Estimation of router causing silent failure

Abstract

Provided are a router estimation system and a router estimation method that are capable of accurately estimating a router that is the cause of a silent failure in a network slice. A policy manager unit (90) specifies, for each of a plurality of slice communications performed in a communication system, the number of pairs for which the slice communication is included in the pair and for which the degree of correlation reduction associated with the pair satisfies a reduction determination condition. The policy manager unit (90) estimates, as a router that is the cause of a drop in performance of a functional element related to a slice communication, at least one router included in a router group existing on the path of the slice communication, in which the number of identified pairs identified on the basis of router group data satisfies a given number-of-pairs condition.

Description

Identifying the router causing the silent failure

[0001] The present disclosure relates to estimating routers responsible for silent failures.

[0002] Patent Literature 1 describes deploying multiple network functions (NFs) included in a network service (NS) to a server on which a container-type application execution environment is installed, and also describes building a network slice and monitoring the NFs.

[0003] International Publication No. 2021 / 171210

[0004] In a communication system such as that described in Patent Document 1, even if no abnormality is detected in a router, which is a component of the communication system, a degradation in the performance of a functional element (NS, NF, etc.) included in the communication system (so-called silent failure) may occur in communication using a network slice that allows the functional element to be used, but it has been difficult to determine the cause of such silent failure.

[0005] The present disclosure has been made in consideration of the above-mentioned situation, and one of its objectives is to provide a router estimation system and a router estimation method that can accurately estimate the router that is the cause of a silent failure in a network slice.

[0006] A router estimation system according to the present disclosure includes one or more processors, and at least one of the one or more processors executes a router group data storage process, a correlation reduction degree calculation process, a reduction determination process, a pair number identification process, and a router estimation process. In the router group data storage process, router group data indicating the router group constituting each of a plurality of network slices configured in a communication system is stored. In the correlation reduction degree calculation process, a correlation reduction degree is calculated, which is a degree of reduction in the strength of the correlation between a performance index value indicating the performance of a functional element performing one slice communication in one slice communication and a performance index value indicating the performance of a functional element performing the other slice communication in the other slice communication, associated with a pair of slice communication, the slice communication being performed by a functional element included in the communication system using a network slice, and another slice communication being performed by a functional element included in the communication system using a network slice but different from the one slice communication. In the reduction determination process, for each of the plurality of pairs, it is determined whether the correlation reduction degree associated with the pair satisfies a given reduction determination condition. In the pair number determination process, for each of a plurality of slice communications performed in the communication system, the number of pairs including the slice communications and for which the correlation reduction degree associated with the pair satisfies the reduction determination condition is determined. In the router estimation process, at least one router included in a router group present on the path of the slice communications, identified based on the router group data, and for which the number of identified pairs satisfies a given pair number condition, is estimated as the router causing the performance degradation of the functional element related to the slice communications.

[0007] In addition, in a router estimation method according to the present disclosure, for each of multiple network slices constructed in a communication system, router group data indicating the router group constituting the network slice is stored. Furthermore, a correlation reduction degree is calculated for each pair of slice communication, where one slice communication is performed by a functional element included in the communication system using a network slice, and another slice communication is performed by a functional element included in the communication system using a network slice but different from the one slice communication. The correlation reduction degree is the degree of reduction in the strength of the correlation between a performance index value indicating the performance of the functional element performing the one slice communication in the one slice communication and a performance index value indicating the performance of the functional element performing the other slice communication in the other slice communication. For each of the multiple pairs, it is determined whether the correlation reduction degree associated with the pair satisfies a given reduction determination condition. Furthermore, for each of the multiple slice communications performed in the communication system, the number of pairs including the slice communication and for which the correlation reduction degree associated with the pair satisfies the reduction determination condition is identified. Furthermore, at least one router included in a router group located on the path of the slice communication, where the number of identified pairs, identified based on the router group data, satisfies a given pair number condition, is estimated to be the router causing the degradation in performance of the functional element related to the slice communication.

[0008] 1 is a diagram illustrating an example of a communication system according to an embodiment of the present invention. FIG. 1 is a diagram illustrating an example of a communication system according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an example of a network service according to an embodiment of the present invention. FIG. 3 is a diagram illustrating an example of an association between elements established in a communication system according to an embodiment of the present invention. FIG. 4 is a functional block diagram illustrating an example of a function implemented in a platform system according to an embodiment of the present invention. FIG. 5 is a diagram illustrating an example of a data structure of physical inventory data. FIG. 6 is a diagram illustrating an example of a configuration of a group of functional elements that communicate using a network slice. FIG. 7 is a diagram illustrating an example of segment routing path management data. FIG. 8 is a diagram illustrating an example of router group management data. FIG. 9 is a diagram illustrating an example of a data structure of correlation degree data. FIG. 10 is a diagram illustrating an example of a data structure of correlation decrease degree data. FIG. 11 is a diagram illustrating an example of a transition of correlation degree when the correlation decrease degree does not satisfy a decrease determination condition. FIG. 12 is a diagram illustrating an example of a transition of correlation degree when the correlation decrease degree satisfies a decrease determination condition. FIG. 13 is a diagram illustrating an example of a transition of correlation degree when the correlation decrease degree satisfies a decrease determination condition. FIG. 14 is a diagram illustrating an example of a data structure of correlation increase degree data. FIG. 15 is a diagram illustrating an example of a transition of correlation degree when the correlation increase degree satisfies an increase determination condition. FIG. 16 is a flow diagram illustrating an example of a processing flow performed in a platform system according to an embodiment of the present invention.

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0010] 1 and 2 are diagrams illustrating an example of a communication system 1 according to an embodiment of the present invention. Fig. 1 is a diagram focusing on the locations of a group of data centers included in the communication system 1. Fig. 2 is a diagram focusing on various computer systems implemented in the group of data centers included in the communication system 1.

[0011] As shown in FIG. 1 , the data centers included in the communication system 1 are classified into a central data center 10 , regional data centers 12 , and edge data centers 14 .

[0012] For example, several central data centers 10 are distributed and located within the area covered by the communication system 1 (for example, within Japan).

[0013] For example, several tens of regional data centers 12 are distributed and placed within the area covered by the communication system 1. For example, if the area covered by the communication system 1 is the entire country of Japan, one or two regional data centers 12 may be placed in each prefecture.

[0014] For example, several thousand edge data centers 14 are distributed within the area covered by the communication system 1. Each edge data center 14 is capable of communicating with communication equipment 18 equipped with an antenna 16. As shown in FIG. 1 , one edge data center 14 may be capable of communicating with several pieces of communication equipment 18. The communication equipment 18 may include a computer such as a server computer. The communication equipment 18 according to this embodiment performs wireless communication with a UE (User Equipment) 20 via the antenna 16. The communication equipment 18 equipped with the antenna 16 is provided with, for example, a radio unit (RU) (described later).

[0015] In this embodiment, the central data center 10, the regional data center 12, and the edge data center 14 each have a plurality of servers arranged therein.

[0016] In this embodiment, for example, the central data center 10, the regional data centers 12, and the edge data centers 14 are capable of communicating with each other. Furthermore, the central data centers 10, the regional data centers 12, and the edge data centers 14 are also capable of communicating with each other.

[0017] 2, the communication system 1 according to this embodiment includes a platform system 30, multiple radio access networks (RANs) 32, multiple core network systems 34, and multiple UEs 20. The core network systems 34, the RANs 32, and the UEs 20 cooperate with each other to realize a mobile communication network.

[0018] The RAN 32 is a computer system equipped with an antenna 16, which corresponds to an eNodeB (eNB) in a fourth-generation mobile communication system (hereinafter referred to as 4G) or a gNB (NR base station) in a fifth-generation mobile communication system (hereinafter referred to as 5G). The RAN 32 according to this embodiment is mainly implemented by a group of servers and communication equipment 18 arranged in an edge data center 14. Note that part of the RAN 32 (for example, a distributed unit (DU), a central unit (CU), a virtual distributed unit (vDU), and a virtual central unit (vCU)) may be implemented in the central data center 10, the regional data center 12, or the communication equipment 18, rather than in the edge data center 14.

[0019] The core network system 34 is a system equivalent to an EPC (Evolved Packet Core) in 4G or a 5G Core (5GC) in 5G. The core network system 34 according to this embodiment is implemented mainly by a group of servers arranged in the central data center 10 and the regional data centers 12.

[0020] The platform system 30 according to this embodiment is configured, for example, on a cloud platform and includes a processor 30a, a storage unit 30b, and a communication unit 30c, as shown in FIG. 2 . The processor 30a is a program-controlled device such as a microprocessor that operates according to a program installed in the platform system 30. The storage unit 30b is, for example, a storage element such as a ROM or RAM, a solid-state drive (SSD), or a hard disk drive (HDD). The storage unit 30b stores programs executed by the processor 30a. The communication unit 30c is, for example, a communication interface such as a network interface controller (NIC) or a wireless local area network (LAN) module. Note that software-defined networking (SDN) may be implemented in the communication unit 30c. The communication unit 30c exchanges data with the RAN 32 and the core network system 34.

[0021] In this embodiment, the platform system 30 is implemented by a group of servers located in the central data center 10. Note that the platform system 30 may also be implemented by a group of servers located in the regional data centers 12.

[0022] In this embodiment, for example, in response to a purchase request for a network service (NS) by a purchaser, the requested network service is constructed in the RAN 32 or the core network system 34. Then, the constructed network service is provided to the purchaser.

[0023] For example, a purchaser such as an MVNO (Mobile Virtual Network Operator) is provided with network services such as voice communication services and data communication services. The voice communication services and data communication services provided by this embodiment are ultimately provided to customers (end users) of the purchaser (MVNO in the above example) who use the UE 20 shown in Figures 1 and 2. The end users can perform voice communication and data communication with other users via the RAN 32 and the core network system 34. The UE 20 of the end user can also access a data network such as the Internet via the RAN 32 and the core network system 34.

[0024] In addition, in this embodiment, an IoT (Internet of Things) service may be provided to an end user who uses a robot arm, a connected car, etc. In this case, for example, the end user who uses the robot arm, the connected car, etc. may become a purchaser of the network service according to this embodiment.

[0025] In this embodiment, a container-type virtualized application execution environment such as Docker (registered trademark) is installed on servers located in the central data center 10, the regional data centers 12, and the edge data center 14, allowing containers to be deployed and run on these servers. A cluster consisting of one or more containers generated by such virtualization technology may be constructed on these servers. For example, a Kubernetes cluster managed by a container management tool such as Kubernetes (registered trademark) may be constructed. Then, a processor on the constructed cluster may execute a container-type application.

[0026] In this embodiment, the network service provided to the purchaser is composed of one or more functional units (for example, network functions (NFs)). In this embodiment, the functional units are implemented as NFs realized by virtualization technology. NFs realized by virtualization technology are called VNFs (Virtualized Network Functions). It does not matter what virtualization technology is used for virtualization. For example, in this description, a CNF (Containerized Network Function) realized by container-type virtualization technology is also included in the VNF. In this embodiment, the network service is described as being implemented by one or more CNFs. Furthermore, the functional units according to this embodiment may correspond to network nodes.

[0027] Fig. 3 is a diagram illustrating an example of a network service in operation. The network service illustrated in Fig. 3 includes, as software elements, NFs such as a plurality of RUs 40, a plurality of DUs 42, a plurality of CUs 44 (CU-CPs (Central Unit - Control Plane) 44a and CU-UPs (Central Unit - User Plane) 44b), a plurality of AMFs (Access and Mobility Management Functions) 46, a plurality of SMFs (Session Management Functions) 48, and a plurality of UPFs (User Plane Functions) 50.

[0028] In the example of Figure 3, RU 40, DU 42, CU-CP 44a, AMF 46, and SMF 48 correspond to elements of the control plane (C-Plane), and RU 40, DU 42, CU-UP 44b, and UPF 50 correspond to elements of the user plane (U-Plane).

[0029] The network service may include other types of NF as software elements. The network service is implemented on computer resources (hardware elements) such as multiple servers.

[0030] In this embodiment, for example, a communication service in a certain area is provided by the network service shown in FIG.

[0031] In this embodiment, it is assumed that the multiple RUs 40, multiple DUs 42, multiple CU-UPs 44b, and multiple UPFs 50 shown in Figure 3 belong to one end-to-end network slice.

[0032] 4 is a diagram schematically illustrating an example of associations between elements established in the communication system 1 in this embodiment. The symbols M and N shown in FIG. 4 represent any integers equal to or greater than 1, and indicate the relationship between the numbers of elements connected by a link. When both ends of a link are a combination of M and N, the elements connected by the link have a many-to-many relationship, and when both ends of a link are a combination of 1 and N or a combination of 1 and M, the elements connected by the link have a one-to-many relationship.

[0033] As shown in FIG. 4, the network service (NS), network function (NF), CNFC (Containerized Network Function Component), pod, and container have a hierarchical structure.

[0034] The NS corresponds to, for example, a network service configured from a plurality of NFs. Here, the NS may correspond to, for example, a granular element such as 5GC, EPC, 5G RAN (gNB), or 4G RAN (eNB).

[0035] In 5G, NFs correspond to elements with granularity such as RU, DU, CU-CP, CU-UP, AMF, SMF, and UPF. In 4G, NFs correspond to elements with granularity such as MME (Mobility Management Entity), HSS (Home Subscriber Server), S-GW (Serving Gateway), vDU, and vCU. In this embodiment, for example, one NS includes one or more NFs. In other words, one or more NFs are under the control of one NS.

[0036] CNFC corresponds to a granularity element such as DU mgmt or DU Processing, for example. CNFC may be a microservice deployed on a server as one or more containers. For example, a certain CNFC may be a microservice that provides some of the functions of DU, CU-CP, CU-UP, etc. Also, a certain CNFC may be a microservice that provides some of the functions of UPF, AMF, SMF, etc. In this embodiment, for example, one NF includes one or more CNFCs. In other words, one or more CNFCs are under the control of one NF.

[0037] A pod is the smallest unit for managing a Docker container in Kubernetes. In this embodiment, for example, one CNFC includes one or more pods. In other words, one CNFC has one or more pods under its control.

[0038] In this embodiment, for example, one pod includes one or more containers, that is, one or more containers are subordinate to one pod.

[0039] Also, as shown in Figure 4, network slices (NSIs) and network slice subnet instances (NSSIs) have a hierarchical structure.

[0040] The NSI can also be considered an end-to-end virtual circuit spanning multiple domains (e.g., from the RAN 32 to the core network system 34). The NSI may be a slice for high-speed, large-capacity communication (e.g., for enhanced Mobile Broadband (eMBB)), a slice for high-reliability and low-latency communication (e.g., for Ultra-Reliable and Low Latency Communications (URLLC)), or a slice for connecting a large number of terminals (e.g., for massive Machine Type Communication (mMTC)). The NSSI can also be considered a virtual circuit of a single domain obtained by dividing the NSI. The NSSI may be a slice of the RAN domain, a slice of a transport domain such as a Mobile Back Haul (MBH) domain, or a slice of the core network domain.

[0041] In this embodiment, for example, one NSI includes one or more NSSIs. That is, one or more NSSIs are subordinate to one NSI. Note that in this embodiment, multiple NSIs may share the same NSSI.

[0042] Furthermore, as shown in FIG. 4, NSSIs and NSs generally have a many-to-many relationship.

[0043] Furthermore, in this embodiment, for example, one NF can belong to one or more network slices. Specifically, for example, one NF can be configured with NSSAI (Network Slice Selection Assistance Information) including one or more S-NSSAI (Sub Network Slice Selection Assist Information). Here, S-NSSAI is information associated with a network slice. Note that an NF does not necessarily have to belong to a network slice.

[0044] Fig. 5 is a functional block diagram showing an example of functions implemented in the platform system 30 according to this embodiment. Note that the platform system 30 according to this embodiment does not need to implement all of the functions shown in Fig. 5, and functions other than the functions shown in Fig. 5 may also be implemented.

[0045] As shown in FIG. 5 , the platform system 30 according to this embodiment functionally includes, for example, an operations support system (OSS) unit 60, an orchestration (E2EO: End-to-End-Orchestration) unit 62, a service catalog storage unit 64, a big data platform unit 66, a data bus unit 68, an AI (Artificial Intelligence) unit 70, a monitoring function unit 72, an SDN controller 74, a configuration management unit 76, a container management unit 78, and a repository unit 80. The OSS unit 60 includes an inventory database 82, a ticket management unit 84, a fault management unit 86, and a performance management unit 88. The E2EO unit 62 includes a policy manager unit 90, a slice manager unit 92, and a lifecycle management unit 94. These elements are implemented primarily using a processor 30 a, a storage unit 30 b, and a communication unit 30 c.

[0046] The functions shown in Figure 5 may be implemented by installing a program including instructions corresponding to the functions in a platform system 30, which is one or more computers, on the platform system 30 and having the processor 30a execute the program. This program may be supplied to the platform system 30 via a computer-readable information storage medium, such as an optical disk, a magnetic disk, a magnetic tape, a magneto-optical disk, or a flash memory, or via the Internet. The functions shown in Figure 5 may also be implemented using circuit blocks, memory, or other LSIs. Those skilled in the art will understand that the functions shown in Figure 5 can be realized in various forms, such as hardware alone, software alone, or a combination thereof.

[0047] The container management unit 78 manages the life cycle of a container, including processes related to the construction of the container, such as the deployment and configuration of the container.

[0048] Here, the platform system 30 according to the present embodiment may include a plurality of container management units 78. A container management tool such as Kubernetes and a package manager such as Helm may be installed in each of the plurality of container management units 78. Each of the plurality of container management units 78 may execute container construction, such as container deployment, for a server group (e.g., a Kubernetes cluster) associated with the corresponding container management unit 78.

[0049] The container management unit 78 does not need to be included in the platform system 30. The container management unit 78 may be provided, for example, in a server managed by the container management unit 78 (i.e., the RAN 32 or the core network system 34), or may be provided in another server that is annexed to the server managed by the container management unit 78.

[0050] In this embodiment, the repository unit 80 stores, for example, container images of containers included in a group of functional units (for example, a group of NFs) that realize a network service.

[0051] The inventory database 82 is a database that stores inventory information, which includes, for example, information about servers that are placed in the RAN 32 and the core network system 34 and that are managed by the platform system 30.

[0052] In this embodiment, inventory data is stored in the inventory database 82. The inventory data indicates the configuration of the elements included in the communication system 1 and the current status of the associations between the elements. The inventory data also indicates the status of resources managed by the platform system 30 (e.g., resource usage status). The inventory data may be physical inventory data or logical inventory data. Physical inventory data and logical inventory data will be described later.

[0053] Fig. 6 is a diagram showing an example of the data structure of physical inventory data. The physical inventory data shown in Fig. 6 is associated with one server. The physical inventory data shown in Fig. 6 includes, for example, a server ID, location data, building data, floor data, rack data, specification data, network data, an operating container ID list, a cluster ID, and the like.

[0054] The server ID included in the physical inventory data is, for example, an identifier of the server associated with the physical inventory data.

[0055] The location data included in the physical inventory data is, for example, data indicating the location (for example, the address of the location) of the server associated with the physical inventory data.

[0056] The building data included in the physical inventory data is, for example, data indicating the building (for example, the building name) in which the server associated with the physical inventory data is located.

[0057] The floor number data included in the physical inventory data is, for example, data indicating the floor number on which the server associated with the physical inventory data is located.

[0058] The rack data included in the physical inventory data is, for example, an identifier of the rack in which the server associated with the physical inventory data is located.

[0059] The specification data included in the physical inventory data is, for example, data indicating the specifications of the server associated with the physical inventory data, and the specification data indicates, for example, the number of cores, memory capacity, hard disk capacity, etc.

[0060] The network data included in the physical inventory data is, for example, data indicating information about the network of the server associated with the physical inventory data, and the network data indicates, for example, the NIC equipped in the server, the number of ports equipped in the NIC, the port ID of the port, etc.

[0061] The operating container ID list included in the physical inventory data is, for example, data that indicates information about one or more containers operating on a server associated with the physical inventory data, and the operating container ID list indicates, for example, a list of identifiers (container IDs) of instances of the containers.

[0062] The cluster ID included in the physical inventory data is, for example, an identifier of the cluster (for example, a Kubernetes cluster) to which the server associated with the physical inventory data belongs.

[0063] The logical inventory data includes topology data indicating the current state of associations between multiple elements included in the communication system 1, such as those shown in Figure 4. For example, the logical inventory data includes topology data including an identifier of a certain NS and identifiers of one or more NFs under the NS. Also, for example, the logical inventory data includes topology data including an identifier of a certain network slice and identifiers of one or more NFs belonging to the network slice.

[0064] The inventory data may also include data indicating the current status of geographical relationships and topological relationships between elements included in the communication system 1. As described above, the inventory data includes location data indicating the locations where the elements included in the communication system 1 are operating, i.e., the current locations of the elements included in the communication system 1. From this, it can be said that the inventory data indicates the current status of the geographical relationships between elements (e.g., the geographical proximity between elements).

[0065] The logical inventory data may also include NSI data indicating information about the network slice. The NSI data indicates attributes such as an identifier of an instance of the network slice and a type of the network slice. The logical inventory data may also include NSSI data indicating information about the network slice subnet. The NSSI data indicates attributes such as an identifier of an instance of the network slice subnet and a type of the network slice subnet.

[0066] The logical inventory data may also include NS data indicating information about NS. The NS data indicates attributes such as an NS instance identifier and an NS type, for example. The logical inventory data may also include NF data indicating information about NF. The NF data indicates attributes such as an NF instance identifier and an NF type, for example. The logical inventory data may also include CNFC data indicating information about CNFC. The CNFC data indicates attributes such as an instance identifier and a CNFC type, for example. The logical inventory data may also include pod data indicating information about pods included in the CNFC. The pod data indicates attributes such as a pod instance identifier and a pod type, for example. The logical inventory data may also include container data indicating information about containers included in the pod. The container data indicates attributes such as a container ID of a container instance and a container type, for example.

[0067] The container ID of the container data included in the logical inventory data and the container ID included in the operating container ID list included in the physical inventory data associate a container instance with the server on which the container instance is running.

[0068] Furthermore, the logical inventory data may include data indicating various attributes such as a host name and an IP address. For example, the container data may include data indicating an IP address of a container corresponding to the container data. For example, the NF data may include data indicating an IP address and a host name of the NF indicated by the NF data.

[0069] The logical inventory data may also include data indicating an NSSAI, including one or more S-NSSAIs, that is set in each NF.

[0070] The inventory database 82 is also able to grasp the resource status as needed in cooperation with the container management unit 78. The inventory database 82 then updates the inventory data stored therein as needed based on the latest resource status.

[0071] In addition, in response to actions being performed, such as constructing a new element included in the communication system 1, changing the configuration of an element included in the communication system 1, scaling an element included in the communication system 1, or replacing an element included in the communication system 1, the inventory database 82 updates the inventory data stored in the inventory database 82.

[0072] The service catalog storage unit 64 stores service catalog data. The service catalog data may include, for example, service template data indicating logic used by the life cycle management unit 94. This service template data includes information necessary for building a network service. For example, the service template data includes information defining NS, NF, and CNFC, and information indicating the correspondence between NS, NF, and CNFC. Furthermore, for example, the service template data includes a workflow script for building a network service.

[0073] An example of service template data is an NSD (NS Descriptor). The NSD is associated with a network service and indicates the types of multiple functional units (e.g., multiple CNFs) included in the network service. The NSD may also indicate the number of each type of functional unit, such as a CNF, included in the network service. The NSD may also indicate the file name of a CNFD (described later) related to the CNF included in the network service.

[0074] An example of service template data is a CNF Descriptor (CNFD). The CNFD may indicate computer resources (e.g., a CPU, memory, hard disk, etc.) required by the CNF. For example, the CNFD may indicate, for each of multiple containers included in the CNF, the computer resources (e.g., a CPU, memory, hard disk, etc.) required by the container.

[0075] The service catalog data may also include information about thresholds (for example, anomaly detection thresholds) that are used by the policy manager 90 to compare with the calculated performance index values. The performance index values ​​will be described later.

[0076] The service catalog data may also include, for example, slice template data, which includes information necessary to perform instantiation of a network slice, including, for example, logic utilized by the slice manager unit 92.

[0077] The slice template data includes information on the "Generic Network Slice Template" defined by the GSM Association (GSMA) ("GSM" is a registered trademark). Specifically, the slice template data includes network slice template data (NST), network slice subnet template data (NSST), and network service template data. The slice template data also includes information indicating the hierarchical structure of these elements, as shown in FIG. 4.

[0078] In this embodiment, for example, the life cycle management unit 94 constructs a new network service in response to a purchase request for an NS from a purchaser.

[0079] For example, in response to a purchase request, the lifecycle management unit 94 may execute a workflow script associated with the network service to be purchased. By executing this workflow script, the lifecycle management unit 94 may instruct the container management unit 78 to deploy a container included in the new network service to be purchased. The container management unit 78 may then obtain a container image of the container from the repository unit 80 and deploy the container corresponding to the container image to a server.

[0080] In addition, in this embodiment, the life cycle management unit 94 executes, for example, scaling and replacement of elements included in the communication system 1. Here, the life cycle management unit 94 may output a container deployment instruction or deletion instruction to the container management unit 78. Then, the container management unit 78 may execute processing such as container deployment or container deletion in accordance with the instruction. In this embodiment, the life cycle management unit 94 is capable of executing scaling and replacement that cannot be handled by a tool such as Kubernetes in the container management unit 78.

[0081] Furthermore, the life cycle management unit 94 may output an instruction to create a communication path to the SDN controller 74. For example, the life cycle management unit 94 presents two IP addresses at both ends of the communication path to be created to the SDN controller 74, and the SDN controller 74 creates a communication path connecting these two IP addresses. The created communication path may be managed in association with these two IP addresses.

[0082] Furthermore, the life cycle management unit 94 may output to the SDN controller 74 an instruction to create a communication path between the two IP addresses that is associated with the two IP addresses.

[0083] In this embodiment, for example, the slice manager unit 92 performs instantiation of a network slice. In this embodiment, for example, the slice manager unit 92 performs instantiation of a network slice by executing logic indicated by a slice template stored in the service catalog storage unit 64.

[0084] The slice manager unit 92 is configured to include the functions of the NSMF (Network Slice Management Function) and the NSSMF (Network Slice Sub-network Management Function), for example, as described in the specification "TS28 533" of the 3GPP (registered trademark) (Third Generation Partnership Project). The NSMF is a function that generates and manages network slices and provides NSI management services. The NSSMF is a function that generates and manages network slice subnets that constitute part of the network slice and provides NSSI management services.

[0085] Here, the slice manager unit 92 may output a configuration management instruction related to the instantiation of the network slice to the configuration management unit 76. Then, the configuration management unit 76 may perform configuration management such as setting in accordance with the configuration management instruction.

[0086] The slice manager unit 92 may also present two IP addresses to the SDN controller 74 and output an instruction to create a communication path between these two IP addresses.

[0087] In this embodiment, the configuration management unit 76 performs configuration management such as setting of element groups such as NFs in accordance with configuration management instructions received from the life cycle management unit 94 and the slice manager unit 92, for example.

[0088] In this embodiment, the SDN controller 74 creates a communication path between two IP addresses associated with a communication path creation instruction received from, for example, the life cycle management unit 94 or the slice manager unit 92. The SDN controller 74 may create a communication path between two IP addresses using a known path calculation method such as Flex Algo.

[0089] Here, for example, the SDN controller 74 may use a segment routing technology (for example, SRv6 (Segment Routing IPv6)) to construct NSIs and NSSIs for aggregation routers, servers, and the like present along the communication paths. Furthermore, the SDN controller 74 may generate NSIs and NSSIs across multiple NFs to be configured by issuing commands to configure a common VLAN (Virtual Local Area Network) for multiple NFs to be configured, and commands to assign the bandwidth and priority indicated in the configuration information to the VLAN.

[0090] In addition, the SDN controller 74 may perform operations such as changing the maximum bandwidth available for communication between two IP addresses without constructing a network slice.

[0091] The platform system 30 according to this embodiment may include multiple SDN controllers 74. Each of the multiple SDN controllers 74 may execute processing such as creating a communication path for a group of network devices, such as an aggregation router, associated with the SDN controller 74.

[0092] In this embodiment, the SDN controller 74 may also change the created communication path as appropriate. For example, the SDN controller 74 may detect the occurrence of a failure in a network device associated with the SDN controller 74, and in response to the detection, change the communication path that passes through the network device created by the SDN controller 74 to a communication path that does not pass through the network device.

[0093] Furthermore, the life cycle management unit 94 or the slice manager unit 92 may output a communication path change instruction to the SDN controller 74. Then, the SDN controller 74 may change the communication path created by the SDN controller 74 in accordance with the change instruction.

[0094] For example, the life cycle management unit 94 or the slice manager unit 92 may output to the SDN controller 74 an instruction to change the communication path associated with the identifier of the network device to be excluded from the communication path. Then, in response to receiving the change instruction, the SDN controller 74 may change the communication path created by the SDN controller 74 to a communication path that excludes the network device identified by the identifier associated with the change instruction (i.e., a communication path that does not pass through the network device identified by the identifier associated with the change instruction).

[0095] In this embodiment, for example, the monitoring function unit 72 monitors the group of elements included in the communication system 1 in accordance with a given management policy. Here, the monitoring function unit 72 may monitor the group of elements in accordance with a monitoring policy specified by a purchaser when purchasing a network service, for example.

[0096] In this embodiment, the monitoring function unit 72 performs monitoring at various levels, such as the slice level, the NS level, the NF level, the CNFC level, and the hardware level of a server or the like.

[0097] For example, in order to perform monitoring at the various levels described above, the monitoring function unit 72 may set a module that outputs metric data in hardware such as a server or in a software element included in the communication system 1. Here, for example, an NF may output metric data indicating metrics that are measurable (identifiable) in the NF to the monitoring function unit 72. Also, a server may output metric data indicating metrics related to hardware that is measurable (identifiable) in the server to the monitoring function unit 72.

[0098] Furthermore, for example, the monitoring function unit 72 may deploy a sidecar container on the server that aggregates metric data indicating metrics output from multiple containers on a CNFC (microservice) basis. This sidecar container may include an agent called an exporter. The monitoring function unit 72 may repeatedly execute, at a given monitoring interval, a process of acquiring metric data aggregated on a microservice basis from the sidecar container using a mechanism of a monitoring tool such as Prometheus, which can monitor container management tools such as Kubernetes.

[0099] The monitoring function unit 72 may monitor performance indicator values ​​for performance indicators described in, for example, “TS 28.552, Management and orchestration; 5G performance measurements” or “TS 28.554, Management and orchestration; 5G end to end Key Performance Indicators (KPI).” Then, the monitoring function unit 72 may acquire metric data indicating the monitored performance indicator values.

[0100] In this embodiment, the monitoring function unit 72 performs a process (enrichment) of aggregating metric data, for example, in a predetermined aggregation unit, thereby generating performance index value data indicating the performance index values ​​of the elements included in the communication system 1 in that aggregation unit.

[0101] For example, for one gNB, performance index value data for the gNB is generated by aggregating metric data indicating the metrics of elements (e.g., network nodes such as DU42 and CU44) under the control of the gNB. In this way, performance index value data indicating communication performance in the area covered by the gNB is generated. Here, for example, performance index value data indicating multiple types of communication performance, such as traffic volume (throughput) and latency, may be generated for each gNB. Furthermore, performance index value data indicating the communication performance of a certain element (e.g., DU42) for a predetermined period may be generated by aggregating metric data indicating the metrics of the element for the predetermined period. Note that the communication performance indicated by the performance index value data is not limited to traffic volume and latency.

[0102] Then, the monitoring function unit 72 outputs the performance index value data generated by the above-mentioned enrichment to the data bus unit 68.

[0103] In this embodiment, for example, the data bus unit 68 receives performance index value data output from the monitoring function unit 72. Then, based on the received one or more pieces of performance index value data, the data bus unit 68 generates a performance index value file including the one or more pieces of performance index value data. Then, the data bus unit 68 outputs the generated performance index value file to the big data platform unit 66.

[0104] In addition, elements such as network slices, NS, NF, CNFC, etc. included in the communication system 1, and hardware such as servers, notify the monitoring function unit 72 of various alerts (for example, notification of an alert triggered by the occurrence of a failure).

[0105] Then, for example, when the monitoring function unit 72 receives the above-mentioned alert notification, it outputs alert message data indicating the notification to the data bus unit 68. Then, the data bus unit 68 generates an alert file in which alert message data indicating one or more notifications are compiled into a single file, and outputs the alert file to the big data platform unit 66.

[0106] In this embodiment, the big data platform unit 66 accumulates, for example, performance index value files and alert files output from the data bus unit 68 .

[0107] In this embodiment, for example, a plurality of trained machine learning models are stored in advance in the AI ​​unit 70. The AI ​​unit 70 uses the various machine learning models stored in the AI ​​unit 70 to perform estimation processing such as future prediction processing of the usage status and service quality of the communication system 1. The AI ​​unit 70 may generate estimation result data indicating the results of the estimation processing.

[0108] The AI ​​unit 70 may perform estimation processing based on the files stored in the big data platform unit 66 and the above-mentioned machine learning model. This estimation processing is suitable for low-frequency prediction of long-term trends.

[0109] The AI ​​unit 70 is also capable of acquiring performance index value data stored in the data bus unit 68. The AI ​​unit 70 may perform estimation processing based on the performance index value data stored in the data bus unit 68 and the above-described machine learning model. This estimation processing is suitable for performing short-term predictions frequently.

[0110] In this embodiment, for example, the performance management unit 88 calculates a performance index value (e.g., KPI) based on metrics indicated by multiple metric data. The performance management unit 88 may calculate a performance index value that is an overall evaluation of multiple types of metrics (e.g., a performance index value related to an end-to-end network slice) that cannot be calculated from a single metric data. The performance management unit 88 may generate overall performance index value data that indicates the performance index value that is the overall evaluation.

[0111] The performance management unit 88 may acquire the above-mentioned performance index value file from the big data platform unit 66. The performance management unit 88 may also acquire estimation result data from the AI ​​unit 70. Then, performance index values ​​such as KPIs may be calculated based on at least one of the performance index value file and the estimation result data. The performance management unit 88 may also directly acquire metric data from the monitoring function unit 72. Then, performance index values ​​such as KPIs may be calculated based on the metric data.

[0112] In this embodiment, the fault management unit 86 detects the occurrence of a fault in the communication system 1 based on, for example, at least one of the above-mentioned metric data, the above-mentioned alert notification, the above-mentioned estimation result data, and the above-mentioned overall performance index value data. The fault management unit 86 may detect the occurrence of a fault that cannot be detected from a single piece of metric data or a single alert notification, for example, based on a predetermined logic. The fault management unit 86 may generate detected fault data that indicates the detected fault.

[0113] The fault management unit 86 may obtain metric data and alert notifications directly from the monitoring function unit 72. The fault management unit 86 may also obtain performance index value files and alert files from the big data platform unit 66. The fault management unit 86 may also obtain alert message data from the data bus unit 68.

[0114] In this embodiment, the policy manager unit 90 executes a predetermined judgment process based on, for example, at least one of the above-mentioned metric data, the above-mentioned performance index value data, the above-mentioned alert message data, the above-mentioned performance index value file, the above-mentioned alert file, the above-mentioned estimation result data, the above-mentioned overall performance index value data, and the above-mentioned detected fault data.

[0115] The policy manager unit 90 may then execute an action according to the result of the determination process. For example, the policy manager unit 90 may output an instruction to construct a network slice to the slice manager unit 92. Also, for example, the policy manager unit 90 may output an instruction to switch a communication path to the slice manager unit 92. Also, the policy manager unit 90 may output an instruction to scale or replace an element to the life cycle management unit 94 according to the result of the determination process.

[0116] The policy manager unit 90 according to this embodiment is capable of acquiring performance index value data stored in the data bus unit 68. The policy manager unit 90 may then execute a predetermined determination process based on the performance index value data acquired from the data bus unit 68. The policy manager unit 90 may also execute a predetermined determination process based on alert message data stored in the data bus unit 68.

[0117] In this embodiment, for example, the ticket management unit 84 generates a ticket indicating the content to be notified to the administrator of the communication system 1. The ticket management unit 84 may generate a ticket indicating the content of the occurred fault data. The ticket management unit 84 may also generate a ticket indicating the value of performance index data or metric data. The ticket management unit 84 may also generate a ticket indicating the determination result by the policy manager unit 90.

[0118] Then, the ticket management unit 84 notifies the administrator of the communication system 1 of the generated ticket. For example, the ticket management unit 84 may send an email with the generated ticket attached to the email address of the administrator of the communication system 1.

[0119] In the communication system 1 according to the present embodiment, a degradation in performance such as NS or NF (so-called silent failure) may occur without an abnormality such as a failure being detected.

[0120] An example of a response to the occurrence of a silent failure, which is executed in the platform system 30 according to this embodiment, will be described below. In the following description, elements that implement a communication function, such as an NS or an NF, will be referred to as functional elements.

[0121] A plurality of network slices are constructed in the communication system 1 according to the present embodiment. A separate group of routers is set as a component for each of the plurality of network slices constructed in the communication system 1 according to the present embodiment. Here, a common router may be set as a component for the plurality of network slices.

[0122] Figure 7 is a diagram schematically showing an example of the configuration of a group of functional elements that communicate using one of the multiple network slices constructed in the communication system 1 of this embodiment.

[0123] The network slice shown in FIG. 7 includes multiple segment routing paths 100 as components. As such, in this embodiment, each of multiple network slices constructed in the communication system 1 may include one or multiple segment routing paths 100 as components. In the segment routing path 100, packet forwarding by segment routing (for example, packet forwarding by SRv6 or SRMPLS (Segment Routing Multi-Protocol Label Switching)) is performed. Each of the multiple segment routing paths 100 may include a router group as a component. Here, a common router may be set as a component in the multiple segment routing paths 100.

[0124] In this embodiment, each of the functional elements included in the communication system 1 can use one or more network slices that are at least a part of the multiple network slices constructed in the communication system 1. The functional elements included in the communication system 1 can perform communication using the network slices available to the functional elements. Hereinafter, communication performed by a functional element using the network slices available to the functional elements will be referred to as slice communication.

[0125] In the example of Figure 7, a group of functional elements that communicate using a network slice includes multiple UPFs 50 (50a, 50b, 50c, ...) and multiple gNBs 102 (102a, 102b, 102c, ...). The gNB 102 includes a DU 42 and a CU 44. Note that the group of functional elements that communicate using the network slice may also include other types of functional elements (e.g., an AMF 46, an SMF 48, etc.).

[0126] In the communication system 1 according to this embodiment, the router group constituting each of the multiple network slices constructed in the communication system 1 is managed. Here, for example, the inventory database 82 may store router group data indicating the router group constituting each of the multiple network slices constructed in the communication system 1.

[0127] The router group data according to this embodiment may include, for example, the segment routing path management data exemplified in FIG. 8 and the router group management data exemplified in FIG. 9 .

[0128] The segment routing path management data in this embodiment is, for example, data indicating one or more segment routing paths 100 through which packets are forwarded in communication performed by a functional element using a network slice available to the functional element.

[0129] As shown in FIG. 8, the segment routing path management data includes, for example, a functional element ID, a slice ID, and a segment routing path ID list.

[0130] In the segment routing path management data, a functional element ID, which is an identifier of a functional element, is associated with a slice ID, which is an identifier of a network slice that the functional element can use. Also, the segment routing path management data is associated with a segment routing path ID list, which is a list of identifiers (segment routing path IDs) of segment routing paths 100 through which packets are forwarded in communication performed by the functional element using the network slice.

[0131] Here, the identifiers of gNB102a, gNB102b, and gNB102c are assumed to be "gNB001", "gNB002", and "gNB003", respectively.

[0132] In this case, the segment routing path management data shown in Figure 8 indicates that gNB 102a, gNB 102b, and gNB 102c can all use multiple network slices, including three network slices with slice IDs "001," "002," and "003," respectively. Note that the available network slices do not need to be common to all functional elements. The available network slices may differ depending on the functional element.

[0133] Hereinafter, the network slice with a slice ID of "001" will be referred to as network slice A. The network slice with a slice ID of "002" will be referred to as network slice B. The network slice with a slice ID of "003" will be referred to as network slice C.

[0134] For example, when gNB102a performs slice communication using network slice A, communication is performed using a segment routing path 100 whose segment routing path ID is one of "001", "002", "003", etc. Furthermore, when gNB102a performs slice communication using network slice B, communication is performed using a segment routing path 100 whose segment routing path ID is one of "011", "012", "013", etc. Furthermore, when gNB102a performs slice communication using network slice C, communication is performed using a segment routing path 100 whose segment routing path ID is one of "021", "022", "023", etc.

[0135] Furthermore, when gNB102b performs slice communication using network slice A, communication is performed using a segment routing path 100 whose segment routing path ID is one of "101", "102", "103", etc. Furthermore, when gNB102b performs slice communication using network slice B, communication is performed using a segment routing path 100 whose segment routing path ID is one of "111", "112", "113", etc. Furthermore, when gNB102b performs slice communication using network slice C, communication is performed using a segment routing path 100 whose segment routing path ID is one of "121", "122", "123", etc.

[0136] Furthermore, when gNB102c performs slice communication using network slice A, communication is performed using a segment routing path 100 whose segment routing path ID is one of "201", "202", "203", etc. Furthermore, when gNB102c performs slice communication using network slice B, communication is performed using a segment routing path 100 whose segment routing path ID is one of "211", "212", "213", etc. Furthermore, when gNB102c performs slice communication using network slice C, communication is performed using a segment routing path 100 whose segment routing path ID is one of "221", "222", "223", etc.

[0137] The router group management data according to this embodiment is, for example, data indicating, for each of a plurality of segment routing paths 100, a route group that is a component of the segment routing path 100.

[0138] 9, the router group management data includes, for example, a segment routing path ID and a router ID list. The segment routing path ID is an identifier of the segment routing path 100. As described above, the segment routing path ID corresponds to an element of the segment routing path ID list included in the segment routing path management data. In the router group management data, the segment routing path ID is associated with a router ID list, which is a list of identifiers (router IDs) of routers that are components of the segment routing path 100 identified by the segment routing path ID.

[0139] 9 indicates that the identifiers of multiple routers that configure a segment routing path 100 having a segment routing path ID of "011" are "10000," "10001," "10002," ..., "20001," "20002," .... The router group management data also indicates that the identifiers of multiple routers that configure a segment routing path 100 having a segment routing path ID of "012" are "10000," "10011," "10012," .... The router group management data also indicates that the identifiers of multiple routers that configure a segment routing path 100 having a segment routing path ID of "013" are "10000," "10021," "10022," ....

[0140] It also shows that the identifiers of multiple routers that make up the segment routing path 100 whose segment routing path ID is "101" are "11000", "11001", "11002", .... It also shows that the identifiers of multiple routers that make up the segment routing path 100 whose segment routing path ID is "102" are "11000", "11011", "11012", ..., "20001", "20002", .... It also shows that the identifiers of multiple routers that make up the segment routing path 100 whose segment routing path ID is "103" are "11000", "11021", "11022", ....

[0141] It also shows that the identifiers of multiple routers that make up the segment routing path 100 whose segment routing path ID is "221" are "12000", "12001", "12002", .... It also shows that the identifiers of multiple routers that make up the segment routing path 100 whose segment routing path ID is "222" are "12000", "12011", "12012", .... It also shows that the identifiers of multiple routers that make up the segment routing path 100 whose segment routing path ID is "223" are "12000", "12021", "12022", ..., "20001", "20003", ....

[0142] 9, a router with a router ID of "20001" is a common component of three segment routing paths 100 whose segment routing path IDs are "011", "102", and "223". Also, a router with a router ID of "20002" is a common component of two segment routing paths 100 whose segment routing path IDs are "011" and "102".

[0143] In addition, in this embodiment, as described above, the slice manager unit 92, the life cycle management unit 94, or the SDN controller 74 may change the segment routing path 100, which is a component of the network slice, or the router, which is a component of the segment routing path 100.

[0144] In this embodiment, in response to such changes in components, the router group data stored in the inventory database 82 (for example, the segment routing path management data shown in FIG. 8 and the router group management data shown in FIG. 9) is updated.

[0145] Therefore, by referring to the router group data, it is possible to identify the segment routing path 100, which is a current component of the network slice, and the router group, which is a current component of the segment routing path 100.

[0146] In this embodiment, for example, the monitoring function unit 72 monitors the performance of each of the multiple functional elements included in the communication system 1 in slice communication using the network slice for each network slice in which the functional element is available.

[0147] Specifically, for example, the performance of gNB 102a in slice communication using network slice A, the performance of gNB 102a in slice communication using network slice B, the performance of gNB 102a in slice communication using network slice C, the performance of gNB 102b in slice communication using network slice A, the performance of gNB 102b in slice communication using network slice B, the performance of gNB 102b in slice communication using network slice C, the performance of gNB 102c in slice communication using network slice A, the performance of gNB 102c in slice communication using network slice B, and the performance of gNB 102c in slice communication using network slice C are monitored.

[0148] Then, for each network slice in which a functional element is available, the monitoring function unit 72 generates performance index value data indicating the performance of the functional element in slice communication using the network slice over a most recent period of a predetermined length (for example, the most recent 15 minutes), for example, at predetermined time intervals (for example, 15-minute intervals).The monitoring function unit 72 then outputs the generated performance index value data to the data bus unit 68 at the time intervals, for example.

[0149] For example, when performance index value data indicating performance during a certain period is generated, the performance index value data associated with that period may be output to the data bus unit 68. For example, performance index value data associated with period data indicating the start and end of that period may be output to the data bus unit 68.

[0150] Then, in response to the performance index value data being output to the data bus unit 68, the policy manager unit 90 may acquire the output performance index value data.

[0151] Examples of performance indicated by the performance index value data include throughput, number of bearer connections, number of attachments, and communication speed (bandwidth). Furthermore, a comprehensive value (e.g., a linear combination value of multiple types of performance index values) calculated based on performance index values ​​indicating multiple types of performance (e.g., throughput and number of bearer connections) may be used as the value of the performance index value data. Note that the performance indicated by the performance index value data is not limited to those described above.

[0152] In this embodiment, for example, the policy manager unit 90 selects a pair of one slice communication, which is a slice communication performed by any functional element included in the communication system 1 using any network slice, and the other slice communication, which is a slice communication performed by any functional element included in the communication system 1 using any network slice and is different from the one slice communication. In other words, two different slice communications are selected to form a pair.

[0153] In addition, the network slice in which the one slice communication is performed may be the same network slice in which the other slice communication is performed. For example, the one slice communication may be slice communication performed by gNB102a using network slice A, and the other slice communication may be slice communication performed by gNB102b using network slice A.

[0154] Alternatively, the network slice in which the one slice communication is performed may be a different network slice from the network slice in which the other slice communication is performed. For example, the one slice communication may be slice communication performed by gNB102a using network slice B, and the other slice communication may be slice communication performed by gNB102b using network slice A.

[0155] Then, the policy manager unit 90 acquires, for example, a plurality of performance index value data each indicating a performance index value indicating the performance of the functional element performing one slice communication in the one slice communication during a period of a specified length of time immediately preceding, and a plurality of performance index value data each indicating a performance index value indicating the performance of the functional element performing the other slice communication in the other slice communication.

[0156] Hereinafter, a performance index value data group including a plurality of performance index value data each indicating a performance index value that indicates the performance of a functional element that performs one slice communication in the one slice communication will be referred to as a first performance index value data group, and a performance index value data group including a plurality of performance index value data each indicating a performance index value that indicates the performance of a functional element that performs the other slice communication in the other slice communication will be referred to as a second performance index value data group.

[0157] For example, if the specified time length is three hours and performance index value data is acquired at 15-minute intervals, the first performance index value data group and the second performance index value data group will each contain 12 performance index value data.

[0158] Here, the period to which each of the multiple performance index value data included in the first performance index value data group is associated is the same period to which each of the multiple performance index value data included in the second performance index value data group is associated.

[0159] Then, the policy manager unit 90 calculates a correlation degree (e.g., a correlation coefficient) indicating the strength of the correlation between the performance index values ​​indicated by the multiple performance index value data included in the first performance index value data group and the performance index values ​​indicated by the multiple performance index value data included in the second performance index value data group.

[0160] The length of the period from the start of the earliest associated performance index value data among the plurality of performance index value data included in the first performance index value data group to the end of the latest associated performance index value data corresponds to the above-mentioned predetermined time length. Similarly, the length of the period from the start of the earliest associated performance index value data among the plurality of performance index value data included in the second performance index value data group to the end of the latest associated performance index value data corresponds to the above-mentioned predetermined time length. The calculated correlation degree is associated with the period, which is the predetermined time length.

[0161] Then, the policy manager unit 90 generates correlation data, an example of which data structure is shown in FIG. 10, based on the calculated correlation.

[0162] As shown in FIG. 10, the correlation data associates, for example, a first slice communication ID, a second slice communication ID, and date and time data.

[0163] For example, the correlation data is set to the value of the correlation calculated as described above.

[0164] The first slice communication ID is an identifier of the one slice communication. The first slice communication ID includes, for example, a combination of a first functional element ID, which is an identifier of a functional element that performs the one slice communication, and a first slice ID, which is an identifier of a network slice in which the one slice communication is performed.

[0165] The second slice communication ID is an identifier of the other slice communication. The second slice communication ID includes, for example, a combination of a second functional element ID, which is an identifier of a functional element that performs the other slice communication, and a second slice ID, which is an identifier of a network slice through which the other slice communication is performed.

[0166] The date and time data is, for example, data indicating a date and time representing a period associated with the correlation indicated by the correlation data. Here, for example, the date and time data may indicate the date and time that is the end or start of the period associated with the correlation. Alternatively, the date and time data may indicate the date and time that is the start and end of the period associated with the correlation.

[0167] In this embodiment, for example, correlation data is generated for each pair of slice communications performed by one of the multiple functional elements included in the communication system 1 using one of the network slices. Hereinafter, a pair of slice communications performed by one of the multiple functional elements included in the communication system 1 using one of the network slices will also be referred to as a slice communication pair.

[0168] The timing of generating the correlation data is not particularly limited. For example, correlation data may be generated based on the latest multiple performance index value data each time performance index value data is acquired. In this case, the periods associated with the correlations indicated by the sequentially generated correlation data will partially overlap.

[0169] Alternatively, the correlation data may be generated based on the latest performance index value data at intervals corresponding to the length of the period associated with the correlation. For example, in the above example, the correlation data may be generated every three hours. In this case, the periods associated with the correlations indicated by the sequentially generated correlation data do not overlap.

[0170] The policy manager unit 90 then calculates a correlation decrease degree, which is the degree of decrease in the strength of the correlation between a performance index value indicating the performance of the functional element performing one slice communication in one slice communication and a performance index value indicating the performance of the functional element performing the other slice communication in the other slice communication, associated with a pair of slice communication, which is slice communication performed by one functional element included in the communication system 1 using one network slice and another slice communication, which is a slice communication performed by one functional element included in the communication system 1 using one network slice but different from the one slice communication. For example, the correlation decrease degree, which is the degree of decrease in the strength of the correlation between the performance index values, is calculated based on multiple correlation data that are associated with the same first slice communication ID and second slice communication ID and are generated in consecutive order. Here, the correlation decrease degree may be the degree of decrease in the correlation coefficient of the performance index values.

[0171] Here, the policy manager unit 90 may calculate the correlation reduction value corresponding to the combination of a specific first slice communication ID and a specific second slice communication ID by subtracting the value of the correlation data whose associated date and time data indicates the most recent date and time from the value of the correlation data whose associated date and time data indicates the second most recent date and time, among the multiple correlation data associated with the specific first slice communication ID and the specific second slice communication ID.

[0172] Alternatively, the policy manager unit 90 may extract a predetermined number of correlation data from among the multiple correlation data associated with the first slice communication ID and the second slice communication ID, in order from the data with the most recent date and time indicated by the date and time data. The policy manager unit 90 may then calculate the average value and standard deviation of the extracted correlation data values. Hereinafter, the value obtained by subtracting twice the calculated standard deviation from the calculated average value will be referred to as v1. That is, if the calculated average value is m and the calculated standard deviation is s, then the value v1 corresponds to the value (m-2s).

[0173] Then, the policy manager unit 90 may calculate the value of the correlation reduction degree corresponding to the combination of the first slice communication ID and the second slice communication ID by subtracting the value of the correlation data whose date and time indicated by the associated date and time data is the most recent from value v1.

[0174] Furthermore, the policy manager unit 90 may extract correlation data whose values ​​are smaller than the above-mentioned value v1 from a predetermined number of correlation data associated with the first slice communication ID and the second slice communication ID, in descending order of the date and time indicated by the associated date and time data.The policy manager unit 90 may then calculate the sum of values ​​obtained by subtracting the value of the correlation data from the value v1 for at least one of the extracted correlation data as the correlation decrease value corresponding to the combination of the first slice communication ID and the second slice communication ID.

[0175] It should be noted that examples of the correlation decrease degree are not limited to those described above.

[0176] Then, the policy manager unit 90 may generate correlation decrease degree data, an example of which data structure is shown in FIG. 11, based on the correlation decrease degree calculated as described above.

[0177] As shown in FIG. 11, the correlation decrease degree data is associated with, for example, a first slice communication ID, a second slice communication ID, and date and time data.

[0178] The correlation decrease degree data is set to, for example, the value of the correlation decrease degree calculated as described above.

[0179] The first slice communication ID and the second slice communication ID are set to, for example, a first slice communication ID and a specific second slice communication ID corresponding to the correlation decrease degree, respectively.

[0180] For example, when a correlation decrease degree is calculated based on a plurality of correlation degree data, a date and time representative of the plurality of correlation degree data is set as the date and time data. Here, for example, the date and time indicated by the date and time data of the most recent of the plurality of correlation degree data indicated by associated date and time data may be set as the value of the date and time data of the correlation decrease degree data. Alternatively, the date and time indicated by the date and time data of the oldest of the plurality of correlation degree data indicated by associated date and time data may be set as the value of the date and time data of the correlation decrease degree data.

[0181] In this embodiment, for example, correlation reduction degree data is generated for each slice communication pair.

[0182] In this embodiment, the policy manager unit 90 acquires a correlation reduction degree, which is the degree of reduction in the strength of the correlation between a performance index value indicating the performance of the functional element performing one slice communication in one slice communication and a performance index value indicating the performance of the functional element performing the other slice communication in the other slice communication, associated with a pair of, for example, one slice communication which is slice communication performed by one functional element included in the communication system 1 using one network slice, and the other slice communication which is slice communication different from the one slice communication performed by one functional element included in the communication system 1 using one network slice.

[0183] Then, in this embodiment, for example, the policy manager unit 90 determines, for each of a plurality of slice communication pairs, whether the correlation decrease degree associated with the slice communication pair satisfies a given decrease determination condition.

[0184] Here, the policy manager unit 90 may acquire the correlation decrease degree data described above. Then, the policy manager unit 90 may determine whether the value of the correlation decrease degree data satisfies the decrease determination condition based on the acquired correlation decrease degree data.

[0185] Here, the policy manager unit 90 may acquire the latest multiple correlation decrease data, and then determine whether or not the combination of the multiple correlation decrease data satisfies the decrease determination condition.

[0186] For example, the correlation decrease degree value may be calculated by subtracting the value of the correlation decrease degree data whose associated date and time data indicates the most recent date and time from the value of the correlation decrease degree data whose associated date and time data indicates the second most recent date and time. In this case, the decrease determination condition may be a condition that "the value of the correlation decrease degree data is equal to or greater than a predetermined value." Alternatively, the decrease determination condition may be a condition that "the values ​​of a predetermined number (e.g., three) of correlation decrease degree data whose associated date and time data indicates the most recent date and time are all equal to or greater than a predetermined value."

[0187] Furthermore, for example, the value of the correlation decrease degree is assumed to be a value obtained by subtracting the value of the correlation degree data for which the associated date and time data indicates the most recent date from the above-mentioned value v1. In this case, the decrease determination condition may be a condition that "the value of the correlation decrease degree data is positive." Alternatively, the decrease determination condition may be a condition that "the values ​​of a predetermined number (e.g., three) of correlation decrease degree data from the most recent date and time indicated by the associated date and time data are all positive."

[0188] Furthermore, for example, the correlation decrease degree value may be the sum of values ​​obtained by subtracting the value of at least one extracted correlation data from the value v1. In this case, the decrease determination condition may be a condition that "the value of the correlation decrease degree data is equal to or greater than a predetermined number."

[0189] 12A is a diagram showing an example of a change in the correlation degree when the correlation decrease degree does not satisfy the decrease determination condition, and FIG. 12B and FIG. 12C are diagrams showing an example of a change in the correlation degree when the correlation decrease degree satisfies the decrease determination condition.

[0190] 12A, 12B, and 12C, the horizontal axis represents the date and time t that represents the period associated with the correlation degree, and the vertical axis represents the correlation degree r.

[0191] For example, a case where the latest correlation degree is significantly reduced from the immediately preceding correlation degree, as shown in FIG. 12B, corresponds to a typical example where the correlation reduction degree satisfies the reduction determination condition.

[0192] Furthermore, a case where the correlation degree fluctuates greatly as shown in FIG. 12C corresponds to a typical example where the correlation decrease degree satisfies the decrease determination condition.

[0193] In this embodiment, for example, the policy manager unit 90 identifies, for each of the multiple slice communications performed in the communication system 1, the number of slice communication pairs that include the slice communication and for which the correlation reduction degree associated with the slice communication pair satisfies the reduction determination condition (hereinafter referred to as the number of relevant pairs).

[0194] Then, in this embodiment, for example, the policy manager unit 90 determines, for each of the multiple slice communications performed in the communication system 1, whether the number of pairs identified for that slice communication satisfies a given pair number condition.

[0195] In this embodiment, for example, the policy manager unit 90 identifies a group of routers on a slice communication path where the number of identified slice communication pairs satisfies a given pair number condition based on the router group data. The policy manager unit 90 then estimates at least one router included in the identified group of routers as the router causing the degradation of the performance of the functional element related to the slice communication. Here, as described above, the path may be a path on which packets are forwarded by segment routing.

[0196] For example, the pair number condition may be a condition that "the number of corresponding pairs is greater than a predetermined number." In this case, the policy manager unit 90 estimates at least one router included in a group of routers present on a slice communication path where the number of identified slice communication pairs is greater than a predetermined number as the router causing the degradation of the performance of the functional element related to the slice communication.

[0197] Furthermore, the pair number condition may be a condition that "the ratio of the number of slice communication pairs including the slice communication, in which the correlation decrease degree associated with the slice communication pair satisfies the decrease determination condition, to the total number of slice communication pairs including the slice communication, is greater than a predetermined ratio." In this case, the policy manager unit 90 may identify, for each of a plurality of slice communications performed in the communication system 1, the ratio of the number of slice communication pairs including the slice communication, in which the correlation decrease degree associated with the slice communication pair satisfies the decrease determination condition, to the total number of slice communication pairs including the slice communication. Then, the policy manager unit 90 may estimate at least one router included in a group of routers present on a path of the slice communication, in which the identified ratio is greater than a predetermined ratio, as the router causing the degradation of the performance of the functional element related to the slice communication.

[0198] For example, assume that the slice communication performed by gNB102a using network slice B satisfies the pair number condition. In this case, for example, in the segment routing path management data, a segment routing path ID included in the segment routing path ID list associated with the functional element ID "gNB001" and the slice ID "002" is identified. The segment routing path ID identified here is, for example, "011," "012," "013," etc.

[0199] Then, for each of the segment routing path IDs identified in this way, a router ID included in the router ID list associated with the segment routing path ID in the router group management data is identified.

[0200] Here, for example, in the router group management data, a router ID list associated with the segment routing path ID "011", a router ID list associated with the segment routing path ID "012", and a router ID list associated with the segment routing path ID "013" are identified.

[0201] Then, a router ID included in at least one of the router ID lists identified in this manner is identified. Hereinafter, a group of router IDs including the router IDs identified in this manner will be referred to as a cause candidate router ID group. Hereinafter, for example, "10000," "10001," "10002," "10011," "10012," "10021," "10022," "20001," "20002," ... are identified as a cause candidate router ID group associated with the gNB 102a and the network slice B.

[0202] In this embodiment, the router identified by the router ID included in the cause candidate router ID group identified in this manner is estimated to be the cause of the degradation of the performance of the gNB 102a. Note that all routers identified by the router ID included in the cause candidate router ID group may be estimated to be the router causing the degradation of the performance of the gNB 102a.

[0203] In this embodiment, there may be multiple slice communications where the number of identified slice communication pairs satisfies the pair number condition. In this case, the policy manager unit 90 may estimate at least one router included in any of the router groups on the paths of the multiple slice communications as the router causing the degradation of the performance of multiple functional elements related to the multiple slice communications.

[0204] For example, in addition to the slice communication performed by gNB 102a using network slice B, the slice communication performed by gNB 102b using network slice A and the slice communication performed by gNB 102c using network slice C also satisfy the pair number condition.

[0205] In this case, as described above, "10000", "10001", "10002", "10011", "10012", "10021", "10022", "20001", "20002", ... are identified as a group of candidate cause router IDs associated with gNB102a and network slice B.

[0206] Similarly, "11000", "11001", "11002", "11011", "11012", "11021", "11022", "20001", "20002", ... are identified as a group of candidate cause router IDs associated with gNB102b and network slice A.

[0207] Then, "12000", "12001", "12002", "12011", "12012", "12021", "12022", "20001", "20003", ... are identified as a group of candidate cause router IDs associated with gNB102c and network slice C.

[0208] Then, the router ID "20001" that is included in all three groups of cause candidate router IDs is estimated to be the router ID of the router that is causing the degradation in performance of the functional element.

[0209] It should be noted that there is no particular restriction on the number of routers that are presumed to be the cause of the degradation of the performance of the functional element.

[0210] In this embodiment, for example, the slice manager unit 92 may output to the SDN controller 74, for each of one or more routers estimated to be the cause of the degradation of the performance of the functional element, an instruction to change the communication path for the network slice that includes the router as a component. Then, the SDN controller 74 may change the communication path created by the SDN controller 74 in accordance with the instruction to change the communication path.

[0211] For example, the slice manager unit 92 may output an instruction to change the communication path associated with the router ID of a router that is presumed to be the cause of the degradation of the performance of the functional element to the SDN controller 74. Then, in response to receiving the instruction to change the communication path created by the SDN controller 74, the SDN controller 74 may change the communication path to one that excludes the router identified by the router ID (i.e., a communication path that does not pass through the router).

[0212] Furthermore, an administrator or the like of the platform system 30 may check whether an abnormality such as a failure or overcapacity has occurred in each of the routers that are presumed to be the cause of the degradation of the performance of the functional elements. Then, the administrator or the like of the platform system 30 may output an instruction to the SDN controller 74 to remove a router in which an abnormality has been confirmed from the communication path. Then, in response to receiving the instruction, the SDN controller 74 may change the communication path created by the SDN controller 74 to a communication path that excludes the router (i.e., a communication path that does not pass through the router).

[0213] In addition, the SDN controller 74 or the slice manager unit 92 may update the segment routing path management data shown in Figure 8 or the router group management data shown in Figure 9 stored in the inventory database 82 in response to a change in the communication path.

[0214] Even if no abnormality is detected in a router, which is a component of the communication system 1 in this embodiment, a degradation in the performance of the functional element included in the communication system 1 (so-called silent failure) may occur in communication using a network slice that is available to the functional element.

[0215] Here, when the performance of a certain functional element deteriorates, it is believed that the correlation between the performance index values ​​of the functional elements in a pair of functional elements including the deteriorated functional element will decrease.

[0216] In light of this, in this embodiment, as described above, for each of the multiple slice communications performed in the communication system 1, the number of slice communication pairs that include the slice communication and for which the correlation reduction degree associated with the slice communication pair satisfies the reduction determination condition is identified. Then, at least one router included in the group of routers present on the path of the slice communication for which the number of identified slice communication pairs satisfies the given pair number condition is estimated to be the router causing the degradation in performance of the functional element related to the slice communication.

[0217] In this way, according to this embodiment, it is possible to accurately estimate the router that is the cause of a silent failure in a network slice.

[0218] In addition, in this embodiment, the policy manager unit 90 may classify multiple slice communications performed in the communication system 1 into multiple slice communication groups based on the strength of correlation between performance index values ​​identified for each slice communication pair.

[0219] For example, a general clustering technique may be used to classify multiple slice communications performed in the communication system 1 into multiple slice communication groups. Here, for example, in each slice communication group, classification may be performed such that the latest correlation value for any slice communication pair whose components are slice communications included in the slice communication group is greater than a predetermined value.

[0220] The policy manager unit 90 may then calculate, for each of a plurality of slice communication groups, a correlation reduction degree, which is the degree of reduction in the strength of correlation between a performance index value indicating the performance of the functional element performing one slice communication in one slice communication and a performance index value indicating the performance of the functional element performing the other slice communication in the other slice communication, which is associated with a pair of one slice communication that is a slice communication included in the slice communication group and another slice communication that is a slice communication included in the slice communication group but different from the one slice communication.

[0221] Then, for each of the multiple slice communication groups, the policy manager unit 90 may determine, for each pair of slice communications included in the slice communication group, whether the correlation reduction degree associated with the pair satisfies the reduction determination condition corresponding to the slice communication group.

[0222] The policy manager 90 may then determine a threshold value corresponding to each of the slice communication groups based on the total number of slice communications included in the slice communication group. For example, a value equivalent to 50% of the total number of slice communications, or a value equivalent to 70% of the total number of slice communications, may be determined as the threshold value.

[0223] Then, the policy manager unit 90 may estimate that at least one router included in a group of routers located on the path of slice communication, whose value representing the number of identified slice communication pairs is greater than a threshold value corresponding to the slice communication group including the slice communication pair, is the router causing the degradation in performance of the functional element related to the slice communication.

[0224] Alternatively, the policy manager unit 90 may determine, for each slice communication included in the slice communication group, the ratio of the number of pairs that include the slice communication and for which the correlation reduction degree associated with the pair satisfies the reduction determination condition to the total number of pairs that include the slice communication.

[0225] The policy manager unit 90 may then estimate that at least one router included in a group of routers located on the path of slice communication whose identified ratio is greater than a predetermined ratio is the router causing the degradation in performance of the functional element related to the slice communication.

[0226] In this way, for each slice communication group, an estimation of the router that is causing the degradation of the performance of the functional element is performed for a relatively small number of slice communications, thereby making it possible to reduce the computational load required to estimate the router that is causing the degradation of the performance of the functional element.

[0227] In addition, in this embodiment, the policy manager unit 90 may calculate a correlation increase degree, which is an increase in the strength of the correlation between a performance index value indicating the performance of a first functional element in a first slice communication and a performance index value indicating the performance of a second functional element in a second slice communication, the performance index value being associated with a pair of slice communications performed by any of a plurality of functional elements included in the communication system 1 using a first network slice and a second slice communication performed by a second functional element using a second network slice. For example, the correlation increase degree, which is an increase in the strength of the correlation between the performance index values, may be calculated based on multiple correlation data that are generated in consecutive order and have the same associated first slice communication ID and second slice communication ID. Here, the correlation increase degree may be an increase in the correlation coefficient of the performance index values.

[0228] Here, the policy manager unit 90 may calculate the correlation increase value corresponding to the combination of a specific first slice communication ID and a specific second slice communication ID by subtracting the value of the correlation data whose associated date and time data indicates the second most recent date and time from the value of the correlation data whose associated date and time data indicates the most recent date and time among the multiple correlation data associated with the specific first slice communication ID and the specific second slice communication ID.

[0229] Alternatively, the policy manager unit 90 may extract a predetermined number of correlation data from among a plurality of correlation data associated with a specific first slice communication ID and a specific second slice communication ID, in order from the data with the most recent date and time indicated by the date and time data. The policy manager unit 90 may then calculate the average value and standard deviation of the extracted correlation data values. Hereinafter, the value obtained by adding twice the calculated standard deviation to the calculated average value will be referred to as v2. That is, if the calculated average value is m and the calculated standard deviation is s, the value v2 corresponds to the value (m + 2s).

[0230] Then, the policy manager unit 90 may calculate the value of the correlation increase degree corresponding to the combination of the first slice communication ID and the second slice communication ID by subtracting the value v2 from the value of the correlation degree data whose associated date and time data indicates the most recent, among the multiple correlation degree data associated with the first slice communication ID and the second slice communication ID.

[0231] It should be noted that examples of the correlation increase degree are not limited to those described above.

[0232] Then, the policy manager unit 90 may generate correlation increase data, an example of which data structure is shown in FIG. 13, based on the correlation increase calculated as described above.

[0233] As shown in FIG. 13, the correlation increase degree data may be associated with, for example, a first slice communication ID, a second slice communication ID, and date and time data.

[0234] The correlation increase data is set to, for example, the value of the correlation increase calculated as described above.

[0235] The first slice communication ID and the second slice communication ID are set to, for example, a first slice communication ID and a second slice communication ID corresponding to the correlation increase degree, respectively.

[0236] For example, when a correlation increase degree is calculated based on a plurality of correlation degree data, a date and time representative of the plurality of correlation degree data is set as the date and time data. Here, for example, the date and time indicated by the date and time data of the most recent of the plurality of correlation degree data associated with the date and time data may be set as the value of the date and time data of the correlation increase degree data. Alternatively, the date and time indicated by the date and time data of the oldest of the plurality of correlation degree data associated with the date and time data may be set as the value of the date and time data of the correlation increase degree data.

[0237] In this embodiment, for example, correlation increase data is generated for each slice communication pair.

[0238] The policy manager unit 90 may then acquire a correlation increase degree, which is the degree of increase in the strength of the correlation between a performance index value indicating the performance of the functional element performing one slice communication in one slice communication and a performance index value indicating the performance of the functional element performing the other slice communication in the other slice communication, associated with a pair of slice communication, where one slice communication is slice communication performed by one functional element included in the communication system 1 using one network slice, and the other slice communication is slice communication performed by one functional element included in the communication system 1 using one network slice and is different from the one slice communication.

[0239] The policy manager unit 90 may then determine, for each of a plurality of slice communication pairs, whether the correlation increase degree associated with that pair satisfies a given increase determination condition.

[0240] Here, the policy manager unit 90 may acquire the correlation increase data described above, and may then determine, based on the acquired correlation increase data, whether or not the value of the correlation increase data satisfies the increase determination condition.

[0241] Alternatively, the policy manager unit 90 may acquire the latest multiple correlation increase data and determine whether a combination of the multiple correlation increase data values ​​satisfies an increase determination condition.

[0242] For example, the correlation increase degree value may be calculated by subtracting the value of the correlation increase degree data whose associated date and time data indicates the second-to-latest date and time from the value of the correlation increase degree data whose associated date and time data indicates the most recent date and time. In this case, the increase determination condition may be that "the value of the correlation increase degree data is equal to or greater than a predetermined value." Alternatively, the increase determination condition may be that "the values ​​of a predetermined number (e.g., three) of correlation increase degree data counted from the most recent date and time indicated by the associated date and time data are all equal to or greater than a predetermined value."

[0243] Furthermore, for example, the correlation increase value is assumed to be a value obtained by subtracting the above-mentioned value v2 from the value of the correlation increase data for which the associated date and time data indicates the most recent date and time. In this case, the increase determination condition may be a condition that "the value of the correlation increase data is positive." Alternatively, the increase determination condition may be a condition that "the values ​​of a predetermined number (e.g., three) of correlation increase data from the most recent date and time indicated by the associated date and time data are all positive."

[0244] 14 is a diagram showing an example of a change in correlation level when the correlation increase level satisfies the increase determination condition, in which the horizontal axis represents the date and time t that represents the period associated with the correlation level, and the vertical axis represents the correlation level r.

[0245] For example, a case where the latest correlation degree has increased significantly from the immediately preceding correlation degree, as shown in FIG. 14, corresponds to a typical example where the correlation increase degree satisfies the increase determination condition.

[0246] Then, when the policy manager unit 90 determines that the correlation increase degree associated with a slice communication pair satisfies the increase determination condition, it may estimate at least one router included in both the first router group located on the path of one slice communication included in the slice communication pair, and the second router group located on the path of the other slice communication included in the slice communication pair, as the router causing the deterioration in performance of the functional element related to the slice communication pair, as determined based on the router group data.

[0247] For example, suppose that it is determined that the correlation increase degree associated with a pair of one slice communication and another slice communication satisfies a given increase determination condition. Then, the policy manager unit 90 may, for example, identify a first group of routers present on the path of the one slice communication. Then, the policy manager unit 90 may, for example, identify a second group of routers present on the path of the other slice communication. Here, as described above, the path may be a path along which packets are forwarded by segment routing.

[0248] The policy manager unit 90 may then estimate that at least one router included in both the first router group and the second router group identified in this manner is the router causing the degradation in performance of the functional element.

[0249] For example, suppose that based on correlation increase data in which the associated first functional element ID, first slice ID, second functional element ID, and second slice ID are gNB001, 002, gNB002, and 001, respectively, it is determined that the correlation increase value indicated by the correlation increase data satisfies the increase determination condition.

[0250] In this case, as described above, "10000", "10001", "10002", "10011", "10012", "10021", "10022", "20001", "20002", ... are identified as a group of candidate cause router IDs associated with gNB102a and network slice B.

[0251] Furthermore, as described above, "11000", "11001", "11002", "11011", "11012", "11021", "11022", "20001", "20002", ... are identified as a group of candidate cause router IDs associated with gNB102b and network slice A.

[0252] Then, the router IDs "20001" and "20002", which are included in both of these two groups of candidate cause router IDs, may be estimated as the router IDs of the routers causing the degradation in performance of the functional element.

[0253] In this way, by using not only the correlation decrease rate but also the correlation increase rate to estimate the router that is causing the performance degradation of a functional element, it becomes possible to more accurately estimate the router that is causing the silent failure.

[0254] In addition, in this embodiment, the policy manager unit 90 may exclude at least one router included in a group of routers located on the slice communication path where the number of identified slice communication pairs does not satisfy a given pair number condition from the routers that are causing the degradation of the performance of the functional element.

[0255] For example, suppose that slice communication performed by gNB 102a using network slice B satisfies the pair number condition. On the other hand, suppose that slice communication performed by gNB 102c using network slice C does not satisfy the pair number condition.

[0256] In this case, "12000", "12001", "12002", "12011", "12012", "12021", "12022", "20001", "20003", ... may be excluded from the router IDs of routers causing the degradation of the performance of the functional element. In other words, in this case, "20002" is estimated to be the router ID of the router causing the degradation of the performance of the functional element.

[0257] In this way, it becomes possible to more accurately identify the router that is the cause of the silent failure.

[0258] Furthermore, the performance management unit 88 may generate, for each network slice in which a functional element is available, overall performance index value data indicating the performance of the functional element in slice communication using the network slice by aggregating the performance index value data generated by the monitoring function unit 72. Then, the policy manager unit 90 may calculate the correlation decrease degree or the correlation increase degree based on the overall performance index value data generated by the performance management unit 88.

[0259] In the above example, for each pair of slice communications performed by a functional element included in the RAN 32 (gNB 102 in the above example), it is determined whether the correlation decrease degree satisfies the decrease determination condition. Also, for each pair of slice communications performed by a functional element included in the RAN 32 (gNB 102 in the above example), it is determined whether the correlation increase degree satisfies the increase determination condition. In this case, the router that is causing the performance degradation of the functional element may be estimated from the group of routers present on the path between the RAN 32 and the core network system 34 (the path between the gNB 102 and the UPF 50 in the above example).

[0260] Here, in this embodiment, for each pair of slice communications performed by a functional element (e.g., UPF 50) included in the core network system 34, it may be determined whether the correlation decrease degree satisfies an increase determination condition. Furthermore, for each pair of slice communications performed by a functional element (e.g., UPF 50) included in the core network system 34, it may be determined whether the correlation increase degree satisfies an increase determination condition. Then, a router that is causing the performance degradation of the functional element may be estimated from among the routers present on the path between the RAN 32 and the core network system 34. In this case, for example, it may be determined whether the correlation decrease degree satisfies the decrease determination condition based on a performance index value related to the UPF 50. Furthermore, it may be determined whether the correlation increase degree satisfies the increase determination condition based on a performance index value related to the UPF 50.

[0261] The present invention is also applicable to estimating routers that are the cause of silent failures in network slices on paths other than those between the RAN 32 and the core network system 34.

[0262] For example, a router on the path (midhaul) between CU44 and DU42 that is the cause of a silent failure in the network slice may be estimated.

[0263] In this case, the policy manager unit 90 may determine whether the correlation decrease degree satisfies a decrease determination condition for each pair of slice communications performed by the CU 44. The policy manager unit 90 may also determine whether the correlation increase degree satisfies an increase determination condition for each pair of slice communications performed by the CU 44. Then, the router that is causing the performance degradation of the CU 44 may be estimated from among the routers present on the path between the CU 44 and the DU 42.

[0264] Furthermore, the value of the performance index value data may be a value indicating the performance of a functional element in the user plane, or may be a value indicating the performance of a functional element in the control plane.

[0265] Then, if it is determined that the degree of correlation decrease for a slice communication pair in the user plane satisfies the decrease judgment condition, or if it is determined that the degree of correlation increase for a slice communication pair in the user plane satisfies the increase judgment condition, the router that is causing the deterioration in performance of the functional element from among the group of routers that are components of the user plane may be estimated.

[0266] In addition, if it is determined that the degree of correlation decrease for a slice communication pair in the control plane satisfies the decrease judgment condition, or if it is determined that the degree of correlation increase for a slice communication pair in the control plane satisfies the increase judgment condition, the router that is causing the deterioration in performance of the functional element from among the group of routers that are components of the control plane may be estimated.

[0267] Furthermore, even if it is determined that the correlation decrease rate for a slice communication pair in the control plane satisfies the decrease judgment condition, or even if it is determined that the correlation increase rate satisfies the increase judgment condition, the router that is causing the deterioration in performance of the functional element may be estimated from the group of routers that are components of the control plane and the user plane.

[0268] Furthermore, a router that is causing a performance degradation of a functional element may be estimated from among a group of routers that are components of one or more network slice subnet instances among a group of routers that exist on a slice communication path. For example, a router that is causing a performance degradation of a functional element may be estimated from among a group of routers in a backhaul portion that exists on the path. Alternatively, a router that is causing a performance degradation of a functional element may be estimated from among a group of routers in a midhaul portion that exists on the path.

[0269] Here, an example of the flow of processing performed in the platform system 30 according to this embodiment to infer the router causing the degradation of the performance of a functional element will be described with reference to the flow diagram shown in FIG.

[0270] In the following processing example, it is assumed that the above-mentioned correlation degree data and correlation decrease degree data have been generated in advance for all slice communication pairs.

[0271] First, the policy manager unit 90 determines whether or not the correlation decrease degree associated with each slice communication pair satisfies the decrease determination condition for each slice communication pair (S101).

[0272] Then, the policy manager unit 90 identifies, for all slice communications, the number of slice communication pairs that include the slice communications and for which the correlation reduction degree associated with the pair satisfies the reduction determination condition (number of relevant pairs) (S102).

[0273] Then, the policy manager unit 90 identifies slice communications in which the number of pairs identified in the process shown in S102 satisfies the pair number condition (S103).

[0274] Then, the policy manager unit 90 identifies a group of routers that exist on the path of the slice communication identified in the process shown in S103 (S104).

[0275] Then, the policy manager unit 90 estimates that the router included in the group of routers identified in the processing shown in S104 is the router causing the degradation in performance of the functional element related to the slice communication (S105), and the processing shown in this processing example is terminated.

[0276] The present invention is not limited to the above-described embodiment.

[0277] For example, the functional units according to this embodiment are not limited to those shown in FIG.

[0278] Furthermore, the functional unit according to this embodiment does not need to be a NF in 5G. For example, the functional unit according to this embodiment may be a network node in 4G, such as an eNodeB, a vDU, a vCU, a Packet Data Network Gateway (P-GW), a Serving Gateway (S-GW), a Mobility Management Entity (MME), or a Home Subscriber Server (HSS).

[0279] Furthermore, the division of roles among the functions shown in FIG. 5 is not limited to the above.

[0280] Furthermore, the functional units according to the present embodiment may be realized using hypervisor-type or host-type virtualization technology instead of container-type virtualization technology. Furthermore, the functional units according to the present embodiment do not need to be implemented by software, but may be implemented by hardware such as electronic circuits. Furthermore, the functional units according to the present embodiment may be implemented by a combination of electronic circuits and software.

[0281] The technology described in the present disclosure can also be expressed as follows: [1] A router group data storage means for storing, for each of a plurality of network slices constructed in a communication system, router group data indicating a router group constituting the network slice; a correlation decrease degree calculation means for calculating a correlation decrease degree, which is a degree of decrease in the strength of correlation between a performance index value indicating the performance of a functional element performing one slice communication in one slice communication and a performance index value indicating the performance of a functional element performing the other slice communication in the other slice communication, associated with a pair of one slice communication, the performance index value indicating the performance of a functional element performing the other slice communication in the one slice communication; a decrease determination means for determining, for each of the plurality of pairs, whether the correlation decrease degree associated with the pair satisfies a given decrease determination condition; and a pair number determination means for determining, for each of a plurality of slice communications performed in the communication system, the number of pairs including the slice communication and for which the correlation decrease degree associated with the pair satisfies the decrease determination condition. and a router estimation means for estimating, based on the router group data, at least one router included in a router group present on a path of the slice communication where the number of identified pairs satisfies a given pair number condition, as the router causing the degradation of performance of the functional element related to the slice communication. [2] The router estimation system described in [1], wherein the router estimation means estimates, based on the router group data, at least one router included in a router group present on a path of the slice communication where the number of identified pairs is greater than a predetermined number, as the router causing the degradation of performance of the functional element related to the slice communication.[3] The router estimation system described in [1] further includes a ratio determination means for determining, for each of multiple slice communications performed in the communication system, the ratio of the number of pairs including the slice communication, in which the correlation reduction degree associated with the pair satisfies the reduction determination condition, to the total number of pairs including the slice communication, and the router estimation means estimates at least one router included in a group of routers located on the path of the slice communication, in which the identified ratio is greater than a predetermined ratio, as the router causing the reduction in performance of the functional element related to the slice communication. [4] The router estimation system described in [1] further includes a classification means for classifying multiple slice communications performed in the communication system into multiple slice communication groups based on the strength of correlation identified for each pair of slice communications, wherein the correlation reduction degree calculation means calculates, for each of the multiple slice communication groups, a correlation reduction degree which is the degree of reduction in the strength of the correlation between a performance index value indicating the performance of a functional element performing one slice communication in one slice communication and a performance index value indicating the performance of a functional element performing the other slice communication in the other slice communication, which are associated with a pair of slice communications that is a slice communication included in the slice communication group and a slice communication that is different from the one slice communication included in the slice communication group, and the reduction determination means determines, for each of the multiple slice communication groups, for each pair of slice communications included in the slice communication group, whether the correlation reduction degree associated with the pair satisfies the reduction determination condition corresponding to the slice communication group.[5] The router estimation system according to [4], further comprising: a threshold determination means for determining a threshold corresponding to each of the plurality of slice communication groups based on the total number of slice communications included in the slice communication group, wherein the router estimation means estimates at least one router included in a router group located on a path of the slice communication for which a value representing the number of identified pairs is greater than the threshold corresponding to the slice communication group including the pair, as the router causing the performance degradation of the functional element related to the slice communication. [6] The router estimation system according to [4], further comprising: a ratio determination means for determining, for each slice communication included in the slice communication group, a ratio of the number of pairs including the slice communication, the number of pairs including the slice communication, the number of pairs for which the correlation decrease degree associated with the pair satisfies the decrease determination condition, to the total number of pairs including the slice communication, wherein the router estimation means estimates at least one router included in a router group located on a path of the slice communication for which the identified ratio is greater than a predetermined ratio, as the router causing the performance degradation of the functional element related to the slice communication. [7] A router estimation system described in any one of [1] to [6], wherein, when there are multiple slice communications in which the number of identified pairs satisfies the pair number condition, the router estimation means estimates at least one router included in any of the groups of routers existing on each path of the multiple slice communications as the router causing the degradation in performance of multiple functional elements related to the multiple slice communications.[8] The communication system further includes a correlation increase degree calculation means for calculating a correlation increase degree, which is an increase degree of the strength of the correlation between a performance index value indicating the performance of the functional element performing one slice communication in one slice communication and a performance index value indicating the performance of the functional element performing the other slice communication in the other slice communication, associated with a pair of one slice communication, which is slice communication performed by one functional element included in the communication system using one network slice, and another slice communication, which is communication performed by one functional element included in the communication system using one network slice and different from the one slice communication; and an increase determination means for determining, for each of a plurality of the pairs, whether the correlation increase degree associated with the pair satisfies a given increase determination condition, The router estimation system according to any one of [1] to [7], wherein, when the correlation increase degree associated with the pair satisfies the increase determination condition, the router estimation means estimates at least one router included in both a first router group present on a path of one slice communication included in the pair and a second router group present on a path of the other slice communication included in the pair, which are identified based on the router group data, as a router causing a decrease in performance of the functional element related to the pair. [9] The router estimation system according to [8], wherein the correlation increase degree is an increase degree of a correlation coefficient of the performance index values.

[10] The router estimation system according to [1] to [9], wherein the router estimation means excludes, from the causing router, at least one router included in a router group present on a path of the slice communication, where the number of identified pairs does not satisfy the pair number condition.

[11] The router estimation system according to any one of [1] to

[10] , wherein the network slice through which the one slice communication is performed is the same network slice as the network slice through which the other slice communication is performed.

[12] The router estimation system according to any one of [1] to

[10] , wherein the network slice in which the one slice communication is performed is different from the network slice in which the other slice communication is performed.

[13] The router estimation system according to any one of [1] to

[12] , wherein the functional element is a functional element included in a radio access network of the communication system, and the router estimation means estimates the causative router from among a group of routers existing on a path between the radio access network and a core network system of the communication system.

[14] The router estimation system according to any one of [1] to

[12] , wherein the functional element is a functional element included in a core network system of the communication system, and the router estimation means estimates the causative router from among a group of routers existing on a path between the core network system and the radio access network of the communication system.

[15] The router estimation system according to any one of [1] to

[12] , wherein the functional element is a CU (Central Unit), and the router estimation means estimates the causative router from among a group of routers present on a path between the CU and a DU (Distributed Unit) included in the communication system.

[16] The router estimation system according to any one of [1] to

[15] , wherein the degree of correlation decrease is the degree of decrease in a correlation coefficient of the performance index values.

[17] The router estimation system according to any one of [1] to

[16] , wherein the path is a path on which packets are forwarded by segment routing.

[18] The router estimation system according to any one of [1] to

[17] , wherein the functional element is a network service or a network function.

[19] For each of a plurality of network slices constructed in a communication system, storing router group data indicating a router group constituting the network slice; calculating a correlation reduction degree, which is a reduction degree of the strength of the correlation between a performance index value indicating the performance of the functional element performing one slice communication in one slice communication and a performance index value indicating the performance of the functional element performing the other slice communication in the other slice communication, associated with a pair of one slice communication, which is slice communication performed by any functional element included in the communication system using any network slice, and another slice communication, which is slice communication performed by any functional element included in the communication system using any network slice and different from the one slice communication; determining, for each of the plurality of pairs, whether the correlation reduction degree associated with the pair satisfies a given reduction determination condition; and identifying, for each of the plurality of slice communications performed in the communication system, the number of pairs including the slice communication and for which the correlation reduction degree associated with the pair satisfies the reduction determination condition; A router estimation method comprising: estimating at least one router included in a router group located on a path of the slice communication, identified based on the router group data, where the number of identified pairs satisfies a given pair number condition, as the router causing the degradation in performance of the functional element related to the slice communication.

Claims

1. A router group data storage process for storing, for each of a plurality of network slices constructed in a communication system, router group data indicating a router group constituting the network slice; a correlation reduction degree calculation process that calculates a correlation reduction degree, which is the degree of reduction in the strength of the correlation between a performance index value indicating the performance of the functional element performing one slice communication in one slice communication and a performance index value indicating the performance of the functional element performing the other slice communication in the other slice communication, associated with a pair of slice communication, which is slice communication performed by one functional element included in the communication system using one network slice, and another slice communication, which is communication performed by one functional element included in the communication system using one network slice and different from the one slice communication; a decrease determination process for determining, for each of the plurality of pairs, whether the correlation decrease degree associated with the pair satisfies a given decrease determination condition; A pair number determination process for determining the number of pairs including each of a plurality of slice communications performed in the communication system, in which the correlation reduction degree associated with the pair satisfies the reduction determination condition; a router estimation process for estimating at least one router included in a router group on a path of the slice communication, where the number of identified pairs satisfies a given pair number condition, as the router causing the degradation of the performance of the functional element related to the slice communication, based on the router group data; A router estimation system that performs

2. In the router estimation process, at least one router included in a group of routers present on a path of the slice communication in which the number of identified pairs is greater than a predetermined number is estimated as the router causing the degradation of the performance of the functional element related to the slice communication. The router estimation system according to claim 1 .

3. For each of a plurality of slice communications performed in the communication system, a ratio determination process is performed to determine the ratio of the number of pairs including the slice communications, in which the correlation reduction degree associated with the pair satisfies the reduction determination condition, to the total number of pairs including the slice communications; In the router estimation process, at least one router included in a group of routers present on a path of the slice communication for which the identified ratio is greater than a predetermined ratio is estimated as the router causing the degradation of the performance of the functional element related to the slice communication. The router estimation system according to claim 1 .

4. A classification process is performed to classify multiple slice communications performed in the communication system into multiple slice communication groups based on the strength of the correlation identified for each pair of the slice communications, In the correlation reduction degree calculation process, for each of the multiple slice communication groups, a correlation reduction degree is calculated, which is the degree of reduction in the strength of the correlation between a performance index value indicating the performance of a functional element performing one slice communication in one slice communication and a performance index value indicating the performance of a functional element performing the other slice communication in the other slice communication, the performance index value being associated with a pair of one slice communication that is a slice communication included in the slice communication group and another slice communication that is a slice communication included in the slice communication group but different from the one slice communication, In the reduction determination process, for each of the plurality of slice communication groups, it is determined whether or not the correlation reduction degree associated with each pair of slice communications included in the slice communication group satisfies the reduction determination condition corresponding to the slice communication group. The router estimation system according to claim 1 .

5. For each of the plurality of slice communication groups, a threshold determination process is performed to determine a threshold corresponding to the slice communication group based on the total number of slice communications included in the slice communication group; In the router estimation process, at least one router included in a group of routers on the path of the slice communication, whose value representing the number of identified pairs is greater than the threshold corresponding to the slice communication group including the pair, is estimated to be the router causing the degradation in performance of the functional element related to the slice communication. The router estimation system according to claim 4 .

6. For each slice communication included in the slice communication group, a ratio determination process is performed to determine the ratio of the number of pairs including the slice communication, in which the correlation reduction degree associated with the pair satisfies the reduction determination condition, to the total number of pairs including the slice communication; In the router estimation process, at least one router included in a group of routers present on a path of the slice communication for which the identified ratio is greater than a predetermined ratio is estimated as the router causing the degradation of the performance of the functional element related to the slice communication. The router estimation system according to claim 4 .

7. In the router estimation process, when there are multiple slice communications in which the number of identified pairs satisfies the pair number condition, at least one router included in any of the router groups present on the respective paths of the multiple slice communications is estimated to be the router causing the degradation in performance of the multiple functional elements related to the multiple slice communications. The router estimation system according to claim 1 .

8. A correlation increase degree calculation process that calculates a correlation increase degree, which is the degree of increase in the strength of the correlation between a performance index value indicating the performance of the functional element that performs one slice communication in one slice communication and a performance index value indicating the performance of the functional element that performs the other slice communication in the other slice communication, which is associated with a pair of slice communication, where the one slice communication is slice communication performed by one functional element included in the communication system using one network slice, and the other slice communication is communication performed by one functional element included in the communication system using one network slice and is different from the one slice communication; an increase determination process for determining, for each of the plurality of pairs, whether the correlation increase degree associated with the pair satisfies a given increase determination condition; In the router estimation process, when the correlation increase degree associated with the pair satisfies the increase judgment condition, at least one router included in both a first router group located on the path of communication of one of the slices included in the pair, and a second router group located on the path of communication of the other slice included in the pair, which are identified based on the router group data, is estimated to be the router causing the deterioration in performance of the functional element related to the pair. The router estimation system according to claim 1 .

9. The correlation increase degree is an increase degree of the correlation coefficient of the performance index values. The router estimation system according to claim 8 .

10. In the router estimation process, at least one router included in a group of routers present on a path of the slice communication where the number of identified pairs does not satisfy the pair number condition is excluded from the router causing the problem. The router estimation system according to claim 1 .

11. The network slice in which the one slice communication is performed is the same network slice as the network slice in which the other slice communication is performed. The router estimation system according to claim 1 .

12. The network slice in which the one slice communication is performed is different from the network slice in which the other slice communication is performed. The router estimation system according to claim 1 .

13. the functional element is a functional element included in a radio access network of the communication system, In the router estimation process, the causative router is estimated from among routers present on a path between the wireless access network and a core network system of the communication system. The router estimation system according to claim 1 .

14. the functional element is a functional element included in a core network system of the communication system, In the router estimation process, the causative router is estimated from among a group of routers present on a path between the core network system and a radio access network of the communication system. The router estimation system according to claim 1 .

15. the functional element is a CU (Central Unit), In the router estimation process, the causative router is estimated from among a group of routers present on a path between the CU and a DU (Distributed Unit) included in the communication system. The router estimation system according to claim 1 .

16. The correlation reduction degree is a reduction degree of the correlation coefficient of the performance index values. The router estimation system according to claim 1 .

17. The route is a route through which packets are forwarded by segment routing. The router estimation system according to claim 1 .

18. the functional element is a network service or a network function; The router estimation system according to claim 1 .

19. For each of a plurality of network slices constructed in the communication system, storing router group data indicating a router group constituting the network slice; Calculating a correlation reduction degree, which is the degree of reduction in the strength of correlation between a performance index value indicating the performance of the functional element performing one slice communication in one slice communication and a performance index value indicating the performance of the functional element performing the other slice communication in the other slice communication, associated with a pair of slice communication, where the slice communication is performed by one functional element included in the communication system using one network slice, and the other slice communication is a slice communication performed by one functional element included in the communication system using one network slice and different from the one slice communication; For each of the plurality of pairs, determining whether the correlation decrease degree associated with the pair satisfies a given decrease determination condition; For each of a plurality of slice communications performed in the communication system, identifying the number of pairs including the slice communications, in which the correlation reduction degree associated with the pair satisfies the reduction determination condition; Estimating at least one router included in a router group located on a path of the slice communication, where the number of identified pairs satisfies a given pair number condition, as the router causing the degradation of the performance of the functional element related to the slice communication, based on the router group data; A router estimation method including: