JP7005815B2 - Communication terminals that make up a multi-hop network, and a multi-hop network - Google Patents

Description

The present invention relates to a communication terminal constituting a multi-hop network and a multi-hop network.

A multi-hop network comprises a plurality of communication terminals. Each communication terminal included in the plurality of communication terminals performs wireless communication with other communication terminals using the power supplied from the power system. Therefore, each communication terminal cannot perform wireless communication with other communication terminals in the event of a power outage in the power system. On the other hand, even if each communication terminal fails and cannot operate, each communication terminal cannot perform wireless communication with another communication terminal. For this reason, the reason why each communication terminal could not perform wireless communication with other communication terminals was that a power system power failure occurred and each communication terminal failed and could not operate. It is difficult to tell which one it is.

Therefore, in addition to the normal power supply unit that supplies the power supplied from the power system to the communication terminals included in the plurality of communication terminals, the standby power supply unit that supplies the power discharged by the power storage such as a battery or a storage battery. It has been proposed to provide the communication terminal with a power failure notification using the power supplied by the standby power supply unit.

In the technique described in Patent Document 1, the wide area monitoring system is composed of a master station, a switching slave station, and a plurality of slave stations (paragraph 0018-0019). The slave station is composed of a main power supply unit, a backup power supply unit, a power supply switching unit, a controller unit, an information storage unit, a wireless communication unit, and a monitoring control unit (paragraph 0027). The main power supply unit supplies power from the grid power supply (paragraph 0028). The backup power supply unit can be composed of a battery, an electric double layer capacitor, or the like, and is used as a backup when the output of the main power supply drops or disappears (paragraph 0029). The power switching unit controls the flow of power supply so as to supply power to the terminal when there is an output voltage of the main power supply (paragraph 0030). When the output of the main power supply is less than the threshold value, the output is switched to the output from the backup power supply unit (paragraph 0030). The controller unit executes power supply switching monitoring and the like by the power supply switching unit (paragraph 0031). The wireless communication unit transmits a signal generated by the controller unit by radio waves, and passes the received signal to the controller unit (paragraph 0033). In the wide area monitoring system, the number of communications of the backup power operating slave station is suppressed, and as a result, the consumption of the backup power supply can be suppressed, and the slave station operating the backup power supply can maintain the communication for a long time (paragraph 0145).

Japanese Unexamined Patent Publication No. 2013-89978

Providing a backup power supply unit in a communication terminal increases the cost of the communication terminal and increases the capital investment required to construct a multi-hop network. The amount of increase in the cost of the communication terminal due to the provision of the standby power supply unit in the communication terminal mainly depends on the capacity of the power storage unit provided in the backup power supply unit. Therefore, it is expected that the capacity of the power storage provided in the backup power supply unit will be reduced.

According to the technique described in Patent Document 1, since the consumption of the backup power supply is suppressed (paragraph 0145), it seems that the capacities of the battery, the electric double layer capacitor, etc. constituting the backup power supply unit can be reduced. However, in the technique described in Patent Document 1, when a large-scale power failure of the grid power supply occurs and all the slave stations become backup power operating slave stations, the communication performed by the main power supply operating slave station is performed. This must be done by the backup power operating slave station, and the number of communications of the backup power operating slave station cannot be suppressed. Considering this, it is not always possible to reduce the capacities of the battery, electric double layer capacitor, etc. that make up the backup power supply unit.

The present invention has been made in view of this problem. An object to be solved by the present invention is to reduce the capacity of the power storage unit provided in the backup power supply unit provided in the communication terminal constituting the multi-hop network.

The present invention is directed to a communication terminal constituting a multi-hop network.

The communication terminal usually includes a power supply unit, a backup power supply unit, a wireless unit, a switching unit, and a control unit.

The normal power supply unit supplies the first electric power supplied from the electric power system.

The backup power supply unit includes an energy storage unit. The backup power supply unit supplies a second power discharged by the power storage.

The wireless unit performs wireless communication with other communication terminals constituting the multi-hop network. The wireless unit switches the communication speed of wireless communication between a first communication speed and a second communication speed faster than the first communication speed. The wireless unit transmits a power failure notification indicating that a power system power failure has occurred by wireless communication.

The switching unit switches the electric power for operating the wireless unit between the first electric power and the second electric power.

When the control unit detects a power failure in the power system, the control unit causes the switching unit to switch the power for operating the wireless unit from the first power to the second power, and causes the wireless unit to change the communication speed of wireless communication. The first communication speed is switched to the second communication speed, and the radio unit is made to transmit a power failure notification.

The present invention is also directed to multi-hop networks.

According to the present invention, when the wireless unit is operated by the second electric power discharged by the electric power storage due to the power failure of the electric power system, the communication speed of the wireless communication is changed from the first communication speed to the second communication speed. It becomes faster and the time required for wireless communication can be shortened. Therefore, the amount of electric power required to operate the wireless unit can be reduced, and the capacity of the power storage can be reduced.

The objects, features, aspects, and advantages of the present invention will be made clearer by the following detailed description and accompanying drawings.

It is a schematic diagram schematically illustrating a multi-hop network including the communication terminal of the first embodiment. It is a flowchart which illustrates the operation at the time of transmitting data of the communication terminal of Embodiment 1-3. It is a block diagram which illustrates the communication terminal of Embodiment 1-3. It is a flowchart which illustrates the control sequence at the time of a power failure of the power system of the communication terminal of Embodiment 1-3. It is a flowchart which illustrates the control sequence at the time of a power failure of the power system of the communication terminal of Embodiment 1-3. It is a time chart which illustrates the time change of the power consumption of the communication terminal of Embodiment 1-3. It is a figure which illustrates the normal-time communication path of a plurality of communication terminals constituting the multi-hop network including the communication terminal of Embodiment 2. FIG. It is a figure which illustrates the communication path at the time of a power failure of the power system of a plurality of communication terminals constituting the multi-hop network including the communication terminal of Embodiment 2. FIG. FIG. 5 is a diagram illustrating a table managed by an aggregation device or a master station provided in a multi-hop network including the communication terminal of the second embodiment. It is a sequence diagram which illustrates the sequence of the processing performed at the time of the power failure of the power system in the multi-hop network provided with the communication terminal of Embodiment 2. It is a sequence diagram which illustrates the sequence of the processing performed at the time of the power failure of the power system in the multi-hop network provided with the communication terminal of Embodiment 2. It is a sequence diagram which illustrates the sequence of the processing performed at the time of the simulated power failure of the electric power system in the multi-hop network provided with the communication terminal of Embodiment 2. FIG. It is a sequence diagram which illustrates the sequence of the processing performed at the time of the simulated power failure of the electric power system in the multi-hop network provided with the communication terminal of Embodiment 2. FIG. It is a figure which illustrates the table stored in the aggregate device at the time of the simulated power failure of the electric power system in the multi-hop network provided with the communication terminal of Embodiment 2. FIG. FIG. 5 is a diagram illustrating a table managed by an aggregation device or a master station provided in a multi-hop network including the communication terminal of the third embodiment. It is a figure which illustrates the communication path at the time of a power failure of the power system of a plurality of communication terminals constituting the multi-hop network including the communication terminal of Embodiment 3. FIG. It is a flowchart illustrating the method of determining the Trunk in the multi-hop network provided with the communication terminal of Embodiment 3. FIG.

1 Embodiment 1
1.1 Multi-hop network FIG. 1 is a schematic diagram schematically showing a multi-hop network including the communication terminal of the first embodiment.

The multi-hop network 1 illustrated in FIG. 1 includes a plurality of communication terminals 11, an aggregation device 12, and a master station 13.

The plurality of communication terminals 11 are four communication terminals 11a, 11b, 11c and 11d, the aggregation device 12 is one aggregation device, and the master station 13 is one master station. However, the multi-hop network 1 may be provided with three or less or five or more communication terminals, two or more aggregation devices, or two or more master stations.

The plurality of communication terminals 11 cover a single multi-hop network area 20.

Each communication terminal 11x included in the plurality of communication terminals 11 can perform wireless communication at the first communication speed and the second communication speed. The second communication speed is faster than the first communication readability. Each communication terminal 11x may be able to perform wireless communication at three or more communication speeds different from each other.

Each communication terminal 11x is electrically connected to the power system 30. As a result, each communication terminal 11x operates by the first electric power supplied from the electric power system 30. Further, each communication terminal 11x includes the backup power supply unit described below, and operates by the second power supplied by the backup power supply unit described below.

Normally, the plurality of communication terminals 11 wirelessly communicate with each other at the first communication speed. Further, the aggregation device 12 performs wireless communication with the communication terminal 11d included in the plurality of communication terminals 11. Further, the master station 13 communicates with the aggregation device 12. As a result, the aggregation device 12 acquires a plurality of data transmitted by the plurality of communication terminals 11, and aggregates the acquired plurality of data. The master station 13 acquires a plurality of aggregated data. The master station 13 manages the entire multi-hop network 1 and distributes control to each communication terminal 11x.

1.2 Normal Transmission Operation of Communication Terminal FIG. 2 is a flowchart illustrating the operation of the communication terminal of the first embodiment when transmitting data.

Each communication terminal 11x included in the plurality of communication terminals 11 normally stands by in a reception state in step S101 shown in FIG. Further, each communication terminal 11x normally executes steps S102 to S105 shown in FIG. 2 when transmitting data. Further, each communication terminal 11x normally returns to the reception state in step S106 illustrated in FIG. 2 after transmitting data.

In step S102, each communication terminal 11x performs carrier sense (CCA), and determines whether or not it is possible to shift to the transmission mode based on the result of CCA. If it is determined that each communication terminal 11x can shift to the transmission mode, step S103 is executed. If it is determined that the communication terminal 11x cannot shift to the transmission mode, step S102 is executed again. As a result, each communication terminal 11x performs CCA until it can be determined that it can shift to the transmission mode, and determines whether or not it can shift to the transmission mode based on the result of CCA. Repeat what you do.

In step S103, each communication terminal 11x shifts to the transmission mode and transmits data by wireless communication. Each communication terminal 11x performs wireless communication at the first communication speed when transmitting data by wireless communication.

In the following step S104, each communication terminal 11x waits for an acknowledgment (ACK) response and determines whether or not the ACK response has been received. An ACK response indicates that the data was successfully transmitted. If each communication terminal 11x determines that the ACK response has been received, step S105 is executed. If each communication terminal 11x determines that the ACK response has not been received, step S102 is executed again. As a result, each communication terminal 11x repeats transmitting data by wireless communication until it can be determined that the ACK response has been received.

In step S105, each communication terminal 11x completes transmitting data.

Each communication terminal 11x waits in the receiving state in step S101 even when the power system 30 has a power failure, executes steps S102 to S105 when transmitting data, and after transmitting the data, in step S106. Return to the reception status.

However, each communication terminal 11x performs wireless communication at a second communication speed higher than the first communication speed when transmitting data by wireless communication in the event of a power failure of the power system 30. As a result, each communication terminal 11x can shorten the time required for transmitting data in the event of a power failure of the power system 30 as compared with the normal time. Generally speaking, the power consumption of each communication terminal 11x while transmitting data is large. Therefore, shortening the time required to transmit the data contributes to reducing the power consumption of each communication terminal 11x during the transmission of the data. Therefore, each communication terminal 11x shortens the time required to transmit data and transmits data by performing wireless communication at a second communication speed faster than the first communication speed when the power system 30 fails. The power consumption of each communication terminal 11x in between is reduced.

1.3 Communication terminal FIG. 3 is a block diagram illustrating a communication terminal according to the first embodiment.

Each communication terminal 11x included in the plurality of communication terminals 11 constitutes a multi-hop network 1.

As shown in FIG. 3, each communication terminal 11x includes a normal power supply unit 101, a backup power supply unit 102, a switching unit 103, a radio unit 104, and a control unit 105.

The normal power supply unit 101, the backup power supply unit 102, and the switching unit 103 constitute a power supply unit 111 that supplies electric power for operating the wireless unit 104 and the control unit 105.

The normal power supply unit 101 is electrically connected to the power system 30. The normal power supply unit 101 supplies the first electric power supplied from the electric power system 30.

The backup power supply unit 102 includes an energy storage unit 121. The backup power supply unit 102 charges the power storage unit 121 with the first electric power supplied by the normal power supply unit 101. Further, the backup power supply unit 102 supplies a second electric power discharged by the energy storage unit 121. The power storage unit 121 is an electric double layer capacitor. The power storage device 121 may be a power storage device other than the electric double layer capacitor. For example, the power storage unit 121 may be a storage battery.

The switching unit 103 switches the electric power for operating the wireless unit 104 and the control unit 105 between the first electric power supplied by the normal power supply unit 101 and the second electric power supplied by the backup power supply unit 102. .. The switching unit 103 may be realized by hardware including a switching element such as a relay, or may be realized by software control.

The wireless unit 104 performs wireless communication with other communication terminals constituting the multi-hop network 1. The wireless unit 104 can switch the communication speed of wireless communication between the first communication speed and the second communication speed. The second communication speed is faster than the first communication speed. The wireless unit 104 transmits a power failure notification indicating that a power failure of the power system 30 has occurred by wireless communication.

The control unit 105 controls the wireless unit 104 and the switching unit 103, and stores data.

The control unit 105 causes the switching unit 103 to set the power for operating the wireless unit 104 and the control unit 105 to the first power supplied by the normal power supply unit 101 during normal operation and when each communication terminal 11x is started. , The wireless unit 104 is made to set the communication speed of wireless communication to the first communication speed. Further, in the event of a power failure of the power system 30, the control unit 105 causes the switching unit 103 to set the power for operating the radio unit 104 and the control unit 105 to the second power supplied by the backup power supply unit 102, and wirelessly. The unit 104 is made to set the communication speed of wireless communication to the second communication speed. Therefore, when the control unit 105 detects a power failure in the power system 30, the switching unit 103 causes the switching unit 103 to switch the power for operating the radio unit 104 and the control unit 105 from the first power to the second power, and wirelessly. The unit 104 is made to switch the communication speed of wireless communication from the first communication speed to the second communication speed.

Further, when the control unit 105 detects a power failure in the power system 30, the control unit 105 causes the wireless unit 104 to transmit a power failure notification.

Further, the control unit 105 sets each communication terminal 11x to the normal operation mode at the normal time and at the time of starting each communication terminal 11x. Further, the control unit 105 sets each communication terminal 11x to a low power consumption mode in the event of a power failure of the power system 30. Therefore, when the control unit 105 detects a power failure in the power system 30, the control unit 105 shifts each communication terminal 11x from the normal operation mode to the low power consumption mode. The normal operation mode is a first mode in which the functions of the communication terminals 11x are not limited. The low power consumption mode is a second mode in which the functions of the communication terminals 11x are limited to the minimum and the power consumption is lower than the power consumption of the normal operation mode. Limiting the functions of each communication terminal 11x to a minimum includes, for example, blocking an external interface that performs communication other than wireless communication.

1.4 Control sequence of the communication terminal at the time of power failure of the power system FIGS. 4 and 5 are flowcharts illustrating the control sequence of the communication terminal of the first embodiment at the time of power failure of the power system.

Steps S111 to S115 illustrated in FIG. 4 are power failure preparation steps for preparing for a power failure of the power system 30. Steps S116 to S120 illustrated in FIG. 4 are power failure notification steps for notifying that a power failure of the power system 30 has occurred. Steps S121 to S124 illustrated in FIG. 5 are power recovery preparation steps for preparing for power recovery of the power system 30.

In step S111, the control unit 105 detects a power failure in the power system 30.

In the following step S112, the control unit 105 controls the switching unit 103. In the switching unit 103, the electric power for operating the wireless unit 104 and the control unit 105 according to the control by the control unit 105 is supplied by the backup power supply unit 102 from the first electric power supplied by the normal power supply unit 101. Switch to power.

In the following step S113, the control unit 105 controls the radio unit 104. The wireless unit 104 switches the communication speed of wireless communication from the first communication speed to the second communication speed according to the control by the control unit 105. As a result, in the power failure notification step, wireless communication is performed at the second communication speed.

In the following step S114, the control unit 105 sets the reset timer. As a result, the time T elapsed since the power for operating the wireless unit 104 and the control unit 105 is switched from the first power supplied by the normal power supply unit 101 to the second power supplied by the backup power supply unit 102. The measurement is started. Further, when the elapsed time T reaches the set time Ts, self-reset of each communication terminal 11x occurs. The set time Ts is a fixed value determined according to the specifications required by the delivery destination of each communication terminal 11x.

The order in which steps S113 and S114 are executed may be changed.

In the following step S115, the control unit 105 shifts each communication terminal 11x from the normal operation mode to the low power consumption mode.

In the following step S116, the control unit 105 controls the radio unit 104. The radio unit 104 performs CCA according to the control by the control unit 105. Further, the control unit 105 determines whether or not the transmission mode can be entered based on the result of the CCA. If it is determined that the transmission mode can be entered, step S117 is executed. If it is determined that the transmission mode cannot be entered, step S116 is executed again.

In step S117, the control unit 105 controls the radio unit 104. The wireless unit 104 shifts to the transmission mode according to the control by the control unit 105, and transmits the power failure notification by wireless communication. The power failure notification transmitted indicates that a power failure of the power system 30 has occurred.

In the following step S118, the control unit 105 controls the radio unit 104. The radio unit 104 shifts to the reception mode according to the control by the control unit 105.

In the following step S119, the control unit 105 controls the radio unit 104. The radio unit 104 waits for an ACK response according to the control by the control unit 105. Further, the control unit 105 determines whether or not the ACK response has been received. If it is determined that the ACK response has been received, step S120 is executed. If it is determined that the ACK response has not been received, step S116 is executed again.

In the following step S120, the control unit 105 shifts each communication terminal 11x to the low power consumption mode.

In the following step S121, the elapsed time T reaches the set time Ts, and self-reset of each communication terminal 11x occurs. At that time, the control unit 105 controls the switching unit 103. In the switching unit 103, according to the control by the control unit 105, the power for operating the wireless unit 104 and the control unit 105 is supplied by the normal power supply unit 101 from the second electric power supplied by the backup power supply unit 102. Switch to power.

After the following step S122, the state of each communication terminal 11x changes depending on whether or not the power system 30 is restored. When the power system 30 is restored, each communication terminal 11x is activated in step S123. If the power system 30 has not been restored, the power of each communication terminal 11x is kept off in step S124.

1.5 Time change of power consumption of the communication terminal FIG. 6 is a time chart illustrating the time change of the power consumption of the communication terminal of the first embodiment. FIG. 6A is a time chart when wireless communication is performed at the first communication speed. FIG. 6B is a time chart when wireless communication is performed at the second communication speed.

6 (a) and 6 (b) illustrate the time change of the power consumption of each communication terminal 11x when each communication terminal 11x transmits a power failure notification once.

As shown in FIGS. _6A and 6B, the power consumption of each communication terminal 11x during the period 131 in which each communication terminal 11x is set to the normal operation mode is Pa [W]. .. Further, the power consumption of each communication terminal 11x during the period 132 in which each communication terminal _11x is set to the low power consumption mode is Pe [W]. Further, the power consumption of each communication terminal 11x during the period 133 in which the radio unit 104 performs CCA is P _c [W]. Further, the power consumption of each communication terminal 11x during the period 134 in which the wireless unit 104 transmits the power failure notification is P _b [W]. Further, the power consumption of each communication terminal 11x during the period 135 in which the radio unit 104 receives the ACK response is P _d [W]. The power consumption P _a , P _b , P _c , P _d and P _e satisfy the relationship of P _a > P _b > P _c > P _d > P _e > 0.

Further, as shown in FIGS. 6 (a) and 6 (b), in both the case where the wireless communication is performed at the first communication speed and the case where the wireless communication is performed at the second communication speed. , The sum of the lengths of periods 132, 133, 134 and 135 is T _s [sec]. When wireless communication is performed at the first communication speed, the length of the period 133 is T _CCA [sec], and the lengths of the periods 134 and 135 are T _Tx and _TRx [sec], respectively. Is. When wireless communication is performed at the second communication speed, the length of the period 133 is T _CCA [sec], but the lengths of the periods 134 and 135 are T _Tx and _TRx [sec], respectively. ] Shorter. Therefore, by switching the wireless communication speed from the first communication speed to the second communication speed, the total length of the periods 134 and 135 in which the wireless communication is performed can be shortened. For example, when the first communication speed is 100 kbps and the second communication speed is 200 kbps, the total length of the periods 134 and 135 in which wireless communication is performed is calculated from (T _Tx + _TRx ) [sec]. It can be shortened to ( _TTx + _TRx ) / 2 [sec]. More generally, when the second communication speed is N times the first communication speed, the sum of the lengths of the periods 134 and 135 in which wireless communication is performed is ( _TTx + _TRx ) [sec]. Can be shortened from (T _Tx + _TRx ) / N [sec]. As a result, the amount of electric power used for wireless communication can be reduced.

1.6 Reduction of Capacitance of Power Storage The capacitance C of the power storage 121 uses the charge Q, the voltage drop V of the power storage 121, the current consumption I, the operating time T, and the power consumption P. , Expressed by equation (1). Equation (1) is obtained from the equation of charge and Ohm's law.

The voltage drop V of the power reservoir 121 is represented by the equation (2) using the normal power supply voltage _Vin [V] and the minimum operating voltage V _low [V] of each communication terminal 11x.

The reduction amount C'[F] of the capacitance C of the power storage unit 121 is the power consumption of each communication terminal 11x in the periods 134 and 135 in which the wireless communication is performed when the wireless communication is performed at the first communication speed. From the capacitance required to cover the power consumption of each communication terminal 11x during the periods 134 and 135 in which wireless communication is performed when wireless communication is performed at the second communication speed, the capacitance required to cover the power consumption The capacity and the power consumption of each communication terminal 11x during the period having a length corresponding to the shortened amount of the lengths 134 and 135 during which wireless communication is performed when each communication terminal 11x is set to the low power consumption mode. It is obtained by reducing the capacitance required to cover the cost. Therefore, the reduction amount C'of the capacitance C of the power storage unit 121 is expressed by the equation (3).

When the second communication speed is N times the first communication speed, the lengths of the periods 134 and 135 when wireless communication is performed at the second communication readability are the first communication speeds, respectively. It is 1/N of the length of the periods 134 and 135 when wireless communication is performed. Therefore, the power consumption of each communication terminal 11x in the periods 134 and 135 when the wireless communication is performed at the second communication reading is the period 134 and 135 when the wireless communication is performed at the first communication reading. It becomes 1 / N of the power consumption of each communication terminal 11x in. From these facts, the reduction amount C'of the capacitance C of the power storage unit 121 represented by the equation (3) takes a positive value.

1.7 Effect of the invention of the first embodiment According to the invention of the first embodiment, when a power failure of the power system 30 occurs and the wireless unit 104 is operated by the second electric power discharged by the power storage unit 121. The communication speed of wireless communication increases from the first communication speed to the second communication speed, and the time required for wireless communication can be shortened. Therefore, the amount of electric power required to operate the wireless unit 104 can be reduced, and the capacity of the electric power storage unit 121 can be reduced.

2 Embodiment 2
2.1 Introduction FIG. 2 is also a flowchart illustrating the operation of the communication terminal of the second embodiment when transmitting data. FIG. 3 is also a block diagram illustrating the communication terminal of the second embodiment. 4 and 5 are also flowcharts illustrating the control sequence of the communication terminal of the second embodiment at the time of power failure of the power system. FIG. 6 is also a time chart illustrating the time change of power consumption of the communication terminal of the second embodiment.

The second embodiment differs from the first embodiment mainly in that it is described below. Regarding the points not described below, the same configuration as that adopted in the first embodiment is adopted in the second embodiment.

2.2 Communication terminal FIG. 7 is a diagram illustrating a normal communication path of a plurality of communication terminals constituting a multi-hop network including the communication terminal of the second embodiment. FIG. 8 is a diagram illustrating a communication path at the time of a power failure of a power system of a plurality of communication terminals constituting a multi-hop network including the communication terminal of the second embodiment.

The plurality of communication terminals 11 include communication terminals CT1-CT10 as shown in FIGS. 7 and 8.

2.3 Switching of communication path The control unit 105 provided in each communication terminal CTx included in the communication terminal CT1-CT10 stores the setting value defining the communication path of the communication terminal CT1-CT10 constituting the multi-hop network 1. .. Further, when the control unit 105 detects a power failure of the power system 30, the control unit 105 switches the set value from the set value at the normal time to the set value at the time of the power failure of the power system 30. The normal setting value is the first setting value for setting the communication path of the communication terminals CT1-CT10 to the normal communication path shown in FIG. 7. The set value of the power system 30 at the time of a power failure is a second set value for setting the communication path of the communication terminals CT1-CT10 to the communication path of the power system 30 shown in FIG. 8 at the time of a power failure. The communication path of the power system 30 shown in FIG. 8 during a power failure is different from the normal communication path shown in FIG. 7.

When the communication path of the communication terminal CT1-CT10 is the communication path at the time of power failure of the power system 30 shown in FIG. 8, the communication path of the communication terminal CT1-CT10 is the normal communication path shown in FIG. Compared to some cases, the communication distance of wireless communication is shortened. As a result, even if the communication speed of wireless communication is switched from the first communication speed to the second communication speed and the communication range of wireless communication is shortened, it is possible to prevent wireless communication from becoming impossible. can do. In addition, it is possible to suppress the failure of CCA and shorten the time required for CCA. Therefore, the power consumption of each communication terminal 11x can be further reduced.

The set value stored in each communication terminal 11x is a numerical value indicating the number of hops required to transmit data from each communication terminal 11x to the aggregation device 12. Hereinafter, the numerical value is referred to as rank. Normally, each communication terminal 11x transmits data by wireless communication to a communication terminal that stores a rank higher than the rank stored by each communication terminal 11x.

2.4 Communication path in normal time FIG. 9 is a diagram illustrating a table managed by an aggregation device or a master station provided in a multi-hop network including the communication terminal of the second embodiment.

The table 141 illustrated in FIG. 9 is managed by the aggregation device 12 or the master station 13. Table 141 shows the terminal number 151 assigned to the communication terminal CT1-CT10, the address 152 assigned to the communication terminal CT1-CT10, the rank153 assigned to the communication terminal CT1-CT10, and the communication terminal CT1 as the end point. And the destination address 154 assigned to each of the communication terminals CT3-CT10 other than CT2. The aggregation device 12 or the master station 13 grasps the communication path at the normal time by referring to the table 141.

The address 152 and the destination address 154 are assigned so that each communication terminal 11x transmits data to a communication terminal to which an address matching the destination address assigned to each communication terminal 11x is assigned. The rank 153 is set so that each communication terminal 11x transmits data to a communication terminal to which a rank higher than the rank given to each communication terminal 11x is given.

According to the table 141 illustrated in FIG. 9, rank "1" is assigned to the communication terminals CT1 and CT2 to which the terminal numbers "1" and "2" are assigned, respectively. Further, rank "2" is assigned to the communication terminals CT3, CT4 and CT5 to which the terminal numbers "3", "4" and "5" are assigned, respectively. Further, rank "3" is assigned to the communication terminals CT6, CT7, CT8 and CT9 to which the terminal numbers "6", "7", "8" and "9" are assigned, respectively. Further, rank "4" is assigned to the communication terminal CT10 to which the terminal number "10" is assigned.

Further, according to the table 141 illustrated in FIG. 9, the address “xx.xxx. The destination address "xx.xxx.xxx.xa" that matches "xxx.xa" is assigned. Further, to the communication terminals CT4 and CT5 to which the terminal numbers "4" and "5" are assigned, respectively, to the address "xx.xxx.xxx.xb" assigned to the communication terminal CT2 to which the terminal number "2" is assigned. The matching destination address "xx.xxx.xxx.xb" is assigned. Further, the destination address “xx.” That matches the address “xx.xxx.xxx.xc” assigned to the communication terminal CT6 to which the terminal number “6” is assigned to the communication terminal CT6 to which the terminal number “3” is assigned. "xxx.xxx.xc" is given. Further, the destination address “xx.” That matches the address “xx.xxx.xxx.xd” assigned to the communication terminal CT7 to which the terminal number “7” is assigned and the communication terminal CT4 to which the terminal number “4” is assigned. "xxx.xxx.xd" is given. Further, to the communication terminals CT8 and CT9 to which the terminal numbers "8" and "9" are assigned, respectively, to the address "xx.xxx.xxx.xe" assigned to the communication terminal CT5 to which the terminal number "5" is assigned. The matching destination address "xx.xxx.xxx.xe" is assigned. Further, the destination address “xx.” That matches the address “xx.xxx.xxx.xf” assigned to the communication terminal CT6 to which the terminal number “10” is assigned to the communication terminal CT10 to which the terminal number “6” is assigned. "xxx.xxx.xf" is given.

As a result, as shown in FIG. 7, normally, the communication terminal CT10 to which the terminal number "10" is assigned transmits data to the communication terminal CT6 to which the terminal number "6" is assigned. Further, the communication terminals CT8 and CT9 to which the terminal numbers "8" and "9" are assigned respectively transmit data to the communication terminal CT5 to which the terminal number "5" is assigned. Further, the communication terminal CT7 to which the terminal number "7" is assigned transmits data to the communication terminal CT4 to which the terminal number "4" is assigned. Further, the communication terminal CT6 to which the terminal number "6" is assigned transmits data to the communication terminal CT3 to which the terminal number "3" is assigned. Further, the communication terminals CT4 and CT5 to which the terminal numbers "4" and "5" are assigned transmit data to the communication terminal CT2 to which the terminal number "2" is assigned. Further, the communication terminal CT3 to which the terminal number "3" is assigned transmits data to the communication terminal CT1 to which the terminal number "1" is assigned. Further, the communication terminals CT1 and CT2 to which the terminal numbers "1" and "2" are assigned respectively transmit data to the aggregation device 12. As a result, the communication path in the normal state becomes the first communication path having a branch and a tree shape.

2.5 Communication path at the time of power failure of the power system As shown in FIG. 8, when the power system 30 has a power failure, the communication terminal CT10 to which the terminal number “10” is assigned is assigned the terminal number “6”. Data is transmitted to the communication terminal CT6. Further, the communication terminal CT6 to which the terminal number "6" is assigned transmits data to the communication terminal CT7 to which the terminal number "7" is assigned. Further, the communication terminal CT7 to which the terminal number "7" is assigned transmits data to the communication terminal CT8 to which the terminal number "8" is assigned. Further, the communication terminal CT8 to which the terminal number "8" is assigned transmits data to the communication terminal CT9 to which the terminal number "9" is assigned. Further, the communication terminal CT9 to which the terminal number "9" is assigned transmits data to the communication terminal CT5 to which the terminal number "5" is assigned. Further, the communication terminal CT5 to which the terminal number "5" is assigned transmits data to the communication terminal CT4 to which the terminal number "4" is assigned. Further, the communication terminal CT4 to which the terminal number "4" is assigned transmits data to the communication terminal CT3 to which the terminal number "3" is assigned. Further, the communication terminal CT3 to which the terminal number "3" is assigned transmits data to the communication terminal CT1 to which the terminal number "1" is assigned. Further, the communication terminal CT1 to which the terminal number "1" is assigned transmits data to the communication terminal CT2 to which the terminal number "2" is assigned. Further, the communication terminal CT2 to which the terminal number "2" is assigned transmits data to the aggregation device 12. As a result, the communication path of the power system 30 at the time of a power failure becomes a second communication path that does not have branching and is in the form of a string of beads. The communication terminal that is the starting point of the communication path in the event of a power failure of the power system 30 is a communication terminal having the lowest rank. For example, the communication terminal serving as a starting point is the communication terminal CT10 to which rank "4" is assigned.

2.6 Sequence of processing at the time of power failure of the power system FIGS. 10 and 11 are sequence diagrams illustrating a sequence of processing performed at the time of power failure of the power system in the multi-hop network including the communication terminal of the second embodiment.

When a power failure occurs in the power system 30, the communication paths of the plurality of communication terminals CT1-CT10 are set to the communication paths of the power system 30 shown in FIG. 8 at the time of the power failure.

Further, as shown in FIG. 11, the wireless unit 104 provided in the communication terminal CT10 as the starting point transmits a power failure notification BN10 indicating that a power failure of the power system 30 has occurred to the next communication terminal CT6 by wireless communication. do. Further, as shown in FIG. 10, the radio unit 104 provided in each communication terminal CTj as a repeater other than the communication terminal CT10 as the start point and the communication terminal CT2 as the end point is the communication terminal in front of the power failure notification BNi. It waits in the reception state for transmission from CTi, and receives the power failure notification BNi from the previous communication terminal CTi by wireless communication while waiting in the reception state. Further, the wireless unit 104 provided in each communication terminal CTj serving as a repeater receives the power failure notification BNi from the previous communication terminal CTi by wireless communication, and then transmits the power failure notification BNj to the next communication terminal CTk by wireless communication. .. Further, the wireless unit 104 provided in the communication terminal CT2, which is the end point, waits in the reception state for the power failure notification BN1 to be transmitted from the previous communication terminal CT1, and while waiting in the reception state, receives the power failure notification BN1 in the previous communication. Received by wireless communication from terminal CT1. Further, the wireless unit 104 provided in the communication terminal CT2, which is the end point, receives the power failure notification BN1 from the previous communication terminal CT1 by wireless communication, and then transmits the power failure notification BN2 to the aggregation device 12 by wireless communication.

The control unit 105 provided in each communication terminal CTj serving as a repeater causes the wireless unit 104 to wait in a reception state when the set waiting time Wj has elapsed from the time Tp when the power system 30 has a power failure. It is started, and after the power failure notification BNi is received from the previous communication terminal CTi, the radio unit 104 stops waiting in the reception state. Further, the control unit 105 provided in the communication terminal CT2, which is the end point, starts waiting in the wireless unit 104 in the reception state when the set waiting time W2 has elapsed from the time when the power system 30 has a power failure. After the power failure notification BN1 is received from the previous communication terminal CT1, the radio unit 104 stops waiting in the reception state.

The radio unit 104 provided in each communication terminal CTj serving as a repeater includes the data included in the power failure notification BNi received from the previous communication terminal CTi in the power failure notification BNj transmitted to the next communication terminal CTk.

2.7 Determination of Waiting Time FIGS. 12 and 13 are sequence diagrams illustrating a sequence of processes performed during a simulated power failure of a power system in a multi-hop network including the communication terminal of the second embodiment.

In the multi-hop network 1, in order to determine the waiting time W1-W9, a simulated power failure of the power system 30 is normally generated. The generated simulated power outage of the power system 30 does not accompany the actual power outage of the power system 30.

When a simulated power outage of the power system 30 occurs, the communication paths of the plurality of communication terminals CT1-CT10 are the power outages of the power system 30 shown in FIG. 8, as in the case of the power outage of the power system 30. It is used as the communication path of time.

Further, as shown in FIGS. 12 and 13, the aggregation device 12 sequentially connects the communication terminal CT2 as the end point and the communication terminals CT1, CT3, CT4, CT5, CT9, CT8, CT7 and CT6 as repeaters. A simulated power failure occurrence notification SBSN is transmitted by wireless communication to the communication terminal CT10 which is the starting point. Further, the wireless unit 104 provided in the communication terminal CT10, which is the starting point, receives the simulated power failure occurrence notification SBSN by wireless communication. Further, as shown in FIG. 13, a simulated power failure of the power system 30 occurs after the wireless unit 104 provided in the communication terminal CT10, which is the starting point, receives the simulated power failure occurrence notification SBSN from the aggregation device 12 by wireless communication. A simulated power failure notification SBN10 indicating that the power has been made is transmitted to the next communication terminal CT6 by wireless communication. Further, as shown in FIG. 12, the wireless unit 104 provided in each communication terminal CTj serving as a repeater receives the simulated power failure notification SBNi from the previous communication terminal CTi by wireless communication. Further, after the wireless unit 104 provided in each communication terminal CTj serving as a repeater receives the simulated power failure notification SBNi from the previous communication terminal CTi by wireless communication, the simulated power failure notification SBNj is transmitted to the next communication terminal CTk by wireless communication. Send. Further, the communication terminal CT2 at the end point receives the simulated power failure notification SBN1 from the previous communication terminal CT1 by wireless communication. Further, after the communication terminal CT2 at the end point receives the simulated power failure notification SBN1 from the previous communication terminal CT1 by wireless communication, the simulated power failure notification SBN2 is transmitted to the aggregation device 12 by wireless communication.

When the communication terminal CT10 serving as a starting point transmits the simulated power failure notification SBN10 to the next communication terminal CT6, the power failure occurrence time Tp at which the simulated power failure is generated is included in the simulated power failure notification SBN10. The power failure occurrence time Tp is the time when the communication terminal CT10, which is the starting point, receives the simulated power failure occurrence notification SBSN.

Each communication terminal CTj serving as a repeater includes the power failure notification reception time Ti for receiving the simulated power failure notification SBNi from the previous communication terminal CTi in the simulated power failure notification SBNj for transmitting the simulated power failure notification SBNi to the next communication terminal CTk, and includes the previous communication terminal CTi. The power failure occurrence time Tp and the power failure notification reception time Th, ..., T10 included in the simulated power failure notification SBNi received from are included in the simulated power failure notification SBNj to be transmitted to the next communication terminal CTk. The communication terminal CT2, which is the end point, includes the power failure notification reception time T1 received from the previous communication terminal CT1 as the simulated power failure notification SBN1 in the simulated power failure notification SBN2 transmitted to the aggregation device 12, and the simulated power failure notification received from the previous communication terminal CT1. The power failure occurrence time Tp included in the power failure notification SBN1 and the power failure notification reception times T3, T4, T5, T9, T8, T7, T6 and T10 are included in the simulated power failure notification SBN2 transmitted to the aggregation device 12.

As a result, the aggregation device 12 receives the power failure occurrence time Tp and the simulated power failure notification SBN2 including the power failure notification reception times T10, T6, T7, T8, T9, T5, T4, T3 and T1. Further, the aggregation device 12 aggregates the power failure occurrence time Tp included in the received simulated power failure notification SBN2 and the power failure notification reception times T10, T6, T7, T8, T9, T5, T4, T3 and T1, and the power failure occurrence time. Reception start time difference ΔT6 = Tp-T10, ΔT7 = Tp-T6, ΔT8 = Tp- T7, ΔT9 = Tp-T8, ΔT5 = Tp-T9, ΔT4 = Tp-T5, ΔT3 = Tp-T4, ΔT1 = Tp-T3 and ΔT2 = Tp-T1 are obtained.

FIG. 14 is a diagram illustrating a table stored in an aggregation device at the time of a simulated power failure of a power system in a multi-hop network including the communication terminal of the second embodiment.

The table 171 illustrated in FIG. 14 is stored in the aggregation device 12. Table 171 shows the terminal numbers 181 assigned to the communication terminals CT10, CT6, CT7, CT8, CT9, CT5, CT4, CT3, CT1 and CT2, respectively, the power failure occurrence time 182 obtained for the communication terminal CT10 as the starting point, and the starting point. Communication terminals CT6, CT7, CT8, CT9, CT5, CT4, CT3, CT1 and CT2 other than the communication terminal CT10, respectively, and the communication terminal CT6 other than the communication terminal CT10 which is the starting point. The reception start time difference 184 obtained for each of CT7, CT8, CT9, CT5, CT4, CT3, CT1 and CT2 is included.

The power failure occurrence time 182 included in the table 171 is the power failure occurrence time Tp described above. The power failure notification reception time 183 included in the table 171 is the power failure notification reception time T10, T6, T7, T8, T9, T5, T4, T3 and T1 described above. The reception start time difference 184 included in the table 171 includes the above-mentioned reception start time difference ΔT6 = Tp-T10, ΔT7 = Tp-T6, ΔT8 = Tp-T7, ΔT9 = Tp-T8, ΔT5 = Tp-T9, ΔT4 =. Tp-T5, ΔT3 = Tp-T4, ΔT1 = Tp-T3 and ΔT2 = Tp-T1.

As shown in FIG. 12, the aggregation device 12 transmits the waiting time information WI2 to the communication terminal CT2 as the end point by wireless communication. Further, the communication terminal CT2, which is the end point, receives the waiting time information WI2 from the aggregation device 12 by wireless communication . Further, each communication terminal CTj as a repeater other than the communication terminal CT2 as the end point and the communication terminal CT10 as the start point receives the waiting time information WIj from the previous communication terminal CTk by wireless communication. Further, each communication terminal CTj serving as a repeater transmits the waiting time information WIi to the next communication terminal CTi by wireless communication.

The waiting time information WI2 includes a reception start time difference ΔT6, ΔT7, ΔT8, ΔT9, ΔT5, ΔT4, ΔT3, ΔT1 and ΔT2. The waiting time information WIj includes the reception start time difference ΔTj, ..., ΔT2. As a result, each communication terminal CTj serving as a repeater obtains the reception start time difference ΔTj. The waiting time Wj is obtained from the reception start time difference ΔTj. When the simulated power failure of the power system 30 is generated only once, the waiting time Wj is the reception start time difference ΔTj itself. When the simulated power failure of the power system 30 occurs a plurality of times, the waiting time Wj is the time between the minimum value and the maximum value of the plurality of reception start time differences ΔTj. As a result, the waiting time Wj can be minimized, and the capacity of the power storage unit 121 can be reduced. The waiting time Wj may be obtained by correcting the reception start time difference ΔTj. When the simulated power failure of the power system 30 is generated a plurality of times, the simulated power failure of the power system 30 may be generated once a day, or a new communication terminal is added to the multi-hop network 1 and the communication path is changed. A simulated power failure of the power system 30 may be generated each time the change is made. Each communication terminal CTj serving as a repeater starts waiting in the receiving state to receive the power failure notification BNi when the waiting time Wj has elapsed since the simulated power failure of the power system 30 was generated. For example, the communication terminal CT6 starts waiting in the receiving state to receive the power failure notification BN10 when the waiting time W6 has elapsed since the simulated power failure of the power system 30 was generated.

Desirably, the aggregation device 12 or the master station 13 transmits the time synchronization information for synchronizing the time information possessed by the communication terminal CT1-CT10 to the communication terminal CT1-CT10. For example, the aggregation device 12 or the master station 13 transmits the time synchronization information to the communication terminals CT1-CT10 once a day at 0:00. As a result, the time information possessed by the communication terminals CT1-CT10 is synchronized, and errors included in the reception start time differences ΔT6, ΔT7, ΔT8, ΔT9, ΔT5, ΔT4, ΔT3, ΔT1 and ΔT2 can be suppressed. At this time, the error in the time required for the time synchronization information to be transmitted from the master station 13 or the aggregation device 12 to the communication terminal CT1-CT10 is on the order of microseconds, and the error in the time information possessed by the communication terminal CT1-CT10. Is on the order of seconds, so there is virtually no need to consider the former error.

2.8 Amount of reduction in capacitance of the power storage device The capacitance Cn of the power storage device 121 when the number of transmissions of the power failure notification is _n times is expressed by the equation (4). Equation (4) can be derived from the time chart illustrated in FIG.

Further, the capacitance C ₁ of the power storage device 121 when the number of transmissions of the power failure notification is one is expressed by the equation (5). Equation (5) can be derived from equation (4).

Therefore, the reduction amount C "of the capacitance of the power storage unit 121 by reducing the number of transmissions of the power failure notification from n times to one time is expressed by the formula (6). The formula (6) is expressed by the formula (6). It can be derived from (4) and equation (5).

2.9 Effect of the invention of the second embodiment According to the invention of the second embodiment, as in the invention of the first embodiment, a power failure of the power system 30 occurs and the power is discharged by the power storage unit 121. When the wireless unit 104 is operated by electric power, the communication speed of wireless communication increases from the first communication speed to the second communication speed, and the time required for wireless communication can be shortened. Therefore, the amount of electric power required to operate the wireless unit 104 can be reduced, and the capacity of the electric power storage unit 121 can be reduced.

In addition, according to the invention of the second embodiment, when a power failure occurs in the power system 30, each communication terminal notifies the power failure in a state where the communication path of the communication terminals CT1-CT10 is a string-shaped communication path. To send. Therefore, each communication terminal transmits the power failure notification only once. Further, two or more communication terminals do not transmit a power failure notification at the same time. Therefore, it is possible to suppress the failure of CCA and to transmit the power failure notification in a short time.

3 Embodiment 3
3.1 Introduction FIG. 2 is also a flowchart illustrating the operation of the communication terminal of the third embodiment when transmitting data. FIG. 3 is also a block diagram illustrating the communication terminal of the third embodiment. 4 and 5 are also flowcharts illustrating the control sequence of the communication terminal of the third embodiment at the time of power failure of the power system. FIG. 6 is also a time chart illustrating the time change of power consumption of the communication terminal of the third embodiment.

The third embodiment differs from the second embodiment mainly in that it is described below. Regarding the points not described below, the same configuration as that adopted in the second embodiment is adopted in the third embodiment.

3.2 Communication path at the time of power failure of the power system In the second embodiment, when a power failure of the power system 30 occurs, all the communication paths of the communication terminals CT1-CT10 are changed from the communication path at the normal time to the power system 30. It is possible to switch to the communication path at the time of power failure. On the other hand, in the third embodiment, when a power failure of the power system 30 occurs, a part of the communication paths of the communication terminals CT1-CT10 are changed from the normal communication path to the communication of the power system 30 at the time of the power failure. Switch to the route. A part of the communication terminals CT1-CT10 is a communication terminal including a power storage unit 121 having a small capacity or a deteriorated power storage unit 121. As a result, even when it is difficult to change all the communication paths of the communication terminal CT1-CT10, it is possible to reduce the amount of power consumed by the communication terminal CT1-CT10 when a power failure occurs in the power system 30. ..

FIG. 15 is a diagram illustrating a table managed by an aggregation device or a master station provided in a multi-hop network including the communication terminal of the third embodiment. FIG. 16 is a diagram illustrating a communication path at the time of a power failure of a power system of a plurality of communication terminals constituting a multi-hop network including the communication terminal of the third embodiment.

The table 201 illustrated in FIG. 15 is managed by the aggregation device 12 or the master station 13. Table 201 shows the terminal number 211 assigned to the communication terminal CT1-CT10, the address 212 assigned to the communication terminal CT1-CT10, the rank213 assigned to the communication terminal CT1-CT10, and the communication terminal CT1 as the end point. And the destination address 214 assigned to the communication terminals CT3-CT10 other than CT2, respectively. Table 201 is further added to the standby power supply capacity 215 obtained for the communication terminals CT1-CT10, the Rank 216 assigned to the communication terminals CT1-CT10, respectively, and the communication terminals CT3-CT10 other than the communication terminals CT1 and CT2 which are the end points. Each includes the assigned destination address 217 at the time of power failure.

The backup power capacity obtained for the communication terminal CTj indicates the capacity of the power storage unit 121 provided in the communication terminal CTj. The capacity of the power storage 121 may be detected in any way. The specific value of the capacity of the power storage unit 121 may be any value. The address 212 and the destination address 217 at the time of a power failure transfer data to a communication terminal having an address corresponding to the destination address at the time of a power failure assigned to each communication terminal 11x by each communication terminal 11x when a power failure of the power system 30 occurs. Granted to send. Further, the Trank 216 is provided so that when a power failure of the power system 30 occurs, each communication terminal 11x transmits data to a communication terminal to which a Rank lower than the Rank assigned to each communication terminal 11x is assigned. To.

According to the table 201 illustrated in FIG. 15, Rank "1" is assigned to the communication terminals CT1 and CT2 to which the terminal numbers "1" and "2" are assigned, respectively. Further, Rank "2" is assigned to the communication terminals CT3 and CT5 to which the terminal numbers "3" and "5" are assigned, respectively. Further, Rank "3" is assigned to the communication terminals CT4, CT7 and CT8 to which the terminal numbers "4", "7" and "8" are assigned, respectively. Further, Rank "4" is assigned to the communication terminals CT6, CT9 and CT10 to which the terminal numbers "6", "9" and "10" are assigned, respectively.

Further, according to the table 201 illustrated in FIG. 15, the address “xx.xxx. The destination address "xx.xxx.xxx.xa" at the time of power failure that matches "xxx.xa" is assigned. Further, the destination address "xx.xxx.xxx.xb" that matches the address "xx.xxx.xxx.xb" given to the communication terminal CT2 to which the terminal number "2" is given to the communication terminal CT5 to which the terminal number "5" is given is " xx.xxx.xxx.xb "is given. Further, the destination address "xx.xxx.xxx.xc" that matches the address "xx.xxx.xxx.xc" assigned to the communication terminal CT7 to which the terminal number "7" is assigned and the communication terminal CT3 to which the terminal number "3" is assigned is ". xx.xxx.xxx.xc "is given. Further, to the communication terminals CT4 and CT8 to which the terminal numbers "4" and "8" are assigned, respectively, to the address "xx.xxx.xxx.xe" assigned to the communication terminal CT5 to which the terminal number "5" is assigned. The matching destination address "xx.xxx.xxx.xe" at the time of power failure is assigned. Further, to the communication terminals CT6 and CT10 to which the terminal numbers "6" and "10" are assigned, respectively, to the address "xx.xxx.xxx.xg" assigned to the communication terminal CT7 to which the terminal number "7" is assigned. The matching destination address "xx.xxx.xxx.xg" at the time of power failure is assigned. Further, the power failure destination address "xx.xxx.xxx.xh" that matches the address "xx.xxx.xxx.xh" assigned to the communication terminal CT9 to which the terminal number "9" is assigned and the communication terminal CT8 to which the terminal number "8" is assigned. xx.xxx.xxx.xh "is given.

As a result, as shown in FIG. 16, when the power system 30 has a power failure, the communication terminals CT6 and CT10 to which the terminal numbers "6" and "10" are assigned are assigned the terminal number "7", respectively. Data is transmitted to the communication terminal CT7. Further, the communication terminal CT9 to which the terminal number "9" is assigned transmits data to the communication terminal CT8 to which the terminal number "8" is assigned. Further, the communication terminals CT4 and CT8 to which the terminal numbers "4" and "8" are assigned respectively transmit data to the communication terminal CT5 to which the terminal number "5" is assigned. Further, the communication terminal CT7 to which the terminal number "7" is assigned transmits data to the communication terminal CT3 to which the terminal number "3" is assigned. Further, the communication terminal CT5 to which the terminal number "5" is assigned transmits data to the communication terminal CT2 to which the terminal number "2" is assigned. Further, the communication terminal CT3 to which the terminal number "3" is assigned transmits data to the communication terminal CT1 to which the terminal number "1" is assigned. Further, the communication terminals CT1 and CT2 to which the terminal numbers "1" and "2" are assigned respectively transmit data to the aggregation device 12.

FIG. 17 is a flowchart illustrating a method of determining a trunk in a multi-hop network including the communication terminal of the third embodiment.

In step S131 illustrated in FIG. 17, the creation of a communication path in the event of a power failure of the power system 30 is started.

In step S132, it is determined whether or not the rank value given to the communication terminal of interest is 1. If it is determined that the rank value is 1, step S133 is executed. If it is determined that the rank value is not 1, step S134 is executed.

In step S133, the Rank value given to the communication terminal of interest is set to the same value as the rank value given to the communication terminal of interest and stored.

In step S134, it is determined whether or not the backup power supply capacity indicating the capacity of the power storage unit 121 provided in the communication terminal of interest is less than the threshold value. If the backup power capacity is less than the threshold, step S135 is executed. If the backup power capacity is equal to or greater than the threshold value, step S133 is executed, and the Rank value given to the communication terminal of interest is set to the same value as the rank value and stored. In step S135, the Rank value given to the communication terminal of interest is set to a lower value than the rank value given to the communication terminal of interest and stored. For example, when the rank value assigned to the communication terminal of interest is 3, the Rank value assigned to the communication terminal of interest is set to 4 and stored. As a result, when the rank value assigned to the communication terminal of interest is 1, the Rank value is set to 1 regardless of whether or not the backup power supply capacity is less than the threshold value. As a result, it is possible to prevent the communication terminal to which rank "1" is assigned from being unable to transmit data to the aggregation device 12. Further, when the rank value given to the communication terminal of interest is 2 or is lower than 2, and the backup power supply capacity is equal to or more than the threshold value, the Rank value is matched with the Rank value. If the rank value given to the communication terminal of interest is 2 or is lower than 2, and the backup power supply capacity is less than the threshold value, the Rank value is set to a value lower than the rank value. Will be done.

Each communication terminal 11x transmits data to a communication terminal to which a rank higher than the rank given to each communication terminal 11x is given. Therefore, for example, when the communication terminal CT4 to which the terminal number "4" is assigned is assigned a rank "2" and a lower Rank "3", the communication terminals around the communication terminal CT4 communicate with each other. Since it has the same Rank as the Trank "3" assigned to the terminal CT4 or a higher rank, the data transmitted by the communication terminal CT4 will not be relayed when a power failure of the power system 30 is detected. As a result, the number of times of transmission of the power failure notification transmitted while the power system 30 has a power failure is only one. As a result, it is possible to reduce the amount of power consumed by the communication terminal having a small backup power capacity while the power system 30 is out of power.

According to the invention of the third embodiment, as in the invention of the first embodiment, when the wireless unit 104 is operated by the second electric power discharged by the electric power storage unit 121 due to the power failure of the electric power system 30. The communication speed of wireless communication increases from the first communication speed to the second communication speed, and the time required for wireless communication can be shortened. Therefore, the amount of electric power required to operate the wireless unit 104 can be reduced, and the capacity of the electric power storage unit 121 can be reduced.

In addition, according to the third embodiment, a plurality of Rank 216s that define the communication path at the time of power failure of the power system 30 are set instead of the rank 213 that defines the communication path at the normal time. The power consumption of the communication terminals CT1-CT10 can be reduced and the capacity of the power reservoir 121 can be reduced while following the existing multi-hop network rules of the multi-hop network 1.

In the present invention, each embodiment can be freely combined, and each embodiment can be appropriately modified or omitted within the scope of the invention.

Although the invention has been described in detail, the above description is exemplary in all aspects and the invention is not limited thereto. It is understood that innumerable variations not illustrated can be assumed without departing from the scope of the present invention.

1 multi-hop network, 11 multiple communication terminals, 11a, 11b, 11c, 11d, CT1, CT2, CT3, CT4, CT5, CT6, CT7, CT8, CT9, CT10 communication terminals, 12 centralizers, 13 master stations, 30 Power system, 101 normal power supply unit, 102 standby power supply unit, 103 switching unit, 104 radio unit, 105 control unit, 121 power storage unit.

Claims (6)

A normal power supply unit that supplies the first power supplied from the power system,
A backup power supply unit including a power storage unit and supplying a second power discharged by the power storage device, and a standby power supply unit.
Wireless communication is performed with other communication terminals constituting the multi-hop network, and the communication speed of the wireless communication is switched between the first communication speed and the second communication speed faster than the first communication speed, and the power is increased. A wireless unit that transmits a power failure notification indicating that a system power failure has occurred by the wireless communication, and
A switching unit that switches the power for operating the wireless unit between the first power and the second power,
When a power failure of the power system is detected, the switching unit is made to switch the power for operating the wireless unit from the first power to the second power, and the wireless unit is made to have the communication speed of the wireless communication. With a control unit that switches from the first communication speed to the second communication speed and causes the radio unit to transmit the power failure notification.
A communication terminal that constitutes a multi-hop network. The control unit
Stores the setting values that define the communication paths of the plurality of communication terminals that make up the multi-hop network.
When a power failure of the power system is detected, the set value is set to a second communication path different from the first communication path from the first set value that sets the communication path as the first communication path. The communication terminal constituting the multi-hop network according to claim 1, which switches to the second set value. The second communication path is a communication terminal constituting the multi-hop network according to claim 2, which is a string of beads. The radio unit is
A simulated power failure notification including the time when the simulated power failure of the power system was generated is received by the wireless communication, indicating that the simulated power failure of the power system has occurred, and the power failure notification is transmitted. Is received in the reception state, and the power failure notification is received by the wireless communication while waiting in the reception state.
The control unit
Obtain the waiting time obtained from the time difference between the power failure occurrence time and the power failure notification reception time when the simulated power failure notification is received.
Communication constituting any of the multi-hop networks according to any one of claims 1 to 3 for causing the radio unit to start waiting in the reception state when the waiting time elapses from the time when the power system power failure occurs. Terminal. The control unit
When a power failure of the power system is detected, the communication terminal constituting the multi-hop network is shifted from the first mode to the second mode having a power consumption lower than the power consumption of the first mode.
When the electric power for operating the wireless unit reaches a set time after the time elapsed since the first electric power is switched to the second electric power, the electric power for operating the wireless unit in the switching unit. A communication terminal constituting any one of claims 1 to 3 for switching from the second electric power to the first electric power. A multi-hop network including a communication terminal constituting any of the multi-hop networks of claims 1 to 3.

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