Apparatus and method for psa-upf relocation in wireless communication system

Abstract

The present disclosure relates to a fifth generation (5G) or pre-5G communication system to be implemented to support higher data transmission rates beyond a fourth generation (4G) communication system such as long term evolution (LTE). According to various embodiments of the present disclosure, a method for operating a network node such as an application function (AF) node in a wireless communication system is provided, the method including the steps of generating an AF request including information related to one or more data path delays, and transmitting the information related to the one or more data path delays to a session management function (SMF) node through a network exposure function (NEF) node.

Description

Technical Field

[0001] The present disclosure relates generally to wireless communication systems, and more particularly, to an apparatus and method for Protocol Data Unit (PDU) Session Anchor-User Plane Function (PSA-UPF) relocation in a wireless communication system. Background Art

[0002] To meet the growing demand for wireless data services since the commercialization of the fourth-generation (4G) communication system, efforts have been underway to develop enhanced fifth-generation (5G) communication systems, or pre-5G communication systems. For this reason, 5G communication systems, or pre-5G communication systems, are referred to as beyond-4G network communication systems or post-Long Term Evolution (LTE) systems.

[0003] 5G communication systems are being considered for implementation in ultra-high frequency (millimeter wave (mmWave)) bands (e.g., the 60 GHz band) to achieve high data transmission rates. For 5G communication systems, technologies such as beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large antennas are being discussed to reduce radio wave path loss and increase the transmission distance of radio waves in ultra-high frequency bands.

[0004] In addition, in 5G communication systems, technologies for the following are being developed to enhance the system's network: evolved small cells, advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device communications (D2D), wireless backhaul, mobile networks, coordinated communications, coordinated multi-point (CoMP), and interference cancellation.

[0005] In addition, in 5G systems, hybrid frequency shift keying as an advanced coding modulation (ACM) scheme, as well as quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC) are being developed; and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as enhanced access technologies. Summary of the Invention

[0006] Technical issues

[0007] Based on the above discussion, the present disclosure relates to an apparatus and method for Protocol Data Unit (PDU) Session Anchor-User Plane Function (PSA-UPF) relocation in a wireless communication system.

[0008] Solution to the problem

[0009] According to various embodiments of the present disclosure, a method for operating an application function (AF) node in a wireless communication system is provided. The method includes: generating an AF request including information related to one or more data path delays; and transmitting the information related to the one or more data path delays to a session management function (SMF) node via a network exposure function (NEF) node.

[0010] According to various embodiments of the present disclosure, an AF node in a wireless communication system is provided. The network includes: at least one transceiver; and at least one processor, wherein the at least one processor is configured to: generate an AF request including information related to one or more data path delays; and transmit the information related to the one or more data path delays to an SMF node via a NEF node.

[0011] Beneficial effects of the present invention

[0012] Apparatuses and methods according to various embodiments of the present disclosure provide an apparatus and method for Protocol Data Unit (PDU) Session Anchor-User Plane Function (PSA-UPF) relocation in a wireless communication system.

[0013] Effects achieved in the present disclosure are not limited to those mentioned above, and other effects not mentioned above may be clearly understood by those skilled in the art based on the description provided below. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a diagram illustrating an example of a 5G system architecture expressed using reference points in a wireless communication system;

[0015] Figure 2 is a diagram illustrating a configuration of a network entity in a wireless communication system according to various embodiments of the present disclosure;

[0016] Figure 3 is a diagram illustrating a network configuration taking into account data path delay in a wireless communication system according to various embodiments of the present disclosure;

[0017] Figure 4 is a diagram illustrating a process of establishing a data path delay database in a wireless communication system according to various embodiments of the present disclosure;

[0018] Figure 5 is a diagram illustrating a process for providing network delay estimation information in a wireless communication system according to various embodiments of the present disclosure;

[0019] Figure 6 is a diagram illustrating a PSA-PPF relocation determination process considering data path delay in a wireless communication system according to various embodiments of the present disclosure;

[0020] Figure 7 is a diagram illustrating an AF service impact request procedure including a data path delay information request in a wireless communication system according to various embodiments of the present disclosure;

[0021] Figure 8 is a diagram illustrating a process of notifying a UPF of a change event and a process of determining whether to relocate an application in an AF in a wireless communication system according to various embodiments of the present disclosure;

[0022] Figure 9 is a diagram illustrating a QoS monitoring process in a wireless communication system according to various embodiments of the present disclosure;

[0023] Figure 10 is a diagram illustrating a one-way packet delay monitoring measurement method in a wireless communication system according to various embodiments of the present disclosure; and

[0024] Figure 11 2 is a diagram illustrating a bidirectional packet delay monitoring and measurement method in a wireless communication system according to various embodiments of the present disclosure. DETAILED DESCRIPTION

[0025] The terms used in this disclosure are used to describe specific embodiments and are not intended to limit the scope of other embodiments. Unless otherwise stated, terms in the singular may include plural forms. All terms used herein, including technical or scientific terms, may have the same meanings as those skilled in the art would normally understand. It will also be understood that terms defined in dictionaries may be interpreted as having the same or similar meanings as the contextual meanings of the relevant prior art, rather than idealized or overly formal meanings, unless explicitly defined as such in the disclosure herein. In some cases, even if terms are defined in the specification, they should not be interpreted as excluding embodiments of the present disclosure.

[0026] In the various embodiments of the present disclosure described below, the hardware method will be described by way of example. However, the various embodiments of the present disclosure include technologies using both hardware and software, and therefore, the software-based method is not excluded.

[0027] The disclosure described below relates to an apparatus and method for processing service traffic in a wireless communication system.

[0028] When used herein, the terms indicating a signal, a channel, control information, a network entity, and a device component are merely examples for ease of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms with the same technical meaning may be used.

[0029] When used herein, the terms used to identify access nodes, network entities or network functions (NFs), messages, interfaces between network entities, and various identification information are merely examples for ease of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms with the same technical meaning may be used.

[0030] In addition, the present disclosure describes various embodiments by using terms used in some communication standards (eg, the Third Generation Partnership Project (3GPP)), but these embodiments are merely examples. Various embodiments of the present disclosure can be easily modified and applied to other communication systems.

[0031] Figure 1 An example of a 5G system architecture expressed using reference points in a wireless communication system is shown.

[0032] refer to Figure 1 , the 5G system architecture may include various components (i.e., network functions (NFs)), and Figure 1 Some of the components are shown, such as Authentication Server Function (AUSF), (Core) Access and Mobility Management Function (AMF), Session Management Function (SMF), Policy Control Function (PCF), Application Function (AF), Unified Data Management (UDM), Data Network (DN), User Plane Function (UPF), (Radio) Access Network ((R)AN), Terminal (i.e., User Equipment (UE)).

[0033] The corresponding NF support functions are as follows.

[0034] -AUSF stores data used for UE authentication.

[0035] -AMF provides UE-based access and mobility management functions, and basically, one UE can be connected to one AMF.

[0036] Specifically, AMF supports functions such as: signaling between CN nodes for mobility between 3GPP access networks, termination of the Radio Access Network (RAN) CP interface (i.e., N2 interface), termination of NAS signaling (N1), NAS signaling security (NAS encryption and integrity protection), AS security control, registration management (registration area management), connectivity management, idle mode UE reachability (including control and execution of paging retransmissions), mobility management control (subscription and policy), intra-system mobility and inter-system mobility support, network slicing support, SMF selection, lawful intercept (regarding AMF events and interface to LI system), providing transmission of session management (SM) messages between UE and SMF, transparent proxy for SM message routing, access authentication, access authorization including roaming authorization check, providing transmission of SMS messages between UE and SMSF, security anchor function (SAF) and / or security context management (SCM).

[0037] Some or all of the functionality of an AMF may be supported in a single instance of an AMF.

[0038] -DN refers to, for example, operator services, Internet access, or third-party services. DN transmits downlink protocol data units (PDUs) to the UPF, or receives PDUs transmitted from the UE from the UPF.

[0039] -PCF receives information about packet flows from application servers and provides functions for determining policies such as mobility management, session management, etc. Specifically, PCF supports functions such as supporting a unified policy framework for controlling network operations, providing policy rules for CP functions (e.g., AMF, SMF, etc.) to implement policy rules, and implementing a front end for accessing relevant subscription information to determine policies within the user data repository (UDR).

[0040] -SMF provides session management functions. If a UE has multiple sessions, the corresponding sessions can be managed by different SMFs.

[0041] Specifically, SMF supports functions such as: session management (e.g., session establishment, correction, and cancellation, including tunnel maintenance between UPF and AN nodes), UE IP address allocation and management (optionally including authentication), selection and control of UP functions, service steering configuration for routing services to appropriate destinations in UPF, termination of interfaces toward policy control functions, implementation of the control part of policies and quality of service (QoS), lawful interception (regarding SM events and interfaces to LI systems), termination of the SM part of NAS messages, downlink data notification, initiator of specific SM information (transmission via AMF over N2 to AN), SSC mode determination of sessions, roaming functions, etc.

[0042] Some or all of the functionality of an SMF may be supported in a single instance of an SMF.

[0043] -UDM stores user subscription data, policy data, etc. UDM consists of two parts, namely, application front end (FE) and user data repository (UDR).

[0044] The FE includes the UDM FE, which is responsible for location management, subscription management, and credentials, and the PCF, which is responsible for policy control. The UDR stores the data required by the functions provided by the UDF-FE, as well as the policy profiles required by the PCF. The data stored in the UDR includes user subscription data, including subscription identifiers, security credentials, access and mobility-related subscription data, session-related subscription data, and policy data. The UDM-FE accesses the subscription information stored in the UDR and supports functions such as authentication credential processing, user identity handling, access authentication, registration / mobility management, subscription management, and SMS management.

[0045] - The UPF transmits the downlink PDU received from the DN to the UE via the (R)AN, and transmits the uplink PDU received from the UE to the DN via the (R)AN.

[0046] Specifically, the UPF supports functions such as: an anchor point for intra-RAT / inter-RAT mobility, an external PDU session point for interconnection with a data network, packet routing and forwarding, a user plane portion of packet inspection and policy rule enforcement, lawful interception, service usage reporting, an uplink classifier for supporting routing of service flows to the data network, a branch point for supporting multi-homed PDU sessions, QoS processing for the user plane (e.g., packet filtering, gating, uplink / downlink rate enforcement), uplink service verification (SDF mapping between service data flows (SDF) and QoS flows), transport layer packet marking within the uplink and downlink, downlink packet buffering, and downlink data notification triggering functions, etc. Some or all of the functions of the UPF may be supported in a single instance of a UPF.

[0047] -AF interacts with the 3GPP core network to provide services (e.g., supporting functions such as: application impact on service routing, network capability exposure mode, interaction with the policy framework for policy control).

[0048] -(R)AN refers to a new radio access network that supports both Evolved-UTRA (E-UTRA), which is an evolved version of 4G radio access technology, and New Radio (NR) access technology (e.g., gNB).

[0049] The gNB supports functions such as: functions for radio resource management (i.e., radio bearer control, radio admission control), connection mobility control, dynamic allocation of resources to UEs in uplink / downlink (i.e., scheduling), Internet Protocol (IP) header compression, encryption and integrity protection of user data flows, selection of AMF upon UE attachment when no route to the AMF is determined based on information provided to the UE, user plane data routing to the UPF, control plane information routing to the AMF, connection establishment and cancellation, scheduling and transmission of paging messages (from the AMF), scheduling and transmission of system broadcast information (from the AMF or operation and maintenance (O&M)), mobility measurements and scheduling and measurement reporting configuration, transport layer packet marking in the uplink, session management, network slicing support, QoS flow management and mapping to data radio bearers, support for UEs in inactive mode, distribution function of NAS messages, NAS node selection function, radio access network sharing, dual connectivity, and tight interworking between NR and E-UTRA.

[0050] UE stands for User Equipment. A User Equipment may be referred to as a terminal, Mobile Equipment (ME), or Mobile Station (MS). A User Equipment may be a portable device such as a notebook computer, mobile phone, personal digital assistant (PDA), smartphone, multimedia device, or a non-portable device such as a personal computer (PC) or vehicle-mounted device.

[0051] To explain clearly, Figure 1 Unstructured Data Storage Network Function (UDSF), Structured Data Storage Network Function (SDSF), Network Exposure Function (NEF) and NF Repository Function (NRF) are not shown, but Figure 5 All NFs shown in FIG can interwork with UDSF, NEF and NRF when necessary.

[0052] -NEF provides means for securely exposing functionality provided by 3GPP network functions (e.g., third parties), internal exposure / re-exposure, application functions, services, and edge computing capabilities. The NEF receives information from other network functions (based on the exposed capabilities of the other network functions). The NEF can store the received information as structured data using standardized interfaces for data storage network functions. The stored information can be re-exposed by the NEF to other network functions (one or more) and application functions (one or more) and can be used for other purposes, such as analysis.

[0053] -NRF supports service discovery. NRF receives NF discovery requests from NF instances and provides information about discovered NF instances to the NF instances. In addition, it maintains the available NF instances and the services supported by the NF instances.

[0054] -SDSF is an optional feature used to support the storage and retrieval of information as structured data by a certain NEF.

[0055] -UDSF is an optional function used to support the storage and retrieval of information as unstructured data by a certain NF.

[0056] For ease of explanation, Figure 1 A reference model is shown when the UE accesses one DN by using one PDU session, but the present disclosure is not limited thereto.

[0057] The UE can access two (i.e., local and central) data networks simultaneously by using multiple PDU sessions. In this case, two SMFs can be selected for different PDU sessions. However, each SMF may have the ability to control both the local UPF and the central UPF within a PDU session.

[0058] Additionally, the UE may simultaneously access two (ie, local and central) data networks provided in a single PDU session.

[0059] In the 3GPP system, the conceptual link connecting the NFs in the 5G system is defined as a reference point. Figure 1 The reference points included in the represented 5G system architecture are exemplified as follows:

[0060] -N1: reference point between UE and AMF;

[0061] -N2: reference point between (R)AN and AMF;

[0062] -N3: reference point between (R)AN and UPF;

[0063] -N4: reference point between SMF and UPF;

[0064] -N5: reference point between PCF and AF;

[0065] -N6: Reference point between UPF and data network;

[0066] -N7: Reference point between SMF and PCF;

[0067] -N8: Reference point between UDM and AMF;

[0068] -N9: reference point between two core UPFs;

[0069] -N10: Reference point between UDM and SMF;

[0070] -N11: Reference point between AMF and SMF;

[0071] -N12: reference point between AMF and AUSF;

[0072] -N13: Reference point between UDM and Authentication Server Function (AUSF);

[0073] - N14: reference point between two AMFs; and

[0074] -N15: Reference point between PCF and AMF in non-roaming case, and between PCF and AMF in visited network in roaming case.

[0075] Figure 2 The configuration of a network entity in a wireless communication system according to various embodiments of the present disclosure is shown.

[0076] The network entity of the present disclosure is a concept including network functions according to system implementation methods. The term "unit" or terms ending with the suffixes "-er" and "-or" used in the following description refer to a unit that processes at least one function or operation and can be implemented by hardware, software, or a combination of hardware and software.

[0077] The network entity according to various embodiments of the present disclosure may include a communication unit 210 , a storage device 220 , and a controller 230 to control overall operations of the network entity 200 .

[0078] The communication unit 210 transmits signals to other network entities and receives signals from other network entities. Therefore, the entirety or a portion of the communication unit 210 may be referred to as a "transmitter 211," a "receiver 213," or a "transceiver 210."

[0079] The storage device 220 may store data such as basic programs, applications, configuration information, etc. used for the operation of the network entity 200. The storage device 220 may be configured by a volatile memory, a non-volatile memory, or a combination of a volatile memory and a non-volatile memory. In addition, the storage device 220 provides the stored data according to the request of the controller 230.

[0080] The controller 230 controls the overall operation of the network entity 200. For example, the controller 230 can transmit and receive signals via the communication unit 210. In addition, the controller 230 can write and read data on or from the storage device 220. In addition, the controller 230 can perform the functions of the protocol stack required by the communication standard. To achieve this, the controller 230 may include a circuit, a dedicated circuit, at least one processor or microprocessor, or may be part of a processor. In addition, the communication unit 210 and a portion of the controller 230 may be referred to as a communication processor (CP). According to various embodiments of the present disclosure, the controller 230 can control the network entity 200 to perform specific operations.

[0081] The communication unit 210 and the controller 230 do not need to be implemented as separate modules and can be implemented as a single chip or a configuration unit in the form of a software block. The communication unit 210, the storage device 220, and the controller 230 can be electrically connected to each other. In addition, the operation of the network entity 200 can be implemented by providing a storage device 220 that stores the corresponding program code in the network entity 200.

[0082] The network entity 200 includes a network node and can be one of the following: base station (RAN), AMF, SMF, UPF, NF, NEF, NRF, CF, NSSF, UDM, AF, AUSF, SCP, UDSF, NWDAF, context storage device, operation, administration and maintenance (OAM), EMS, configuration server, identifier (ID) management server.

[0083] Various embodiments of the present disclosure provide a method for managing sessions based on the mobility of a terminal in a cellular wireless communication system, such as a 5G system. Various embodiments of the present disclosure relate to a method for relocating an application server accessed by a terminal based on the mobility of the terminal in edge computing.

[0084] 3GPP, which is responsible for the standardization of cellular mobile communications, calls the new core network structure 5G Core (5GC) to achieve the evolution from the existing 4G LTE system to the 5G system and continues to standardize it.

[0085] Compared with the Evolved Packet Core (EPC), which is the network core for existing 4G, 5GC supports the following distinct functions.

[0086] First, network slicing is introduced in 5GC. 5GC should support various types of terminals and services, as required by 5G. For example, these types of terminals and services may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC). These terminals and services have different requirements for the core network. For example, eMBB services require high data rates, while URLLC services require high stability and low latency. A network slicing solution is recommended to meet these requirements for various services.

[0087] Network slicing is a method of virtualizing a physical network to form multiple logical networks, and the corresponding network slice instances (NSIs) can have different characteristics. Therefore, each NSI has a network function (NF) suitable for its own characteristics and can meet various service requirements. By allocating an NSI suitable for the service characteristics required by each terminal, a variety of 5G services can be effectively supported.

[0088] Second, 5GC can smoothly support the network virtualization paradigm by separating the mobility management function and the session management function. In the existing 4G LTE, all terminals can receive services in the network by exchanging signaling with a single core device, which is the mobility management entity (MME) responsible for registration, authentication, mobility management and session management functions. However, in 5G, the number of terminals has increased explosively, and the mobility and service / session characteristics to be supported are subdivided according to the type of terminal. For this reason, if all functions are supported by a single device such as MME, the scalability of adding entities according to necessary functions may be degraded. Therefore, various functions are being developed based on the structure of separating the mobility management function and the session management function in order to enhance scalability according to the function / implementation complexity of the core device responsible for the control plane and the signaling load.

[0089] In the prior art 3GPP 5G core network, the relocation of the PDU Session Anchor - User Plane Function (PDU-UPF) does not take into account data path latency. That is, in the prior art 3GPP 5G core network, the relocation of the PSA-UPF is determined by utilizing topology information in the Session Management Function (SMF). Various embodiments of the present disclosure provide a method for a 5G core network and application that determines whether to relocate the PSA-UPF based on a request from an application function requiring low-latency services by taking into account data path latency.

[0090] According to various embodiments of the present disclosure, the 5G core network and applications determine the mobility of the PSA-UPF by considering the latency of the data path. When a terminal receiving services of one or more applications leaves the service area where the currently connected applications are located and a handover occurs, and the PSA-UPF moves, the terminal's IP address may change and the service may be interrupted.

[0091] According to various embodiments of the present disclosure, when an existing data path in an area to which a terminal moves satisfies a delay requested by an application, service interruption can be minimized by not performing PSA-UPF relocation by considering the delay requested by the application.

[0092] According to various embodiments of the present disclosure, when the terminal moves and a service is provided through a newly changed path, or when the delay requested by the application is not met, a path to a new PSA-UPF can be reconfigured and a service that meets the delay time requested by the application can be provided.

[0093] Figure 3 A network configuration considering data path delay in a wireless communication system according to various embodiments of the present disclosure is shown.

[0094] refer to Figure 3 , the terminal 311 is connected to the RAN nodes 321 , 322 , 323 , 324 , 325 , and 326 through a Uu interface, and the delay time between the terminal 311 and the RAN nodes 321 , 322 , 323 , 324 , 325 , and 326 is expressed as Duu.

[0095] The RAN nodes 321, 322, 323, 324, 325, 326 and the UPFs 331, 332 are connected to each other via the N3 interface, and the delay time of the N3 section is expressed as Dn3. The delay time between the RAN nodes 321, 322, 323, 324, 325, 326 and the UPFs 331, 332 may be the network delay time that occurs when packets pass through network switches and routers installed between the physical RAN nodes 321, 322, 323, 324, 325, 326 and the UPFs 331, 332. This delay time Dn3 may be proportional to the physical distance. Figure 3 , RAN node 1 321 located at a close distance from the data center where the UPF 331 is located may have a delay time of 1 ms, RAN node 2 322 located at an intermediate distance may have a delay time of 4 ms, and RAN node 3 323 located at a long distance may have a delay time of 9 ms.

[0096] The UPF 331 and the UPF 332 are connected to each other via the N9 interface, and the delay time of the N9 portion is expressed as Dn9. Similar to the delay time between the RAN nodes 321, 322, 323, 324, 325, 326 and the UPFs 331, 332, the delay time between the UPFs 331, 332 may be a network delay time that occurs when a packet passes through a network switch and router installed between the UPFs 331, 332, and such a delay time Dn9 may be proportional to the physical distance. Figure 3 , the two UPFs 331 , 332 may have a delay time of 9 ms therebetween.

[0097] The data path delay D in the 5G core network can be calculated as shown in Equation 1 presented below:

[0098] D=Duu+Dn3+Dn9....Equation 1

[0099] In Equation 1, D is the delay time between the terminal 311 and the PSA-UPF 332. Duu is the UL / DL packet delay time between the terminal 311 and the RAN node 323. Dn3 is the UL / DL packet delay time between the RAN node 323 and the UPF 331. Dn9 is the packet delay time between the intermediate UPF (I-UPF) 331 and the PSA-UPF 332 when the I-UPF is present.

[0100] The SMF 340 connects to the PSA-UPF 332 via the UPF N3 interface to perform QoS monitoring and monitoring reporting functions.

[0101] The PCF 350 provides a QoS monitoring function for measuring a delay time, and receives a QoS monitoring request from a network function (NF) requesting the QoS monitoring function such as the NWDAF 360, and provides a function of the requested QoS monitoring report.

[0102] The NWDAF 360 configures a database about the following by utilizing the QoS monitoring function: terminal location, RAN node identifier (ID), UPF identifier, PSA-UPF identifier, SMF service area, packet delay time about the UPF service area, and delay time for each interface in Uu, Dn3, and Dn9.

[0103] refer to Figure 1 , in step 301 , the NWDAF 360 transmits a monitoring request to the PCF 350 .

[0104] In step 302, the PCF 350 transmits a QoS monitoring policy on a service data flow (SDF) among policy and charging control (PCC) rules.

[0105] In step 303, the SMF 340 activates the measurement of D of Equation 1. Specifically, the SMF 340 generates / changes a PDU session.

[0106] In step 304, the PSA-UPF 332 measures the round trip time (RTT) per QoS flow, per UE, or General Packet Radio Service (GPRS) Tunneling Protocol-User Plane (GTP-U) level.

[0107] In step 305, the PSA-UPF 332 transmits the QoS monitoring report to the SMF 340 and / or the NWDAF 360. In addition, the SMF 340 transmits the QoS monitoring report to the PCF 350 and / or the NWDAF 360. In addition, the PCF 350 transmits the QoS monitoring report to the NWDAF 360.

[0108] In step 306, the NWDAF 360 performs database storage and establishment. According to an embodiment, the database may store at least one of the following: terminal location, RAN node ID, UPF ID, SMF ID, SMF service area, UPF service area, packet data delay D, Duu, Dn3 / n9.

[0109] <First embodiment>

[0110] In the first embodiment, reference will be made to Figure 4 Describe the process of establishing a data path delay database. The process of establishing a data path delay database follows Figure 4 The process shown.

[0111] Figure 4 The data path delay database establishment process in a wireless communication system according to various embodiments of the present disclosure is shown.

[0112] exist Figure 4 Step 400 before step 401 (in Figure 4 ), the NWDAF 480 selects a plurality of sample terminals (UEs) 420 to collect data on packet network delay.

[0113] At step 410, the NWDAF 480 transmits a QoS monitoring request regarding the sample UE 420 selected at step 400 to the PCF 470. The QoS monitoring request transmitted by the NWDAF 480 to the PCF 470 may include the following information:

[0114] (1) Terminal identification information: This information may include at least one of a Subscription Permanent Identifier (SUPI), a General Public Subscription Identifier (GPSI), and a Mobile Subscriber Integrated Services Digital Network (ISDN) (MS-ISDN) number for identifying the terminal. Alternatively, this information may include a group identifier for displaying multiple terminal identification information;

[0115] (2) Local information indicating terminals existing in a specific area: When all or some terminals in a specific area are targeted, the information may include area of ​​interest (AOI) information. The AOI information may include at least one of a tracking area collection, a UPF service area, an SMF service area, a cell list, and a RAN node identifier list; and

[0116] (3) QoS monitoring information for each terminal requesting a QoS report: This information indicates the QoS measurement information to be measured and includes the following information:

[0117] (3-1) Delay time measurement information in each section;

[0118] (3-1-1) Data delay time information between the terminal and PSA-UPF;

[0119] (3-1-2) Measurement information in each section (identification information of each time and each section of the Uu interface, N3 or N9); and

[0120] (3-1-3) One-way or two-way measurement information.

[0121] In step 402, the PCF 470 that receives the QoS monitoring request from the NWDAF 480 may identify whether the request information complies with the operator's policy and may approve the QoS monitoring request. When the PCF 470 approves the QoS monitoring, the PCF 470 transmits the QoS monitoring policy to the SMF 460. The QoS monitoring policy includes the following.

[0122] In step 403, the SMF 460 initiates a QoS measurement process or a network delay measurement process. Specifically, in step 403, QoS measurement may be activated and a PDU session may be generated / changed. In step 404, the SMF 460 may transmit a QoS monitoring request to the RAN 430. In step 405, the SMF 460 may transmit a QoS monitoring request to the I-UPF 440. Figure 9 The detailed QoS measurement process is described in the fifth embodiment.

[0123] At step 406, PSA-UPF 450, I-UPF 440, and RAN 430 measure the RTT on the Uu, N3, and N9 interfaces. The RTT measurement may include a QoS monitoring report on PSA-UPF 450. Figure 9 The detailed QoS measurement process is described in the fifth embodiment.

[0124] In step 407, PSA-UPF 450 transmits a QoS monitoring report to SMF 460 based on the measured RTT. In step 408, PSA-UPF 450 may transmit the QoS monitoring report on the SMF to SMF 460. In step 409, SMF 460 may transmit the QoS monitoring report to PCF 470. In step 410, PCF 470 may transmit the QoS monitoring report to NWDAF 480. In step 411, SMF 460 may directly transmit the QoS monitoring report to NWDAF 480. In step 412, PSA-UPF 450 may directly transmit the QoS monitoring report to NWDAF 480.

[0125] The QoS monitoring report transmitted by PCF 470 to NWDAF 480 may include the following information:

[0126] (1) Information on the delay time spent in the terminal and PSA-UPF (RTT information or one-way delay time information);

[0127] (2) Information on the delay time spent in the Uu interface (RTT information or one-way delay time information);

[0128] (3) Information about the delay of the N3 section;

[0129] (3-1) Delay information in the N3 section: one-way delay time or RTT; and

[0130] (3-2) Identification information of the N3 part: UPF identifier and RAN node ID information, tunnel identifier (e.g., Tunnel Endpoint Identifier (TEID) and UPF and PSA-UPF addresses) information; and

[0131] (4) Information about the delay in the N9 section;

[0132] (4-1) Delay time information of the N9 part: one-way delay information or RTT delay time information; and

[0133] (4-2) Identification information (I-UPF identifier and PSA-UPF identifier) ​​and tunnel identifier (eg, TEID and I-UPF, PSA-UPF address) information of the N9 part.

[0134] Among the information included in the QoS monitoring report transmitted by the PCF 470 to the NWDAF 480 , the information on the delay time may include statistical information indicating results of multiple measurements of the delay time, such as an average value, a maximum value, a minimum value, or a median value.

[0135] In step 413, NWDAF 480 records the RTT value measured for the selected terminal. In step 413, NWDAF 480 may store and establish a database. The information stored in the database may include UE location, RAN node ID, UPF ID, SMF ID, SMF service area, UPF service area, and packet data delays for Uu, N3, and N9. For step 413, steps 401 and 407 may be repeatedly performed for multiple selected terminals. The information stored in the database in step 413 may include at least one of the following:

[0136] (1) Terminal location information;

[0137] (2) RAN node ID;

[0138] (3)UPF ID, SMF ID;

[0139] (4) UPF service area information, SMF service area information;

[0140] (5) Packet data delay information measured for each of the Uu, N3, and N9 interfaces.

[0141] <Second embodiment>

[0142] In the second embodiment, reference will be made to Figure 5 Describes the process of providing network delay estimation information.

[0143] Figure 5 A process of providing network delay estimation information in a wireless communication system according to various embodiments of the present disclosure is shown.

[0144] The NWDAF 520 may provide network delay information estimated from information collected by measuring QoS according to the location of the terminal, a radio access technology (RAT) type, a RAN node ID, and a UPF ID.

[0145] In step 501, the SMF or other consumer NF 510 transmits a request for estimation information about the data path to the NWDAF 520. The request in step 501 may include at least one of the following information: current UE location, RAT type, RAN node ID, UPF ID, SMF ID, UPF service area.

[0146] In step 502, NWDAF 520 estimates estimable delay information based on the collected information by considering the terminal's current location, current time, service area time, service area UPF ID, and UPF path. Depending on the embodiment, delay time D can be estimated by considering the UE location, RAT type, RAN node ID, and UPF ID. Depending on the embodiment, delay time D2 can be estimated by considering the UE location, RAT type, RAN node ID, and UPF path.

[0147] In step 503 , the NWDAF 520 transmits the network delay information estimated at step 502 to the consumer NF (eg, SMF) 510 that has requested the estimation.

[0148] <Third embodiment>

[0149] In the third embodiment, reference will be made to Figure 6 Describe the PSA-UPF relocation process based on network delay requirements.

[0150] Figure 6 A PSA-UPF relocation determination process considering data path delay in a wireless communication system according to various embodiments of the present disclosure is illustrated.

[0151] The AF 660 generates an AF request message in step 601. When generating the AF request message, the AF 660 may generate the AF request message including a delay requirement of a data path required by an application.

[0152] The latency requirements for the data path can include the following information.

[0153] (1) Maximum data path delay time: The value of the maximum data path delay time is the target delay time of the data path targeted by AF 660. When SMF 620 is able to perform application relocation through AF impact request, the delay time of the data path between the relocated PSA-UPF and the terminal should be less than or equal to the value of the maximum data path delay time provided in this information. SMF 620 can obtain the estimated delay time between the PSA-UPF reselected according to the movement of the terminal and the terminal. SMF 620 can use a value previously calculated for the estimated delay time, or can obtain the estimated delay time by requesting from NWDAF. SMF 620 can determine whether the estimated delay time between the terminal and the PSA-UPF meets the requirements for the requested data path delay time, and therefore, can determine whether to relocate the PSA-UPF.

[0154] (2) Minimum delay time preference indicator for data path: When the SMF 620 selects the UPF 610 or the PSA-UPF, the AF 660 may select the UPF 610 or the PSA-UPF having the minimum delay time with respect to the data path between the terminal and the UPF 610 or the PSA-UPF.

[0155] At step 602, the AF 660 transmits an Nnef_TrafficInfluence_Create / Update / Delete message to the NEF 650. The message at step 602 may include at least one of AF impact data and data path delay requirements.

[0156] In step 603 , the NEF 650 , which receives the message of step 602 from the AF 660 , may store / update / remove data path delay related information in / from the UDR 640 .

[0157] In step 604 , the NEF 650 transmits an Nnef_TrafficInfluence_Create / Update / Delete message to the AF 660 .

[0158] In step 605 , when the information related to the data path delay changes, the UDR 640 transmits a Nudr_DM_Notify message to the PCF 630 that has subscribed to the corresponding information change notification service.

[0159] In step 606, PCF 630 transmits an Npcf_SMpolicyControl_updatednotify message to SMF 620. The message in step 606 may include information related to the relocation of the PSA-PCF based on the data path delay requirement. Specifically, in step 606, PCF 630 transmits PCC rules including traffic steering implementation control information and traffic steering control information affected by AF to SMF 620.

[0160] The service steering implementation control information affected by AF may include at least one of the following information:

[0161] (1) Data Network Access Identifier (DNAI) list;

[0162] (2) business-oriented policy identifier;

[0163] (3) N6 service routing information; and

[0164] (4) AF subscription information about UP change events,

[0165] (4-1) Early notice or late notice;

[0166] (4-2) notification destination address and notification correlation ID; and

[0167] (4-3)AF confirmation.

[0168] The service steering control information may include at least one of the following information:

[0169] (1) Terminal IP address maintenance indicator;

[0170] (1-1) The SMF 620 determines whether to reselect the PSA by using the terminal IP address maintenance indicator.

[0171] (2) a shortest data path delay preference indicator; and

[0172] (2-1) The SMF 620 selects the PSA-UPF with the minimum data path delay time by using the shortest data path delay preference indicator,

[0173] (3) target delay requirement;

[0174] (3-1) The SMF 620 determines whether to reselect the PSA by using the target delay requirement indicator.

[0175] In step 607, the SMF 620 that receives the PCC rule from the PCF 630 performs user plane reconfiguration of the PDU session. To perform user plane reconfiguration, the SMF 620 performs the following operations:

[0176] (1) Add, change, or delete a UPF (e.g., an uplink classifier UPF (ULCL UPF) or a branch point UPF);

[0177] (2) allocating a new Internet Protocol version 6 (IPv6) to a terminal to which IPv6 multihoming is applied;

[0178] (3) Change to the UPF belonging to the target DNAI provided with the new business-oriented rules;

[0179] (4) Subscribe to the area of ​​interest notification service in AMF;

[0180] (5) Select a PSA-UPF that satisfies the requested data path delay time;

[0181] (6) PSA-UPF reselection is considered by the SMF 620 when the terminal performs a handover (HO) procedure, when the terminal leaves or enters the AOI, and when the terminal transmits a registration request due to location movement; and

[0182] (7) When determining PSA-UPF reselection, determine whether to reselect the PSA-UPF by considering the requested data path delay time and selecting the PSA-UPF with the minimum data path delay time among multiple PSA-UPFs or selecting the PSA-UPF that meets the required delay time.

[0183] <Fourth embodiment>

[0184] In the fourth embodiment, reference will be made to Figure 7 and Figure 8 A method for relocating applications based on data path latency is described.

[0185] Figure 7 An AF service impact request procedure including a data path delay information request in a wireless communication system according to various embodiments of the present disclosure is illustrated.

[0186] The AF 760 generates an AF request message in step 701. When generating the AF request message, the AF 760 may generate the AF request message including a delay requirement of a data path required by an application.

[0187] In step 702, AF 760 transmits an Nnef_TrafficInfluence_Create / Update / Delete message to NEF 750. The message in step 702 may include at least one of AF influence data and data path delay requirements. Specifically, in step 702, when the terminal enters a state where PSA-UPF relocation in the target DNAI is possible, AF 760 requests information for determining application relocation through NEF 750. The request of AF 760 includes information for AF subscription to events of the SMF 720 corresponding thereto. This information may be information for subscribing to UPF path change events for a PDU session. In addition, AF 760 requests information about the delay time of the data path estimated for each target DNAI.

[0188] In step 703 , the NEF 750 receiving the request of the AF 760 stores / updates / removes the data path delay related information in / from the UDR 740 .

[0189] In step 704 , the NEF 750 transmits an Nnef_TrafficInfluence_Create / Update / Delete message to the AF 760 .

[0190] In step 705 , when the information related to the data path delay changes, the UDR 740 transmits a Nudr_DM_Notify message to the PCF 730 that has subscribed to the corresponding information change notification service.

[0191] In step 706, PCF 730 transmits an Npcf_SMpolicyControl_Updatednotify message to SMF 720. The message in step 706 may include information related to traffic steering implementation control affected by AF and information related to data path delay requirements. Specifically, in step 706, PCF 730 transmits PCC rules including traffic steering implementation control information affected by AF and traffic steering control information to SMF 720.

[0192] The steering implementation control information affected by the AF included in the PCC rules includes the DNAI list, service steering policy identifier, N6 service routing information, and AF subscription information about UPF change events. The AF subscription information includes information about whether to request advance notification, notification target address, notification correlation ID, and AF confirmation.

[0193] According to an embodiment, the message at step 706 may further include at least one of an indicator requesting delay time information of a data path estimated for each target DNAI and an indicator requesting delay time information of a data path currently experienced by the terminal.

[0194] Figure 8 A process of notifying a UPF of a change event and a process of determining application relocation in an AF in a wireless communication system according to various embodiments of the present disclosure are illustrated.

[0195] In step 801, the SMF 820 determines whether the conditions for AF notification triggering are met.

[0196] At step 802, the SMF 820 transmits an Nsmf_EventExposure_Notify message to the AF 840. The message at step 802 may include at least one of information on advance notification, data path delay, and information on target DNAI.

[0197] In step 803, the AF 840 that receives the advance notification of step 802 from the SMF 820 determines application relocation. When determining application relocation, the AF 840 considers the delay time on the data path received directly from the SMF 820 or received via the NEF 830. If the estimated network delay time does not meet the level required by the application when performing application relocation to the target DNAI, the AF 840 may not determine to perform application relocation to the target DNAI. If the delay time of the data path to the target PSA-UPF reported from the SMF 820 meets the level required by the application, the AF 840 may determine to relocate the application.

[0198] In step 804, AF 840 transmits an Nnet_trafficinfluence_apprelationinfo message to SMF 820. The message in step 804 may include at least one of information regarding whether to request PSA relocation and information regarding the target DNAI. Specifically, if AF 840 determines to relocate the application, AF 840 transmits a request to SMF 820 to relocate the PSA-UPF to the target DNAI. AF 840's request may be transmitted through NEF 830.

[0199] In step 805, SMF 820 may add, relocate, or remove a UPF. Specifically, upon receiving the AF service impact application relocation information, SMF 820 may determine to relocate the PSA-UPF to the target DNAI specified in AF 840 and perform the UPF relocation process.

[0200] In step 806, SMF 820 transmits a NSmf_EventExposure_Notify message to AF 840. The message in step 806 may include information about the postponed notification. Specifically, SMF 820 that successfully performs PSA-UPF relocation transmits a notification message to AF 840, which notifies the successful execution of PSA-UPF relocation.

[0201] In step 807 , the AF 840 transmits the Nnef_Trafficinfluence_AppRelationInfo message to the SMF 820 .

[0202] When an SMF event that satisfies the UPF path change event subscription conditions occurs, the SMF 820 that receives the PCC rule from the PCF reports this directly to the AF 840 or reports it through the NEF 830. When the AF impact request received from the AF 840 includes a request indicator for information on the delay time of the data path estimated for each target DNAI, the SMF 820 transmits information on the estimated delay time of the UPF path from the current terminal to the PSA-UPF indicated by the target DNAI to the AF 840. The SMF 820 can calculate the estimated delay time by itself and can obtain the information on the estimated delay time by querying the NWDAF.

[0203] <Fifth embodiment>

[0204] In the fifth embodiment, reference will be made to Figure 9 Describe the QoS monitoring process.

[0205] Figure 9 A QoS monitoring process in a wireless communication system according to various embodiments of the present disclosure is illustrated.

[0206] The QoS monitoring process may be performed for each terminal or for each QoS flow provided by the terminal.

[0207] In step 901 , the AF 960 transmits a QoS monitoring request message to the PCF 950 .

[0208] In step 902, the PCF 950 generates a QoS monitoring policy approved for the service data flow based on the QoS monitoring request message received from the AF 960. The PCF 950 may include the generated QoS monitoring policy in a PCC rule and may transmit it to the SMF 940. The QoS monitoring policy included in the PCC rule may include at least one of the following information:

[0209] (1) QoS monitoring target identifier;

[0210] (1-1) Terminal identifier, QoS flow identifier and PDU session identifier;

[0211] (2) QoS monitoring period or activation time;

[0212] (3) measurement information for QoS monitoring; and

[0213] (3-1) Maximum transmission rate, average transmission rate, minimum transmission rate, and transmission time;

[0214] (3-2) Related RAN node ID and UPF identification information;

[0215] (3-3) RAT type;

[0216] (3-4) Partial information of Uu, N3, and N9;

[0217] (3-5) Transmission delay information: one-way or two-way transmission delay information between the terminal and the UPF or between the terminal and the PSA-UPF, UL and DL separation information, and information of nodes involved in the transmission delay; and

[0218] (3-6) Transmission delay information for each part.

[0219] In step 903, the SMF 940 activates the measurement of the delay time D and generates / changes the PDU session. Specifically, after receiving the QoS monitoring policy, the SMF 940 initiates QoS measurement for each terminal or each QoS flow of the terminal for QoS monitoring reporting.

[0220] In step 904, the SMF 940 transmits a QoS monitoring request message to the RAN 920. The QoS monitoring request message may include information of the QoS monitoring policy received from the PCF 950. For example, the QoS monitoring request message may include monitoring parameters included in the QoS monitoring policy received by the SMF 940 from the PCF 950.

[0221] Upon receiving the QoS monitoring request message, the RAN 920 may measure QoS monitoring for uplink and downlink packets related to the Uu interface of the terminal 910. The information measured by the RAN 920 may include at least one of a measurement period, maximum, average, and minimum transmission rates for uplink packets. If the QoS monitoring request message includes a request for delay time, the RAN 920 measures the delay time for uplink and downlink packets related to the Uu interface. The delay time may be measured separately for uplink and downlink packets, and the RTT may be measured. The delay time may be measured multiple times.

[0222] After measuring according to the QoS monitoring request, the RAN 920 reports the delay of uplink and downlink packets and the QoS monitoring result to the PSA-UPF 930. According to the QoS monitoring request, the RAN 920 may report the result of the QoS monitoring to the SMF 940.

[0223] In step 905, the SMF 940 transmits a QoS monitoring request message to the PSA-UPF 905. The QoS monitoring request message may include monitoring parameters included in the approved QoS monitoring policy received by the SMF 940 from the PCF 950.

[0224] The PSA-UPF 930 that receives the QoS monitoring request message can measure the transmission delay of the packet by using a one-way packet delay monitoring measurement method or a two-way packet delay monitoring measurement method. Figure 10 and Figure 11 Describes one-way packet delay monitoring measurements and two-way packet delay monitoring measurements.

[0225] Figure 10 A one-way packet delay monitoring and measurement method in a wireless communication system according to various embodiments of the present disclosure is shown.

[0226] refer to Figure 10 , when the RAN 920 and the UPF 930 share absolute time, one-way packet delay monitoring measurements can be performed by utilizing timestamps.

[0227] In step 1001, the PSA-UPF 1020 transmits a General Packet Radio Service (GPRS) Tunneling Protocol User Plane (GTP-U) header of a downlink packet to the RAN 1010. The GTP-U header may include timestamp information.

[0228] In step 1002, the RAN calculates the downlink packet delay. According to an embodiment, when the PSA-UPF 1020 calculates the uplink packet transmission delay, the PSA-UPF 1020 may calculate the uplink packet transmission delay by using the local time known by the PSA-UPF 1020 and the timestamp information included in the GTP-U header transmitted by the RAN 1010. According to an embodiment, when the RAN 1010 calculates the downlink packet transmission delay, the RAN 1020 may calculate the downlink packet transmission delay by using the local time known by the PSA-UPF 1020 and the timestamp information included in the GTP-U header transmitted by the PSA-UPF 1020.

[0229] In step 1003, the RAN 1010 may include the result of measuring the downlink packet delay in the GTP-U header of the uplink packet and may transmit it to the PSA-UPF 1020. According to an embodiment, the RAN 1010 may transmit a dummy uplink packet without a payload as a monitoring result packet to the PSA-UPF 1020. The GTP-U header of the dummy uplink packet may include the result of measuring the downlink packet delay.

[0230] Figure 11 A two-way packet delay monitoring and measurement method in a wireless communication system according to various embodiments of the present disclosure is shown.

[0231] refer to Figure 11 , assuming that the RAN 1120 and the PSA-UPF 1130 have the same packet delay time, the delay time between the RAN 1120 and the PSA-UPF 1130 can be measured by using the round trip time (RTT).

[0232] In step 1101, the PSA-UPF 1130 transmits a downlink monitoring packet to the RAN 1120. In step 1101, the GTP-U header of the downlink monitoring packet includes a QoS flow identifier (QFI), a tunnel identifier (e.g., a tunnel endpoint identifier (TEID)), a packet sequence number (e.g., a sequence number, SEQ#), a QMP indicator (QoS Management Protocol Identifier), and a currently measured local time (time 1, T1).

[0233] At step 1102, the RAN 1120 receiving the downlink monitoring packet records the packet sequence number (eg, sequence number, SEQ#) and the current local time (time 2, T2).

[0234] In step 1103 , the RAN 1120 performs measurement of a packet delay time with respect to a Uu interface between the terminal 1110 and the RAN 1120 .

[0235] In step 1104, the RAN that receives the monitoring packet response from the terminal transmits the uplink monitoring packet to the PSA-UPF 1130. In step 1104, the GTP-U header of the uplink monitoring packet includes a QoS Management Protocol (QMP) identifier, a corresponding packet sequence number (SEQ#), a transmission delay time of the Uu portion, T2, and a local time (time 5, T5) at which the monitoring packet response is received from the terminal.

[0236] In step 1104, the PSA-UPF 1130 records the local time (time 6, T6) of receipt of the uplink monitoring packet and calculates the round trip time (RTT) between the RAN 1120 and the PSA-UPF 1130 by comparing it with the transmission time of the corresponding downlink monitoring packet, which is identified by the QoS flow identifier (QFI), the tunnel identifier (e.g., the tunnel endpoint identifier (TEID)) and the packet sequence number (e.g., sequence number, SEQ#).

[0237] When an event that satisfies the QoS monitoring report condition received from the SMF occurs, the PSA-UPF 1130 reports the occurrence of the corresponding event to the SMF. The QoS monitoring report condition may include at least one of the following conditions:

[0238] (1) Measurement period expiration: When the SMF gives a measurement period, this event is reported to the SMF when the measurement period expires after the measurement starts.

[0239] (2) Exceeding the threshold of the delay time: When the threshold information about the measurement period is received from the SMF and the delay time exceeding the threshold information is measured, this event is reported;

[0240] (3) PDU session termination;

[0241] (4) QoS flow deletion;

[0242] (4-1) When an explicit QoS flow deletion procedure request occurs, the PSA-UPF 1130 reports the measured QoS monitoring information to the SMF.

[0243] (5) QoS flow information changes;

[0244] (5-1) When the base station changes due to handover of the terminal 1110, the PSA-UPF 1130 transmits the statistical information collected from the previous base station and tunnel to the SMF,

[0245] (6) Deactivation of PDU session;

[0246] (6-1) When the UPF connection of the PDU session is deactivated, the PSA-UPF 1130 reports the QoS monitoring information to the SMF.

[0247] (7) Receiving a new QoS monitoring request: When a new QoS monitoring request is received for the same QoS flow, the statistical information on QoS monitoring that has been measured previously is reported to the SMF.

[0248] The methods according to the claims or embodiments disclosed in this disclosure may be implemented as hardware, software, or a combination of both.

[0249] When implemented as software, a computer-readable storage medium for storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors in an electronic device. The one or more programs include instructions for allowing the electronic device to execute the method according to the claims or embodiments disclosed in this disclosure.

[0250] The program (software module or software) can be stored in a random access memory, a non-volatile memory including a flash memory, a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic disk storage device, a compact disc-ROM (CD-ROM), a digital versatile disc (DVD) or other forms of optical storage devices, and a cassette tape. Alternatively, the program can be stored in a memory configured to be combined with all or some of these storage media. In addition, the configured memory can be plural in number.

[0251] In addition, the program can be stored in an attachable storage device that can access the electronic device through a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WLAN), or a storage area network (SAN), or a communication network configured by combining these networks. The storage device can access the device that performs the embodiments of the present disclosure via an external port. In addition, additional storage devices on the communication network can access the device that performs the embodiments of the present disclosure.

[0252] In the above-mentioned specific embodiments of the present disclosure, the elements included in the present disclosure are expressed in singular or plural form, depending on the specific embodiment. However, for ease of explanation, the singular or plural form is appropriately selected according to the proposed situation, and the present disclosure is not limited to a single element or multiple elements. An element expressed in plural form can be configured in singular form, and an element expressed in singular form can be configured in plural form.

[0253] Although specific embodiments have been described in the detailed description of the present disclosure, it will be understood by those skilled in the art that various changes may be made thereto without departing from the spirit and scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited by the described embodiments, but by the appended claims or the equivalents of the claims.

[0254] [Industrial Applicability]

[0255] The present disclosure relates generally to wireless communication systems, and more particularly, to an apparatus and method for Protocol Data Unit (PDU) Session Anchor-User Plane Function (PSA-UPF) relocation in a wireless communication system.

Claims

1. A method performed by a policy control function (PCF) in a wireless communication system, the method comprising: receiving an application function AF request message including data path delay requirement information from a network exposure function (NEF) entity; as well as transmitting the AF-affected service steering implementation control information including the data path delay requirement information to a session management function (SMF) entity, wherein the data path delay requirement information includes a maximum allowed user plane delay; and Among the at least one PSA-UPF entity that meets the maximum allowed user plane delay, a PSA-UPF entity with a minimum user plane delay is used to perform protocol data unit (PDU) session anchor-user plane function PSA-UPF relocation.

2. The method according to claim 1, wherein The minimum user plane delay is based on an estimated user plane delay between a user equipment (UE) and at least one PSA-UPF entity that satisfies the maximum allowed user plane delay.

3. The method according to claim 1, in, The service steering implementation control information affected by AF is included in a Policy and Charging Control (PCC) rule.

4. The method according to claim 2, wherein: The estimated user plane delay is based on information from a Network Data Analysis Function (NWDAF) entity.

5. A method performed by a session management function (SMF) entity in a wireless communication system, the method comprising: receiving, from a policy control function (PCF) entity, traffic steering implementation control information affected by an application function (AF) including data path delay requirement information, wherein the data path delay requirement information includes a maximum allowed user plane delay; and A protocol data unit (PDU) PSA-UPF relocation is performed using a session anchor-user plane function (PSA-UPF) entity having a minimum user plane delay among at least one PSA-UPF entity satisfying the maximum allowed user plane delay.

6. The method according to claim 5, wherein: The minimum user plane delay is obtained from an estimated user plane delay between a user equipment (UE) and at least one PSA-UPF entity that satisfies the maximum allowed user plane delay.

7. The method according to claim 5, in, The service steering implementation control information affected by AF is included in a Policy and Charging Control (PCC) rule.

8. The method according to claim 6, wherein: The estimated user plane delay is based on information from a Network Data Analysis Function (NWDAF) entity.

9. A policy control function (PCF) entity in a wireless communication system, the PCF entity comprising: transceiver; and at least one processor operatively coupled to the transceiver and configured to: receiving an application function (AF) request message including data path delay requirement information from a network exposure function (NEF) entity; and transmitting the AF-affected service steering implementation control information including the data path delay requirement information to a session management function (SMF) entity, wherein the data path delay requirement information includes a maximum allowed user plane delay; and Among the at least one PSA-UPF entity that meets the maximum allowed user plane delay, a PSA-UPF entity with a minimum user plane delay is used to perform protocol data unit (PDU) session anchor-user plane function (PSA-UPF) relocation.

10. The PCF entity according to claim 9, wherein: The minimum user plane delay is based on an estimated user plane delay between a user equipment (UE) and at least one PSA-UPF entity that satisfies the maximum allowed user plane delay.

11. The PCF entity according to claim 9, in, The service steering implementation control information affected by AF is included in a Policy and Charging Control (PCC) rule.

12. The PCF entity according to claim 10, wherein: The estimated user plane delay is based on information from a Network Data Analysis Function (NWDAF) entity.

13. A session management function (SMF) entity in a wireless communication system, the SMF entity comprising: transceiver; and at least one processor operatively coupled to the transceiver and configured to: receiving, from a policy control function (PCF) entity, traffic steering implementation control information affected by an application function (AF) including data path delay requirement information, wherein the data path delay requirement information includes a maximum allowed user plane delay; and A protocol data unit (PDU) PSA-UPF relocation is performed using a session anchor-user plane function (PSA-UPF) entity having a minimum user plane delay among at least one PSA-UPF entity satisfying the maximum allowed user plane delay.

14. The SMF entity according to claim 13, wherein: The minimum user plane delay is obtained from an estimated user plane delay between a user equipment (UE) and at least one PSA-UPF entity that satisfies the maximum allowed user plane delay.

15. The SMF entity according to claim 13, wherein: The service steering implementation control information affected by AF is included in a Policy and Charging Control (PCC) rule.

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