JP6748541B2 - Communication system, communication device, and communication method - Google Patents

Description

The present invention relates to a communication system, a communication device and a communication method.

A network is composed of multiple wireless stations to which actuators that control various sensors or various devices are connected, and home security, safety management and health management for the elderly and children, facility management for buildings, factory control, A communication system used for monitoring and measurement management of various meters such as water, gas, and electricity is known.

For example, the 426 MHz band used in the conventional wireless disaster prevention system is set as a frequency allocation band for a specific low power wireless station dedicated to security, and the 920 MHz band having a faster communication speed is targeted for a specific low power wireless station for data. There is disclosed a wireless disaster prevention system capable of improving reliability of abnormality occurrence monitoring and shortening processing time by using the frequency allocation band (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2015-1914

In the standard for wireless equipment in the 920 MHz band (for example, ARIB STD-T108), the time during which a wireless signal can be continuously transmitted is defined to be shorter than in the case of the 426 MHz band. On the other hand, in order to reduce battery consumption in the wireless station and save power, the wireless signal receiving operation is generally performed intermittently rather than always. Therefore, in the specific low power radio station in the 920 MHz band, in order to perform the intermittent reception, it is necessary to lengthen the transmission time of the radio signal to some extent, and it may not be possible to satisfy the standard.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a communication system capable of satisfying the provisions of the standard even when performing intermittent reception, a communication device configuring the communication system, and a communication method. And

A communication system according to the present invention is a communication system for performing communication between a first communication device and a second communication device, wherein the first communication device is a packet signal and a packet composed of one or a plurality of packets. The second communication device includes a first transmitter that transmits a plurality of related information to the second communication device after a predetermined pause, and the second communication device includes a receiver that performs intermittent reception periodically, and a packet in the receiver. And a second transmitting unit that transmits a response signal to the first communication device at a required time when the packet signal is not transmitted, which is determined based on the received packet-related information. To do.

The communication system according to the present invention is characterized in that the required time is after the time when the last packet transmitted by the first transmitter is transmitted.

The communication system according to the present invention is characterized in that the second transmitting unit transmits the response signal a plurality of times between the required time point and a time point before the required time point.

In the communication system according to the present invention, the second communication device includes a determination unit that determines a reception level of a signal before the second transmission unit transmits the response signal, and the second transmission unit includes the determination unit. If the reception level determined by the unit is higher than a predetermined threshold value, the response signal is not transmitted.

In the communication system according to the present invention, the second communication device specifies the required time point based on a variable added to the packet received by the receiving unit, the length of the packet signal, and the length of the idle period. It is characterized by including a specific unit.

A communication device according to the present invention is a communication device that communicates with another communication device, wherein a packet signal composed of one or a plurality of packets and packet-related information are separated by a predetermined pause period. It is characterized by comprising a first transmitter for transmitting a plurality of data to another communication device.

A communication device according to the present invention is a communication device that communicates with another communication device, and includes a receiving unit that periodically performs intermittent reception, and a packet related received packet when the receiving unit receives the packet. And a transmitting unit that transmits a response signal to the other communication device at a required time when the packet signal is not transmitted, which is determined based on the information.

A communication method according to the present invention is a communication method for performing communication between a first communication device and a second communication device, wherein the first transmission unit of the first communication device includes one or a plurality of packets. A plurality of packet signals and packet-related information that are transmitted to the second communication device with a predetermined pause period, and the receiving unit of the second communication device periodically performs intermittent reception, When the receiving unit receives a packet, the second transmitting unit transmits a response signal to the first communication device at a required time when the packet signal is not transmitted, which is determined based on the received packet-related information. It is characterized by

According to the present invention, it is possible to meet the requirements of the standard even when performing intermittent reception.

It is explanatory drawing which shows an example of a structure of the communication system of this Embodiment. It is a block diagram which shows an example of a structure of the wireless main|base station of this Embodiment. It is a block diagram which shows an example of a structure of the wireless handset of this Embodiment. It is explanatory drawing which shows 1st Example of the communication method of the wireless telemeter system of this embodiment. It is explanatory drawing which shows the example of the conventional communication method as a comparative example. It is explanatory drawing which shows 2nd Example of the communication method of the wireless telemeter system of this embodiment. It is explanatory drawing which shows 3rd Example of the communication method of the wireless telemeter system of this embodiment. It is explanatory drawing which shows 4th Example of the communication method of the wireless telemeter system of this embodiment. It is a flow chart which shows an example of the processing procedure of the transmitting side of the wireless telemeter system of this embodiment. It is a flow chart which shows an example of the processing procedure by the side of a receiving of a radio telemetry system of this embodiment.

[Embodiment 1]
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing an example of the configuration of the communication system of the present embodiment. In the present embodiment, a wireless telemeter system will be described as an example of a communication system, but the communication system is not limited to a wireless telemeter system, and may be a wireless telecontrol system, or a system for data transmission, etc. It may be.

The wireless telemeter system has a host computer 1 and a center-side network control device 2 as a center side configuration, and is connected to a wireless master device 10, a plurality of wireless slave devices 20, and each wireless slave device as a terminal side configuration. It has a meter 40 which is operated.

The center-side network control device 2 and the wireless master device 10 are connected to a wide area wireless network N1 such as a PHS network or a FOMA network, and perform wireless communication via the wide area wireless network N1. In the example shown in FIG. 1, the device on the center side and the device on the terminal side are connected by the wide area wireless network N1, but the device is connected by a communication network such as a wired IP network or a public network. Good. Further, in the example shown in FIG. 1, the number of the wireless master devices 10 connected to the wide area wireless network N1 is one, but a plurality of wireless master devices 10 may be connected.

The center-side network control device 2 is provided, for example, in a public network of a telecommunications carrier and has a function of controlling communication with a terminal side via the wide area wireless network N1. When the center side network control device 2 receives a telegram to be transmitted from the host computer 1 to the terminal side, the center side network control device 2 transmits the telegram to the terminal side by a communication method conforming to the communication standard of the wide area wireless network N1. Further, when the center side network control device 2 receives the electronic message transmitted from the terminal side via the wide area wireless network N1, the center side network control device 2 transmits the received electronic message to the host computer 1.

The wireless master device 10 is connected to the center side via a wide area wireless network N1 and is communicatively connected to a plurality of wireless slave devices 20 via a narrow area wireless network N2.

When receiving a message from the center side through the short-range wireless network N2, the wireless slave device 20 determines whether or not the message is a message addressed to itself. When the ID of its own device is designated as the destination address of the received electronic message, the wireless slave device 20 determines that the received electronic message is the electronic message addressed to itself, and based on the content of the data included in the electronic message. Performs various processes. Further, when the communication connection is established between the center side and the meter 40 connected to the own device, the wireless slave device 20 transfers a message received from the outside to the meter 40 connected to the own device.

The wireless slave device 20 sends a message to the wireless master device 10 when an event that should be notified to the center side occurs in the device itself or when a message including data such as a meter reading value is received from the meter 40 connected to the device itself. To send. When receiving the electronic message transmitted from the wireless slave device 20, the wireless master device 10 transmits the electronic message to the host computer 1 by wireless communication via the wide area wireless network N1.

The meter 40 is a measuring instrument that measures the usage of supplies such as water, gas, and electricity supplied from a business entity to consumers and outputs a measurement result (meter reading value). The meter 40 is, for example, an 8-bit meter, and has a function of communicating with the center side by an 8-bit message format.

In the wireless telemeter system of the present embodiment, when collecting the meter reading values measured by the meter 40 on the center side, the host computer 1 issues a meter reading instruction to one or a plurality of wireless slave devices 20 through the wide area wireless network N1. give. Each wireless slave device 20 acquires meter reading data from the meter 40 connected to the wireless slave device 20, and transmits a telegram including data indicating the meter reading value to the host computer 1 via the wireless master device 10. Further, when a calling event (calling factor) such as an alarm to be notified to the center side occurs, the meter 40 makes a call to the center side via the wireless slave device 20 connected to itself.

FIG. 2 is a block diagram showing an example of the configuration of the wireless master device 10 of the present embodiment. The wireless master device 10 includes a control unit 11, a display unit 12, an operation unit 13, a wide-area wireless communication unit 14, a short-range wireless communication unit 15, a storage unit 16 and the like that control the entire wireless master device 10. Each hardware unit included in the wireless master device 10 operates by electric power supplied from a battery (not shown).

The control unit 11 includes, for example, a CPU, a ROM, and the like, and the CPU executes a control program stored in the ROM in advance to control each hardware unit included in the wireless master device 10.

The storage unit 16 is composed of, for example, a non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory), and is necessary for setting information regarding the operation of the wireless master device 10 and for communicating via the wide area wireless network N1. Information, information necessary for communication via the short-range wireless network N2, and the like are stored.

The wide area wireless communication unit 14 performs radio communication via the wide area wireless network N1 by transmitting and receiving radio waves through the antenna 141. When the wireless master device 10 receives, for example, a telegram including the meter reading value of the meter 40 from the wireless slave device 20 through the short-range wireless communication unit 15, the radio master device 10 transmits the telegram to the host computer 1 on the center side. The wide area wireless communication unit 14 drives the antenna 141 to emit a radio wave, thereby performing a process of transmitting a telegram complying with the communication standard of the wide area wireless network N1.

In addition, when the wide area wireless communication unit 14 receives a radio wave from the antenna 141, the wide area wireless communication unit 14 acquires a telegram by decoding the received radio wave. The wide area wireless communication unit 14 outputs a message obtained by decoding to the control unit 11. When the electronic message output from the wide area wireless communication unit 14 is acquired, the control unit 11 performs a process according to the electronic message and a process of transferring the electronic message to the wireless slave device 20 through the short range wireless communication unit 15.

The short-range wireless communication unit 15 communicates with a plurality of wireless slave devices 20 by a predetermined wireless communication method by transmitting and receiving radio waves through the antenna 151. As the wireless communication system, for example, a specific low power wireless system is adopted. In the specific low power wireless system, a 920 MHz band having a higher communication speed is used as a frequency allocation band in addition to the 426 MHz band. In the 920 MHz band, the standard of wireless equipment (for example, ARIB STD-T108) must be satisfied.

The short-range wireless communication unit 15 intermittently transmits a beacon as a search signal for searching for the wireless slave device 20 that is a transmission destination of a message. This beacon includes a wireless device number for identifying the wireless master device 10. In addition, when the short-range wireless communication unit 15 receives a beacon transmitted by the wireless slave device 20, and has data to be transmitted, the narrowband wireless communication unit 15 sends the wireless slave device 20 specified by the wireless device number included in the beacon to Send a message containing data.

The display unit 12 includes an LED, a liquid crystal display panel, and the like, and can display information to be notified to a worker or the like who performs maintenance work based on a control signal output from the control unit 11.

The operation unit 13 is configured by various switches such as a DIP switch, buttons, and the like, and can receive various setting operations by a worker who performs maintenance work, for example. The control unit 11 performs required control based on the setting content output from the operation unit 13 and controls the storage unit 16 to store the setting content as necessary.

FIG. 3 is a block diagram showing an example of the configuration of the wireless slave device 20 of the present embodiment. The wireless slave device 20 includes a control unit 21, a display unit 22, an operation unit 23, a short-range wireless communication unit 24, a connection unit 25, a storage unit 26 and the like that control the entire wireless slave device 20. Each hardware unit included in the wireless slave device 20 operates by electric power supplied from a battery (not shown).

The control unit 21 includes, for example, a CPU, a ROM, and the like, and the CPU executes a control program stored in the ROM in advance to control each hardware unit included in the wireless slave device 20.

The storage unit 26 is composed of, for example, a non-volatile memory such as an EEPROM, and stores setting information regarding the operation of the wireless slave device 20, information necessary for communication via the short-range wireless network N2, and the like.

The short range wireless communication unit 24 communicates with the wireless master device 10 by a predetermined wireless communication method by transmitting and receiving radio waves through the antenna 241. The short range wireless communication unit 24 has the same function as the narrow range wireless communication unit 15 in the wireless master device 10.

The connection unit 25 includes one or a plurality of ports for connecting the meter 40.

The display unit 22 includes an LED, a liquid crystal display panel, and the like, and can display information to be notified to a worker or the like who performs maintenance work based on a control signal output from the control unit 21.

The operation unit 23 is configured by various switches such as a DIP switch, buttons, and the like, and can receive various setting operations by a worker who performs maintenance work, for example. The control unit 21 performs required control based on the setting content output by the operation unit 23, and controls to store the setting content in the storage unit 26 as necessary.

Next, the operation of the wireless telemeter system of this embodiment will be described. In the following description, the wireless master device 10 is the transmitting side and the wireless slave device 20 is the receiving side. The wireless slave device 20 may be the transmitting side and the wireless master device 10 may be the receiving side.

FIG. 4 is an explanatory diagram showing a first embodiment of the communication method of the wireless telemeter system of this embodiment. In FIG. 4, the horizontal arrow indicates the passage of time. The transmitting side is the wireless master device 10 and corresponds to the first communication device. The receiving side is the wireless slave device 20, and corresponds to the second communication device. On the transmitting side and the receiving side, Tx represents a signal transmitting unit, and Rx represents a signal receiving unit. The transmitting side may be the wireless slave device 20 and the receiving side may be the wireless master device 10.

The short-range wireless communication unit 15 on the transmitting side has a function as a first transmitting unit and transmits a packet signal including one or a plurality of activation signals (also referred to as packets) and packet-related information for a predetermined pause period. Send multiple items to the receiving side with no space. That is, a plurality of packet signals are transmitted with a predetermined pause period between adjacent packet signals.

In one packet signal, one or a plurality of activation signals are continuously transmitted. In the example of FIG. 4, as an example, one packet signal is configured by four continuous activation signals. Note that the number of activation signals forming the packet signal is not limited to four. Further, in the example of FIG. 4, the number of activation signals forming each packet signal is four, but the number of activation signals may be different for each packet signal.

The activation signal is a signal used to establish communication between the transmission side and the reception side, and is composed of, for example, bit synchronization, frame synchronization, header, data and error check. Each activation signal is the same.

The packet related information can be, for example, the number of packets. For example, the short-range wireless communication unit 15 adds a unique variable indicating the number of activation signals up to the last activation signal among the activation signals included in the last transmitted packet signal to each activation signal of the plurality of packet signals. .. The unique variable may be, for example, a down counter that is decremented by 1 each time an activation signal is transmitted. In the example of FIG. 4, for convenience, the activation signal of the down counter X is represented as an activation signal X. For example, activation signal 1 is the last activation signal for which the down counter is 1. Note that the way of expressing the unique variable is not limited to the example of FIG. The packet-related information is not limited to the number of packets, but may be the remaining time (time information) until the last packet is transmitted.

In the example of FIG. 4, the packet signal transmitted last includes four start signals to which the down counters 4, 3, 2, 1 are added in the order of transmission. The activation signal of the down counter 1 is the last activation signal. The packet signal transmitted before the packet signal transmitted last after the pause period Td includes four activation signals to which the down counters 8, 7, 6, 5 are added in the order of transmission.

The upper limit of the packet signal length T (also referred to as transmission time) is defined in a standard of wireless equipment (for example, ARIB STD-T108). For example, the transmission time T must be within 200 ms. At this time, the rest period Td needs to be longer than 2 ms.

The short-range wireless communication unit 24 on the reception side has a function as a reception unit and periodically performs intermittent reception. In the intermittent reception, for example, when the intermittent reception cycle is Tr, the reception operation is performed only for a predetermined reception time every intermittent reception cycle Tr.

The short-range wireless communication unit 24 has a function as a second transmission unit, and when receiving the activation signal transmitted by the transmission side, it determines based on the received packet-related information (for example, a down counter of the activation signal), The response signal is transmitted to the transmitting side at a required time when the packet signal is not transmitted (at the time indicated by reference numeral t1 in the example of FIG. 4). The required time point may be a time point from the time point when the last activation signal (for example, the down counter is 1) is transmitted to the time point when a predetermined response completion time (waiting time for receiving a response) elapses. Further, the required time point may be a pause period between packets.

As shown in FIG. 4, it is assumed that the down counter of the activation signal received by the receiving side performing intermittent reception is 8. In this case, the activation signals of the down counters 10 and 9 are not received by the receiving side. By the last activation signal (down counter is 1), seven activation signals of down counters 7-1 are transmitted from the transmission side, so calculate the time until all seven activation signals are transmitted. , The response signal is transmitted to the transmission side at a time t1 within a predetermined response completion time after the transmission of all the activation signals (the down counter is 7-1) is completed.

With the above configuration, when the transmission side intermittently transmits the packet signal with the packet signal length T within the upper limit and the pause period Td, so that the reception side satisfies the provisions of the standard. When an arbitrary start signal (start signal of the down counter 8 in the example of FIG. 4) is received, based on the down counter (inherent variable) of the received start signal, the last start signal (down in the example of FIG. 4 is generated. It is possible to specify the timing at which the activation signal of the counter 1) is transmitted. Then, the reception side can establish communication between the transmission side and the reception side by transmitting the response signal to the transmission side at the specified timing, and even when performing intermittent reception, the standard specifications are satisfied. be able to.

The required time point (time point t1 in the example of FIG. 4) is after the time point when the activation signal (the activation signal of the down counter 1 in the example of FIG. 4) transmitted last by the transmitting side is transmitted. Accordingly, when the transmitting side provides the response completion time waiting for the response signal after the time when the last activation signal is transmitted, the receiving side can reliably transmit the response signal to the transmitting side.

The required time t1 can be specified as follows.

That is, the control unit 21 on the receiving side has a function as an identifying unit, and identifies the required time point based on the down counter added to the received activation signal, the length of the packet signal, and the length of the pause period. You can For example, when the time from the time when the activation signal is received to the required time t1 is Ts, the required time can be specified based on the equation Ts=(N/A)×T+B×Td. Here, T is the length of the packet signal, N is the number of activation signals up to the last activation signal (7 in the example of FIG. 4), and A is the number of activation signals constituting one packet signal (example of FIG. 4). 4), Td is the length of the pause period, and B is the number of pause periods existing before the last packet signal is transmitted (1 in the example of FIG. 4). As a result, the timing for transmitting the response signal can be obtained by receiving an arbitrary activation signal in the packet signal transmitted intermittently.

FIG. 5 is an explanatory diagram showing an example of a conventional communication method as a comparative example. As shown in FIG. 5, on the receiving side, in order to reduce battery consumption in the wireless station and to save power, the wireless signal receiving operation is performed intermittently for a predetermined time every intermittent receiving cycle Tr. Reception is more common. In this case, on the transmitting side, it is necessary to lengthen the transmission time of the radio signal to some extent (for example, longer than the intermittent reception cycle Tr), and it may not be possible to satisfy the standard (for example, ARIB STD-T108). .. On the other hand, according to the present embodiment, as described with reference to FIG. 4, it is possible to satisfy the regulation of the standard even when performing the intermittent reception.

Also, on the receiving side, the short-range wireless communication unit is stopped and stands by in a low power consumption state until the response signal is transmitted to the transmitting side after receiving the activation signal, so that power saving can be achieved. it can.

[Embodiment 2]
FIG. 6 is an explanatory diagram showing a second embodiment of the communication method of the wireless telemeter system of this embodiment. In the second embodiment, as shown in FIG. 6, the short-range wireless communication unit 24 on the receiving side transmits a response signal a plurality of times between a required time point and a time point before the required time point. In the example of FIG. 6, when the required time point is t13, the short-range wireless communication unit 24 on the reception side transmits a response signal to the transmission side at times t11 and t12 prior to the required time point t13. The number of times the response signal is transmitted is not limited to three. The description of the same parts as those in the first embodiment shown in FIG. 4 will be omitted.

According to the second embodiment, based on the down counter (inherent variable) of the activation signal received by the receiving side, even if there is an error or the like at the specified required time t13, the response signal is sent from the time before the required time t13. Is transmitted multiple times, the response signal can be reliably received on the transmitting side.

Further, the short-range wireless communication unit 24 on the receiving side has a function as a determination unit and determines the reception level of the signal before transmitting the response signal. The signal is a carrier signal and is not limited to a packet signal. The short-range wireless communication unit 24 on the receiving side does not transmit the response signal when the determined reception level is higher than the predetermined threshold. That is, when performing wireless transmission, the short-range wireless communication unit 24 on the reception side determines the reception level of a packet signal transmitted by another wireless station (for example, the transmission side) (also referred to as carrier sense), and the reception level is If it is equal to or higher than the predetermined threshold (also referred to as carrier busy), wireless transmission is not performed, and if the reception level is lower than the predetermined threshold, wireless transmission is performed.

In the example of FIG. 6, at the time point t11, the short-range wireless communication unit 24 on the receiving side performs carrier sense before transmitting the response signal. Since the transmission side is transmitting the activation signal 2, the carrier becomes busy, and the short-range wireless communication unit 24 on the reception side does not transmit the response signal at time t11. Similarly, at time t12, the short-range wireless communication unit 24 on the receiving side performs carrier sense before transmitting the response signal. Since the transmitting side is transmitting the activation signal 1, the carrier becomes busy, and the short-range wireless communication unit 24 on the receiving side does not transmit the response signal at time t12.

On the other hand, at the time point t13, since the carrier side does not become busy after the transmission side transmits the final activation signal 1, the short-range wireless communication unit 24 on the reception side can transmit the response signal at the time point t13.

As described above, when the receiving side transmits the response signal a plurality of times, the short-range wireless communication unit 24 performs carrier sense before transmitting each response signal. When the transmitting side is transmitting the activation signal, the carrier becomes busy and the receiving side does not transmit the response signal. However, after the transmitting side transmits the final activation signal, the carrier is not busy and the receiving side can transmit the response signal.

That is, when the response signal is transmitted a plurality of times, carrier sense is performed before each transmission. If the carrier becomes busy, it can be determined that the transmitter is transmitting the activation signal.After the carrier busy state, the transmitter completes the transmission of the last activation signal at the first time when the carrier is not busy. It can be determined that it did. Therefore, by transmitting the response signal at the time when the carrier is not busy first, the response signal can be transmitted within the response completion time even if the required time cannot be specified accurately, and the response signal is sent at the transmitting side. Can be reliably received.

[Third Embodiment]
FIG. 7 is an explanatory diagram showing a third embodiment of the communication method of the wireless telemeter system of this embodiment. In the third embodiment, as illustrated in FIG. 7, the short-range wireless communication unit 24 on the receiving side performs the intermittent reception operation for a predetermined time from a time point t31 before the required time point t32. In the example of FIG. 7, the activation signal 2 is received during the intermittent reception period after time t31, and then the activation signal 1 is received. When receiving the activation signal 1, the short-range wireless communication unit 24 on the reception side transmits a response signal to the transmission side. As a result, even when the required time cannot be accurately specified, the response signal can be transmitted within the response completion time, and the transmission side can reliably receive the response signal.

Note that in the example of FIG. 7, two activation signals are received during the intermittent reception period after time t31, but the length of the intermittent reception period is not limited to the example of FIG. 7. The description of the same parts as those in the first embodiment shown in FIG. 4 will be omitted.

[Embodiment 4]
FIG. 8 is an explanatory view showing a fourth embodiment of the communication method of the wireless telemeter system of this embodiment. FIG. 8 shows a state in which the transmitting side transmits the activation signals 6 to 1 (the activation signals of the down counter being 6 to 1). The transmitting side performs carrier sense before transmitting each activation signal. As shown in FIG. 8, with respect to the activation signals 6, 5, and 4, as a result of carrier sense, carrier busy did not occur. Therefore, the transmission side transmits the activation signals 6, 5, and 4 to the reception side. However, with respect to the activation signals 3, 2, and 1, it is assumed that the transmission side cannot transmit the activation signals 3, 2, and 1 because the carrier is busy.

Then, if the transmission side does not receive the response signal from the reception side, it can be seen that the activation signals 6 to 4 are not received by the reception side. That is, it can be considered that the intermittent reception period on the receiving side exists somewhere within the period in which the activation signals 3 to 1 are transmitted (in the example of FIG. 8, the period between time t41 and time t42). Therefore, the start signals 3 to 1 are transmitted after the time point t43, which is shifted by the intermittent reception cycle Tr from the transmission time point t41 of the start signal 3 which could not be transmitted due to carrier busy.

As a result, the transmitting side can reliably transmit the activation signal at the timing at which any of the activation signals 3-1 is received during the intermittent reception period. Further, the receiving side can receive any of the activation signals 3-1 and can reliably transmit the response signal to the transmitting side. Further, the transmitting side does not need to retransmit the activation signals 6 to 1, so that the communication amount can be reduced.

FIG. 9 is a flowchart showing an example of a processing procedure on the transmitting side of the wireless telemeter system of this embodiment. For convenience, the main body of processing will be described below as the control unit 11. The control unit 11 sets a counter in the data of the activation signal (S11) and transmits the activation signal to the receiving side (S12).

The control unit 11 determines whether or not all the activation signals have been transmitted (S13), and when all the activation signals have not been transmitted (NO in S13), determines whether or not a predetermined transmission time T has elapsed. The determination is made (S14). When the predetermined transmission time T has not elapsed (NO in S14), the control unit 11 subtracts 1 from the counter of the activation signal to be transmitted next (S16), and performs the process of step S12.

When the predetermined transmission time T has elapsed (YES in S14), the control unit 11 stops the transmission of the activation signal during the pause period Td (S15) and performs the process of step S16. When all the activation signals have been transmitted (YES in S13), the control unit 11 waits for reception (S17), receives the response signal transmitted by the reception side (S18), and ends the process.

FIG. 10 is a flowchart showing an example of the processing procedure on the receiving side of the wireless telemeter system of this embodiment. For convenience, the main body of processing will be described below as the control unit 21. The control unit 21 determines whether or not the activation signal is received (S31), and when the activation signal is not received (NO in S31), the process of step S31 is continued.

When the activation signal is received (YES in S31), the control unit 21 calculates (specifies) the required time point for transmitting the response signal based on the received counter of the activation signal (S32). The control unit 21 transmits the response signal at a time point that is a predetermined time before the calculated required time point (S33).

The control unit 21 determines whether or not the response signal could be transmitted (S34). In this case, the control unit 21 performs carrier sense and does not transmit the response signal when the carrier is busy. If the carrier is not busy, a response signal is transmitted.

When the response signal cannot be transmitted (NO in S34), the control unit 21 transmits the response signal again (S35) and performs the process of step S34. When the response signal can be transmitted (YES in S34), the control unit 21 ends the process.

The wireless master device 10 and the wireless slave device 20 of the present embodiment can also be realized using a general-purpose computer including a CPU (processor), a RAM (memory), and the like. That is, as shown in FIGS. 9 and 10, by loading a computer program defining the procedure of each process into a RAM (memory) provided in the computer and executing the computer program by a CPU (processor), the wireless master Various processes of the device 10 and the wireless slave device 20 can be realized.

In the above-described embodiment, the wireless master device 10 is the transmitting side and the wireless slave device 20 is the receiving side. However, the wireless slave device 20 may be the transmitting side and the wireless master device 10 may be the receiving side. In this case, the respective units of the wireless master device 10 and the wireless slave device 20 may be replaced.

In the present embodiment, the counter (down counter) is used as the unique variable of the activation signal (packet), but the unique variable is not limited to the down counter, and is not limited to the received activation signal. Any number, code or the like can be used as long as the number of the activation signals transmitted up to the last activation signal can be known.

A communication system according to the present embodiment is a communication system that performs communication between a first communication device and a second communication device, and the first communication device includes a packet signal composed of one or a plurality of packets. The second communication device includes a first transmitter that transmits a plurality of packet-related information to the second communication device with a predetermined pause period, and the second communication device includes a receiver that periodically performs intermittent reception, and the receiver. A second transmitting unit that transmits a response signal to the first communication device when a packet is received, the response signal being determined based on the received packet-related information and at a required time when the packet signal is not transmitted. And

The communication device of the present embodiment is a communication device that communicates with another communication device, and provides a packet signal composed of one or a plurality of packets and packet-related information with a predetermined pause period. It is characterized by comprising a first transmitting unit for transmitting a plurality of to the other communication device.

The communication device according to the present embodiment is a communication device that communicates with another communication device, and includes a receiving unit that performs periodic intermittent reception, and a packet that is received when the receiving unit receives the packet. And a transmission unit that transmits a response signal to the other communication device at a required time when the packet signal is not transmitted, which is determined based on the related information.

The computer program according to the present embodiment is a computer program for causing a computer to perform communication with another communication device, and includes a packet signal and packet-related information including one or a plurality of packets. It is characterized in that a process for transmitting a plurality of and to a plurality of other communication devices is executed after a predetermined pause period.

The computer program of the present embodiment is a computer program for causing a computer to perform communication with another communication device, and in the case where the computer performs a process of performing intermittent reception periodically and a packet is received. A process of transmitting a response signal to the other communication device at a required time when the packet signal is not transmitted, which is determined based on the received packet related information.

The communication method according to the present embodiment is a communication method in which communication is performed between a first communication device and a second communication device, and the first transmission unit of the first communication device includes one or a plurality of packets. A plurality of packet signals and packet-related information to be transmitted to the second communication device with a predetermined pause period, and the receiving unit of the second communication device periodically performs intermittent reception, and the second communication device. When the receiving unit receives a packet, the second transmitting unit transmits a response signal to the first communication device at a required time when the packet signal is not transmitted, which is determined based on the received packet-related information. It is characterized by doing.

A first transmission unit (transmission unit) (15) of a first communication device (communication device) (10) transmits a packet signal composed of one or a plurality of packets and packet related information after a predetermined pause period. 2 Multiple transmissions to the communication device (another communication device) (20). The first communication device is also referred to as the transmitting side. That is, a plurality of packet signals are transmitted with a predetermined pause period between adjacent packet signals. In one packet signal, one or more packets are continuously transmitted. A packet is composed of, for example, bit synchronization, frame synchronization, header, data and error check, and each packet is the same. In addition, in the present embodiment, the packet is also referred to as a start signal.

The packet related information can be, for example, the number of packets. For example, the first transmission unit of the first communication device assigns a unique variable indicating the number of packets up to the last packet included in the packet signal transmitted last to each packet of the plurality of packet signals and transmits the packet. can do. For example, when 8 packets are divided into 2 packet signals and transmitted, each packet signal is composed of 4 consecutive packets, and a number from 8 to 1 is assigned as a unique variable in the packet transmission order. can do. In this case, the unique variable can be like a down counter that is decremented by 1 each time a packet is transmitted. The packet-related information is not limited to the number of packets, and may be the remaining time (time information) until the last packet is transmitted.

The receiving unit (24) of the second communication device (communication device) periodically performs intermittent reception. In the intermittent reception, for example, when the intermittent reception cycle is Tr, the reception operation is performed only for a predetermined reception time every intermittent reception cycle Tr. The second communication device is also referred to as a receiving side.

When the receiving unit receives the packet, the second transmitting unit (24) of the second communication device transmits the response signal to the first communication unit at a required time when the packet signal is not transmitted, which is determined based on the received packet-related information. Send to the device (another communication device). The required time can be, for example, a time between the time when the last packet (for example, the down counter is 1) is transmitted and the time when a predetermined response completion time (time for waiting for a response) elapses. .. Further, the required time point may be a pause period between packets.

For example, assume that the first transmitter of the first communication device divides eight packets into two packet signals and transmits the two packet signals. It is assumed that the down counter (unique variable) of the packet received by the receiving unit of the second communication device during the predetermined receiving time is 6. In this case, the packets of the down counters 8 and 7 are not received by the receiving unit. Up to the last packet (down counter is 1), 5 packets of down counters 5 to 1 are transmitted, so calculate the time until all 5 packets are transmitted, and transmit all packets. A response signal is transmitted to the first communication device (another communication device) at a time after the completion of the above and within a predetermined response completion time.

With the above-described configuration, when the transmitting side intermittently transmits the packet signal with the packet signal length within the upper limit value and the pause period so as to satisfy the standard, the receiving side can When a packet is received, the timing at which the last packet is sent can be identified based on the down counter (unique variable) of the received packet. Then, the reception side can establish communication between the transmission side and the reception side by transmitting the response signal to the transmission side at the specified timing, and even when performing intermittent reception, the standard specifications are satisfied. be able to.

The communication system according to the present embodiment is characterized in that the required time is after the time when the last packet transmitted by the first transmitter is transmitted.

The required time is after the time when the last packet transmitted by the first transmitter is transmitted. Accordingly, when the transmitting side provides a response completion time waiting for a response signal after the time when the last packet is transmitted, the receiving side can reliably transmit the response signal to the transmitting side.

The communication system according to the present embodiment is characterized in that the second transmitting unit transmits the response signal a plurality of times between the required time point and a time point before the required time point.

The second transmitter (24) transmits the response signal a plurality of times between the required time point and the time point before the required time point. As a result, even if there is an error in the required time point based on the down counter (unique variable) of the packet received by the receiving side, the response signal is transmitted multiple times from the time point before the required time point, so Can be reliably received.

In the communication system of the present embodiment, the second communication device includes a determination unit that determines a reception level of a signal before the second transmission unit transmits the response signal, and the second transmission unit is the When the reception level determined by the determination unit is higher than a predetermined threshold, the response signal is not transmitted.

The determination unit (24) of the second communication device determines the reception level of the signal before the response signal is transmitted by the second transmission unit. The signal is a carrier signal and is not limited to a packet signal. The second transmission unit does not transmit the response signal when the reception level determined by the determination unit is higher than the predetermined threshold. That is, when performing wireless transmission, the determination unit determines the reception level of a signal transmitted by another wireless station (for example, the transmission side) (also referred to as carrier sense), and when the reception level is equal to or higher than a predetermined threshold ( Radio transmission is not performed, but radio transmission is performed when the reception level is less than a predetermined threshold.

Thereby, for example, when the reception side transmits the response signal a plurality of times, the determination unit performs the carrier sense before transmitting each response signal. When the transmitting side is transmitting the packet, the carrier becomes busy and the receiving side does not transmit the response signal. However, after the sender sends the last packet, the carrier does not become busy and the receiver can send the response signal. Therefore, even if the receiving side has an error or the like at the required time point based on the down counter of the packet received, the transmitting side can reliably receive the response signal.

In the communication system of the present embodiment, the second communication device identifies the required time point based on a variable added to the packet received by the receiving unit, the length of the packet signal, and the length of the idle period. Is provided.

The specifying unit (21) of the second communication device specifies the required time point based on the variable added to the packet received by the receiving unit, the length of the packet signal, and the length of the idle period. For example, if the time from the time when the packet is received to the required time is Ts, the required time can be specified based on the equation Ts=(N/A)×T+B×Td. Here, T is the length of the packet signal, N is the number up to the last packet, A is the number of packets constituting one packet signal, Td is the length of the idle period, and B is the number of the idle period. As a result, when an arbitrary packet in the packet signal transmitted intermittently is received, the timing of transmitting the response signal can be obtained.

DESCRIPTION OF SYMBOLS 10 Wireless main unit 11 Control part 12 Display part 13 Operation part 14 Wide area wireless communication part 15 Narrow area wireless communication part 16 Storage part 20 Wireless cordless handset 21 Control part 22 Display part 23 Operation part 24 Short range wireless communication part 25 Connection part 26 Memory

Claims (7)

A communication system for performing communication between a first communication device and a second communication device,
The first communication device,
A first transmitting unit for transmitting a plurality of packet signals composed of one or a plurality of packets and packet related information to the second communication device with a predetermined pause period.
The second communication device,
A receiving section that performs intermittent reception periodically
When a packet is received by the receiving unit, a specifying unit that specifies a required time point based on the received packet-related information,
A second transmission unit that transmits a response signal to the first communication device at a time point when the packet signal is not transmitted and at a required time point that is specified by the specification unit. The required time is
The communication system according to claim 1, which is after a time point when a packet transmitted last by the first transmission unit is transmitted. The second transmitter is
The communication system according to claim 1 or 2, wherein the response signal is transmitted a plurality of times between the required time point and a time point before the required time point. The second communication device,
A determination unit that determines the reception level of the signal before transmitting the response signal by the second transmission unit,
The second transmitter is
The communication system according to claim 1, wherein the response signal is not transmitted when the reception level determined by the determination unit is higher than a predetermined threshold value. The second communication device,
The identification unit that identifies the required time point based on the variable added to the packet received by the reception unit, the length of the packet signal, and the length of the idle period. 4. The communication system according to any one of 4 above. A communication device for communicating with another communication device,
A receiving unit that periodically and intermittently receives a packet signal composed of one or a plurality of packets and packet-related information, which the other communication device transmits after a predetermined pause period .
When a packet is received by the receiving unit, a specifying unit that specifies a required time point based on the received packet-related information,
A communication unit, which transmits a response signal to the other communication device at a time point when the packet signal is not transmitted and at a required time point specified by the specification unit. A communication method for performing communication between a first communication device and a second communication device,
The first transmission unit of the first communication device,
A plurality of packet signals composed of one or a plurality of packets and packet related information are transmitted to the second communication device with a predetermined pause period.
The receiving unit of the second communication device,
Do intermittent reception periodically,
The specific part is
When a packet is received by the receiving unit, a required time point is specified based on the received packet-related information,
The second transmission unit of the second communication device,
A communication method, wherein a response signal is transmitted to the first communication device at a time point when the packet signal is not transmitted and at a required time point specified by the specifying unit.

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