Patent Publication Number: US-2018054347-A1

Title: Router

Description:
TECHNICAL FIELD 
     The present invention relates to a router, and more particularly to a router for communicating with a device connected to a WAN (Wide Area Network). 
     BACKGROUND ART 
     Conventionally, PoE (Power over Ethernet (Trade Mark))-enabled devices, for example, have been controlled by a server on a cloud via a router. 
     CITATION LIST 
     Patent Literature 
     PTL 1: Japanese Unexamined Patent Application Publication No. 2009-165310 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, if the PoE-enabled device become unresponsive due to a freeze, a hang-up or the like, and then communications between the server in the cloud and the PoE-enabled device are impossible, there is a problem that the PoE-enabled device cannot be operated stably. 
     An object of the present invention is to provide a router that can operate the PoE-enabled device stably. 
     Solution to Problem 
     To achieve the above object, according to one aspect of the present invention, a router comprises a WAN communication unit communicating with a device connected to a WAN, a wired LAN communication unit communicating with a PoE-enabled device connected to a LAN by a LAN cable, a power supply unit supplying power to the PoE-enabled device via the LAN cable, and a control unit controlling a restart of the PoE-enabled device if the PoE-enabled device is in an unresponsive state. 
     In the above-described router according to the present invention, the WAN communication unit communicates by wireless with the device connected to the WAN. 
     In the above-described router according to the present invention, the control unit controls the restart of the PoE-enabled device by having the power supply unit execute a control for stopping a supply of power to the PoE-enabled device and thereafter starting the supply of power. 
     In the above-described router according to the present invention further comprises a storage unit storing an operation schedule for the PoE-enabled device, wherein the control unit controls the PoE-enabled device based on the operation schedule. 
     In the above-described router according to the present invention, in a case where the power is supplied from a secondary battery which is installed outside, the control unit senses a remaining battery level of the secondary battery and changes the operation schedule according to the remaining battery level. 
     Advantageous Effects of Invention 
     According to the present invention, the PoE-enabled device can be operated stably. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  illustrates a configuration of a router  100  according to a first embodiment of the present invention. 
         FIG. 2  illustrates a configuration of a PoE-power by the router  100  according to the first embodiment of the present invention. 
         FIG. 3  is a system configuration diagram illustrating an example of an operating system for a PoE-enabled device using the router  100  according to the first embodiment of the present invention. 
         FIG. 4  is a flow chart illustrating a flow of a main process executed by a main control unit of the router  100  according to the first embodiment of the present invention. 
         FIG. 5  is a flow chart illustrating a flow of a PoE-enabled device control process executed by the main control unit of the router  100  according to the first embodiment of the present invention. 
         FIG. 6  is a flow chart illustrating a flow of life-and-death determination/return process in the main control unit of the router  100  according to the first embodiment of the present invention. 
         FIG. 7  is a flow chart illustrating the flow of life-and-death determination/return process in the main control unit of the router  100  according to the first embodiment of the present invention. 
         FIG. 8  illustrates a configuration of a router  700  according to a second embodiment of the present invention. 
         FIG. 9  is a flow chart illustrating a flow of a main process executed by a main control unit of the router  700  according to the second embodiment of the present invention. 
         FIG. 10  is a flow chart illustrating a flow of a secondary battery determination process of the main control unit of the router  700  according to the second embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
     A router  100  according to a first embodiment of the present invention will be described with reference to  FIGS. 1 to 7 . It should be noted that, in all drawings referred to below, individual components are illustrated in sizes and at relative dimensional ratios, which are set different from actual ones as appropriate for easier understanding. 
       FIG. 1  is a block diagram illustrating the configuration of the router  100  according to this embodiment. The router  100  includes a main control unit  101  for routing and controlling various electric circuits in the router  100 . Also, the router  100  includes a storage unit  103  for storing various control programs and matters necessary for executing the various control programs, and includes a storage unit  105  for storing the transmitted data and the like from a device connected to the router  100  via a LAN (Local Area Network) cable. The device connected to the router  100  via the LAN cable is hereinafter sometimes referred to as “LAN device”. The matters necessary for executing the various control programs include, for example, information of an operation schedule and tables of operational conditions for the LAN device, commands for the LAN device and electric power setting matters for the LAN device. The router  100  also includes a wired WAN communication unit  107  which communicates with a device connected to the WAN by wire, a wireless WAN communication unit  109  which communicates with a device connected to the WAN by wireless, and a wired LAN communication/power supply unit  111  which communicates with the LAN device and supplies power to the LAN device by wire if the LAN device is a PoE-enabled device. The router  100  also includes a data communication unit  113  which communicates by wire with a detector (e.g., a detector including an infrared sensor and/or a temperature sensor or the like). The router  100  also includes a power supply unit  115  which converts the DC voltage obtained from the outside into a predetermined DC voltage, and supplies the predetermined DC voltage to various circuits in the router  100 . Further, the router  100  includes various interfaces (WAN interface  117   a , LAN interface  117   b , DIO interface  117   c ). Further, in the router  100  of the present embodiment, the LAN interface is provided only one, however, a plurality of LAN interfaces may be provided. In this case, a plurality of wired LAN communication/power supply unit  111  may be provided a same number as a number of the LAN interfaces. Further, the wireless WAN communication unit  109  or the storage unit  105  may in some cases be external to the router  100  via a predetermined interface. The wired WAN communication unit  107  and the wireless WAN communication unit  109  can also communicate with devices connected to networks other than the WAN. 
     The main control unit  101  includes a CPU, and an internal storage device such as a RAM or the like. The CPU reads and executes various control programs and various setting matters stored in the storage unit  103 , thereby the main control unit  101  can control the routing and the LAN device. Further, if the LAN device is the PoE-enabled device, the main control unit  101  can control a PoE-power (e.g., controlling the PoE-power to the on state or the off state) by controlling the wired LAN communication/power supply unit  111 . Further, the main control unit  101  executes the life-and-death monitoring of the PoE-enabled device. If the PoE-enabled device does not respond, the main control unit  101  can control a restart of the PoE-enabled device by sending a reset command to the PoE-enabled device or by changing the PoE-power into the off state first and then changing the PoE-power into the on state. 
     Operation schedule information of the LAN device stored in the storage unit  103  includes, for example, information on an operational date in a predetermined time period and the start time and the end time in the operational date. Further, an operational condition table stored in the storage unit  103  includes, for example, information of the timetable for sending a command from the main control unit  101  to the LAN device, which is coupled with the operation schedule information. The details will be described later. 
     The wireless WAN communication unit  109  includes an antenna  109   a  for connecting to the mobile phone communication network (e.g., 3G or 4GLTE), a WiMAX network, or a PHS network or the like. The wireless WAN communication unit  109  can transmit data sent from the main control unit  101  to a server or a terminal provided in the cloud via a base station. Further, the wireless WAN communication unit  109  can receive data transmitted from the server or the terminal provided in the cloud via the base station, and then can send the data to the main control unit  101 . Further, the wireless WAN communication unit  109  includes an antenna  109   b  for receiving radio waves of the GPS (Global Positioning System). The main control unit  101  can derive position information from the GPS radio wave, and can add the position information to the data to be transmitted from the wired WAN communication unit  107  or the wireless WAN communication unit  109 . A user or an administrator can easily determine where the received data was sent from by adding the position information to the data to be transmitted from the wireless WAN communication unit  109 . Further, the antenna  109   b  may be provided separately from the wireless WAN communication unit  109 . 
     The wired LAN communication/power supply unit  111  can transmit a command sent from the main control unit  101  to the LAN device and can receive data sent from the LAN device and then transmit the received data to the main control unit  101 . Further, the wired LAN communication/power supply unit  111  can output a predetermined voltage made by the power supply unit  115  to a communication line or an empty line in the LAN cable based on the control of the main control unit  101 . The details will be described later. 
     The data communication unit  113  can transmit by wire a command sent from the main control unit  101  to a device (e.g., a detector or a lighting equipment) connected to the DIO interface  117   c . The data communication unit  113  can receive data sent from the device and then transmit to the main control unit  101 . Further, there is a case where the human sensor is connected to the DIO interface  117   c . In this case, when the output voltage of the human sensor exceeds the predetermined threshold, the data communication unit  113  sends the main control unit  101  the predetermined data indicating that a person has been sensed. Further, there is a case where a plurality of DIO interfaces are provided. For example, there may be cases where the human sensor and the lighting equipment are connected to each DIO interface. In this case, based on the output voltage of the human sensor, the main control unit  101  may control the lighting device and the LAN device. Further, the main control unit  101  may execute control of the LAN device based on the data transmitted from the detector and the lighting equipment connected to the DIO interface. Further, the main control unit  101  may execute control of the detector and the lighting equipment connected to the DIO interface based on data transmitted from the LAN device. Further, the detector and the lighting equipment may be connected by wireless to the data communication unit  113 . 
     A predetermined voltage (DC) is supplied to the power supply unit  115  via an AC adapter  150  from an external power source (AC). Further, the power supply unit  115  supplies a predetermined voltage necessary for operation of the various circuits provided in the router  100  and a predetermined voltage necessary for the PoE-power. 
     With reference to  FIG. 2 , a configuration of the PoE-power by the router  100  according to the present embodiment will now be described below.  FIG. 2  is a block diagram showing a state in which a PoE-enabled camera  300  is connected to the router  100  via a LAN cable  200 . The wired LAN communication/power supply unit  111  of the router  100  includes a wired communication control unit  111   a  and a power supply control unit  111   b  for supplying power conformed to a predetermined standard (e.g., IEEE802.3af/IEEE802.3at). The wired communication control unit  111   a  is connected to the main control unit  101  via the communication line D 1 . A predetermined voltage is supplied to the power supply control unit  111   b  via a voltage line P 1 . The voltage of the voltage line P 1  is used to supply to the PoE-enabled camera  300 . Further, the power supply control unit  111   b  is connected to the main control unit  101  via the communication line D 1 . Therefore, the main control unit  101  controls the power control unit  111   b  via the communication line D 1  and then controls the power supply to the PoE-enabled camera  300 . 
     The power supply control unit  111   b  outputs a predetermined voltage to the communication line D 2  connected to the LAN interface  117   b  based on the control of the main control unit  101 . Further, a predetermined voltage outputted to the communication line D 2  is supplied to the PoE-enabled camera  300  via the LAN interface  117   a  and the LAN cable  200 . 
     The PoE-enabled camera  300  shown in  FIG. 2  is operated by the PoE-power as a power source. The PoE-enabled camera  300  includes a camera unit  301  having an imaging function and a control unit  303  that performs overall control. Further, the PoE-enabled camera  300  includes a wired communication unit  305  which communicates via a LAN cable with the device located outside. The PoE-enabled camera  300  includes a communication/power separation unit  307  for separating communication data and power for the PoE-power which are input via the LAN cable. The PoE-enabled camera  300  includes a power supply unit  309 . The power supply unit  309  converts a voltage sent from the communication/power separation unit  307  to a predetermined voltage and supplies the predetermined voltage to each section. The PoE-enabled camera  300  includes a LAN interface  311 . 
     Further, in the PoE-enabled camera  300 , the control unit  303  is activated automatically by inputting a predetermined voltage to the power supply unit  309  via the LAN cable  200 , the LAN interface  311  and the communication/power separation unit  307 . Therefore, the router  100  can restart the PoE-enabled camera  300  by changing the PoE-power to the PoE-enabled camera  300  into the off state first and then changing the PoE-power into the on state. 
       FIG. 3  is a system configuration diagram illustrating an example of an operating system for the PoE-enabled camera  300  using the router  100  according to the present embodiment. The PoE-enabled camera  300  is connected to the router  100  by the LAN cable  200 . Further, the router  100  can communicate with a base station  400  using the wireless by the built-in (or external) wireless WAN communication unit  109 . Therefore, the router  100  can communicate with a predetermined server  501  (hereinafter, sometimes referred to as “center  501 ”) provided on a cloud  500  or a terminal  600  which is used by a user or an administrator. 
     The control shown to the above is performed on the PoE-enabled camera  300  based on model number information, rating information, the control programs, the operation schedule information, the operational condition table and command information corresponding to the model number (hereinafter, sometimes collectively referred to as “operational information”) stored in the storage unit  103  of the router  100 . Further, the operational information is transmitted from the center  501  to the router  100  and then stored in the storage unit  103 . The operational information may also be directly transmitted from the terminal  600  to the router  100  without going through the center  501  and then stored in the storage unit  103 . Further, the router  100  may make an inquiry to the center  501  at a predetermined frequency (e.g., the frequency of once a day), and the operational information may be transmitted from the center  501  to the router  100  based on the inquiry and then stored in the storage unit  103 . 
     Further, if the command information corresponding to the model number information (the model number of the PoE-enabled camera  300 ) which is stored in the storage unit  103  is not stored in the storage unit  103 , there is a case that the router  100  automatically make an inquiry to the center  501  and then based on the inquiry the center  501  send the command information corresponding to the model number information. Further, the model number information stored in the storage unit  103  may be managed by the user or the administrator via the center  501  or the terminal  600 . Further, the model number information stored in the storage unit  103  may also be managed by the router  100  which guesses automatically the model number of the camera. For example, the router  100  transmits several commands (e.g., a command requesting the current time and/or a command requesting the camera model information) corresponding to a certain model number (e.g., model number x) to the camera and analyzes the response contents from the camera thereby guessing the model number of the connected camera. If the response contents do not correspond to the transmitted commands or there is no response, the router  100  judges the model number of the connected camera is not the model number x. By executing the above-mentioned process to all the model numbers stored in the storage unit  103 , the router  100  guesses the camera&#39;s model number. Further, the model number information stored in the storage unit  103  may be managed by the center  501  or the terminal  600  which guesses automatically the model number of the camera. In this case, in the process described above, the router  100  transmits the commands sent to the camera and the response contents from the camera to the center  501  or the terminal  600  at any time or collectively, and then the center  501  or the terminal  600  analyzes the response contents or the like thereby guessing the camera&#39;s model number. By this analysis, there is a case that the center  501  or the terminal  600  determines that there is no command information corresponding to the model number of the connected camera in the storage unit  103  of the router  100 . In this case, in the process described above, the center  501  or the terminal  600  transmits the commands not on the router  100  to the camera, then analyzes the response contents thereby guessing the camera&#39;s model number. Further, the center  501  or the terminal  600  replaces the model number information stored in the storage unit  103  of the router  100  with the guessed model number information, then stores the command information corresponding to the model number information in the storage unit  103  of the router  100 . 
     The router  100  transmits images captured by the PoE-enabled camera  300  to the center  501 . The user or the administrator can check the images stored in the center  501  by operating the terminal  600 . The router  100  may communicate with the center  501  or the terminal  600  via the wired WAN communication unit  107 . The present system may not be used one of the center  501  or the terminal  600 . 
       FIG. 4  is a flow chart showing a flow of a main process of the main control unit  101  of the router  100  in the system shown in  FIG. 3 . The main process may be initiated on the basis of the start time stored in the RAM of the main control unit  101  or may be initiated at the time of startup of the main control unit  101 . In step S 101 , the main control unit  101  reads the operation schedule information stored in the storage unit  103 . The operation schedule information includes information such as the operation start time and end time and operational conditions table number of the PoE-enabled camera  300 . In step S 103  subsequent to step S 101 , the main control unit  101  determines whether the current time is within an operating period of the PoE-enabled camera  300  based on the operation schedule information read by the main control unit  101 . If the current time is within the operating period, the main control unit  101  reads the model number information (model number of the PoE-enabled camera  300 ) stored in the storage unit  103  (step S 105 ). Next, in step S 107 , the main control unit  101  executes a PoE-enabled device control process, and ends the main process after the PoE-enabled device control process. Further, if the main process is started outside the operating period on the ground that the main control unit  101  was restarted outside the operating period, the main control unit  101  executes a start time setting process in step S 109  since the current time is outside of the operating period. In the process of step S 109 , if the current time is before a today&#39;s operation start time, the today&#39;s operation start time is stored in the RAM as the start time. If the current time is after a today&#39;s operation end time, a next day&#39;s operation start time is stored in the RAM as the start time. After the process in step S 109 , the main control unit  101  finishes the main process. Further, after the completion of the main process, the router  100  may move to a sleep mode or a low power mode until the start time. Further, the main control unit  101  interrupts the main process when receiving a command for directly controlling the PoE-enabled camera from the center  501  or the terminal  600  even while the main process is being executed. Therefore, even when the router  100  is controlling the PoE-enabled camera  300 , the center  501  or the terminal  600  is possible to preferentially control the PoE-enabled camera. Incidentally, although the operation schedule information in the present embodiment includes the operation start time and end time and the operational condition table number of the PoE-enabled camera  300 , it is not necessarily limited thereto. The operation schedule information may not include the operation start time and end time and the operational condition table number of the PoE-enabled camera  300 , may also have information other than these. This also applies to the operational condition table described later. 
       FIG. 5  is a flow chart showing a flow of a PoE-enabled device control process in step S 107  shown in  FIG. 4 . In step S 201 , the main control unit  101  reads the operational condition table that is linked to the operation schedule information from the storage unit  103 . The operational condition table includes the items necessary for the PoE-enabled device control process. For example, the operational condition table includes information of various settings matter of the PoE-enabled camera  300 , a time table for sending commands to the PoE-enabled camera  300 , the compression ratio for compressing the image data sent from the PoE-enabled camera  300  and data transmission destination address of the image data and the like. In step S 203  subsequent to step S 201 , the main control unit  101  controls the wired LAN communication/power supply unit  111 , and executes control for supplying a predetermined power to the PoE-enabled camera  300 . Further, the main control unit  101  transmits a predetermined command to the PoE-enabled camera  300  by controlling the wired LAN communication/power supply unit  111 , and sets the PoE-enabled camera  300  based on the model number information of the PoE-enabled camera  300 , command information corresponding to the model number information and various setting matters for the PoE-enabled camera  300  in the operational condition table read from the storage unit  103 . 
     In step S 205  subsequent to step S 203 , the main control unit  101  transmits a predetermined command (e.g., an image data requesting command for one picture) to the PoE-enabled camera  300  by controlling the wired LAN communication/power supply unit  111  based on the time table in the operational condition table read from the storage unit  103 . In step S 207  subsequent to step S 205 , the main control unit  101  determines whether the requested image data was received from the PoE-enabled camera  300  within a predetermined time. In step S 207 , if the main control unit  101  determines that the requested image data was received from the PoE-enabled camera  300  within the predetermined time, the main control unit  101  executes a process of step S 209 . In step S 209 , the main control unit  101  compresses the received image data based on an image compression ratio in the operational condition table. The main control unit  101  may also compress the received image data based on the image compression ratio corresponding to the radio wave receiving condition at the antenna  109   a  of the wireless WAN communication unit  109 . 
     In step S 211  subsequent to step S 209 , the main control unit  101  executes the data transmission destination decision process. In the data transmission destination decision process, the main control unit  101  decides to transmit the image data to the data transmission destination address in the operational conditions table or store the image data in the storage unit  105  based on the radio wave receiving state at the antenna  109   a  of the wireless WAN communication unit  109 . For example, in a case where it is desired to collectively transmit a plurality of image data in a time zone in which the communication fee becomes cheap, the main control unit  101  may decide to store the image data in the storage unit  105  regardless of the radio wave reception state of the antenna  109   a . Further, for example, when the data communication amount has exceeded or is likely to exceed a predetermined upper limit, the main control unit  101  may decide to store the image data in the storage unit  105  regardless of the radio wave receiving state of the antenna  109   a . Further, the main control unit  101  may transmit the image data stored in the storage unit  105  automatically based on another control program. The main control unit  101  may also transmit the image data stored in the storage unit  105  based on a request from the center  501  or the terminal  600 . 
     In step S 213  subsequent to step S 211 , the main control unit  101  determines whether the transmission destination of the image data is the data transmission destination address in the operational condition table based on the result of step S 211 . When transmitting image data to the data destination address in the operational condition table, the main control unit  101  executes a data transmission process (step S 215 ). In the data transmission process, the main control unit  101  executes process (e.g., a process for dividing the image data into a plurality of packets or a process for applying an IP address corresponding to the data transmission destination address to the plurality of packets) for transmitting the image data compressed in step S 209 . The main control unit  101  also controls the wireless WAN communication unit  109  and transmits the image data to the destination address. The main control unit  101  also may give the position information of the GPS indicated in the above to the packets or the image data to be transmitted. In step S 211 , if the main control unit  101  decides to store the compressed image data in the storage unit  105 , the main control unit  101  stores the compressed image data in the storage unit  105  (step S 217 ). 
     In step S 219  subsequent to step S 215  or S 217 , the main control unit  101  determines whether the current time has passed the end time based on the operation schedule information. If the current time is before the end time, the main control unit  101  returns to step S 205  and then executes a process subsequent to step S 205 . If the current time has passed the end time, the main control unit  101  also executes a process of step S 225 . 
     In step S 207 , when the main control unit  101  determines that the requested image data was not received from the PoE-enabled camera  300  within a predetermined time, the main control unit  101  executes the life-and-death determination/return process in step S 221  (details will be described later). In step S 223  subsequent to step S 221 , the main control unit  101  determines whether a life-and-death decision flag is on or off based on the process of step S 221 . In case the life-and-death decision flag is off, the main control unit  101  determines the PoE-enabled camera  300  is in a responsive state and executes the process in step S 205 . In case the life-and-death decision flag is on, the main control unit  101  determines the PoE-enabled camera  300  is not in the responsive state and executes the process in step S 225 . 
     In step S 225 , the main control unit  101  controls the wired LAN communication/power supply unit  111  and changes the PoE-power into the off state. In step S 227  subsequent to step S 225 , the main control unit  101  stores the start time of the next day in the RAM and ends the PoE-enabled device control process based on the operation schedule information. 
       FIGS. 6 and 7  are flow charts showing a flow of a life-and-death determination/return process in step S 221  shown in  FIG. 5 .  FIG. 6  shows the flow of the life-and-death determination process for the PoE-enabled camera  300 .  FIG. 7  shows the flow of the process to return the PoE-enabled camera  300  from the unresponsive state. 
     In step S 301 , the main control unit  101  sends a predetermined command to the PoE-enabled camera  300 . In step S 303  subsequent to step S 301 , the main control unit  101  determines whether a predetermined information is received from the PoE-enabled camera  300  within a predetermined time. In case the predetermined information is received from the PoE-enabled camera  300  within the predetermined time, the main control unit  101  sets a number of reception errors to zero (step S 305 ), sets a number of reset command transmissions to zero (step S 307 ), sets a number of power resets to zero (step S 309 ) and sets the life-and-death decision flag to turn off (step S 311 ), and then ends the life-and-death decision/return process. 
     In step S 303 , in case the main control unit  101  determines the predetermined information is not received from the PoE-enabled camera  300  within the predetermined time, the main control unit  101  executes the process of updating the number of reception errors (step S 313 ). In step S 315  subsequent to step S 313 , the main control unit  101  determines whether the number of reception errors is larger than an upper limit of reception errors in the operational condition table. If the number of reception errors is greater than the upper limit of reception errors, the main control unit  101  sets the number of reception errors to zero (step S 317 ). Further, when the number of reception errors is less than the upper limit of reception errors, the main control unit  101  executes the process of step S 329  shown in  FIG. 7 . 
     In step S 319  subsequent to step S 317 , based on an upper limit of power resets in the operational condition table, the main control unit  101  determines whether the number of power resets is greater than the upper limit of power resets. If the number of power resets is greater than the upper limit of power resets, the main control unit  101  abandons the returning process to the PoE-enabled camera  300 , sets the number of power resets to zero (step S 321 ) and then executes the process for changing the PoE-power into the off state (step S 323 ). Next, the main control unit  101  turns on the life-and-death decision flag (step S 325 ), sends the center  501  that the PoE-enabled camera  300  is the unresponsive state (step S 327 ) and then ends the life-and-death decision/return process. Further, in step S 319 , if the number of power resets is not more than the upper limit of power resets, the main control unit  101  executes the process of step S 329  shown in  FIG. 7 . 
     In step S 329  shown in  FIG. 7 , based on an upper limit of sent reset commands in the operational condition table, the main control unit  101  determines whether a number of sent reset commands is equal to or less than the upper limit of sent reset commands. If the number of sent reset commands is equal to or less than the upper limit of sent reset commands, the main control unit  101  executes a process to send a reset command to the PoE-enabled camera  300  (step S 331 ). Next, the main control unit  101  updates the number of sent reset commands (step S 333 ) and executes a process for awaiting a predetermined time until the restart of the PoE-enabled camera  300  is completed (step S 335 ). Further, after execution of the process of step S 335 , the main control unit  101  returns to step S 301  and executes on and after step S 301 . 
     In step S 329 , if the number of sent reset commands is greater than the upper limit of sent reset commands, the main control unit  101  executes a process of resetting the power of the PoE-enabled camera  300  (step S 337 ). The process of resetting the power of the PoE-enabled camera  300  is executed by the wired LAN communication/power supply unit  111  controlled by the main control unit  101 . In the process of resetting the power of the PoE-enabled camera  300 , the PoE-power is changed into the off state first, and after an elapse of a certain period of time (e.g., ten seconds) the PoE-power is changed into the on state. Next, the main control unit  101  updates the number of power resets (step S 339 ) and then executes a process to wait a predetermined time until the restart of the PoE-enabled camera  300  is completed (step S 341 ). Further, after execution of the process of step S 341 , the main control unit  101  returns to step S 301  and executes on and after step S 301 . 
     In this way, the main control unit  101  of the router  100  performs the life-and-death monitoring of the PoE-enabled camera  300  connected with the router  100  and if the main control unit  101  determines the PoE-enabled camera  300  is in the unresponsive state, the main control unit  101  executes a process for restarting of the PoE-enabled camera  300 . Further, since the router  100  includes the wired LAN communication/power supply unit  111  having a PoE-power function, it is possible to stop supplying power and then restart supplying power to the PoE-enabled camera  300 . By this, the router  100  can automatically restart the PoE-enabled camera  300  in the unresponsive state and can realize a stable operation of the PoE-enabled camera  300 . 
     The following effects can be obtained by the combination of the router  100  and the PoE-enabled camera  300  according to the present embodiment. 
     (1) In the case of PoE-enabled camera  300  is hung up, the router  100  can forcibly restart and return the PoE-enabled camera  300  by changing the PoE-power into the off state or the on state. 
     (2) The router  100  can monitor the condition and execute the settings of the PoE-enabled camera  300  by sending predetermined commands to the PoE-enabled camera  300 . 
     (3) The router  100  can supply power to the PoE-enabled camera  300  during only the scheduled time thereby realizing power saving. 
     (4) The router  100  can change the shooting mode of the PoE-enabled camera  300 , can collect the log of the PoE-enabled camera  300  and can control the start and stop of the shooting or the like. 
     (5) The router  100  can operate the PoE-enabled camera  300  in various ways. For example, the router  100  can operate to supply power to the PoE-enabled camera  300  from sunrise to sunset. Further, the router  100  can operate to supply power every five minutes to the PoE-enabled camera  300  and to stop the power after the PoE-enabled camera  300  transmits the shooting data. The router  100  can also operate to supply power for five minutes in response to a human sensor or a trigger signal from the external. The power supply time for the PoE-enabled camera  300  can be set variably from the router  100  or the center  501  on the cloud. 
     Conventionally, it was necessary to monitor the PoE-enabled device to stably operate from a remote location. Therefore, when the PoE-enabled device was frozen, it was necessary to automatically reboot by using a PoE-enabled device which has a watchdog timer function. Alternatively, when the PoE-enabled device was frozen, it was necessary to reboot the PoE-enabled device from the remote location by changing the power supply to the PoE-enabled device from the off state to the on state. In each case, manufacturing cost or operation cost to the PoE-enabled device is increased. According to the router  100  of the present embodiment, there is no need to monitor the PoE-enabled device from the remote location. Further, there is no need to have the watchdog timer function in the PoE-enabled device. According to the router  100 , it is possible to reduce the manufacturing cost and the operation cost to the PoE-enabled device. In the case of controlling the supply of power to the PoE-enabled device by the control signal from the remote location, if the network line on the WAN side is interrupted and the control signal cannot reach to the PoE-enabled device, there is a problem that the supply of power to the PoE-enabled device cannot be controlled from the remote location. According to the router  100  of the present embodiment, even if the network line on the WAN side is interrupted, control of the supply of power to the PoE-enabled device is properly carried out. 
     The router  100  of the present embodiment, for example, may also include an FTP (File Transfer Protocol) function, a function for sending a mail at the time of a camera abnormality and a function for networking such as DDNS (Dynamic Domain Name System) function provided generally in an IP camera. The router  100  can perform an operation which is equal to or higher than that of the IP camera which has the above-mentioned functions to an inexpensive IP camera and a non-IP camera that they do not have the above-mentioned functions, thereby reducing overall operational costs. Further, there is also an effect that the development cost and the manufacturing cost for the IP camera can be reduced by providing the router  100  with functions concerning networking for the IP camera. The router  100  may also be provided with the function of the NVR (Network Video Recorder). Therefore, a large-scale server corresponding to the NVR is not required, and there is a merit that it is easy to build and manage the system. 
     Second Embodiment 
     A router  700  according to a second embodiment of the present invention will be described with reference to FIGS.  8  to  10 .  FIG. 8  is a block diagram illustrating a configuration of the router  700  according to the present embodiment. In  FIG. 8 , the same reference numeral is given to the same configuration as the configuration of the router  100  shown in  FIG. 1  and the description thereof may be omitted. 
     A predetermined power is supplied from a secondary battery  800  which is placed outside to a power supply unit  115  of the router  700 . The secondary battery  800  is charged by power generated at solar panels  900  which are placed outside. The router  700  includes a remaining battery level monitoring unit  701  that monitors the remaining battery level of the secondary battery  800 . The remaining battery level monitoring unit  701  includes a voltmeter for measuring the output voltage of the secondary battery  800 . The remaining battery level monitoring unit  701  can send the measurement value of the output voltage of the secondary battery  800  to the main control unit  101  based on commands sent from the main control unit  101 . The main control unit  101  can control the LAN-device based on the measurement values of the output voltage of the secondary battery  800 . The remaining battery level monitoring unit  701  may include an ammeter in place of the voltmeter. In this case, the remaining battery level monitoring unit  701  measures the output current of the secondary battery  800 , thereby the main control unit  101  senses the battery remaining amount of the secondary battery  800 . The battery remaining amount of the secondary battery  800  may be sensed by the main control unit  101  only. In this case, the main control unit  101  senses the battery remaining amount of the secondary battery  800  based on the amount of power generated at the solar panels which was inferred from the daylight hours and the rated output of the solar panels or the like, and based on the operating time of the router  700  and the LAN-device. Further, a plurality of operation schedule information corresponding to the battery remaining amount of the secondary battery  800  is stored in the storage unit  103  of the router  700 . Therefore, the main control unit  101  can control the LAN-device based on the operation schedule corresponding to the battery remaining amount of the secondary battery  800 . 
     In this embodiment, the router  700  is used instead of the router  100  in the system shown in  FIG. 3 . Further, the secondary battery  800  and the solar panels  900  are used as a power source for the router  700 .  FIG. 9  is a flow chart showing a flow of a main process of the main control unit  101  of the router  700 . The main process may be started at the start time stored in the RAM in the main control unit  101 . The main process may also be started at startup of the main control unit  101 . Further, the main process may be started based on a predetermined schedule (e.g., frequency of once per hour). In step S 401 , the main control unit  101  executes a secondary battery determination process (details will be described later). In step S 403  subsequent to step S 401 , the main control unit  101  determines whether a secondary battery determination flag which is set by the process of step S 401  is on or off. If the secondary battery determination flag is off, the main control unit  101  reads the operation schedule information from the storage unit  103  which is determined on the secondary battery determination process (step S 405 ). Step S 407  is the same as step S 103  shown in  FIG. 4 , step S 409  is the same as step S 105  shown in  FIG. 4 , step S 411  is the same as step S 107  shown in  FIG. 4  and step S 413  is the same as step S 109  shown in  FIG. 4 . Therefore, descriptions of the process of steps S 407 -S 413  are omitted. 
     In step S 403 , if the secondary battery determination flag is on, the main control unit  101  determines that it is impossible to operate the PoE-enabled camera  300  with the battery remaining amount of the secondary battery  800  and then executes the process for changing the POE-power into the off state (step S 415 ). Then, the main control unit  101  executes the process of setting the router  700  to the low power mode (step S 417 ), and ends the main process. 
       FIG. 10  is a flow chart showing a flow of the secondary battery determination process in step S 401  shown in  FIG. 9 . In step S 501 , the main control unit  101  executes the output voltage measurement process for the secondary battery. In the output voltage measurement process for the secondary battery, the main control unit  101  measures the output voltage of the secondary battery  800  by controlling the remaining battery level monitoring unit  701 . In step S 503  subsequent to step S 501 , the main control unit  101  stores the output voltage value of the secondary battery  800  sent from the remaining battery level monitoring unit  701  in the storage unit  105 . In step S 505  subsequent to step S 503 , the main control unit  101  determines whether the PoE-enabled camera  300  can be operated or not based on the output voltage value of the secondary battery  800 . For example, the main control unit  101  determines that it is impossible to operate the PoE-enabled camera  300  when the output voltage value of the secondary battery  800  is below the predetermined voltage value or is rapidly decreased. In step S 505 , if the main control unit  101  determines that it is possible to operate the PoE-enabled camera  300 , the main control unit  101  turns off the secondary battery determination flag (step S 507 ), determines the operation schedule (step S 509 ), and ends the secondary battery determination process. In step S 509 , the main control unit  101  determines a operation schedule information corresponding to the output voltage value of the secondary battery  800  from a plurality of operation schedule information stored in the storage unit  103 . In step S 505 , if the main control unit  101  determines that it is impossible to operate the PoE-enabled camera  300 , the main control unit  101  turns on the secondary battery determination flag (step S 511 ), transmits the abnormality to the center (step S 513 ), and ends the secondary battery determination process. 
     In case the secondary battery  800  installed outside is used as the power source of the router  700 , the main control unit  101  of the router  700  senses the battery remaining amount of the secondary battery  800  and changes the operation schedule of the PoE-enabled camera  300  according to the battery remaining amount of the secondary battery  800 . Therefore, even when the secondary battery is used as the power source, the router  700  can operate the PoE-enabled camera  300  stably. 
     The following effects can be obtained by the combination of the router  700 , the PoE-enabled camera  300  and the secondary battery  800  according to the present embodiment. 
     (1) In case the router  700  determines the charge of the secondary battery  800  is a good state, the router  700  controls the PoE-enabled camera  300  so as to shoot in the ordinary schedule (e.g., a schedule for the shooting of one minute every hour from seven o&#39;clock in the morning until eighteen o&#39;clock in the evening). 
     (2) In case the router  700  determines the charge of the secondary battery  800  is a bad state, the router  700  controls the PoE-enabled camera  300  so as to shoot in the power-saving mode schedule (e.g., a schedule for the shooting of thirty seconds every three hours from seven o&#39;clock in the morning until eighteen o&#39;clock in the evening). 
     (3) The router  700  can sense the consumption degree of the secondary battery  800  based on the log information on an output voltage value of the secondary battery  800 . 
     (4) The router  700  can send an alert when the router  700  has measured an abrupt voltage drop of the output voltage value of the secondary battery  800 . 
     (5) The router  700  can send an alert when the output voltage of the secondary battery  800  does not increase despite the solar panels has been connected to the secondary battery  800  during the day. 
     (6) When the router  700  intends to communicate with the center, even if any problem is occurred and it becomes impossible to communicate with the center via the wired WAN communication unit  107 , the router  700  can send data and alerts to the center via the wireless WAN communication unit  109 . 
     A monitoring device for monitoring the secondary battery, a PoE-power device and a device for controlling these devices are needed in the conventional operation of the PoE-device using the secondary battery as the power source. The router  700  according to the present embodiment can assume all the functions of these devices described above. Therefore, since the number of devices is reduced, the production cost and the operation cost become cheaper and overall power consumption is also reduced. 
     Technical features (configuration requirements) described in each of the above embodiments are combinable with each other. It is possible to form new technical features by combining the technical features. The PoE-enabled devices applicable to each of the embodiments described above include not only the PoE-compatible camera but also all PoE-compatible devices such as PoE-enabled IP phones, payment terminals, POSs, personal computers, PLCs, sensor units and the like. 
     The present invention is not limited to the above embodiments, and the present invention can be variously modified. 
     While the above embodiments are described in connection with the router to which the PoE-enabled device is connected as one example of the router, the present invention is not limited to that example and is applicable to a router to which the network device other than the PoE-enabled device can be connected (e.g., USB connection) or a network device which includes the PoE-power unit and a router function unit as well. The above-described embodiments are the preferred example of the present invention and various technically preferable limitations are imposed in the foregoing description. The scope of the present invention is not to be unduly limited by the foregoing description. Not all the configurations described in each of the above embodiments are necessarily essential elements of the present invention. 
     INDUSTRIAL APPLICABILITY 
     The present invention can be widely utilized in the router that is connected to various network devices. 
     REFERENCE SIGNS LIST 
     
         
         
           
               100 ,  700  router 
               101  main control unit 
               103 ,  105  storage unit 
               107  wired WAN communication unit 
               109  wireless WAN communication unit 
               111  wired LAN communication/power supply unit 
               113  data communication unit 
               115  power supply unit 
               200  LAN cable 
               300  PoE-enabled camera 
               400  base station 
               500  cloud 
               501  center 
               600  terminal 
               701  remaining battery level monitoring unit