JP5602102B2 - Master station device - Google Patents

Description

  The present invention relates to a wireless communication system.

In a wireless communication system for unattended monitoring, if there is no response from the target communication device, it is necessary to investigate the state and installation status of the communication device at the installation location in order to know the cause of communication failure. there were.
Since this method requires a great deal of time and labor until recovery, a method for grasping the cause of the inability to communicate has been studied.

For example, in Patent Document 1, a wireless terminal in a wireless communication system includes a detection intensity detection unit that measures RSSI (Received Signal Strength Indicator) of a received wireless signal, RSSI and a predetermined threshold value. Communication state determining means for calculating a margin and communication state monitoring means for determining whether the margin value is within a predetermined range.
The wireless terminal measures RSSI and compares the margin calculated from RSSI with a predetermined range to determine whether the communication environment has deteriorated.

JP 2010-244160 A

  The conventional method cannot distinguish whether the deterioration of the communication state is due to an obstacle on the communication link, radio wave interference, a decrease in the remaining battery level of the communication terminal, or a malfunction of the communication terminal itself. is there.

  The main object of the present invention is to solve the above-described problems, and the main object of the present invention is to realize a configuration that can identify the cause of the deterioration of the communication state in the wireless communication system.

The master station apparatus according to the present invention is
A master station device that communicates with a slave station device that uses a battery as a power source via a wireless communication path,
A test frame transmitter for transmitting a test frame for measuring the state of the wireless communication path to the slave station device via the wireless communication path;
After the test frame is transmitted by the test frame transmission unit a predetermined number of times, a measurement result collection request for requesting the slave station device to transmit a measurement result measured by the slave station device is sent to the wireless communication path. A measurement result collection request transmitter for transmitting to the slave station device via,
At least one of an RSSI (Received Signal Strength Indicator) value measured at the time of receiving each test frame by the slave station device and a calculated value calculated from the RSSI value measured at the time of receiving each test frame is measured by the slave station device. Measurement result reception for receiving a slave station measurement result indicating the number of received test frames and a remaining battery level of the slave station device measured by the slave station device from the slave station device via the wireless communication path And
And a state determination unit that analyzes the measurement result received by the measurement result reception unit and determines the state of the slave station device and the state of the wireless communication path.

  According to the present invention, the RSSI value measured by the slave station device, the number of receptions of the test frame, and the remaining battery level are used to determine the state of the slave station device and the state of the wireless communication path. Can be specified.

FIG. 3 shows a configuration example of a master station apparatus according to the first embodiment. FIG. 3 shows a configuration example of a slave station apparatus according to the first embodiment. FIG. 6 shows a configuration example of a master station device according to Embodiment 2. FIG. 6 shows a configuration example of a master station apparatus according to Embodiment 3. FIG. 10 shows a configuration example of a master station apparatus according to Embodiment 4; FIG. 6 shows a configuration example of a slave station apparatus according to Embodiment 4; FIG. 10 shows a configuration example of a relay station apparatus according to the fourth embodiment. FIG. 10 is a diagram illustrating a configuration example of a master station device according to a fifth embodiment. FIG. 10 is a diagram illustrating a configuration example of a slave station device according to the fifth embodiment. FIG. 10 is a diagram illustrating a configuration example of a relay station apparatus according to a fifth embodiment. FIG. 10 is a diagram illustrating a configuration example of a master station device according to a sixth embodiment. FIG. 10 shows a configuration example of a slave station apparatus according to the sixth embodiment. FIG. 11 shows a configuration example of a relay station apparatus according to the sixth embodiment. FIG. 4 is a flowchart showing an operation example according to the first embodiment. FIG. 4 is a flowchart showing an operation example according to the first embodiment. FIG. 4 is a flowchart showing an operation example according to the first embodiment. FIG. 9 is a flowchart showing an operation example according to the second embodiment. FIG. 9 is a flowchart showing an operation example according to the third embodiment. FIG. 9 is a flowchart showing an operation example according to the third embodiment. FIG. 10 is a flowchart showing an operation example according to the fourth embodiment. FIG. 10 is a flowchart showing an operation example according to the fourth embodiment. FIG. 9 is a flowchart showing an operation example according to the fifth embodiment. FIG. 9 is a flowchart showing an operation example according to the fifth embodiment. FIG. 9 is a flowchart showing an operation example according to the fifth embodiment. FIG. 9 is a flowchart showing an operation example according to the fifth embodiment. FIG. 9 is a flowchart showing an operation example according to the fifth embodiment. FIG. 10 is a flowchart showing an operation example according to the sixth embodiment. FIG. 3 is a diagram illustrating an example of a system configuration according to the first embodiment. FIG. 4 is a diagram illustrating an example of a system configuration according to a second embodiment. FIG. 10 is a diagram showing a system configuration example according to the third embodiment. FIG. 10 is a diagram illustrating an example of a system configuration according to a fourth embodiment. FIG. 3 shows an example of a test frame format according to the first embodiment. FIG. 4 is a diagram showing an example of a measurement result collection request format according to the first embodiment. FIG. 4 is a diagram showing an example of a measurement result collection response format according to the first embodiment. The figure which shows the example of the multihop measurement result collection request format which concerns on Embodiment 4. FIG. The figure which shows the example of the multihop measurement result collection response seeking format which concerns on Embodiment 4. FIG. The figure which shows the example of the multihop measurement request format which concerns on Embodiment 4. FIG. FIG. 5 is a diagram showing an example of a failure management information table according to the first embodiment. FIG. 10 is a diagram illustrating an example of a failure management information table according to the third embodiment. FIG. 10 is a diagram illustrating an example of a failure management information table according to the fourth embodiment. FIG. 10 is a diagram illustrating an example of a failure management information table according to the fifth embodiment. FIG. 10 is a diagram illustrating an example of node failure management information according to the fifth embodiment. FIG. 20 is a diagram showing an example of a failure management information table according to the sixth embodiment. FIG. 20 is a diagram illustrating an example of node failure management information according to the sixth embodiment. FIG. 9 is a diagram showing an example of a test frame transmission frequency list according to the second embodiment. The flowchart figure which shows the hardware structural examples of the main | base station apparatus etc. which concern on Embodiment 1-6.

Embodiment 1 FIG.
In the wireless communication system according to the present embodiment and the subsequent embodiments, all wireless terminals have means for measuring changes in the communication environment and the state of the terminals.
One management terminal has means for collecting.
Furthermore, it has a means for discriminating a failure factor from the status information collected by the management terminal.
As a result, the system administrator can always monitor the wireless communication system, and when a failure occurs on the wireless communication system, it is possible to estimate the improvement measures in advance without conducting a field survey.

  Embodiment 1 describes a method for periodically monitoring the communication state and the state of a wireless terminal and determining a failure factor when a failure occurs.

[System Configuration of Embodiment 1]
FIG. 28 shows an example of a system configuration according to the present embodiment.
In FIG. 28, a master station device 1100 is a wireless terminal that is driven by a commercial power source and controls a wireless network.
The slave station device 1200 is a wireless terminal that is driven by a battery as a power source and performs unattended monitoring using a sensor or the like.
The master station device 1100 is also referred to as a master station.
Similarly, the slave station device 1200 is also referred to as a slave station.
The wireless link N10 is a wireless communication path used by the master station device 1100 and the slave station device 1200 during communication.
Hereinafter, when referring to an arbitrary wireless terminal, it is called a node.

[Configuration of master station in the first embodiment]
FIG. 1 is a diagram showing a configuration of master station apparatus 1100 according to the present embodiment.

  The wireless transmission unit 101 is a unit (for example, a circuit such as a wireless chip) that modulates a packet and transmits the packet wirelessly to a transmission destination node address (slave station apparatus 1200 in this embodiment).

  The wireless receiving means 102 is means (for example, a circuit such as a wireless chip) that receives wireless radio waves from the slave station device 1200 and decodes them into packets.

  The time measuring means 103 is means for measuring time and periodically notifying time, and is an element such as an RTC (Real Time Clock).

The test frame generation means 104 is a means for generating a test frame for measuring a link state by holding a transmission frame number for identifying a test frame and holding a test frame transmission count which is the number of times a test frame is transmitted in one measurement. (For example, a program).
The test frame is a packet for measuring the state of the radio link N10, and is transmitted from the radio transmission unit 101 to the slave station device 1200 via the radio link N10.
Note that the test frame generation unit 104 and the wireless transmission unit 101 correspond to an example of a test frame transmission unit.

The measurement result collection transmission unit 105 is a unit (for example, a program) that generates a measurement result collection request packet (hereinafter also referred to as a measurement result collection request).
That is, the measurement result collection / transmission means 105 generates a packet that requests the slave station apparatus 1200 to transmit the measurement result measured by the slave station apparatus 1200.
The measurement result collection request packet is transmitted from the wireless transmission unit 101 to the slave station device 1200 via the wireless link N10 after the test frame is transmitted a predetermined number of times.
Note that the measurement result collection transmission unit 105 and the wireless transmission unit 101 correspond to an example of a measurement result collection request transmission unit.

The measurement result recording unit 106 extracts a measurement result from a measurement result collection response packet (hereinafter also referred to as a measurement result collection response) received by the wireless reception unit 102 from another node (in the present embodiment, the slave station device 1200). A means (for example, a program) for recording in a failure management information table to be described later.
In the measurement result collection response packet from the slave station device 1200, the battery state (remaining battery level) in the slave station device 1200, the average RSSI (Received Signal Strength Indicator) value at the time of receiving the test frame, the RSSI standard deviation, The number of successful test frame receptions at station apparatus 1200 is included.
The battery state, average RSSI, RSSI standard deviation, and number of successful test frame receptions are collectively referred to as failure management information.
The wireless receiving means 102 that receives the measurement result collection response packet from the slave station device 1200 corresponds to an example of a measurement result receiving unit.
Note that the measurement result of the slave station device 1200 is also referred to as a slave station measurement result.

The failure management information table storage unit 107 holds a failure management information table for storing failure management information, and is a recording element such as a DRAM (Dynamic Random Access Memory).
In the failure management information table, failure management information, that is, battery status, average RSSI, RSSI standard deviation, and the number of successful test frame receptions are written.
Details of the failure management information table will be described later.

The failure determination means 108 holds a battery state threshold value for determining a battery exhaustion, an RSSI threshold value and a packet loss rate threshold value used for determination of the link state, and a link state coefficient which is a system requirement for the link state. It is means (for example, a program) for determining the state of the slave station device 1200 and the state of the radio link N10 from the management information and determining the cause of failure.
The failure determination unit 108 corresponds to an example of a state determination unit.

[Configuration of Slave Station in Embodiment 1]
FIG. 2 is a diagram illustrating a configuration example of the slave station device 1200.
2, components having the same numbers as those of the master station device 1100 of FIG. 1 have the same functions.
In the slave station device 1200, the wireless reception unit 102 receives the test frame and the measurement result collection request packet transmitted from the master station device 1100.
In addition, the wireless reception unit 102 measures the RSSI value at the time of receiving a test frame every time a test frame is received.
In the slave station apparatus 1200, the wireless reception unit 102 corresponds to an example of a test frame reception unit and a measurement result collection request reception unit.

The battery state measuring unit 201 is a circuit such as a voltmeter for measuring the remaining battery level or a battery remaining amount measuring IC (Integrated Circuit).
The battery state measuring unit 201 corresponds to an example of a battery remaining amount measuring unit.

The measurement result collection response unit 202 is a unit (for example, a program) that generates a measurement result collection response packet including a slave station measurement result (failure management information) measured by the slave station device 1200.
The measurement result collection response packet is transmitted from the wireless transmission unit 101 to the master station device 1100 via the wireless link N10.
The measurement result collection response unit 202 and the wireless transmission unit 101 correspond to an example of a measurement result transmission unit.

  The link state measurement unit 203 holds the number of successful test frame receptions, which is the number of times the test frame has been received, extracts the transmission source node address from the test frame, acquires the RSSI value from the wireless reception unit 102, and acquires the measurement result collection response packet Is a means (for example, a program) for creating and recording a measurement result to be notified.

The measurement management information recording means 204 is a recording element such as a DRAM that stores the measurement result of the own station.
More specifically, the measurement management information recording unit 204 holds an average RSSI value, an RSSI standard deviation, the number of successful test frame receptions, and a measurement sequence number.
Information held by the measurement management information recording unit 204 is referred to as measurement management information.
The measurement management information recording unit 204 corresponds to an example of a storage unit.

[Data Structure of Embodiment 1]
FIG. 38 shows a failure management information table T100 that stores data held by the master station device 1100 for determining the cause of failure.

The failure management information table T100 is held by the failure management information table storage unit 107.
The failure management information table T100 includes a measurement sequence number for identifying a measurement cycle, a battery state (remaining battery level) of the slave station device 1200, and communication for measuring link status between the master station device 1100 and the slave station device 1200 (test frame). The average RSSI that is the average value of the RSSI measured in the communication), the RSSI standard deviation that is the standard deviation of the RSSI, and the number of successful test frame receptions that are the number of times the slave station device 1200 has received the test frame.
A plurality of test frames are transmitted for one measurement sequence number.

[Frame format of the first embodiment]
FIG. 32 shows an example of a test frame format C100 that is a frame format of a test frame used for link state measurement.

  The test frame format C100 is a measurement that identifies a broadcast address that is a transmission destination node address used for broadcasting, a transmission source node address that represents a node that transmitted the test frame, a command ID that represents the test frame, and measurement of failure management information. Sequence number, the number of test frame transmissions, which is the total number of times that one node transmits a test frame at the same measurement sequence number, and a transmission frame that is reset when the measurement sequence number is updated and incremented for each test frame transmission Have a number.

  FIG. 33 shows an example of a measurement result collection request format C300 that is a frame format of a measurement result collection request in which the master station device 1100 requests transmission of a measurement result to another node.

  The measurement result collection request format C300 has a transmission destination node address, a transmission source node address, a command ID indicating a measurement result collection request, a command sequence number, and a measurement sequence number.

  FIG. 34 shows an example of a measurement result collection response format C400 that is a frame format of a measurement result collection response for a node to send a measurement result to the master station device 1100.

  The measurement result collection response format C400 includes a transmission destination node address, a transmission source node address, a command ID indicating a measurement result collection response, a command sequence number indicating a response to the measurement result collection request, a measurement sequence number, and a transmission source node. It has measurement results such as the measured remaining battery level, the number of successful test frame receptions, and RSSI.

[Operation of Embodiment 1]
FIG. 14 shows an example of operations of master station apparatus 1100 and slave station apparatus 1200 according to the present embodiment.

The time measuring means 103 of the master station device 1100 causes the test frame generating means 104 to start transmitting test frames periodically.
The test frame generation unit 104 of the master station device 1100 generates a test frame C100 having the address of the master station device 1100 as a transmission source node address, and transmits the test frame C100 to the wireless transmission unit 101.
The wireless transmission means 101 modulates the test frame C100 into a radio signal and transmits it to the slave station device 1200 via the wireless link N10 (S101).

The radio reception unit 102 of the slave station apparatus 1200 receives the radio wave, demodulates it into a packet, and transmits the test frame C100 to the link state measurement unit 203 when it is determined as the test frame C100 by the command ID.
In addition, the wireless reception unit 102 measures the RSSI value when the test frame C100 is received.
The link state measuring unit 203 acquires the RSSI value from the wireless receiving unit 102, and the link state (average RSSI, RSSI standard deviation, number of successful test frame receptions) obtained by the test frame C100 is a method shown in FIG. It records in the measurement management information recording means 204 (S102).

The test frame generation means 104 of the master station device 1100 determines whether the number of times that the test frame has been transmitted is less than the predetermined number of times of test frame transmission (S103), and if the number of times that the test frame has been transmitted is less than the number of times of test frame transmission (Yes), The master station device 1100 and the slave station device 1200 repeat the processing from S101 to S103.
If the number of test frame transmissions is equal to or greater than the number of test frame transmissions (No), the master station device 1100 performs the process of S104.
The test frame generation unit 104 of the master station device 1100 notifies the measurement result collection transmission unit 105.
When the measurement result collection / transmission means 105 receives the notification, it generates a measurement result collection request C200.
The measurement result collection / transmission means 105 transmits the measurement result collection request C200 to the wireless transmission means 101, and the wireless transmission means 101 transmits it to the slave station apparatus 1200 via the wireless link N10 (S104).

The wireless reception unit 102 of the slave station device 1200 receives the radio signal, demodulates it into a packet, and notifies the battery state measurement unit 201 when it is determined as the measurement result collection request C200 by the command ID.
The battery state measuring unit 201 measures the battery voltage built in the slave station device 1200, and records the battery voltage as the battery state in the measurement management information recording unit 204 (S105).
The measurement result collection response unit 202 of the slave station device 1200 generates a measurement result collection response C300 including the battery state, average RSSI, RSSI standard deviation, and number of successful test frame receptions as failure management information from the measurement management information recording unit 204. The transmission unit 101 transmits the data to the master station device 1100 via the wireless link N10 (S106).

When the radio reception means 102 of the master station device 1100 receives the radio signal, demodulates it into a packet, and determines that the measurement result collection response C300 is based on the command ID, the fault management information (battery status, average RSSI, RSSI standard deviation, test frame) The number of successful receptions) is taken out and transmitted to the measurement result recording means 106.
The measurement result recording unit 106 records the failure management information in the failure management information table T100 of the failure management information table storage unit 107 (S107).
Then, the failure determination unit 108 of the master station device 1100 performs failure factor determination according to the procedure shown in FIG. 16 described later (S108).

FIG. 15 shows an example of an operation in which the slave station device 1200 receives the test frame C100 and measures the link state.
The flow of FIG. 15 shows the details of S102 of FIG.

  When the link state measuring unit 203 receives the test frame C100 and the RSSI value from the wireless receiving unit 102, it refers to the measurement management information in the measurement management information recording unit 204 (S701).

The link state measuring unit 203 compares the measurement sequence number held in the measurement management information with the measurement sequence number of the test frame C100 (S702). If they are different (No), the link state measuring unit 203 is a measurement management information recording unit. The measurement management information recorded in 204 is cleared, and the measurement sequence number obtained by the test frame C100 is recorded.
Further, the link state measuring unit 203 sets the RSSI value (RSSI value acquired from the wireless receiving unit 102) of the test frame C100 as an average RSSI, sets the RSSI standard deviation to 0, and sets the number of successful test frame receptions to 1 (S703).
When the measurement sequence number held in the measurement management information is the same as the measurement sequence number of the test frame C100 (Yes), the link state measurement unit 203 increments the number of successful test frame receptions.
Then, the link state measuring unit 203 updates the average RSSI and the RSSI standard deviation from the measured RSSI, the held average RSSI, the RSSI standard deviation, and the number of successful test frame receptions (S704).

FIG. 16 shows an example of the operation of failure determination processing of the master station device 1100 that uses the slave station device 1200 as a failure determination target node.
The flow of FIG. 16 shows the details of S108 of FIG.

The failure determination unit 108 refers to the failure management information table T100 from the failure management information table storage unit 107, and extracts the value of the battery state for a certain past period.
The battery state threshold value is compared with the average value of the battery state value for the past certain period (S201), and if the average value of the battery state value for the past certain period is below the battery state threshold value (Yes), the failure The determination means 108 determines that the slave station device 1200 is out of battery.
If the average value of the battery state values in the past certain period exceeds the battery state threshold value (No), the process of S202 is performed.

The failure determination unit 108 refers to the failure management information table T100 from the failure management information table storage unit 107 to check whether failure management information for a certain past period is recorded (S202), and records failure management information for a certain past period. If not (Yes), the failure determination unit 108 determines that the target node is a node failure or a node isolation.
When failure management information for a certain past period is recorded, the failure determination unit 108 performs the process of S203.

The failure determination unit 108 refers to the failure management information table T100 of the failure management information table storage unit 107, and extracts the average RSSI, RSSI standard deviation, and the number of successful test frame receptions over a certain period in the past. For example, when the operation of FIG. 14 is performed in a cycle of 30 minutes, the average RSSI, the RSSI standard deviation, and the number of successful test frame receptions each collected in 3 hours.
The failure determination means 108 calculates the average value of the packet loss rate calculated from the average RSSI, RSSI standard deviation, the number of successful test frame receptions and the number of test frame transmissions over a certain period in the past, the time average average RSSI, and the time average RSSI. Standard deviation and time-average packet loss rate are calculated respectively.
For example, the packet loss rate is calculated by dividing the number of successful test frame receptions by the number of test frame transmissions.
For example, the time average average RSSI is calculated by adding the six average RSSIs and dividing by six. For example, the time average RSSI standard deviation is calculated by the following equation.

Where σ is a time average RSSI standard deviation, σi (i = 1,..., 6) is a numerical value of each of the six RSSI standard deviations, θ is an average RSSI, and θi (i = 1,..., 6). ) Is a numerical value of each of the six average RSSIs, N is the sum of the number of successful receptions of the six test frames, and ni is a numerical value of each of the six average RSSIs.
Further, the failure determination unit 108 calculates an RSSI evaluation value from the time average average RSSI, the time average RSSI standard deviation, and the link state coefficient. The RSSI evaluation value is an index for evaluating the deterioration of the radio wave propagation environment and the occurrence of radio wave interference in consideration of changes in the RSSI value.
For example, the RSSI evaluation value is calculated by subtracting a numerical value obtained by multiplying the time average RSSI standard deviation by the link state coefficient from the time average RSSI. The link state coefficient is a sensitivity for detecting deterioration of the radio wave propagation environment and radio wave interference when the link state changes. The larger the link state coefficient, the higher the sensitivity, and even a small change is detected as a failure.
It is determined whether the time-average packet loss rate is equal to or greater than the packet loss rate threshold value and the RSSI evaluation value is lower than the RSSI threshold value (S203). If Yes, the failure determination unit 108 indicates that the radio wave propagation environment has deteriorated. judge.
That is, it is determined that the radio wave propagation environment has deteriorated because there are obstacles on the wireless link.
If No in S203, the process of S204 is performed.
The failure determination means 108 determines whether the above-mentioned time average packet loss rate is equal to or higher than the packet loss rate threshold and the RSSI evaluation value is equal to or higher than the RSSI threshold (S204). .
That is, it is determined that the target communication is hindered by radio waves other than communication between the master station device 1100 and the slave station device 1200.
If No in S204, it is determined as normal.

[Effect of Embodiment 1]
As described above, according to the first embodiment, in a wireless communication system including two nodes, a master station and a slave station, the link state can be evaluated in consideration of the change in the RSSI fluctuation range due to the change in the communication environment.
When the communication is impossible or the communication quality is deteriorated, the master station can analyze the failure factor.

In the above description, the slave station apparatus 1200 updates the average RSSI value and the RSSI standard deviation each time a test frame is received, and notifies the master station apparatus 1100 of the average RSSI value and the RSSI standard deviation.
Instead, the slave station device 1200 stores the RSSI value when each test frame is received, notifies the master station device 1100 of the RSSI value when each test frame is received, and the master station device 1100 receives each test frame. The average RSSI value and the RSSI standard deviation may be calculated from the RSSI value at the time of reception.

In the above, the number of successful test frame receptions is stored in the failure management information table T100, and the failure determination unit 108 uses the number of successful test frame receptions in the failure management information table T100 during the failure determination process (FIG. 16). The packet loss rate is calculated.
Instead, when the measurement result collection response is received, the failure determination unit 108 calculates the packet loss rate using the number of successful test frame receptions included in the measurement result collection response, and the calculated packet loss rate is managed as a failure management. You may make it store in information table T100.

Embodiment 2. FIG.
In the first embodiment, the method of transmitting a test frame from the master station and measuring the RSSI and the packet loss rate for measuring the link state has been described.
However, this method eliminates the effects of short-term changes in the communication environment and always increases the number of test frame transmissions in order to measure the link state with reliable accuracy. It will be.
In Embodiment 2, a radio communication system will be described in which the number of test frame transmissions is reduced when the link state is good and the number of test frame transmissions is increased when the link state is bad.

Configuration differences
The second embodiment is realized by adding a sample number control means 109 to the master station device 1100 of the first embodiment.
FIG. 45 is an example of a test frame transmission frequency list T600 held by the sample number control means 109.
The test frame transmission frequency list T600 includes RSSI evaluation values and the corresponding number of test frame transmissions.

FIG. 3 is an example of a configuration of master station apparatus 1100 in the second embodiment.
Since the constituent elements other than the sample number control means 109 are the same as those in the first embodiment, description thereof is omitted.
The sample number control means 109 is a means (for example, a program) that holds the test frame transmission frequency list T600 and determines (changes) the number of test frame transmissions according to the state of the radio link. Equivalent to.
The configuration of slave station apparatus 1200 is the same as that of the first embodiment, and a description thereof will be omitted.

[Difference in operation]
FIG. 17 is an example of the operation in the second embodiment.
Since S101 to S108 are the same as those in the first embodiment, description thereof is omitted.
The sample number control means 109 of the master station device 1100 receives the RSSI evaluation value from the failure determination means 108.
The sample number control unit 109 refers to the test frame transmission number list T600, selects the number of test frame transmissions corresponding to the RSSI evaluation value, and changes the number of test frame transmissions held by the test frame generation unit 104 (S109).

[Effect of Embodiment 2]
As described above, according to the second embodiment, normally, the number of test frame transmissions is reduced to suppress power consumption, and when the link state deteriorates, the number of test frame transmissions is increased to improve the measurement accuracy of the link state. Can be increased.

Embodiment 3 FIG.
In the second embodiment, the method of changing the number of test frame transmissions according to the link state in the radio communication system including the master station and the slave stations has been described.
However, in this system, failure management information cannot be collected and stored in a wireless communication system used by a plurality of nodes.
In the third embodiment, a method corresponding to a wireless communication system composed of one master station and a plurality of slave stations will be described.

Configuration differences
FIG. 29 is an example of a system configuration in the third embodiment.
The master station device 1100 is a wireless communication terminal that is driven by a commercial power source.
The slave station device 2200, the slave station device 2300, and the slave station device 2400 are wireless communication terminals that are driven using a battery as a power source.
N20, N21, and N22 are wireless links used for communication between the master station device 1100 and the slave station device 2200, the master station device 1100 and the slave station device 2300, and the master station device 1100 and the slave station device 2400, respectively.

FIG. 39 is a failure management information table T200 held by the failure management information table storage unit 107 of the master station device 1100 according to the third embodiment.
The failure management information table T200 includes fields of measurement sequence numbers and failure management information corresponding to the nodes in the system.
The field of failure management information includes a node address for identifying a corresponding node, a battery state, an average RSSI, an RSSI standard deviation, and the number of successful test frame receptions.

FIG. 4 is an example of a configuration of master station device 1100 in the third embodiment.
Since the components other than the transmission node management unit 110 are the same as those of the master station device 1100 of the first embodiment, description thereof is omitted.
The transmission node management unit 110 is a unit (for example, a program) that holds an address list of slave stations that communicate with the master station device 1100.
The slave station device 2200, the slave station device 2300, and the slave station device 2400 are the same as the configuration of the slave station device 1200 of the first embodiment, and thus the description thereof is omitted.

[Difference in operation]
18 and 19, the slave station device 2200, slave station device 2300, and slave station device 2400 in Embodiment 3 perform measurement, and the master station device 1100 collects fault management information and determines whether there is a fault and the cause of the fault. It is an example of the operation | movement to perform.

The time measuring means 103 of the master station device 1100 causes the test frame generating means 104 to start transmitting test frames periodically.
The test frame generation unit 104 generates a test frame C100 having the address of the master station device 1100 as a transmission source node address, and transmits the test frame C100 to the wireless transmission unit 101.
The wireless transmission means 101 modulates the test frame C100 into a radio wave signal and transmits it by broadcast to the slave station device 2200, the slave station device 2300, and the slave station device 2400 (S301).

The wireless reception unit 102 of the slave station device 2200 receives the radio signal, demodulates it into a packet, and transmits the test frame C100 to the link state measurement unit 203 when it is determined as the test frame C100 by the command ID.
In addition, the wireless reception unit 102 measures the RSSI value when the test frame C100 is received.
The link state measuring unit 203 acquires the RSSI value from the wireless receiving unit 102, and the link state obtained by the test frame C100 is stored in the measurement management information recording unit 204 by the method of S701 to S704 (FIG. 15) of the first embodiment. Recording is performed (S302).
The slave station device 2300 records the link state in the measurement management information recording unit 204 in the same manner as in S302 (S303).
The slave station device 2400 records the link state in the measurement management information recording unit 204 by the same method as in S302 (S304).

The test frame generation means 104 of the master station device 1100 determines whether the number of test frame transmissions is less than the number of test frame transmissions (S305). If the number of test frame transmissions is less than the number of test frame transmissions (Yes), the master station The apparatus 1100, the slave station apparatus 2200, the slave station apparatus 2300, and the slave station apparatus 2400 repeat the processing from S301 to S304.
If the number of test frame transmissions is equal to or greater than the number of test frame transmissions (No), the master station device 1100 performs the process of S306.

The test frame generation unit 104 of the master station device 1100 notifies the measurement result collection transmission unit 105.
When the measurement result collection / transmission unit 105 receives the notification, the node list of the slave station device 2200 is acquired by referring to the address list from the transmission node management unit 110, and the destination node address is the node address of the slave station device 2200. A measurement result collection request C200 is generated.
The measurement result collection transmission unit 105 transmits the measurement result collection request C200 to the wireless transmission unit 101, and transmits the measurement result collection request C200 to the slave station device 2200 by the wireless transmission unit 101 (S306).

The wireless reception unit 102 of the slave station device 2200 receives the radio signal, demodulates it into a packet, and notifies the battery state measurement unit 201 when it is determined as the measurement result collection request C200 by the command ID.
The battery state measuring unit 201 measures the battery voltage built in the slave station device 2200, and records the battery voltage as the battery state in the measurement management information recording unit 204 (S307).
The measurement result collection response unit 202 of the slave station device 2200 generates a measurement result collection response C300 including the battery state, average RSSI, RSSI standard deviation, and number of successful test frame receptions as failure management information from the measurement management information recording unit 204. The wireless transmission means 101 transmits to the master station device 1100 (S308).

When the radio reception unit 102 of the master station device 1100 receives the radio signal, demodulates it into a packet, determines that the measurement result collection response C300 is based on the command ID, extracts the transmission source node address and the fault management information, and measures the measurement result recording unit 106.
The measurement result recording unit 106 records the failure management information in a field where the transmission source node address is equal to the node address of the failure management information table T200 of the failure management information table storage unit 107 (S309).

The measurement result recording unit 106 of the master station device 1100 notifies the measurement result collection / transmission unit 105 after recording the failure management information of one node.
Upon receiving the notification, the measurement result collection / transmission means 105 refers to the address list from the transmission node management means 110 to acquire the node address of the slave station device 2300, and the transmission destination node address is the node address of the slave station device 2300. A measurement result collection request C200 is generated.
The measurement result collection transmission unit 105 transmits the measurement result collection request C200 to the wireless transmission unit 101, and transmits the measurement result collection request C200 to the slave station device 2300 by the wireless transmission unit 101 (S310).

The slave station device 2300 records the remaining battery level of the local station in the same manner as in S307 (S311).
Further, the slave station device 2300 transmits a measurement result collection response C300 including the failure management information of the local station to the master station device 1100 in the same manner as in S308 (S312).

  The master station device 1100 records the failure management information of the slave station device 2300 in the corresponding field of the failure management information table T200 of the failure management information table storage unit 107 in the same manner as in S309 (S313).

  Further, the master station device 1100 transmits a measurement result collection request C200 to the slave station device 2400 in the same manner as in S310 (S314).

The slave station device 2400 records the remaining battery level of the local station in the same manner as in S307 (S315).
Further, the slave station device 2400 transmits a measurement result collection response C300 including the fault management information of the local station to the master station device 1100 in the same manner as in S308 (S316).

  The master station device 1100 records the failure management information of the slave station device 2400 in the corresponding field of the failure management information table T200 of the failure management information table storage unit 107 in the same manner as in S309 (S317).

Next, the master station device 1100 selects one of the nodes in the system, and performs failure factor determination including S201 to S204 (FIG. 16) (S318).
The failure determination means 108 of the master station refers to the failure management information field of the failure management information table T200 to determine whether all nodes have been selected (S319), and when all nodes have been selected (Yes), the processing ends.
If all the nodes have not been selected (No), S318 is performed with reference to the failure management information of the unselected nodes.

[Effect of Embodiment 3]
As described above, according to the third embodiment, it is possible to detect the failure of each slave station and determine the cause of the failure in the wireless communication system including one master station and a plurality of slave stations.

Embodiment 4 FIG.
In the third embodiment, a method for detecting a failure and determining a failure factor in a wireless communication system including one master station and a plurality of slave stations has been described.
However, in this method, in a wireless communication system having a relay station that relays communication between the master station and the slave station, it is not possible to detect a failure between the master station and the slave station and determine the cause of the failure.
In the fourth embodiment, a method corresponding to a radio communication system having a relay station will be described.

Configuration differences
FIG. 30 is an example of a system configuration in the fourth embodiment.
The master station device 1100 is a wireless communication terminal that is driven by a commercial power source.
The slave station device 1200 is a wireless communication terminal that is driven using a battery as a power source.
The relay station device 1300 is a wireless communication terminal that is driven using a battery as a power source.
Relay station apparatus 1300 is also referred to as a relay station.
The master station device 1100 and the slave station device 1200 are the same as those shown in the first embodiment.
N30 is a radio link used when the master station device 1100 and the relay station device 1300 communicate with each other.
The wireless link N30 corresponds to an example of a master station wireless communication path.
N31 is a radio link used when the relay station apparatus 1300 and the slave station apparatus 1200 communicate with each other.
The wireless link N31 corresponds to an example of a slave station wireless communication path.
Hereinafter, when referring to an arbitrary master station, slave station, or relay station, it is referred to as a node.

FIG. 35 is an example of a measurement result collection request C500 in the fourth embodiment.
In the present embodiment, a communication path for storing an address from the transmission source node to the transmission destination node is added to the measurement result collection request C200.

FIG. 36 is an example of a measurement result collection response C600 according to the fourth embodiment.
In the present embodiment, a communication path is added to the measurement result collection response C300.

FIG. 37 shows an example of a measurement request C700 in which the master station device 1100 requests the relay station device 1300 to transmit a test frame.
The measurement request C400 includes a transmission destination node address, a transmission source node address, a communication path, a command ID indicating a measurement request, a command sequence number added sequentially for each measurement request transmitted to confirm the success of the measurement request transmission, It has a sequence number and the number of test frame transmissions.

FIG. 40 is an example of the failure management information table T300 held by the failure management information table storage unit 107 of the master station device 1100 according to the fourth embodiment.
The failure management information table T300 has a transmission source node address as link state information in addition to the failure management information table T200.

FIG. 5 is an example of a configuration of master station apparatus 1100 in the fourth embodiment.
Since the components other than the measurement request transmission unit 111, the communication path management unit 112, and the link state measurement unit 203 are the same as those in the third embodiment, description thereof is omitted.
The measurement request transmission unit 111 is a unit (for example, a program) that generates a measurement request C700.
The communication path management unit 112 is a unit (for example, a program) that manages nodes to be relayed during communication.
The link state measuring unit 203 is the same as the link state measuring unit 203 provided in the slave station device 1200 according to the first to third embodiments.

FIG. 6 is an example of a configuration of slave station apparatus 1200 in the fourth embodiment.
Since the components other than the routing unit 205 are the same as those in the first to third embodiments, the description thereof is omitted.
The routing unit 205 is a unit (for example, a program) that controls and holds information on nodes relayed from received packets.

FIG. 7 is an example of a configuration of relay station apparatus 1300 in the fourth embodiment.
Since the constituent elements other than the test frame generation unit 104 are the same as those of the slave station apparatus 1200, description thereof is omitted.
The test frame generation means 104 is the same as the test frame generation means 104 provided in the master station device 1100.

Similarly to slave station apparatus 1200 of Embodiment 1, relay station apparatus 1300 according to the present embodiment provides a plurality of test frames for measuring the state of radio link N30 with master station apparatus 1100 from master station apparatus 1100. When the measurement result collection request packet is received from the master station device 1100, the remaining battery level is measured and failure management information (remaining battery level, RSSI value, number of successful test frame receptions) is received. ) Is sent to the master station device 1100.
In addition, relay station apparatus 1300 transmits a test frame for measuring the state of radio link N31 with slave station apparatus 1200 to slave station apparatus 1200 a plurality of times, similar to master station apparatus 1100 of the first embodiment. Then, a measurement result collection request packet is transmitted, and a measurement result collection response packet is received from the slave station device 1200.
Further, relay station apparatus 1300 transmits the measurement result collection response packet received from slave station apparatus 1200 to master station apparatus 1100.

Thus, in relay station apparatus 1300, radio receiving means 102 receives the test frame and measurement result collection request packet from master station apparatus 1100, and corresponds to an example of a test frame reception unit and a measurement result collection request reception unit. To do.
The measurement management information recording unit 204 holds an average RSSI value, an RSSI standard deviation, the number of successful test frame receptions, and a measurement sequence number, and corresponds to an example of a storage unit.
The battery state measuring unit 201 corresponds to an example of a battery remaining amount measuring unit.
The measurement result collection response unit 202 and the wireless transmission unit 101 generate and transmit a measurement result collection response packet including the relay station measurement result (failure management information) measured by the relay station device 1300. The measurement result collection response packet received from the device 1200 is transmitted, and corresponds to an example of a measurement result transmission unit.

The test frame generation unit 104 and the wireless transmission unit 101 generate and transmit a test frame, which corresponds to an example of a test frame transmission unit.
The wireless transmission unit 101 transmits a measurement result collection request packet and corresponds to an example of a measurement result collection request transmission unit.
Further, the wireless reception unit 102 receives the measurement result collection response packet from the slave station device 1200, and further corresponds to an example of a measurement result receiving unit.

[Difference in operation]
20 and 21, the master station device 1100, the slave station device 1200, and the relay station device 1300 according to the fourth embodiment perform measurement, and the master station device 1100 collects fault management information and determines the presence / absence of a fault and the cause of the fault. It is an example of operation | movement.

The timer 103 of the master station device 1100 causes the test frame generator 104 to start transmitting a test frame.
The test frame generation unit 104 generates a test frame C100 having the address of the master station device 1100 as a transmission source node address, and transmits the test frame C100 to the wireless transmission unit 101.
The wireless transmission unit 101 modulates the test frame C100 into a radio signal and transmits it to the relay station device 1300 by broadcast (S401).

The radio reception unit 102 of the relay station apparatus 1300 receives the radio wave, demodulates it into a packet, and when it is determined as the test frame C100, transmits the test frame C100 to the link state measurement unit 203.
In addition, the wireless reception unit 102 measures the RSSI value when the test frame C100 is received.
The link state measuring unit 203 acquires the RSSI value from the wireless receiving unit 102, measures the RSSI, and measures and manages the link state obtained by the test frame C100 by the method of S701 to S704 (FIG. 15) of the first embodiment. The information is recorded in the information recording unit 204 (S402).

The test frame generation means 104 of the master station device 1100 determines whether the number of times that the test frame has been transmitted is less than the number of times of test frame transmission (S404), and if the number of times that the test frame has been transmitted is less than the number of times of test frame transmission (Yes), The device 1100 and the relay station device 1300 repeat the processes of S401, S402, and S404.
If the number of test frame transmissions is equal to or greater than the number of test frame transmissions (No), the master station device 1100 performs the process of S405.
The test frame generation unit 104 of the master station device 1100 notifies the measurement request transmission unit 111 when the test frame is transmitted as many times as the number of test frame transmissions.
Upon receiving the notification, the measurement request transmission unit 111 acquires the node address of the relay station device 1300 from the transmission node management unit 110, generates a measurement request C700 whose transmission destination node address is the node address of the relay station device 1300, and wirelessly Transmit to the transmission means 101.
The wireless transmission unit 101 refers to the communication path corresponding to the relay station apparatus 1300 that is the transmission destination node address of the measurement request C700 from the communication path management unit 112, acquires information without relay, and sets the communication path of the measurement request C700 as the communication path. Write.
The wireless transmission unit 101 transmits the measurement request C700 to the relay station apparatus 1300 that is the next node address of the communication path (S405).

The wireless receiving means 102 of the relay station device 1300 receives the radio signal, demodulates the packet, and confirms the transmission destination node and the communication path.
Since the node address next to the transmission destination node and the communication path is the relay station device 1300, the wireless reception unit 102 determines that the packet is addressed to itself.
When determining that the measurement request C700 is based on the command ID of the packet, the wireless reception unit 102 sets and notifies the test frame generation unit 104 of the number of test frame transmissions.
The test frame generation unit 104 of the relay station apparatus 1300 generates a test frame C100, and transmits the test frame C100 by broadcast by the wireless transmission unit 101 (S406).

The wireless reception unit 102 of the master station device 1100 receives the radio signal, demodulates it into a packet, and transmits the test frame C100 to the link state measurement unit 203 when it is determined as the test frame C100 by the command ID.
In addition, the wireless reception unit 102 measures the RSSI value when the test frame C100 is received.
The link state measurement unit 203 acquires the RSSI value from the wireless reception unit 102, and uses the method of S701 to S704 (FIG. 15) according to the first embodiment to determine the link state obtained from the test frame C100. (S407).

The radio reception unit 102 of the slave station apparatus 1200 receives the radio signal, demodulates it into a packet, and transmits the test frame C100 to the link state measurement unit 203 when it is determined as the test frame C100 by the command ID.
In addition, the wireless reception unit 102 measures the RSSI value when the test frame C100 is received.
The link state measuring unit 203 acquires the RSSI value from the wireless receiving unit 102, and the link state obtained by the test frame C100 is stored in the measurement management information recording unit 204 by the method of S701 to S704 (FIG. 15) of the first embodiment. Recording is performed (S408).

The test frame generation unit 104 of the relay station device 1300 compares the number of times the test frame has been transmitted with the number of times the test frame has been transmitted (S409), and if the number of times the test frame has been transmitted is less than the number of times of test frame transmission (Yes), S406 to S409. Process up to.
If the number of test frame transmissions is equal to or greater than the number of test frame transmissions (No), the test frame transmission is terminated.

The measurement request transmission unit 111 of the master station device 1100 detects by time measurement that the test frame generation unit 104 of the relay station device 1300 ends the transmission of the test frame, and notifies the measurement result collection transmission unit 105 of the measurement result transmission.
Upon receiving the notification, the measurement result collection / transmission means 105 refers to the address list from the transmission node management means 110 to acquire the node address of the relay station apparatus 1300, and the transmission destination node address is the node address of the relay station apparatus 1300. A measurement result collection request C500 is generated and transmitted to the wireless transmission means 101.
The wireless transmission unit 101 refers to the communication path corresponding to the relay station apparatus 1300 that is the transmission destination node address of the measurement result collection request C500 from the communication path management unit 112, acquires information without relay, and communicates the measurement request C700. Write to the route.
The wireless transmission unit 101 transmits a measurement result collection request C500 to the relay station device 1300 (S410).

The wireless receiving means 102 of the relay station device 1300 receives the radio signal, demodulates the packet, and confirms the transmission destination node and the communication path.
Since the node address next to the transmission destination node and the communication path is the relay station device 1300, the wireless reception unit 102 determines that the packet is addressed to itself.
The wireless reception unit 102 records information without relay as a communication path to the parent station device 1100 that is a transmission source node in the routing unit 205.
When determining that the measurement result collection request C500 is based on the command ID of the packet, the wireless reception unit 102 notifies the measurement result collection response unit 202.
The measurement result collection response unit 202 notifies the battery state measurement unit 201.
The battery state measuring unit 201 measures the battery voltage built in the relay station device 1300, and records the battery voltage as the battery state in the measurement management information recording unit 204 (S411).
The measurement result collection response unit 202 of the relay station apparatus 1300 generates a measurement result collection response C600 including the battery state, average RSSI, RSSI standard deviation, and number of successful test frame receptions as failure management information from the measurement management information recording unit 204. Transmit to the wireless transmission means 101.
The wireless transmission unit 101 refers to the routing unit 205, acquires information without relay as the communication path corresponding to the parent station device 1100 by the transmission destination node, and writes it in the communication path of the measurement result collection response C 600.
The wireless transmission unit 101 transmits a measurement result collection response C600 to the master station device 1100 (S412).

The wireless receiving means 102 of the master station device 1100 receives the radio signal, demodulates the packet, and confirms the communication path with the destination node.
Since the node address next to the transmission destination node and the communication path is the master station device 1100, the wireless reception means 102 determines that the packet is addressed to the own station.
When the wireless reception unit 102 determines that the measurement result collection response C600 is based on the command ID of the packet, the wireless reception unit 102 transmits the measurement result collection response 106 to the measurement result recording unit 106.
The measurement result recording unit 106 records the failure management response in a field in which the source node address and the node address of the failure management information table T300 of the failure management information table storage unit 107 are equal (S414).
The measurement result recording unit 106 of the master station device 1100 notifies the measurement result collection / transmission unit 105 after recording the failure management information of one node.
Upon receiving the notification, the measurement result collection / transmission means 105 refers to the address list from the transmission node management means 110 to acquire the node address of the slave station apparatus 1200, and the transmission destination node address is the node address of the slave station apparatus 1200. A measurement result collection request C500 is generated and transmitted to the wireless transmission means 101.
The wireless transmission means 101 refers to the communication path corresponding to the transmission destination node corresponding to the slave station apparatus 1200 from the communication path management means 112, acquires the relay station apparatus 1300, and writes it in the communication path of the measurement result collection request C500.
The wireless transmission unit 101 transmits a measurement result collection request C500 to the relay station apparatus 1300 that is the next node address of the communication path (S414).

The wireless receiving means 102 of the relay station apparatus 1300 receives radio waves, demodulates the packets, and confirms the destination node and the communication path.
Since the destination node is not the node address of relay station apparatus 1300, radio reception means 102 transmits the packet to routing means 205.
The routing unit 205 transmits the packet to the wireless transmission unit 101.
The wireless transmission unit 101 transmits a packet (measurement result collection request C500) to the slave station device 1200.

The wireless receiving means 102 of the slave station device 1200 receives the radio wave, demodulates the packet, and confirms the communication path with the transmission destination node.
Since the transmission destination node is the slave station device 1200, it is determined as a packet addressed to the own station.
The wireless reception unit 102 records the node address of the relay station device 1300 in the routing unit 205 as a communication path to the master station device 1100 that is a transmission source node.
When determining that the measurement result collection request C500 is based on the command ID, the wireless reception unit 102 transmits the measurement result collection request C500 to the measurement result collection response unit 202.
The measurement result collection response unit 202 notifies the battery state measurement unit 201.
The battery state measuring unit 201 measures the battery voltage and records the battery voltage as the battery state in the measurement management information recording unit 204 (S415).
The measurement result collection response unit 202 of the slave station device 1200 generates a measurement result collection response C600 including the battery state, average RSSI, RSSI standard deviation, and number of successful test frame receptions as failure management information from the measurement management information recording unit 204. Transmit to the wireless transmission means 101.
The wireless transmission unit 101 refers to the routing unit 205, acquires the node address of the relay station device 1300 as the communication route corresponding to the master station device 1100 as the transmission destination node, and writes it in the communication route of the measurement result collection response C 600. .
The measurement result collection response unit 202 transmits a measurement result collection response C600 to the wireless transmission unit 101.
The wireless transmission unit 101 transmits the measurement result collection response C600 to the relay station device 1300 (S417).

The wireless receiving means 102 of the relay station device 1300 receives radio waves, demodulates the packet, and confirms the destination node and the communication path.
Since the destination node is not the node address of relay station apparatus 1300, radio reception means 102 transmits the packet to routing means 205.
The routing unit 205 transmits the packet to the wireless transmission unit 101.
The wireless transmission unit 101 transmits a packet (measurement result collection response C600) to the master station device 1100 (S418).

The wireless receiving means 102 of the master station device 1100 receives radio waves, demodulates the packet, and confirms the communication path with the destination node.
Since the destination node is the node address of the master station device 1100, it is determined as a packet addressed to the own station.
When determining that the measurement result collection response C600 is based on the command ID, the wireless reception unit 102 transmits the measurement result collection response C600 to the measurement result recording unit 106.
The measurement result recording unit 106 records the failure management information in a field where the transmission source node address and the node address of the failure management information table T300 of the failure management information table storage unit 107 are equal (S419).
The master station selects one of the nodes in the system, and performs failure factor determination including S201 to S204 (FIG. 16) (S420).
The failure determination means 108 of the master station refers to the failure management information field of the failure management information table T200 to determine whether all the nodes have been selected (S421). When all the nodes have been selected (Yes), the processing ends.
If all the nodes have not been selected (No), S420 is performed with reference to the failure management information of the unselected nodes.

[Effect of Embodiment 4]
As described above, according to the fourth embodiment, failure detection and failure factor determination can be performed in a wireless communication system including a relay station that relays communication between a master station and a slave station.

Embodiment 5 FIG.
In the fourth embodiment, a method for detecting a failure and determining a failure factor in a wireless communication system including a relay station between the master station and the slave station has been described.
However, in this method, even in the period from when a failure occurs until maintenance is performed, in a wireless communication system including a redundant relay station for the master station to secure a communication path with the slave station, the redundant relay station or Failure detection and failure factor determination in the radio link is not possible.
In the fifth embodiment, a method of performing failure detection and failure factor determination in a wireless communication system having redundant relay stations and wireless links will be described.

Configuration differences
FIG. 31 is a system configuration diagram according to the fifth embodiment.
The master station device 1100 is a wireless terminal that is driven by a commercial power source.
The slave station device 1200 is a wireless terminal that is driven using a battery as a power source.
The relay station device 1300 is a wireless terminal that is driven by a battery as a power source and relays communication between the master station device 1100 and the slave station device 1200.
The relay station device 1400 is a redundant wireless terminal that uses a battery as a power source and is used as a substitute for the relay station device 1300 when a failure occurs in the communication path between the master station device 1100 and the slave station device 1200.
Relay station device 1300 is also referred to as relay station 1300, and relay station device 1400 is also referred to as relay station 1400.
The master station device 1100, the slave station device 1200, and the relay station device 1300 are the same as those shown in the fourth embodiment.
The relay station device 1300 corresponds to an example of a first relay station device, and the relay station device 1400 corresponds to an example of a second relay station device.
N40 is a wireless link used when the master station device 1100 and the relay station device 1300 communicate with each other.
The wireless link N40 corresponds to an example of a first relay station wireless communication path.
N41 is a radio link used when the relay station apparatus 1300 and the slave station apparatus 1200 communicate with each other.
The wireless link N41 corresponds to an example of a first slave station wireless communication path.
N42 is a wireless link used when the master station device 1100 and the relay station device 1400 communicate with each other.
The wireless link N42 corresponds to an example of a second relay station wireless communication path.
N43 is a wireless link used when the relay station apparatus 1400 and the slave station apparatus 1200 communicate with each other.
The wireless link N43 corresponds to an example of a second slave station wireless communication path.
N45 is a radio link used when the relay station apparatus 1300 and the relay station apparatus 1400 communicate with each other.
The wireless link N45 corresponds to an example of a wireless communication path between relay stations.

FIG. 41 is an example of the failure management information table T400 held by the failure management information table storage unit 107 of the master station device 1100 according to the fifth embodiment.
In addition to the failure management information table T300, the failure management information table T400 holds information on a plurality of link states according to the number of radio links used by the node.

FIG. 42 shows node failure management information T500 held by measurement management information recording means 204 of slave station apparatus 1200, relay station apparatus 1300, and relay station apparatus 1400 in the fifth embodiment.
The node failure management information T500 includes a measurement sequence number, a battery state, and a plurality of link states.
The link state includes a source node address, an average RSSI, an RSSI standard deviation, and the number of successful test frame receptions.

FIG. 8 shows an example of the configuration of master station apparatus 1100 in the fifth embodiment.
Since the components other than the communication path changing unit 115 are the same as those in the fourth embodiment, description thereof is omitted.
The communication path changing unit 115 is a unit (for example, a program) that changes the communication path according to the failure determination result.
In other words, the communication path changing unit 115 selects the relay station device 1300 or the relay station device 1400 as an active communication destination based on the determination result of the failure determination unit 108.
The communication path changing unit 115 corresponds to an example of a relay station selection unit.

FIG. 9 is an example of a configuration of slave station apparatus 1200 in the fifth embodiment.
Since the components other than the node failure management information recording unit 206 are the same as those in the fourth embodiment, description thereof is omitted.
The node failure management information recording unit 206 is a recording element such as a DRAM that holds the node failure management information T500.

FIG. 10 is an example of a configuration of relay station apparatus 1300 and relay station apparatus 1400 in the fifth embodiment.
In addition to the configuration of relay station apparatus 1300 of the fourth embodiment, node failure management information recording means 206 is added.

[Difference in operation]
FIG. 26 is an example of an operation in which the node receives the test frame C100 and measures the link state in the fifth embodiment.
The flow of FIG. 26 is applied to all of the master station device 1100, the slave station device 1200, the relay station device 1300, and the relay station device 1400.

When the link state measuring unit 203 receives the test frame C100, the node failure management information T500 is referred to from the node failure management information recording unit 206 (S801).
The measurement sequence number held by the link state measurement unit 203 is compared with the measurement sequence number of the test frame C100 (S802). If they are different (No), the link state measurement unit 203 is recorded in the measurement management information recording unit 204. The node failure management information T500 is cleared, and the measurement sequence number obtained from the test frame C100 is recorded.
Further, the link state measuring means 203 sets the source node address of the test frame C100 as the node address, the RSSI of the test frame C100 as the average RSSI, and the RSSI standard deviation as 0 in one field of the link state of the node failure management information T500. The number of successful test frame receptions is set to 1 (S803).
When the stored measurement sequence number and the measurement sequence number of the test frame C100 are the same (Yes), the link state measurement unit 203 includes a link state field corresponding to the transmission source node address of the test frame C100 in the node failure management information T500. It is confirmed whether there is any (S804).
If there is no corresponding link status field in the node failure management information T500 (No), the source node address of the test frame C100 is set as the node address and the RSSI of the test frame C100 is set in the link status field in which the link status is not recorded. The average RSSI is set, the RSSI standard deviation is set to 0, and the number of successful test frame receptions is set to 1 (S805).
If there is a corresponding link state field in the node failure management information T500 (Yes), the link state measuring unit 203 increments the number of successful test frame receptions in the corresponding link state field.
Then, the average RSSI and the RSSI standard deviation are updated from the measured RSSI, the held average RSSI, the RSSI standard deviation, and the number of successful test frame receptions (S806).

  22, FIG. 23, FIG. 24, and FIG. 25 show the master station device 1100, the slave station device 1200, the relay station device 1300, and the relay station device 1400 according to the fifth embodiment, and the master station device 1100 performs fault management information. Is an example of an operation of collecting and determining the presence / absence of a failure and a factor.

The timer 103 of the master station device 1100 causes the test frame generator 104 to start transmitting a test frame.
The test frame generation unit 104 generates a test frame C100 having the address of the master station device 1100 as a transmission source node address, and transmits the test frame C100 to the wireless transmission unit 101.
The wireless transmission means 101 modulates the test frame C100 into a radio signal and transmits it by broadcast to the relay station device 1300 and the relay station device 1400 (S501).

The radio reception unit 102 of the relay station apparatus 1300 receives the radio signal, demodulates it into a packet, and when it is determined as the test frame C100, transmits the test frame C100 to the link state measurement unit 203.
In addition, the wireless reception unit 102 measures the RSSI value when the test frame C100 is received.
The link state measuring unit 203 obtains the RSSI value from the wireless receiving unit 102, and the link state obtained by the test frame C100 is obtained from the node failure management information T500 of the node failure management information recording unit 206 by the method of S801 to S806 in FIG. (S502).

  The relay station apparatus 1400 records the link state by the same method as S502 (S503).

The test frame generation means 104 of the master station device 1100 determines whether the number of test frame transmissions is less than the number of test frame transmissions (S504). If the number of test frame transmissions is less than the number of test frame transmissions (Yes), the master station The device 1100, the relay station device 1300, and the relay station device 1400 repeat the processes of S501, S502, and S503.
If the number of test frame transmissions is equal to or greater than the number of test frame transmissions (No), the master station device 1100 performs the process of S505.
The test frame generation unit 104 of the master station device 1100 notifies the measurement request transmission unit 111 when the test frame is transmitted as many times as the number of test frame transmissions.
Upon receiving the notification, the measurement request transmission unit 111 acquires the node address of the relay station device 1300 from the transmission node management unit 110, generates a measurement request C700 whose transmission destination node address is the node address of the relay station device 1300, and wirelessly Transmit to the transmission means 101.
The wireless transmission unit 101 refers to the communication path corresponding to the relay station apparatus 1300 that is the transmission destination node address of the measurement request C700 from the communication path management unit 112, acquires information without relay, and sets the communication path of the measurement request C700 as the communication path. Write.
The wireless transmission unit 101 transmits the measurement request C700 to the relay station device 1300 that is the next node address of the communication path (S505).

The wireless receiving means 102 of the relay station apparatus 1300 receives the radio signal, demodulates the packet, and confirms the destination node and the communication path.
Since the node address next to the transmission destination node and the communication path is the relay station device 1300, the wireless reception unit 102 determines that the packet is addressed to itself.
When determining that the measurement request C700 is based on the command ID of the packet, the wireless reception unit 102 sets and notifies the test frame generation unit 104 of the number of test frame transmissions.
The test frame generation unit 104 of the relay station apparatus 1300 generates a test frame C100, and transmits the test frame C100 by broadcast by the wireless transmission unit 101 (S506).

The wireless reception unit 102 of the master station device 1100 receives the radio signal, demodulates it into a packet, and transmits the test frame C100 to the link state measurement unit 203 when it is determined as the test frame C100 by the command ID.
In addition, the wireless reception unit 102 measures the RSSI value when the test frame C100 is received.
The link state measurement unit 203 acquires the RSSI value from the wireless reception unit 102, and records the link state obtained by the test frame C100 in the failure management information table storage unit 107 by the method of S801 to S806 in FIG. 26 (S507). .

The relay station apparatus 1400 records the link state by the same method as in S502 (S508).
The slave station device 1200 records the link state by the same method as in S502 (S509).

The test frame generation unit 104 of the relay station apparatus 1300 compares the number of times the test frame has been transmitted with the number of times the test frame has been transmitted (S510), and if the number of times the test frame has been transmitted is less than the number of times of test frame transmission (Yes), S506 to S509. Process up to.
If the number of test frame transmissions is equal to or greater than the number of test frame transmissions (No), the test frame transmission is terminated.

The measurement request transmission unit 111 of the master station device 1100 detects by time measurement that the test frame generation unit 104 of the relay station device 1300 finishes transmitting the test frame, and generates a measurement request C700 to the relay station device 1400. To start.
The measurement request transmission unit 111 acquires the node address of the relay station device 1400 from the transmission node management unit 110, generates the measurement request C700 whose transmission destination node address is the node address of the relay station device 1400, and sends it to the wireless transmission unit 101. Send.
The wireless transmission unit 101 refers to the communication path corresponding to the relay station device 1400 that is the transmission destination node address of the measurement request C700 from the communication path management unit 112, acquires information without relay, and sets the communication path of the measurement request C700 as the communication path. Write.
The wireless transmission unit 101 transmits the measurement request C700 to the relay station device 1400 that is the next node address of the communication path (S511).

The relay station apparatus 1400 transmits the test frame C100 by broadcast in the same manner as in S506 (S512).
The master station device 1100 records the link state by the same method as S507 (S513).
The relay station apparatus 1300 records the link state by the same method as S502 (S514).
The slave station device 1200 records the link state by the same method as S502 (S515).

The test frame generation means 104 of the relay station device 1400 compares the number of times the test frame has been transmitted with the number of times the test frame has been transmitted (S516), and if the number of times the test frame has been transmitted is less than the number of times of test frame transmission (Yes), S512 to S515. Perform the process.
If the number of test frame transmissions is equal to or greater than the number of test frame transmissions (No), the test frame transmission is terminated.

The measurement request transmission unit 111 of the master station device 1100 detects by time measurement that the test frame generation unit 104 of the relay station device 1300 ends the transmission of the test frame, and notifies the measurement result collection transmission unit 105 of the measurement result transmission.
Upon receiving the notification, the measurement result collection / transmission means 105 refers to the address list from the transmission node management means 110 to acquire the node address of the relay station apparatus 1300, and the transmission destination node address is the node address of the relay station apparatus 1300. A measurement result collection request C500 is generated and transmitted to the wireless transmission means 101.
The wireless transmission unit 101 refers to the communication path corresponding to the relay station apparatus 1300 that is the transmission destination node address of the measurement result collection request C500 from the communication path management unit 112, acquires information without relay, and communicates the measurement request C700. Write to the route.
The wireless transmission unit 101 transmits a measurement result collection request C500 to the relay station device 1300 (S517).

The wireless receiving means 102 of the relay station device 1300 receives the radio signal, demodulates the packet, and confirms the transmission destination node and the communication path.
Since the node address next to the transmission destination node and the communication path is the relay station device 1300, the wireless reception unit 102 determines that the packet is addressed to itself.
The wireless reception unit 102 records information without relay as a communication path to the master station device 1100 that is a transmission source node in the routing unit 205.
When the wireless reception unit 102 determines that the measurement result collection request C500 is based on the command ID of the packet, the wireless reception unit 102 notifies the measurement result collection response unit 202.
The measurement result collection response unit 202 notifies the battery state measurement unit 201.
The battery state measuring unit 201 measures the battery voltage built in the relay station device 1300, and records the battery voltage as the battery state in the measurement management information recording unit 204 (S518).
The measurement result collection response unit 202 of the relay station apparatus 1300 generates a measurement result collection response C600 including the data of the node failure management information T500 as failure management information from the measurement management information recording unit 204, and transmits the measurement result collection response C600 to the wireless transmission unit 101.
The wireless transmission unit 101 refers to the routing unit 205, acquires information without relay as a communication path corresponding to the parent station device 1100 by the transmission destination node, and writes it in the communication path of the measurement result collection response C 600.
The wireless transmission unit 101 transmits a measurement result collection response C600 to the master station device 1100 (S519).

  The measurement result collection response C600 transmitted by the relay station device 1300 includes the average RSSI value, the RSSI standard deviation at the time of receiving the test frame from the parent station device 1100, the number of successful receptions of the test frame from the parent station device 1100, the relay The average RSSI value, the RSSI standard deviation when the test frame is received from the station apparatus 1400, the number of successful receptions of the test frame from the relay station apparatus 1400, and the remaining battery level of the relay station apparatus 1300 are included.

The wireless receiving means 102 of the master station device 1100 receives the radio wave, demodulates the packet, and confirms the destination node and the communication path.
Since the node address next to the transmission destination node and the communication path is the master station device 1100, the wireless reception means 102 determines that the packet is addressed to the own station.
When the wireless reception unit 102 determines that the measurement result collection response C600 is based on the command ID of the packet, the wireless reception unit 102 transmits the measurement result to the measurement result recording unit 106.
The measurement result recording unit 106 records the failure management information in a field where the transmission source node address and the node address of the failure management information table T400 of the failure management information table storage unit 107 are equal (S520).
The measurement result recording unit 106 of the master station device 1100 notifies the measurement result collection / transmission unit 105 after recording the failure management information of one node.
Upon receiving the notification, the measurement result collection / transmission means 105 refers to the address list from the transmission node management means 110 to acquire the node address of the relay station apparatus 1400, and the transmission destination node address is the node address of the relay station apparatus 1400. A measurement result collection request C500 is generated and transmitted to the wireless transmission means 101.
The wireless transmission unit 101 refers to the communication path corresponding to the relay station apparatus 1400 as the transmission destination node from the communication path management unit 112, acquires information without relay, and writes it in the communication path of the measurement result collection request C500.
The wireless transmission unit 101 transmits a measurement result collection request C500 to the relay station device 1400 (S521).

The relay station device 1400 measures the remaining battery level in the same manner as in S518 (S522).
The relay station apparatus 1400 transmits a measurement result collection response C600 to the master station apparatus 1100 in the same manner as in S519 (S523).

  Note that the measurement result collection response C600 transmitted by the relay station device 1400 includes the average RSSI value, the RSSI standard deviation when the test frame is received from the master station device 1100, the number of successful receptions of the test frame from the master station device 1100, the relay The average RSSI value, the RSSI standard deviation at the time of receiving a test frame from the station apparatus 1300, the number of successful receptions of the test frame from the relay station apparatus 1300, and the remaining battery level of the relay station apparatus 1400 are included.

The master station device 1100 records the failure management information of the relay station device 1400 in the failure management information table T400 in the same manner as in S520 (S524).
The measurement result recording unit 106 of the master station device 1100 notifies the measurement result collection / transmission unit 105 after recording the failure management information of one node.
Upon receiving the notification, the measurement result collection / transmission means 105 refers to the address list from the transmission node management means 110 to acquire the node address of the slave station apparatus 1200, and the transmission destination node address is the node address of the slave station apparatus 1200. A measurement result collection request C500 is generated and transmitted to the wireless transmission means 101.
The wireless transmission means 101 refers to the communication path corresponding to the transmission destination node corresponding to the slave station apparatus 1200 from the communication path management means 112, acquires the relay station apparatus 1300, and writes it in the communication path of the measurement result collection request C500.
The wireless transmission unit 101 transmits the measurement result collection request C500 to the relay station apparatus 1300 that is the next node address of the communication path (S525).

The wireless receiving means 102 of the relay station device 1300 receives the radio signal, demodulates the packet, and confirms the transmission destination node and the communication path.
Since the destination node is not the node address of relay station apparatus 1300, radio reception means 102 transmits the packet to routing means 205.
The routing unit 205 transmits the packet to the wireless transmission unit 101.
The wireless transmission unit 101 transmits a packet (measurement result collection request C500) to the slave station device 1200 (S526).

The wireless receiving means 102 of the slave station device 1200 receives the radio signal, demodulates the packet, and confirms the destination node and the communication path.
Since the transmission destination node is the slave station device 1200, it is determined as a packet addressed to the own station.
The wireless reception unit 102 records the node address of the relay station device 1300 in the routing unit 205 as a communication path to the master station device 1100 that is a transmission source node.
When the wireless reception unit 102 determines that the measurement result collection request C500 is based on the command ID, the wireless reception unit 102 transmits the measurement result collection request C500 to the measurement result collection response unit 202.
The measurement result collection response unit 202 notifies the battery state measurement unit 201.
The battery state measuring unit 201 measures the battery voltage and records the battery voltage as the battery state in the measurement management information recording unit 204 (S527).
The measurement result collection response unit 202 of the slave station device 1200 generates a measurement result collection response C600 including the data of the node failure management information T500 as failure management information from the measurement management information recording unit 204, and transmits the measurement result collection response C600 to the wireless transmission unit 101.
The wireless transmission unit 101 refers to the routing unit 205, acquires the node address of the relay station device 1300 as the communication route corresponding to the master station device 1100 as the transmission destination node, and writes it in the communication route of the measurement result collection response C 600. .
The measurement result collection response unit 202 transmits a measurement result collection response C600 to the wireless transmission unit 101.
The wireless transmission unit 101 transmits a measurement result collection response C600 to the relay station device 1300 (S528).

  Note that the measurement result collection response C600 transmitted by the slave station device 1200 includes the average RSSI value, the RSSI standard deviation when the test frame is received from the relay station device 1300, the number of successful receptions of the test frame from the relay station device 1300, the relay The average RSSI value, RSSI standard deviation at the time of receiving the test frame from the station apparatus 1400, the number of successful reception of the test frame from the relay station apparatus 1400, and the remaining battery level of the slave station apparatus 1200 are included.

  Relay station apparatus 1300 relays the packet in the same manner as in S526 and transmits the packet to master station apparatus 1100 (S529).

The master station device 1100 records the failure management information of the slave station device 1200 in the failure management information table T400 in the same manner as in S520 (S530).
The master station device 1100 selects one of the nodes in the system, and performs failure factor determination including S201 to S204 (FIG. 16) (S531).
The failure determination unit 108 of the master station device 1100 refers to the failure management information field of the failure management information table T400 to determine whether all the nodes have been selected (S532). When all the nodes have been selected (Yes), the processing ends. .
If not all nodes have been selected (No), S531 is performed with reference to the failure management information of unselected nodes.

The failure determination unit 108 of the master station device 1100 notifies the communication path change unit 115 when the failure determination process of all nodes is completed.
In the communication path changing unit 115, a failure has occurred in a node or radio link on the path from the master station device 1100 to the relay station device 1300, the master station device 1100 to the relay station device 1400, and the master station device 1100 to the slave station device 1200. Then, a node or wireless link in which no failure has occurred is selected, and the communication path is updated (S533).

[Effect of Embodiment 5]
As described above, according to the fifth embodiment, there is a node that is used as an alternative when a failure occurs. In a wireless communication system in which each node has a plurality of wireless links, a failure is caused for all nodes and wireless links. Can be detected and the cause of the failure can be determined.

Embodiment 6 FIG.
In the fifth embodiment, in the wireless communication system having redundant nodes and wireless links, the method of performing failure detection and failure factor determination for all nodes and wireless links has been described.
However, with this method, it is impossible to determine the cause of packet loss due to the radio wave interference temporarily generated or the deterioration of the radio wave propagation environment due to, for example, shaking of the vegetation.
In the sixth embodiment, a method for determining packet loss due to temporary deterioration of the communication environment will be described.

Configuration differences
FIG. 43 shows an example of the configuration of the failure management information table T700 held by the failure management information table storage unit 107 of the master station device 1100.
In addition to the failure management information table T400, a plurality of error logs including an error type indicating an error type and error information indicating the content of the error are provided.

FIG. 44 shows an example of node failure management information T800 held by the node failure management information recording unit 206 of the slave station device 1200, the relay station device 1300, and the relay station device 1400.
In addition to the node failure management information T700, it has a plurality of error logs.

FIG. 11 is an example of a configuration of master station apparatus 1100 in the sixth embodiment. Other than the error log recording unit 114 is the same as that of the fifth embodiment, and thus description thereof is omitted.
The error log recording means 114 is means (for example, a program) for recording information on communication errors that have occurred during wireless transmission / reception.
The error log recording unit 114 corresponds to an example of a communication error information storage unit.

FIG. 12 is an example of a configuration of slave station apparatus 1200 in the sixth embodiment.
Error log recording means 114 is added to the configuration of slave station apparatus 1200 of the fifth embodiment.

FIG. 13 is an example of configurations of relay station apparatus 1300 and relay station apparatus 1400 in the sixth embodiment.
Error log recording means 114 is added to the configuration of relay station apparatus 1300 and relay station apparatus 1400 of the fifth embodiment.

  The operation of the error log recording means 114 in the master station device 1100 is as follows.

If wireless transmission means 101 sends an error due to CSMA / CA (Carrier Sense Multiple Access / Collision Aidance) at the time of packet transmission, the information of the packet transmitted when the ACK (Acknowledgement) cannot be received after packet transmission is error log Transmit to the recording means 114.
Also, when the wireless reception unit 102 receives a packet, a CRC error that is a CRC (Cyclic Redundancy Check) mismatch with a value higher than the RSSI threshold value is transmitted to the error log recording unit 114 in the same manner.
The error log recording unit 114 acquires the error type and error information from the packet, and records the error log in the failure management information table T500 of the failure management information table storage unit 107 of the master station device 1100.

The error log recording unit 114 in the slave station device 1200, the relay station device 1300, and the relay station device 1400 records an error log in the node failure management information T800 of the node failure management information recording unit 206 by the same method.
As described in the fifth embodiment, the error log recorded in the node failure management information T800 is included in the measurement result collection response C600 and notified to the master station device 1100.

[Difference in operation]
FIG. 27 is an example of failure factor determination performed by the failure determination unit 108 of the master station device 1100 according to the sixth embodiment.
Since S601 to S604 are the same as S201 to S204 (FIG. 16) in the fifth embodiment, description thereof is omitted.

If there is a record in the error log (the error log in the error log recording unit 114 or the error log included in the measurement result collection response C600) (YES in S605), a temporary error may occur during transmission / reception of the packet indicated by the error log. Judge that it occurred.
For example, if a CSMA / CA error is recorded, it is determined that communication has temporarily interfered around the transmitting node.
Further, for example, when a CRC error is recorded, it is determined that communication is temporarily mixed around the receiving node.
[Effect of Embodiment 5]
As described above, according to the sixth embodiment, it is possible to grasp the temporarily deteriorated communication environment.

In the above first to sixth embodiments,
Test frame generation means for transmitting a test frame for measuring the link state;
A measurement result collection requesting means for collecting data measured by the slave station, and
A failure factor determination means for detecting a failure and determining a failure factor from the collected data;
A master station with
Battery state measuring means for measuring the remaining battery power;
A link state measuring means for measuring the number of times the RSSI and the test frame are received;
Means for wirelessly communicating measured data;
A wireless communication system consisting of a slave station having the above has been described.

In the third embodiment,
A transmission node management means for managing a plurality of slave stations;
A fault management information table for storing the link status and node status data recorded for each node separately;
A master station with
A radio communication system including a plurality of slave stations has been described.

In the fourth embodiment,
A measurement request transmission means for transmitting a packet and requesting test frame transmission;
A communication path management means for managing the order of nodes to be relayed;
A master station with
Routing means for controlling wireless communication including relay nodes;
A test frame generating means;
Battery state measuring means;
Link state measuring means;
Means for wirelessly communicating measured data;
A relay station comprising:
A radio communication system comprising slave stations has been described.

In the fifth embodiment,
Fault management information table storage means for separately recording link state information of a plurality of radio links for each node;
A communication path changing means for changing to a communication path to an alternative node or wireless link when the communication performance with the slave station deteriorates;
A master station with
A wireless communication system including a relay station and a slave station that includes failure management information recording means for separately recording link state information of a plurality of wireless links has been described.

In the first to sixth embodiments,
Means for determining battery exhaustion by comparing an average value of battery state information for a predetermined period and a battery state threshold value for all nodes;
Means for determining that there is a node failure by not being able to receive data for a predetermined period for all nodes;
For all wireless links, the node has a packet loss rate of a predetermined period equal to or higher than a packet loss rate threshold value and an RSSI evaluation value calculated from RSSI of a predetermined period is less than the RSSI threshold value. Means for determining that the radio wave propagation environment has deteriorated, indicating that the radio wave propagation property has deteriorated,
For all wireless links, the node has a packet loss rate of a predetermined period equal to or greater than a packet loss rate threshold value and an RSSI evaluation value calculated from RSSI of a predetermined period is equal to or greater than an RSSI threshold value. Radio interference that interferes with the target communication by radio waves other than the target communication,
The failure determination means for determining the failure factor has been described.

In the first to sixth embodiments,
The failure determination means for determining the deterioration of the radio wave propagation environment or the radio wave interference by calculating the RSSI evaluation value from the average value and standard deviation of the RSSI measured within a predetermined period and comparing it with the RSSI threshold value has been described. .

In the second embodiment,
A wireless communication system has been described in which the number of times the master station and the relay station transmit test frames is changed according to the failure factor determination of the master station.

In the sixth embodiment,
A wireless communication system that records an error log composed of packet information and error information when a packet loss occurs during wireless transmission or reception has been described.

  In the sixth embodiment, the failure determination unit that determines the cause of packet loss for each packet based on the error log has been described.

Finally, a hardware configuration example of the master station device 1100, the slave station device 1200, the relay station device 1300, and the relay station device 1400 (hereinafter referred to as the master station device 1100) described in the first to sixth embodiments will be described.
FIG. 46 is a diagram illustrating an example of hardware resources such as the master station device 1100 described in the first to sixth embodiments.
The configuration in FIG. 46 is merely an example of the hardware configuration of the master station device 1100 and the like, and the hardware configuration of the master station device 1100 and the like is not limited to the configuration shown in FIG. There may be.

46, the master station device 1100 and the like include a CPU 911 (also referred to as a central processing unit, a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, and a processor) that executes a program.
The CPU 911 is connected to, for example, a ROM (Read Only Memory) 913, a RAM (Random Access Memory) 914, a communication board 915, a display device 901, and a magnetic disk device 920 via the bus 912, and controls these hardware devices. To do.
Further, the CPU 911 may be connected to an input device such as a keyboard and a mouse.
The CPU 911 may be connected to an FDD 904 (Flexible Disk Drive), a compact disk device 905 (CDD), or the like.
Further, instead of the magnetic disk device 920, a storage device such as an SSD (Solid State Drive), an optical disk device, or a memory card (registered trademark) read / write device may be used.

  The communication board 915 can wirelessly communicate with other nodes.

The magnetic disk device 920 stores an operating system 921 (OS), a program group 923, and a file group 924.
The programs in the program group 923 are executed by the CPU 911 using the operating system 921.

The RAM 914 temporarily stores at least part of the operating system 921 program and application programs to be executed by the CPU 911.
The RAM 914 stores various data necessary for processing by the CPU 911.

The program group 923 stores programs for executing the functions described as “to means” and “to part” in the description of the first to sixth embodiments.
The program is read and executed by the CPU 911.

In the file group 924, in the description of the first to sixth embodiments, “determination of”, “determination of”, “measurement of”, “calculation of”, “calculation of”, “comparison of” ”,“ Update of ”,“ setting of ”,“ registration of ”,“ selection of ”,“ input of ”,“ output of ”, etc. Data, signal values, variable values, and parameters are stored as items of “˜file” and “˜database”.
The “˜file” and “˜database” are stored in a recording medium such as a disk or a memory.
Information, data, signal values, variable values, and parameters stored in a storage medium such as a disk or memory are read out to the main memory or cache memory by the CPU 911 via a read / write circuit.

In addition, the arrows in the flowcharts described in the first to sixth embodiments mainly indicate input / output of data and signals.
Data and signal values are recorded in the memory of the RAM 914, the magnetic disk of the magnetic disk device 920, and other recording media.
Data and signals are transmitted online via a bus 912, signal lines, cables, or other transmission media.

Moreover, what is described as “to means” and “to part” in the description of the first to sixth embodiments may be “to circuit”, “to device”, and “to device”. It may be “˜step”, “˜procedure”, “˜processing”.
That is, the process of the master station device 1100 and the like can be regarded as a data processing method by the steps, procedures, and processes shown in the flowcharts described in the first to sixth embodiments.
In addition, what is described as “˜means” and “˜unit” may be realized by firmware stored in the ROM 913.
Alternatively, it may be implemented only by software, or only by hardware such as elements, devices, substrates, and wirings, by a combination of software and hardware, or by a combination of firmware.
Firmware and software are stored as programs in a recording medium such as a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, and a DVD.
The program is read by the CPU 911 and executed by the CPU 911.
That is, the program causes the computer to function as “to means” and “to part” in the first to sixth embodiments. Alternatively, the procedures and methods of “to means” and “to part” in the first to sixth embodiments are executed by a computer.

  101 wireless transmission means, 102 wireless reception means, 103 timing means, 104 test frame generation means, 105 measurement result collection transmission means, 106 measurement result recording means, 107 failure management information table storage means, 108 failure determination means, 109 sample number control 110, transmission node management means, 111 measurement request transmission means, 112 communication path management means, 114 error log recording means, 115 communication path change means, 201 battery state measurement means, 202 measurement result collection response means, 203 link state measurement means 204 measurement management information recording means, 205 routing means, 206 node failure management information recording means, 1100 master station device, 1200 slave station device, 1300 relay station device, 1400 relay station device, 2200 slave station device, 2300 slave station device, 2400 children Apparatus.

Claims (16)

A master station device that communicates with a slave station device via a wireless communication path,
A test frame transmitter for transmitting a test frame for measuring the state of the wireless communication path to the slave station device via the wireless communication path;
After the test frame is transmitted by the test frame transmission unit a predetermined number of times, a measurement result collection request for requesting the slave station device to transmit a measurement result measured by the slave station device is sent to the wireless communication path. A measurement result collection request transmitter for transmitting to the slave station device via,
RSSI (Received) measured at the time of receiving each test frame by the slave station device
And Signal Strength Indicator) value and at least one of the calculated value calculated from the RSSI values measured during each test frame receiving said child station measurement result and the reception frequency of the test frame measured by the slave station devices are shown A measurement result receiving unit for receiving from the slave station device via a wireless communication path;
Based on at least one of the RSSI value and the calculated value indicated in the slave station measurement result, the number of test frame receptions of the slave station device, and the number of test frame transmissions by the test frame transmission unit, the packet loss rate and the RSSI When the calculated packet loss rate is equal to or higher than the threshold value and the calculated RSSI evaluation value is less than the threshold value, it is determined that the radio wave propagation environment in the wireless communication path has deteriorated, A state determination unit that determines that radio wave interference has occurred in the wireless communication path when the calculated packet loss rate is equal to or greater than a threshold value and the calculated RSSI evaluation value is equal to or greater than the threshold value. A master station device. The master station device is
Communicates with a slave station device powered by a battery via a wireless communication path,
The measurement result receiver
A slave station measurement result indicating the remaining battery level of the slave station device measured by the slave station device is received from the slave station device via the wireless communication path,
The state determination unit
The battery unit of the said slave station apparatus is determined to be insufficient when the remaining battery level of the said slave station apparatus shown in the said slave station measurement result is less than a threshold value. Master station device. The master station device further includes:
A transmission frequency determination unit that determines the number of transmissions of the test frame by the test frame transmission unit according to the state of the wireless communication path;
The measurement result collection request transmission unit
Transmitting the measurement result collection request to the slave station device via the wireless communication path after the test frame transmission unit transmits a test frame for the number of transmissions determined by the transmission number determination unit. The master station device according to claim 1. The transmission number determination unit
When the state of the wireless communication path deteriorates, increase the number of test frame transmission by the test frame transmission unit,
4. The master station apparatus according to claim 3 , wherein when the state of the wireless communication path is improved, the number of test frame transmissions by the test frame transmission unit is decreased. The master station device further includes:
A communication error information storage unit for storing communication error information indicating a communication error detected in communication with the slave station device;
The state determination unit
Analyzes the communication error information stored in the communication error information storage unit and the child station measurement result received by the measurement result receiving unit, to determine the state and status of the wireless communication path of the slave station devices The master station device according to claim 2 . The measurement result receiver
The master station device according to claim 1, wherein a slave station measurement result indicating a communication error detected in the slave station device is received through communication with the master station device. The master station device is
Communicates with multiple slave station devices powered by batteries via multiple wireless channels,
The test frame transmission unit
Transmitting a test frame to the plurality of slave station devices;
The measurement result collection request transmission unit
For each slave station device, after a test frame has been sent a predetermined number of times, send a measurement result collection request,
The measurement result receiver
For each slave station device, receive the slave station measurement results,
The state determination unit
3. The master station device according to claim 2 , wherein for each slave station device, the slave station measurement result is analyzed to determine the status of the slave station device and the state of the wireless communication path with the slave station device. A master station apparatus for performing communication through a medium Tsugikyoku apparatus by radio communication path,
A test frame transmission unit for transmitting a test frame for measuring the state of the wireless communication path to the relay station device via the wireless communication path;
After the test frame is transmitted by the test frame transmission unit a predetermined number of times, a measurement result collection request for requesting the relay station apparatus to transmit a measurement result measured by the relay station apparatus is sent to the wireless communication path. A measurement result collection request transmitter for transmitting to the relay station device via,
The relay station apparatus measures at least one of an RSSI (Received Signal Strength Indicator) value measured when each test frame is received by the relay station apparatus and a calculated value calculated from the RSSI value measured when each test frame is received. a measurement result receiving unit that receives from the relay station apparatus relay station measurement result and the reception frequency is shown in the test frame via the wireless communication path has,
Based on at least one of the RSSI value and the calculated value indicated in the relay station measurement result, the number of test frame receptions of the relay station device, and the number of test frame transmissions by the test frame transmission unit, the packet loss rate and the RSSI When the calculated packet loss rate is equal to or higher than the threshold value and the calculated RSSI evaluation value is less than the threshold value, it is determined that the radio wave propagation environment in the wireless communication path has deteriorated, A state determination unit that determines that radio wave interference has occurred in the wireless communication path when the calculated packet loss rate is equal to or greater than a threshold value and the calculated RSSI evaluation value is equal to or greater than the threshold value. A master station device. The master station device is
Communicates with a relay station device that uses a battery as a power source via a wireless communication path,
The measurement result receiver
Receiving a relay station measurement result indicating the remaining battery level of the relay station device measured by the relay station device from the relay station device via the wireless communication path;
The state determination unit
9. The battery according to claim 8 , wherein when the battery level of the relay station device indicated by the relay station measurement result is less than a threshold value, it is determined that the battery of the relay station device is insufficient. Master station device. The master station device further includes:
A communication error information storage unit for storing communication error information indicating a communication error detected in communication with the relay station device;
The state determination unit
Analyzing the relay station measurement result received by the measurement result receiving unit and the communication error information stored in the communication error information storage unit to determine the state of the relay station device and the state of the wireless communication path The master station apparatus according to claim 9 . The measurement result receiver
The master station apparatus according to claim 8 , wherein a relay station measurement result indicating a communication error detected in the relay station apparatus is received through communication with the master station apparatus. The master station device is
It manages a slave station device that uses a battery as a power source, and communicates with the relay station device via a wireless communication path.
The measurement result receiver
A test frame for measuring a state of a slave station wireless communication path which is a wireless communication path between the relay station apparatus and the slave station apparatus is transmitted from the relay station apparatus via the slave station wireless communication path. After a certain number of times
At least one of the RSSI value measured at the time of receiving each test frame by the slave station device and the calculated value calculated from the RSSI value measured at the time of receiving each test frame, and the number of times of receiving the test frame measured by the slave station device And a slave station measurement result indicating the remaining battery level of the slave station device measured by the slave station device is received from the relay station device via the wireless communication path,
The state determination unit
9. The master station apparatus according to claim 8 , wherein the slave station measurement result received by the measurement result receiving unit is analyzed to determine the state of the slave station apparatus and the state of the slave station wireless communication path. . The master station device is
Communicates with the first relay station device using the battery as a power source via the first relay station wireless communication path,
Communicates with the second relay station device using the battery as a power source via the second relay station wireless communication path,
The test frame transmission unit
Transmitting a test frame for measuring the state of the first relay station wireless communication path to the first relay station apparatus via the first relay station wireless communication path;
Transmitting a test frame for measuring the state of the second relay station wireless communication path to the second relay station apparatus via the second relay station wireless communication path;
The measurement result collection request transmission unit
After the test frame transmission unit transmits the test frame to the first relay station device a predetermined number of times, the measurement result measured by the first relay station device with respect to the first relay station device is displayed. Sending a measurement result collection request to request transmission to the first relay station device via the first relay station wireless communication path,
After the test frame transmission unit transmits the test frame to the second relay station device a predetermined number of times, the measurement result measured by the second relay station device with respect to the second relay station device is displayed. Transmitting a measurement result collection request for transmission to the second relay station device via the second relay station wireless communication path;
The measurement result receiver
At least one of an RSSI value measured when each test frame is received by the first relay station device and a calculated value calculated from an RSSI value measured when each test frame is received, and the first relay station device measures the RSSI value. The first relay station wireless communication is the first relay station measurement result indicating the number of received test frames and the remaining battery level of the first relay station apparatus measured by the first relay station device. Receiving from the first relay station device via the path,
At least one of the RSSI value measured when each test frame is received by the second relay station device and the calculated value calculated from the RSSI value measured when each test frame is received, and the second relay station device measures the RSSI value. A second relay station measurement result indicating the number of received test frames and the second relay station device's remaining battery level measured by the second relay station device. Receiving from the second relay station device via the path,
The state determination unit
Analyzing the first relay station measurement result received by the measurement result receiving unit to determine the state of the first relay station device and the state of the first relay station wireless communication path;
Analyzing the second relay station measurement result received by the measurement result receiving unit, and determining the state of the second relay station device and the state of the second relay station wireless communication path, The master station device according to claim 8 . The master station device is
Communicating with the first relay station apparatus via a first slave station radio communication path, communicating with the second relay station apparatus via a second slave station radio communication path, and using a battery as a power source Managing the slave station devices that
The first relay station device
Transmitting a test frame for measuring the state of the first slave station wireless communication path to the slave station device via the first slave station wireless communication path;
The second relay station device is
Transmitting a test frame for measuring the state of the second slave station wireless communication path to the slave station device via the second slave station wireless communication path;
The measurement result receiver
At least one of an RSSI value measured when each test frame is received from the first relay station device by the slave station device and a calculated value calculated from an RSSI value measured when each test frame is received, and the slave station device The number of test frame receptions from the first relay station device measured by the above, the RSSI value measured when each slave frame device receives each test frame from the second relay station device, and each test frame reception At least one of the calculated values calculated from the measured RSSI values, the number of receptions of the test frame from the second relay station device measured by the slave station device, and the child measured by the slave station device A slave station measurement result indicating the remaining battery level of the station device is received from the first relay station device via the first relay station wireless communication path;
The state determination unit
Analyzing the slave station measurement results received by the measurement result receiving unit to determine the state of the slave station device, the state of the first slave station wireless communication path, and the state of the second slave station wireless communication path The master station device according to claim 13 , wherein The first relay station device and the second relay station device can communicate via an inter-relay station wireless communication path,
The measurement result receiver
The test frame transmission unit transmits a test frame to the first relay station device a predetermined number of times, and a test frame for measuring the state of the inter-relay radio channel is the second relay station. After being transmitted a predetermined number of times from the device to the first relay station device via the inter-relay station wireless communication path,
At least one of an RSSI value measured when each test frame is received from the master station device by the first relay station device and a calculated value calculated from an RSSI value measured when each test frame is received; The number of test frame receptions from the master station device measured by the relay station device, the RSSI value and each test measured when each test frame is received from the second relay station device by the first relay station device At least one of the calculated values calculated from the RSSI value measured at the time of frame reception, the number of receptions of the test frame from the second relay station device measured by the first relay station device, and the first The first relay station wireless communication channel indicates the first relay station measurement result indicating the battery remaining amount of the first relay station device measured by the relay station device. It received from the first relay station apparatus via,
The test frame transmission unit transmits a test frame to the second relay station device a predetermined number of times, and a test frame for measuring a state of the inter-relay station wireless communication path is the first relay station. After being transmitted a predetermined number of times from the device to the second relay station device via the inter-relay station wireless communication path,
At least one of an RSSI value measured when each test frame is received from the master station device by the second relay station device and a calculated value calculated from an RSSI value measured when each test frame is received; The number of test frame receptions from the master station device measured by the relay station device, the RSSI value measured by the second relay station device when each test frame is received from the first relay station device, and each test At least one of the calculated values calculated from the RSSI value measured at the time of frame reception, the number of times the test frame is received from the first relay station device measured by the second relay station device, and the second A second relay station measurement result indicating the remaining battery level of the second relay station device measured by the relay station device is used as the second relay station wireless communication path. It received from the second relay station apparatus via,
The state determination unit
Analyzing the first relay station measurement result received by the measurement result receiving unit to determine the state of the first relay station device and the state of the first relay station wireless communication path;
Analyzing the second relay station measurement result received by the measurement result receiving unit to determine the state of the second relay station device and the state of the second relay station wireless communication path,
And analyzing at least one of the first relay station measurement result and the second relay station measurement result, according to claim 13 or 14, characterized in that analyzing the state of the relay station between wireless communication channel Master station device. The master station device further includes:
Claim 13, characterized by having the basis of the state determination unit of the judgment result, the relay station selection section that selects either a communication destination of the working of the first relay station apparatus and the second relay station device 15. The master station device according to any one of 15 .

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