Communication system, monitoring apparatus, monitoring method, and program

Abstract

To contribute to housing specific terminals in a return communication area.SOLUTION: A monitoring device pre-registers, for a specific base station that can shift to a return communication mode among a plurality of base stations, specific terminals that will be housed in a return communication area of the specific base station, among a plurality of terminals when the specific base station shifts to the return communication mode, and adjacent areas of other base stations that are adjacent to the return communication area of the specific base station. When the monitoring device detects a failure in communication between the specific base station and an EPC for wide-area communication, the monitoring device determines that the specific base station has shifted to the return communication mode, and instructs the EPC for wide-area communication to delete terminal information of specific terminals housed in the adjacent areas among the specific terminals from the EPC for wide-area communication.SELECTED DRAWING: Figure 21

Description

Technical Field

[0001] The present disclosure relates to a communication system, a monitoring device, a monitoring method, and a program.

Background Art

[0002] In a Public Safety communication system (PS-LTE) using LTE (Long Term Evolution), a wide-area communication EPC (Evolved Packet Core) that enables mutual communication between terminals belonging to communication areas of different base stations is provided, and a retransmission communication EPC is also provided. Normally, the base station is connected to the wide-area communication EPC and operates in the wide-area communication mode to provide a wide-area communication service. Among the base stations, those that can transition to the retransmission communication mode connect to the retransmission communication EPC and transition to the retransmission communication mode to provide a retransmission communication service when a communication failure occurs with the wide-area communication EPC.

[0003] However, when a situation occurs where a wide-area communication area that provides a wide-area communication service and a retransmission communication area that provides a retransmission communication service coexist, communication between the base station that provides the wide-area communication service and the base station that provides the retransmission communication service is not possible, so mutual communication between the terminal in the wide-area communication area and the terminal in the retransmission communication area cannot be performed.

[0004] In this case, there is a desire to use a specific terminal centered on the retransmission communication area and enable mutual communication between specific terminals. To meet this desire, it is necessary to accommodate the specific terminal in the retransmission communication area. Therefore, recently, technologies for accommodating terminals in the retransmission communication area have been proposed (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, the technique described in Patent Document 1 mentioned above is a technique for accommodating a terminal located within a handover communication area in the handover communication area. However, among the specific terminals to be accommodated in the handover communication area, there are also terminals located outside the handover communication area. However, with the technique described in Patent Document 1, it is not possible to accommodate a terminal located outside the handover communication area in the handover communication area.

[0007] Therefore, recently, there has been a demand for a technique that can contribute to accommodating a specific terminal in a handover communication area regardless of whether the specific terminal is located inside or outside the handover communication area.

[0008] Therefore, an object of the present disclosure is to provide a communication system, a monitoring device, a monitoring method, and a program that can contribute to accommodating a specific terminal in a handover communication area in view of the above-described problems.

Means for Solving the Problems

[0009] A communication system according to one aspect includes: an EPC (Evolved Packet Core) for wide-area communication; a plurality of base stations that are connected to the EPC for wide-area communication and operate in a wide-area communication mode during normal times; a plurality of terminals; and a monitoring device, wherein the monitoring device pre-register, for a specific base station among the plurality of base stations that can transition to a handover communication mode, a specific terminal to be accommodated in the handover communication area of the specific base station when the specific base station transitions to the handover communication mode, and an adjacent area of another base station adjacent to the handover communication area of the specific base station; When detecting a communication failure between the specific base station and the EPC for wide-area communication, it is determined that the specific base station has transitioned to the relaying communication mode, and the EPC for wide-area communication is instructed to delete the terminal information of the specific terminals among the specific terminals that are accommodated in the adjacent area from the EPC for wide-area communication.

[0010] A communication system according to another aspect is an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in the wide-area communication mode, a plurality of terminals, and a monitoring device, and the monitoring device For a specific base station among the plurality of base stations that can transition to the relaying communication mode, when the specific base station transitions to the relaying communication mode, the specific terminals accommodated in the relaying communication area of the specific base station among the plurality of terminals, the adjacent area of another base station adjacent to the relaying communication area of the specific base station, and the specific access class assigned to the SIM (Subscriber Identity Module) of the specific terminals are registered in advance. When detecting a communication failure between the specific base station and the EPC for wide-area communication, it is determined that the specific base station has transitioned to the relaying communication mode, and the other base stations are instructed to restrict the connection of the specific terminals with the specific access class assigned to the SIM to the adjacent area.

[0011] A monitoring device according to one aspect is a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in the wide-area communication mode, and a plurality of terminals, a memory, and at least one processor coupled to the memory, and the at least one processor For a specific base station among the plurality of base stations that can transition to the relay communication mode, a specific terminal accommodated in the relay communication area of the specific base station when the specific base station transitions to the relay communication mode among the plurality of terminals, and an adjacent area of another base station adjacent to the relay communication area of the specific base station are registered in advance. When a failure in communication between the specific base station and the EPC for wide-area communication is detected, it is determined that the specific base station has transitioned to the relay communication mode, and the EPC for wide-area communication is instructed to delete the terminal information of the specific terminal accommodated in the adjacent area among the specific terminals.

[0012] A monitoring device according to another aspect is a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in the wide-area communication mode, and a plurality of terminals. a memory, and at least one processor coupled to the memory. The at least one processor For a specific base station among the plurality of base stations that can transition to the relay communication mode, a specific terminal accommodated in the relay communication area of the specific base station when the specific base station transitions to the relay communication mode among the plurality of terminals, an adjacent area of another base station adjacent to the relay communication area of the specific base station, and a specific access class assigned to the SIM (Subscriber Identity Module) of the specific terminal are registered in advance. When a failure in communication between the specific base station and the EPC for wide-area communication is detected, it is determined that the specific base station has transitioned to the relay communication mode, and the other base station is instructed to restrict the connection of the specific terminal with the specific access class assigned to the SIM to the adjacent area.

[0013] A monitoring method according to one aspect A monitoring method executed by a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are connected to the EPC for wide-area communication and operate in a wide-area communication mode during normal times, and a plurality of terminals, comprising: For a specific base station among the plurality of base stations that can transition to a relay communication mode, registering in advance a specific terminal among the plurality of terminals that is accommodated in the relay communication area of the specific base station when the specific base station transitions to the relay communication mode, and an adjacent area of another base station adjacent to the relay communication area of the specific base station; When detecting a failure in communication between the specific base station and the EPC for wide-area communication, determining that the specific base station has transitioned to the relay communication mode, and instructing the EPC for wide-area communication to delete terminal information of the specific terminal among the specific terminals that is accommodated in the adjacent area from the EPC for wide-area communication.

[0014] A monitoring method according to another aspect is as follows: A monitoring method executed by a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are connected to the EPC for wide-area communication and operate in a wide-area communication mode during normal times, and a plurality of terminals, comprising: For a specific base station among the plurality of base stations that can transition to a relay communication mode, registering in advance a specific terminal among the plurality of terminals that is accommodated in the relay communication area of the specific base station when the specific base station transitions to the relay communication mode, an adjacent area of another base station adjacent to the relay communication area of the specific base station, and a specific access class assigned to the SIM (Subscriber Identity Module) of the specific terminal; When detecting a failure in communication between the specific base station and the EPC for wide-area communication, determining that the specific base station has transitioned to the relay communication mode, and instructing the other base station to restrict connection of the specific terminal with the specific access class assigned to the SIM to the adjacent area.

[0015] A program according to one aspect is for a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in a wide-area communication mode, and a plurality of terminals, for a specific base station among the plurality of base stations that can transition to a fold-back communication mode, a specific terminal that is accommodated in the fold-back communication area of the specific base station when the specific base station transitions to the fold-back communication mode among the plurality of terminals, and an adjacent area of another base station adjacent to the fold-back communication area of the specific base station, a procedure for pre-registering; when a communication failure between the specific base station and the EPC for wide-area communication is detected, determining that the specific base station has transitioned to the fold-back communication mode, and instructing the EPC for wide-area communication to delete terminal information of the specific terminal accommodated in the adjacent area from among the specific terminals.

[0016] A program according to another aspect is for a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in a wide-area communication mode, and a plurality of terminals, for a specific base station among the plurality of base stations that can transition to a fold-back communication mode, a specific terminal that is accommodated in the fold-back communication area of the specific base station when the specific base station transitions to the fold-back communication mode among the plurality of terminals, an adjacent area of another base station adjacent to the fold-back communication area of the specific base station, and a specific access class assigned to the SIM (Subscriber Identity Module) of the specific terminal, a procedure for pre-registering; when a communication failure between the specific base station and the EPC for wide-area communication is detected, determining that the specific base station has transitioned to the fold-back communication mode, and instructing the other base station to restrict connection of the specific terminal, to which the specific access class is assigned to the SIM, to the adjacent area. [Effect of the Invention]

[0017] According to the above aspect, an effect is obtained in that a communication system, a monitoring device, a monitoring method, and a program that can contribute to accommodating a specific terminal in a folded-back communication area can be provided. [Brief Description of the Drawings]

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Embodiments for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that, for the sake of clarity of explanation, the following description and drawings are appropriately omitted and simplified. Also, in each of the following drawings, the same elements are denoted by the same reference numerals, and redundant explanations are omitted as necessary. Further, the specific numerical values and the like shown below are merely examples for facilitating the understanding of the present disclosure, and are not limited thereto.

[0020] <Related Art> Before describing the embodiments of the present disclosure, the related art will be described. First, with reference to FIG. 1, a configuration example of the communication system 9S will be described. As shown in FIG. 1, the communication system 9S includes base stations 20-A and 20-B, terminals 30-1 to 30-5, a wide area communication network 40, an EPC 50-1 for wide area communication, an EPC 50-2 for relay communication, and application servers 60-1 and 60-2, and is a communication system using LTE.

[0021] In the drawings shown in FIG. 1 and hereinafter, the base stations 20-A and 20-B are appropriately shown as base stations A and B. Also, the terminals 30-1 to 30-5 are appropriately shown as terminals 1 to 5. Further, the EPC 50-1 for wide area communication is appropriately shown as EPC #1. Also, the EPC 50-2 for relay communication is appropriately shown as #2.

[0022] Also, in the following description, when not specifying which base stations 20-A and 20-B, they are referred to as base station 20. Also, when not specifying which terminals 30-1 to 30-5, they are referred to as terminal 30.

[0023] Also, in the drawings shown in FIG. 1 and hereinafter, two base stations 20 and four or five terminals 30 are respectively shown. However, the number of these components is an example and is not limited thereto.

[0024] The EPC50-1 for wide-area communication is connected to the wide-area communication network 40 and is an EPC that enables mutual communication between terminals 30 belonging to the communication areas of different base stations 20-A and 20-B. On the other hand, the EPC50-2 for relay communication is connected to the base station 20-A.

[0025] The base station 20-B is a base station that can transition to the relay communication mode. That is, normally, the base station 20-B is connected to the EPC50-1 for wide-area communication via the wide-area communication network 40 and operates in the wide-area communication mode to provide wide-area communication services. Therefore, normally, the EPC50-2 for relay communication is not used. However, when a failure occurs in the communication with the EPC50-1 for wide-area communication, the base station 20-B connects to the EPC50-2 for relay communication, transitions to the relay communication mode, and provides relay communication services.

[0026] On the other hand, the base station 20-A is a base station that cannot transition to the relay communication mode. That is, normally, the base station 20-A is connected to the EPC50-1 for wide-area communication via the wide-area communication network 40 and operates in the wide-area communication mode to provide wide-area communication services. However, when a failure occurs in the communication with the EPC50-1 for wide-area communication, the base station 20-A does not transition to the relay communication mode.

[0027] Next, with reference to FIG. 2, an example of the normal operation of the communication system 9S will be described. As shown in FIG. 2, normally, the base stations 20-A and 20-B are connected to the EPC50-1 for wide-area communication via the wide-area communication network 40, operate in the wide-area communication mode, and provide wide-area communication services.

[0028] Therefore, the communication areas of base stations 20-A and 20-B both become wide-area communication areas. Therefore, among terminals 30-1 to 30-5 accommodated in the communication areas (wide-area communication areas) of base stations 20-A and 20-B, any terminals 30 can communicate with each other. For example, communication is possible between terminal 30-2 accommodated in the communication area (wide-area communication area) of base station 20-A and terminal 30-3 accommodated in the communication area (wide-area communication area) of base station 20-B (state S101).

[0029] Next, with reference to FIG. 3, an operation example when a failure occurs in the communication between base station 20-A and EPC 50-1 for wide-area communication in communication system 9S will be described. As shown in FIG. 3, when a failure (such as a line failure) occurs in the communication between base station 20-A and EPC 50-1 for wide-area communication (step S111), base station 20-A cannot connect to EPC 50-1 for wide-area communication. Therefore, base station 20-A connects to EPC 50-2 for relay communication and transitions to the relay communication mode (step S112). As a result, the communication area of base station 20-A becomes a relay communication area. Therefore, communication is possible between terminals 30-1 and 30-2 accommodated in the communication area (relay communication area) of base station 20-A (state S113).

[0030] Also, terminal 30-3 is located at the boundary between the communication area (relay communication area) of base station 20-A and the communication area (wide-area communication area) of base station 20-B. Here, it is assumed that the radio wave from base station 20-B is stronger than the radio wave from base station 20-A. Therefore, terminal 30-3 is accommodated in the communication area (wide-area communication area) of base station 20-B (state S114). Also, terminals 30-4 and 30-5 are also accommodated in the communication area (wide-area communication area) of base station 20-B.

[0031] However, communication cannot be established between base station 20-A and base station 20-B. Therefore, terminals 30-1 and 30-2 accommodated in the communication area (repeater communication area) of base station 20-A and terminals 30-3 to 30-5 accommodated in the communication area (wide-area communication area) of base station 20-B cannot communicate with each other. For example, terminals 30-2 accommodated in the communication area (repeater communication area) of base station 20-A and terminal 30-3 accommodated in the communication area (wide-area communication area) of base station 20-B cannot communicate with each other (state S115).

[0032] Next, with reference to FIG. 4, problems of the communication system 9S will be described. As shown in FIG. 4, when a failure occurs in the communication between base station 20-A and wide-area communication EPC 50-1 (step S121), base station 20-A connects to repeater communication EPC 50-2 and transitions to the repeater communication mode (step S122). When base station 20-A transitions to the repeater communication mode, terminals 30-1 and 30-2 accommodated in the communication area (repeater communication area) of base station 20-A and terminals 30-3 to 30-5 accommodated in the communication area (wide-area communication area) of base station 20-B cannot communicate with each other.

[0033] However, among users who communicate centering on the communication area of base station 20-A, there are also users who, when base station 20-A transitions to the repeater communication mode, want to accommodate specific terminals 30 in the communication area (repeater communication area) of base station 20-A as much as possible and enable mutual communication between the specific terminals 30. Hereinafter, it is assumed that the specific terminals 30 are terminals 30-1 to 30-4.

[0034] However, in a communication system using LTE, the terminal 30 does not have a function to specify the base station 20 and connect to the specified base station 20. Therefore, although the terminal 30-3, which is a specific terminal 30, is located within the communication area (repeater communication area) of the base station 20-A, when the radio wave from the base station 20-B is stronger than the radio wave from the base station 20-A, it is accommodated in the communication area (wide-area communication area) of the base station 20-B (state S123). Therefore, the terminal 30-3 cannot communicate with the terminal 30-2 accommodated in the communication area (repeater communication area) of the base station 20-A (state S124).

[0035] Also, in the communication area (wide-area communication area) of the EPC 50-1 for wide-area communication and the communication area (repeater communication area) of the EPC 50-2 for repeater communication, the system code (PLMN: Public Land Mobile Network) is the same (state S125). Therefore, the terminal 30-3 cannot select the base station 20 by switching the SIM (Subscriber Identity Module).

[0036] Therefore, in order to accommodate the terminal 30-3 in the communication area (repeater communication area) of the base station 20-A, it is necessary to move the terminal 30-3 to a place where the radio wave from the base station 20-A becomes stronger.

[0037] Also, the terminal 30-4, which is a specific terminal 30, is accommodated in the communication area (wide-area communication area) of the base station 20-B. Therefore, the terminal 30-4 cannot notice that the base station 20-A has transitioned to the repeater communication mode. Therefore, it is not possible to prompt the terminal 30-4 to move to the communication area (repeater communication area) of the base station 20-A.

[0038] Therefore, each embodiment described below can contribute to accommodating specific terminals 30, namely terminals 30-1 to 30-4 (especially terminals 30-3 and 30-4 accommodated in the wide-area communication area), in the communication area (repeater communication area) of the base station 20-A when the base station 20-A transitions to the repeater communication mode.

[0039] <Embodiment 1> Hereinafter, Embodiment 1 will be described. First, with reference to FIG. 5, a configuration example of the communication system 1S will be described. As shown in FIG. 5, the communication system 1S differs from the communication system 9S in FIG. 1 in that a monitoring device 10 is provided. Note that, as will be described later, the communication system 1S also includes other components such as a mail server 70, but these other components are omitted from FIG. 5.

[0040] The monitoring device 10 is connected to the wide-area communication network 40. Note that the detailed operation of the monitoring device 10 will be described in the following description of the operation of the communication system 1S.

[0041] Hereinafter, with reference to FIGS. 6 and 7, an operation example of the communication system 1S will be described. Here, it is assumed that the Tracking Area Identifiers (TAIs) of two communication areas of the base station 20-B are “XXX” and “YYY”, respectively.

[0042] As shown in FIG. 6, the monitoring device 10 pre-determines a specific base station 20 that can transition to the fold-back communication mode and registers the information. Further, for the pre-determined specific base station 20, the monitoring device 10 pre-determines a specific terminal 30 to be accommodated in the communication area (fold-back communication area) when the base station 20 transitions to the fold-back communication mode, and the TAI of an adjacent area that is adjacent to the communication area of the base station 20 and is a communication area of another base station 20 other than the base station 20, and registers the information (step S201).

[0043] FIG. 7 shows an example of information predetermined for base station 20-A, which is a specific base station 20 predetermined by monitoring device 10. In the example of FIG. 7, the TAI of the adjacent area of base station 20-A is the TAI "XXX" of the communication area of base station 20-B. Also, the specific terminals 30 to be accommodated in the communication area (repeater communication area) of base station 20-A are terminals 30-1 to 30-4. Hereinafter, it is assumed that the base station 20 predetermined by monitoring device 10 as a specific base station 20 is only base station 20-A.

[0044] The monitoring device 10 monitors the presence or absence of a communication failure between base station 20-A and the EPC 50-1 for wide area communication by periodically checking the communication between base station 20-A, which is a specific base station 20 predetermined in advance, and the EPC 50-1 for wide area communication (step S202).

[0045] When the monitoring device 10 detects a communication failure between base station 20-A and the EPC 50-1 for wide area communication (step S203), it determines that base station 20-A has transitioned to the repeater communication mode.

[0046] Then, based on the registered information, the monitoring device 10 checks terminals 30-1 to 30-4, which were previously determined as specific terminals 30 for base station 20-A, and checks the communication area of the TAI "XXX", which was previously determined as the adjacent area for base station 20-A. Then, the monitoring device 10 selects the terminals 30 among the previously determined terminals 30-1 to 30-4 that are accommodated in the communication area of the previously determined TAI "XXX".

[0047] Specifically, the monitoring device 10 queries the wide-area communication EPC 50-1 for the presence information of terminals 30-1 to 30-4 (step S204). As a result, the monitoring device 10 obtains presence information indicating that terminal 30-3 is accommodated in the communication area of TAI "XXX". Also, the monitoring device 10 obtains presence information indicating that terminal 30-4 is accommodated in the communication area of TAI "YYY". On the other hand, since terminals 30-1 and 30-2 are accommodated in the communication area of base station 20-A (the loop-back communication area), presence information cannot be obtained. Therefore, the monitoring device 10 determines whether the TAI "XXX" and "YYY" of the communication areas in which terminals 30-3 and 30-4 are respectively accommodated match the TAI "XXX" defined in advance as the TAI of the adjacent area for base station 20-A. Here, since the TAI "XXX" of the communication area in which terminal 30-3 is accommodated matches, terminal 30-3 is selected.

[0048] Therefore, the monitoring device 10 requests the wide-area communication EPC 50-1 to delete the terminal information (e.g., SIM information) of terminal 30-3 (step S205). In response to this, the wide-area communication EPC 50-1 deletes the terminal information of terminal 30-3 (step S206).

[0049] Since the terminal information of terminal 30-3 has been deleted from the wide-area communication EPC 50-1, terminal 30-3 can no longer connect to the wide-area communication network 40 (base station 20-B) (state S207). Therefore, terminal 30-3 can be directed to be accommodated in the communication area of base station 20-A (the loop-back communication area). In the example of FIG. 6, terminal 30-3 is located within the communication area of base station 20-A (the loop-back communication area). Therefore, terminal 30-3 is connected to base station 20-A and is accommodated in the communication area of base station 20-A (the loop-back communication area) (state S208). As a result, terminal 30-3 can communicate with terminal 30-2 accommodated in the communication area of base station 20-A (the loop-back communication area) (state S209).

[0050] In addition, the terminal 30-4 is not accommodated in the communication area of the TAI "XXX" that has been previously defined as an adjacent area for the base station 20-A. Therefore, the terminal information of the terminal 30-4 is not deleted from the EPC 50-1 for wide-area communication, and the state of being connected to the wide-area communication network 40 continues (state S210).

[0051] Also, the terminal 30-5 is not a specific terminal 30 previously defined for the base station 20-A. Therefore, the terminal information of the terminal 30-5 is not deleted from the EPC 50-1 for wide-area communication, and the state of being connected to the wide-area communication network 40 continues (state S211).

[0052] The processes of steps S202 to S206 described above are repeatedly executed periodically until the communication failure between the base station 20-A and the EPC 50-1 for wide-area communication, which was previously defined in the process of step S201, is recovered.

[0053] Next, with reference to FIG. 8, problems that occur along with the operations described in FIG. 6 in the communication system 1S will be described. As shown in FIG. 8, among the terminals 30 from which the terminal information has been deleted from the EPC 50-1 for wide-area communication, it is assumed that there will be terminals 30 located outside the communication area (handover communication area) of the base station 20-A. Here, it is assumed that the terminal 30-3 has had its terminal information deleted from the EPC 50-1 for wide-area communication and is located outside the communication area (handover communication area) of the base station 20-A.

[0054] In this case, since the terminal 30-3 is located outside the communication area (handover communication area) of the base station 20-A, it cannot be connected to the base station 20-A (state S221). Also, since the terminal information of the terminal 30-3 has been deleted from the EPC 50-1 for wide-area communication, it can no longer be connected to the base station 20-B either (state S222). However, the terminal 30-3 cannot recognize that the reason it can no longer be connected to the base station 20-B is due to the transition to the handover communication mode of the previously defined base station 20-A (state S223). Therefore, the terminal 30-3 cannot be accommodated (moved) into the communication area (handover communication area) of the base station 20-A.

[0055] In addition, among the terminals 30 previously specified as specific terminals for the base station 20-A, there may be a terminal 30 that is not accommodated in the communication area of the TAI "XXX" previously defined as an adjacent area for the base station 20-A, and for which terminal information has not been deleted from the EPC 50-1 for wide-area communication. Here, it is assumed that the terminal 30-4 is not accommodated in the communication area of the TAI "XXX" and terminal information has not been deleted from the EPC 50-1 for wide-area communication.

[0056] In this case, the terminal 30-4 remains connected to the wide-area communication network 40 (state S224). However, the terminal 30-4 does not know that the previously defined base station 20-A has transitioned to the folded-back communication mode (that is, it can no longer communicate with the terminals 30 accommodated in the communication area (folded-back communication area) of the base station 20-A). Therefore, even if the terminal 30-4 needs to move to the communication area (folded-back communication area) of the base station 20-A, it cannot move.

[0057] Therefore, hereinafter, in the communication system 1S, an operation example performed as a countermeasure for the problem described with reference to FIG. 8 will be described. First, with reference to FIGS. 9 to 10, an operation example performed as a countermeasure for the problem of the terminal 30-3 described with reference to FIG. 8 in the communication system 1S will be described.

[0058] As shown in FIG. 9, since the terminal information of the terminal 30-3 has been deleted from the EPC 50-1 for wide-area communication, the terminal 30-3 receives a Reject from the EPC 50-1 for wide-area communication. In addition, since the terminal 30-3 is located outside the communication area (folded-back communication area) of the base station 20-A, it transitions from within the circle (within the communication area of the TAI "XXX" of the base station 20-B) to outside the circle (step S231).

[0059] Terminal 30-3 receives a Reject from the wide-area communication EPC 50-1 and, upon receiving the transition from within the circle to outside the circle, displays a screen as shown in FIG. 10 on the screen of terminal 30-3 (step S232).

[0060] That is, terminal 30-3 displays, on the screen of terminal 30-3, a message indicating that the predetermined base station 20-A has transitioned to the folded-back communication mode and a message prompting the user of terminal 30-3 to move to the communication area (folded-back communication area) of base station 20-A.

[0061] Furthermore, terminal 30-3 also displays, on the screen of terminal 30-3 together with the above messages, an area map of the communication area (folded-back communication area) of base station 20-A and the current position information of terminal 30-3 superimposed on a map.

[0062] Note that among the information necessary for terminal 30-3 to display the above screen, except for the position information of terminal 30-3, it is held in advance inside terminal 30-3, and the position information of terminal 30-3 is acquired by GPS (Global Positioning System). Thereby, terminal 30-3 can display the above screen even in an out-of-circle state. Also, assume that the above function of terminal 30-3 is also provided in a specific terminal 30 other than terminal 30-3.

[0063] Next, with reference to FIG. 11, in communication system 1S, an example of an operation performed as a countermeasure for the problem of terminal 30-4 described in FIG. 8 will be described. As shown in FIG. 11, terminal 30-4 is accommodated not in the communication area of TAI "XXX" previously defined as an adjacent area for base station 20-A but in the communication area of TAI "YYY". Therefore, the terminal information of terminal 30-4 is not deleted from the wide-area communication EPC 50-1, and the state of being connected to the wide-area communication network 40 continues (state S241).

[0064] Therefore, the monitoring device 10 notifies the terminal 30-4 by email of a message indicating that the predetermined base station 20-A has transitioned to the folded-back communication mode (step S242).

[0065] Next, with reference to FIGS. 12 and 13, an example of the operation sequence of the communication system 1S will be described. FIGS. 12 and 13 show the operation sequence diagram of the communication system 1S divided vertically into two parts and represented by two drawings.

[0066] Also, here, it is assumed that the predetermined specific base station 20 is the base station 20-A, the predetermined specific terminals 30 for the base station 20-A are the terminals 30-1 to 30-4, and the adjacent area predetermined for the base station 20-A is the communication area of the TAI "XXX" of the base station 20-B.

[0067] As shown in FIGS. 12 and 13, the monitoring device 10 periodically monitors the presence or absence of a communication failure between the base station 20-A and the EPC 50-1 for wide-area communication by checking the SCTP (Stream Control Transmission Protocol) session with the EPC 50-1 for wide-area communication (steps S251, S252). Here, it is assumed that in step S252, a communication failure between the base station 20-A and the EPC 50-1 for wide-area communication is detected.

[0068] Then, the monitoring device 10 determines that the base station 20-A has transitioned to the folded-back communication mode, and sequentially inquires of the EPC 50-1 for wide-area communication about the presence information of the terminals 30-1 to 30-4 predetermined for the base station 20-A (steps S253, S254, S255, S257).

[0069] Here, it is assumed that the terminals 30-1 and 30-2 are accommodated in the communication area (folded-back communication area) of the base station 20-A. Therefore, in steps S253 and S254, the monitoring device 10 cannot obtain the presence information of the terminals 30-1 and 30-2.

[0070] Also, assume that the terminal 30-3 is within the communication area of the TAI "XXX" of the base station 20-B. Therefore, in step S255, the monitoring device 10 obtains the presence information indicating that the terminal 30-3 is within the communication area of the TAI "XXX". Here, the TAI "XXX" matches the TAI "XXX" of the adjacent area previously defined for the base station 20-A. Therefore, the monitoring device 10 sends an information deletion command to the wide-area communication EPC 50-1 and requests to delete the terminal information of the terminal 30-3 (step S256). In response to this, the wide-area communication EPC 50-1 deletes the terminal information of the terminal 30-3.

[0071] Also, assume that the terminal 30-4 is within the communication area of the TAI "YYY" of the base station 20-B. Therefore, in step S257, the monitoring device 10 obtains the presence information indicating that the terminal 30-4 is within the communication area of the TAI "YYY". Here, the TAI "YYY" does not match the TAI "XXX" of the adjacent area previously defined for the base station 20-A. Therefore, the monitoring device 10 notifies the terminal 30-4 by email, via the mail server 70, of a message indicating that the previously defined base station 20-A has transitioned to the folded-back communication mode (step S258).

[0072] Thereafter, the terminal 30-3 sends updated presence information to the wide-area communication EPC 50-1 (step S259). However, the terminal information of the terminal 30-3 has been deleted from the wide-area communication EPC 50-1. Therefore, the terminal 30-3 receives a Reject from the wide-area communication EPC 50-1 (step S260), and as a result, transitions from within the circle to outside the circle.

[0073] However, it is assumed that the terminal 30-3 is also located within the communication area (the folding communication area) of the base station 20-A. Therefore, the terminal 30-3 transmits a connection request to the base station 20-A (step S261). This connection request is transferred from the base station 20-A to the EPC 50-2 for folding communication. The EPC 50-2 for folding communication permits the connection of the terminal 30-3 and transmits a connection permission to the base station 20-A (step S262). This connection permission is transferred from the base station 20-A to the terminal 30-3. As a result, the terminal 30-3 will be accommodated in the communication area (the folding communication area) of the base station 20-A.

[0074] As described above, according to the first embodiment, the monitoring device 10 pre-determines and registers a specific terminal 30 to be accommodated in the folding communication area, which is the communication area of a specific base station 20 when the specific base station 20 transitions to the folding communication mode, and an adjacent area, which is the communication area of another base station 20 adjacent to the folding communication area of the specific base station 20, for a specific base station 20 that can transition to the folding communication mode. When the monitoring device 10 detects a failure in the communication between the specific base station 20 and the EPC 50-1 for wide-area communication, it determines that the specific base station 20 has transitioned to the folding communication mode. Then, the monitoring device 10 requests the EPC 50-1 for wide-area communication to delete the terminal information of the specific terminal 30 accommodated in the adjacent area from the EPC 50-1 for wide-area communication. Therefore, it is possible to direct the specific terminal 30, which is accommodated in the adjacent area and whose terminal information has been deleted from the EPC 50-1 for wide-area communication, to be accommodated in the folding communication area of the specific base station 20. This can contribute to accommodating the specific terminal 30 in the folding communication area.

[0075] At this time, among the specific terminals 30 whose terminal information has been deleted from the EPC 50-1 for wide-area communication, the specific terminal 30 located within the folding communication area of the specific base station 20 can be accommodated in the folding communication area.

[0076] On one hand, among the specific terminals 30 from which terminal information has been deleted from the wide-area communication EPC50-1, a specific terminal 30 located outside the folded-back communication area of a specific base station 20 displays, on the screen, a message indicating that the specific base station 20 has transitioned to the folded-back communication mode and a message prompting the movement of the specific terminal 30 to the folded-back communication area of the specific base station 20. Further, the monitoring device 10 notifies, by email, a specific terminal 30 for which terminal information has not been deleted from the wide-area communication EPC50-1 of a message indicating that the specific base station 20 has transitioned to the folded-back communication mode. Thereby, the user of the specific terminal 30 located outside the folded-back communication area of the specific base station 20 can be prompted to move to the folded-back communication area of the specific base station 20.

[0077] <Embodiment 2> Hereinafter, Embodiment 2 will be described. In Embodiment 2, for convenience, the communication system is referred to as communication system 2S. The configuration of communication system 2S is the same as that of communication system 1S described above.

[0078] Hereinafter, with reference to FIGS. 14 and 15, an operation example of communication system 2S will be described. Here, it is assumed that the two communication areas of base station 20-B are cell "AAA" and cell "BBB".

[0079] As shown in FIG. 14, the monitoring device 10 pre-determines a specific base station 20 that can transition to the folded-back communication mode and registers the information thereof. Further, for the pre-determined specific base station 20, the monitoring device 10 pre-determines a specific terminal 30 to be accommodated in the communication area (folded-back communication area) when the base station 20 transitions to the folded-back communication mode, a specific AC (Access Class) assigned to the SIM of the specific terminal 30, and an adjacent cell that is adjacent to the communication area of the base station 20 and is a cell of another base station 20 other than the base station 20, and registers the information thereof (step S301).

[0080] FIG. 15 shows an example of information predefined for base station 20-A, which is a predefined specific base station 20 by monitoring device 10. In the example of FIG. 15, the adjacent cell of base station 20-A is cell "AAA" of base station 20-B. Also, specific terminals 30 to be accommodated in the communication area (repeater communication area) of base station 20-A are terminals 30-1 to 30-4. Further, the specific AC allocated to the SIMs of terminals 30-1 to 30-4, which are specific terminals 30, is AC12. Hereinafter, it is assumed that the base station 20 predefined as a specific base station 20 by monitoring device 10 is only base station 20-A.

[0081] Monitoring device 10 monitors the presence or absence of communication failure between base station 20-A and EPC 50-1 for wide area communication by periodically checking the communication between base station 20-A, which is a predefined specific base station 20, and EPC 50-1 for wide area communication (step S302).

[0082] When monitoring device 10 detects a communication failure between base station 20-A and EPC 50-1 for wide area communication (step S303), it determines that base station 20-A has transitioned to the repeater communication mode.

[0083] Then, based on the registered information, monitoring device 10 checks cell "AAA" of base station 20-B, which was predefined as the adjacent cell for base station 20-A, also checks terminals 30-1 to 30-4, which were predefined as specific terminals 30 for base station 20-A, and also checks AC12, which was predefined as the specific AC for base station 20-A. Then, monitoring device 10 sends an AC connection restriction command to base station 20-B to restrict the connection of terminals 30 with AC12 allocated to their SIMs to cell "AAA" (step S304). Note that monitoring device 10 may also predefine an AC connection restriction command for a specific base station 20 and register the information.

[0084] Then, the terminals 30 with AC12 allocated to their SIMs cannot connect to cell "AAA" due to the AC connection restriction. Here, the predetermined terminal 30-3 is located at the boundary between the communication area (the folded-back communication area) of the base station 20-A and the cell "AAA" (the wide-area communication area) of the base station 20-B. However, due to the relationship of the radio wave strength, it is assumed that the terminal 30-3 is accommodated in the cell "AAA" (the wide-area communication area) of the base station 20-B. However, since AC12 is allocated to the SIM of the terminal 30-3, the terminal 30-3 cannot connect to the cell "AAA" of the base station 20-B where the AC connection restriction is imposed (state S305). Therefore, the terminal 30-3 can be directed to be accommodated in the communication area (the folded-back communication area) of the base station 20-A. In the example of FIG. 14, the terminal 30-3 is also located within the communication area (the folded-back communication area) of the base station 20-A. Therefore, the terminal 30-3 is connected to the base station 20-A and is accommodated in the communication area (the folded-back communication area) of the base station 20-A (state S306). As a result, the terminal 30-3 can communicate with the terminal 30-2 accommodated in the communication area (the folded-back communication area) of the base station 20-A (state S307).

[0085] Also, the predetermined terminal 30-4 is accommodated in the cell "BBB" of the base station 20-B where the AC connection restriction is not imposed. Therefore, the terminal 30-4 continues to be connected to the wide-area communication network 40 (state S308).

[0086] Also, the terminal 30-5 is accommodated in the cell "AAA" of the base station 20-B. However, since the terminal 30-5 is not a specific terminal 30 predetermined for the base station 20-A, AC12 is not allocated to the SIM, and the AC connection restriction cannot be imposed. Therefore, the terminal 30-5 continues to be connected to the wide-area communication network 40 (state S309).

[0087] Next, with reference to FIG. 16, in the communication system 2S, problems that occur accompanying the operations described in FIG. 14 will be described. As shown in FIG. 16, among the terminals 30 previously specified as specific terminals for the base station 20-A, there may be a terminal 30 that is subject to AC connection restriction in the cell "AAA" of the base station 20-B previously defined as an adjacent cell for the base station 20-A and is located outside the communication area (repeater communication area) of the base station 20-A. Here, assume that the terminal 30-3 is subject to AC connection restriction in the cell "AAA" of the base station 20-B and is located outside the communication area (repeater communication area) of the base station 20-A.

[0088] In this case, since the terminal 30-3 is located outside the communication area (repeater communication area) of the base station 20-A, it cannot be connected to the base station 20-A (state S311). Also, since the terminal 30-3 is subject to AC connection restriction, it cannot be connected to the base station 20-B either (state S312). However, the terminal 30-3 cannot recognize that the reason it cannot be connected to the base station 20-B is due to the transition to the repeater communication mode of the previously defined base station 20-A (state S313). Therefore, the terminal 30-3 cannot be accommodated (moved) into the communication area (repeater communication area) of the base station 20-A.

[0089] Moreover, among the terminals 30 previously specified as specific terminals for the base station 20-A, there may be a terminal 30 that is not accommodated in the cell "AAA" previously defined as an adjacent cell for the base station 20-A and is not subject to AC connection restriction. Here, assume that the terminal 30-4 is not accommodated in the cell "AAA" and is not subject to AC connection restriction.

[0090] In this case, the terminal 30-4 remains connected to the wide area communication network 40 (state S314). However, the terminal 30-4 does not know that the predetermined base station 20-A has transitioned to the folded-back communication mode (that is, the mutual communication with the terminal 30 accommodated in the communication area (folded-back communication area) of the base station 20-A has become impossible). Therefore, even if the terminal 30-4 needs to move to the communication area (folded-back communication area) of the base station 20-A, it cannot move.

[0091] Therefore, hereinafter, in the communication system 2S, an operation example performed as a countermeasure for the problem described with reference to FIG. 16 will be described. First, with reference to FIG. 17, in the communication system 2S, an operation example performed as a countermeasure for the problem of the terminal 30-3 described with reference to FIG. 16 will be described.

[0092] As shown in FIG. 17, when the base station 20-B receives from the monitoring device 10 an AC connection restriction command for restricting the connection to the cell "AAA" of the terminal 30 to which AC12 is allocated in the SIM, the base station 20-B notifies AC12, to which the AC connection restriction is applied, into the cell "AAA" (step S321). This notification is also received by the terminal 30-3.

[0093] Since the AC connection restriction is applied to the terminal 30-3 in the cell "AAA" of the base station 20-B and the terminal 30-3 is located outside the communication area (folded-back communication area) of the base station 20-A, the terminal 30-3 transitions from within the circle (within the circle of the cell "AAA" of the base station 20-B) to outside the circle (step S322).

[0094] The terminal 30-3 confirms, based on the notification, that the AC connection restriction is applied to the terminal 30-3, and in response to having transitioned from within the circle to outside the circle, the terminal 30-3 displays on the screen of the terminal 30-3 a screen as shown in FIG. 10 above (step S323).

[0095] That is, the terminal 30-3 displays, on the screen of the terminal 30-3, a message indicating that the predetermined base station 20-A has transitioned to the folded-back communication mode, and a message prompting the user of the terminal 30-3 to move to the communication area (folded-back communication area) of the base station 20-A.

[0096] Furthermore, the terminal 30-3 displays, on the screen of the terminal 30-3, together with the above message, an area map of the communication area (folded-back communication area) of the base station 20-A, and the current position information of the terminal 30-3 superimposed on a map.

[0097] Note that, among the information necessary for the terminal 30-3 to display the above screen, except for the position information of the terminal 30-3, it is held in advance inside the terminal 30-3, and the position information of the terminal 30-3 is acquired by GPS. Thereby, the terminal 30-3 can display the above screen even in an out-of-service area. Also, it is assumed that the above function of the terminal 30-3 is also provided in a specific terminal 30 other than the terminal 30-3.

[0098] Next, referring to FIG. 18, in the communication system 2S, an operation example performed as a countermeasure for the problem of the terminal 30-4 described in FIG. 16 will be described. As shown in FIG. 18, the monitoring device 10 notifies, by mail, all the terminals 30-1 to 30-4 defined in advance as specific terminals 30 for the predetermined base station 20-A, of a message indicating that the predetermined base station 20-A has transitioned to the folded-back communication mode (step S331).

[0099] Here, the terminals 30-1 and 30-2 are accommodated in the communication area (folded-back communication area) of the base station 20-A. Also, the terminal 30-3 is under AC connection restriction in the cell "AAA" of the base station 20-B. Therefore, since the terminals 30-1 to 30-3 are not connected to the wide-area communication network 40, they cannot receive the mail from the monitoring device 10 (state S332).

[0100] On the other hand, the terminal 30-4 is accommodated in the cell "BBB" of the base station 20-B where AC connection restriction is not imposed. Therefore, since the terminal 30-4 remains connected to the wide-area communication network 40, it can receive emails from the monitoring device 10 (state S333).

[0101] Next, with reference to FIGS. 19 and 20, an example of the operation sequence of the communication system 2S will be described. Note that FIGS. 19 and 20 show the operation sequence diagram of the communication system 2S divided vertically into two parts and represented by two drawings.

[0102] Also, here, it is assumed that the specific base station 20 determined in advance is the base station 20-A, the specific terminals 30 determined in advance for the base station 20-A are the terminals 30-1 to 30-4, the specific AC determined in advance for the base station 20-A is AC12, and the adjacent cell determined in advance for the base station 20-A is the cell "AAA" of the base station 20-B.

[0103] As shown in FIGS. 19 and 20, the monitoring device 10 periodically checks the SCTP (Stream Control Transmission Protocol) session with the wide-area communication EPC 50-1 to monitor the presence or absence of communication failure between the predetermined base station 20-A and the wide-area communication EPC 50-1 (steps S341, S342). Here, it is assumed that in step S342, a communication failure between the base station 20-A and the wide-area communication EPC 50-1 is detected.

[0104] Then, the monitoring device 10 determines that the base station 20-A has transitioned to the fallback communication mode, and transmits an AC connection restriction command to the base station 20-B to restrict the connection of the terminal 30 with AC12 assigned to the SIM to the cell "AAA" (step S343).

[0105] When the base station 20-B receives the AC connection restriction command from the monitoring device 10, it restricts the connection of the terminal 30 to which AC12 is allocated in the SIM to the cell "AAA". As a result, the terminal 30 to which AC12 is allocated in the SIM cannot connect to the cell "AAA" because the AC connection restriction is applied.

[0106] Also, when the base station 20-B receives the AC connection restriction command from the monitoring device 10, it notifies the inside of the cell "AAA" of the AC12 to which the AC connection restriction is applied (step S344).

[0107] Here, it is assumed that the terminal 30-3 was accommodated in the cell "AAA" of the base station 20-B. Therefore, the terminal 30-3 can confirm that the AC connection restriction is applied to the terminal 30-3 by the notification. Also, the terminal 30-3 cannot connect to the cell "AAA" because the AC connection restriction is applied, and it transitions from inside the coverage area to outside the coverage area.

[0108] However, it is assumed that the terminal 30-3 is also located within the communication area (handover communication area) of the base station 20-A. Therefore, the terminal 30-3 transmits a connection request to the base station 20-A (step S345). This connection request is transferred from the base station 20-A to the EPC 50-2 for handover communication. The EPC 50-2 for handover communication permits the connection of the terminal 30-3 and transmits a connection permission to the base station 20-A (step S346). This connection permission is transferred from the base station 20-A to the terminal 30-3. As a result, the terminal 30-3 will be accommodated in the communication area (handover communication area) of the base station 20-A.

[0109] Also, while transmitting the AC connection restriction command to the base station 20-B, the monitoring device 10 notifies all the terminals 30-1 to 30-4 by email of a message indicating that the base station 20-A has transitioned to the handover communication mode (steps S347 to S350).

[0110] Here, it is assumed that the terminals 30-1 and 30-2 are accommodated in the communication area (the folding communication area) of the base station 20-A. Also, as described above, for the terminal 30-3, in the cell "AAA" of the base station 20-B, an AC connection restriction is imposed, and it is in a state of having transitioned from within the circle to outside the circle, or in a state of being accommodated in the communication area (the folding communication area) of the base station 20-A. Therefore, the terminals 30-1 to 30-3 cannot receive emails from the monitoring device 10.

[0111] On the other hand, it is assumed that the terminal 30-4 is accommodated in the cell "BBB" of the base station 20-B where no AC connection restriction is imposed. Therefore, the terminal 30-4 can receive emails from the monitoring device 10.

[0112] As described above, according to the second embodiment, the monitoring device 10 pre-determines and registers, for a specific base station 20 that can transition to the folding communication mode, a specific terminal 30 accommodated in the folding communication area which is the communication area of the specific base station 20 when the specific base station 20 transitions to the folding communication mode, an adjacent cell which is a cell of another base station 20 adjacent to the folding communication area of the specific base station 20, and a specific AC allocated to the specific terminal 30. When the monitoring device 10 detects a communication failure between the specific base station 20 and the EPC 50-1 for wide-area communication, it determines that the specific base station 20 has transitioned to the folding communication mode. Then, the monitoring device 10 transmits an AC connection restriction command to the other base station 20 to restrict the connection of the specific terminal 30 with the specific AC allocated to the SIM to the adjacent cell. Therefore, it is possible to direct the specific terminal 30 accommodated in the above adjacent cell and subject to the connection restriction to the above adjacent cell to be accommodated in the folding communication area of the specific base station 20. This can contribute to accommodating the specific terminal 30 in the folding communication area.

[0113] At this time, among the specific terminals 30 subject to the connection restriction to the above adjacent cell, the specific terminal 30 located within the folding communication area of the specific base station 20 can be accommodated in the folding communication area.

[0114] On the other hand, among the specific terminals 30 to which connection restriction to the adjacent cells is applied, a specific terminal 30 located outside the folded communication area of a specific base station 20 displays, on the screen, a message indicating that the specific base station 20 has transitioned to the folded communication mode and a message prompting movement to the folded communication area of the specific base station 20. Further, the monitoring device 10 notifies, by mail, all the specific terminals 30 of a message indicating that the specific base station 20 has transitioned to the folded communication mode. Thereby, it is possible to prompt the user of the specific terminal 30 located outside the folded communication area of the specific base station 20 to move to the folded communication area of the specific base station 20.

[0115] <Embodiment 3> This Embodiment 3 corresponds to an embodiment obtained by conceptually generalizing the above-described Embodiment 1. First, with reference to FIG. 21, a configuration example of the communication system 3S will be described.

[0116] As shown in FIG. 21, the communication system 3S includes a monitoring device 100, base stations 200-A and 200-B, terminals 300-1 to 300-4, a wide area communication network 400, and an EPC 500 for wide area communication. Here, in FIG. 21, the communication area a is the communication area of the base station 200-A, and the communication areas b1 and b2 are the communication areas of the base station 200-B.

[0117] In the following description, when not specifying which of the base stations 200-A and 200-B it is, it is referred to as the base station 200. Also, when not specifying which of the terminals 300-1 to 300-4 it is, it is referred to as the terminal 300. Also, in FIG. 21, two base stations 200 and four terminals 30 are shown respectively. However, the number of these components is an example and is not limited thereto.

[0118] The base stations 200-A and 200-B are connected to the EPC 500 for wide area communication and operate in the wide area communication mode during normal times.

[0119] The monitoring device 100 pre-registers the following information in advance for a specific base station 200 among the base stations 200-A and 200-B that can transition to the repeater communication mode. · Among the terminals 300-1 to 300-4, a specific terminal 300 that is accommodated in the repeater communication area, which is the communication area of the specific base station 200 when the specific base station 200 transitions to the repeater communication mode · An adjacent area that is the communication area of another base station 200 adjacent to the repeater communication area of the specific base station 200

[0120] The monitoring device 100 monitors the communication failure between the specific base station 200 and the EPC 500 for wide area communication. When a failure is detected, it determines that the specific base station 200 has transitioned to the repeater communication mode. Then, the monitoring device 100 instructs the EPC 500 for wide area communication to delete the terminal information of the specific terminal 300 among the specific terminals 300 that is accommodated in the adjacent area from the EPC 500 for wide area communication.

[0121] Here, it is assumed that the base station 200-A is the specific base station 200 that can transition to the repeater communication mode. Therefore, the communication area a of the base station 200-A becomes the repeater communication area. Also, the communication area b1 of the base station 200-B is adjacent to the communication area a. Therefore, the base station 200-B becomes another base station 200, and the communication area b1 of the base station 200-B becomes the adjacent area.

[0122] Also, here, it is assumed that the terminals 300-1 to 300-4 are the specific terminals 300. Also, before the occurrence of a communication failure between the base station 200-A and the EPC 500 for wide area communication, it is assumed that the terminal 300-1 is accommodated in the communication area a of the base station 200-A, the terminals 300-2 and 300-3 are accommodated in the communication area b1 of the base station 200-B, and the terminal 300-4 is accommodated in the communication area b2 of the base station 200-B.

[0123] Therefore, for base station 200-A, which is a specific base station 200, the monitoring device 100 pre-registers terminals 300-1 to 300-4 as specific terminals 300, and communication area b1 of base station 200-B as an adjacent area of other base stations 200.

[0124] In addition, the monitoring device 100 monitors the communication failure between base station 200-A and the EPC 500 for wide-area communication. When a failure is detected, it is determined that base station 200-A has transitioned to the fallback communication mode. Then, the monitoring device 100 instructs the EPC 500 for wide-area communication to delete the terminal information of terminals 300-2 and 300-3, which are among the specific terminals 300-1 to 300-4 and are accommodated in the above adjacent area (communication area b1), from the EPC 500 for wide-area communication.

[0125] Next, with reference to FIG. 22, an example of the operation flow of communication system 3S will be described. As shown in FIG. 22, the monitoring device 100 pre-registers the following for a specific base station 200 that can transition to the fallback communication mode (step S401). · Specific terminals 300 to be accommodated in the fallback communication area, which is the communication area of the specific base station 200 when the specific base station 200 transitions to the fallback communication mode · Adjacent area, which is the communication area of another base station 200 adjacent to the fallback communication area of the specific base station 200

[0126] The monitoring device 100 monitors the communication failure between the specific base station 200 and the EPC 500 for wide-area communication (step S402). When a failure is detected (Yes in step S403), it is determined that the specific base station 200 has transitioned to the fallback communication mode (step S404).

[0127] Then, the monitoring device 100 instructs the EPC 500 for wide-area communication to delete the terminal information of the specific terminals 300 that are accommodated in the above adjacent area from the EPC 500 for wide-area communication (step S405).

[0128] As described above, according to the third embodiment, for a specific base station 200 that can transition to the folded-back communication mode, the monitoring device 100 pre-registers a specific terminal 30 accommodated in the folded-back communication area, which is the communication area of the specific base station 200 when the specific base station 200 transitions to the folded-back communication mode, and an adjacent area, which is the communication area of another base station 20 adjacent to the folded-back communication area of the specific base station 200. When the monitoring device 100 detects a communication failure between the specific base station 200 and the EPC 500 for wide-area communication, it determines that the specific base station 200 has transitioned to the folded-back communication mode. Then, the monitoring device 100 instructs the EPC 500 for wide-area communication to delete the terminal information of the specific terminal 300 accommodated in the adjacent area from the EPC 500 for wide-area communication. Therefore, the specific terminal 300 accommodated in the adjacent area and whose terminal information has been deleted from the EPC 500 for wide-area communication can be directed to be accommodated in the folded-back communication area of the specific base station 200. This can contribute to accommodating the specific terminal 300 in the folded-back communication area.

[0129] Among the specific terminals 300 whose terminal information has been deleted from the EPC 500 for wide-area communication and are located outside the folded-back communication area of the specific base station 200, the specific terminal 300 may display on the screen a message indicating that the specific base station 200 has transitioned to the folded-back communication mode and a message prompting movement to the folded-back communication area of the specific base station 200. Further, on the above screen, the specific terminal 300 may also display, superimposed on a map, an area diagram of the folded-back communication area of the specific base station 200 and the current position information of the specific terminal 300.

[0130] Here, the specific terminals 300 from which the terminal information has been deleted from the EPC 500 for wide-area communication are terminals 300-2 and 300-3. Among these, since terminal 300-2 is located within the folded-back communication area of base station 200-A, which is a specific base station 200, it can be accommodated within the folded-back communication area. On the other hand, since terminal 300-3 is located outside the folded-back communication area of base station 200-A, the above screen is displayed. Therefore, the user of terminal 300-3 can be prompted to move to the folded-back communication area.

[0131] In addition, the monitoring device 100 may notify, by email, a message indicating that a specific base station 200 has transitioned to the folded-back communication mode to a specific terminal 300 from which the terminal information has not been deleted from the EPC 500 for wide-area communication.

[0132] Here, the specific terminal 300 from which the terminal information has not been deleted from the EPC 500 for wide-area communication is terminal 300-4. Therefore, the user of terminal 300-4 can be prompted to move to the folded-back communication area of the specific base station 20.

[0133] <Embodiment 4> This Embodiment 4 corresponds to an embodiment that generalizes the above-described Embodiment 2 to a higher concept. In this Embodiment 4, the communication system is, for convenience, referred to as communication system 4S. The configuration of communication system 4S is the same as that of the above-described communication system 3S.

[0134] The monitoring device 100 pre-registers the following for a specific base station 200 among base stations 200-A and 200-B that can transition to the folded-back communication mode. · Among terminals 300-1 to 300-4, a specific terminal 300 that is accommodated in the folded-back communication area, which is the communication area of the specific base station 200 when the specific base station 200 transitions to the folded-back communication mode · The adjacent area, which is the communication area of another base station 200 adjacent to the folded-back communication area of the specific base station 200 · The specific AC (access class) assigned to the SIM of the specific terminal 300

[0135] The monitoring device 100 monitors the communication failure between a specific base station 200 and the EPC 500 for wide-area communication. When a failure is detected, it determines that the specific base station 200 has transitioned to the fallback communication mode. Then, the monitoring device 100 instructs the other base station 200 as described above to restrict the connection of a specific terminal 300, to which a specific AC is assigned in the SIM, to the adjacent area as described above.

[0136] Here, it is assumed that the base station 200-A is a specific base station 200 that can transition to the fallback communication mode. Therefore, the communication area a of the base station 200-A becomes the fallback communication area. Also, the communication area b1 of the base station 200-B is adjacent to the communication area a. Therefore, the base station 200-B becomes the other base station 200, and the communication area b1 of the base station 200-B becomes the adjacent area.

[0137] Also, here, it is assumed that the terminals 300-1 to 300-4 are specific terminals 300. Before the occurrence of the communication failure between the base station 200-A and the EPC 500 for wide-area communication, the terminal 300-1 is accommodated in the communication area a of the base station 200-A, the terminals 300-2 and 300-3 are accommodated in the communication area b1 of the base station 200-B, and the terminal 300-4 is accommodated in the communication area b2 of the base station 200-B.

[0138] Therefore, the monitoring device 100 pre-registers the terminals 300-1 to 300-4 as specific terminals 300 for the base station 200-A, which is a specific base station 200, the communication area b1 of the base station 200-B as the adjacent area of the other base station 200, and the ACs assigned to the terminals 300-1 to 300-4 as specific ACs.

[0139] Also, the monitoring device 100 monitors the communication failure between the base station 200-A and the EPC 500 for wide-area communication. When a failure is detected, it determines that the base station 200-A has transitioned to the fallback communication mode. Then, the monitoring device 100 instructs the base station 200-B to restrict the connection of the terminals 300-1 to 300-4, to which a specific AC is assigned in the SIM, to the communication area b1, which is the adjacent area as described above.

[0140] Next, with reference to FIG. 23, an example of the operation flow of the communication system 4S will be described. As shown in FIG. 23, the monitoring device 100 pre-registers the following for a specific base station 200 that can transition to the folded-back communication mode (step S411). · A specific terminal 300 accommodated in the folded-back communication area, which is the communication area of the specific base station 200 when the specific base station 200 transitions to the folded-back communication mode · An adjacent area, which is the communication area of another base station 200 adjacent to the folded-back communication area of the specific base station 200 · A specific AC assigned to the SIM of the specific terminal 300

[0141] The monitoring device 100 monitors the communication failure between the specific base station 200 and the EPC 500 for wide-area communication (step S412). When a failure is detected (Yes in step S413), it is determined that the specific base station 200 has transitioned to the folded-back communication mode (step S414).

[0142] Then, the monitoring device 100 instructs the other base station 200 to restrict the connection of the specific terminal 300 with the specific AC assigned to the SIM to the above adjacent area (step S415).

[0143] As described above, according to the fourth embodiment, for a specific base station 200 that can transition to the folded-back communication mode, the monitoring device 100 pre-registers a specific terminal 300 accommodated in the folded-back communication area, which is the communication area of the specific base station 200 when the specific base station 200 transitions to the folded-back communication mode, an adjacent area that is the communication area of another base station 20 adjacent to the folded-back communication area of the specific base station 200, and a specific AC assigned to the specific terminal 300. When the monitoring device 100 detects a communication failure between the specific base station 200 and the EPC 500 for wide-area communication, it determines that the specific base station 200 has transitioned to the folded-back communication mode. Then, the monitoring device 100 instructs the above-mentioned other base station 200 to restrict the connection of the specific terminal 300, to which the specific AC is assigned in the SIM, to the above-mentioned adjacent area. Therefore, it is possible to direct the specific terminal 300, which is accommodated in the above-mentioned adjacent area and whose connection to the above-mentioned adjacent area is restricted, to be accommodated in the folded-back communication area of the specific base station 200. This can contribute to accommodating the specific terminal 300 in the folded-back communication area.

[0144] Among the specific terminals 300 whose connection to the above-mentioned adjacent area is restricted, the specific terminal 300 located outside the folded-back communication area of the specific base station 200 may display, on the screen, a message indicating that the specific base station 200 has transitioned to the folded-back communication mode and a message prompting the movement of the specific terminal 300 to the folded-back communication area of the specific base station 200. Further, on the above-mentioned screen, the specific terminal 300 may also display, on the map, an area map of the folded-back communication area of the specific base station 200 and the current position information of the specific terminal 300 superimposed on each other.

[0145] Here, the specific terminals 300 whose connection to the adjacent area is restricted are terminals 300-2 and 300-3. Among these, since terminal 300-2 is located within the folded communication area of base station 200-A which is a specific base station 200, it can be accommodated in the folded communication area. On the other hand, since terminal 300-3 is located outside the folded communication area of base station 200-A, the above screen is displayed. Therefore, it is possible to prompt the user of terminal 300-3 to move to the folded communication area.

[0146] In addition, the monitoring device 100 notifies all specific terminals 300 by email of a message indicating that the specific base station 200 has transitioned to the folded communication mode. Here, for terminal 300-4, the connection to the adjacent area is not restricted. Therefore, it is possible to prompt the user of terminal 300-4 to move to the folded communication area of specific base station 20.

[0147] <Hardware Configuration of the Monitoring Device According to the Embodiment> Subsequently, with reference to FIG. 24, a hardware configuration example of a computer 900 that realizes the above-described monitoring devices 10 and 100 will be described. The computer 900 shown in FIG. 9 includes a processor 901 and a memory 902. The processor 901 and the memory 902 are coupled to each other.

[0148] The processor 901 may be, for example, a microprocessor, an MPU (Micro Processing Unit), or a CPU (Central Processing Unit). The processor 901 may include a plurality of processors.

[0149] The memory 902 is composed of a combination of a volatile memory and a non-volatile memory. The memory 902 may include a storage located away from the processor 901. In this case, the processor 901 may access the memory 902 via an I (Input) / O (Output) interface (not shown).

[0150] The memory 902 may store software modules (computer programs) including instruction groups and data for performing the processing by the above-described monitoring devices 10, 100.

[0151] Also, in some implementations, the processor 901 may be configured to perform the processing of the above-described monitoring devices 10, 100 by reading and executing software modules from the memory 902.

[0152] Also, the above-described program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, the computer-readable medium or the tangible storage medium includes RAM, ROM, flash memory, SSD, or other memory technologies, CD (Compact Disc)-ROM, DVD (Digital Versatile Disc), Blu-ray (registered trademark) disc, or other optical disc storage, magnetic cassette, magnetic tape, magnetic disk storage, or other magnetic storage devices. The program may be transmitted on a transitory computer-readable medium or a communication medium. By way of example and not limitation, the transitory computer-readable medium or the communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

[0153] As described above, the present disclosure has been described with reference to the embodiments, but the present disclosure is not limited to the above-described embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. And each embodiment can be combined with other embodiments as appropriate.

[0154] Also, each drawing is merely an illustration for explaining one or more embodiments. Each drawing is not associated with only one specific embodiment, but may be associated with one or more other embodiments. As can be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, embodiments that are not explicitly illustrated or described. Not all of the features or steps shown in any one drawing for explaining exemplary embodiments are necessarily essential, and some features or steps may be omitted. The order of the steps described in any drawing may be changed as appropriate.

[0155] Also, some or all of the above embodiments can be described as follows, but are not limited thereto. (Appendix 1) An EPC (Evolved Packet Core) for wide-area communication, A plurality of base stations that are connected to the EPC for wide-area communication and operate in a wide-area communication mode during normal times, A plurality of terminals, A monitoring device, and The monitoring device For a specific base station among the plurality of base stations that can transition to a folded-back communication mode, when the specific base station transitions to the folded-back communication mode, a specific terminal accommodated in the folded-back communication area of the specific base station and an adjacent area of another base station adjacent to the folded-back communication area of the specific base station are registered in advance, When a communication failure between the specific base station and the EPC for wide-area communication is detected, it is determined that the specific base station has transitioned to the folded-back communication mode, and the EPC for wide-area communication is instructed to delete the terminal information of the specific terminals accommodated in the adjacent area among the specific terminals. A communication system. (Appendix 2) Among the specific terminals from which terminal information has been deleted from the EPC for wide-area communication, the specific terminals located outside the folded-back communication area of the specific base station display, on the screen, a message indicating that the specific base station has transitioned to the folded-back communication mode and a message prompting movement to the folded-back communication area of the specific base station. The communication system according to Addendum 1. (Addendum 3) Among the specific terminals from which terminal information has been deleted from the EPC for wide-area communication, the specific terminals located outside the folded-back communication area of the specific base station display, on the screen, an area map of the folded-back communication area of the specific base station and the current position information of the specific terminals overlaid on a map. The communication system according to Addendum 2. (Addendum 4) The monitoring device notifies, by email, the specific terminals for which terminal information has not been deleted from the EPC for wide-area communication of a message indicating that the specific base station has transitioned to the folded-back communication mode. The communication system according to Addendum 1. (Addendum 5) An EPC (Evolved Packet Core) for wide-area communication, A plurality of base stations that are normally connected to the EPC for wide-area communication and operate in the wide-area communication mode, A plurality of terminals, And a monitoring device, The monitoring device, For a specific base station among the plurality of base stations that can transition to the folded-back communication mode, prior to registration, the specific terminals accommodated in the folded-back communication area of the specific base station when the specific base station transitions to the folded-back communication mode among the plurality of terminals, the adjacent area of another base station adjacent to the folded-back communication area of the specific base station, and the specific access class assigned to the SIM (Subscriber Identity Module) of the specific terminals. When detecting a communication failure between the specific base station and the EPC for wide-area communication, it is determined that the specific base station has transitioned to the loopback communication mode, and the other base stations are instructed to restrict the connection of the specific terminal with the specific access class assigned to the SIM to the adjacent area. Communication system. (Appendix 6) Among the specific terminals whose connection to the adjacent area is restricted, the specific terminals located outside the loopback communication area of the specific base station display, on the screen, a message indicating that the specific base station has transitioned to the loopback communication mode and a message prompting movement to the loopback communication area of the specific base station. The communication system according to Appendix 5. (Appendix 7) Among the specific terminals whose connection to the adjacent area is restricted, the specific terminals located outside the loopback communication area of the specific base station display, on the screen, an area map of the loopback communication area of the specific base station and the current position information of the specific terminal superimposed on a map. The communication system according to Appendix 6. (Appendix 8) The monitoring device notifies, by email, all the specific terminals of a message indicating that the specific base station has transitioned to the loopback communication mode. The communication system according to Appendix 5. (Appendix 9) A monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in a wide-area communication mode, and a plurality of terminals, A memory, At least one processor coupled to the memory, The at least one processor, For a specific base station among the plurality of base stations that can transition to the folded-back communication mode, a specific terminal accommodated in the folded-back communication area of the specific base station among the plurality of terminals when the specific base station transitions to the folded-back communication mode, and an adjacent area of another base station adjacent to the folded-back communication area of the specific base station are registered in advance. When a communication failure between the specific base station and the EPC for wide-area communication is detected, it is determined that the specific base station has transitioned to the folded-back communication mode, and the EPC for wide-area communication is instructed to delete the terminal information of the specific terminal accommodated in the adjacent area among the specific terminals from the EPC for wide-area communication. It is configured as such. Monitoring device. (Appendix 10) The at least one processor is further configured to notify, by email, a message indicating that the specific base station has transitioned to the folded-back communication mode to the specific terminal for which the terminal information has not been deleted from the EPC for wide-area communication. The monitoring device according to Appendix 9. (Appendix 11) A monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in a wide-area communication mode, and a plurality of terminals, A memory, At least one processor coupled to the memory, and is provided with, The at least one processor, For a specific base station among the plurality of base stations that can transition to the folded-back communication mode, a specific terminal accommodated in the folded-back communication area of the specific base station among the plurality of terminals when the specific base station transitions to the folded-back communication mode, an adjacent area of another base station adjacent to the folded-back communication area of the specific base station, and a specific access class assigned to the SIM (Subscriber Identity Module) of the specific terminal are registered in advance. When a failure in communication between the specific base station and the EPC for wide-area communication is detected, it is determined that the specific base station has transitioned to the loopback communication mode, and the other base stations are instructed to restrict the connection of the specific terminal, to which the specific access class is allocated in the SIM, to the adjacent area. Monitoring device. (Appendix 12) The at least one processor is further configured to notify, by email, all the specific terminals of a message indicating that the specific base station has transitioned to the loopback communication mode. The monitoring device according to Appendix 11. (Appendix 13) A monitoring method executed by a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in a wide-area communication mode, and a plurality of terminals, For a specific base station among the plurality of base stations that can transition to the loopback communication mode, registering in advance a specific terminal that is accommodated in the loopback communication area of the specific base station when the specific base station transitions to the loopback communication mode among the plurality of terminals, and an adjacent area of another base station adjacent to the loopback communication area of the specific base station. When a failure in communication between the specific base station and the EPC for wide-area communication is detected, it is determined that the specific base station has transitioned to the loopback communication mode, and the EPC for wide-area communication is instructed to delete the terminal information of the specific terminal accommodated in the adjacent area among the specific terminals from the EPC for wide-area communication. Monitoring method. (Appendix 14) A monitoring method executed by a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in a wide-area communication mode, and a plurality of terminals, For a specific base station among the plurality of base stations that can transition to the repeater communication mode, a specific terminal accommodated in the repeater communication area of the specific base station when the specific base station transitions to the repeater communication mode among the plurality of terminals, an adjacent area of another base station adjacent to the repeater communication area of the specific base station, and a specific access class assigned to the SIM (Subscriber Identity Module) of the specific terminal are registered in advance. When detecting a communication failure between the specific base station and the EPC for wide-area communication, it is determined that the specific base station has transitioned to the repeater communication mode, and the other base station is instructed to restrict the connection of the specific terminal with the specific access class assigned to the SIM to the adjacent area. Monitoring method. (Appendix 15) In a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in the wide-area communication mode, and a plurality of terminals For a specific base station among the plurality of base stations that can transition to the repeater communication mode, a procedure for registering in advance a specific terminal accommodated in the repeater communication area of the specific base station when the specific base station transitions to the repeater communication mode among the plurality of terminals and an adjacent area of another base station adjacent to the repeater communication area of the specific base station. When detecting a communication failure between the specific base station and the EPC for wide-area communication, it is determined that the specific base station has transitioned to the repeater communication mode, and the EPC for wide-area communication is instructed to delete the terminal information of the specific terminal accommodated in the adjacent area among the specific terminals from the EPC for wide-area communication. Program. (Appendix 16) In a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in the wide-area communication mode, and a plurality of terminals For a specific base station among the plurality of base stations that can transition to the repeater communication mode, a specific terminal accommodated in the repeater communication area of the specific base station when the specific base station transitions to the repeater communication mode among the plurality of terminals, an adjacent area of another base station adjacent to the repeater communication area of the specific base station, and a specific access class assigned to the SIM (Subscriber Identity Module) of the specific terminal. A procedure for pre-registering them. When detecting a communication failure between the specific base station and the EPC for wide-area communication, it is determined that the specific base station has transitioned to the repeater communication mode, and the other base station is instructed to restrict the connection of the specific terminal with the specific access class assigned to the SIM to the adjacent area. A procedure for causing it to execute. Program.

[0156] Also, some or all of the elements (for example, configurations and functions) described in Appendices 2 to 4 subordinate to Appendix 1 may be subordinate to Appendices 13 and 15 in the same subordinate relationship as Appendices 2 to 4. Also, some or all of the elements (for example, configurations and functions) described in Appendices 6 to 8 subordinate to Appendix 5 may be subordinate to Appendices 14 and 16 in the same subordinate relationship as Appendices 6 to 8. Some or all of the elements described in any appendix can be applied to various hardware, software, recording means for recording software, systems, and methods.

Description of Signs

[0157] 1S~4S Communication System 10 Monitoring Device 20-A, 20-B Base Stations 30-1~30-5 Terminals 40 Wide-Area Communication Network 50-1 EPC for Wide-Area Communication 50-2 EPC for Repeater Communication 60-1, 60-2 Application Servers 70 Mail Server 100 Monitoring Device 200-A, 200-B Base Stations Terminals 300-1 to 300-4 Wide Area Communication Network 400 EPC for Wide Area Communication 500 Computer 900 Processor 901 Memory 902

Claims

1. An EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in a wide-area communication mode, a plurality of terminals, and a monitoring device, wherein the monitoring device for a specific base station among the plurality of base stations that can transition to a folded-back communication mode, a specific terminal accommodated in the folded-back communication area of the specific base station when the specific base station transitions to the folded-back communication mode among the plurality of terminals, and an adjacent area of another base station adjacent to the folded-back communication area of the specific base station are registered in advance, when a communication failure between the specific base station and the EPC for wide-area communication is detected, it is determined that the specific base station has transitioned to the folded-back communication mode, and the EPC for wide-area communication is instructed to delete the terminal information of the specific terminal accommodated in the adjacent area among the specific terminals from the EPC for wide-area communication, a communication system.

2. Among the specific terminals from which the terminal information has been deleted from the EPC for wide-area communication, the specific terminals located outside the folded-back communication area of the specific base station display, on the screen, a message indicating that the specific base station has transitioned to the folded-back communication mode and a message prompting movement to the folded-back communication area of the specific base station. The communication system according to Claim 1.

3. An EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in a wide-area communication mode, a plurality of terminals, and a monitoring device, wherein the monitoring device for a specific base station among the plurality of base stations that can transition to a folded-back communication mode, a specific terminal accommodated in the folded-back communication area of the specific base station when the specific base station transitions to the folded-back communication mode among the plurality of terminals, an adjacent area of another base station adjacent to the folded-back communication area of the specific base station, and a specific access class assigned to the SIM (Subscriber Identity Module) of the specific terminal are registered in advance, when a communication failure between the specific base station and the EPC for wide-area communication is detected, it is determined that the specific base station has transitioned to the folded-back communication mode, and the other base station is instructed to restrict the connection of the specific terminal with the specific access class assigned to the SIM to the adjacent area. a communication system.

4. Among the specific terminals whose connection to the adjacent area is restricted, the specific terminal located outside the folding communication area of the specific base station displays, on the screen, a message indicating that the specific base station has transitioned to the folding communication mode and a message prompting the movement of the specific terminal to the folding communication area of the specific base station. The communication system according to claim 3.

5. A monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in a wide-area communication mode, and a plurality of terminals, comprising: a memory; at least one processor coupled to the memory, wherein the at least one processor: For a specific base station among the plurality of base stations that can transition to the folding communication mode, pre-register a specific terminal accommodated in the folding communication area of the specific base station when the specific base station transitions to the folding communication mode among the plurality of terminals, and an adjacent area of another base station adjacent to the folding communication area of the specific base station. When detecting a failure in the communication between the specific base station and the EPC for wide-area communication, it is configured to determine that the specific base station has transitioned to the folding communication mode and instruct the EPC for wide-area communication to delete the terminal information of the specific terminal accommodated in the adjacent area from the EPC for wide-area communication. Monitoring device.

6. A monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in a wide-area communication mode, and a plurality of terminals, comprising: a memory; at least one processor coupled to the memory, wherein the at least one processor: For a specific base station among the plurality of base stations that can transition to the folding communication mode, pre-register a specific terminal accommodated in the folding communication area of the specific base station when the specific base station transitions to the folding communication mode among the plurality of terminals, an adjacent area of another base station adjacent to the folding communication area of the specific base station, and a specific access class assigned to the SIM (Subscriber Identity Module) of the specific terminal. When a failure in communication between the specific base station and the EPC for wide-area communication is detected, it is determined that the specific base station has transitioned to the repeater communication mode, and the other base stations are instructed to restrict the connection of the specific terminal with the specific access class assigned to the SIM to the adjacent area. It is configured as such. Monitoring device. **Claim 7** A monitoring method executed by a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in the wide-area communication mode, and a plurality of terminals, For a specific base station among the plurality of base stations that can transition to the repeater communication mode, registering in advance a specific terminal accommodated in the repeater communication area of the specific base station when the specific base station transitions to the repeater communication mode among the plurality of terminals, and an adjacent area of another base station adjacent to the repeater communication area of the specific base station. When a failure in communication between the specific base station and the EPC for wide-area communication is detected, it is determined that the specific base station has transitioned to the repeater communication mode, and the EPC for wide-area communication is instructed to delete the terminal information of the specific terminal accommodated in the adjacent area from among the specific terminals. Monitoring method. **Claim 8** A monitoring method executed by a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in the wide-area communication mode, and a plurality of terminals, For a specific base station among the plurality of base stations that can transition to the repeater communication mode, registering in advance a specific terminal accommodated in the repeater communication area of the specific base station when the specific base station transitions to the repeater communication mode among the plurality of terminals, an adjacent area of another base station adjacent to the repeater communication area of the specific base station, and a specific access class assigned to the SIM (Subscriber Identity Module) of the specific terminal. When detecting a communication failure between the specific base station and the EPC for wide-area communication, determining that the specific base station has transitioned to the loopback communication mode, and instructing the other base stations to restrict the connection of the specific terminal with the specific access class assigned to the SIM to the adjacent area. Monitoring method.

9. In a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in the wide-area communication mode, and a plurality of terminals. For a specific base station among the plurality of base stations that can transition to the loopback communication mode, a procedure for pre-registering a specific terminal accommodated in the loopback communication area of the specific base station when the specific base station transitions to the loopback communication mode among the plurality of terminals, and an adjacent area of another base station adjacent to the loopback communication area of the specific base station. When detecting a communication failure between the specific base station and the EPC for wide-area communication, determining that the specific base station has transitioned to the loopback communication mode, and instructing the EPC for wide-area communication to delete the terminal information of the specific terminal accommodated in the adjacent area from the EPC for wide-area communication. Program.

10. In a monitoring device in a communication system including an EPC (Evolved Packet Core) for wide-area communication, a plurality of base stations that are normally connected to the EPC for wide-area communication and operate in the wide-area communication mode, and a plurality of terminals. For a specific base station among the plurality of base stations that can transition to the loopback communication mode, a procedure for pre-registering a specific terminal accommodated in the loopback communication area of the specific base station when the specific base station transitions to the loopback communication mode among the plurality of terminals, an adjacent area of another base station adjacent to the loopback communication area of the specific base station, and a specific access class assigned to the SIM (Subscriber Identity Module) of the specific terminal. When detecting a communication failure between the specific base station and the EPC for wide-area communication, determining that the specific base station has transitioned to the loopback communication mode, and instructing the other base stations to restrict the connection of the specific terminal with the specific access class assigned to the SIM to the adjacent area. Program.

Images