JPH1155176A - Radio communication terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a radio communication terminal, which has a long operable time of a battery capacity by monitoring the battery capacity and switching to a 1st operation mode that reduces power consumption of a battery, when the battery capacity becomes a 1st reference value or less. SOLUTION: A controlling part 11 inputs a voltage signal of a battery 10 from a battery capacity monitoring part 9, which always monitors a capacity of the battery 10 and compares the voltage signal with a 1st reference voltage. When the voltage signal is the 1st reference voltage or less, it makes a call out to a center device and notifies a telegraphic message to the effect that the battery capacity drops. After that, it switches to such a power saving mode (1st operation mode) as to reduce the power consumption of the battery 10. For instance, a power supply changeover switch 20 is controlled in a fixed cycle (prescribed interval) by start from a clock 21, and the supply/stop of a power source to a sending and receiving part 18 and a TDMA processing part 25 is controlled. Then, it is possible to obtain a radio communication terminal, which has long operable time of the battery capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication terminal driven by a battery, and more particularly to a wireless communication terminal used for wireless meter reading of gas, water, electricity, and the like.

[0002]

2. Description of the Related Art FIG. 7 shows a conventional PHS (Personal Handy Phone System) disclosed, for example, in JP-A-9-9359.
stem: second-generation cordless telephone system) It is a block diagram showing a wireless communication system using a terminal device. In the figure, 19 is an antenna for transmitting and receiving radio waves,
The switch (SW) 8 switches between the transmitter 17 and the receiver 15 connected to the antenna 19. The transmission unit 17 and the reception unit 15 are connected to the digital modulation / demodulation unit 16, respectively, and form a transmission / reception unit 18. The transmitting and receiving unit 18 is T
DMA (Time Division Multipul Access) processing unit 2
1 is connected to a control unit 11 that performs the entire processing.

In the case of handling ordinary voice, the microphone 3 is connected via a speech codec unit 31 and a voice changing circuit 32.
3. Connected to the speaker 34. Reference numerals 26, 27, and 30 denote man-machine interfaces, respectively, which are a key input unit, a display unit, and a ringer. 13, 14, 24
Are memories, a ROM 14 stores a program of the control unit 11, and a RAM 13 stores a work area of the program and data. 28 and 29 are PH
An ID chip 29 for separating the S ID storage unit and its interface 28.

Next, the operation of a conventional radio communication system using a PHS terminal will be described. In a conventional system, a public base station (not shown) transmits an LCCH (Logical Control Channel) superframe every 1.2 seconds. The PHS terminal (slave) always receives the LCCH frame from the antenna 19 every 1.2 seconds. That is, SW8 is connected to the receiving side,
The TDMA processing unit 2 is transmitted via a transmission / reception unit 18 including a reception unit 15, a transmission unit 17, and a digital modulation / demodulation unit 16.
At 5, data is received from a predetermined time slot on the time axis.

In the received data, if there is a call connection request for the self, the call connection operation is performed. At other times, the receiving operation is repeated in a cycle of 1.2 seconds. The data is transmitted to the control unit 11 during call connection control, and to the speech codec unit 31 and the voice conversion circuit 32 when voice processing is performed after connection of the call. In the case of a call connection, a response to the connection request
After the data is loaded in the time slot specified by the call connection request by the processing unit 25, the data is output from the antenna 19 via the data transmission / reception unit 18 and SW8. That is, while the slave unit is in standby, all circuits are always powered on (battery) every 1.2 seconds.

[0006]

In a conventional wireless communication system, a slave always receives an LCCH superframe constantly transmitted from a public base station at a cycle of 1.2 seconds. Then, since the same operation is performed even when the battery capacity is reduced, the operable time of the slave unit is short, and when an urgent alarm call is issued from the slave unit, operation may not be performed due to a decrease in battery capacity. There was a problem.
In particular, when the PHS terminal is used for wireless meter reading, there is no substitute device unlike the case where the PHS terminal is used as a mobile phone terminal because of the inherent reason that the PHS terminal is used fixedly at the place where it is installed. Is remarkable. further,
Even if the PHS terminal displays the remaining battery capacity, there is also an inherent problem with meter reading that the information cannot be recognized.

The present invention has been made to solve such a problem, and has as its object to provide a wireless communication terminal having a long operable time with respect to a battery capacity. It is another object of the present invention to provide a wireless communication terminal capable of operating for a long time with respect to the battery capacity and capable of surely performing emergency transmission.

[0008]

SUMMARY OF THE INVENTION A wireless communication terminal according to the present invention is driven by a battery, collects meter reading data of a meter reading meter connected by wire, and wirelessly communicates with a base station connected to a communication network. And transmits the meter reading data to a center device connected to the communication line network, the wireless communication terminal monitors the capacity of the battery, and the battery capacity is set to a first value. When the value becomes equal to or less than a reference value, the wireless communication terminal is switched to a first operation mode in which power consumption of the battery is reduced.

In the first operation mode, the receiving process is stopped at predetermined intervals. In the first operation mode, reception processing is performed only at night. Also, the wireless communication terminal monitors the capacity of the battery, and when the battery capacity becomes equal to or less than a second reference value smaller than the first reference value, the wireless communication terminal sets the power consumption of the battery to be lower. It is formed so as to switch to the second operation mode in which it becomes smaller. In the second operation mode, the reception process from the base station is stopped.

[0010] Further, while collecting meter reading data of a meter reading meter driven by a battery and connected by a wire,
Communicate wirelessly with a base station connected to a communication network,
In a wireless communication terminal for transmitting the meter reading data to a center device connected to the communication line network, the wireless communication terminal transmits a transmission signal to the upstream station according to a reception level of a reception signal from an upstream station. And a transmission level setting unit for setting the transmission level of. Also, when the wireless communication terminal is installed, the transmission level is set.

Still further, in a wireless communication terminal driven by a battery and wirelessly communicating with a base station connected to a communication network, the wireless communication terminal monitors the capacity of the battery, and the capacity of the battery is monitored. When the wireless communication terminal device is equal to or less than the first reference value, the wireless communication terminal is switched to an operation mode in which the power consumption of the battery is reduced, and the base station is notified that the battery capacity is equal to or less than the first value reference value. It is formed to transmit a telegram.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, embodiments of the present invention will be described. 1 is a system configuration diagram of a wireless meter reading system according to Embodiment 1 of the present invention, FIG. 2 is a hardware block diagram of a wireless meter reading terminal according to Embodiment 1 of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 3 is a configuration diagram of a superframe of an LCCH (Logical Control Channel) according to mode 1;
FIG. 3 is a diagram illustrating a frame configuration, and FIG. FIG. 4 is a voltage characteristic diagram of the wireless metering system according to the first embodiment of the present invention as the battery changes over time. FIG. 5 is a flowchart illustrating an operation mode of the wireless metering terminal according to the first embodiment of the present invention. is there.

In FIG. 1, reference numeral 1 denotes a center device comprising a workstation (computer) 2 and a terminal adapter 3 for PIAFS (PHS Internet Accel Forum) for connecting to an ISDN (communication network) 7; PHS also connected to ISDN network 7
Public base station 4. Reference numeral 5 denotes a slave unit (wireless meter reading terminal), which is connected by a wire 30 to a meter meter 6 for meter reading of gas, water, electricity, and the like, and wirelessly connected to the public base station 4 by a transmission / reception unit 18.

In FIG. 2, reference numeral 19 denotes an antenna for transmitting and receiving radio waves, and a switch (SW) 8 switches between a transmitting unit 17 and a receiving unit 15 connected to the antenna 19. The transmission unit 17 and the reception unit 15 are connected to the digital modulation / demodulation unit 16, respectively, and form a transmission / reception unit 18. The transmission / reception unit 18 is a TDMA (Time Division Multip
ul Access) is connected via the processing unit 25 to the control unit 11 which performs the entire processing. Reference numerals 13, 14, and 24 are memories, respectively. The ROM 14 stores a program of the control unit 11, and the RAM 13 stores a work area of the program and data. Reference numeral 22 denotes a transmission unit 17 for inputting a transmission signal modulated by the digital modulation / demodulation unit 16 during transmission.
Is a synthesizer that supplies a wireless carrier wave to the.

Reference numeral 9 denotes a battery capacity monitoring unit which monitors the capacity of the battery 10 and constantly notifies the control unit 11 of the monitoring result. Reference numeral 20 denotes a power switch, which controls the supply of power to the transmission / reception unit 18 according to a command from the control unit 11. 21 is a clock. Communication with meter reading meter 6
SIO (Serial Input Output) 12,
This is performed via a meter reading meter I / F (interface) circuit 23. Note that the reception processing unit is formed by the reception unit 15, the digital modulation / demodulation unit 16, and the TDMA processing unit 25.

Next, the operation will be described with reference to FIG.
The battery capacity monitoring unit 9 constantly monitors the capacity of the battery 10. In the normal mode S10, the LCC from the public base station 4
The H superframe is received at a cycle of 1.2 seconds. L
The CCH superframe is a BCCH frame, SCC
It is composed of an H frame, PCH and the like (FIG. 3). First, the TDMA processing unit 2 receives the BCCH in the frame and determines at which timing on the frame the data should be received.
Judge with 5. After the determination, the reception processing is performed only for the specific slot P1. When recognizing that the information is for itself in the received frame, the child device 5 connects the call and realizes communication with the center device 1. Further, when there is a transmission request from the meter reading meter 6, the slave unit 5 requests connection of a call to the public base station 4, and realizes communication with the center device 1 after connection.

Here, in PHS communication, TDMA
(Time Division Multipul Access) / TDD (Time
Division Duplex). This means that 4 slots are transmitted from the base station 4 to the slave 5 and that the slave 5
4 slots are allocated to the uplink from the base station 4. The LCCH is a logical control channel composed of BCCH, SCCH, PCH, and the like, and the LCCH superframe is a frame having a minimum period based on a combination of these channels.

BCCH (Broadcast Control Channe)
l: broadcast channel) includes information such as an indication of a time slot position of a TDMA / TDD to be received, a configuration and an instruction of an LCCH superframe, and the like. SCCH (Signalling
The Control Channel (individual cell channel) includes information for connection of a call (connects with a called party) and is a point-to-point bidirectional channel between a base station and a slave unit. PCH (Paging Control Channe
l: paging channel) includes information for paging for connection of a call (connecting with a called party),
This is a point-multipoint downlink one-way channel between the base station and the slave unit.

While the communication process is being performed in the normal mode (S10), the control unit 11 constantly monitors the capacity of the battery 10, that is, the control unit 11 sends the voltage signal V of the battery 10 from the battery capacity monitoring unit 9. The voltage signal V and the first reference voltage V
And 1 (S12). Then, the voltage signal V becomes the first
Is higher than the reference voltage V1 in the normal mode (S1).
The communication process is performed according to 0). On the other hand, when the voltage signal V is equal to or lower than the first reference voltage V1 (time t1 in FIG. 4), a call is made to the center device 1 and a message indicating that the battery capacity has decreased is transmitted (S14).

Thereafter, the mode is switched to the power saving mode A (first operation mode) in which the power consumption of the battery 10 is reduced (S16). For example, the power supply switch 20 is turned on at a constant cycle (at a predetermined interval) upon activation from the clock 21 shown in FIG.
It controls the supply / stop of power to the transmission / reception unit 18 and the TDMA processing unit 25. For example, the transmitting and receiving unit 18 and T
When power is supplied to the DMA processing unit 25 for only three hours a day, the power consumption of the transmission / reception unit 18 and the TDMA processing unit 25 is lower than in the normal mode (S10) in which power is supplied all day. This is approximately 1/8, and the power consumption of the slave unit 5 is also approximately 1/6 to 1/8.

This is because the power consumption of the transmission / reception unit 18 and the TDMA processing unit 25 is sufficiently large as compared with the power consumption of the CPU of the control unit 11 and occupies most of the power consumption of the slave unit 5. is there. In the above description, the case where the transmission / reception processing is stopped at predetermined intervals in the first operation mode has been described. However, since the frequency of the transmission processing based on the call from the handset 5 is low, the transmission processing to the reception processing unit is not performed. Only supply of power may be stopped at a predetermined interval, that is, only reception processing may be stopped at a predetermined interval. Further, instead of stopping the supply of power to the reception processing unit, the supply of power to the reception unit 15 may be stopped.

It should be noted that the predetermined interval is only for the nighttime transmission / reception unit 1.
8 and a power supply to the TDMA processing unit 25. At this time, the nighttime communication by the PHS generally has better radio conditions and lower traffic than the daytime.
Since the communication failure between the slave unit 5 and the center device 1 decreases and the actual time of data transmission decreases, the transmission / reception unit 18 and the TD
The power consumption of the MA processing unit 25 can be reduced.

In the power saving mode A (S16), the control unit 11 constantly monitors the capacity of the battery 10, that is, receives the voltage signal V of the battery 10 from the battery capacity monitoring unit 9, 2 is compared with the reference voltage V2 (S1).
8). When the voltage signal V is higher than the second reference voltage V2, the communication processing is performed in the power saving mode A (S16). On the other hand, when the voltage signal V is equal to or lower than the second reference voltage V2 (time t2 in FIG. 4), a call is made to the center device 1, and
A message indicating that the battery capacity has decreased is transmitted (S20).

Thereafter, the mode is switched to the power saving mode B (second operation mode) in which the power consumption of the battery 10 is reduced (S22). For example, the power supply to the transmission / reception unit 18 and the digital modulation / demodulation unit 16 is stopped, and only the terminal call initiated by the meter reading meter 6 is operated. That is,
An incoming call from the center device 1 will not be accepted. When receiving the activation request from the meter reader 6, the control unit 11 outputs a command to the power switch 20 to supply power to the transmission / reception unit 18 and the digital modulation / demodulation unit 16.
Thereafter, the control unit 11 connects the call to enable communication. At this time, since the driving voltage of the CPU of the control unit 11 is the main power consumption source, the power consumption is approximately 1/10 to 1/5 compared to the normal mode (S10).

Since the operation mode is switched according to the monitoring state of the battery capacity as configured as described above, it is possible to provide the slave unit 5 whose operation time is longer than the battery capacity. Also,
The operation mode is switched according to the monitoring state of the battery capacity, and the slave unit 5 transmits a message indicating that the battery capacity has decreased. Therefore, the operation time is longer than the battery capacity, and
It is possible to provide the slave unit 5 capable of surely performing emergency transmission. In particular, the operation mode is switched so that the operation time of the slave unit 5 is prolonged when the battery capacity is reduced in the slave unit 5 for meter reading which is fixed and used in a fixed position. There is an effect that it is possible to surely respond to the emergency command from 6. In addition, the slave unit 5 for meter reading is used by being fixed at a fixed position.
Since non-periodic monitoring is not normally performed and there is no alternative means, the effect is remarkably greater than when the operation time of the mobile phone terminal is extended. In addition, since the slave unit 5 is fixedly used, a function corresponding to handover is not required, and the antenna can be installed with directivity of the antenna.

Further, since the child device 5 transmits the messages (S14) and (S16) indicating that the battery capacity has decreased, the battery capacity of the child device 5 can be monitored on the center device 1 side. Furthermore, two types of messages (S
14) and (S16) are received by the center device 1, so that the battery capacity of the slave unit 5 can be reliably monitored. Also,
Further, in order to improve the monitoring accuracy of the battery capacity of the slave unit 5,
A configuration may be such that a failure or a decrease in battery capacity is recognized when there is no response from a predetermined slave unit 5 to a call from the center apparatus 1. Further, the slave unit 5 used for the gas or water meter reading meter 6 is preferably driven by the battery 10 because the commercial AC power may not be taken from the outside in some cases. In particular, the slave unit 5 driven by the battery 10 is used. 5
Is preferably used for the gas meter meter 6 because the risk of ignition is extremely low.

In the first embodiment, the case where the capacity of the battery 10 is monitored by a voltage drop as shown in FIG. 4 has been described, but another method may be used. For example, the configuration may be such that the power consumption is calculated and monitored in accordance with the usage status of the child device 5 or may be simply monitored based on the usage time of the child device 5. In any case, the handset 5 is fixed at a fixed position, and the frequency of calls is almost fixed unless an emergency such as a failure occurs, so that the consumption of the battery 10 can be easily estimated and used at any position. However, the monitoring accuracy can be remarkably improved as compared with a portable telephone terminal whose usage frequency is irregular.

Embodiment 2 Hereinafter, a second embodiment of the present invention will be described. FIG. 6 is a system configuration diagram of a wireless meter reading system according to Embodiment 2 of the present invention. In the figure, 32 is provided separately from the slave unit 5 and
A reception level detector 34 detects a reception level of a reception signal from the (upstream station), and a transmission level setting unit 34 sets the transmission level of the transmission signal according to the reception level detected by the reception level detector 32. The other configuration is the same as that of the first embodiment, and a description thereof will be omitted.

Next, the operation will be described. At the time of setting the slave unit 5 for wireless meter reading, a call for test connection is made from the slave unit 5 to the center apparatus 1. When handset 5 receives a call from center device 1 via public base station 4 in response to this call, control unit 11 outputs a reception signal input via transmission / reception unit 18 to reception level detection unit 32. Reception level detection unit 32
Then, the electric field strength of the received signal is measured, and the received level is displayed. The operator or setting person sets the transmission level at the transmission level setting section 34 while watching this display. Control unit 11
Then, the transmission / reception unit 18 is caused to perform subsequent transmission at the set transmission level. Other operations are the same as those in the first embodiment, and a description thereof will be omitted.

With the above configuration, the minimum required transmission level is determined based on the conditions such as the distance from the slave 5 to the public base station 4 and the environment based on the reception level detected by the reception level detector 32. The transmission and reception unit 1
8 can be provided to a minimum, and the mobile device 5 can operate for a long time with respect to the battery capacity.

Further, since the transmission level is set when the slave unit 5 is installed, the power consumption in the transmission / reception unit 18 is minimized from the start of use, and the slave unit 5 having a long operation time with respect to the battery capacity is used. Can be provided. Further, since the meter unit 5 for meter reading is used in a fixed position and the conditions such as the distance from the slave unit 5 to the public base station 4 and the environment hardly change, the transmission level for constantly monitoring the reception level is set. Control over the reception level detection unit 32 and the transmission level setting unit 34 is not required as compared with the case of resetting, and the number of tasks to be processed by the control unit 11 is reduced, and the power consumption of the slave unit 5 can be reduced. In addition, since it is not necessary to provide the reception level detection unit 32 for each slave unit 5, the configuration can be simplified.

Note that the reception level detection unit 32 may be incorporated in the slave unit 5 so that the reception level is detected and the transmission level is changed each time communication is performed with the public base station 4. For example, this is effective when conditions such as the distance from the slave unit 5 to the public base station 4 and the environment change. Further, the case where the detection of the reception level and the setting of the transmission level are performed via the control unit 11 has been described.
2 and the transmission level setting unit 34 may be connected to perform detection / setting. Also, the case where the transmission level is set when the slave unit 5 is installed has been described.
It is also effective to reset when the (upstream station) is installed.

In the first and second embodiments, the case where the all-day reception processing is performed in the normal mode has been described.
The reception processing may be performed only for several hours in a day. Also, when the mobile device 5 wirelessly communicates with the public base station 4 (upstream station) connected to the ISDN network 7, it means that there is a relay station between the mobile device 5 and the public base station 4, and the mobile device 5 is a relay station. This also includes the case where the communication with the public base station 4 is performed via the public key. At this time, the relay station becomes the upstream station with respect to the slave unit 5, and the public base station 4 becomes the upstream station with respect to the relay station. The communication between the relay station and the public base station 4 is in the public mode, but the communication between the slave unit 5 and the relay station may be in a transistor mode other than the public mode. The case where the slave unit 5 is used for wireless meter reading has been described, but the slave unit 5 may be used for other purposes, for example, a facility monitoring system.

[0034]

A wireless communication terminal according to the present invention is driven by a battery, collects meter reading data of a meter meter connected by wire, and wirelessly communicates with a base station connected to a communication network. A wireless communication terminal that transmits the meter reading data to a center device connected to the communication line network, wherein the wireless communication terminal monitors the capacity of the battery, and determines that the battery capacity is equal to or less than a first reference value. The wireless communication terminal is configured to be switched to the first operation mode in which the power consumption of the battery is reduced, so that the wireless communication terminal having a long operable time with respect to the battery capacity is provided. Can be.

In the first operation mode, the reception process is stopped at predetermined intervals, so that the operable time is longer than the battery capacity, and it is possible to transmit data reliably in an emergency.

In the first operation mode, the reception process is performed only at night, so that the reliability of communication is improved, the operable time is longer with respect to the battery capacity, and the transmission can be reliably performed in an emergency. It is possible.

The wireless communication terminal monitors the capacity of the battery. When the battery capacity falls below a second reference value smaller than the first reference value, the wireless communication terminal transmits the battery to the battery. Since it is formed so as to switch to the second operation mode in which power consumption is reduced, the operable time can be further extended with respect to the battery capacity, and the center device can surely monitor the state of the battery of the wireless terminal. it can.

In the second operation mode, the process of receiving from the base station is stopped, so that the operable time is longer than the battery capacity, and it is possible to transmit data reliably in an emergency.

In addition to collecting meter reading data of a meter meter driven by a battery and connected by wire,
Communicate wirelessly with a base station connected to a communication network,
In a wireless communication terminal for transmitting the meter reading data to a center device connected to the communication line network, the wireless communication terminal transmits a transmission signal to the upstream station according to a reception level of a reception signal from an upstream station. Since the transmission level setting unit for setting the transmission level is provided, a wireless communication terminal having a long operable time with respect to the battery capacity can be provided.

Since the transmission level is set when the wireless communication terminal is installed, the power consumption can be minimized from the start of use.

Further, in a wireless communication terminal driven by a battery and wirelessly communicating with a base station connected to a communication line network, the wireless communication terminal monitors the capacity of the battery, and the capacity of the battery is monitored. When the wireless communication terminal device is equal to or less than the first reference value, the wireless communication terminal is switched to an operation mode in which the power consumption of the battery is reduced, and the base station is notified that the battery capacity is equal to or less than the first value reference value. It is possible to provide a wireless communication terminal which is formed so as to transmit a message, has a long operable time with respect to the battery capacity, and can surely transmit in an emergency.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a wireless meter reading system according to Embodiment 1 of the present invention.

FIG. 2 is a hardware block diagram of the wireless meter reading terminal according to Embodiment 1 of the present invention.

FIG. 3 is a configuration diagram of a superframe of the LCCH according to Embodiment 1 of the present invention.

FIG. 4 is a voltage characteristic diagram of the wireless metering system according to Embodiment 1 of the present invention in accordance with a change over time of a battery.

FIG. 5 is a flowchart illustrating an operation mode of the wireless meter reading terminal according to Embodiment 1 of the present invention.

FIG. 6 is a system configuration diagram of a wireless meter reading system according to Embodiment 2 of the present invention.

FIG. 7 is a block diagram illustrating a conventional wireless communication system using a PHS terminal.

[Explanation of symbols]

1 center device, 2 workstation, 3
TAP, public base station, 5 slave unit, 6 meter meter, 7 ISDN network capacity monitoring 10 battery 11 control unit, 12 SIO RA
M 14 ROM 18 transmitting / receiving unit, 19 antenna, 20 power switch 21 clock, 30 wire, 32
Receive level detector, 34 Transmit level detector

Claims (8)

[Claims] 1. A meter driven by a battery, which collects meter reading data of a meter meter connected by wire, and wirelessly communicates with a base station connected to a communication network to transmit the meter reading data to the communication network. In the wireless communication terminal for transmitting to the connected center device, the wireless communication terminal monitors the capacity of the battery, and when the battery capacity becomes equal to or less than a first reference value, the wireless communication terminal is activated. A wireless communication terminal formed to switch to a first operation mode in which power consumption of the battery is reduced. 2. The wireless communication terminal according to claim 1, wherein in the first operation mode, power supply to the reception processing unit is stopped at predetermined intervals. 3. The wireless communication terminal according to claim 1, wherein the first operation mode supplies power to the reception processing unit only at night. 4. The wireless communication terminal monitors the capacity of the battery, and when the battery capacity falls below a second reference value smaller than the first reference value, the wireless communication terminal transmits the battery to the battery. The wireless communication terminal according to claim 1, wherein the wireless communication terminal is configured to switch to a second operation mode in which power consumption is reduced. 5. The wireless communication terminal according to claim 4, wherein the power supply to the reception processing unit is stopped in the second operation mode. 6. A meter driven by a battery, which collects meter reading data of a meter meter connected by wire, and wirelessly communicates with a base station connected to a communication network to transmit the meter reading data to the communication network. A wireless communication terminal for transmitting to a connected center device, wherein the wireless communication terminal sets a transmission level of a transmission signal to be transmitted to the upstream station according to a reception level of a reception signal from an upstream station. A wireless communication terminal device comprising a unit. 7. The wireless communication terminal according to claim 6, wherein a transmission level is set when the wireless communication terminal is installed. 8. A wireless communication terminal that is driven by a battery and wirelessly communicates with a base station connected to a communication network, wherein the wireless communication terminal monitors the capacity of the battery, and this battery capacity is equal to or less than the battery capacity. 1, when the wireless communication terminal is switched to an operation mode in which the power consumption of the battery is reduced, and a message to the effect that the battery capacity has fallen below the reference value of the first value is transmitted to the base station. A wireless communication terminal device configured to transmit a message.