JP2012178682A - Radio telemeter system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio telemeter system which ensures reliability of communication.SOLUTION: The radio telemeter system 1 includes: a terminal-side network control unit 14 communicably connected to a center-side network control unit 11 by radio; a master unit 15 connected to the terminal-side network control unit; a slave unit 16 communicably connected to the master unit 15 by radio; and a microcomputer meter 17 connected to the slave unit 16. At least one of the master unit 15 and the slave unit 16 configures wireless communication according to the environmental status of electric waves. The radio telemeter system 1 has, among other functions, a function for setting the frequency of a radio channel for wireless communication between the master unit 15 and the slave unit 16, a function for setting the antenna power for wireless communication, and a function for detecting whether data received under the wireless communication environment set by the functions is a noise or not.

Description

  The present invention relates to a radio telemeter system, and in particular, a terminal-side network control device connected to a center-side network control device via a communication line, a parent device wired to the terminal-side network control device, and a parent device The present invention relates to a specific low-power radio telemeter system including a slave unit that is wirelessly connected to each other and that is connected to a microcomputer meter.

  For example, in a wireless telemeter system that has been conventionally developed for gas and water meters such as Japanese Patent Application Laid-Open No. 10-198881 (hereinafter referred to as Patent Document 1), wireless communication can be performed without being affected by other communication. A proposed system has been proposed. As a conventional method disclosed in Patent Document 1 or the like, there is a means for specifying identification information of a system with a wireless device, in which the transmission side continuously transmits identification information and receives it. The side detects the radio wave, and when the transmitted identification information is detected and the identification information corresponds to its own identification information, it performs wireless communication with each other.

  By the way, in the conventional radio telemeter system, since the radio terminal master unit or the radio terminal slave unit is operated by a battery, in order to reduce battery consumption, by performing a reception operation intermittently, A carrier sense operation for discriminating the presence / absence of a radio wave from the counterpart wireless terminal (parent device or slave device) is intermittently performed.

  Operation with intermittent carrier sense can determine the presence or absence of radio waves, including not only the counterpart wireless terminal but also radio waves from other wireless terminal systems and radio waves emitted by home appliances. May receive radio waves. As a result, the wireless terminal parent device or the wireless terminal child device has a problem that the battery is wasted.

  As a means for solving this problem, the partner wireless terminal (receiving terminal) is called using the shortened information of the identification information of the wireless terminal, and the receiving wireless terminal side uses the shortened information from the calling terminal (transmitting terminal) to identify itself. A method for reducing battery consumption by determining whether or not the information shortened information matches is disclosed.

  However, even in this system, there is a problem that transmission or reception cannot be performed when the transmission terminal overlaps communication with another terminal or the like when transmitting to the counterpart terminal.

  In order to solve this problem, the applicant of the present application is Japanese Patent Application Laid-Open No. 2008-160680 (hereinafter referred to as Patent Document 2). In the wireless telemeter system, the wireless master device or the wireless slave device is provided for each time series of a plurality of wireless channels. After selecting the wireless channel that uses the empty channel for each hour based on the information of the empty channel, notifying the selected wireless channel for each hour to multiple wireless slave units, and after notifying the multiple wireless slave units , A method of changing to a wireless channel that has received the notification and communicating using the wireless channel is disclosed. In other words, in order to maintain the reliability of communication, an unused wireless unused channel is used.

JP-A-10-198881 JP 2008-160680 A

  By the way, the radio channel is defined in “Standard ARIB (Association of Radio Industries and Businesses) STD-T96”. In this standard, 1 to 33 channels can be used when the wireless antenna power is 1 mW or less. On the other hand, when the antenna power exceeds 1 mW and is 10 mW or less, 17 to 33 channels can be used. In other words, when the antenna power is more than 1 mW and 10 mW or less, there are fewer usable channels than when the antenna power is 1 mW or less. For this reason, there are cases where there are no wireless channels that can be used for channels with antenna power exceeding 1 mW and not more than 10 mW due to the influence of radio waves from other wireless terminal systems, radio waves emitted by home appliances, and the like. When the antenna power is 1 mW or less, there are many radio channels that can be selected. However, since the power to be transmitted is small, the radio reach distance is shorter than that when the antenna power exceeds 1 mW and is 10 mW or less.

  A terminal-side network control device connected to the center-side network control device via a public network line, a wireless master device connected to the terminal-side network control device, and a plurality of wireless devices wirelessly connected to the wireless master device Means for setting a frequency of a radio channel for wireless base unit or wireless handset to communicate in a wireless telemeter system comprising a handset and a plurality of microcomputer meters respectively connected to the plurality of wireless handset units; And means for setting a wireless communication speed, means for setting antenna power, and means for detecting radio wave environment conditions, and means for changing both transmission power and communication speed according to the radio wave environment conditions. Further, when changing the transmission power and the communication speed according to the radio wave environment, the communication speed varies stepwise.

  The present invention has been made in view of such problems, and an object thereof is to provide a radio telemeter system that ensures communication reliability.

  In order to achieve the above object, according to one aspect of the present invention, a radio telemeter system is connected to a terminal-side network control device connected to the center-side network control device so as to be capable of wireless communication, and to the terminal-side network control device. A parent device, a child device connected to the parent device so as to be capable of wireless communication, and a microcomputer meter connected to the child device. At least one of the parent device and the child device includes control means for setting wireless communication according to the radio wave environment, and the control means is for wireless communication between the parent device and the child device. First setting means for setting the frequency of the wireless channel, second setting means for setting the antenna power for wireless communication, and third setting means for setting the communication speed of wireless communication And detecting whether or not the data received under the wireless communication environment set by the first setting means, the second setting means, and the third setting means is noise, Detecting means for detecting. The first setting means and the second setting means perform the setting in accordance with the detection result of the detection means, and the third setting means determines the communication speed in accordance with the setting of the antenna power in the second setting means. Set.

  Preferably, the third setting means sets the communication speed stepwise in accordance with the setting of the antenna power in the second setting means.

  Preferably, when the antenna power is set to be greater than 1 mW and equal to or less than 10 mW, the second setting means detects noise in the detection means for all channels that can be used with the antenna power set by the first setting means. If detected, the antenna power is set to 1 mW or less.

  More preferably, when the second setting means sets the antenna power to 1 mW or less, the third setting means sets the communication speed to be greater than 1 mW and 10 mW or less when the second setting means sets the antenna power to 1 mW or less. Set the communication speed slower than the communication speed that was set at times.

  According to the present invention, the reliability of communication can be ensured by changing the antenna power and the communication speed according to the radio wave environment.

It is a figure which shows the specific example of a structure of the radio | wireless telemeter system concerning this Embodiment. It is a block diagram which shows the specific example of the internal structure of the main | base station contained in the radio | wireless telemeter system concerning this Embodiment. It is a block diagram which shows the specific example of the internal structure of the subunit | mobile_unit contained in the radio | wireless telemeter system concerning this Embodiment. It is a figure explaining operation | movement of the center polling communication from the center side network control apparatus to a meter / sensor in the radio | wireless telemeter system concerning this Embodiment. It is a figure explaining the communication operation | movement at the time of the call from the meter / sensor which is a terminal side in the radio | wireless telemeter system concerning this Embodiment. It is a block diagram showing the specific example of the function structure of the main | base station or a subunit | mobile_unit for intermittent carrier sense operation | movement. It is the flowchart showing the flow of the intermittent carrier sense operation | movement between a main | base station and a subunit | mobile_unit.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same.

<System configuration>
FIG. 1 is a diagram showing a specific example of the configuration of the radio telemeter system 1 according to the present embodiment.

  Referring to FIG. 1, a radio telemeter system 1 includes a terminal device 13 connected to a center-side network control device 11 via a mobile radio network 12, and one or more slave units 16a, 16b,. Including. The slave units 16a, 16b,... Are representatively referred to as a slave unit 16.

  The terminal device 13 includes a terminal-side network control device 14 connected to the center-side network control device 11 via the mobile radio network 12, and a parent device 15 connected to the terminal-side network control device 14 in a wired or wireless manner. Including.

  The master unit 15 is connected to the slave unit 16. For this connection, a specific low-power radio is preferably used. .. Are connected to microcomputer meters (hereinafter referred to as meters / sensors) 17a, 17b,... Such as gas and water by wire or wirelessly. The meters / sensors 17a, 17b,...

<Device configuration>
FIG. 2 is a block diagram showing a specific example of the internal configuration of base unit 15.

  Referring to FIG. 2, base unit 15 stores I / F (interface) 21 for communicating with terminal-side network control device 14, information for identifying meter / sensor 17, and information related to meter reading values. A nonvolatile memory 22, a CPU (Central Processing Unit) 23, an antenna 24, a wireless communication unit 25, a ROM (Read Only Memory) 26, a RAM (Random Access Memory) 27, and a battery 28 are included.

  The CPU 23 executes a communication operation to be described later by reading a program stored in the ROM 26 and executing the RAM 27 as a work area.

FIG. 3 is a block diagram showing a specific example of the internal configuration of the handset 16.
Referring to FIG. 3, slave unit 16 includes a meter I / F (interface) 31 for communicating with meter / sensor 17, a non-volatile memory for storing meter information that is information related to meter / sensor 17, and the like. 32, CPU 33, radio wave output to base unit 15, antenna 34 for receiving radio wave from base unit 15, radio communication unit 35 for converting communication signal with base unit 15, CPU 33 ROM 36 for storing a program to be executed, RAM 37 for temporarily storing data for CPU 33 to process information, and battery 38 for supplying power to CPU 33 and the like.

  The CPU 33 executes a communication operation to be described later by reading a program stored in the ROM 36 and executing the RAM 37 as a work area. As an example, it is determined whether or not the signal transmitted from the wireless communication unit 35 is a signal addressed to its own ID.

  The wireless communication unit 35 intermittently performs a carrier sensing operation for determining the presence or absence of a radio wave from the counterpart terminal by performing a reception operation intermittently.

<Communication operation in wireless telemeter system>
In the radio telemeter system according to the present embodiment, communication from the center side network control device 11 to the meter / sensor 17 and communication from the meter / sensor 17 to the center side network control device 11 are performed.

  FIG. 4 is a diagram for explaining the operation of the center polling communication from the center side network control device 11 to the meter / sensor 17 in the radio telemeter system 1.

  Referring to FIG. 4, first, a connection request issued from center-side network control device 11 is received by terminal-side network control device 14 via mobile radio network 12 (step S11). In response to this, the terminal-side network control device 14 is activated.

  When the terminal-side network control device 14 is activated, it sends an activation signal to the parent device 15 (step S12). The base unit 15 receives the activation signal and activates it.

  When the master unit 15 is activated, it transmits a startup signal to the slave unit 16 (step S13). The subunit | mobile_unit 16 receives the signal of the starting, and starts.

  When the slave unit 16 is activated, it sends an activation signal to the meter / sensor 17 (step S14). The meter / sensor 17 receives the activation signal and activates.

  When the connection from the center side network control device 11 to the meter / sensor 17 is established, the meter / sensor 17 passes through the handset 16, the base unit 15, and the terminal side network control device 14 to the center side network control device 11 to the meter / sensor. Meter reading data at the sensor 17 is transmitted (steps S15 to S18). As a result, the center side network control device 11 acquires meter reading value data of the meter / sensor 17.

  FIG. 5 is a diagram illustrating a communication operation when a call is made from the meter / sensor 17 on the terminal side in the wireless telemeter system 1. As a case where there is a calling factor from the meter / sensor 17 on the terminal side, there is a case where the meter / sensor 17 reports meter reading data to the center.

  Referring to FIG. 5, a start signal is sent from meter / sensor 17 (step S21). The subunit | mobile_unit 16 receives the signal of the starting, and starts.

  When the child device 16 is activated, it transmits an activation signal to the parent device 15 (step S22). The base unit 15 receives the activation signal and activates it.

  When the master unit 15 is activated, it sends an activation signal to the terminal-side network control device 14 (step S23). The terminal-side network control device 14 receives the activation signal and activates it.

  When the terminal-side network control device 14 is activated, it transmits a connection request to the center-side network control device 11 via the mobile radio network 12 (step S24), and establishes a connection with the center-side network control device 11.

  When the connection from the center side network control device 11 to the meter / sensor 17 is established, the center side network control device 11 passes through the terminal side network control device 14, the parent device 15, and the child device 16 to the meter / sensor 17. Meter reading value data is requested (steps S25 to S28). In response to this request, meter reading data at the meter / sensor 17 is transmitted from the meter / sensor 17 to the center side network control device 11 via the slave unit 16, the base unit 15, and the terminal side network control device 14 ( Steps S29 to S32). As a result, the center side network control device 11 acquires meter reading value data of the meter / sensor 17.

<Wireless communication between master unit and slave unit>
The wireless communication between the parent device 15 and the child device 16 for realizing communication for the center side network control device 11 to acquire meter reading value data of the meter / sensor 17 will be further described.

  The wireless communication unit 25 of the parent device 15 and the wireless communication unit 35 of the child device 16 perform an operation of transmitting and receiving data intermittently at a timing at which there is no exchange of the activation signal or the signal requesting the meter value, and the partner terminal Detects and configures a channel that can be used for wireless communication. This operation is called intermittent carrier sense. The channel capable of wireless communication detected by the intermittent carrier sensing operation is transmitted to the CPU 23 of the parent device 15 and the CPU 33 of the child device 16.

  Specifically, at the timing described above, base unit 15 and handset 16 enter a mode in which an intermittent carrier sense operation is performed, and perform the following operations. At this time, one of the parent device 15 and the child device 16 becomes a transmission side device, and the other becomes a reception side device.

  The transmission side device and the reception side device are not necessarily fixed. That is, at a certain timing, the master unit 15 becomes a transmission side device and the slave unit 16 becomes a reception side device. At other timings, the slave unit 16 becomes a transmission side device and the master unit 15 becomes a reception side device. As such, the functions may be interchanged.

  The transmission side device continuously transmits data at the above timing for a period longer than the reception interval in the reception side device. For example, if the reception interval at the receiving side apparatus is 18 seconds, the transmitting side apparatus continuously transmits data for 19 seconds. At this time, the transmitting apparatus transmits the identification code (ID) of the own apparatus and the identification code (ID) of the receiving apparatus as data.

  The receiving side device determines whether or not the received data is a wireless communication request addressed to the own device to which the own device ID (or identification code) is attached. When the received data is a wireless communication request addressed to the own apparatus, the wireless data is received, and after appropriate processing is performed, a wireless response is made to the transmission side apparatus.

  The partner terminal ID and the transmission / reception channel number are input in advance at the timing when the parent device 15 and the child device 16 are installed at the installation location, for example, so that the non-volatile memory 22 of the parent device 15 and the child device 16 are previously set. It is assumed that it is stored in the nonvolatile memory 32. Therefore, by using this information, it is possible to communicate with the partner apparatus without interference with other terminals. Alternatively, one or two radio channel numbers are automatically set from a plurality of radio channels according to the installation location, and the set radio channel numbers are stored in the nonvolatile memory 22 of the parent device 15 and the child device 16. It may be stored in the nonvolatile memory 32.

<Functional configuration>
FIG. 6 is a block diagram showing a specific example of a functional configuration on the device side serving as a receiving-side device of the parent device 15 and the child device 16 for executing the intermittent carrier sensing operation. The functions shown in FIG. 6 are mainly realized in the CPU 23 by reading and executing a program stored in the ROM 26 when the receiving device is the parent device 15. Alternatively, when the receiving side device is the slave unit 16, the CPU 33 reads and executes a program stored in the ROM 36 and is mainly realized in the CPU 33. Note that at least a part may be realized by the hardware configuration shown in FIG. 2 or FIG.

  Referring to FIG. 6, the receiving side apparatus has, as the above functions, an input unit 101 for receiving input of data received by receiving radio waves of a predetermined frequency by the wireless communication unit 25 (or 35), and the data And a determination unit 103 for determining the presence or absence of noise at the frequency received by the wireless communication unit 25 (or 35) based on detection by the detection unit 102. And a channel setting unit 104 for setting (changing) a radio channel used for communication in the radio communication unit 25 (or 35) according to the determination result, that is, a frequency of radio waves to be transmitted and received, and the radio communication unit 25 (or 35), a power setting unit 105 for setting the antenna power for communication, and wireless communication in the wireless communication unit 25 (or 35). And a speed setting unit 106 for setting the communication speed of.

<Operation flow>
FIG. 7 is a flowchart showing the flow of the intermittent carrier sensing operation between the parent device 15 and the child device 16. The operation represented by the flowchart of FIG. 7 is executed at a timing at which there is no exchange of the activation signal, the signal requesting the meter value, or the like in the transmission side device of the parent device 15 and the child device 16. That is, the operation represented by the flowchart of FIG. 7 is realized by the CPU of the transmission side device reading out a program stored in the ROM and executing it on the RAM.

  Referring to FIG. 7, in step S <b> 101, the CPU of the transmission-side apparatus sets the wireless communication unit to use the antenna power that is greater than 1 mW and 10 mW or less as the wireless communication with respect to the reception-side apparatus.

  The standard ARIB STD-T96 stipulates that 17 to 33 channels can be used when the wireless antenna power is greater than 1 mW and less than or equal to 10 mW. Therefore, in step S103, the CPU of the transmission side apparatus selects one of the 17 to 33 channels that can be used as a candidate channel.

  The CPU of the transmission side device periodically performs carrier sense in the frequency band of the selected candidate channel, and investigates whether or not there is noise in the channel. That is, when data transmitted by radio waves of the set frequency is analyzed and the ID included therein matches the identification code of the own device, it is determined as data to be received, and when the ID does not match Discard it as noise.

  As a result of performing carrier sense for a certain time (for example, one hour), if there is noise at a specified ratio (for example, 30 minutes or more) of the certain time (YES in step S105), the above steps of 17 to 33 channels If a radio channel different from the candidate channel selected in S103 can be used (YES in step S107), the process returns to step S103, and the CPU of the transmission side device selects another radio channel from the available radio channels. Select candidate channels for. Then, carrier sense is periodically performed on the candidate channel by repeating the subsequent operations, and it is investigated whether or not there is noise in the candidate channel.

  On the other hand, if all the channels 17 to 33 are not usable (NO in step S107), in step S109, the CPU of the transmission side device sets the antenna power to 1 mW for the wireless communication unit as wireless communication to the reception side device. Set as follows.

  The standard ARIB STD-T96 stipulates that channels 1 to 33 can be used when the antenna power is 1 mW or less. Therefore, the CPU of the transmission side device investigates a usable radio channel without noise from channels 1 to 33 (YES in step S111), and selects in step S103 out of channels 1 to 33 in step S113. A noise-free radio channel different from the selected candidate channel is selected. In step S115, the CPU of the transmission side apparatus changes the communication data rate according to the frequency of the selected radio channel.

  For example, in step S109, when the communication data rate is 100 kbps in a situation where the wireless antenna power exceeds 1 mW and is 10 mW or less, the antenna power is changed to 1 mW or less in step S115. Changes the communication data rate to 50 kbps, which is 100 kbps or less. By changing the communication data rate in this way, it is possible to increase the wireless reachable distance.

  That is, the wireless reachable distance is shortened by reducing the antenna power output in step S109. On the other hand, since the communication data rate and the arrival distance are correlated, the arrival distance becomes longer when the communication data rate is reduced. Therefore, by reducing the communication data rate in step S115, it is possible to cancel the distance that has been reduced by reducing the antenna power output in step S109.

  More preferably, when changing the communication data rate in step S115, the CPU of the transmission side apparatus can communicate with the reception side apparatus from the initial communication data rate (for example, 100 kbps) by a predetermined amount (for example, 10 kbps). Decrease in steps while checking whether or not. As a result, the amount of decrease in the communication data rate can be minimized, and the communication data rate can be prevented from being reduced more than necessary.

<Effect of Embodiment>
In the radio telemeter system 1 according to the present embodiment, the above-described intermittent carrier sense operation is executed between the parent device 15 and the child device 16, thereby changing the antenna power and communication data rate according to the radio wave environment. As a result, communication can be performed between the parent device 15 and the child device 16 in a highly reliable frequency band without noise. That is, the reliability of communication between the parent device 15 and the child device 16 can be ensured.

  In addition, by performing the intermittent carrier sense operation described above, the communication rate when the wireless antenna power is 10 mW is stepped according to the presence or absence of noise in communication between the parent device 15 and the child device 16. Will be updated (decreased). Therefore, even if the wireless antenna power reaches 1 mW, the maximum communication rate can be secured at that power.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Wireless telemeter system, 11 Center side network control apparatus, 12 Mobile radio network, 13 Terminal apparatus, 14 Terminal side network control apparatus, 15 Master unit, 16, 16a, 16b Slave unit, 17, 17a, 17b Sensor, 21 terminal Side network controller communication I / F, 22, 32 Non-volatile memory, 24, 34 Antenna, 25, 35 Wireless communication unit, 26, 36 ROM, 27, 37 RAM, 28, 38 Battery, 31 Meter I / F, 101 Input unit, 102 detection unit, 103 determination unit, 104 channel setting unit, 105 power setting unit, 106 speed setting unit.

Claims (4)

A terminal-side network control device connected to the center-side network control device so as to enable wireless communication;
A master unit connected to the terminal-side network control device;
A slave unit connected to the master unit for wireless communication;
Comprising a microcomputer meter connected to the slave unit,
At least one of the parent device and the child device includes a control unit for setting the wireless communication according to a radio wave environment situation,
The control means includes
First setting means for setting a frequency of a wireless channel for the wireless communication between the parent device and the child device;
Second setting means for setting antenna power for the wireless communication;
Third setting means for setting a communication speed of the wireless communication;
By detecting whether or not the data received under the wireless communication environment set by the first setting means, the second setting means, and the third setting means is noise, the radio wave Detection means for detecting environmental conditions,
The first setting means and the second setting means perform the setting according to the detection result of the detection means,
The third setting unit is a radio telemeter system that sets the communication speed in accordance with the setting of the antenna power in the second setting unit.   2. The radio telemeter system according to claim 1, wherein the third setting unit sets the communication speed stepwise in accordance with the setting of the antenna power in the second setting unit. 3.   When the antenna power is set to be greater than 1 mW and less than or equal to 10 mW, the second setting means performs noise in the detection means for all channels that can be used with the antenna power set by the first setting means. The radio telemeter system according to claim 1 or 2, wherein the antenna power is set to 1 mW or less when a radio wave is detected.   The third setting means sets the communication speed when the second setting means sets the antenna power to 1 mW or less, and the second setting means sets the antenna power to greater than 1 mW and 10 mW or less. The radio telemeter system according to claim 3, wherein the wireless telemeter system is set to a communication speed that is slower than the communication speed that was set when the setting was made.

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