Method and device for providing a connection with a terminal to use edge computing services

Abstract

The present disclosure relates to a communication technology for integrating Internet of Things (IoT) technology with a fifth generation (5G) or pre-fifth generation (pre-5G) communication system that supports higher data transfer rates than fourth generation (4G) communication systems such as Long Term Evolution (LTE), and a system thereof. The present disclosure may be applied to intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail business, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology. According to various embodiments of the present invention, a method for providing DNS server or edge computing service configuration server information to a terminal to support an operation in which the terminal discovers an edge server may be provided.

Description

Technical Field

[0001] The present disclosure relates to a communication system, and a method for providing a DNS server or edge computing service configuration server information to a terminal to support an operation of discovering an edge server by the terminal. Background Art

[0002] In order to meet the increasing demand for wireless data traffic since the deployment of 4G communication systems, efforts have been made to develop improved fifth-generation 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "super 4G networks" or "post-LTE systems".

[0003] 5G communication systems are considered to be implemented in higher frequency (mmWave) bands (e.g., 60 GHz band) in order to achieve higher data rates. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technologies are discussed in 5G communication systems.

[0004] In addition, in 5G communication systems, developments for system network improvements are being made based on advanced small cells, cloud radio access network (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multi-point (CoMP), receiver-side interference cancellation, etc.

[0005] In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superimposed coding (SWSC) as advanced coding modulation (ACM), and filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as advanced access technologies have been developed.

[0006] Compared with traditional 4G systems, 5G systems are considering supporting more types of services. For example, the most representative services can include ultra-wideband mobile communication services (enhanced mobile broadband (eMBB)), ultra-high reliability / low latency communication services (ultra-reliable low-latency communication (URLLC)), large-scale device-to-device communication services (massive machine type communication (mMTC)), and next-generation broadcast services (evolved multimedia broadcast / multicast service (eMBMS)). A system that provides URLLC services can be referred to as a URLLC system, and a system that provides eMBB services can be referred to as an eMBB system. The terms "service" and "system" can be used interchangeably.

[0007] Among these services, the URLLC service is a new service being considered in the 5G system compared to the existing 4G system. Compared to other services, the URLLC service needs to meet ultra-high reliability (e.g., a packet error rate of about 10-5) and low latency (e.g., about 0.5 msec) conditions. To meet these stringent conditions thus required, the URLLC service may need to apply a shorter transmission time interval (TTI) than the eMBB service, and various operation schemes adopting this are now being considered.

[0008] The Internet, a human-centric connected network in which humans generate and consume information, is evolving into the Internet of Things (IoT) where distributed entities (such as things) exchange and process information without human intervention. The Internet of Everything (IoE) has emerged as a combination of IoT technology and big data processing technology through connection to cloud servers. As IoT implementation requires technical elements such as "sensing technology", "wired / wireless communication and network infrastructure", "service interface technology", and "security technology", sensor networks, machine-to-machine (M2M) communication, machine type communication (MTC), etc. have been studied recently.

[0009] Such an IoT environment can provide intelligent Internet technology services that create new value for human life by collecting and analyzing data generated between connected things. Through the integration and combination of existing information technology (IT) and various industrial applications, IoT can be applied to various fields, including smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0010] In line with this, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as sensor networks, machine type communication (MTC), and machine-to-machine (M2M) communication can be implemented through beamforming, MIMO, and array antennas. The application of cloud radio access network (RAN) as the above big data processing technology can also be considered an example of the integration between 5G technology and IoT technology. SUMMARY OF THE INVENTION

[0011] TECHNICAL PROBLEM

[0012] The terminal should be connected to the edge server to use the edge computing service. However, the edge server can be set in each region, and correspondingly, the terminal needs to know the edge service that the terminal should connect to in the corresponding region. For this purpose, the terminal should be able to connect to the DNS server or configuration server operated by the service provider providing the edge computing service. Thereafter, the terminal can obtain the address of the edge server to be connected by the terminal from the corresponding server, connect to the edge server, and use the edge computing service. Correspondingly, the present disclosure proposes a method for providing server information notifying the terminal of the edge server that the terminal should connect to.

[0013] The technical subject pursued in the present disclosure may not be limited to the above technical subject, and through the following description, those skilled in the art to which the present disclosure pertains can clearly understand other technical subjects not mentioned.

[0014] Technical solution

[0015] A method for communicating of a terminal for solving this problem according to an embodiment of the present disclosure includes: sending a first message including information for requesting to use an edge computing service to a Session Management Function (SMF); and receiving, from the SMF, a second message including information about a configuration server including configuration information for receiving an edge computing service, where the information about the configuration server is configured by a Policy and Charging Function (PCF) based on the information for requesting to use an edge computing service.

[0016] The first message may be a PDU session establishment message or a PDU session modification request message.

[0017] The information about the configuration server may be received through a Protocol Configuration Option (PCO).

[0018] The information about the configuration server may include information about the configuration server determined based on at least one of information related to the location of the terminal and information related to the load of the configuration server.

[0019] A method for communicating of an SMF for solving this problem according to an embodiment of the present disclosure includes: receiving, from a terminal, a first message including information for requesting to use an edge computing service of the terminal; sending a second message for configuring a policy to a Policy and Charging Function (PCF), the second message including the information for requesting to use an edge computing service; receiving, from the PCF, a third message including information about a configuration server configured based on the information for requesting to use an edge computing service and including configuration information for receiving an edge computing service; and sending, to the terminal, a fourth message including the information about the configuration server.

[0020] The fourth message may include a Protocol Configuration Option (PCO) containing the information about the configuration server.

[0021] To solve this problem, a terminal according to an embodiment of the present disclosure includes: a transceiver; and a controller configured to send a first message including information for requesting to use an edge computing service to a Session Management Function (SMF) and receive a second message including information about a configuration server including configuration information for receiving the edge computing service from the SMF, wherein the information about the configuration server is configured by a Policy and Charging Function (PCF) based on the information for requesting to use the edge computing service.

[0022] An SMF for solving the problem according to an embodiment of the present disclosure includes: a transceiver; and a controller configured to receive a first message including information of the terminal for requesting to use an edge computing service from the terminal, send a second message including the information for requesting to use the edge computing service for configuring a policy to a Policy and Charging Function (PCF), receive a third message including information about a configuration server including configuration information for receiving the edge computing service configured based on the information for requesting to use the edge computing service from the PCF, and send a fourth message including the information about the configuration server to the terminal.

[0023] Beneficial technical effects

[0024] According to an embodiment of the present disclosure, a terminal can obtain information about a server capable of receiving information about a server to which the terminal can initially connect to receive an edge computing service. Accordingly, the terminal can discover an edge server to which the terminal should connect through communication with the corresponding server and use the edge computing service through the edge server. In addition, the terminal can receive this information through a connection of a mobile communication system and thus can receive the corresponding information without any operation of an additional application layer. That is, the information about the server can be obtained through a basic operation of establishing a data connection to the mobile communication system or exchanging policy information by accessing the mobile communication system. In addition, a mobile communication service provider can provide the corresponding information only to terminals allowed to use the edge computing service. Further, the terminal can receive information about a server suitable for the current location of the terminal according to a function of detecting the location of the terminal, which is a basic function of the mobile communication system. Alternatively, the terminal can receive information about the server according to a PLMN to which the terminal should connect.

[0025] The beneficial effects obtainable from the present disclosure may not be limited to the above effects, and through the following description, those skilled in the art to which the present disclosure pertains can clearly understand other effects not mentioned. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Illustrates a system architecture for providing an edge computing service, a system architecture of a 5G mobile communication system, and the relationship between them according to an embodiment of the present disclosure.

[0027] Figure 2 Illustrates the structure of an application within a terminal, an enabling layer that enables edge computing services, and a communication layer that accesses a mobile communication system according to an embodiment of the present disclosure. In addition, Figure 2 Illustrates the structure of an edge application server within an edge server that provides edge computing services, an enabling function that enables edge computing services, and a platform or orchestration function for an edge computing system.

[0028] Figure 3 Illustrates a process according to an embodiment of the present disclosure, in which a terminal establishes a data connection by accessing a 5G mobile communication system. The terminal can receive information about the server to which it should initially connect through this process.

[0029] Figure 4 Illustrates a process according to an embodiment of the present disclosure, in which a terminal registers with a 5G mobile communication system. The terminal can receive a policy including information about the server to which it should initially connect through this process.

[0030] Figure 5 Illustrates a method according to an embodiment of the present disclosure, in which a terminal uses a PDU session modification procedure based on changes in the terminal's mobility or network information to update information about the server for edge computing services to which the terminal should initially connect to the terminal.

[0031] Figure 6 Illustrates a method according to an embodiment of the present disclosure, in which a terminal uses an update policy based on changes in the terminal's mobility or information within the network to update the process of updating information about the server for edge computing services to which the terminal should initially connect to the terminal.

[0032] Figure 7 Is a block diagram illustrating a terminal according to an embodiment of the present disclosure.

[0033] Figure 8 Is a block diagram illustrating a network entity according to an embodiment of the present disclosure. Detailed Description of the Embodiments

[0034] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that in the drawings, the same or similar elements are designated by the same or similar reference numerals as much as possible. In addition, detailed descriptions of known functions or configurations that may obscure the subject matter of the present disclosure will be omitted.

[0035] When describing the embodiments of the present disclosure, descriptions related to well-known technical content in the art and not directly related to the present disclosure will be omitted. The omission of such unnecessary descriptions is intended to prevent confusion of the gist of the present disclosure and to more clearly convey the gist.

[0036] For the same reason, in the accompanying drawings, some elements may be exaggerated, omitted, or shown schematically. In addition, the size of each element does not fully reflect the actual size. In the drawings, the same or corresponding elements have the same reference numerals.

[0037] Advantages and features of the present disclosure, and ways to realize them, will be clear by referring to the embodiments described in detail below in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments set forth below, but may be implemented in various different forms. The following embodiments are provided only for fully disclosing the present disclosure and informing those skilled in the art of the scope of the present disclosure, and the present disclosure is only defined by the scope of the appended claims. Throughout this specification, the same or similar reference numerals denote the same or similar elements.

[0038] Here, it will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing apparatus create a method for implementing the functions specified in the flowchart block or blocks. These computer program instructions can also be stored in a computer-usable or computer-readable memory, which can direct a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-usable or computer-readable memory produce an article of manufacture including instructions means for implementing the functions specified in the flowchart block or blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

[0039] In addition, each block of the flowchart illustrations may represent a module, segment, or portion of code that includes one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions recited in the blocks may occur out of order. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

[0040] As used herein, a "unit" refers to a software element or a hardware element that performs a predetermined function, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). However, the meaning of "unit" is not always limited to software or hardware. A "unit" can be configured to be stored in an addressable storage medium or to execute on one or more processors. Thus, a "unit" includes, for example, software elements, object-oriented software elements, class elements or task elements, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and parameters. The elements and functions provided by a "unit" can be combined into a smaller number of elements or "units", or divided into a larger number of elements or "units". Additionally, elements and "units" can be implemented to reproduce one or more CPUs within a device or a secure multimedia card.

[0041] In the 3GPP next-generation communication system, architectures for implementing edge computing services are being continuously discussed. Edge computing technology can be referred to as mobile edge computing or multi-access edge computing, and for convenience, is referred to as MEC in the present disclosure. MEC is a technology that installs a radio base station or a gateway (or UFP) near a radio base station, and applies distributed cloud computing technology thereon so that various services and cached contents are located near a user terminal, thereby alleviating congestion in the mobile core network, achieving low-latency communication in data communication with a terminal (UE: user equipment), and creating new services on this basis. The MEC system provides cloud computing capabilities and an IT service environment to application developers or content providers at the edge of the mobile network. In particular, the MEC system can provide ultra-low latency and high-capacity bandwidth to an application to enable real-time network information access. Thus, an application providing an MEC service can provide services to a terminal through a 5G system. In addition, the 5G system can provide a function through which a terminal using an MEC service accesses the MEC system. Not only the 5G system but also the 4G system can provide functions for MEC services.

[0042] For ease of description, some terms and names defined in the Third Generation Partnership Project Long Term Evolution (3GPP LTE) standard can be used. However, the present disclosure is not limited to the terms and names, and can be equally applied to systems following other standards.

[0043] Figure 1 Shows an MEC system structure, a 5G mobile communication system structure, and the correlation between them according to an embodiment of the present disclosure.

[0044] The following describes Figure 1 the network entities or network nodes shown in

[0045] The core network 110 of 5G may include the following network functions. The Access and Mobility Management Function (AMF) 112 is a network function that manages the mobility of the UE 120. The Session Management Function (SMF) 113 is a network function that manages the packet data network connection provided to the UE 120. This connection is called a Protocol Data Unit (PDU) session. The Policy and Charging Function (PCF) 114 is a network function that applies the service policies and charging policies of the mobile communication service provider and the policies for the PDU session to the UE 120. UDM (not shown) is an abbreviation for Unified Data Management, and is a network function that stores information about subscribers. The Network Exposure Function (NEF) 115 can access the information for managing the UE in the 5G network and subscribe to the mobility management events of the corresponding UE 120, to subscribe to the session management events of the corresponding UE 120, configure the charging information of the corresponding UE 120, request a change in the PDU session policy of the corresponding UE 120, and send small data to the corresponding UE 120. 5G-RAN 111 is a base station that provides wireless communication functions to the UE 120. UPF 116 is an abbreviation for User Plane Function, and serves as a gateway for sending the packets sent and received by the UE 120. UPF 116 can be located near the edge server 151 to support MEC, and accordingly achieves low-latency transmission by directly sending data packets to the edge network 130. UPF 116 can be connected to the data network 140 connected through the Internet, and routes the data that should be sent through the Internet between the packets sent by the UE 120 to the Internet data network 140.

[0046] The MEC system architecture 150 may include the UE 120, the edge server 151, and the configuration server 153. The UE 120 that supports the MEC system 150 may include an MEC enabling layer 220 within the UE 120, and refer to Figure 2 for a detailed description of the structure. The edge server 151 is a server to which the UE 120 accesses to use the MEC service, and third-party application servers are driven in the edge server 151. Refer to Figure 2Describe its detailed structure. To indicate the terms of the edge server 151, the edge computing server, MEC server, MEC server, MEC server, multi-access edge host, edge computing platform, MEC micro cloud, and edge hosting environment may be used interchangeably, but are not limited thereto. The configuration server 153 performs the function of sending configuration information to the UE 120 to use the MEC service. The configuration server 153 knows the deployment of each location of the edge server 151. Before using the MEC service, the UE 120 may access the configuration server 153 and receive the configuration information required to use the MEC service (e.g., information about the edge server accessed at a specific location). The configuration information 153 may be referred to as an edge enabling configuration function or an edge data network configuration server, but is not limited thereto, and may correspond to any access server capable of providing the UE 120 with configuration information to use the MEC service.

[0047] In addition, there is a DNS server 154 for the MEC service. The DNS server 154 may be used to resolve the IP address of the edge server 151 or resolve the IP address of the application server driven on the edge server 151. That is, the DNS server 154 may be a network function that knows information about the edge server 151 or information about the application server driven on the edge server 151. The DNS server 154 may exist in each edge network covering a specific area, or one DNS server may exist in the entire MEC system. When the DNS server 154 for the MEC exists in each edge network covering a specific area, the UE 120 should know the information about the DNS server 154 at the corresponding location, which may operate according to the embodiments of the present disclosure. When there is only one DNS server 154 for the MEC in the entire MEC system, the DNS server 154 should know the information about the edge servers installed in the entire network and the information about the application servers that can be provided in the MEC system, and this information may be provided by the orchestration system to the DNS server 154.

[0048] The UE 120 can access the 5G system 110 through the 5G base station 111 and establish a data connection. To provide MEC services to the UE 120, the 5G system 110 can allocate the UPF 116 for accessing the corresponding edge network 150, and the UE 120 can communicate with the edge server 151 and with the third application server running in the edge server 151 through the UPF 116. The edge server 151 can negotiate with the PCF 114 or the NEF 115 of the 3GPP network. Through the negotiation, the edge server 151 can provide the information required by the UE 120 to use the MEC service to the 5G mobile communication system 110 through the PCF 114 or the NEF 115, or the edge server 151 can use the exposure function provided by the NEF 115 of the 5G mobile communication system to an external server (for example, reporting the location of the UE 120, reporting session-related events of the UE 120, etc.).

[0049] Figure 2 Shows the structure of an enabling layer that enables MEC services for applications within a UE and a communication layer that accesses a mobile communication system. In addition, Figure 2 Shows the structure of an edge application server within an edge server that provides edge computing services, an enabling function that enables edge computing services, and a platform or orchestration function for an edge computing system.

[0050] Refer to Figure 2, the application 210 of the UE 120 is an application provided by a third party. That is to say, the application 210 is a client application for a specific application service executed within the UE 120. The application 210 can be called a client app (application), a UE application, an application client, etc., but is not limited thereto, and can correspond to any client application executed within the UE 120. Multiple applications 210 can be executed within the UE 120. At least one of the applications 210 can use the MEC service. The enabling layer 220 within the UE 120 is a layer for performing operations within the UE 120 to use the MEC service. The enabling layer 220 can be called an enabler client, an MEC activation (enabling) layer, an MEC enabling layer (MEL), an implementation layer, an MEC layer, a multi-access edge enabling layer, a UE enabling client, an edge enabler client, etc., but is not limited thereto, and can correspond to any layer / client within the UE 120 that performs operations within the UE 120 to use the MEC service. The enabling layer 220 can determine which application 210 can use the MEC service and perform operations to connect the network interface to the application server providing the MEC service to send the data of the UE client application. In addition, the enabling layer 220 can perform operations for establishing a data connection with the 3GPP communication layer to use the MEC service. The 3GPP communication layer (3GPP Comm.Layer) 230 is a layer that performs modem operations for using a mobile communication system and is used for establishing a wireless connection for data communication, registering the UE 120 in the mobile communication system, establishing a connection for data transmission in the mobile communication system, and sending and receiving data.

[0051] Figure 2Shows the edge application servers 250 (Edge Application 1, Edge Application 2, and Edge Application 3), the enabling function 260 that enables MEC services to the corresponding edge application servers 250, and the platform or orchestration function 270 for the edge computing system, where the edge application servers 250 are application servers provided by a third party within the edge server 151 that provides MEC services. The edge application servers 250 are application servers provided by a third party and correspond to the servers accessed by third-party client applications of the UE 120 to use services. The edge application servers 250 can be referred to as MEC applications, multi-access edge applications, edge application servers, edge applications, etc., but are not limited thereto, and can correspond to any application server provided by a third party within the edge server 151. The enabling function 260 can perform the function of managing information about the edge application servers 250 and can be used to identify which edge application is currently executing in the edge network and manage the fully qualified domain name (FQDN) or Internet Protocol (IP) address required to send data to the corresponding edge application servers 250 to notify the enabling layer 220 of the UE 120. In addition, the enabling function 260 can act as a proxy to allow the edge application servers 250 to use the exposure functions provided by the 3GPP network 110, i.e., the NEF 115 of the 5G mobile communication system (mobile-related events of the UE 120, session-related events, service path change events of the UE 120, etc.). That is, according to a request from the edge application servers 250, the enabling function 260 can allow the invocation of exposure services provided by the NEF 115 of the 5G mobile communication system and the use of the required network exposure functions. The enabling function 260 can be referred to as an MEC enabling layer, an edge enabling server function, an MEC enabling layer server, a multi-access enabling layer, an edge enabling server, etc., but is not limited thereto, and can correspond to any function used to perform the function of enabling the edge application servers 250 to enable MEC services. The platform function 270 can be the platform function of the system to which the edge server 151 included in the edge network 150 is connected, or can be an orchestration function. The platform function or orchestration function can include middleware applications or infrastructure services for configuring the MEC system architecture. That is, the platform function 270 can deploy or distribute the edge servers 151 included in the edge network 150, perform operations such as adding edge application packages to the edge servers 151 or executing the edge application servers 250 in the edge servers 151, or perform the function of configuring information (e.g., IP address and FQDN) of the edge application servers 250 in the edge servers 151. In addition, the platform function 270 can support the function of providing the edge application servers 250 with the use of platform services provided by the 5G system (e.g., reports on network conditions, requests to change the service path of the UE 120, reports on the location information of the UE 120, etc.).The platform function 270 may be referred to as a multi-access edge platform, an edge computing infrastructure, etc., but is not limited thereto, and may correspond to any function that performs the platform function of the system to which the edge server included in the edge network is connected.

[0052] Figure 3 According to a PDU session establishment operation showing an embodiment of the present disclosure in which a UE accesses a 5G system to establish a data connection. The UE may receive information related to the server to which it should initially access through this process.

[0053] According to an embodiment of the present disclosure, a method is proposed through Figure 3 the process, the UE 120 obtains DNS server information for discovering the edge server 151 to which the UE 120 should access to use the MEC service from the 5G system. The DNS server 154 may be used to resolve the IP address of the edge server 151 or the IP address of the application server driven on the edge server. That is, the DNS server 154 may be a network function that knows information related to the edge server 151 or information related to the application server driven on the edge server. The DNS server 154 may exist in each edge network covering a specific area, or one DNS server may exist in the entire MEC system.

[0054] In another example, a method is proposed through Figure 3 the process, the UE 120 obtains the address (e.g., IP address or FQDN) of the initial access server 153 from which the UE 120 can receive configuration information to use the MEC service from the 5G system. The initial access server 153 is a server that provides configuration information for the UE 120 to use the MEC service and is referred to as an MEC configuration server. The MEC configuration server 153 performs the function of sending configuration information for using the MEC service to the UE 120. The configuration server 153 knows the deployment of each location of the edge server 151. Before using the MEC service, the UE 120 may access the configuration server 153 and receive configuration information required to use the MEC service, for example, information related to the edge server accessed at a specific location.

[0055] At least one of the embodiment in which the address of 1) the DNS server 154 is configured and the embodiment in which the address of 2) the MEC configuration server 153 is configured may be applied to Figure 3 the operation.

[0056] In operation 310, the terminal (UE) 120 may configure a PDU session establishment request corresponding to an SM NAS message and send it (via the RAN 111) to the AMF 112 to establish a PDU session. The UE 120 may insert the data network name (DNN) that the UE expects to use into the PDU session establishment message, send the PDU session establishment message to the AMF 112, and configure the DNN to have a DNN value for MEC. Alternatively, the default DNN that the UE 120 should use in the 5G system may be a DNN that can use MEC. DNN information may be used when the SMF 113 or the PCF 114 determines whether the corresponding DNN is a DNN for MEC that is allowed to be used by the UE 120. The DNN value for MEC may be based on a preset value in the UE 120. Alternatively, the UE 120 may include an indicator indicating that the PDU session requested by the UE in the PDU session establishment message is a PDU session that uses MEC services. When a mobile communication service provider uses a general DNN, such as the Internet DNN for MEC services, if the UE 120 requests a PDU session through the Internet DNN, it cannot be determined whether the corresponding PDU session is a PDU session that uses MEC, and thus the indicator may be inserted into the message by the UE 120 and sent to the AMF 112. The indicator may include the meaning of indicating that the session policy of the MEC service needs to be applied to the corresponding PDU session. Alternatively, the indicator may indicate the ID of the service provider that provides the MEC service, which may be used in the 5G system in the form of an AF service identifier. The AF service identifier may be information pre-configured in the MEC service-support function in the UE, or information included in the configuration information of the MEC service in the UE. The above indicator may be used by the SMF 113 or the PCF 114 in the following operations to determine the application of the MEC service for the corresponding PDU session.

[0057] In operation 315, the AMF 112 may select the SMF 113 based on the DNN value or the location of the UE 120, and send an Nsmf_PDUSession_CreateSMContext request message to the selected SMF 113. The AMF 112 inserts the PDU session establishment request message received from the UE 120 into this message.

[0058] In order to obtain the session-related subscription information of the corresponding UE 120 based on the PDU session establishment request message received from the UE 120, in operation 320, the SMF 113 may perform the process of registering in the UDM 117 indicating that the SMF 113 is the serving SMF and the process of obtaining the subscription information for managing the session of the corresponding UE 120.

[0059] As an optional operation, when the PDU session establishment request message received from the UE 120 in operation 310 includes a DNN for MEC, the SMF 113 may insert an indicator of the subscription information requesting MEC services into the message sent to the UDM 117, so as to obtain the subscription information of the MEC DNN during the operation of the UDM 117 to obtain the subscription information. Alternatively, when an indicator indicating that the UE 120 expects to use MEC services is included in operation 310, the SMF 113 may insert an indicator of the subscription information requesting MEC services into the message sent to the UDM 117 based on this indicator. The indicator may be an identifier indicating the data for MEC services in the subscription information. The UDM 117 that receives this message may provide the SMF 113 with the subscription information for MEC services. The subscription information may include authorization information indicating whether the UE 120 can use MEC services, information related to the area where the UE 120 can use MEC services, information related to the DNS server that the UE 120 should use, information related to the MEC configuration server to which the UE 120 should initially connect to receive configuration information, an AF service identifier indicating the MEC service provider ID used by the UE, etc.

[0060] In operation 325, the SMF 113 may perform an SM policy association establishment procedure with the PCF 114 for the corresponding DNN based on the PDU session establishment request message received from the UE 120. At this time, the SMF 113 may send the DNN requested by the UE 120 to the PCF 114. The PCF 114 that receives this information may determine that the corresponding DNN is a DNN for MEC services, and then configure the session-related policy to be sent to the SMF 113 to include information for using MEC services. Alternatively, when the corresponding PDU session establishment request in operation 310 includes an indicator for using MEC services, the UE 120 may perform an SM policy association establishment procedure, which includes an indicator that the corresponding PDU session to the PCF 114 will use MEC services, and the PCF 114 that receives this indicator may configure the session-related policy to be sent to the SMF 113 to include information for using MEC services. In another detailed example, the indicator may be in the form of an AF service identifier indicating the ID of the MEC service provider. This may be an indicator received from the UE or an indicator obtained from the UE's subscription information. Thereafter, when performing the SM policy association establishment procedure in the PCF 114, the SMF 113 may include information related to the current location of the UE 120 (e.g., cell ID, tracking area, etc.) to notify the PCF 114. When MEC-related information is thereafter sent to the SMF 113 for the PDU session of the corresponding UE 120, the PCF 114 may determine which information should be known based on the location information of the UE 120.

[0061] According to the operable operations in operation 320, the SMF 113 may identify whether the corresponding UE 120 and the DNN requested by the corresponding UE 120 are permitted to use MEC services based on the subscription information of the UE 120. When the UE 120 is a UE permitted to use MEC services or when the DNN requested by the UE 120 is a DNN permitted to use MEC services, the SMF 113 may send an indicator indicating the permitted use of MEC services, an indicator indicating the DNN's use of MEC services, or an AF service identifier indicating the MEC service provider ID to the PCF 114 during the policy association with the PCF 114. The PCF 114 may configure MEC service-related information for the corresponding UE based on this and send it to the SMF 113. Alternatively, after determining that the DNN included in the corresponding request is a DNN for MEC services for the policy association requested by the SMF, the PCF may determine to configure MEC service-related information for the corresponding UE.

[0062] The PCF 114 can insert the information of the MEC service into the session-related policy information that should be provided to the SMF 113 through the above process. The PCF 114 can determine whether to provide the information of the MEC service based on the user information stored in the Unified Data Repository (UDR). At this time, considering the MEC service provider used, it can be determined whether to provide the information about the corresponding MEC service. The information of the MEC service can be the DNS server address that the UE 120 should access when using the MEC service through the corresponding PDU session. In another example, the information of the MEC service can be the address of the initial access server, that is, the MEC configuration server that the UE 120 should access to receive relevant configuration information when using the MEC service through the corresponding PDU session. The address of the DNS server 154 or the address of the MEC configuration server 153 can follow the format of an IP address. Alternatively, the address of the configuration server 153 can follow the FQDN format. In this case, the UE 120 can obtain the IP address of the MEC configuration server 153 through a DNS query when receiving the FQDN in the following operations. When the PCF 114 determines that the MEC service for which information should be provided for the corresponding PDU session, the PCF 114 can notify the SMF 113 of the address of the DNS server 154 or the address of the MEC configuration server 153 closest to the current location of the UE 120 (considering the location of the UE 120 received from the SMF 113). In another example, when the PCF 114 determines the address of the DNS server 154 or the address of the MEC configuration server 153 that can be accessed and used at the current location of the UE 120, the PCF 114 can select the information related to the server closest to the current location of the UE 120 among the DNS servers and MEC configuration servers 153 with a small load (which can be used at the current location of the UE 120) considering the load status of the network, and provide the selected server information to the SMF 113.

[0063] According to an embodiment, in order to update the address of the DNS server 154 or the address of the MEC configuration server 153 suitable for the location of the UE 120, the PCF 114 may subscribe to an event of a location change of the UE 120 in the SMF 113. When the PCF 114 subscribes to the location change event of the UE 120 in the SMF 113, the PCF 114 may configure and request an area of interest (AoI) (an area in which the mobility of the UE 120 should be determined), which may be configured in the form of a tracking area list or a cell list. When determining the area of interest (AoI), the PCF 114 may make a decision by considering information related to the area covered by the edge network 150 that may be used in the current area of the UE 120. For example, when the UE 120 leaves a specific area corresponding to the AoI, the PCF 114 may configure a report related to the event in the SMF 113, and when receiving the event report from the SMF 113, may determine the location of the UE 120 again and update the address of the DNS server 154 or the address of the MEC configuration server 153 in the SMF 113 for this purpose.

[0064] When providing the address of the DNS server 154 or the address of the MEC configuration server 153, the PCF 114 may configure a mapping indicating the server information that should be used and the area in which the server information should be used, and send it to the SMF 113. For example, the PCF may configure, in the form of a list, the address of the DNS server 154 or the address of the MEC configuration server 153 that should be accessed in tracking area 1, tracking area 2, tracking area 3, and tracking area 4, and the address of the DNS server 154 or the address of the MEC configuration server 153 that should be accessed in tracking area 10, tracking area 11, and tracking area 12, and send it to the SMF 113. The SMF 113 that receives this information may determine the future mobility of the UE 120, and determine to update the address of the DNS server 154 or the address of the MEC configuration server 153 that should be accessed in the area where the UE 120 is currently located to the UE 120. According to an embodiment, the SMF 113 that receives this information from the PCF 114 may configure, in the form of a list, the information obtained by mapping the address of the DNS server 154 or the address of the MEC configuration server 153 to location information (e.g., a tracking area list), and determine to send this list to the UE 120.

[0065] According to an embodiment, the PCF 114 may further include authorization information indicating whether the UE 120 can use the MEC service, information related to the area where the UE 120 can use the MEC service (tracking area list, cell list, etc.), information related to the time period during which the UE 120 can use the MEC service (e.g., one month, from which day of a month to which day of a month, etc.), and send the above information to the SMF 113. When the SMF 113 receives the area information and the UE 120 leaves the corresponding area, the SMF 113 may determine that a PDU session for using the MEC service cannot be provided to the UE 120, notify the PCF 114 of the current location of the UE 120, and request a new policy or release the PDU session of the UE 120. When receiving the time information, the SMF 113 may determine that a PDU session for using the MEC service cannot be provided to the UE 120 at the time point when the corresponding time has passed, and may request a new policy from the PCF 114 or release the PDU session of the UE 120.

[0066] The PCF 114 may send policy and charging control (PCC) rules, which the SMF 113 should apply to the PDU session to be used by the UE 120. The information proposed in the embodiment may be included as part of the PCC rule, or may be separately configured as information for the MEC service in addition to the PCC rule and then sent. When configuring the PCC rule, the PCF 114 may include a list of traffic detection rules, traffic forwarding rules, or information for identifying the UPF 116 that should be assigned to establish the corresponding PDU session (e.g., data network access identifier (DNAI)) required to provide the MEC service in the corresponding PDU session. After receiving this information, the SMF 113 may select the UPF 116 based on this information and apply this information when sending a session establishment request to the UPF 116.

[0067] In operation 330, the SMF 113 may perform a UPF selection process based on the policy information received from the PCF 114, and perform an N4 session establishment process with the selected UPF 116. When the SMF 113 receives a DNAI list from the PCF 114, the SMF 113 selects a UPF 116 corresponding to the DNAI to which it can connect based on the current location of the UE 120. When the information received from the PCF 114 includes information related to the area in which the DNN for MEC can be used, the SMF 113 selects a UPF 116 that can support the corresponding service area based on the current location of the UE 120. When selecting the UPF 116, the SMF 113 may determine whether the UPF 116 is a UPF that can be connected to the edge network 150 to which the PDU session access requested by the UE 120 is connected, and select a UPF that can be connected to the corresponding edge network 150. In addition, the SMF 113 may perform an N4 session establishment process including sending a DNAI, a packet forwarding action rule, and a packet implementation rule to the corresponding UPF 116, enabling data transmission and reception to and from the edge network 150.

[0068] In operation 335, the SMF 113 may configure the PCO to be provided to the UE 120 based on the session-related policy information received from the PCF 114. PCO is an abbreviation for Protocol Configuration Option, and corresponds to a container containing additional configuration information required to use the corresponding PDU session and information exchanged between the UE 120 and the SMF 113. The SMF 113 may include the address of the DNS server 154 or the MEC configuration server 153 from the PCF 114 in the PCO. When the SMF 113 receives from the PCF 114 a list including the address pair of the DNS server 154 or the MEC configuration server 153 and the area (e.g., tracking area list, cell list, etc.) in which the address value is available, the SMF 113 may insert the list into the PCO and send the PCO to the UE 120. Alternatively, when the SMF 113 receives from the PCF 114 a list including the address pair of the DNS server 154 or the MEC configuration server 153 and the area (e.g., tracking area list, cell list, etc.) in which the address value is available, the SMF 113 may configure the address of the DNS server 154 or the MEC configuration server 153 as the PCO according to the current location of the UE 120 and send the PCO to the UE 120.

[0069] Alternatively, the SMF 113 may configure the PCO according to pre-configured values in the SMF 113. When the information received by the SMF 113 from the PCF 114 does not include the addresses of the DNS server 154 or the MEC configuration server 153, or when the policy procedure with the PCF 114 is not considered, the SMF 113 may insert the addresses of the DNS server 154 or the MEC configuration server 153 into the PCO provided to the UE 120 according to the pre-configured values. When the pre-configured information in the SMF 113 has a list including address pairs of the DNS server 154 or the MEC configuration server 153 and regions (such as a tracking area list, a cell list, etc.) where the address values are available, the SMF 113 may insert this list into the PCO and send the PCO to the UE 120. Alternatively, when there is a list including address pairs of the DNS server 154 or the MEC configuration server 153 and regions (such as a tracking area list, a cell list, etc.) where the address values are available in the pre-set information in the SMF 113, the SMF 113 may configure the address of the DNS server 154 or the MEC configuration server 153 as the PCO according to the current location of the UE 120 and send the PCO to the UE 120.

[0070] The PCO may be included in the session management NAS message corresponding to the PDU session establishment acceptance and sent to the UE 120 as a NAS message by the AMF 112.

[0071] The SMF 113 may insert the PDU session establishment acceptance message sent to the UE 120 and the N2 message sent to the RAN 111 into the Namf_Communication_N1N2messageTransfer message and send it to the AMF 112. The N2 message includes the PDU session ID, the QoS profile, the QoS flow ID, tunnel information related to the side of the UPF 116 for the N3 tunnel connection between the RAN 111 and the UPF 116, etc.

[0072] The AMF 112 may send an ACK for the Namf_Communication_N1N2messageTransfer to the SMF 113.

[0073] In operation 340, the AMF 112 sends the message received from the SMF 113 to the RAN 111. This message includes the N2 SM message received from the SMF 113 and the N1 SM NAS message received from the SMF 113.

[0074] In operation 345, the RAN 111 receives the message of operation 340 and performs an RRC signaling procedure for establishing a data radio bearer with the UE 120 based on the QoS information included in the N2 SM message. In addition, the RAN 111 sends the received NAS message to the UE 120.

[0075] The UE 120 that receives the PDU session establishment acceptance message from the SMF 113 completes the PDU session establishment process. The UE 120 identifies the PCO information included in the PDU session establishment acceptance message and identifies the address of the DSN server 154 or the MEC configuration server 153 included in the PCO. With this information, the UE 120 can know the DNS server 154 to which the UE should connect for the corresponding PDU session. Alternatively, when the UE 120 identifies the address of the MEC configuration server 153, the UE can know the address of the server to which the UE should initially connect for the corresponding PDU session. Having identified this information, the NAS layer of the UE 120 sends this information to the higher layer (i.e., the enabling layer) 220 via an AT command. The AT command is a method for sending commands between the 3GPP communication layer 230 and the higher layer (e.g., the application layer 210, including the enabling layer 220 structured according to the present disclosure) and indicates an operation to notify the higher layer of the information required to use the network. The enabling layer 220 of the UE 120 can perform an AT command connection registration with the NAS layer of the 3GPP communication layer 230 and can register a command that gives the address of the DNS server 154 or a command that gives the address of the MEC configuration server 153. The NAS layer 230 of the UE 120 that identifies the PCO of the SM NAS message via operation 345 sends the address of the DNS server or the address of the MEC configuration server received by the UE via the PCO to the enabling layer 220 according to the registered AT command. The enabling layer 220 stores this information. When receiving the DNS server address via the AT command, the enabling layer 220 stores the DNS server address and then, if a DNS query is generated by an App that uses the corresponding DNN (i.e., the DNN for MEC) in the future, identifies the stored DNS server address and sends the DNS query to the corresponding server 154. When the enabling layer 220 receives the MEC configuration server address via the AT command, the enabling layer 220 stores the MEC configuration server address and then uses this address to access the MEC configuration server 154 in order to register in the MEC service or receive the required configuration information. When receiving a list that includes the address pair of the DNS server 154 or the MEC configuration server 153 and the area (e.g., tracking area list, cell list, etc.) in which the address value is available via the PCO, the NAS layer 230 of the UE 120 can send this list to the enabling layer 220 via an AT command. The enabling layer 220 stores this information. In this case, if a DNS query is generated by an App that uses the corresponding DNN (i.e., the DNN for MEC) in the future, the enabling layer identifies the stored location information and the corresponding DNS server address and sends the DNS query to the corresponding server 154.When the enabling layer 220 receives the MEC configuration server address and its location information via an AT command, the enabling layer stores it, and then identifies the MEC configuration server 153 corresponding to the current location of the UE 120, and accesses the corresponding server in order to register in the MEC service, receive the required configuration information, or access the MEC configuration server 153.

[0076] In operation 350, the RAN 111 sends a response to operation 340 to the AMF 112. The message includes an N2 SM message containing the PDU session ID and tunnel information related to the RAN side for the N3 tunnel connection with the UPF. In addition, the message may include information such as the established QoS flow.

[0077] The AMF 112 that receives the message in operation 350 may send the N2 SM message contained in the message in operation 350 to the SMF 113 in operation 355.

[0078] In operation 360, the SMF 113 may perform an N4 session modification procedure with the UPF 116 based on the N2 SM message received in operation 355. At this time, the SMF 113 may send the N3 tunnel information about the RAN size received from the RAN 111 to the UPF 116, and also send a packet forwarding rule therefor. Through such an operation, the UPF 116 and the RAN 111 can determine that a tunnel connection for data transmission / reception has been established.

[0079] In operation 365, the SMF 113 may send a response to operation 355 to the AMF 112.

[0080] Now, the UE 120 can perform data transmission and reception through the established PDU session.

[0081] Figure 4 According to the process by which a UE according to an embodiment of the present disclosure receives policy information from a 5G system after accessing the 5G system and performing a registration process. The UE can receive a policy including information related to the server to which the UE should initially connect through this process.

[0082] According to an embodiment of the present disclosure, a method is proposed through Figure 4In the process, UE 120 obtains information related to the DNS server 154 for the edge server 151 that the UE 120 should access to use MEC services from the 5G system. The DNS server 154 can resolve the IP address of the edge server 151, or can be used to resolve the IP address of the application server running on the edge server 151. That is to say, the DNS server 154 can be a network function that knows information related to the edge server 151 or information related to the application server running on the edge server. The DNS server 154 can exist in each edge network covering a specific area, or one DNS server can exist in the entire MEC system.

[0083] In operation 410, the UE 120 may perform a registration procedure to register in the 5G system. The UE 120 may perform the registration procedure when the UE initially accesses the 5G system, when the UE periodically notifies the 5G system of its own reachability, when the UE 120 is located in another area and thus leaves the registration area received from the 5G system, when the UE desires to change the service to be used (e.g., a change in network slice, etc.), or to request policy information. After establishing an RRC connection with the RAN 111, the UE 120 may insert a registration request message corresponding to the NAS message sent to the AMF 112 into the RRC message and send the RRC message. According to a detailed embodiment of the present disclosure, the UE 120 may insert an identifier (Network Slice Selection Assistance Information (NSSAI)) indicating a network slice for MEC into the registration request message and send the registration request. Alternatively, according to a detailed embodiment of the present disclosure, the UE 120 may insert a NAS message (i.e., a UE STATEINDICATION (UE state indication) message) requesting a policy from the PCF 114 into the registration request message and send the registration request message. After determining to use the MEC service, the UE 120 may insert a policy for the MEC service into the UE STATE INDICATION message (i.e., a UE Policy Selection Identifier (UPSI)). According to an embodiment, the enabling layer 220 for the MEC service within the UE 120 may require policy information for MEC and request policy information from the NAS layer of the 3GPP layer 230, and the NAS layer may determine, based on this, to request a policy for the MEC service and determine the UPSI. The UPSI information may be used to determine that the PCF 114 should provide a policy for the MEC service to the UE 120 in the following operations. In addition, the UE 120 may insert an identifier of the operating system executed in the UE 120 (e.g., Android, IOS, etc.) into the UE STATE INDICATION message. Additionally, the UE 120 may include information for identifying the version of the operating system (e.g., Android 9.0, IOS 12.1, etc.).

[0084] In operation 420, the AMF 112 may infer the AMF that previously served the UE 120 based on the ID of the UE 120 included in the registration request message sent by the UE 120. The AMF 112 that determines the AMF that previously served the UE 120 may request the context of the UE 120 from the corresponding AMF. After receiving the context of the UE 120, the AMF 112 stores the context and uses it to manage the UE 120. According to an embodiment, the AMF 112 that determines the AMF to which the UE 120 initially accesses the 5G system may generate a context for managing the UE 120. To notify the UDM 117 that the AMF 112 serves the corresponding UE 120, the AMF 112 may perform a registration process in the UDM 117 and also perform a process of obtaining the subscription information of the corresponding UE 120.

[0085] When the UE 120 performs an initial registration process, in operation 430, the AMF 112 may perform an AM policy association establishment process to obtain the policy information required to manage the corresponding UE 120. Alternatively, when the UE 120 that sends the registration request is not a UE served by the AMF 112, the policy information required to manage the corresponding UE 120 is not pre-stored, and thus the AMF 112 may perform an AM policy association update process with the PCF 114 in order to receive the policy information. Through this process, the AMF 112 may obtain the policy information for managing the access or mobility of the UE 120 and store the policy information in the context of the UE 120 to manage the UE 120.

[0086] When the UE 120 sends a registration request message including a NAS message (i.e., UE STATE INDICATION message) requesting a policy from the PCF 114, and the UE 120 performs an initial registration process in the network or the serving AMF changes due to the mobility of the UE 120, the AMF 112 may perform a UE policy association establishment process with the PCF 114 in operation 435 in order to receive the policy information of the corresponding UE 120. According to an embodiment, when there is a UE policy association that has been previously established by the PCF 114 and the UE 120 has sent a NAS message requesting a policy (i.e., UE STATE INDICATION message), the AMF 112 may send a UE policy update request to the PCF 114. The AMF 112 may notify the PCF 114 of the current location of the UE 120 through this process.

[0087] The AMF 112 may send a UE STATE INDICATION message corresponding to a NAS message for a policy received from the UE 120 to the PCF 114 through a registration procedure. The PCF 114 that receives the UE STATE INDICATION message identifies the UPSI within the UE STATE INDICATION message. When the UE 120 includes an identifier requesting policy information for MEC as the UPSI value of the UE STATE INDICATION message in operation 410, the PCF 114 may determine that the UE 120 requests policy information for using MEC services. The PCF 114 may identify whether the UE 120 is a UE that can use MEC services based on subscription information. When the UE STATE INDICATION message sent by the UE 120 includes the ID of the operating system executed in the UE 120, the PCF 114 may identify the operating system used by the UE 120 based on this information and configure policy information that can be applied to the corresponding operating system. For example, after determining whether MEC or a DNN for MEC can be used for a specific application in the Android OS, the PCF 114 may apply this determination when configuring the policy information. In addition, when receiving the current location of the UE 120 from the AMF 112, the PCF 114 may determine the policy information required for MEC services based on the current location of the UE 120. Since MEC services are mainly intended to use the network close to a specific area, there is no need to provide information on MEC services far from the current location of the UE 120, and thus the PCF 114 may determine the policy information required for MEC services based on the current location of the UE 120. Alternatively, regardless of the current location of the UE 120, the PCF 114 may determine to provide information on all MEC services that can be used by the UE 120 within the corresponding PLMN.

[0088] According to an embodiment of the present disclosure, the PCF 114 may configure the policy information to be provided to the UE 120 that has requested policy information for MEC services in 1) the type of UE Routing Selection Policy (URSP) or 2) the type of MEC policy.

[0089] 1) URSP is an abbreviation for UE Routing Selection Policy and corresponds to information indicating the SSC mode to be used when the UE 120 performs data transmission and reception, the network slice to be used, the DNN to be used, the PDU session type (e.g., IPv4, IPv6, etc.), the access type to be used (e.g., RAN, WiFi, etc.), and the rules for the IP address to be used. The URSP includes a service descriptor and a routing descriptor. The service descriptor may include an App ID, a destination IP 3-tuple (address, protocol ID, and port number), a destination FQDN, a DNN, connection capabilities (ISM, MMS, Internet, etc.), and the like. After determining the mapping of the service sent by the application layer 210 of the UE120 according to the service descriptor, the SSC mode, network slice information, DNN, PDU session type (IPv4, IPv6, etc.), and access type (3GPP or Non3GPP) can be applied to the connection to the PDU session. For example, when Application A of the UE 120 requests a service through any FQDN, the corresponding application ID and the service descriptor for the destination FQDN can be found, and it can be determined which DNN should be used based on the routing descriptor for the service descriptor. According to an embodiment, for the UE 120 using the MEC service, the PCF 114 may additionally configure the information required for the MEC service and apply it to the URSP. In the method according to an embodiment of the present disclosure, the information required for the MEC service added to the URSP may include one or more of the following information.

[0090] Information added to [service descriptor]

[0091] - Connection capabilities indicating that the MEC service can be used

[0092] - Identifier of the MEC-supported application (OD ID + OS application ID)

[0093] - FQDN for accessing the MEC service

[0094] - A list of location information where the service descriptor is valid (e.g., tracking area list, cell list, PLMN list, GPS information, etc.)

[0095] - Time information where the service descriptor is valid (e.g., from January 2, 2019 to February 2, 2019, from March 4, 2019 to March 4, 2020, the time zone to which the current UE belongs, UTC reference time information, etc.)

[0096] Information added to [routing descriptor]

[0097] - DNS server address or FQDN to which the UE 120 should connect

[0098] - DNS server address, a list of valid location information in the FQDN thereof (e.g., tracking area list, cell list, PLMN list, GPS information, etc.), or valid time

[0099] - The MEC configuration server address or FQDN to which the UE 120 should connect

[0100] - MEC configuration server address, a list of valid location information in the FQDN thereof (e.g., tracking area list, cell list, PLMN list, GPS information, etc.), or valid time

[0101] When it is determined to use the MEC service through the service descriptor based on the added information, the routing descriptor is applied. Determining to use the MEC service through the service descriptor may mean that the service requested by the application of the UE 120 is a service using the DNN for MEC, the information indicating that the service requested by the application of the UE 120 is a connection using the MEC service is included in the connection capability, or the application requesting the service is an application for using the MEC service.

[0102] According to an embodiment, when determining information about the DNS server 154 or the MEC configuration server 153, considering the load conditions of the corresponding servers, the PCF 114 may select a server for the MEC service with the minimum load or supporting the service area closest to the current location of the UE 120 or including the current location of the UE 120.

[0103] 2) In the method according to an embodiment of the present disclosure, the PCF 114 may configure policy information for the MEC service in the form of a policy independent of policies such as ANDSF, URSP, etc. In the present disclosure, for convenience, this may be referred to as the MEC policy. The PCF 114 may configure the information for the MEC service that the UE 120 should use in the MEC policy and send the MEC policy to the UE 120. The information included in the MEC policy may include one or more of the following information.

[0104] - Identifier of the application supporting MEC (OD ID + OS application ID)

[0105] - FQDN for accessing to use the MEC service

[0106] - A list of location information where the MEC policy is valid (e.g., tracking area list, cell list, PLMN list, GPS information, etc.)

[0107] - Time information where the MEC policy is valid (e.g., from January 2, 2019 to February 2, 2019, from March 4, 2019 to March 4, 2020, the time zone to which the current UE belongs, UTC reference time information, etc.)

[0108] - The DNS server address or FQDN to which the UE 120 should connect

[0109] - DNS server address, a list of valid location information where the FQDN is included (e.g., tracking area list, cell list, PLMN list, GPS information, etc.), or valid time

[0110] - The MEC configuration server address or FQDN to which the UE 120 should connect, or the address or FQDN of the server to which the UE 120 using the MEC service should initially connect

[0111] - The MEC configuration server or server address for initial access, or a list of valid location information where the FQDN is included (e.g., tracking area list, cell list, PLMN list, GPS information, etc.), or valid time

[0112] According to an embodiment, when determining information about the DNS server 154 or the MEC configuration server 153, considering the load condition of the corresponding server, the PCF 114 may select a server for MEC service with the minimum load or supporting the service area closest to the current location of the UE 120 or including the current location of the UE 120.

[0113] The operations after the information is sent to the UE 120 are described in detail below. After configuring the policy information, the PCF 114 may insert the policy information into a NAS message corresponding to the MANAGE UE POLICY COMMAND and send the NAS message to the AMF 112. The AMF 112 may recognize the message as a container containing policy information without analyzing the message. In operation 440, the AMF 112 may send the NAS message (i.e., the policy container) containing the policy information received from the PCF 114 to the UE 120.

[0114] In operation 440, the AMF 112 may send a registration acceptance message to the UE 120 to accept the registration process of the UE 120. When operation 435 is executed and the AMF 112 receives the policy container that should be sent to the UE 120 in operation 435 from the PCF 114, the AMF 112 may insert the policy container into the registration acceptance message and send the registration acceptance message to the UE 120.

[0115] The UE 120 may receive a registration acceptance message. When the registration acceptance message includes a policy container, e.g., a MANAGE UE POLICY COMMAND sent by the PCF 114 via the AMF 112, the UE 120 identifies it and applies it to the UE operation. The process by which the UE 120 applies the received information is described below.

[0116] When the UE 120 newly receives a Globally Unique Temporary Identifier (GUTI) via the registration acceptance message of operation 440, in operation 450 the UE 120 may send a registration completion message to the AMF 112 to complete the registration process. According to an embodiment, when the UE 120 receives a MANAGE UE POLICY COMMAND message via the registration acceptance message of operation 440, the UE 120 may insert a MANAGE UE POLICY COMPLETE message indicating that the MANAGE UE POLICY COMMAND message has been well applied in the policy container, and send the policy container to the AMF 112. The AMF 112 may send the policy container to the PCF 114.

[0117] When the PCF 114 does not provide the policy information for using the MEC service to the UE 120 via operations 410 to 450, that is, when the UE 120 does not insert a UE STATE INDICATION requesting the policy information into the registration request message, the PCF 114 may know which UE 120 accesses the network according to the AM policy establishment process in operation 430. Accordingly, the PCF 114 may determine that the corresponding UE 120 is a UE using the MEC service based on the subscription information or user information, and determine the policy information required to provide the MEC service to the UE 120. Therefore, the PCF 114 may perform operation 460 to provide the policy information for the MEC service to the UE 120. According to an embodiment, the PCF 114 may perform operation 460 to update the new policy information to the UE 120 even if the policy information for using the MEC service has been provided to the UE 120 in operations 410 to 450.

[0118] In operation 460, the PCF 114 may perform a UE policy update process with the AMF 112 to provide the policy information to the UE 120. This operation is a process in which the PCF 114 configures the policy information that should be sent to the UE 120 via a NAS message and sends the policy information to the AMF 112 in the form of a policy container, and the AMF 112 may send the policy information received through this process to the UE 120 in the following operation.

[0119] After determining that UE 120 is a UE using the MEC service based on subscription information or user information stored in PCF 114 or obtained from UDR, PCF 114 may configure policy information for the MEC service according to the embodiments of the present disclosure described for the corresponding UE 120 in operation 435.

[0120] According to an embodiment of the present disclosure, PCF 114 may configure the policy information to be provided to UE 120 requesting policy information for the MEC service in 1) the type of URSP or 2) the type of MEC policy.

[0121] 1) URSP is an abbreviation of UE Routing Selection Policy and corresponds to information on rules indicating the SSC mode to be used when UE 120 performs data transmission and reception, the network slice to be used, the DNN to be used, the PDU session type (e.g., IPv4, IPv6, etc.), the access type to be used (e.g., RAN, WiFi, etc.), and the IP address to be used. The URSP includes a service descriptor and a routing descriptor. The service descriptor may include an application ID, a destination IP 3-tuple (address, protocol ID, and port number), a destination FQDN, a DNN, a connection capability (ISM, MMS, Internet, etc.), etc. After determining the match of the traffic sent by the application layer 210 of UE 120 according to the service descriptor, the SSC mode, network slice information, DNN, PDU session type (IPv4, IPv6, etc.), and access type (3GPP or Non3GPP) included in the routing descriptor may be applied and connected to the PDU session. For example, when application A of UE 120 requests traffic through any FQDN, the corresponding application ID and the service descriptor for the destination FQDN can be found, and it can be determined which DNN should be used based on the routing descriptor for the service descriptor. According to an embodiment, for UE 120 using the MEC service, PCF 114 may additionally configure the information required for the MEC service and apply it to the URSP. In the method according to an embodiment of the present disclosure, the information required for the MEC service added to the URSP may include one or more of the following information.

[0122] Information added to [traffic descriptor]

[0123] - Connection capability indicating that the MEC service can be used

[0124] - Identifier of the MEC-supported application (OD ID + OS application ID)

[0125] - FQDN for accessing to use the MEC service

[0126] - The service descriptors therein are a list of valid location information (e.g., a list of tracking areas, a list of cells, a list of PLMNs, GPS information, etc.)

[0127] - The service descriptors therein are valid time information (e.g., from January 2, 2019 to February 2, 2019, from March 4, 2019 to March 4, 2020, the time zone to which the current UE belongs, UTC reference time information, etc.)

[0128] Information added to [the routing descriptor]

[0129] - The DNS server address or FQDN to which UE 120 should connect

[0130] - The DNS server address, the FQDN therein is a list of valid location information (e.g., a list of tracking areas, a list of cells, a list of PLMNs, GPS information, etc.), or valid time

[0131] - The MEC configuration server address or FQDN to which UE 120 should connect

[0132] - The MEC configuration server address, the FQDN therein is a list of valid location information (e.g., a list of tracking areas, a list of cells, a list of PLMNs, GPS information, etc.), or valid time

[0133] When it is determined to use the MEC service through the service descriptor based on the added information, the routing descriptor is applied. Determining to use the MEC service through the service descriptor may mean that the service requested by the application of UE 120 is a service using the DNN for MEC, the information indicating that the service requested by the application of UE 120 is a service using the connection of the MEC service is included in the connection capability, or the application requesting the service is an application for using the MEC service.

[0134] According to an embodiment, when determining the information about the DNS server 154 or the MEC configuration server 153, considering the load conditions of the corresponding servers, the PCF 114 may select a server for the MEC service with the minimum load or supporting the service area closest to the current location of UE 120 or including the current location of UE 120.

[0135] 2) In the method according to an embodiment of the present disclosure, the PCF 114 may configure the policy information for the MEC service in the form of a policy independent of policies such as ANDSF and URSP. In the present disclosure, for convenience, this may be referred to as the MEC policy. The PCF 114 may configure the information for the MEC service that UE 120 should use in the MEC policy and send the MEC policy to UE 120. The information included in the MEC policy may include one or more of the following information.

[0136] - MEC-enabled application (OD ID + OS application ID) identifier

[0137] - FQDN for accessing to use MEC services

[0138] - List of location information where the MEC policy is effective (e.g., tracking area list, cell list, PLMN list, GPS information, etc.)

[0139] - Time information where the MEC policy is effective (e.g., from January 2, 2019 to February 2, 2019, from March 4, 2019 to March 4, 2020, current UE time zone, UTC reference time information, etc.)

[0140] - DNS server address or FQDN that UE 120 should access

[0141] - DNS server address, list of location information where the FQDN is effective (e.g., tracking area list, cell list, PLMN list, GPS information, etc.), or effective time

[0142] - MEC configuration server address or FQDN that UE 120 should access, or address or FQDN of the server that UE 120 initially should access when using MEC services

[0143] - MEC configuration server or server address for initial access, or list of location information where the FQDN is effective (e.g., tracking area list, cell list, PLMN list, GPS information, etc.), or effective time

[0144] According to the embodiment, when determining information about DNS server 154 or MEC configuration server 153, considering the load conditions of the corresponding servers, PCF 114 may select a server for MEC services with the minimum load or supporting the service area closest to the current location of UE 120 or including the current location of UE 120.

[0145] The operations after this information is sent to UE 120 are described in detail below. After configuring the policy information, PCF 114 may insert the policy information into a NAS message corresponding to MANAGE UE POLICY COMMAND and send the NAS message to AMF 112. AMF 112 may recognize the message as a container containing policy information without analyzing the message. AMF 112 may send the NAS message (i.e., the policy container) received from PCF 114 to UE 120 in operation 470.

[0146] The PCF 114 can configure the addresses of the DNS servers 154 or the addresses of the MEC configuration servers 153 that can be accessed for each location in the form of a list, and may not send the list to the UE 120. In this case, the PCF 114 may need to provide the addresses of the DNS servers 154 or the addresses of the MEC configuration servers 153 suitable for the corresponding location based on the current location of the UE 120. Accordingly, the PCF 114 can configure location monitoring events in the AMF 112 to detect changes in the location of the UE 120. The PCF 114 can configure information about the area of interest (i.e., the area of interest), and subscribe to the monitoring events in the AMF 112 to identify the mobility of the UE 120 in units of specific areas. In this case, when the UE 120 leaves or enters the area of interest, the AMF 112 can notify the PCF 114 of the location of the UE 120 together with the leaving or entering, and the PCF 114 can determine whether to update the policy for the MEC service to the UE 120 based on the received location of the UE 120.

[0147] Since the UE 120 remains in a connected state after registration is completed, the AMF 112 can send the policy information received from the PCF 114 in operation 460 to the UE 120 via a NAS message in operation 470. The NAS message may include the MANAGE UE POLICY COMMAND message sent by the PCF 114 to the UE 120.

[0148] In operation 480, the UE 120 can identify the NAS message of operation 470 received from the AMF 112, and when the MANAGE UE POLICY COMMAND message is included therein, identify the message and apply it to the UE operation. The UE 120 can insert MANAGE UE POLICY COMPLETE (Manage UE Policy Complete), indicating that the MANAGE UE POLICY COMMAND message has been well applied, into the policy container, and send the policy container to the AMF 112 in operation 480. In operation 490, the AMF 112 can send the policy container to the PCF 114. The process of the UE 120 applying the received policy information is described below.

[0149] When receiving a policy for using MEC services from the PCF 114 according to an embodiment, the UE 120 may apply the policy to UE operations. When the PCF 114 sends a policy for using MEC services to the UE 120 through an extension of the URSP, the UE 120 may operate as follows. When receiving the URSP from the PCF 114, the NAS layer 230 of the UE 120 may send the URSP information to the layer that serves to process the URSP of the UE 120. According to an embodiment, the NAS layer 230 of the UE 120 may send the information to the layer that processes the URSP through an AT command. The AT command is a method for sending commands between the 3GPP communication layer 230 and higher layers (e.g., the application layer 210, including the enabling layer 220 or the URSP processing layer according to the structure of the present disclosure), and indicates an operation of notifying higher layers of information required to use the network. The URSP processing layer or the enabling layer 220 of the UE 120 may perform an AT command connection registration with the NAS layer of the 3GPP communication layer 230 and accordingly register a command that gives the URSP information. The layer that serves to process the URSP of the UE 120 may apply the URSP information received from the NAS layer 230. The layer that serves to process the URSP of the UE 120 may determine whether a request from the enabling layer 220 or the application layer 210 includes a connection capability indicating that MEC services can be used.

[0150] To use MEC services, the UE 120 becomes aware of the DNS server 154 to which the UE 120 should connect through URSP information. For example, when the application layer 210 or the enabling layer 220 of the UE 120 requests DNS resolution for any FQDN, a service descriptor that matches the corresponding application ID with the destination FQDN can be found, and for the service descriptor, the DNS server 154 to which the connection should be made and the query should be sent can be determined based on the routing descriptor. In addition, when determining the matching service descriptor, the UE 120 may determine whether the current location of the UE 120 belongs to the list of valid location information stated in the service descriptor. Alternatively, considering the current location of the UE 120 as stated in the routing descriptor, the UE 120 may determine the address of the corresponding DNS server 154. Alternatively, the UE 120 may compare the valid time information stated in the service descriptor with the time when the DNS resolution is requested, and when the time corresponds to the valid time, determine an operation according to the routing descriptor. Alternatively, considering the current time stated in the routing descriptor, the UE 120 may determine the address of the DNS server 154 for which the current time is determined to be valid.

[0151] Alternatively, when the UE 120 identifies the address of the MEC configuration server 153 (or the address of the server to which it should initially connect) through the URSP, the UE 120 starts to know the server to which it should connect in order to use the MEC service. For example, the enabling layer 220 of the UE 120 may send a message to the corresponding server address by identifying information related to the server in the URSP for the initial access to the MEC service. In addition, the UE 120 may determine whether the current location of the UE 120 belongs to the list of valid location information stated in the service descriptor. Alternatively, considering the current location of the UE 120 stated in the routing descriptor, the UE 120 may determine the address of its corresponding MEC configuration server 153. Alternatively, the UE 120 may determine the valid time information stated in the service descriptor, and when the valid time information corresponds to the valid time, it may determine the address of the MEC configuration server 153 configured according to the routing descriptor for the initial access. Alternatively, considering the current time stated in the routing descriptor, the UE 120 may determine the address of the MEC configuration server 153 for which the current time is determined to be valid.

[0152] When the PCF 114 sends a policy for using the MEC service to the UE 120 in the form of an MEC policy, the UE 120 may operate as follows. When receiving the MEC policy from the PCF 114, the NAS layer 230 of the UE 120 sends the MEC policy to the enabling layer 220 that serves to execute the MEC service of the UE 120. That is, according to the present disclosure, the NAS layer 230 of the UE 120 may send MEC policy information to the enabling layer 220. The NAS layer 230 of the UE 120 may send information to the layer that serves to process the MEC policy through an AT command. The AT command is a method of sending a command between the 3GPP communication layer 230 and a higher layer (e.g., the application layer 210, including the enabling layer 220 having the structure according to the present disclosure), and indicates an operation of notifying the higher layer of information required to use the network. The enabling layer 220 of the UE 120 may perform an AT command connection registration with the NAS layer of the 3GPP communication layer 230 and register the command that gives the MEC policy information. The enabling layer 220 of the UE 120 applies the MEC policy information received from the NAS layer 230. The enabling layer 220 of the UE 120 may know the applications that can use the MEC service, and accordingly may determine whether to apply the MEC policy.

[0153] To use MEC services, UE 120 becomes aware of the DNS server 154 that UE 120 should access via MEC policy information. For example, when application 210 or enabling layer 220 of UE 120 requests DNS resolution for any FQDN, UE 120 can access any DNS server 154 based on the corresponding application ID and destination FQDN and determine whether to send a query. Additionally, considering the current location of UE 120, UE 120 can determine whether its current location belongs to the list of valid location information stated in the MEC policy information. Alternatively, considering the current location of UE 120, UE 120 can determine the address of the corresponding DNS server 154. Alternatively, UE 120 can compare the validity time information in the MEC policy information with the time when the DNS resolution is requested, and when the time corresponds to the validity time, determine to send the DNS query to the corresponding DNS server 154. Alternatively, considering the current time, UE 120 can determine the address of the DNS server 154 where the current time is determined to be valid among the information in the MEC policy information and send a DNS query.

[0154] Alternatively, when UE 120 identifies the address of the MEC configuration server 153 (or the address of the server that should be accessed initially) via MEC policy information, UE 120 starts to know the server that should be accessed to use MEC services. For example, enabling layer 220 of UE 120 can send a message to the corresponding server address by identifying the information about the server in the MEC policy information for initial access to MEC services. Additionally, considering the current location of UE 120, UE 120 can determine the address of the corresponding MEC configuration server 153. Alternatively, UE 120 can determine whether the initial access corresponds to the validity time information in the MEC policy, and when the initial access corresponds to the validity time, determine to perform the initial access to the address of the configured MEC configuration server 153.

[0155] Figure 5 Illustrates a method for updating "DNS server information for discovering the edge server that UE should access to use MEC services" or "MEC configuration server information that UE should initially access to use MEC services" in a UE through a PDU session modification procedure according to an embodiment of the present disclosure.

[0156] Via Figure 5 's procedure, SMF 113 sends updated PCO information to UE 120. The PCO information for MEC services can follow the embodiments proposed in Figure 3 of the present disclosure.

[0157] The PDU session modification procedure can be executed under the following conditions.

[0158] - The location of the UE 120 changes: The SMF 113 that determines the location change of the UE 120 can newly allocate a UPF 116 suitable for the current location of the UE 120 or trigger a PDU session modification procedure to send MEC service-related information valid at the current location of the UE 120. That is, the SMF 113 can trigger a PDU session modification procedure to provide the address of the DNS server 154 or the address of the MEC configuration server 153 that can be used for the MEC service by the UE 120 at the current location of the UE 120 through the PCO. Alternatively, the PCF 114 that determines the location change of the UE 120 can update the SM policy association to send the MEC service-related information valid at the current location of the UE 120 to the UE 120 and provide the MEC service-related information to the SMF 113, so that this information can be sent to the UE 120 through the PDU session modification procedure. That is, after determining the current location of the UE 120, the PCF 114 can send the address of the DNS server 154 or the address of the MEC configuration server 153 that can be used for the MEC service by the UE 120 at the current location to the SMF 113 through the SM policy update procedure, and the SMF 113 can execute the PDU session modification procedure to provide this information to the UE 120 through the PCO.

[0159] -Change in the subscription information of UE 120: UE 120 did not use the MEC service but has just subscribed to an additional service of the mobile communication service provider to use the MEC service. It can be determined that the mobile communication service provider should provide UE 120 with the information required to use the MEC service. Accordingly, UDM 117 can perform a subscription information update process with SMF 113, and thus SMF 113 can provide MEC service-related information to UE 120 through a PDU session modification process, that is, information about the DNS server 154 or the MEC configuration server 153 that UE 120 should access to use the MEC service. Alternatively, PCF 114 can determine based on the changed subscription information of UE 120 that the values for using the MEC service should be sent to UE 120, and provide MEC service-related information to SMF 113 through an SM policy association update process. SMF 113 that receives the MEC service-related information can perform a PDU session modification process to provide UE 120 with information about the DNS server 154 or the MEC configuration server 153 that UE 120 should access to use the MEC service through PCO. Conversely, when UE 120 has used the MEC service but has just released the additional service of the mobile communication service provider that it no longer uses the MEC service, the mobile communication service provider can determine to update the PCC rule to SMF 113 to prevent UE 120 from using the MEC service, or provide an updated PCO for invalidating the MEC service information that UE 120 should use. For example, it can be determined to change the address of the DNS server 154 used to use the MEC service to the DNS server address for general Internet services. Accordingly, SMF 113 can provide updated PCO information through a PDU session modification process.

[0160] - Request from a third party: A request to provide MEC services for a specific UE or DNN to the 5G system can be made to the service provider offering the MEC services or the service provider executing an application on the MEC services. This can be provided through a service level agreement or an OAM system. The mobile communication service provider receiving the request can determine the information required to provide the MEC services to the UE using the corresponding DNN or the specific UE through the 5G system. Accordingly, the UDM 117 or the PCF 114 can update the information about the UE 120 to the information for using the MEC services and notify the update to the SMF 113. That is, the UDM 117 can send the address of the DNS server 154 or the address of the MEC configuration server 153 that the UE 120 can use for the MEC services to the SMF 113. Alternatively, the PCF 114 can provide the address of the DNS server 154 or the address of the MEC configuration server 153 that the UE 120 can use for the MEC services to the SMF 113 as the SM policy information of the PDU session used by the UE 120. Alternatively, the OAM system can notify the SMF 113 of the address of the DNS server 154 or the address of the MEC configuration server 153 required to provide the MEC services to a specific DNN. The UDM 117, the PCF 114, or the SMF 113 receiving the information from the OAM system can execute a PDU session modification procedure to provide the UE 120 with the information required to use the MEC services, that is, the address of the DNS server 154 or the address of the MEC configuration server 153. Alternatively, in order to change the connection of the PDU session used by the UE 120 to the edge network, while the PDU session modification procedure is being executed, the address of the DNS server 154 or the address of the MEC configuration server 153 that should be used for the MEC can be sent through the PCO.

[0161] - Request from the UE 120: The UE 120 can send a PDU session modification request to the SMF 113 to receive the information required for the MEC services through the PCO to use the MEC services. On the other hand, the UE 120 can notify the SMF 113 through a PDU session modification request of no longer using the MEC services in the corresponding PDU session. The SMF 113 receiving this can provide or release the information for the MEC services and provide it to the UE 120 through the PCO. The release method can be a method of omitting the corresponding value from the PCO or inserting another value (for example, the DNS server for Internet services) into the PCO.

[0162] In operation 510, the UE 120 may configure a PDU session modification request corresponding to an SM NAS message and send it to the AMF 112 to modify the PDU session. The UE 120 may insert the data network name (DNN) to be used by the UE into the PDU session modification message, which may indicate the DNN for MEC. In addition, the UE 120 may insert PCO information into the PDU session modification message and may insert an indicator requesting information related to the DNS server 154 or the MEC configuration server 153 for MEC services into the PCO. This may be used when the SMF 113 configures a corresponding value in the PCO.

[0163] In operation 515, the AMF 112 may select the SMF 113 and send an Nsmf_PDUSession_CreateSMContext request message to the selected SMF 113. The AMF 112 may insert the PDU session modification request message received from the UE 120 into this message and send this message to the SMF 113. After performing operation 510 and operation 515, the SMF 113 may perform an SM policy association modification process with the PCF 114 for the corresponding DNN based on the PDU session modification request message received from the UE 120. Operation 520 may be performed even when operation 510 and operation 515 are not performed. Operation 520 is an operation performed by the PCF 114 to notify the SMF 113 of updated policy information. This may be performed when the subscription information is changed or when there is a request from a third party among the above conditions. Due to this process, the SMF 113 that determines the information update for MEC services may update the PCO value and send the PCO value to the UE 120. In this case, an SM NAS message corresponding to the PDU session modification command may be used. This message may be sent to the AMF 112 in operation 530, and the AMF 112 may send this message to the UE 120 via the RAN 111 in operation 535 and operation 540.

[0164] Operation 525 is an operation performed by the UDM 117 to notify the SMF 113 of updated subscription information. Operation 525 can be performed regardless of operation 520. In addition, operation 525 can be performed regardless of operation 510 and operation 515. As a result of this process, the SMF 113 that determines that the MEC service can be provided to the corresponding UE 120 can update the values required for the MEC service in the PCO value (information about the DNS server 154 or information about the MEC configuration server 153), and send it to the UE 120. In this case, an SM NAS message corresponding to the PDU session modification command can be used. This message can be sent to the AMF 112 in operation 530, and the AMF 112 can send this message to the UE 120 in operations 535 and 540.

[0165] In operation 530, the SMF 113 can configure the N2 SM message to be sent to the RAN 111 based on the session-related policy information received from the PCF 114. In addition, the SMF 113 can insert the PCO value determined through this process into the message (PDU session modification command) requesting to modify the PDU session to the UE 120. The SMF 113 can send the Namf_Communication_N1N2messageTransfer message including this message to the AMF 112. The AMF 112 can send an ACK for the Namf_Communication_N1N2messageTransfer to the SMF 113.

[0166] In operation 535, the AMF 112 can send the message received from the SMF 113 to the RAN 111. This message includes the N2 SM message received from the SMF 113 and the N1 SM NAS message received from the SMF 113.

[0167] In operation 540, the RAN 111 can receive the message of operation 535 from the AMF 112, and perform the RRC signaling process for establishing the data radio bearer according to the QoS information included in the N2 SM message. In addition, the RAN 111 can send the received NAS message to the UE 120. The UE 120 recognizes the N1 SM NAS message received from the SMF 113 and recognizes the PCO included in this message. According to Figure 3In the embodiments of the present disclosure shown, the UE 120 may use the address of the DNS server 154 included in the PCO or the information about the MEC configuration server 153 for the MEC service. The UE 120 may configure the PDU session modification completion message indicating the completion of the PDU session modification process as an N1 SM NAS message and send the message to the SMF 113.

[0168] In operation 545, the RAN 111 may send a response to operation 540 to the SMF 113. The message may include an N2SM message and, when the UE 120 configures and sends the PDU session modification completion message as an N1 SM NAS message, may also include an N1 SM NAS message.

[0169] In operation 550, the AMF 112 that receives the message of operation 545 may send the N2SM message and the N1 SM NAS message included in the message of operation 545 to the SMF 113.

[0170] In operation 555, the SMF 113 may perform an N4 session modification process with the UPF 117 based on the N2 SM message received in operation 550. At this time, the SMF 113 may send the N3 tunnel information about the size of the RAN received from the RAN 111 to the UPF 117 and also send the packet forwarding rule therefor. In operation 560, the SMF 113 may send a message as a response to operation 550 to the AMF 112.

[0171] Figure 6 A method of updating the "DNS server information for discovering the edge server to which the UE should connect to use the MEC service" or the "MEC configuration server information to which the UE should initially connect to use the MEC service" in the UE through a policy update process according to an embodiment of the present disclosure is shown.

[0172] The policy update process may be performed under the following conditions.

[0173] -Change in the location of UE 120: The PCF 114 that determines the change in the location of UE 120 may perform a policy update process to send MEC service-related information that is valid at the current location of UE 120. That is, after determining the current location of UE 120, the PCF 114 may send the address of the DNS server 154 or the address of the MEC configuration server 153 that is closest to the current location of UE 120 to UE 120 through the URSP or the MEC policy. Alternatively, after detecting the current location of UE 120, the PCF 114 may send the address of the DNS server 154 that supports the edge network or the address of the MEC configuration server 153 to UE 120 through the URSP or the MEC policy to allow UE 120 to use the edge network that can be used at the current location of UE 120. Alternatively, when determining the address of the DNS server 154 or the address of the MEC configuration server 153 that can be used at the current location of UE 120, the PCF 114 may determine the best server taking into account the load status of the corresponding server and determine the server to provide the address to UE 120. The URSP or MEC policy configured by the PCF 114 may follow the URSP or MEC policy for the MEC service processed in the embodiments according to the present disclosure Figure 4 of the URSP or MEC policy for the MEC service processed in the embodiments.

[0174] -Change in the subscription information of UE 120: When UE 120 is not using the MEC service but has just subscribed to an additional service of the mobile communication service provider to use the MEC service, the mobile communication service provider may determine that the information required to use the MEC service should be provided to UE 120. Accordingly, the PCF 114 may receive an update of the subscription information from the UDR and may thus determine to provide the MEC service-related information to UE 120, that is, the information about the DNS server 154 or the information about the MEC configuration server 153 that UE 120 should access to use the MEC service. The PCF 114 may configure a URSP or MEC policy for it, which may follow the Figure 4URSP or MEC policies for MEC services processed in the embodiments of. On the other hand, when UE 120 has used MEC services but has just released the additional services of the mobile communication service provider to prevent the use of MEC services, the mobile communication service provider needs to update the policy information configured in UE 120 to prevent UE 120 from using MEC services. For example, operations such as deactivating MEC-related information in the URSP or deactivating the MEC policy can be performed, and UE 120 can be notified of the deactivation through the updated URSP or policy information. For example, the service descriptor and routing descriptor for using MEC services can be removed, and new service descriptors and routing descriptors can be sent to UE 120. Alternatively, the MEC policy information can be cleared and sent to UE 120, and thus UE 120 can be notified of the deactivation.

[0175] - Request from a third party: A request to provide MEC services for a specific UE or DNN to the 5G system can be made to the service provider providing the MEC services or the service provider executing the application on the MEC services. This can be provided through a service level agreement or an OAM system. The mobile communication service provider receiving the request can determine the information required to use the MEC services for the UE using the corresponding DNN or the specific UE through the 5G system. Accordingly, PCF 114 can update the policy information for UE 120 to information that can use MEC services, configure it as a URSP or MEC policy, and send the URSP or MEC policy to UE 120. Alternatively, the OAM system can notify PCF 114 of the address of DNS server 154 or the address of MEC configuration server 153 required to provide MEC services to specific UE 120. According to the embodiments of the present disclosure Figure 4 proposed, PCF 114 receiving information from the OAM system can perform a policy update process to provide UE 120 with the information required to use MEC services, that is, the URSP or MEC policy.

[0176] Operation 610 is a process in which PCF 114 determines a policy update according to the above conditions.

[0177] In operation 620, PCF 114 can configure a NAS message for the policy corresponding to the MANAGE UE POLICY COMMAND message and send the NAS message to AMF 112 to send the updated policy to UE 120. AMF 112 cannot analyze the message, but can determine UE 120 to which the NAS message for the policy should be sent.

[0178] When the UE 120 is in the CM-IDLE (CM idle) state, the AMF 112 may page the UE in operation 630 to send a NAS message for the policy to the UE 120. When the UE 120 is already in the CM-connected state in operation 645, the AMF 112 may send the NAS message for the policy received from the PCF 114 to the UE 120 in operation 650.

[0179] When the UE 120 is in the CM-IDLE state, the AMF 112 may page the UE 120 in operation 630 to send a NAS message for the policy to the UE 120. In operation 645, the UE 120 that receives the message may transition to the CM-connected state by performing the service request procedure in operation 340.

[0180] Due to the UE 120 transitioning to the CM-connected state, in operation 650, the AMF 112 may send a NAS message for the policy received from the PCF 114 to the UE 120, which is the MANAGE UE POLICY COMMAND. This message may include the URSP or MEC policy information configured by the PCF 114 in operation 610. The information in the URSP or MEC policy according to this embodiment may follow Figure 4 the embodiment. In operation 650, the UE 120 that receives the URSP or MEC policy may apply it to internal operations. The method by which the UE 120 applies it may follow Figure 4 the embodiment.

[0181] In operation 660, the UE 120 may configure a NAS message for the policy (which is MANAGE UE POLICY COMPLETE) to send a response indicating that the policy information has been well applied to the PCF 114 and send it to the AMF 112. The AMF 112 may send it to the PCF 114 in operation 670, and the PCF 114 may know that the UE 120 has received and well applied the policy.

[0182] Figure 7 is a diagram showing the configuration of a UE according to the present disclosure.

[0183] The UE 120 according to an embodiment of the present disclosure may include a transceiver 720 and a controller 710 that controls the overall operation of the UE 120. The transceiver 720 may include a transmitter 721 and a receiver 723.

[0184] The transceiver 720 may send signals to other network entities and receive signals from other network entities.

[0185] The controller 710 may control the UE 120 to perform one of the operations in the above embodiments. At the same time, the controller 710 and the transceiver 720 do not have to be implemented as separate modules, but may be implemented as one element (such as a single chip). The controller 710 and the transceiver 720 may be electrically connected. For example, the controller 710 may be a circuit, a dedicated circuit, or at least one processor. In addition, the operations of the UE 120 may be performed by including a storage device storing the corresponding program code in a predetermined element within the UE.

[0186] Figure 8 is a diagram showing the configuration of a network entity according to the present disclosure.

[0187] A network entity according to an embodiment of the present disclosure may include a transceiver 820 and a controller 810 that controls the overall operation of the network entity. The transceiver 820 may include a transmitter 821 and a receiver 823.

[0188] The transceiver 820 may send signals to other network entities and receive signals from other network entities.

[0189] The controller 810 may control the network entity to perform one of the operations in the above embodiments. At the same time, the controller 810 and the transceiver 820 do not have to be implemented as separate modules, but may be implemented as one element (such as a single chip). The controller 810 and the transceiver 820 may be electrically connected. For example, the controller 810 may be a circuit, a dedicated circuit, or at least one processor. In addition, the operations of the network entity may be performed by including a storage device storing the corresponding program code in a predetermined element within the network entity.

[0190] The network entity may be one of the RAN 111, AMF 112, SMF 113, UPF 116, PCF 114, UDM 117, UDR, edge server 151, configuration server 153, and DNS server 154.

[0191] It should be noted that the block diagrams, example diagrams of control / data signal transmission methods, example diagrams of operation procedures, and Figures 1 to 8 the diagrams shown in Figures 1 to 8 are not intended to limit the scope of the present disclosure. That is, it should not be construed that

[0192] When a predetermined element in a base station or a UE device includes a storage device storing corresponding program code, operations of the base station or the UE can be performed. That is, a controller of the base station or the UE device can perform operations by reading and executing the program code stored in the storage device via a processor or a central processing unit (CPU).

[0193] Various elements and modules of an entity, a base station or a UE used in the specification can be operated by using a hardware circuit, for example, a complementary metal oxide semiconductor-based logic circuit, firmware, software, and / or a combination of hardware, or a combination of firmware and / or software inserted into a machine-readable medium. For example, various electrical structures and methods can be performed by using transistors, logic gates, and circuits such as application-specific integrated circuits.

[0194] Although specific embodiments have been described in the detailed description of the present disclosure, various modifications and changes can be made thereto without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the embodiments, but should be defined by the appended claims and their equivalents.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: Sending a first message for requesting protocol data unit (PDU) session establishment to an access and mobility management function (AMF), the first message including information indicating a request for edge computing service; And Receiving a second message from the AMF, the second message including a protocol configuration option (PCO), wherein the PCO includes first information indicating whether the terminal is authorized to use the edge computing service and second information about a configuration server for providing edge configuration information to the terminal.

2. The method according to claim 1, wherein The first message is a PDU session establishment request message.

3. The method according to claim 1, wherein, The configuration server is determined based on at least one of the terminal's location or the local configuration of the session management function (SMF), and Wherein, the edge configuration information includes information for establishing a connection with a server providing the edge computing service.

4. The method according to claim 1, wherein The second message further includes at least one of third information about a DNS server for the terminal to send Domain Name System (DNS) queries or fourth information about the spatial validity condition of the second information about the configuration server.

5. A terminal in a wireless communication system, the terminal comprising: A transceiver; And A controller, coupled to the transceiver and configured to: Send a first message for requesting protocol data unit (PDU) session establishment to an access and mobility management function (AMF), the first message including information indicating a request for edge computing service, and Receive a second message from the AMF, the second message including a protocol configuration option (PCO), wherein the PCO includes first information indicating whether the terminal is authorized to use the edge computing service and second information about a configuration server for providing edge configuration information to the terminal.

6. The terminal according to claim 5, wherein, The first message is a PDU session establishment request message.

7. The terminal according to claim 5, wherein, The configuration server is determined based on at least one of the terminal's location or the local configuration of the session management function (SMF), and Wherein, the edge configuration information includes information for establishing a connection with a server providing the edge computing service.

8. The terminal according to claim 5, wherein, The second message further includes at least one of third information about a DNS server for the terminal to send Domain Name System (DNS) queries or fourth information about the spatial validity condition of the second information about the configuration server.

9. A method performed by a session management function (SMF) in a communication system, the method comprising: Receiving a first message for requesting protocol data unit (PDU) session establishment from a terminal, the first message including information indicating a request for edge computing service; Sending a second message for obtaining the subscription information of the terminal to a unified data management (UDM); Receiving a third message from the UDM, the session management subscription information included in the third message including first information indicating whether the terminal is authorized to use the edge computing service based on information associated with the edge computing service; And Sending a fourth message to the terminal, the fourth message including a protocol configuration option (PCO), wherein the PCO includes first information indicating whether the terminal is authorized to use the edge computing service and second information about a configuration server for providing edge configuration information to the terminal.

10. The method according to claim 9, wherein, The first message is a PDU session establishment request message.

11. The method according to claim 9, wherein The configuration server is determined based on at least one of the location of the terminal or the local configuration of the SMF, and wherein the edge configuration information includes information for establishing a connection with a server providing edge computing services.

12. The method according to claim 9, wherein The fourth message further includes at least one of third information about a DNS server for the terminal to send a Domain Name System (DNS) query, or fourth information about the spatial validity condition of the second information about the configuration server.

13. A Session Management Function (SMF) in a communication system, the SMF comprising: a transceiver; and a controller coupled to the transceiver and configured to: receive, from a terminal, a first message for requesting protocol data unit (PDU) session establishment, the first message including information indicating a request for edge computing services, send a second message to a Unified Data Management (UDM) for obtaining subscription information of the terminal, receive, from the UDM, a third message including subscription information for session management, the subscription information for session management including first information indicating whether the terminal is authorized to use edge computing services based on information associated with edge computing services, and send a fourth message to the terminal, the fourth message including a Protocol Configuration Option (PCO), wherein the PCO includes first information indicating whether the terminal is authorized to use edge computing services and second information about a configuration server for providing edge configuration information to the terminal.

14. The SMF according to claim 13, wherein, The first message is a PDU session establishment request message, wherein the configuration server is determined based on at least one of the location of the terminal or the local configuration of the SMF, and wherein the edge configuration information includes information for establishing a connection with a server providing edge computing services.

15. The SMF according to claim 13, wherein, The fourth message further includes at least one of third information about a DNS server for the terminal to send a DNS query, or fourth information about the spatial validity condition of the second information about the configuration server.

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