TWI452915B - Wireless terminal device and wireless communication system - Google Patents

Description

Wireless terminal device and wireless communication system

The present invention relates to a wireless terminal device that constitutes a wireless mesh network system.

In one of the networks of conventional mobile communication devices, wireless terminal devices that cannot communicate directly can communicate with each other via a relay device (a wireless terminal device that relays communication). A technology of a wireless mesh network in which wireless terminal devices communicate with each other has been developed. The wireless network as described above is generally referred to as a mesh network. Regardless of the base station or the fixed office or the mobile office, the data communication between the wireless terminal devices is performed by relaying a plurality of wireless terminal devices in the middle. Form a network.

In the network system configured as described above, the data transmitted from the wireless terminal device of the transmission source is transmitted by the wireless terminal device on the relay path constructed based on the communication quality between the wireless terminal devices. A hop is transmitted to the wireless terminal device of the final destination. In the network system as described above, a technique for further improving communication reliability is described in Patent Document 1. Specifically, it is described that the wireless terminal device holds a plurality of antennas, and the antenna used for communication with each of the plurality of wireless terminal devices in the vicinity is the most excellent in wireless quality at the time of reception. Antennas to improve communication reliability.

(previous technical literature)

(Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. 2010-98595.

As described above, in the technique described in Patent Document 1, an antenna having the best reception quality is selected from among a plurality of antennas. However, when the number of relay signals (the number of relays) increases between the wireless terminal devices from the transmission source to the final destination, since the communication reliability is lowered as a whole of the system, only consideration and adjacency are considered. The quality of the communication between the wireless terminal devices is such that the antenna is selected, and there is a problem that the optimal antenna cannot be selected. Further, in a gateway or a wireless terminal device, since the relay path is constructed based on the communication quality between the wireless terminal devices, it is impossible for each wireless terminal device to know in advance which wireless terminal is from the periphery. The device receives the data. Therefore, in a wireless terminal device that holds a plurality of antennas, when a specific wireless terminal device is in standby while selecting a state in which the wireless quality is the best antenna, the selected antenna is not necessarily the best antenna (it is not optimal) The antenna is received), and the reliability of communication will be reduced.

The present invention has been developed in view of the foregoing problems, and is to select and use the best antenna among the plurality of antennas in the wireless mesh network to obtain a wireless terminal device that provides high reliability communication. And wireless communication systems for the purpose.

In order to solve the above problems and achieve the object, the present invention is a wireless terminal device having a plurality of antennas and forming a mesh network together with the gateway, and when using the mesh network, by using the foregoing The plurality of antennas communicate with other peripheral terminals belonging to the wireless terminal device in the vicinity to obtain relays for displaying the number of relays from the adjacent terminal devices to the gateways when the antennas are used. The information is measured, and the communication quality between each adjacent terminal is measured, and then the antenna to be used for communication in the mesh network is determined according to the relay number information and communication quality.

The wireless terminal device of the present invention achieves an effect of achieving higher reliability communication than the case where only the antenna to be used is selected in consideration of the communication quality with other wireless terminals in the vicinity.

Hereinafter, embodiments of the wireless terminal device and the wireless communication system according to the present invention will be described in detail with reference to the drawings. Further, the invention is not limited by the embodiment.

(embodiment)

Fig. 1 is a view showing an example of a configuration of a wireless communication system including a wireless terminal device (hereinafter referred to as a wireless terminal device) according to the present invention. As shown in the figure, the wireless communication system includes a management server 1, a gateway 2, and wireless terminals 5A to 5H. In the following, when the common items (device configuration, function, operation, and the like) of the wireless terminal devices 5A to 5H are described, the aggregation wireless terminals 5A to 5H are described as the wireless terminal device 5.

The management server 1 and the gateway 2 are configured to communicate via the wide area network 3, and the server 1 and the gateway 2 are managed, for example, by a communication cable 4 and a wide area network belonging to an optical cable. Road network 3 is connected. The gateway 2 and the wireless terminal 5 are provided with a plurality of antennas, and one antenna is used for transmission and reception of signals. Further, the wireless terminal device 5 is connected to a power meter 6 such as a metering power amount by wire or wirelessly, and the wireless terminal device 5 manages the measurement data of the power meter 6 via the gateway 2 The server 1 transmits. At this time, the wireless terminal device 5 that cannot directly communicate with the gateway device 2 transmits the measurement data via the other wireless terminal device 5 to the gateway device 2. In the example of Fig. 1, the wireless terminals 5C to 5H are located in a place where direct communication with the gateway 2 is impossible, and the measurement data is transmitted via the other wireless terminal 5.

The details of each device constituting the wireless communication system shown in Fig. 1 will be described.

Although not shown, the management server 1 includes a central control unit, a communication control unit, and a memory device; the central control unit controls the function of the system; and the communication control unit is provided for transmission via the wide area network. 3, communication with the gateway 2 and the wireless terminal device 4; and the memory device stores measurement data such as the amount of power obtained by the gateway 2 and the wireless terminal 5. The management server 1 communicates with the wireless terminal device 5, and collects measurement data (power consumption, etc.) measured by the power meter 6 provided by the user or the like.

Fig. 2 is a view showing an example of the configuration of the gateway 2; As shown in the figure, the gateway 2 includes a central control unit 21, a wireless processing unit 22, a communication control unit 23, and a light output/input unit 24. The central control unit 21 performs data processing with the management server 1 or the wireless terminal device 5. The wireless processing unit 22 performs wireless communication control for performing communication between the wireless terminal device 5 and the wireless network. The communication control unit 23 performs wired communication control for managing the communication between the server 1 and the wired network. The light output/input unit 24 performs processing for connecting to the wide area network 3 via the optical cable 4 (conversion processing from an electric signal to an optical signal, and conversion processing from an optical signal to an electric signal).

Further, as shown in FIG. 3, the wireless processing unit 22 includes an antenna switch 221, a radio unit 222, a wireless I/F (interface) unit 223, a radio network control unit 244, and a routing table 225. a routing table and a wireless communication control unit 226; the antenna switch 221 is configured to switch a plurality of antennas 220; the wireless unit 222 performs a wireless modulation and demodulation process, and has a The illustrated communication quality measuring unit 227 performs a communication quality measuring unit 227 that measures the communication quality (for example, received electric field strength) between the wireless terminal unit 5; the wireless network control unit 244 performs the wireless terminal unit 5 The generation and configuration management of the wireless network; the routing table 225 describes the destination when receiving the signal transmitted from the management server 1 to the destination of the wireless terminal 5; and the wireless communication control unit 226 All functions of the wireless processing unit 222 are controlled, data processing with the central control unit 21 is performed, and control of the antenna switch 221 is performed. Further, in the third drawing, although two antennas 220 are provided, three or more antennas may be used.

The gateway 2 thus constructed forms part of a mesh network, and the wireless processing unit 22 communicates with the wireless terminal 5.

In the wireless processing unit 22, the wireless network control unit 224 communicates with the wireless terminal device 5 via the antenna 220 and the wireless unit 222. Further, address allocation for all the wireless terminal devices 5, registration processing to the mesh network of the wireless terminal device 5, and management of the mesh network are performed.

Further, in the gateway 2, when the central control unit 21 receives the request data from the management server 1 via the light output/input unit 24 and the communication control unit 23 (requires transmission of the measurement data of the power meter 6), the wireless controller The wireless network control unit 224 in the processing unit 22 transmits the data. When receiving the request information transmitted by the central control unit 21, the wireless network control unit 224 analyzes the request data and grasps the wireless terminal device 5 destined for the destination specified by the management server 1. Further, according to the routing table 225, the transmission request data (transfer) is transmitted via the wireless I/F unit 223, the wireless unit 222, the antenna switch 221, and the antenna 220.

Fig. 4 is a view showing an example of the configuration of the wireless terminal unit 5. As shown in the figure, the wireless terminal device 5 includes a plurality of antennas 50, an antenna switch 51, a wireless unit 52, a wireless I/F unit 53, a data relay processing unit 54, a routing table 55, an adjacent terminal information table 56, The communication control unit 57, the timer unit 58, the memory unit 59, and the power meter communication processing unit 60; the plurality of antennas 50 are used for wireless communication with the gateway 2 and/or other wireless terminals 5. The antenna switch 51 switches a plurality of antennas 50 and the wireless unit 52 to perform wireless modulation and demodulation processing, and measures the gateway 2 and/or other wireless by the communication quality measuring unit 61. The received electric field strength between the terminal devices 5; the data relay processing unit 54 receives data not transmitted to itself from other materials received from the gateway 2 and/or other wireless terminal devices 5 The device (gate device 2 or other wireless terminal device 5) transmits the routing table 55 for recording the transmission of data not addressed to itself (the gateway device 2 or other wireless terminal device 5 as the destination data). Destination; the adjacent terminal information table 56 is stored with the wireless device located at the periphery Information on the electric field strength between the gateway device 2 or another wireless terminal device 5 and the number of relays from the surrounding wireless terminal devices 5 to the gateway device 2; the communication control unit 57 has The control antenna switch 51 selects and determines the function of the antenna determining unit that uses the antenna from among the plurality of antennas 50, and has a function of processing the data transmitted to itself; the timing unit 58 is used to periodically acquire the aforementioned information ( The electric field strength and the relay number information); the memory unit 59 stores the measurement data acquired from the electric power meter 6; and the electric power meter communication processing unit 60 is configured to communicate with the electric power meter 6. Further, in the fourth drawing, although two antennas 50 are provided, three or more antennas may be used.

The wireless terminal device 5 configured as described above transmits and receives data to and from the gateway 2 or other wireless terminal device 5. When the wireless terminal device 5 receives the data, the data relay processing unit 54 confirms whether or not the data is transmitted to itself, and transmits the data to itself, to the communication control unit 57, and performs processing in the communication control unit 57. . On the other hand, when it is not transmitted to itself, the data relay processing unit 54 determines the relay destination based on the routing table 55, and relays the data via the wireless I/F unit 53, the wireless unit 52, the antenna switch 51, and the antenna 50. . Further, when there is routing information in the received data, the data relay processing unit 54 does not perform the data relay processing based on the routing information based on the routing table 55. Further, when the response data for the measurement data transmission request from the management server 1 is transmitted, the response data (measurement data) is transmitted to the material relay processing unit 54, and in the data relay processing unit 54, according to the routing table 55 The relay destination is determined, and the response data is transmitted via the wireless I/F unit 53, the wireless unit 52, the antenna switch 51, and the antenna 50.

The communication control unit 57 acquires measurement data from the electric meter 6 via the electric power meter communication processing unit 60. The acquired measurement data is stored in the storage unit 59 for storage.

The timer unit 58 starts counting when the predetermined condition is satisfied, and then, when the predetermined time elapses, notifies the communication control unit 57. The communication control unit 57 that has received the notification is included in the received information when it transmits a request for information (see below) to the other wireless terminal devices 5 and receives a response to the response signal to the request. Information materials that are responded to by the information materials are extracted. Further, at this time, in the wireless unit 52, the communication product quality measuring unit 61 performs electric field intensity measurement at the time of receiving the information data response. The information material extracted by the communication control unit 57 and the electric field intensity measured by the communication product quality measuring unit 61 are stored in the adjacent terminal information table 56.

Next, the operation of the wireless communication system according to the present embodiment will be described using Figs. 5 to 9 . First, an operation shown in FIG. 5, that is, an operation when the mesh network formed by the gateway 2 and the wireless terminals 5A to 5F is newly added to the wireless terminal device 5G will be described. Further, the wireless terminal device 5G is configured to be able to directly communicate with any of the wireless terminal devices 5A to 5F, but is newly provided at a position that cannot be directly communicated with the gateway 2. The wireless terminal device 5G includes a plurality of antennas (herein two antennas #1 and #2 are described), and when the mesh network is added, one antenna is selected from a plurality of antennas.

When the wireless terminal set 5G is newly set (step S11), the wireless terminal set 5G first, in order to select an antenna to be used after joining the mesh network, by other wireless terminal devices 5 capable of direct communication (hereinafter, In order to acquire the information material as a condition (antenna selection condition), the number of relays (upper limit value) set to the gateway 2 and the threshold value of the electric field strength to the adjacent terminal device (lower limit) Value) (step S12). In the case of new settings, it is better to obtain the majority of the information to select the antenna. Therefore, for example, the number of relays set to the gateway 2 = the maximum number of relays allowed in the wireless communication system, the electric field intensity threshold = the lowest received electric field strength. In the example shown in Fig. 5, the wireless terminal devices 5A to 5F become adjacent terminal devices.

The wireless terminal device 5G, next, selects an antenna #1 belonging to one of the plurality of antennas (step S13), and uses the antenna #1 to insert the antenna selection condition (to the gateway) set in the aforementioned step S12. The information material of the number of relays up to 2 and the electric field strength threshold value between the adjacent terminal devices is required to be broadcasted (Broadcast) (step S14).

When the neighboring terminals (wireless terminals 5A, 5B, 5C, 5D, 5E, and 5F) that have received the information request are acquired, the antenna selection conditions (the number of relays to the gateway 2 and the adjacent) in the information request are obtained. The electric field strength threshold between terminals). In addition, the electric field strength is measured while receiving the information request, and the measurement result is maintained. The received information material is not required to be transmitted to other wireless terminals 5.

Further, the wireless terminal devices 5A to 5F that have received the information request, the number of relays up to the gateway 2, and the electric field strength measured when receiving the information material request (represented with the wireless terminal device 5G) The communication quality) is compared with the antenna selection condition obtained by the information material request, and when the antenna selection condition is satisfied, the information of the information including the number of relays to the gateway 2 is returned as the information data. (Step S15). That is, "the number of relays to the number of relays to the gateway 2", the number of relays displayed by the antenna selection condition, and the electric field strength measured when the information data is requested to be received ≧ the electric field strength displayed by the antenna selection condition When the limit value is established, the information information is returned. When so performed, it is possible to prevent the wireless traffic from being unnecessarily increased, and it is possible to suppress power consumption. In addition, the wireless terminal device 5G measures the electric field strength when receiving the information data response, and maintains the measurement result.

The wireless terminal device 5G, after a certain period of time after transmitting the information material request in step S14, transmits the information material (in the gateway device 2) that is received by the information information received by each of the adjacent terminal devices (the wireless terminal devices 5A to 5F). The information of the relay number) and the electric field strength measured when receiving the information data are maintained as the information of the antenna #1 (antenna information).

Next, the wireless terminal device 5G selects the antenna #2 (step S16), and uses the antenna #2 to perform the broadcast of the information material request having the antenna selection condition set in the above-described step S12 in the same manner as the above-described step S14. Transfer (step S17).

When the adjacent terminal devices (the wireless terminal devices 5A to 5F) that have received the information request are the same as the case where the information material request is received in the above-described step S14, the number of relays to the gateway device 2 is reached, and in step S17 The electric field strength measured when receiving the information request is compared with the antenna selection condition obtained by the information data request, and when the antenna selection condition is satisfied, the number of relays including the number of relays to the gateway 2 is returned. The information information of the information is responded (step S18).

The wireless terminal device 5G receives the information of the number of relays up to the gateway 2 in response to the information data received by each of the adjacent terminals after a certain period of time has elapsed after the information material request is transmitted in step S17, and receives the information. The electric field strength measured at the time of data response is maintained as information of antenna #2. Further, since the number of relays from the adjacent terminal device to the gateway device 2 is not affected by the antenna selected by the wireless terminal device 5, the information information can be received in the state where the antenna #2 is selected. In response, the processing is performed without extracting the relay number information to reduce the processing load.

When the wireless terminal device 5G includes three or more antennas, the same processing is repeated by selecting another antenna (the same processing as steps S14 and S15).

The wireless terminal 5G selects (uses) each of the antennas to perform the transmission of the information request and the reception of the information data response, and determines the antenna to be used according to the collected antenna information when the collection of the antenna information is completed ( Step S19). The details of the processing of this step S19 will be additionally described.

When the wireless terminal 5G determines the antenna to be used, the antenna determined by the use is used, and the network of the final destination set to the gateway 2 is added to the gateway 2 directly or via the adjacent terminal. The transfer is performed (steps S20, S21). In the example of Fig. 5, the network joining request transmitted from the wireless terminal 5G reaches the gateway 2 via the wireless terminal 5B.

The gateway 2 that has received the network join request performs the process of adding the wireless terminal 5G of the request source to the mesh network, and returns the network join response (steps S22, S23).

When the wireless terminal 5G joins the response from the network transmitted by the gateway 2 to receive directly or via the adjacent terminal, the network joining process is completed.

By the sequence as described above, the wireless terminal set 5G determines the antenna to be used when joining the mesh network.

Next, it is necessary to periodically check the necessity of changing the antenna used to complete the wireless terminal device (assuming the wireless terminal device 5G) to be added to the mesh network, and when it is determined that it is necessary, the operation of changing the antenna will be described using FIG. This action is not necessary, but compared to wireless communication and wired communication, the status (communication quality) is less stable, and other wireless terminals 5 will be newly added to the mesh network, or will be from the network. In the case where the network is disconnected and the possibility of changing the relay path is changed, it is preferable to perform it.

When the addition to the mesh network is completed, the wireless terminal device 5G performs setting (initialization) of the timer value for determining the necessity of changing the antenna (determination of the antenna change necessity) to be started periodically (step S31). For example, when the antenna change necessity determination is performed once every hour, the timer value is set to 1 hour. The setting of the timer value is performed, for example, by the communication control unit 57. After that, it is monitored whether or not the time set in step S31 has elapsed (step S32), and the monitoring is continued until the set time elapses (step S32: NO).

When the time set in step S31 has elapsed (step S32: YES), the wireless terminal device 5G collects the information material used for the determination of the necessity of the change of the antenna used from the adjacent terminal device to the adjacent terminal device. Obtaining the information material as a condition (antenna selection condition), setting the number of relays (upper limit value) up to the gateway 2 and the threshold value (lower limit value) of the electric field strength to the adjacent terminal device (step S33) . This step S33 is the same processing as the above-described step S12. In order to avoid radio interference (interference to other communication) during the periodic processing after joining the network, the conditions for the response of the adjacent terminal are limited, for example, the number of relays set to the gateway 2 = 3, the electric field strength threshold Value = 90 dBμV. Further, it is also possible to set only one of the relay number and the electric field intensity threshold.

Next, the wireless terminal device 5G selects one antenna #1 among the plurality of antennas (step S34), and uses the antenna #1 to insert the antenna selection condition set in the aforementioned step S33 (to the gateway 2) The information material of the number of relays and the electric field intensity threshold is required to be transmitted by broadcast (step S35). This step S34 is the same processing as the above-described step S14.

The wireless terminal device 5G confirms whether the information data response has been received by the adjacent terminal device within a certain period of time, performs electric field strength measurement and maintains the measured value when receiving the information data response, and maintains the relay of the information data response. The number (the number of relays up to the gateway 2) (steps S36, S37, and S38). If the state of the certain time has not elapsed after the transmission of the information material request in step S35 (step S39: NO), steps S36 to S38 are repeated. On the other hand, when a certain period of time has elapsed (step S39: YES), it is checked whether or not all of the antennas have been selected, that is, whether or not the above-described steps S35 to S39 have been executed using each of the provided antennas. (Step S40). When the selection of all the antennas is not completed (step S40: NO), the antenna is switched to the unselected antenna (step S41), and the aforementioned steps S35 to S39 are executed again. When the selection of all the antennas is completed (step S40: YES), the antenna to be used is determined based on the antenna information belonging to the information obtained by repeatedly performing the processes of the aforementioned steps S35 to S398 (step S42). The method of determining the antenna to be used is the same as the method of determining the antenna used in the aforementioned network joining operation.

After determining the antenna to be used, the wireless terminal device 5G updates the number of relays from itself to the gateway 2 (step S43). When the step S43 is ended, the process returns to the aforementioned step S31 to set the time value. After that, the above actions are continued.

Next, the antenna information collected by the wireless terminal device 5 based on the transmission of the information request and the reception of the information data response (the number of relays from the adjacent terminal to the gateway 2 and the electric field when receiving the information data) (Strength) An example of determining the operation of the antenna to be used (the operations of the above-described steps S19 and S42) will be described using Figs. 7 to 9 .

Fig. 7 is a view showing an example of communication quality information indicating the electric field strength between the wireless terminal device 5 and the adjacent terminal device. In the illustrated example, the corresponding electric field strength quality rank is set as the communication quality information. "1" is the highest quality.

Fig. 8 is a view showing information referred to when determining an antenna to be used by the wireless terminal device 5. For example, the information referred to (held) by the wireless terminal device 5G is displayed. This information is obtained by receiving information data responses from other wireless terminals (wireless terminals 5A to 5H) via the wireless terminal 5G. Further, it is held as the adjacent terminal information table 56.

In Fig. 8, the "terminal number" is information (identifier) that uniquely displays each of the surrounding wireless terminal devices 5. In Fig. 8, for convenience of explanation, a wireless terminal device corresponding to the terminal number is described. The "number of relays from the other wireless terminal devices to the gateway" is displayed from the other wireless terminal (the transmission source of the information data response) corresponding to the terminal number to the gateway 2 Successive information (relay number information), and extracted from the received information data response. "Quality ranking between wireless terminals in the vicinity" is the electric field strength (communication quality) when the received information information of each antenna (in the figure, antenna #1 and antenna #2) is displayed. ) information. In order to reduce the amount of information, the information on the electric field strength converted to the quality order according to the table shown in Fig. 7 (correspondence table of electric field strength and quality order) is set as "quality ranking with the wireless terminal in the vicinity". In the example of Fig. 8, the communication between the wireless terminal device 5G and the wireless terminal devices 5A and 5H is unstable, and the wireless terminal device 5G cannot receive the information data response from the wireless terminal devices 5A and 5H. Therefore, the information corresponding to the wireless terminals 5A and 5H (the number of relays obtained by the other wireless terminal devices to the gateway and the quality order between the wireless terminals in the vicinity) becomes "none". Respond." The "multiplication calculation value of the number of relays and the quality order" is "the number of relays from the other wireless terminal devices to the gateway" and "the quality order between the wireless terminals that are located in the vicinity" Multiply the result.

Fig. 9 is a view showing an example of an antenna sequence to be determined by the wireless terminal unit 5G for holding the information (the adjacent terminal information) shown in Fig. 8, and the display is determined according to the antenna selection conditions described in Fig. 9. The action of the antenna used. The antenna selection conditions are composed of the conditions 1 to 3. In the condition 1, the "number of relays to the gateway 2" is set to "3 or less". In Condition 2, the "Quality Order" is set to "5 or more". In the condition 3, the "multiplication calculation value of the relay number and the quality order" is set to "8 or less".

In the wireless terminal device 5G, in the determination operation of the antenna to be used, first, the wireless terminal device 5 that satisfies the condition 1 is specifically defined. In the example shown in Fig. 9, the wireless terminal devices 5B, 5C, 5D, and 5E can be specifically defined for the terminal that satisfies the condition 1. Next, a wireless terminal 5 that satisfies condition 2 is specifically defined for each antenna. In the example shown in FIG. 9, in the case of using the antenna #1, the terminal that satisfies the condition 2 specifically defines the wireless terminal devices 5B, 5C, 5D, 5E, 5F; in the case of using the antenna #2 For terminals that satisfy Condition 2, wireless terminals 5B, 5C, 5D, 5E, and 5F are specifically defined. The wireless terminal 5 that satisfies condition 3 is specifically defined for each antenna. In the example shown in FIG. 9, in the case where the antenna #1 is used, the terminal that satisfies the condition 3 specifically defines the wireless terminal devices 5B, 5C, 5D, and 5F; when the antenna #2 is used, the condition is satisfied. In terms of the terminal of 3, the wireless terminals 5B, 5C, 5D, and 5F are specifically defined.

When the special definition of the terminals satisfying Condition 1, Condition 2, and Condition 3, respectively, is completed, then, the wireless terminal device 5G extracts the wireless terminal device 5 satisfying the conditions 1 to 3 for each antenna (in the example of Fig. 9, in When either antenna #1 or antenna #2 is used, the wireless terminals 5B, 5C, and 5D are extracted. Then, the average value of the "multiplied calculation value of the number of relays and the quality order" of the extracted wireless terminal unit 5 is calculated for each antenna. That is, the average value of the "multiplication calculation value of the relay number and the quality order" of the wireless terminal device 5 satisfying the conditions 1 to 3 when the antenna #1 is used is calculated, and the conditions 1 to 3 are satisfied when the antenna #2 is used. The average value of the "multiply calculated value of the number of relays and the quality order" of the wireless terminal device 5. Based on the results calculated as described above, the antenna to be used is decided. Specifically, an antenna smaller than the calculated average value is determined as the antenna to be used. In the illustrated example, the average value when antenna #1 is used = 5, and the average value when antenna #2 is used = 6.6. Therefore, the antenna #1 is determined as the antenna to be used.

Further, the wireless terminal device 5 updates the relay number information from itself to the gateway 2 after executing the process of determining the antenna to be used. Specifically, when the determined antenna is used, the number of relays from the wireless terminal device 5 to the gateway 2 that minimizes the "multiplication calculation value of the number of relays and the quality order" is set to one, and is set as The number of relays from itself to the gateway 2. In the illustrated example, when the determined antenna #1 is used, the wireless terminal 5 that is the smallest in the "multiplication calculation value of the number of relays and the quality order" is the wireless terminal device 5B. Then, since the number of relays from the wireless terminal device 5B to the gateway 2 is 1, the number of relays from the self to the gateway 2 is set (updated) to two.

As described above, the wireless terminal device 5, when joining the mesh network (at the time of startup), and periodically transmitting the information data request to the adjacent terminal device to collect the relay to the gateway device 2 when the joining is completed. Number, and communication quality (electric field strength) information with other wireless terminals, and then decide which antenna to use (or decide).

Although the operation when determining the antenna to be used is described, the wireless terminal device 5 inserts the gateway to the gateway when it receives the information request from the adjacent terminal (the wireless terminal that determines the antenna to be used). The information of the number of relays up to the device 2 is transmitted back to the wireless terminal 5 of the transmission source.

According to the above, the wireless communication system according to the present embodiment includes at least one wireless terminal that is fixedly disposed in the vicinity of the power meter, and at least one wireless terminal that wirelessly relays data measured by the power meter. In the wireless terminal, a plurality of antennas are reserved. During startup (when the mesh network is added) and when the mesh network is added, the antennas are periodically selected and used in sequence to obtain settings. The number of relays to the gateway 2 held by the other wireless terminal devices, and the communication quality (electric field strength) with other wireless terminals, and the quality of the communication and the number of relays are determined. Antenna used. In this way, it is possible to use an antenna that can obtain the best communication quality among a plurality of antennas by considering the number of relays that have a large influence on the communication quality up to the gateway 2 and the electric field strength between the adjacent wireless terminals. Communicate. As a result, higher reliability communication can be realized as compared with a conventional system that selects an antenna to be used only considering the communication quality with other wireless terminals in the vicinity.

In addition, the wireless terminal device displays the number of relays to the gateway and the reception quality required for the information material for the information data request for the information of the number of relays required to the other wireless terminal devices to the gateway device 2. The antenna selection condition of the threshold value of (electric field strength) is set and transmitted. On the other hand, when receiving the information data request, the information information response to the response to the request is returned only when the set antenna selection condition is satisfied. . Therefore, the wireless terminal that receives the information request is that the number of relays until the gateway is below the number of relays specified by the antenna selection condition, and the electric field strength when the information material is required to be received is selected by the antenna. When the electric field strength specified by the condition exceeds the threshold value, the information data is transmitted, so that it is possible to suppress radio interference between the communication of the information material for obtaining the antenna selection and other communication.

(industrial availability)

As described above, the wireless terminal device of the present invention is extremely useful as a wireless terminal device that selects one antenna from among a plurality of antennas for communication, and is particularly suitable for forming a wireless communication terminal of a mesh network.

1. . . Management server

2. . . Gateway

3. . . WAN

4. . . Communication cable (optical cable)

5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H. . . Wireless terminal device

6. . . Electric meter

twenty one. . . Central control department

twenty two. . . Wireless processing unit

23, 57. . . Communication control department

twenty four. . . Optical input and output unit

50, 220. . . antenna

51, 221. . . Antenna switch

52, 222. . . Wireless department

53,223. . . Wireless I/F department

54. . . Data relay processing unit

55, 225. . . Routing table

56. . . Adjacent terminal information table

58. . . Timing department

59. . . Memory department

60. . . Electric meter communication processing department

61,227. . . Communication quality measurement department

224. . . Wireless network control department

226. . . Wireless communication control department

S11 to S23. . . step

Fig. 1 is a view showing an example of the configuration of a wireless communication system including the wireless terminal device of the present invention.

Fig. 2 is a view showing an example of the structure of the gateway.

Fig. 3 is a view showing an example of the configuration of a wireless processing unit provided in the gateway.

Fig. 4 is a diagram showing an example of the configuration of a wireless terminal.

Figure 5 is a sequence diagram showing an example of when a wireless terminal is added to a mesh network.

Fig. 6 is a view showing an example of an operation for changing the use of the antenna by the wireless terminal.

Figure 7 is a diagram showing an example of communication quality information.

Figure 8 is a diagram showing an example of information referred to by the wireless terminal when deciding which antenna to use.

Fig. 9 is a view showing an example of the order of the antennas to be used by the wireless terminal which holds the information (the adjacent terminal information) shown in Fig. 8.

2. . . Gateway

5A, 5B, 5C, 5D, 5E, 5F, 5G. . . Wireless terminal device

S11 to S23. . . step

Claims (3)

A wireless terminal device having a plurality of antennas, sequentially using the plurality of antennas to communicate with surrounding peripheral terminals belonging to other wireless terminal devices, and forming a mesh network together with the gateway, including The information acquisition unit acquires information on the number of relays from each adjacent terminal device to the gateway device when each antenna is used, and measures the communication quality with each adjacent terminal device from each adjacent terminal device. The information obtaining unit responds to the information, and performs the acquisition of the number of relays of the adjacent terminal itself that has received the information request, and the communication of the information information transmitted from the adjacent terminal that has received the information information request. Determination of quality, wherein the information response system has information on the number of relays of adjacent terminals that have received the information information request, and is transmitted in the following cases, that is, in each of the foregoing adjacent terminals An adjacent terminal device that receives the aforementioned information data request transmitted by each of the antennas in order to obtain the information of the relay number Comparing the value of the communication quality obtained by receiving the aforementioned information request with the lower limit of the communication quality obtained from the information request, and the value of the communication quality obtained by receiving the information request When the value is greater than or equal to the lower limit value, the number of relays obtained from the information information request is compared with the number of relays of the adjacent terminal itself that has received the information information request, and the foregoing information data request has been received. The aforementioned number of relays of the adjacent terminal itself is taken from the aforementioned information data requirements. When the number of relays is less than the number of relays; the antenna switch is used to switch the antenna to be used; and the antenna determining unit uses the information of the relay number obtained by the information acquisition unit from the information information. And the communication quality in response to the information information, when joining the mesh network, determining an antenna to be used from among the antennas, and causing the antenna switch to select the determined antenna. A wireless communication system comprising: a wireless terminal device, as described in claim 1; and a gateway device for housing the wireless terminal device. The wireless communication system according to claim 2, wherein the management server is configured to collect power measurement data measured by a power meter provided by the user; the wireless terminal device has a connection. The power meter acquires the function of the power measurement data, and transmits the obtained power measurement data to the management server via the gateway.