Method and apparatus for updating terminal path selection policy for user plane function selection in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. An operation method of a network exposure function (NEF) according to an embodiment of the present disclosure may comprise the steps of: transmitting, to a user plane function (UPF), a first message (Nupf_GetPrivateUEIP_Get request) for requesting a private UE IP of a UE; receiving, from the UPF, a second message (Nupf_GetPrivateUEIP_Get response) including the private UE IP of the UE; transmitting, to unified data management (UDM), a third message (Nudm_SDM_Get request) for requesting an AF-specific UE identifier; and receiving, from the UDM, a fourth message (Nudm_SDM_Get response) including the AF-specific UE identifier.

Description

Method and device for updating terminal path selection policy for user plane function selection in wireless communication system

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for updating a URSP to select a UPF.

[0002] The present disclosure relates to a method and device for using a UPF service in a communication system.

[0003] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz (THz) band (for example, 3 THz band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0004] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

[0005] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0006] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0007] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0008] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0009] The disclosed embodiment seeks to provide a method and device capable of effectively providing a service in a wireless communication system.

[0010] In addition, the present disclosure provides a communication method and device for using a UPF service in a communication system.

[0011] Additionally, the present disclosure provides a method and device for requesting / providing terminal identification information using a UPF service in a communication system.

[0012] In addition, the present disclosure provides a method and device for requesting / providing terminal identification information using a UPF service between a UPF (user plane function) and an AF (application function) in a communication system.

[0013] A method for operating a Network Exposure Function (NEF) for searching for an AF-specific user equipment (UE) identifier (AF-specific UE ID) in a wireless communication system according to one embodiment of the present disclosure may include: transmitting a first message (Nupf_GetPrivateUEIP_Get request) requesting a private IP address (private UE IP) of a UE to a user plane function (UPF); receiving a second message (Nupf_GetPrivateUEIP_Get response) including the private IP address of the UE from the UPF; transmitting a third message (Nudm_SDM_Get request) requesting the AF-specific UE identifier to a unified data management (UDM); and receiving a fourth message (Nudm_SDM_Get response) including the AF-specific UE identifier from the UDM. The second message (Nupf_GetPrivateUEIP_Get response) may further include the SUPI (subscription permanent identifier) ​​or MSISDN (mobile station international integrated services digital network number) of the UE.

[0014] In a wireless communication system according to one embodiment of the present disclosure, a Network Exposure Function (NEF) device for searching for an AF-specific user equipment (UE) identifier (AF-specific UE ID) may include a transceiver; and a processor. The processor may transmit a first message (Nupf_GetPrivateUEIP_Get request) requesting a private IP address (private UE IP) of a UE to a user plane function (UPF), receive a second message (Nupf_GetPrivateUEIP_Get response) including the private IP address of the UE from the UPF, transmit a third message (Nudm_SDM_Get request) requesting the AF-specific UE identifier to a unified data management (UDM), and receive a fourth message (Nudm_SDM_Get response) including the AF-specific UE identifier from the UDM. The second message (Nupf_GetPrivateUEIP_Get response) may further include the SUPI (subscription permanent identifier) ​​or MSISDN (mobile station international integrated services digital network number) of the UE.

[0015] The disclosed embodiment provides a device and method capable of effectively providing a service in a wireless communication system.

[0016] FIG. 1 illustrates the structure of a 5G network according to one embodiment of the present disclosure.

[0017] FIG. 2 illustrates an example of a UPF Modules / Functions design according to one embodiment of the present disclosure.

[0018] FIG. 3 illustrates an example of deploying Heavy UPF and Light UPF according to one embodiment of the present disclosure.

[0019] FIG. 4 illustrates an example of a route selection method for transmitting a service flow of a UE to a DN according to one embodiment of the present disclosure.

[0020] FIG. 5 illustrates an example of a route selection method for transmitting a service flow of a UE to a DN via a Light UPF according to one embodiment of the present disclosure.

[0021] FIG. 6 illustrates an example of a method for selecting a path when there are multiple UPFs capable of performing UPF Functionality requested by a service flow according to one embodiment of the present disclosure.

[0022] FIG. 7 is a flowchart illustrating the operation of a UE according to one embodiment of the present disclosure.

[0023] FIG. 8 is a diagram showing the configuration of a UE according to an embodiment of the present disclosure.

[0024] FIG. 9 is a diagram illustrating a configuration of a network entity according to an embodiment of the present disclosure.

[0025] FIG. 10 is a diagram showing an example of a datagram header of a TCP / IP protocol stack and an IP Layer (IPv4-based) in a communication system according to an embodiment of the present disclosure.

[0026] FIG. 11 is a diagram illustrating an IP layer including a UCMP protocol according to an embodiment of the present disclosure.

[0027] FIG. 12 is a diagram illustrating an example of an IP datagram including a UCMP protocol message and a UCMP protocol message format included in the IP datagram according to an embodiment of the present disclosure.

[0028] FIG. 13 is a diagram showing an example of the operation of the UCMP protocol according to an embodiment of the present disclosure.

[0029] FIG. 14a, FIG. 14b and FIG. 14c are diagrams for explaining methods for an AF to request and receive a UE ID using a User Plane (CP) through a UPF in a DN of an external network in a communication system according to an embodiment of the present disclosure.

[0030] FIG. 15 is a diagram for explaining a conventional method in which an AF in a DN of an external network requests and receives a UE ID using a Control Plane (CP) through an NEF of 5GC in a communication system according to an embodiment of the present disclosure.

[0031] FIG. 16 is a diagram showing the configuration of a network entity in a communication system according to an embodiment of the present disclosure.

[0032] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. It should be noted that, where possible, identical components are represented by identical reference numerals throughout the attached drawings. Furthermore, detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted.

[0033] In describing the embodiments herein, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present invention will be omitted. This is to avoid obscuring the gist of the present disclosure by omitting unnecessary explanations and to convey the gist more clearly.

[0034] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0035] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

[0036] At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0037] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0038] Here, the term '~ unit' used in the present embodiment means a software or hardware component such as an FPGA or ASIC, and the '~ unit' performs certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium and may be configured to play one or more processors. Accordingly, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. Additionally, components and '~parts' may be implemented to regenerate one or more CPUs within a device or secure multimedia card.

[0039] Hereinafter, the base station is an entity that performs resource allocation of a terminal, and may be at least one of a Node B, a BS (Base Station), an eNB (eNode B), a gNB (gNode B), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In addition, the embodiments of the present disclosure may be applied to other communication systems having a similar technical background or channel type to the embodiments of the present disclosure described below. In addition, the embodiments of the present disclosure may be applied to other communication systems through some modifications without significantly departing from the scope of the present disclosure at the discretion of a person having skilled technical knowledge.

[0040] In the following description, terms used to identify connection nodes, terms referring to network entities or network functions (NFs), terms referring to messages, terms referring to interfaces between network objects, terms referring to various identification information, etc. are provided as examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

[0041] For convenience of explanation, some terms and names defined in the 3rd generation partnership project long-term evolution (3GPP) standards may be used. However, the present disclosure is not limited to these terms and names, and can be equally applied to systems conforming to other standards.

[0042] FIG. 1 illustrates the structure of a 5G network according to one embodiment of the present disclosure.

[0043] Referring to Figure 1, the network entities or network nodes that constitute the 5G network are described as follows.

[0044] (R)AN ((Radio) Access Network) is an entity that performs wireless resource allocation of a terminal, and may be at least one of an eNode B, Node B, BS (Base Station), NG-RAN (NextGeneration Radio Access Network), 5G-AN, a wireless access unit, a base station controller, or a node on a network.

[0045] A terminal may include a UE (User Equipment), an NG UE (NextGeneration UE), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing communication functions. Furthermore, while the embodiments of the present disclosure will be described below using a 5G system as an example, the embodiments of the present disclosure may also be applied to other communication systems with similar technical backgrounds. Furthermore, the embodiments of the present disclosure may be applied to other communication systems with some modifications, as determined by a person skilled in the art, without significantly departing from the scope of the present disclosure.

[0046] As wireless communication systems evolve from 4G to 5G, a new core network, NextGen Core (NG Core) or 5GC (5G Core Network), is defined. This new core network virtualizes all existing network entities (NEs) into network functions (NFs). According to one embodiment of the present disclosure, a network function (NF) may refer to a network entity, a network component, or a network resource.

[0047] According to one embodiment of the present disclosure, 5GC may include NFs as illustrated in FIG. 1. Of course, the present invention is not limited to the example illustrated in FIG. 1, and 5GC may include more or fewer NFs than the number of NFs illustrated in FIG. 1.

[0048] The Access and Mobility Management Function (AMF) may be a network function that manages the access and mobility of a terminal (UE). For example, AMF may perform network functions such as registration, connection, reachability, mobility management, access verification, authentication, and mobility event generation.

[0049] The Session Management Function (SMF) may be a network function that manages the Packet Data Network (PDN) connection provided to the user equipment (UE). The PDN connection may be referred to as a Packet Data Unit (PDU) Session. For example, the SMF may perform network functions such as session management through the establishment, modification, and release of sessions and the maintenance of tunnels between the UPF (131) and the RAN required for this, the allocation and management of the IP (Internet protocol) address of the UE, the selection and control of the user plane, the control of traffic processing in the UPF, and the control of the collection of charging data.

[0050] PCF (Policy Control Function) may be a network function that applies the mobile carrier's service policy, charging policy, and PDU Session policy to the terminal.

[0051] Unified Data Management (UDM) can be a network function that stores subscriber information. For example, UDM can perform functions such as generating authentication information for 3GPP security, processing user identifiers (user IDs), managing a list of network functions supporting UEs, and managing subscription information.

[0052] The Network Exposure Function (NEF) may provide information about a terminal to a server outside the 5G network. Additionally, NEF may provide the ability to store information necessary for 5G network services in the UDR.

[0053] The User Plane Function (UPF) may be a gateway function that transmits user data (PDU) to the Data Network (DN). More specifically, the UPF may perform a data processing function so that data transmitted by a terminal can be transmitted to an external network or data received from an external network can be transmitted to the terminal. For example, the UPF (131) may perform network functions such as serving as an anchor between radio access technologies (RATs), packet routing and forwarding, packet inspection, user plane policy application, traffic usage report creation, and buffering.

[0054] NRF (Network Repository Function) can perform the function of discovering NF.

[0055] AUSF (Authentication Server Function) can perform terminal authentication in 3GPP access networks and non-3GPP access networks.

[0056] NSSF (Network Slice Selection Function) can perform the function of selecting a Network Slice Instance provided to a terminal.

[0057] The Application Function (AF) can perform functions that provide information related to services or applications. The AF can access the NEF for resource discovery and interact with the PCF to enable policy control. Furthermore, the AF can request traffic routing for applications from the operator network and provide application services to subscribers.

[0058] SCP (Service Communication Proxy) can perform network functions that enable dynamic scaling and management of communications and services in 5G networks. Within a 5G service-based architecture, SCP can provide a variety of functions, from simplifying network topology to load balancing, overload handling, and message processing.

[0059] DN (Data Network) can be a data network where terminals transmit and receive data to use network operator services or third-party services.

[0060] According to one embodiment of the present disclosure, when a UPF is composed of several modules and functions (hereinafter, referred to only as modules) according to a modular design, a URSP (UE Route Selection Policy) update method is proposed to determine which modules a specific service flow (Service Flow or IP Flow) uses to select a PDU Session using a UPF.

[0061] In one embodiment of the present disclosure, equipment (i.e. AF) located in the DN can use, for example, the N6 Interface (User Plane, In-band) to exchange control messages with the UPF using the UPF service.

[0062] According to one embodiment of the present disclosure, a network device or network function located inside or outside a 5G Core Network network is proposed to request and obtain an AF specific UE ID (i.e. External Identifier) ​​using a UPF service provided by UPF.

[0063] FIG. 2 illustrates an example of a UPF Modules / Functions design according to one embodiment of the present disclosure.

[0064] The services provided by UPF can be divided into mandatory functionality and optional functionality. Mandatory functionality includes at least one function required for the services defined by the standard to be provided by UPF. Optional functionality may include at least one function required to provide additional services beyond the UPF functions defined by the standard.

[0065] Mandatory functionality provided by UPF may include at least one of a data storage module, a data processing module, a packet processing module, a packet buffer module, a policy rule enforcement module, a traffic usage reporting module, a traffic verification module, and a quality of service (QoS) handling module.

[0066] Optional functionality provided by UPF may include at least one of a network address translation (NAT) module for network address translation, a domain name system (DNS) snooping module, a firewall module, a traffic optimization module, a shallow packet inspection (SPI) module, and a deep packet inspection (DPI) module.

[0067] Referring to FIG. 2, in the present disclosure, a UPF that modularizes all functions according to the Module Design and includes only essential functions excluding additional functions may be referred to as a Light UPF, and a UPF that includes both essential functions and additional functions without modularizing functions may be referred to as a Heavy UPF.

[0068] For example, the UPF may include a packet processing module to receive user packets from the DN and transmit them to the UE, and to receive user packets from the UE and transmit them to the DN.

[0069] For example, UPF may include an SPI module (shallow packet inspection) and / or a DPI module (deep packet inspection) for inspecting user packets received from UE or DN. However, the SPI module (shallow packet inspection) and the DPI module (deep packet inspection) are not services / functions that UPF must provide as defined in the standard.

[0070] Modularizing UPF by function allows for the expansion and reduction of resources for each module, thereby expanding the flexibility of UPF resource provision. Furthermore, modularizing UPF by function allows for the addition and / or deletion of non-essential features as needed, potentially resulting in cost savings compared to a fully featured UPF.

[0071] FIG. 3 illustrates an example of deploying Heavy UPF and Light UPF according to one embodiment of the present disclosure.

[0072] Referring to FIG. 3, the system may include at least one of a UE (310 or 311), a Heavy UPF (320), a Light UPF (330), and a DN (340). The Heavy UPF (320) may include mandatory functionalities and all optional functionalities. The Light UPF (330) may include mandatory functionalities and at least one specific optional functionality.

[0073] For example, mandatory functionalities of Light UPF (330) may include a data processing module (331) and a plurality of other modules. For example, specific optional functionalities of Light UPF (330) may include at least one of a caching module (332), a network address translation (NAT) module (333), a firewall module (334), and a DPI module (335).

[0074] For example, DN (340) may include a content service provider (341) capable of providing content to UE (310 or 311), a public service provider (342) capable of providing public services to UE (310 or 311), and a banking service provider (343) capable of providing banking services to UE (310 or 311).

[0075] According to one embodiment, in an environment where the system uses Heavy UPF (320), the UE (310) can perform data transmission and reception with the DN (340) using the same Heavy UPF (320) regardless of the service flow used.

[0076] According to one embodiment, in an environment where the system uses Light UPF (330), the UE (311) selects Light UPF (330) that provides different additional functions according to the requirements of the service flow.

[0077] For example, when using a service flow for a banking service in UE (311), the UE (311) can perform data communication with a banking service provider (343) within DN (340) by using a Light UPF (340) including a data processing module (331), which is an essential function, and a firewall module (334) that provides a firewall function for security.

[0078] For example, when using a service flow for a video streaming service in UE (311), the UE (311) can perform data communication with a content service provider (341) within DN (340) by using a Light UPF (340) including a data processing module (331), which is an essential function, a caching module (332) that provides a caching function that can reduce transmission delay, and a NAT module (333).

[0079] For example, when using a service flow for public services in UE (311), the UE (311) can perform data communication with a public service provider (342) within DN (340) by using Light UPF (340) including a data processing module (331) which is an essential function, a firewall module (334) which provides a firewall function for security, and a DPI module (335).

[0080] FIG. 4 illustrates an example of a route selection method for transmitting a service flow of a UE to a DN according to one embodiment of the present disclosure.

[0081] Referring to FIG. 4, the system may include at least one of a UE (410), a base station (420), a first Heavy UPF (430), a second Heavy UPF (440), and a DN (450). Each of the first Heavy UPF (430) and the second Heavy UPF (440) may include mandatory functionalities and all optional functionalities.

[0082] For example, DN (450) may include a content service provider (451) that can provide content to UE (410), a public service provider (452) that can provide public services to UE (410), and a banking service provider (453) that can provide banking services to UE (410).

[0083] In a 5G network, URSP (UE Route Selection Policy) information can be used to select a path for transmitting a service flow generated from a UE (410) to a DN (450).

[0084] In one embodiment, the URSP information may include a prioritized list of URSP rules. In one embodiment, each URSP rule may include at least one of a Rule Precedence for application priority, a Traffic Descriptor for distinguishing service flows, and a List of Route Selection Descriptors for selecting a route for the service flows distinguished by the Traffic Descriptor.

[0085] According to one embodiment, the traffic descriptor may include at least one of application descriptors, IP descriptors, domain descriptors, non-IP descriptors, and data network name (DNN).

[0086] According to one embodiment, each Route Selection Descriptor may include at least one of Route Selection Descriptor Precedence, Route Selection Components, and Route Selection Validation Criteria for application priority of each Route Selection Descriptor.

[0087] According to one embodiment, Route Selection Components may include at least one of Session and Service Continuity (SSC) Mode Selection, Network Slice Selection, DNN Selection, PDU Session Type Selection, and Access Type preference.

[0088] Tables 1 to 3 describe the UE Route Selection Policy information described in 3GPP standard document TS 23.503.

[0089] [Table 1] UE Route Selection Policy

[0090]

[0091] According to one embodiment, a UE Route Selection Policy (URSP) may be pre-configured in the UE (410). According to one embodiment, the URSP may be configured by a network entity (or PCF).

[0092] In one embodiment, the PCF may transmit or provide the URSP to the UE (410) during the initial registration procedure. In one embodiment, the PCF may transmit or provide the URSP to the UE (410) when the location of the UE (410) changes or when the AMF managing the mobility of the UE (410) changes.

[0093] In one embodiment, URSP may be used to determine whether to associate application traffic detected by the UE (410) with a previously created PDU session, offload application traffic detected by the UE to a non-3GPP access network other than the PDU session, or request creation of a new PDU session.

[0094] In one embodiment, the URSP may include at least one of a service and session continuity mode (SSC) selection policy, a network slice selection policy, a data network name (DNN) selection policy, a non-seamless offloading policy, and an access type preference indicating whether to prefer a 3GPP access network or a non-3GPP access network.

[0095] [Table 2] UE Route Selection Policy Rule

[0096]

[0097] [Table 3] Route Selection Descriptor

[0098]

[0099] In Fig. 4, the service flow generated by the UE (410) is distinguished by a traffic descriptor, and a path can be selected by the corresponding Route Selection Components. Here, selecting a path may mean selecting a PDU Session.

[0100] According to one embodiment, if there is a PDU Session that satisfies the Route Selection Components value among the existing PDU Sessions created by the UE (410), the UE (410) can transmit a newly created service flow to the DN (450) using the PDU Session.

[0101] According to one embodiment, if there is no PDU Session that satisfies the Route Selection Components value among the existing PDU Sessions created by the UE (410), the UE (410) can create a new PDU Session using the Route Selection Components value and transmit the service flow to the DN (450) using the newly created PDU Session.

[0102] In an example of Figure 4, the values ​​of Route Selection Components are as follows.

[0103] SSC Mode Selection: SSC 1

[0104] Network Slice Selection: S-NSSAI #1

[0105] DNN Selection: DNN #1

[0106] PDU Session Type Selection: IP Type

[0107] In FIG. 4, since PDU Session #1 among the existing PDU Sessions (PDU Session #1, PDU Session #2) satisfies the Route Selection Components, the service flow generated in UE (410) selects a path to PDU Session #1, and UE (410) can transmit data to DN (450) using PDU Session #1.

[0108] In this disclosure, in an environment where a Light UPF with a module design is deployed, i.e., where different UPFs provide different services, there is a limitation in selecting a path for a service flow using only the existing URSP rule. To solve this, a method is proposed that allows the service flow path to be selected by considering the Light UPF by extending the existing URSP rule.

[0109] FIG. 5 illustrates an example of a route selection method for transmitting a service flow of a UE to a DN via a Light UPF according to one embodiment of the present disclosure.

[0110] Referring to FIG. 5, the system may include at least one of a UE (510), a base station (520), a first Light UPF (530), a second Light UPF (540), and a DN (550). Each of the first Light UPF (530) and the second Light UPF (540) may include mandatory functionalities and at least one specific optional functionality.

[0111] For example, the first Light UPF (530) may be configured with mandatory functionality including a data processing module (531) and a plurality of modules, and specific optional functionality including a firewall module (532). For example, the second Light UPF (540) may be configured with mandatory functionality including a data processing module (541) and a plurality of modules, and specific optional functionality including a caching module (542).

[0112] For example, the DN (550) may include a content service provider (551) (e.g., Netflix) that can provide content to the UE (510), a public service provider (552) that can provide public services to the UE (510), and a banking service provider (553) that can provide banking services to the UE (510).

[0113] Referring to FIG. 5, a UE (510) can create two PDU Sessions (PDU Session #1, PDU Session #2). The two PDU Sessions (PDU Session #1, PDU Session #2) can have the same Route Selection Components values ​​except for the UPF Functionality value.

[0114] For example, PDU Session #1 can be connected to DN (550) through the first Light UPF (530) to which a Firewall module (532) has been added. For example, PDU Session #2 can be connected to DN (550) through the second Light UPF (540) to which a Caching module (542) has been added.

[0115] For example, the UPF Functionality value of the Route Selection Components for a newly created service flow may be defined as a Firewall value. The UE (510) may select PDU Session #1 using the first Light UPF (530) with the Firewall additional function according to the Route Selection Components value and use it to transmit and receive the service flow to and from the DN (500).

[0116] Table 4 below shows an extended URSP rule including the List of UPF Functionality Descriptors values ​​proposed in this disclosure.

[0117] [Table 4] Extended Route Selection Descriptor

[0118]

[0119] In Table 4, List of UPF Functionality Descriptors shows the list of UPF Functionality Descriptors, and the components of UPF Functionality Descriptors are described in Table 5.

[0120] Referring to Tables 1 to 4, the Extended Route Selection Descriptor of Table 4 may be included in a UE Route Selection Policy (URSP). According to one embodiment, the URSP may be pre-configured in the UE (510). According to one embodiment, the URSP may be configured by a network entity (or PCF).

[0121] In one embodiment, the PCF may transmit or provide the URSP to the UE (510) during the initial registration procedure. In one embodiment, the PCF may transmit or provide the URSP to the UE (510) when the location of the UE (510) changes or when the AMF managing the mobility of the UE (510) changes.

[0122] In one embodiment, URSP may be used to determine whether to associate application traffic detected by the UE (510) with a previously created PDU session or to request the creation of a new PDU session.

[0123] Table 5 below shows the UPF Functionality Descriptors proposed in this disclosure.

[0124] [Table 5] UPF Functionality Descriptors

[0125]

[0126] Referring to Table 5, UPF Functionality Descriptor Precedence indicates the priority in applying the UPF Functionality Descriptor.

[0127] Referring to Table 5, UPF Functionality Components can be composed of UPF Functionality values ​​and Mandatory or Optional values. However, UPF Functionality Components values ​​are not limited to the values ​​listed above. UPF Functionality Components values ​​can include more values ​​as needed. For example, UPF Functionality Components values ​​can include more values ​​related to Light UPF (such as packet processing capability) and / or the performance of additional features.

[0128] UPF Functionality indicates the UPF additional functionality required by the service flow. UPF Functionality values ​​can include NAT, DNS Snooping, Firewall, Traffic Optimization, Shallow Packet Inspection, and / or Deep Packet Inspection, but are not limited to the values ​​listed above.

[0129] Mandatory or Optional indicates whether the UPF Functionality value is a mandatory function or an additional function for processing the service flow. In one embodiment, if the UPF Functionality value is a mandatory function for processing the service flow, a Light UPF capable of performing the UPF Functionality must be selected. If the UPF Functionality value is an additional function for processing the service flow, a Light UPF that cannot perform the UPF Functionality may be selected in some cases.

[0130] In one embodiment, Optional UPF Functionality Components cannot have a UPF Functionality Descriptor Precedence value that takes precedence over Mandatory UPF Functionality Components.

[0131] FIG. 6 illustrates an example of a method for selecting a path when there are multiple UPFs capable of performing UPF Functionality requested by a service flow according to one embodiment of the present disclosure.

[0132] Referring to FIG. 6, the system may include at least one of a UE (610), a base station (620), a Heavy UPF (630), a first Light UPF (640), a second Light UPF (650), and a DN (660). The Heavy UPF (630) may include mandatory functionalities and all optional functionalities. Each of the first Light UPF (640) and the second Light UPF (650) may include mandatory functionalities and at least one specific optional functionality.

[0133] For example, the first Light UPF (640) may be configured with mandatory functionality including a data processing module (641) and a plurality of modules, and specific optional functionality including a firewall module (642). For example, the second Light UPF (650) may be configured with mandatory functionality including a data processing module (651) and a plurality of modules, and specific optional functionality including a firewall module (652) and a caching module (653).

[0134] For example, DN (660) may include a content service provider (651) capable of providing content to UE (610), a public service provider (652) capable of providing public services to UE (610), and a banking service provider (653) capable of providing banking services to UE (610).

[0135] In FIG. 6, UE (610) can create three PDU Sessions (PDU Session #1, PDU Session #2, PDU Session #3). The three PDU Sessions (PDU Session #1, PDU Session #2, PDU Session #3) can have the same Route Selection Components except for UPF Functionality.

[0136] For example, if the UPF Functionality required by the service flow is Firewall, this function can be provided by all UPFs (630, 640, 650) that handle three PDU Sessions (PDU Session #1, PDU Session #2, PDU Session #3). In this case, the UE (610) may consider the load information of each UPF and decide which UPF (or PDU Session) to select based on the Network Policy or UE implementation.

[0137] In one embodiment, the UE (610) may select a PDU Session that utilizes a UPF that can provide the least number of additional functions among the UPFs that can provide the UPF Functionality required by the service flow. In this case, a UPF that provides the least number of UPF Functionality may handle fewer service flows than a UPF that provides more UPF Functionality. However, this is merely an example, and the present disclosure is not limited to the method for selecting a path for a service flow.

[0138] FIG. 7 is a flowchart illustrating the operation of a UE according to one embodiment of the present disclosure.

[0139] Referring to FIG. 7, in operation 710, the UE may receive a URSP (UE route selection policy) related message including information about UPF (user plane function) functionality from a network entity.

[0140] According to one embodiment, the information regarding the UPF function may include first information indicating the UPF function and second information indicating whether the UPF function is essential.

[0141] According to one embodiment, the first information indicating the UPF function may include at least one of network address translation (NAT), domain name system (DNS) snooping, a firewall, traffic optimization, shallow packet inspection (SPI), and deep packet inspection (DPI).

[0142] According to one embodiment, the second information indicating whether the UPF function is mandatory may include a first value (mandatory) indicating that the UPF function is a mandatory function; or a second value (optional) indicating that the UPF function is an additional function.

[0143] In operation 720, the UE may select a packet data unit (PDU) session based on information about the UE's service flow and the UPF function.

[0144] In one embodiment, the additional functions of the UPF function may be configured differently depending on the service flow of the UE.

[0145] In operation 730, the UE can communicate with the data network based on the selected PDU session.

[0146] FIG. 8 is a diagram showing the configuration of a UE according to an embodiment of the present disclosure.

[0147] A UE according to one embodiment of the present disclosure may include a processor (820) that controls the overall operation of the UE, a transceiver (800) including a transmitter and a receiver, and a memory (810). Of course, the UE is not limited to the above example, and the UE may include more or fewer components than those illustrated in FIG. 8.

[0148] According to one embodiment of the present disclosure, the transceiver (800) can transmit and receive signals with network entities or other terminals. The signals transmitted and received with the network entities may include control information and data. In addition, the transceiver (800) can receive signals via a wireless channel, output them to the processor (820), and transmit the signals output from the processor (820) via the wireless channel.

[0149] According to one embodiment of the present disclosure, the processor (820) can control the terminal to perform any one of the operations described above. Meanwhile, the processor (820), the memory (810), and the transceiver (800) do not necessarily have to be implemented as separate modules, and of course, they can be implemented as a single component in the form of a single chip. In addition, the processor (820) and the transceiver (800) can be electrically connected. In addition, the processor (820) can be an Application Processor (AP), a Communication Processor (CP), a circuit, an application-specific circuit, or at least one processor.

[0150] The processor (820) may receive a URSP (UE route selection policy) related message containing information about the UPF (user plane function) functionality from a network entity. The processor (820) may select a PDU (packet data unit) session based on the service flow of the UE and the information about the UPF functionality. The processor (820) may control communication with a data network based on the selected PDU session.

[0151] According to one embodiment of the present disclosure, the memory (810) can store data such as basic programs, application programs, and setting information for the operation of the UE. In particular, the memory (810) provides the stored data upon request of the processor (820). The memory (810) can be configured as a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, there can be a plurality of memories (810). In addition, the processor (820) can perform the above-described embodiments based on a program for performing the above-described embodiments of the present disclosure stored in the memory (810).

[0152] FIG. 9 is a diagram illustrating the configuration of a network entity according to an embodiment of the present disclosure.

[0153] A network entity according to one embodiment of the present disclosure may include a processor (920) that controls the overall operation of the network entity, a transceiver (900) including a transmitter and a receiver, and a memory (910). Of course, the present invention is not limited to the above example, and the network entity may include more or fewer components than those illustrated in FIG. 9.

[0154] According to one embodiment of the present disclosure, the transceiver (900) can transmit and receive signals with at least one of other network entities or terminals. The signals transmitted and received with at least one of the other network entities or terminals may include control information and data.

[0155] According to one embodiment of the present disclosure, the processor (920) can control a network entity to perform any one of the operations described above. Meanwhile, the processor (920), the memory (910), and the transceiver (900) do not necessarily have to be implemented as separate modules, and can of course be implemented as a single component in the form of a single chip. In addition, the processor (920) and the transceiver (600) can be electrically connected. In addition, the processor (920) can be an Application Processor (AP), a Communication Processor (CP), a circuit, an application-specific circuit, or at least one processor.

[0156] The processor (920) can generate a URSP (UE route selection policy) related message that includes information about the UPF (user plane function) functionality. The processor (920) can control transmission of the UPSP related message to a UE (user equipment). A PDU (packet data unit) session of the UE can be selected based on the service flow of the UE and the information about the UPF functionality.

[0157] According to one embodiment of the present disclosure, the memory (910) can store data such as basic programs, application programs, and setting information for the operation of a network entity. In particular, the memory (910) provides the stored data upon request of the processor (620). The memory (910) can be configured as a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, there can be a plurality of memories (910). In addition, the processor (920) can perform the above-described embodiments based on a program for performing the above-described embodiments of the present disclosure stored in the memory (910).

[0158] FIG. 10 illustrates an example of a datagram header (Packet Header) of a TCP / IP protocol stack and an IP Layer (IPv4-based) in a communication system according to an embodiment of the present disclosure.

[0159] According to one embodiment of the present disclosure, the UPF and the AF within the DN described in the example of FIG. 1 may be a router and a server, respectively. The UPF and the AF within the DN may communicate via the N6 interface using a transmission control protocol (TCP) / internet protocol (IP) protocol stack to transmit and receive user data. The TCP / IP protocol stack of FIG. 10 may include an application layer (1001), a transport layer (1002), an IP layer (1003), a data link layer (1005), and a physical layer (1006).

[0160] Since UPF is a router device, it can basically include the IP layer (1003). Therefore, an in-band protocol that transmits control messages between UPF and AF within DN can exist in the IP layer (1003). The header of an IP datagram (or IP packet) processed in the IP layer (1003) can include the following fields.

[0161] - Version: Indicates whether it is an IPv4 packet or an IPv6 packet.

[0162] - Header length: Indicates the header length of the IP packet.

[0163] - Service type: Indicates the transmission priority of IP packets.

[0164] - Total length: Indicates the total length including the IP packet header and data.

[0165] - ID (identification), Flags, Fragment Offset: Indicates information related to data segmentation.

[0166] - TTL (time to live): An integer value that is decremented by 1 each time data passes through a router on the network.

[0167] - Header Checksum: Represents the checksum of the entire header.

[0168] - Source IP address, destination IP address: Indicates the source and destination IP addresses.

[0169] In addition, the header of the IP datagram (i.e., IP packet) of FIG. 10 may include a Protocol field (1010). Based on IPv6, the next header field can perform the function of the protocol field. In the present disclosure, the IPv4 protocol is described, but this can be equally applied to the IPv6 protocol. The protocol field (next header field based on IPv6) (1010) is, for example, an 8-bit field that defines an upper layer protocol that uses the service of the IP layer (1003). Various types of upper layer protocols, such as TCP, UDP (user datagram protocol), ICMP (internet control message protocol), and IGMP (internet group management protocol), can use the IP layer (1003).

[0170] In one embodiment of the present disclosure, the use of the UCMP (UPF Control Message Protocol) protocol as an in-band protocol in the Protocol field (1010) is described as an example. However, the Protocol field (1010) is not limited thereto, and it is also possible to use other in-band protocols.

[0171] The UCMP protocol can be assigned one of the unused Protocol fields. In this disclosure, it is assumed that number 144 has been assigned, for example. However, this is not limited to this, and new protocol names and IP protocol numbers can be used in various ways, not limited to the embodiments of this disclosure.

[0172] FIG. 11 illustrates an IP layer including the UCMP protocol according to an embodiment of the present disclosure. The IP layer (1100) of FIG. 11 corresponds to the IP layer (1003) of FIG. 10.

[0173] According to one embodiment of the present disclosure, the UCMP protocol (1104) may be included in the IP layer (1100) like the existing IGMP, ICMP, and ARP (address resolution protocol) protocols (1101, 1102, 1103). The IGMP protocol (1101) is a protocol used by the TCP / IP protocol suite to perform dynamic multicasting, the ICMP protocol (1102) is a protocol for notifying the cause of an error or diagnosing a network status when an error occurs during IP packet transmission, and the ARP protocol (1103) is a protocol for converting a logical IP address into a MAC (medium access control) address. In addition, the UCMP protocol may exist above the IP layer. The UCMP protocol (1104) illustrated in FIG. 11 is illustrated based on IPv4, but is not limited thereto, and may be equally applied to IPv6.

[0174] FIG. 12 illustrates an example of an IP datagram including a UCMP protocol message and a format of a UCMP protocol message included in the IP datagram according to an embodiment of the present disclosure.

[0175] As described above, in the embodiment of the present disclosure, the value of the aforementioned Protocol field (210) of the IP header (1201) in the IP datagram (i.e., IP packet) may be, for example, a value of 144 indicating the UCMP protocol. The UCMP header (1202) included in the IP datagram may include at least one of a UPF service name (1211), a service operation (1212), and an operation semantic (1213) value. The UCMP data (1203) included in the IP datagram may include parameter values ​​required for the UPF service. Of course, the present invention is not limited to the above example. The UCMP (protocol) message may include a UCMP header (1202) and UCMP data (1203).

[0176] FIG. 13 illustrates an example of the operation of the UCMP protocol according to an embodiment of the present disclosure. In the example of FIG. 13, the IP datagram of FIG. 12 may be used.

[0177] Referring to FIG. 13, in step 1301, an AF, which is an external server located in the DN, may request subscription to a UPF service by sending a Nupf_EventExposure_Subscribe Request message (which may be simply referred to as a "subscription request message for UPF service") to the UPF in order to use a specific service of the UPF. At this time, in step 1301, the AF may generate a UCMP (protocol) message as described in the example of FIG. 12, include it in an IP datagram, and transmit it to the UPF. The IP datagram may include the Nupf_EventExposure_Subscribe Request message. As described above, the protocol field (reference number 1010 in FIG. 10) of the IP header (1201) may include, for example, a value of '144' to indicate that the corresponding IP datagram includes a UCMP message. In the above IP header (1201), the source IP address field may be entered as the AF's IP address, for example, '179.153.110.3'. In the above IP header (1201), the destination IP address field may be entered as the terminal's IP address, for example, '192.110.33.5'. This is an example provided for the convenience of explaining the source IP address and destination IP address.

[0178] According to one embodiment of the present disclosure, the following values ​​are entered in the UCMP header (1202) of the UCMP message in the subscription request message for the UPF service. The Service Name field (1211) may be entered with the value 'Nupf_EventExposure' indicating the UPF service name. This indicates the name of the service that the AF will request from the UPF.

[0179] According to one embodiment of the present disclosure, the Service Operations field (1212) of the UCMP header (1202) may include a 'Subscribe' value indicating service subscription. This indicates a service operation that the AF requests from the UPF.

[0180] According to one embodiment of the present disclosure, the Operation Semantics field (1213) of the UCMP header (1202) may include a 'Request' value indicating a service request. This represents a definition of an operation indicating that the AF is requesting a service from the UPF.

[0181] According to one embodiment of the present disclosure, the UCMP Data field (1203) may include parameter value(s) required for a corresponding service subscription request. The parameter value(s) may include at least one of various values, such as an Event ID, a terminal IP address, a Generic Public Subscription Identifier (GPSI), a Data Network Name (DNN), and a Single Network Slice Selection Assistance Information (S-NSSAI). Of course, the present invention is not limited to the above examples.

[0182] According to one embodiment of the present disclosure, in step 1301, the IP datagram is transmitted from the AF to the PSA (PDU Session Anchor) UPF, which is the home router of the terminal. The UPF can process the IP header (1201) of the received IP datagram. At this time, the UPF, which confirms that the value of the protocol field (1010) of the IP header (1201) is, for example, '144', can recognize / identify that the IP datagram includes the UCMP message described in the example of FIG. 12. That is, the UPF, which received the IP datagram, can identify that the IP datagram does not include user data transmitted to the user (terminal) but includes a UCMP message requesting a service from the UPF serving the terminal. The UPF can confirm the UCMP message and process the requested service subscription. The UPF can discard the IP datagram without transmitting it to the terminal.

[0183] Thereafter, in step 1302, the UPF may transmit a Nupf_EventExposure_Subscribe Response message (which may be simply referred to as a "subscription response message for UPF service") containing the result of the requested service subscription processing to the AF. To this end, the UPF generates a UCMP message to be included in the Nupf_EventExposure_Subscribe Response message. The IP datagram transmitted from the UPF to the AF in step 502 may include the Nupf_EventExposure_Subscribe Response message. In the subscription response message for the UPF service, the UCMP message may include a UCMP header (1202) and UCMP data (1203), as in the example of FIG. 12. The UCMP header (1202) may include the following values. The Service Name field (1211) of the UCMP header (1202) includes a value of 'Nupf_EventExposure', which is the UPF service name. The Service Operations field (1212) of the UCMP header (1202) contains a 'Subscribe' value, which is a service subscription. The Operation Semantics field (1213) of the UCMP header (1202) contains a 'Response' value, which is a response to a service request. The UCMP Data field (1203) may contain parameter value(s) required for the corresponding service subscription request response.

[0184] The IP datagram illustrated in FIG. 13 and the UCMP protocol message included in the IP datagram are examples and are not limited thereto, and may be modified in various ways depending on system settings, UPF services requested by AF, etc.

[0185] FIGS. 14a, 14b and 14c are drawings for explaining methods for requesting and receiving terminal identification information (UE ID) from an AF using a User Plane (UP) through a UPF in a DN of an external network in a communication system according to an embodiment of the present disclosure.

[0186] Figure 14a illustrates an example of a method for providing terminal identification information (UE ID) when the UPF has / stores / knows an AF specific UE Identifier (i.e., External Identifier) ​​as terminal identification information (UE ID) of the corresponding terminal.

[0187] Referring to FIG. 14a, in step 1401, the AF may request a UEID (i.e., an External Identifier) ​​from the UPF using the Nupf_EventExposure_Subscribe service operation. The Nupf_EventExposure_Subscribe request message (i.e., a subscription request message for the UPF service) that the AF transmits to the UPF in step 1401 may include at least one of the parameter(s) in the following [Table 6] for using the UPF Event Exposure service.

[0188] [Table 6]

[0189]

[0190] The parameter(s) of [Table 6] for using the above UPF Event Exposure service are only an example, and it is also possible to use other parameter(s) in addition to the parameter(s) of [Table 6] or to use the parameter(s) of [Table 6] in various ways. In addition, in the step 1401, the Nupf_EventExposure_Subscribe request message may further include at least one of the parameters of MTC Provider Information, Application Port ID, IP domain, corresponding DNN and / or S-NSSAI.

[0191] In step 1402, the UPF can provide the AF with a UE ID (i.e., an AF-specific UE Identifier) ​​via a Nupf_EventExposure_Notify message in response to the Nupf_EventExposure_Subscribe request message. The UPF can receive the UE ID from the SMF when creating a PDU Session to provide a service to the UE. If the UPF has the UE ID information, the UPF can respond directly to the AF's request as in step 1402.

[0192] Figure 14b illustrates an example of a method for providing UE ID when the UPF does not have / store / know the AF specific UE Identifier (i.e., External Identifier) ​​as the UE ID of the corresponding terminal.

[0193] Referring to Fig. 14b, steps 1411 and 1412 are the same as steps 1401 and 1402 of Fig. 14a, and thus, a detailed description thereof will be omitted. If the UPF, which has received the Nupf_EventExposure_Subscribe request message, has a UE ID (i.e., an AF specific UE Identifier), it can provide the UE ID (i.e., an AF specific UE Identifier) ​​to the AF through a Nupf_EventExposure_Notify message. However, if the UPF does not have a UE ID (i.e., an AF specific UE Identifier), the UPF transmits an N4 Session Request message to the SMF in step 1413. The N4 Session Request message may include at least one of an N4 Session ID, a Request Info Type: AF specific UE ID, an AF ID, a corresponding DNN, and / or an S-NSSAI. In addition, the N4 Session Request message may further include at least one of MTC Provider Information, an Application Port ID, and an IP domain.

[0194] In step 1414, the SMF may provide the UPF with an AF specific UE ID via an N4 Session Response message in response to the N4 Session Request message. The UPF, which has received the N4 Session Response message, may provide the AF specific UE ID to the AF via an Nupf_EventExposure_Notify message in response to the request of step 1411 in step 1415. The Nupf_EventExposure_Notify message may further include information related to the UPF service along with the AF specific UE ID.

[0195] Figure 14c illustrates another example of a method for providing UE ID when the UPF does not have / store / know the AF specific UE Identifier (i.e., External Identifier) ​​as the UE ID of the corresponding terminal.

[0196] Referring to Fig. 14c, steps 1421 and 1422 are the same as steps 1401 and 1402 of Fig. 14a, and thus, a detailed description thereof will be omitted. If the UPF, which has received the Nupf_EventExposure_Subscribe request message, has a UE ID (i.e., an AF specific UE Identifier), it can provide the UE ID (i.e., an AF specific UE Identifier) ​​to the AF through the Nupf_EventExposure_Notify message. However, if the UPF does not have a UE ID (i.e., an AF specific UE Identifier), the UPF can request the AF specific UE Identifier (i.e., an External Identifier) ​​of the UE from the UDM using the Nudm_SDM (subscriber data management)_Get service operation in step 1423. The Nudm_SDM_Get request message transmitted by the UPF to the UDM in step 1423 may include at least one of the following information: SUPI of the corresponding UE, Application Port ID, MTC Provider Information, or AF Identifier. In addition, the Nudm_SDM_Get request message may further include at least one of the following information: corresponding DNN and / or S-NSSAI, SMF ID, and PDU Session ID.

[0197] In step 1424, the UDM may provide the AF specific UE Identifier (i.e., External Identifier) ​​of the corresponding UE to the UPF through a Nudm_SDM_Get response message in response to the Nudm_SDM_Get request message. In step 1425, the UPF, which has received the Nudm_SDM_Get response message, may provide the AF specific UE ID to the AF through a Nupf_EventExposure_Notify message. In addition, the Nupf_EventExposure_Notify message may further include information related to the UPF service along with the AF specific UE ID.

[0198] At least one of the embodiments of FIGS. 14A to 14C may be implemented in combination or selectively. Furthermore, in the embodiments of FIGS. 14A to 14C, subscription request / response messages for UPF services transmitted and received between AF and UPF may be transmitted in IP datagrams according to the UCMP protocol described in the embodiments of FIGS. 12 and 13.

[0199] Figure 15 is a diagram illustrating a conventional method in which an AF requests and receives terminal identification information (UE ID) from a DN of an external network using a Control Plane (CP) via an NEF of a 5GC. The basic functions of each NF in Figure 15 can be referenced from the description in Figure 1.

[0200] In step 1501, the AF transmits an Nnef_UDID_Get request message to the NEF to request a UE ID. The Nnef_UDID_Get request message includes a UE address (IP address or MAC address) and an AF ID. The Nnef_UDID_Get request message may also include the following information: Port Number, MTC (Machine Type Communication) Provider Information, Application Port ID, and IP domain. In addition, it may also include a DNN (Data Network Name) and S-NSSAI (Single-Network Slice Selection Assistance Information).

[0201] In step 1502, the NEF can authorize the AF's request in step 1501. If the AF has the authority, the NEF can authorize the AF's request and execute the request. If the NEF fails to authorize the AF, the NEF sends an authorization failure message to the AF and the request is not executed. The NEF determines the DNN and S-NSSAI corresponding to the AF's request. The DNN and S-NSSAI information may be provided by the AF or may be determined using the AF ID and MTC Provider Information. If the Port Number is received from the AF in step 1501, the NEF can recognize that the UE IP address provided by the AF is not a private IP address allocated by 5GC.

[0202] In step 1502, if the UE IP address provided by the AF is not a private IP address allocated by 5GC (i.e., a public IP address), the NEF performs the operations from step 1503 to step 1506. If the UE IP address provided by the AF is a private IP address, the operations from step 1503 to step 1506 may be omitted. The operations from step 1503 to step 1506 will be described below.

[0203] In step 1503, the NEF can obtain the IP address of the UPF through the NRF using the Nnrf_NFDiscovery service operation. Here, the UPF is a UPF that has changed the private IP address of the UE into a public IP address using a Network Address Translation (NAT) device. The Nnrf_NFDiscovery request message transmitted from the NEF to the NRF in step 1503 includes the public IP address of the UE. In addition, this Nnrf_NFDiscovery request message can include the IP domain, DNN, and S-NSSAI associated with the AF ID.

[0204] In step 1504, NRF provides NEF with the IP address of the UPF that includes / inherently contains the NAT that changed the private IP address of the UE to a public IP address via the Nnrf_NFDiscovery response message.

[0205] In step 1505, the NEF, which has acquired the IP address of the UPF, requests the private IP address of the UE from the UPF using the Nupf_GetPrivateUEIP_Get service operation. The Nupf_GetPrivateUEIP_Get request message includes the public IP address and port number of the UE. In addition, this Nupf_GetPrivateUEIP_Get request message may include the IP domain, DNN, and S-NSSAI associated with the AF ID.

[0206] In step 1506, the UPF sends a Nupf_GetPrivateUEIP_Get response message to the NEF in response to receiving the Nupf_GetPrivateUEIP_Get request message. The Nupf_GetPrivateUEIP_Get response message includes the private IP address and (optionally) the IP domain of the UE. Since the UPF knows the private IP address of the UE, which is converted to the public IP address of the UE using the NAT function, the UPF can provide the private IP address of the UE to the NEF. In an optional embodiment, if the UPF has the SUPI (Subscription Permanent Identifier) ​​or GPSI (e.g., MSISDN (Mobile Station International ISDN (Integrated Services Digital Network) Number) information of the UE, the UPF sends the SUPI or GPSI (e.g., MSISDN) information to the NEF, in which case steps 1507 and 1508 below may be omitted.

[0207] In steps 1507 and 1508, the NEF requests the BSF (Binding Support Function) for the UE's session binding information using the Nbsf_Management_Discovery service operation. The Nbsf_Management_Discovery request message that the NEF sends to the BSF in step 1507 includes the UE's IP address, IP domain, and / or DNN and / or S-NSSAI. If the session binding information provided by the BSF does not include the UE's SUPI information, the NEF sends a Response message to the AF including a Result value indicating that the UE ID is not available for provision.

[0208] In step 1509, the NEF, which has received the session binding information of the UE, requests the AF specific UE Identifier (i.e., External Identifier) ​​of the UE from the UDM, which manages the subscription information of the terminal, using the Nudm_SDM_Get service operation (i.e., Nudm_SDM_Get request message). The Nudm_SDM_Get request message transmitted by the NEF to the UDM in step 1509 may include at least one of the SUPI or GPSI (MSISDN) of the UE and the Application Port ID, MTC Provider Information, or AF Identifier. In step 1510, the UDM provides the AF specific UE Identifier (i.e., External Identifier) ​​of the UE requested by the AF to the NEF through the Nudm_SDM_Get response message.

[0209] Then, at step 1511, the NEF can provide the AF with the AF specific UE Identifier (i.e., External Identifier) ​​of the UE provided from the UDM.

[0210] Among the above-described procedures, in step 1509, the NEF provides the GPSI (MSISDN) as a parameter to the UDM using the Nudm_SDM_Get request message (i.e., Nudm_SDM_Get service operation) transmitted to the UDM, and the UDM can obtain the SUPI value of the terminal by performing an identifier translation procedure using the received GPSI information. The UDM can search for the UE External ID value using the SUPI value and the AF ID value and transmit the searched value to the NEF.

[0211] The procedure performed in the existing CP-based UE ID (i.e. AF specific UE Identifier) ​​request method described in Fig. 15 has the following three problems.

[0212] 1. Complex and inefficient procedures; the procedure in Figure 15 involves multiple NFs, including the AF requesting the UE ID, the NEF, the BSF, the NRF, the UDM, and the UPF. This not only generates a lot of control signaling but also places a load on each NF.

[0213] 2. The execution result for the UE ID request is not guaranteed; if there is no terminal SUPI information in the session binding information provided from the BSF during the procedure of Fig. 15, the UE ID request procedure cannot be performed.

[0214] 3. Inefficient use of public IP address resources; The procedure in Figure 15 transmits the public IP address of the UE to the NRF and requests the address of the UPF that provided the IP address. To achieve this, each UPF instance must register with the NRF the public IP address pool it can provide. This means that each UPF has a fixed public IP pool. However, since the number of UEs served by each UPF varies, the number of public IP addresses required by each UPF also varies. Ultimately, to provide stable service, each UPF must have a public IP address pool that is significantly larger than the expected number of UEs it is expected to serve. Furthermore, a UPF that actually provides service to significantly fewer UEs than the expected number of UEs wastes a large number of unused public IP addresses. Conversely, a UPF may face limitations in providing smooth service due to a lack of public IP addresses.

[0215] Accordingly, in order to solve the above-mentioned problem, the present disclosure proposes a UE ID request method based on User Plane (UP).

[0216] FIG. 16 is a diagram illustrating the configuration of a network entity in a communication system according to an embodiment of the present disclosure. The network entity may be one of the AF, UPF, SMF, and UDM described in the embodiments of FIGS. 10 to 15.

[0217] The configuration of FIG. 16 may include a processor (1620) that controls the overall operation of a network entity according to one embodiment of the present disclosure, a transceiver (1600) including a transmitter and a receiver, and a memory (1610). Of course, the present invention is not limited to the above example, and the network entity may include more or fewer components than the configuration illustrated in FIG. 16. The transceiver (1600) may be referred to as a transceiver for wired or wireless communication.

[0218] According to one embodiment of the present disclosure, the transceiver (1600) can transmit and receive signals with network entities or other network entities. The signals transmitted and received with other network entities may include control information and data. In addition, the transceiver (1600) can receive signals through a wired / wireless channel, output the signals to the processor (1620), and transmit the signals output from the processor (1620) through the wired / wireless channel.

[0219] According to one embodiment of the present disclosure, the processor (1620) may control the operation of a network entity to perform any one of the operations of the embodiments of FIGS. 10 to 15 described above. Meanwhile, the processor (1620), the memory (1610), and the transceiver (1600) do not necessarily have to be implemented as separate modules, and may of course be implemented as a single component in the form of a single chip. In addition, the processor (1620) and the transceiver (1600) may be electrically connected. In addition, the processor (1620) may be an Application Processor (AP), a Communication Processor (CP), a circuit, an application-specific circuit, or at least one processor.

[0220] According to one embodiment of the present disclosure, the memory (1610) can store data such as basic programs, application programs, and setting information for the operation of a network entity. In particular, the memory (1610) provides the stored data upon request of the processor (1620). The memory (1610) can be configured as a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, there can be a plurality of memories (1610). In addition, the processor (1620) can perform the above-described embodiments based on a program for performing the above-described embodiments of the present disclosure stored in the memory (1610).

[0221] It should be noted that the aforementioned configuration diagrams, examples of control / data signal transmission methods, examples of operational procedures, and configuration diagrams are not intended to limit the scope of the present disclosure. That is, not all components, entities, or operational steps described in the embodiments of the present disclosure should be construed as essential components for implementing the disclosure, and implementations may be made within a scope that does not detract from the essence of the disclosure even if only some components are included. Furthermore, each embodiment may be combined and operated as needed. For example, parts of the methods proposed in the present disclosure may be combined to operate network entities and terminals.

[0222] The operations of the base station or terminal described above can be realized by providing a memory device storing the corresponding program code in any component within the base station or terminal device. That is, the control unit of the base station or terminal device can execute the operations described above by reading and executing the program code stored in the memory device using a processor or CPU (Central Processing Unit).

[0223] It should be noted that the aforementioned configuration diagrams, examples of control / data signal transmission methods, examples of operational procedures, and configuration diagrams are not intended to limit the scope of the present disclosure. That is, not all components, entities, or operational steps described in the embodiments of the present disclosure should be construed as essential components for implementing the disclosure, and implementations may be made within a scope that does not detract from the essence of the disclosure even if only some components are included. Furthermore, each embodiment may be combined and operated as needed. For example, parts of the methods proposed in the present disclosure may be combined to operate network entities and terminals.

[0224] The operations of a network entity, base station, or terminal described above can be realized by providing a memory device storing the corresponding program code in any component within the network entity, base station, or terminal device. That is, the control unit of the network entity, base station, or terminal device can execute the operations described above by reading and executing the program code stored in the memory device using a processor or CPU (Central Processing Unit).

[0225] The various components and modules of the network entity, base station or terminal device described in this specification may be operated using hardware circuits, such as logic circuits based on complementary metal oxide semiconductors, firmware, software and / or hardware and firmware and / or software embedded in a machine-readable medium. For example, various electrical structures and methods may be implemented using electrical circuits such as transistors, logic gates and application-specific semiconductors.

[0226] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of the present disclosure.

[0227] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0228] Additionally, the program may be stored in an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present disclosure.

[0229] In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed in the singular or plural form, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0230] Meanwhile, although the detailed description of the present disclosure has described specific embodiments, it is obvious that various modifications are possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be determined not only by the scope of the following claims but also by equivalents of the scope of the claims. In other words, it will be apparent to those skilled in the art that other modifications based on the technical idea of ​​the present disclosure are possible. In addition, each of the above embodiments can be combined and operated with each other as needed. For example, parts of the methods proposed in the present disclosure can be combined with each other to operate a base station and a terminal. In addition, although the above embodiments have been presented based on a 5G, NR system, other modifications based on the technical idea of ​​the above embodiments can be implemented with other systems such as LTE, LTE-A, and LTE-A-Pro systems.

[0231] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. In a method of operating a Network Exposure Function (NEF) for searching for an AF specific UE (user equipment) identifier (AF specific UE ID) in a wireless communication system, An action of sending a first message (Nupf_GetPrivateUEIP_Get request) requesting a private IP address (private UE IP) of the UE to the UPF (user plane function); An action of receiving a second message (Nupf_GetPrivateUEIP_Get response) containing the private IP address of the UE from the UPF; An action of transmitting a third message (Nudm_SDM_Get request) requesting the AF specific UE identifier to UDM (unified data management); and Including an operation of receiving a fourth message (Nudm_SDM_Get response) including the AF specific UE identifier from the UDM; A method, characterized in that the second message (Nupf_GetPrivateUEIP_Get response) further includes a SUPI (subscription permanent identifier) ​​or MSISDN (mobile station international integrated services digital network number) of the UE.

2. In the first paragraph, the third message (Nudm_SDM_Get request) is A method characterized in that it further includes at least one of the SUPI of the UE, the MSISDN of the UE, an application port identifier (application port ID), machine type communication (MTC) provider information, and an application function (AF) identifier.

3. In paragraph 1, A method characterized in that, when the UPF has information about the SUPI of the UE or the MSISDN of the UE, a message exchange procedure for session binding information of the UE between the NEF and a binding support function (BSF) is omitted.

4. In paragraph 1, An operation of requesting the AF specific UE identifier and receiving a message (Nnef_UDID_Get request) including address information of the UE (UE address) and the ID of the AF from the AF; and A method further comprising the action of approving a request for said AF specific UE identifier.

5. In paragraph 1, An action of transmitting a message (Nnrf_NFDiscovery request) containing the public IP address of the UE to the NRF (network repository function); and A method further comprising an action of receiving a message (Nnrf_NFDiscovery response) including an IP address of the UPF from the NRF.

6. In paragraph 5, A method characterized in that the public IP address of the UE is converted to the private IP address of the UE based on the NAT (network address translation) function of the UPF.

7. In paragraph 1, A method further comprising the action of transmitting the AF specific UE identifier received from the UDM to the AF.

8. In a NEF (Network Exposure Function) device for searching for an AF specific UE (user equipment) identifier (AF specific UE ID) in a wireless communication system, Transmitter and receiver; and comprising a processor, said processor comprising: The first message (Nupf_GetPrivateUEIP_Get request) requesting the private IP address of the UE is sent to the UPF (user plane function), Receive a second message (Nupf_GetPrivateUEIP_Get response) containing the private IP address of the UE from the UPF, A third message (Nudm_SDM_Get request) requesting the above AF specific UE identifier is transmitted to UDM (unified data management), Receive a fourth message (Nudm_SDM_Get response) including the AF specific UE identifier from the UDM, A device characterized in that the second message (Nupf_GetPrivateUEIP_Get response) further includes a SUPI (subscription permanent identifier) ​​or MSISDN (mobile station international integrated services digital network number) of the UE.

9. In paragraph 8, the third message (Nudm_SDM_Get request) is A device characterized in that it further includes at least one of the SUPI of the UE, the MSISDN of the UE, an application port identifier (application port ID), machine type communication (MTC) provider information, and an application function (AF) identifier.

10. In paragraph 8, A device characterized in that, when the UPF has information about the SUPI of the UE or the MSISDN of the UE, a message exchange procedure for session binding information of the UE between the NEF and a binding support function (BSF) is omitted.

11. In the 8th paragraph, the processor, Requesting the AF specific UE identifier and receiving a message (Nnef_UDID_Get request) including address information of the UE (UE address) and the ID of the AF from the AF, A device characterized by approving a request for the AF specific UE identifier.

12. In the 8th paragraph, the processor, Send a message (Nnrf_NFDiscovery request) containing the public IP address of the above UE to NRF (network repository function), A device characterized by receiving a message (Nnrf_NFDiscovery response) including the IP address of the UPF from the NRF.

13. In paragraph 12, A device characterized in that the public IP address of the UE is converted to the private IP address of the UE based on the NAT (network address translation) function of the UPF.

14. In the 8th paragraph, the processor, A device characterized by transmitting the AF specific UE identifier received from the UDM to the AF.

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