JP2009088670A - Remote location monitoring system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a remote location monitoring system and method for allowing remote place monitoring of high reliability which is not influenced by communication situations, allowing a content needing a large transmission band to be accessible, suppressing loads on a monitoring center and a network, grasping where the communication is disconnected, and allowing a channel to be established without being influenced by a firewall, such as a router. <P>SOLUTION: An IP communications network 21 and a backup channel 5 are used to monitor abnormality notification information from a sensor part 12 of a remote controller 3, a VPN channel 4 is established on the IP communications network 21 between the monitoring center 1 and a monitoring device 3, when information on the abnormality notification is transmitted, and security is maintained. When abnormality occurs to the communication via the IP communications network 21, the VPN channel 4 is switched to the backup channel 5 by a channel switch part 11, the abnormality is notified, and monitoring is continued. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a remote location monitoring system and method suitable for monitoring a remote location via a network and a backup communication path.

  In the conventional technology, when a remote place is monitored using a sensor, most of them use PSTN or ISDN as a communication path. This is because most of the services provided by the IP communication network are best effort, and the arrival of the communication is not guaranteed, so that the service cannot be used for a service that requires the reliable arrival of the communication. Remote sensor monitoring using an IP communication network is used for home monitoring by a user who does not require much reliability and urgency.

Further, as a conventional technique using a backup communication path, an alarm is sent to the monitoring center as abnormality detection information from a monitoring device connected to the IP communication network and a backup device connected to other than the IP communication network. (See Patent Document 1).
JP 2006-285645 A

  However, with the spread of the Internet and mobile phones, general households not installing PSTN or ISDN are increasing. In such homes, it is difficult to apply conventional remote sensor monitoring. Further, conventional remote sensor monitoring using PSTN or ISDN cannot be continued when the communication line is disconnected. In addition, since the router and ONU require power, monitoring cannot be continued even if power is supplied from the uninterruptible power supply to the monitoring device during a power failure. In addition, remote sensor monitoring using IP telephones has different network specifications for each IP telephone company, so review the monitoring system specifications for each company so that remote sensor monitoring is possible. There was a need to do. The monitoring cannot be performed unless the specifications of the monitoring system are changed every time a device used in the network is upgraded.

  In addition, since remote sensor monitoring using an IP communication network communicates via an IP communication network that can be accessed by an unspecified number of people, it can be accessed from unauthorized terminals or the contents of communication can be seen. There was sex.

  Further, when connecting to the IP network, depending on the communication service, it becomes a best-effort quality class, so that it is possible to secure more reliability if a backup communication path can be secured.

  The present invention has been made in view of the above, and an object of the present invention is to enable highly reliable remote monitoring that is not affected by the communication status, and to use content that requires a large transmission band. It is an object of the present invention to provide a remote location monitoring system and method capable of suppressing a load, grasping where a communication is disconnected, and establishing a communication path without being affected by a firewall such as a router.

  In order to achieve the above object, the present invention according to claim 1 is configured to perform monitoring by connecting to a monitoring device installed in the remote location and monitoring the remote location. In a remote monitoring system in which a monitoring center is connected via an IP communication network, the monitoring device transmits a sensor unit for acquiring the situation and information detected by the sensor unit to the monitoring center And an information transmission unit for performing an establishment request for establishing the VPN communication path to be connected to the IP communication network while reducing the risk of data eavesdropping, impersonation, and falsification between the monitoring device and the monitoring center. A VPN communication path establishing unit, a backup communication path provided in advance independently of the VPN communication path, and switching to the backup communication path provided separately in advance when communication of the VPN communication path is impossible A communication channel switching unit for transmitting data, a device-side backup communication unit for transmitting the information to the monitoring center via the backup communication channel, and when the power supply to the monitoring device is stopped, An uninterruptible power supply for supplying power necessary for maintaining the function, and the monitoring center receives the establishment request from the VPN communication path establishment unit and establishes the VPN communication path Communication via the backup communication path between the communication path establishment receiving section, the information receiving section for receiving the information transmitted from the information transmitting section, and the apparatus side backup communication section when the communication is impossible A center-side backup communication unit for performing

  Further, the present invention described in claim 2 is the center connection for transmitting the VPN communication path establishment request to the VPN communication path establishment unit via the backup communication path. A request unit is provided.

  According to a third aspect of the present invention, in the first or second aspect, the monitoring device monitors normality / abnormality for connection to the center-side backup communication unit via the backup communication path, and if there is an abnormality, A backup communication path function monitoring unit is provided for instructing the VPN communication path establishment unit to always establish the VPN communication path.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the monitoring device uses a connection maintenance confirmation unit to connect the monitoring center and the monitoring device over the IP communication network. Disconnection monitoring unit for requesting a response to the router and constantly monitoring whether or not communication with the monitoring center is possible, and disconnection notification to the monitoring center via the backup communication path when the response is not received A disconnection notification unit for performing the disconnection notification, and the monitoring center issues a disconnection notification reception unit for receiving the disconnection notification from the monitoring device and a telephone under a router above the monitoring device. An external line communication unit for making a call, and a disconnection point for confirming and identifying whether the disconnection point between the monitoring center and the monitoring device is higher or lower than the router based on the result of the call A confirmation section; Provided.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the monitoring device has a SIP client function and is used to perform extension communication with a telephone in the monitoring center. A call unit, and the monitoring center includes a SIP server function for controlling the monitoring device and the telephone set of the monitoring center, and a center side extension call unit for performing the extension call with the device side extension call unit. Prepare.

  According to a sixth aspect of the present invention, a monitoring device is installed at a remote location to monitor the status of the remote location, and the monitoring center is connected to the monitoring device via an IP communication network to perform the monitoring. A remote location monitoring method, comprising: a step of acquiring the situation in a sensor unit in the monitoring device; a step of transmitting information detected by the sensor unit to an information transmission unit to the monitoring center; and establishing a VPN communication path Issuing a request for establishing a VPN communication path connecting the monitoring device and the monitoring center on the IP communication network in a unit; providing a backup communication path in advance independently of the VPN communication path; A step of switching to the backup communication path provided separately in advance when communication of the VPN communication path is impossible in the path switching section; Transmitting the information to the monitoring center via the backup communication path in the unit, and supplying power necessary for maintaining the function of the monitoring device when the power supply to the monitoring device is stopped in the uninterruptible power supply unit. A step of executing, a step of establishing the VPN communication path in response to the establishment request from the VPN communication path establishment unit in a VPN communication path establishment receiving unit in the monitoring center, and an information receiving unit Receiving the information transmitted from the information transmission unit in step, and performing communication via the backup communication path with the apparatus side backup communication unit when the communication is disabled in the center side backup communication unit Execute.

  According to the present invention, it is possible to perform highly reliable remote monitoring that is not affected by the communication status, use content that requires a large transmission band, suppress the load on the monitoring center and the network, and disconnect the communication at any location. It is possible to provide a remote location monitoring system and method capable of grasping whether or not a communication path is established without being affected by a firewall such as a router.

  FIG. 1 shows a configuration diagram of a remote monitoring system according to an embodiment of the present invention.

  In FIG. 1, in order to configure a remote monitoring system, a monitoring center 1, a monitoring destination 2 to be monitored, an IP communication network 21 that connects the monitoring center 1 and the monitoring destination 2 to be communicable, and a backup A communication network 22 is shown.

  The monitoring center 1 includes a VPN (Virtual Private Network) communication path establishment receiving unit 9 and an external line communication unit 23 connected to the IP communication network 21, a center side backup communication unit 7 connected to the backup communication network 22, and a center connection. A request unit 24, a disconnection notification receiving unit 25, an information receiving unit 26, an extension SIP (Session Initiation Protocol) server unit 27, a center side extension call unit 28, and a disconnection location confirmation unit 29 are provided.

  Further, the monitoring destination 2 set in the remote place from the monitoring center 1 is connected to the monitoring communication device 22 connected to the backup communication network 22 and the IP communication network 21, and to the interconnection between the IP communication network 21 and the monitoring device 3. 1 includes an ONU (Optical Network Unit) 20 and a router 19, and an external line communication unit 30 provided in the router 19. The monitoring device 3 of the monitoring destination 1 can establish the VPN communication path 4 via the IP communication network 21 and can further establish the backup communication path 5 via the backup communication network 22.

  The monitoring device 3 includes a device-side backup communication unit 6 connected to the backup communication network 22, a VPN communication path establishment unit 8 connected to the IP communication network 21, a disconnection monitoring unit 18, and a device-side extension call unit 17. , Communication channel switching unit 11, information transmission unit 10, sensor unit 12, uninterruptible power supply unit 13, backup communication channel monitoring function unit 14, center connection request receiving unit 15, disconnection notification unit 16, It has.

  FIG. 2 is an explanatory diagram for explaining the operation of the embodiment of the remote monitoring system having the configuration shown in FIG.

  First, normal monitoring using a remote monitoring system will be described.

  The monitoring device 3 monitors information obtained from the sensor unit 12. The sensor unit 12 includes a sensor 31 that detects impact, fire, heat, water leakage, sound, infrared rays, opening and closing of windows and doors, fluctuation of heat rays caused by an intruder into the room, etc., and converts it into an electrical signal for output. ing. Moreover, the camera 32 for capturing the monitoring target with an image is also provided. Signals from these sensors 31 and cameras 32 are output from the sensor unit 12 to the monitoring device 3 as information.

  The monitoring device 3 is connected to the IP communication network 21 via the router 19 and the ONU 20. The monitoring center 1 is also connected to the IP communication network 21 and is connected to the monitoring center device 36 that constitutes the monitoring center 1. The monitoring center device 36 includes the VPN communication path establishment receiving unit 9 and the external line communication unit 23, the center side backup communication unit 7, the center connection request unit 24, the disconnection notification receiving unit 25, the information receiving unit 26, the extension The configuration includes a SIP server unit 27, a center side extension call unit 28, and a disconnection location confirmation unit 29.

  When any abnormality is detected by the sensor 31 or the camera 32 in the sensor unit 12, information on the abnormality detection is transmitted to the monitoring device 3. The monitoring device 3 receives this information and establishes a VPN communication path 4 with the monitoring center 1. For this establishment, each of the monitoring center 1 and the monitoring device 3 authenticates that the communication partner is the regular monitoring device 3 or the monitoring center 1 by mutual electronic authentication with the electronic certificate 34 acquired by the monitoring center 1 and the monitoring device 3. The private line (VPN communication path 4) encrypted is established.

  Note that abnormality notification information may be used for the authentication executed here. In this case, when establishing a dedicated communication path from the monitoring apparatus 3 to the monitoring center 1 using the VPN communication path 4 via the IP communication network 21, backup communication is performed from the monitoring apparatus 3 to the monitoring center 1. Authentication is performed using the normality of the monitoring device 3 attached to the information for notifying the abnormality transmitted through the path 5.

  As another method, ID and PASS may be used for authentication. In this case, when establishing a dedicated communication path from the monitoring apparatus 3 to the monitoring center 1 using the VPN communication path 4 via the IP communication network 21, the ID and PASS stored in the monitoring apparatus 3 in advance are stored. Use to authenticate.

  When the authentication is completed, the monitoring center 1 is then notified of a signal that has detected an abnormality via the VPN communication path 4. Note that the VPN communication path 4 is established only when an abnormality is detected, and after the necessary information is transmitted, the VPN communication path 4 is closed again, and does not occupy the traffic of the IP communication network 21 at normal times when there is no abnormality.

  If the establishment of the VPN communication path 4 fails for some reason, another backup communication network 22 independent of the IP communication network 21 is established, and the abnormality detected by the sensor unit 12 is notified to the monitoring center 1 as information. To do.

  A process for notifying the monitoring center 1 of the abnormality in the monitoring as information will be described in detail with reference to the flowchart shown in FIG. In FIG. 3, when the process is started, the sensor unit 12 detects an abnormality in the monitoring device 3 (S1). By this detection, the information transmission unit 10 sends information for notifying this abnormality to the communication switching unit 11. The communication switching unit 11 is connected to both the VPN communication path establishment unit 8 and the apparatus-side backup communication unit 6 and functions to switch the communication path to one of them.

  Here, it is determined whether or not communication is possible on the VPN communication path 4 (S2). This determination is made based on whether or not the VPN communication path establishment unit 8 has established the VPN communication path 4 on the IP communication network 21, and it is determined as Yes if it has been established. When the VPN communication path 4 is established, an abnormality notification is sent to the monitoring center 1 through the VPN communication path 4, and the process ends (S5). The abnormality notification is input to the VPN communication path establishment receiving unit 9 of the monitoring center 1 through the VPN communication path 4, and is transmitted to the information receiving unit 26 through this.

  If it is determined in step S2 that communication via the VPN communication path 4 is not possible (No), the apparatus-side backup communication unit 6 uses the backup communication network 22 with the center-side backup communication unit 7 of the monitoring center 1. A backup communication path 5 is established. Then, the information is received by the center side backup communication unit 7 through the backup channel 5 through the communication channel switching unit 11, and is transmitted to the information reception unit 26, and the process ends (S4).

  Next, FIG. 4 shows a flowchart of the operation when the backup communication path 5 cannot be used.

  First, the monitoring device 3 is activated (S10). In this activation, it is confirmed whether or not connection to the backup communication network 22 is possible (S11). In this confirmation, when it is determined that connection is possible (Yes), it is continuously confirmed whether or not connection to the backup communication network 22 is possible again. The confirmation executed here is executed by the backup channel function monitoring unit 14.

  If it is determined in step S11 that connection to the backup communication network 22 is impossible (No), the monitoring apparatus 3 establishes the VPN communication path 4 (S12). The establishment of the backup communication network 22 is always maintained so that the VPN communication path 4 is always connected.

  In this way, when the backup communication path 5 cannot be applied to the remote monitoring system, the VPN communication path 4 between the monitoring center 1 and the monitoring device 3 via the IP communication network 21 is always established in advance. The monitoring center 1 can be notified when the sensor unit 12 detects an abnormality or when a call is made from the extension telephone 33 (see FIG. 2) of the monitoring device 3.

  Next, FIG. 5 shows a flowchart in the case where the monitoring center 1 instructs the monitoring device 3 to establish the VPN communication path 4.

  First, after receiving the data from the center connection request unit 24 of the center apparatus 1 via the backup communication path 5 via the center side backup communication section 7 and by the apparatus side backup communication section 6, the VPN communication path is sent to the center connection request receiving section 15. 4 is transmitted (S20). The center connection request receiving unit 15 of the monitoring device 3 confirms whether or not the VPN communication path 4 is established by the VPN communication path establishment unit 8 (S21). Here, if it is confirmed that it has been established (Yes), the process ends.

  If it is confirmed that the VPN communication path 4 is not established (No), the center connection request receiving unit 15 notifies the center connection requesting unit 24 that the VPN communication path 4 is not established via the backup communication path 5. . The center connection request unit 24 notifies the monitoring apparatus 3 of the IP connection request via the backup communication path 5 established in the backup communication network 22 (S22). This notification is received by the center connection request receiving unit 15, and the VPN communication path establishment unit 8 is instructed to establish the VPN communication path 4, and the establishment is executed and completed (S23).

  Thus, when connecting to the monitoring apparatus 3 from the monitoring center 1 side, the VPN communication path 4 can be established only when necessary by using the backup communication network 22. Thereby, the equipment burden on the monitoring center 1 side can be reduced. When the backup communication path 5 cannot be established, the VPN communication path 4 is established from the monitoring device 3 side.

  Also, remote control from the monitoring center 1 to the monitoring device 3 can be realized, and the monitoring device 3 is controlled remotely from the monitoring center 1 via the IP communication network 21 to obtain more accurate sensor information. Monitoring may be performed.

  Next, FIG. 6 shows a flowchart of processing for disconnection monitoring.

  First, the disconnection monitoring unit 18 of the monitoring device 3 executes Ping (Packet Internet Groper) using, for example, Internet Control Message Protocol (ICMP) as a connection maintenance confirmation unit for the router 19. It is confirmed whether there is a response from the router 19 to this Ping (S30). If there is a response here (Yes), the monitoring center 1 is then pinged to check whether there is a response (S31). If there is a response from the monitoring center 1 (Yes), the control returns to step S30 again.

  If there is no Ping response from the router 19 in step S30 (No), the backup communication path 5 is established on the backup communication network 22 with respect to the monitoring center 1, and the IP is transmitted through the backup communication path 5. A connection abnormality to the communication network 21 is notified (S32). The disconnection notification unit 16 included in the monitoring device 3 issues an instruction to the device-side backup communication unit 6 to establish the backup communication path 5 and transmits the notification to the center-side backup communication unit 7 via the backup communication path 5. The disconnection notification receiving unit 25 is notified.

  Next, based on the disconnection notification receiving unit 25 receiving the disconnection notification, the disconnection location confirmation unit 29 provided in the monitoring center 1 is connected to the external line communication unit 23 of the monitoring center 1 with respect to the external line under the router 19 of the monitoring device 3. Connect to the calling unit 30 (S33). With this connection, the disconnection state is determined based on the returned connection response information.

  In the configuration shown in FIG. 1, an extension call can be performed between the monitoring center 1 and the monitoring device 3. This extension call can be executed without using a communication network provided by a general carrier. The monitoring destination 3 includes a device-side extension call unit 17, and the monitoring center 1 includes a center-side extension call unit 28. A VPN communication path 4 is established and connected between the two parties via the VPN communication path establishment receiving unit 9, the VPN communication path establishment unit 8, and the IP communication network 21, thereby enabling mutual communication and communication.

  As one configuration for realizing the extension call function, the monitoring apparatus 3 has a client function based on SIP, for example, in the apparatus-side extension call section 17, and the monitoring center 1 has an extension telephone (IP telephone) 33 (see FIG. 2). The center-side extension call unit 28 is provided with a SIP server function for controlling the extension telephone on the monitoring center 1 side.

  With such a configuration, for example, the extension telephone 33 in the monitoring device 3 automatically makes a call to a callee registered in advance when the receiver goes up.

  In addition, the monitoring center 1 may be provided with an application that previously creates information that associates the extension number with the property of the monitoring device 3 and derives a coping method simultaneously with the incoming call from the monitoring device 3.

  Furthermore, by setting the destination of the extension telephone 33 in the monitoring device 3 to an emergency organization other than the monitoring center 1, an application that automatically notifies the emergency organization when the handset is lifted can be provided.

  Further, when the extension telephone 33 cannot make a call due to busy or the like, the extension call may be executed with a reserved extension call destination registered in advance.

  According to the embodiment of the present invention described above, since the disconnection of communication via the IP communication network is monitored and used together with the backup communication path, the IP is transmitted via the IP communication network having lower reliability than PSTN and ISDN. Even if an abnormality occurs in the communication network, remote monitoring can be continued and remote monitoring with high reliability is possible.

  Further, since the sensor information is transmitted via an IP communication network having a transmission band larger than that of PSTN or ISDN, contents requiring a large transmission band such as high-quality monitoring video can be used.

  Also, only when an abnormality is detected by the sensor or when an extension call is made from the monitoring device, a dedicated communication path encrypted using VPN is established from the monitoring device to the monitoring center. Can be suppressed.

  Also, the disconnection between the monitoring device and the monitoring center is divided into several sections, the disconnection is monitored using ICMP, and a call is sent from the monitoring center to the telephone under the router, so that communication via the IP communication network can be performed. It is possible to grasp at which point the wire is disconnected.

  In addition, since a dedicated communication path encrypted using VPN is established between the monitoring center and the monitoring device, the IP can be used without being influenced by the service specifications of the IP communication network connection company. The communication network connection company is not limited.

  In addition, since an extension SIP server is installed in the monitoring center and is not affected by the service specifications or restrictions of the IP communication network connection company, a SIP environment can be flexibly constructed.

  In addition, since a dedicated communication path encrypted using VPN is established from the monitoring device under the router to the monitoring center, the communication path can be established without being affected by the specifications of the router such as a firewall. .

  It enables highly reliable remote monitoring that is not affected by the communication status, enables use of content that requires a large transmission band, suppresses the load on the monitoring center and network, and grasps where communication is disconnected Thus, it is possible to provide a remote location monitoring system and method capable of establishing a communication path without being affected by a firewall such as a router.

The block diagram of embodiment of this invention is shown. An explanatory view for explaining operation of an embodiment of the invention is shown. The flowchart of the abnormality notification process of embodiment of this invention is shown. The flowchart of the backup communication network connection availability confirmation processing of embodiment of this invention is shown. The flowchart of the center connection process of embodiment of this invention is shown. The flowchart of the connection monitoring process of embodiment of this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Monitoring center 2 ... Monitoring destination 3 ... Monitoring apparatus 4 ... VPN communication path 5 ... Backup communication path 6 ... Apparatus side backup communication part 7 ... Front end side backup communication part 8 ... VPN communication path establishment part 9 ... VPN communication path establishment reception Unit 10: Information transmission unit 11: Communication channel switching unit 12 ... Sensor unit 13 ... Uninterruptible power supply unit 14 ... Backup communication channel function monitoring unit 15 ... Center connection request receiving unit 16 ... Disconnection notification unit 17 ... Device side extension communication unit 18 ... Disconnection monitoring unit 19 ... Router (firewall)
20 ... ONU
DESCRIPTION OF SYMBOLS 21 ... IP communication network 22 ... Backup communication network 23 ... Outside line call part 24 ... Center connection request part 25 ... Disconnection notification receiving part 26 ... Information receiving part 27 ... Extension SIP server part 28 ... Center side extension call part 29 ... Confirm disconnection location Unit 30 ... External line communication unit 31 ... Sensor 32 ... Camera 33, 35 ... Extension phone 34 ... Electronic certificate

Claims (6)

A remote location monitoring system in which a monitoring device installed in the remote location for monitoring the status of the remote location and a monitoring center connected to the monitoring device for performing the monitoring are connected via an IP communication network In
The monitoring device
A sensor unit for acquiring the situation;
An information transmission unit for transmitting information detected by the sensor unit to the monitoring center;
A VPN communication path establishment unit for issuing an establishment request for establishing the VPN communication path to be connected on the IP communication network while reducing the risk of data eavesdropping, impersonation, and falsification between the monitoring apparatus and the monitoring center;
A backup communication path provided in advance independently of the VPN communication path;
A communication path switching unit for switching to the backup communication path provided separately in advance when communication of the VPN communication path is impossible;
An apparatus-side backup communication unit for transmitting the information to the monitoring center via the backup communication path;
An uninterruptible power supply for supplying power necessary for maintaining the function of the monitoring device when power supply to the monitoring device is stopped;
With
The monitoring center is
A VPN communication path establishment receiving unit for establishing the VPN communication path in response to the establishment request from the VPN communication path establishment unit;
An information receiving unit for receiving the information transmitted from the information transmitting unit;
A center side backup communication unit for performing communication via the backup communication path with the device side backup communication unit when the communication is disabled;
A remote location monitoring system comprising: The monitoring center is
The remote location monitoring system according to claim 1, further comprising a center connection request unit for transmitting a request for establishment of the VPN communication path to the VPN communication path establishment unit via the backup communication path. The monitoring device
Backup communication path function for monitoring normality / abnormality of connection to the center side backup communication section via the backup communication path, and instructing the VPN communication path establishment section to always establish the VPN communication path in the event of an abnormality The remote monitoring system according to claim 1, further comprising a monitoring unit. The monitoring device
Disconnection monitoring unit for requesting a response to the upper router of the monitoring center and the monitoring device via the IP communication network using a connection maintenance confirmation unit and constantly monitoring whether or not communication with the monitoring center is possible When,
A disconnection notification unit for performing a disconnection notification to the monitoring center via the backup communication path when there is no response,
With
The monitoring center is
A disconnection notification receiving unit for receiving the disconnection notification from the monitoring device;
An external line communication unit for making a call to a telephone under a router above the monitoring device;
A disconnection location confirmation unit for confirming and identifying whether the disconnection location between the monitoring center and the monitoring device is higher or lower than the router based on the result of the call;
The remote location monitoring system according to claim 1, further comprising: The monitoring device
A device-side extension call unit for carrying out extension communication with a telephone in the monitoring center having a SIP client function;
The monitoring center is
2. A center-side extension call unit for carrying out the extension call with the device-side extension call unit having a SIP server function for controlling the monitoring device and the telephone set of the monitoring center. 4. The remote location monitoring system according to any one of 4 above. A remote location monitoring method for performing monitoring by installing a monitoring device in a remote location to monitor the status of the remote location, and connecting a monitoring center to the monitoring device via an IP communication network,
In the monitoring device,
Obtaining the situation in the sensor unit;
Transmitting information detected by the sensor unit to the monitoring center in an information transmission unit;
Issuing a request for establishing a VPN communication path for connecting the monitoring device and the monitoring center on the IP communication network in a VPN communication path establishing unit;
Providing a backup communication path in advance independently of the VPN communication path;
A step of switching to the backup communication path separately provided in advance when communication of the VPN communication path is impossible in the communication path switching section;
Transmitting the information to the monitoring center via the backup communication path in a device-side backup communication unit;
Supplying power necessary for maintaining the function of the monitoring device when power supply to the monitoring device is stopped in the uninterruptible power supply unit;
A step of performing
In the monitoring center,
Establishing a VPN communication path in response to the establishment request from the VPN communication path establishment section in a VPN communication path establishment receiving section;
Receiving the information transmitted from the information transmitting unit in an information receiving unit;
Performing communication via the backup communication path with the apparatus-side backup communication unit when the communication is impossible in the center-side backup communication unit;
The remote location monitoring method characterized by performing.

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