JP5590396B2 - Wireless transmission / reception device and wireless communication network - Google Patents

Description

  The present invention relates to a wireless transmission / reception apparatus and a wireless communication network.

  A certain type of wireless communication network in which a plurality of wireless transmission / reception devices are interspersed and connected by a wireless network has attracted attention. In this wireless communication network, when a wireless transmission / reception device receives a message packet from another wireless transmission / reception device, it unconditionally transmits a message packet having the same content. That is, the wireless transmission / reception device also functions as a transfer device. Such transfer is repeated so that the message packet is finally transmitted to the target wireless transmission / reception apparatus.

Alternatively, in the case of broadcast communication, when a wireless transmission / reception device receives a message packet from another wireless transmission / reception device, the wireless transmission / reception device captures the message packet as necessary and transfers a message packet having the same content. By repeating such transfer, the message packet is finally transmitted to all the wireless transmission / reception devices.
Each wireless transceiver does not have communication path information. Therefore, since the transfer is performed without storing the communication path information in the wireless transmission / reception device, the capacity of the memory included in each wireless transmission / reception device can be reduced. In addition, wireless communication is possible even when the processing speed of the communication control unit (CPU) is low.

  However, a large number of wireless transmission / reception devices are in a transmission state at random simultaneously. As a result, there are cases where the radio traffic increases and becomes in an interference state, and the quality of the communication path cannot be maintained. In addition, since each wireless transmission / reception device is in a transmission state for a long time, power consumption in each wireless transmission / reception device is large, and it is difficult to use for a long time in a wireless transmission / reception device operating with a battery. This also occurred.

  Therefore, in order to solve such a problem, an original transmission source that is the address of the wireless transmission / reception device that first transmitted the message packet included in the message packet transferred by the wireless transmission / reception device to each wireless transmission / reception device. When the address and the message packet identification information for identifying the message packet are stored, and then the information included in the message packet received by the wireless transmission / reception apparatus matches the stored original transmission source address and message packet identification information Has proposed a method for controlling so as not to forward received message packets (Patent Document 1).

  In a wireless communication network employing this control method, each wireless transmitting / receiving device is provided with a return prevention function that does not transfer a message packet that has been transferred once and thereafter. That is, each wireless transmission / reception apparatus does not transfer again when the received message packet is a reverse message packet. As a result, the power consumption of the wireless transmission / reception apparatus can be reduced, and the performance of the wireless communication network can be improved.

JP 2010-114851 JP 2010-114852 JP

  In a transmission / reception relay system in which wireless transmission / reception devices having such a return prevention function are connected by a wireless communication network, when each wireless transmission / reception device receives a message packet transferred once, the transfer of the message packet is performed. By not performing the process, a situation may occur in which the message packet is stopped without being transferred from any wireless transmission / reception device before the message packet is finally transmitted to the target wireless transmission / reception device.

The reason for this is considered that the return prevention function of each wireless transmission / reception device works while the message packet bypasses each wireless transmission / reception device before the message packet reaches the destination wireless transmission / reception device. It is done.
Accordingly, an object of the present invention is to reduce the probability of occurrence of a situation in which a message packet is stopped due to the return prevention function of the wireless transmission / reception device, and a user-friendly wireless transmission / reception device, and its wireless transmission / reception It is to provide a wireless communication network applied to a device.

In order to achieve the above object, a wireless transmission / reception apparatus according to the present invention includes a transfer function for transferring a message packet from another wireless transmission / reception apparatus through a wireless communication network, and a message once transferred. If the same message packet a packet is received a predetermined number of times after, provided with anti-return function not transfer of the message packet, and a stop setting means which is set to stop the forwards message packets. The “predetermined number of times” may be an integer number of 2 or more. Further, when the message packet is received, a determination is made to determine whether or not to automatically activate the stop setting means according to a combination of the wireless transmission / reception device that is the destination of the message packet and the wireless transmission / reception device that is the original transmission source Means.

According to the wireless transmission / reception apparatus having this configuration, a message packet is transmitted from any of the wireless transmission / reception apparatuses. The wireless transmission / reception apparatus that has received the message packet transfers the message packet. Usually, such a transfer is performed one or more times, and the message packet reaches the target wireless transmission / reception device and is received. The wireless transmission device, when the same message packets once transfer message packets received a predetermined number of times since, with has a return preventing function does not transfer of the message packet, to stop the forwards message packets Is provided with stop setting means. Furthermore, since the stop setting unit is automatically provided with a determination unit that determines whether or not to operate the stop setting unit, when the “destination wireless transmission / reception device” cannot be directly communicated, the wireless transmission / reception device Such a stop setting means is made to function so as not to transfer the message packet from the wireless transmission / reception apparatus. As a result, “the message packet is bypassed before the message packet is finally transmitted to the target wireless transmission / reception device, and the return prevention function of each wireless transmission / reception device works, and the message packet stops. ”Can be reduced.

The stop setting means may include an operation member capable of manually setting transfer stop. In this case, the administrator or user of the wireless communication network can manually set the stop setting unit of the wireless transmission / reception device in a place where direct communication with many wireless transmission / reception devices is not possible .

The wireless transmission / reception apparatus may previously have a propagation condition table for determining whether to automatically activate the stop setting unit for each wireless transmission / reception apparatus serving as a destination.
The message packet may be a packet in which one or a plurality of wireless transmission / reception apparatuses serving as destinations are specified, or a packet in which a destination is not specified.
The “destination wireless transmission / reception device” refers to one or more wireless transmission / reception devices that are finally targeted. This “destination wireless transmission / reception device” is specified by using the “destination address” when another wireless transmission / reception device transmits a message packet. It may be specified by registering the “destination” as seen from the “device”.

Even when a message packet is transmitted without specifying a destination address, such as broadcast communication or broadcast, if the wireless transceiver that receives the message packet itself captures the message packet, specify the destination address. Thus, the present invention can be applied in the same manner as a wireless transmission / reception apparatus that performs transmission.
The wireless communication network of the present invention is configured by connecting the wireless transmission / reception apparatus of the present invention.

  As described above, according to the present invention, by not causing any wireless transceiver to transfer a message packet, the transfer route is shortened so that the message packet reaches the target wireless transceiver in the shortest course. be able to.

It is a figure which shows the outline | summary of a radio | wireless communication network. It is a block diagram of a radio | wireless transmission / reception apparatus. It is a figure which shows the structure of a control data area. It is a figure which shows the content of the log | history table of a radio | wireless transmitter / receiver. It is a flowchart for demonstrating the process of the "return prevention function" in which the transfer stop procedure which is the characteristics of this invention is set. It is a flowchart for demonstrating the setting procedure of the transfer stop concerning other embodiment. It is a figure which shows an example of the propagation condition table of the wireless transmission / reception apparatus A. It is a figure which shows the outline | summary of the radio | wireless communication network applied to broadcast communication.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a diagram showing an outline of a wireless communication network. The wireless communication network includes wireless transmission / reception devices A to H and a wireless network that connects them. The wireless transmission / reception devices A to H basically have the same configuration. However, within a feasible range, for example, some of the wireless transmission / reception devices A to H can have different configurations, for example, a part of the wireless transmission / reception devices may have a configuration dedicated to reception or a configuration dedicated to transmission. In FIG. 1, among the wireless transmission / reception apparatuses A to F, the wireless transmission / reception apparatus F functions as a dedicated reception apparatus. In the embodiment illustrated in FIG. 1, the number of wireless transmission / reception devices is described as eight, but the number of wireless transmission / reception devices is not limited thereto. Moreover, although it demonstrates as each of the radio | wireless transmission / reception apparatus AH being a radio | wireless transmission / reception apparatus which moves, the one part or all part may be attached to a fixed position.

  Although the frequency band used in a wireless network is not limited, For example, it is set as each frequency band of 429 MHz, 1.2 GHz, and 2.4 GHz. In addition, the transmission power of the wireless transmission / reception apparatus is a specific low power of about 1 to 10 mW. In addition, each communicable range of the wireless transmission / reception apparatus is, for example, a range of about 200 m to 300 m. In this specification, “wireless” includes infrared communication.

  FIG. 2 is a block diagram of the wireless transmission / reception apparatus A. Other wireless transmission / reception devices have the same configuration as the wireless transmission / reception device A. In FIG. 2, a portion surrounded by a broken line is a wireless transmission / reception device A. The wireless transmission / reception device A includes a transmission unit 102, a reception unit 103, a communication control unit 104, a ROM (Read Only Memory) 105, and a RAM (Random Access Memory). 106, an interface unit 107, a power supply unit 108, a stop setting switch 110, an indicator 111, and an internal sensor 112. Further, an antenna 101 and other input / output devices 109 are provided outside the wireless transmission / reception device A.

The transmission unit 102 and the reception unit 103 are configured integrally with a modulation unit, a power amplification unit, a high frequency amplification unit, and a demodulation unit.
The communication control unit 104 is configured around a central processing unit (CPU), and its function is to execute a control program stored in the ROM 105 while using the RAM 106 which is a temporary storage area. The RAM 106 is non-volatile, and also functions as a history table that stores information on reception history, which will be described later, and a propagation condition table that stores conditions related to radio wave propagation of the wireless transmission / reception apparatuses A to H. The interface unit 107 employs asynchronous serial communication. The communication control unit 104, the ROM 105, the RAM 106, and the interface unit 107 are mounted on one microcomputer.

The power from the power supply unit 108 is supplied to the transmission unit 102, the reception unit 103, the communication control unit 104, and the like, and is also supplied to other input / output devices 109 connected as necessary. The power supply unit 108 is, for example, a lithium ion battery or a dry battery.
The stop setting switch 110 is a switch that is set so as to stop the reception or transmission of the message packet of the wireless transmission / reception apparatus. For example, a DIP switch or a slide switch is used. The indicator 111 is turned on when a test signal for measuring radio wave sensitivity up to each wireless transceiver is received. When the test signal is received, if the radio wave sensitivity is higher than a predetermined threshold value, the green light is turned on. When the radio wave sensitivity is lower than the predetermined threshold value, red is lit, and when the radio wave does not reach, it is not lit.

As the other input / output device 109, for example, a fire alarm as various sensors, an automatic meter reading device such as gas, electricity, and water, and a valve controller and an alarm transmitter as various actuators are used. Furthermore, various input / output devices such as a microphone and a headphone are appropriately used depending on the application.
In addition, the reception-only wireless transmission / reception device F provided for the purpose of collecting information from each wireless transmission / reception device in one place may have, for example, a printer as an input / output device.

  The internal sensor 112 is a function of the other input / output device 109 by the wireless transmission / reception device itself. For example, a wireless transmission / reception apparatus can be installed outdoors and a message packet can be transmitted when the temperature reaches a predetermined temperature. Further, a wireless transmission / reception device may be installed on the slope of a mountain, and a message packet may be transmitted when the wireless transmission / reception device falls down due to a sediment disaster or the like.

  The message packet of data to be transmitted has a preamble area indicating the start of the message packet, a synchronization area for synchronizing data, a length area describing the length of data to be communicated (how many bytes), A control data area, an original transmission source ID area, a message area, and a CRC (CRC: Cyclic Redundancy Check) area are included. This message packet structure is used for communication between all wireless transmission / reception apparatuses in the wireless network of the embodiment shown in FIG.

  In the original transmission source ID area, the identification number of the wireless transmission / reception apparatus that first transmitted the message packet is specified. In the message area, the content of the message (information) to be communicated is specified. The CRC area is also called a cyclic redundancy check area. Except for the preamble area and the synchronization area, the cyclic redundancy code for the length area to the message area is generated and stored, and whether or not the information is normally transmitted. Has been made so that you can check.

As shown in FIG. 3, the control data area includes a destination address, a transmission source address, a message packet type, message packet identification information, a valid data length, a frequency number, a remaining retransmission count / maximum transfer count, an original transmission source address, and the like. Described.
Here, the destination address is an address (identification address) unique to the wireless transmission / reception device F that is a wireless transmission / reception device that should receive information. A plurality of wireless transmission / reception devices can be designated as the destination address.

The transmission source address will be described with reference to FIG. 1. In the message packet transmitted from the wireless transmission / reception device A to the wireless transmission / reception device D, the identification address of the wireless transmission / reception device A, and from the wireless transmission / reception device D to the wireless transmission / reception device E. In the transferred message packet, the identification address of the wireless transmission / reception device D is the source address.
The types of message packets can be broadly classified as data signals or test signals for measuring radio wave sensitivity up to each wireless transmission / reception device. Further, in the case of a data signal, it is described what kind of message packet it is, for example, whether it is sensor data or voice.

The message packet identification information is a number for identifying each message packet.
The valid data length indicates how many bytes are valid data in the message area.
The frequency number is given in advance for each frequency to be transmitted, and even when a plurality of transmission frequencies are selected in the wireless network, it is possible to recognize which frequency is used by the frequency number. it can.

  The remaining number of retransmissions is data set by the wireless transmission / reception apparatus that is the original transmission source. This is obtained by subtracting the current number of retransmissions from the maximum number of retransmissions allowed in advance, and indicates the number of remaining retransmissions that are permitted. The maximum number of retransmissions is the number of times that a message packet having the same content is allowed to be retransmitted from a wireless transmission / reception device of the original transmission source to a wireless transmission / reception device having the same destination.

Whether or not the destination is the same wireless transmission / reception device is specified by the transmission source address and the destination address in the control data area.
The maximum number of transfers indicates how many wireless transmission / reception apparatuses are allowed to transmit the message packet from the original transmission / reception apparatus to the destination wireless transmission / reception apparatus (limit number). If the number of transfers is equal to or greater than the maximum number of transfers, the transfer from the wireless transmission / reception device is stopped.

  The original transmission source address is the address of the wireless transmission / reception device that first transmitted the message packet. Referring to FIG. 1, in the message packet transmitted from the wireless transmission / reception apparatus A to the wireless transmission / reception apparatus D, the identification address of the wireless transmission / reception apparatus A is transferred from the wireless transmission / reception apparatus D to the wireless transmission / reception apparatus E. The identification address of the wireless transmission / reception apparatus A is similarly written in the packet.

In the wireless communication network of the present embodiment, the communication control unit 104 of the wireless transmission / reception device sets a transfer waiting time when receiving a message packet from another wireless transmission / reception device through the wireless communication network, and within the transfer waiting time. If it is determined that no wireless transceiver has received the message packet, it has a transfer function for starting transfer of the message packet.
In this transfer function, when there are a plurality of wireless transmission / reception devices in a communicable area, a state in which the wireless transmission / reception devices cooperatively change the time of carrier sense and transfer is simultaneously performed from the plurality of wireless transmission / reception devices. A system (cooperative transfer) that prevents the occurrence is used. Here, “carrier sense” refers to a certain time (carrier sense time) as a starting point (carrier sense time starting point), waiting for a predetermined time (carrier sense time), and transmission (transfer) from another wireless transmission / reception device within that predetermined time. This is a technology in which when it recognizes that there is no transmission, it starts transferring itself, and when it recognizes that transmission (transfer) from another wireless transmission / reception apparatus has been performed, it does not transfer itself. The carrier sense time is a time set for each wireless transmission / reception device within a certain upper limit value range. Note that setting the carrier sense time in the initial stage causes duplication in the initial carrier sense time, and the simultaneous transfer state may be fixed. Therefore, “random weight” is added (see Patent Document 1).

Further, the communication control unit 104 has a return prevention function that does not transfer the message packet when the same message packet as the message packet transferred once is received after the second time. This return prevention function will be described.
Prior to the description of the “return prevention function”, first, a conventional transfer method will be described. In the conventional transfer method, a wireless transmission / reception device (second wireless transmission / reception device) that receives information from another wireless transmission / reception device (first wireless transmission / reception device) transfers the received information unconditionally. At this time, the number of wireless transmission / reception devices that receive information from the first wireless transmission / reception device is not limited to the second wireless transmission / reception device, and may be plural. Similarly, the wireless transmission / reception device (third wireless transmission / reception device) that has received information from the second wireless transmission / reception device also transfers unconditionally. Also in this case, the number of wireless transmission / reception devices that receive information from the second wireless transmission / reception device is not limited to the third wireless transmission / reception device, and there may be a plurality of wireless transmission / reception devices. In this way, information is transferred from one to the next, and signal transmission beyond the communicable distance of one wireless transmission / reception device is enabled.

  Information may be transmitted from the first wireless transceiver to the second wireless transceiver, and further to the first wireless transceiver. The transmission of information from the second wireless transmission / reception device to the first wireless transmission / reception device in this manner is referred to as “return”. As a result of reversal, the same information is repeatedly exchanged between the first wireless transceiver and the second wireless transceiver.

In this way, the reversal is repeated between the wireless transmission / reception devices many times.
In the above, only the relationship that occurs between the two wireless transmission / reception devices has been described, but a similar relationship occurs in every part of the wireless network. This results in a lot of unnecessary transmissions. In the example of FIG. 1, the purpose of communication is achieved when information is transmitted from the wireless transmission / reception device A to the wireless transmission / reception device F. Thereafter, it is not necessary to emit a radio wave related to this information. However, according to the conventional transfer method, each wireless transmission / reception apparatus continues to emit unnecessary radio waves in a disorderly manner until the transfer count reaches the maximum transfer count. The “return prevention function” is a technique for preventing the occurrence of such a situation.

FIG. 5 is a flowchart showing the processing of the “return prevention function” performed in each wireless transmission / reception device. The processing of the “return prevention function” is performed mainly by the CPU of the communication control unit 104.
Prior to the description of the flowchart shown in FIG. 5, “message packet history” (hereinafter, abbreviated as history), which is the content of the history table formed in the RAM 106, will be described.

  FIG. 4 is a diagram illustrating the contents of a history table of a certain wireless transmission / reception device (hereinafter abbreviated as the wireless transmission / reception device). In the RAM 106 of the wireless transmission / reception device, a part of the content of the control data (FIG. 3) of the message packet received by the wireless transmission / reception device is held as a history table. The order of history 1, history 2, history 3, and history 4 is the order in which the wireless transmitting / receiving apparatus has received the message packet. That is, the message packet represented by the history 1 is received at the earliest time, and then the message packets regarding each of the history 2, the history 3, and the history 4 are sequentially received by the wireless transmission / reception apparatus. Each history is stored in a history table of the RAM 106 in a first-in first-out manner. That is, after a series of “return prevention function” processing is completed, the oldest history 1 is deleted, the number of each history is incremented, and the history received next to history 4 (referred to as history 5) is history 4 Overwritten on top of. The pointer can be used to specify which history is to be read. The contents stored for each of history 1 to history 4 are “original transmission source address”, “message packet type”, “message packet identification information”, and “number of remaining retransmissions”.

The history table may be a part of the content of the control data of the message packet transmitted by the wireless transmission / reception device, instead of a part of the content of the control data of the message packet received by the wireless transmission / reception device. At this time, the order of the history indicates the order in which the wireless transmission / reception apparatus transmits message packets.
The flowchart shown in FIG. 5 will be described. First, in step S1, the communication control unit 104 recognizes reception of a received message packet (one newly received message packet). More specifically, every time the receiving unit 103 receives a message packet, the content of the control data is transferred to the communication control unit 104, and the communication control unit 104 recognizes the reception.

  In step S2, the communication control unit 104 determines whether or not the original transmission source of the received message packet is itself (the wireless transmission / reception apparatus). Since the communication control unit 104 stores the identification address assigned in advance to its own wireless transmission / reception device, if the original transmission source address matches the identification address, affirmative (Yes), that is, the wireless transmission / reception device If it is determined that it is the original transmission source and the original transmission source address and the identification address do not match, it is negative (No), that is, it is determined that the wireless transmission / reception apparatus is not the original transmission source.

  If the result of determination in step S2 is Yes, the original transmission source is the wireless transmission / reception device, and the message packet transmitted by the wireless transmission / reception device is received by the wireless transmission / reception device via another wireless transmission / reception device. There is nothing else to do. Therefore, the process proceeds to step S9. In step S9, the communication control unit 104 discards the received message packet. Here, discarding the received message packet means that the message packet corresponding to Yes as a result of the determination in step S2 is not transferred. After the processing in step S9, the series of return prevention function processing ends.

If the result of the determination at step S2 is No, the process proceeds to step S3. In step S <b> 3, it is determined whether or not “setting of transfer stop” has been made in the wireless transmission / reception apparatus. This transfer stop setting is a feature of the present invention, and its meaning will be described later.
If “transfer stop setting” has not been made, the communication control unit 104 reads the previously received history from the history table of the RAM 106 in step S4. In this case, in the loop constituted by step S4 to step S6, the history read first is the history 4 (most recent history) shown in FIG. Note that if the number of histories to be read is set to one, the process of step S6 is not required.

In step S5, the communication control unit 104 compares the content of the history 4 received previously with the content of the information (history 5) included in the message packet received this time.
There are four comparison contents: “original transmission source address”, “message packet type”, “message packet identification information”, and “number of remaining retransmissions”, and these four are compared. . When the “message packet type” is fixed to one type, the comparison contents are “original transmission source address”, “message packet identification information”, and “remaining retransmission count”. However, the types of comparison contents are not limited to 3 to 4, and it is sufficient that the identity of the message packet can be specified, and it may be even smaller. For example, two of “original transmission source address” and “message packet identification information” may be used.

  In the following description, it is assumed that there are four comparison targets. When the contents of the information (history 5) included in the received message packet and the contents of the history 4 coincide with each other, it is determined affirmative (Yes) in step S5 and received. If the content of the information (history 5) included in the message packet does not match the content of the history 4, it is determined to be negative (No).

If the result of the determination in step S5 is Yes, it is “reverse”, so that the process moves to step S9, and the series of processing ends without the wireless transmitting / receiving apparatus transferring. If the result of the determination at step S5 is No, the process proceeds to step S6.
In step S6, the communication control unit 104 determines whether the information (history 5) included in the received message packet has been compared with the contents of all the history tables. That is, four comparisons are made between the contents of history 5 and the contents of history 4, the contents of history 5 and the contents of history 3, the contents of history 5 and the contents of history 2, and the contents of history 5 and the contents of history 1. It is determined whether or not.

When it is determined that the comparison between the content of the information (history 5) contained in the received message packet and the content of the other four histories is complete, it is determined to be affirmative (Yes), The process proceeds to step S7 without comparison. If it is determined that the process has not ended, the process returns to step S4.
In step S4, the communication control unit 104 reads a history that has not been compared with the information (history 5) included in the received message packet. That is, if only the comparison between the history 5 and the history 4 is completed, the history 3 that is not compared is read. Since the processes in steps S4 to S6 are included in the loop, they are repeated a plurality of times.

  In the processing so far, when it is found in step S5 that the content of the information (history 5) included in the message packet matches the content of the history stored in the RAM, the process immediately proceeds to step S9, and the message packet is changed. Although it was abandoned, the following modifications are also possible. In step S5, the number of times that the contents match is counted. If two or more predetermined times (for example, two times) match, the process may proceed to step S9 for the first time. That is, it is a process of recognizing reversal up to once and prohibiting transfer when it occurs twice.

In step S7, the communication control unit 104 transfers the received message packet (message packet related to the history 5).
Then, as shown in step S8, the message packet (message packet related to the history 5) is written in the RAM 106 as the history 4, the original history 4 is moved to the history 3, the original history 3 is moved to the history 2, and the original The history 2 is moved to the history 1 and the original history 1 is discarded.

  Further, when the history table is a part of the content of the control data of the message packet transmitted by the wireless transmission / reception device, the “reception history” in steps S4 and S8 is read as “transmission history”. Note that setting the history table in this way is preferable because the message packet can be transferred once and the possibility of message packet loss is reduced. That is, at this time, even if the same message packet is received before the first received packet is not transferred (transmitted) due to carrier sense, the message packet is not transferred yet. The degree can be transferred.

This completes the reverse process.
That is, the contents of the reverse processing described above are summarized as follows. When the information (history 5) included in the received message packet matches the information regarding each of the multiple transfers stored in any of the history 4 to history 1 of the RAM 106, the received message packet is Control not to transfer.

By applying the above-mentioned “return prevention function” to the conventional transfer method, at least the latest plurality of message packets are compared with the currently received message packet, and whether or not the message packet is “returned back”. I can confirm. In this way, the occurrence of reverse return can be effectively prevented by the processing of the “return prevention function”.
However, in actual operation, in a transmission / reception relay system in which wireless transmission / reception devices provided with such a return prevention function are connected by a wireless communication network, each wireless transmission / reception device finally has a target wireless transmission / reception. Before the message packet is transmitted to the device, a situation may occur in which the message packet is stopped without being transferred from any wireless transmission / reception device.

The reason for this is considered that the return prevention function of each wireless transmission / reception device works while the message packet bypasses each wireless transmission / reception device before the message packet reaches the destination wireless transmission / reception device. It is done.
Therefore, in the embodiment of the present invention, it is determined whether or not “setting of transfer stop” has been made in the wireless transceiver (FIG. 5; step S3). The transfer stop setting is set so that the system administrator operates the stop setting switch 110 (FIG. 2) to stop the transfer of the message packet of the wireless transmission / reception apparatus.

  The standard for stopping the transfer is to perform a test signal transmission / reception operation for measuring radio wave sensitivity between the receiver F and each radio transceiver, and each radio transceiver that has received the test signal has a predetermined threshold. When the value is higher than the value, the green color of the indicator 111 is turned on. When the radio wave sensitivity is lower than the predetermined threshold value, red is lit, and when the radio wave does not reach, it is not lit.

Next, the transmission of the test signal of the reception source F is stopped, and the wireless transmission / reception device showing red, for example, the wireless transmission / reception device D located between A and the reception source F transmits the test signal, and the wireless transmission / reception device If A shows green, the transfer function of the wireless transceiver D that transmitted the test signal is turned ON. According to the above procedure, it is determined which of the wireless transmission / reception apparatuses stops the transfer.
As a result, by adopting the reverse processing, the return prevention function of each wireless transmission / reception device works while the wireless packet transmission / reception device bypasses each wireless transmission / reception device before reaching the destination wireless transmission / reception device. Can be prevented. Therefore, the number of times that the original transmission source has to retransmit is reduced, and the time when the message packet is wasted can be reduced. Therefore, when a battery that cannot be recharged is used for the power supply unit of the wireless transmission / reception device. Prevents the battery from being consumed, and when a rechargeable battery is used, the battery can be used without being charged.

Next, another embodiment of the present invention will be described.
FIG. 6 is a partial flowchart showing another embodiment of “transfer stop setting” in the “return prevention function” process (FIG. 5). When the communication control unit 104 recognizes reception of the message packet in step S1, in step S2, the communication control unit 104 determines whether or not the original transmission source of the received message packet is itself (the wireless transmission / reception apparatus). If the original transmission source matches the identification address, the process proceeds to step S9, and the communication control unit 104 discards the received message packet. Up to this point, the processing procedure is the same as in FIG.

If the original transmission source does not match the identification address in step S2, the process proceeds to step S3a. In step S3a, the destination wireless transmitter / receiver is searched using the propagation condition table.
Here, the propagation condition table is a table for determining whether or not to transfer a message packet received from another wireless transmission / reception device. Whether or not to perform the transfer is determined according to a predetermined condition depending on the combination of the “original transmission / reception apparatus” and the “destination wireless transmission / reception apparatus” of the message packet. The predetermined condition is, for example, set so that the received message packet is not forwarded when the wireless transmission / reception apparatus is located on the opposite side of the destination wireless transmission / reception apparatus as viewed from the original transmission / reception apparatus To do. As a result, the “return” of the message packet can be suppressed, and as a result, the loss of the message packet can be prevented. The propagation condition table is individually held by each wireless transmission / reception device, and is stored in the RAM 106, for example.

FIG. 7 is a diagram illustrating an example of a propagation condition table of the wireless transmission / reception apparatus A. In the propagation condition table held by the wireless transmission / reception apparatus A, the wireless transmission / reception apparatuses of the original transmission source are denoted as A to H, and the wireless transmission / reception apparatuses as destinations are denoted as A to H. In the table, “◯” means that a message packet is transferred, and “X” means that a message packet is not transferred.
According to the propagation condition table, when a message packet is transmitted from the wireless transmission / reception apparatus D as the original transmission source to the wireless transmission / reception apparatus F that is the destination, the propagation condition table of the wireless transmission / reception apparatus A in FIG. Yes. This is because the wireless transmission / reception device A is located on the opposite side of the destination wireless transmission / reception device F as viewed from the original wireless transmission / reception device D, and there is a risk of packet loss or transfer delay via the wireless transmission / reception device A. Because there is, it is “x”.

  Next, when a message packet is transmitted from the wireless transmission / reception apparatus H that is the original transmission source to the wireless transmission / reception apparatus G that is the destination, the propagation condition table of the wireless transmission / reception apparatus A is “◯”. This is because the wireless transmission / reception apparatus A is located between the wireless transmission / reception apparatus H as the original transmission source and the wireless transmission / reception apparatus G as the destination. For example, even when a packet does not reach between the wireless transmission / reception apparatuses C and E, The packet can be surely delivered to the wireless transmission / reception apparatus G as the destination via the transmission / reception apparatus A. In this propagation condition table, each wireless transmission / reception apparatus has a separate table, and by determining whether or not transfer is necessary, network congestion can be further avoided.

In general, the propagation condition table can be created based on the position information of each wireless transmission / reception device and the distance information between the wireless transmission / reception devices, but may be created as follows.
The own wireless transmission / reception device issues a command to collect the history table of each wireless transmission / reception device, and collects the history table from each wireless transmission / reception device. When collecting, by collecting together the original transmission source address of each wireless transmission / reception device, it is possible to associate the collected history table with the wireless transmission / reception device that transmitted the history table. Based on these collected history tables, a wireless transmission / reception apparatus having a reception history is specified with reference to a history table of a wireless transmission / reception apparatus as a destination. A message packet whose original wireless transmission / reception apparatus is the original transmission source is set to “x” in its own propagation condition table. The message packet whose original transmission source is the other wireless transmission / reception apparatus is set to “◯”. That is, it means that a message packet whose original transmission source is the wireless transmission / reception device in the history table of the destination wireless transmission / reception device is not transferred.

In step S3a, if the received message packet corresponds to “x” in the propagation condition table, the process proceeds to step S9 and the received message packet is discarded. When it corresponds to “◯” in the propagation condition table, the process proceeds to step S4 to enter a process of determining a history match.
Instead of manually setting the transfer stop in this way, the propagation condition table is created by referring to the history table of the wireless transmission / reception device as the destination collected by each wireless transmission / reception device. Then, the message packet from the wireless transmission / reception device in the history table is not transferred, and the message packet from the wireless transmission / reception device not in the history table is transferred after the return prevention check.

Therefore, as compared with the case where the transfer stop setting is manually performed, the destination wireless transmission / reception apparatus does not need to be fixed exclusively for reception. Any wireless transmission / reception device written in the propagation condition table has an advantage that the transfer stop can be handled regardless of which wireless transmission / reception device is the destination.
FIG. 8 is a diagram showing an outline of a wireless communication network in the case of broadcast transmission for transmitting the message packet whose destination is not specified. Among the wireless transmission / reception apparatuses A to H, the wireless transmission / reception apparatuses F, G, H located far from the center register themselves as “destination” as viewed from “other wireless transmission / reception apparatuses”. In addition to functioning as a receiver for capturing packets, the transfer of message packets is stopped by setting the stop setting means. Similar to the radio transceivers F, G, and H, the radio transceiver D has a transfer function in addition to functioning as a receiver. The other radio transmission / reception devices B, C, and E do not receive and function only for transfer. In such an embodiment shown in FIG. 8, the radio transmission / reception apparatuses H, F, and G located far away from the center are supposed not to transfer message packets from the radio transmission / reception apparatus by causing the stop setting means to function. For example, the message packet is bypassed before the message packet is finally transmitted to the target wireless transmission / reception device, and the return prevention function of each wireless transmission / reception device works, and the message packet stops. The occurrence probability of the situation can be reduced. Note that it is a matter of operation to determine which wireless transmission / reception device has the function of not transferring message packets, and it is necessary to set it to the optimum state while confirming whether communication is performed smoothly. do it.

  Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above-described embodiments. For example, the determination in steps S3a and S3b in the flowchart of FIG. 6 is performed using the propagation condition table, but the calculation may be performed based on the coordinate information of each wireless transmission / reception apparatus without using the table. In addition, various modifications can be made within the scope of the present invention.

A to H Radio transceiver 101 Antenna 102 Transmitter 103 Receiver 104 Communication controller 105 ROM (Read Only Memory)
106 RAM (Random Access Memory)
107 Interface unit 108 Power supply unit 109 Other input / output device 110 Stop setting switch

Claims (5)

A wireless transceiver connected to a wireless communication network,
When a message packet is received from another wireless transmission / reception device through the wireless communication network, the transfer means for transferring the message packet and the same message packet as the message packet transferred once are received after a predetermined number of times, with a return prevention means does not transfer the message packet, and a stop setting means which is set to stop the forwards message packets,
Further, when the message packet is received, a determination is made to determine whether or not to automatically activate the stop setting means according to a combination of the wireless transmission / reception device that is the destination of the message packet and the wireless transmission / reception device that is the original transmission source radio transceiver, characterized in that it comprises means. The wireless transceiver is further in accordance with a combination of a wireless transmission device and the original source of the wireless transmission device of the destination, with advance whether the propagation conditions table automatically actuating the stop setting means, according to claim 1, wherein Wireless transceiver. Said message packet, the radio transceiver according to claim 1 or claim 2 as the destination one or more wireless transceiver is a packet specified. The wireless transmission / reception apparatus according to claim 1, wherein the message packet is a packet whose destination is not specified. Etc. plurality of radio transceiver equipment with a radio communication network for connecting the bovine,
The wireless transmission / reception device receives a message packet from another wireless transmission / reception device through the wireless communication network, and transfers the message packet. when receiving, the return prevention means does not transfer of the message packet, in the case where a stop setting means which is set to stop the forwards message packets, and further receives the message packet, the message packet A wireless communication network comprising: a determination unit that determines whether or not to automatically activate the stop setting unit according to a combination of a wireless transmission / reception device that is a destination of a wireless transmission device and a wireless transmission / reception device that is an original transmission source .

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