JP5507856B2 - Wireless communication system - Google Patents

Description

  The present invention relates to a wireless communication system used as a wireless sensor network, and more particularly to a wireless communication system that is resistant to interference and can easily construct a network with reduced power consumption and cost.

[Description of Prior Art]
In networks using wireless communication, there are systems using weak wireless, systems using ZigBee, and systems using specific low power.
The system using weak radio is based on the weak radio standard of the domestic radio law, and mainly uses the 300 MHz band, and is excellent in radio wave diffraction and power consumption, but because the output is small, the communication distance is short, Low resistance to jamming waves. In addition, it is necessary to construct a network with a higher-level application.

  A system using ZigBee is a system using the IEEE 802.15.4 standard, and uses the 2.4 GHz band ISM band (Industry Science Medical band). Since the application layer and the network layer are built in as a function of the wireless module, it is said that system network construction is easy. However, since the 2.4 GHz band is used, interference occurs in an area where Wi-Fi is installed. In addition, the diffractive property is poor, and a plurality of terminals must be installed, which increases the total number of terminals and increases power consumption.

  In addition, a system using specific low power is a system using the RCR-STD-T67 standard of the domestic radio law, and the 400 MHz band is used, and the usage, data speed, and frequency (band) are determined in detail. The network is built with higher-level applications. Although the output is large and the communication distance is long, the current consumption is large, and the anti-interference performance is poor due to analog modulation / demodulation.

[Requirements for wireless sensor network]
For example, a wireless sensor network is provided with sensors that detect the state (voltage, current, gas flow rate, temperature, etc.) of a device (monitored device) installed in a factory and the like, and data from each sensor is transmitted via a wireless system. This is a system that can collectively manage the operating states of the devices in the entire factory by transmitting to the server and performing totalization analysis on the server.

In such a system, it has excellent anti-interference performance so as not to interfere with other systems, low power consumption so that it can be operated for a long time even with battery drive, and sensing data is personal information that should be kept confidential. A wireless system that is highly confidential and can be realized at low cost is desired.
Furthermore, as a network control, it is required to be able to construct a P2P (Peer-to-Peer) type network that connects sensor terminals distributed in an area without infrastructure.
Furthermore, it is desirable to be able to realize a system application capable of accurately grasping the state of an object based on sensed information and data and providing a service according to the purpose.

  In addition, as a technique regarding the wireless sensor network system, Japanese Patent Application Laid-Open No. 2005-150883, “Device Monitoring System” (Applicant: Mitsubishi Electric Corporation, Patent Document 1), Japanese Patent Application Laid-Open No. 2006-054834, “Information Processing Device, Information” "Processing Method" (Applicant: Mitsubishi Electric Corporation, Patent Document 2), JP 2006-279927 A "Monitoring Control Device, Monitoring System, Monitoring Method, Program and Recording Medium" (Applicant: OMRON Corporation, Patent Document 3).

  In Patent Document 1, a single wireless unit is mounted on the sensor terminal side, and a plurality of wireless units are mounted on the site supervisory terminal side, and a method for wireless communication is selected according to the situation. Describes a device monitoring system for sending data received from a host device to a host device.

  Patent Document 2 includes a plurality of communication units / protocols on the device-side adapter, and a single communication unit on the access point (router) side, and selects which standard to communicate according to the situation, The router describes a system for sending data received from a device-side adapter to a host device.

  Patent Document 3 describes a system that includes a single wireless unit on the sensor terminal side and a plurality of wireless units on the main controller side, and selects a standard for wireless communication depending on the situation. .

JP 2005-150883 A JP 2006-054834 A JP 2006-279927 A

  However, the conventional wireless communication system using each communication method has excellent interference resistance performance, low power consumption, low cost, and can be easily realized in the wireless sensor network system. There was a problem that not.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wireless communication system that is excellent in anti-interference performance, low power consumption, low cost, and easy to construct a network.

The present invention for solving the problems of the above-described conventional example includes a sensor for monitoring a device state of a monitored device, a slave unit for wirelessly transmitting data detected by the sensor, and receiving data from the slave unit And a data server for storing the detected data, wherein the master unit includes three or more slots in which a plurality of types of radio units that approximate frequency bands can be mounted. , a single antenna, and a control unit that controls associated with communication using a single antenna, the type of the radio unit is identified by a combination of frequency bands and wireless standards and data rates, the control unit, A group number indicating the other party that communicates with the wireless unit is assigned to and stored in the mounted wireless unit. The wireless unit with the same group number communicates with the same frequency band and the same data rate. Among the slots, the first radio unit assigned the first group number is mounted in the first slot, and the second slot can be assigned the second group number. 2 wireless units can be mounted, and a third wireless unit to which a third group number can be assigned can be mounted in the third slot .

Further, according to the present invention, in the radio communication system, the slave unit uses a fourth slot, a fifth slot, a single antenna, and a single antenna that can be mounted with a radio unit that approximates a frequency band. A control unit that performs control associated with the communication, and the type of the radio unit is specified by a combination of a frequency band, a radio standard, and a data rate, and the control unit is connected to the radio unit with respect to the mounted radio unit. A group number indicating a group to perform communication is assigned and stored, and communication with a wireless unit having the same group number at the same frequency band and the same data rate is possible. Either the second or third group number is assigned, and a fourth wireless unit capable of communicating with the wireless unit of the parent device to which the assigned group number is assigned is mounted. In the fifth slot, 4th group Is characterized in that the fifth wireless unit-loop number is available for grant can be mounted.

The present invention, in the wireless communication system, the base unit comprising an access point in the d rear, the position child machine in the parent machine area, the same frequency band, the radio unit of the same data rate is mounted In addition, the same group number is assigned to each radio unit, and radio units having different frequency bands are mounted in adjacent areas, and different group numbers are assigned .

  Further, the present invention is characterized in that, in the wireless communication system, the control unit of the slave unit performs time division transmission according to a schedule preset for each wireless unit.

The present invention, in the wireless communication system, the slave unit which is located near the boundary of the first area and the second area, the fourth to the first group number in the first frequency band is associated with A wireless unit and a fifth wireless unit associated with the second group number in the second frequency band, and the control unit of the slave unit is a fourth wireless unit that is the fourth unit The communication is performed by the communication unit, and the fifth wireless unit is controlled to communicate with the base unit in the second area.

Further, according to the present invention, in the above wireless communication system, the master unit serving as an access point in the area includes a first wireless unit whose wireless standard is weak wireless and a wireless standard whose output is higher than that of weak wireless . and a second radio unit, the control unit of the master unit, the slave unit in the area communicating with the first wireless unit, communication with the base unit connected to the data server in the second wireless unit It is characterized by controlling to communicate.

  According to the present invention, in the wireless communication system, the slave unit includes a peripheral noise level measuring unit that measures a surrounding electric field noise level, and the control unit of the slave unit transmits the data to the master unit according to a preset schedule. When transmitting to the network, measure the ambient electric field noise level, perform transmission processing if the noise level is less than a preset threshold, and if the noise level is greater than or equal to the threshold, It is characterized by controlling to wait until transmission becomes good.

  According to the present invention, in the wireless communication system, the parent device includes ambient noise level measurement means for measuring an ambient electric field noise level, and the control unit of the parent device transmits a control signal to the child device. When the noise level is less than a preset threshold, transmission processing is performed. If the noise level is equal to or greater than the threshold, transmission is performed until the noise level is good. It is characterized by controlling to wait.

According to the present invention, a sensor for monitoring the device state of a monitored device, a slave unit that wirelessly transmits data detected by the sensor, a master unit that receives data from the slave unit, and storing the detected data a wireless communication system comprising a data server for base unit includes three or more slots capable of mounting a plurality of types of radio section approximating a frequency band, a single antenna, the single antenna a control unit for controlling accompanying communications and using the type of the radio unit is identified by a combination of frequency bands and wireless standards and data rates, the control unit, to the onboard radio unit, the radio unit The group number indicating the other party to communicate with is assigned and stored, and communication with the radio unit of the same group number at the same frequency band and the same data rate is possible. Includes a first radio unit to which a first group number is assigned, and a second radio unit to which a second group number can be assigned to the second slot. Since a wireless communication system in which a third wireless unit that can be assigned a third group number can be mounted in the slot of, the frequency band, wireless standard, and data rate can be arbitrarily set according to the installation location and environment of the system. can be selected, by selecting an optimal radio unit, it is possible to perform wireless communication, there is Rutotomoni can perform stable communication, Ru can improve the convenience of the system construction effects.

Further, according to the present invention, the slave unit is associated with communication using the fourth slot, the fifth slot, a single antenna, and a single antenna that can be equipped with a radio unit that approximates a frequency band. A control unit that performs control, and the type of the radio unit is specified by a combination of a frequency band, a radio standard, and a data rate, and the control unit communicates with the radio unit with respect to the installed radio unit. And a wireless unit having the same group number can communicate with the same frequency band and the same data rate, and the fourth slot has first, second, and second group numbers. 3 is assigned, and a fourth wireless unit capable of communicating with the wireless unit of the parent device to which the assigned group number is assigned is mounted, and a fourth group is provided in the fifth slot. Number that can be assigned Since the radio portion of the are with the radio communication system can be mounted, by selecting an optimal radio unit in accordance with the installation location and environment of the system, it is possible to perform wireless communication, it is possible to perform stable communication effective.

Further, according to the present invention, the base unit comprising an access point in the d rear, the position child machine in the parent machine area, the same frequency band, the radio unit of the same data rate is mounted, the radio unit Are assigned the same group number, and the radio units of different frequency bands are mounted in adjacent areas, and the above wireless communication system is assigned different group numbers. Between the adjacent areas and the interference between adjacent areas can be reduced.

  Further, according to the present invention, since the control unit of the slave unit performs the above-described wireless system in which time division transmission is performed according to a schedule set in advance for each radio unit, the slave units in the same area transmit at the same time and are congested. There is an effect that can be prevented.

According to the present invention, the handset located near the boundary between the first area and the second area includes a fourth radio unit associated with the first group number in the first frequency band, And a fifth radio unit associated with the second group number in the second frequency band, and the control unit of the slave unit communicates with the master unit in the first area by the fourth radio unit. Since the wireless communication system controls the communication with the base unit in the second area by the fifth wireless unit, the slave unit transmits data from the base unit in the first area, for example, to the fourth wireless unit. The data of the monitored device in the area provided at a location away from the data server belongs to the adjacent area by being received by the communication unit and transmitted to the base unit in the second area by the fifth wireless unit. You can upload to the data server by relaying sequentially via the slave unit. With weak small radio, a system for collectively monitoring the data server data in a wide range of the sensor, there is an effect that can be easily constructed at a low cost.

Further, according to the present invention, the master unit serving as the access point in the area, the first radio unit wireless standard is weak radio and the second wireless unit wireless standard is weak radio than the large output standard The control unit of the parent device communicates with the child device in the area through the first wireless unit, and communicates with the parent device connected to the data server through the second wireless unit. In the area, weak wireless communication can be performed to reduce the power consumption of the battery-powered slave unit, and a relay point is provided by high-power wireless communication with the master unit connected to the data server. Without being able to communicate directly, can quickly store data in the server, and significantly reduce power consumption and cost compared to performing all communications using high-power wireless standards. is there.

  Further, according to the present invention, the slave unit includes ambient noise level measuring means for measuring the ambient electric field noise level, and the control unit of the slave unit transmits the data to the master unit according to a preset schedule. In addition, the ambient electric field noise level is measured, and transmission processing is performed when the noise level is lower than a preset threshold value. When the noise level is equal to or higher than the threshold value, the noise level is improved. Since the above wireless communication system is controlled to wait for transmission until the transmission is completed, the reliability of communication from the slave unit to the master unit can be improved.

  Further, according to the present invention, the parent device includes the ambient noise level measuring means for measuring the ambient electric field noise level, and the control unit of the parent device transmits the control signal to the When the noise level is less than a preset threshold value, transmission processing is performed, and when the noise level is equal to or higher than the threshold value, control is performed to wait for transmission until the noise level becomes good. Therefore, the reliability of communication from the parent device to the child device can be improved.

It is a schematic block diagram of the radio | wireless communications system (this system) which concerns on embodiment of this invention. It is explanatory drawing which shows the example of the radio | wireless part used for the main | base station 1 and the subunit | mobile_unit 2 of this system. It is a model explanatory view showing the outline of network construction of this system. It is explanatory drawing which shows the network structural example using this system. It is a schematic explanatory drawing which shows the time division transmission control of this system.

[Summary of Invention]
Embodiments of the present invention will be described with reference to the drawings.
A wireless communication system according to an embodiment of the present invention includes a sensor attached to a monitored device, a slave unit that acquires and transmits data from the sensor, a server that remotely monitors the status of a plurality of monitored devices, It consists of a master unit that performs wireless communication with a plurality of slave units, acquires data from each sensor and sends it to the server, and the master unit and slave units can be equipped with a plurality of wireless units, According to the system installation location and communication environment, from among multiple types of radio units specified by the combination of the frequency band, radio standard, and data rate, the radio unit is selected and incorporated as appropriate at the time of system construction. A group ID is assigned to each wireless unit so that communication is possible only between wireless units having the same group ID, and it is difficult to be affected by interference, and has a wide range of sensors with low power consumption and low cost. Effect In which it can be remotely monitored manner.

  In addition, the communication system according to the embodiment of the present invention performs weak wireless communication between an area parent device and a plurality of child devices in the area, and two child devices located in areas where two areas are adjacent to each other. The slave unit includes a radio unit, and one of the radio units communicates with one area master unit and the other radio unit communicates with the other area master unit, and is connected to a data server. A network that can communicate with the main master unit by relaying the slave unit in the adjacent area even in an area far from the master unit, and acquires data from a wide range of sensors using a weak radio with a small output Can be easily constructed at low cost, and a wide range of devices can be monitored.

  In the communication system according to the embodiment of the present invention, the main master unit and the area master unit communicate with each other using a high-output and high-speed wireless standard, and the area master unit and the slave units in the area communicate with each other. Is designed to perform weak wireless communication, and even without a relay point, data can be transmitted directly from a distant area base unit to the main base unit at high speed, and all communications can be performed at high power and high speed. Compared with using the wireless standard, the power consumption can be greatly reduced and the cost can be reduced.

  In addition, in the wireless communication system according to the embodiment of the present invention, communication between a master unit and a plurality of slave units in an area is performed in a time division manner using the same frequency band, and the slave unit transmits alarm information. When transmitting to the main unit, measure the surrounding noise level, and when the noise level is high or when another slave unit is transmitting, wait for transmission and wait until the noise level becomes good Transmission is performed, and the reliability of communication from the child device to the parent device can be improved.

  In the communication system according to the embodiment of the present invention, when the master unit transmits a control signal or the like to the slave unit in the area, the surrounding noise level is measured. It waits for transmission and performs transmission after the noise level becomes good, so that the reliability of communication from the parent device to the child device can be improved.

[Schematic Configuration of Embodiment: FIG. 1]
FIG. 1 is a schematic configuration diagram of a radio communication system (present system) according to an embodiment of the present invention.
As shown in FIG. 1, this system includes a sensor 3 attached to a monitored device (not shown), a slave unit 2 that acquires data from the sensor 3 and transmits the data to a host, and a slave unit 2. A base unit 1 that performs wireless communication, a data server 4 that acquires data from the sensor 3 via the base unit 1 and collectively monitors the status of monitored devices, and a data server 4 that is connected to another system or maintenance And a router 5 connected to a terminal for use.
Here, for simplicity of explanation, only one master unit 1 and one slave unit 2 are shown, but a plurality of slave units 2 are usually provided, and depending on the form of the network, the data server 4 has In addition to the parent device 1 to be connected, a parent device 1 serving as an access point for each area is provided to communicate with the child device 2 in the area.

[Configuration of each part: Fig. 1]
Each part will be described.
[Configuration and operation of base unit]
The base unit 1 usually communicates with a plurality of handset units 2 to acquire sensing data from the plurality of sensors 3 and send it to the data server 4. The base unit 1 performs wireless communication with the antenna 11 and the handset unit 2. A wireless unit 12 that performs control, a CPU (Central Processing Unit) 13 that performs control such as communication control, a LAN conversion unit 14 that is connected to the router 4, an RTC (Real Time Clock) 15 that manages the current time, A power generation unit 16 that generates power to be supplied to each unit, an AC-adapter 17 that acquires power, and a battery 18 for power failure countermeasures are provided. The CPU corresponds to a “control unit” recited in the claims.

  As a feature of this system, the base unit 1 can accommodate a plurality of wireless units (wireless modules) 12. In the example of FIG. 1, only one radio unit 12 is provided, but there are a plurality of slots in which the radio unit 12 is mounted, and the radio unit 12 is appropriately inserted into the slot and used as necessary. It is something that can be done.

The radio units 12 to be accommodated are identified by a combination of a used frequency band, a radio communication standard, and a data rate, and each radio unit 12 is assigned a group ID by the CPU 13. Communication is possible only between the wireless units 12 and 22 to which the same group ID is assigned. The group ID corresponds to a “group number” described in the claims.
Further, in this system, the use frequency band of each radio unit 12 is close, and the antenna 11 can be shared by a plurality of radio units 12. An example of the radio unit will be described later.

  Moreover, the main | base station 1 communicates by a time division using the same channel as all the subunit | mobile_units 2 for every radio | wireless part 12. FIG. Therefore, transmission processing and reception processing between the parent device 1 and the child device 2 are normally performed according to a schedule linked with the child device 2. The time division transmission / reception process will be described later.

As a feature of this system, the CPU 13 selects which radio unit 12 to use for each group ID, that is, for each group of the other party, according to the design of the system, from among a plurality of radio units 12 mounted. To do. And corresponding to each radio | wireless part 12, the schedule of a time division transmission / reception, ID (user ID) of the radio | wireless part 22 of the subunit | mobile_unit 2 used as the communicating party of each radio | wireless part 12, or the radio | wireless part of another main | base station 1 12 IDs (user IDs) are stored.
In this system, normally, the same type of wireless unit with the same group ID is selected as the wireless unit of the parent device 1 and the child device 2 in the same area.

  Further, the CPU 13 of the parent device 1 controls the child device 2 by transmitting a control signal instructing RTC rewriting (time setting) information, a sensing interval in the sensor 3, and the like to each child device 2. Such control information is input from, for example, a maintenance terminal. And a control signal is transmitted with respect to all the subunit | mobile_units 2 at predetermined time, such as once a day, for example. If necessary, the RTC rewrite information may be transmitted together with an Ack / Nack response to a preset time division transmission schedule of the slave unit.

Further, although not shown, the base unit 1 is provided with an ambient noise measuring means, and measures the ambient noise level in accordance with an instruction from the CPU 13.
Then, base unit 1 of this system compares the value of ambient electric field noise measured at the time of transmission with a preset threshold value to determine whether the ambient noise state is good or not. In this case, transmission is possible, and when it is not good, processing for waiting for transmission is performed.

[Configuration and operation of handset 2]
The subunit | mobile_unit 2 transmits the data detected with the sensor 3 to the main | base station 1, and receives the control information from the main | base station 1, The radio | wireless part 22 which performs radio | wireless communication with the antenna 21, the main | base station 1, CPU 23 for communication control, sensor interface 24 connected to sensor 3, RTC (Real Time Clock) 25 for managing the current time, log of data (sensing data) acquired from sensor 3 and transmission status , An LED 27a, b that lights or blinks when an alarm occurs, a speaker 28 that generates an alarm sound, and a battery 29 that supplies power.

Further, as a feature of this system, a plurality of wireless units (wireless modules) 22 can be mounted on the slave unit 2 as well. Each wireless unit 22 is specified by a combination of a used frequency band, a wireless communication standard, and a data rate. Each wireless unit 22 is assigned a group ID, and between the wireless units 12 and 22 to which the same group ID is assigned. Can only communicate.
Moreover, since the frequency band used by each radio | wireless part 22 is near, the antenna 21 may be one.
And what kind of radio | wireless part 22 each subunit | mobile_unit 2 is mounted is selected at the time of system design, and is suitably mounted.
In addition, time division transmission is performed so that a plurality of slave units 2 in the area transmit simultaneously and do not become congested. The type of the radio unit 22 will be described in detail later.

  The CPU 23 performs communication control similarly to the parent device, and stores the group ID and the wireless unit 22 in association with each other. When a plurality of radio units 22 are installed, which radio unit 22 is used for each group ID is selected. And corresponding to each radio | wireless part 22, the schedule (time division transmission / reception), ID (user ID) of the radio | wireless part of the main | base station 1 of the other party which communicates in each radio | wireless part 22, or another subunit | mobile_unit 2 ) Is remembered.

  Further, the CPU 23 acquires sensing data from the sensor 1, stores it as a log in the memory 26 together with the acquisition time, and transmits it to the parent device 1 according to a preset schedule. For example, the control of storing the sensing data acquired every 5 minutes in the memory 26 and transmitting it to the parent device 1 every hour can be considered.

  Further, when the sensing data from the sensor 3 is out of the normal range stored in advance, the CPU 23 transmits an alarm to the main unit 1 and controls the LEDs 27a and b and the speaker 28 so that they can be recognized at the site. To inform the surroundings.

  In the example of FIG. 1, the CPU 23 detects the electric field level of the received signal from the parent device 1 as a transmission pilot electric field check, and turns on the LED 27a as being within the stable communication area if it is above a certain level. Thereby, at the time of system construction, it becomes possible to install the subunit | mobile_unit 2 confirming that it is in a stable communication area with LED27a.

  In addition, the CPU 23 monitors the battery voltage, and when it becomes less than a certain voltage, the CPU 27 notifies the surroundings that the voltage has become low by blinking the LED 27 b and outputting an alarm sound from the speaker 28.

  Further, the CPU 23 receives the control information (maintenance information) from the base unit 1 with the wireless unit 22 in a reception state at a predetermined time, for example, once a day. Control signals received by the slave unit 2 from the master unit 1 include the sensing interval of the sensor 3, rewriting of RTC information, sensor 3 and equipment inspection request information, and the like.

  Then, before transmitting the sensing information and the abnormality notification (alert) information to the main unit 1, the CPU 23 temporarily sets the wireless unit 22 in a reception state to check the surrounding noise and the presence / absence of transmission from other units. Check the noise electric field level, and if it is good, send. If it is bad, it waits for transmission and checks again after a certain time. If the time is over, it will be transmitted at the next transmission.

  In addition, since the slave unit 2 includes the battery 25, it can be installed easily even after the system is constructed, and the installation location is not selected, and it is not affected by noise generated in the monitored device. It is possible to improve the reliability.

[Sensor 3]
The sensor 3 is attached to or near the monitored device, and measures data such as voltage, current, gas flow rate, temperature, etc. in order to monitor the operating state of the monitored device, and the measurement result or abnormality is detected as an event, pulse or analog. The data is output to the handset 2 as data.

[Data server 4]
The data server 4 is a computer including a control unit such as a CPU, a main memory as a work memory, a storage unit for storing processing programs, data, and the like, and sensing from the sensor 3 in the network transmitted from the parent device 1. Accumulate and analyze data.
[Maintenance terminal]
The maintenance terminal reads and displays the sensing data stored in the data server 4 according to an operator's instruction, and generates and manages transmission schedules of the parent device 1 and the child device 2.

[Outline of the operation of this system: Fig. 1]
The operation of the radio communication system having the above configuration will be briefly described.
For example, in a system composed of one master unit 1 and a plurality of slave units 2, a plurality of radio units 12 are mounted on the master unit 1, and one radio unit 22 is mounted on each slave unit 2. The case where this is done will be described.
When the system is constructed, it is set which frequency band, standard, and data rate are used for communication between the parent device 1 and each child device 2, and when the group ID is given, the CPU 13 of the parent device 1 The CPU 23 of each slave unit 2 stores the group ID and the set wireless unit in association with each other.
Furthermore, the master unit 1 stores the user IDs and transmission / reception schedules of the radio units of the plurality of slave units 2 that are communication partners, and each slave unit 2 stores the user ID and transmission / reception schedule of the radio unit of the master unit 1. Remember.

And the main | base station 1 performs radio | wireless communication with the some subunit | mobile_unit 2, receives the sensing data from the sensor 3 from the subunit | mobile_unit 2, outputs it to the data server 4, and transmits a control signal to the subunit | mobile_unit 2. Then, the sensing interval of the sensor 3 and the transmission schedule of the slave unit 2 are remotely controlled.
The data server 4 stores and analyzes sensing data collected from the sensors 3 in the network.

  Wireless communication between the parent device 1 and the plurality of child devices 2 is performed in a time-sharing manner according to a preset schedule using the selected wireless unit. As a result, the system can be constructed at a low cost and a transmission / reception collision can be prevented.

The CPU 22 of the slave unit 2 receives and stores in advance the schedule created by the maintenance terminal and transmitted from the master unit 1, is activated by the RTC 25 according to the schedule, acquires the sensing data from the sensor 3, Store in the memory 26. Further, the acquired sensing data is transmitted to the parent device 1 periodically or according to a schedule. The subunit | mobile_unit 2 will be in a reception state for a fixed time after transmission, and waits for a reception confirmation (Ack).
The base unit 1 performs a reception operation in accordance with the schedule of the handset 2, receives the sensing data transmitted from the handset 2, and outputs it to the data server 4.

  When the control of the sensor 31 or the slave unit 2 is necessary, the master unit 1 is activated according to the intermittent reception schedule of the slave unit 2 according to an instruction (manual or RTC) from the maintenance terminal and the corresponding slave unit 2 transmits a control signal to the wireless unit 2 and performs an intermittent reception operation according to the schedule. Upon receiving the control signal, the slave unit 2 performs processing such as changing the sensing interval and adjusting the RTC time.

Furthermore, as a feature of this system, the master unit 1 and the slave unit 2 measure the electric field noise of the surroundings at the time of transmission, determine the communication environment, and transmit if good, and if not good, It waits until it becomes, and transmits again. Thereby, the reliability of communication can be improved.
In particular, in this system, since all the slave units 2 communicating with the same radio unit of the master unit 1 communicate at the same frequency, a schedule is set to perform transmission / reception operations in a time division manner. By measuring this, it can be confirmed that the other handset 2 in the vicinity is not transmitting, and a communication collision can be surely avoided.

[Example of wireless unit: Fig. 2]
Next, an example of a wireless unit used in the parent device 1 and the child device 2 will be described with reference to FIG. FIG. 2 is an explanatory diagram illustrating an example of a wireless unit used in the parent device 1 and the child device 2 of the present system.
As described above, in this system, it is possible to mount a plurality of types of radio units with different combinations of frequency bands, standards, and data rates, and select and mount them appropriately according to the network design. Further, the mounted wireless unit is used in association with the group ID.

As shown in FIG. 2, the type of the radio unit is specified by a combination of a frequency band, a category of a radio standard, and a data rate.
As frequency bands, there are 301.08 MHz (band B1), 312.15 MHz (band B2), and 314.06 MHz (band B3). There is. STD-T93 is a standard newly established in 2007, and high output is permitted only in the band from 312 to 315 MHz.
The data rates corresponding to each category include 1200 bps and 75 bps, and STD-T93 includes 1200 bps and 19.2 kbps.

In the example of FIG. 2, the radio unit used in the band B1 includes a weak 1200 bps or 75 bps radio unit, and no STD-T93 radio unit.
The band B2 and the band B3 include weak 1200 bps and 75 bps and STD-T93 1200 bps and 19.2 kbps radio units, respectively.

  The communicable distance of each wireless unit is about 90 m for a weak 1200 bps output and about 150 m for 75 bps under the condition of line-of-sight / 2 m above the ground. Further, the high output STD-T93 has a 1200 bps of about 700 m and a 19.2 kbps of about 450 m.

[Group ID]
Further, in this system, a group ID is assigned to each group (for example, each area) constituting the network, and the CPU of each terminal (base unit 1 or handset 2) associates the wireless unit with the group ID. I remember it. The wireless units having the same group number communicate with each other. Here, it is assumed that IDs A to J are assigned as group IDs.

  The group ID is also used, for example, when resetting the RTC in the group. When the RTC rewrite control information is transmitted from the base unit 1 with the group ID, the wireless unit having the group ID is transmitted. Only the RTC can be rewritten.

[User ID]
Further, in this system, a user ID is set as an identification number of each radio unit, and here, an ID having an arbitrary number of bits on a data frame is set. The user ID is used when controlling RTC rewriting for a specific slave unit 2 or the like.

[Combinable combinations]
And as a condition of the radio | wireless part which can communicate mutually, it is necessary for it to be the same data rate in the same frequency band by the same group ID.
For example, even with the same group ID, the weak 1200 bps of the band B1 and the weak 1200 bps of the band B2 cannot communicate with each other because the frequency bands are different.
Further, the weak 1200 bps of the band B2 and the weak 75 bps of the band B2 cannot communicate because of the different data rates.
On the other hand, the weak 1200 bps of the band B3 and 1200 bps of the STD-T93 of the band B3 have the same frequency band and data rate, and therefore communication is possible if they have the same group ID.
Further, even if the wireless units have the same data band and the same data rate, if the group IDs do not match, the received data is discarded by the CPU, and communication is not possible.

[Overview of network configuration: Fig. 3]
Next, an example of a network constructed using this system will be described with reference to FIG. FIG. 3 is a schematic explanatory diagram showing an outline of network construction of this system.
First, as shown in FIG. 3A, when the master unit 1 and the slave units 2a to 2g communicate with each other, the basic network includes a system in which all the slave units 2 directly transmit / receive to / from the master unit 1. Conceivable.
In the example of FIG. 3A, the parent device 1 and the child devices 2a to 2g all communicate with the same group ID “A” at a weak 75 bps in the band B1.

However, as shown in FIG. 3B, in order to stabilize communication with the slave unit 2 (here, the slave unit 2b) installed away from the master unit 1, the nearest slave unit 2 (here Then, the slave unit 2a) can be used as a relay point, and the slave unit 2b can communicate with the master unit 1 via the slave unit 2a.
In this case, the radio unit of the slave unit 2b is changed to a weak 75 bps radio unit of the group ID “B” band B2, and the slave unit 2a is changed to a weak 75 bps radio unit of the group ID “A” band B1. In addition, a weak 75 bps radio unit of the group ID “B” band B2 is installed.

That is, the slave unit 2a communicates with the master unit 1 by a weak 75 bps wireless unit of the group ID “A” band B1, and communicates with the slave unit 2b by the weak 75 bps of the group ID “B” band B2. Communicate with the wireless unit. The subunit | mobile_unit 2a transmits the sensing data from the subunit | mobile_unit 2b to the main | base station 1, and transmits the control information from the main | base station 1 to the subunit | mobile_unit 2b. In the slave unit 2a, a schedule is set for each wireless unit in order to prevent congestion at the time of transmission, and the transmission timing is controlled by the CPU 23.
Thereby, the subunit | mobile_unit 2b can perform the stable communication via the subunit | mobile_unit 2a nearby.

[Example of network configuration: Fig. 4]
Next, a network configuration example using this system will be described with reference to FIG. FIG. 4 is an explanatory diagram showing a network configuration example using the present system.
In FIG. 4, the main base unit 100 connected to the data server 4, area base units 120, 130, 140, 150, and 160 as access points in each area, and slave units provided in each area are configured. 1 shows a communication network.

In FIG. 4, among the radio units of the main base unit, the area base unit, and the slave unit, the radio unit of the band B1 is shown with a double frame, the radio unit of the band B2 is shown with a single frame, and the radio unit of the band B3 is It is shown with a thick frame. Each wireless unit is assigned a corresponding group ID, which is indicated by A to H in the figure.
Moreover, the arrow in a figure has shown the uplink.

In the network shown in FIG. 4, two types of network connection methods are shown.
The first method is a method in which two types of weak wireless units are installed in the slave unit at the end of the area and relayed sequentially, and the two areas shown on the left side of FIG. 4 are connected by this method. ing.
In the second method, an access point (area master unit) equipped with a weak radio unit and an STD-T93 radio unit is installed at the center of each area, and output is made for connection to the main master unit 1. This is a method using STD-T93 with a large size, and the three areas on the right side of FIG. 4 are connected by this method.
In any method, the transmission of the slave unit is performed in a time-sharing manner under the control of the CPU in each slave unit so as not to be congested.

First, the uplink in the left area where the network is formed by the first method will be described.
The area having the group ID D shown in the upper left of FIG. 4 (referred to as “area D”) is composed of an area parent device 130 serving as an access point and child devices 131 to 133 and 121.
The area master unit 130 and the slave units 131 to 133 each include a weak 75 bps radio unit (group ID: D) (hereinafter, “D radio unit”) in the band B2. In addition to the D radio unit, the slave unit 121 further includes a weak 75 bps radio unit (group ID: F) (hereinafter “F radio unit”) in the band B3.

Data from the slave units 131 to 133 is transmitted to the area master unit 130 by the D radio unit, and is transmitted from the area master unit 130 to the slave unit 121 by the D radio unit. The area parent device 130 stores the user ID of the child device 121 as a route for uploading.
The slave unit 121 receives the sensing data from the area master unit 130 by the D radio unit, and transmits the sensing data acquired by itself to the area base unit 120 in the adjacent area by the F radio unit.

The area parent device 120 receives the sensing data from the child devices 121 and 122 to 123 and transmits the sensing data to the child device 110.
In addition to the F radio unit, slave unit 110 includes a weak 75 bps radio unit (group ID: H) (hereinafter referred to as “H radio unit”) in band B1.

Further, the main base unit 100 is equipped with an H radio unit and a 19.2 kbps radio unit (group ID: I) (hereinafter referred to as “I radio unit”) of STD-T93 in the band B3.
Then, the slave unit 110 receives data from the area master unit 120 by the F radio unit and transmits the data to the main master unit 100 from the H radio unit. The main master unit 100 receives the sensing data from the slave unit 110 by the H radio unit. In this way, all the sensing data in the areas D and F are transmitted to the main master unit 100 and stored in the data server 4.

In this way, by using a weak wireless system with a small output and relaying it via the slave unit 2 located near the boundary of a plurality of areas, sensing data from sensors distributed over a wide range can be obtained at low cost. It can be collected.
Moreover, since the frequency band used between adjacent areas is changed, interference can be prevented.

Next, areas A, B, and C in which a network is formed by the second method will be described.
Area A with group ID A is composed of area master unit 150 and slave units 151-154. The slave units 151 to 154 include a weak 75 bps wireless unit (group ID: A) (hereinafter referred to as “A wireless unit”) in the band B1. In addition to the A radio unit, the area master device 150 includes the I radio unit described above.

  Data from the slave units 151 to 154 is collected in the area master unit 150 via the A radio unit, and is transmitted from the area master unit 150 to the main master unit 100 via the I radio unit. The area base unit 150 stores the user ID of the main base unit 100 as a route for uploading.

  As described above, the area master unit 150 uses the weak radio A wireless unit for communication within the area, and the communication with the distant main master unit 100 can have a large output and a long communication distance. By using the 19.2 kbps I wireless unit of STD-T93 that can be used, the power consumption of the battery-powered slave unit 2 can be reduced, and direct communication with the main master unit 100 is possible without providing a relay point. Become. Further, when the wireless unit I is used, the communication speed is high and data can be collected quickly.

Similarly, in the area B, the data collected in the wireless unit area master unit 160 having a weak bandwidth of 75 bps in the band B2 is transmitted to the main master unit 100 by the I radio unit.
In area C, communication is performed in a weak 75 bps wireless unit (group ID: C) (hereinafter referred to as “C wireless unit”) in the band B3 in the area C. Data is transmitted to 100.

Note that the area master units 140, 150, and 160 all communicate directly with the main master unit 100 using I radio units, so that time division is performed in advance corresponding to the group ID “I” so that no collision occurs during transmission. The transmission schedule is set.
In this way, sensing data from sensors provided in all areas in the system is transmitted to the main server 100 via the network and stored in the data server 4.
A control signal (downlink) from the main base unit 100 is transmitted through a path opposite to the above-described uplink.

[Time division multiple access control: Fig. 5]
In this system, in a network with the same group ID, time division transmission processing is performed in order to avoid collision during transmission. The time division control of this system will be described with reference to FIG. FIG. 5 is a schematic explanatory diagram illustrating time division transmission control of the present system.
FIG. 5 shows transmission control of two slave units (“terminal” in the figure) belonging to the same area.
Each slave unit stores in advance a schedule for data acquisition (measurement), transmission, and reception from the sensor, and the CPU performs processing according to the schedule with reference to the RTC. In this example, the slave unit is set to transmit to the master unit every hour.

  As shown in FIG. 5, in the terminal (1), for example, it is set to transmit at 12:00, 13:00, and the measurement data from the sensor 3 is acquired immediately before the start of transmission, Alternatively, the log is read from the memory, and transmission to the parent device (area parent device) 1 is started at 12:00. At that time, as described above, the surrounding noise level is measured, and if it is good, it is transmitted, and if it is bad, it waits for transmission. The terminal (1) performs a reception operation for a predetermined time after the transmission operation, and waits for a reception confirmation (Ack) from the parent device 1.

When waiting for transmission, when not receiving Ack, or when receiving a retransmission request, transmission is performed again, and if necessary, transmission processing is performed until 12:01. That is, in this area, the time between 12: 00 and 12: 01 is assigned in advance as a transmission time of the terminal (1) in advance, and other terminals do not transmit in this time zone.
Similarly, the terminal (2) is assigned 12:05 to 12:06, 13:05 to 13:06... As a transmission schedule every day.

In the example of FIG. 5, the transmission is scheduled to start every 5 minutes, and the interval (guard time) from the end of transmission of the terminal (1) to the start of transmission of the terminal (2) is 4 minutes.
Each slave unit stores in advance the timing of 4 minutes excluding the time zone transmitted by the own terminal and other terminals, and any slave unit transmits when an abnormal value is detected by the sensor 3. An alarm for notifying the parent machine of an abnormality is transmitted with a guard time of 4 minutes.

  When alarm transmission is performed, the slave unit measures the noise level and confirms that no other slave unit is transmitting before transmitting. If the noise level is not good, it waits for transmission and attempts transmission at the next guard time. Thereby, even when the same frequency is used, collision at the time of transmission can be prevented.

In addition, when transmitting control information from the master unit to the slave unit, a time is set in advance, such as 9:00 once a day, and when that time is reached, all the slave units are in an intermittent reception state. It waits for control information from the machine.
It is also possible to transmit the control information together with Ack for periodic transmission from the slave unit.

[Effect of the embodiment]
The wireless communication system according to the embodiment of the present invention includes a parent device 1 that transmits received data to the data server 4 and a plurality of child devices 2 that transmit data from the sensor 3 to the parent device 1. The master unit 1 and the slave unit 2 can be equipped with a plurality of types of radio units specified by a combination of a frequency band, a radio standard, and a data rate. Since the wireless communication system performs communication using the wireless unit selected by the CPU, the optimal wireless unit is selected according to the installation location and environment of the system and between the parent device 1 and the child device 2 Wireless communication can be performed, and stable communication can be performed.

  Further, according to the present system, the CPUs of the master unit 1 and the slave unit 2 store a group ID in association with each mounted radio unit, and store the same frequency band, the same data rate, and the same group ID. Wireless units that can communicate with each other in the area centering on the base unit 1 serving as an access point, select radio units having the same frequency band and the same data rate, and assign the same group ID. At the same time, different group IDs are given to radios in different areas, and radio units in different frequency bands are selected between adjacent areas, enabling communication between terminals in the area, There is an effect that interference between adjacent areas can be reduced.

  Moreover, according to this system, since the subunit | mobile_unit 2 is made to perform time division transmission according to the preset schedule, it prevents that the subunit | mobile_unit 2 in the same area transmits simultaneously, and becomes congested. There is an effect that can.

  Further, according to the present system, the slave unit 2 located near the boundary between the two areas includes the first radio unit having the first group ID in the first frequency band and the second unit in the second frequency band. A second wireless unit having a group ID of 2 is provided, and the slave unit 2 communicates with the master unit 1 in the first area by the first radio unit, and with the master unit 1 in the second area. Since the second wireless unit is configured to communicate with the second wireless unit, the slave unit 2 receives, for example, data from the first unit in the first wireless unit, and the second wireless unit receives the second data. It is possible to transmit to the data server 4 by sequentially relaying the sensing data of the area provided at a place away from the data server 4 by the slave unit 2 belonging to the adjacent area. Can be used for low-cost, wide-range sensors using a weak radio with low output. The chromatography data to the data server 4 efficiently an effect can easily build a system that can be uploaded.

  In addition, according to the present system, the area base unit serving as an access point includes a weak radio unit having a third group ID and a radio unit having a high output radio standard having a fourth group ID. It is a system that communicates with a slave unit in the area with a weak wireless unit, and communicates with a remote main unit using a high-powered standard wireless unit. The power consumption of the driven slave unit can be reduced, and high-output and high-speed wireless communication enables direct communication with the main master unit connected to the data server without providing a relay point, allowing data to be quickly stored in the server. In addition, there is an effect that the power consumption and cost can be greatly reduced as compared with the case where all of the high-output and high-speed wireless standards are used.

  Further, according to the present system, the slave unit 2 includes the ambient noise level measurement unit that measures the ambient electric field noise level, and when transmitting data from the sensor 3 to the master unit 1 according to a preset schedule, When the ambient electric field noise level is measured and the noise level is less than a preset threshold value, transmission processing is performed assuming that the communication environment is good, and when the noise level is equal to or higher than the threshold value, Since the wireless communication system waits for transmission until the noise level becomes good, there is an effect that the reliability of communication from the slave unit to the master unit can be improved.

  Further, according to this system, the base unit 1 includes the peripheral noise level measuring means for measuring the ambient electric field noise level, and measures the ambient noise level when transmitting the control signal to the slave unit 2. When the noise level is high, transmission is waited and transmission is performed after the noise level becomes good, and there is an effect that the reliability of communication from the parent device to the child device can be improved.

  INDUSTRIAL APPLICABILITY The present invention is suitable for a wireless communication system that is resistant to interference and can easily construct a network with reduced power consumption and cost.

  DESCRIPTION OF SYMBOLS 1 ... Master unit, 2 ... Slave unit, 3 ... Sensor, 4 ... Data server, 5 ... Router, 11, 21 ... Antenna, 12, 22 ... Radio | wireless part, 13, 23 ... CPU, 14 ... LAN conversion part, 15, 25 ... RTC, 16 ... power generation unit, 17 ... AC-adapter, 18, 29 ... battery, 24 ... sensor interface, 26 ... memory, 27 ... LED, 28 ... speaker, 100 ... main master unit, 120, 130, 140 , 150, 160 ... Area master unit

Claims (8)

A sensor that monitors the device status of the monitored device, a slave that wirelessly transmits data detected by the sensor, a master that receives data from the slave, and a data server that stores the detected data A wireless communication system comprising:
The base unit includes three or more slots capable of mounting a plurality of types of radio section approximating a frequency band, a single antenna, and said control unit for controlling accompanying communications using a single antenna Prepared ,
The type of the radio unit is specified by a combination of a frequency band, a radio standard, and a data rate,
The control unit assigns and stores a group number indicating a partner to communicate with the wireless unit to the mounted wireless unit, and the same frequency band and the same as the wireless unit of the same group number Enables communication at data rates,
Among the slots, a first radio unit assigned a first group number is mounted in the first slot,
In the second slot, a second radio unit that can be assigned a second group number can be mounted,
A wireless system , wherein a third wireless unit to which a third group number can be assigned can be mounted in the third slot . The slave unit includes a fourth slot and a fifth slot in which a radio unit that approximates a frequency band can be mounted, a single antenna, and a control unit that performs control associated with communication using the single antenna. With
  The type of the radio unit is specified by a combination of a frequency band, a radio standard, and a data rate,
  The control unit assigns and stores a group number indicating a group communicating with the wireless unit to the mounted wireless unit, and the wireless unit having the same group number, the same frequency band, and the same data Communication at a rate,
  Any one of the first, second, and third group numbers is assigned to the fourth slot, and a fourth radio that can communicate with the radio unit of the parent device to which the assigned group number is assigned. Part is mounted,
  The wireless system according to claim 1, wherein a fifth wireless unit to which a fourth group number can be assigned can be mounted in the fifth slot. A base unit comprising an access point in the d rear, wherein the position child machine in the area of the master unit, the same frequency band, is equipped with a radio unit of the same data rate, the in each radio unit the same group number while being applied, the adjacent areas between the mounted radio unit of different frequency bands, the radio communication system according to claim 1 or 2 wherein different group numbers, characterized in that it is applied. 4. The wireless communication system according to claim 2 , wherein the control unit of the slave unit performs time division transmission according to a schedule set in advance for each wireless unit. The handset located near the boundary between the first area and the second area includes a fourth radio unit associated with the first group number in the first frequency band, and a second in the second frequency band. A fifth wireless unit associated with the group number of
The control unit of the slave unit controls communication with the base unit in the first area through the fourth radio unit and communication with the base unit in the second area through the fifth radio unit. The wireless communication system according to claim 2 , wherein the wireless communication system is a wireless communication system. The master unit serving as the access point in the area, includes a first radio unit wireless standard is weak radio and a second radio unit the wireless standard is a standard of a large output from the weak radio,
The control unit of the master unit controls communication with the slave unit in the area by the first radio unit, and communication with the master unit connected to the data server is communicated by the second radio unit. The wireless communication system according to claim 1 , wherein the wireless communication system is a wireless communication system. The slave unit includes ambient noise level measurement means for measuring the ambient electric field noise level, and the control unit of the slave unit determines the ambient electric field noise level when transmitting data to the master unit according to a preset schedule. Measure and perform transmission processing when the noise level is lower than a preset threshold value, and control to wait for transmission until the noise level is good when the noise level is equal to or higher than the threshold value wireless communication system according to any one of claims 1 to 6, characterized in that. The master unit includes ambient noise level measurement means for measuring the ambient electric field noise level, and the control unit of the master unit measures the ambient noise level when transmitting a control signal to the slave unit, The transmission processing is performed when it is less than a set threshold value, and when the noise level is equal to or higher than the threshold value, control is performed to wait for transmission until the noise level becomes good. The wireless communication system according to any one of 1 to 7.

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