JP2013207463A - Radio communication device and control system using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication device and a control system using the same device, capable of preferential communication in distinction of the own radio network from another radio network, irrespective of an interference condition from the other radio network.SOLUTION: In a radio communication device constituted by a plurality of communication stations, a communication station on the transmission side transmits a communication frame that includes, in a header portion, identification information enabling the recognition of master-slave relationship between which communication is to be made. From the identification information in the header of the received communication frame, a communication station on the reception side confirms the master-slave relationship between which communication is to be made, to perform preferential communication with the communication station on the transmission side.

Description

  The present invention relates to a wireless communication apparatus and a control system using the same, and more particularly, to a wireless communication apparatus that performs data communication with emphasis on real-time performance in a multi-hop wireless network and a control system using the wireless communication apparatus.

  As a technique for performing communication between desired radio stations, there is a multi-hop radio network communication technique in which a plurality of radio stations are installed as relay stations between the radio stations and data is exchanged in a multi-hop manner. On the other hand, in recent years, along with cost reduction of wireless communication devices such as wireless LAN (Local Area Network) and standardization of sensor network technologies such as Bluetooth (registered trademark) and ZigBee (registered trademark), expectation of application of wireless technology in the industrial field. The number of application cases is increasing.

  Examples of applications of the multi-hop wireless network described above in the industrial field include, for example, application to social infrastructure projects such as electric power and transportation, and monitoring and control networks of manufacturing industries such as FA (Factory Automation) and PA (Process Automation). It is expected to contribute to the reduction of monitoring and control cables.

  Specifically, by making a wired cable for transmitting and receiving control signals and detection signals wireless, it is possible to reduce the cable laying cost and the maintenance cost during periodic inspection. Further, by utilizing wireless technology, a business operator can respond more flexibly to operational changes such as addition of devices and changes in the configuration of devices.

  On the other hand, in order to apply wireless technology to a control network, it is necessary to be able to exchange control information in an emergency while maintaining communication reliability even when interference occurs.

  Carrier sense multiple access / collision avoidance method CSMA / CA (Carrier Sense Multiple Access / Collision Aidance), which is an access control method in the wireless communication conforming to the IEEE 802.11 standard, which is widely used at present, has priority as in emergency information. In the case of transmitting high information, a method is known in which communication is preferentially performed by shortening a back-off time, which is a transmission waiting time before transmission, as compared with normal priority information.

  Further, as a method for enabling preferential communication, Patent Document 1 describes a wireless communication apparatus including a communication control method for performing communication without providing a back-off time.

JP 2004-194237 A

  However, in the method of Patent Document 1, when a wireless node including a base station and a terminal station receives data, it is a wireless network to which its own wireless node belongs (hereinafter referred to as its own wireless network) or other wireless network. The high-speed communication mode is started regardless of whether it is a network (hereinafter referred to as another wireless network).

  For this reason, assuming that the wireless node that performs communication with reduced back-off time is that of another wireless network, because of the communication waiting time that occurs when truly urgent communication occurs in its own wireless network, There was a problem that communication with high priority was hindered in the own wireless network.

  From the above, in the present invention, a wireless communication device that distinguishes between its own wireless network and other wireless networks and can preferentially communicate regardless of interference from other wireless networks, and a control system using the wireless communication device are provided. The purpose is to provide.

  As described above, in the present invention, a wireless communication apparatus including a plurality of communication stations, the communication station on the transmission side uses identification information that can recognize the parent-child relationship that it is a communication partner as a header part. The receiving communication station confirms the parent-child relationship that it should communicate with the identification information in the received header in the communication frame, and prioritizes communication with the transmitting communication station. A wireless communication device that performs communication and a control system using the wireless communication device.

  According to the present invention, when a truly urgent transmission data exists in the own wireless network in a wireless network having an open communication connection, communication is preferentially performed regardless of interference from other wireless networks. It becomes possible to do.

The figure which shows the structure of the communication station S used with a communication network. The figure which shows the typical structure of a communication network. The figure which shows the example of arrangement | positioning state of the communication node (communication station) in a network. The figure which shows an exclusive communication frame structure. The figure which shows the transmission processing flow of an exclusive communication frame. The figure which shows an example of the reception processing flow of an exclusive communication frame. The figure which shows another example of the reception processing flow of an exclusive communication frame. The figure which shows the example of an observed waveform. The figure which compared and showed the transmission and reception processing of this invention system.

  Next, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  A typical configuration of the communication network will be described with reference to FIG. The communication network includes communication stations S such as a base station SB, a relay station ST, and a terminal station SE. Consider a case where a communication network is applied to a plant control device as an FA, for example. In this case, the base station SB is provided on the control device side of the central operation room that controls the entire plant, and the terminal station SE is provided on the operation terminal equipment on the plant site side or the process quantity detector. The relay station ST is installed at an appropriate location where the communication environment between the central operation room where the control device is installed and the site is good.

  In the communication network, a plurality of relay stations ST may exist. Alternatively, the relay station ST may not be provided, and the communication station may be configured by two opposing communication stations (base station SB and terminal station SE). One communication station may hold one antenna or a plurality of antennas in order to realize more stable communication.

  A configuration of the communication station S used in the communication network will be described with reference to FIG. First, the basic configuration of the communication station S will be described. As a basic configuration, the communication station S includes a reception unit Rc and transmission unit Sd that are responsible for transmission and reception of communication frames, a communication frame analysis unit Fa that performs processing for transmitting a communication frame received by the reception unit Rc, and a transmission buffer Bs. A normal transmission mode unit MA, an exclusive transmission mode unit MB, and a communication frame synthesis unit Fm.

  In the present invention, an additional communication interference determination unit Id that determines the presence or absence of interference from another system, an exclusive communication frame recognition unit Fb that receives and determines an exclusive communication frame, and an exclusive communication frame generation unit Fg are added to the basic configuration. Prepared.

  In the present invention, when an output is obtained in any of the added circuit portions Id and Fb, the transmission mode is selected via the OR circuit OR. The transmission mode includes a normal transmission mode by the normal transmission mode unit MA and an exclusive transmission mode by the exclusive transmission mode unit MB, and one of these is selected. When the other system interference determination unit Id detects interference, an exclusive communication frame is generated in the exclusive communication frame generation unit Fg.

  As a result, the transmission means Sd transmits the communication frame generated by the communication frame synthesis unit Fm or the exclusive communication frame generated by the exclusive communication frame generation unit Fg.

  Note that the communication station S in FIG. 1 describes only a standard configuration when used as the base station SB, the relay station ST, and the terminal station SE. Therefore, when used as the relay station ST, the configuration of FIG.

  On the other hand, when used as the base station SB or the terminal station SE, it is connected to an appropriate control device. In the case of the base station SB, a signal from the control device that controls the entire plant is given to the transmission means Sd, and the communication frame obtained to the reception means Rc is given to the control device. In the case of the terminal station SE, the communication frame obtained by the receiving means Rc is given to the operation terminal equipment or the process amount detector, and the state on the site side is transmitted from the transmitting means Sd to the control device for controlling the entire plant.

  As described above, the communication station S of FIG. 1 can be used as the base station SB, the relay station ST, and the terminal station SE, but the communication station S has any function in order to achieve the functions of the present invention. Also good. For this reason, in the following description, the relay station ST will be described in mind unless particularly necessary.

  The schematic operation of the FIG. 1 apparatus will be described below. First, the communication frame received by the receiving means Rc is transmitted to the communication frame analysis unit Fa. The communication frame analysis unit Fa holds, for example, a table in which route information is recorded in advance. In the route information, for example, the IDs of the respective communication stations are stored in the order of the route as the route from the base station SB to the terminal station SE via the relay station ST. Usually, since a plurality of relay stations ST and terminal stations SE are installed, a specific route is set between the specific terminal station SE and the base station SB. It is not designed to go anywhere.

  When receiving the communication frame, the communication frame analysis unit Fa refers to the table and sends the communication frame to a desired destination on a specific route. This process is a routing process in a TCP / IP (Transmission Control Protocol / Internet Protocol) network.

  Communication data sent to the transmission buffer Bs via the communication frame analysis unit Fa is sent to the normal transmission mode unit MA and the exclusive transmission mode unit MB. Either the normal transmission mode unit MA or the output of the exclusive transmission mode unit MB is selected by the selector SL and sent to the communication frame synthesis unit Fm. In the communication frame synthesis unit Fm, after adding header information of a desired destination, the communication frame is transmitted to the transmission unit Sd, so that the communication frame is transmitted to the desired destination.

  Note that the selector SL selects the output of the normal transmission mode unit MA when normal, and selects the output of the exclusive transmission mode unit MB when there is an output of the OR circuit OR. The OR circuit OR provides an output by determining one or both of the interference status determination result (output of the other system interference determination unit Id) and the exclusive transmission start frame reception result (output of the exclusive communication frame recognition unit Fb). The output of the OR circuit OR is given when the communication environment is poor or when it is necessary to transmit urgent information with high priority, and the output of the exclusive transmission mode unit MB is selected.

  Further, according to the circuit of FIG. 1, when the output of the other system interference determination unit Id is obtained, an exclusive communication frame is generated in the exclusive communication frame generation unit Fg and is transmitted via the transmission unit Sd.

  Hereinafter, the significance and operation of the added circuit portion will be described in detail. First, interference in communication is considered. FIG. 3 shows an arrangement state of communication nodes (communication stations) in the network as shown in FIG. Here, communication is performed from the own station (relay station ST1) to a desired communication station (for example, base station SB).

  Among these, the relay station ST1 and the base station SB are communication stations having a relationship of path information recorded in advance in the table of the communication frame analysis unit Fa. A specific frequency channel ch1 is assigned to the communication here. Further, the relay station STn and the base station SB are also communication stations having a relationship of route information recorded in advance. For communication between the relay station STn and the base station SB, a specific frequency channel chn different from the frequency channel ch1 is allocated. As a result, the relay station ST1 and the base station SB constitute the own radio network Net1. The relay station STn and the base station SB constitute the own radio network Netn.

  On the other hand, consider a case where a signal from another communication station STX using a specific frequency channel ch1 of the own radio network Net1 is received by the base station SB or the relay station ST1. In this case, the communication of the communication station STX may be an obstacle to the communication of the own wireless network Net1. In the following description, the communication station STX is referred to as an interfering station in the sense of a station that gives a fault. The side that receives a communication failure from the interfering station is called an interfered (station).

  However, it is assumed that the interfering station is a communication station S belonging to the own radio network Net1 and a case where the interfering station is a communication station S not belonging to the own radio network Net1. Here, a network other than the own wireless network Net1 is referred to as another wireless network. In the present invention, the own wireless network and the other wireless network are discriminated, and post processing suitable for each is executed.

  In FIG. 1, the determination of the interference situation is executed in the other system interference determination unit Id. Interference from other systems can be confirmed by observing the received signal strength from other nodes, for example, as used in the carrier sensing mechanism in the carrier sense multiple access / collision avoidance method CSMA / CA described above. Therefore, it is possible to continuously observe the received signal strength and observe the occupation rate of the communication channel within a certain time.

  An example of the observed interference waveform is shown in FIG. In FIG. 8, the horizontal axis represents time, and the vertical axis represents received signal strength RSSI. Normally, the reception signal level L0 is set to a reception level at which the channel is busy. In general, the change in this value is observed with the busy period within a predetermined time as the occupation ratio. For example, the presence / absence of interference is determined based on whether or not a threshold (L0) set in accordance with the communication environment of the wireless system is exceeded.

  Next, exclusive communication processing will be described. As this premise, it is assumed that the self-communication station has emergency information to be urgently transmitted to a higher-level communication station. Further, it is assumed that there is interference from the other node (other communication station) to the own communication station. The exclusive communication process is a process for exclusively executing communication of the own communication station in preference to communication from other nodes.

  However, depending on whether the interfering station belongs to its own wireless network that needs to transmit emergency information or belongs to another wireless network, for example, whether or not control such as temporarily waiting for communication is possible is possible. Come different. In order to perform temporary standby control, it is necessary to establish a method for discriminating whether an interfering station belongs to the own radio network or another radio network.

  Therefore, in the present invention, it is discriminated whether the interfering station belongs to the own radio network or another radio network. However, it is not sufficient to know the network type to which the interfering station belongs. It is necessary to consider what should be done as a post process after the network type is known. Therefore, in the present invention, as described in Patent Document 1, assuming that another communication station performs exclusive communication in a state where the back-off time is shortened, the self-communication station similarly shortens the back-off time. However, it is necessary to complete the exclusive communication in advance of others. Furthermore, it is necessary to notify the desired communication partner (for example, base station) of identification information for distinguishing the partner to communicate with. As a result, a desired communication partner can perform communication focused only on the own communication station without being confused by the interfering station.

  As identification information in this case, information that can be known only when belonging to the own wireless network, such as a MAC address, a data type, or an extended service set identifier (ESSID), is used as part of the frame header in the exclusive communication frame. Can do. However, in order to observe the communication packet and prevent the exclusive communication frame from being intentionally copied, a part of the frame header including the identification information may be encrypted together with the communication data.

  FIG. 4 shows an exclusive communication frame configuration. In general, a communication frame includes a frame header FH, communication data FD, and a frame end FE. On the other hand, in the case of an exclusive communication frame, exclusive communication start request information FHa and identification information FHb are included in a part of the frame header FH. As the identification information FHb, it is preferable to use information that can be known only when belonging to the own wireless network, such as a MAC address, a data type, or an ESSID.

  Next, regarding exclusive communication processing, processing when an exclusive communication frame is transmitted and received will be described. In FIG. 1, normal communication processing is normally executed, and exclusive communication processing is performed as necessary. Since the present invention is characterized by exclusive communication processing, the description of normal communication processing will be omitted unless necessary in the following description. First, the exclusive communication frame transmission process will be described with reference to the process flow of FIG. For example, when transmitting a signal from the site to the center, the exclusive communication frame is transmitted from the relay station or the terminal station in FIG. 2, and the base station corresponds to a desired communication partner that receives the exclusive communication frame.

  However, as a premise of the processing here, the communication station has a function of constantly monitoring the interference state as described above. With this function, the occupancy rate of the transmission path in a specific frequency channel is used to observe whether or not the threshold value in the occupancy rate adjusted in advance to the propagation environment using the wireless system is exceeded. If a value equal to or greater than the threshold value is detected in the occupation ratio, it indicates that the communication environment has deteriorated.

  In the first process step S100 of the transmission process flow of FIG. 5, for example, the relay station ST on the transmission side confirms that the interfered state is equal to or greater than the threshold value and that the communication environment is in a poor condition. If it is not inferior (No), the subsequent processing is not necessary, and a general transmission process (normal communication process: process flow not shown) when the communication environment is normal is executed.

  If the communication environment is inferior (Yes), it is determined in processing step S101 whether there is data to be sent urgently in the transmission waiting packet. As a result of the determination, if there is no emergency information (No), the subsequent processing is not necessary, and a general transmission process (normal communication process: process flow not shown) is executed. When urgent information exists (Yes), the process of process step S102 is executed.

  According to these execution condition determinations in the processing steps S100 and S101, the subsequent processing is executed on the assumption that the communication environment is inferior and emergency information exists.

  If urgent information exists (Yes), the frame header information (FH in FIG. 4) of the communication frame is analyzed in processing step S102, and whether or not the interfering station corresponds to the own system in processing step S103. Determine. For example, it is confirmed that the identification information FHb includes information that can be known only when belonging to the own wireless network, such as a MAC address, a data type, or an ESSID.

  In this state, since emergency information exists (processing step S101), communication (emergency communication) by shortening the back-off time is executed regardless of the determination result of processing step S103. However, the subsequent processing differs depending on whether or not the interfering station corresponds to the own wireless network.

  That is, when the interfering station corresponds to the own wireless network (processing step S103 (Yes)), after the back-off time is shortened (processing step S104), the exclusive frame is sent (processing step S106). .

  On the other hand, when the interfering station is another wireless network (processing step S103 (No)), the back-off time is shortened (processing step S105). Thereafter, a transmission frame to which the above-mentioned identification information FHb is added is sent to the desired communication partner (base station SB), which indicates that the local station should communicate with (processing step S107). As will be described separately in the description of the reception process, the desired communication partner (base station SB) that has received the identification information FHb discards communication from the interfering station and prioritizes communication with the own radio station. To do.

  When the transmission side processing at the time of exclusive communication in FIG. 5 is arranged, when there is interference and there is emergency information, an exclusive communication frame with parent-child relationship information is transmitted when the interference is in another wireless network. .

  Next, processing when an exclusive communication frame is received will be described with reference to the processing flow of FIG. In the case of the system configuration of FIG. 2, there is a possibility that all communication stations (base station, relay station, terminal station) receive exclusive communication frames. For this reason, the processing flow of FIG. 6 needs to be provided in all communication stations.

  In the processing of FIG. 6, first, in processing step S201, “determination of presence / absence of transmission response using identification information FHb for exclusive communication” is performed. This determination can be performed by checking the identification information FHb in the frame header FH of the received frame shown in FIG. As the identification information FHb, information that can be known only when belonging to the own wireless network, such as a MAC address, a data type, or an ESSID, is used. Needless to say, in the case of a communication frame that does not include the identification information FHb for exclusive communication, the following exclusive communication reception processing is not executed and normal reception processing is performed.

  Next, in processing step S202, it is confirmed whether “the wireless station list to be communicated is described”. This confirms that the communication station is in the relationship of the path information recorded in advance in the table of the communication frame analysis unit Fa. The other party not described in the route information is a communication station of another wireless network, and in processing step S206, it will not respond even if it receives from this communication station in the future. For example, the wireless station list is registered to indicate that there is no response (no response is required).

  Alternatively, when the interference is the master station, a reception rejection notification is transmitted to the communication station of the other wireless network, and the communication station is notified as an interfering station. May be to urge the reduction of transmission power.

  In the processing step S203 of the next stage after confirming that the communication station is in the relationship of the path information, “existence of exclusive communication start request in communication frame” is confirmed. This can be executed by checking the exclusive communication start request FHa in the frame header FH of the received frame shown in FIG. When the exclusive communication start request FHa does not exist, the own station executes normal data communication packet response processing.

  If there is an exclusive communication start request in the communication frame, in the next processing step S204, “confirm whether the destination address is addressed to the own station” or not. If it is not addressed to the own station, the own station is a relay station, so in processing step S208, a routing process corresponding to the destination is executed with reference to the routing table. As the relay transmission processing in the processing step S208 of FIG. 6 in the case of a relay station, there is one that requests an interrupted notification to the host and a change of a communication frequency channel to be used.

  When the address of the destination is addressed to the own station, the own station is a base station in the case of communication for the base station, or a terminal station in the case of communication for the terminal station. In this case, in the processing step S205 of the next stage, the own station performs “change of network setting according to information type in exclusive frame correspondence notification”. In the network setting changing process, for example, priority communication (interrupt control with reduced back-off time) is performed with a communication station in the own network that requests exclusive communication.

  Alternatively, if interference on the same frequency channel continues for a long time, the slave station requests the master station to change the channel, and in response to this, the master station switches to communication on the new frequency channel and is stable. Communication can also be continued. In this case, an exclusive communication frame including identification information is used to verify the parent-child relationship that should constitute the own wireless network. Further, the parent station from which the slave station requests channel change is not limited to the parent station that has been the communication party until now, but may be another station that can communicate more stably.

  The processing in FIG. 6 has been described above, but the processing in FIG. 6 is configured to be compatible with all base stations, relay stations, and terminal stations, including lower nodes. Accordingly, the processing flow of FIG. 6 is standardly provided in all of the base station, the relay station, and the terminal station.

  The meaning of this processing flow will be summarized. For example, in the case of a relay station, if it is not a wireless station to communicate with, it will not respond even if it is received in the future, and since it is not an address addressed to itself, normal relay processing is executed. On the other hand, in the case of a base station for communication addressed to a base station or a terminal station for communication addressed to a terminal station, if it is not a wireless station to be communicated, it will not respond even if it receives in the future. Priority communication (interrupt control with a shortened back-off time) is executed with a communication station in its own network that requests exclusive communication by the change in

  By the way, in the communication network configuration of FIG. 2, there are cases where there are no relay stations, and base stations and terminal stations are arranged on a one-to-one basis. The exclusive reception process in this case can be performed as shown in FIG.

  In a communication system configuration in which there is no relay station and the base station and terminal station are arranged one-to-one, when an exclusive communication frame is received, there are other stations that want to perform exclusive communication, and the own station desires Or the interfering station that interferes with the communication of other stations.

  Therefore, in the processing flow of FIG. 7, first, in processing step S301, it is determined whether the own station is an AP (AccessPoint) of a desired communication counterpart station or other interfering station.

  If the own station is an AP, in processing step S302, reception other than communication from the child is discarded. That is, when communication from the interfering station is accepted, it is discarded, and communication with the communication node that has received the exclusive communication frame is performed thereafter.

  Further, when the own station is a station other than the AP, that is, an interfering station, communication of the own station is stopped. However, when there is another AP that does not perform emergency communication and can perform normal communication, it is possible to perform communication with the AP.

  For this reason, in processing step S303, the base station on the upper level of the network is notified that the exclusive communication frame has been received, and measures are taken to enable early communication of communication data.

  Subsequently, in processing step S304, it is confirmed that a notification of correspondence to the exclusive frame is received from the base station. In the case of confirmation, in the processing step S305, the response described in the notification, for example, the network setting such as the change of the frequency channel is changed. Thereby, communication can be resumed.

  The processing on the transmission side has been described with reference to the processing flow in FIG. 5 and the processing on the reception side has been described with reference to the processing flows in FIGS. 6 and 7. More specifically, the following additional processing is performed. It is also effective to execute processing.

  For example, the master station that has received the parent-child relationship performs a reception refusal notification to the node that has given interference. As a result, the node that has caused interference can grasp the fact and take improvement measures such as reducing the signal transmission power. Here, the parent-child relationship is a communication station having a relationship of route information recorded in advance in the table of the communication frame analysis unit Fa. This means that the relay station ST is a child and the base station SB is a parent.

  Further, the slave station that has received the communication frame including the identification information notifies the master station that is different from the master station that has been communicating so far that the identification information has been received. The slave station that has received the communication frame including the identification information switches to a different communication frequency channel. This can be used, for example, when it is desired to change the communication path intentionally, for example, when the master station guides to a new master station using exclusive communication.

  FIG. 9 shows a comparison of transmission and reception processing of the method of the present invention. In this figure, in the horizontal direction, transmission side processing and reception side processing in the case of the method of the present invention are described separately. Further, in the vertical direction, the case where the interfering node exists in the own wireless network and the case where it does not exist are shown.

  In this figure, first, in the case where the interfering node is present in the own wireless network, transmission of an exclusive communication frame with a shortened back-off time is executed by the processing in processing steps S104 and S106 of FIG. . This corresponds to an interrupt notification to the receiving side.

  The receiving side receiving this is different in the handling process between the case of a relay station and the case of a base station (explained by transmission to a base station). In the case of the relay station, the interrupted transmission to the host and the change of the communication frequency channel to be used are requested by the relay transmission process in the processing step S208 of FIG. In the case of the base station, the network setting is changed by the relay transmission process in the processing step S208 of FIG.

  In the case where the interfering node exists in another wireless network, the transmission at the processing steps S105 and S107 in FIG. 5 is performed as the transmission side processing, and the exclusive communication frame with parent-child relationship information with reduced backoff time is transmitted. To do. Upon receiving this, the receiving-side master station blocks subsequent reception responses in the processing step S206 of FIG. 6 after the parent-child determination.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments are described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. In addition, it is possible to add, delete, and replace other configurations for a part of each embodiment.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files that realize each function can be stored in a recording device such as a memory, a hard disk, or an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

  In addition, the control lines and information lines are those that are considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

S: communication station Rc: reception means Sd: transmission means Bs: transmission buffer Fa: communication frame analysis unit Id: other system interference determination unit Fb: exclusive communication frame recognition unit Fg: exclusive communication frame generation unit MA: normal transmission mode MB: Exclusive transmission mode B
Fm: Communication frame composition unit

Claims (10)

A wireless communication device composed of a plurality of communication stations,
The communication station on the transmitting side transmits a communication frame including identification information in the header part that can recognize the parent-child relationship that the communication partner is a partner,
The receiving communication station confirms the parent-child relationship that it is a partner to communicate from the identification information of the received header in the communication frame, and performs preferential communication with the transmitting communication station. Wireless communication device. The wireless communication device according to claim 1,
As identification information for recognizing the parent-child relationship, information that can be known only when a specific frequency channel is allocated and belongs to the own wireless network composed of communication stations existing on a predetermined communication path is used. A wireless communication device. The wireless communication device according to claim 2,
A wireless communication apparatus using a MAC address, a data type, or an ESSID as information that can be known only when belonging to the own wireless network. The wireless communication device according to claim 1,
The communication station on the transmission side uses a communication frame that includes identification information that can recognize the parent-child relationship in the header portion when there is communication path interference and there is information to be transmitted urgently. A wireless communication apparatus characterized in that the communication is performed by reducing the back-off time. The wireless communication device according to claim 2,
When the communication station on the transmitting side has communication path interference, has information to be transmitted urgently, and the communication path interference is caused by a communication station that does not belong to its own wireless network, A wireless communication apparatus characterized in that communication is performed using a communication frame including identification information capable of recognizing a parent-child relationship in a header portion, and this communication is performed by shortening a back-off time. The wireless communication device according to any one of claims 1 to 5,
When the communication station on the receiving side is a relay station, it receives a communication frame containing identification information that can recognize the parent-child relationship in a header part, and relays it to the address of the other party to be transmitted,
A wireless communication apparatus, wherein when a receiving communication station is transmitted to a self-address, a network configuration setting change from the transmitting communication station to the self-communication station is performed. The wireless communication device according to any one of claims 1 to 6,
A wireless communication apparatus, wherein a receiving communication station transmitted to a self-address confirms a parent-child relationship and performs a reception refusal notification to a communication station that has given interference. The wireless communication apparatus according to any one of claims 1 to 7,
The communication station that has received the communication frame including the identification information notifies the higher-order communication station that is different from the higher-order communication station that has been communicating so far that the identification information has been received. Wireless communication device. The wireless communication device according to claim 8,
A wireless communication apparatus, wherein a communication station that has received a communication frame including the identification information performs switching to a different communication frequency channel. A control system using the wireless communication device according to any one of claims 1 to 9,
Check that one of the communication station on the transmission side and the communication station on the reception side is connected to the control device provided in the center, and the other of the communication station on the transmission side and the communication station on the reception side is connected to the equipment on the site side. A control system using a featured wireless communication device.

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