Method and apparatus for relocating server serving application in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate than a 4G communication system such as LTE. Specifically, a method performed by a target base station in a wireless communication system according to various embodiments of the present disclosure comprises the steps of: receiving a handover request message from a source base station; determining a computing function (CF) identified by a data network access identifier (DNAI) associated with the target base station as a candidate of the target CF based on the handover request message; identifying, from among the candidates of the target CF, the candidate of the target CF corresponding to each data network (DN) related to distributed processing of relocation of the application of the UE performing the handover as the target CF; and transmitting a handover request ACK message to the source base station, the handover request ACK message including information on the identified target CF, where the target CF may connect a network to an application server serving an application of the UE performing the handover.

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for supporting relocation of an application server providing a service to an application of a terminal performing handover in the wireless communication system. Background Art

[0002] A review of the evolution of wireless communications from generation to generation reveals that this development has primarily focused on technologies for human-targeted services, such as voice-based services, multimedia services, and data services. Following the commercialization of fifth-generation (5G) communication systems, an exponential increase in the number of connected devices is expected to connect to communication networks. Examples of things connected to the network include vehicles, robots, drones, home appliances, displays, smart sensors installed in various infrastructure, construction machinery, factory equipment, and more. Mobile devices are expected to evolve into various form factors, such as augmented reality glasses, virtual reality headsets, and holographic devices. To provide a variety of services by connecting hundreds of billions of devices and things in the sixth generation (6G) era, efforts are underway to develop improved 6G communication systems. For these reasons, 6G communication systems are being referred to as "beyond 5G" systems.

[0003] 6G communication systems are expected to be implemented by 2030, with a maximum transmission rate of 1,000 gigabits per second (bps) and a radio latency of 100 microseconds. This means that 6G communication systems will be 50 times faster than 5G communication systems and have a radio latency that is 1 / 10 of that of 5G communication systems.

[0004] To achieve such high data rates and ultra-low latency, 6G communication systems are being considered in the terahertz band (e.g., the 95 GHz to 3 THz band). Because path loss and atmospheric absorption in the terahertz band are expected to be more severe than in the millimeter-wave band introduced in 5G, technologies that ensure signal transmission distance, or coverage, will become even more critical. Key technologies for ensuring coverage will require the development of multi-antenna transmission technologies, including radio frequency (RF) components, antennas, novel waveforms with better coverage than OFDM, beamforming and massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, and massive antennas. Furthermore, new technologies for improving the coverage of terahertz band signals, such as metamaterial-based lenses and antennas, orbital angular momentum (OAM), and reconfigurable smart surfaces (RIS), are being discussed.

[0005] Furthermore, to improve frequency efficiency and system networks, the following technologies are being developed for 6G communication systems: full-duplex technology for enabling uplink (UE transmission) and downlink (Node B transmission) to use the same frequency resources simultaneously at the same time; network technologies for integrated utilization of satellites, high-altitude platform stations (HAPS), and other systems; innovative network architecture technologies for supporting mobile Node Bs and achieving network operation optimization and automation; dynamic spectrum sharing technology with conflict avoidance based on spectrum usage prediction; AI-based communication technologies for achieving system optimization by utilizing artificial intelligence (AI) from the technical design stage and internalizing end-to-end AI support functions; and next-generation distributed computing technologies for enabling services with complexity exceeding the computing capabilities of UEs by utilizing ultra-high-performance communication and computing resources (e.g., mobile edge computing (MEC) and cloud). Furthermore, efforts are underway to further enhance connectivity between devices, optimize networks, promote software implementation of network entities, and increase the openness of wireless communications by designing new protocols for use in 6G communication systems, developing hardware-based security environments and mechanisms for secure data usage, and developing technologies for maintaining privacy.

[0006] This research and development of 6G communication systems is expected to enable the next hyperconnected experience in a new dimension through the hyperconnectivity of 6G communication systems, encompassing both connections between objects and between people and objects. Specifically, it is expected that services such as truly immersive XR, high-fidelity mobile holograms, and digital replicas will be provided through 6G communication systems. Furthermore, with enhanced security and reliability, services such as remote surgery, industrial automation, and emergency response will be provided through 6G communication systems, and these services will therefore be applied in a variety of fields, including the industrial, medical, automotive, and home appliance sectors. Summary of the Invention

[0007] Technical issues

[0008] Various embodiments disclosed herein provide a method and apparatus for supporting relocation of an application server providing a service to an application of a terminal performing handover in a wireless communication system.

[0009] Solution to the problem

[0010] According to various embodiments of the present disclosure, a method performed by a target base station in a wireless communication system may include: receiving a handover request message from a source base station, determining a computing function (CF) identified by a data network access identifier (DNAI) associated with the target base station as a target CF candidate based on the handover request message, determining a target CF candidate corresponding to each data network (DN) as a target CF among the target CF candidates, each DN being related to distributed processing of application relocation of a terminal (UE) performing handover, and sending a handover request ACK message including information about the determined target CF to the source base station, wherein the target CF connects a network with an application server that provides services for the application of the terminal performing handover.

[0011] According to various embodiments of the present disclosure, a device of a target base station in a wireless communication system may include a communication unit and a controller, wherein the controller is configured to perform control to: receive a handover request message from a source base station, determine a computing function (CF) identified by a data network access identifier (DNAI) associated with the target base station as a target CF candidate based on the handover request message, determine a target CF candidate corresponding to each data network (DN) as a target CF among the target CF candidates, each DN being related to distributed processing of application relocation information of a terminal (UE) performing handover, and send a handover request ACK message including information about the determined target CF to the source base station, and wherein the target CF connects a network to an application server that provides services for an application of the terminal performing handover.

[0012] According to the present disclosure, a method performed by a source base station in a wireless communication system may include: sending a handover request message to a target base station, receiving a handover request ACK message including information about a determined target computing function (CF) from the target base station, and based on the handover request ACK message, transmitting information about the target CF to a source CF associated with the source base station and corresponding to a data network name (DNN), the DNN being related to distributed processing of application relocation of a terminal (UE) performing the handover and associated with the target CF.

[0013] According to the present disclosure, a device of a source base station in a wireless communication system may include a communication unit and a controller, wherein the controller is configured to perform control to: send a handover request message to a target base station, receive a handover request ACK message including information about a determined target computing function (CF) from the target base station, and based on the handover request ACK message, transmit information about the target CF to a source CF associated with the source base station and corresponding to a data network name (DNN), the DNN being related to distributed processing of application relocation of a terminal (UE) performing the handover and associated with the target CF. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A distributed wireless network environment in a wireless communication system according to an embodiment of the present disclosure is shown.

[0015] Figure 2 A wireless network environment of a mobile terminal in a wireless communication system according to an embodiment of the present disclosure is shown.

[0016] Figure 3 is a flowchart illustrating an operation of a relocation server that provides a service for an application of a terminal that performs handover of a base station according to an embodiment of the present disclosure.

[0017] Figure 4 is a flowchart illustrating an operation of determining a target compute function (CF) according to an embodiment of the present disclosure.

[0018] Figure 5 is a flowchart illustrating an operation of transmitting determined information about a target CF according to an embodiment of the present disclosure.

[0019] Figure 6 is a flowchart illustrating the operation of a CF supporting relocation of an application according to an embodiment of the present disclosure.

[0020] Figure 7 is a flowchart illustrating an operation of reporting that support for relocation of an application has been completed according to an embodiment of the present disclosure.

[0021] Figure 8 is a flowchart illustrating an operation of supporting relocation of a server that provides a service for an application of a terminal that performs handover according to an embodiment of the present disclosure.

[0022] Figure 9 The operation of the target base station according to an embodiment of the present disclosure is illustrated.

[0023] Figure 10 The operation of the source base station according to an embodiment of the present disclosure is illustrated.

[0024] Figure 11 The structure of a base station according to an embodiment of the present disclosure is shown.

[0025] Figure 12 The structure of a UE according to an embodiment of the present disclosure is shown.

[0026] Figure 13 The structure of a server according to an embodiment of the present disclosure is shown.

[0027] With respect to the description of the drawings, the same or similar reference numerals may be used to designate the same or similar elements. DETAILED DESCRIPTION

[0028] Various aspects of the claimed subject matter are now described with reference to the accompanying drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. However, it may be apparent that such aspects may be practiced without these specific details.

[0029] The terms used in this disclosure are only used to describe specific embodiments and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions unless they are clearly different in context. The terms used herein (including technical and scientific terms) may have the same meaning as those generally understood by those skilled in the art to which this disclosure belongs. Unless clearly defined in this disclosure, those terms as defined in commonly used dictionaries may be interpreted as having meanings equivalent to the contextual meanings in the relevant art and should not be interpreted as having ideal or overly formal meanings. In some cases, even the terms defined in this disclosure should not be interpreted as excluding embodiments of the present disclosure.

[0030] In the following description, for the sake of convenience, terms referring to signals (e.g., message, signal, signaling, sequence, and stream), terms referring to resources (e.g., symbol, slot, subframe, radio frame (RF), subcarrier, resource element (RE), resource block (RB), bandwidth part (BWP), and opportunity), terms for operations (e.g., step, method, process, and procedure), terms referring to data (e.g., information, parameter, variable, value, bit, symbol, and codeword), terms referring to channels, terms referring to control information (e.g., downlink control information (DCI), medium access control element (MAC CE), and radio resource control (RRC) signaling), terms referring to network entities, terms referring to device elements, etc. are illustratively used. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to subject matter having equivalent technical meanings may be used.

[0031] Various aspects are described herein with reference to wireless terminals and / or base stations. A wireless terminal can refer to a device that provides voice and / or data connectivity to a user. A wireless terminal can be connected to a computing device such as a laptop or desktop computer, or it can be a self-contained device such as a personal digital assistant (PDA). A wireless terminal may also be referred to as a system, subscriber unit, subscriber station, mobile station, mobile, remote station, access point, remote terminal, access terminal, user terminal, user agent, user device, or user equipment. A wireless terminal can be a subscriber station, wireless device, cellular phone, PCS phone, cordless phone, Session Initiation Protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless connectivity, or other processing device connected to a wireless modem. A base station (e.g., access point) can refer to a device in an access network that communicates with wireless terminals over the air interface through one or more sectors. A base station can act as a router between the wireless terminal and the rest of the access network, which may include an Internet Protocol (IP) network, by converting received air interface frames to IP packets. The base station also coordinates attribute management of the air interface.

[0032] As described in the present disclosure, a data network name (DNN) associated with distributed processing of relocation of an application server providing services for an application of a UE performing handover may refer to a data network name (hereinafter, DNN) corresponding to an application whose computing server or application server is distributed in a single cell or in multiple cells according to ultra-high capacity and ultra-low latency requirements, and therefore requires distribution and processing of application relocation in a cell-by-cell basis. However, even if the server is not distributed in a single cell or in multiple cells, when application relocation needs to be performed simultaneously with a UE handover, the DNN of the application that requires relocation may also be considered as a DNN associated with the relocation of the application server providing services for the application of the UE performing handover.

[0033] A computing function (CF) as described in this disclosure may refer to an entity or node that interfaces (or connects, accesses, or communicates) with an application server (or computing server or edge application server (EAS)) and a network to exchange information between the server and the network. Furthermore, a CF may also refer to an entity or node that interfaces (or connects, accesses, or communicates) with an application server that provides services for applications of a UE performing a handover and the network. A CF may also refer to an application server that provides services for applications of a UE performing a handover. In other words, an application server itself may act as a CF to exchange information with network functions (NFs) within the network.

[0034] The Compute Exposure Function (CEF) entity described in this disclosure may refer to an NF that exposes the capabilities of a CF and server and performs translation between the CF and network entities, thereby interfacing (or connecting, accessing, or communicating) the network and the CF. The CEF entity can expose information related to the UE based on the UE's mobility. In this example, when the CF is in an untrusted state, the server can communicate with internal network entities through the CEF.

[0035] In addition, the application of the UE described in the present disclosure is an application provided by a third party and may refer to a client application program executed on the UE for a specific application service. Multiple applications may be executed on the UE.

[0036] Figure 1 A distributed wireless network environment in a wireless communication system according to an embodiment of the present disclosure is shown.

[0037] refer to Figure 1 Some networks / systems can be configured in a distributed manner as network environments, each of which includes multiple application / computing servers and multiple base stations. Such network environments can be referred to as distributed network environments or distributed computing environments. A distributed computing environment can refer to an environment in which computing resources are distributed across the network. In a distributed computing environment, computing resources with different characteristics can be distributed across the network, and UEs can access applications provided by computing resources close to the UE through the Radio Access Network (RAN) and a locally distributed User Plane Function (UPF) entity.

[0038] At the same time, a network with a distributed computing environment may be required to support services for applications that require ultra-high capacity and ultra-low latency network environments (for example, holograms, XR, deep neural networks, and V2X). In an example, an application requiring ultra-high capacity and ultra-low latency network environments may be an application that requires computing that exceeds the capacity of the UE or uses high-performance AI.

[0039] In the following, for ease of description, some terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP) specifications may be used. However, the present disclosure is not limited by the terms and names and is also applicable to systems complying with other specifications.

[0040] refer to Figure 1 ,As the layers become higher from the center, the computing power and ,capacity of computing resources can be increased, and the ,computation can be performed faster, thus reducing the computing ,latency.

[0041] When the server is located near the user equipment (UE), such as at a cell site, communication delay can be reduced.

[0042] At the same time, when a UE participates in a computation, it participates directly in the computation. Therefore, the communication delay for sending and receiving data to and from the computation server can be reduced or eliminated. However, computation delays may increase due to low computational power.

[0043] Thus, in a distributed computing environment, multiple different servers with various computing capabilities, computing resource utilization states, computing power, and communication characteristics (e.g., distance-dependent communication delay) can be distributed across the network. Therefore, there is an increasing need for networks to support dynamic computing services in distributed computing environments.

[0044] For dynamic computing services, the process of relocating the server providing application services can be performed after the handover process caused by inter-cell mobility of the UE is completed. When a UE moves from a previously located cell to another, the handover process caused by inter-cell mobility is performed. Having received a message indicating the handover process has been performed, the core network can select a user plane function (UPF) entity to change. The UPF (or a network entity capable of executing a UPF) can act as a gateway for transmitting transmitted and received packets. The UPF can achieve low-latency transmission by directly transmitting data packets to edge data networks without passing them through the internet. The UPF can also connect to data networks connected via the internet. In a distributed computing environment, not only servers but also UPF entities can be distributed. The core network can collect information about multiple distributed UPF entities and perform application function (AF) relocation to match the server to which the UE is moving with the UPF entity. The core network can select an AF associated with a server that can provide services to the moving UE and the area of ​​the cell to which the UE is moving, and relocate the AF. Subsequently, the core network can select an edge application server (EAS) associated with the relocated AF and relocate the EAS. The UPF entity that has received the relocation information of the AF and EAS can configure the UPF entity to interface with (or connect, access or communicate with) the server to which the UE is to move (UPF configuration).

[0045] This process of relocating a server for providing a service for an application according to the movement of the UE is performed sequentially and after the handover process of the UE, and thus may cause a significant time delay. That is, the conventional process of relocating a server for providing a service for an application is performed sequentially at the upper layer of the core network, which may cause communication delay.

[0046] In the present disclosure, methods and apparatuses are described for simultaneously or in parallel performing a handover procedure of a UE and a procedure related to relocating a server providing services for an application of the UE.

[0047] Figure 2 The wireless network environment of a mobile UE in a wireless communication system according to an embodiment of the present disclosure is shown. In particular, Figure 2 Show Figure 1 The network environment in the distributed computing environment is shown, where application servers are deployed down to the cell sites.

[0048] In a distributed computing environment where each computing server has a small coverage, when the UE moves, it may be necessary to simultaneously perform application relocation based on the application server's requirements for ultra-low latency and ultra-high capacity while performing the switching process caused by inter-cell mobility.

[0049] According to an embodiment of the present disclosure, when a UE receives a service from a first server 201 supporting a service within a first cell 203, when the UE moves to the area of ​​a second cell 207, the UE or the UE's application may need to receive a service from a second server 205 located in the second cell 207. For example, when the UE moves from the area of ​​the first cell 203 to the area of ​​the second cell, to the extent that the UE needs to receive a service from the second server 205 instead of the first server 201, very low communication latency and computing latency, or high-capacity computing, may be required. In this case, the moving UE may require a network environment that can not only perform a handover process but also support the relocation of applications. Application relocation may mean that when the UE moves, the UE's application needs to receive a service from the server to which the UE is moving.

[0050] According to an embodiment of the present disclosure, even when one cell does not correspond to one server, the UE may need a network environment that can support the relocation of an application. For example, in the case where the third to fifth cells 211, 213, and 217 provide services to the UE through the third server 209, and the sixth to eighth cells 219, 221, and 223 provide services to the UE through the fourth server 215, when the UE moves from the area of ​​the third to fifth cells 211, 213, and 217 to the area of ​​the sixth to eighth cells 219, 221, and 223, the UE may need a network environment in which the server supporting the service for the application is relocated from the third server 209 to the fourth server 215.

[0051] According to embodiments of the present disclosure, even when a UE performs inter-cell mobility, if all cells share the same server, application relocation may not be required. For example, when the UE moves from the third cell 211 to the fourth cell 213 or the fifth cell 217 (all cells share the third server 209), the UE performs a handover procedure. However, since the server remains the third server, relocation of the server supporting the application may not be required.

[0052] Figure 3is a flowchart illustrating an operation of a relocation server that provides a service for an application of a UE that performs handover of a base station according to an embodiment of the present disclosure.

[0053] Reference Figure 3 , a process for relocating a server providing a service for an application according to the movement of the UE may be performed simultaneously with a handover process of the UE. Figure 3 based on Figure 2 It shows a case where a server providing services for an application of the UE performing handover needs to be relocated when the UE moves.

[0054] In operation 315, when the UE moves from the source cell to the target cell, the source base station 303 may send a handover request message (handover request message) to the target base station 305. The handover request message may include information about a data network (DN) related to a distributed process for relocating an application of the UE performing the handover. The information about the DN described in the present disclosure may include, for example, a data network name (DNN) related to a distributed process for relocating an application of the UE performing the handover, and a data network access identifier (DNAI) for each DNN. In addition, the handover request message may include protocol data unit (PDU) session ID information of the UE performing the handover. However, the handover request message is not limited thereto and may include various types of information.

[0055] In operation 317 , the target base station 305 , which has received the handover request message from the source base station 303 , may determine a candidate for a target computing function (CF) that interfaces (or connects, accesses, or communicates) an application with a server that provides a service for an application of the UE performing the handover.

[0056] The cell corresponding to a specific base station may belong to the service area of ​​the application server identified by the specific DNAI. The target base station 305 may determine, based on the received handover request message, whether the DNAI associated with the source base station 303 is the same as the DNAI associated with the target base station 305 for each DNN related to the distributed processing of the relocation of the UE's application, to determine whether to perform the process of determining the target CF.

[0057] When, for each DNN related to the distributed processing of relocation of the UE's application, the DNAI associated with the source base station 303 and the DNAI associated with the target base station 305 are different, the target base station 305 may determine to perform a process of determining a target CF. When the target base station 305 determines to perform a process of determining a target CF, the target base station 305 may determine a CF identified by a DNAI associated with the target base station 305 as a candidate for the target CF, for each DNN related to the distributed processing of relocation of the UE's application, the DNAI associated with the target base station 305 being different from the DNAI associated with the source base station 303.

[0058] On the other hand, when the DNAI associated with source base station 303 and the DNAI associated with target base station 305 are identical for each DNN related to distributed processing of application relocation for the UE, target base station 305 may determine not to perform the process of determining a target CF. This may indicate that source base station 303 and target base station 305 are within the service area of ​​the same application server. When the DNAI associated with source base station 303 and the DNAI associated with target base station 305 are identical for each DNN related to distributed processing of application relocation for the UE, the target CF may not be determined because the same UPF entity and application server as used before the UE performed handover are available without changing the UPF entity or DNAI. In this case, target base station 305 may store information indicating that the DNAI associated with source base station 303 and target base station 305 are identical for each DNN related to distributed processing of application relocation for the UE, and may include information indicating that the DNAIs are identical in the N2 Path Switch Request message sent to AMF entity 309 in operation 325. However, the N2 path switch request message is not limited thereto and may include various types of information.

[0059] In operation 319 , the target base station 305 may receive information related to application relocation from the candidates of the target CF determined in operation 317 .

[0060] The target base station 305 may transmit information related to the distributed processing of application relocation of the UE performing the handover to the candidate 307 of the target CF. The candidate 307 of the target CF having received the message from the target base station 305 may transmit information related to the distributed processing of application relocation of the UE to an application server (or computing server, or edge application server (EAS)) to which the target base station interfaces (or connects, accesses, or communicates) for each CF.

[0061] According to an embodiment of the present disclosure, the information related to the distributed processing of application relocation sent by the candidate 307 of the target CF may include the following pieces of information.

[0062] - Information about currently available computing resources and information about access availability

[0063] -DNN, which corresponds to each docked application server in the candidate of target CF

[0064] - DNAI of each docked application server in the candidate of the specified target CF

[0065] The information about admission availability may include information about whether a computing / application server connected to each of the candidates for the target CF lacks available resources for providing services for the application of the UE performing the handover, or whether the server can additionally support a new UE.

[0066] The target base station 305 may update the status of the target CF based on the received information.

[0067] However, the information related to application relocation is not limited thereto and may include various types of information.

[0068] In operation 321 , the target base station 305 may determine a target CF for docking (or connecting, accessing, or communicating) an application in the target CF candidate 307 and a server providing services for an application of the UE performing the handover based on the received information related to the application relocation of the target CF candidate 307 .

[0069] According to an embodiment of the present disclosure, if it is recognized that a specific server cannot provide services for the application of the UE performing the handover, the target base station 305 may not determine the target CF candidate corresponding to the specific server as the target CF. For example, if it is ensured that the specific server lacks available resources for providing services for the application of the UE performing the handover or cannot additionally support the admission availability information of the new UE, the target base station may not determine the target CF candidate corresponding to the specific server as the target CF.

[0070] In operation 323, the target base station 305 may send a handover request ACK message (handover request confirmation message) for the handover of the UE to the source base station 303. The handover request ACK message may include the following information.

[0071] - Information that can indicate the DNN related to the distributed processing of the application relocation, which corresponds to the target CF

[0072] - Information about the application server (or computing server or edge application server (EAS)) connected to the target CF, as well as information about the indicating server

[0073] - Internal network address information of the target CF

[0074] - External network Internet address information of the application server (or computing server or edge application server (EAS)) connected to the target CF

[0075] Information indicating a distributed network (DNN) associated with distributed processing for application relocation may be included in the Handover Request ACK message as a parameter called DNN, where the DNN corresponds to the target CF. Furthermore, information about the application server interfaced with the target CF and information indicating the server may be included in the Handover Request ACK message as a parameter called Target DNAI.

[0076] However, the handover request ACK is not limited thereto and may include various types of information.

[0077] The operation of the source base station 303 having received the handover request ACK message will be described in operation 329 .

[0078] In operation 325, the target base station 305 may send an N2 path switch request message to the AMF entity 309. The N2 path switch request message may include a DNAI together with a PDU session ID, only for the DNN for which the target CF is selected in the DNN related to the distributed processing of application relocation, in which the PDU session of the UE performing the handover is established. For the PDU session of the DNN related to the distributed processing of application relocation for which the target CF is not selected, and the PDU session of the DNN not related to application relocation, the target base station 305 may include only the PDU session ID in the N2 path switch request.

[0079] According to an embodiment of the present disclosure, based on the indication stored in operation 371 that for each DNN related to the distributed processing of the UE's application relocation, the DNAI associated with the source base station 303 and the DNAI associated with the target base station 305 are the same information, the target base station 305 can include information including an indication that the DNAI is the same in the N2 path switching request message.

[0080] According to an embodiment of the present disclosure, the target base station 305 may not determine the target CF stored in the process of determining the candidate of the target CF, but include information in the N2 path switching request message indicating that for each DNN related to the distributed processing of the UE's application relocation, the DNAI associated with the source base station 303 and the DNAI associated with the target base station 305 are the same.

[0081] In operation 327, the access and mobility management function (AMF) entity 309 may transmit an Nsmf_PDUSession_UpdateSMContext request message to the session management function (SMF) entity 311 based on the N2 path switching request message received from the target base station 305. The relocation or change of the server providing a service for the application of the UE may be configured through the AMF entity, the SMF entity, and the UPF entity.

[0082] In operation 329 , the source base station 303 may transmit information related to a target CF corresponding to the DNN related to application relocation included in the handover request ACK message received from the target base station 305 to a CF associated with the source base station (hereinafter, source CF).

[0083] The information related to the target CF corresponding to the DNN related to application relocation may include the following pieces of information.

[0084] - Internal network address information of the target CF

[0085] - External network Internet address information of the application server (or computing server or edge application server (EAS)) connected to the target CF

[0086] - DNN indication information of the DN associated with the distributed processing of the application relocation, which corresponds to the target CF

[0087] However, the information related to the target CF corresponding to the DNN related to application relocation is not limited thereto and may include various types of information.

[0088] In operation 331, the SMF entity 311 may identify a PDU session for performing relocation of a server due to application relocation based on the Nsmf_PDUSession_UpdateSMContext request message transmitted from the AMF entity 309. For a PDU session in which a DNAI corresponding to a DNN is transmitted together with a PDU session ID, a target CF is selected for the DNN in a DNN related to distributed processing of application relocation, and the SMF entity may identify that application relocation is to be performed. The SMF entity 311 may determine to change the UPF entity for the PDU session identified as being used to perform application relocation to a UPF entity corresponding to the DNAI that has been transmitted for the DNN, and a target CF is selected for the DNN in a DNN related to distributed processing of application relocation.

[0089] For a PDU session in which DNAI is not transmitted together with the PDU session ID, the SMF entity may determine whether the UPF entity needs to be changed, and if so, may change the UPF entity and, if necessary, perform procedures related to application relocation.

[0090] In operation 333, the source CF 301 may communicate with the target CF using the internal network address information of the target CF transmitted from the source base station 303 in operation 329, and may exchange information for application relocation of the UE for performing the handover. The information for application relocation of the UE may include, for example, information related to the application context of the UE. However, the information for application relocation of the UE is not limited thereto and may include various types of information. In addition, the source CF 301 and the target CF may exchange information required to relocate the CF from the source CF 301 to the target CF, which connects the network to the application server that provides services for the UE's applications.

[0091] In operation 335, the application server (or computing server, edge application server (EAS)) to which the source CF 301 interfaces (or is connected to, accesses, or communicates) and the application server to which the target CF interfaces may exchange application server context information and information related to the relocation of the application server at the application level via the Internet using the external network Internet address information provided in operation 329. Furthermore, a related process may be performed to relocate a CF from the source CF 301 to the target CF, the CF being connected to the application server providing a service for the UE's application.

[0092] In operation 337, the target CF may recognize that the relocation of the CF and the server providing services for the UE's application has been completed through the operation of operation 335. In this case, the target CF may transmit information indicating that the relocation has been completed to the target base station 305.

[0093] In operation 339, after receiving information from the target CF indicating that the relocation of the CF and the server providing services for the UE's application has been completed, the target base station 305 can include an indication in the N2 SM message that the relocation of all DNNs that have determined the target CF in the DNNs related to the distributed processing of the application relocation of the UE performing the handover has been completed, and transmit the message to the AMF entity 309.

[0094] In operation 341, the AMF entity 309 may transfer the N2 SM message received from the target base station 305 to the SMF entity 311.

[0095] In operation 343, after receiving the N2 SM message, the SMF entity 311 may perform UPF configuration for a PDU session corresponding to a DNN of a DN related to distributed processing of application relocation of a UE performing handover.

[0096] After performing UPF configuration, applications of the UE that has performed the handover procedure can operate with the help of the relocated server that provides services for the applications.

[0097] Figure 4 is a flowchart illustrating an operation of determining a target compute function (CF) according to an embodiment of the present disclosure. Figure 4 Show Figure 3 Another embodiment of the operation of the target base station 305 determining the target CF (from operation 315 to operation 321).

[0098] In operation 410 , the target base station 305 may update the state of the CF corresponding to the DNN related to the distributed processing of application relocation of the UE performing handover periodically or when an event state (eg, a change in admission availability) occurs.

[0099] The target base station 305 may send a message to the CF requesting information related to distributed processing of application relocation of the UE performing the handover. The CF having received the message from the target base station 305 may send information related to application relocation of the UE for each application server to which the CF is connected (or connected, accessed, or communicated) to the target base station.

[0100] According to an embodiment of the present disclosure, the information related to the distributed processing of application relocation sent by the candidate 307 of the target CF may include the following pieces of information.

[0101] - Information about currently available computing resources and information about access availability

[0102] -DNN corresponding to each CF

[0103] -DNAI corresponding to each CF

[0104] The information about admission availability may include information about whether a computing / application server connected to each of the candidates for the target CF lacks available resources for providing services for the application of the UE performing the handover, or whether the server can additionally support a new UE.

[0105] The target base station 305 may update the status of the CF based on the received information.

[0106] However, the information related to the distributed processing of application relocation is not limited thereto and may include various types of information.

[0107] In operation 420, the target base station 305 may receive a handover request message from the source base station 301. The handover request message may include information about a data network (DN) related to the distributed processing of the relocation of the application of the UE performing the handover. The information about the DN described in the present disclosure may include, for example, a data network name (DNN) related to the distributed processing of the relocation of the application of the UE performing the handover and a data network access identifier (DNAI). In addition, the handover request message may include protocol data unit (PDU) session ID information of the UE performing the handover. However, the handover request message is not limited thereto and may include various types of information.

[0108] In operation 430 , the target base station 305 may determine candidates for a target CF based on the handover request message received from the source base station 301 .

[0109] The cell corresponding to a specific base station may belong to the service area of ​​the application server identified by the specific DNAI. The target base station 305 may determine whether the DNAI associated with the source base station 303 is the same as the DNAI associated with the target base station 305 for each DNN related to the distributed processing of the relocation of the UE's application based on the received handover request message, so as to determine whether to perform the process of determining the target CF.

[0110] When, for each DNN related to the distributed processing of relocation of the UE's application, the DNAI associated with the source base station 303 and the DNAI associated with the target base station 305 are different, the target base station 305 may determine to perform a process of determining a target CF. When the target base station 305 determines to perform a process of determining a target CF, the target base station 305 may determine a CF identified by a DNAI associated with the target base station 305 as a candidate for the target CF, for each DNN related to the distributed processing of relocation of the UE's application, the DNAI associated with the target base station 305 being different from the DNAI associated with the source base station 303.

[0111] On the other hand, when the DNAI associated with source base station 303 and the DNAI associated with target base station 305 are identical for each DNN related to distributed processing of application relocation for the UE, target base station 305 may determine not to perform the process of determining a target CF. This may indicate that source base station 303 and target base station 305 are within the service area of ​​the same application server. When the DNAI associated with source base station 303 and the DNAI associated with target base station 305 are identical for each DNN related to distributed processing of application relocation for the UE, the target CF may not be determined because the same UPF entity and application server as used before the UE performed handover are available without changing the UPF entity or DNAI. In this case, target base station 305 may store information indicating that the DNAI associated with source base station 303 and target base station 305 are identical for each DNN related to distributed processing of application relocation for the UE, and may include information indicating that the DNAIs are identical in the N2 Path Switch Request message sent to AMF entity 309 in operation 325. However, the N2 path switch request message is not limited thereto and may include various types of information.

[0112] In operation 440, the target base station 305 may determine a target CF from the target CF candidates 307 based on the determined state information of the target CF candidates 307. The target CF is connected to (or connects to, accesses, or communicates with) an application and a server that provides services for the application of the UE performing the handover. Specifically, the target base station may determine the target CF candidate based on the state of the CF updated in operation 410. Therefore, the target base station 305 can determine the target CF candidate based on the state information of the CF that has been received, without having to identify additional state information for each CF.

[0113] According to an embodiment of the present disclosure, if it is recognized that a specific server cannot provide services for the application of the UE performing the handover, the target base station 305 may not determine the target CF candidate corresponding to the specific server as the target CF. For example, if it is ensured that the specific server lacks available resources for providing services for the application of the UE performing the handover or cannot additionally support the admission availability information of the new UE, the target base station may not determine the target CF candidate corresponding to the specific server as the target CF.

[0114] Figure 5 is a flowchart illustrating an operation of transmitting determined information about a target CF according to an embodiment of the present disclosure. Figure 5 Show Figure 3 Another embodiment of the operation (from operation 323 to operation 327) of sending and receiving information about the determination of the target CF by the base station and the network entity. Figure 3 Repeated description of operations 315 to 321 described in .

[0115] After determining the target CF, the target base station 305 may send a message for handover of the UE and relocation of the application server providing services for the UE's application to the source base station 303 and the AMF entity 309. When the operation of determining the target CF is completed, the target base station 305 may send a corresponding message including necessary information to the source base station 303 and the AMF entity 309. The messages do not necessarily have to be sent sequentially and may be sent simultaneously.

[0116] Reference Figure 5 In operation 510, the target base station 305 may send a target CF / EAS / info message for handover of the UE and relocation of the server providing service for the application to the source base station 303. The target CF / EAS / info message may include the following information.

[0117] - Information that can indicate the DNN related to the distributed processing of the application relocation, which corresponds to the target CF

[0118] - Information about the application server (or computing server or edge application server (EAS)) connected to the target CF, as well as information indicating the server

[0119] - Internal network address information of the target CF

[0120] - External network Internet address information of the application server (or computing server or edge application server (EAS)) connected to the target CF

[0121] Information indicating the DNN associated with the distributed processing of application relocation, corresponding to the target CF, can be included in the TargetCF / EASinfo message as a parameter called DNN. Furthermore, information about the application server interfaced by the target CF and information indicating the server can be included in the TargetCF / EASinfo message as a parameter called TargetDNAI.

[0122] However, the target CF / EAS / info message is not limited thereto and may include various types of information.

[0123] In operation 520, the target base station 305 may send a distributed relocation information message associated with application relocation of the moving UE to the AMF entity 309. Figure 5 The distributed relocation information message may correspond to Figure 3The distributed relocation information message may include a DNAI together with a PDU session ID, and is only used for the DNN for which a target CF is selected in the DNN related to the distributed processing of application relocation, in which a PDU session of the UE performing handover is established. For the PDU session of the DNN related to the distributed processing of application relocation for which a target CF is not selected, and the PDU session of the DNN not related to application relocation, the target base station 305 may only include the PDU session ID in the N2 path switch request.

[0124] In operation 530, the AMF entity 309 may transmit the distributed relocation information message received from the target base station to the SMF entity 311.

[0125] The message sent in operations 510 to 530 may refer to the message sent in Figure 3 The message transmitted and received in the handover process described in operations 323 to 327 is a new message different from the message transmitted and received in the handover process. Therefore, the message transmitted and received in operations 510 to 530 may not necessarily be transmitted at the same time as the message transmitted and received regarding the handover process.

[0126] Figure 6 is a flowchart illustrating the operation of a CF supporting relocation of an application according to an embodiment of the present disclosure. Figure 6 Shown Figure 3 In an additional embodiment of the operations (operations 333 to 335) in the embodiment, the source CF can communicate with the target CF by using the internal network address information of the target CF transmitted from the source base station 303, and can exchange information for application relocation of the UE performing the handover. Figure 3 A repeated description of operations 315 to 331 described in .

[0127] refer to Figure 6 In operation 610, the source CF 301 may communicate with the target CF by using the internal network address information of the target CF transmitted from the source base station 303, and may exchange information for application relocation of the UE for performing the handover. The information for application relocation of the UE may include, for example, information related to the application context of the UE. However, the information for application relocation of the UE is not limited thereto and may include various types of information. In addition, the source CF 301 and the target CF may exchange information required to relocate the CF from the source CF 301 to the target CF, which connects the network to the application server that provides services for the UE's application.

[0128] In operations 620 to 640, the source CF 301 and the target CF may exchange not only information related to the UE's application context within the network, but also application server context information and information related to relocation of application servers, which have been exchanged at the application level between application servers via the Internet.

[0129] In operation 650, the application server (or computing server, edge application server (EAS)) to which the source CF 301 interfaces (or is connected to, accesses, or communicates) and the application server to which the target CF interfaces may exchange application server context information and information related to the relocation of the application server at the application level via the Internet using the external network Internet address information provided in operation 329. Furthermore, based on the application server context information and the information related to the relocation of the application server, a related process may be performed to relocate the CF from the source CF 301 to the target CF, which is connected to the application server that provides services for the UE's application.

[0130] Figure 7 is a flowchart illustrating an operation of reporting that support for relocation of an application has been completed according to an embodiment of the present disclosure. Figure 7 Shown in Figure 3 Another embodiment of the target CF reporting that the support for the relocation of the application has been completed (from operation 337 to operation 341). Figure 3 A repeated description of operations 315 to 335 described in .

[0131] Reference Figure 7 In operation 710, when the relocation of the server providing services for the application of the UE performing the handover from the application server associated with the source base station 303 to the application server associated with the target base station 305 is completed, each target CF can directly report to the SMF entity 311 that the relocation has been completed. In addition, when the CF relocation from the source CF docking the application server associated with the source base station to the target CF docking the application server associated with the target base station is completed, the target CF can report to the SMF entity 311 that the relocation has been completed. Since each target CF has a different DNN associated with the distributed processing of the relocation, each target CF can perform relocation for the PDU session ID for which the DNAI corresponding to the selected DNN associated with the distributed processing of the relocation has been transmitted. Whenever the relocation of the server and the CF is completed, each target CF can send an affirmative response to the SMF entity 311 indicating that the relocation has been completed. Conversely, when all target CFs have completed the relocation of the server providing services for the application of the UE performing the handover and the relocation of the CF docked (or connected, accessed or communicated) with the server from the source CF to the target CF, the relocation can be performed. Figure 3 In operation 337 , the target CF sends a positive response to the target base station 305 .

[0132] In operation 720, the SMF entity 311 may perform UPF configuration based on a message received from each target CF indicating that the relocation has been completed. Specifically, whenever the SMF entity 311 receives a message from each target CF indicating that the target CF has been relocated to a server providing services for an application of the UE performing the handover and that the CF interfaced with the server has been relocated from the source CF to the target CF, the SMF entity 311 may perform UPF configuration for a PDU session that supports services for the application of the UE performing the handover and is associated with the corresponding target CF. By performing a UPF configuration operation each time the relocation process of the corresponding target CF is completed at the MF entity 311, the delay time can be reduced until the relocation process of all target CFs is completed.

[0133] Figure 8 is a flowchart illustrating an operation of supporting relocation of a server that provides a service for an application of a UE that performs handover according to an embodiment of the present disclosure. Figure 8 The present invention shows a case where a handover process and a process of relocating an application of a UE are performed because the UE needs to receive services from different cells and different servers during the movement of the UE. Figure 8 is briefly shown with reference to Figure 3 A flowchart illustrating the contents.

[0134] refer to Figure 8 In operation 810, a handover preparation process may be performed. The source base station may send a handover request message to the target base station. Upon receiving the handover request message, the target base station may perform a process of determining whether a target CF needs to be determined.

[0135] In operation 815 , based on the handover request message from the source base station, the target base station may identify information indicating that a CF supporting a service for an application for a UE performing handover may be changed (or relocated) with respect to relocation of the application.

[0136] In operation 820, the target base station may determine a target CF that will support services for the application in connection with application relocation of the UE based on the handover request message from the source base station. The process associated with relocation from the source CF to the target CF may be performed through information exchange between the target CF and the source base station, and between the source base station and an associated CF (hereinafter, the source CF).

[0137] In operation 825 , processes related to relocation of the application server that interfaces the CF with the computing resources may also be performed.

[0138] In operation 830, a handover procedure may be performed. The source base station may receive a handover request ACK message including handover-related information from the target base station, and based on the received message, may perform a procedure for changing a base station performing data communication with the UE from the source base station to the target base station.

[0139] In operation 840, a UPF selection process may be performed. When the UE moves and requires not only handover but also a change in the application server providing services for the UE's applications, the UPF entity that interfaces with the application server and the network may also need to be changed. In this case, a process for selecting the changed UPF entity may be performed.

[0140] The process of operations 830 to 840 may be performed simultaneously or in parallel with operations 815 to 825 .

[0141] In operation 850, after receiving the N2 SM message, the SMF entity may perform UPF configuration for a PDU session related to application relocation of the UE performing handover.

[0142] In operation 860, an N2 path switch request message for performing communication with a relocated server that provides a service for an application of the moved UE may be transmitted and received according to the UPF configuration.

[0143] In operation 870 , source radio access network (RAN) resources may be released according to the CF, and the server may be changed based on the relocation of the application.

[0144] Figure 9 The operation of the target base station according to an embodiment of the present disclosure is illustrated.

[0145] Reference Figure 9 In operation 910, the target base station may receive a handover request message from the source base station. The handover request message may include information about a data network (DN) related to the distributed processing of the relocation of the application of the UE performing the handover. The information about the DN described in the present disclosure may include, for example, a data network name (DNN) related to the distributed processing of the relocation of the application of the UE performing the handover, and a data network access identifier (DNAI). In addition, the handover request message may include protocol data unit (PDU) session ID information of the UE performing the handover. However, the handover request message is not limited thereto and may include various types of information.

[0146] In operation 920, based on the handover request message received from the source base station, the target base station may determine, for each DNN related to the distributed processing of the relocated application of the UE, a CF identified by a data network access identifier (DNAI) associated with the target base station as a candidate for a target computing function (CF) of the application of the UE to be interfaced (or connected, accessed, or communicated) with the application server to perform the handover. The CF identified by the DNAI may transmit information between the application server and the network.

[0147] The cell corresponding to a specific base station may belong to the service area of ​​the application server identified by the specific DNAI. The target base station may determine, based on the received handover request message, whether the DNAI associated with the source base station is the same as the DNAI associated with the target base station for each DNN related to the distributed processing of the relocation of the UE's application, to determine whether to perform the process of determining the target CF.

[0148] When, for each DNN related to the distributed processing of relocation of the UE's application, the DNAI associated with the source base station and the DNAI associated with the target base station are different, the target base station may determine to perform a process of determining a target CF. When the target base station determines to perform a process of determining a target CF, the target base station may determine a CF identified by a DNAI associated with the target base station as a candidate for the target CF, for each DNN related to the distributed processing of relocation of the UE's application, the DNAI associated with the target base station being different from the DNAI associated with the source base station.

[0149] On the other hand, when the DNAI associated with the source base station and the DNAI associated with the target base station 305 are the same for each DNN related to the distributed processing of the relocation of the UE's application, the target base station may determine not to perform the process of determining the target CF. This may indicate that the source base station and the target base station are within the service area of ​​the same application server. In the case where the DNAI associated with the source base station and the DNAI associated with the target base station are the same for each DNN related to the distributed processing of the relocation of the UE's application, the target CF may not be determined because the same UPF entity and application server as those used before the UE performed the handover are available without changing the UPF entity or DNAI. At this time, the target base station may store information indicating that the DNAI associated with the source base station and the target base station are the same for each DNN related to the distributed processing of the UE's application relocation, and may include information including an indication of the same DNAI in the N2 path switching request message sent to the AMF entity in the future. However, the N2 path switching request message is not limited to this and may include various types of information.

[0150] In operation 930, the target base station may determine, among the determined candidates for the target CF, a target CF candidate corresponding to each DN related to the distributed process of application relocation of the UE performing handover as the target CF.

[0151] The target base station may receive information related to application relocation of the UE performing handover from the candidate of the target CF. The target base station may send a message requesting information related to distributed processing of application relocation of the UE performing handover to the candidate of the target CF, and the candidate of the target CF having received the message from the target base station may send information related to application relocation of the UE to the target base station for use in an application server with which each CF is docked (or connected, accessed, or communicated).

[0152] According to an embodiment of the present disclosure, information related to the distributed processing of application relocation sent by candidates of the target CF may include the following pieces of information.

[0153] - Information about currently available computing resources and information about access availability

[0154] -DNN, which corresponds to each docked application server in the candidate of target CF

[0155] - DNAI of each docked application server in the candidate of the specified target CF

[0156] The information about admission availability may include information related to whether a computing / application server connected to each of the candidates for the target CF can support a service of an application for the UE performing the handover, or whether the computing / application server can support an additional UE.

[0157] However, the information related to application relocation is not limited thereto and may include various types of information.

[0158] The target base station may update the state of the target CF based on the received information. The target base station 305 may determine, based on the received information related to the application relocation of the target CF candidate 307, a target CF for docking (or connecting, accessing, or communicating) the application and the server providing services for the application of the UE performing the handover among the target CF candidates 30.

[0159] According to an embodiment of the present disclosure, if it is recognized that a specific server cannot provide a service for an application of a UE performing handover, the target base station may not determine a target CF candidate corresponding to the specific server as a target CF. For example, if it is ensured that the specific server lacks available resources for providing a service for an application of a UE performing handover or cannot additionally support admission availability information of a new UE, the target base station may not determine a target CF candidate corresponding to the specific server as a target CF.

[0160] In operation 940, the target base station 305 may transmit a handover request ACK message (handover request confirmation message) including information on the determined target CF to the source base station. The handover request ACK message may include the following information.

[0161] - Information that can indicate the DNN related to the distributed processing of the application relocation, which corresponds to the target CF

[0162] - Information about the application server (or computing server or edge application server (EAS)) connected to the target CF, as well as information indicating the server

[0163] - Internal network address information of the target CF

[0164] - External network Internet address information of the application server (or computing server or edge application server (EAS)) connected to the target CF

[0165] Information indicating the distributed network (DNN) associated with the target CF and related to distributed processing for application relocation may be included in the Handover Request ACK message as a parameter called DNN. Furthermore, information about the target CF's interface application server and information indicating the server may be included in the Handover Request ACK message as a parameter called Target DNAI.

[0166] However, the handover request ACK message is not limited thereto and may include various types of information.

[0167] Will refer to Figure 10 The operation of the source base station that has received the handover request ACK message is described.

[0168] As described above, when the server providing a service for an application needs to be relocated based on the mobility of a UE performing a handover, the target base station can determine a target CF to interface with (or connect, access, or communicate with) computing resources and the application server in order to change the application server providing the service for the application. Information related to the application relocation can be sent to and received from the determined target CF, and accordingly, the application server and CF supporting the service for the UE's application can ultimately be changed (or relocated).

[0169] According to the present disclosure, when a UE including an application that requires computing that exceeds the UE's capacity or uses high-performance AI moves, the UE can perform a switching process caused by inter-cell mobility and simultaneously relocate a server that provides services for the application and a CF that docks (or connects, accesses, or communicates) the application and the server, thereby effectively reducing computing delays.

[0170] Figure 10 The operation of the source base station according to an embodiment of the present disclosure is illustrated.

[0171] Reference Figure 10 In operation 1010, when a UE moves from a source cell to a target cell, the source base station may transmit a handover request message (handover request message) to the target base station. The handover request message may include information about a data network (DN) related to a distributed process for relocating an application of the UE performing the handover. The information about the DN described in the present disclosure may include, for example, a data network name (DNN) related to a distributed process for relocating an application of the UE performing the handover, and a data network access identifier (DNAI). In addition, the handover request message may include protocol data unit (PDU) session ID information of the UE performing the handover. However, the handover request message is not limited thereto and may include various types of information.

[0172] In operation 1020, the source base station may receive a handover request ACK message (handover request confirmation message) from the target base station, the handover request ACK message including information about the target CF determined by the target base station. The handover request ACK message may include the following information. However, the handover request ACK message is not limited thereto and may include various types of information.

[0173] - Information that can indicate the DNN related to the distributed processing of the application relocation, which corresponds to the target CF

[0174] - Information about the application server (or computing server or edge application server (EAS)) connected to the target CF, as well as information indicating the server

[0175] - Internal network address information of the target CF

[0176] - External network Internet address information of the application server (or computing server or edge application server (EAS)) connected to the target CF

[0177] Information indicating the distributed network (DNN) associated with the target CF and related to distributed processing for application relocation may be included in the Handover Request ACK message as a parameter called DNN. Furthermore, information about the target CF's interface application server and information indicating the server may be included in the Handover Request ACK message as a parameter called Target DNAI.

[0178] However, the handover request ACK is not limited thereto and may include various types of information.

[0179] In operation 1030, the source base station may transmit information about the target CF to a source CF associated with the source base station and corresponding to the target CF based on the handover request ACK message received from the target base station. Specifically, the source base station may transmit information related to the target CF included in the handover request ACK message received from the target base station to a CF associated with the source base station (hereinafter, the source CF), the target CF corresponding to the DNN related to the distributed processing to which the relocation is applied.

[0180] The information related to the target CF corresponding to the DNN related to application relocation may include the following pieces of information.

[0181] - Internal network address information of the target CF

[0182] - External network Internet address information of the application server connected to the target CF

[0183] - Information that can indicate the DNN related to the distributed processing of the application relocation, which corresponds to the target CF

[0184] However, the information related to the target CF corresponding to the DNN related to application relocation is not limited thereto and may include various types of information.

[0185] Thereafter, the source base station may connect the target CF to a source CF associated with the source base station and corresponding to the target CF, so that the source CF sends and receives messages to and from the target CF, the messages including information for distributed processing of application relocation of the UE performing the handover.

[0186] Figure 11 The structure of a base station according to various embodiments of the present disclosure is shown.

[0187] Reference Figure 11 , the base station 1100 includes a communication unit 1110 , a storage device 1120 and a controller 1130 .

[0188] The communication unit 1110 performs functions for transmitting and receiving signals over a radio channel. For example, the communication unit 1110 converts baseband signals into bit streams according to the system's physical layer specifications. For example, during data transmission, the communication unit 1110 generates complex symbols by encoding and modulating the transmit bit stream. Furthermore, during data reception, the communication unit 1110 demodulates and decodes the baseband signal to recover the received bit stream. Furthermore, the wireless communication unit 1110 up-converts the baseband signal into a radio frequency (RF) band signal, transmits the up-converted RF band signal via an antenna, and then down-converts the RF band signal received via the antenna back to a baseband signal.

[0189] To this end, wireless communication unit 1110 may include transmit filters, receive filters, amplifiers, mixers, oscillators, digital-to-analog converters (DACs), analog-to-digital converters (ADCs), and the like. Furthermore, communication unit 1110 may include multiple transmit / receive paths. Furthermore, wireless communication unit 1110 may include at least one antenna array comprising multiple antenna elements. In terms of hardware, wireless communication unit 1110 may include a digital unit and an analog unit, with the analog unit comprising multiple subunits depending on operating power, frequency, and the like.

[0190] Communication unit 1110 can transmit / receive signals. To this end, communication unit 1110 may include at least one transceiver. For example, communication unit 1110 can transmit synchronization signals, reference signals, system information, messages, control information, data, etc. In addition, communication unit 1110 can perform beamforming.

[0191] Communication unit 1110 transmits and receives signals as described above. Therefore, all or part of communication unit 1110 may be referred to as a "transmitter," "receiver," or "transceiver." In the following description, "transmission and reception via a radio channel" includes the communication unit 1110 performing the aforementioned processing.

[0192] The storage device 1120 can store basic programs, applications, and data used for the operation of the master base station, such as configuration information. The storage device 1120 may include memory. The storage device 1120 may include volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. In addition, the storage device 1120 provides stored data upon request from the controller 1130.

[0193] Controller 1130 controls the overall operation of base station 1100. For example, controller 1130 transmits / receives signals via communication unit 1110. Furthermore, controller 1130 stores data in storage device 1120 and reads data from storage device 1120. Furthermore, controller 1130 may execute the functions of a protocol stack required by communication specifications. To this end, controller 1130 may include at least one processor.

[0194] Figure 11 The structure of the base station 1100 shown is merely an example of a base station, and examples of base stations for performing various embodiments of the present disclosure are not limited to Figure 11 That is, some elements may be added, omitted or changed according to various embodiments.

[0195] exist Figure 11In the present disclosure, the base station 1100 has been described as a single entity, but the present disclosure is not limited thereto. In addition to centralized deployment, the base station 1100 according to various embodiments of the present disclosure can be implemented to build an access network with distributed deployment. According to an embodiment, the base station can be divided into a central unit (CU) and a digital unit (DU). The CU can be implemented to perform upper layer functions (e.g., packet data convergence protocol (PDCP) and RRC), and the DU can be implemented to perform lower layer functions (e.g., medium access control (MAC) and physical (PHY)). The DU of the base station can form beam coverage on the radio channel.

[0196] Figure 12 1 shows a structure of a UE 1200 according to various embodiments of the present disclosure.

[0197] Figure 12 The structure shown in FIG1 may be understood as the structure of UE 1200. As used below, terms such as “unit” and “device” refer to a unit configured to process at least one function or operation and may be implemented as hardware, software, or a combination of hardware and software.

[0198] refer to Figure 12 , UE 1200 includes a communication unit 1210, a storage device 1220 and a controller 1230.

[0199] The communication unit 1210 performs functions for transmitting and receiving signals via a radio channel. For example, the communication unit 1210 performs conversion functions between baseband signals and bit streams according to the system's physical layer specifications. For example, during data transmission, the communication unit 1210 generates complex symbols by encoding and modulating the transmit bit stream. Furthermore, during data reception, the communication unit 1210 demodulates and decodes the baseband signal to recover the received bit stream. Furthermore, the communication unit 1210 up-converts the baseband signal to an RF band signal, transmits the RF band signal via an antenna, and down-converts the RF band signal received via the antenna to a baseband signal. For example, the communication unit 1210 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC.

[0200] Furthermore, the communication unit 1210 may include multiple transmit / receive paths. Furthermore, the communication unit 1210 may include an antenna unit. The communication unit 1210 may include at least one antenna array configured with multiple antenna elements. In terms of hardware, the communication unit 1210 may include digital circuits and analog circuits (e.g., radio frequency integrated circuits (RFICs)). The digital and analog circuits may be implemented in a single package. Furthermore, the communication unit 1210 may include multiple RF chains. The communication unit 1210 may perform beamforming. To assign directionality to transmitted / received signals based on the configuration of the controller 1230, the communication unit 1210 may apply beamforming weights to the signals. Depending on the embodiment, the communication unit 1210 may include a radio frequency (RF) block (or RF unit). The RF block may include a first RF circuit associated with the antenna and a second RF circuit associated with baseband processing. The first RF circuit may be referred to as the RF antenna (RF-A). The second RF circuit may be referred to as the RF baseband (RF-B).

[0201] Furthermore, the communication unit 1210 can transmit and receive signals. To this end, the communication unit 1210 may include at least one transceiver. Furthermore, the communication unit 1210 may receive downlink signals. Downlink signals may include synchronization signals (SS), reference signals (RS) (e.g., demodulation (DM)-RS or phase tracking reference signal (PTRS)), system information (e.g., MIB, SIB, residual system information (RMSI) or other system information (OSI)), configuration messages, control information, downlink data, and the like. The communication unit 1210 may also transmit uplink signals. Uplink signals may include random access-related signals (e.g., random access preamble (RAP) (or message 1 (Msg1) or message 3 (Msg3)), reference signals (e.g., sounding reference signal (SRS), DMRS, or PTRS), power headroom reports (PHR), and the like).

[0202] Furthermore, the communication unit 1210 may include different communication modules for processing signals in different frequency bands. Furthermore, the communication unit 1210 may include multiple communication modules to support a variety of different radio access technologies. For example, the various radio access technologies may include Bluetooth Low Energy (BLE), Wireless Fidelity (Wi-Fi), Wi-Fi Gigabyte (WiGig), cellular networks (e.g., Long Term Evolution (LTE) or New Radio (NR)), etc. Furthermore, the different frequency bands may include Super High Frequency (SHF) bands (e.g., 2.5 GHz or 5 GHz bands), millimeter wave (mmWave) bands (e.g., 38 GHz or 60 GHz bands), etc. Furthermore, the communication unit 1210 may use the same type of radio access technology in different frequency bands, such as unlicensed bands for License Assisted Access (LAA) or Citizens Broadband Radio Service (e.g., 3.5 GHz).

[0203] Communication unit 1210 transmits and receives signals as described above. Therefore, all or part of communication unit 1210 may be referred to as a "transmitter," "receiver," or "transceiver." In the following description, "transmission and reception via a radio channel" includes the communication unit 1210 performing the aforementioned processing.

[0204] The storage device 1220 may store basic programs, applications, and data, such as configuration information, for the operation of the master base station. The storage device 1220 may include volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory. In addition, the storage device 1220 provides stored data upon request from the controller 1230.

[0205] Controller 1230 controls the overall operation of UE 1200. For example, controller 1230 transmits / receives signals via communication unit 1210. Furthermore, controller 1230 stores data in storage device 1220 and reads data from storage device 1220. Furthermore, controller 1230 can execute the functions of the protocol stack required by the communication specification. To this end, controller 1230 may include at least one processor. Controller 1230 may include at least one processor or microprocessor, or may be part of a processor. Furthermore, communication unit 1210 and a portion of controller 1230 may be referred to as a communication processor (CP). Controller 1230 may include various modules for performing communications. According to various embodiments, controller 1230 may control the UE to perform operations according to various embodiments.

[0206] Figure 13 The structure of a server according to an embodiment of the present disclosure is shown.

[0207] refer to Figure 13, the server may include a communication unit 1310, a storage device 1320, and a controller 1330. As used herein, the controller 1330 may be defined as a circuit, an application specific integrated circuit, or at least one processor.

[0208] The server may correspond to at least one of a computing server, an application server, or a data network server.

[0209] The communication unit 1310 may transmit / receive signals with other network entities. For example, the communication unit 1310 may transmit / receive information with other servers via a specific interface.

[0210] In addition, the storage 1320 may store at least one of information transmitted / received through the communication unit 1310 and information generated by the controller 1330 .

[0211] The controller 1323 may control the overall operation of the server according to an embodiment of the present disclosure. For example, the controller 1330 may control the signal flow between the various blocks to perform operations according to the above flowchart.

[0212] The embodiments of the present disclosure described and illustrated in the specification and drawings are merely specific examples presented to facilitate explanation of the technical content of the present disclosure and to aid understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is clear to those skilled in the art that other variations based on the technical ideas of the present disclosure can be implemented. In addition, the above-mentioned various embodiments can be used in combination as needed.

[0213] As described above, the method performed by a target base station in a wireless communication system according to various embodiments of the present disclosure may include: receiving a handover request message from a source base station, identifying a computing function (CF) identified by a data network access identifier (DNAI) associated with the target base station as a target CF candidate based on the handover request message, identifying a target CF candidate corresponding to each data network (DN) among the target CF candidates as a target CF, wherein each DN is related to distributed processing of application relocation of a terminal performing handover, and sending a handover request ACK message including information about the identified target CF to the source base station, wherein the target CF connects the network to an application server that provides services for the application of the terminal performing handover.

[0214] According to various embodiments of the present disclosure, the method may further include sending an N2 path switching request message to an access and mobility management function (AMF) entity, and the N2 path switching request message may include PDU session ID information, which corresponds to a data network name (DNN) associated with the target CF in a distributed processing of application relocation of the terminal performing the handover.

[0215] According to various embodiments of the present disclosure, the method may further include: receiving a message from the determined target CF based on the target CF, the message including information indicating that the relocation of the CF connecting the network with the application server providing services for the application of the terminal performing the handover is completed and the relocation of the application server is completed, and transmitting the message to the AMF entity through the N2 SM message.

[0216] According to various embodiments of the present disclosure, determining the target CF candidate may include: for a DNN related to distributed processing of relocation of an application server of a terminal, determining whether the DNAI associated with the source base station is the same as the DNAI associated with the target base station, determining the target CF candidate when the DNAI associated with the source base station is different from the DNAI associated with the target base station, and not determining the target CF candidate and storing information indicating that the DNAI is the same when the DNAI associated with the source base station and the DNAI associated with the target base station are the same.

[0217] According to various embodiments of the present disclosure, determining the target CF candidate may further include: requesting information related to application relocation from the target CF candidate, and receiving the information related to application relocation from the target CF candidate.

[0218] According to various embodiments of the present disclosure, the handover request message may include information on a DNN related to a distributed process of application relocation of a terminal performing handover and PDU session ID information of the terminal.

[0219] According to various embodiments of the present disclosure, the handover request ACK message may include indicator information of the DNN associated with the target CF, DNAI information associated with the target CF, and network address information of the target CF, among information about the DNN related to the relocated distributed processing of the application server that provides services for the application of the terminal performing the handover.

[0220] As described above, the device of a target base station in a wireless communication system according to various embodiments of the present disclosure may include a communication unit and a controller, wherein the controller is configured to perform control to: receive a handover request message from a source base station, determine a computing function (CF) identified by a data network access identifier (DNAI) associated with the target base station as a target CF candidate based on the handover request message, determine a target CF candidate corresponding to each data network (DN) among the target CF candidates as a target CF, each DN being related to distributed processing of application relocation information of a terminal (UE) performing handover, and transmit a handover request ACK message including information about the determined target CF to the source base station. Furthermore, the target CF connects the network to an application server that provides a service for an application of the terminal performing handover.

[0221] According to various embodiments of the present disclosure, the controller may be configured to send an N2 path switching request message to an access and mobility management function (AMF) entity, and the N2 path switching request message may include PDU session ID information, the PDU session ID information corresponding to a data network name (DNN) associated with a target CF in a distributed processing of application relocation of a terminal performing handover.

[0222] According to various embodiments of the present disclosure, the controller may be configured to perform control to receive a message from the determined target CF based on the target CF, the message including information indicating completion of relocation of the CF connecting the network with the application server providing services for the application of the terminal performing the handover and completion of relocation of the application server, and transmit the message to the AMF entity through the N2 SM message.

[0223] According to various embodiments of the present disclosure, for a DNN related to distributed processing of relocation of an application server of a terminal, the controller may be configured to perform control to determine whether the DNAI associated with the source base station is the same as the DNAI associated with the target base station, determine a target CF candidate in a case where the DNAI associated with the source base station and the DNAI associated with the target base station are different, and, in a case where the DNAI associated with the source base station and the DNAI associated with the target base station are the same, not determine the target CF candidate and store information indicating that the DNAI is the same.

[0224] According to various embodiments of the present disclosure, the controller may be configured to perform control to request information related to application relocation from a target CF candidate, and receive information related to application relocation from the target CF candidate.

[0225] According to various embodiments of the present disclosure, the handover request message may include information on a DNN related to a distributed process of application relocation of a terminal performing handover and PDU session ID information of the terminal.

[0226] According to various embodiments of the present disclosure, the handover request ACK message may include indicator information of the DNN associated with the target CF, DNAI information associated with the target CF, and network address information of the target CF among information about the DNN related to the relocated distributed processing of the application server that provides services for the application of the terminal performing the handover.

[0227] As described above, the method performed by a source base station in a wireless communication system according to various embodiments of the present disclosure may include: sending a handover request message to a target base station, receiving a handover request ACK message including information about a determined target computing function (CF) from the target base station, and based on the handover request ACK message, transmitting information about the target CF to a source CF associated with the source base station and corresponding to a data network name (DNN), the DNN being related to distributed processing of application relocation of a terminal (UE) performing the handover and associated with the target CF.

[0228] According to various embodiments of the present disclosure, the method may further include connecting the source CF to the target CF so that the source CF and the target CF can transmit and receive messages including information for distributed processing of application relocation of the terminal performing handover.

[0229] According to various embodiments of the present disclosure, the handover request message may include information on a DNN related to a distributed process of application relocation of a terminal performing handover and PDU session ID information of the terminal.

[0230] According to various embodiments of the present disclosure, the handover request ACK message may include indicator information of the DNN associated with the target CF in the DNN related to the distributed processing of the relocation of the application server of the terminal performing the handover, DNAI information associated with the target CF, and network address information of the target CF.

[0231] As described above, the device of the source base station in the wireless communication system according to various embodiments of the present disclosure may include a communication unit and a controller, wherein the controller is configured to perform control to send a handover request message to the target base station, receive a handover request ACK message from the target base station, the handover request ACK message including information about the determined target computing function (CF), and based on the handover request ACK message, transmit information about the target CF to the source CF, the source CF being associated with the source base station and corresponding to a data network name (DNN), the DNN being related to the distributed processing of application relocation of the terminal (UE) performing the handover and being associated with the target CF.

[0232] According to various embodiments of the present disclosure, the controller may be configured to perform control to connect the source CF to the target CF so that the source CF and the target CF can transmit and receive messages including information for distributed processing of application relocation of a terminal performing handover.

Claims

1. A method performed by a target base station in a wireless communication system, the method comprising: receiving a handover request message from a source base station; identifying, based on the handover request message, a compute function (CF) identified by a data network access identifier (DNAI) associated with the target base station as a target CF candidate; identifying a target CF candidate corresponding to each data network (DN) among the target CF candidates as a target CF, wherein each DN is associated with a distributed process of application relocation of a user equipment (UE) performing handover; and Sending a handover request ACK message including information about the identified target CF to the source base station, The target CF connects the network to an application server serving an application of the UE performing the handover.

2. The method according to claim 1, further comprising: Send an N2 Path Switch Request message to the Access and Mobility Management Function (AMF) entity, The N2 path switch request message includes PDU session ID information, where the PDU session ID information corresponds to a data network name (DNN) associated with the target CF in a distributed process related to application relocation of the UE performing the handover.

3. The method according to claim 2, further comprising: receiving, based on the target CF, from the identified target CF, a message including information indicating completion of relocation of the CF connecting the network with the application server serving the application of the UE performing the handover and completion of relocation of the application server; and The message is delivered to the AMF entity via the N2 SM message.

4. The method according to claim 1, wherein Identification of target CF candidates includes: For a DNN related to distributed processing of relocation of an application server of a UE, identifying whether a DNAI associated with a source base station and a DNAI associated with a target base station are the same; Identifying a target CF candidate in the event that the DNAI associated with the source base station and the DNAI associated with the target base station are different; and In the case where the DNAI associated with the source base station and the DNAI associated with the target base station are the same, the target CF candidate is not identified and information indicating that the DNAIs are the same is not stored.

5. The method according to claim 1, wherein Identification of target CF candidates also includes: Requesting information related to application relocation from the target CF candidate; and Receive information related to application relocation from the target CF candidate.

6. A device for a target base station in a wireless communication system, the device comprising: Communication unit; and controller, The controller is configured to perform control to: receiving a handover request message from a source base station; identifying, based on the handover request message, a compute function (CF) identified by a data network access identifier (DNAI) associated with the target base station as a target CF candidate; identifying a target CF candidate corresponding to each data network (DN) among the target CF candidates as a target CF, wherein each DN is associated with distributed processing of application relocation information of a user equipment (UE) performing handover; and Sending a Handover Request ACK message including information about the identified target CF to the source base station, and The target CF connects the network to an application server serving an application of the UE performing the handover.

7. The apparatus according to claim 6, wherein The controller is configured to perform control to send an N2 path switch request message to an access and mobility management function (AMF) entity, and The N2 path switch request message includes PDU session ID information, where the PDU session ID information corresponds to a data network name (DNN) associated with the target CF in a distributed process related to application relocation of the UE performing the handover.

8. The apparatus according to claim 7, wherein The controller is configured to perform control to: receiving, based on the target CF, from the identified target CF, a message including information indicating completion of relocation of the CF connecting the network with the application server serving the application of the UE performing the handover and completion of relocation of the application server; and The message is delivered to the AMF entity via the N2 SM message.

9. The apparatus according to claim 6, wherein The controller is configured to perform control to: For a DNN related to distributed processing of relocation of an application server of a UE, identifying whether a DNAI associated with a source base station and a DNAI associated with a target base station are the same; Identifying a target CF candidate when the DNAI associated with the source base station and the DNAI associated with the target base station are different; and In the case where the DNAI associated with the source base station and the DNAI associated with the target base station are the same, the target CF candidate is not identified and information indicating that the DNAIs are the same is not stored.

10. The apparatus according to claim 6, wherein The controller is configured to perform control to: Requesting information related to application relocation from the target CF candidate; and Receive information related to application relocation from the target CF candidate.

11. The apparatus according to claim 6, wherein The handover request message includes information on a DNN related to a distributed process of application relocation of a UE performing handover and PDU session ID information of the UE.

12. The apparatus according to claim 6, wherein The handover request ACK message includes indicator information of the DNN associated with the target CF, DNAI information associated with the target CF, and network address information of the target CF among information about the DNN related to the relocation of the application server serving the application of the UE performing the handover.

13. A method performed by a source base station in a wireless communication system, the method comprising: Sending a handover request message to the target base station; receiving a handover request ACK message from the target base station, the handover request ACK message including information about the identified target compute function (CF); and Based on the handover request ACK message, information about the target CF is transmitted to the source CF associated with the source base station and corresponding to the data network name (DNN), wherein the DNN is associated with the target CF and is related to the distributed processing of application relocation of the user equipment (UE) performing the handover.

14. A device for a source base station in a wireless communication system, the device comprising: Communication unit; and controller, The controller is configured to perform control to: Sending a handover request message to the target base station; receiving a handover request ACK message from the target base station, the handover request ACK message including information about the identified target compute function (CF); and Based on the handover request ACK message, information about the target CF is transmitted to the source CF associated with the source base station and corresponding to the data network name (DNN), wherein the DNN is associated with the target CF and is related to the distributed processing of application relocation of the user equipment (UE) performing the handover.

15. The apparatus according to claim 14, wherein The controller is configured to perform control to connect the source CF to the target CF so as to transmit and receive a message including information of a distributed process for application relocation of a UE performing handover.

Images