JP2006052946A - Wireless communication system and wireless communication device with time measurement function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To add a generic receiving device, being not to join in a peculiar transmission route, to a wireless communication system for transmitting accurate time information by wireless through the peculiar transmission route. <P>SOLUTION: Slave devices 3, each comprising a wireless IC tag, decode time information received by wireless from higher-rank devices to correct time measurement time of a time measurement part based on the time information thus acquired. They produce and transmit transmission information for correcting time measurement time of lower-rank devices with rank information showing own ranks added to the measurement time of the measurement part. Further, at definite points of time, time information of the same format as existing time information such as a JYY standard wave signal is produced and broadcast on faint airwaves. If a device is disposed around the slave devices 3, which is not capable of joining in the transmission of time information by using the peculiar transmission route but is capable of receiving generic time information such as the standard wave signal, the measurement time of the device can be corrected. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wireless communication system that sequentially transmits time information in a system to correct the time, and a wireless communication apparatus having a timekeeping function used for the wireless communication system.

  A wireless type in which the parent clock transmits the reference time information wirelessly, and the child clocks arranged around the base clock receive this and correct the time based on the reference time information of the parent clock to match the time of the parent clock. Is known (Patent Document 1).

JP 2002-148371 A

  In the parent-child clock system described in Patent Document 1, since time information is transferred in a relay manner in the system, a wireless communication system can be installed in a relatively large site or a complex building. The position can be selected or changed relatively freely. However, since the parent-child clock system of Patent Document 1 is configured to transmit time information in a relay manner between child clocks in the system, a child clock that cannot enter a route for transmitting time information in a relay manner is included in the system. Can not be placed in. For this reason, there is a limit to the number of devices constituting the system. In addition, there is a problem that it is difficult to redo the transmission of the time information again when the transmission of the time information fails when transmitting the time information in a relay manner.

  Although Patent Document 1 is mainly conscious of a “clock” as a component of a parent-child clock system, the same problem is caused by time from other devices regardless of whether or not the time measurement and display are the main functions. Various electronic devices (for example, information processing terminals (PDA (Personal Data Assistance), notebooks, etc.) having a clocking function that receives information and corrects its clocking time while transmitting its clocking time PC, laptop PC, handy terminal), wireless tag, IC tag, wireless IC tag, IC chip, game machine, audio equipment, etc.).

The present invention has been made to solve the above-described problems of the prior art. A device that cannot enter a route for transmitting time information in a relay manner is arranged in the system, and an accurate time is set. It is an object of the present invention to provide a radio communication system capable of timing and a device used therefor.
The present invention also provides a wireless communication system having a timekeeping function capable of acquiring accurate time information in a relatively short time and correcting the timekeeping time even when transmission of time information fails, and the wireless communication system. An object is to provide a wireless communication device to be used.

In order to achieve the above object, a wireless communication system of the present invention includes:
A wireless communication system including a parent device that wirelessly transmits time information and a child device that receives time information from the parent device and corrects the time of its own time measuring means,
The parent device includes wireless transmission means for wirelessly transmitting time information,
The child device is
Timekeeping means,
Receiving means for receiving time information wirelessly;
Correction means for correcting the time measured by the time measuring means based on the received time information;
Data processing means for executing predetermined data processing based on the time measured by the time measuring means;
Based on the corrected time of the time measuring means, time information for correcting the time of another child device is created, and rank information for distinguishing from the time information received by the receiving means is attached to the time information. Transmitting means for transmitting to a lower rank child device in the system;
Broadcast means for broadcasting the time information at a predetermined time, and
The frequency of transmission of the broadcast signal by the broadcasting means is higher than the frequency of transmission of time information by the transmitting means,
It is characterized by that.

  The broadcasting means broadcasts, for example, time information of the same modulation method at the same frequency as the long wave standard radio wave, and time signal information of the same modulation method at the same frequency as a predetermined time signal broadcasted on a television or radio. Features.

  The broadcast means broadcasts, for example, the minimum information necessary for time correction.

  For example, the communication speed when the broadcasting means transmits time information by broadcast is set to be slower than the communication speed of time information by the transmitting means.

  For example, the transmission unit transmits the time information using a carrier wave having a first frequency, and the broadcasting unit performs broadcast transmission using a carrier wave having a second frequency different from the first frequency. In this way, interference can be prevented.

  For example, the slave device includes a wireless tag or an information terminal that transmits its own identification information together with time information.

  The slave device is composed of, for example, a radio tag provided with data storage means and sealed with resin. In this case, the data processing means stores time information indicating the time measured by the time measuring means in the data storage means in response to a predetermined trigger signal, and the time information stored in the data storage means is directly or data processed. And output to the outside wirelessly.

A wireless communication apparatus according to the second aspect of the present invention is
An identification information storage unit for storing identification information for identifying itself;
Timekeeping means,
Data processing means for executing predetermined data processing based on the time measured by the time measuring means;
Time information receiving means for wirelessly receiving time information with rank information transmitted from other devices ranked higher than the self; and
Correction means for correcting the time measured by the time measuring means based on the time information received by the time information receiving means;
Based on the time measured by the time measuring means, the time information for creating time information for correcting the time measured by the other device at a predetermined timing and distinguishing it from the time information received by the receiving means is the time. A transmission means for attaching to the information and transmitting it to another device having a lower rank than itself;
Broadcast means for broadcasting the time information for specifying the time at a frequency higher than the transmission frequency of the transmission means based on the time measured by the time measurement means;
It is characterized by comprising.

  With the above configuration, the present invention can sequentially transmit time information from the parent device to the upper child device and from the child device to the lower child device. On the other hand, since each child device transmits time information by broadcast transmission at a high frequency, even a device that does not belong to the sequential transmission route can correct the time by the time information transmitted by broadcast. Even when the time information transmitted via the transmission route cannot be received, it can be used for time correction using the broadcast time information. Furthermore, the time information can be transmitted to a reception-only device or another device that does not constitute the wireless communication system.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)

FIG. 1 shows a schematic configuration of a wireless communication system 1 according to a first embodiment of the present invention.
The wireless communication system 1 includes a parent device 2, a plurality of child devices 3, a repeater 4, and a reception-only child device 5.
In FIG. 1, the plurality of child devices 3 include a plurality of first rank child devices 3A1 and 3A2, a plurality of second rank child devices 3B1 and 3B2, a plurality of third rank child devices 3C1, 3C2, and 3C3. Including.
The repeater 4 includes repeaters 41 and 42.
The reception-only child device 5 does not receive the time information transmitted in a relay manner, but includes dedicated child devices 5A, 5B, 5C, 5D, 5E, and 5F that receive the broadcast-transmitted time information.

  Between the parent device 2 and the first rank child devices 3A1 and 3A2, between the first rank child device 3A1 and the second rank child device 3B1, between the first rank child device 3A2 and the second rank child device 3B2. Between the second rank child device 3B1 and the third rank child device 3C1, between the second rank child device 3B2 and the repeater 41, the second rank child device 3B2 and the third rank child device 3C2, and Between the 3C3 and between the slave device 3C3 of the third rank and the repeater 42 are connected so as to be capable of bidirectional communication with radio waves having a predetermined output and a predetermined frequency. Therefore, in the wireless communication system 1, various information including time information is bidirectionally transmitted in a relay manner. The output (power) and frequency of the radio waves are selected so that they do not require a license or permission under legal regulations. The radio waves may have the same frequency.

  Further, between the second rank child device 3B1 and the reception-only child devices 5A and 5B in FIG. 1, between the third rank child device 3C1 and the reception-only child device 5C, and between the repeater 41 and the reception-only child device 5D. Between the repeater 42 and the reception-only child devices 5E and 5F, time information necessary for time correction is broadcasted only in the direction toward the reception-only child devices 5A, 5B, 5C, 5D, 5E, and 5F. The frequency of the carrier wave for the broadcast transmission may be the same as the frequency of the carrier wave for transmitting the time information transmitted in the relay system in the wireless communication system 1 or may be different to completely avoid interference. Good. In addition, the communication speed obtained by modulating the time information transmitted by broadcast is slower than the communication speed obtained by modulating various information transmitted by relay transmission in the wireless communication system 1. By reducing the communication speed, a high-speed response is not required for the reception-only slave devices 5A, 5B, 5C, 5D, 5E, and 5F, and an inexpensive receiver can be used. Furthermore, the information transmitted by broadcast is limited to the information necessary for the time adjustment by the reception-only slave devices 5A, 5B, 5C, 5D, 5E, and 5F, thereby saving power when transmitting.

  The parent device 2 has the configuration shown in the block diagram of FIG. That is, the parent device 2 receives an external standard time information radio wave (broadcast time signal, long wave standard radio wave or global time system (GPS) time information, etc.) by the antenna 20 and the receiver 21 and receives the decoder 22. To set the time code of the standard time information. Not limited to this, the parent device 2 may receive the standard time information via a telephone such as a telephone JJY or a dedicated line.

The time for the parent device 2 to receive the standard time information from the outside can be controlled in a predetermined time zone by the identification number storage unit 27 that controls the power supply control unit 29 that supplies power to the receiver 21. The time code of the received standard time information is sent to the time correction unit 23 via the decoder 22. Then, based on the time code of the standard time information, the time correction unit 23 creates correction information for correcting the time measured by the time measuring unit 24 so as to match the standard time, and sends the correction information to the time measuring unit 24. The timer unit 24 corrects the time display of the time display unit 25 by correcting its own time so as to match the standard time.
In addition, the time measuring unit 24 transmits time information for transmitting to the child device 3 and correcting the time of the child device 3 to the encoder 26. The encoder 26 receives data for identifying the information from the parent device 2 from the identification number storage unit 27, attaches this to the time information, and sends the reference time information to the generator and the transmitter 28.

  The transmitter 28 is supplied with power from the power supply control unit 29 at a predetermined time when the parent device 2 transmits the reference time information. Then, the transmitter 28 transmits the encoded reference time information of the encoder 26 to the slave device 3 in the wireless communication system 1 with a predetermined frequency and output carrier wave via the antenna 20.

  As will be described later, the parent device 2 transmits information that conveys the state from each child device (except for the reception-only child devices 5A, 5B, 5C, 5D, 5E, and 5F) in the wireless communication system 1 to the antenna 20 and The information is received by the receiver 21, the information is identified from each child device 3 by the decoder 22, and the state of each child device 3 is displayed on the display unit 19. Abnormality in status data from each slave device (excluding reception-only slave devices 5A, 5B, 5C, 5D, 5E, and 5F) in the wireless communication system 1, such as inability to decode time information, unsuccessful reception, etc. , The administrator of the wireless communication system 1 can know this by viewing the display unit 19. Similarly, various information uploaded from each child device 3, for example, an identification number, a pair of identification number and data acquired or generated by the child device 3, and the like can be checked.

  The radio wave transmitted by the parent device 2 and the radio wave transmitted by each child device 3 may have the same frequency. However, transmission is performed by shifting the time so that the transmission times of the parent device 2 and the child device 3 do not match, thereby avoiding interference. Instead of this, interference may be avoided by setting the radio wave transmitted by the parent device 2 and the radio wave transmitted by each child device to different frequencies.

  The power supply control unit 29 follows the current time supplied from the time measuring unit 24 and the identification number supplied from the identification number storage unit 27 identifying the parent device 2, and the transmission time of the reference time information and the child device 3. Only during radio wave reception time, power is sent to the transmitter 28, the receiver 21, and other necessary circuits to save power consumption.

  The slave devices 3A1, 3A2, 3B1, 3B2, 3C1, 3C2, 3C3 shown in FIG. 1 are constituted by so-called wireless IC tags, for example, and as shown in FIG. 3, a communication circuit 301, a timer circuit 302, and a memory 303 and a processor 304, which are enclosed in a package 305.

The communication circuit 301 performs wireless communication with other devices.
The timer circuit 302 counts the current time.
The memory 303 stores an operation program of the processor 304 and an individual identification number and identification information (ID) of the child device 3. Also, it functions as a work area for the processor 304.

  The processor 304 performs various data processing according to the function of the wireless IC tag. For example, the processor 304 includes the identification information (ID) in the transmission information, for example, in the uplink for transmitting information from the lower rank apparatus to the upper rank apparatus. As a result, the identification information is transmitted to the parent device 2 in a relay manner, and the parent device 2 can confirm the presence / absence of the child device 3, for example, can confirm the presence of an article attached with a wireless IC tag. For example, if the wireless IC tag is a data logger such as a thermometer, the processor 304 includes the data history such as the temperature history obtained at a predetermined time interval in the transmission information at the time of uplink together with the identification information. These pieces of information are also transmitted to the parent device 2, and the parent device 2 can check the temperature history of each device. Similarly, output data of various sensors (humidity sensor, pressure sensor, gas meter, water meter, power meter) (not shown) are collected and stored in association with the time measured by the timer circuit 302. And wirelessly transmitted through the communication circuit 301 together with the identification information. When the processor 304 receives an inquiry command addressed to itself from the outside via the communication circuit 301, the processor 304 transmits a response signal including its own identification information (ID) via the communication circuit 301. In addition, when the inquiry command is received, identification information of the issuer of the inquiry command is recorded in the memory 303, and when a predetermined read command is received, the history information stored in the memory 303 is transmitted via the communication circuit 301. You may make it transmit to an external device.

  Further, the processor 304 is time correction information (information for correcting the time measured by the timer circuit 302 from the parent device 2 or the child device 3 higher than the self device 2 via the communication circuit 301. Are called reference time information and those from the child device 3 are referred to as reference time information), and the time measured by the timer circuit 302 is corrected based on the time information included in the received time correction information. A response signal or the like is transmitted via the communication circuit 301 at the next uplink.

  In addition, the processor 304 broadcasts time information as appropriate for the reception-only slave device 5 (5A to 5E) shown in FIG. 1 (for example, an unspecified number of reception-only signals that can receive radio waves without specifying the other party). (Transmission to transmit time information directly to the slave device 5).

  The package 305 is formed of a radio wave-transmitting resin material in a rectangular parallelepiped or cubic shape having, for example, several centimeters to several millimeters, and encloses the entire package 305 while enabling communication with the outside through the communication circuit 301.

  It is to be noted that information for correcting the frequency band of a radio signal (radio wave) used for transmission / reception of a command and a response signal for executing data processing originally scheduled by the radio communication system 1 and the time measurement time of the timer circuit 302 and its The frequency band of the radio signal used for response transmission / reception can be the same even in another band that can be sufficiently separated by the communication circuit 301.

Next, with reference to FIG. 4, details of the configuration of the main functions of each of the child devices 3A1 to 3C3 shown in FIG. 3 will be described by taking the child device 3A that directly receives the reference time information from the parent device 2 as an example. .
Each child device 3 has the same configuration, and can communicate bidirectionally with the parent device 2 and the other child devices 3 by the antenna 30, the receiver 31, and the transmitter 38.

  The slave device 3 includes a broadcast transmission antenna 40 and a transmitter 41, and can broadcast time information to the reception-only slave devices 5 (5A, 5B, 5C, 5D, 5E, and 5F). The frequency of the carrier wave for broadcast transmission output from the transmitter 41 is the same as the frequency of the carrier wave output from the transmitter 38 for transmitting information in a relay manner in the wireless communication system 1 or May be different to avoid completely. The communication speed obtained by modulating the time information for broadcast transmission output from the transmitter 41 is set slower than the communication speed obtained by modulating the information transmitted by the relay transmission in the wireless communication system 1 by the transmitter 38. As a result, an inexpensive receiver can be used as the reception-only slave devices 5A, 5B, 5C, 5D, 5E, and 5F. Furthermore, the information broadcasted by the transmitter 41 is limited to the information necessary for the time correction by the reception-only slave devices 5A, 5B, 5C, 5D, 5E, and 5F supplied from the time information generation unit 43. The power saving when the slave device 3 transmits may be achieved. Then, the slave device 3 controls the power supply time to the transmitter 41 by the time measuring unit 34, the individual identification number storage unit 37, and the power supply control unit 42 so that the transmitter 41 performs broadcast transmission at the time of broadcast transmission described later. To do.

The configuration of the child device 3 in FIG. 4 will be described by taking the first rank device 3A1 as an example.
The slave device 3 receives the radio information including the reference time information from the master device 2 by the antenna 30 and the receiver 31, converts the time information by the decoder 32, and sends the time code to the time correction unit 33. Further, the decoder 32 decodes the information indicating that it has been sent from the parent device 2 and sends it to the rank control unit 35. The rank control unit 35 stops power supply from the power supply control unit 39 to the receiver 31 and other circuits, and stops reception for a predetermined time until reception of the next reference time information.

  When the decoder 32 cannot restore the time information sent from the parent device 2 (or another child device 3) to the time code, the time adjustment by the time adjustment unit 33 is stopped. Then, it instructs not to send the time information to other child devices. Then, at the time of uplink, the reception failure of the time information is notified to the parent device 2 wirelessly via the encoder 36, the transmitter 38 and the antenna 30. The notification of the child device sent to the parent device 2 is displayed on the display unit 19 of the parent device 2 and / or the administrator of the wireless communication system 1 or the management device via the transmitter 28 or the like of the parent device 2 Sent to. If the time information sent from the parent device 2 (or another child device) cannot be restored to the time code, the child device 3 receives only the child devices 5A, 5B, 5C, 5D, and 5E described later. 5F, the time information broadcast from the other child devices 3 is received by the receiver 31 instead, converted into the time code by the decoder 32, and the time correction unit 33 uses its own time measuring unit. The time 34 may be corrected. However, in this case, time information is not transmitted to other child devices.

  The time correction unit 33 creates correction information for correcting its own time based on the reference time information received from the parent device 2, corrects the time of the time measuring unit 34, and matches the time of the parent device 2. Then, based on the time of the time measuring unit 34, first rank reference time information for correcting the time of the second rank child device 3 B 1 is created and sent to the encoder 36. This reference time information of the first rank is transmitted at a predetermined transmission time of a child device 3A1 of the first rank described later. The reference time information of the first rank is time information of the time measuring unit 34 corresponding to a predetermined transmission time of the child device 3A1 of the first rank, which is different from the reference time information from the parent device 2 and is a time longer than that. This is later time information. The time of the time measuring unit 34 is also supplied to the time information generating unit 43 in order to transmit time information by broadcast transmission.

  The encoder 36 adds data for distinguishing from the reference time information of the parent device to the reference time information of the first rank. Based on the information from the decoder 32, the rank control unit 35 sends data indicating that the time information to be transmitted is the first rank reference time information to the encoder 36. In addition, the individual identification number storage unit 37 provides the encoder 36 with data for identifying the child device 3A from the other child devices 3 in the wireless communication system 1. The encoder 36 includes, in the first rank reference time information from the time measuring unit 34, data indicating that it is the first rank reference time information from the rank control unit 35, and a specific child from the individual identification number storage unit 37. The data indicating the device 3A is added and sent to the transmitter 38.

  The transmitter 38 transmits information to another child device via the antenna 30 at a predetermined transmission time. This predetermined transmission time is determined as will be described later, and does not overlap with the transmission time of the parent device 2 and other child devices 3 that use the same transmission frequency, thereby avoiding interference. The transmission time of each child device is the rank of the child device, that is, the first rank child device 3A that directly receives the reference time information from the parent device 2, and the first rank reference time from the first rank child device. The time is sequentially shifted in accordance with the second rank child device 3B that receives the information and the third rank child device 3C that receives the second rank reference time information from the second rank child device. ing. Furthermore, there are a plurality of child devices (for example, child devices 3A1 and 3A2 in the first rank, child devices 3B1 and 3B2 in the second rank, and child devices 3C1, 3C2, and 3C3 in the third rank) at the same rank. In order to obtain this, each child device is further subdivided according to the individual identification number of the child device, and is transmitted at the assigned transmission time.

  The power supply control unit 39 obtains its own rank from the rank control unit 35, obtains its own individual identification number from the individual identification number storage unit 37, and is assigned based on its own rank and individual identification number. Knowing that the time has been reached from the time measuring unit 34, power is supplied to the transmitter 38 and transmission is performed.

  The power supply control unit 39 starts supplying power to the receiver 31 during the transmission time of the time information from the parent device 2 and the child device of higher rank than its own rank, receives the time information, and receives the time information after the reception. Stop supplying power to Here, since the first child device 3A1 has the highest rank, the receiver 31 is operated during the transmission time of the parent device 2. As a result, power consumption for reception can be saved. In addition to this, the reception of the first or second rank reference time information transmitted by another child device is prevented, thereby preventing repeated correction of time and transmission of reference time information again.

  In addition, the child device 3 transmits information such as whether or not the time information has been successfully received to the parent device 2 at a predetermined uplink time. As will be described later, this predetermined uplink time is a time zone different from the time information transmission time, and a different time is allocated for each rank and for each individual identification number. When the power supply control unit 39 learns from the time measuring unit 34, the individual identification number storage unit 37, and the rank control unit 35 that the predetermined time has come, it receives information on its own individual identification number and time information. Transmitter 38 is used to transmit uplink information to parent device 2 including information indicating availability or ID (identification information) separate from the individual identification number, information generated or collected by child device 3, and the like. To supply power.

  Furthermore, the child device 3A is a subordinate rank child device, for example, whether or not the second rank child device 3B and the third rank child device 3C can receive the notification of the individual identification number and the reception of time information. When uplink information is transmitted to the parent device 2, radio waves are relayed. For this reason, the child device 3A supplies power to the receiver 31 during a time period when the child device of the lower rank transmits the reception status information to the parent device, and receives radio waves from the child device of the lower rank.

  The second rank child device 3B has the same configuration as the first child device 3A and performs a similar operation. The child device 3B of the second rank analyzes that the reference time information of the first rank from the child device 3A of the first rank is received by the decoder 32 and notifies the rank control unit 35 of the analysis. The rank control unit 35 identifies that it is a child device of the second rank, sends to the encoder 36 a decoder indicating that the time information transmitted by itself is the reference time information of the second rank, and further In order to perform reception and transmission at the reception time and transmission time assigned to the rank child devices, the power supply time is supplied to the receiver 31 and the transmitter 38 via the power supply control unit 39. After receiving the reference time information of the first rank, the receiver 31 stops receiving for a certain time until the reception time of the next reference time information of the first rank, and receives the time information transmitted by the child devices of other ranks. Prevent receiving.

  In the above description of the operation, the child device 3B of the second rank has been described as being in a state where it cannot receive the reference time information transmitted from the parent device 2, but when the reference time information from the parent device 2 can be received. Can operate as the first rank child device 3A, and the time information transmitted by itself can be used as the first rank reference time information. In this way, the child device is generally in a state where it can be received when the time information of the higher rank is transmitted, detects whether it can receive the time information of the higher rank, and the time information of the higher rank is obtained. If it can be received, it may be switched to reception of that rank.

  The time correction unit 33 corrects the time of its own clock unit 34 based on the reference time information of the first rank. Then, the second rank child device 3C sends second rank reference time information to be used for time correction to the encoder 36. The encoder 36 adds the individual identification number of the child device 3B from the individual identification number storage unit 37 to the time information and information indicating the second rank reference time information, and sends the information to the transmitter 38. The second rank reference time information transmitted by the second rank child device 3B is time information at the transmission time assigned by the second rank and the individual identification number as will be described later.

  The third rank child devices 3C1, 3C2, 3C3 perform the same configuration and operation as the first rank child device 3A and the second rank child device 3B. The repeaters 41 and 42 have basically the same configuration as the child devices 3A, 3B, and 3C of the respective ranks, and are provided with individual identification numbers as child devices. The repeaters 41 and 42 are the ranks of the third and fourth child devices, respectively. In addition, it is good also as what consists of a reception / transmission part for a simple radio wave repeater as a repeater.

  FIG. 1 shows the first rank child devices 3A1, 3A2 to the third rank child devices 3C1, 3C2, 3C3. However, more child devices are arranged and bidirectional communication is performed by radio waves in a relay manner. It can also be connected as possible.

  Each child device 3 has its own individual identification number in the individual identification number storage unit 37, but otherwise has the same configuration. When the rank control unit 35 receives reference time information from the parent device 2, the first rank When receiving the first rank reference time information from the first rank child apparatus 3A, the second rank child apparatus 3B or the second rank child apparatus 3B from the second rank child apparatus 3A When the reference time information is received, the slave device 3C of the third rank is automatically ranked. As a result, the child devices 3 can be exchanged.

  Next, with reference to FIG. 5, the configuration of the reception-only slave devices 5A, 5B, 5C, 5D, 5B, and 5F that receive time information only by broadcast transmission and correct the time will be described. FIG. 5 shows the reception-only slave device 5A as an example. The reception-only child device 5A receives the time information broadcast from the child device 3 through the antenna 50, and the decoder 52 restores the time code. As described above, since the time information broadcast from the slave device 3 is modulated at a relatively low communication speed, the receiver 51 and the decoder 52 can use a device with a low processing speed, and have an inexpensive configuration. be able to. If the acquisition of the time code is successful, the power control unit 55 is notified and the power supply to the receiver 51 is stopped. Then, the time correction unit 53 corrects the time of its own clock unit 54.

  When the time counting unit 54 reaches the broadcast transmission time of the slave device 3 after a predetermined time (for example, 24 hours later), the time counting unit 54 supplies power to the receiver 51 over a certain period of time via the power supply control unit 55 to obtain time information by broadcast transmission. Receive. However, if the time code is successfully restored from the reception time information, the power supply to the receiver 51 is stopped by the decoder 52 even within a certain time.

  Broadcast transmission by the slave device 3 is performed once a day, for example, for one hour from 2 am to 3 am simultaneously with the downlink for relay transmission of time information of the wireless communication system 1, for example. . With reference to FIG. 6, the method of broadcast transmission and downlink by the child device 3 in this case will be described.

  The power supply control unit 39 (processor 304) of the child device 3 periodically acquires time information (h) from the time measuring unit 34 (block S501). If it is the downlink time zone (h = 2) (block S502), the rank number r is acquired from the rank control unit 35 of the child device 3 (block S503). Then, the individual identification number n is acquired from the individual identification number storage unit 37 of the child device 3 (block S504). Next, the current time information, m minutes and s seconds (2:00:00 am immediately after the start of the downlink time) is acquired from the clock unit 34 (block S505). Next, it is determined whether m = r−1 (block S506). If the child device 3 is the first-rank child device 3A1, r = 1. Therefore, if the current time is m = 0 minutes, it is next determined whether or not s = n−1 (block S507). If the child device 3 is the first-rank child device 3A1, n = 1. Therefore, if the current time is s = 0 seconds, the time measuring unit 34 sends the time information, m minutes s sand, to the encoder 36 for encoding for the downlink, and rank information r, After encoding with the identification number n, it transmits from the transmitter 38 via the antenna 30 (block S508). Even if the slave device 3 is in the first rank (r = 1), in the case of the slave device 3A2, n = 2, s = 2−1 = 1, and s = 0 seconds (block S507). ), The process returns to block 501.

  In the case of the second rank (r = 2) child device (for example, 3A1, 3B2), the value of r−1 is 1 at 2:00:00 am, so the block S506 is changed to the block S509. go. For example, if the individual identification number of the child device 3B1 is n = 1, when s = 0 seconds (block 509), the child device 3B1 obtains the time information “m minutes s seconds” from the time measuring unit 34. The time information generator 43 encodes the data for broadcast transmission, sends it to the transmitter 41, and broadcasts from the transmitter 41 via the antenna 40 using a carrier wave having a frequency different from that of the downlink (block 510). The information transmitted by broadcast is limited to the minimum time information necessary for time adjustment, and is transmitted with modulation having a communication speed relatively lower than that of the downlink. For example, if the individual identification number of the child device 3B2 is n = 2, s = 2−1 = 1, and if s = 0 seconds (block 509), the process returns to block 501. Here, it is assumed that the downlink from the parent device 2 to the first rank child device 3 is performed at 1:59 am 0 second, one minute before 2:00 am. However, the present invention is not limited to this, and the above-described operation may be applied by setting the rank of the parent device 2 to 1 and increasing the number of racks of each child device 3 by one.

  Next, time allocation for downlink and broadcast transmission for transmitting time information for time adjustment between the parent device and the child device will be described with reference to FIG. FIG. 7 illustrates the case of a child device having the second rank (r = 2) and the individual identification number 3 (n = 3). Downlink and broadcast transmission is performed as described above, for example, once a day using 1 hour at 2am, but the time required for each child device 3 to receive and transmit time information is within that time. Assigned time, in this example 1 second. When the slave device 3 receives the time information for a while, the power of the receiver 31 can be turned off as described above, thereby preventing unnecessary power consumption. Subsequent reception of time information is not performed after the reception by the receiver is stopped, so that repeated time correction and transmission can be prevented. Each child device 3 has a higher rank among time information such as receivable reference time information, first rank reference time information, second rank reference time information, etc., that is, time information closer to the parent device 2. It is configured to receive with priority.

  Note that downlink and broadcast transmissions are not limited to once a day. If downlink and broadcast transmission are performed once every two to three hours, cumulative errors of devices in the system can be further suppressed. Some low-accuracy devices have a one-day error of about one second due to the influence of quality and temperature changes in the installation environment. In such a case, the downlink and broadcast transmissions once a day are not possible. Since there is a risk of deviating from the method of completing communication within one second of the system of this example, it is difficult to adopt it for the slave device. For this reason, if the system performs downlink 1 broadcast and broadcast transmission at intervals of once every 2 to 3 hours, the accumulated error of the devices in the system can be suppressed, and even a low-accuracy device can be adopted as a child device. System construction is possible at low cost.

  As shown in FIG. 7, time information of the first rank child device 3A in which 1 minute from 2:00 am to 2:01 am is rank 1 (r = 1), that is, reference time information of the first rank This is the downlink transmission time zone. This one-minute time zone is further subdivided into 60 time zones at 1-second intervals, and assigned in correspondence with the individual identification number (specific number between 1 and 60) of the first child device 3A. Downlink transmission is performed in 1 second of the specified time zone. In the downlink transmission time zone of the time information of the second rank child device 3B in which 1 minute from 2:01 to 2: 2 is rank 2 (r = 2), that is, the reference time information of the second rank is there. This one-minute time zone is further subdivided into 60 time zones at 1-second intervals, and assigned in correspondence with the individual identification number (specific number between 1 and 60) of the second rank child device 3B. The downlink transmission is performed for 1 second in the designated time zone. The downlink transmission time of the child device 3 with the individual identification number 3 (n = 3) is 1 second between 2: 1: 2 and 3 seconds. The same applies when there are child devices of the following ranks. In this way, even if radio waves having the same frequency are used, there is no interference.

  Next, the broadcast transmission time is performed for 1 second corresponding to the individual identification number other than the transmission time zone of its own rank. In the case of a child device having the second rank (r = 2) and the individual identification number 3 (n = 3), broadcast transmission is performed every 2 to 3 seconds at 2 o'clock except for 2: 1 o'clock. . If the frequency of the carrier wave for broadcast transmission is set to be different from the frequency of the carrier wave for downlink transmission, interference can be completely avoided. In a system in which ranks are dynamically allocated, it is necessary to allocate and identify individual identification numbers of each child device in the system in the range of 1 to 60 without duplication in order to facilitate management of transmission time zones. However, one child device may be specified by a combination of a rank and an individual identification number. In this case, the child devices of the same individual identification number of different ranks also perform broadcast transmission in the same time zone, but the child devices 3 of different ranks are separated from each other in distance, so that radio wave output for broadcast transmission is appropriately selected. Thus, interference is avoided.

  Next, referring to FIG. 8, the parent device 2 from the first to third rank child devices 3A, 3B, 3C (except for the reception-only child devices 5A, 5B, 5C, 5D, 5E, and 5F). Next, uplink time allocation for transmitting information indicating the reception status of each child device by radio wave will be described. The information of each child device 3 includes the individual identification number of the child device, the availability of reception of time information for time correction, the rank of the received time information (that is, the reference time information, the reference time information of the first and second ranks) And the individual identification number of the transmission source of the received time information. Further, the identification information (ID; separate from the individual identification number) of the child device 3 and information generated or collected by each child device 3 (for example, temperature / pressure / humidity history information, meter (gas meter, water meter) , Electric meter), etc. Uplink is performed once a day, for example, using 1 hour at 3am, but the time required for each child device to transmit information is The allocated time, which is 1 second in this example, can prevent wasteful power consumption, and the reception operation for relaying is started in each child device at the start of the uplink. The link collects information in the parent device, monitors the operation status of the entire system, uses it for maintenance work, and can change the position of the repeater or the position of the child device if necessary.

  As shown in FIG. 8, uplink transmission is started from a lower child device by the reverse of the downlink case. That is, one minute from 3 o'clock to 3 o'clock is a transmission time zone of information of a rank 60 child device. This 1-minute time zone is further subdivided into 60 time zones at 1-second intervals, and 1 of the time zones assigned to each individual identification number (specific number between 1 and 60) of the child device. Send in seconds. The radio waves transmitted by the slave device 3 are sequentially relayed by the host slave device 3 and sent to the master device 2.

  One minute from 3:57 to 3:58 is a transmission time zone of information of the repeater 41 and the slave devices 3C1, 3C2, and 3C3 having rank 3. This 1 minute time zone is further subdivided into 60 time zones at 1 second intervals as described above, and the repeater 41 and the slave devices 3C1, 3C2, 3C3 are assigned time corresponding to their own individual identification numbers. Transmission is performed in 1 second of the band. This information is received by the rank 2 child device 3B1 or 3B2, and added to the information of the child devices 3B1 and 3B2 and relayed when the child devices 3B1 and 3B2 are uplinked.

  One minute from 3:58 to 3:59 is a transmission time zone of information of the second rank child devices 3B1 and 3B2 having rank 2. This 1-minute time zone is further subdivided into 60 time zones at 1-second intervals as described above, and the child devices 3B1 and 3B2 are assigned their own individual identification numbers (specific numbers between 1 and 60). Transmission is performed in one second of the corresponding time zone. The umbilical reports of the second rank child devices 3B1 and 3B2 are received by the first rank child devices 3A1 and 3A2, added to the information of the child devices 3A1 and 3A2, relayed, and delivered to the parent device 2.

  The first child devices 3A1 and 3A2 which are the first ranks are directly connected to the parent device 2 during one second assigned corresponding to the individual identification number within one minute from 3:59 to 4:00. Send information to. In this way, even if radio waves having the same frequency are used, there is no interference.

  The parent device 2 receives the reception status information from all the child devices 3 at 4 o'clock, and the reception status information is displayed on the display unit 19. Based on the displayed reception status, it is possible to confirm whether each slave device has actually received time information and corrected the time and the propagation path. The reliability of the wireless communication system 1 can be increased by moving the wireless communication system.

  The reception status information transmitted from the child device 3 to the parent device 2 includes information (rank) indicating the reception status of time information, for example, as shown in FIG. 9A, according to the function of the child device 3. , Individual identification number, transmission source individual identification number, success / failure of reception, success / failure of correction, etc.) or as shown in FIGS. 9 (b) and 9 (c) Information obtained by processing / processing information may be included. The parent device 2 displays these pieces of information on the display unit 19 or outputs them as data.

  Note that time information broadcast transmission from each of the slave devices 3A, 3B, 3C, etc. may be performed in the same way as in the downlink at the time of uplink or instead of at the time of the downlink. Furthermore, the broadcast transmission may be performed several times a day at a predetermined time regardless of the downlink or uplink. Furthermore, the broadcast unit for broadcast transmission may be installed only in the slave device that performs broadcast transmission, or alternatively, it is installed as a standard in each of the slave devices 3A, 3B, 3C and the master device 2, and receives Broadcast transmission is performed for each child device 3A, 3B, 3C and parent device 2 via the wireless network of the wireless communication system 1 according to the installation status of the dedicated child devices 5A, 5B, 5C, 5D, 5E, and 5F. For this purpose, a separate switch unit that can switch the broadcast unit for activation or deactivation may be provided. Furthermore, the power supply control units 39 and 42 of the child device 3 described in the embodiment may be a single power supply control unit, and the encoder 36 and the time information generation unit 43 may be configured by a single device. The antennas 30 and 40 may be used in common.

  With this configuration, a time signal is transmitted from each child device 3 to the vicinity at a predetermined timing. Therefore, accurate time information can be transmitted to a general tag chip that does not have a function of participating in the relay route of time information.

(Modification)
For example, if the decoder 32 (processor 304) of the child device 3 cannot receive time information from the host device for a certain period or longer, the decoder 32 (the processor 304) changes the reception frequency of the receiver 31 and the like. A time signal transmitted by broadcast may be received and given to the time correction unit 33.
Note that the timing for performing broadcast transmission is arbitrary, and may be performed every hour or every time.

(Second Embodiment)
The time information generating unit 43 of the child device 3 illustrated in FIG. 4 is configured by, for example, a JJY encoder. The JJY encoder receives the current time from the time measuring unit 34 and encodes the current time by the same modulation method as the long wave standard radio wave (so-called long wave JJY) provided by the National Institute of Information and Communications Technology. Time information modulated into a so-called time code is generated. With such a configuration, the current time measured by the time measuring unit 34 can be broadcasted from the antenna 40 by radio waves having the same carrier frequency and the same modulation method as the long wave standard radio waves. As described above, the radio wave transmitted by the transmitter 41 is a low-power radio wave that is not subject to legal regulations and does not require a license.

  In this case, it is assumed that the slave device 3 and the reception-only slave device 5 are installed in a place where it is difficult to reach the longwave standard radio wave, but avoid as much as possible the interference between the broadcast time information and the actual longwave standard radio wave. Is preferred. There are two types of carrier waves for the long-wave standard radio wave: 40 kHz for the Otakado and Yama standard radio wave transmission stations in Fukushima Prefecture and 60 kHz for the Haganeyama standard radio wave transmission station in Saga Prefecture. Therefore, for example, by setting the frequency of the long wave standard radio wave on the side where electric field intensity is low in the area where the child device 3 is installed as the frequency of the carrier wave of the second time information of the transmitter 41, interference with the long wave standard radio wave is suppressed as much as possible. It is desirable. For example, in the eastern Japan region, the frequency of the carrier wave of the transmitter 41 is 60 kHz. In order to realize this, the frequency setting unit 61 can set the frequency of the carrier wave of the transmitter 41 to either 40 kHz or 60 kHz.

  Therefore, as shown in FIG. 10, the frequency setting unit 61 may be arranged in the slave device 3. The frequency setting unit 61 sets the frequency of the carrier wave by an input unit (not shown). For example, a dip switch or an input key may be provided as the input unit. Not limited to this, at the time of downlink, the time information transmitted from the parent device 2 to the child device 3 is transmitted with frequency identification information (information indicating which frequency of 40 kHz or 60 kHz is used), and the decoder The frequency setting information may be obtained at 32, and the frequency identification information may be input to the frequency setting unit 61 as shown by the broken line, thereby setting the frequency.

  As a result, a device (such as a clock or an IC tag) having an off-the-shelf time correction function that corrects the time using the long wave standard radio wave can be installed in the indoor facility where the long wave standard radio wave does not reach. Thus, it is possible to increase the number of devices (IC tags or the like) 3 that substantially constitute the wireless communication system.

  Further, as shown in FIG. 11, a frequency setting unit 62 indicated by a broken line is provided in the parent device 2, and the above-described frequency identification information is sent to the encoder 26, and the frequency identification information is attached to the first time information. You may make it transmit from the transmitter 28. FIG. The frequency setting unit 62 may be configured to be able to input frequency identification information for setting the frequency of the carrier by an input unit (not shown).

(Third embodiment)
The time information generated by the time information generator 43 is not limited to the same time signal as the long wave standard radio wave and the same frequency and modulation method. For example, the time information may be the same time signal as the FM or AM broadcast frequency band and modulation method. The time information encoded in the same manner as the time code of the long wave standard radio wave may be transmitted in the frequency band and modulation method of FM or AM broadcasting.

  In this case, for example, as illustrated in FIG. 12, the time information generation unit 43 includes a JJY encoder 431 and a time signal signal generation device 432. The time signal generator 432 receives the current time from the time measuring unit 5 and generates the same time signal as the FM or AM broadcast time signal from 0 minutes 10 seconds to 1 to 3 seconds per hour. The transmitter 41 is composed of a transmitter of a frequency band of FM or AM broadcasting and a modulation method. In the transmitter 41, for example, a predetermined frequency band and modulation scheme are set by an input unit (not shown). When the transmitter 41 is activated by the power supply control unit 42, the transmitter 41 modulates the time signal from the time signal generator 432 with a predetermined modulation method, and is in a predetermined frequency band and is not subject to legal restrictions and requires a license. It transmits from the antenna 40 with a low-power radio wave that does not. Further, the JJY encoder 431 does not generate a time code for one minute, for example, before and after the time signal signal generator 432 generates a time signal, but generates a time code in other time zones, and the transmitter 41 The time code from the JJY encoder 431 is modulated by a predetermined modulation method, and is transmitted from the antenna 40 by a low-power radio wave in a predetermined frequency band that is not subject to legal regulations and does not require a license.

  In the present embodiment, the radio wave correction device that corrects the time by the time signal of the frequency band of FM or AM broadcast and the modulation method, and the radio wave correction that corrects the time by the time code of the frequency band of FM or AM broadcast and the modulation method. The second time information can be supplied to the device, and two different types of radio wave correction devices can coexist.

  Furthermore, the transmitter 41 of the slave device includes an interface 41K that outputs a signal sent to the antenna 40 to a wiring 41J such as a power line and a dedicated line. If necessary, the transmitter 41 has a radio wave connection to the slave device 3 having a wired connection function. It is possible to supply time information to the correction device by wire through the wiring 41J or by electromagnetic radiation from the antenna 40. For this reason, it becomes possible to supply time information to a wide range of radio wave correction devices within the range of low-power radio that is not subject to legal regulations and does not require a license.

(Fourth embodiment)
In the first to third embodiments described above, the slave device 3 is provided with the broadcast transmission unit. However, the parent device 2 or the parent device 2 may be provided with the broadcast transmission unit. In this case, for example, as shown in FIG. 13, the parent device 2 is provided with a broadcast antenna 40, a transmitter 41, a power supply control unit 42, a time information generation unit 43, a frequency setting unit 61, and the like, similar to the child device. Deploy. These operations are the same as those described with respect to the child device 3.

In the above embodiment, the wireless IC tag is shown as the slave device 3. However, the present invention is applicable to any other electronic device having a wireless communication function.
For example, as shown in FIG. 14, a wireless device 6 (PDA, portable wireless device, notebook computer, laptop computer) having a communication circuit 601, a timer circuit 602, a memory 603, an input unit 604, a display unit 605, and a processor 606 Etc.), etc., and can be applied to various devices that do not mainly use timekeeping and timekeeping time.

Further, the medium for wireless communication between apparatuses is not limited to radio waves, and may be light or ultrasonic waves.
Furthermore, the number of slave devices constituting one wireless system, the width (period) of each channel when performing time division communication, the time required for uplink and downlink, etc. are also arbitrary, and the number of slave devices and channel detection It can be set as appropriate in consideration of the accuracy of the network and the period of time available for the downlink and uplink. Further, for example, the parent device 2 transmits the reference time information at any timing in the rank 1 transmission time zone in FIG. 5, and the rank 1 to 59 in the transmission time zones in rank 2 to 60 in FIG. 5, respectively. The child device 3 may transmit the reference time information. Furthermore, the individual identification number does not need to be a number that is numeric information, and may be identification information for distinguishing each other. The setting method of rank (hierarchy order, transmission order) is also arbitrary.

  In the above embodiment, in order to facilitate understanding, each slave device 3 is a receiver that is always on to receive commands and instructions generated at an arbitrary timing, separately from the receiver 21. However, it is also possible to use the same receiver for downlink and uplink and for receiving commands. In this case, it is only necessary to tune and receive only the command signal after the rank control unit 35 outputs the rank information at the downlink or after the transmission is completed at the uplink. .

  In addition, it is arbitrary what kind of processing is performed in the wireless communication system 1, the slave device 3, and the reception-only slave device 5 using a timekeeping unit maintained at an accurate value. For example, if the child device 3 is a thermometer, for example, every time a predetermined time is measured, the measurement data of the temperature sensor is read and stored in the memory to obtain a temperature history at predetermined time intervals, If the child device 3 is a game machine such as a slot machine, for example, a history of coins inserted and discharged at predetermined time intervals can be obtained. In addition, for example, when there is a predetermined instruction / request from the outside (when the first trigger occurs), the requested processing is executed and the execution time is recorded together with the processing content, and the uplink is performed. The stored time information and processing contents may be wirelessly transmitted or output at the time or when there is an instruction / request from the outside (when the second trigger occurs). For example, if the child device 3 is a gas meter, the time is transmitted together with the usage amount data in response to a wireless request from the meter reading terminal, and the transmission information is recorded together with the ID of the requesting meter reading terminal. A history may be taken. For example, the timekeeping time is corrected, and the information collected in the uplink processing is transmitted.

  In addition, the hardware configuration and operation described above can be arbitrarily changed as long as equivalent functions can be realized. For example, the portion described as “storage unit” such as the individual identification information storage unit may be configured to record and store individual identification information in a semiconductor memory or a magnetic storage device, while a dip switch or the like It may be configured to continue to output predetermined data according to the setting.

The block diagram of the radio | wireless communications system (time information transmission system) which concerns on the 1st Embodiment of this invention. FIG. 2 is a block diagram of the parent device shown in FIG. 1. FIG. 2 is a block diagram of the child device shown in FIG. 1. The block diagram centering on the transmission / reception part of the subunit | mobile_unit shown in FIG. FIG. 2 is a block diagram of the reception-only child device shown in FIG. 1. 6 is a flowchart illustrating a method of downlink transmission and broadcast transmission of the wireless communication system according to the embodiment. The time chart which shows time allocation of the downlink transmission of the time information for time correction of the radio | wireless communications system by embodiment, and broadcast transmission. The time chart which shows the time allocation at the time of the uplink of the information of the child apparatus of the radio | wireless communications system by embodiment. It is a figure which shows the structural example of the reception status information transmitted at the time of an uplink. The block diagram of the subunit | mobile_unit which concerns on 2nd Embodiment. The block diagram of the parent apparatus which concerns on 2nd Embodiment. The block diagram centering on the transmission / reception part of the subunit | mobile_unit which concerns on 3rd Embodiment. The block diagram of the parent apparatus which concerns on 4th Embodiment. The figure which shows the other structural example of a subunit | mobile_unit.

Explanation of symbols

1 wireless communication system 2 parent device 3 (3A1, 3A2, 3B1, 3B2, 3C1, 3C2, 3C3) child device (wireless IC tag)
4 Repeater 5 Receive-only slave device

Claims (8)

A wireless communication system including a parent device that wirelessly transmits time information and a child device that receives the time information from the parent device and corrects the time of its own clock means,
The parent device includes wireless transmission means for wirelessly transmitting time information,
The child device is
Timekeeping means,
Receiving means for receiving time information wirelessly;
Correction means for correcting the time measured by the time measuring means based on the received time information;
Data processing means for executing predetermined data processing based on the time measured by the time measuring means;
Based on the corrected time of the time measuring means, time information for correcting the time of another child device is created, and rank information for distinguishing from the time information received by the receiving means is attached to the time information. Transmitting means for transmitting to a lower rank child device in the system;
Broadcast means for broadcasting the time information at a predetermined time, and
The frequency of transmission of the broadcast signal by the broadcasting means is higher than the frequency of transmission of time information by the transmitting means,
A wireless communication system.   2. The broadcast means broadcasts time information of the same modulation method at the same frequency as a long wave standard radio wave or a time signal information of the same modulation method at the same frequency as a predetermined time signal. Wireless communication system.   The wireless communication system according to claim 1, wherein the broadcasting unit broadcasts information necessary for time correction.   4. The radio according to claim 1, wherein a communication speed at which the broadcasting unit broadcasts time information is set to be slower than a communication speed of time information by the transmitting unit. 5. Communications system. The transmission means transmits the time information using a carrier wave having a first frequency,
The broadcast means performs broadcast transmission using a carrier wave having a second frequency different from the first frequency.
The wireless communication system according to claim 1, wherein the wireless communication system is a wireless communication system.   The wireless communication system according to claim 1, wherein the slave device is configured by a wireless tag or an information terminal.   The slave device is composed of a wireless tag having a data storage means and a package, and the data processing means responds to a predetermined trigger signal to the timekeeping information indicating the timekeeping time of the timekeeping means in the data storage means. Means for storing and processing the time information stored in the data storage means directly or by data and outputting the information to the outside wirelessly, and the package is made of a material capable of transmitting wireless signals and encloses the whole. The wireless communication system according to claim 1, wherein: An identification information storage unit for storing identification information for identifying itself;
Timekeeping means,
Data processing means for executing predetermined data processing based on the time measured by the time measuring means;
Time information receiving means for wirelessly receiving time information with rank information transmitted from other devices ranked higher than the self; and
Correction means for correcting the time measured by the time measuring means based on the time information received by the time information receiving means;
Based on the time measured by the time measuring means, the time information for creating time information for correcting the time measured by the other device at a predetermined timing and distinguishing it from the time information received by the receiving means is the time. A transmission means for attaching to the information and transmitting it to another device having a lower rank than itself;
Broadcast means for broadcasting the time information for specifying the time at a frequency higher than the transmission frequency of the transmission means based on the time measured by the time measurement means;
A wireless communication device having a timekeeping function.

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