JP6922371B2 - Wireless communication system - Google Patents

Description

The present invention relates to a wireless communication system.

It has a wireless communication system consisting of a master unit that is a wireless terminal and a plurality of slave units having a multi-stage configuration, and a center device. There is a meter reading system that collects data (Patent Document 1).

In this meter reading system, the center device and the master unit communicate with each other via a wireless or wired public line, and are composed of "master unit-1st stage slave unit-2nd stage slave unit -...- Nth stage slave unit". The wireless communication in the wireless communication system is operated by selecting one wireless channel from a plurality of wireless channels provided in a predetermined frequency band of the specific low power radio. Further, when a plurality of wireless communication systems are adjacent to each other, the wireless channels used for each wireless communication system are different so as to prevent interference.

In addition, if the communication success rate on the wireless channel used decreases due to the influence of noise or jamming radio waves, there is no such influence by direct operation of the terminal at the installation site or remote instruction from the center device. There is also an operation of changing to a wireless channel to stabilize communication quality.

Here, the remote instruction from the center device is executed according to the following procedures (i) to (iii) so that the change of the wireless channel does not affect the wireless communication between the terminals whose wireless channel has not been changed thereafter.
(i) Change the wireless channel of the slave unit at the end of the wireless communication system (the bottom of the multi-stage configuration) one by one.
(ii) When the change of the wireless channel of all the terminal slave units is completed, the wireless channel of the slave unit one step higher is changed one by one.
(iii) Repeat the change of the wireless channel of all the upper slave units one step at a time, and when the change of the wireless channel of all the slave units is completed, finally change the wireless channel of the master unit and complete the change of the wireless channel. Let me.

Japanese Unexamined Patent Publication No. 2010-87761

However, direct operation of the terminal at the installation site requires going to the location of the slave unit installed over a wide area, resulting in poor work efficiency. In addition, there is a problem in terms of safety when it is installed in a high place.

On the other hand, the remote instruction from the center device does not need to go to the installation site, so there is no problem like the terminal operation at the site. However, since it is necessary to change the wireless channel one by one from the terminal terminals in the wireless communication system, it takes communication time for the number of communication times for the number of communication times until the change of the wireless channel of all the terminals is completed. In addition, if there is a handset that fails to change the wireless channel, direct operation on site is required.

The present invention has been made to solve such a problem, and an object thereof is composed of a master unit which is a wireless terminal and a plurality of slave units having a multi-stage configuration, and meter reading data of each slave unit is transmitted via a higher terminal. In a wireless communication system capable of transmitting data to the center device, the time required to change the wireless channel by a remote instruction from the center device is shortened.

The present invention comprises a base unit and a plurality of slave machines multistage a wireless terminal, the meter reading data for each child device a wireless communication system capable of transmitting to the center apparatus via the upper terminal, the radio channel change target terminal the higher level terminals of the machine, in accordance with an instruction from the center device, and broadcasts a radio channel change instruction, and relays wireless channel change response from the respect to the broadcast transmission radio channel change target handset to the center apparatus, wherein radio channel change target slave unit, depending on the radio channel change instruction from the host terminal, to the upper terminal, transmitting the radio channel change response, changes the own terminal radio channel, the radio channel change The higher-level terminal of the failed slave unit receives the wireless channel change instruction from the center device for the slave unit on the changed wireless channel, and based on the received wireless channel change instruction, sends the slave unit on the wireless channel before the change. It is a wireless communication system that transmits.

According to the present invention, in a wireless communication system including a master unit which is a wireless terminal and a plurality of slave units having a multi-stage configuration and capable of transmitting meter reading data of each slave unit to a center device via a higher-level terminal, a wireless channel is set as a center device. It is possible to shorten the time required for changing by remote instruction from.

It is a figure which shows the meter reading system including the wireless communication system which concerns on embodiment of this invention. It is a block diagram which shows the schematic structure of the slave unit in FIG. It is a block diagram which shows the schematic structure of the master unit in FIG. It is a block diagram which shows the schematic structure of the center apparatus in FIG. It is a sequence diagram which shows the radio channel change procedure in the meter reading system shown in FIG. It is a figure which shows the outline of the telegram which the meter reading system shown in FIG. 1 is used in a radio channel change procedure. It is a figure which shows the state which the isolated terminal which failed to change a radio channel exists in the meter reading system shown in FIG. It is a sequence diagram which shows the recovery procedure of the isolated terminal in the meter reading system shown in FIG. It is a figure which shows the outline of the telegram which the meter reading system shown in FIG. 1 is used in the recovery procedure of an isolated terminal. It is a figure which shows the communication route which transmits the meter reading data of a slave unit via a plurality of wireless communication systems with different wireless channels. It is a figure which shows the outline of the telegram transmitted by the communication route shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<Structure of meter reading system>
FIG. 1 is a diagram showing a meter reading system including a wireless communication system according to an embodiment of the present invention.
This wireless communication system is used, for example, in a meter reading system for gas and water meters, and is a plurality of (here, eight) slave units 40a to which are wireless terminals provided in each meter reading device (meter, etc.). It is composed of a master unit 30 that manages the slave units 40a to 40h as subordinate slave units and relays meter reading data from the slave units 40a to 40h to the center device 10. The master unit 30 is connected to the center device 10 via a public communication line 20 such as a mobile phone line. In the following description, when the slave units 40a to 40h are not distinguished, the slave unit 40 is used.

The master unit 30 can communicate with the slave unit 40 by the specific low power radio, and the slave units 40 can also communicate with each other by the specific low power radio. Further, the slave unit 40 transmits the meter reading data to the center device 10 via the master unit 30, and the multi-stage configuration (here, the three-stage configuration) enables more meter reading data to be collected.

In the present embodiment, the slave units 40a and 40b are connected to the first stage of the number of relay stages, that is, directly below the master unit 30. Further, in the second stage of the number of relay stages, the slave units 40c and 40d are connected directly under the slave unit 40a, and the slave units 40d and 40e are connected directly under the slave unit 40b. Further, in the third stage of the number of relay stages, the slave units 40f and 40g are connected directly under the slave unit 40c, the slave unit 40g is connected directly under the slave unit 40d, and the slave unit 40h is directly under the slave unit 40e. It is connected. Moreover, the radio channel of all terminals is set to channel 1 (Ch1 in the drawing).

Here, in each terminal (slave unit 40), the higher-level terminal is registered as a communication route. That is, for example, the slave unit 40c is registered in the slave unit 40f, the slave unit 40a is registered in the slave unit 40c, and the master unit 30 is registered in the slave unit 40a as a higher-level terminal (communication route). The meter reading data of the slave unit 40f is sequentially relayed by the slave unit 40c, the slave unit 40a, and the master unit 30 which are the communication routes, and is notified to the center device 10. Further, various instructions from the center device 10 are also notified to the slave unit 40f via this communication route.

<Structure of slave unit>
FIG. 2 is a block diagram showing a schematic configuration of the slave unit 40 in FIG.
As shown in the figure, the slave units 40 (40a to 40h) include a control unit 41, a wireless transmission / reception unit 42, a storage unit 43, an external I / F (interface) unit 44, and a display unit, each of which is connected to the control unit 41. It is composed of 45 and an operation input unit 46, and an antenna 47 is connected to the wireless transmission / reception unit 42.

The control unit 41 is composed of, for example, a microprocessor and peripheral circuits thereof, and controls the entire slave unit 40, performs arithmetic processing, and the like. The wireless transmission / reception unit 42 performs wireless communication with another slave unit 40 and the master unit 30 by a specific low power radio. The storage unit 43 includes a non-volatile memory such as a ROM, a rewritable non-volatile memory such as a flash memory, and a volatile memory such as a RAM. The ROM stores a control program and a wireless channel change program necessary for operating the slave unit 40. Further, the RAM stores each program being executed by the control unit 41 and information necessary for executing the program, for example, a communication information table (ID of a higher terminal, wireless channel, electric field strength, number of relay stages, etc.). In addition, various setting data and the like are stored in the rewritable non-volatile memory. An external device such as a meter for gas or water is connected to the external I / F unit 44. The display unit 45 is composed of LEDs and the like, and is a user I / F that displays the operating state and the like of the slave unit 40. The operation input unit 46 includes buttons, switches, and the like, and is a user I / F for inputting a predetermined setting for the slave unit 40. The antenna 47 transmits and receives radio waves.

<Configuration of master unit>
FIG. 3 is a block diagram showing a schematic configuration of the master unit 30 in FIG.
The master unit 30 includes a control unit 31, a storage unit 32 connected to the control unit 31, a wireless transmission / reception unit 33, a network control unit 34, a display unit 35, and an operation input unit 36.

The control unit 31 is composed of, for example, a microprocessor and peripheral circuits thereof, and controls the entire master unit 30 and performs arithmetic processing and the like. The storage unit 32 includes a non-volatile memory such as a ROM, a rewritable non-volatile memory such as a flash memory, and a volatile memory such as a RAM. The ROM stores a control program and a wireless channel change program necessary for operating the master unit 30. In addition, each program being executed by the control unit 31 and information necessary for executing the program are stored in the RAM. In addition, various setting data and the like are stored in the rewritable non-volatile memory. The wireless transmission / reception unit 33 performs wireless communication with the slave unit 40 by the specified low power radio. The network control unit 34 communicates with the center device 10 via the public communication line 20. The display unit 35 is composed of LEDs and the like, and displays the operating state and the like of the master unit 30. The operation input unit 36 includes buttons, switches, and the like, and is a user I / F for inputting a predetermined setting for the master unit 30. The antenna 37 transmits and receives radio waves.

<Configuration of center device>
FIG. 4 is a block diagram showing a schematic configuration of the center device 10 in FIG.
The center device 10 includes a control unit 11, a network control unit 12, a storage unit 13, a display unit 14, and an operation input unit 15, each of which is connected to the control unit 11.

The control unit 11 is composed of, for example, a microprocessor and peripheral circuits thereof, and controls the entire center device 10 and performs arithmetic processing and the like.

The storage unit 13 includes a non-volatile memory such as a ROM, a rewritable non-volatile memory such as a flash memory or a hard disk, and a volatile memory such as a RAM. The ROM stores a control program and the like necessary for operating the center device 10. In addition, each program being executed by the control unit 11 and information necessary for executing the program are stored in the RAM. In addition, the rewritable non-volatile memory communicates with the terminal ID of each slave unit 40 registered, the management data table consisting of information about the external device connected to each slave unit 40, the terminal ID of the master unit 30, and the like. In addition to the information about the system required for the above, the data of the external device transmitted from the master unit 30 and the like are stored.

The display unit 14 is, for example, a liquid crystal display (LCD), and displays information on the meter reading system, information on an external device connected to the slave unit 40, an operation screen at the time of input to the center device 10, and the like. The operation input unit 15 has input means such as a keyboard and a mouse for inputting various data and commands to the center device 10 from the outside.

<Procedure for changing wireless channel>
FIG. 5 is a sequence diagram showing a radio channel changing procedure in the meter reading system shown in FIG. 1, and FIG. 6 is a diagram showing an outline of a telegram used in the radio channel changing procedure. Using these figures, a procedure for changing the radio channels of the master unit 30 and the slave units 40a to 40a in FIG. 1 from channel 1 to channel 2 will be described.

First, since the center device 10 changes the wireless channels of the terminal (bottom) slave units 40f and 40g, the communication route from the master unit 30 to the slave unit 40a with respect to the slave unit 40c, which is a common upper terminal. To transmit a radio channel change instruction message (sequences S1 to S3).

FIG. 6A shows an outline of the radio channel change instruction telegram. Here, the "ID of the master unit 30 (indicated as" master unit 30 ID "in the figure. Hereinafter, the same applies to other terminals)", "ID of the slave unit 40a", and "ID of the slave unit 40c" are wireless. The communication route in the communication system, that is, the "ID of the master unit 30" represents the source, and the "ID of the slave unit 40c" represents the destination (destination). Further, "broadcast" is the content of the instruction to the slave unit 40c, "wireless channel change" is the content instructed by the slave unit 40c to the surrounding terminals by "broadcast", and "Ch2" is the content to be instructed to change. Represents a channel.

Upon receiving the radio channel change instruction message, the slave unit 40c broadcasts a radio channel change instruction message instructing the surrounding terminals to change the radio channel to channel 2 (sequence S4). This radio channel change instruction telegram is obtained by removing the "master unit ID", "slave unit 40a ID", and "broadcast" from the telegram shown in FIG. 6A.

When the slave units 40f and 40g, which are the wireless channel change targets, receive the broadcast wireless channel change instruction message (sequences S5 and S6), they are registered in the storage unit 43 of their own terminal as a higher-level terminal (communication route). Since it is from the slave unit 40c, a radio channel change response message is transmitted to the slave unit 40c (sequences S7 and S9), and the radio channel is changed (sequences S8 and S10). The slave unit 40c transmits a radio channel change complete terminal response message to the center device 10 by the communication route from the slave unit 40a to the master unit 30 (sequences S11 to S13, S14 to S16).

FIG. 6B shows an outline of the radio channel change complete terminal response message transmitted by the master unit 30 to the center device 10. Here, the "ID of the slave unit 40f / ID of the slave unit 40g" is the ID of the terminal for which the change of the wireless channel has been completed. In FIG. 5, since it is assumed that the wireless channel change response telegram is transmitted in the order of the slave unit 40f and the slave unit 40g, the “ID of the slave unit 40f” is included in the message packet transmitted in the sequence S13. The "ID of the slave unit 40g" is stored in the telegram packet that is stored and transmitted in the sequence S16. However, the handset 40c can also transmit the radio channel change completion terminal response of the handset 40f and 40g in one message.

Before starting the radio channel change procedure shown in FIG. 5, since the radio channels of the master unit 30 and the slave units 40a to 40h are set to channel 1, the radio channels stored in the storage unit 13 of the center device 10 The contents of the management table are shown in Table 1 below.

Then, when the radio channel change completion terminal response message is received in sequences S13 and S16 and it is known that the radio channels of the slave unit 40f and the slave unit 40g have been changed to channel 2, the radio channels of those slave units are changed to channel 2. Change to.

Since the center device 10 manages the terminal connection configuration and also manages the wireless channel for each terminal ID, there is no terminal under the slave unit 40d whose wireless channel should be changed due to this combination. It turns out. Therefore, the slave unit 40d does not need to be instructed to broadcast the radio channel change instruction telegram (can be omitted).

Then, in order to change the wireless channel of the terminal slave unit 40h, the center device 10 then connects the slave unit 40e, which is the upper terminal of the slave unit 40h, to the wireless channel by the communication route from the master unit 30 to the slave unit 40b. Send a change instruction message (the sequence diagram is omitted hereafter). FIG. 6C shows an outline of the radio channel change instruction telegram.

Upon receiving the radio channel change instruction message, the slave unit 40e broadcasts a radio channel change instruction message instructing the surrounding terminals to change the radio channel to channel 2.

When the handset 40h, which is the target of changing the radio channel, receives the broadcasted radio channel change instruction message, it is from the handset 40e registered as the higher-level terminal (communication route), so that the handset 40e is used. In response, the radio channel change response message is transmitted to change the radio channel. The slave unit 40e transmits a radio channel change complete terminal response message to the center device 10 via the communication route from the slave unit 40b to the master unit 30. FIG. 6D shows an outline of the radio channel change complete terminal response message transmitted by the master unit 30 to the center device 10. The center device 10 that has responded to the terminal responding to the radio channel change complete changes the radio channel of the slave unit 40h to channel 2.

By the above procedure, the procedure for changing the radio channel of the slave units 40f to 40h, which is the terminal (third stage) terminal, is completed. Next, the center device 10 performs a procedure for changing the radio channels of the slave units 40c to 40e, which are the second-stage terminals, and when the procedure is completed, the radio channels of the slave units 40a and 40b, which are the first-stage terminals, are changed. Perform the procedure. Since the contents of these procedures are the same as the procedure for changing the radio channel of the slave units 40f to 40h, the description thereof will be omitted. Then, when the change of the wireless channels of all the slave units 40 is completed, the change of the wireless channels is completed by finally changing the wireless channels of the master unit 30. The radio channel management table of the center device 10 when the radio channel change is completed is shown in Table 2 below.

As described in detail above, the radio channel changing procedure according to the embodiment of the present invention has the following features (1) and (2).
(1) By transmitting a wireless channel change instruction message by broadcast from a higher-level terminal of the wireless channel change target terminal, the wireless channels of a plurality of terminals whose transmission route is the higher-level terminal can be changed at the same time. The time required to change the wireless channel can be shortened.
(2) The wireless channel can be changed without breaking the current communication route configuration.

<Recovery of isolated terminal>
FIG. 7 is a diagram showing a state in which there is an isolated terminal that has failed to change the radio channel in the meter reading system shown in FIG. 8 is a sequence diagram showing a recovery procedure of an isolated terminal in the meter reading system shown in FIG. 1, and FIG. 9 is a diagram showing an outline of a telegram used in the isolated terminal recovery procedure. The procedure for changing the radio channel of the isolated terminal that failed to change the radio channel from channel 1 to channel 2 will be described with reference to these figures. Here, the "isolated terminal" means a terminal that cannot communicate with a higher-level terminal that is a communication route.

Here, as shown in FIG. 7, the case where the master unit 30 and the slave units 40a to 40g succeed in changing to the wireless channels 1 and 2 and the slave unit 40h fails is illustrated. For example, since the slave unit 40h could not receive the broadcast of the wireless channel change instruction message from the slave unit 40e and the slave unit 40h did not transmit the wireless channel change response, the change to the wireless channel of the slave unit 40h was stopped and the second stage. When the wireless channel of the terminal above the eyes is successfully changed, the state shown in FIG. 7 is obtained. The radio channel management table in this case is shown in Table 3 below.

When the change to the wireless channel fails in the slave unit 40 constituting the wireless communication system and an isolated terminal occurs, the center device 10 needs to individually instruct the change of the wireless channel. That is, in the case of FIG. 7, it is necessary to instruct the slave unit 40h to change from channel 1 to channel 2. However, since the channels other than the slave unit 40h have been changed to the channel 2, it is not possible to instruct the change of the wireless channel on the channel 1.

Therefore, the center device 10 uses channel 2 for communication between the master unit 30 and the slave unit 40b and the slave unit 40e, and uses channel 1 for communication between the slave unit 40e and the slave unit 40h to instruct a wireless channel change. Send a telegram.

That is, the center device 10 transmits the radio channel change request telegram shown in FIG. 9A to the master unit 30 (FIG. 8: sequence S101). The radio channel change request message is transmitted to the slave unit 40e via the master unit 30-slave unit 40b (sequences S102 and S103). Wireless communication during this period is performed using channel 2.

Upon receiving the wireless channel change request message, the slave unit 40e transmits a wireless channel change request message instructing the slave unit 40h to change to the wireless channel 2 using the channel 1 (sequence S104). The outline of this telegram consists of "ID of slave unit 40h", "wireless channel change", and "change channel (channel 2)" in the radio channel change request telegram shown in FIG. 9A.

When the slave unit 40h receives the wireless channel change instruction message, it is from the slave unit 40e registered as a higher-level terminal (communication route). Therefore, the slave unit 40e is notified of the wireless channel change response message. Transmission is performed using radio channel 1 and the radio channel is changed from channel 1 to channel 2 (sequences S105, S106).

The slave unit 40e transmits a radio channel change response telegram to the center device 10 along the communication route from the slave unit 40b to the master unit 30 (sequences S107 to S109). FIG. 9B shows an outline of the radio channel change response telegram transmitted by the master unit 30 to the center device 10. The center device 10 that has received a radio channel change response telegram changes the wireless channel of the slave unit 40h to channel 2. As a result, the radio channel management table is as shown in Table 2.

As described above, according to the isolated terminal recovery procedure according to the embodiment of the present invention, the wireless channel column used for communication between the isolated terminal and its higher-level terminal is provided in the message from the center device 10. The isolated state can be eliminated.

<Communication via wireless communication systems with different wireless channels>
FIG. 10 is a diagram showing a communication route for transmitting meter reading data of a slave unit via a plurality of wireless communication systems having different wireless channels, and FIG. 11 is an outline of a telegram transmitted by the communication route shown in FIG. It is a figure which shows.

As shown in FIG. 10, there are a channel 1 group, a channel 2 group, a channel 3 group, and a channel 4 group, which are wireless communication systems using the wireless channel 1, the wireless channel 2, the wireless channel 3, and the wireless channel 4, respectively.

A slave unit that can be connected to the area of channel 1, channel 2, channel 3, channel 4, that is, the master units 30-1, 30-2, 30-3, and 30-4 of each group in a multi-stage configuration. The installation area of is partially overlapped. Here, a part of the areas of the channel 1 group and the channel 2 group, the channel 2 group and the channel 3 group, and the channel 3 group and the channel 4 group overlap.

Therefore, the master unit 30-1 arranged in the overlapping area belongs to the channel 1 group, the slave unit 40-2 belongs to the channel 2 group, the slave unit 40-3 belongs to the channel 3 group, and the slave unit 40-4 belongs to the channel 4 group. ing.
For example, when the master unit 30-1 transmits to the slave unit 40-2, the master unit 30-1 can switch to the channel 2 and transmit.
As a result, when the meter reading data of the slave unit 40-4 of the channel 4 group is acquired from the center device 10, the master unit 30-1 → the slave unit 40-2 is not used via the master unit 30-4 (dotted line in the figure). → It can be acquired by the communication route of the slave unit 40-3. FIG. 11 shows an outline of the telegram transmitted by the center device 10 to the master unit 30-1.
Regarding the slave unit 40-3, when acquiring the meter reading data of the own terminal from the center device 10, it is possible to acquire the meter reading data from the master unit 30-1 → the slave unit 40-2 instead of via the master unit 30-3. can. The same applies to the slave unit 40-2.

10 ... Center device, 30 ... Master unit, 31,41 ... Control unit, 33, 42 ... Wireless transmission / reception unit, 34 ... Network control unit, 40, 40-1 to 40-3, 40a to 40h ... Slave unit.

Claims (1)

It is a wireless communication system that consists of a master unit that is a wireless terminal and a plurality of slave units in a multi-stage configuration, and can transmit meter reading data of each slave unit to the center device via a higher-level terminal.
Top terminal of a wireless channel change target slave unit, in response to an instruction from the center device, and broadcasts a radio channel change instruction, the center device radio channel change response from the respect to the broadcast transmission radio channel change target handset Relay to
The radio channel change target slave unit, depending on the radio channel change instruction from the host terminal, to the upper terminal, transmitting the radio channel change response, changes the radio channel of the own terminal,
The host terminal of the slave unit that failed to change the wireless channel receives the wireless channel change instruction from the center device for the slave unit on the changed wireless channel, and based on the received wireless channel change instruction, on the wireless channel before the change. A wireless communication system that transmits to the slave unit.

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