Control device, and control method

Abstract

To provide a control device and a control method capable of reducing a decrease in battery life more than before.SOLUTION: A control device 1 includes a master unit determination part 103 for determining a master unit 2 having large reception strength as a master unit 2 for performing communication with a slave unit 3 among a plurality of master units 2 on the basis of a comparison result by a reception strength comparison part 102 in the case that a reception strength acquisition part 101 acquires information showing reception strength in the communication with a common slave unit 3 with the plurality of master units 2, and an operation control part 104 for making operation continue about the master unit 2 for performing communication with the slave unit 3 and stopping operation about remaining master units 2 among the plurality of master units 2 from which information showing reception strength is acquired by the reception strength acquisition part 101. The operation control part 104 performs transmission strength adjustment of the slave unit 3 so as to make reception strength by the master unit 2 performing communication with the slave unit 3 to be within a prescribed range.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a control device and a control method. [Background technology]

[0002] Wireless sensor slave units may be unable to transmit their sensor status to the master unit due to communication problems. Conventionally, countermeasures for this problem have been taken by increasing the transmission strength or by increasing the number of master units to prevent communication leaks.

[0003] However, both methods have the problem of increased battery consumption and shorter battery life. The latter method also shortens battery life because the number of communication partners increases and communication frequency increases.

[0004] For example, as shown in Non-Patent Document 1, there is a method of transmitting to two parent devices (GW), but since the transmission strength and time are not adjusted, the battery life on the child device side cannot be optimized. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] https: / / www.jstage.jst.go.jp / article / sicejl / 56 / 7 / 56_534 / _pdf Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, conventionally, in order to cope with the case where a slave unit is unable to transmit the sensor status to the master unit due to a communication failure, methods have been adopted such as increasing the transmission strength or increasing the number of master units to prevent communication omissions. However, both methods have the problem of increasing battery consumption and shortening battery life.

[0007] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a communication system that can reduce the decrease in battery life compared to conventional systems. [Means for solving the problem]

[0008] The communication system according to the present disclosure includes a reception strength acquisition unit that acquires information indicating the reception strength in communication between a parent unit and a child unit; a reception strength comparison unit that compares the reception strengths when the reception strength acquisition unit acquires information indicating the reception strength in communication between a parent unit and a child unit that is common to multiple parent units; a parent unit determination unit that, based on the comparison result by the reception strength comparison unit, determines the parent unit with the highest reception strength from among the multiple parent units for which information indicating reception strength has been acquired by the reception strength acquisition unit as the parent unit that will communicate with the child unit; and an operation control unit that, based on the determination by the parent unit determination unit, continues operation of the parent unit that communicates with the child unit from among the multiple parent units for which information indicating reception strength has been acquired by the reception strength acquisition unit, and stops operation of the remaining parent units, and is characterized in that the operation control unit adjusts the transmission strength of the child unit so that the reception strength of the parent unit communicating with the child unit is within a predetermined range. [Effects of the Invention]

[0009] According to the present disclosure, the configuration as described above makes it possible to reduce the decrease in battery life compared to conventional configurations. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an example of the configuration of a communication system according to a first embodiment. [Figure 2] 1 is a diagram illustrating an example of the configuration of a control device according to a first embodiment. [Figure 3] 4 is a flowchart showing an example of the operation of the control device according to the first embodiment. [Figure 4] FIG. 2 is a diagram illustrating an example of the operation of the communication system according to the first embodiment. [Figure 5] FIG. 2 is a diagram illustrating an example of the operation of the communication system according to the first embodiment. [Figure 6] FIG. 10 is a diagram illustrating an example of the configuration of a control device according to a second embodiment. [Figure 7] FIG. 10 is a diagram illustrating an example of the operation of the communication system according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail with reference to the drawings. Embodiment 1 FIG. 1 is a diagram illustrating an example of the configuration of a communication system according to the first embodiment. As shown in Fig. 1, for example, a communication system includes a control device 1, a plurality of base units 2, and one or more slave units 3. The base units 2 are multiplexed to maintain communication reliability, and the communication system shown in Fig. 1 uses two base units 2 (a first base unit 2-1 and a second base unit 2-2). Fig. 1 also shows two slave units 3 (a first slave unit 3-1 and a second slave unit 3-2).

[0012] In addition, in the communication system of embodiment 1, the focus is on optimizing communication from the slave device 3 to the master device 2, so the transmission strength (transmission RSSI) refers to the strength of communication transmitted by the slave device 3, and the reception strength (reception RSSI) refers to the strength of communication received by the master device 2. In addition, since the communication method and standard in the communication system of embodiment 1 is assumed to be a sensor-based monitoring system, from a security standpoint, the communication method and standard are assumed to be such that the parent device 2 and the child device 3 can mutually confirm the communication status (return an ACK).

[0013] The control device 1 is a device that manages and controls the master device 2 and the slave device 3 . An example of the configuration of this control device 1 will be described later.

[0014] The base unit 2 communicates with the handset 3 . The master device 2 notifies the control device 1 of information indicating the communication strength (reception RSSI) in communication with the slave device 3.

[0015] The slave 3 communicates with the master 2. The slave 3 is a wireless sensor slave that measures state quantities and transmits data indicating the measurement results to the master 2. The slave 3 is also battery-powered.

[0016] Next, a configuration example of the control device 1 according to the first embodiment will be described with reference to FIG. The control device 1 includes a reception strength acquisition unit 101, a reception strength comparison unit 102, a master device determination unit 103, and an operation control unit 104, as shown in FIG.

[0017] The control device 1 is realized by a processing circuit such as a system LSI (Large Scale Integration), or a CPU (Central Processing Unit) that executes a program stored in a memory or the like.

[0018] The reception strength acquisition unit 101 acquires information indicating the reception strength (reception RSSI) in communication between the master device 2 and the slave device 3.

[0019] When the reception strength acquisition unit 101 acquires information indicating the reception strength in communication between a common slave unit 3 and multiple base units 2, the reception strength comparison unit 102 compares the reception strengths. In this case, it is desirable that the reception strength comparison unit 102 performs the comparison using an average of the reception strengths obtained multiple times.

[0020] Based on the comparison result by the reception strength comparison unit 102, the parent device determination unit 103 determines the parent device 2 with the highest reception strength from among the multiple parent devices 2 for which information indicating reception strength has been acquired by the reception strength acquisition unit 101 as the parent device 2 that will communicate with the child device 3.

[0021] Based on the decision made by the parent device decision unit 103, the operation control unit 104 continues operation of the parent device 2 that communicates with the child device 3, out of the multiple parent devices 2 for which information indicating reception strength has been acquired by the reception strength acquisition unit 101, and stops operation of the remaining parent devices 2.

[0022] In addition, if the results obtained by the reception strength acquisition unit 101 indicate that the parent unit 2 and the child unit 3 communicating with each other have a one-to-one relationship, the operation control unit 104 continues operation of the parent unit 2 communicating with the child unit 3.

[0023] Furthermore, the operation control unit 104 adjusts the transmission strength of the parent device 2 communicating with the child device 3 so that the reception strength at the parent device 2 is within a predetermined range. The predetermined range is a range that allows communication reliability to be maintained between the parent device 2 and the child device 3. As a specific example of this predetermined range, for example, in the case of Bluetooth communication, a range of -80 dBm to -60 dBm is generally considered sufficient. In addition, when the surrounding environment changes over time, the operation control unit 104 can expect to stabilize communication by periodically adjusting the transmission intensity.

[0024] Furthermore, the operation control unit 104 may extend the communication interval between the handset 3 and the base unit 2 with which the handset 3 is communicating.

[0025] When communication between the master unit 2 and the slave unit 3 is cut off, the operation control unit 104 performs reconnection processing for all the master units 2 and the slave units 3 in question. In this reconnection process, for example, the operation control unit 104 instructs the slave unit 3 to continue transmission at maximum transmission power, and instructs all the master units 2 to receive communication from the slave unit 3 and, as soon as reception is possible, to return the communication at maximum transmission power. Then, when the reconnection is confirmed, the control device 1 performs the process again to determine the master unit 2 that will continue operation.

[0026] Next, an example of the operation of the control device 1 according to the first embodiment shown in Fig. 2 will be described with reference to Fig. 3. In the following, a case where the operation control unit 104 adjusts the transmission intensity of the handset 3 will be described. In an example of operation of the control device 1 according to embodiment 1 shown in FIG. 2, as shown in FIG. 3, first, the reception strength acquisition unit 101 acquires information indicating the reception strength (reception RSSI) in communication between the parent device 2 and the child device 3 (step ST101).

[0027] Next, the reception strength acquisition unit 101 determines whether or not information indicating the reception strength in communication between the multiple base units 2 and the common handset 3 has been acquired (step ST102).

[0028] In this step ST102, if the reception strength acquisition unit 101 determines that it has not acquired information indicating the reception strength in communication between multiple base units 2 and a common handset 3, that is, if the base unit 2 and handset 3 that communicate are in a one-to-one relationship, the operation control unit 104 continues operation for the base unit 2 that communicates with that handset 3 (step ST103). After that, the sequence proceeds to step ST106.

[0029] On the other hand, if the reception strength acquisition unit 101 determines in step ST102 that information indicating the reception strength in communication between the multiple base units 2 and the common handset 3 has been acquired, the reception strength comparison unit 102 compares the reception strengths (step ST104). At this time, it is desirable that the reception strength comparison unit 102 performs the comparison using an average of the reception strengths measured multiple times (for example, five times).

[0030] Next, based on the comparison result by the reception strength comparison unit 102, the master unit determination unit 103 determines the master unit 2 with the highest reception strength among the multiple master units 2 for which information indicating reception strength has been acquired by the reception strength acquisition unit 101 as the master unit 2 that will communicate with the slave unit 3. Then, based on the determination by the master unit determination unit 103, the operation control unit 104 continues the operation of the master unit 2 that will communicate with the slave unit 3 among the multiple master units 2 for which information indicating reception strength has been acquired by the reception strength acquisition unit 101, and stops the operation of the remaining master units 2 (step ST105).

[0031] Next, the operation control section 104 adjusts the transmission strength of the handset 3 so that the reception strength at the base unit 2 communicating with the handset 3 falls within a predetermined range (step ST106). In addition, when the surrounding environment changes over time, the operation control unit 104 can expect to stabilize communication by periodically adjusting the transmission intensity.

[0032] Next, the operation control section 104 determines whether the communication between the parent device 2 and the child device 3, whose operation has been continued by the operation control section 104, has been disconnected (step ST107).

[0033] In this step ST107, if the operation control unit 104 determines that the communication between the parent unit 2 and the child unit 3 has not been disconnected, it continues the communication between the parent unit 2 and the child unit 3 (step ST108).

[0034] On the other hand, if the operation control unit 104 determines in step ST107 that communication between the parent unit 2 and the child unit 3 has been disconnected, it performs reconnection processing for all parent units 2 and the child units 3 (step ST109). In this reconnection process, for example, the operation control unit 104 instructs the slave unit 3 to continue transmission at maximum transmission power, and instructs all master units 2 to receive communication from the slave unit 3 and, as soon as reception is possible, to return the communication at maximum transmission power. After that, the sequence returns to step ST101.

[0035] For example, as shown in FIG. 4, suppose that the first base unit 2-1 starts communication with the first handset 3-1 and the second handset 3-2, and the second base unit 2-2 starts communication with the first handset 3-1 and the second handset 3-2.

[0036] In this case, the reception strength acquisition unit 101 acquires information indicating the reception strength from the first terminal 2-1 at the first base terminal 2-1 and the reception strength from the second terminal 3-2 at the first base terminal 2-1. The reception strength acquisition unit 101 also acquires information indicating the reception strength from the first handset 3-1 at the second base unit 2-2 and the reception strength from the second handset 3-2 at the second base unit 2-2.

[0037] Then, the reception strength comparison unit 102 compares the reception strength from the first handset 3-1 at the first base unit 2-1 with the reception strength from the first handset 3-1 at the second base unit 2-2. Here, it is assumed that the reception strength from the first handset 3-1 at the first base unit 2-1 is greater than the reception strength from the first handset 3-1 at the second base unit 2-2. Furthermore, the reception strength comparison unit 102 compares the reception strength from the second handset 3-2 at the first base unit 2-1 with the reception strength from the second handset 3-2 at the second base unit 2-2. Here, it is assumed that the reception strength from the second handset 3-2 at the second base unit 2-2 is greater than the reception strength from the second handset 3-2 at the first base unit 2-1.

[0038] In this case, the master unit determination unit 103 selects the first master unit 2-1, which has the stronger reception strength, as the master unit 2 that will communicate with the first slave unit 3-1. Furthermore, the master device determination unit 103 selects the second master device 2-2, which has the stronger reception strength, as the master device 2 that will communicate with the second slave device 3-2.

[0039] Then, as shown in FIG. 5, the operation control unit 104 causes the first base unit 2-1 to continue communication with the first handset 3-1 and to stop communication with the second handset 3-2. Furthermore, the operation control unit 104 causes the second base unit 2-2 to continue communication with the second handset 3-2 and to stop communication with the first handset 3-1.

[0040] Here, if the handset 3 communicates with a plurality of base units 2, the power consumption of the handset 3 increases, leading to a reduction in the battery life. Therefore, the control device 1 according to the first embodiment sets up a one-to-one correspondence between the parent devices 2 and the child devices 3 that continue communication. Specifically, when a plurality of parent devices 2 communicate with a child device 3, the control device 1 according to the first embodiment compares the reception RSSIs at that time and determines the parent device 2 with the larger reception RSSI as the parent device 2 that will communicate with that child device 3. This makes it possible for the control device 1 according to the first embodiment to maintain the reliability of communication between the parent device 2 and the child device 3 while maintaining the battery life of the child device 3. That is, the control device 1 according to the first embodiment reduces the reception standby time and the number of ACK transmissions for acknowledging reception compared to when a plurality of parent devices 2 and child devices 3 communicate, which leads to a reduction in power consumption.

[0041] Furthermore, the control device 1 according to the first embodiment can further extend the battery life of the slave device 3 by adjusting the output of the slave device 3 so that the reception RSSI at the master device 2 falls within a predetermined range. That is, when the transmission strength of the slave device 3 is high, the power consumption increases. Therefore, by adjusting the transmission strength of the slave device 3 so that the reception RSSI at the master device 2 falls within a predetermined range that allows communication reliability to be maintained, it is possible to further reduce power consumption while maintaining communication reliability.

[0042] Furthermore, in the control device 1 according to the first embodiment, it is possible to further extend the battery life of the slave device 3 by extending the communication interval between the master device 2 and the slave device 3. For example, immediately after the start of communication, the communication interval is shortened (for example, every second) to check whether the communication is stable, and once it is confirmed that the communication is stable and the received RSSI is within a predetermined range, the communication interval is gradually extended, for example, to 10 seconds, 1 minute, and 10 minutes, thereby making it possible to further reduce power consumption.

[0043] As described above, according to this embodiment 1, the control device 1 includes a reception strength acquisition unit 101 that acquires information indicating the reception strength in communication between the base unit 2 and the handset 3, a reception strength comparison unit 102 that compares the reception strengths when the reception strength acquisition unit 101 acquires information indicating the reception strength in communication between the base unit 2 and a handset 3 that is common to multiple base units 2, a base unit determination unit 103 that determines, based on the comparison result by the reception strength comparison unit 102, the base unit 2 with the highest reception strength among the multiple base units 2 for which information indicating reception strength has been acquired by the reception strength acquisition unit 101, as the base unit 2 that will communicate with the handset 3, and an operation control unit 104 that, based on the determination by the base unit determination unit 103, continues operation of the base unit 2 that communicates with the handset 3 among the multiple base units 2 for which information indicating reception strength has been acquired by the reception strength acquisition unit 101, and stops operation of the remaining base units 2, and the operation control unit 104 adjusts the transmission strength of the base unit 2 that is communicating with the handset 3 so that the reception strength at the base unit 2 is within a predetermined range. As a result, the control device 1 according to the first embodiment can reduce the reduction in battery life compared to conventional devices.

[0044] Furthermore, according to the first embodiment, when communication between a master unit 2 and a slave unit 3 is cut off, the operation control unit 104 performs reconnection processing for all master units 2 and the slave units 3 in question. As a result, the control device 1 according to the first embodiment can also cope with a case where communication between the master device 2 and the slave device 3 is cut off.

[0045] Furthermore, according to the first embodiment, the operation control section 104 extends the communication interval between the handset 3 and the base unit 2 with which the handset 3 is communicating. This makes it possible to further reduce power consumption in the control device 1 according to the first embodiment.

[0046] Furthermore, according to this embodiment 1, the control method includes a step in which the reception strength acquisition unit 101 acquires information indicating the reception strength in communication between the master unit 2 and the slave unit 3; a step in which the reception strength comparison unit 102, when the reception strength acquisition unit 101 acquires information indicating the reception strength in communication between the master unit 2 and a slave unit 3 that is common to multiple master units 2, compares the reception strengths; and a step in which the master unit determination unit 103, based on the comparison result by the reception strength comparison unit 102, selects one of the multiple master units 2 for which the reception strength information has been acquired by the reception strength acquisition unit 101 as the master unit. The method includes a step of determining a parent unit 2 with a high reception strength as the parent unit 2 that will communicate with the child unit 3, a step of an operation control unit 104 continuing operation of the parent unit 2 that is communicating with the child unit 3, among the multiple parent units 2 for which information indicating reception strength has been acquired by the reception strength acquisition unit 101, based on the determination by the parent unit determination unit 103, and stopping operation of the remaining parent units 2, and a step of the operation control unit 104 adjusting the transmission strength of the child unit 3 so that the reception strength of the parent unit 2 that is communicating with the child unit 3 is within a predetermined range. As a result, the control method according to the first embodiment can reduce the reduction in battery life compared to conventional methods.

[0047] Embodiment 2 Fig. 6 is a diagram showing a configuration example of a control device 1 according to embodiment 2. In the control device 1 according to embodiment 2 shown in Fig. 6, the operation control unit 104 is changed to an operation control unit 104b in comparison with the control device 1 according to embodiment 1 shown in Fig. 2. The other configuration example of the control device 1 according to embodiment 2 shown in Fig. 6 is the same as the configuration example of the control device 1 according to embodiment 1, and the same reference numerals are used and only the different parts will be described.

[0048] Based on the determination by the parent device determination unit 103, the operation control unit 104b continues operation of the parent device 2 that communicates with the child device 3 among the multiple parent devices 2 for which information indicating reception strength has been acquired by the reception strength acquisition unit 101, and causes the remaining parent devices 2 that communicate with the child device 3 to operate at a low frequency.

[0049] In addition, if the results obtained by the reception strength acquisition unit 101 indicate that the parent unit 2 and the child unit 3 communicating with each other have a one-to-one relationship, the operation control unit 104b continues operation of the parent unit 2 communicating with the child unit 3.

[0050] Furthermore, the operation control unit 104b adjusts the transmission strength of the handset 3 so that the reception strength at the base unit 2 communicating with the handset 3 falls within a predetermined range. In addition, when the surrounding environment changes over time, the operation control unit 104b can be expected to stabilize communication by periodically adjusting the transmission intensity.

[0051] Furthermore, the operation control unit 104b may extend the communication interval between the handset 3 and the base unit 2 with which the handset 3 is communicating.

[0052] It should be noted that the operation control unit 104b may switch the master unit 2 that communicates with the slave unit 3 when the master unit 2 determined by the master unit determination unit 103 is changed.

[0053] For example, as shown in FIG. 4, suppose that the first base unit 2-1 starts communication with the first handset 3-1 and the second handset 3-2, and the second base unit 2-2 starts communication with the first handset 3-1 and the second handset 3-2.

[0054] In this case, the reception strength acquisition unit 101 acquires information indicating the reception strength from the first terminal 2-1 at the first base terminal 2-1 and the reception strength from the second terminal 3-2 at the first base terminal 2-1. The reception strength acquisition unit 101 also acquires information indicating the reception strength from the first handset 3-1 at the second base unit 2-2 and the reception strength from the second handset 3-2 at the second base unit 2-2.

[0055] Then, the reception strength comparison unit 102 compares the reception strength from the first handset 3-1 at the first base unit 2-1 with the reception strength from the first handset 3-1 at the second base unit 2-2. Here, it is assumed that the reception strength from the first handset 3-1 at the first base unit 2-1 is greater than the reception strength from the first handset 3-1 at the second base unit 2-2. Furthermore, the reception strength comparison unit 102 compares the reception strength from the second handset 3-2 at the first base unit 2-1 with the reception strength from the second handset 3-2 at the second base unit 2-2. Here, it is assumed that the reception strength from the second handset 3-2 at the second base unit 2-2 is greater than the reception strength from the second handset 3-2 at the first base unit 2-1.

[0056] In this case, the master unit determination unit 103 selects the first master unit 2-1, which has the stronger reception strength, as the master unit 2 that will communicate with the first slave unit 3-1. Furthermore, the master device determination unit 103 selects the second master device 2-2, which has the stronger reception strength, as the master device 2 that will communicate with the second slave device 3-2.

[0057] As shown in FIG. 7, the operation control unit 104b allows the first base unit 2-1 to continue communication with the first handset 3-1 and to communicate less frequently with the second handset 3-2. Furthermore, the operation control unit 104b causes the second base unit 2-2 to continue communication with the second handset 3-2 and to communicate less frequently with the first handset 3-1. For example, the slave unit 3 communicates once per minute with the master unit 2 that performs constant communication, and communicates once per 10 minutes with the master unit 2 that performs infrequent communication.

[0058] In this way, in the control device 1 according to the first embodiment, the parent device 2 and the child device 3 that communicate with each other are in a completely one-to-one relationship, whereas in the control device 1 according to the second embodiment, constant communication is performed one-to-one, and other communication between the parent device 2 and the child device 3 is infrequent communication. As a result, in the control device 1 according to the second embodiment, although power consumption increases slightly compared to the first embodiment, it is possible to further improve communication reliability.

[0059] Furthermore, in the control device 1 according to the second embodiment, when the reception strength of the base unit 2 performing infrequent communication becomes stronger than that of the base unit 2 performing constant communication due to a change in the surrounding environment or the like, the base unit 2 performing infrequent communication may be switched to the base unit 2 performing constant communication. This makes it possible to further improve communication reliability in the control device 1 according to the second embodiment.

[0060] As described above, according to the second embodiment, the control device 1 includes a reception strength acquisition unit 101 that acquires information indicating reception strength in communication between the master unit 2 and the slave unit 3, a reception strength comparison unit 102 that compares the reception strengths when the reception strength acquisition unit 101 acquires information indicating reception strength in communication between the master unit 2 and the slave unit 3 that is common to multiple master units 2, and a reception strength comparison unit 102 that, based on the comparison result by the reception strength comparison unit 102, selects a master unit 2 with a higher reception strength from the multiple master units 2 for which information indicating reception strength has been acquired by the reception strength acquisition unit 101 and assigns the master unit 2 with the higher reception strength to the slave unit 3. and an operation control unit 104b which, based on the determination by the parent device determination unit 103, causes the parent device 2 communicating with the handset 3 to continue operating among the multiple parent devices 2 for which information indicating reception strength has been acquired by the reception strength acquisition unit 101, and causes the remaining parent devices 2 communicating with the handset 3 to operate less frequently, and the operation control unit 104b adjusts the transmission strength of the parent device 2 communicating with the handset 3 so that the reception strength at the parent device 2 is within a predetermined range. As a result, the control device 1 according to the second embodiment can improve communication reliability compared to the control device 1 according to the first embodiment.

[0061] Furthermore, according to the second embodiment, when the master device 2 determined by the master device determination unit 103 is changed, the operation control unit 104b switches the master device 2 that communicates with the slave device 3. As a result, the control device 1 according to the second embodiment can further improve communication reliability.

[0062] Furthermore, according to the second embodiment, the control method includes a step in which the reception strength acquisition unit 101 acquires information indicating the reception strength in communication between the master unit 2 and the slave unit 3; a step in which the reception strength comparison unit 102, when the reception strength acquisition unit 101 acquires information indicating the reception strength in communication between the master unit 2 and the slave unit 3 that is common to multiple master units 2, compares the reception strengths; and a step in which the master unit determination unit 103, based on the comparison result by the reception strength comparison unit 102, selects the master unit 2 having the greatest reception strength from among the multiple master units 2 for which the reception strength acquisition unit 101 has acquired information indicating the reception strength. as the parent unit 2 that will communicate with the handset 3; a step in which, based on the determination by the parent unit determination unit 103, the operation control unit 104b continues operation of the parent unit 2 that communicates with the handset 3 out of the multiple parent units 2 for which information indicating reception strength has been acquired by the reception strength acquisition unit 101, and causes the remaining parent units 2 that communicate with the handset 3 to operate at a low frequency; and a step in which the operation control unit 104b adjusts the transmission strength of the parent unit 2 that is communicating with the handset 3 so that the reception strength at the parent unit 2 is within a predetermined range. As a result, the control method according to the second embodiment can further improve communication reliability compared to the control method according to the first embodiment.

[0063] It should be noted that the embodiments may be freely combined, or any of the components in each embodiment may be modified, or any of the components in each embodiment may be omitted. [Explanation of symbols]

[0064] 1. Control device 2 Base unit 3 Handsets 101 Reception strength acquisition unit 102 Receiving strength comparison unit 103 Parent device determination unit 104, 104b Operation control unit

Claims

1. a reception strength acquisition unit that acquires information indicating reception strength in communication between the master unit and the slave unit; a reception strength comparison unit that compares the reception strengths when the reception strength acquisition unit acquires information indicating reception strengths in communication between the plurality of base units and the common slave units; a master unit determination unit that determines, based on a comparison result by the reception strength comparison unit, a master unit having a high reception strength among the plurality of master units for which information indicating reception strength has been acquired by the reception strength acquisition unit, as a master unit that will communicate with the slave unit; and an operation control unit that, based on the determination by the master unit determination unit, continues operation of the master unit that communicates with the slave unit, among the plurality of master units for which information indicating reception strength has been acquired by the reception strength acquisition unit, and stops operation of the remaining master units; The operation control unit adjusts the transmission strength of the slave unit so that the reception strength of the master unit communicating with the slave unit falls within a predetermined range. A control device characterized by:

2. When communication between the parent device and the child device is disconnected, the operation control unit performs a reconnection process for all the parent devices and the child devices.

2. The control device according to claim 1.

3. a reception strength acquisition unit that acquires information indicating reception strength in communication between the master unit and the slave unit; a reception strength comparison unit that compares the reception strengths when the reception strength acquisition unit acquires information indicating reception strengths in communication between the plurality of base units and the common slave units; a master unit determination unit that determines, based on a comparison result by the reception strength comparison unit, a master unit having a high reception strength among the plurality of master units for which information indicating reception strength has been acquired by the reception strength acquisition unit, as a master unit that will communicate with the slave unit; and an operation control unit that, based on the determination by the master unit determination unit, causes the master unit that communicates with the slave unit to continue operating among the plurality of master units for which information indicating reception strength has been acquired by the reception strength acquisition unit, and causes the remaining master units that communicate with the slave unit to operate at a low frequency; The operation control unit adjusts the transmission strength of the slave unit so that the reception strength of the master unit communicating with the slave unit falls within a predetermined range. A control device characterized by:

4. The operation control unit switches the master unit that communicates with the slave unit when the master unit determined by the master unit determination unit is changed.

4. The control device according to claim 3.

5. The operation control unit extends a communication interval between the child device and the parent device that is communicating with the child device.

5. The control device according to claim 1, wherein the control device is a control unit for controlling a vehicle.

6. a reception strength acquisition unit acquiring information indicating reception strength in communication between the master unit and the slave unit; a reception strength comparison unit comparing the reception strengths when the reception strength acquisition unit acquires information indicating reception strengths in communication between the plurality of base units and the common slave units; a step in which a master device determination unit determines, based on a comparison result by the reception strength comparison unit, a master device having a higher reception strength among the plurality of master devices for which information indicating reception strength has been acquired by the reception strength acquisition unit, as a master device that will communicate with the slave device; an operation control unit, based on the determination by the master unit determination unit, continuing the operation of the master unit that communicates with the slave unit, among the plurality of master units for which information indicating reception strength has been acquired by the reception strength acquisition unit, and stopping the operation of the remaining master units; the operation control unit adjusting the transmission strength of the slave unit so that the reception strength of the master unit communicating with the slave unit falls within a predetermined range; A control method comprising:

7. a reception strength acquisition unit acquiring information indicating reception strength in communication between the master unit and the slave unit; a reception strength comparison unit comparing the reception strengths when the reception strength acquisition unit acquires information indicating reception strengths in communication between the plurality of base units and the common slave units; a step in which a master device determination unit determines, based on a comparison result by the reception strength comparison unit, a master device having a higher reception strength among the plurality of master devices for which information indicating reception strength has been acquired by the reception strength acquisition unit, as a master device that will communicate with the slave device; an operation control unit, based on the determination by the master unit determination unit, causing the master unit that communicates with the slave unit among the plurality of master units for which information indicating reception strength has been acquired by the reception strength acquisition unit to continue operation, and causing the remaining master units that communicate with the slave unit to operate at a low frequency; the operation control unit adjusting the transmission strength of the slave unit so that the reception strength of the master unit communicating with the slave unit falls within a predetermined range; A control method comprising:

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