Communication based on multi-access session

Abstract

One disclosure of the present specification provides a method. The method may comprise the steps of: transmitting, through 3GPP access, a first registration request message to a first network entity related to mobility; receiving a first registration accept message from the first network entity through the 3GPP access; receiving, from a second network entity related to a policy related to a UE, a URSP rule in which an access type preference is set to dual steer; transmitting, through the 3GPP access, a first PDU session establishment request message related to a MA PDU session to a third network entity related to a session; and transmitting a second PDU session establishment request message through non-3GPP access.

Description

Communication based on multi-access sessions

[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] Scenarios and service requirements for terminals receiving services via two 3GPP access points are being discussed. However, conventional technology has the problem that terminals registering with the network via two 3GPP access points are either not supported or inefficient.

[0006] According to one embodiment of the present disclosure, a method is provided. The method may include: transmitting a first registration request message to a first network entity associated with mobility via a 3GPP access; receiving a first registration acceptance message from the first network entity via the 3GPP access; receiving a URSP rule, in which an access type preference is set to dual-steer, from a second network entity associated with a policy associated with the UE; transmitting a first PDU session establishment request message associated with an MA PDU session to a third network entity associated with the session via the 3GPP access; and transmitting a second PDU session establishment request message via the non-3GPP access.

[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: receiving information related to a first UE from a network entity related to mobility; acquiring subscriber information of the first UE from a UDR; generating a URSP rule in which an access type preference is set to dual-steer based on the subscriber information of the first UE; and transmitting the URSP rule to the first UE.

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

[0010] Figure 1 illustrates an example of a communication system to which the implementation of this specification is applied.

[0011] Figure 2 illustrates an example of a wireless device to which the implementation of the present specification is applied.

[0012] Figure 3 shows an example of a UE to which the implementation of this specification is applied.

[0013] Figure 4 shows an example of a 5G system structure to which the implementation of this specification is applied.

[0014] Figures 5 and 6 illustrate examples of a PDU session establishment procedure to which the implementation of the present specification applies.

[0015] Figure 7 shows an example in which an MA PDU session is created.

[0016] Figure 8 shows an example of applying ATSSS rules to an MA PDU session.

[0017] FIG. 9 is an example of an overlay-underlay architecture according to one embodiment of the disclosure of the present specification.

[0018] FIG. 10A and FIG. 10B illustrate an example of a procedure according to one embodiment of the disclosure of the present specification.

[0019] FIG. 11 illustrates an example of operations according to one embodiment of the disclosure of the present specification.

[0020] The following techniques, devices, and systems can be applied to various wireless multiple access systems. Examples of multiple access systems include Code Division Multiple Access (CDMA) systems, Frequency Division Multiple Access (FDMA) systems, Time Division Multiple Access (TDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, and 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).

[0021] For convenience of explanation, the implementation of this specification is primarily described in relation to a 3GPP-based wireless communication system. However, the technical features of this specification are not limited thereto. For example, the following detailed description is provided based on a mobile communication system corresponding to a 3GPP-based wireless communication system, but aspects of this specification that are not limited to a 3GPP-based wireless communication system can be applied to other mobile communication systems.

[0022] For terms and technologies used in this specification that are not specifically described, reference may be made to wireless communication standard documents published prior to this specification.

[0023] As used herein, "A or B" can mean "only A," "only B," or "both A and B." Alternatively, as used herein, "A or B" can be interpreted as "A and / or B." For example, as used herein, "A, B or C" can mean "only A," "only B," "only C," or "any combination of A, B and C."

[0024] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0025] In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted identically to “at least one of A and B.”

[0026] Additionally, in this specification, “at least one of A, B and C” can mean “only A”, “only B”, “only C”, or “any combination of A, B and C”. Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C”.

[0027] Additionally, parentheses used herein may mean "for example." Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information." In other words, "control information" in this specification is not limited to "PDCCH," and "PDCCH" may be proposed as an example of "control information." Furthermore, even when indicated as "control information (i.e., PDCCH)", "PDCCH" may be proposed as an example of "control information."

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

[0029] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein may be applied to various fields requiring wireless communication and / or connectivity between devices (e.g., 5G).

[0030] Hereinafter, the present specification will be described in more detail with reference to the drawings. In the following drawings and / or description, the same reference numbers may refer to the same or corresponding hardware blocks, software blocks, and / or functional blocks, unless otherwise indicated.

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

[0032] The 5G usage scenario shown in FIG. 1 is only an example, and the technical features of this specification can be applied to other 5G usage scenarios not shown in FIG. 1.

[0033] The three main requirement categories for 5G are (1) enhanced mobile broadband (eMBB), (2) massive machine type communication (mMTC), and (3) ultra-reliable and low latency communications (URLLC).

[0034] Referring to FIG. 1, a communication system (1) includes wireless devices (100a to 100f), a base station (BS; 200), and a network (300). FIG. 1 illustrates a 5G network as an example of a network of the communication system (1), but the implementation of the present disclosure is not limited to a 5G system and can be applied to future communication systems beyond the 5G system.

[0035] The base station (200) and the network (300) may be implemented as wireless devices, and a particular wireless device may operate as a base station / network node in relation to other wireless devices.

[0036] 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.

[0037] In this specification, wireless devices (100a to 100f) may be referred to as user equipment (UE). The UE may include, for example, a mobile phone, a smartphone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a slate PC, a tablet PC, an ultrabook, a vehicle, a vehicle with autonomous driving 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.

[0038] 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).

[0039] 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, at least some of the various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of the present specification.

[0040] 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.

[0041] 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).

[0042] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0043] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a band from 410 MHz to 7125 MHz, as shown in Table 2 below. That is, FR1 may include frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency bands above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 may include unlicensed bands. Unlicensed bands may be used for various purposes, such as for communications for vehicles (e.g., autonomous driving).

[0044] Frequency Range DefinitionFrequency RangeSubcarrier SpacingFR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0045] 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.

[0046] Figure 2 illustrates an example of a wireless device to which the implementation of the present specification is applied.

[0047] 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.

[0048] 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).

[0049] 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).

[0050] 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).

[0051] 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.

[0052] 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.

[0053] 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).

[0054] 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).

[0055] 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).

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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).

[0062] 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).

[0063] 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.

[0064] 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.

[0065] In this specification, a base station may be referred to as a Node B, an eNode B (eNB), or a gNB.

[0066] Figure 3 shows an example of a UE to which the implementation of this specification is applied.

[0067] Referring to FIG. 3, the UE (100) can correspond to the first wireless device (100) of FIG. 2.

[0068] 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).

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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).

[0073] 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).

[0074] 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.

[0075] 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).

[0076] Figure 4 shows an example of a 5G system structure to which the implementation of this specification is applied.

[0077] The 5G system (5GS; 5G system) structure consists of the following network functions (NF; Network Function).

[0078] - AUSF (Authentication Server Function)

[0079] -AMF (Access and Mobility Management Function)

[0080] - DN (Data Network), for example, operator services, Internet access, or third-party services.

[0081] - USDF (Unstructured Data Storage Function)

[0082] - NEF (Network Exposure Function)

[0083] - I-NEF (Intermediate NEF)

[0084] - NRF (Network Repository Function)

[0085] - NSSF (Network Slice Selection Function)

[0086] - PCF (Policy Control Function)

[0087] - SMF (Session Management Function)

[0088] - UDM (Unified Data Management)

[0089] - UDR (Unified Data Repository)

[0090] - UPF (User Plane Function)

[0091] - UCMF (UE radio Capability Management Function)

[0092] - AF (Application Function)

[0093] - UE (User Equipment)

[0094] - (R)AN ((Radio) Access Network)

[0095] - 5G-EIR (5G-Equipment Identity Register)

[0096] - NWDAF (Network Data Analytics Function)

[0097] - CHF (CHarging Function)

[0098] 또한, 다음과 같은 네트워크 기능이 고려될 수 있다.

[0099] - N3IWF (Non-3GPP InterWorking Function)

[0100] - TNGF (Trusted Non-3GPP Gateway Function)

[0101] - W-AGF (Wireline Access Gateway Function)

[0102] 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.

[0103] 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.

[0104] 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.

[0105] The 5G system architecture includes the following benchmarks:

[0106] - N1: Reference point between UE and AMF.

[0107] - N2: Reference point between (R)AN and AMF.

[0108] - N3: Reference point between (R)AN and UPF.

[0109] - N4: Reference point between SMF and UPF.

[0110] - N6: Reference point between UPF and data network.

[0111] - N9: Reference point between two UPFs.

[0112] The following benchmarks illustrate the interactions that exist between NF services in NF.

[0113] - N5: Reference point between PCF and AF.

[0114] - N7: Reference point between SMF and PCF.

[0115] - N8: Reference point between UDM and AMF.

[0116] - N10: Reference point between UDM and SMF.

[0117] - N11: Reference point between AMF and SMF.

[0118] - N12: Reference point between AMF and AUSF.

[0119] - N13: Reference point between UDM and AUSF.

[0120] - N14: Reference point between two AMFs.

[0121] - N15: Reference point between PCF and AMF for non-roaming scenarios, and reference point between PCF and AMF of visited network for roaming scenarios.

[0122] - N16: Reference point between two SMFs (in case of roaming, between the SMF of the visited network and the SMF of the home network)

[0123] - N22: Reference point between AMF and NSSF.

[0124] In some cases, two NFs may need to be interconnected to serve a UE.

[0125] Describes the PDU session establishment procedure. See Section 4.3.2 of 3GPP TS 23.502 V16.3.0 (2019-12).

[0126] Figures 5 and 6 illustrate examples of a PDU session establishment procedure to which the implementation of the present specification applies.

[0127] Establishing a PDU session may involve:

[0128] - UE-initiated PDU session establishment procedure

[0129] - PDU session handover between 3GPP and non-3GPP initiated by UE

[0130] - PDU session handover from UE-initiated EPS to 5GS.

[0131] - Network-triggered PDU session establishment procedure

[0132] 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.

[0133] Figures 5 and 6 specify a procedure for establishing a PDU session associated with a single connection type at a given time.

[0134] 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.

[0135] First, the procedure of Fig. 5 is explained.

[0136] (1) Step 1: To establish a new PDU session, the UE generates a new PDU session ID.

[0137] 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.

[0138] 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."

[0139] 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.

[0140] (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.

[0141] 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.

[0142] 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.

[0143] 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:

[0144] - When the SMF ID and AMF corresponding to the PDU session ID belong to the same PLMN;

[0145] - If the SMF ID corresponding to the PDU session ID belongs to HPLMN;

[0146] Otherwise, AMF rejects the PDU session establishment request with an appropriate rejection cause.

[0147] AMF rejects requests from emergency-registered UEs whose request type does not indicate "Emergency Request" or "Existing Emergency PDU Session".

[0148] (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).

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] (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.

[0154] (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.

[0155] 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.

[0156] 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.

[0157] (6) Step 6: Optional secondary authentication / authorization may be performed.

[0158] (7a) Step 7a: When dynamic policy and charging control (PCC) is used in a PDU session, the SMF can perform PCF selection.

[0159] (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.

[0160] (8) Step 8: SMF selects one or more UPFs.

[0161] (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.

[0162] (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.

[0163] 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.

[0164] (11) Step 11: SMF sends an N1N2 message transfer message (e.g. Namf_Communication_N1N2 Message Transfer) to AMF.

[0165] 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:

[0166] - CN Tunnel Info: Corresponds to the core network address of the N3 tunnel corresponding to the PDU session;

[0167] - QFI (QoS flow ID) corresponding to one or more QoS (quality of service) profiles;

[0168] - PDU Session ID: Indicates to the UE the association between RAN resources and a PDU session for the UE;

[0169] - S-NSSAI with value for serving PLMN (i.e. HPLMN S-NSSAI, or VPLMN S-NSSAI in case of LBO roaming);

[0170] - User plane security enforcement information determined by SMF;

[0171] - 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.

[0172] - RSN (redundancy sequence number) parameter

[0173] 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.

[0174] 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.

[0175] 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.

[0176] (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.

[0177] (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.

[0178] (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.

[0179] If N2 SM information is not included in step 11, steps 14-16b and 17 below are omitted.

[0180] Now, the procedure of Fig. 6 following the procedure of Fig. 5 is described.

[0181] (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.

[0182] (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.

[0183] (16a) Step S16a: SMF initiates the N4 session modification procedure with UPF. SMF provides AN tunnel information and corresponding forwarding rules to UPF.

[0184] (16b) Step S16b: UPF provides an N4 session modification response to SMF.

[0185] After this step, the UPF can forward any DL packets that may have been buffered for this PDU session to the UE.

[0186] (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.

[0187] (17) Step 17: SMF sends an update SM context response message (e.g., Nsmf_PDUSession_UpdateSMContext Response) to AMF.

[0188] After this step, AMF forwards the relevant events to which SMF subscribes.

[0189] (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.

[0190] (19) Step 19: For PDU session type IPv6 or IPv4v6, SMF may generate and send an IPv6 Router Advertisement to the UE.

[0191] (20) Step 20: SMF can perform SM policy association modification initiated by SMF.

[0192] (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.

[0193] <Multi-Access (MA) PDU Session>

[0194] In the prior art, an MA PDU session is a session that can simultaneously provide service to 3GPP access and non-3GPP access using one PDU session.

[0195] Figure 7 shows an example in which an MA PDU session is created.

[0196] The MA PDU session has a separate session tunnel for each access, with one PDU session established over a 3GPP access and the other PDU session established over an untrusted non-3GPP access (e.g., WLAN AN).

[0197] Since it is one session in the above MA-PDU session, the MA PDU session has the following characteristics.

[0198] (i) one DNN;

[0199] (ii) one UPF anchor (UPF-A);

[0200] (iii) one PDU type (e.g., IPv6);

[0201] (iv) one session IP address;

[0202] (v) One SSC mode

[0203] (vi) One HPLMN S-NSSAI.

[0204] The MA-PDU session enables a multipath data link between the UE and UPF-A. This can be implemented below the IP layer.

[0205] A MA-PDU session can be established through one of the following procedures:

[0206] (i) It can be established through two separate PDU session establishment procedures. This is called separate establishment.

[0207] (ii) It can be established through a single MA PDU session establishment procedure. That is, MA PDU sessions are established simultaneously in two accesses with a single session creation request. This is called combined establishment.

[0208] After an MA-PDU session is established, SM (Session Management) signaling related to the MA PDU session can be transmitted and received through arbitrary access.

[0209] A. Individual establishment of MA PDU sessions

[0210] An MA PDU session can be established through two separate PDU session establishment procedures. For example, a UE can establish an MA PDU session on a 3GPP access, and then perform a PDU session establishment procedure on a non-3GPP access to add a non-3GPP access to the MA PDU session established on the 3GPP access. The request type in the establishment request message for adding the second access can be set to “MA PDU Request.”

[0211] B. Establishment of a bond

[0212] MA PDU sessions can be established simultaneously for 3GPP access and non-3GPP access through a single procedure. This single procedure can be called a UE-requested MA PDU session establishment procedure. This procedure can be useful when a UE wishes to establish an MA PDU session while the UE is already registered to 5GC through two accesses. Instead of performing two separate PDU session establishment procedures, the UE can establish an MA PDU session by performing a single MA PDU session establishment procedure.

[0213] Figure 8 shows an example of applying ATSSS rules to an MA PDU session.

[0214] Referring to FIG. 8, when an SMF wants to move an IP flow transmitted over a non-3GPP access to a 3GPP access while a MA (multi-access) PDU session is established, an updated ATSSS (Access Traffic Steering, Switching and Splitting) rule can be transmitted through the 3GPP access.

[0215] A concrete example of the MA PDU session establishment procedure is described. 3GPP TS 23.502 V18.4.0 S4.22.2 can be referenced.

[0216] For example, for non-roaming or roaming via local breakout, the MA PDU session establishment procedure may be performed as in the following example.

[0217] The signal flow of MA PDU session setup when the UE is not roaming or when the UE is roaming and the PDU Session Anchor (PSA) is located in the VPLMN is based on the examples of FIGS. 5 and 6, with the following differences and explanations:

[0218] - The UE can transmit the PDU Session Establishment Request message over 3GPP access or non-3GPP access. In the steps below, unless otherwise specified, it is assumed that the PDU Session Establishment Request message is transmitted over 3GPP access.

[0219] - In step 1 of FIGS. 5 and 6, the UE may provide the request type in the UL NAS transmission message as “MA PDU request” and include the ATSSS function in the PDU session establishment request message.

[0220] The "MA PDU Request" request type in a UL NAS transport message can inform the network that this PDU session establishment request is to establish a new MA PDU session and apply one or more steering functions (e.g., see TS 23.501 V 18.4.0 clause 5.32.6) to steer the traffic of this MA PDU session over multiple accesses.

[0221] If a UE requests S-NSSAI and the UE is registered for both accesses, the UE must request an S-NSSAI that is allowed for both accesses.

[0222] The UE may inform the AMF whether it supports non-3GPP access path switching (e.g., whether the UE can switch the non-3GPP access path of a MA PDU session from a source non-3GPP connection (N3IWF / TNGF) to a target non-3GPP connection (another N3IWF / TNGF)).

[0223] - In step 2 of FIGS. 5 and 6, if the AMF supports MA PDU sessions, the AMF may select an SMF that supports MA PDU sessions. If the AMF supports non-3GPP access path switching and the UE indicated in step 1 that it supports non-3GPP access path switching, the AMF may select an SMF that supports non-3GPP access path switching if an SMF is available.

[0224] - In step 3 of FIGS. 5 and 6, the AMF may indicate to the SMF that the request is for a MA PDU session by including an "MA PDU request" indication. Additionally, the AMF may indicate to the SMF whether the UE is registered over both connections. If the UE is registered over both accesses but the requested S-NSSAI is not allowed over both accesses, the AMF may reject the MA PDU session establishment. If the AMF supports non-3GPP access path switching while maintaining two N2 connections for non-3GPP access, and the selected SMF supports non-3GPP path switching and the UE indicated in step 1 that it supports non-3GPP access path switching, the AMF may indicate to the SMF whether the UE supports non-3GPP path switching.

[0225] AMF may reject a PDU session setup request if the request is for a LADN.

[0226] - In step 4 of FIGS. 5 and 6, the SMF can retrieve information on whether the MA PDU session is allowed through session management subscription data.

[0227] - In step 7 of FIGS. 5 and 6, if dynamic PCC is used for the MA PDU session, the SMF may send the "MA PDU Request" indication to the PCF in the SM Policy Control Create message and transmit the ATSSS function of the MA PDU session. The SMF provides the PCF with the currently used access type and RAT type. The PCF determines whether to allow the MA PDU session based on the operator policy and subscription data.

[0228] The PCF can provide PCC rules containing MA PDU session control information. From the received PCC rules, the SMF can derive (a) ATSSS rules to be transmitted to the UE for uplink traffic steering, switching, and splitting control, and (b) N4 rules to be transmitted to the UPF for downlink traffic steering, switching, and splitting control. If the UE indicates that it supports "ATSSS-LL function", the SMF can derive measurement assistance information.

[0229] - The remaining steps in Figures 5 and 6 allow the SMF to establish user plane resources over the 3GPP connection, i.e. the connection over which the PDU session setup request was sent:

[0230] - In step 10 of FIG. 5 and FIG. 6, the N4 rule for the MA PDU session derived by the SMF is transmitted to the UPF, and two N3 UL CN tunnel informations are allocated by the UPF. If the ATSSS LL function is supported for the MA PDU session, the SMF may instruct the UPF to start performance measurement for this MA PDU session.

[0231] - In step 11 of FIGS. 5 and 6, for a MA PDU session, the SMF includes an "MA PDU Session Accepted" indication in the Namf_Communication_N1N2MessageTransfer message transmitted to the AMF, and informs the AMF that the N2 SM information included in this message should be transmitted over a 3GPP connection. The AMF marks this PDU session as an MA PDU session based on the received "MA PDU Session Accepted" indication. If the AMF indicated in step 3 that it supports non-3GPP path switching while maintaining two N2 connections for a non-3GPP connection, the SMF indicates that it supports non-3GPP path switching in the PDU Session Setup Accept message.

[0232] - In step 13, the UE receives a PDU Session Establishment Accept message indicating that the requested MA PDU session has been successfully established. This message includes the ATSSS rules for the MA PDU session derived by the SMF.

[0233] - After step 18 of FIGS. 5 and 6, if the SMF is informed in step 2 that the UE is registered via both connections, the SMF also starts configuring user plane resources via the non-3GPP connection. The SMF sends Namf_Communication_N1N2MessageTransfer containing the N2 SM information to the AMF and informs the AMF that the N2 SM information should be transmitted via the non-3GPP connection. The Namf_Communication_N1N2MessageTransfer does not contain the N1 SM container for the UE because it was sent to the UE in step 13. After this step, two N3 tunnels between the PSA and the RAN / AN are established.

[0234] The last step above is not executed if the UE is registered via only one access, in which case the MA PDU session is established with user plane resources via only one access. The method for adding user plane resources to the access of an MA PDU session is specified in Section 4.22.7.

[0235] Describes an example of adding user plane resources. 3GPP TS 23.502 V18.4.0 S4.22.7 can be referenced.

[0236] If the UE establishes an MA PDU session but no user plane resources are set up for one access of the MA PDU session, the following explanation may apply:

[0237] - When the UE wants to add a user plane resource through an access, the UE initiates a UE request PDU session establishment procedure through this access, according to the examples of FIGS. 5 and 6. The UE may set the request type to "MA PDU request" in the UL NAS transmission message and set the same PDU session ID as the already established MA PDU session.

[0238] - The PDU Session Setup Accept message received by the UE may include updated ATSSS rules for the MA PDU session.

[0239] - If the SMF receives a PDU Session Establishment Request message through an access and the SMF already has an SM context for that access, the SMF may send a PDU Session Establishment Accept message to the UE while reactivating user plane resources through that access without releasing the existing SM context.

[0240] Regarding multi-access, discussions are ongoing regarding steering, switching, and splitting UE traffic across two 3GPP access links. For example, the following objectives are being discussed (SP-231802: SID for Study on Multi-Access (DualSteer and ATSSS_Ph4) - FS_MASSS), and the use cases and service requirements are described, for example, in TR 22.841 V19.0.0 "Study on Upper layer traffic steer, switch, and split over dual 3GPP access."

[0241] Note that solutions related to dual steer should not impact VPLMNs and / or HPLMNs that do not support dual steer related features.

[0242] #1: Investigate overall architectural and functional enhancements to 5GS to support dual-steer devices (e.g., DualSteer Devices) (see TS 22.261 for the definition of a DualSteer Device). A DualSteer Device can support traffic steering and switching of user data (for different services) across two 3GPP access networks. A DualSteer Device may comprise (a) a single UE for non-simultaneous data transmission over both networks, or (b) two separate UEs for simultaneous data transmission over both networks. A subscriber of a DualSteer Device may have two subscriptions / SUPIs from the same operator, sharing a single subscription profile. For a particular service, a DualSteer Device shall transmit all traffic for that service using only a single 3GPP access network at any given time.

[0243] The following scenarios may be considered:

[0244] 1. When there are two NR / 5GC accesses in a single PLMN (HPLMN or VPLMN), and each access is an NR Terrestrial Network (TN) or an NR Non-Terrestrial Network (NTN);

[0245] 2. Two NR / 5GC accesses (each access being an NR TN or NR NTN) in two different PLMNs (two VPLMNs or a VPLMN and an HPLMN);

[0246] 3. NR / 5GC access and E-UTRA / EPC access in two different PLMNs (including two VPLMNs or a VPLMN and an HPLMN);

[0247] 4. NR / 5GC access and E-UTRA / EPC access in a single PLMN (HPLMN or VPLMN);

[0248] 5. PNI-NPN (PNI-NPN integrated with HPLMN or PNI-NPN integrated with VPLMN) and PLMN access (TN / NTN to TN or NTN). This scenario assumes only asynchronous transmission.

[0249] Note that each subscription / Subscription Permanent Identifier (SUPI) of a Dual-Steer device can only be used to connect to one of the 3GPP accesses at any given time.

[0250] #1.1: For each of the above scenarios, whether and how to improve the subscription aspect could be studied.

[0251] #1.2: It may be studied whether this affects the dual-steer device registration process.

[0252] #1.3: Session Management Improvements and Policies:

[0253] - To support dual-steer devices, whether and how to improve the network policy provided by HPLMN within the dual-steer devices and network may be studied.

[0254] - Whether and how to improve session management procedures for initial steering and potential subsequent switching can be studied. Traffic policy is entirely controlled by the HPLMN. For sessions potentially subject to switching, data anchoring can be assumed in the HPLMN, or in the case of PNI-NPNs and PLMNs, data anchoring can be assumed in the PNI-NPN. Methods for selecting the PSA UPF in the HPLMN can be studied to ensure that traffic across 3GPP accesses is routed to the same PSA UPF during switching.

[0255] Referring to the use case examples of TR 22.841 V1.1.0, a UE may be provided with services via two 3GPP accesses (or 3GPP access links). For example, a UE may be provided with services from two 3GPP accesses connected to one CN (Core Network) (or may be provided with services from two 3GPP accesses belonging to the same network). Alternatively, a UE may be provided with services from two 3GPP accesses connected to different CNs (or may be provided with services from two 3GPP accesses belonging to different networks). In addition, the networks may be PLMNs or NPNs.

[0256] And, for some services, traffic may be steered, switched, and split through a PDU Session formed through two 3GPP accesses. Here, this PDU Session may be referred to as a Multi-Access (MA) PDU Session. In the prior art, an MA PDU Session was established through a 3GPP access and a non-3GPP access, but in the disclosure of this specification, a PDU Session may be established through two 3GPP accesses.

[0257] For some services, traffic may be transmitted through a PDU Session established via a single 3GPP access.

[0258] DualSteer devices are being discussed. It is assumed that a single DualSteer device has two subscriptions / SUPIs from the same operator. Accordingly, a terminal can perform registration through each of the two subscriptions, each with its own 3GPP access.

[0259] In the prior art, a UE with a single subscription registered with only one 5G CN for 3GPP access. However, to receive services through two 3GPP accesses, a UE (e.g., a dual-steer device) may need to register with two 5G Core networks (CNs). Furthermore, to receive services through two 3GPP accesses, a UE (e.g., a dual-steer device) may need to register separately for each 3GPP access within a single 5G CN.

[0260] Additionally, since dual-steer devices use different subscriptions for each of the two 3GPP accesses, a method is needed for the network to support MA PDU sessions using two subscriptions to perform traffic switching / steering.

[0261] In the disclosure of this specification, various examples are described for supporting a dual-steer device to perform communications based on two 3GPP accesses. For example, an example is described for supporting traffic control for a PDU session of a dual-steer device using two subscriptions.

[0262] According to various examples of the disclosure of this specification, a method for creating (or establishing) a PDU session based on dual 3GPP access comprises a combination of one or more of the operations / configurations / steps described below.

[0263] In this specification, UE (User Equipment) and terminal may be used as terms with the same meaning.

[0264] In this specification, the terms “Subscriber” and “User” may be used interchangeably.

[0265] In this specification, Application Function (AF) and Application Server (AS) may be used as terms with the same meaning.

[0266] The methods presented below may be performed or used in combination or complementary manner.

[0267] In the disclosure of this specification, Multi-Access (MA) PDU Session may be used as a term having the same meaning as Dual-Access (DA) PDU Session, Dual Steer (DS) PDU Session, Dual Steering PDU Session, Dual 3GPP Access (MA) PDU Session, Multi 3GPP Access PDU Session, etc. In addition, in various examples of the disclosure of this specification, this MA PDU session may mean "A PDU Session that provides a PDU connectivity service, which can use one 3GPP access network at a time, or simultaneously two 3GPP access networks."

[0268] In the explanation below, PLMN can be interpreted as SNPN, Equivalent PLMN, etc., and SNPN can be interpreted as PLMN.

[0269] An example of supporting DualSteer using an overlay-underlay architecture is described.

[0270] A dual-steer device may include two SUPIs (i.e., two USIMs) and Permanent Equipment Identifiers (PEIs) corresponding to each SUPI. The dual-steer device can register with the network via two 3GPP access points, using each SUPI and its corresponding PEI.

[0271] The PCF can provide the UE with enhanced URSP rules. For example, the URSP rules may include a Route Selection Descriptor (RSD), which may include DualSteer preference information. The DualSteer preference information may be, for example, an Access Type preference set to "DualSteer."

[0272] The PCF can generate a "DualSteer" preference based on the UE context policy control subscription information retrieved from the UDR. To support this, the UE can indicate capabilities related to enhanced URSP rules within a policy container during the registration procedure. For example, the UE can transmit a registration request message containing a policy container that includes capabilities related to enhanced URSP.

[0273] As another example, instead of PCF using the Access Type preference of the URSP rule to indicate that DualSteer is required, it could create a new Route Selection Descriptor (RSD) and add information indicating that DualSteer is required.

[0274] Furthermore, regardless of whether the terminal includes enhanced URSP capability in the policy container, the PCF can include DualSteer-related information in the URSP rule. In this case, for backward compatibility, the PCF can generate a URSP rule that includes both RSDs containing DualSteer-related information and RSDs without DualSteer information. Furthermore, the PCF can configure the RSDs so that the RSDs containing DualSteer information have a higher priority than the RSDs without DualSteer information.

[0275] The PCF may reference subscriber information according to an example in Table 3. The example in Table 3 may include dual steering information according to an embodiment of the disclosure of the present specification.

[0276] Information Name Description Category Subscriber Category List of category identifiers associated with the subscriber Optional Tracing Requirements Tracing requirements defined in TS 32.421 V18.1.0 Optional PEI Permanent Equipment Identifier of the UE Optional OS Identifies the operating system supported by the UE Optional ANDSP Indication Indicates UE support for ANDSP Optional URSP Provisioning Support Indication in EPS Indicates UE support for URSP provisioning in EPS Optional S-NSSAI Subscription Information Contains a list of subscribed S-NSSAIs and a list of subscribed DNNs associated with the S-NSSAIs. For each DNN, it contains the allowed PDU session types, allowed SSC modes, LBO roaming allowance indication, ATSSS information (NOTE 1) and dual steer information (NOTE 3). Optional Subscriber Spend Limit Management Indicates whether the PCF should enforce UE policies according to subscriber spend limits. Optional CHF Address The address of the Charging Function and optionally the associated CHF instance ID and CHF set ID (see clause 6.3.1.0 of TS 23.501 [2]). The address of the Charging Function and optionally the associated CHF instance ID and CHF set ID (see clause 6.3.1.0 of TS 23.501 V18.4.0). Optional Subscriber Spend Limit Identifier and Status of Policy Counters A list of spend limit identifiers and status of policy counters.Optional Restricted Status Indicates that the UE has a status of Restricted, accompanied by a reason and a timestamp at which this status was stored (NOTE 2). OptionalNOTE 1: The ATSSS information is defined in TS 23.502 V18.4.0 Table 5.2.3.3.1-1 and indicates whether MA PDU session establishment is permitted. NOTE 2: The accompanying reason is according to the exception ID defined in TS 23.288 V18.4.0 Table 6.7.5.1-1, e.g. Unexpected UE location. NOTE 3: The DualSteer information indicates whether MA PDU session establishment is permitted using the overlay-underlay architecture.

[0277] Table 3 is an example of UE context policy control subscription information according to one embodiment of the disclosure of this specification.

[0278] For example, the PCF can retrieve UE context policy control subscription information from the UDR, such as the example in Table 3. Based on the UE context policy control subscription information, the PCF can set the access type preference of the path selection descriptor (RSD) included in the URSP rule to “DualSteer” or generate an RSD containing information related to DualSteer.

[0279] PCF can transmit URSP rules to dual steer devices.

[0280] For example, a dual-steer device can use an overlay-underlay architecture based on the received URSP rules. It can establish a MA PDU session to use dual 3GPP access, as shown in Figure 9 below. A dual-steer device can include two UEs (e.g., UE#1 and UE#2). The dual-steer device can perform the following actions:

[0281] - For example, UE#1 can register to 5GC via NG-RAN#1.

[0282] - UE#2 can register to 5GC via NG-RAN#2 and establish a PDU session to provide underlay network to UE#1.

[0283] - UE#1 can select N3IWF and register to 5GC through the underlay network provided by PDU Session of UE#2.

[0284] For reference, even if an operation according to an embodiment of the disclosure of the present specification is applied, the N3IWF selection operation of UE#1 is not affected. The PDU session of UE#2 may be used exclusively for UE#1 to provide connectivity to UE#1 (e.g., using a dedicated DNN / S-NSSAI for the PDU session providing connectivity to N3IWF).

[0285] - UE#1 can establish a multi-access PDU session through NG-RAN#1 and N3IWF via the underlay network.

[0286] The network can also configure the UE (UE#2) used as the underlay network to prevent it from using other general services. For example, the subscriber information of the UE (UE#2) used as the underlay network can be configured to only allow PDU sessions that can be connected to the N3IWF. In other words, the network can prevent UE#2 from using other services by forcing it to use only a specific DNN / S-NSSAI.

[0287] In addition, the subscriber information of UE#2 may include information for operating as an underlay network for the PDU Session provided by UE#2. For example, information indicating that the DNN / S-NSSAI used in the PDU Session is used for the underlay network (or the PDU Session providing connectivity for DualSteer support) may be stored in the subscriber information of UE#2. This may be stored in the subscriber information of UE#2 in the UDR as "S-NSSAI subscription information." When the PCF of UE#2 obtains the subscriber information of UE#2 and generates a URSP rule, the PCF may include information indicating that the PDU Session is used for the underlay network in the Traffic Descriptor. For example, the connection capability of the Traffic Descriptor may include information indicating that the PDU Session is for underlay. For example, based on the information indicating that the PDU Session is for underlay, UE#2 may generate a PDU Session for UE#1.

[0288] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals, messages, and fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0289] FIG. 9 is an example of an overlay-underlay architecture according to one embodiment of the disclosure of the present specification.

[0290] According to FIG. 9, an example of an overlay-underlay architecture to support dual steering is shown.

[0291] According to the example of FIG. 9, UE#2 can register with 5GC via NG-RAN#2 and establish a PDU session to provide the underlay network to UE#1. UE#1 can connect to N3IWF of UE#1 using PDU session of UE#2.

[0292] UE#1 can establish a multi-access PDU session based on N3IWF via NG-RAN#1 and the underlay network.

[0293] The SMF of the MA PDU session (e.g., the SMF of the overlay network) is unaware that the access leg via the non-3GPP access is configured for dual-steer. To inform the SMF that the non-3GPP access leg is used for dual-steer, when the UE establishes the MA PDU session via the N3IWF, the UE may transmit a PDU Session Establishment Request message with information related to dual-steer (e.g., a dual-steer indication). For example, the PDU Session Establishment Request message may include information related to dual-steer, or the PDU Session Establishment Request message may be transmitted together with information related to dual-steer. This information is reported to the PCF, which may update the PCC rules to prevent traffic splitting over the dual 3GPP access. Alternatively, the operator may configure the network to use DualSteer only for certain DNN and S-NSSAI combinations, allowing the network to enforce the DualSteer policy without any indication from the UE.

[0294] For another example, based on the IP address information that a terminal (e.g., UE#1 of a dual-steer device) uses to access the N3IWF, the SMF can determine that the terminal accessed via the underlay network. According to the prior art, when a terminal accesses via the N3IWF and sends a PDU Session Establishment message to the SMF, the N3IWF transmits ULI information to the SMF. In this case, the N3IWF transmits the IP address / port information that the terminal used to access the N3IWF to the SMF. Based on the IP address / port information, if the IP address is an IP used in 5GC, the SMF can determine that the terminal accessed via the underlay network. Based on the fact that the operator has set specific IP address range information in the SMF in advance, the SMF can determine that the IP address is an IP used in 5GC. Based on this information, the SMF can recognize that the terminal accessed via the underlay network, and the SMF can notify the PCF that the terminal accessed via the underlay network. Based on this, PCF can set PCC rules to prevent traffic splitting through dual 3GPP access. For example, only steering modes that allow transmission in only one direction at a time, such as Active-Standby mode, can be set.

[0295] If the dual-steer device wants to use actual non-3GPP access, UE#1 of the dual-steer device can trigger a non-3GPP path switching procedure as described in section 4.22.9.5 of TS 23.502 or MOBIKE according to IETF RFC 4555.

[0296] When a dual-steer device registers on the same network via two 3GPP access points (i.e., the overlay network and underlay network are the same network), the dual-steer device may receive service from the same cell. To avoid this situation, the operator can configure different RFSP Index values ​​in the subscription data of UE#1 and UE#2.

[0297] For another example, instead of UE#1 connecting via N3IWF, the UE can use the conclusion of KI#2.2 of TR 23.700-54 V0.1.0 to connect directly to UPF. For example, UE#1 can directly create UPF and IPsec tunnel, or if using high layer functionality, create MPQUIC connection directly over UPF. In this case, the UE can signal that it will connect to non-3GPP access via 3GPP access via MA PDU Session creation or via PDU Session modification procedure. Also, instead of signaling that it will connect to non-3GPP access via 3GPP access via underlay network, the UE can signal it via non-3GPP access. For example, when creating an IPsec tunnel, the UE can signal that it will connect to non-3GPP access via underlay network via IKE signaling. Alternatively, the terminal can transmit relevant information to the user plane via PMF messages. When information is transmitted through the UPF, such as IKE signaling or PMF, the UPF can notify the SMF.

[0298] According to one embodiment of the disclosure of the present specification, during the registration procedure, the UE may indicate the functionality of the enhanced URSP rules in the policy container.

[0299] For MA PDU session establishment, the following may apply:

[0300] - When a UE establishes a MA PDU session over a non-3GPP access over an underlay network with 3GPP access, the UE may indicate that the MA PDU session request is for dual steering.

[0301] - SMF can report dual steering indications to PCF.

[0302] The UE may support enhanced URSP rules indicating dual-steer preference.

[0303] When a UE establishes a MA PDU session over a non-3GPP access over an underlay network with 3GPP access, the UE may indicate DualSteer.

[0304] SMF can report dual-steer indications to PCF.

[0305] PCF can support enhanced URSP rules indicating dual-steer preference.

[0306] Based on the dual-steer indication from SMF, PCF can update PCC rules to prevent traffic splitting for dual 3GPP access.

[0307] UDR can indicate whether dual-steer is preferred by updating UE context policy control subscriber information.

[0308] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals, messages, and fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0309] FIG. 10A and FIG. 10B illustrate an example of a procedure according to one embodiment of the disclosure of the present specification.

[0310] A dualsteer device may include UE#1 and UE#2.

[0311] In the examples of FIGS. 10A and 10B , AMF#1, SMF#1, UE PCF#1, SM PCF#1, and N3IWF#1 may be network entities included in an overlay network. AMF#2, SMF#2, and UPF#2 may be network entities included in an underlay network. Note that although UE PCF#1 and SM PCF#1 are independently depicted in the examples of FIGS. 10A and 10B , this is merely an example, and UE PCF#1 and SM PCF#1 may also be included in a single PCF (e.g., PCF#1).

[0312] 1. UE#1 can send a registration request message to AMF#1.

[0313] For example, UE#1 can send a Registration Request message to AMF#1 to connect to the overlay network. During this process, UE#1 can announce that it supports URSP rules related to DualSteer. For example, UE#1 can include capability information (e.g., capabilities related to DualSteer, and / or URSP related to DualSteer) in the Registration Request message. For example, UE#1 can include capability information in the Registration Request message, and / or UE#1 can include capability information in a transparent UE Policy Container included in the Registration Request.

[0314] 2. AMF#1 can send a Registration Accept message to UE#1.

[0315] 3. UE#1 and PCF (e.g., UE PCF#1) can perform actions related to UE policy update.

[0316] Note that although step 3 in FIGS. 10A and 10B is depicted as being performed after step 2, this is merely an example. Step 3 may be performed at any point in time, not just after step 2. For example, step 3 may be performed after step 1 but before step 2.

[0317] UE PCF#1 can transmit the URSP rule for DualSteer to the terminal. For example, UE PCF#1 can transmit the URSP rule for DualSteer to UE#1. For example, based on the capability information provided by UE#1 in step 1, UE PCF#1 can transmit the URSP rule for DualSteer to UE#1.

[0318] 4. UE#1 can send a PDU session establishment request message to SMF#1.

[0319] For example, based on the URSP rule received in step 3 having access type preference = DualSteer set, UE#1 can create (or establish) an MA PDU session. To do this, UE#1 can request the creation of an MA PDU session by sending a PDU Session Establishment Request message.

[0320] For example, UE#1 can send a NAS message including a request type and a PDU session establishment request message to AMF#1, and AMF#1 can send a request type and a PDU session establishment request message to SMF#1. Here, the request type can be set to “MA PDU Request.”

[0321] 5. SMF#1 creates an SM Policy Association with SM PCF#1, and SMF#1 can receive PCC rules for MA PDU sessions from SM PCF#1.

[0322] 6. SMF#1 can send a PDU Session Establishment Accept message to UE#1.

[0323] For example, SMF#1 can generate an ATSSS rule based on the PCC rule provided by SM PCF#1. SMF#1 can send a PDU Session Establishment Acceptance message including the ATSSS rule to UE#1.

[0324] 7. UE#2 can send a Registration Request message to AMF#2 to connect to the underlay network.

[0325] 8. AMF#2 can send a Registration Accept message to UE#2.

[0326] 9. UE#2 can send a PDU Session Establishment Request message to SMF#2 to create a PDU session for UE#1.

[0327] 10. SMF#2 can send a PDU Session Establishment Accept message to UE#2.

[0328] 11. For example, UE#1 can select N3IWF#1 of the overlay network using the PDU session created by UE#2 and transmit a Registration Request message to perform a registration procedure through non-3GPP access to the overlay network.

[0329] Here, the PDU session created by UE#2 is established in the underlay network based on 3GPP access, but UE#1 and / or the overlay network can utilize the connection based on UE#2's PDU session as a non-3GPP access.

[0330] 12. AMF#1 can send a Registration Accept message to UE#1 allowing registration for non-3GPP access.

[0331] 13. UE#1 can send a PDU session establishment request message to SMF#1 using the PDU session of UE#2.

[0332] For example, UE#1 can transmit a PDU Session Establishment Request message to create a user plane through non-3GPP access for the MA PDU session created through steps 4 to 6. At this time, UE#1 can transmit the PDU Session Establishment Request message using the same PDU Session ID, DNN, S-NSSAI, etc. used in steps 4 to 6. For detailed process, the conventional MA PDU session creation process can be referenced. For example, 3GPP TS 23.502 V18.4.0 can be referenced. In addition, UE#1 can transmit information related to dual-steer (e.g., an indication indicating that it is an operation for DualSteer) together with the PDU Session Establishment Request message, or include information related to dual-steer in the PDU Session Establishment Request message.

[0333] 14. SMF#1 can perform SM PCF#1 and SM Policy Association modifications.

[0334] For example, SMF#1 can transmit information to SM PCF#1 that the terminal operates in DualSteer mode based on the information related to dual steering received from UE#1 in step 13. SF PCF#1 can set a PCC rule to not split traffic based on this information. For example, SM PCF#1 can set a PCC rule to not use a steering mode that transmits traffic using both accesses, such as Load-Balancing steering mode or Priority-based steering mode.

[0335] 15. SMF#1 can send a PDU Session Establishment Acceptance message to UE#1.

[0336] For example, SMF#1 can generate an ATSSS rule to be transmitted to the UE based on the PCC rule received from SM PCF#1. SMF can then send a PDU Session Establishment Accept message containing the ATSSS rule to UE#1. Additionally, SMF#1 can generate an N4 rule based on the PCC rule, and SMF#1 can transmit the N4 rule to the UPF.

[0337] Hereinafter, with reference to FIG. 11, an example of operations according to an embodiment of the disclosure of the present specification is described. The example of FIG. 11 may include operations based on an example including at least one of Examples 1 to 6 of the disclosure of the present specification.

[0338] The following drawings are intended to illustrate specific examples of the present specification. The names of specific devices and the names of specific signals, messages, and fields depicted in the drawings are provided for illustrative purposes only, and the technical features of this specification are not limited to the specific names used in the drawings.

[0339] FIG. 11 illustrates an example of operations according to one embodiment of the disclosure of the present specification.

[0340] For reference, the procedure illustrated in FIG. 11 is merely an example, and the scope of the disclosure of this specification is not limited by the example in FIG. 11.

[0341] For example, with respect to the example of FIG. 11, the operations described in the examples of FIGS. 1 to 10b may also be applied. For example, even if operations, contents, etc. are not directly described in the example of FIG. 11, operations, contents, etc. described in various examples of the disclosure of this specification may be applied.

[0342] The operations illustrated in FIG. 11 are merely examples, and the scope of the disclosure of this specification is not limited to the operations illustrated in FIG. 11.

[0343] In the example of FIG. 11, the first to fourth network entities may be network entities included in an overlay network. For example, the first network entity may be a network entity related to mobility (e.g., AMF). For example, the second network entity may be a network entity related to policies related to the UE (e.g., UE PCF). For example, the third network entity may be a network entity related to a session (e.g., SMF). For example, the fourth network entity may be a network entity related to non-3GPP access (e.g., N3IWF).

[0344] For reference, although not illustrated in FIG. 11, an example of the operation of a fifth network entity may be described below. The fifth network entity may be a network entity (e.g., SM PCF) involved in a policy related to the session.

[0345] In step (S1101), the first UE may transmit a registration request message to the first network entity. For example, the first UE may transmit the registration request message to the first network entity via 3GPP access.

[0346] For example, a registration request message may include capability information related to supporting URSP rules related to dual steer.

[0347] After step (S1101) is performed, the first network entity can transmit information related to the first UE to the second network entity. In this case, the second network entity can obtain subscriber information of the first UE from the Unified Data Repository (UDR). For example, the second network entity can generate a URSP rule in which the access type preference is set to the dual-steer based on the subscriber information of the first UE. The second network entity can transmit the generated URSP rule to the first UE.

[0348] For example, the second network entity may transmit a URSP rule with an access type preference set to dual-steer to the first UE based on capability information related to supporting URSP rules related to dual-steer and / or subscriber information of the first UE.

[0349] In step (S1102), the first network entity may transmit a registration acceptance message to the first UE. For example, the first UE may receive the registration acceptance message from the first network entity via 3GPP access.

[0350] At step (S1103), the second network entity may transmit the URSP rule to the first UE.

[0351] For example, a URSP rule may include an access type preference. The access type preference may be set to dual-steer by a second network entity.

[0352] In step (S1104), the first UE may transmit a PDU session establishment request message to a third network entity. For example, the first UE may transmit the PDU session establishment request message to the third network entity via 3GPP access.

[0353] For example, the PDU session establishment request message of step (S1104) may be a request message for establishing an MA PDU session.

[0354] Before step (S1105) is performed, the first UE may perform an operation for registering for non-3GPP access. For example, the first UE may transmit a second registration request message via the non-3GPP access. In this case, when the first UE transmits the second registration request message to the fourth network entity, the fourth network entity may transmit the registration request message to the first network entity. For example, the first UE may receive a second registration acceptance message via the non-3GPP access.

[0355] In step (S1105), the first UE may transmit a second PDU session establishment request message via non-3GPP access. For example, when the first UE transmits a PDU session establishment request message via non-3GPP access, the fourth network entity may transmit the PDU session establishment request message to the third network entity.

[0356] For example, a first UE may transmit a PDU session establishment request message of step (S1105) to create a user plane via non-3GPP access for an MA PDU session.

[0357] In the example of FIG. 11, the non-3GPP access may be based on a PDU session established by a second UE included in the dual-steer device. For example, the first UE may transmit or receive signals via the non-3GPP access based on a PDU session established by the second UE.

[0358] For example, based on subscriber information of the second UE, the PDU session of the second UE can be used to provide connectivity for dual-steer support to the first UE.

[0359] For example, the second UE may perform the following actions before establishing the PDU session. For example, the second UE may transmit a registration request message to the AMF of the underlay network. For example, the second UE may receive a registration acceptance message from the AMF of the underlay network. For example, the second UE may transmit a PDU session establishment request message related to the PDU session to the SMF of the underlay network. For example, the second UE may receive a PDU session establishment acceptance message related to the PDU session from the SMF of the underlay network.

[0360] For example, a second PDU session establishment request message may be transmitted together with information related to the MA PDU request and information related to dual steering. For example, a second PDU session establishment request message may include information related to the MA PDU request and information related to dual steering, or an NAS message may be transmitted that includes the second PDU session establishment request message, information related to the MA PDU request, and information related to dual steering.

[0361] For example, the third network entity may transmit information related to dual-steer to the fifth network entity. For example, the information related to dual-steer may cause the fifth network entity to update (or generate) a PCC rule so that traffic for one service is transmitted over one 3GPP access for the first UE. For example, the third network entity may forward information related to dual-steer received from the first UE to the fifth network entity, or may transmit information related to the first UE performing an operation related to dual-steer to the fifth network entity.

[0362] For example, based on information related to dual-steer, a fifth network entity may update (or generate) a PCC rule, with respect to a first UE, such that traffic for one service is transmitted over one 3GPP access. The fifth network entity may then forward the PCC rule to a third network entity.

[0363] A third network entity may generate an ATSSS rule based on the PCC rule and transmit the ATSSS rule to the first UE. The third network entity may generate an N4 rule based on the PCC rule and transmit the N4 rule to a network entity associated with the user plane (e.g., UPF).

[0364] According to one embodiment of the disclosure of the present specification, a PCF can generate a URSP rule including information related to dual-steering (e.g., dual-steering preference information) based on subscriber information of a terminal. The PCF can transmit the URSP rule to a terminal (e.g., a dual-steering device).

[0365] According to one embodiment of the disclosure of the present specification, a terminal may determine to establish an MA PDU Session using dual 3GPP access through an underlay network based on a URSP rule. The terminal may establish an MA PDU Session using dual 3GPP access.

[0366] According to one embodiment of the disclosure of this specification, a terminal may notify the network that it is connecting via an underlay network. For example, when a terminal creates an MA PDU Session or performs an access addition via the underlay network, information indicating that the terminal is connecting via the underlay network may be transmitted.

[0367] According to one embodiment of the disclosure of this specification, the SMF can recognize that a terminal is accessing via an underlay network and inform the PCF that the terminal is accessing via the underlay network. Accordingly, the PCF can set a PCC rule to prevent traffic splitting through dual 3GPP access.

[0368] This specification may have various effects.

[0369] For example, a terminal can effectively receive services through two 3GPP accesses. For example, a single terminal can perform registration through two 3GPP accesses. For example, an MA PDU Session supporting dual 3GPP access can be created using an overlay architecture.

[0370] MA PDU Sessions supporting dual 3GPP access can be created using overlay architecture.

[0371] For reference, the operation of the terminal described in this specification (e.g., UE#1, UE#2, first UE, second UE, dual-steer device including two UEs, etc.) 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). One or more processors (102 or 202) may control one or more memories (104 or 204) and one or more transceivers (105 or 206), and execute instructions / programs stored in one or more memories (104 or 204) to perform operations of a terminal (e.g., UE) described in the disclosure of this specification.

[0372] 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.

[0373] For reference, the operations of a network node (e.g., AMF, SMF, UPF, UDM, H-PCF, NEF, AF, N3IWF, 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 the 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). 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 operations of a network node or base station as described in the disclosure of this specification.

[0374] 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.

[0375] 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.

[0376] 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.

[0377] 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 in which a first User Equipment (UE) included in a dual steer device transmits a first registration request message to a first network entity related to mobility via 3rd Generation Partnership Project (3GPP) access; A step in which the first UE receives a first registration acceptance message from the first network entity via the 3GPP access; A step in which the first UE receives a UE Route Selection Policy (URSP) rule in which an access type preference is set to dual-steer from a second network entity related to a policy related to the UE; The step of the first UE transmitting a first PDU session establishment request message related to a Multi Access (MA) Protocol Data Unit (PDU) session to a third network entity related to the session via the 3GPP access; and The first UE comprises a step of transmitting a second PDU session establishment request message through the non-3GPP access to create a user plane through the non-3GPP access for the MA PDU session, The above non-3GPP access is based on a PDU session established by a second UE included in the dual-steer device, The above second PDU session establishment request message is transmitted together with information related to the MA PDU request and information related to dual steering, A method for causing a fifth network entity related to a policy related to a session to update a PCC rule so that traffic for one service is transmitted through one 3GPP access, the information related to the above dual steering.

2. In paragraph 1, A method wherein the above registration request message includes capability information related to supporting URSP rules related to dual steer.

3. In paragraph 2, A method in which the URSP rule is received based on the capability information transmitted.

4. In any one of paragraphs 1 to 3, The first UE transmits a second registration request message via the non-3GPP access; and A method further comprising the step of the first UE receiving a second registration acceptance message via the non-3GPP access.

5. In any one of paragraphs 1 to 4, The second UE transmits a registration request message; The second UE receives a registration acceptance message; The second UE transmits a third PDU session establishment request message related to the PDU session; and A method further comprising the step of the second UE receiving a PDU session establishment acceptance message related to the PDU session.

6. In any one of paragraphs 1 to 5, A method wherein, based on subscriber information of the second UE, the PDU session of the second UE is used to provide connectivity for dual-steer support to the first UE.

7. In the device, 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 above command being executed by the one or more processors is a method according to any one of claims 1 to 6.

8. At least one processor; and At least one memory storing instructions and being operably electrically connected to the at least one processor, The operations performed based on the above instruction being executed by the at least one processor are: An apparatus comprising a method according to any one of claims 1 to 6.

9. A non-transitory computer-readable medium (CRM) that records commands, The above instructions, when executed by one or more processors, cause the one or more processors to perform a method according to any one of claims 1 to 6. CRM.

10. A step of receiving information related to a first User Equipment (UE) from a network entity related to mobility; A step of obtaining subscriber information of the first UE from the Unified Data Repository (UDR); and A step of generating a UE Route Selection Policy (URSP) rule in which an access type preference is set to dual-steer based on subscriber information of the first UE; and A method comprising the step of transmitting the URSP rule to the first UE.

11. In the device, the device: 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; The operation performed based on the command being executed by the one or more processors comprises the steps of: receiving information related to a first User Equipment (UE) from a network entity related to mobility; A step of obtaining subscriber information of the first UE from the Unified Data Repository (UDR); and A step of generating a UE Route Selection Policy (URSP) rule in which an access type preference is set to dual-steer based on subscriber information of the first UE; and A device, comprising a step of transmitting the URSP rule to the first UE.

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