Server, User Equipment, and Methods Thereof

Abstract

A first edge enabler server (EES) (5A) transmits, to an edge configuration server (7) or to an edge enabler client (EEC) (2) of user equipment (UE), a control message which indicates that it is planned that the first EES will be shut down or become unavailable. Thus, it is possible, for example, for the edge configuration server, the EEC, or both to carry out a process or a procedure which is necessary for avoiding or mitigating the effects of a planned shutdown of the EES.

Description

[Technical field]

[0001] The present disclosure relates to wireless communication networks, and more particularly to an apparatus and method for edge computing. [Background technology]

[0002] Edge computing aims to move applications, data, and computing power (services) from centralized points (e.g., centralized data centers) to locations closer to users (e.g., distributed data centers). The European Telecommunications Standards Institute (ETSI) Industry Specification Group called Multi-access Edge Computing (MEC) is standardizing application platforms and APIs for edge computing. For example, MEC offers application developers and content providers a cloud computing capabilities and information technology (IT) services environment in the Radio Access Network (RAN) in close proximity to mobile subscribers. This environment provides ultra-low latency and high bandwidth, as well as direct access to radio network information generation (e.g., subscriber location and cell load) that can be leveraged by applications and services.

[0003] The Third Generation Partnership Project (3GPP (registered trademark)) SA6 working group is working on standardizing an architecture for enabling Edge Applications (see, for example, Non-Patent Document 1). This architecture of 3GPP is sometimes called the EDGEAPP architecture. The EDGEAPP architecture provides a specification of an enabling layer to facilitate communication between application clients (ACs) running on a User Equipment (UE) and applications deployed at an edge. According to the EDGEAPP architecture, edge applications provided by Edge Application Servers (EASs) are provided to the ACs of a UE by an Edge Configuration Server (ECS) and an Edge Enabler Server (EES) via an Edge Enabler Client (EEC) of the UE.

[0004] An AC running on a UE needs to discover server applications (i.e., EAS in 3GPP SA6 terminology, or MEC application in ETSI ISG MEC terminology) on an edge cloud. The AC can use other clients on the UE, i.e., EEC, for server application discovery. The EEC provides ACs with discovery of available EASs in an Edge Data Network (EDN). The EDN is a local data network that supports an architecture for enabling edge applications. The EDN includes one or more EESs and one or more EASs.

[0005] The UE is initially provisioned with the configuration information required to connect to the EDN from the ECS. More specifically, the EEC of the UE communicates with the ECS for service provisioning. Service provisioning allows the EEC to configure the configuration information about available edge computing services based on the UE location, service requirements, service performances, and connectivity. Such configuration information for one EDN is called EDN configuration information. The ECS provides the EEC with a list of EDN configuration information for one or more EDNs.

[0006] Next, the EEC selects an EES based on the EDN configuration information. The EEC may perform a registration procedure called EEC registration to the EES to provide information that can be used by the EES in edge computing services. The EEC registration enables the EES to initialize, update, and remove information resources related to the EEC. The EEC registration also enables the sharing of EEC context between each entity (UE and Application Server) in the EDGEAPP architecture. The decision on whether or not the EEC registration is permitted (EEC registration permission decision) is based on the Security credentials and / or at least one Application Client Profile (AC Profile(s)) provided by the EEC. To register the EEC, the EEC makes an EEC registration request to the EES.

[0007] Furthermore, the EEC can communicate with the EES and perform EAS discovery for the AC. EAS discovery allows the EEC to obtain information about available EASs of interest. Discovery of the EAS(s) is based on matching EAS discovery filters provided by the EEC. For EAS discovery, the EEC makes an EAS discovery request to the EES to request information about the equipment, connections or settings required to provide the service in the EDN. Such information includes, for example, information about available edge computing services and information about the servers in the EDN. [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] 3GPP TS 23.558 V17.0.0 (2021-06) "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Architecture for enabling Edge Applications; (Release 17)", June 2021 Summary of the Invention [Problem to be solved by the invention]

[0009] The inventors have examined the EDGEAPP architecture and found various problems. One of these problems relates to a planned shutdown of an EES. A planned shutdown can also be called a scheduled shutdown, a controlled shutdown, or a graceful shutdown. Specifically, when an EES (hereinafter referred to as EES-A) is shut down or made unavailable in a planned manner, it may be preferable for the EEC context managed by the EES-A to be taken over by another EES. To achieve this, it is effective to prompt the EEC registered in the EES-A to send an EEC registration request to the EES-B before the EES-A is shut down. However, such a procedure is not specified in Non-Patent Document 1.

[0010] Other issues also relate to planned shutdowns of EESs. In particular, if an EES (hereafter referred to as EES-A) is shut down or made unavailable in a planned manner, it may be desirable to notify EECs registered with EES-A in advance of this. This could enable the EECs to take appropriate action, for example to gracefully deregister from EES A or to ask another EES B to register the EEC. However, such a procedure is not specified in Non-Patent Document 1.

[0011] One of the objectives that the embodiments disclosed in this specification aim to achieve is to provide an apparatus, a method, and a program that contribute to solving at least one of the problems described above. It should be noted that this objective is only one of the objectives that the embodiments disclosed in this specification aim to achieve. Other objectives or objectives and novel features will be apparent from the description of this specification or the accompanying drawings. [Means for solving the problem]

[0012] In a first aspect, a first EES includes a memory and at least one processor coupled to the memory, the at least one processor configured to send a control message to an edge configuration server indicating that the first EES is to be shut down or made unavailable.

[0013] In a second aspect, a method performed by a first EES includes sending a control message to an edge configuration server indicating that the first EES is to be shut down or made unavailable.

[0014] In a third aspect, a first EES includes a memory and at least one processor coupled to the memory, the at least one processor configured to send a control message to a UE indicating that the first EES is to be shut down or disabled.

[0015] In a fourth aspect, a method performed by a first EES includes transmitting a control message to a UE indicating that the first EES is to be shut down or made unavailable.

[0016] In a fifth aspect, an edge configuration server includes a memory and at least one processor coupled to the memory, the at least one processor configured to receive a control message from a first EES indicating that the first EES is to be shut down or unavailable, and in response to receiving the control message, to transmit a service provisioning notification or response to the UE prompting the UE to transmit an EEC registration request to a second EES different from the first EES.

[0017] In a sixth aspect, a method performed by an edge configuration server includes (a) receiving a control message from a first EES indicating that the first EES is to be shut down or made unavailable, and (b) in response to receiving the control message, sending a service provisioning notification or response to the UE prompting the UE to send an EEC registration request to a second EES that is different from the first EES.

[0018] In a seventh aspect, an edge configuration server includes a memory and at least one processor coupled to the memory, the at least one processor configured to receive a control message from a first EES indicating that the first EES is to be shut down or unavailable, and in response to receiving the control message, to send a service provisioning notification or response to a UE indicating that the first EES is to be shut down or unavailable.

[0019] In an eighth aspect, a method performed by an edge configuration server includes (a) receiving a control message from a first EES indicating that the first EES is to be shut down or unavailable, and (b) in response to receiving the control message, sending a service provisioning notification or response to a UE indicating that the first EES is to be shut down or unavailable.

[0020] In a ninth aspect, a UE includes a memory and at least one processor coupled to the memory, the at least one processor configured to receive a control message from the first EES or an edge configuration server indicating that a first EES is to be shut down or unavailable, and in response to receiving the control message, the at least one processor configured to send an edge enabler client (EEC) registration request to a second EES different from the first EES.

[0021] In a tenth aspect, a method performed by a UE includes (a) receiving a control message from a first EES or an edge configuration server indicating that a first EES is to be shut down or made unavailable, and (b) in response to receiving the control message, sending an edge enabler client (EEC) registration request to a second EES different from the first EES.

[0022] In an eleventh aspect, a UE includes a memory and at least one processor coupled to the memory, the at least one processor configured to receive a control message from the first EES or an edge configuration server indicating that a first EES is to be shut down or unavailable, and in response to receiving the control message, the at least one processor configured to send an EEC deregistration request to the first EES.

[0023] In a twelfth aspect, a method performed by a UE includes (a) receiving a control message from a first EES or an edge configuration server indicating that a first EES is to be shut down or made unavailable, and (b) in response to receiving the control message, sending an EEC deregistration request to the first EES.

[0024] In a thirteenth aspect, the program comprises a set of instructions (software code) which, when loaded into a computer, causes the computer to perform a method according to any of the second, fourth, sixth, eighth, tenth or twelfth aspects described above. Effect of the Invention

[0025] According to the above-mentioned aspects, it is possible to provide an apparatus, a method, and a program that contribute to solving at least one of the above-mentioned problems. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a diagram illustrating an example of a network architecture according to an embodiment. [Diagram 2] FIG. 11 is a sequence diagram showing an example of the operation of the EES and ECS according to the embodiment. [Diagram 3] 1 is a flowchart illustrating an example of an operation of an ECS according to an embodiment. [Figure 4] 1 is a flowchart illustrating an example of an operation of an ECS according to an embodiment. [Diagram 5] 10 is a flowchart illustrating an example of an operation of an EEC according to the embodiment. [Figure 6] 10 is a flowchart illustrating an example of an operation of an EEC according to the embodiment. [Figure 7] A sequence diagram showing an example of the operation of the EEC, EES, and ECS according to the embodiment. [Figure 8] A sequence diagram showing an example of the operation of the EEC, EES, and ECS according to the embodiment. [Figure 9] A sequence diagram showing an example of the operation of the EEC and EES according to the embodiment. [Figure 10] 10 is a flowchart illustrating an example of an operation of an EEC according to the embodiment. [Figure 11] 10 is a flowchart illustrating an example of an operation of an EEC according to the embodiment. [Figure 12] A sequence diagram showing an example of the operation of the EEC, EES, and ECS according to the embodiment. [Figure 13] A sequence diagram showing an example of the operation of the EEC, EES, and ECS according to the embodiment. [Figure 14] FIG. 2 is a block diagram showing an example of the configuration of a UE according to the embodiment. [Figure 15] FIG. 2 is a block diagram showing an example of the configuration of a server according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] In the following, specific embodiments will be described in detail with reference to the drawings. In each drawing, the same or corresponding elements are denoted by the same reference numerals, and duplicated descriptions will be omitted as necessary for clarity of explanation.

[0028] The multiple embodiments described below can be implemented independently or in appropriate combination. These multiple embodiments have different novel features. Therefore, these multiple embodiments contribute to solving different objects or problems and provide different effects.

[0029] The following embodiments will be described mainly with respect to a 3GPP system (eg, a 5G system (5GS)). However, these embodiments may be applied to other wireless communication systems.

[0030] As used herein, depending on the context, "if" may be interpreted to mean "when," "at or around the time," "after," "upon," "in response to determining," "in accordance with a determination," or "in response to detecting." These expressions may be interpreted to have the same meaning, depending on the context.

[0031] <First embodiment> FIG. 1 illustrates an example of a network architecture according to a number of embodiments, including the present embodiment. The architecture of FIG. 1 corresponds to the 3GPP EDGEAPP architecture. Each of the elements illustrated in FIG. 1 is a functional entity, providing functions and interfaces defined by 3GPP. Each of the elements (functional entities) illustrated in FIG. 1 can be implemented, for example, as a network element on dedicated hardware, as a software instance running on dedicated hardware, or as a virtualized function instantiated on an application platform.

[0032] In the example of FIG. 1, User Equipment (UE) 1 includes an Edge Enabler Client (EEC) 2 and one or more Application Clients (ACs) 3. In other words, the EEC 2 and one or more ACs 3 are arranged in the UE 1 and operate on the UE 1. Although not explicitly shown in FIG. 1, the UE 1 communicates with a 3GPP core network 8 via an access network (eg, a Radio Access Network (eg, a NG Radio Access Network (NG-RAN)). This allows the UE 1 to provide connectivity to the EEC 2 and AC(s) 3 with a data network via the access network and the 3GPP core network 8. The 3GPP core network 8 may be one or a combination of a 5G Core (5GC) and an Evolved Packet Core (EPC).

[0033] The EEC2 provides supporting functions required by the AC(s) 3. Specifically, the EEC2 provides provisioning of configuration information to enable exchange of application data traffic with an Edge Application Server (EAS). In addition, the EEC2 provides functionality for discovery of one or more EASs available in the Edge Data Network (EDN) 4. The EEC2 uses the EAS endpoint information obtained during EAS discovery for routing outgoing application data traffic to the EAS. Furthermore, the EEC2 provides functionality for EEC registration (i.e., registration, update, and de-registration) with one or more Edge Enabler Servers (EESs) 5.

[0034] Each AC3 is an application running on a UE1. Each AC3 connects to one or more EASs to utilize edge computing services and exchanges application data traffic with these EASs.

[0035] The EDN 4 is a local data network that supports an architecture for enabling edge applications. An EDN 4 includes one or more EESs 5 and one or more EASs 6. The EDN 4 may be a Local Area Data Network (LADN). The LADN allows limited access to a DN (and corresponding Data Network Name (DNN)) only in one or more specific areas. Outside this area, the UE 1 cannot access the DN (and DNN). The area in which the LADN DNN is available is called the LADN service area and is configured in the network as a set of Tracking Areas (TAs). DNNs that do not use the LADN feature do not have a LADN service area and are not restricted by this feature. The LADN service area is provided to the UE 1 by the Access and Mobility Management Function (AMF) in the 3GPP core network 8 when the UE 1 registers. This allows the UE 1 to know the area in which the LADN (or EDN) is available and not to try to access the LADN (or EDN) outside this area.

[0036] Each EES5 provides supporting functions required by one or more EASs6 and EEC2. In particular, each EES5 provides the provisioning of configuration information to the EEC2, enabling the exchange of application data traffic with the EAS(s)6. Each EES5 provides the functionality of registration (i.e., registration, update, and de-registration) of the EEC2 and EAS(s)6. EEC registration allows the creation, update, and removal of information resources related to the EEC2 in the EES5. EEC registration allows the EES5 to manage the EEC context of the EEC2.

[0037] The EEC context includes information about the EEC2 for receiving the edge enabler service. More specifically, the EEC context may include an EEC context ID, endpoint information of a source EES, and a service session context. The EEC context ID is an identifier assigned to the EEC context. The endpoint information of the source EES is an endpoint address (e.g., Uniform Resource Identifier (URI) and / or Internet Protocol (IP) address) of the EES5A that provided the EEC context. The service session context may include an identifier (EAS ID) of an EAS6 that provides an application service, and endpoint information (e.g., URI and / or IP address) of the EAS6.

[0038] Each EES5 provides the functionality of application context transfer between EASs. This functionality is required for edge application mobility (or application context relocation) for service continuity. Edge application mobility relocates application context or application instance or both related to a user (i.e., AC) from a source EAS (or EDN or LADN) to a target EAS (or EDN or LADN). Edge application mobility is triggered by UE mobility events or non-UE mobility events. UE mobility events include, for example, intra-EDN UE mobility, inter-EDN UE mobility, and LADN-related UE mobility. Non-UE mobility events include, for example, EAS or EDN overload situations, and EAS maintenance (e.g. graceful shutdown of an EAS).

[0039] Each EES 5 supports the functionality of an Application Programming Interface (API) invoker and an API exposing function. Each EES 5 may interact directly (e.g., via a Policy Control Function (PCF) or a Policy Control and Charging Rules Function (PCRF)) or indirectly (e.g., via a Network Exposure Function (NEF) or a Service Capability Exposure Function (SCEF)) with the 3GPP core network 8 to access the services and capabilities of network functions within the 3GPP core network 8. Each EES 5 may support external exposure of the services and capabilities of the 3GPP network functions to the EAS(s) 6.

[0040] Each EAS 6 is located in the EDN 4 and executes a server function of an application. The server function of the application may be available only at the edge. In other words, the server function of the application may be available only as an EAS. However, the server function of the application may be available both at the edge and in the cloud. In other words, the server function of the application may be available as an EAS and also as an application server in the cloud. The cloud here means a central cloud located farther from the UE 1 than the EDN 4. Thus, the application server in the cloud means a server located in a centralized location (e.g., a centralized data center). Each EAS 6 may consume or use 3GPP core network capabilities. Each EAS 6 may directly invoke a 3GPP core network function API. Alternatively, each EAS 6 may consume or use 3GPP core network capabilities via the EES 5 or via the NEF or SCEF.

[0041] The Edge Configuration Server (ECS) 7 provides supporting functions required by the EEC 2 to connect to the EES(s) 5. Specifically, the ECS 7 provides provisioning to the EEC 2 of a list of EDN configuration information for one or more EDNs. The EDN configuration information includes, for one EDN (e.g., EDN 4), the configurations required to connect to the EDN by the EEC 2. Specifically, the EDN configuration information for the EDN 4 includes an identification of the EDN 4 (e.g., DNN or Access Point Name (APN)) and a list of one or more EESs 5.

[0042] More specifically, the EDN configuration information for the EDN4 includes an "EDN connection information" IE and a "List of EESs" IE, and may further include a "Lifetime" IE. The EDN connection information IE indicates information required for EDN connection. The information required for EDN connection includes a DNN or an APN, and may further include at least one of a Single-Network Slice Selection Assistance Information (S-NSSAI) or an EDN Topological Service Area. The S-NSSAI indicates a network slice. The List of EESs IE indicates a list of one or more EESs5 of the EDN4. The EES list includes an EES ID and an EES Endpoint (eg, URI, Internet Protocol (IP) address) of each EES. The EES list may include EASIDs of one or more EASs6 associated with each EES. The EES list may include one or more DNAIs associated with each EES or each EAS. The Lifetime IE indicates a validity period of the EDN configuration information. In other words, the Lifetime IE indicates the time duration during which the EDN configuration information is valid and will be stored or cached in EEC2 (or UE1).

[0043] Additionally, the ECS 7 provides EES(s) 5 registration (i.e., registration, update, and de-registration) functions. Additionally, the ECS 7 supports API invoker and API exposing function functions. The ECS 7 may interact directly (e.g., via a PCF) or indirectly (e.g., via a NEF or SCEF) with the 3GPP core network 8 to access services and capabilities of network functions within the 3GPP core network 8. The ECS 7 may be located within the Mobile Network Operator (MNO) domain that provides the 3GPP core network 8, or may be located in a third-party domain of a service provider (e.g., an Edge Computing Service Provider (ECSP)).

[0044] 1 shows only representative elements for ease of explanation. For example, ECS 7 may be connected to multiple EDNs including EDN 4.

[0045] The following describes the operation of EEC2, EES5, and ECS7 with respect to a planned shutdown of EES5 (hereinafter referred to as EES-A or EES5A), which may also be referred to as a scheduled shutdown, a controlled shutdown, or a graceful shutdown.

[0046] 2 shows an example of the operation of the EES 5A and the ECS 7 regarding a planned shutdown of the EES 5A. In step 201, the EES 5A sends a control message to the ECS 7 indicating that the EES 5A is to be shut down or made unavailable. In other words, the EES 5A notifies the ECS 7 of the planned shutdown in advance before the planned shutdown of the EES 5A is executed.

[0047] As shown in FIG. 2, the control message of step 201 may be an EES registration update request. The EES registration update request requests the ECS 7 to update the registration of the EES 5A. The EES registration update procedure enables the EES 5A to update the ECS 7 when there is a change in the information in the EES 5A. In response to the information of the EES 5A (e.g., AC Profile(s) or EES Profile(s)) being updated, the EES 5A may send the EES registration update request to the ECS 7. Additionally or alternatively, the EES 5A may send the EES registration update request to the ECS 7 before the expiration time of the EES registration elapses in order to maintain an active registration status. The expiration time is indicated to the EES 5A by the previous EES registration response or EES registration update response. Although not shown in FIG. 2, the ECS 7 may respond to the EES 5A by an EES registration update response. Note that the control message in step 201 may be a message different from the EES registration update request. For example, the control message may be a newly defined message.

[0048] The control message of step 201 may include an indication or information to indicate that the EES5A is scheduled to be shut down or unavailable. The indication or information may be referred to as, for example, but not limited to, a planned, scheduled, controlled, or normal shutdown notification. The planned, scheduled, controlled, or normal shutdown of the EES5A may be a deletion of the EES5A from the EDN4, or a temporary shutdown or unavailability for any purpose such as regular maintenance. Additionally or alternatively, the control message of step 201 may indicate a grace period until the EES5A becomes unavailable, or a date and time or period during which the EES5A is unavailable. In other words, the indication or notification of the planned shutdown may be information indicating a grace period until the EES5A becomes unavailable, or a date and time or period during which the EES5A is unavailable. Alternatively, the control message of step 201 may include, in addition to the indication or information described above, information indicating a grace period until the EES5A becomes unavailable, or a date and time or period during which the EES5A is unavailable. Additionally or alternatively, the control message of step 201 may include information or indication to cause ECS7 to send a service provisioning notification or response to EEC2 to prompt EEC2 to send an EEC registration request to an EES different from EES5A.

[0049] According to the operation of EES5A and ECS7 described with reference to Figure 2, EES5A notifies ECS7 of a planned shutdown of EES5A in advance, enabling ECS7 to take any necessary actions or procedures to avoid or mitigate the effects of the planned shutdown of EES5A.

[0050] In one example, in response to receiving the control message of step 201, the ECS7 may send a service provisioning notification or response to the EEC2 to prompt the EEC2 of the UE1 to send an EEC registration request to an EES (hereinafter referred to as EES-B or EES5B) different from the EES5A. In other words, the control message of step 201 may cause the ECS7 to send a service provisioning notification or response to the EEC2 to prompt the EEC2 to send an EEC registration request to the EES5B. The EEC2 sending the EEC registration request to the EES5B may cause the EES5B to request the EES5A to transfer the EEC context of the EEC2 to the EES5B.

[0051] In another example, in response to receiving the control message of step 201, ECS7 may send a service provisioning notification or response to EEC2 indicating that EES5A is to be shut down or made unavailable. In other words, the control message of step 201 may cause ECS7 to send a service provisioning notification or response to EEC2 indicating that EES5A is to be shut down or made unavailable. This may enable EEC2 to take appropriate action, such as, for example, gracefully deregistering from EES5A or asking another EES (e.g., EES5B) to perform EEC registration.

[0052] Figure 3 is a flow chart showing an example of the operation of the ECS 7. Step 301 corresponds to step 201 of Figure 2. Specifically, the ECS 7 receives a control message from the EES 5A indicating that the EES 5A is to be shut down or made unavailable. The control message may be an EES registration update request.

[0053] In step 302, in response to receiving the control message in step 301, the ECS 7 transmits a service provisioning notification or response to the EEC 2 to prompt the EEC 2 of the UE 1 to transmit an EEC registration request to the EES 5B different from the EES 5A. Specifically, when a service provisioning procedure based on the Subscribe / Notify model is used, the ECS 7 transmits a service provisioning notification to the EEC 2. In this case, the ECS 7 may transmit a service provisioning notification in response to receiving the control message in step 302. That is, the ECS 7 may transmit a service provisioning notification immediately after receiving the control message in step 302. On the other hand, when a service provisioning procedure based on the Request / Response model is used, the ECS 7 transmits a service provisioning response to the EEC 2. In this case, the ECS 7 may transmit a service provisioning response to the EEC 2 in response to receiving a service provisioning request from the EEC 2 after receiving the control message in step 302. EEC2 may send a service provisioning request to ECS7 before the expiration (or lifetime) of the EDN configuration information for EDN4 stored in EEC2 expires.

[0054] In one example, the service provisioning notification or response of step 302 may indicate a list of one or more EESs, including EES5B and excluding EES5A. Specifically, the service provisioning notification or response of step 302 may include EDN configuration information for EDN4. The EDN configuration information may include a list of one or more EESs, including EES5B and excluding EES5A. EES5B may provide a service area that at least partially overlaps with the service area of ​​EES5A that is to be shut down. In response to receiving the control message of step 301, ECS7 may select EES5B as an alternative server for EES5A and generate an updated list of EESs (including EES5B and excluding EES5A) for EEC2 of UE1.

[0055] The service provisioning notification or response of step 302 causes EEC2, which is registered with EES5A, to send an EES registration request to EES5B. By EEC2 sending an EEC registration request to EES5B, EES5B can request EES5A to transfer the EEC context of EEC2 to EES5B. This is expected to allow EES5B to take over the EEC context for EEC2 that was managed by EES5A before EES5A was shut down.

[0056] The procedure in FIG. 3 is an example and may be modified as appropriate. For example, as already described, the control message in step 301 may indicate a grace period until EES5A cannot be used, or a date and time or period during which EES5A cannot be used. In other words, the control message in step 301 may include information indicating a grace period until EES5A cannot be used, or a date and time or period during which EES5A cannot be used. The ECS7 may indicate to the EEC2, via the service provisioning notification or response in step 302, a grace period until EES5A cannot be used, or a date and time or period during which EES5A cannot be used. In other words, the ECS7 may include information indicating a grace period until EES5A cannot be used, or a date and time or period during which EES5A cannot be used, in the service provisioning notification or response in step 302. The ECS5 may recalculate or update the grace period until EES5A cannot be used, taking into account the timing of sending the service provisioning notification or response. In this case, EEC2 may operate to send an EEC registration request to EES5B before EES5A is shut down. If EEC2 cannot send an EEC registration request to EES5B before EES5A is shut down, EEC2 may request EEC deregistration to EES5A. However, sending an EEC deregistration to EES5A is not necessarily required. This is because EEC2 may no longer be able to properly communicate with EES5A because EES5A has been shut down. Also, even if EES5A does not receive an explicit EEC deregistration, if an EEC registration update request is not received from EEC2 before the expiration time of the EEC registration has elapsed, EES5A will treat EEC2 as being implicitly deregistered.

[0057] Figure 4 is a flow chart illustrating another example of the operation of the ECS 7. Step 401 corresponds to step 201 of Figure 2. Specifically, the ECS 7 receives a control message from the EES 5A indicating that the EES 5A is to be shut down or made unavailable. The control message may be an EES registration update request.

[0058] In step 402, in response to receiving the control message of step 401, the ECS 7 sends a service provisioning notification or response to the EEC 2 of the UE 1, indicating that the EES 5A is to be shut down or made unavailable. This is expected to allow the EEC 2 registered with the EES 5A to be notified in advance of the planned shutdown of the EES 5A. The EEC 2 can take appropriate action, for example, to normally deregister from the EES 5A or to ask another EES (e.g., EES 5B) to perform EEC registration. In other words, the service provisioning notification or response of step 402 may cause the EEC 2 to send an EEC registration request to an EES (e.g., EES 5B) different from the EES 5A. The service provisioning notification or response of step 402 may cause the EEC 2 to send an EEC deregistration request to the EES 5A that is to be made unavailable in a planned manner. Additionally or alternatively, the service provisioning notification or response of step 402 may cause EEC2 to determine whether to send an EEC registration request to EES5B or an EEC deregistration request to EES5A.

[0059] The procedure in FIG. 4 is an example, and may be modified as appropriate. For example, as already described, the control message in step 401 may indicate a grace period until EES5A cannot be used, or a date and time or period during which EES5A cannot be used. In other words, the control message in step 401 may include information indicating a grace period until EES5A cannot be used, or a date and time or period during which EES5A cannot be used. The ECS7 may indicate to the EEC2, via the service provisioning notification or response in step 402, a grace period until EES5A cannot be used, or a date and time or period during which EES5A cannot be used. In other words, the ECS7 may include information indicating a grace period until EES5A cannot be used, or a date and time or period during which EES5A cannot be used, in the service provisioning notification or response in step 402. The ECS5 may recalculate or update the grace period until EES5A cannot be used, taking into account the timing of sending the service provisioning notification or response. In this case, EEC2 may operate to send an EEC registration request to EES5B before EES5A is shut down. If EEC2 cannot send an EEC registration request to EES5B before EES5A is shut down, EEC2 may request EEC deregistration from EES5A. However, as already explained, sending an EEC deregistration to EES5A is not necessarily required.

[0060] In the procedure of Fig. 3 or 4, the trigger that causes the ECS 7 to perform step 302 or step 402 is not limited to the control message (or the display or information contained therein) of step 301 or step 401. For example, the ECS 7 may monitor the status of the EES(s) registered with the ECS 7 using a network / server status monitoring method that is not dependent on the EDGEAPP architecture. In this case, the ECS 7 may perform step 302 or step 402 in response to determining, based on this monitoring, that an EDN information update such as a change in the EES is necessary.

[0061] FIG. 5 is a flowchart showing an example of the operation of the EEC2. Step 501 corresponds to step 402 in FIG. 4. Specifically, the EEC2 receives a service provisioning notification or response from the ECS7 indicating that the EES5A is scheduled to be shut down or unavailable. The service provisioning notification or response in step 501 may include an indication or information to indicate that the EES5A is scheduled to be shut down or unavailable. The indication or information may be referred to as, for example, but not limited to, a planned, scheduled, controlled, or graceful shutdown notification. Additionally or alternatively, the service provisioning notification or response in step 501 may indicate a grace period until the EES5A becomes unavailable, or a date and time or period when the EES5A is unavailable. In other words, the indication or notification of the planned shutdown may be information indicating a grace period until the EES5A becomes unavailable, or a date and time or period when the EES5A is unavailable. Alternatively, the service provisioning notification or response in step 501 may include, in addition to the above indication or information, information indicating a grace period until EES5A cannot be used, or a date and time or period during which EES5A cannot be used.

[0062] The service provisioning notification or response of step 501, in addition to the indication or notification of the planned shutdown, may include EDN configuration information for EDN4. The EDN configuration information may include a list of one or more EESs, not including EES5A, and including EES5B. EES5B may provide a service area that at least partially overlaps with the service area of ​​EES5A that is planned to be shut down or unavailable.

[0063] In step 502, in response to receiving the service provisioning notification or response in step 501, EEC2 sends an EEC registration request to EES5B, which is different from EES5A. The EEC registration request includes information for identifying an EEC context for EEC2 stored in a source EES (i.e., EES5A). The information may include one or both of an identifier (Source EES ID) and an endpoint of the source EES (i.e., EES5A). Additionally or alternatively, the information may include an EEC context ID. The endpoint of the source EES is an endpoint address (e.g., URI and / or IP address) of EES5A that provided the EEC context. The EEC context ID is an identifier of the EEC context obtained from a previous EEC registration.

[0064] By sending an EEC registration request to EES5B, EES5B can request EES5A to transfer the EEC context of EEC2 to EES5B, which is expected to allow EES5B to take over the EEC context for EEC2 that was managed by EES5A before EES5A was shut down.

[0065] If the service provisioning notification or response in step 501 indicates a grace period until EES5A becomes unavailable, or a date and time or period during which EES5A becomes unavailable, EEC2 may operate to send an EEC registration request to EES5B before the shutdown of EES5A. If EEC2 cannot send an EEC registration request to EES5B before the shutdown of EES5A, EEC2 may request EEC deregistration to EES5A. Specifically, EEC2 may request EEC deregistration to EES5A in response to the expiration of the grace period until EES5A becomes unavailable. However, as already described, sending an EEC deregistration to EES5A is not necessarily required. Alternatively, EEC2 may obtain new EDN configuration information from ECS7 if it cannot send an EEC registration request to EES5B before the shutdown of EES5A. Specifically, the EEC2 may send a service provisioning request to the ECS7 in response to the expiration of a grace period until the EES5A becomes unavailable.

[0066] FIG. 6 is a flowchart showing another example of the operation of the EEC2. Step 601 corresponds to step 402 in FIG. 4. Specifically, the EEC2 receives a service provisioning notification or response from the ECS7 indicating that the EES5A is scheduled to be shut down or unavailable. The service provisioning notification or response in step 601 may include an indication or information to indicate that the EES5A is scheduled to be shut down or unavailable. The indication or information may be referred to as, for example, but not limited to, a planned, scheduled, controlled, or graceful shutdown notification. Additionally or alternatively, the service provisioning notification or response in step 601 may indicate a grace period until the EES5A becomes unavailable, or a date and time or period when the EES5A is unavailable. In other words, the indication or notification of the planned shutdown may be information indicating a grace period until the EES5A becomes unavailable, or a date and time or period when the EES5A is unavailable. Alternatively, the service provisioning notification or response in step 601 may include, in addition to the above indication or information, information indicating a grace period until EES5A cannot be used, or a date and time or period during which EES5A cannot be used.

[0067] The service provisioning notification or response of step 601, in addition to the indication or notification of the planned shutdown, may include EDN configuration information for EDN4. The EDN configuration information may include a list of one or more EESs, not including EES5A, and including EES5B. EES5B may provide a service area that at least partially overlaps with the service area of ​​EES5A that is planned to be shut down or unavailable.

[0068] In step 602, the EEC2 transmits an EEC deregistration request to the EES5A in response to receiving the service provisioning notification or response in step 601. This is expected to successfully deregister the EEC2 from the EES5A that is to be shut down. If the service provisioning notification or response in step 601 indicates a grace period until the EES5A will no longer be available, or a date and time or period during which the EES5A will no longer be available, the EEC2 may operate to transmit an EEC deregistration request to the EES5A prior to the shutdown of the EES5A.

[0069] FIG. 7 is a sequence diagram showing an example of the operation of EEC2, EES5A, EES5B, and ECS7. Although not explicitly shown in FIG. 7, it is assumed that both EES5A and EES5B have completed EES registration with ECS7. In step 701, EEC2 and ECS7 perform a service provisioning procedure. The service provisioning procedure may be based on a Subscribe / Notify model or a Request / Response model. ECS7 sends a service provisioning notification or response to EEC2 that includes EDN configuration information for EDN4. The EDN configuration information includes a list of EES(s). The EES list includes at least EES5A. The EES list may further include EES5B.

[0070] In step 702, EES5A sends an EES registration update request to ECS7. The EES registration update request includes an indication or information to indicate that EES5A is scheduled to be shut down or unavailable. The indication or information may be referred to as, for example, but not limited to, a planned, scheduled, controlled, or graceful shutdown notification. Additionally or alternatively, the EES registration update request may indicate a grace period until EES5A is unavailable, or a date, time, or period during which EES5A is unavailable. In other words, the indication or notification of a planned shutdown may be information indicating a grace period until EES5A is unavailable, or a date, time, or period during which EES5A is unavailable. Alternatively, the EES registration update request may include information indicating a grace period until EES5A is unavailable, or a date, time, or period during which EES5A is unavailable. In step 703, ECS7 responds to EES5A with an EES registration update response.

[0071] In step 704, the ECS 7 sends a service provisioning notification or response to the EEC 2. Specifically, the ECS 7 selects one or more EECs 2 that are affected by the planned shutdown of the EES 5A. The ECS 7 may select EECs 2 that are already configured with an EES list that includes the EES 5A. The ECS 7 then sends a service provisioning notification or response to each of these EECs 2. The service provisioning notification or response includes updated EDN configuration information. The updated EDN configuration information includes a list of one or more EESs that does not include the EES 5A and includes the EES 5B. The EES 5B may provide a service area that at least partially overlaps with the service area of ​​the EES 5A that is being planned to be shut down or unavailable.

[0072] If a service provisioning procedure based on a Subscribe / Notify model is used, the ECS 7 may transmit a service provisioning notification to the EEC 2 in response to receiving the EES registration update request in step 702. That is, the ECS 7 may transmit a service provisioning notification (step 704) to the EEC 2 immediately after receiving the EES registration update request in step 702. Alternatively, if a service provisioning procedure based on a Request / Response model is used, the ECS 7 may transmit a service provisioning response (step 704) to the EEC 2 in response to receiving a service provisioning request from the EEC 2 after receiving the EES registration update request in step 702.

[0073] The service provisioning notification or response of step 704 may further indicate a grace period before EES5A will be unavailable, or a date and time or period when EES5A will be unavailable. Additionally or alternatively, the service provisioning notification or response of step 704 may include an indication or information to indicate that EES5A is to be shut down or unavailable. Such an indication or information may be referred to as, for example and without limitation, a planned, scheduled, controlled, or graceful shutdown notification. Additionally or alternatively, the service provisioning notification or response of step 704 may include information or indication to prompt EEC2 to send an EEC registration request to an EES different from EES5A.

[0074] In step 705, EEC2, in response to receiving the service provisioning notification or response in step 704, sends an EEC registration request to EES5B. The EEC registration request includes information for identifying an EEC context for EEC2 stored in the source EES (i.e., EES5A). The information may include one or both of an identifier (Source EES ID) of the source EES (i.e., EES5A) and an endpoint. Additionally or alternatively, the information may include an EEC context ID.

[0075] The EES5B detects that information for identifying the EEC context related to EEC2 stored in the source EES is included in the EEC registration request of step 705. In response, the EES5B performs an EEC Context Pull relocation procedure. Specifically, in step 706, the EES5B requests the EEC context from the source EES, EES5A (EEC Context Pull request). The request may include the EEC context ID received from EEC2. In step 707, in response to receiving the request from the target EES, EES5B, the EES5A sends a response including the EEC context of EEC2 (EEC Context Pull response) to the EES5B.

[0076] In step 708, EES5B responds to EEC2 with an EEC registration response.

[0077] According to the procedure in FIG. 7, it is expected that EES5B will take over the EEC context for EEC2 managed by EES5A before EES5A is shut down.

[0078] Fig. 8 is a sequence diagram showing another example of the operations of the EEC2, the EES5A, the EES5B, and the ECS7. Although not explicitly shown in Fig. 8, it is assumed that both the EES5A and the EES5B have completed EES registration with the ECS7. Steps 801 to 803 are similar to steps 701 to 703 in Fig. 7.

[0079] In step 804, ECS7 sends a service provisioning notification or response to EEC2. The service provisioning notification or response may include an indication or information to indicate that EES5A is to be shut down or made unavailable. The indication or information may be referred to as, for example, but not limited to, a planned, scheduled, controlled, or graceful shutdown notification. Additionally or alternatively, the service provisioning notification or response may indicate a grace period before EES5A will be unavailable, or a date and time or period during which EES5A will be unavailable.

[0080] The service provisioning notification or response of step 804 may further include updated EDN configuration information, including a list of one or more EESs excluding EES5A and including EES5B, which may provide a service area that at least partially overlaps with the service area of ​​EES5A that is intentionally shut down or unavailable.

[0081] In response to receiving the service provisioning notification or response, the EEC2 of the UE1 performs either or both of alternative method 1 and alternative method 2. As an example, if the EEC2 determines that a transfer of an EEC context (creation of an EEC context in a destination EES (e.g., EES5B)) is required, the EEC2 may select alternative method 1. Otherwise, the EEC2 may select alternative method 2. In alternative method 1, the EEC2 sends an EEC registration request to the EES5B (step 805). The EEC registration request includes information for identifying an EEC context related to the EEC2 stored in the source EES (i.e., EES5A). The information may include one or both of an identifier (Source EES ID) of the source EES (i.e., EES5A) and an endpoint. Additionally or alternatively, the information may include an EEC context ID. The EEC registration request causes the EEC5B to receive the EEC context from the EES5A. This would allow EES5B to take over the EEC context for EEC2 that was managed by EES5A before EES5A was shut down.

[0082] In alternative method 2, the EEC2 sends an EEC deregistration request to the EES5A (step 806). This is expected to successfully deregister the EEC2 from the EES5A that is shut down. Alternatively, the EEC2 may delete (locally release) the EEC Context information held within the EEC2 without sending an EEC deregistration request to the EES5A.

[0083] <Second embodiment> An example of a network architecture according to this embodiment is the same as the example described with reference to Fig. 1. This embodiment provides details of the operation of EEC2 and EES5 regarding a planned shutdown of EES5 (hereinafter referred to as EES-A or EES5A). A planned shutdown can also be called a scheduled shutdown, a controlled shutdown, or a graceful shutdown.

[0084] 9 shows an example of the operation of the EEC2 and the EES5A regarding a planned shutdown of the EES5A. In step 901, the EES5A transmits a control message to the EEC2 indicating that the EES5A is to be shut down or made unavailable. In other words, the EES5A notifies the EEC2 of the planned shutdown in advance before executing the planned shutdown of the EES5A.

[0085] As shown in FIG. 9, the control message in step 901 may be an EEC registration update response. In this case, the EES5A sends the EEC registration update response in response to receiving an EEC registration update request from the EEC2. The EEC registration update request requests the EES5A to update the registration of the EEC2. The EEC registration update procedure enables the EEC2 to update the EES5A when there is a change in the information in the EEC2. In response to the information (e.g., AC Profile(s)) of the EEC2 being updated, the EEC2 may send the EEC registration update request to the EES5A. Additionally or alternatively, the EEC2 may send the EEC registration update request to the EES5A before the expiration time of the EEC registration elapses in order to maintain an active registration status. The expiration time is indicated to the EEC2 by the previous EEC registration response or the EEC registration update response. Although not shown in FIG. 9, EES 5A may respond to EES 5A with an EES registration update response.

[0086] Note that the control message in step 901 may be a message different from the EEC registration update response. For example, the control message may be an EEC registration response, an EEC de-registration response, an Edge Application Server (EAS) discovery response, or an EAS discovery notification. Alternatively, the control message may be a newly defined message. For example, it may be a network-initiated EEC de-registration request.

[0087] The control message of step 901 may include an indication or information to indicate that EES5A is scheduled to be shut down or unavailable. The indication or information may be referred to as, for example, but not limited to, a planned, scheduled, controlled, or graceful shutdown notification. Additionally or alternatively, the control message may indicate a grace period before EES5A will be unavailable, or a date and time or period when EES5A will be unavailable. Additionally or alternatively, the control message of step 901 may include information or an indication to prompt EEC2 to send an EEC registration request to an EES different from EES5A.

[0088] According to the operation of EEC2 and EES5A described with reference to Figure 9, EES5A notifies EEC2 of a planned shutdown of EES5A in advance, which enables EEC2 to take necessary actions or procedures to avoid or mitigate the effects of the planned shutdown of EES5A.

[0089] In one example, in response to receiving the control message of step 901, EEC2 may send an EEC registration request to an EES (hereinafter referred to as EES-B or EES5B) different from EES5A. In other words, the control message of step 901 may cause EEC2 to send an EEC registration request to EES5B. By EEC2 sending an EEC registration request to EES5B, EES5B can request EES5A to transfer the EEC context of EEC2 to EES5B.

[0090] In another example, in response to receiving the control message of step 901, EEC2 may send an EEC deregistration request to EES5A. In other words, the control message of step 901 may cause EEC2 to send an EEC deregistration request to EES5A. This can enable EEC2 to successfully deregister from EES5A, which is being shut down.

[0091] In yet another example, EEC2 may determine whether to send an EEC registration request to EES5B or an EEC deregistration request to EES5A based on the control message of step 901. In other words, the control message of step 901 may cause EEC2 to determine whether to send an EEC registration request to EES5B or an EEC deregistration request to EES5A.

[0092] FIG. 10 is a flowchart showing an example of the operation of the EEC2. Step 1001 corresponds to step 901 in FIG. 9. Specifically, the EEC2 receives a control message from the EES5A indicating that the EES5A is scheduled to be shut down or unavailable. The control message of step 1001 may include an indication or information for indicating that the EES5A is scheduled to be shut down or unavailable. The indication or information may be referred to as, for example, but not limited to, a planned, scheduled, controlled, or normal shutdown notification. Additionally or alternatively, the control message of step 1001 may indicate a grace period until the EES5A becomes unavailable, or a date and time or period when the EES5A is unavailable. In other words, the indication or notification of the planned shutdown may be information indicating a grace period until the EES5A becomes unavailable, or a date and time or period when the EES5A is unavailable.

[0093] In step 1002, in response to receiving the service provisioning notification or response in step 1001, EEC2 sends an EEC registration request to EES5B, which is different from EES5A. The EEC registration request includes information for identifying an EEC context for EEC2 stored in a source EES (i.e., EES5A). The information may include one or both of an identifier (Source EES ID) and an endpoint of the source EES (i.e., EES5A). Additionally or alternatively, the information may include an EEC context ID. The endpoint of the source EES is an endpoint address (e.g., one or both of a URI and an IP address) of EES5A that provided the EEC context. The EEC context ID is an identifier of the EEC context obtained from a previous EEC registration.

[0094] By sending an EEC registration request to EES5B, EES5B can request EES5A to transfer the EEC context of EEC2 to EES5B, which is expected to allow EES5B to take over the EEC context for EEC2 that was managed by EES5A before EES5A was shut down.

[0095] If the control message of step 1001 indicates a grace period until EES5A becomes unavailable, or a date and time or period during which EES5A becomes unavailable, EEC2 may operate to transmit an EEC registration request to EES5B before the shutdown of EES5A. If EEC2 cannot transmit an EEC registration request to EES5B before the shutdown of EES5A, EEC2 may request EEC deregistration to EES5A. Specifically, EEC2 may request EEC deregistration to EES5A in response to the expiration of the grace period until EES5A becomes unavailable. However, as already described, transmission of EEC deregistration to EES5A is not necessarily required. Alternatively, EEC2 may obtain new EDN setting information from ECS7 if it cannot transmit an EEC registration request to EES5B before the shutdown of EES5A. Specifically, the EEC2 may send a service provisioning request to the ECS7 in response to the expiration of a grace period until the EES5A becomes unavailable.

[0096] FIG. 11 is a flowchart showing another example of the operation of the EEC2. Step 1101 corresponds to step 901 in FIG. 9. Specifically, the EEC2 receives a control message from the EES5A indicating that the EES5A is scheduled to be shut down or unavailable. The control message in step 1101 may include an indication or information for indicating that the EES5A is scheduled to be shut down or unavailable. The indication or information may be referred to as, for example, but not limited to, a planned, scheduled, controlled, or normal shutdown notification. Additionally or alternatively, the control message in step 1101 may indicate a grace period until the EES5A becomes unavailable, or a date and time or period when the EES5A is unavailable. In other words, the indication or notification of the planned shutdown may be information indicating a grace period until the EES5A becomes unavailable, or a date and time or period when the EES5A is unavailable.

[0097] In step 1102, EEC2 transmits an EEC deregistration request to EES5A in response to receiving the control message in step 1101. This is expected to successfully deregister EEC2 from EES5A, which is to be shut down. If the service provisioning notification or response in step 1101 indicates a grace period until EES5A becomes unavailable, or a date and time or period during which EES5A becomes unavailable, EEC2 may operate to transmit an EEC deregistration request to EES5A prior to the shutdown of EES5A.

[0098] FIG. 12 is a sequence diagram showing an example of the operation of EEC2, EES5A, EES5B, and ECS7. Although not explicitly shown in FIG. 12, it is assumed that both EES5A and EES5B have completed EES registration with ECS7. In step 1201, EEC2 and ECS7 perform a service provisioning procedure. The service provisioning procedure may be based on a Subscribe / Notify model or a Request / Response model. ECS7 transmits a service provisioning notification or response to EEC2, which includes EDN configuration information for EDN4. The EDN configuration information includes a list of EES(s). The EES list includes at least EES5A and EES5B. EES5B may provide a service area that at least partially overlaps with the service area of ​​EES5A, which is shut down or unavailable on a planned basis.

[0099] In step 1202, EEC2 sends an EEC registration update request to EES5A. In step 1203, EES5A responds to EEC2 with an EEC registration update response. The EEC registration update response includes an indication or information to indicate that EES5A is scheduled to be shut down or unavailable. The indication or information may be referred to as, for example, but not limited to, a planned, scheduled, controlled, or graceful shutdown notification. Additionally or alternatively, the EEC registration update response may indicate a grace period before EES5A will be unavailable, or a date and time or period when EES5A will be unavailable. In other words, the indication or notification of a planned shutdown may be information indicating a grace period before EES5A will be unavailable, or a date and time or period when EES5A will be unavailable.

[0100] Note that the messages in steps 1202 and 1203 are not limited to an EEC registration update request and an EEC registration update response. For example, they may be an EEC registration request and an EEC registration response, an EEC deregistration request and an EEC deregistration response, or an EAS discovery request and an EAS discovery response.

[0101] In step 1204, EEC2, in response to receiving the EEC registration update response (or other control message) in step 1203, sends an EEC registration request to EES5B. The EEC registration request includes information for identifying an EEC context for EEC2 stored in the source EES (i.e., EES5A). The information may include one or both of an identifier (Source EES ID) of the source EES (i.e., EES5A) and an endpoint. Additionally or alternatively, the information may include an EEC context ID.

[0102] The EES5B detects that information for identifying the EEC context related to the EEC2 stored in the source EES is included in the EEC registration request of step 1204. In response, the EES5B performs an EEC Context Pull relocation procedure. Specifically, in step 1205, the EES5B requests the EEC context from the source EES, EES5A (EEC Context Pull request). The request may include the EEC context ID received from the EEC2. In step 1206, in response to receiving the request from the target EES, EES5B, the EES5A sends a response including the EEC context of the EEC2 (EEC Context Pull response) to the EES5B.

[0103] In step 1207, EES5B responds to EEC2 with an EEC registration response.

[0104] According to the procedure of FIG. 12, it is expected that EES5B will take over the EEC context for EEC2 managed by EES5A before EES5A is shut down.

[0105] Fig. 13 is a sequence diagram showing another example of the operation of the EEC2, the EES5A, the EES5B, and the ECS7. Although not explicitly shown in Fig. 13, it is assumed that both the EES5A and the EES5B have completed EES registration with the ECS7. Steps 1301 to 1303 are similar to steps 1201 to 1203 in Fig. 12.

[0106] In response to receiving the EEC registration update response (or other control message) in step 1303, the EEC2 of the UE1 performs either or both of alternative method 1 and alternative method 2. As an example, the EEC2 may select alternative method 1 if it determines that an EEC context transfer (EEC context generation in the destination EES (e.g., EES5B)) is required. Otherwise, the EEC2 may select alternative method 2. In alternative method 1, the EEC2 transmits an EEC registration request to the EES5B (step 1304). The EEC registration request includes information for identifying an EEC context related to the EEC2 stored in the source EES (i.e., EES5A). The information may include one or both of an identifier (Source EES ID) of the source EES (i.e., EES5A) and an endpoint. Additionally or alternatively, the information may include an EEC context ID. The EEC registration request causes EES5B to receive the EEC context from EES5A, which will hopefully allow EES5B to take over the EEC context for EEC2 that was managed by EES5A before EES5A was shut down.

[0107] In alternative method 2, the EEC2 sends an EEC deregistration request to the EES5A (step 1305). This is expected to successfully deregister the EEC2 from the EES5A that is being shut down. Alternatively, the EEC2 may delete (locally release) the EEC Context information held within the EEC2 without sending an EEC deregistration request to the EES5A.

[0108] Next, the following describes configuration examples of the UE1, EES5, EAS6, ECS7, and EES51 according to the above-mentioned embodiments. FIG. 14 is a block diagram showing a configuration example of the UE1. The Radio Frequency (RF) transceiver 1401 performs analog RF signal processing to communicate with a RAN node. The RF transceiver 1401 may include multiple transceivers. The analog RF signal processing performed by the RF transceiver 1401 includes frequency up-conversion, frequency down-conversion, and amplification. The RF transceiver 1401 is coupled to the antenna array 1402 and the baseband processor 1403. The RF transceiver 1401 receives modulation symbol data (or OFDM symbol data) from the baseband processor 1403, generates a transmission RF signal, and provides the transmission RF signal to the antenna array 1402. The RF transceiver 1401 also generates a baseband reception signal based on the reception RF signal received by the antenna array 1402, and provides the baseband reception signal to the baseband processor 1403. The RF transceiver 1401 may include an analog beamformer circuit for beamforming, which may include, for example, multiple phase shifters and multiple power amplifiers.

[0109] The baseband processor 1403 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. Digital baseband signal processing includes (a) data compression / decompression, (b) data segmentation / concatenation, (c) generation / decomposition of transmission format (transmission frame), (d) transmission line coding / decoding, (e) modulation (symbol mapping) / demodulation, and (f) generation of OFDM symbol data (baseband OFDM signal) by Inverse Fast Fourier Transform (IFFT). Meanwhile, control plane processing includes communication management of layer 1 (e.g., transmission power control), layer 2 (e.g., radio resource management, and hybrid automatic repeat request (HARQ) processing), and layer 3 (e.g., signaling related to attachment, mobility, and call management).

[0110] For example, the digital baseband signal processing by the baseband processor 1403 may include signal processing of a Service Data Adaptation Protocol (SDAP) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a Physical (PHY) layer. Also, the control plane processing by the baseband processor 1403 may include processing of a Non-Access Stratum (NAS) protocol, a Radio Resource Control (RRC) protocol, MAC Control Elements (CEs), and Downlink Control Information (DCIs).

[0111] The baseband processor 1403 may perform Multiple Input Multiple Output (MIMO) encoding and precoding for beamforming.

[0112] The baseband processor 1403 may include a modem processor (e.g., Digital Signal Processor (DSP)) that performs digital baseband signal processing and a protocol stack processor (e.g., Central Processing Unit (CPU) or Micro Processing Unit (MPU)) that performs control plane processing. In this case, the protocol stack processor that performs control plane processing may be shared with the application processor 1404 described later.

[0113] The application processor 1404 is also called a CPU, an MPU, a microprocessor, or a processor core. The application processor 1404 may include multiple processors (multiple processor cores). The application processor 1404 executes a system software program (operating system (OS)) and various application programs (e.g., a call application, a web browser, a mailer, a camera operation application, and a music playback application) read from the memory 1406 or a memory not shown, thereby implementing various functions of the UE1.

[0114] In some implementations, the baseband processor 1403 and the application processor 1404 may be integrated on a single chip, as shown by the dashed line (1405) in Figure 14. In other words, the baseband processor 1403 and the application processor 1404 may be implemented as a single System on Chip (SoC) device 1405. An SoC device may also be called a system Large Scale Integration (LSI) or a chipset.

[0115] The memory 1406 is a volatile memory or a non-volatile memory, or a combination thereof. The memory 1406 may include a plurality of physically independent memory devices. The volatile memory is, for example, a Static Random Access Memory (SRAM) or a Dynamic RAM (DRAM), or a combination thereof. The non-volatile memory is a Mask Read Only Memory (MROM), an Electrically Erasable Programmable ROM (EEPROM), a flash memory, or a hard disk drive, or any combination thereof. For example, the memory 1406 may include an external memory device accessible from the baseband processor 1403, the application processor 1404, and the SoC 1405. The memory 1406 may include an internal memory device integrated in the baseband processor 1403, the application processor 1404, or the SoC 1405. Furthermore, the memory 1406 may include a memory in a Universal Integrated Circuit Card (UICC).

[0116] The memory 1406 may store one or more software modules (computer programs) 1407 including instructions and data for performing the processes by the UE 1 described in the above embodiments. In some implementations, the baseband processor 1403 or the application processor 1404 may be configured to read the software modules 1407 from the memory 1406 and execute them to perform the processes by the UE 1 described in the above embodiments using the drawings.

[0117] In addition, the control plane processing and operations performed by UE1 described in the above embodiment can be realized by elements other than the RF transceiver 1401 and the antenna array 1402, i.e., at least one of the baseband processor 1403 and the application processor 1404, and the memory 1406 storing the software module 1407.

[0118] The operations performed by EEC2 and AC(s)3 of UE1 described in the above embodiments can be realized by at least one of a baseband processor 1403 and an application processor 1404 and a memory 1406 storing software modules 1407.

[0119] FIG. 14 shows a configuration example of the EES5 (EES5A, EES5B). The EAS6 and ECS7 may also have a similar configuration to that shown in FIG. 14. Referring to FIG. 14, the EES5 (or the EAS6, or the ECS7) includes a network interface 1501, a processor 1502, and a memory 1503. The network interface 1501 is used, for example, to communicate with other network functions (NFs) or nodes. The network interface 1501 may include, for example, a network interface card (NIC) compliant with the IEEE 802.3 series.

[0120] The processor 1502 may be, for example, a microprocessor, a Micro Processing Unit (MPU), or a Central Processing Unit (CPU). The processor 1502 may include multiple processors.

[0121] The memory 1503 is composed of a volatile memory and a non-volatile memory. The memory 1503 may include a plurality of physically independent memory devices. The volatile memory is, for example, a static random access memory (SRAM) or a dynamic RAM (DRAM), or a combination thereof. The non-volatile memory is, for example, a mask read only memory (MROM), an electrically erasable programmable ROM (EEPROM), a flash memory, or a hard disk drive, or any combination thereof. The memory 1503 may include a storage located away from the processor 1502. In this case, the processor 1502 may access the memory 1503 via the network interface 1501 or an I / O interface not shown.

[0122] The memory 1503 may store one or more software modules (computer programs) 1504 including instructions and data for performing processing by the EES5 (or EAS6, or ECS7) described in the above-mentioned embodiments. In some implementations, the processor 1502 may be configured to read the software modules 1504 from the memory 1503 and execute them to perform processing by the EES5 (or EAS6, or ECS7) described in the above-mentioned embodiments.

[0123] As described with reference to FIG. 14 and FIG. 15, each of the processors of UE1, EES5, EAS6, and ECS7 according to the above-mentioned embodiments can execute one or more programs including instructions for making a computer execute the algorithm described with reference to the drawings. The programs include instructions (or software codes) for making a computer execute one or more functions described in the embodiments when the programs are loaded into a computer. The programs may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, computer-readable media or tangible storage media include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disk (DVD), Blu-ray (registered trademark) disk or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The programs may be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, the transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

[0124] The above-described embodiment is merely an example of the application of the technical idea obtained by the inventor of the present invention. In other words, the technical idea is not limited to the above-described embodiment, and various modifications are possible.

[0125] For example, some or all of the above embodiments may be described as, but are not limited to, the following supplementary notes.

[0126] (Appendix 1) a first edge enabler server (EES), Memory, and at least one processor coupled to the memory and configured to send a control message to an edge configuration server indicating that the first EES is to be shut down or made unavailable; Equipped with 1st EES. (Appendix 2) The control message causes the edge configuration server to send a service provisioning notification or response to a User Equipment (UE), prompting the UE to send an Edge Enabler Client (EEC) registration request to a second EES different from the first EES; The first EES as set out in Appendix 1. (Appendix 3) The control message causes the edge configuration server to send a service provisioning notification or response to a User Equipment (UE) indicating that the first EES is to be shut down or made unavailable. 1. A first EES as referred to in appendix 1 or 2. (Appendix 4) The control message is an EES registration update request requesting the edge configuration server to update the registration of the first EES. 4. The first EES according to any one of claims 1 to 3. (Appendix 5) The control message indicates a grace period until the first EES cannot be used, or a date and time or a period during which the first EES cannot be used, 5. The first EES according to any one of claims 1 to 4. (Appendix 6) 1. A method performed by a first edge enabler server (EES), comprising: sending a control message to an edge configuration server indicating that the first EES is to be shut down or made unavailable. method. (Appendix 7) A program for causing a computer to perform a method for a first edge enabler server (EES), comprising: The method includes sending a control message to an edge configuration server indicating that the first EES is to be shut down or made unavailable. program. (Appendix 8) a first edge enabler server (EES), Memory, and at least one processor coupled to the memory and configured to send a control message to a User Equipment (UE) indicating that the first EES is to be shut down or disabled; Equipped with 1st EES. (Appendix 9) The control message causes the UE to send an Edge Enabler Client (EEC) registration request to a second EES different from the first EES. The first EES as set out in Appendix 8. (Appendix 10) The control message causes the UE to send an Edge Enabler Client (EEC) deregistration request to the first EES. The first EES as set out in Appendix 8. (Appendix 11) The control message causes the UE to determine whether to send an Edge Enabler Client (EEC) registration request to a second EES or to send an EEC deregistration request to the first EES. The first EES as set out in Appendix 8. (Appendix 12) The control message indicates a grace period until the first EES cannot be used, or a date and time or a period during which the first EES cannot be used, The first EES according to any one of appendix 8 to 11. (Appendix 13) The control message is an Edge Enabler Client (EEC) registration update response, an EEC registration response, an EEC deregistration response, an Edge Application Server (EAS) discovery response, or an EAS discovery notification; The first EES according to any one of appendix 8 to 12. (Appendix 14) 1. A method performed by a first edge enabler server (EES), comprising: transmitting a control message to a User Equipment (UE) indicating that the first EES is to be shut down or made unavailable. method. (Appendix 15) A program for causing a computer to perform a method for a first edge enabler server (EES), comprising: The method includes transmitting a control message to a User Equipment (UE) indicating that the first EES is to be shut down or made unavailable. program. (Appendix 16) Memory, and coupled to the memory; and receiving a control message from a first Edge Enabler Server (EES) indicating that the first EES is to be shut down or made unavailable; In response to receiving the control message, sending a service provisioning notification or response to a User Equipment (UE) prompting the UE to send an Edge Enabler Client (EEC) registration request to a second EES different from the first EES; at least one processor configured to An edge configuration server comprising: (Appendix 17) the service provisioning notification or response indicates a list of one or more EESs that does not include the first EES and that includes the second EES; 17. The edge configuration server according to claim 16. (Appendix 18) the second EES provides a service area that at least partially overlaps with a service area of ​​the first EES. 18. An edge configuration server according to claim 16 or 17. (Appendix 19) the at least one processor is configured to select the second EES as an alternative server for the first EES in response to receiving the control message. An edge configuration server according to any one of appendixes 16 to 18. (Appendix 20) The control message is an EES registration update request requesting the edge configuration server to update the registration of the first EES. An edge configuration server according to any one of appendix 16 to 19. (Appendix 21) The control message and the service provisioning notification or response indicate a grace period until the first EES cannot be used, or a date and time or a period during which the first EES cannot be used, An edge configuration server according to any one of appendix 16 to 20. (Appendix 22) A method performed by an edge configuration server, comprising: receiving a control message from a first Edge Enabler Server (EES) indicating that the first EES is to be shut down or made unavailable; and In response to receiving the control message, sending a service provisioning notification or response to a User Equipment (UE) prompting the UE to send an Edge Enabler Client (EEC) registration request to a second EES different from the first EES; A method for providing the above. (Appendix 23) A program for causing a computer to execute a method for an edge configuration server, the method comprising: receiving a control message from a first Edge Enabler Server (EES) indicating that the first EES is to be shut down or made unavailable; and In response to receiving the control message, sending a service provisioning notification or response to a User Equipment (UE) prompting the UE to send an Edge Enabler Client (EEC) registration request to a second EES different from the first EES; A program that includes: (Appendix 24) Memory, and coupled to the memory; and receiving a control message from a first Edge Enabler Server (EES) indicating that the first EES is to be shut down or made unavailable; In response to receiving the control message, sending a service provisioning notification or response to a User Equipment (UE) indicating that the first EES is to be shut down or made unavailable. at least one processor configured to An edge configuration server comprising: (Appendix 25) The service provisioning notification or response causes the UE to send an Edge Enabler Client (EEC) registration request to a second EES different from the first EES. 25. An edge configuration server as described in Supplementary Note 24. (Appendix 26) The service provisioning notification or response causes the UE to send an Edge Enabler Client (EEC) deregistration request to the first EES; 25. An edge configuration server as described in Supplementary Note 24. (Appendix 27) The service provisioning notification or response causes the UE to determine whether to send an Edge Enabler Client (EEC) registration request to a second EES or to send an EEC deregistration request to the first EES. 25. An edge configuration server as described in Supplementary Note 24. (Appendix 28) The control message is an EES registration request requesting the edge configuration server to update the registration of the first EES. An edge configuration server according to any one of appendix 24 to 27. (Appendix 29) The control message and the service provisioning notification or response indicate a grace period until the first EES cannot be used, or a date and time or a period during which the first EES cannot be used, An edge configuration server according to any one of appendices 24 to 28. (Appendix 30) A method performed by an edge configuration server, comprising: receiving a control message from a first Edge Enabler Server (EES) indicating that the first EES is to be shut down or made unavailable; and In response to receiving the control message, sending a service provisioning notification or response to a User Equipment (UE) indicating that the first EES is to be shut down or made unavailable; A method for providing the above. (Appendix 31) A program for causing a computer to execute a method for an edge configuration server, the method comprising: receiving a control message from a first Edge Enabler Server (EES) indicating that the first EES is to be shut down or made unavailable; and In response to receiving the control message, sending a service provisioning notification or response to a User Equipment (UE) indicating that the first EES is to be shut down or made unavailable; A program that includes: (Appendix 32) Memory, and coupled to the memory; and receiving a control message from a first edge enabler server (EES) or edge configuration server indicating that the first EES is to be shut down or made unavailable; In response to receiving the control message, sending an edge enabler client (EEC) registration request to a second EES different from the first EES. at least one processor configured to User Equipment (UE) equipped with the (Appendix 33) The at least one processor is configured to determine whether to send the EEC registration request to the second EES or to send an EEC deregistration request to the first EES based on the control message. 32. The UE according to claim 32. (Appendix 34) The control message indicates a grace period until the first EES cannot be used, or a date and time or a period during which the first EES cannot be used, 34. The UE according to claim 32 or 33. (Appendix 35) The control message is a service provisioning notification or response sent by the edge configuration server. 35. The UE according to any one of appendix 32 to 34. (Appendix 36) The control message is transmitted by the first EES. 35. The UE according to any one of appendix 32 to 34. (Appendix 37) The control message is an Edge Enabler Client (EEC) registration update response, an EEC registration response, an EEC deregistration response, an Edge Application Server (EAS) discovery response, or an EAS discovery notification; UE as described in Appendix 36. (Appendix 38) A method performed by a User Equipment (UE), comprising: receiving a control message from a first edge enabler server (EES) or edge configuration server indicating that the first EES is to be shut down or made unavailable; and In response to receiving the control message, sending an edge enabler client (EEC) registration request to a second EES different from the first EES; A method for providing the above. (Appendix 39) A program for causing a computer to perform a method for User Equipment (UE), the method comprising: receiving a control message from a first edge enabler server (EES) or edge configuration server indicating that the first EES is to be shut down or made unavailable; and In response to receiving the control message, sending an edge enabler client (EEC) registration request to a second EES different from the first EES; A program that includes: (Appendix 40) Memory, and coupled to the memory; and receiving a control message from a first edge enabler server (EES) or edge configuration server indicating that the first EES is to be shut down or made unavailable; In response to receiving the control message, sending an edge enabler client (EEC) deregistration request to the first EES. at least one processor configured to User Equipment (UE) equipped with the (Appendix 41) The at least one processor is configured to determine, based on the control message, whether to send an EEC registration request to a second EES different from the first EES or to send the EEC deregistration request to the first EES. 40. The UE according to claim 40. (Appendix 42) The control message indicates a grace period until the first EES cannot be used, or a date and time or a period during which the first EES cannot be used, 42. The UE according to claim 40 or 41. (Appendix 43) The control message is a service provisioning notification or response sent by the edge configuration server. 43. The UE according to any one of appendices 40 to 42. (Appendix 44) The control message is transmitted by the first EES. 43. The UE according to any one of appendices 40 to 42. (Appendix 45) The control message is an Edge Enabler Client (EEC) registration update response, an EEC registration response, an EEC deregistration response, an Edge Application Server (EAS) discovery response, or an EAS discovery notification; 44. The UE described in Appendix 44. (Appendix 46) A method performed by a User Equipment (UE), comprising: receiving a control message from a first edge enabler server (EES) or edge configuration server indicating that the first EES is to be shut down or made unavailable; and In response to receiving the control message, sending an Edge Enabler Client (EEC) deregistration request to the first EES; A method for providing the above. (Appendix 47) A program for causing a computer to perform a method for User Equipment (UE), the method comprising: receiving a control message from a first edge enabler server (EES) or edge configuration server indicating that the first EES is to be shut down or made unavailable; and In response to receiving the control message, sending an Edge Enabler Client (EEC) deregistration request to the first EES; A program that includes:

[0127] This application claims priority based on Japanese Patent Application No. 2021-132616, filed on August 17, 2021, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0128] 1. User Equipment (UE) 2 Edge Enabler Client (EEC) 3 Application client (AC) 4. Edge Data Network (EDN) 5、5A、5B Edge Enabler Server(EES) 6 Edge Application Server (EAS) 7 Edge Configuration Server (ECS) 1403 Baseband Processor 1404 Application Processor 1406 Memory 1407 Module 1502 Processor 1503 Memory 1504 Module

Claims

1. a first edge enabler server (EES), means for transmitting a control message to a User Equipment (UE) indicating that the first EES is to be shut down or made unavailable; First EES.

2. The control message causes the UE to send an Edge Enabler Client (EEC) registration request to a second EES different from the first EES. The first EES of claim 1 .

3. The control message causes the UE to send an Edge Enabler Client (EEC) deregistration request to the first EES. The first EES of claim 1 .

4. The control message causes the UE to determine whether to send an Edge Enabler Client (EEC) registration request to a second EES or to send an EEC deregistration request to the first EES. The first EES of claim 1 .

5. The control message indicates a grace period until the first EES cannot be used, or a date and time or a period until the first EES cannot be used, A first EES according to any one of claims 1 to 4.

6. The control message is an Edge Enabler Client (EEC) registration update response, an EEC registration response, an EEC deregistration response, an Edge Application Server (EAS) discovery response, or an EAS discovery notification. A first EES according to any one of claims 1 to 4.

7. 1. A method performed by a first edge enabler server (EES), comprising: transmitting a control message to a User Equipment (UE) indicating that the first EES is to be shut down or made unavailable. method.

8. A program for causing a computer to perform a method for a first edge enabler server (EES), comprising: The method comprises transmitting a control message to a User Equipment (UE) indicating that the first EES is to be shut down or made unavailable. program.

9. A method for receiving a control message from a first edge enabler server (EES) or an edge configuration server indicating that the first EES is to be shut down or made unavailable; means for sending an edge enabler client (EEC) registration request to a second EES different from the first EES in response to receiving the control message; User Equipment (UE) equipped with

10. The method further comprises: determining whether to send an EEC registration request to the second EES or an EEC deregistration request to the first EES based on the control message. The UE of claim 9.

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