Network management device, network management method, and program

Abstract

A network management device according to an embodiment of the present invention comprises: a first determination unit that, on the basis of first traffic information corresponding to a first time of a wireless network constituted by a plurality of base stations and a plurality of terminals, determines, for each of the plurality of terminals, a first base station to be associated therewith on a one-to-one basis; and a calculation unit that calculates, in association with the first time, a first number of one or more first terminals associated on a one-to-one basis with a second base station of a failure target from among the first base stations.

Description

Network management device, network management method, and program

[0001] The embodiments relate to a network management device, a network management method, and a program.

[0002] 2. Description of the Related Art When a large-scale failure occurs in a communication network due to a disaster or the like, technology is being considered that can quickly determine the location of the failure and the impact on services caused by the failure.

[0003] For example, when targeting a fixed communication network, users are associated one-to-one with aggregation facilities, so by estimating the number of users belonging to an aggregation facility, it is possible to calculate the number of users affected by a failure.

[0004] Japanese Patent No. 6655524 Japanese Patent Application Laid-Open No. 2020-65202 International Publication No. 2021 / 131002 International Publication No. 2020 / 240706 International Publication No. 2021 / 166228 Japanese Patent Application Laid-Open No. 2019-149774

[0005] However, in a wireless communication network, users communicate by establishing sessions with multiple base stations. Therefore, if the number of users belonging to a base station is estimated based on the number of sessions, there is a possibility that the number of users affected by a failure will be counted twice. Therefore, when targeting a wireless communication network, there is a possibility that the number of users affected by a failure will not be accurately determined.

[0006] The present invention has been made in light of the above circumstances, and its object is to provide a means for accurately determining the number of users affected by a failure in a wireless network.

[0007] A network management device according to one aspect includes a first determination unit and a calculation unit. The first determination unit determines, for each of a plurality of terminals, a first base station having a one-to-one correspondence with a second base station that is a failure target among the first base stations, based on first traffic information corresponding to a first time in a wireless network configured of the plurality of base stations and the plurality of terminals. The calculation unit calculates, in association with the first time, a first number of one or more first terminals having a one-to-one correspondence with a second base station that is a failure target among the first base stations.

[0008] According to the embodiment, it is possible to provide a means for accurately determining the number of users affected by a failure in a wireless network.

[0009] FIG. 1 is a block diagram showing an example of a network management system and a network according to the first embodiment. FIG. 2 is a block diagram showing an example of the hardware configuration of a network management device according to the first embodiment. FIG. 3 is a block diagram showing an example of the functional configuration of a network management device according to the first embodiment. FIG. 4 is a flowchart showing an example of the number of affected users calculation process in the network management device according to the first embodiment. FIG. 5 is a block diagram showing an example of the functional configuration of a network management device according to a second embodiment. FIG. 6 is a diagram showing an example of data stored in an area DB of the network management device according to the second embodiment. FIG. 7 is a flowchart showing an example of the number of affected users calculation process in the network management device according to the second embodiment. FIG. 8 is a diagram showing a first example of the number of affected users calculation process in the network management device according to the second embodiment. FIG. 9 is a diagram showing a second example of the number of affected users calculation process in the network management device according to the second embodiment.

[0010] Hereinafter, embodiments will be described with reference to the drawings. In the following description, components having the same functions and configurations will be denoted by the same reference numerals.

[0011] 1. First Embodiment 1.1 Configuration 1.1.1 Network Management System FIG. 1 is a block diagram showing an example of a network management system and a network according to a first embodiment.

[0012] The network management system 1 is a system that evaluates the effect on users of a network NW in response to a failure that occurs in the network NW, for example. The network management system 1 includes a network management device 100 and a network monitoring device 200.

[0013] The network NW is an example of a topology to be managed by the network management system 1. The network NW includes a wireless network. The wireless network included in the network NW is composed of, for example, multiple base stations B and multiple terminals T. The base station B is a wireless station that relays between the terminals T and an external information network in the wireless network. The terminals T are, for example, portable communication devices such as smartphones.

[0014] 1 shows an example in which a network NW is configured with three base stations B1, B2, and B3 and three terminals T1, T2, and T3. Terminal T1 has established a session with each of base stations B1 and B2. Terminal T2 has established a session with each of base stations B2 and B3. Terminal T3 has established a session with each of base stations B2 and B3.

[0015] The network monitoring device 200 is, for example, a computer such as a server. The network monitoring device 200 periodically collects traffic information in the network NW. The network monitoring device 200 also periodically collects location information of terminals T included in the network NW. The network monitoring device 200 periodically transmits the collected traffic information and location information to the network management device 100 as monitoring information. Furthermore, when a failure occurs in the network NW, the network monitoring device 200 transmits information about the base station B that is the target of the failure to the network management device 100.

[0016] The network management device 100 is, for example, a computer such as a server. When the network management device 100 receives information about a failure in the network NW from the network monitoring device 200, the network management device 100 evaluates the impact of the failure on users of the network NW.

[0017] 1.1.2 Hardware Configuration of the Network Management Device Next, the hardware configuration of the network management device according to the first embodiment will be described.

[0018] 2 is a block diagram showing an example of the hardware configuration of the network management device according to the first embodiment. As shown in FIG. 2, the network management device 100 includes a control circuit 11, a communication module 12, a user interface 13, a storage 14, a drive 15, and a storage medium 16.

[0019] The control circuit 11 is a circuit that controls the overall components of the network management device 100. The control circuit 11 includes a CPU (Central Processing Unit), RAM (Random Access Memory), and ROM (Read Only Memory). The ROM of the control circuit 11 stores programs and the like used in various processes in the network management device 100. The CPU of the control circuit 11 controls the entire network management device 100 in accordance with the programs stored in the ROM of the control circuit 11. The RAM of the control circuit 11 is used as a working area for the CPU of the control circuit 11.

[0020] The communication module 12 is, for example, a circuit used for communicating data with the network monitoring device 200 .

[0021] The user interface 13 is an interface that manages communication between a user and the control circuit 11. The user interface 13 includes input devices and output devices. The input devices include, for example, a keyboard, a touch panel, and operation buttons. The output devices include, for example, an LCD (Liquid Crystal Display) or an EL (Electroluminescence) display. The user interface 13 converts input from the user into an electrical signal and then transmits it to the control circuit 11. The user interface 13 outputs the execution result based on the user input to the user.

[0022] The storage 14 includes, for example, a hard disk drive (HDD) or a solid state drive (SSD). The storage 14 stores information used in various processes in the network management device 100.

[0023] The drive 15 is a device for reading software stored in the storage medium 16. The drive 15 includes, for example, a CD (Compact Disk) drive and a DVD (Digital Versatile Disk) drive.

[0024] The storage medium 16 is a medium that stores software electrically, magnetically, optically, mechanically, or chemically, and may store programs for executing various processes in the network management device 100.

[0025] 1.1.3 Functional Configuration of the Network Management Device Next, the functional configuration of the network management device according to the first embodiment will be described.

[0026] 3 is a block diagram showing an example of the functional configuration of a network management device according to the first embodiment. A route DB 21, an entity DB 22, and a specification DB 23 are stored in the storage 14 of the network management device 100. The CPU of the control circuit 11 of the network management device 100 loads a program stored in the ROM of the control circuit 11 or the storage medium 16 into the RAM of the control circuit 11. The CPU of the control circuit 11 then interprets and executes the program loaded into the RAM of the control circuit 11. As a result, the network management device 100 functions as a computer including a monitoring information acquisition unit 24, a connection relationship determination unit 25, an affected user number calculation unit 26, an impact extent evaluation unit 27, and an output unit 28.

[0027] The route DB 21 is a database that stores information about sessions established between the base station B and the terminal T in the network NW. The route DB 21 for the network NW shown in Fig. 1 stores, for example, the information that communication routes are formed between the terminal T1 and the base station B1, between the terminal T1 and the base station B2, between the terminal T2 and the base station B2, between the terminal T2 and the base station B3, between the terminal T3 and the base station B2, and between the terminal T3 and the base station B3.

[0028] The entity DB 22 is a database that stores information about entities that constitute the network NW. An entity is a representation of physical and logical resources that constitute the network NW in a unified format that is independent of the type of network NW.

[0029] Physical resources include, for example, a base station B and a terminal T that constitute a wireless network as shown in Fig. 1, and communication devices that constitute a fixed network (not shown). Logical resources include, for example, a termination point encapsulation (TPE), a network forwarding domain (NFD), and a forwarding relationship encapsulation (FRE). Here, TPE represents a termination point of a communication protocol. NFD represents a connection relationship between TPE and NFD. FRE represents an entity of an information transfer path generated on NFD.

[0030] The specification DB 23 is a database that stores, as specification information, characteristics specific to the network NW corresponding to the entities stored in the entity DB 22. The specification information includes information such as the name of the characteristic and the allowable values ​​of the attributes. The specification information may also include hierarchical information. The hierarchical information is, for example, information indicating the hierarchical relationship between communication devices.

[0031] The monitoring information acquisition unit 24 acquires, as monitoring information, traffic information occurring in the network NW and location information of the terminal T within the network NW from the network monitoring device 200. The monitoring information acquisition unit 24 inputs the acquired monitoring information to the connection relationship determination unit 25.

[0032] The connection relationship determination unit 25 maps the monitoring information to the communication paths established within the network NW stored in the path DB 21. Based on the monitoring information mapped to the communication paths, the connection relationship determination unit 25 extracts the path (main utilization path) that each terminal T mainly uses for communication. The connection relationship determination unit 25 determines that there is a one-to-one connection relationship between the terminal T and the base station B that are connected via the extracted main utilization path. The connection relationship determination unit 25 inputs the connection relationship determination result to the affected user number calculation unit 26. In the following description, the connection relationship between the base station B and the terminal T that has a one-to-one connection relationship may be expressed as "terminal T belongs to base station B."

[0033] The affected user number calculation unit 26 calculates the number of users affected by a failure that has occurred in the network NW as the number of affected users based on the determination result of the connection relationship. Specifically, the affected user number calculation unit 26 calculates the total number of terminals T that belong to the base station B that is the target of the failure as the number of affected users. The affected user number calculation unit 26 inputs the calculated number of affected users to the impact extent evaluation unit 27.

[0034] The impact extent evaluation unit 27 evaluates the extent of the impact of the failure on the network NW based on the entity DB 22, the specification DB 23, and the number of affected users. The impact extent evaluation unit 27 inputs the evaluation result of the impact extent to the output unit 28.

[0035] The output unit 28 outputs the evaluation result of the extent of influence to the user.

[0036] 1.2 Operation Next, the operation of the network management device according to the first embodiment will be described.

[0037] FIG. 4 is a flowchart showing an example of the process of calculating the number of affected users in the network management device according to the first embodiment.

[0038] When an instruction to calculate the number of affected users is issued (start), the monitoring information acquisition unit 24 acquires traffic information and location information of the network NW from the network monitoring device 200 (S11). The timing at which the instruction to calculate the number of affected users is issued may be periodic or may be irregular in response to the occurrence of a specific event, such as when a failure occurs.

[0039] The connection relationship determination unit 25 refers to the route DB 21 and maps the traffic information and location information acquired in the process of S11 to a communication route established in the network NW (S12).

[0040] The connection relationship determination unit 25 selects the terminal T (S13).

[0041] The connection relationship determination unit 25 extracts a main utilization route for the terminal T selected in the process of S13 based on the traffic information and location information mapped in the process of S12 (S14). Specifically, for example, the connection relationship determination unit 25 may extract, as the main utilization route, a route associated with the latest traffic for the selected terminal T. Furthermore, for example, the connection relationship determination unit 25 may extract, as the main utilization route, a route with the largest traffic volume for the selected terminal T.

[0042] The connection relationship determination unit 25 determines that the terminal T selected in the process of S13 belongs to the base station B connected via the main utilization route extracted in the process of S14 (S15).

[0043] The connection relationship determination unit 25 determines whether or not all the terminals T in the network NW have been selected (S16).

[0044] If there is an unselected terminal T (S16; no), the connection relationship determination unit 25 selects an unselected terminal T (S13). Then, the subsequent processes of S14 to S16 are executed. In this way, the processes of S13 to S16 are repeatedly executed until all terminals T in the network NW are selected.

[0045] If all terminals T are selected (S16; yes), the affected user number calculation unit 26 calculates the total number of terminals T that are determined to belong to the base station B that is the target of the failure as the number of affected users based on the result of the judgment process of S15 (S17).

[0046] When the process of S17 is completed, the process of calculating the number of influenced users is completed (END).

[0047] 1.3 Effects of the First Embodiment According to the first embodiment, the connection relationship determination unit 25 determines a base station that has a one-to-one correspondence with each of multiple terminals T based on traffic information of the network NW. The affected user number calculation unit 26 calculates the number of terminals that have been determined to have a one-to-one correspondence with the base station that is the failure target based on the connection relationship determination result. This makes it possible to set a main usage route that defines a one-to-one connection relationship between terminal T and base station B, even when terminal T has established sessions with multiple base stations B. Therefore, when calculating the number of affected users, it is possible to prevent duplicate counting of the number of terminals T affected by the failure. This makes it possible to accurately grasp the number of users affected by the failure.

[0048] 2. Second Embodiment Next, a second embodiment will be described. The second embodiment differs from the first embodiment in that it assumes a case where monitoring information cannot be obtained in real time when calculating the number of affected users. The following mainly describes configurations and operations that differ from the first embodiment. Descriptions of configurations and operations that are equivalent to those of the first embodiment will be omitted as appropriate.

[0049] 2.1 Functional Configuration of Network Management Device Fig. 5 is a block diagram showing an example of the functional configuration of a network management device according to the second embodiment. Fig. 5 corresponds to Fig. 3 in the first embodiment.

[0050] In the second embodiment, an area DB 29 is further stored in the storage 14 of the network management device 100. The network management device 100 also functions as a computer that further includes a handover determination unit 30.

[0051] The area DB 29 is a database that stores information about an area in which the terminal T can communicate and information about the base station B located within that area.

[0052] FIG. 6 is a diagram illustrating an example of data stored in the area DB of the network management device according to the second embodiment.

[0053] 6, the area DB 29 stores information about areas A1, A2, and A3 in which terminals T1, T2, and T3 can communicate, respectively. The area DB 29 also stores information about base stations B belonging to each of the areas A1, A2, and A3 in association with each other. The example of FIG. 6 shows a case where base station B1 belongs to area A1, base stations B2 and B3 belong to area A2, and base station B3 belongs to area A3.

[0054] By referring to the area DB 29, the network management device 100 can determine that terminal T1 can communicate with base station B1, that terminal T2 can communicate with base stations B2 and B3, and that terminal T3 can communicate with base station B3. Furthermore, because base stations B2 and B3 belong to area A2, the network management device 100 can determine that terminal T2 can transition (handover) from a state in which it is communicating with base station B2 to a state in which it is communicating with base station B3.

[0055] Returning to FIG. 5, the functional configuration of the network management device 100 will be described.

[0056] Based on the connection relationship determination result, the handover determination unit 30 extracts terminals T that belong to the failed base station B (i.e., terminals T that may be counted in the number of affected users). The handover determination unit 30 refers to the area DB 29 and determines whether the extracted terminals T can be handed over from the failed base station B to a normal base station B. The handover determination unit 30 inputs the handover possibility determination result to the affected user number calculation unit 26.

[0057] Based on the result of the handover possibility determination, the affected user number calculation unit 26 excludes the terminal T that has been determined to be able to be handed over from the failed base station B to a normal base station B from the targets for calculating the number of affected users. The affected user number calculation unit 26 calculates the number of affected users taking into account the exclusion result.

[0058] 2.2 Affected User Number Calculation Processing Fig. 7 is a flowchart showing an example of affected user number calculation processing in the network management device according to the second embodiment. Fig. 7 corresponds to Fig. 4 in the first embodiment.

[0059] The processes of S21 to S27 in Fig. 7 are associated with time t2. Prior to the processes of S21 to S27 in Fig. 7, the number of affected users associated with time t1 is calculated by the processes of S11 to S17 in Fig. 4, which are associated with time t1 before time t2. Time t1 is, for example, immediately after the occurrence of a failure. Time t2 is several minutes after the occurrence of the failure.

[0060] When an instruction to calculate the number of affected users corresponding to time t2 is issued (start), the monitoring information acquisition unit 24 determines whether traffic information and location information of the network NW can be acquired from the network monitoring device 200 (S21).

[0061] If the traffic information and location information of the network NW corresponding to time t2 can be acquired from the network monitoring device 200 (S21; yes), the network management device 100 executes the normal number of affected users calculation process (S10). Specifically, the network management device 100 executes the processes of S11 to S17 in FIG. 4 of the first embodiment as the normal number of affected users calculation process of S10. In this way, if the traffic information and location information can be acquired in real time in response to an instruction to calculate the number of affected users corresponding to time t2, the number of affected users corresponding to time t2 is calculated based on the traffic information and location information acquired in association with time t2.

[0062] If the traffic information and location information of the network NW corresponding to time t2 cannot be obtained from the network monitoring device 200 (S21; no), the handover determination unit 30 updates information about the area to which base station B belongs based on the latest location information of terminal T (S22). The latest location information is the location information obtained when the most recent affected user number calculation process was executed (i.e., associated with time t1). As a result, the area DB 29 updated in the process of S22 reflects information about base station B that is present in an area capable of communicating with terminal T immediately after the occurrence of the failure.

[0063] The handover determination unit 30 selects the terminal T determined to belong to the base station that is the failure target in the most recent affected user number calculation process (that is, corresponding to time t1) (S23).

[0064] The handover determination unit 30 determines, based on the area DB 29 updated in the process of S22, whether or not there is a normal base station belonging to an area capable of communicating with the terminal T selected in the process of S23 (S24).

[0065] If there is a normal base station belonging to an area that can communicate with the terminal T selected in the processing of S23 (S24; yes), the affected user number calculation unit 26 excludes the terminal T selected in the processing of S23 from the calculation of the number of terminals belonging to the base station B that is the target of failure (S25).

[0066] After the processing of S25, or if there is no normal base station belonging to an area capable of communicating with the terminal T selected in the processing of S23 (S24; no), the handover determination unit 30 determines whether or not all terminals T determined to belong to the base station B subject to failure in the most recent affected user number calculation processing have been selected (S26).

[0067] If there is an unselected terminal T among the terminals T determined to belong to the failure target base station B in the most recent affected user number calculation process (S26; no), the handover determination unit 30 selects the unselected terminal T (S23). Then, the subsequent processes of S24 to S26 are executed. In this way, the processes of S23 to S26 are repeatedly executed until all terminals T determined to belong to the failure target base station B in the most recent affected user number calculation process are selected.

[0068] When all terminals T determined to belong to the base station B that is the failure target in the most recent affected user number calculation process are selected (S26; yes), the affected user number calculation unit 26 calculates the total number of terminals T determined to belong to the base station B that is the failure target as the affected user number corresponding to time t2 based on the result of the determination process of S15 in the most recent affected user number calculation process and the exclusion result of the process of S25 (S27).

[0069] When the process of S27 or the process of S10 is completed, the process of calculating the number of influenced users is completed (end).

[0070] 2.3 Specific Examples FIG. 8 is a diagram showing a first example of the process of calculating the number of affected users in the network management device according to the second embodiment. FIG. 9 is a diagram showing a second example of the process of calculating the number of affected users in the network management device according to the second embodiment. The first example corresponds to the process of calculating the number of affected users corresponding to time t1. The second example corresponds to the process of calculating the number of affected users corresponding to time t2, which is after time t1. At both times t1 and t2, base stations B1 and B2 are the base stations that are subject to failure. FIG. 8 assumes a case where monitoring information can be obtained in real time at time t1. FIG. 9 assumes a case where monitoring information cannot be obtained in real time at time t2.

[0071] First, the process of calculating the number of affected users corresponding to time t1 will be described.

[0072] 8, in the process of calculating the number of affected users corresponding to time t1, traffic information is acquired in real time. Accordingly, the communication paths between terminal T1 and base station B1, between terminal T2 and base station B2, and between terminal T3 and base station B3 are determined to be the main paths used, respectively. Then, since base stations B1 and B2 are the base stations subject to the failure, the number of affected users is calculated to be two, terminals T1 and T2.

[0073] Next, the process of calculating the number of affected users corresponding to time t2 will be described.

[0074] As shown in Figure 9, in the calculation process for the number of affected users corresponding to time t2, traffic information is not acquired in real time. Accordingly, the area DB 29 is updated based on the location information acquired in the calculation process for the number of affected users corresponding to time t1. As a result, it is determined that base station B1 belongs to area A1, base stations B2 and B3 belong to area A2, and base station B3 belongs to area A3. Therefore, it is estimated that terminal T2 is unable to communicate due to a failure of base station B2 at time t1, but will be able to hand over to a normal base station B3 at time t2 and will be able to communicate. Therefore, the number of affected users is calculated to be one, that is, terminal T1.

[0075] 2.3 Effects of the Second Embodiment According to the second embodiment, the handover determination unit 30 determines, based on location information corresponding to time t1, whether a normal base station B is present within the communication area for each terminal T determined to be affected by the failure in the affected user number calculation process corresponding to time t1. When traffic information corresponding to time t2, which is later than time t1, is not available, the affected user number calculation unit 26 calculates the affected user number corresponding to time t2 by excluding the number of terminals T determined to have a normal base station B present within the communication area as a result of the determination process by the handover determination unit 30 from the affected user number corresponding to time t1. This makes it possible to calculate the number of terminals T affected by the failure while taking into account terminals T that can return to a communication-enabled state through handover, even when traffic information and location information cannot be obtained in real time. Therefore, a more realistic number of affected users can be determined even in a situation where the information necessary for calculating the affected user number cannot be obtained in real time.

[0076] 3. Modifications, etc. Various modifications can be applied to the above-described embodiment.

[0077] In the above-described embodiment, the case where the program that executes the affected user number calculation process is executed by the network management device 100 has been described, but this is not limiting. For example, the program that executes the affected user number calculation process may be executed by a computing resource on a cloud.

[0078] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0079] DESCRIPTION OF SYMBOLS 1... Network management system 11... Control circuit 12... Communication module 13... User interface 14... Storage 15... Drive 16... Storage medium 21... Route DB 22... Entity DB 23... Specification DB 24... Monitoring information acquisition unit 25... Connection relationship determination unit 26... Affected user number calculation unit 27... Influence range evaluation unit 28... Output unit 29... Area DB 30... Handover determination unit 100... Network management device 200... Network monitoring device

Claims

1. A network management device comprising: a first determination unit that determines a first base station that is in one-to-one correspondence with each of the plurality of terminals based on first traffic information corresponding to a first time in a wireless network composed of a plurality of base stations and a plurality of terminals; and a calculation unit that calculates a first number of one or more first terminals that are in one-to-one correspondence with a second base station that is a failure target among the first base stations, in correspondence with the first time.

2. A network management device as described in claim 1, further comprising a second determination unit that determines whether or not a normal third base station is present within a communication area for each of the one or more first terminals based on first location information corresponding to the first time for the multiple terminals, and wherein when second traffic information corresponding to a second time after the first time is not obtained, the calculation unit calculates a second number corresponding to the second time by excluding from the first number the number of second terminals for which it has been determined that the third base station is present within a communication area.

3. A network management method comprising: determining a first base station having a one-to-one correspondence for each of the plurality of terminals based on first traffic information corresponding to a first time in a wireless network composed of a plurality of base stations and a plurality of terminals; and calculating a first number of one or more first terminals having a one-to-one correspondence with a second base station that is a failure target among the first base stations, in correspondence with the first time.

4. A program for causing a computer to function as each unit of the network management device according to claim 1 or 2.

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