JP2022083604A - Wireless communication relay device, retry control method of wireless communication relay device, and retry control program - Google Patents

Abstract

To reduce the power consumption of a repeater.SOLUTION: A repeater 13 includes: an arithmetic unit 22 including an operation mode setting unit 31 for setting any of a plurality of operation modes associated with the number of retries, a packet communication control unit 32 for controlling packet communication and detecting the success or failure of communication establishment according to the reception state of packets from a slave unit 12, a failure number comparison determination unit 33 that makes a first determination according to whether or not the number of failures of communication establishment is equal to or more than a prescribed number, and a state detection determination unit 34 for making a second determination by calculating the probability of success or failure of communication establishment with the slave unit 12 during a predetermined period; a transmitting/receiving unit 21 for transmitting and receiving packets to/from a master unit 11 and the slave unit 12; and a power supply unit 23 for supplying power. The operation mode setting unit 31 sets the operation mode according to at least one of the first determination and the second determination. The packet communication control unit 32 performs control to change the number of retries to establish communication to the slave unit 12 according to the operation mode.SELECTED DRAWING: Figure 2

Description

The present invention relates to a wireless communication relay device, a retry control method for the wireless communication relay device, and a retry control program.

In recent years, a device that operates using a lead storage battery whose charging method is solar power generation has been used. For example, a device using a lead storage battery whose charging method is solar power generation may be used as a slave unit in wireless communication or a relay device that relays between the master unit and the slave unit.

Here, when the charging method of each device is solar power generation, it is conceivable that the power generation will stop due to sunshine conditions such as bad weather and snow cover. When the establishment of communication between the relay device and the slave unit fails due to the stop of power generation or the like, the relay device performs an operation of trying to establish communication with the slave unit. Typically, the relay device retries the slave unit a predetermined number of retries.

Patent Document 1 describes a configuration in which the degree of communication failure for a communication system network is obtained according to the number of acquisition failures and the continuous standby time that is less than the stable standby time ST.

Patent Document 2 describes that when a failure cause is associated with the measurement data to be inspected, data acquisition is retried according to the associated failure cause.

Japanese Unexamined Patent Publication No. 2007-202073 Japanese Unexamined Patent Publication No. 2018-055512

However, even if a certain handset falls into an unrecoverable situation due to a failure or the like, if the retry process is repeated from the relay device to the handset, extra power is consumed. By consuming extra power of the relay device in this way, if the power of the relay device is cut off, it may not be possible to communicate with other slave units relayed by the relay device. There is.

An object of the present disclosure is to provide a wireless communication relay device, a retry control method for the wireless communication relay device, and a retry control program for solving the above-mentioned problems.

The wireless communication relay device according to the present invention is a wireless communication relay device that relays wireless packet communication established between a master unit and one or more slave units, and is a communication with the slave unit. Of the plurality of operation modes having the number of retries to try to establish as a parameter, the operation mode setting unit for setting one of the operation modes controls the packet communication between the master unit and the slave unit, and the slave unit. When the packet communication control unit that detects the success or failure of the establishment of communication with the slave unit according to the reception status of the packet from the packet communication control unit and the packet communication control unit detects the failure of the communication establishment, the communication is established. The failure count comparison determination unit that makes the first determination based on whether or not the number of failures is equal to or greater than the specified number calculates the probability of success or failure of communication establishment with the slave unit in a predetermined period, and the calculated probability is specified. A calculation unit having a state detection determination unit that makes a second determination based on whether or not the probability is higher than the probability of The operation mode setting unit includes a unit, a power supply unit that supplies power to the transmission / reception unit, and the operation mode setting unit according to at least one of the first determination and the second determination. The operation mode is set, and the packet communication control unit controls to change the number of retries to try to establish communication to the slave unit according to the operation mode.

Further, the retry control method of the wireless communication relay device is a retry control method of the wireless communication relay device that relays wireless communication by packet communication established between the master unit and one or more slave units. The packet communication control unit detects the success or failure of the establishment of communication with the slave unit according to the reception status of the packet from the slave unit, and the packet communication control unit detects the failure of the establishment of communication. In that case, the first determination is made based on whether or not the number of failures in establishing communication is equal to or greater than the specified number.
The probability of success or failure of establishing communication with the slave unit in a predetermined period is calculated, the second determination is made based on whether or not the calculated probability is higher than the specified probability, and the first determination and the first determination are made. Depending on at least one of the determinations in 2, it is determined which operation mode is to be set among the plurality of operation modes in which the number of retries attempting to establish communication with the slave unit is specified.

Further, the retry control program is a retry control program of a wireless communication relay device that relays wireless communication by packet communication established between a master unit and one or more slave units, and is a packet communication control unit. However, depending on the reception status of the packet from the slave unit, the success or failure of the establishment of communication with the slave unit is detected, and when the packet communication control unit detects the failure of the establishment of communication, the establishment of communication is established. The first determination is made based on whether or not the number of failures is equal to or greater than the specified number of times, the probability of success or failure of establishing communication with the slave unit in a predetermined period is calculated, and whether the calculated probability is higher than the specified probability. A plurality of operation modes in which a second determination is made depending on whether or not, and the number of retries attempting to establish communication with the slave unit is specified according to at least one of the first determination and the second determination. Of these, determine which operation mode to set.

As a result, the number of retries can be changed according to the communication state between the relay device and the slave unit, and the power consumption of the relay device can be reduced.

It is a figure which shows an example of the structure of the wireless packet communication system which concerns on Embodiment 1. FIG. It is a figure which showed an example of the functional block of the relay device which concerns on Embodiment 1. FIG. It is a figure which showed the other example of the functional block of the relay device which concerns on Embodiment 1. FIG. It is a figure which shows the example of the transition of the operation mode of the relay device which concerns on Embodiment 1. FIG. It is a figure which shows an example of the operation timeline of the related wireless packet communication system. It is a figure which shows an example of the operation of the wireless packet communication system when there is no response from a slave unit to a relay device with respect to the health check signal which concerns on Embodiment 1. FIG. It is a figure which shows an example of the operation of the wireless packet communication system when the failure of a slave unit is found by the health check signal which concerns on Embodiment 1. FIG. It is a figure which showed the functional block of the relay device which concerns on Embodiment 2. FIG. It is a figure which shows the example of the transition of the operation mode of the relay device which concerns on Embodiment 2. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an example of the configuration of the wireless packet communication system 1. Here, as shown in FIG. 1, one master unit 11, a plurality of slave units 12, and a relay device (hereinafter, repeater) 13 that relays between the master unit 11 and the slave unit 12 are provided. ..

The master unit 11 is a device that transmits / receives information by packet communication with the slave unit 12 via the repeater 13. Typically, the master unit 11 is an access point that transmits information acquired from the slave unit 12 to a server (not shown). The master unit 11 is not limited to the one having this function, and may be any one that performs packet communication with the slave unit 12 via the repeater 13.

The slave unit 12 is a terminal that transmits / receives information by packet communication with the master unit 11 via the repeater 13.

The repeater 13 is a device that operates with electric power supplied by a battery provided in the main body of the repeater 13. For example, this battery is charged by solar power generation. Further, the repeater 13 performs a communication retry when a communication connection is established with each of the plurality of slave units 12 or the communication connection cannot be established.

In the repeater 13, the operation mode setting unit 31 described later sets which of the "normal mode", "communication priority mode", and "power saving mode" the operation mode is to operate. The repeater 13 changes the number of attempts to establish communication with the slave unit 12 according to the operation mode.

Further, in the repeater 13, the operating state can be switched between the "active state" and the "sleep state". That is, in the repeater 13, the operating state can be set to the "active state" when the communication is relayed frequently, or the "sleep state" can be set when the communication is not relayed. can. For example, the active state consumes more power than the sleep state, but the relay of normal communication is executed without delay. The sleep state consumes less power than the active state and waits for the start of communication. It is in a waiting state for.

Therefore, for example, in the repeater 13, the operation mode may be the power saving mode and the operation state may be the sleep state. The same applies to other operating modes and other operating states.

Here, an example of the configuration of the repeater 13 will be described. As shown in FIG. 2, the repeater 13 includes a transmission / reception unit 21, a calculation unit 22, and a power supply unit 23 in which a battery is stored.

The transmission / reception unit 21 transmits / receives packets by packet communication with the master unit 11 and the slave unit 12. In the following, packet communication between the transmission / reception unit 21 and the master unit 11 will be described as wireless packet communication, and similarly, packet communication between the transmission / reception unit 21 and the slave unit 12 will be described as wireless packet communication.

The transmission / reception unit 21 inputs the received packet from the master unit 11 to the calculation unit 22, and outputs the transmission packet from the calculation unit 22 to the master unit 11. Further, the transmission / reception unit 21 transmits / receives packets according to the instructions of the packet communication control unit 32 of the calculation unit 22 described later.

The calculation unit 22 includes an operation mode setting unit 31, a packet communication control unit 32, a failure count comparison determination unit 33, a state detection determination unit 34, and a storage unit 35. The arithmetic unit 22 can be realized by a combination of a CPU (Central Processing Unit), a main storage device, an auxiliary storage device, and the like.

Hereinafter, as shown in FIG. 3, the calculation unit 22 will be described as having a power supply voltage monitoring unit 36.

The operation mode setting unit 31 sets which of the plurality of operation modes the repeater 13 is to be operated. Here, the plurality of operation modes are three types, "normal mode", "communication priority mode", and "power saving mode". It should be noted that each operation mode has information on the number of retries attempting to establish communication as a parameter. In the following, attempting to establish communication may be referred to as "retry", and the number of retries attempting to establish communication may be simply referred to as "number of retries".

Further, the operation mode setting unit 31 can set the operation mode according to the determination by at least one of the failure count comparison determination unit 33 and the state detection determination unit 34.

In the following, the operation mode setting unit 31 sets the operation mode according to the information from the packet communication control unit 32, the failure count comparison determination unit 33, the state detection determination unit 34, and the power supply voltage monitoring unit 36. Describe that.

Here, in the normal mode, the default value is set for the parameter of the number of retries. The number of retries, which is the default value, is 10. Similarly, in the communication priority mode, the communication itself is a mode set when it is possible. In this communication priority mode, the number of retries is five. Similarly, in the power saving mode, priority is given to power saving of the repeater 13. In the power saving mode, the number of retries is set to 2.

Which operation mode is set by the operation mode setting unit 31 by using the determination by the failure count comparison determination unit 33 (first determination), the determination by the state detection determination unit 34 (second determination), or the like. The method for determining the above will be described in detail later.

The number of these retries is an example, and the optimum number of retries can be set according to the situation. For example, if it is important to be able to communicate without saving much power, the number of retries in the communication priority mode can be set to eight. Further, in the power saving mode, the number of retries can be set to one in order to reduce the power consumption as much as possible.

Further, in the power saving mode, the number of retries can be changed according to whether or not a failure of the slave unit 12 is known or the remaining amount of the battery used as the power supply unit 23. Specifically, the number of retries in the power saving mode can be any of 0 to 2.

In particular, when it is determined by the monitoring by the power supply voltage monitoring unit 36 that the battery level of the power supply unit 23 has a margin, the number of retries can be set to be large. On the other hand, if the battery level of the power supply unit 23 is low, the number of retries can be set to be small in order to save power.

The operation mode setting unit 31 can output information on which operation mode is set to the packet communication control unit 32.

The packet communication control unit 32 attaches / detaches a header of a packet exchanged with the transmission / reception unit 21, gives an instruction to send / receive to / from the transmission / reception unit 21, and gives an instruction to retry communication. In other words, the packet communication control unit 32 can control packet communication with the master unit 11 and the slave unit 12.

Further, the packet communication control unit 32 can control the transmission / reception of information necessary for packet communication control with each functional unit in the calculation unit 22. For example, when the failure count comparison determination unit 33, the state detection determination unit 34, and the power supply voltage monitoring unit 36 make a determination using the information stored in the storage unit 35 as described later, the storage unit 35 by each unit is used. It is possible to control the acquisition of information from the storage unit 35 and control the writing of information to the storage unit 35.

Further, the packet communication control unit 32 can detect the success or failure of establishment of communication with the slave unit 12 according to the reception state of the packet from the slave unit 12.

Further, for example, the packet communication control unit 32 can execute control for notifying the master unit 11 so as to try to establish communication with the slave unit 12 as many times as the number of retries according to the operation mode. In particular, when the packet communication control unit 32 fails to establish communication with the slave unit 12 (hereinafter, may be referred to as communication NG), a Time Out notification indicating that there is no response within a predetermined time and a Time Out notification. The operation of the transmission / reception unit 21 is controlled so that the information on the number of retries according to the set operation mode is transmitted to the master unit 11.

The failure count comparison determination unit 33 is the packet communication control unit 32, and acquires the number of failures in an attempt to establish communication with the slave unit 12. In particular, when the packet communication control unit 32 attempts to establish communication with the slave unit 12 and fails, the failure count comparison determination unit 33 continuously fails as a result of continuously attempting to establish communication. The number of retries is acquired, and it is determined whether or not the number of retries exceeds a predetermined number of times (first threshold value). In other words, the failure count comparison determination unit 33 determines whether or not the number of times the connection is NG in the most recent continuous attempt to establish communication with the slave unit 12 exceeds the specified number of times. The comparison determination with the first threshold value by the failure number comparison determination unit 33 is referred to as the first determination.

It is assumed that the information on the specified number of retries used as the first threshold value in the determination of the failure count comparison determination unit 33 is stored in the storage unit 35. For example, the failure count comparison determination unit 33 obtains information on the specified number of retries from the storage unit 35 and compares it with the actual retry count to make the first determination. Further, the failure count comparison determination unit 33 outputs the result of the first determination to the operation mode setting unit 31.

In addition, the packet to be transmitted / received in order to try to establish the communication with the slave unit 12 related to the first determination of the failure count comparison determination unit 33 is referred to as an actual communication packet.

The state detection determination unit 34 acquires the transmission / reception status of the packet with the slave unit 12 and determines the status. More specifically, the state detection determination unit 34 acquires information on the success or failure of receiving the health check packet from the slave unit 12 for the health check packet transmitted / received to / from the slave unit 12 via the transmission / reception unit 21. ..

Further, the state detection determination unit 34 calculates the probability of success or failure of receiving the health check packet from the slave unit 12 in a certain period set arbitrarily. Then, the state detection determination unit 34 determines whether or not this probability exceeds a predetermined probability (second threshold value). The comparison determination with the second threshold value by the state detection determination unit 34 is referred to as the second determination.

Here, it is assumed that the information of the predetermined probability used as the second threshold value in the determination of the state detection determination unit 34 is stored in the storage unit 35. For example, the state detection determination unit 34 can make a second determination by comparing the calculated probability with the probability of using the second threshold value stored in the storage unit 35. The state detection determination unit 34 outputs the result of the second determination to the operation mode setting unit 31.

The state detection determination unit 34 can store the success / failure information when an attempt is made to establish communication between the repeater 13 and the slave unit 12 in the storage unit 35 using the health check packet. Further, the state detection determination unit 34 can store the result of calculating the probability of success / failure of establishment of communication in a certain period in the storage unit 35. Further, the state detection determination unit 34 can store the error code indicating the failure of the slave unit 12 in the storage unit 35 when the health check packet contains the error code.

Here, the health check packet is a packet that can include information indicating that the slave unit 12 has failed when the slave unit 12 for which the repeater 13 is trying to establish a connection has failed. ..

Here, the health check packet used by the state detection determination unit 34 to make the second determination is different from the actual signal packet used by the failure count comparison determination unit 33 to make the first determination. It shall be.

The storage unit 35 stores information on the first threshold value used in the first determination of the failure count comparison determination unit 33, information on the second threshold value used in the second determination of the state detection determination unit 34, and a health check packet. It stores information on success or failure when an attempt is made to establish communication between the repeater 13 and the slave unit 12, and information to that effect if an error code is included in the health check packet.

The information stored in the storage unit 35 is not limited to these, and the storage unit 35 can store and update various parameters used in the repeater 13. Further, in the storage unit 35, these parameters are referred to as necessary from each unit of the repeater 13.

The power supply voltage monitoring unit 36 monitors the remaining amount of the battery used in the power supply unit 23 according to the voltage level. Further, the power supply voltage monitoring unit 36 notifies the operation mode setting unit 31 of the monitored voltage level information.

Next, the procedure for changing the operation mode of the operation mode setting unit 31 will be described with reference to FIGS. 4 to 6.

First, it is assumed that the operation mode of the repeater 13 is the normal mode, and the operation mode setting unit 31 changes the setting from the normal mode to another operation mode. Refer to FIG. 4 for the conditions (1) to (3). I will explain.

(1) The operation mode setting unit 31 detects a failure in establishing communication in the packet communication control unit 32, makes a first determination in the failure count comparison determination unit 33, and is the latest as a result of the first determination. The second determination of the state detection determination unit 34 during a certain period before the failure of establishment of continuous communication is more than the first threshold value and the failure of establishment of communication is detected by the packet communication control unit 32. If the probability of successful establishment of communication with the slave unit 12 is higher than the second threshold value, the power saving mode is changed and set.

This is because if the communication success / failure probability is a good value, that is, if the communication success probability is high, the radio wave condition was good until just before, but the communication failed suddenly due to the failure of the handset 12 or the radio wave. This is because it can be considered to be the effect of the interference of. Further, even if the retries are continued in this state, the power is consumed excessively. Therefore, the repeater 13 is set to the power saving mode in which the number of retries is small.

(2) The operation mode setting unit 31 detects a failure in establishing communication in the packet communication control unit 32, makes a first determination in the failure count comparison determination unit 33, and is the latest as a result of the first determination. The second determination of the state detection determination unit 34 during a certain period before the failure of establishment of continuous communication is more than the first threshold value and the failure of establishment of communication is detected by the packet communication control unit 32. If the probability of successful establishment of communication with the slave unit 12 is lower than the second threshold value, the mode is changed to the communication priority mode and set.

This is because if the probability of success or failure of communication in the second determination is poor, that is, if the probability of successful communication is low, it is not a failure of the handset 12, but the originally bad radio wave condition worsens due to disturbance or the like, and communication fails. Can be thought of as. Therefore, in the repeater 13, communication may be established by retries, so the communication priority mode in which the number of retries is medium is set.

(3) In the second determination, if the health check packet received from the slave unit 12 contains an error code indicating a failure of the slave unit 12, the operation mode setting unit 31 changes to the power saving mode and sets the operation mode setting unit 31. do.

This is because it is considered desirable to reduce the number of retries attempting to establish communication in a state where the failure of the slave unit 12 is known. Therefore, the repeater 13 suppresses power consumption as a power saving mode in which the number of retries is small.

Next, it is assumed that the operation mode of the repeater 13 is the communication priority mode, and the conditions (4) to (6) in which the operation mode setting unit 31 changes the setting from the communication priority mode to another operation mode are shown in FIG. Will be described with reference to.

(4) The operation mode setting unit 31 detects the success of communication establishment in the packet communication control unit 32, and succeeds in establishing communication with the slave unit 12 by the second determination of the state detection determination unit 34. If the probability is higher than the second threshold value, change to the normal mode and set.

For example, the second determination in the state detection determination unit 34 is before the packet communication control unit 32 detects the success of the communication establishment, and the probability of success or failure of the latest communication establishment can be used.

It is considered that the communication state has been improved due to the solution of the problem occurring in the handset 12 and the improvement of the problem of interference, and the normal mode is set.

(5) The operation mode setting unit 31 detects a failure in establishing communication in the packet communication control unit 32, makes a first determination in the failure count comparison determination unit 33, and is the latest as a result of the first determination. If the number of failures in establishing continuous communication is greater than the first threshold value, the power saving mode is changed and set.

It is considered that the establishment of communication has failed due to the failure of the slave unit 12 or the influence of radio wave interference, and the power saving mode is set.

(6) In the second determination, if the health check packet received from the slave unit 12 contains an error code indicating a failure of the slave unit 12, the operation mode setting unit 31 changes to the power saving mode and sets the operation mode setting unit 31. do. This is the same as the reason (3) above.

Next, it is assumed that the operation mode of the repeater 13 is the power saving mode, and the condition for the operation mode setting unit 31 to change the setting from the power saving mode to another operation mode will be described.

(7) In the power saving mode, the operation mode setting unit 31 shifts to the normal mode when the packet communication control unit 32 detects success in establishing communication. When this operation mode is changed, it is possible to shift to the normal mode regardless of the communication success / failure probability (second determination result) within a predetermined time of the state detection determination unit 34.

This is because, for example, when it is considered that the slave unit 12 has recovered from the state in which communication fails due to a failure, the communication success / failure probability before the recovery is considered to be insignificant.

Next, with reference to FIGS. 5 to 7, the operation of each part of the wireless packet communication system 1 will be described along the timeline. Here, the transition from the normal mode to the power saving mode and the transition from the normal mode or the communication priority mode to the power saving mode described in (1), (2), (3), (5) and (6) above are performed. The operation of each part of the case will be described.

Note that FIG. 5 is a diagram showing a timeline of the operation of the related wireless packet communication system, and shows an example in which retry control is not performed according to the state of the slave unit.

Specifically, FIG. 5 shows a state in which there is no response from the slave unit when a command is transmitted from the master unit to the slave unit via the repeater. Further, at this time, it is assumed that the state of the slave unit is unknown for both the master unit and the repeater.

This master unit retries communication according to the specifications. At this time, the repeater cannot control sleep during that period and keeps starting up all the time, which consumes power.

Next, in FIG. 6, in the wireless packet communication system 1, before attempting communication using a packet of actual communication, the communication status of the repeater 13 and the slave unit 12 using the health check signal is confirmed in advance, and then. The timeline shows the flow of operations when communicating using actual communication packets and shifting to the power saving mode.

In other words, in FIG. 6, in FIG. 6, the repeater 13 makes a second determination of the communication status with the slave unit 12 by using the transmission / reception of the health check signal, and the failure count comparison determination unit 33 actually communicates with the slave unit 12. An example is shown in which the operation mode setting unit 31 sets the operation mode by the first determination using the packet of. Further, FIG. 6 shows that the repeater 13 can enter a sleep state and reduce power consumption based on these determination results.

Specifically, the repeater 13 uses the transmission / reception unit 21 to transmit a packet related to the health check signal with the slave unit 12 (S1), and attempts to receive the response. As a result, the repeater 13 confirms the success or failure of the establishment of communication with the slave unit 12. Here, it is assumed that the repeater 13 has not responded to the health check signal (S2). The repeater 13 stores in the storage unit 35 that there is no response from the health check signal from the slave unit 12.

Here, the state detection determination unit 34 of the repeater 13 can calculate the probability of whether or not the connection has been successfully established from the responses of the health check signals a plurality of times in a predetermined period. Further, the state detection determination unit 34 can determine, as the second determination, whether or not the calculated probability is higher than the second threshold value stored in the storage unit 35. In the repeater 13, the calculated probability and the second determination result can be stored in the storage unit 35 (S3).

After that, the master unit 11 transmits a command to the slave unit 12 via the repeater 13 (S4-1). That is, the repeater 13 relays the packet (actual communication packet) including the command transmitted from the master unit 11 and transmits it to the slave unit 12 (S4-2), and determines whether or not the slave unit 12 responds to this. Confirm (S5).

Here, the repeater 13 indicates that there is no response from the slave unit 12 even after a certain period of time has elapsed, and that the establishment of the communication connection between the repeater 13 and the slave unit 12 has failed. Explain as recognized. In other words, the packet communication control unit 32 has detected a communication NG with respect to the slave unit 12. The repeater 13 stores in the storage unit 35 that the communication NG with respect to the slave unit 12 is detected.

Here, the repeater 13 activates the operation at least after receiving the actual communication packet from the master unit 11.

At this time, the repeater 13 notifies the master unit 11 that the communication with the slave unit 12 is in the TimeOut state (TimeOut notification), and the repeater 13 performs the operation set by the operation mode setting unit 31. A notification regarding the number of retries according to the mode is transmitted (S6). For example, in the repeater 13, the operation mode is determined by the second determination by the state detection determination unit 34 and the failure number comparison determination unit 33 that makes the first determination with the specified number of failures, which is the first threshold value, as one. To set.

Here, it is assumed that the operation mode set in the repeater 13 is the power saving mode, and the number of retries is set to one as the power saving mode. At this time, information indicating that the number of retries is one is transmitted from the repeater 13 to the master unit 11 together with the TimeOut notification.

After that, the master unit 11 retransmits the command according to the number of retries received from the repeater 13 (S7-1).

Upon receiving the notification from the repeater 13 that the number of retries is one, the master unit 11 retransmits the command to the slave unit 12 via the repeater 13 once after the notification is received.

As a result, the repeater 13 relays the command transmission by the actual communication from the master unit 11 so as to be transmitted to the slave unit 12 (S7-2). Then, the repeater 13 detects that there is no response from the slave unit 12 (S8).

Similar to S6, the repeater 13 transmits a notification (TimeOut notification) to the master unit 11 that the communication with the slave unit 12 is in the TimeOut state (S9).

Further, at this time, since the retry to the slave unit 12 is completed by the number of retries notified to the master unit 11, the repeater 13 shifts to the sleep state assuming that the subsequent retransmission control is not required (S10).

In other words, in the repeater 13, under the control of the packet communication control unit 32, the repeater 13 itself shifts to the sleep state, and the transmission / reception unit 21 sends a control signal for controlling the retry to the master unit 11. Can be sent via. As a result, the repeater 13 can be put into a sleep state to save power, and the operation of the master unit 11 can be controlled so that a command is not sent from the master unit 11 to the repeater 13 in the sleep state.

Here, in FIG. 6, it is assumed that the number of retries of communication using the actual communication packet is one, but it may be two or more times. In this case, in the repeater 13, in the failure count comparison determination unit 33, as the first determination, information on whether or not the communication failure of the number of times of the first threshold value or more preset in the storage unit 35 is continuous or not. The operation mode can be changed by using.

As shown in FIG. 4, when the recovery of the communication state between the repeater 13 and the slave unit 12 is recognized after the lapse of a predetermined time, the repeater 13 can shift the operation mode to the normal mode. .. In this case, typically, the repeater 13 changes from the sleep state to the active state to be in a state suitable for executing retransmission control.

Next, in FIG. 7, in the wireless packet communication system 1, before attempting communication by a packet of actual communication, the repeater 13 determines the communication state with the slave unit 12 by using the transmission / reception of the health check signal. An example is shown in which the number of retries is set to 0 in response to the information that the slave unit 12 is out of order.

Specifically, the repeater 13 uses the transmission / reception unit 21 to transmit a packet related to the health check signal with the slave unit 12 (S21), and attempts to receive the response. As a result, the repeater 13 confirms the success or failure of the establishment of communication with the slave unit 12. Here, it is assumed that the repeater 13 includes the content that the slave unit 12 has failed as a response to the health check signal (S22). In the repeater 13, information to the effect that the slave unit 12 is out of order can be stored in the storage unit 35.

After that, the master unit 11 transmits a command to the slave unit 12 via the repeater 13 (S23).

Here, since the repeater 13 remembers that the slave unit 12 has failed, the repeater 13 that has received the command from the master unit 11 has failed the slave unit 12 with respect to the master unit 11. It returns a notification to that effect and notifies that the number of retries is 0 (S24).

Further, the repeater 13 shifts to the sleep state because the retransmission control is not required (S25). As a result, the repeater 13 can save electric power.

Also in this case, if the recovery of the communication state between the repeater 13 and the slave unit 12 is recognized after the lapse of a predetermined time, the repeater 13 can shift the operation mode to the normal mode.

As shown in FIG. 4, when the recovery of the communication state between the repeater 13 and the slave unit 12 is recognized after the lapse of a predetermined time, the repeater 13 may shift the operation mode to the normal mode. can.

In this way, the repeater 13 checks whether or not the communication state with the slave unit 12 using the health check signal is good before attempting communication using the actual communication packet, and the slave unit 12 It is possible to detect whether or not a failure has occurred. Then, when a failure has occurred in the slave unit 12, the communication from the master unit 11 to the slave unit 12 is not relayed by the actual signal, the operation mode is set to the power saving mode, and the master unit 11 is retried. Notify you not to do it and put it to sleep. As a result, the repeater 13 can reduce power consumption.

Further, in the repeater 13, when the health check signal does not include a signal indicating the failure of the slave unit 12, the second determination can be made based on the success probability of communication using the health check signal. After that, the repeater 13 tries to connect the communication using the actual communication packet to the slave unit 12, and when the connection fails, whether or not the number of consecutive failures is equal to or more than the predetermined first threshold value. The first determination can be made. Further, in the repeater 13, the operation mode can be set to any one of the normal mode, the communication priority mode, and the power saving mode by using the determination results of the first determination and the second determination.

In the repeater 13, the number of retries for communication from the master unit 11 can be set so that the number of retries is set according to the operation mode set in this way. Further, the repeater 13 can appropriately put the sleep state into the sleep state when the relay is not required according to the set number of retries.

Embodiment 2
Next, a wireless packet communication system 2 that uses the electric field strength detection unit 44 instead of the state detection determination unit 34 that uses the health check signal shown in the first embodiment will be described.

That is, the wireless packet communication system 2 includes a master unit 11, a slave unit 12, and a relay device (hereinafter referred to as a repeater) 14 that relays between the master unit 11 and the slave unit 12. In the following, the parts that perform the same functions as the components used in the wireless packet communication system 1 shown in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The repeater 14 includes a transmission / reception unit 21, a calculation unit 24, and a power supply unit 23 in which a battery is stored.

The calculation unit 24 includes an operation mode setting unit 31, a packet communication control unit 32, a failure count comparison determination unit 33, an electric field strength detection unit 44, a storage unit 35, and a power supply voltage monitoring unit 36. The arithmetic unit 24 can be realized by a combination of a CPU (Central Processing Unit), a main storage device, an auxiliary storage device, and the like.

The electric field strength detecting unit 44 extracts the electric field strength information stored in the RSSI (Received Signal Strength Indicator) field in the header information of the packet from the packets received by the packet communication control unit 32. Further, the electric field strength detecting unit 44 can store the electric field strength information in the case where the communication is successful in the storage unit 35.

Further, the electric field strength detecting unit 44 can also calculate the average value of RSSI in an arbitrarily determined period retroactively from the time of successful reception, and store the calculated value in the storage unit 35.

In the wireless packet communication system 2, the determination result of comparing the average value of RSSI detected by the electric field strength detecting unit 44 in a predetermined period with the threshold value (third threshold value) stored in the storage unit in advance is carried out. It can be used in place of the second determination using the health check signal shown in the first embodiment.

Here, a procedure for changing the operation mode by using the electric field strength information instead of the method using the health check signal will be described.

First, it is assumed that the operation mode of the repeater 14 is the normal mode, and the conditions (8) to (10) in which the operation mode setting unit 31 changes the setting from the normal mode to another operation mode are referred to FIG. I will explain.

(8) The operation mode setting unit 31 detects a failure in establishing communication in the packet communication control unit 32, makes a first determination in the failure count comparison determination unit 33, and is the latest as a result of the first determination. The number of failures in establishing continuous communication is greater than the first threshold value, and the electric field detected by the electric field strength detection unit 44 during a certain period before the failure in establishing communication is detected by the packet communication control unit 32. If the average value of the intensity is higher than the third threshold value, the power saving mode is changed and set.

This is because the radio wave condition was good until just before, but the communication suddenly failed because it is considered to be the influence of the failure of the handset 12 or the interference of the radio wave. Further, even if the retries are continued in this state, the power is consumed excessively. Therefore, the repeater 14 is set to the power saving mode in which the number of retries is small.

(9) The operation mode setting unit 31 detects a failure in establishing communication in the packet communication control unit 32, makes a first determination in the failure count comparison determination unit 33, and is the latest as a result of the first determination. The number of failures in establishing continuous communication is greater than the first threshold value, and the electric field detected by the electric field strength detection unit 44 during a certain period before the failure in establishing communication is detected by the packet communication control unit 32. If the average value of the intensity is lower than the third threshold value, the mode is changed to the communication priority mode and set.

This is because if the probability of success or failure of communication in the second determination is poor, that is, if the probability of successful communication is low, it is not a failure of the handset 12, but the originally bad radio wave condition worsens due to disturbance or the like, and communication fails. Can be thought of as. Therefore, in the repeater 14, since communication may be established by retries, the communication priority mode in which the number of retries is medium is set.

Next, it is assumed that the operation mode of the repeater 14 is the communication priority mode, and the conditions (10) to (12) for the operation mode setting unit 31 to change the setting from the communication priority mode to another operation mode are shown in FIG. Will be described with reference to.

(10) If the operation mode setting unit 31 detects the success of communication establishment by the packet communication control unit 32 and the average value of the electric field strength detected by the electric field strength detection unit 44 is higher than the third threshold value, Change to normal mode and set.

It is considered that the communication state has been improved due to the solution of the problem occurring in the handset 12 and the improvement of the problem of interference, and the normal mode is set.

(11) The operation mode setting unit 31 detects a failure in establishing communication in the packet communication control unit 32, makes a first determination in the failure count comparison determination unit 33, and is the latest result of the first determination. If the number of failures in establishing continuous communication is greater than the first threshold value, the power saving mode is changed and set.

It is considered that the establishment of communication has failed due to the failure of the slave unit 12 or the influence of radio wave interference, and the power saving mode is set.

Next, it is assumed that the operation mode of the repeater 14 is the power saving mode, and the condition for the operation mode setting unit 31 to change the setting from the power saving mode to another operation mode will be described.

(12) In the power saving mode, the operation mode setting unit 31 shifts to the normal mode when the packet communication control unit 32 detects success in establishing communication. When this operation mode is changed, the transition to the normal mode can be performed regardless of the average value of the electric field strength detected by the electric field strength detecting unit 44.

Since the repeater 14 makes a determination by RSSI, it is not necessary to add a new antenna for measuring the radio field strength, and the repeater 14 can be executed at low cost.

The processing in each part according to the present invention can be realized by causing a computer or the like to execute a program. More specifically, a program stored in the program memory for executing processing in each part of the danger avoidance device is loaded into the main storage device, and the program is executed and realized under the control of the CPU. Here, the program can be stored and supplied to the computer using various types of non-transitory computer readable media. Non-temporary computer-readable media include various types of tangible storage media. Examples of non-temporary computer readable media include magnetic recording media (eg flexible disks, magnetic tapes, hard disk drives), optomagnetic recording media (eg optomagnetic disks), CD-ROMs (Read Only Memory), CD-Rs, Includes CD-R / W, semiconductor memory (eg, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)). The program may also be supplied to the computer by various types of temporary computer readable media. Examples of temporary computer readable media include electrical, optical, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path. Further, the processing in each part of the navigation device is not limited to being realized by software by a program, and may be realized by any combination of hardware, firmware, and software.

The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the spirit.

For example, in the repeater 13 shown in the first embodiment, the information on the number of retries is transmitted when the response to the master unit 11 is performed, but the present invention is not limited to this, and the number of retries is determined at any other timing. Does not prevent you from sending information.

Further, the failure count comparison determination unit 33 describes that when the packet communication control unit 32 detects a communication NG, the number of the most recent continuous connection NG is counted, but the present invention is not limited to this. For example, the current communication NG detected by the packet communication control unit 32 and the latest one connection NG in the past are excluded, and the continuous connection NG before that is counted, and the like can be arbitrarily changed. .. This also applies to the calculation of the probability of the state detection determination unit 34 shown in the first embodiment and the calculation of the average value of RSSI by the electric field strength detection unit 44 shown in the second embodiment.

It is also possible to simultaneously use both the method using the health check signal shown in the first embodiment and the method using the RSSI field shown in the second embodiment.

1 Wireless packet communication system 2 Wireless packet communication system 11 Master unit 12 Slave unit 13 Relay unit 14 Relay unit 21 Transmission / reception unit 22 Calculation unit 23 Power supply unit 24 Calculation unit 31 Operation mode setting unit 32 Packet communication control unit 33 Failure count comparison judgment unit 34 State detection judgment unit 35 Storage unit 36 Power supply voltage monitoring unit 44 Electric field strength detection unit

Claims (10)

A wireless communication relay device that relays wireless packet communication established between a master unit and one or more slave units.
An operation mode setting unit for setting one of a plurality of operation modes having the number of retries for establishing communication with the slave unit as a parameter, and an operation mode setting unit.
A packet communication control unit that controls packet communication with the master unit and the slave unit and detects the success or failure of establishment of communication with the slave unit according to the reception status of the packet from the slave unit.
When the packet communication control unit detects a failure in establishing communication, a failure count comparison determination unit that makes a first determination based on whether or not the number of communication establishment failures is equal to or greater than a specified number of times, and a failure count comparison determination unit.
A calculation unit having a state detection determination unit that calculates the probability of success or failure of communication establishment with the slave unit in a predetermined period and makes a second determination based on whether or not the calculated probability is higher than the specified probability. When,
A transmission / reception unit that transmits / receives packets to / from the master unit and the slave unit.
The arithmetic unit, the transmission / reception unit, and a power supply unit that supplies electric power to the transmission / reception unit are provided.
The operation mode setting unit is
The operation mode is set according to at least one of the first determination and the second determination.
The packet communication control unit controls to change the number of retries attempting to establish communication to the slave unit according to the operation mode.
Wireless communication relay device. The state detection determination unit is
When making the second determination, the packet communication control unit calculates the probability using the result of the success or failure of the communication establishment in the period before the failure of the establishment of the communication with the slave unit is detected.
The wireless communication relay device according to claim 1. The transmission / reception unit transmits / receives an actual communication packet and a health check packet having information on a failure of the slave unit as transmission / reception of a packet to the slave unit.
The packet communication control unit detects the success or failure of establishment of communication with the slave unit according to the reception state of the actual communication packet from the slave unit.
The state detection determination unit calculates the probability of success or failure of establishing communication with the handset from the reception state of the health check packet from the handset, and determines whether the calculated probability is higher than the specified probability. The second determination is made.
The wireless communication relay device according to claim 2. The operation mode setting unit is
The operation modes include a communication priority mode in which the number of retries is set to a predetermined number, a normal mode in which the number of retries is set to be larger than the communication priority mode, and a power saving mode in which the number of retries is set to be smaller than the communication priority mode. The wireless communication relay device according to any one of claims 1 to 3. The operation mode setting unit is
The transition from the normal mode to another operation mode is
(1) The probability that the first determination is made, the number of failures in establishing the communication is larger than the specified number of times, and the establishment of communication with the slave unit by the second determination is successful is a predetermined value. If it is higher, it shifts to the power saving mode,
(2) The probability that the first determination is made, the number of failures in establishing the communication is greater than the specified number of times, and the probability of success in establishing communication with the slave unit by the second determination is a predetermined value. If it is lower, the mode shifts to the communication priority mode.
(3) In the second determination, if the health check packet received from the slave unit contains an error code indicating a failure of the slave unit, the mode shifts to the power saving mode.
Do it by either
The transition from the communication priority mode to another operation mode is
(4) If the packet communication control unit detects the success of the communication establishment and the probability of the success of the communication establishment with the slave unit by the second determination is higher than the predetermined value, the normal mode is set. Migration,
(5) If the first determination is made and the number of failures in establishing the communication exceeds the specified number, the mode shifts to the power saving mode.
(6) In the second determination, if the health check packet received from the slave unit contains an error code indicating a failure of the slave unit, the mode shifts to the power saving mode.
Do it by either
The transition from the power saving mode to another operation mode is
(7) When the packet communication control unit detects success in establishing communication, the mode shifts to the normal mode.
The wireless communication relay device according to claim 4. The calculation unit further includes a power supply monitoring unit.
The power supply monitoring unit monitors the remaining amount of the battery used as the power supply unit according to the voltage level.
The operation mode setting unit is
When the operation mode is the power saving mode, whether or not the health check packet received from the slave unit in the second determination includes an error code indicating the failure of the slave unit, and the power supply monitoring unit. The number of retries is changed depending on at least one of whether or not the remaining amount of the battery acquired by the above is larger than a predetermined value.
The wireless communication relay device according to claim 4 or 5. The state detection determination unit calculates the probability of success or failure of communication establishment with the slave unit a plurality of times at predetermined periods, and then calculates the probability of success or failure of communication establishment with the slave unit.
The arithmetic unit
At least, the information of the specified number of times used for the first determination of the failure number comparison determination unit, the information of the specified probability used in the second determination of the state detection determination unit, and the plurality of times. A storage unit for storing the calculated probability of success or failure of communication establishment with the slave unit is further provided.
The wireless communication relay device according to any one of claims 2 to 6. The state detection determination unit is
Instead of calculating the probability of success or failure of establishing communication with the slave unit in a predetermined period and making a second determination based on whether or not the calculated probability is higher than the specified probability.
Information on the radio wave strength is acquired from the packet received by the transmission / reception unit, and a determination is made based on whether or not the acquired radio wave strength is stronger than the specified strength.
The wireless communication relay device according to any one of claims 1 to 7. It is a retry control method of a wireless communication relay device that relays wireless communication by packet communication established between a master unit and one or more slave units.
The packet communication control unit detects the success or failure of establishment of communication with the slave unit according to the reception status of the packet from the slave unit.
When the packet communication control unit detects a failure in establishing communication, the first determination is made based on whether or not the number of failures in establishing communication is equal to or greater than the specified number.
The probability of success or failure of establishing communication with the slave unit in a predetermined period is calculated, and a second determination is made based on whether or not the calculated probability is higher than the specified probability.
Depending on at least one of the first determination and the second determination, the operation mode is set to any of the plurality of operation modes in which the number of retries attempting to establish communication with the slave unit is specified. A retry control method for a wireless communication relay device to determine whether or not. It is a retry control program of a wireless communication relay device that relays wireless communication by packet communication established between a master unit and one or more slave units.
The packet communication control unit detects the success or failure of establishment of communication with the slave unit according to the reception status of the packet from the slave unit.
When the packet communication control unit detects a failure in establishing communication, the first determination is made based on whether or not the number of failures in establishing communication is equal to or greater than the specified number.
The probability of success or failure of establishing communication with the slave unit in a predetermined period is calculated, and a second determination is made based on whether or not the calculated probability is higher than the specified probability.
Depending on at least one of the first determination and the second determination, the operation mode is set to any of the plurality of operation modes in which the number of retries attempting to establish communication with the slave unit is specified. A retry control program that determines whether or not.

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