JP7201293B2 - wireless communication network system - Google Patents

Description

The present invention comprises a wireless communication network including a wireless terminal base unit and a plurality of wireless terminal slave units, and a center system communicably connected to the wireless terminal master unit, wherein the plurality of wireless terminal slave units are wireless terminals. The present invention relates to a wireless communication network system communicably connected to a center system via a base unit.

A mesh network type wireless communication network is known in which wireless terminal devices (hereinafter referred to as "wireless terminals") dispersed in a specific area perform wireless data communication with each other directly or via a relay to exchange information. .

Conventionally, for example, a plurality of wireless terminals in a wireless communication network each have system configuration information including information on the minimum number of times of communication from the own device to a destination device, and the minimum number corresponding to a certain wireless terminal in the system configuration information. A wireless communication network system is known in which it is determined that a certain wireless terminal is missing when the number of communications is not consecutive with the minimum number of communications corresponding to any other wireless terminal in the system configuration information (for example, , see Patent Document 1).

Japanese Patent No. 3711759

However, conventional techniques have problems. That is, a wireless communication network system in which one of a plurality of wireless terminals serves as a parent device and is communicatively connected to the center system, and other wireless terminals serve as child devices and are communicatively connected to the center system via the parent device. In the conventional system, when the parent device is lost or stopped due to a malfunction and is removed from the wireless communication network, the child device cannot connect to the parent device and is isolated from the center system. Since the isolated child device cannot communicate with the center system, it is preferable to have it join another wireless communication network as soon as possible. However, in the conventional wireless communication network system, there was no slave device that detects the absence of the master device and joins another wireless communication network. Also, in a wireless communication network, there are, for example, about 40 wireless terminal slave units, and if they simultaneously join another wireless communication network, the entry operation that should have been successful fails due to communication collision. However, there was a risk that it would take a long time to reconstruct the wireless communication network.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wireless communication network system capable of quickly reconstructing a wireless communication network in the event that a wireless terminal base unit is lost.

(1) In order to solve the above problems, one aspect of the present invention provides a wireless communication network that connects a wireless terminal base unit and a plurality of wireless terminal slave units so that they can communicate with each other directly or via one or more relays. and a center system communicatively connected to the wireless terminal base unit, wherein the plurality of wireless terminal slave units are communicably connected to the center system via the wireless terminal base unit. wherein, when the plurality of wireless terminal slave units detect that the wireless terminal master unit of the wireless communication network to which the wireless terminal slave unit belongs is missing, they each enter another wireless communication network with a time lag. do.

According to the wireless communication network system configured as described above, the wireless terminal slave unit isolated from the center system due to the lack of the wireless terminal master unit joins another wireless communication network with a time lag. The number of unsuccessful entry operations is reduced, and the wireless communication network can be quickly reconstructed.

(2) In the wireless communication network system described in (1), the wireless terminal slave unit included in the wireless communication network to which the missing wireless terminal master unit belongs is a wireless terminal that belongs to another wireless communication network and can communicate directly. and joining said another wireless communication network to which the discovered wireless terminal belongs.

According to the wireless communication network system configured as described above, an isolated wireless terminal child device can join another wireless communication network according to the communication environment, and a highly reliable communication path can be formed.

(3) In the wireless communication network system described in (1) or (2), when the wireless terminal master is lost due to suspension, the wireless terminal master to be deactivated belongs to the wireless terminal master to be deactivated. A dissolution command for dissolving a network is transmitted directly or through one or more relays to a plurality of wireless terminal slave units included in a wireless communication network, and the wireless terminal slave units that have received the dissolution command are in the separate wireless communication network. It is preferable to participate in

According to the wireless communication network system configured as described above, by transmitting the dissolution command to the wireless terminal slave unit before the wireless terminal master unit stops, the wireless terminal slave unit can detect the lack of the wireless terminal master unit at an early stage. Since it is possible to enter another wireless communication network, it is possible to reduce the number of times of communication performed until the wireless communication network is reconfigured after the wireless terminal base unit is stopped, and the wireless communication network can be quickly reconfigured. .

(4) In the wireless communication network system described in any one of (1) to (3), when the wireless terminal master unit is lost due to loss, the first wireless communication network to which the lost wireless terminal master unit belongs the wireless terminal slave unit that detects that the wireless terminal master unit has disappeared in the second period transmits loss information about the loss of the wireless terminal master unit to other wireless terminal slave units in the wireless communication network to which the wireless terminal slave unit belongs; It is preferable that the wireless terminal slave unit detects the loss of the wireless terminal master unit by receiving the loss information.

According to the wireless communication network system configured as described above, it is possible to suppress unnecessary communication by wireless terminal slave units that have lost their wireless terminal master unit, and to quickly reconstruct the wireless communication network.

According to the present invention, it is possible to realize a wireless communication network system capable of quickly reconstructing a wireless communication network when a wireless terminal base unit is lost.

1 is a configuration diagram of a wireless communication network system according to an embodiment of the present invention; FIG. 1 is a schematic configuration diagram of a wireless terminal device; FIG. FIG. 4 is a diagram showing a hop count table held by each wireless terminal; FIG. 10 is a timing chart of reconstruction operation when the parent machine is stopped; FIG. It is a figure explaining dissolution command transmission operation|movement and restart operation|movement. It is a figure explaining entry operation|movement. FIG. 11 is a timing chart of reconstruction operation when the parent device is lost; FIG. FIG. 8 is a diagram for explaining an operation at t1 in FIG. 7; It is a figure explaining operation|movement at t2 time of FIG. 7, and t3 time. FIG. 8 is a diagram for explaining an operation at t4 in FIG. 7; FIG. 8 is a diagram for explaining an operation at t5 in FIG. 7; FIG. 3 illustrates a wireless communication network system after reconstruction;

An embodiment of a wireless communication network system according to the present invention will be described below with reference to the drawings.

(Regarding the configuration of the wireless communication network system)
FIG. 1 is a configuration diagram of a wireless communication network system 10 according to an embodiment of the present invention.
The wireless communication network system 10 comprises wireless communication networks 12A, 12B, 12C. The wireless communication network system 10 of this embodiment includes three wireless communication networks 12A, 12B, and 12C, but the number of wireless communication networks 12 may be one, or four or more.

The wireless communication network 12A is constructed by connecting a plurality of wireless terminal devices (hereinafter referred to as "wireless terminals") 1Aa, 1Ab, 1Ac, 1Ad, and 1Ae so that they can communicate with each other directly or through one or more relays. ing. As with the wireless communication network 12A, a wireless communication network 12B is constructed by a plurality of wireless terminals 1Ba to 1Be, and a wireless communication network 12C is constructed by wireless terminals 1Ca to 1Ce.

In the wireless communication network 12A, one wireless terminal 1Aa among a plurality of wireless terminals 1Aa to 1Ae is wired to an external device 11A. The wireless terminal 1Aa is communicatively connected to the center system 14 via the external device 11A, and constitutes a parent device. On the other hand, other wireless terminals 1Ab to 1Ae in the wireless communication network 12A are not connected to the external device 11A. The wireless terminals 1Ab to 1Ae are communicably connected to the center system 14 via the wireless terminal 1Aa of the parent device and the external device 11A, and constitute slave devices. The base wireless terminal 1Aa assigns identification information (such as a network ID) for identifying the wireless terminals 1Ab to 1Ae within the wireless communication network 12A. The wireless terminals 1Aa to 1Ae can perform two-way communication with the center system 14 by controlling the communication protocol with the center system 14 by the external device 11A.

Similarly, in the radio communication network 12B, the radio terminal 1Ba constitutes a parent device, and the radio terminals 1Bb to 1Be constitute child devices. Further, in the radio communication network 12C, the radio terminal 1Ca constitutes a parent device, and the radio terminals 1Cb to 1Ce constitute child devices.

Each of the wireless terminals 1Aa, 1Ba, and 1Ca is an example of a "wireless terminal parent device". The wireless terminals 1Ab to 1Ae, 1Bb to 1Be, and 1Cb to 1Ce are examples of "multiple wireless terminal slave units" included in the wireless communication networks 12A to 12C, respectively. The radio terminals 1Ab-1Ae, 1Bb-1Be, 1Cb-1Ce have similar configurations. The wireless terminals 1Aa, 1Ba, 1Ca are configured similarly to the wireless terminals 1Ab-1Ae, 1Bb-1Be, 1Cb-1Ce, except for the function of managing the wireless communication networks 12A, 12B, 12C. Therefore, in the following description, the suffixes Aa to Ae, Ba to Be, and Ca to Ce of the wireless terminals 1Aa to 1Ae, 1Ba to 1Be, and 1Ca to 1Ce are omitted when there is no particular need to distinguish them.

FIG. 2 is a schematic configuration diagram of the wireless terminal 1. As shown in FIG. In the wireless terminal 1, the storage unit 3, the communication unit 4, the timer 5, and the battery 6 are connected to the control unit 2, and the control unit 2 is supplied with power from the battery 6 to be driven. The storage unit 3 stores data and programs. The control unit 2 executes programs stored in the storage unit 3 while reading and writing data in the storage unit 3 to control the operation of the wireless terminal 1 . The communication unit 4 is hardware connected to the communication network 13 forming the wireless communication network 12 and controlling communication with other devices. The timer 5 is hardware for measuring time.

The storage unit 3 stores, for example, a hop count table 31, an adjacency research program 32, a communication control program 33, and a reconstruction program .

FIG. 3 is a diagram showing the hop count table 31 held by each wireless terminal 1. As shown in FIG. FIG. 3 shows wireless terminals 1Ba to 1Be constituting the wireless communication network 12B and hop count tables 31Ba to 31Be held by them.

The hop count table 31 stores information relating to the number of times of communication until data sent from the own device reaches the destination device from the own device. For example, the wireless terminals 1Ba to 1Be have their own hop count tables 31Ba to 31Be, respectively.

Since the configurations of the hop count tables 31Ba to 31Be are the same, taking the hop count table 31Bb of the wireless terminal 1Bb as an example, the wireless terminal 1Bb can transfer data to the wireless terminals 1Ba and 1Bd in one communication. . Therefore, the hop count table 31Bb stores "1" in the fields 311Bb and 314Bb indicating the number of times of communication of the wireless terminals 1Ba and 1Bd.

Also, the wireless terminal 1Bb can transfer data to the wireless terminals 1Bc and 1Be with at least two communications. Therefore, the hop count table 31Bb stores "2" in the fields 313Bb and 315Bb indicating the number of times of communication of the wireless terminals 1Bc and 1Be.

Since the own device (wireless terminal 1Bb) does not perform communication, the hop number table 31Bb stores "0" in the field 312Bb of the number of times of communication of the own device.

Therefore, based on the number of times of communication stored in the hop count table 31Bb, the wireless terminal 1Bb distinguishes between adjacent wireless terminals and non-adjacent wireless terminals (which can wirelessly communicate via relay or cannot communicate directly). , can be distinguished.

The hop count table 31Bb stores parent information 320 indicating that the wireless terminal 1Ba serving as the parent device is the parent device. Therefore, the wireless terminal 1Bb can be distinguished between the parent device and the child device based on the presence or absence of the parent information 320. FIG.

Here, the communication state of the wireless terminal 1 changes moment by moment depending on the network environment. Therefore, the wireless communication network 12B updates the hop count tables 31Ba to 31Be periodically (for example, every 72 hours).

Returning to FIG. 1, the adjacency research program 32 determines whether another wireless terminal 1 in the wireless communication network 12 can communicate directly from its own device (adjacent) or whether it can communicate wirelessly from its own device via a relay (direct communication). or not adjacent to each other). The communication performance of the wireless terminal 1 varies depending on the model and communication environment. Therefore, when updating the hop count table 31, the control unit 2 executes the adjacency investigation program 32 to investigate the adjacency relationship.

During normal data communication, the communication control program 33 is based on the hop count table 31 of the own device, within the wireless communication network 12, the own device and another wireless terminal 1 communicate with each other directly or via a relay wirelessly. It controls the wireless terminal 1 so as to perform data communication. For example, the communication control program 33 is executed by the control unit 2 when its own device communicates with the center system 14 .

The reconfiguration program 34 causes its own device to join another wireless communication network 12 by setting a time lag between itself and another wireless terminal 1 when its parent device is lost. It is something that can be done.

(Regarding rebuilding operation)
Next, the reconstruction operation performed by the wireless communication network system 10 will be described with reference to FIGS. 4 to 12. FIG. FIG. 4 is a timing chart of the reconstruction operation when the parent machine is stopped. FIG. 5 is a diagram for explaining the dissolution command transmission operation and the restart operation. FIG. 6 is a diagram for explaining the entry operation. FIG. 7 is a timing chart of the reconstruction operation when the parent device is lost. FIG. 8 is a diagram for explaining the operation at t1 in FIG. FIG. 9 is a diagram for explaining the operation at t2 and t3 in FIG. FIG. 10 is a diagram for explaining the operation at t4 in FIG. FIG. 11 is a diagram for explaining the operation at t5 in FIG. FIG. 12 is a diagram showing the wireless communication network system 10 after reconstruction.

A wireless communication network system 10 is applied, for example, to automatic meter reading of gas usage, and a wireless terminal 1 is built in a gas meter installed in a house. Each of the wireless communication networks 12A, 12B, and 12C can be configured with a maximum of 50 wireless terminals 1, but is configured with about 40 wireless terminals 1 in preparation for the entry of wireless terminals 1 into the network. Since all wireless terminals 1 included in each of the wireless communication networks 12A, 12B, and 12C cannot be shown in the drawings, only some of the wireless terminals 1 included in the wireless communication network 12B are shown in FIGS. ing.

In the wireless communication network system 10, when the gas usage is automatically read, the center system 14 connects the wireless terminals 1Aa to 1Ae, 1Ba to each of the wireless communication networks 12A, 12B, 12C via the external devices 11A, 11B, 11C. 1Be, 1Ca to 1Ce are requested to transmit the gas meter reading results. Base wireless terminals (hereinafter also referred to as "wireless terminal base units") 1Aa, 1Ba, 1Ca directly receive transmission requests from the external devices 11A, 11B, 11C, respectively, and transmit meter reading results of their own devices to the external devices 11A, 11B, 11C. 11B, 11C to the center system 14, and the transmission request is directly or relayed to the wireless terminal of the slave unit (hereinafter also referred to as "wireless terminal slave unit") 1Ab to 1Ae, 1Bb to 1Be, 1Cb to 1Ce transfer through. On the other hand, when the wireless terminal slaves 1Ab to 1Ae, 1Bb to 1Be, 1Cb to 1Ce receive the transmission request from the wireless terminal masters 1Aa, 1Ba, 1Ca, the wireless terminal masters 1Aa, 1Ba, 1Ca and other wireless terminal slaves The meter reading results of the own device are returned to the center system 14 via the machines 1Ab-1Ae, 1Bb-1Be, 1Cb-1Ce and the external devices 11A, 11B and 11C.

Here, the wireless terminal masters 1Aa, 1Ba, 1Ca are replaced together with the external devices 11A, 11B, 11C when they reach the service life (for example, 10 years). For example, when the wireless terminal master 1Ba and the external device 11B are replaced with the wireless terminal master 1X and the external device 11X, the wireless terminal master 1Ba is stopped and dropped from the wireless communication network 12B. The wireless terminal slaves 1Bb to 1Be maintain the hop count tables 31Bb to 31Be storing the parent information 320 in the wireless terminal master 1Ba even after the wireless terminal master 1Ba is lost, and execute the communication control program 33. , even if an attempt is made to communicate with the center system 14 based on the hop count tables 31Bb to 31Be, the communication with the center system 14 fails because the newly replaced wireless terminal base unit 1X and the external device 11X cannot be connected. In other words, the wireless terminal slave units 1Bb-1Be are isolated from the center system 14, and the center system 14 cannot automatically receive meter reading results from the wireless terminal slave units 1Bb-1Be.

Further, for example, the wireless terminal base unit 1Ba may disappear due to a failure or deterioration of the communication environment, and may be missing from the wireless communication network 12B. In this case, similarly to the above, the wireless terminal slave units 1Bb-1Be are isolated from the center system 14, and the center system 14 cannot automatically receive meter reading results from the wireless terminal slave units 1Bb-1Be.

In order to solve the above problem, when the wireless terminal slave units 1Bb to 1Be detect the lack of the wireless terminal master unit 1Ba and try to join another wireless communication network 12 (another wireless terminal master unit 1X) all at once. , there is a risk that communication that should be successful may fail due to communication collision, and it may take time to reconstruct the wireless communication network 12 .

Therefore, in the wireless communication network system 10 of the present embodiment, when the wireless terminal slave units 1Bb to 1Be detect that the wireless terminal master unit 1Ba of the wireless communication network 12B to which the wireless terminal slave unit 1Bb belongs is missing, a time lag is provided to wireless communication network 12X (in other words, another wireless terminal base unit 1X). Since the wireless terminal slave units 1Bb to 1Be enter the network with a time lag, the failure of the entry operation that should succeed due to communication collision is reduced, and the wireless communication network 12X can be quickly reconstructed. In the following, the reconstruction operation of the wireless communication network system 10 will be specifically described by dividing the reconstruction operation when the base unit is stopped and the reconstruction operation when the base unit is lost.

(Regarding the reconstruction operation when the main unit is stopped)
The reconstruction operation when the parent machine is stopped will be described with reference to FIGS. 4 to 6. FIG. Here, a case where the wireless terminal master unit 1Ba is stopped in order to replace it with the wireless terminal master unit 1X will be described as an example.

For example, when the wireless terminal master unit 1Ba is replaced with the wireless terminal master unit 1X, it receives a stop instruction from the center system 14 or receives a user's terminal stop operation, and receives the stop instruction (t50 ), wireless terminal slave units 1Bb to 1Be included in the wireless communication network 12B to which the own device belongs (wireless terminal slave units 1Bb to 1Be subordinate to the own device, other wireless terminal slave units 1Bb stored in the hop count table 31Ba 1Be), a dissolution command for dissolving the wireless communication network 12B is transmitted (t51), and then stopped (t60).

After receiving the dissolution command, the wireless terminal slave units 1Bb to 1Be establish a time lag between themselves and the other wireless terminal slave units 1Bb to 1Be after restarting to establish another wireless communication network 12X (in other words, another wireless terminal slave unit 12X). (t52 to t59). Note that the wireless terminal slave units 1Bb to 1Be start restarting after the wireless terminal base unit 1Ba stops and join the network. This is because if the wireless terminal slave units 1Bb to 1Be are restarted before the wireless terminal master unit 1Ba is stopped, the wireless terminal slave units 1Bb to 1Be may join the wireless terminal master unit 1Ba before the suspension.

In this embodiment, the wireless terminal base unit 1Ba creates order designation information that designates the entry order, includes it in the dissolution command, and transmits it to the wireless terminal slave units 1Bb to 1Be, thereby providing a time lag. The order of entry may be determined by the wireless terminal master unit 1Ba based on the hop count table 31Ba in ascending order of the number of times of communication, or may be created according to instructions from the center system 14. FIG. Note that the measures for setting a time lag are not limited to this. It may be stored in advance when the network 12B is constructed.

As shown in FIG. 5, the wireless terminal cordless handset 1Bb is restarted upon receiving the dissolution command from the wireless terminal master 1Ba. As a result, the hop count table 31Bb of the wireless terminal slave unit 1Bb is initialized, and a field for storing information specifying the wireless terminal 1 (for example, identification information or a network ID individually assigned to the wireless terminal 1), or , the field indicating the number of communications is blanked out. Similarly, the radio terminals 1Bc-1Be have their hop count tables 31Bc-31Be initialized. As a result, the hop count tables 31Bb to 31Be of the wireless terminal slave units 1Bb to 1Be do not store the parent information 320, respectively, and the wireless communication network 12B is dissolved.

As shown in FIG. 6, each of the wireless terminal slaves 1Bb to 1Be executes the adjacency research program 32 according to the order designation information included in the dissolution command received from the wireless terminal master 1Ba, and terminates the wireless terminal master 1X. It discovers and joins the wireless terminal base unit 1X.

For example, when the control unit 2 executes the adjacency research program 32, the wireless terminal slave unit 1Bb uses the communication unit 4 to enter a standby state in which it waits for a beacon. At this time, the wireless terminal base unit 1X and the wireless terminal slave units 1Bc to 1Be, which do not execute the adjacency survey program 32, use the communication unit 4 to intermittently transmit beacons.

When the wireless terminal slave unit 1Bb receives a beacon from the wireless terminal master unit 1X during standby operation, it exchanges the hop number table 31X and the hop number table 31Bb with the wireless terminal master unit 1X. The hop count table 31X stores parent information 320 in its own device. Based on the hop count table 31X received from the wireless terminal master device 1X, the wireless terminal slave device 1Bb recognizes that the wireless terminal master device 1X is the master device. store the parent information 320 in the . As a result, the wireless terminal slave unit 1Bb joins the wireless terminal master unit 1X. That is, the wireless terminal slave unit 1Bb joins the wireless communication network 12X managed by the wireless terminal master unit 1X.

Similarly, when the control unit 2 executes the adjacency research program 32 and exchanges the tables, the other wireless terminal slave units 1Bc to 1Be also use the wireless terminal master unit 1X as the master unit based on the parent information 320. and participates in the wireless terminal base unit 1X (wireless communication network 12X).

In this manner, the wireless communication network system 10 transmits the dissolution command before the wireless terminal master 1Ba stops, so that the wireless terminal slaves 1Bb to 1Be can quickly detect the lack of the wireless terminal master 1Ba. Join another wireless communication network 12X (another wireless terminal base unit 1X). Therefore, the wireless terminal slave units 1Bb to 1Be become able to communicate with the center system 14 via the newly replaced wireless terminal master unit 1X and the external device 11X immediately after the wireless terminal master unit 1Ba is lost due to the stoppage. , useless adjacency determination and communication via the missing radio terminal base unit 1Ba are avoided. Therefore, the wireless terminal cordless handsets 1Bb to 1Be reduce the number of times of communication performed until the wireless communication network 12X is reconstructed after the wireless terminal base unit 1Ba is stopped, and quickly reconstruct the wireless communication network 12X. be able to. Further, useless communication is suppressed in each of the wireless terminal slave units 1Bb to 1Be, and consumption of the battery 6 is suppressed.

(Description of reconstruction operation when the master unit is lost)
The reconstruction operation when the parent device is lost will be described with reference to FIGS. 7 to 12. FIG. Here, a case where the wireless terminal master 1Ba and the external device 11B are replaced with the wireless terminal master 1X and the external device 11X without transmitting a stop command will be described as an example.

When the wireless terminal master unit 1Ba is stopped without transmitting a stop command, the wireless terminal master unit 1Ba disappears from the wireless communication network 12B as shown at t0 in FIG. Since the wireless terminal slaves 1Bb to 1Be do not receive the stop command, they cannot detect the disappearance of the wireless terminal master 1Ba immediately after the wireless terminal master 1Ba is stopped. Therefore, the wireless terminal slave units 1Bb to 1Be maintain the hop count tables 31Ba to 31Be at the time of loss shown in FIG.

As shown in FIG. 3, in the hop count tables 31Ba to 31Be at the point of loss, values corresponding to the configuration of the wireless communication network 12B are set for the number of times of communication of the wireless terminal base unit 1Ba. Therefore, even if each of the wireless terminal slave units 1Bb to 1Be executes the communication control program 33 using the control unit 2 and transmits data such as meter reading results to the center system 14 based on the hop count tables 31Bb to 31Be, , the direct communication between the wireless terminal base unit 1Ba and the wireless terminal slave unit 1Bb and the direct communication between the wireless terminal master unit 1Ba and the wireless terminal slave unit 1Bc fail, and the meter reading result is sent to the center system 14. Can not. Further, the wireless terminal slave units 1Bb to 1Be cannot receive requests from the center system 14 because the wireless terminal master unit 1Ba cannot communicate with the center system 14 via the external device 11B.

The wireless terminal slave units 1Bb to 1Be execute the adjacency research program 32 using the control unit 2, respectively, when the hop count tables 31Bb to 31Be are updated.

For example, as shown in FIG. 7, the wireless terminal slave unit 1Bb performs adjacency determination (t1). As indicated by M1a in FIG. 8, the wireless terminal slave device 1Bb receives the beacon from the wireless terminal slave device 1Bd and exchanges the hop count table 31Bb of its own device with the hop count table 31Bd of the wireless terminal slave device 1Bd. The wireless terminal slave unit 1Bb determines that the wireless terminal slave unit 1Bd that has undergone the table exchange is adjacent (can communicate directly), and the value stored in the field 314Bb indicating the number of times of communication of the wireless terminal slave unit 1Bd in the hop count table 31Bb. Maintain "1".

On the other hand, as indicated by M1b in FIG. 8, the wireless terminal slave unit 1Bb cannot receive the beacon from the lost wireless terminal master unit 1Ba, so it does not exchange tables with the wireless terminal master unit 1Ba. The wireless terminal slave unit 1Bb determines that the wireless terminal master unit 1Ba, which cannot exchange tables, is not adjacent (cannot communicate directly). In the hop count table 31Bd acquired from the wireless terminal slave device 1Bd, the wireless terminal slave device 1Bb reads out the value "2" from the field 311Bd of the wireless terminal master device 1Ba containing the parent information 320, and sets the read value "2" to the wireless terminal master device 1Bd. The number of times of communication "1" for the direct communication between terminal slave units 1Bb and 1Bd is added, and the number of times of communication to wireless terminal base unit 1Ba is calculated to be "3". Then, the wireless terminal slave device 1Bb stores the calculated numerical value "3" in the field 311Bb indicating the number of times of communication with the wireless terminal master device 1Ba in the hop count table 31Bb of its own device. As a result, in the hop count table 31Bb, the number of times of communication of the wireless terminal base unit 1Ba is changed from "1" (see FIG. 3) to "3" (see FIG. 8).

As a result, the wireless terminal slave unit 1Bb, for example, executes the communication control program 33 using the control unit 2, and when transmitting data such as meter reading results to the center system 14, directly transmits the data to the wireless terminal master unit 1Ba. Failure of communication with the wireless terminal base unit 1Ba is avoided without transmission.

Next, for example, as shown at t2 in FIG. 7, the wireless terminal slave unit 1Bc performs adjacency determination (t2). As shown in FIG. 9, similarly to t1, the wireless terminal slave unit 1Bc determines that the wireless terminal master unit 1Ba is not adjacent (see M2b in the figure) and that the wireless terminal slave unit 1Bd is adjacent (see M2a in the figure). reference). In this case, similarly to the wireless terminal slave device 1Bb, the wireless terminal slave device 1Bc sets the value of the field 311Bc of the wireless terminal master device 1Ba to "1" (see FIGS. 3 and 8) in the hop count table 31Bc of its own device. ) to “3” (see FIG. 9). As a result, the wireless terminal slave unit 1Bc, for example, uses the control unit 2 to execute the communication control program 33, and when transmitting data such as meter reading results to the center system 14, directly transmits the data to the wireless terminal master unit 1Ba. Failure of communication with the wireless terminal base unit 1Ba is avoided without transmission.

Thereafter, as shown at t3 in FIG. 7, the wireless terminal slave unit 1Bd first detects the disappearance of the wireless terminal master unit 1Ba.

Specifically, the wireless terminal slave unit 1Bd acquires the hop count tables 31Bb and 31Bc of the wireless terminal slave units 1Bb and 1Bc when exchanging tables with the wireless terminal slave units 1Bb and 1Bc. As shown in FIG. 9, the wireless terminal cordless handset 1Bd stores "3" in the field 311Bb of the hop count table 31Bb and the field 311Bc of the hop count table 31Bc. The value stored in the field 311Bd indicating the number of times of communication of the terminal base unit 1Ba is changed from "2" to "3".

Based on the changed hop count table 31Bd, the wireless terminal slave unit 1Bd detects that the number of communications "3" of the wireless terminal master unit 1Ba is not consecutive with the number of communications of the other wireless terminals 1Bb to 1Be. In this case, the wireless terminal slave unit 1Bd detects that the wireless terminal master unit 1Ba has disappeared. That is, the wireless terminal cordless handset 1Bd first detects the disappearance of the wireless terminal base 1Ba within the wireless communication network 12B.

After that, the wireless terminal slave unit 1Bd generates loss information indicating that the master unit has disappeared, as shown in FIG. 7 (t4).

That is, as shown in FIG. 10, the wireless terminal slave unit 1Bd deletes information stored in the field 311Bd indicating the number of times of communication with the wireless terminal master unit 1Ba from the numerical value "3" in the hop count table 31Bd of the wireless terminal slave unit 1Bd. (missing) is changed to specific information (a space in this embodiment). The hop count table 31Bd includes specific information about the wireless terminal 1Ba including the parent information 320, so that it becomes loss information indicating the loss of the wireless terminal base 1Ba.

Then, as shown in FIG. 7, the wireless terminal slave unit 1Bd transmits erasure information (t5). That is, as shown in FIG. 11, the wireless terminal slave unit 1Bd broadcasts the hop count table 31Bd storing specific information (space in this embodiment) in the field 311Bd of the wireless terminal base unit 1Ba as lost information. do. That is, the wireless terminal slave unit 1Bd directly transmits the hop count table 31Bd including specific information to the wireless terminal slave units 1Bb, 1Bc, and 1Be that are determined to be adjacent (the value of the number of communications is "1"). do. Although not shown in the drawing, if there is a wireless terminal slave unit adjacent to the wireless terminal slave units 1Bb, 1Bc, and 1Be, the wireless terminal slave units 1Bb, 1Bc, and 1Be specify the adjacent wireless terminal slave units. directly transmits the hop count table 31Bd including the information of

As shown in FIG. 7, the wireless terminal slaves 1Bb, 1Bc, and 1Be that have received the loss information respectively detect that the wireless terminal master 1Ba has disappeared (t6, t7, t8). In this manner, in the wireless communication network 12B, the loss information is spread from the wireless terminal slave unit 1Bd to the other wireless terminal slave units 1Bb, 1Bc, and 1Be, and the loss of the wireless terminal master unit 1Ba is known.

As shown in FIG. 7, when the wireless terminal slave units 1Bb to 1Be detect the disappearance of the wireless terminal master unit 1Ba, they are restarted. It joins the network 12X (another wireless terminal base unit 1X) (t52 to t59). Since this restart and entry operation are the same as the restructuring operation at the time of stop, the explanation is omitted.

In the above-described wireless communication network system 10, the wireless terminal slave unit 1Bd first detects the loss of the wireless terminal master unit 1Ba without performing adjacency determination, and the wireless terminal slave unit 1Bd first detects the loss of the wireless terminal master unit 1Ba. , the other wireless terminal slave unit 1Be detects the loss of the wireless terminal master unit 1Ba without performing adjacency determination. can be made known to the wireless terminal cordless handsets 1Bb to 1Be. Then, since the wireless terminal slave units 1Bb to 1Be that have detected the disappearance of the wireless terminal master unit 1Ba enter another wireless communication network 12X (wireless terminal master unit 1X) with a time lag, entry failure due to communication collision may occur. decrease. Therefore, according to the wireless communication network system 10 of the present embodiment, the wireless communication network 12X can be quickly reconstructed, and the wireless terminal base unit 1X and the external device 11X, which are newly replaced with the wireless terminal slave units 1Bb to 1Be, can be reconfigured. It becomes possible to communicate with the center system 14 via. Furthermore, since the number of adjacency determinations and communication failures are suppressed, consumption of the battery 6 of each of the wireless terminal slave units 1Bb to 1Be is suppressed.

In the above description, the wireless terminal slaves 1Bb to 1Be participate in the same wireless terminal master 1X when the wireless terminal master 1Ba is replaced with the wireless terminal master 1X and lost. On the other hand, for example, as shown in FIG. 12, when the wireless terminal base unit 1Ba is missing from the wireless communication network 12B due to a failure or deterioration of the communication environment, the wireless terminal slave units 1Bb, 1Bd, and 1Be Wireless terminal slave units 1Bb to 1Be enter separate wireless communication networks 12A and 12C (wireless terminal base units 1Aa and 1Ca), such as entering the communication network 12C and wireless terminal slave unit 1Bc entering the wireless communication network 12A. You can do it. As a result, the wireless communication networks 12A and 12C are reconfigured as wireless communication networks 12Ax and 12Cx with their communication paths changed.

(summary)
As described above, the wireless communication network system 10 of the present embodiment connects the wireless terminal masters 1Aa, 1Ba, 1Ca and the plurality of wireless terminal slaves 1Ab to 1Ae, 1Bb to 1Be, 1Cb to 1Ce directly or through one or more Wireless communication networks 12A, 12B, and 12C communicatively connected to each other via relays, and a center system 14 communicatively connected to wireless terminal base units 1Aa, 1Ba, and 1Ca, and wireless terminal cordless handsets 1Ab to In a wireless communication network system 10 in which 1Ae, 1Bb to 1Be, 1Cb to 1Ce are communicably connected to a center system 14 via wireless terminal base units 1Aa, 1Ba, 1Ca, a plurality of wireless terminal slave units 1Ab to 1Ae, 1Bb. When 1Be, 1Cb-1Ce detects that the wireless terminal masters 1Aa, 1Ba, 1Ca of the wireless communication networks 12A, 12B, 12C to which the device belongs are missing, they set a time lag to connect to another wireless communication network 12A, 12B, 12C Entry into 12B and 12C, respectively.

According to such a wireless communication network system 10, for example, the wireless terminal slave units 1Bb to 1Be isolated from the center system 14 due to the lack of the wireless terminal master unit 1Ba can be transferred to another wireless communication network 12X (or wireless Entry into the communication networks 12A, 12C) reduces failures of entry operations that should be successful due to communication collisions, and enables rapid reconstruction of 12X (or wireless communication networks 12Ax, 12Cx).

It should be noted that the present invention is not limited to the above embodiments, and can be applied in various ways.

(1) For example, in the above embodiment, the hop count table 31Bd is used to inform the wireless terminal slave units 1Bb to 1Be of the loss of the wireless terminal master unit 1Ba, but the notification method is not limited to this. For example, only the information indicating the loss may be transmitted from the wireless terminal slave unit 1Bd that first detects the loss of the master unit to the other wireless terminal slave units 1Bb, 1Bc, and 1Be. However, by using the hop count table 31 used for data communication, the data to be stored in the storage unit 3 can be reduced, and the storage load can be reduced.

(2) For example, in the above embodiment, the wireless terminal slave units 1Bb to 1Be included in the wireless communication network 12B to which the missing wireless terminal base unit 1Ba belongs belong to separate wireless communication networks 12A and 12C and are capable of direct communication. The wireless terminal 1 is searched for and entered into another wireless communication network 12A, 12C to which the found wireless terminal 1 belongs. On the other hand, the wireless terminals 1 to be connected in the case where the wireless terminal base unit 1Ba is lost may be determined in advance for each of the wireless terminal slave units 1Bb to 1Be so that they can join another wireless communication network 12. . However, each time the wireless terminal base unit 1Ba is lost, the wireless terminal slave units 1Bb to 1Be search for the wireless terminals 1 belonging to the different wireless communication networks 12A and 12C. At the same time, it is possible to enter another wireless communication network and reconstruct a highly reliable wireless communication network 12 .

(3) For example, in the above embodiment, when the wireless terminal master unit 1Ba is lost due to loss, the loss of the wireless terminal master unit 1Ba is first detected in the wireless communication network 12B to which the lost wireless terminal master device 1Ba belongs. The wireless terminal slave unit 1Bd stores loss information (a hop count table 31Bd in which the number of times of communication of the wireless terminal master unit 1Ba is used as a space) regarding the loss of the wireless terminal master unit 1Ba, and stores it in another wireless communication network 12B to which the wireless terminal slave unit 1Bd belongs. By transmitting to the terminal slave units 1Bb, 1Bc, and 1Be and receiving the loss information, the wireless terminal slave units 1Bb to 1Be detect the lack of the wireless terminal master unit 1Ba. On the other hand, the wireless terminal cordless handset 1Bd detected first may not transmit the erasure information. However, the wireless terminal slave unit 1Bd, which first detects the loss of the base unit, transmits the loss information, thereby suppressing the wireless terminal slave unit 1Be from performing unnecessary communication (adjacency determination), thereby allowing the wireless communication network 12 to operate. It can be rebuilt early. Moreover, consumption of the battery 6 can be reduced.

(4) For example, in the above embodiment, when the wireless terminal master 1Ba is lost due to suspension, multiple to the wireless terminal cordless handsets 1Bb to 1Be directly or through one or more relays, and the wireless terminal cordless handsets 1Bb to 1Be that receive the disbanding command connect to another wireless communication network 12X (separate network 12X). (1X) wireless terminal master unit). On the other hand, the wireless terminal master unit 1Ba to be stopped may not transmit the dissolution command, and the wireless communication network 12 may be reestablished according to the reconstruction operation when the master unit is lost. However, when the wireless terminal master unit 1Ba is stopped, the wireless terminal slave units 1Bb to 1Be can quickly detect the lack of the wireless terminal master unit 1Ba by transmitting a dissolution command and establish another wireless communication network 12X ( Since it is possible to enter another wireless terminal base unit 1X), the number of times of communication (adjacency determination) performed from when the wireless terminal base unit 1Ba is stopped until the wireless communication network 12X is rebuilt is reduced, and the wireless communication network 12X can be rebuilt early. Also, it is possible to reduce consumption of the batteries 6 of the wireless terminal cordless handsets 1Bb to 1Be.

1Ba wireless terminal base unit 1Bb to 1Be wireless terminal slave unit 10 wireless communication network system 14 center system 12B wireless communication network

Claims (3)

One or more wireless communication networks that communicably connect a wireless terminal base unit and a plurality of wireless terminal slave units directly or via one or more relays, and a center that communicably connects the wireless terminal base unit. a wireless communication network system in which the plurality of wireless terminal slave units are communicably connected to the center system via the wireless terminal base unit,
When the plurality of wireless terminal slave units detects that the wireless terminal master unit of the wireless communication network to which the wireless terminal slave unit belongs is missing, each enters a communicable wireless communication network with a time lag;
The wireless terminal parent device and the plurality of wireless terminal slave devices each have a hop count table that stores information about the number of times data sent from the device reaches a destination device from the device itself, and the hop count table but the parent information indicating that it is the parent device is stored in the wireless terminal serving as the parent device;
a wireless terminal child device included in the wireless communication network to which the missing wireless terminal parent device belongs initializes the hop count table and enters a state in which the parent information is not stored;
After initializing the hop count table, the wireless terminal child device searches for a wireless terminal that belongs to a communicable wireless communication network and is capable of direct communication, exchanges the hop count table with the found wireless terminal, and obtains the received hop count. A wireless terminal to be a parent is recognized based on the parent information stored in the table, and the found wireless terminal belongs by storing the parent information in the wireless terminal recognized by the initialized hop count table. joining the communicable wireless communication network;
A wireless communication network system characterized by: In the wireless communication network system according to claim 1 ,
Dissolution of the network by dissolving the network from the wireless terminal master unit to which the wireless terminal master unit is suspended, when the wireless terminal master unit is lost due to the suspension, to a plurality of wireless terminal slave units included in the wireless communication network to which the wireless terminal master unit to which the wireless terminal master unit to be suspended belongs Sending a command directly or through one or more relays, and having received the dissolution command, the wireless terminal child device joins the communicable wireless communication network;
A wireless communication network system characterized by: In the wireless communication network system according to claim 1 or claim 2 ,
When the wireless terminal master unit is lost due to loss, the wireless terminal slave unit that first detects the loss of the wireless terminal master unit in the wireless communication network to which the lost wireless terminal master unit belongs is the wireless terminal master unit. to other wireless terminal slaves in the wireless communication network to which the device belongs, and the wireless terminal slaves detect the loss of the wireless terminal master by receiving the loss information. thing,
A wireless communication network system characterized by:

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