JP6075229B2 - Wireless relay monitoring system and monitoring terminal simultaneous startup program. - Google Patents

Description

  The present invention relates to a wireless relay monitoring system and a monitoring terminal simultaneous activation program when a monitoring terminal installed at a monitoring point transmits information on the monitoring point.

  As an example of a system that transmits information on a monitoring point by a monitoring terminal to an external device, a sewer water level monitoring system that measures and transmits a water level in a sewer pipe with a measurement communication terminal is known.

  For example, a water level measurement and data transmission method using an optical fiber stretched around a sewer pipe has been put into practical use in a part of a large city (see Patent Documents 1 and 2). However, when an optical fiber is used, the optical fiber may be damaged to cause a transmission failure. In addition, the construction work of the optical fiber requires labor and a great installation cost.

  Therefore, a technique for transmitting measurement data such as a water level measured by a measurement communication terminal using a mobile phone line (for example, an LTE line or a 3G line) or a specific low-power radio without using a cable such as an optical fiber is proposed. (See Patent Documents 3 and 4).

JP 2003-132774 A Japanese Patent Application Laid-Open No. 07-62719 Japanese Patent Laid-Open No. 2003-6780 JP 2007-218740 A

  However, when power is supplied from the power source to the measurement communication terminal by wiring work, the wiring work cost is high, and the introduction cost may increase. Further, when a measurement communication terminal that operates independently using a battery (battery) as a power source is used, it is necessary to frequently replace the battery, which may increase the running cost due to the replacement cost of the battery.

  In this case, if a system that turns on the main power supply only during communication measurement is constructed, battery consumption can be suppressed, but the measurement in the sewer pipe is mainly performed in units of manholes. In order to measure, a measurement communication terminal equipped with a water level meter must be installed for each manhole. This increases the communication cost each time the number of measurement communication terminals is increased.

  The present invention has been made in order to solve the above-described problems of the prior art, and a problem to be solved is to provide a system that can be operated at a low cost by suppressing a communication cost when adding a monitoring terminal. .

  The present invention provides a monitoring terminal for power saving driving using a battery at a monitoring point, and in a wireless relay monitoring system when the monitoring terminal transmits information on the monitoring point to an external device, information transmission of the monitoring terminal is a short distance A relay receiving terminal for relaying via wireless communication is provided.

  The relay receiving terminal of the present invention is installed in the vicinity of the monitoring terminal, and can always communicate with a commercial power source or the like. Here, since the monitoring terminal and the receiving terminal for relay are communicated by short-range wireless communication, contracts for mobile phone lines and the like can be minimized. At this time, if the relay receiving terminal can relay the information transmission of a plurality of monitoring terminals, the number of relay receiving terminals can be reduced and the cost can be reduced.

  As one aspect of the present invention, there is a method in which any of the monitoring terminals functions as a relay receiving terminal and performs short-range wireless communication with other monitoring terminals. Here, by making the monitoring terminal function as a relay receiving terminal, the number of terminals using a mobile phone line or the like is limited, and installation work and installation cost of the relay receiving terminal are not required.

  At this time, the time of simultaneous activation may be set based on the absolute time information acquired by each monitoring terminal by GPS, and the information may be relayed while each monitoring terminal is simultaneously activated and performs multi-hop communication. As a result, all the monitoring terminals can be activated simultaneously, which contributes to a longer battery life. In particular, since GPS time information can be used, accurate simultaneous activation becomes possible.

  In addition, each monitoring terminal may start at the same time by sharing time with time correction to acquire absolute time, and relay information while performing multi-hop communication. In this case, it is not necessary to provide a GPS reception function in the monitoring terminal, and the monitoring terminal can be reduced in size and cost can be reduced. The present invention may be a program that causes a monitoring terminal (computer) to function as a simultaneous activation terminal having the above-described configurations.

  ADVANTAGE OF THE INVENTION According to this invention, the monitoring cost at the time of expansion of a monitoring terminal can be suppressed, and the monitoring system which can be operate | moved at low cost can be provided.

The block diagram of a sewer water level monitoring system. The block diagram of the measurement communication terminal of a sewer water level monitoring system. The system block diagram at the time of using a mobile telephone line for a measurement communication terminal. The lineblock diagram showing communication of a 1st embodiment of the present invention. The block diagram which shows the communication of 2nd Embodiment. The block diagram which shows the communication of 3rd Embodiment. The flowchart which shows the operation example 1 of simultaneous starting of each measurement communication terminal in 3rd Embodiment. The flowchart which shows the operation example 2 of simultaneous starting of the same each measurement communication terminal. The conceptual diagram of correction time.

  Hereinafter, a wireless relay monitoring system according to an embodiment of the present invention will be described. This relay monitoring system adopts a communication method for performing communication using a power-saving radio or the like for the monitoring terminal instead of a communication method via a wide area network of mobile phone lines for each monitoring terminal. Here, an example of application of the present invention to a sewer water level monitoring system will be described.

≪Sewerage water level monitoring system≫
A sewer monitoring system to which the present invention is applied will be described with reference to FIGS. As shown in FIG. 1, the sewer water level monitoring system 1 includes a measurement communication terminal 4 attached to the bottom surface of the manhole cover 7 and a power supply for driving the measurement communication terminal 4 which is also attached to the bottom surface of the manhole cover 7. A battery (battery) 5 to be supplied, a water level sensor 8 for measuring the water level P in the manhole M, and an antenna 6 mounted on the surface of the manhole cover 7 are provided.

  The configuration of the measurement communication terminal 4 is shown in FIG. As shown in FIG. 2, the measurement communication terminal 4 supplies power to the CPU 9 and the like 9 by turning on the main power switch 13 and the CPU and peripheral circuits (hereinafter referred to as CPU and the like) 9 that execute the measurement communication of the water level P. Main power circuit 11, CPU power activation circuit 12 for turning on / off main power switch 13, GPS receiving unit (hereinafter abbreviated as GPS) 16, antenna 16 for GPS 16, and backup power switch 15 on And a backup power supply circuit 14 for supplying power to the activation circuit 12, an RTC circuit (hereinafter abbreviated as RTC) 18 and the communication circuit 10, and the GPS 16 and the antenna 17 have arbitrary configurations. Each circuit 10, 12, 14, 18 functions as a backup power supply operating unit B.

  That is, since the backup power switch 15 is in an on state except during maintenance and repair, the circuits 10, 12, 14, and 18 are always supplied with power, and the measurement communication terminal 4 performs power saving operation. Here, the power saving operation means a state of the power saving mode in which the power source of the battery 5 is supplied only to the backup power source operating unit B.

  Accordingly, the communication circuit 10 is supplied with power during standby in the power saving mode, receives a call start command via the upper network (local network / wide area network), and turns on the main power switch 13 in response to the command to turn on the main power switch 13. The power supply circuit 11 can be activated. According to this circuit system, the water level can be arbitrarily measured by a higher order command.

  The RTC 18 is constituted by an integrated circuit having a computer clock function, and outputs an ON signal to the activation circuit 12 when the current time coincides with the activation time set for activation of the measurement communication terminal 4. Here, the CPU 9 or the like 9 confirms the state of the activation circuit 12 so that the activation instruction (CPU activation trigger) of the CPU or the like is either (A) the activation time by the RTC 18 or (B) the call activation instruction via the host network. And the responsibility of transmitting the water level measurement value of the water level sensor 8 to the upper network through the communication circuit 10 is executed. This is called a measurement communication mode.

  Further, the CPU 9 or the like 9 itself outputs a power-off command to the activation circuit 12 after the measurement communication of the water level measurement value is completed, and turns off the main power switch 13. Therefore, according to the sewer water level monitoring system 1, the power source of the CPU 9 is turned on and operates according to the start conditions (A) and (B), and the main power circuit 11 is turned off by outputting a power off command after the measurement communication. Power consumption of the battery 5 is suppressed.

  Based on FIG. 3, a system configuration in the case of using a mobile phone line for communication of the measurement communication terminal 4 will be described. Here, the measurement communication terminal 4 is installed on the manhole cover 7 and monitored with respect to the manhole M determined as a measurement target in advance according to the arrangement state and the branching state of the manhole M. At this time, the measurement communication terminal 4 directly accesses the upper network (wide area network / local network) W of the mobile phone line.

  In FIG. 3, manholes M1 to Mn indicate the manholes M to be monitored, and 4-1 to 4-n indicate the measurement communication terminals 4 installed on the manhole covers 7 of the manholes M1 to Mn. Here, the measured value of the water level P measured by the measurement communication terminals 4-1 to 4-n is stored in the information collecting server S in the network W via the host network W of the mobile phone line. Based on this accumulated information, monitoring, analysis, warning, service provision, etc. are performed by local governments.

  Although the present invention will be described by taking a sewer water level monitoring system as an example, a plurality of monitoring point information such as turbidity, hydrogen sulfide, and pH may be selected in addition to the water level. For example, as long as the information can be transmitted, the information is not limited to the maintenance management information of the sewer pipe, and may be image information or the like, and the information on the monitoring point can be collected.

<< First Embodiment >>
A first embodiment of the present invention will be described with reference to FIG. Here, the wireless relay monitoring system of the present invention is applied to the sewer water level monitoring system 1. In the configuration of FIG. 3, each measurement communication terminal 4-1 to 4 -n directly accesses the upper network W, so that the communication cost increases each time the measurement communication terminal 4 is added. That is, a line usage fee for a cellular phone network or the like is generated each time in the manhole M unit, and the communication usage fee may increase.

  On the other hand, in the configuration of FIG. 4, the relay receiving terminal 20 is attached in the vicinity of each of the measurement communication terminals 4-1 to 4 -n. In FIG. 4, the relay receiving terminals 20-1 to 20-n are installed in the vicinity of the measurement communication terminals 4-1 to 4-n.

  At this time, the measurement communication terminals 4-1 to 4-n use the short-distance wireless communication L that can be used without a license, instead of the cellular phone network or the wired communication, in order to eliminate the use fee. This short-range wireless communication L is wireless communication that does not require a radio license using radio waves such as a 400 MHz band, a 950 MHz band, a 920 MHz band, and a 2.4 GHz band, which are generally called specific power-saving radios. For example, “Bluetooth (registered trademark) ) "Etc. can also be used.

  Specifically, the communication circuit 10 of each measurement communication terminal 4-1 to 4-n has a configuration corresponding to the short-range wireless communication L. For example, as the communication circuit 10, a 0.5 square inch small transceiver may be mounted for Bluetooth.

  In this case, if each of the measurement communication terminals 4-1 to 4-n shifts from the power saving mode to the measurement communication mode, the nearby relay reception terminals 20-1 to 20-n via the short-range wireless communication L Enable communication. The measurement communication terminals 4-1 to 4-n are each mounted on the manhole cover 7 and operate with the battery 5 that does not require a commercial power source.

  Further, the relay receiving terminals 20-1 to 20-n are configured to be operable in a state in which communication is always possible with a trademark power source. Therefore, time management such as simultaneous activation of the relay receiving terminals 20-1 to 20-n and simultaneous activation with the measurement communication terminals 4-1 to 4-n is not necessary. Here, it is assumed that the manholes M1 to Mn are buried in the basement of the road G, and each of the relay receiving terminals 20-1 to 20-n is attached to a power pole or the like in the roadside band (within a distance of 10 m from the manhole cover 7). And). It is assumed that the relay receiving terminal 20-n supports both near field communication L / wide area wireless communication I.

  Further, each of the measurement communication terminals 4-1 to 4-n and the relay receiving terminals 20-1 to 20-n can constitute a mesh type network such as Zigbee (registered trademark), or a star type, a tree type, It is also possible to configure various types of networks of ring type and link type.

  Then, the measurement communication terminal 4 measures the water level of the sewer water level P, and transmits the information as event information to the nearby relay receiving terminal 20 by the short-range wireless communication L. This relay receiving terminal 20 can perform multi-hop wireless transmission, can relatively shorten the transmission distance between individual relay receiving terminals 20, and each relay receiving terminal 20 can also perform near field communication. Information transmission in L becomes possible. As a result, the wireless transmission power of the measurement communication terminal 4 can be reduced to save the power consumption of the measurement communication terminal 4 and extend the life of the battery 5.

  According to this configuration, not only the effect of saving power consumption and extending the life of the battery 5 but also communication can be performed while using the conventional manhole cover 7. That is, since the relay receiving terminal 20 is installed on a power pole or the like within a distance of 10 m from the manhole cover 7, the measurement communication terminal 4 installed on the lower surface of the manhole cover 7 can communicate with the relay receiving terminal located at a very short distance. The measured value can be transmitted to the outside of the manhole M by the short-range wireless communication L through a built-in antenna (not shown) (not shown).

  For example, the measurement communication terminal 4-1 in FIG. 4 transmits the measurement value of the water level P to the relay receiving terminal 20-1 by the short-range wireless communication L in the measurement communication mode. Further, an ad hoc communication network is constructed between the relay receiving terminals 20-1 to 20-n, and the relay receiving terminals 20-1 to 20-n are sequentially transmitted by the short-range wireless communication L.

  Note that the relay receiving terminal 20-n uses the short-range wireless communication L / wide-area wireless communication I (including a mobile phone line) to send the measurement value to the information collection server via the upper network W (wide-area network / local area network). S to S.

  At this time, in order to transmit information between the measurement communication terminal 4 and the relay receiving terminal 20 and between each relay receiving terminal 20 by the short-range wireless communication L, when using a mobile phone line as the wide area wireless communication I, The number of line contracts can be kept to a minimum, contributing to a reduction in communication costs. Further, since the relay receiving terminal 20 is always on standby with the power turned on, there is an advantage that time management is unnecessary.

<< Second Embodiment >>
A second embodiment of the present invention will be described based on FIG. In the first embodiment of FIG. 4, since the measurement communication terminal 4 and the relay reception terminal 20 are arranged in units of manholes M, the configuration of “measurement communication terminal 4: relay reception terminal 20 = 1: 1” is used. there were. In contrast, the second embodiment of FIG. 5 has a configuration of “measurement communication terminal 4: relay receiving terminal 20 = n (n ≧ 2): 1”.

  According to this configuration, when the measurement communication terminal 4 is a short-range wireless communication L that enables long-distance (about several km) communication as compared with the first embodiment, the measurement communication terminal mounted on the plurality of manhole covers 7. 4-1 to 4-n can be collectively connected to the relay receiving terminal 20, and the number of the relay receiving terminals 20 can be reduced. This contributes to the reduction of the installation cost.

  Therefore, the specific power-saving radio technology used in the short-range wireless communication L between the terminals 4 and 20 covers a range (area) of several hundred m to several km, and is specified for each terminal 4 and 20. Built-in power-saving wireless module.

  As described above, the first embodiment in FIG. 4 is a configuration example that requires a relay receiving device in units of manholes. However, in the second embodiment in FIG. 5, “measurement communication terminal 4: relay receiving terminal 20 = n”. Since (n ≧): 1 ”is configured, the relay receiving terminal 20 operates to acquire the measurement values of the plurality of measurement communication terminals 4. Note that the relay receiving terminal 20 transmits the measurement value to the information collecting server S via the upper network W by the wide area wireless communication I. However, the communication between the relay receiving terminal 20 and the upper network W can be handled by the short-range wireless communication L, and the number of the relay receiving terminals 20 can be reduced as in the case of the wide area wireless communication I.

«Third embodiment»
A third embodiment of the present invention will be described with reference to FIG. Although this configuration is almost the same as that in FIG. 4, the relay receiving terminal 20 installed in the vicinity of each manhole cover 7 is abolished, and the short-range wireless communication L is performed between the measurement communication terminals 4. Thereby, the installation cost of the relay receiving terminal 20 can be reduced, and the cost can be further suppressed.

  At this time, radio waves for communication between the measurement communication terminals 4 pass horizontally on the ground, and the propagation space is halved. Therefore, the distance between the measurement communication terminals 4 needs to be short. The short-range wireless communication L used between the measurement communication terminals 4 is a radio license using radio waves of 400 MHz band, 950 MHz band, 920 MHz band, 2.4 GHz band, etc., which are generally called specific power-saving radios as described above. Unnecessary wireless communication.

  Here, the measurement communication terminal 4 installed on the lower surface of the manhole cover 7 performs short-range wireless communication L so that communication can be performed while using the conventional manhole cover 7, and therefore the antenna 6 mounted on the surface of the manhole cover 7. Send radio waves via. As a result, it is possible to reduce wiring work costs and power supply work for communication lines.

  If it demonstrates based on FIG. 6, the other party of the near field communication L by the measurement communication terminal 4-1 of the manhole M1 will be the measurement communication terminal 4-2 of the nearby manhole M2. Here, the measurement communication terminals 4-1 to 4-n construct an ad hoc communication network, and the measured values of the water level P measured by the measurement communication terminal 4-1 are in the order of the measurement communication terminals 4-2 and 4-n. And is transmitted to the information collection server S via the upper network W by the short-range wireless communication L / wide-area wireless communication I.

  However, since the measured value of the water level P measured by the measurement communication terminal 4-1 is sequentially transmitted to the measurement communication terminals 4-2 and 4-n, the measurement communication terminals 4-2 and 4-n that perform communication are activated simultaneously. There is a need to. At this time, the measurement communication terminals 4-1 to 4-n have the main power switch 13 turned on almost simultaneously by the respective RTCs 18 regardless of whether the GPS 16 is mounted or not, and the measurement communication terminals 4 that have completed transmission of the measurement values. In -1 to 4-n, the main power switch 13 is sequentially turned off. Hereinafter, an operation example of simultaneous activation of the measurement communication terminals 4-1 to 4-n will be described.

(1) Operation example 1 of simultaneous activation of each measurement communication terminal
The simultaneous activation of the measurement communication terminals 4-1 to 4-n using the absolute time of the GPS 16 will be described with reference to FIG. It is assumed that the backup power switch 15 is turned on and the backup power circuit 14 is turned on at the same time.

  S01 to S05: Here, the measurement communication terminals 4-1 to 4-n obtain absolute time information in the measurement communication mode. The absolute time information is acquired by the GPS 16 of the measurement communication terminals 4-1 to 4-n. This acquisition of absolute time is effective for time management in which the apparatus is activated at the time of communication standby in the power saving mode, because all measurement communication terminals 4-1 to 4-n can acquire the same time.

  Specifically, in the measurement communication terminals 4-1 to 4-n, the main power supply circuit 11 is powered on when the main power switch 13 is turned on, and shifts to the measurement communication mode (S01). At this time, absolute time information is obtained from the GPS 16 (S02).

  Based on the absolute time information obtained here, the absolute time is set as the current time in the RTC 18, and then the time for starting up next so that all the measurement communication terminals 4-1 to 4-n can perform multi-hop wireless transmission ( The same time is set for each terminal 4-1 to 4-n.) Is set as the activation time (S03). After this setting, the main power switch 13 is turned off, the power supply to the main power circuit 11 is cut off (S04), and the mode is shifted to the power saving mode (S05).

  S06 to S09: The measurement communication terminals 4-1 to 4-n confirm on / off of activation by the RTC 18 (S06). That is, the RTC 18 outputs an ON signal to the activation circuit 12 if the activation time set in S03 and the current time coincide, but does not output an ON signal if the two times do not coincide, and the power saving mode of S05 To maintain.

  When the activation circuit 12 receives the ON signal from the RTC 18, the activation circuit 12 turns on the main power switch 13 to turn on the main power circuit 11 (S07). As a result, the CPU 9 and the water level sensor 8 can be operated, shift to the measurement communication mode (S08), the main power switch 13 is turned off after the measurement communication processing is completed, and the power supply to the main power supply circuit 11 is cut off ( S09) and return to the power saving mode of S05.

  According to this operation example 1, since ON / OFF is determined at the activation time set based on the absolute time information of the GPS 16, accurate simultaneous activation becomes possible. Moreover, since all the measurement communication terminals 4-1 to 4-n can be activated simultaneously, it is possible to contribute to extending the life of the battery 5.

(2) Operation example 2 of simultaneous activation of each measurement communication terminal
Although the operation example 1 enables accurate simultaneous activation, the GPS 16 is required for all the measurement communication terminals 4-1 to 4-n. Here, the simultaneous activation of each measurement communication terminal that does not require the reception function of the GPS 16 will be described with reference to FIG.

  In this case, the time information of any measurement communication terminal 4 or server (or the information collection server S) may be shared without using the time information of the GPS 16 so that all the measurement communication terminals 4-1 to 4-n can share the time information. Simultaneous activation is realized. Here, an example in which time information is shared mainly based on time information of an arbitrary measurement communication terminal 4 will be described.

  It is assumed that the backup power switch 15 is turned on in advance and the backup power circuit 14 of the measurement communication terminals 4-1 to 4-n is turned on in the same manner as in the first operation example.

  S11 to S16: The main power switch 13 of the measurement communication terminals 4-1 to 4-n is turned on, and the main power supply circuit 11 is powered on to shift to the measurement communication mode (S11).

  After the transition to the measurement communication mode, transmission / reception of time information of the measurement communication terminal 4 that is a reference for time sharing is executed (S12). Here, as an example, the measurement communication terminal 4-1 is a reference terminal. The measurement communication terminal 4-1 only transmits time information.

  On the other hand, when a terminal other than the measurement communication terminal 4-1 sets the received time information as it is in the RTC 18 as shown in FIG. 9, the time difference Δt increases as the distance from the measurement communication terminal 4-1 increases.

  Therefore, the CPU 9 corrects Δt time based on the communication processing time t measured in advance (S13). The corrected time information and the next activation time are set in the RTC 18 (S14). After this setting, the main power switch 13 is turned off, the power supply of the main power supply circuit 11 is cut off (S15), and the mode is shifted to the power saving mode (S16).

  An example in which absolute time information is distributed from the server when the measurement communication terminals 4-1 to 4-n are not equipped with the GPS 16 will also be described. If the time required for communication processing is tm at this time, if the absolute time ta is acquired via the communication processing time tm after the distribution of the absolute time information, the absolute time “t set” at the measurement communication terminal 4 is expressed by the equation (1). ).

Expression (1): “t set” (absolute time setting time) = ta (distributed absolute time) −tm (communication processing time)
The calculation result of Table 1 is obtained from this equation (1).

  Here, assuming that the relay communication processing time is t, the relay processing time Δt = nt for the number of relay stages (the number of measurement communication terminals 4) n.

  If the time in consideration of such communication time delay is set in the RTC 18, the RTCs 18 of the measurement communication terminals 4-1 to 4-n can keep substantially the same time. Since the resolution of the current RTC 18 is about 100 ms, when the communication time is corrected for a short time, the measurement communication terminals 4-1 to 4-n can set almost the same time but the number of relay stages is large. In setting the time, it is important to correct the time delay.

  Since the communication processing time is fixed in advance, the communication processing time can be fixed in advance by the CPU of the measurement communication device 4 and the communication performance. Further, at the time of manufacture, when it is installed at the site (manhole M), it is easy to set the time of the RTC 18 by connecting to the server 1: 1 without easily performing multistage relay.

  S17 to S20: Here, the same operation process as that of S06 to S09 of the operation example 1 is executed. In other words, in the measurement communication terminals 4-1 to 4-n, on / off of activation by the RTC 18 is confirmed (S17). At this time, the RTC 18 outputs an ON signal to the activation circuit 12 if the activation time set in S14 coincides with the current time, but does not output an ON signal if the two times do not coincide, and the power saving mode of S16 To maintain.

  When the activation circuit 12 receives the on signal from the RTC 18, the activation circuit 12 turns on the main power switch 13 to turn on the main power circuit 11 (S18). As a result, the CPU 9 and the water level sensor 8 become operable, and the mode shifts to the measurement communication mode (S19). After the measurement communication process is completed, the main power switch 13 is turned off and the power supply to the main power supply circuit 11 is cut off ( S20) and return to the power saving mode of S16.

  Here, all the measurement communication terminals 4-1 to 4-n can be activated simultaneously at the time set in the RTC 18 without using the GPS 16, which can contribute to cost reduction of the measurement communication terminal 4 and downsizing of the apparatus. Moreover, since all the measurement communication terminals 4-1 to 4-n can be activated simultaneously, it is possible to contribute to extending the life of the battery 5.

≪Programs≫
The present invention can also be configured as a program for simultaneously starting the computer as the measurement communication terminal 4 in the first and second operation examples. According to this program, the measurement communication terminal 4 can execute part or all of S01 to S09 and S11 to S20.

  The program can be provided through a network such as a website or e-mail. The program is stored in a recording medium such as a CD-ROM, DVD-ROM, CD-R, CD-RW, DVD-R, DVD-RW, MO, HDD, BD-ROM, BD-R, or BD-RE. It is also possible to record, save and distribute. This recording medium is read using a recording medium driving device, and the program code itself realizes the processing of the above embodiment, so that the recording medium also constitutes the present invention.

1 ... Sewer water level monitoring system 4 ... Measurement communication terminal (monitoring terminal)
5 ... Battery (control power supply)
DESCRIPTION OF SYMBOLS 6 ... Antenna 7 ... Manhole cover 8 ... Water level sensor 9 ... CPU and peripheral circuit 10 ... Communication circuit 11 ... Main power supply circuit 12 ... CPU power supply starting circuit 13 ... Main power switch 14 ... Backup power supply circuit 15 ... Backup power switch 16 ... GPS Unit 17 ... GPS antenna 18 ... RTC
20 ... Reception terminal for relay B ... Backup power supply operation unit G ... Road I ... Wide area network communication L ... Near field communication M ... Manhole P ... Water level S ... Information management server (external device)
W ... Upper network

Claims (2)

A wireless relay monitoring system in which a plurality of monitoring terminals that drive power saving using batteries are installed at a monitoring point, and the monitoring terminal transmits information on the monitoring point to an external device,
A short-range wireless communication network is constructed between the monitoring terminals, and the time information of the specific monitoring terminal is transmitted to each other monitoring terminal via the network to share the time information between the monitoring terminals,
Each of the monitoring terminals starts simultaneously at a time determined based on the shared time information, and the specific monitoring terminal relays transmission of the information regarding the other monitoring terminals via the network ,
Each of the other monitoring terminals corrects the time information of the specific monitoring terminal based on the communication processing time measured in advance , and starts at a time determined based on the corrected time information ,
The time information of the specific monitoring terminal is transmitted to each of the other monitoring terminals by multi-hop wireless communication, and the communication processing time is determined according to the number of relay monitoring terminals of the multi-hop wireless communication. Communication relay system. A program for simultaneously starting a monitoring terminal for causing a computer to function as the monitoring terminal according to claim 1 .

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