JP7166191B2 - wireless network system - Google Patents

Description

The present invention relates to wireless network systems.

In the past, gas usage data was recorded by meters, and meter readers traveled around the area to collect the data from the meters. An automatic meter reading system that collects to a center is becoming popular.

In order to realize such an automatic meter-reading system, it would be costly to connect each meter to a communication line individually by wire. A multi-hop network that relays radio waves between machines and transmits data like a bucket brigade is used, and this multi-hop network covers a wide communication range while collecting data in the wireless base unit. , data is transmitted from a wide area terminal wired to the wireless master unit to a host computer in the center via a wide area communication line such as PHS (Personal Handy-phone System) or LTE (Long Term Evolution).

In such a multi-hop network, each wireless slave unit in the network is identified and managed by the wireless master unit by the wireless unit number, and was originally conceived as an automatic meter reading system for collective housing. Therefore, when new housing complexes were built, radio numbers were assigned to each radio slave unit by manual operation.

Such a highly convenient automatic meter reading system is spreading to general detached houses, but it is difficult to introduce the automatic meter reading system to all the detached houses in a specific area all at once. Therefore, the wireless base unit is provided with a number issuing function for automatically allocating a wireless unit number to a new wireless slave unit so that the wireless master unit can issue a number to each of the wireless slave units. A radio number is assigned.

Prior art document information related to this type of automatic meter reading system includes the following patent document 1 and the like.

JP-A-2002-218569

However, the redundancy of the automatic meter reading system (measures to avoid system down by operating similar subsystems in the system always in parallel even if one of them fails) and the wireless base unit If there are multiple wireless base units in the same network, such as when replacing due to lifespan, there is a possibility that the same wireless base unit number will be issued for different wireless base units. There is a concern that communication may not be performed normally when the overlap occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a wireless network system capable of avoiding a situation in which normal communication cannot be performed due to duplication of wireless device numbers.

The present invention comprises a multi-hop network in which data from each wireless slave device is relayed by radio waves between a plurality of wireless slave devices and collected in a wireless master device, and each wireless slave device in the network is wirelessly In a wireless network system in which the wireless base unit identifies and manages the wireless base unit by the base unit number and assigns the wireless base unit a wireless base unit number to a new wireless base unit, wherein each of the wireless base units has the base unit number. It is characterized by implementing a determination means for detecting duplication of wireless device numbers, and configured to restart the wireless slave device itself and re-acquire a new wireless device number when a wireless device number duplication is detected. It is something to do.

Therefore, in this way, when a plurality of wireless master units exist in the same network, even if the same wireless slave unit numbers are issued for different wireless slave units, each wireless slave unit By the judgment means implemented in , duplication of its own radio device number is detected, and the radio slave device that detects the duplication of the radio device number restarts itself and acquires a new radio device number. A situation in which communication cannot be performed normally due to duplication of radio numbers is avoided.

Furthermore, in carrying out the present invention, each wireless slave device transmits a normal hop count table including its own information to surrounding wireless slave devices in the initial hop count table exchange performed when new entry into the network. It is preferable that the judging means detects duplication of the radio number when the radio number is included in the response to the transmission.

In addition, each wireless slave device transmits an empty hop count table that does not contain its own information to the surrounding wireless slave devices before exchanging the hop count table for the first time when it newly joins the network. The determination means may be configured to detect duplication of the wireless device number when the wireless device number is included.

Further, each wireless slave unit determines whether or not the wireless slave unit can receive a wide-area terminal update notification addressed to itself from the wireless master unit within a predetermined time after the initial exchange of the hop count table at the time of new entry into the network. It may be configured to detect duplication of numbers.

According to the wireless network system of the present invention described above, each wireless slave unit is equipped with determination means for detecting duplication of wireless device numbers, and when the determination means detects duplication of wireless device numbers, the wireless slave device itself restarts and reacquires a new radio number, it is possible to avoid a situation in which normal communication cannot be performed due to duplication of radio numbers.

BRIEF DESCRIPTION OF THE DRAWINGS It is the whole block diagram which applied the 1st Example of this invention to the automatic meter-reading system. FIG. 2 is a schematic diagram showing the structure of the wireless base station of FIG. 1; 2 is a schematic diagram showing the structure of the wireless slave device of FIG. 1; FIG. FIG. 4 is a block diagram showing a state before a new wireless slave device enters; FIG. 11 is a block diagram showing a state after a new wireless slave device has entered; FIG. 10 is a block diagram showing a state in which wireless slave devices with duplicate wireless device numbers have entered; 4 is a flow chart of a procedure for detecting duplication of wireless device numbers in the first embodiment; 8 is a flow chart of a procedure for detecting duplication of wireless device numbers in the second embodiment; 11 is a flow chart of a procedure for detecting duplication of radio numbers in the third embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention, exemplified in the case of a wireless network system applied to an automatic meter reading system for gas usage. Data from each wireless slave unit 20 is relayed by radio waves between a plurality of wireless slave units 20 connected to meters 1 and 2 (only two are shown in FIG. a wide area terminal 4 connected to the wireless master device 10 after the data from each wireless slave device 20 is integrated in the wireless master device 10. to a host computer 7 in a center 6 via a wide area communication line 5 such as PHS (Personal Handy-phone System) or LTE (Long Term Evolution).

In such a wireless network system, each wireless slave device 20 in the network 3 is identified and managed by the wireless master device 10 by the wireless device number, and a new wireless slave device 20 is identified by the wireless master device 10. For example, the five wireless slave units 20 shown in FIG. The wireless slave device 20 periodically transmits a short frame containing its own wireless device number, then waits for reception to check whether there is a transmission request addressed to itself, and then returns to the original state, repeating intermittent transmission. It's like The radio number of the radio base station 10 itself in FIG. 1 is FD.

The configuration of the wireless base unit 10 is as shown in FIG. 2. The communication unit 11 transmits and receives data by wireless communication with each wireless slave unit 20, and each wireless slave unit 20 is identified and managed by the wireless unit number. A control unit 12, an operation unit 13 for manually operating the initial settings of the wireless base unit 10, an exchange unit 14 for exchanging a hop count table, which will be described in detail later, with surrounding wireless slave units 20, and each wireless slave unit. 20, an issuing unit 16 for issuing the wireless device number of the wireless slave device 20 newly entering the network 3, and the response from each wireless slave device 20. and a storage unit 17 for storing information.

Also, the configuration of the wireless slave device 20 is as shown in FIG. A control unit 22 for judging whether or not the communication is relayed if it is addressed to the wireless base unit 10, a response unit 23 for instructing a response to the received wireless communication, and an operation for manually operating the initial settings of the wireless slave unit 20. 24, an acquisition unit 25 that performs number issuance request communication with the surrounding wireless slave units 20 or wireless base units 10 in order to acquire the wireless unit number at startup, and a hop count table exchange, which will be described in detail later, performed by the surrounding units. Information obtained based on the response from each wireless slave device 20, the exchange unit 26 that performs with the wireless slave device 20 or the wireless master device 10, the determination unit 27 that determines whether or not the wireless device number overlaps, which will be described in detail later. and a storage unit 28 for storing.

Each wireless slave device 20 is assigned a wireless device number by the wireless master device 10 when it newly joins the network 3. When activated by an activation instruction from the unit 24, a number issuance request communication for acquiring a wireless unit number is sent to the surrounding wireless slave units 20 or wireless master units 10 according to instructions from the acquiring unit 25. ing.

Furthermore, the wireless master device 10 that has received the number issue request communication by relay transfer from the wireless slave device 20 (wireless slave device 20 that is not the originator) or by direct communication from the wireless slave device 20 that is the originator receives the number issuance request communication. A new wireless device number is issued and number issue response communication is performed. , and in order to determine the communication path between the surrounding wireless slave device 20 or wireless base device 10 and the network 3, the switching unit 26 instructs to perform communication called hop number table switching.

The exchange of the hop count table means that the shortest number of wireless slave devices 20 (the number of hops) through which the other wireless slave device 20 can be reached is stored in a hop count table that is associated with the wireless device number. While transmitting to the wireless slave device 20 of the network 3, it refers to mutual communication in which the hop count table returned from the surrounding wireless slave devices 20 is received as a response. When the directly communicable route changes, the contents of the hop number table are edited and exchanged with each other to cope with the change of the network 3. The hop number table is exchanged at regular intervals. The repeatedly executed and exchanged hop count table is stored in the storage section 28 of each wireless slave device 20 .

A unique ID is assigned to the wireless slave unit 20 and the meters 1 and 2 connected to the wireless slave unit 20 by wire. However, the wireless master device 10 that has detected the entry of a new wireless slave device 20 into the network 3 by exchanging the hop count table for the first time detects the ID of the wide area terminal 4 wired to itself. to the new wireless slave unit 20, and a wide area terminal update notification for acquiring the IDs of the wireless slave unit 20 and its meters 1 and 2 is performed.

Here, a case where a wireless slave device 20 (wireless slave device number 04) that cannot directly communicate with the wireless master device 10 among the wireless slave devices 20 in the network 3 newly enters will be described as an example. As shown in the state before the device 20 participates, when the ones connected by the arrows in FIG. The number table is as shown in Table 1 below.

As shown in FIG. 5, when a new wireless slave device 20 (wireless device number 04) enters the network 3, this new wireless slave device 20 (wireless device number 04) is in a position where direct communication is possible. The hop count table is exchanged with two wireless slave devices 20 (wireless device number 01) and 20 (wireless device number 02). Assuming that the hop number table is exchanged with the wireless slave apparatus 20 (wireless apparatus number 01), the content of the hop number table of the wireless slave apparatus 20 (wireless apparatus number 04) in the initial state is as shown in the upper part of Table 2 below. Since the hop count table has not yet been exchanged with another wireless slave device 20, only its own wireless device number 04 and hop count (own hop count is 0) are registered in the hop count table. On the other hand, the contents of the hop count table of the wireless slave device 20 (wireless device number 01) are as shown in the lower part of Table 2 below.

Then, when the wireless slave device 20 (wireless device number 04) and the wireless slave device 20 (wireless device number 01) exchange the hop count tables, the wireless slave device 20 (wireless The wireless slave device 20 (wireless device number 01) is registered in the hop count table of the wireless slave device 20 (wireless device number 04) with a hop count of 1, and is also registered in the hop count table of this wireless slave device 20 (wireless device number 01). The radio numbers 00, 02, and 03 of the radio slave unit 20 and the radio number FD of the radio base unit 10 are registered with the number of hops +1. Child device 20 (wireless device number 04) is registered with a hop number of one.

Next, when the wireless slave device 20 (wireless device number 04) and the wireless slave device 20 (wireless device number 02) exchange the hop count table, the wireless slave device 20 (wireless device number 04) and the wireless slave device 20 ( The contents of the hop count table for the wireless device number 02) are as shown in the upper and lower rows of Table 4 below. ) exchanges the hop count table, the hop count table of the wireless slave device 20 (wireless device number 02) is added to the hop count table of the wireless slave device 20 (wireless device number 04) as shown in the upper and lower rows of Table 5 below. is updated to 1 and registered, and the hop counts of the other wireless slave devices 20 (wireless device numbers 00, 01, 03) and the wireless master device 10 (wireless device number FD) are changed to the wireless slave device 20 (wireless device number FD). The number of hops registered in the hop number table of No. 02) is updated to a smaller value than the number of hops registered in the hop number table + 1 (in this example, no update occurs), and the wireless slave device 20 (wireless device number 02), the wireless slave device 20 (wireless device number 04) is registered with a hop count of 1 in the hop count table.

Thereafter, the wireless slave devices 20 (wireless device number 01) and (wireless device number 02) whose hop count tables have been updated notify the surrounding wireless slave devices 20 and wireless master devices 10 that the hop count table has been updated. , the hop count tables are exchanged, and the same processing as described above is repeated. Finally, the hop count tables of all the wireless slave devices 20 and wireless base devices 10 in the network 3 are shown in Table 6 below. updated as follows.

At this time, in the example of FIG. 5, only one wireless master device 10 exists in the network 3, but in the case of making the automatic meter reading system redundant or replacing the wireless master device 10 due to its lifespan, etc., As mentioned above, when a plurality of wireless base stations 10 exist in the same network 3, the same wireless device number may be issued to different wireless slave devices 20. FIG.

Therefore, in this embodiment, determination means for detecting duplication of radio numbers is implemented in each of the radio slave units 20 as the determination unit 27, and when duplication of radio numbers is detected, the radio slave unit 20 It is configured so that it restarts itself and acquires a new wireless device number. hop count table is transmitted to the surrounding wireless slave units 20, and if the response to the transmission includes the own wireless unit number, the determining unit 27 (see FIG. 3) detects duplication of the wireless unit number. I'm trying

For example, as shown in FIG. 6, the wireless slave device 20 newly entering the network 3 (indicated by the wireless slave device number 03 in FIG. 6) is assigned the same wireless slave device number 03 as another wireless slave device 20. In this case, first, if the wireless slave device 20 (wireless device number 03 ) and the wireless slave device 20 (wireless device number 01) in a communicable position exchange the hop count table for the first time, the wireless slave device 20 in the initial state is The contents of the hop count table for (wireless device number 03 ) are as shown in the upper part of Table 7 below, and the contents of the hop count table for wireless slave device 20 (wireless device number 01) are shown in Table 7 below. It is as shown in the lower part.

When the wireless slave device 20 (wireless device number 03 ) and the wireless slave device 20 (wireless device number 01) exchange the hop count table for the first time, the hop count table includes its own wireless device number. The decision unit 27 (see FIG. 3) of the wireless slave device 20 (wireless device number 03 ) finds whether or not the wireless device number 03 is in the hop count table from the wireless slave device 20 (wireless device number 01). If it is confirmed that it is included, it is determined that there is a duplication of radio numbers, so the radio slave unit 20 (radio number 03 ) restarts itself and acquires a new radio number, After the wireless device number 04, which is not duplicated, is newly issued, the hop count table is exchanged again to eliminate the duplication of the wireless device numbers.

FIG. 7 is a flow chart showing a series of flow in which the wireless slave device 20 newly entering the network 3 confirms whether or not its own wireless device number overlaps in the initial exchange of the hop count table. After the number issuance request communication for acquiring the radio number is performed in S1, it is checked in step S2 whether or not the radio number has been acquired. While the communication is repeated, when the acquisition of the wireless device number is confirmed, the process proceeds to step S3 and the first time flag is turned on.

Next, in step S4, the hop count table is exchanged, and in the next step S5, it is checked whether or not the initial flag is on. If it is confirmed that the initial flag is on, the process advances to step S6 to turn off the initial flag. After that, the process proceeds to step S7, and it is confirmed whether or not the received hop number table of the exchange partner includes its own wireless device number.

In step S7, if the received hop number table of the exchange partner includes the own radio number, it is determined that the radio number overlaps, so the process returns to step S1. The number issuance request communication for reacquiring a new radio number will be executed again. Since it is determined that no duplication has occurred, the hop number table is edited in step S8, and then it is checked in step S9 whether or not the hop number table has been updated.

Here, in the first hop number table exchange that is performed immediately after acquiring the wireless device number, the hop number table is updated due to the new entry of the wireless device itself. In order to notify the surrounding wireless slave device 20 or wireless base device 10 of the update, the process returns to step S4 and the hop count table exchange is performed again. Since the first time flag has already been turned off, steps S6 and S7 are bypassed from step S5, and the hop number table is edited in step S8. After that, the reception process of various update notifications in step S10 is performed, and then the process ends.

In addition, as a second embodiment, an empty hop number table that does not contain information about itself is transmitted to the surrounding wireless slave units 20 before the initial exchange of the hop number table at the time of new entry into the network. Each wireless slave device 20 may be configured so that the determining unit 27 (see FIG. 3) detects duplication of the wireless device number when the own wireless device number is included.

For example, as shown in FIG. 6 used in the previous explanation, a wireless slave device 20 newly entering the network 3 (indicated by wireless slave device number 03 in FIG. 6) has the same wireless slave device number as another wireless slave device 20. 03 is assigned, in this second embodiment, the wireless slave device 20 (wireless device number 02), the wireless slave device 20 (wireless device number 02) responds with a hop count table as shown in Table 8 below, and the hop count table includes its own wireless device number 03. Whether or not there is is searched by the determination unit 27 (see FIG. 3) of the wireless slave device 20 (wireless device number 03 ).

As a result, if it is confirmed that the hop number table from the wireless slave device 20 (wireless device number 02) contains the wireless device number 03 of itself, it is determined that the wireless device number overlaps. 27 (see FIG. 3), the wireless slave device 20 (wireless device number 03 ) restarts itself and acquires a new wireless device number, and a new wireless device number 04 that is not duplicated is issued. After that, the hop count table is exchanged again for the first time to eliminate the duplication of the wireless device numbers.

FIG. 8 is a flow chart showing a series of flow in which the wireless slave device 20 newly entering the network 3 confirms whether or not its own wireless device number overlaps before the initial hop count table exchange. After the number issuance request communication for acquiring the radio number is performed in step S11, it is checked in step S12 whether or not the radio number has been acquired. While the request communication is repeated, when it is confirmed that the wireless device number has been acquired, the process proceeds to step S13, and an empty hop count table that does not include its own information is transmitted to the wireless slave device 20 at a communicable position.

Then, in the next step S14, it is checked whether or not the own radio number is included in the hop number table that has responded to the transmission of the empty hop number table, and if the own radio number is included. If so, it is determined that the radio number is duplicated, so the process returns to step S11 and the number issuance request communication for reacquiring a new radio number is executed again.

At this time, if the own radio unit number is not included in the preceding step S14, it is determined that there is no duplication of radio unit numbers, so the process proceeds to the next step S15, where the first exchange of the hop count table is performed. Once done, the hop-count table is edited in step S16, and then it is checked in step S17 if there has been an update to the hop-count table.

Here, in the first hop number table exchange that is performed immediately after acquiring the wireless device number, the hop number table is updated due to its own new entry. In order to notify the surrounding wireless slave device 20 or wireless base device 10 of the update, the process returns to step S15, and the hop count table is exchanged again. When there is no more update of the hop count table, the process proceeds to step S18, and after various update notifications are received, the process ends.

In addition, as a third embodiment, when a wide area terminal update notification addressed to itself from the wireless base unit 10 cannot be received within a predetermined time after the initial exchange of the hop count table at the time of new entry into the network, the determination unit 27 Each wireless slave device 20 may be configured to detect duplicate wireless device numbers (see FIG. 3).

That is, the wireless master device 10 that has detected the entry of a new wireless slave device 20 into the network 3 by exchanging the hop count table for the first time changes the ID of the wide area terminal 4 (see FIG. 1) connected thereto by wire. A wide area terminal update notification is provided to the wireless slave unit 20 and to acquire the IDs of the wireless slave unit 20 and its meters 1 and 2 (see FIG. 1).

At this time, if a wide-area terminal update notification addressed to itself from the wireless master device 10 cannot be received within a predetermined time after the initial exchange of the hop count table, another wireless slave device 20 whose wireless device number overlaps with itself cannot be received. Since it is presumed that the wide area terminal update notification has been sent, in the third embodiment, after the first exchange of the hop count table, the wide area terminal update notification addressed to itself from the wireless base unit 10 is not received within a predetermined time. 3, the determination unit 27 (see FIG. 3) determines that the radio slave unit 20 (radio unit number 03 ) is restarted and restarts itself. After the wireless device number is reacquired and a new non-overlapping wireless device number 04 is issued, the hop count table exchange is performed again for the first time to eliminate the duplication of the wireless device numbers.

FIG. 9 is a flow chart showing a series of flow in which the wireless slave device 20 newly entering the network 3 confirms whether or not its own wireless device number overlaps after the initial exchange of the hop count table. After the number issuance request communication for acquiring the radio number is performed in S21, it is checked in step S22 whether or not the radio number has been acquired. Communication repeats.

After that, when the acquisition of the wireless device number is confirmed, the process proceeds to step S23, where the hop number table is exchanged for the first time. After the hop number table is edited in the next step S24, the hop number table is updated in step S25. It is checked whether there was

Here, in the first hop number table exchange that is performed immediately after acquiring the wireless device number, the hop number table is updated due to its own new entry. In order to notify the surrounding wireless slave device 20 or wireless master device 10 of the update, the process returns to step S23 and the hop count table is exchanged again.

Then, when the hop number table is no longer updated in step S25 due to the second and subsequent hop number table exchanges, a timer (which may be incorporated in hardware or implemented in software) starts timing in step S26. Then, in the next step S27, reception processing of various update notifications is performed in parallel behind the timing, and in step S28, it is confirmed whether or not a wide area terminal update notification has been received.

At this time, if the reception of the wide area terminal update notification is confirmed in the previous step S28, it is determined that there is no duplication of the wireless device numbers, so the timer is stopped in the next step S29 and then the process ends. However, if the reception of the wide area terminal update notification is not confirmed in the previous step S28, the process proceeds to step S30, where the predetermined time has elapsed in which the wide area terminal update notification will be received from the wireless base unit 10 after the first hop count table exchange. (whether or not the time has expired), and before the predetermined time elapses, the process returns to step S27 to wait for the reception of the update notification. becomes.

However, if it is confirmed in the previous step S30 that the predetermined time has elapsed, it is determined that there is duplication of the wireless device numbers and that another wireless slave device 20 has been notified of the wide area terminal update notification. Therefore, the process is returned to step S21, and the number issuance request communication for reacquiring a new radio number is executed again.

It should be noted that the wireless network system of the present invention is not limited to the above-described embodiments, and is not limited to application to an automatic meter reading system regarding the amount of gas used. Of course, various changes can be made in .

3 Network 10 Wireless master device 20 Wireless slave device 27 Determination unit (determination means)

Claims (4)

A multi-hop network for relaying radio waves between a plurality of wireless slave units and collecting data from each wireless slave unit in a wireless master unit, wherein each wireless slave unit in the network is identified by a wireless unit number. In a wireless network system in which a wireless master unit identifies and manages and assigns a wireless unit number to a new wireless slave unit by the wireless master unit, each wireless slave unit detects duplicate wireless unit numbers. A wireless network system characterized in that it is configured so that when a duplication of a wireless device number is detected, the wireless slave device itself restarts and acquires a new wireless device number again. . Each wireless slave device transmits a normal hop count table including its own information to the surrounding wireless slave devices in the initial hop count table exchange performed when it newly joins the network, and responds with its own wireless slave device number. 2. The wireless network system according to claim 1, wherein the judging means is configured to detect duplication of the wireless device number when the . Each wireless slave device transmits an empty hop count table that does not contain its own information to surrounding wireless slave devices before exchanging the hop count table for the first time when it newly joins the network. 2. The wireless network system according to claim 1, wherein the judging means detects duplication of the wireless device number when the wireless device number is included. If each wireless slave unit cannot receive a wide area terminal update notification addressed to itself from the wireless master unit within a predetermined time after the initial exchange of the hop count table at the time of new entry into the network, the wireless slave unit determines the wireless unit number by the determination means. 2. The wireless network system of claim 1, configured to detect duplication.

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