control one or more other components of the UE (100) to implement the descriptions, functions, procedures, proposals, methods and / or flowcharts disclosed herein. A layer of a radio interface protocol may be implemented in the processor (102). The processor (102) may include an ASIC, other chipsets, logic circuits and / or data processing devices. The processor (102) may be an application processor. The processor (102) may include at least one of a DSP, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and a modem (modulator and demodulator). An example of the processor (102) is the SNAPDRAGON manufactured by Qualcomm®. TM Series processors, EXYNOS made by Samsung® TM Series processors, A-series processors made by Apple®, HELIO made by MediaTek® TM ATOM series processors made by Intel® TM It can be found in the series processors or the corresponding next-generation processors.

[0071] Memory (104) is operatively coupled to the processor (102) and stores various information for operating the processor (102). Memory (104) may include ROM, RAM, flash memory, memory cards, storage media, and / or other storage devices. When the implementation is implemented in software, the techniques described herein may be implemented using modules (e.g., procedures, functions, etc.) that perform the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed herein. The modules may be stored in memory (104) and executed by the processor (102). Memory (104) may be implemented within the processor (102) or external to the processor (102), in which case it may be communicatively coupled to the processor (102) via various methods known in the art.

[0072] A transceiver (106) is operably coupled to the processor (102) and transmits and / or receives a radio signal. The transceiver (106) includes a transmitter and a receiver. The transceiver (106) may include a baseband circuit for processing a radio frequency signal. The transceiver (106) controls one or more antennas (108) to transmit and / or receive a radio signal.

[0073] 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).

[0074] The display (143) outputs the results processed by the processor (102). The keypad (144) receives input to be used by the processor (102). The keypad (144) can be displayed on the display (143).

[0075] A SIM card (145) is an integrated circuit that securely stores an International Mobile Subscriber Identity (IMSI) and associated keys, and is used to identify and authenticate subscribers in mobile devices such as mobile phones and computers. Additionally, many SIM cards can store contact information.

[0076] 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).

[0077] Figure 4 shows an example of a 5G system structure to which the implementation of this specification is applied.

[0078] The 5G system (5GS; 5G system) structure consists of the following network functions (NF; Network Function).

[0079] - AUSF (Authentication Server Function)

[0080] -AMF (Access and Mobility Management Function)

[0081] - DN (Data Network), for example, operator services, Internet access, or third-party services.

[0082] - USDF (Unstructured Data Storage Function)

[0083] - NEF (Network Exposure Function)

[0084] - I-NEF (Intermediate NEF)

[0085] - NRF (Network Repository Function)

[0086] - NSSF (Network Slice Selection Function)

[0087] - PCF (Policy Control Function)

[0088] - SMF (Session Management Function)

[0089] - UDM (Unified Data Management)

[0090] - UDR (Unified Data Repository)

[0091] - UPF (User Plane Function)

[0092] - UCMF (UE radio Capability Management Function)

[0093] - AF (Application Function)

[0094] - UE (User Equipment)

[0095] - (R)AN ((Radio) Access Network)

[0096] - 5G-EIR (5G-Equipment Identity Register)

[0097] - NWDAF (Network Data Analytics Function)

[0098] - CHF (CHarging Function)

[0099] 또한, 다음과 같은 네트워크 기능이 고려될 수 있다.

[0100] - N3IWF (Non-3GPP InterWorking Function)

[0101] - TNGF (Trusted Non-3GPP Gateway Function)

[0102] - W-AGF (Wireline Access Gateway Function)

[0103] Figure 4 illustrates the 5G system architecture for a non-roaming case using a reference point representation showing how various network functions interact with each other.

[0104] For clarity of the point-to-point diagram in Figure 4, UDSF, NEF, and NRF are not illustrated. However, all network functions shown can interact with UDSF, UDR, NEF, and NRF as needed.

[0105] 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.

[0106] The 5G system architecture includes the following benchmarks:

[0107] - N1: Reference point between UE and AMF.

[0108] - N2: Reference point between (R)AN and AMF.

[0109] - N3: Reference point between (R)AN and UPF.

[0110] - N4: Reference point between SMF and UPF.

[0111] - N6: Reference point between UPF and data network.

[0112] - N9: Reference point between two UPFs.

[0113] The following benchmarks illustrate the interactions that exist between NF services in NF.

[0114] - N5: Reference point between PCF and AF.

[0115] - N7: Reference point between SMF and PCF.

[0116] - N8: Reference point between UDM and AMF.

[0117] - N10: Reference point between UDM and SMF.

[0118] - N11: Reference point between AMF and SMF.

[0119] - N12: Reference point between AMF and AUSF.

[0120] - N13: Reference point between UDM and AUSF.

[0121] - N14: Reference point between two AMFs.

[0122] - N15: Reference point between PCF and AMF for non-roaming scenarios, and reference point between PCF and AMF of visited network for roaming scenarios.

[0123] - N16: Reference point between two SMFs (in case of roaming, between the SMF of the visited network and the SMF of the home network)

[0124] - N22: Reference point between AMF and NSSF.

[0125] In some cases, two NFs may need to be interconnected to serve a UE.

[0126] Describes the PDU session establishment procedure. See Section 4.3.2 of 3GPP TS 23.502 V16.3.0 (2019-12).

[0127] Figures 5 and 6 illustrate examples of a PDU session establishment procedure to which the implementation of the present specification applies.

[0128] Establishing a PDU session may involve:

[0129] - UE-initiated PDU session establishment procedure

[0130] - PDU session handover between 3GPP and non-3GPP initiated by UE

[0131] - PDU session handover from UE-initiated EPS to 5GS.

[0132] - Network-triggered PDU session establishment procedure

[0133] A PDU session may be associated with either (a) a single connection type at a given time, i.e., either a 3GPP connection or a non-3GPP connection, or (b) multiple connection types simultaneously, i.e., one 3GPP connection and one non-3GPP connection. A PDU session associated with multiple connection types is called a multi-access (MA) PDU session and may be requested by an access traffic steering, switching, splitting (ATSS) capable UE.

[0134] Figures 5 and 6 specify a procedure for establishing a PDU session associated with a single connection type at a given time.

[0135] In the procedures shown in Figures 5 and 6, it is assumed that the UE is already registered with the AMF, so unless the UE is emergency registered, the AMF has already retrieved the user subscription data from the UDM.

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

[0137] (1) Step 1: To establish a new PDU session, the UE generates a new PDU session ID.

[0138] The UE initiates the PDU session establishment procedure requested by the UE by sending an NAS message containing a PDU session establishment request message within the N1 SM container. The PDU session establishment request message includes the PDU session ID, the requested PDU session type, the requested session and service continuity (SSC) mode, 5G SM capabilities, Protocol Configuration Options (PCO), the SM PDU DN Request Container, and the UE Integrity Protection Maximum Data Rate.

[0139] If the PDU session establishment is a request to establish a new PDU session, the request type is "Initial Request." If the request refers to an existing PDU session switching between a 3GPP connection and a non-3GPP connection, or a PDU session handover from an existing packet data network (PDN) connection in the EPC, the request type is "Existing PDU Session." If the PDU session establishment is a request to establish a PDU session for emergency services, the request type is "Emergency Request." If the request refers to an existing PDU session for emergency services switching between a 3GPP connection and a non-3GPP connection, or a PDU session handover from an existing PDN connection for emergency services in the EPC, the request type is "Existing Emergency PDU Session."

[0140] The UE includes the S-NSSAI from the allowed NSSAI of the current connection type. If a mapping of allowed NSSAIs (Mapping of Allowed NSSAIs) is provided to the UE, the UE provides both the S-NSSAI of the VPLMN (visited VPLMN) from the allowed NSSAIs and the corresponding S-NSSAI of the HPLMN from the mapping of allowed NSSAIs.

[0141] (2) Step 2: AMF selects an SMF. If the request type indicates "Initial Request" or the request is due to a handover from an EPS or other non-3GPP connection provided by an AMF, AMF stores the connection type of the PDU session as well as the association of S-NSSAI(s), data network name (DNN), PDU session ID, and SMF ID.

[0142] If the request type is "Initial Request" and the message also contains a previous PDU session ID representing an existing PDU session, AMF selects an SMF and stores the association of the new PDU session ID, S-NSAI(s), and the selected SMF ID.

[0143] If the request type indicates "Existing PDU Session," AMF selects an SMF based on the SMF-ID received from the UDM. AMF updates the stored connection type for the PDU session.

[0144] If the request type indicates "Existing PDU Session", which refers to an existing PDU session moving between a 3GPP connection and a non-3GPP connection, and if the serving PLMN S-NSSAI of the PDU session is in the allowed NSSAI of the target connection type, the PDU session establishment procedure may be performed in the following cases:

[0145] - When the SMF ID and AMF corresponding to the PDU session ID belong to the same PLMN;

[0146] - If the SMF ID corresponding to the PDU session ID belongs to HPLMN;

[0147] Otherwise, AMF rejects the PDU session establishment request with an appropriate rejection cause.

[0148] AMF rejects requests from emergency-registered UEs whose request type does not indicate "Emergency Request" or "Existing Emergency PDU Session".

[0149] (3) Step 3: If the AMF is not associated with an SMF for the PDU session ID provided by the UE (e.g., when the request type indicates "Initial Request"), the AMF invokes the Create SM Context request procedure (e.g., Nsmf_PDUSession_CreateSMContext Request). If the AMF is already associated with an SMF for the PDU session ID provided by the UE (e.g., when the request type indicates "Existing PDU Session"), the AMF invokes the Update SM Context request procedure (e.g., Nsmf_PDUSession_UpdateSMContext Request).

[0150] The AMF transmits the S-NSSAI of the serving PLMN to the SMF from the allowed NSSAI. For a roaming scenario of local breakout (LBO), the AMF also transmits the corresponding S-NSSAI of the HPLMN to the SMF from the mapping of the allowed NSSAI.

[0151] The AMF ID is the UE's GUAMI, which uniquely identifies the AMF serving the UE. The AMF passes the PDU session ID along with the N1 SM container containing the PDU session establishment request message received from the UE. The GPSI (generic public subscription identifier) ​​is included if available to the AMF.

[0152] If a UE in limited service state is registered for emergency services without providing SUPI, the AMF provides PEI instead of SUPI. If a UE in limited service state is registered for emergency services while providing SUPI but is not authenticated, the AMF indicates that the SUPI is not authenticated. If the SMF does not receive a SUPI for the UE or if the AMF indicates that the SUPI is not authenticated, the UE is considered unauthenticated.

[0153] AMF can include a PCF ID in Nsmf_PDUSession_CreateSMContext. This PCFID identifies the home PCF (H-PCF) in non-roaming cases and the visited PCF (V-PCF) in LBO roaming cases.

[0154] (4) Step 4: If the session management subscription data for the S-NSSAI of the corresponding SUPI, DNN, or HPLMN is not available, the SMF can retrieve the session management subscription data from the UDM and be notified when the subscription data is modified.

[0155] (5) Step 5: SMF sends a create SM context response message (e.g., Nsmf_PDUSession_CreateSMContext Response) or an update SM context response message (e.g., Nsmf_PDUSession_UpdateSMContext Response) to AMF according to the request received in step 3.

[0156] 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.

[0157] If the SMF decides not to accept the PDU session establishment, the SMF rejects the UE request by sending a NAS SM signal including the relevant SM rejection cause by responding to the AMF with an Nsmf_PDUSession_CreateSMContext Response. The SMF also indicates to the AMF that the PDU session ID is considered released and the SMF proceeds to step 20 below, aborting the PDU session establishment procedure.

[0158] (6) Step 6: Optional secondary authentication / authorization may be performed.

[0159] (7a) Step 7a: When dynamic policy and charging control (PCC) is used in a PDU session, the SMF can perform PCF selection.

[0160] (7b) Step 7b: SMF performs the SM policy association establishment procedure to establish a PCF and SM policy association, and obtains the basic PCC rules for the PDU session.

[0161] (8) Step 8: SMF selects one or more UPFs.

[0162] (9) Step 9: The SMF may provide information about the satisfied policy control request trigger conditions by performing the SM policy association modification procedure initiated by the SMF.

[0163] (10) Step 10: If the request type indicates an "Initial Request," the SMF may initiate the N4 Session Establishment procedure with the selected UPF. Otherwise, the SMF may initiate the N4 Session Modification procedure with the selected UPF.

[0164] In step 10a, the SMF can send an N4 session establishment / modification request to the UPF, providing packet detection, enforcement, and reporting rules to be installed in the UPF for the PDU session. In step 10b, the UPF can confirm by sending an N4 session establishment / modification response.

[0165] (11) Step 11: SMF sends an N1N2 message transfer message (e.g. Namf_Communication_N1N2 Message Transfer) to AMF.

[0166] The N1N2 Message Forwarding message may contain N2 SM information. The N2 SM information carries the following information that the AMF will forward to the (R)AN:

[0167] - CN Tunnel Info: Corresponds to the core network address of the N3 tunnel corresponding to the PDU session;

[0168] - QFI (QoS flow ID) corresponding to one or more QoS (quality of service) profiles;

[0169] - PDU Session ID: Indicates to the UE the association between RAN resources and a PDU session for the UE;

[0170] - S-NSSAI with value for serving PLMN (i.e. HPLMN S-NSSAI, or VPLMN S-NSSAI in case of LBO roaming);

[0171] - User plane security enforcement information determined by SMF;

[0172] - UE integrity protection maximum data rate received in PDU Session Establishment Request message: if integrity protection is indicated as "Preferred" or "Required" in the user plane security enforcement information.

[0173] - RSN (redundancy sequence number) parameter

[0174] The N1N2 message transfer message may include an N1 SM container. The N1 SM container includes a PDU Session Establishment Accept message that the AMF will provide to the UE. The PDU Session Establishment Accept message includes the S-NSSAI from the allowed NSSAI. For the LBO roaming scenario, the PDU Session Establishment Accept message includes the S-NSSAI from the allowed NSSAI for the VPLMN, and also includes the corresponding S-NSSAI of the HPLMN from the mapping of the allowed NSSAI received by the SMF in step 3.

[0175] Multiple QoS rules, QoS flow levels, and QoS parameters may be included in the PDU session establishment accept message and N2 SM information within the N1 SM container, if required, for QoS flows associated with QoS rules and QoS profiles.

[0176] If the PDU session establishment fails between steps 5 and 11, the N1N2 message forwarding message contains an N1 SM container containing a PDU session establishment rejection message, but does not contain N2 SM information. The (R)AN sends an NAS message containing a PDU session establishment rejection message to the UE. In this case, steps 12-17 below are omitted.

[0177] (12) Step 12: AMF sends a NAS message containing the PDU Session ID and PDU Session Establishment Accept message destined for the UE and the N2 SM information received from SMF to (R)AN within an N2 PDU Session Request message.

[0178] (13) Step 13: The (R)AN may perform AN-specific signaling exchanges with the UE related to the information received from the SMF. For example, in the case of the NG-RAN, the UE may perform an RRC connection reconfiguration with the UE to set up the necessary NG-RAN resources related to the QoS rules for the PDU session request received in step 12.

[0179] (R)AN forwards the NAS message (PDU Session ID, N1 SM container (PDU Session Establishment Accept message)) received in step 12 to the UE. (R)AN provides the NAS message to the UE only if the AN-specific signaling exchange with the UE includes (R)AN resource additions related to the received N2 command.

[0180] If N2 SM information is not included in step 11, steps 14-16b and 17 below are omitted.

[0181] Now, the procedure of Fig. 6 following the procedure of Fig. 5 is described.

[0182] (14) Step 14: (R)AN sends an N2 PDU Session Response message to AMF. The N2 PDU Session Response message may include PDU Session ID, cause, N2 SM information (PDU Session ID, AN tunnel information, accepted / rejected QFI list, user plane enforcement policy notification), etc.

[0183] (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.

[0184] (16a) Step S16a: SMF initiates the N4 session modification procedure with UPF. SMF provides AN tunnel information and corresponding forwarding rules to UPF.

[0185] (16b) Step S16b: UPF provides an N4 session modification response to SMF.

[0186] After this step, the UPF can forward any DL packets that may have been buffered for this PDU session to the UE.

[0187] (16c) Step 16c: If the SMF is not yet registered for this PDU session, the SMF may register with the UDM for the given PDU session.

[0188] (17) Step 17: SMF sends an update SM context response message (e.g., Nsmf_PDUSession_UpdateSMContext Response) to AMF.

[0189] After this step, AMF forwards the relevant events to which SMF subscribes.

[0190] (18) Step 18: At any time during the procedure after Step 5, if the PDU session establishment is not successful, the SMF can notify the AMF by calling Nsmf_PDUSession_SMContextStatusNotify (release). The SMF can also release the created N4 session, the PDU session address (e.g., IP address) if assigned, and possibly the association with the PCF. In this case, Step 19 below is omitted.

[0191] (19) Step 19: For PDU session type IPv6 or IPv4v6, SMF may generate and send an IPv6 Router Advertisement to the UE.

[0192] (20) Step 20: SMF can perform SM policy association modification initiated by SMF.

[0193] (21) Step 21: If the PDU session establishment fails after step 4, the SMF may unsubscribe for modification of session management subscription data if the SMF no longer processes the UE's PDU session.

[0194] 3GPP has standardized agreed-upon solutions to various key issues for supporting Edge Computing in 5G. In the previous Release 17 (e.g., 3GPP TR 23.748 V17.0.0: Study on enhancement of support for Edge Computing in 5G Core network), in Key Issue #1, the following Objective was reviewed to support the procedure for finding Edge Application Servers on terminals through the 5G core network.

[0195] Key Issue #1: Discovery of Edge Application Servers

[0196] In edge computing deployments, a single application service can typically be provided by multiple edge application servers deployed at different sites. These multiple edge application server instances hosting the same content or service can use a single IP address (anycast address) or different IP addresses. Before an application / UE connects to a service, it is crucial for the application / UE to discover the IP address of a suitable edge application server (e.g., the nearest server). This allows traffic to be locally routed to the edge application server via the UL CL / BP mechanism, optimizing service latency, traffic routing paths, and user experience. Furthermore, if the discovered edge application server is not optimal (e.g., after the UE has moved away), a new edge application server can replace the old one to service the application / UE.

[0197] Reselection of an edge application server can be triggered by events occurring at the 5GS or application layer. For example, in the first case, it could be triggered by a network-initiated user plane change, such as a mobility event (e.g., a handover), or a failure event that ultimately triggers a 5GS. In the second case, it could be triggered by an edge application server becoming congested or unavailable. This requirement depends on whether the application can tolerate changes in application server instances.

[0198] To support efficient search of edge application servers, the following aspects should be studied:

[0199] - How can UE find a suitable edge application server to serve the application / UE?

[0200] - Consider scenarios where the UE needs to be aware of the presence of an application server in the edge hosting environment (if any) and scenarios where the UE does not need to be aware of the presence of an application server in the edge hosting environment (if any).

[0201] - What information (if any) is available to support these search mechanisms?

[0202] - What additional information, if any, should be discovered about EAS through these discovery mechanisms?

[0203] - Whether UE rediscovery of Edge Application Servers is supported when the previous Edge Application Server is not optimal or becomes unavailable to the UE, and if so, how.

[0204] - Should Edge Application Server discovery and PSA UPF selection and reselection be performed jointly? If so, how?

[0205] If your solution to this major problem is to use DNS, you should also consider the following aspects:

[0206] - How can we account for PSAs that have different DNS resolutions for different applications?

[0207] - Should 5GC support DNS resolution?

[0208] Regarding the agenda, an agreement was reached on the EAS discovery procedure that supports the conventional DNS mechanism through 5GC during the terminal's EAS (Edge Application Server) search process. Accordingly, a new NF (Network Function) called Edge Application Server Discovery Function (EASDF) was introduced. 5GC can control DNS procedures with terminals through EASDF. In addition, 5GC can forward DNS query messages transmitted from terminals through EASDF to the local DNS server, so that the local DNS server can resolve these messages.

[0209] As agreed upon contents supporting this, service procedures such as EAS Discovery Procedure with EASDF and EAS Discovery Procedure with Local DNS Server / Resolver have been described since Release 17 and are currently included in the Release 18 TS 23.548 V18.3.0 standard.

[0210] Below, the EAS Discovery Procedure with EASDF included in TS 23.548 V18.3.0 is described.

[0211] For reference, in the disclosure of this specification, search or navigation may both mean Discovery.

[0212] When EASDF needs to process UE DNS queries, the following applies:

[0213] - The AF may provide EAS deployment information to the NEF for storage in the UDR as defined in clause 6.2.3.4 of TS 23.548 V18.3.0. The SMF may retrieve the EAS deployment information from the NEF as described in clause 6.2.3.4 of TS 23.548 V18.3.0 or may have the information pre-configured locally. The EAS deployment information is used by the EASDF to generate DNS message processing rules and is not dedicated to a specific UE session.

[0214] EAS distribution information can be applied to all PDU sessions with a specific DNN, S-NSSAI, and / or a specific internal group identifier.

[0215] - SMF may provide a BaselineDNS pattern (BaselineDNSPattern) to EASDF. The BaselineDNS pattern is derived from the EAS distribution information provided by AF and is not dedicated to a specific PDU session; SMF configures EASDF with the BaselineDNS pattern according to the procedure defined in clause 6.2.3.4 of TS 23.548 V18.3.0.

[0216] The baseline DNS message detection template ID can be used to reference the baseline DNS message detection template in EASDF and derive an array of FQDN ranges and / or an array of EAS IP address ranges. The baseline DNS processing task ID can be used to reference baseline DNS processing task information in EASDF and derive task-related parameters.

[0217] The Baseline DNS Message Detection Template ID and Baseline DNS Processing Job ID must be unique per SMF set if the SMF set controls the EASDF, and must otherwise be unique per SMF within the EASDF baseline.

[0218] A BaselineDNSPattern can contain one or more entries, each of which represents a baseline DNS message detection template or baseline DNS processing task information. Each BaselineDNSPattern entry can be updated or deleted using the baseline DNS message detection template ID or baseline DNS processing task ID to identify the updated or deleted entry.

[0219] - Baseline DNS message detection template

[0220] - Baseline DNS message detection template ID

[0221] - DNS Message Type = DNS Query or DNS Response:

[0222] - If DNS message type = DNS query: - Array of (FQDN ranges).

[0223] - If DNS Message Type = DNS Response: - Array of FQDN ranges and / or array of EAS IP address ranges.

[0224] - Baseline DNS handling actions information: - Baseline DNS handling action ID: (ECS option, local DNS server IP address)

[0225] - During the PDU session establishment procedure, the SMF may obtain EAS distribution information from the NEF if the EAS distribution information is not yet available (e.g., by subscribing to the NEF with respect to that information as described in clause 6.2.3.4.3 of TS 23.548 V18.3.0). If the EAS distribution information is pre-configured for the SMF, the SMF may select the EASDF and provide its address to the UE as the DNS server to be used for the PDU session.

[0226] The SMF configures the EASDF with DNS message processing rules to process DNS messages related to the UE. DNS message processing rules have a unique identifier and contain information used to detect and take action on DNS messages. DNS processing rules are defined as follows:

[0227] - Priority of DNS message processing rules;

[0228] - DNS processing rule ID;

[0229] - Baseline DNS message detection template ID and / or DNS message detection template (optional, if present, contains one or more of the following):

[0230] - DNS Message Type = DNS Query or DNS Response:

[0231] - If the DNS message type is a DNS query: an array of source IP addresses (i.e., UE IP addresses) (FQDN ranges) (optional).

[0232] - If the DNS message type is DNS response: an array of FQDN ranges and / or an array of EAS IP address ranges (optional).

[0233] - DNS message identifier (if received from EASDF);

[0234] - Action(s) (including one or more actions); possible actions include:

[0235] - Reporting Action: DNS message content is reported to SMF (e.g., target FQDN and, if available, IP address information provided back by the DNS server). This reporting action may include the "reporting-once" flag. If this flag is included, EASDF will report DNS message content to SMF only once, when the DNS message detection template matches the first incoming DNS query or DNS response message.

[0236] - Forwarding: Forwards DNS messages to DNS servers / resolvers(es) as follows (e.g., see A to C):

[0237] A. Contains information for constructing an optional EDNS Client Subnet Option to be included in DNS messages or used to replace an EDNS Client Subnet Option received in a DNS query message from the UE. (Information for EASDF to construct the EDNS Client Subnet Option is contained in a DNS processing rule or the baseline DNS processing task ID serves as a reference to the baseline DNS processing task information.) This corresponds to Option A, defined below.

[0238] B. Information about the destination address of a DNS message may be included as a DNS server address specified in a DNS processing rule, or the baseline DNS processing task ID included in the DNS processing rule may reference the destination address information of the DNS message. In this case, if the rule does not include a DNS server address provided by SMF, EASDF must forward the DNS message to the locally pre-configured default DNS server / resolver. This corresponds to Option B, defined below.

[0239] C. Responds directly to DNS requests. In this case, EASDF is configured by SMF not to forward DNS queries to a DNS server, but instead generates responses based on the EAS IP address provided by SMF.

[0240] - Control Action: Perform one or more of the following control actions on DNS messages:

[0241] - Constructs a DNS response from a DNS query based on the indicated IP address (e.g., a generic EAS). EASDF is expected to process the constructed response in the same way as a response received from a remote DNS server.

[0242] - Buffer DNS messages.

[0243] - Sends the buffered DNS response message to the UE.

[0244] - Delete cached DNS response messages.

[0245] When EASDF forwards DNS messages (to a DNS server via UE or N6), EASDF uses its own address as the source address of the DNS message. When EASDF forwards DNS messages to the UE, it either replaces the received EDNS Client Subnet option with the option provided by the UE (i.e., if provided by the UE) or removes all received EDNS Client Subnet options, depending on the configuration.

[0246] SMF can use the following information to create DNS message processing rules related to PDU sessions:

[0247] - local settings related to the PDU session (DNN, S-NSSAI, internal group identifier); and / or

[0248] - EAS distribution information provided by AF or preset in SMF; and / or

[0249] - Information derived from the UE location, such as the candidate L-PSA; and / or

[0250] - PDU session information such as PDU session L-PSA and ULCL / BP; and / or

[0251] - Internal group identifier received from session management subscription data of UDM; and / or

[0252] - IP address or DNAI (e.g., common EAS, common DNAI) cached locally or retrieved from UDR via PCF.

[0253] - The FQDN in the DNS query may match the FQDN provided by SMF in the DNS message detection template, as per SMF's instructions. In this case, EASDF will implement one of the following options based on the DNS message processing rules:

[0254] - Option A: EASDF includes or replaces the EDNS Client Subnet (ECS) option in the DNS query message as defined in RFC 7871 and sends the DNS query message to a DNS server to resolve the FQDN. The DNS server can resolve the EAS IP address by considering the EDNS Client Subnet option and send the DNS response to EASDF;

[0255] - Option B: EASDF sends a DNS query message to the local DNS server responsible for resolving the FQDN within the LDN. EASDF receives a DNS response message from the local DNS server.

[0256] SMF's instruction for a matching FQDN may also instruct EASDF to contact SMF. SMF then provides DNS message processing rules to EASDF;

[0257] - If the DNS query of the UE does not match the DNS message processing rules set by the SMF, the EASDF may forward the DNS query to a preset DNS server / resolver for DNS resolution;

[0258] - When EASDF receives DNS response message, EASDF notifies SMF of EAS information (i.e. EAS IP address, corresponding IP address in ECS DNS option) if DNS message reporting condition provided by SMF is satisfied (i.e. EAS IP address or FQDN is within IP / FQDN range). SMF can then select target DNAI based on EAS information and trigger UL CL / BP and L-PSA insertion as specified in clause 6.3.3 of TS 23.501 V18.0.0 according to notification.

[0259] Once UL CL / BP and L-PSA are inserted, SMF can now decide to have DNS messages for the FQDN handled by the local DNS resolver / server.

[0260] To prevent the EASDF from sending duplicate DNS message reports that would trigger UL CL / BP insertion corresponding to the same DNAI, the following actions may be taken. For example, the SMF may instruct the EASDF to report only on DNS messages corresponding to the reporting-once control information of the DNS message detection template by sending reporting-once control information (i.e., a DNS message processing rule with a DNS message detection template that includes EAS IP address ranges with report-once indication set) to the EASDF. Additionally, the SMF may instruct the EASDF not to report DNS responses corresponding to some FQDN ranges and / or EAS IP address ranges to the SMF while the relevant EASDF is configured to report DNS responses after UL CL / BP and L-PSA are inserted for those EAS IP address ranges for a pre-configured session breakout (e.g., when UL CL / BP and L-PSA are inserted for those EAS IP address ranges for a pre-configured session breakout). After removing or changing the L-PSA, the SMF can instruct the EASDF to resume reporting DNS messages.

[0261] Depending on local configuration, the SMF may decide that interactions between the EASDF and DNS servers for a DN should occur via the UPF. In this case, the SMF sends the corresponding N4 rule to this UPF, instructing this UPF to forward DNS messages between the EASDF and external DNS servers. In this case, the DNS messages between the EASDF and DNS servers described in this section are transparently transmitted via this UPF.

[0262] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals / messages / fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0263] FIG. 7a and FIG. 7b are examples of an EAS search procedure based on EASDF according to one embodiment of the disclosure of the present specification.

[0264] An example of an EAS discovery procedure with EASDF is described.

[0265] 1. The UE sends a PDU session establishment request to the SMF as shown in step 1 of Figures 5 and 6. The SMF retrieves the UE subscription information from the UDM (optionally including UE authorization indication for EAS discovery via EASDF) and verifies whether the UE is authorized to discover EAS via EASDF. If not authorized, this procedure terminates and subsequent steps are skipped.

[0266] 2. During the PDU session setup procedure, the SMF selects the EASDF as described in section 6.3 of TS 23.501 V18.0.0. Based on the UE subscription information, the SMF may select the EASDF as the DNS server for the PDU session.

[0267] The SMF may indicate to the UE that the use of the EDC function is allowed for the PDU session, or may indicate to the UE that the use of the EDC function is required for the PDU session.

[0268] If, based on local configuration, SMF determines that interaction between the EASDF and DNS servers of a DN should occur via the PSA UPF, SMF configures the PSA UPF within the N4 rule to forward DNS messages between the EASDF and the DN.

[0269] 3. For the selected EASDF, SMF calls the Neasdf_DNSContext_Create request (including the UE IP address, SUPI, DNN, notification endpoint, and (DNS message processing rules)).

[0270] This step is performed before step 11 of the PDU session establishment procedure of FIGS. 5 and 6.

[0271] EASDF creates a DNS context for the PDU session and stores the UE IP address, SUPI, notification endpoint, and potentially provided DNS message processing rules in the context.

[0272] DNS message processing rules are provided to EASDF before a DNS query message is received by EASDF or as a result of a DNS query report.

[0273] 4. EASDF calls the service operation Neasdf_DNSContext_Create response.

[0274] After this step, the SMF includes the IP address of the EASDF as the DNS server / resolver for the UE in the PDU Session Setup Accept message as defined in step 11 of section 4.3.2.2.1 of TS 23.502 V18.0.0. The UE configures the EASDF as the DNS server for that PDU session.

[0275] If the UE requests to acquire a UE IP address via DHCP and the SMF supports DHCP-based IP address configuration, the SMF responds to the UE via a DHCP response with the assigned UE IP address and / or a DNS server address containing the IP address of the EASDF.

[0276] 5. The SMF may invoke a Neasdf_DNSContext_Update request (containing the EASDF context ID and (DNS message processing rules)) to the EASDF. The update may be triggered by UE mobility, such as when the UE moves to a new location, or by EASDF reporting a DNS query with a specific FQDN. The update may also be triggered by insertion / removal of a local PSA, for example, an update of rules for processing DNS messages from the UE, or new PCC rule information.

[0277] 6. EASDF responds with a Neasdf_DNSContext_Update response.

[0278] 7. If necessary, the UE's application uses the EDC function to send a DNS query to the EASDF. The UE sends a DNS query message to the EASDF.

[0279] 8. If a DNS query message matches a DNS message detection template in a DNS message processing rule for reporting, EASDF sends a DNS message report to SMF by calling a Neasdf_DNSContext_Notify request (with information about the DNS query, e.g., the target FQDN of the DNS query). EASDF may add a DNS message identifier to the Neasdf_DNSContext_Notify request. The DNS message identifier uniquely identifies the reported DNS message and is used to associate the corresponding DNS message processing rule included in the Neasdf_DNSContext_Update request with the identified DNS message. The DNS message identifier is generated by EASDF.

[0280] 9. SMF responds with a Neasdf_DNSContext_Notify response.

[0281] 10. The DNS message processing rules for the FQDN received in the report may need to be updated (e.g., to provide information updates to build / replace EDNS Client Subnet Options information). In this case, SMF calls the Neasdf_DNSContext_Update request (DNS Message Processing Rules) to EASDF. If EASDF provided a DNS message identifier, SMF adds this DNS message identifier to the corresponding DNS message processing rule included in Neasdf_DNSContext_Update. If EASDF did not provide a DNS message identifier, SMF can uniquely identify the DNS message using the DNS message type (request) and the target FQDN.

[0282] For Option A, the DNS processing rule includes the corresponding IP address to be used to establish / replace the EDNS Client Subnet option. For Option B, the DNS processing rule includes the corresponding local DNS server IP address. Additionally, the DNS processing rule can simply direct EASDF to forward DNS queries to a preconfigured DNS server / resolver.

[0283] 11. If SMF provides a DNS message processing rule along with a DNS message identifier, EASDF applies the DNS message processing rule only to that DNS message. EASDF responds with a Neasdf_DNSContext_Update response.

[0284] 12. EASDF processes DNS query messages received from UE as follows:

[0285] - For Option A, EASDF adds / replaces the EDNS Client Subnet option to the DNS query message as specified in RFC 7871 and sends it to the C-DNS server;

[0286] - For Option B, when EASDF receives the EDNS Client Subnet option in a DNS query, it removes it and forwards the DNS query message to the local DNS server.

[0287] If the DNS message detection template within the DNS message processing rules provided by SMF does not match the FQDN requested in the DNS query, EASDF can simply forward the DNS query to a pre-configured DNS server / resolver.

[0288] 13. EASDF receives a DNS response containing the EAS IP address determined by the DNS system and verifies whether the DNS response can be forwarded to the UE.

[0289] 14. If the EAS IP address or FQDN in the DNS response message matches a DNS message detection template provided by SMF, EASDF sends a DNS message report to SMF by calling Neasdf_DNSContext_Notify request containing EAS information. If EASDF receives multiple EAS IP addresses from the DNS server it contacts, the DNS message report may contain multiple EAS IP addresses. The DNS message report may include the FQDN and EDNS client subnet option received in the DNS response message. EASDF may also add a DNS message identifier to the report. The DNS message identifier uniquely identifies the reported DNS response, and EASDF can associate the corresponding DNS message processing rule included in the Neasdf_DNSContext_Update request with the identified DNS response. The DNS message identifier is generated by EASDF.

[0290] Depending on the rules for processing received DNS messages, EASDF may wait for an SMF command (step 17) without sending a DNS response message to the UE (i.e., buffering the DNS response message).

[0291] If DNS responses need to be buffered and reported to SMF, and the report-once control information is set, EASDF will report to SMF only once by calling the Neasdf_DNSContext_Notify request for DNS responses that match the DNS message detection template.

[0292] 15. SMF calls the Neasdf_DNSContext_Notify response service operation.

[0293] 16. SMF can perform UL CL / BP and local PSA selection and insert UL CL / BP and local PSA.

[0294] Based on the EAS information received from EASDF in Neasdf_DNSContext_Notify, other UPF selection criteria specified in section 6.3.3 of TS 23.501 V18.0.0, and service experience or DN performance analysis of edge applications described in TS 23.288 V18.0.0, the SMF can determine the DNAI. In addition, the SMF can determine the relevant N6 traffic routing information for the DNAI according to the N6 traffic routing information for the DNAI included in the EAS deployment information, and set up the local PSA UPF with the forwarding actions derived from the N6 traffic routing information. The SMF can perform UL CL / BP and local PSA selection and insertion as described in TS 23.502 V18.0.0. For the UL CL, the traffic detection rules and traffic routing rules are determined by the SMF according to the IP address range per DNAI included in the EAS deployment information, or the PCC rules received from the PCF, or the pre-configured information.

[0295] 17. SMF calls the Neasdf_DNSContext_Update request (DNS message processing rule). If EASDF provided a DNS message identifier, SMF adds this identifier to the corresponding DNS message processing rule included in the Neasdf_DNSContext_Update request. If EASDF did not provide a DNS message identifier, SMF can uniquely identify the DNS response message using the DNS message type (response) and the FQDN.

[0296] A DNS message processing rule with a control action of "Send buffered DNS response message to UE" instructs the EASDF to send the buffered DNS response to the UE in step 14. Other DNS message processing rules may instruct the EASDF to no longer send DNS response messages corresponding to the FQDN range and / or EAS IP address range.

[0297] 18. If SMF provides a DNS message processing rule along with a DNS message identifier, EASDF applies the DNS message processing rule only to the corresponding DNS response. EASDF responds with a Neasdf_DNSContext_Update response.

[0298] 19. If instructed to send a buffered DNS response to the UE in step 17, the EASDF sends the DNS response to the UE and processes the EDNS Client Subnet option as described above.

[0299] During the PDU session release procedure, SMF calls the Neasdf_DNSContext_Delete service to remove the DNS context.

[0300] Describes an example of an EAS lookup procedure using a local DNS server / resolver.

[0301] If DNS messages are processed by a local DNS resolver / server, the DNS query is routed to the local DNS resolver / server corresponding to the DNAI associated with the L-PSA. The SMF selects the local DNS server address based on the DNAI corresponding to the inserted local PSA, the local configuration, and the EAS distribution information in the AF request, as specified in TS23.548 V18.3.0 Section 6.2.3.4.2. Depending on the operator's configuration, one of the following options may apply (during or after PDU session establishment) when the UL CL / BP and local PSA are inserted:

[0302] - Option C: The SMF configures the local DNS server as the new DNS server for the UE. The SMF may indicate to the UE that the use of the EDC feature is allowed for the PDU session or that the use of the EDC feature is required for the PDU session. The SMF also configures traffic routing rules in the UL CL (e.g., containing the local DNS server address) or BP (e.g., new IP prefix @ local PSA) to route traffic containing DNS query messages destined for the L-DN to the L-PSA. The L-DNS server communicates with other DNS servers to resolve DNS queries locally or recursively.

[0303] - Option D: If you configure SMF to allow DNS queries for FQDN (range) queries to be routed locally on the UL CL, subsequent DNS queries for FQDN (range) will be routed locally to the local DNS server.

[0304] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals / messages / fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0305] FIG. 8 illustrates an example of an EAS discovery procedure based on a local DNS server / resolver according to one embodiment of the disclosure of the present specification.

[0306] Figure 8 is an example of EAS discovery with local DNS server / resolver.

[0307] 0. The UE sends a PDU Session Establishment Request to the SMF as shown in step 1 of Figures 5 and 6. The SMF retrieves the UE subscription information from the UDM (which may optionally include an indication of UE authorization for EAS discovery via EASDF) and verifies whether the UE is authorized to discover EAS via EASDF. If not authorized, the EASDF-related tasks in this procedure are skipped.

[0308] 1. SMF inserts UL CL / BP and local PSA.

[0309] The UL CL / BP / Local PSA insertion can be triggered by DNS messages as described in TS 23.548 V18.0.0 section 6.2.3.2.2. Alternatively, the SMF can pre-configure the UL CL / BP and Local PSA before the UE sends the DNS Query message (e.g., when the UE moves). In this case, the SMF includes the IP address of the local DNS server in the PDU Session Setup Acknowledge message according to step 11 of section 4.3.2.2.1 of TS 23.502 V18.0.0 or the network-initiated PDU session modification procedure. The UE configures the local DNS server as the DNS server for that PDU session.

[0310] When the UL CL / BP and the local PSA are inserted or changed simultaneously, the SMF sets the UL CL / BP for DNS query processing:

[0311] For Option C, steps 2 and 3 are performed:

[0312] 2. After the PDU session is established and UL CL / BP and local PSA are inserted, the SMF sends a PDU session modification command (local DNS server address) to the UE.

[0313] If the local DNS server IP address of the local data network needs to be notified or updated to the UE based on the operator's policy or the mobility of the UE, the SMF sends a PDU Session Modification Command (Local DNS Server Address) to the UE.

[0314] 3. The UE responds with a PDU Session Modification Command Ack.

[0315] The UE sets the local DNS server as the DNS server for the PDU session. The UE then sends the following DNS query to the designated local DNS server.

[0316] If EASDF is used as a DNS server for a PDU session, SMF can remove the EASDF's DNS context by calling the Neasdf_DNSContext_Delete service.

[0317] 4. If required (see TS 23.548 V18.0.0 section 5.2.1), the application in the UE sends a DNS query to the DNS resolver / DNS server specified by the SMF in step 0 using the EDC functionality as described in TS 23.548 V18.0.0 section 6.2.4. The UE sends the DNS query message. In case of IPv6 multihoming, the UE selects the source IP prefix according to the IPv6 multihoming routing rules provided by the SMF.

[0318] 5. The DNS query message is forwarded to the local DNS server and processed as described below:

[0319] - For Option C, the target address of the DNS query is the IP address of the local DNS server. The DNS query is forwarded to the local DNS server by the UL CL / BP and the local PSA. The local DNS server either resolves the FQDN of the DNS query on its own or recursively resolves the EAS IP address by communicating with other DNS servers.

[0320] - For Option D: The local PSA forwards DNS traffic to a local DNS server that either resolves the FQDN target of the DNS query itself or communicates with a C-DNS server to recursively resolve the EAS IP address.

[0321] 6. The local PSA receives a DNS response message from the local DNS server and forwards it to the UL CL / BP, which then forwards the DNS response message to the UE.

[0322] If SMF decides to remove the UL CL / BP and Local PSA as defined in clause 4.3.5.5 of TS 23.502 V18.0.0, eg, due to UE mobility, the SMF sends a PDU Session Modification Command to configure the new address of the DNS server on UE (eg to set it to the address of EASDF).

[0323] For example, if the SMF decides to remove the UL CL / BP and local PSA as defined in clause 4.3.5.5 of TS 23.502 V18.0.0 due to UE mobility, the SMF sends a PDU Session Modification command to set the new address of the DNS server in the UE (e.g. to set it to the address of the EASDF).

[0324] As described above, 5GC can support EAS discovery procedures. 5GC can select an EASDF or local DNS server / resolver for a DNS query message transmitted by a terminal and resolve the message based on a controllable format. Furthermore, 5GC can provide the terminal with an EAS IP address. Furthermore, even after the terminal's EAS discovery process, the 5GC supports edge relocation / EAS rediscovery procedures for changing the EAS providing services to the terminal based on a request from the AF or a decision by 5GC (specifically, the SMF).

[0325] In the conventional EAS discovery support procedure, the SMF can determine the DNS server to provide to the terminal. The DNS server address information can be the address of a local DNS server located geographically close to the terminal or the address of the EASDF. The SMF can determine the DNS server based on the EDI (EAS Deployment Information) provided by the AF or the local configuration.

[0326] EDI information provided by AF may include information such as DNN, S-NSSAI, FQDN(s), DNAI(s), DNS Server Information, and EAS IP address range Information. When AF transmits EDI information, EDI information is stored in UDR through NEF, and this information can be referenced by SMF. In addition, this information may be preconfigured in SMF. SMF can perform EASDF selection and DNS message handling rule generation based on EDI information.

[0327] The EASDF can receive DNS message handling rules from the SMF. Based on the DNS message handling rules, the EASDF can report to the SMF the receipt of DNS queries from terminals or DNS response messages from DNS servers / resolvers. Based on the reported information, the SMF can update the DNS message handling rules for the EASDF.

[0328] In conventional EAS discovery support technology using EASDF, SMF only references static information within EDI provided by AF. SMF has the problem of setting DNS message handling rules and supporting terminal DNS procedures based solely on static information.

[0329] Conventional technology lacks support for referencing dynamically changing information, such as resource status or load information within each Edge Application Server. Consequently, when EAS overload occurs, the service experience of terminals can deteriorate. Depending on the EAS overload situation, edge relocation may be requested from the AF. However, this poses a problem: new terminals may continue to receive static EAS information provided in the past. Consequently, for terminals whose load status has not been previously considered, the edge relocation procedure must be performed after EAS discovery.

[0330] According to the prior art, the SMF and EASDF can provide edge computing services to terminals. The SMF and / or EASDF receive EAS Deployment Information (EDI) from the AF. Conventional EDI contains only static information. This poses a problem: the network cannot utilize EAS load information, which changes in real time. Furthermore, even if the network utilizes EAS load information, the SMF must manage this information, resulting in signaling overhead.

[0331] For example, according to the prior art, AF provides EAS Deployment Information (EDI) to SMF / EASDF. SMF and / or EASDF can support edge computing services to terminals based only on static information in EDI.

[0332] Given the nature of edge computing applications, 5GC needs a way to receive dynamically changing information, such as EAS load status, to provide optimal EAS information to terminals. Furthermore, 5GC needs a way to support EAS discovery for new terminals and edge relocation procedures for existing terminals based on dynamically changing information, such as EAS load status.

[0333] Furthermore, the method of providing 5GC with dynamically updated EAS load information via control plane signaling and managing it poses a problem of signaling overhead. Therefore, a more efficient method is needed to provide 5GC with this information.

[0334] 5G network deployment scenarios often involve a centralized Control Plane NF (specifically, AMF, SMF) and a localized User Plane NF (e.g., UPF, EASDF). In these scenarios, the SMF faces the challenge of managing excessive amounts of information to support edge computing. Considering these scenarios, it may be beneficial for local NFs to manage dynamically updated information.

[0335] Due to the nature of Edge Computing applications, 5GC requires a method to receive dynamically changing (or updated) information, such as EAS load status, to provide optimal EAS information to terminals. According to various examples disclosed in this specification, 5GC can support EAS discovery for new terminals and Edge relocation procedures for existing terminals based on this dynamically changing information.

[0336] The way 5GC receives and manages each EAS load information dynamically updated via control plane signaling can incur signaling overhead. Therefore, a more efficient method for 5GC to receive this information is needed.

[0337] The disclosure of this specification proposes operations aimed at supporting EAS discovery and edge relocation for terminals receiving edge computing services. For example, when an AF transmits information related to changes in a specific EAS overload situation to the local EASDF, the local EASDF can track / update this information and request / perform edge relocation from the SMF.

[0338] AF can provide EAS overload situation change information to 5GC. For example, the existing Naf_EventExposure_Subscribe service operation can be extended. Based on this, 5GC (specifically EASDF) can receive notifications of EAS overload situations through NEF. AF can also include an overload threshold in the service. When the overload situation is resolved, 5GC can receive notifications from AF again.

[0339] According to the disclosure of this specification, 5GC (specifically, EASDF) can receive notifications regarding the occurrence and release of overload situations for a specific EAS. Based on the notifications, 5GC can request edge relocation for terminals receiving services from the corresponding EAS. Furthermore, this information can be referenced and considered during the EAS discovery process for new terminals.

[0340] The EASDF may then receive notification from the AF that the EAS overload condition has been resolved. In this case, the EASDF may request an update to the DNS message handling rules so that the relevant EAS information can be provided to the terminal again.

[0341] According to one embodiment of the disclosure of this specification, the EASDF can receive a notification from the AF regarding the occurrence and release of an EAS overload situation at the request of the EASDF. Based on the notification, the EASDF can make an edge relocation decision and request EAS (re)discovery. The disclosure of this specification describes a method for supporting such operations.

[0342] For the procedures and / or messages described in the various examples of the disclosure herein, existing procedures / messages may be utilized as is. Alternatively, existing procedures / messages may be extended and used. Alternatively, new procedures / messages may be defined and used.

[0343] In the disclosure of this specification, User Equipment (UE) and terminal may be used as terms with the same meaning.

[0344] Below, we will primarily describe the contents proposed in this specification. If prior art operations are performed in connection with the disclosed operations of this specification, a detailed description thereof will be omitted. For the detailed operations and functions related to the EAS rediscovery procedure and Set of UEs described above, TS 23.548 V18.2.0 will be referred to. The methods presented below can be performed or used in combination or complementary manner.

[0345] 1. First example of disclosure of this specification

[0346] According to a first example of the disclosure of this specification, 5GC can obtain EAS overload related information from AF.

[0347] The AF can provide information related to changes in the overload status of each EAS providing Edge computing services to the terminal to the 5GC (specifically, the EASDF). Based on this information, the 5GC can support Edge relocation decisions for the terminal and EAS (re)discovery procedures.

[0348] 5GC (especially EASDF) can obtain EAS overload status change information from AF. The following describes the differences between the subscription procedure for specific events from 5GC to AF and the AF influence on traffic routing procedure described in the TS 23.501 V18.0.0, TS 23.502 V18.0.0 and TS 23.288 V18.0.0 standards and the procedure according to the first example of the disclosure of this specification.

[0349] 1-1. Example of EASDF obtaining EAS overload information according to the Data Collection from AF procedure.

[0350] EAS overload information can be obtained by following the Data Collection from AF procedure.

[0351] For example, conventional technology supports a Data Collection procedure in which NWDAF receives specific Events and related information from AF. This service procedure is described in sections 6.2.2.2 and 6.2.2.3 of the TS 23.288 V18.0.0 standard. NWDAF can subscribe to specific Events directly from AF or through NEF.

[0352] The Nnef_EventExposure_Subscribe service operations and the Naf_EventExposure_Subscribe service operations of the prior art may include the following information. For example, the following may be included: Event ID(s) identifying a specific event defined in 5GC, Type information for Event Parameters, Event Filter Information specifying Value(s), and Event Reporting Information related to Event reporting settings. The AF may send a notification containing information about a specific Event for the corresponding subscription.

[0353] The above conventional procedures and services are currently limited in their use to only allow NWDAF to perform data analytics.

[0354] Accordingly, the disclosure of this specification defines a new Event ID for obtaining EAS overload status change information from the EASDF. Furthermore, Event Filter Information and Event Reporting Information are extended, enabling the EASDF to perform the above-mentioned service operations and procedures.

[0355] To support subscription to specific event-related information from AF through conventional NEF, application-specific data information (including AF identifier) ​​can be provisioned from O&M to NEF.

[0356] The EASDF can subscribe to an AF that serves terminals managed by the EASDF. For example, the EASDF can subscribe to the AF through the NEF to inform the AF of changes in EAS overload conditions. Accordingly, the EASDF can perform the NEF discovery and selection process through the NRF. For example, the EASDF can query by sending a message containing the AF identifier. The EASDF can receive the corresponding AF identifier from the SMF during the DNS context creation process based on information in the EDI, etc.

[0357] According to the above proposed procedure, EASDF can subscribe to EAS overload situation change information to AF within the EAS discovery procedure of the terminal.

[0358] 1-2. Example of EASDF obtaining EAS overload information according to the AF traffic influence on traffic routing procedure.

[0359] We propose an example of extending the Nnef_TrafficInfluence service within the existing Application Function influence on traffic routing procedure. By extending this service, the EASDF can obtain overload situation information for a specific EAS from the AF. Separately from the EASDF request of [1-1] above, the AF can provide the IP address information of the EAS and the overload indication for the purpose of notifying the AF of an overload situation for the specific EAS. This operation can be utilized to prevent new terminals from connecting to an EAS in an overload situation based on the AF request.

[0360] The AF can include / store the corresponding information (e.g., information about a specific EAS in an Overload state) in the Traffic Influence information in the UDR via the NEF. For example, the information about a specific EAS in an Overload state can be identified by an IP address. For example, the information about a specific EAS in an Overload state can be the IP address(es) of the EAS(s) in an Overload state. The PCF can forward the PCC rule including the corresponding information received from the AF to the serving SMFs of the PDU Session associated with the DNN / S-NSSAI in the AF request. The serving SMF of the PDU Session can provide the corresponding information to the EASDF when selecting an EASDF and creating a DNS context in the EAS discovery procedure of the terminal.

[0361] Depending on the change in the overload status of the above EAS, the AF may operate in a manner of releasing the previously provided overload indication including the address of the corresponding EAS. For example, depending on whether specific EAS(s) are overloaded, the AF may transmit an overload indication (e.g., Set to 'true') together with the IP address that identifies the EASs in the overload status. Based on the information transmitted by the AF, the NEF may, for example, store and manage the IP addresses of the EASs in the overload status within the UDR. The overload status may be resolved for a specific EAS. In this case, the AF may transmit the overload indication set to 'false' together with the IP address of the corresponding EAS. Then, the NEF may exclude the corresponding EAS from the EASs in the overload status within the UDR.

[0362] 2. Second example of disclosure of this specification

[0363] A second example of the disclosure of this specification describes an example of how EASDF utilizes EAS overload status change information.

[0364] EASDF can obtain EAS overload situation change information based on the procedure described in the first example of the disclosure of this specification. EASDF can support edge computing of UE based on the obtained EAS overload situation change information.

[0365] Determining / requesting / performing Edge relocation and EAS (re)discovery procedures of the UE may be supported based on a combination of one or more of the following actions / configurations / steps:

[0366] 2-1. How EASDF decides / requests edge relocation.

[0367] Conventional Edge relocation decisions can be made upon request from AF or based on terminal mobility in 5GC (especially SMF).

[0368] In the procedure described in the first example of the disclosure of this specification, the AF can provide information related to the overload / congestion situation of a specific EAS and information such as DNN / S-NSSAI associated therewith to the EASDF.

[0369] The EASDF may be aware of an overload / congestion situation for a specific EAS. In this case, the EASDF may notify one or more SMFs controlling the EASDF of information related to the overload / congestion situation for the specific EAS. Alternatively, the EASDF may request the SMF to relocate the edge for terminals using the EAS.

[0370] The SMF may determine and / or perform edge relocation. Depending on the edge relocation decision / performance, the SMF may transmit an EAS rediscovery indication to the terminal via the PDU Session Modification procedure. The terminal may refresh stale EAS information and perform the EAS (re)discovery procedure to acquire an EAS IP address again.

[0371] For example, for stale EAS information, the following explanation may apply:

[0372] The terminal internally stores the address of the application server through DNS procedures for connection to the application server. Therefore, the terminal can attempt to connect to the application server using the internally stored server address without having to perform the DNS procedure to find the server each time.

[0373] At this time, the PDU Session Modification procedure may be performed according to the SMF's edge relocation decision. The SMF may transmit a PDU Session Modification Command message to the terminal. The message may include DNAI information in the [impact field] field along with an EAS re-discovery indication. Alternatively, the message may include an EAS re-discovery indication and the [impact field] field may be empty.

[0374] If DNAI information is included in the [impact field], the terminal may recognize the Application Server information contained within / corresponding to the DNAI as stale information. The terminal may delete the stored address information for the Application Servers and perform a DNS procedure to find a new server.

[0375] Additionally, the PDU session modification message may contain only the EAS re-discovery indication, with the impact field left blank. In this case, the terminal clears all internally stored application server addresses and, if necessary, performs a new DNS procedure to obtain the server address.

[0376] 2-2. How EASDF considers EAS load information in the EAS Re-discovery procedure.

[0377] Based on the EAS overload situation change information obtained according to the first example of the disclosure of the present specification, the EASDF can support the EAS discovery procedure of the terminal considering the load situation of the server. The EAS overload situation change information can be overload information for a specific EAS provided by the AF, and can also be load information for each EAS according to the subscription of 5GC (particularly SMF).

[0378] Prior art EAS discovery procedures did not consider dynamic load information from the Application Server. This could lead to a terminal being targeted for edge relocation to find another EAS when an EAS overload situation occurred. Furthermore, EAS discovery procedures for new terminals could also provide the terminal with EAS address information for overload situations.

[0379] In the disclosure of this specification, a method is proposed in which an EASDF supporting an EAS discovery procedure by a terminal refers to EAS load or overload situation information.

[0380] The EASDF can support EAS discovery based on EAS load / overload status information based on EAS information provided through the terminal's DNS procedure. The DNS response received from the DNS server / resolver may include multiple EAS IP addresses. The SMF can modify / reassemble the corresponding content (e.g., EAS information) based on EAS load / overload information.

[0381] The above-described EAS information modification / recombination method can be performed by pre-filtering specific EAS IP address information based on EAS overload information. Alternatively, the EAS information modification / recombination method can be performed by changing / recombining priorities based on EAS load conditions.

[0382] The proposed scheme allows DNS responses containing modified / recombined EAS information based on EAS load / overload to be transmitted to terminals. This facilitates optimal EAS selection. Furthermore, signaling and edge relocation procedures for resolving overload situations from AF to 5GC can be reduced.

[0383] The disclosure of this specification describes an example of EAS re-discovery based on EAS overload information from the EASDF. In this regard, reference is made to FIGS. 9A and 9B below. The examples in FIGS. 9A and 9B include an example of an EAS re-discovery due to EAS overload procedure.

[0384] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals / messages / fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0385] FIG. 9a and FIG. 9b illustrate examples of an EAS re-search procedure according to one embodiment of the disclosure of the present specification.

[0386] Figures 9a and 9b illustrate an example of an EAS rescan procedure due to EAS overload.

[0387] In the examples of FIGS. 9a and 9b, steps 1a to 1c may refer to operations according to prior art.

[0388] For example, in step 1a, NEF may send a request message related to NF management (e.g., Nnrf_NFManagement_NFUpdate_request) to NRF.

[0389] For example, in step 1b, NRF can store the NF profile.

[0390] For example, in step 1c, NRF may send a response message related to NF management (e.g., Nnrf_NFManagement_NFUpdate_response) to NEF.

[0391] According to steps 1a to 1c, registration with NEF can be performed for information that AF can provide.

[0392] After registration, the NEF's registration information (i.e., NEF profile) containing the relevant information may be stored in the NRF. Information that the AF can provide may include information that the AF can notify the EAS of a congestion situation.

[0393] In step 2, the UE and the SMF may perform a PDU session establishment procedure. For example, the PDU session establishment procedure according to the examples of FIGS. 5 and 6 may be performed.

[0394] In step 3, SMF can select EASDF.

[0395] In step 4, SMF may send a request message related to DNS context creation (e.g., Neasdf_DNSContext_Create Request) to EASDF. EASDF may send a response message related to DNS context creation (e.g., Neasdf_DNSContext_Create Response) to SMF.

[0396] In steps 2 to 4, a DNS Context may be created after EASDF selection is performed in the terminal's PDU Session establishment procedure. During this process, the SMF may obtain EAS Deployment Information from the AF via UDR or NEF. The SMF may also set the AF ID included in the EAS Deployment Information within the DNS Context.

[0397] In step 1d, EASDF may send a request message (e.g., Nnrf_NFDiscovery_Request_request) related to a discovery request to NRF.

[0398] In step 1e, NRF may send a response message (e.g., Nnrf_NFDiscovery_Request_response) related to the discovery request to EASDF.

[0399] In steps 1d to 1e, the EASDF can query the NRF for information available from AFs. The EASDF can obtain available data and NEF information that can be provided for each AF. In this process, the EASDF can also obtain NEF information that can provide EAS overload situation information among the AFs that the terminals are servicing by using the AF ID information in the DNS Context.

[0400] For example, the EASDF can search for information that can be provided from each AF by using the AF IDs stored in the DNS context as identifiers. Among the AFs deployed in the network, there may be AFs that support the function of providing EAS overload situation information through NEF and AFs that do not support such function. The EASDF needs to know the AFs and NEFs that support this function. However, the EASDF cannot search for whether all AFs in the network support this function. The EASDF can use the AF IDs (e.g., serving AFs) stored in the DNS context to find AFs that can provide EAS overload situation information among the serving AFs of the terminal.

[0401] In step 5, EASDF may send messages related to event subscription or event unsubscription (e.g., Nnef_EventExposure_Subscribe / Nnef_EventExposure_Unsubscribe) to NEF.

[0402] In step 6, NEF can forward the message transmitted by EASDF to AF.

[0403] In steps 5 and 6, EASDF can subscribe / unsubscribe to EAS overload situation information from AF via NEF. For example, EASDF can subscribe / unsubscribe to events related to EAS overload situation information.

[0404] For example, EASDF can subscribe / unsubscribe to EAS overload situation information from AF via SMF and NEF. When EASDF subscribes / unsubscribes via SMF and NEF, EASDF can perform the subscription / unsubscription without directly knowing the AF ID.

[0405] Regardless of how the subscription to EAS overload situation information is performed, the EASDF may also receive notification of EAS overload situation information directly from the AF.

[0406] In step 7, the AF may send an event-related notification message (e.g., Naf_EventExposure_Notify) to the NEF. The notification message may include the target UE identifier, the EAS IP address, and an overload indication.

[0407] In step 8, the NEF may send the notification message (e.g., Nnef_EventExposure_Notify) sent by the AF to the EASDF. The notification message may include the target UE identifier, the EAS IP address, and an overload indication.

[0408] In steps 7 and 8, the AF can provide address information (e.g., EAS IP address) for the EAS in an overload situation and address information of the terminal receiving service from the EAS (e.g., target UE identifier) ​​to the EASDF through the NEF.

[0409] Notifications sent by AF may include information about terminals requiring EAS rediscovery. For example, notification messages may include a list of specific terminals (e.g., terminal IP addresses), the number of terminals that must be reduced to resolve congestion, or information indicating that no more terminals can be serviced.

[0410] In step 9, EASDF may send a request message related to DNS context notification to SMF.

[0411] In step 9, the EASDF can determine which terminals require EAS rediscovery based on the information received in step 8. The EASDF can identify terminals connected to the EAS that are in an overloaded state and the SMFs serving the terminals. The EASDF can request EAS re-discovery by sending a request message including terminal information and DNN / S-NSSAI information to the SMF. Instead of the EASDF receiving the terminal address information from the AF, the EASDF can also know the EAS address currently being used by a specific terminal based on the DNS response that the EASDF responds to the terminal. Based on this EAS address, the EASDF can also generate a list of terminals that directly use the EAS that is in an overloaded state.

[0412] Additionally, the EASDF may receive information from the AF indicating that it is no longer able to service the terminal. In this case, the EASDF may transmit the information indicating that the AF is unable to service the terminal to the SMF along with the EAS address information. Based on this information, the SMF may determine not to use the EAS address anymore when performing EAS discovery for other terminals.

[0413] In step 10, the SMF may send a PDU Session Modification Command message to the UE. The PDU Session Modification Command message may include an EAS rescan indication and / or an impact field. The EAS rescan indication may contain information related to EAS rescan.

[0414] In step 11, the UE may send a PDU Session Modification Command ack message to the SMF.

[0415] In step 12, an EAS re-discovery procedure may be performed. For example, steps 7 through 19 of the EAS re-discovery procedure according to section 6.2.3.2.2 of TS23.548 V17.6.0 may be performed.

[0416] In steps 10 to 12, the SMF may perform EAS re-discovery of the terminal upon a request from the EASDF in step 9. The SMF may transmit a PDU Session Modification Command including an EAS re-discovery indication to the terminal. Based on the received indication, the terminal may perform a DNS cache refresh and a DNS procedure to find a new EAS. During the DNS procedure, the EAS information provided to the terminal may include EAS information in an overload situation. In this case, the EASDF may decide / perform to delete or prioritize the corresponding record on its own according to local configuration or according to a DNS message handling rule update from the SMF.

[0417] For example, the following explanation may apply to a record. A terminal may receive EAS information from a DNS server. EAS information may include multiple application server address information, and each address information may be referred to as a record. Therefore, deleting / prioritizing a record may mean excluding a specific application server address or adjusting the order of records according to priority. Generally, when a terminal receives a DNS response message containing multiple server address records, the terminal attempts to connect to the server address at the top in sequence.

[0418] Additionally, EASDF manages EAS overload status information within EASDF, and EAS overload status can also be referenced in the EAS discovery procedure of a new terminal.

[0419] In the method proposed in the first and / or second examples of the disclosure of the present specification, the 5GC (particularly the EASDF) can receive load information per EAS or overload situation changes for a specific EAS from the AF. Based on the information related to the overload situation changes, the 5GC can support edge relocation decision / request of a terminal and EAS re-discovery. The following description may be applied to the method of receiving EAS load / overload information from the AF and the method of requesting edge relocation of a terminal to the SMF. For example, these operations may be performed based on an extended service operation of a conventional service operation, a new service operation, or a conventional service procedure or a new service procedure. In addition, conventional parameters may be reused or new indications or parameters may be generated and transmitted.

[0420] 3. Third example of disclosure of this specification

[0421] The third example of the disclosure of this specification describes an example of a procedure based on the various examples of the disclosure of this specification described above.

[0422] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals / messages / fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0423] FIG. 10 illustrates an example of operations according to one embodiment of the disclosure of the present specification.

[0424] For reference, the procedure illustrated in FIG. 10 is merely an example, and the scope of the disclosure of this specification is not limited by the example in FIG. 10.

[0425] For example, with respect to the example of FIG. 10, the operations described in the examples of FIGS. 1 to 9A and 9B may also be applied. For example, even if operations, contents, etc. are not directly described in the example of FIG. 10, operations, contents, etc. described in various examples of the disclosure of this specification may be applied.

[0426] The operations illustrated in FIG. 10 are merely examples, and the scope of the disclosure of this specification is not limited to the operations illustrated in FIG. 10.

[0427] Note that before step (S1001) is performed, the following actions may be performed. For example, EASDF may receive a DNS context creation request message from SMF. For example, EASDF may send a DNS context creation response message to SMF.

[0428] For example, a DNS context creation response message may include received EAS distribution information provided by AF.

[0429] At step (S1001), EASDF can send an NF search request message to NRF.

[0430] For example, an NF search request message may include information querying the AF for information it can provide.

[0431] In step (S1002), the NRF may transmit an NF discovery response message to the EASDF.

[0432] For example, an NF search response message may include data that the AF can provide and information related to one or more NEFs associated with the AF.

[0433] For example, the EASDF may store information from the NEF that can provide EAS overload situation information to the AF based on the NF search response message received.

[0434] For example, the EASDF may send an event subscription message to the NEF requesting notification regarding an EAS overload situation. In this case, the event notification message may be received based on the transmission of the event subscription message.

[0435] In step (S1003), the AF can transmit an event notification message to the EASDF.

[0436] For example, the event notification message may include burrow information, address information of an overloaded EAS, and information related to a UE requiring EAS rescan.

[0437] For example, based on the event notification message, the EASDF may determine edge relocation for the UE. For example, based on the edge relocation decision, the EASDF may transmit a request message of step (S1004).

[0438] For example, based on an event notification message, the EASDF may identify the SMF serving the UE.

[0439] At step (S1004), EASDF may send a request message to SMF.

[0440] For example, the EASDF may send a request message requesting EAS re-discovery to the SMF serving the UE based on an event notification message.

[0441] For example, the request message can be used by the SMF to send a PDU Session Modification Command message to the UE for EAS re-discovery.

[0442] For example, based on the event notification message including information that the AF cannot service the terminal, the request message may include EAS address information and information that the service is unavailable.

[0443] For example, the request message may further include one or more UE information and DNN, S-NSSAI information that require EAS re-discovery.

[0444] In step (S1005), the SMF may transmit a PDU session modification command message to the UE.

[0445] For example, the PDU Session Modification Command message can be used by the UE to perform DNS cache refresh operations and DNS procedures to discover a new EAS.

[0446] For example, the SMF may receive a PDU session modification ack message from the UE.

[0447] The operations proposed in the disclosure of this specification can be performed by the EASDF. The EADSF can perform the operations proposed in the disclosure of this specification for terminals receiving edge computing services through 5GC. The AF can provide information on EAS overload / congestion situations and information on the target using the EAS.

[0448] According to one embodiment of the disclosure of the present specification, an EASDF can subscribe to EAS overload / congestion situation information from an AF. The EASDF can receive information related to the event through an NEF.

[0449] For example, EASDF can query NRF for information provided by AF. EASDF can perform NEF discovery and selection process for AFs that can provide EAS overload / congestion information among AFs that serve terminals that it manages. EASDF can receive EAS overload / congestion information from AFs through NEF.

[0450] For example, SMF can provide AF identifier information required during the NEF discovery and selection process to EASDF during the DNS context creation process.

[0451] For example, EASDF can subscribe / unsubscribe to AF via the above NEF for EAS overload / congestion information.

[0452] For example, EASDF can subscribe / unsubscribe to AF via SMF and NEF for EAS overload / congestion information.

[0453] For example, AF can transmit notification information regarding EASDF subscriptions. Notification information can include EAS address information in overload / congestion situations, address information of terminals using the EAS, and information indicating that the terminal can no longer be serviced.

[0454] For example, the EAS overload / congestion related information can be stored and updated within the EASDF.

[0455] For example, based on the EAS overload / congestion related information, the EASDF can identify the SMFs serving the terminals using the corresponding EAS.

[0456] For example, instead of receiving terminal address information from AF, the EASDF can perform the following actions: Based on the DNS response from the terminal, the EASDF can determine the EAS address currently in use by a specific terminal, and based on the EAS address, it can also create / manage a list of terminals that directly use the EAS that has experienced overload.

[0457] For example, EASDF can decide / request Edge relocation of a terminal based on EAS overload / congestion situation information.

[0458] For example, if EASDF is aware of an overload / congestion situation of an EAS, EASDF can decide / request edge relocation for terminals receiving services from that EAS.

[0459] For example, the EASDF may receive EAS overload / congestion situation information from the AF according to the first example of the disclosure of this specification. Based on the EAS overload / congestion situation information, the EASDF may determine which terminals require EAS rediscovery.

[0460] For example, the EASDF can identify terminals connected to an EAS that are in an overload / congestion situation and the SMFs serving those terminals. The EASF can request EAS re-discovery from those SMFs. This decision can be made based on local configuration or permission / request from the AF.

[0461] For example, in the EAS (re-)discovery procedure of the terminal, the EASDF can update the EAS information to be provided to the terminal.

[0462] For example, EASDF can support EAS (re-)discovery procedure of terminals based on EAS overload / congestion related information.

[0463] For example, the EASDF may be aware of EAS address information in an overload situation. In this case, records in the EAS information received through DNS operations may be updated in the EAS re-discovery procedure of a terminal according to the second example of the disclosure of this specification, or in the EAS discovery procedure of a new terminal.

[0464] For example, when EASDF performs record updates in EAS information provided to the terminal, EASDF can perform the following actions: EASDF can delete EAS information in an overload situation from the record, or change the priority between records.

[0465] For example, the EASDF may receive information from the AF in the first example of the disclosure of this specification indicating that a particular EAS can no longer service terminals. In this case, the EASDF may notify the SMF of the corresponding EAS address information.

[0466] For example, the SMF may receive information from the EASDF about EAS addresses that can no longer service terminals. Based on this information, the SMF may also prevent the terminal from connecting to the corresponding EAS during the new terminal EAS discovery procedure.

[0467] This specification may have various effects.

[0468] For example, in edge computing services, terminal service experience can be improved. Signaling overhead for handling overload situations can be reduced. EAS relocation procedures can be performed efficiently.

[0469] For example, Edge computing services can be effectively supported through 5GC. Information on changes in the load / overload status of an Edge Application Server can directly affect Edge computing services through 5GC. According to the disclosure of this specification, information on changes in the load / overload status of an Edge Application Server can be referenced / managed in an EASDF. Based on the information on changes in the load / overload status, a core network including an EASDF can determine Edge relocation of a terminal and support an EAS re-discovery procedure.

[0470] For example, signaling overhead can be reduced. Specifically, based on subscriptions from the EASDF, information about overload / congestion situations can be efficiently received, rather than dynamically changing EAS-specific loads. For example, terminals can be prevented from connecting to an overloaded EAS, and by performing relocation, requests and procedures for performing edge relocation of terminals from a conventional AF can be reduced.

[0471] For example, EAS overload / congestion related information may be provided by policies / decisions within the AF. For example, EAS overload / congestion related information may be received based on subscriptions from 5GC (particularly EASDF). According to one embodiment of the disclosure of the present specification, information about overload / congestion situations, rather than dynamically changing EAS-specific loads, can be efficiently received, and signaling overhead can be reduced. For example, load information within a server is typically expressed as a percentage and can change very quickly. If an update message is received every time the rapidly changing load information changes, there is a problem of large signaling overhead. Accordingly, in the disclosure of the present specification, overload situation status information, rather than rapidly changing load information, can be received based on policies and / or decisions of the AF / application layer. This can prevent the problem of wasted signaling.

[0472] For example, the EASDF can manage / reference information related to EAS overload / congestion. The EASDF can determine / request an EAS discovery procedure for a terminal based on the EAS load / overload situation. The EASDF can determine / request an edge relocation for a terminal receiving existing edge computing services. This can prevent the terminal from connecting to an EAS in an overload situation in the conventional EAS discovery procedure. Accordingly, requests and procedures for performing edge relocation for the terminal from the AF can be reduced.

[0473] For example, to reduce the burden of information and logic required to support Edge computing from the conventional SMF, the local EASDF can effectively determine and support information management and service procedures.

[0474] The effects that can be achieved through the specific examples of this specification are not limited to the effects listed above. For example, a person with ordinary skill in the relevant technical field may understand or derive various technical effects from this specification. Accordingly, the specific effects of this specification are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of this specification.

[0475] For reference, the operation of the terminal (e.g., UE, terminal) described in this specification can be implemented by the devices of FIGS. 1 to 3 described above. For example, the terminal can be the first device (100) or the second device (200) of FIG. 2. For example, the operation of the terminal described in this specification can be processed by one or more processors (102 or 202). The operation of the terminal described in this specification can be stored in one or more memories (104 or 204) in the form of instructions / programs (e.g., instructions, executable codes) executable by one or more processors (102 or 202). The one or more processors (102 or 202) control one or more memories (104 or 204) and one or more transceivers (105 or 206), and execute the instructions / programs stored in one or more memories (104 or 204) to perform the operation of the terminal (e.g., UE) described in the disclosure of this specification.

[0476] Additionally, the commands for performing the operations of the terminal described in the disclosure of this specification may be stored in a non-volatile computer-readable storage medium. The storage medium may be included in one or more memories (104 or 204). In addition, the commands recorded in the storage medium may be executed by one or more processors (102 or 202) to perform the operations of the terminal described in the disclosure of this specification.

[0477] For reference, the operations of a network node (e.g., AMF, PCF, SMF, UPF, UDM, NEF, AF, NRF, UPF UL CL / BP, UPF L-PSA, UPF PSA, EASDF, DNS server, local DNS resolver, local DNS server, C-DNS, etc.) or a base station (e.g., NG-RAN, gNB, RAN, (R)AN, etc.) described in this specification may be implemented by the devices of FIGS. 1 to 3 described below. For example, the network node or the base station may be the first device (100) or the second device (200) of FIG. 2. For example, the operations of a network node or the base station described in this specification may be processed by one or more processors (102 or 202). The operations of the terminal described in this specification may be stored in one or more memories (104 or 204) in the form of instructions / programs (e.g., instructions, executable codes) executable by one or more processors (102 or 202). The one or more processors (102 or 202) may control one or more memories (104 or 204) and one or more transceivers (106 or 206), and execute instructions / programs stored in one or more memories (104 or 204) to perform the operations of the network node or base station described in the disclosure of this specification.

[0478] Additionally, the instructions for performing the operations of the network node or base station described in the disclosure of this specification may be stored in a non-volatile (or non-transitory) computer-readable storage medium having the instructions recorded thereon. The storage medium may be included in one or more memories (104 or 204). In addition, the instructions recorded in the storage medium may be executed by one or more processors (102 or 202) to perform the operations of the network node or base station described in the disclosure of this specification.

[0479] Although the preferred embodiments have been described above by way of example, the disclosure of this specification is not limited to such specific embodiments, and may be modified, changed, or improved in various forms within the scope described in the spirit and claims of this specification.

[0480] In the exemplary system described above, the methods are described based on a flowchart as a series of steps or blocks. However, the order of the steps described is not limited, and some steps may occur in a different order or simultaneously with other steps described above. Furthermore, those skilled in the art will understand that the steps depicted in the flowchart are not exclusive, and other steps may be included, or one or more steps in the flowchart may be deleted without affecting the scope of the invention.

[0481] The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined to implement a device, and the technical features of the device claims of this specification may be combined to implement a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined to implement a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined to implement a method. Other implementations are within the scope of the claims.

Claims

1. A step of transmitting a Network Function (NF) discovery request message containing information querying information that an Application Function (AF) can provide to the NRF; A step of receiving an NF search response message from the NRF, The above NF search response message includes data that the AF can provide and information related to one or more NEFs associated with the AF; A step of receiving an event notification message from the NEF; The above event notification message includes overload information, address information of the overloaded Edge Application Server (EAS), and information related to the User Equipment (UE) requiring EAS re-discovery; and A step of transmitting a request message requesting EAS re-discovery to a Session Management Function (SMF) serving the UE based on the event notification message, A method characterized in that the above request message is used by the SMF to transmit a PDU session modification command message to the UE for EAS re-discovery.

2. In paragraph 1, Further comprising the step of transmitting an event subscription message requesting notification related to an EAS overload situation to the NEF; A method characterized in that the above event notification message is received based on the transmission of the above event subscription message.

3. In paragraph 1 or 2, A method further comprising the step of storing information of an NEF capable of providing EAS overload situation information of the AF based on the reception of the NF search response message.

4. In any one of paragraphs 1 to 3, Further comprising a step of determining edge relocation for the UE based on the event notification message, A method characterized in that the request message is transmitted based on the edge relocation being determined.

5. In any one of paragraphs 1 to 4, A method characterized in that the request message includes EAS address information and information that the service is unavailable, based on the event notification message including information that the AF cannot service the terminal.

6. In any one of paragraphs 1 to 5, Further comprising a step of identifying an SMF serving the UE based on the event notification message; The above request message is, A method characterized in that it further includes one or more UE information and DNN, S-NSSAI information requiring EAS re-discovery.

7. In any one of paragraphs 1 to 6, A step of receiving a Domain Name System (DNS) context creation request message from a Session Management Function (SMF); and Further comprising the step of transmitting a DNS context creation response message to the SMF, A method characterized in that the above DNS context creation response message includes EAS deployment information received from the AF.

8. One or more transmitters and receivers; one or more processors; and comprising one or more memories capable of storing instructions and being operable to the one or more processors; A device wherein the operation performed based on the command being executed by the one or more processors is a method according to any one of claims 1 to 7.

9. A step of receiving a Protocol Data Unit (PDU) session establishment request message from User Equipment (UE); A step of transmitting a PDU session establishment acceptance message to the UE; A step of receiving a request message requesting Edge Application Server (EAS) re-discovery from an Edge Application Server Discovery Function (EASDF); and A method comprising the step of transmitting a PDU session modification command message including information requesting the EAS re-discovery to the UE.

10. In paragraph 9, Further comprising the step of receiving a PDU session modification ack message from the UE, A method characterized in that the above PDU session modification command message is used by the UE to perform a DNS cache refresh operation and a DNS procedure for searching for a new EAS.

11. In either of paragraphs 9 or 10, A step of transmitting a Domain Name System (DNS) context creation request message to the EASDF; and Further comprising the step of receiving a DNS context creation response message from the EASDF, A method characterized in that the DNS context creation response message includes EAS deployment information provided by the AF to the EASDF.

12. One or more transmitters and receivers; one or more processors; and comprising one or more memories capable of storing instructions and being operable to the one or more processors; A device according to any one of claims 9 to 11, wherein the operation performed based on the above command being executed by the one or more processors.

13. Step of transmitting a Protocol Data Unit (PDU) session establishment request message to the Session Management Function (SMF); A step of receiving a PDU session establishment acceptance message from the SMF; and A method comprising the step of receiving a PDU session modification command message from the SMF, the PDU session modification command message including information requesting the EAS re-discovery.

14. In paragraph 13, A method further comprising the step of performing a DNS cache refresh operation and a DNS procedure for searching for a new EAS based on the information requesting the EAS re-search being received.

15. One or more transmitters and receivers; one or more processors; and comprising one or more memories capable of storing instructions and being operable to the one or more processors; A device wherein the operation performed based on the command being executed by the one or more processors is a method according to any one of claims 13 to 14.

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