JP6432725B2 - WIRELESS DEVICE, WIRELESS COMMUNICATION SYSTEM WITH THE SAME, AND PROGRAM RUNNED IN WIRELESS DEVICE - Google Patents

Description

  The present invention relates to a radio apparatus, a radio communication system including the radio apparatus, and a program executed in the radio apparatus.

  2. Description of the Related Art Conventionally, a technique is known in which identification information of a wireless device that is shifted from a sleep state to an activated state is represented by a frame length to activate the wireless device (Patent Document 1).

  In the technique described in Patent Document 1, a transmission-source wireless device generates a wireless frame having a frame length indicating identification information of a wireless device to be activated, and the generated wireless frame is transmitted to a wireless communication partner. Send to a wireless device. Then, the counterpart radio apparatus receives the radio frame and detects the frame length by detecting the received signal of the received radio frame at the sampling interval with an envelope. Thereafter, the counterpart wireless device decodes the detected frame length into the identification information, and shifts from the sleep state to the activated state when the decoded identification information matches its own identification information.

  Then, the transmission source wireless device performs wireless communication with the counterpart wireless device.

  A wireless sensor network including a plurality of sensor terminals and a management terminal is known (Patent Document 2).

  The plurality of sensor terminals includes a sensor. The management terminal constructs a communication path for communicating with the plurality of sensor terminals, and performs wireless communication with each sensor terminal based on the constructed communication path. Then, the management terminal collects sensor values detected by each sensor terminal.

Patent No. 5190569 JP 2013-055551 A

  However, by applying the technology described in Patent Document 1 to the wireless sensor network described in Patent Document 2, at least one sensor terminal existing on the route from the sensor terminal that is the transmission source of sensor values to the management terminal is provided. When it is assumed that sensor values are transmitted from the transmission source sensor terminal to the management terminal while being sequentially activated, there are the following problems.

  Even when the number of sensor terminals constituting the wireless sensor network is small, there is a problem that the frame length and the number of frames constituting the wakeup ID increase, and power consumption due to transmission of the wakeup ID increases.

  In addition, the sensor terminal with a small number of activations and the sensor terminal with a large number of activations have the same overhead for activation, which increases the power consumption of the entire wireless sensor network.

  Accordingly, the present invention has been made to solve such a problem, and an object of the present invention is to provide a radio apparatus capable of reducing power consumption due to transmission of identification information.

  Another object of the present invention is to provide a wireless communication system including a wireless device capable of reducing power consumption due to transmission of identification information.

  Furthermore, another object of the present invention is to provide a program executed in a wireless device capable of reducing power consumption due to transmission of identification information.

  According to the embodiment of the present invention, the wireless device includes a detection unit, a collection unit, and an allocation unit. The detecting means detects a topology indicating an arrangement state of the wireless devices constituting the wireless network, and based on the topology information indicating the detected topology, the total number of wireless devices constituting the wireless network, and the wireless devices constituting the wireless network Included, and a proximity index indicating the degree of proximity from the first wireless device that collects data from other wireless devices, the number of adjacent wireless devices adjacent to the wireless device constituting the wireless network, and each wireless device Either the number of hops between the devices, or the total number of child nodes existing in a lower layer than each wireless device constituting the wireless network and located at a position of 1 hop or more from each wireless device constituting the wireless network To detect. The collection means includes a control count that is the number of times that the radio apparatus is controlled in a desired time length, a received signal strength in each radio apparatus, and a frame transmission number that is the number of frames transmitted in a desired time length in each radio apparatus. Collect one. The allocation means sequentially increases the frame length or the frame length and the number of frames from the reference identification information defined by the shortest frame length and the smallest number of frames based on either the detection result by the detection means or the collection result by the collection means. In this way, an assignment process for assigning identification information for controlling the wireless device to all the wireless devices constituting the wireless network is executed.

  A radio apparatus according to an embodiment of the present invention uses a variety of indices detected based on topology information indicating the topology of radio apparatuses constituting a radio network, or collected indices to generate a frame from reference identification information. Identification information is assigned to all wireless devices constituting the wireless network so that the length or the frame length and the number of frames sequentially increase. As a result, the identification information of the wireless devices constituting the wireless network differs in frame length or frame length and number of frames depending on each wireless device. Then, a wireless device that transmits identification information to a wireless device to which identification information defined by a shorter frame length and a smaller number of frames is assigned transmits the wireless frame constituting the identification information with less power consumption.

  Accordingly, power consumption due to transmission of identification information can be reduced.

  In addition, a wireless device to which identification information defined by a shorter frame length and a smaller number of frames is assigned receives a wireless frame constituting the identification information with low power consumption.

  Therefore, power consumption due to reception of the identification information can be reduced.

  Preferably, when the number of times of control is collected by the collecting means, the allocating unit executes the allocating process from the wireless device having the largest number of times of control toward the wireless device having the smallest number of times of control.

  Since the wireless device having a larger number of times of control is assigned identification information defined by a shorter frame length and a smaller number of frames, power consumption due to reception of the identification information can be reduced. Further, the time required for one control can be shortened.

  Preferably, the allocating unit executes the allocation process based on the total number of wireless devices when the total number of wireless devices is detected by the detecting unit.

  Depending on the total number of wireless devices, the number of identification information used is determined. Then, the determined number of pieces of identification information have different frame lengths or frame lengths and frame numbers.

  Therefore, compared to a case where all pieces of identification information are defined by the same number of frames, power consumption due to transmission and reception of identification information in each wireless device can be reduced, and power consumption of the wireless network can be reduced.

  Preferably, the assignment unit executes the assignment process from the wireless device closest to the first wireless device to the wireless device farthest from the first wireless device when the proximity index is detected by the detection unit.

  A wireless device closer to the first wireless device is assigned identification information defined by a shorter frame length and a smaller number of frames, and a wireless device farther from the first wireless device has a longer frame number and a larger frame number. The identification information defined by is assigned.

  Therefore, even if the wireless device close to the first wireless device is controlled, the power consumption required for the control can be reduced. Also, the wireless device close to the first wireless device has the controlled number of times. Even if it increases, the time required for control can be shortened.

  Preferably, the allocation unit executes allocation processing from a radio device having the largest number of adjacent radio devices to a radio device having the smallest number of adjacent radio devices when an adjacent radio device is detected by the detection unit.

  A wireless device with a larger number of adjacent wireless devices is assigned identification information defined by a shorter frame length and a smaller number of frames, and a wireless device with a smaller number of adjacent wireless devices has a longer frame number and a larger number of frames. The identification information defined by is assigned.

  Therefore, a wireless device having a large number of adjacent wireless devices can reduce power consumption required for being controlled even if the number of times of control is increased, and a wireless device having a large number of adjacent wireless devices is controlled. The time required for control can be shortened even if the number of times is increased.

  Preferably, when the reception signal strength is collected by the collection unit, the assignment unit performs an assignment process from a wireless device having a wireless link having the smallest received signal strength to a wireless device having a wireless link having the largest received signal strength. Run.

  A wireless device having a wireless link with a lower received signal strength is assigned identification information defined by a shorter frame length and a smaller number of frames, and a wireless device having a wireless link with a higher received signal strength has a longer frame length and Identification information defined by a larger number of frames is assigned.

  Therefore, it is possible to increase the probability of successfully controlling a wireless device having a wireless link with low received signal strength. In addition, it is possible to reduce the overhead at the time of retransmission of the wakeup signal due to the failure of the control of the wireless device having the wireless link having a small received signal strength.

  Preferably, when the number of hops is detected by the detection unit, the allocation unit executes the allocation process while allocating the same identification information to two wireless devices having a hop count of h (h is an integer of 1 or more) hops or more. .

  Identification information defined by a shorter frame length and a smaller number of frames is reused between wireless devices separated by more than h hops. As a result, the frame length and the number of frames that define the identification information used in the wireless network are reduced.

  Therefore, power consumption due to transmission / reception of identification information in each wireless device can be reduced, and power consumption of the wireless network can be reduced.

  Preferably, when the number of frame transmissions is collected by the collection unit, the allocation unit executes the allocation process from the wireless device having the largest number of frame transmissions to the wireless device having the smallest number of frame transmissions.

  A wireless device with a larger number of frame transmissions is assigned identification information defined by a shorter frame length and a smaller number of frames, and a wireless device with a smaller number of frame transmissions is defined by a longer frame length and a larger number of frames. Identification information is assigned.

  Therefore, a wireless device with a large number of frame transmissions can reduce power consumption required to be controlled even if the number of times of control is increased, and a wireless device with a large number of frame transmissions has a large number of times of control. Even so, the time required for control can be shortened.

  Preferably, when the total number of child nodes is detected by the detection unit, the allocation unit executes an allocation process from a wireless device having the largest number of child nodes to a wireless device having the smallest number of child nodes.

  A wireless device with a larger total number of child nodes is assigned identification information defined by a shorter frame length and a smaller number of frames, and a wireless device with a smaller total number of child nodes is defined by a longer frame length and a larger number of frames. Identification information is assigned.

  Therefore, a wireless device with a large total number of child nodes can reduce power consumption required to be controlled even if the number of controlled times increases, and a wireless device with a large total number of child nodes can be controlled Even if there is a large amount, the time required for control can be shortened.

  According to the embodiment of the present invention, the wireless device controls the other wireless device using the identification information assigned by the wireless device according to any one of claims 1 to 9. The apparatus includes a holding unit and first and second transmission units. The holding unit holds the first identification information assigned to the wireless device and the second identification information assigned to the adjacent wireless device adjacent to the wireless device. The first transmission means generates a number of first radio frames having a frame length that defines the second identification information and equal to the number of frames that defines the second identification information. 1 radio frame is transmitted. The second transmitting unit transmits data when the first transmitting unit receives the first notification indicating that the adjacent wireless device is controllable information after the first transmitting unit transmits the first wireless frame.

  When the assigned identification information is defined by a shorter frame length and a smaller number of frames, power consumption due to transmission of the first radio frame can be reduced. In addition, the time required for transmitting the first radio frame can be shortened.

  Preferably, when an error occurs in the second identification information, the first transmission unit generates a second radio frame having a frame length representing the MAC address of the adjacent radio apparatus as the backup ID, and the generated A second radio frame is transmitted.

  When the second identification information is incorrect, the adjacent wireless device is controlled using the MAC address of the adjacent wireless device.

  Therefore, even if the second identification information is incorrect, the adjacent wireless device can be controlled.

  Furthermore, according to the embodiment of the present invention, the radio apparatus includes a transmission unit, a reception unit, and an allocation unit. The transmitting means transmits a first radio frame having a frame length indicating an identification information allocation request for controlling the radio apparatus. The receiving unit receives an identification information list including identification information of another wireless device and identification information of a wireless device adjacent to the other wireless device. The assigning means is based on the n (n = 0, 1, 2, 3,...) Identification information lists received by the receiving means until the number of transmissions of the first radio frame reaches a reference value. Among the identification information not assigned to other wireless devices, the identification information defined by the shortest frame length and the smallest number of frames is assigned to the wireless device.

  Identification information that is not assigned to the adjacent wireless device is autonomously assigned to the wireless device.

  Accordingly, identification information can be assigned in accordance with the topology of the wireless devices constituting the wireless network.

  Preferably, the transmission unit waits for a certain period of time when the reception unit receives the first radio frame from another radio apparatus, and after the certain period of time has elapsed, the number of transmissions of the first radio frame reaches a reference value. To retransmit the first radio frame.

  More identification information lists are collected, and among the identification information not included in the collected more identification information lists, the identification information defined by the shortest frame length and the smallest number of frames is assigned to the wireless device. It is done.

  Therefore, it can suppress that the same identification information is allocated to the said radio | wireless apparatus and adjacent radio | wireless apparatus.

  Preferably, when the transmission unit determines that there is a wireless device to which the same identification information is assigned between adjacent wireless devices adjacent to the wireless device after assigning the identification information to the wireless device, the identification information is further A reassignment instruction for instructing reassignment is transmitted to the adjacent wireless device.

  Therefore, it is possible to suppress the same identification information from being assigned to a plurality of adjacent wireless devices.

  Preferably, when the assignment unit completes the assignment of the identification information, the transmission unit further includes an assignment completion message including the identification information assigned by the assignment unit and the identification information assigned to the wireless device adjacent to the wireless device. Send.

  The assigned identification information can be shared between the wireless device and the adjacent wireless device.

  Furthermore, according to an embodiment of the present invention, a wireless communication system includes the wireless device according to any one of claims 1 to 15.

  Therefore, power consumption in the wireless communication system can be reduced.

  Further, according to the embodiment of the present invention, in the program for causing a computer to execute, the detecting means detects the topology indicating the arrangement state of the wireless devices constituting the wireless network, and topology information indicating the detected topology. Based on the total number of wireless devices constituting the wireless network, the proximity indicating the degree of proximity from the first wireless device included in the wireless devices constituting the wireless network and collecting data from other wireless devices Index, the number of adjacent wireless devices adjacent to the wireless devices that make up the wireless network, the number of hops between the wireless devices, and the wireless network that is in a lower layer than each wireless device that makes up the wireless network A first step of detecting any of the total number of child nodes existing at a position of 1 hop or more from each wireless device; The number of times the collection means controls the wireless device in a desired time length, the received signal strength in each wireless device, and the number of frames transmitted in the desired time length in each wireless device. The second step of collecting either one of the reference identification information defined by the shortest frame length and the smallest number of frames based on either the detection result by the detection unit or the collection result by the collection unit. Causing the computer to execute a third step of executing allocation processing for assigning identification information for controlling the wireless device to all the wireless devices constituting the wireless network so that the frame length or the frame length and the number of frames sequentially increase. .

  By executing the program according to the embodiment of the present invention, the reference identification is performed using various indices detected based on the topology information indicating the topology of the wireless devices constituting the wireless network or collected various indices. Identification information is assigned to all wireless devices constituting the wireless network so that the frame length or the frame length and the number of frames sequentially increase from the information. As a result, the identification information of the wireless devices constituting the wireless network differs in frame length or frame length and number of frames depending on each wireless device. A wireless device that transmits a signal including identification information to a wireless device to which identification information defined by a shorter frame length and a smaller number of frames is allocated transmits the wireless frame constituting the identification information with less power consumption. .

  Accordingly, power consumption due to transmission of identification information can be reduced.

  In addition, a wireless device to which identification information defined by a shorter frame length and a smaller number of frames is assigned receives a wireless frame constituting the identification information with low power consumption.

  Therefore, power consumption due to reception of identification information can be reduced.

  Preferably, when the number of times of control is collected by the collecting means, in the third step, the assigning means executes assignment processing from the wireless device having the largest number of controls to the wireless device having the smallest number of controls.

  By executing the program according to the embodiment of the present invention, a wireless device with a larger number of times of control is assigned identification information defined by a shorter frame length and a smaller number of frames. Can be reduced. Further, the time required for one control can be shortened.

  Preferably, when the total number of wireless devices is detected by the detecting unit, the allocating unit executes an allocation process based on the total number of wireless devices in the third step.

  By executing the program according to the embodiment of the present invention, the number of identification information to be used is determined depending on the total number of wireless devices. Then, the determined number of pieces of identification information have different frame lengths or frame lengths and frame numbers.

  Therefore, compared to a case where all pieces of identification information are defined by the same number of frames, power consumption due to transmission and reception of identification information in each wireless device can be reduced, and power consumption of the wireless network can be reduced.

  Preferably, when the proximity index is detected by the detecting unit, the allocating unit allocates from the wireless device closest to the first wireless device to the wireless device farthest from the first wireless device in the third step. Execute the process.

  By executing the program according to the embodiment of the present invention, identification information defined by a shorter frame length and a smaller number of frames is assigned to a wireless device closer to the first wireless device. The far radio device is assigned identification information defined by a longer frame number and a larger frame number.

  Therefore, even if the number of times that the wireless device close to the first wireless device is controlled can reduce power consumption when controlled, the wireless device close to the first wireless device is controlled. Even if the number of times increases, the time required for control can be shortened.

  Preferably, when the adjacent wireless device is detected by the detecting unit, the assigning unit assigns from the wireless device having the largest number of adjacent wireless devices to the wireless device having the smallest number of adjacent wireless devices in the third step. Execute the process.

  By executing the program according to the embodiment of the present invention, a wireless device having a larger number of adjacent wireless devices is assigned identification information defined by a shorter frame length and a smaller number of frames, and the number of adjacent wireless devices is reduced. The fewer wireless devices are assigned identification information defined by a longer frame number and a larger frame number.

  Therefore, a wireless device with a large number of adjacent wireless devices can reduce power consumption when controlled even if the number of times of control is increased, and a wireless device with a large number of adjacent wireless devices is controlled. Even if the number of times increases, the time required for control can be shortened.

  Preferably, when the reception signal strength is collected by the collection unit, the allocating unit, in the third step, from the wireless device having the wireless link having the smallest received signal strength to the wireless device having the wireless link having the largest received signal strength The allocation process is executed toward

  By executing the program according to the embodiment of the present invention, identification information defined by a shorter frame length and a smaller number of frames is assigned to a wireless device having a wireless link with a smaller received signal strength, and the received signal strength is reduced. A wireless device having a large wireless link is assigned identification information defined by a longer frame length and a larger number of frames.

  Therefore, it is possible to increase the probability of successfully controlling a wireless device having a wireless link with low received signal strength. In addition, it is possible to reduce overhead at the time of retransmission of a signal including identification information due to a control failure of a wireless device having a wireless link having a small received signal strength.

  Preferably, when the number of hops is detected by the detecting means, the assigning means assigns the same identification information to two wireless devices having the number of hops equal to or greater than h (h is an integer equal to or greater than 1) in the third step. While executing the allocation process.

  By executing the program according to the embodiment of the present invention, identification information defined by a shorter frame length and a smaller number of frames is reused between wireless devices separated by h hops or more. As a result, the frame length and the number of frames that define the identification information used in the wireless network are reduced.

  Therefore, power consumption due to transmission / reception of identification information in each wireless device can be reduced, and power consumption of the wireless network can be reduced.

  Preferably, in the third step, when the number of frame transmissions is collected by the collecting unit in the third step, the allocating unit executes an allocation process from a wireless device having the largest number of frame transmissions to a wireless device having the smallest number of frame transmissions. To do.

  By executing the program according to the embodiment of the present invention, a wireless device with a larger number of frame transmissions is assigned identification information defined by a shorter frame length and a smaller number of frames, and a wireless device with a smaller number of frame transmissions. Identification information defined by a longer frame length and a larger number of frames is assigned.

  Therefore, a wireless device with a large number of frame transmissions can reduce power consumption required to be controlled even if the number of times of control is increased, and a wireless device with a large number of frame transmissions has a large number of times of control. Even so, the time required for control can be shortened.

  Preferably, in the third step, when the total number of child nodes is detected by the detection unit, the allocation unit performs allocation processing from a wireless device having the largest total number of child nodes to a wireless device having the smallest total number of child nodes. Execute.

  By executing the program according to the embodiment of the present invention, a wireless device having a larger total number of child nodes is assigned identification information defined by a shorter frame length and a smaller number of frames, and a wireless device having a smaller total number of child nodes. The device is assigned identification information defined by a longer frame length and a larger number of frames.

  Therefore, a wireless device with a large total number of child nodes can reduce power consumption when controlled even if the number of controlled times increases, and a wireless device with a large total number of child nodes has a controlled number of times. Even if it increases, the time when it is controlled can be shortened.

  Furthermore, according to an embodiment of the present invention, a program for causing a computer to execute the identification information assigned by causing the computer to execute the program according to any one of claims 17 to 25. A program for causing a computer to execute control of another wireless device by using the first identification information assigned to the wireless device and an adjacent wireless device adjacent to the wireless device. The fourth step for holding the second identification information and the first transmission means have a frame length that defines the second identification information, and the number of frames that defines the second identification information. A fifth step of generating an equal number of first radio frames, and transmitting the generated first radio frames, and a second transmission means are provided by the first transmission means. After 1 radio frame is transmitted, upon receiving the first notification that adjacent radio device is a controllable state, a program for executing a sixth step of transmitting the data to the computer.

  By executing the program according to the embodiment of the present invention, when identification information defined by a shorter frame length and a smaller number of frames is assigned, power consumption due to transmission of the first radio frame can be reduced. In addition, the time required for transmitting the first radio frame can be shortened.

  Preferably, when an error occurs in the second identification information, the first transmission means has a second frame length indicating the backup ID generated based on the MAC address of the adjacent wireless device in the fifth step. Is generated, and the generated second radio frame is transmitted.

  By executing the program according to the embodiment of the present invention, when the second identification information is incorrect, the adjacent wireless device is controlled using the MAC address of the adjacent wireless device.

  Therefore, even if the second identification information is incorrect, the adjacent wireless device can be controlled.

  Further, according to the embodiment of the present invention, in the program for causing a computer to execute, the transmission means transmits a first radio frame having a frame length indicating an identification information allocation request for controlling the radio apparatus. A first step of receiving, a second step of receiving an identification information list including identification information D of another wireless device and identification information of a wireless device adjacent to the other wireless device; Based on the n (n = 0, 1, 2, 3,...) Identification information list received by the receiving means until the number of transmissions of the first radio frame reaches the reference value, A third step of assigning to the wireless device the identification information defined by the shortest frame length and the smallest number of frames among the identification information not assigned to the device; It is because of the program.

  By executing the program according to the embodiment of the present invention, identification information that is not assigned to the adjacent wireless device is autonomously assigned to the wireless device.

  Accordingly, identification information can be assigned in accordance with the topology of the wireless devices constituting the wireless network.

  Preferably, when the receiving unit receives the first radio frame from another radio apparatus, the transmitting unit waits for a predetermined time, and when the predetermined time has elapsed, in the first step, the transmitting unit transmits the first radio frame. The first radio frame is retransmitted until the number of times reaches the reference value.

  By executing the program according to the embodiment of the present invention, more identification information lists are collected, and among the identification information not included in the collected more identification information lists, the shortest frame length and the smallest Identification information defined by the number of frames is assigned to the wireless device.

  Therefore, it can suppress that the same identification information is allocated to the said radio | wireless apparatus and adjacent radio | wireless apparatus.

  Preferably, the program to be executed by the computer includes a wireless device in which the same identification information is assigned between adjacent wireless devices adjacent to the wireless device after the transmission unit assigns the identification information to the wireless device. If so, the computer is further caused to execute a seventh step of transmitting a reassignment instruction for instructing reassignment of identification information to the adjacent wireless device.

  By executing the program according to the embodiment of the present invention, it is possible to suppress the same identification information from being assigned to a plurality of adjacent wireless devices.

  Preferably, in the program to be executed by the computer, when the assignment of the identification information by the assignment unit is completed, the transmission unit performs the identification information assigned by the assignment unit and the identification information assigned to the wireless device adjacent to the wireless device. And causing the computer to further execute an eighth step of transmitting an assignment completion message including:

  By executing the program according to the embodiment of the present invention, the assigned identification information can be shared between the wireless device and the adjacent wireless device.

  According to the embodiment of the present invention, power consumption due to transmission of identification information can be reduced.

1 is a schematic diagram of a wireless sensor network according to an embodiment of the present invention. FIG. It is the schematic which shows the structure of the radio | wireless node shown in FIG. It is a block diagram of the control packet DIO. It is a block diagram of control packet DAO. It is a figure which shows the frame length and frame number which comprise wakeup ID. It is a figure which shows the correspondence table which shows the correspondence of frame length and data. It is a block diagram of the routing table which the route control part shown in FIG. 2 holds. It is a figure which shows the arrangement | positioning state of the radio | wireless node in the radio | wireless sensor network shown in FIG. It is a flowchart for demonstrating operation | movement when constructing | assembling a path | route. It is a figure which shows the example of the topology constructed | assembled according to the flowchart shown in FIG. It is a figure which shows the specific example of the routing table shown in FIG. 6 is a diagram illustrating an example in which a wakeup ID is assigned to a wireless node by an assignment method 1. FIG. 10 is a diagram illustrating an example in which a wakeup ID is assigned to a wireless node by an assignment method 3. FIG. 6 is a diagram illustrating an example in which a wakeup ID is assigned to a wireless node by an assignment method 4. FIG. 6 is a diagram illustrating an example in which a wakeup ID is assigned to a wireless node by an assignment method 5. FIG. It is a figure which shows the example which allocated wakeup ID when it is h = 3. 10 is a diagram illustrating an example in which a wakeup ID is assigned to a wireless node by an assignment method 7. FIG. 6 is a diagram illustrating an example in which a wakeup ID is assigned to a wireless node by an assignment method 8. FIG. It is a flowchart for demonstrating the allocation method of the wakeup ID by embodiment of this invention. It is a flowchart which shows the detailed operation | movement of step S23 shown in FIG. It is a figure which shows another corresponding table which shows the correspondence of frame length and data. It is a flowchart explaining the operation | movement which performs autonomous allocation of a wakeup ID. It is a flowchart which shows the interruption routine by an unallocated radio | wireless node. 10 is a flowchart for explaining the operation of an assigned wireless node that has received a wakeup ID assignment request message in autonomous assignment of a wakeup ID. 10 is a flowchart for explaining the operation of an assigned wireless node that has received a wakeup ID reassignment instruction in autonomous assignment of a wakeup ID. It is a figure which shows the operation | movement which starts a wireless node. 3 is a flowchart for explaining a sensor value transfer operation in the wireless sensor network shown in FIG. 1.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a schematic diagram of a wireless sensor network according to an embodiment of the present invention. Referring to FIG. 1, a wireless sensor network 10 according to an embodiment of the present invention includes wireless nodes 1 to 7.

  The wireless nodes 1 to 7 are arranged in the wireless communication space. For example, the wireless nodes 1 to 7 perform wireless communication in a 920 MHz band corresponding to IEEE802.15.4g.

  Each of the wireless nodes 2 to 7 has a sensor.

  The wireless nodes 1 to 7 construct paths from the wireless nodes 2 to 7 to the wireless node 1 using RPL: IPv6 Routing Protocol for Low-Power and Lossy Networks (RFC 6550). Further, the wireless nodes 1 to 7 maintain a route from each of the wireless nodes 2 to 7 to the wireless node 1 using RPL by a method described later.

  When a path from each of the wireless nodes 2 to 7 to the wireless node 1 is established, the wireless sensor network 10 has a topology in which the wireless nodes 1 to 7 are arranged in a hierarchical structure. In this case, the wireless node 1 is arranged in the highest layer, and the wireless nodes 2 to 7 are arranged in a tree shape below the second layer.

  In the embodiment of the present invention, the wireless node 1 is also referred to as “sink”. Based on the topology of the wireless nodes 1 to 7 in the wireless sensor network 10, the wireless node 1 assigns wake-up IDs defined by the frame length and the number of frames to the wireless nodes 1 to 7 by a method described later. The wakeup ID is an ID for shifting each of the wireless nodes 1 to 7 from the sleep state to the activated state.

  When the wireless node 1 assigns the wakeup ID to the wireless nodes 1 to 7, the wireless node 1 transmits the assigned wakeup ID to the wireless nodes 2 to 7. More specifically, the wireless node 1 transmits the wakeup ID assigned to the wireless node 2 and the wakeup IDs of the wireless nodes 1, 3, 5 adjacent to the wireless node 2 to the wireless node 2. Similarly, the wireless node 1 assigns the wakeup ID assigned to each of the wireless nodes 3 to 7 and the wakeup ID assigned to the wireless node adjacent to each of the wireless nodes 3 to 7 to each of the wireless nodes 3 to 7. Send to.

  Each of the wireless nodes 2 to 7 receives its own wakeup ID and the wakeup ID of the wireless node adjacent to itself from the wireless node 1, and receives the received wakeup ID and the wireless adjacent to itself. Holds the wakeup ID of the node.

  Each of the wireless nodes 2 to 7 detects a sensor value by a sensor (not shown). Then, each of the wireless nodes 2 to 7 activates the detected sensor value on the path from the wireless node 1 to the wireless node 1 sequentially using the wake-up ID to the wireless node 1 (= sink). Send.

  In this case, the wireless node existing on the path from each of the wireless nodes 2 to 7 to the wireless node 1 transfers the sensor value received from the other wireless node by a method described later.

  Each of the wireless nodes 1 to 7 activates an adjacent wireless node using the MAC address as a backup ID when the wakeup ID is not assigned or when the wakeup ID is incorrect.

  FIG. 2 is a schematic diagram showing the configuration of the wireless node 1 shown in FIG. Referring to FIG. 2, radio node 1 includes antennas 11 and 12, radio communication unit 13, control unit 14, route control unit 15, allocation unit 16, wakeup signal reception unit 17, and wakeup. A signal determination unit 18.

  The wireless node 1 has a sleep state and an activated state. The sleep state is a state in which the wakeup signal reception unit 17 and the wakeup signal determination unit 18 operate and the wireless communication unit 13, the control unit 14, the path control unit 15, and the allocation unit 16 stop operating.

  The activated state is a state in which the wakeup signal receiving unit 17 and the wakeup signal determining unit 18 stop operating, and the wireless communication unit 13, the control unit 14, the path control unit 15, and the allocation unit 16 are operating. is there.

  The antenna 11 is connected to the wireless communication unit 13. The antenna 12 is connected to the wake-up signal receiving unit 17.

  When receiving the activation signal from the wake-up signal determination unit 18, the wireless communication unit 13 shifts from the sleep state to the activation state. The wireless communication unit 13 has a built-in timer, and performs an intermittent operation at regular intervals T when the wakeup signal reception unit 17 and the wakeup signal determination unit 18 are stopped. In other words, the wireless communication unit 13 shifts to the activation state during the time T_1 of the fixed interval T, and shifts to the sleep state during the time T_2 of the fixed interval T. T_1 and T_2 satisfy T_1 + T_2 = T.

  When establishing a route in the wireless sensor network 10 or maintaining the established route, the wireless communication unit 13 receives a control packet from the control unit 14, modulates the received control packet, and transmits the modulated control packet via the antenna 11. To do. The wireless communication unit 13 receives a control packet via the antenna 11, demodulates the received control packet, and outputs the demodulated control packet to the control unit 14. The control packet is composed of DIO and DAO.

  The wireless communication unit 13 receives a packet including data via the antenna 11, demodulates the received packet, and outputs the demodulated packet to the control unit 14. The wireless communication unit 13 receives a packet including data from the control unit 14, modulates the received packet, and transmits the modulated packet via the antenna 11.

  Furthermore, the wireless communication unit 13 measures the number N of frame transmissions, which is the number of wireless frames transmitted per hour. Then, the wireless communication unit 13 outputs the measured frame transmission number N to the control unit 14.

  When the control unit 14 receives the activation signal from the wakeup signal determination unit 18, the control unit 14 shifts from the sleep state to the activation state. The control unit 14 has a built-in timer. When the wakeup signal receiving unit 17 and the wakeup signal determining unit 18 are stopped, the control unit 14 performs intermittent operation at a constant interval T in the same manner as the wireless communication unit 13. Do.

  When establishing a route in the wireless sensor network 10 or maintaining the established route, the control unit 14 receives a control packet from the route control unit 15 and outputs the received control packet to the wireless communication unit 13. In addition, the control unit 14 receives a control packet from the wireless communication unit 13 and outputs the received control packet to the route control unit 15.

  The control unit 14 receives the frame transmission number N from the wireless communication unit 13 and outputs the received frame transmission number N to the allocation unit 16.

  The control unit 14 receives the wake-up ID assigned to the wireless nodes 1 to 7 from the assignment unit 16. Further, the control unit 14 receives the topology in the wireless sensor network 10 from the route control unit 15. Then, the control unit 14 refers to the topology and detects a wireless node adjacent to each of the wireless nodes 1 to 7. Then, the control unit 14 holds the wakeup ID of the wireless node 1 and the wakeup ID of the wireless node adjacent to the wireless node 1. Further, the control unit 14 generates a packet including the wakeup ID of the wireless node 2 and the wakeup ID of the wireless node adjacent to the wireless node 2, and outputs the generated packet to the wireless communication unit 13. Further, the control unit 14 similarly applies the wakeup ID of the wireless node A (= any of the wireless nodes 3 to 7) and the wireless node adjacent to the wireless node A to each of the wireless nodes 3 to 7. A packet including the wakeup ID is generated, and the generated packet is output to the wireless communication unit 13.

  When the wireless node ADJ adjacent to the wireless node 1 shifts from the sleep state to the activated state, the control unit 14 has a frame length that defines the wake-up ID of the wireless node ADJ that is held, and the wireless node ADJ The number of radio frames equal to the number of frames defining the wakeup ID is generated, and the generated radio frames are output to the radio communication unit 13 as a wakeup signal.

  The control unit 14 receives the MAC address of the wireless node ADJ from the path control unit 15. When the wakeup ID assigned by the assignment unit 16 is incorrect, the control unit 14 calculates a hash value of the MAC address (= backup ID) of the wireless node ADJ. Thereafter, the control unit 14 converts the calculated hash value into a frame length by a method to be described later, generates a radio frame having the converted frame length, and uses the generated radio frame as a wake-up signal as the radio communication unit 13. Output to.

  The control unit 14 receives a sensor value (= data) from a sensor (not shown) and generates a packet including the received sensor value. Then, the control unit 14 outputs the generated packet to the wireless communication unit 13.

  The control unit 14 receives a packet including data from the wireless communication unit 13 and determines whether or not the transmission destination of the received packet is the wireless node 1. Then, when the control unit 14 determines that the transmission destination of the packet is the wireless node 1, the control unit 14 extracts data from the packet and accepts the extracted data. On the other hand, when the control unit 14 determines that the transmission destination of the packet is a wireless node other than the wireless node 1, the control unit 14 outputs a packet including data to the wireless communication unit 13.

  When the path control unit 15 receives the activation signal from the wakeup signal determination unit 18, the path control unit 15 shifts from the sleep state to the activation state. Further, the path control unit 15 performs an intermittent operation at a constant interval T in the same manner as the wireless communication unit 13 when the wakeup signal reception unit 17 and the wakeup signal determination unit 18 are stopped.

  When establishing a route in the wireless sensor network 10 or maintaining the established route, the route control unit 15 generates a control packet and outputs the generated control packet to the control unit 14. The route control unit 15 receives a control packet from the control unit 14 and establishes or maintains a route in the wireless sensor network 10 based on the received control packet. Then, the route control unit 15 holds route information indicating the established or maintained route. In addition, the path control unit 15 holds topology information indicating the topology indicating the arrangement state of the wireless nodes 1 to 7 in the wireless sensor network 10.

  The route control unit 15 detects the MAC address of the wireless node with reference to the route information in response to the request for the MAC address of the wireless node, and outputs the detected MAC address to the control unit 14.

  When the allocating unit 16 receives the activation signal from the wakeup signal determining unit 18, the allocating unit 16 shifts from the sleep state to the activated state. The allocation unit 16 receives topology information from the path control unit 15 in the activated state. Then, the allocating unit 16 refers to the topology information, allocates a wakeup ID defined by the frame length and the number of frames to the wireless nodes 1 to 7 by a method described later, and transmits the allocated wakeup ID to the control unit 14. Output.

  The wake-up signal receiving unit 17 and the wake-up signal determining unit 18 have a built-in timer, and shift to an activated state at regular intervals.

  When detecting the reception power in the activated state, the wakeup signal receiving unit 17 receives the wakeup signal via the antenna 12, detects the received signal of the received wakeup signal at the sampling interval, and detects the detected signal. The frame length is detected based on the detection value. More specifically, the wakeup signal reception unit 17 counts the number of “1” in the detection value, and detects the frame length by multiplying the counted number by the sampling interval. The wakeup signal receiving unit 17 detects the frame length at least once to detect the frame length and the number of frames. Then, wakeup signal reception unit 17 outputs the detected frame length and number of frames to wakeup signal determination unit 18.

  The wakeup signal determination unit 18 holds the wakeup ID (= frame length and number of frames) and MAC address of the wireless node 1 in advance. The wakeup signal determination unit 18 holds a correspondence table indicating the relationship between the frame length and data in advance. Further, the wakeup signal determination unit 18 receives the frame length and the number of frames from the wakeup signal reception unit 17.

  Then, wakeup signal determination unit 18 determines whether or not the received frame length and the number of frames match the frame length and the number of frames that define the wakeup ID. When the wakeup signal determination unit 18 determines that the received frame length and the number of frames match the frame length and the number of frames that define the wakeup ID, the wakeup signal determination unit 18 generates an activation signal to generate the wireless communication unit 13, the control unit 14, Output to the route control unit 15 and the allocation unit 16.

  On the other hand, when the wakeup signal determination unit 18 determines that the received frame length and the number of frames do not match the frame length and the number of frames that define the wakeup ID, the wakeup signal determination unit 18 determines the frame length received from the wakeup signal reception unit 17. Refer to the correspondence table and convert it to data. Then, the wakeup signal determination unit 18 determines whether the converted data matches the held MAC address. When it is determined that the converted data matches the MAC address, the wakeup signal determination unit 18 generates an activation signal and outputs the activation signal to the wireless communication unit 13, the control unit 14, the route control unit 15, and the allocation unit 16.

  On the other hand, when it is determined that the converted data does not match the MAC address, the wakeup signal determination unit 18 discards the frame length and the number of frames and outputs nothing.

  When a broadcast ID or multicast ID, which will be described later, is used, the wakeup signal determination unit 18 generates an activation signal and determines the wireless communication unit 13 when the converted data matches the broadcast ID or multicast ID. The data is output to the control unit 14, the route control unit 15 and the allocation unit 16.

  On the other hand, when it is determined that the converted data does not match the broadcast ID or the multicast ID, the wakeup signal determination unit 18 discards the converted data and outputs nothing.

  The wake-up signal receiving unit 17 and the wake-up signal determining unit 18 shift to the activated state at regular intervals and perform the above-described operation, and when the above-described operation ends, shift to the sleep state. That is, the wakeup signal reception unit 17 and the wakeup signal determination unit 18 perform an intermittent operation.

  Each of the wireless nodes 2 to 7 illustrated in FIG. 1 has a configuration in which the assigning unit 16 is deleted from the wireless node 1 illustrated in FIG. Then, upon receiving the frame transmission number N from the wireless communication unit 13, the control unit 14 of the wireless nodes 2 to 7 generates a packet including the received frame transmission number N, and transmits the generated packet to the wireless communication unit 13 and It transmits to the wireless node 1 (= sink) via the antenna 11.

  FIG. 3 is a configuration diagram of the control packet DIO. Referring to FIG. 3, control packet DIO includes a root address, a transmission destination, a transmission source, an ID storage unit, a Rank, and a DTSN.

  The address of the root is composed of the address of the wireless node 1 that is a sink. The transmission destination includes the address of the wireless node that is the transmission destination of the control packet DIO. The transmission source consists of the address of the wireless node that generated the control packet DIO. The ID storage unit consists of ESSID or PANID. Rank is 256 × n (n is a positive integer), and increases by “256” every time the number of hops from the wireless node 1 (= sink) increases by one. Rank represents that the smaller the numerical value, the closer to the sink (= wireless node 1). The DTSN is a positive integer, and increases by “1” every time one wireless node (= any one of the wireless nodes 1 to 7) generates a new control packet DIO. The DTSN is a criterion for determining whether or not to transmit the control packet DAO when each of the wireless nodes 1 to 7 receives the control packet DIO from the same wireless node. More specifically, when each of the wireless nodes 1 to 7 receives the control packet DIO from the same wireless node, the DTSN of the received control packet DIO increases from the DTSN of the previously received control packet DIO. If it is determined that the DTSN of the received control packet DIO is not greater than the DTSN of the previously received control packet DIO, the control packet DAO is not transmitted. An increase in DTSN corresponds to a change in the parent node.

  FIG. 4 is a configuration diagram of the control packet DAO. Referring to FIG. 4, control packet DAO includes a parent node address, a transmission source, and a DAOSsequence.

  The address of the parent node is present on the sink side by one hop from the wireless node that generates the control packet DAO, and includes the addresses of all the wireless nodes that can wirelessly communicate with the wireless node that generates the control packet DAO.

  The transmission source consists of the address of the wireless node that generates the control packet DAO. DAOSsequence is the sequence number of the control packet DAO. The initial value of DAOSsequence is “240”. DAOSsequence consists of an integer in the range of “0” to “255”. DAOSsequence is incremented each time a new control packet DAO is transmitted. When DAOSsequence is smaller than “128”, the maximum value is “127”, and when DAOSsequence is “128” or more, the maximum value is “255”. DAOSsequence becomes “0” after “255”, and then incremented by “1”.

  Whether or not the control packet DAO is new is determined by the following method. Here, the two DAOS sequences to be compared are A and B, respectively.

(I) When A is “128” to “255” and B is “0” to “127”. When (256 + B−A) is less than or equal to SEQUENCE_WINDOW (= 16), A is more than B small.

  If (256 + B−A) is greater than SEQUENCE_WINDOW (= 16), B is smaller than A.

  Then, it is determined that the control packet DAO having the larger one (A or B) is new.

(Ii) When both values are “127” or less, or “128” or more • When the absolute value of the difference between the two values is SEQUENCE_WINDOW (= 16) or less, the comparison result becomes the result as it is.

  When the absolute value of the difference between the two values is larger than SEQUENCE_WINDOW (= 16), it is determined that the two values A and B cannot be compared.

  In this case, it may be determined that the received control packet DAO is not the latest or the control packet DAO having the last received DAOS sequence is determined to be the latest.

  In the embodiment of the present invention, the following three wakeup IDs are defined.

(1) Unicast ID
(2) Multicast ID
(3) Broadcast ID

  The unicast ID is a wakeup ID indicating an arbitrary wireless node, and is an ID that can uniquely identify a wireless node such as a MAC address of each wireless node.

  The multicast ID is a wake-up ID for shifting a specific group of wireless nodes in the radio wave range to an activated state.

  The multicast ID includes a local multicast ID, a parent multicast ID, and a child multicast ID.

  The local multicast ID is a wake-up ID for shifting a wireless node of the same system represented by ESSID or PANID to an activated state.

  The Parent multicast ID is a wake-up ID indicating a wireless node group that can become a parent node when viewed from the wireless nodes 2 to 7 in the wireless sensor network 10.

  The child multicast ID is a wake-up ID indicating a wireless node group accommodated as a child node when viewed from the wireless nodes 1 to 7 in the wireless sensor network 10.

  The broadcast ID is a wake-up ID that can shift all wireless nodes in the radio wave range to the activated state, and is determined in advance in the wireless sensor network 10. The broadcast ID is set in advance in the route control unit 15 of the wireless nodes 1 to 7.

  In the embodiment of the present invention, the above-described unicast ID, multicast ID, and broadcast ID are used as the wake-up ID.

  FIG. 5 is a diagram showing the frame length and the number of frames constituting the wakeup ID. Note that the allocation table TBL1 shown in FIG. 5 is based on the premise that the number of bits that can be expressed by one frame length is 4 bits.

  Referring to FIG. 5, allocation table TBL1 includes a wakeup ID (hereinafter referred to as “WuID”), a first frame length, a second frame length, a third frame length,. Is an integer greater than or equal to 1).

  WuID is defined by at least one frame length and at least one frame number. WuID1 is defined by a frame length of 10.8 [ms] and the number of one frame. WuID2 is defined by a frame length of 12.8 [ms] and the number of one frame. Similarly, WuID3 to WuID16 are 14.8 [ms], 16.8 [ms], 18.8 [ms], 20.8 [ms], 22.8 [ms], and 24.8, respectively. [Ms], 26.8 [ms], 28.8 [ms], 30.8 [ms], 32.8 [ms], 34.8 [ms], 36.8 [ms], 38.8 [ms] ms], 40.8 [ms] and the number of frames.

The frame length of 10.8 [ms] is the shortest frame length in the wireless system used in the wireless sensor network 10. Then, 2 [ms] was added as needed to identify the frame length as an interval to obtain a frame length of 12.8 [ms] to 40.8 [ms]. Therefore, when one WuID is represented by one frame length, the identifiable WuIDs are 16 WuID1 to WuID16. This is because 2 ⁴ = 16 because one frame length represents 4 bits. WuID1 to WuID16 are defined by one frame length and one frame number assigned in ascending order.

  When it is necessary to create 17 or more WuIDs, the 17th and subsequent WuIDs are defined by two frame lengths and two frame numbers.

  More specifically, WuID 17 is defined by a frame length of 10.8 [ms], 12.8 [ms] and a number of two frames. WuID 18 is defined by a frame length of 12.8 [ms] and 14.8 [ms] and a number of two frames. WuID 19 is defined by a frame length of 14.8 [ms], 16.8 [ms] and the number of two frames. WuID 20 is defined by a frame length of 16.8 [ms] and 18.8 [ms] and a number of two frames. Hereinafter, similarly, WuID 31 is defined by a frame length of 38.8 [ms], 40.8 [ms] and the number of two frames.

  WuID17 to WuID31 are defined by two frame lengths and two frame numbers assigned in ascending order of the sum of the first frame length and the second frame length.

  When 32 or more WuIDs need to be created, the WuID 32 is defined by a frame length of 10.8 [ms], 12.8 [ms], and 14.8 [ms] and the number of three frames. The WuID 33 is defined by a frame length of 12.8 [ms], 14.8 [ms], 16.8 [ms] and the number of three frames. The 34th and subsequent WuIDs are similarly defined by three frame lengths and three frame numbers. Thus, the 32nd and subsequent WuIDs are defined by the three frame lengths and the three frame numbers assigned in ascending order of the sum of the three frame lengths.

  When WuID cannot be defined by 3 frame lengths and 3 frame numbers, WuID is defined by 4 frame lengths and 4 frame numbers assigned in ascending order of 4 frame lengths. The

  Hereinafter, similarly, WuID is defined by m frame lengths and m frame numbers.

  The assignment unit 16 of the wireless node 1 holds an assignment table TBL1, and assigns wakeup IDs to the wireless nodes 1 to 7 by various methods to be described later with reference to the assignment table TBL1.

In the above description, a case where one frame length represents a 4-bit bit value and 15 WuIDs are defined by two frame lengths and two frame numbers has been described. In this form, even when two frame lengths are the same, it is allowed. Therefore, one frame length represents a bit value of 4 bits, and WuID is represented by two frame lengths and two frame numbers. In the case of defining, 16 × 16 = 256 WuIDs can be defined. In addition, when one frame length represents a 4-bit bit value and the WuID is defined by three frame lengths and three frame numbers, 16 × 16 × 16 = 4096 WuIDs are similarly set. Can be defined. Therefore, when one frame length represents a bit value of 4 bits and WuiD is defined by m frame lengths and the number of m frames, 16 ^m WuIDs can be defined. When the WuID is defined by two or more frame lengths and two or more frame numbers, the frame length and the number of frames are assigned in ascending order of the sum of the two or more frame lengths.

  In the allocation table TBL1, the difference between the two frame lengths is not limited to 2 [ms], but may be other than 2 [ms] as long as the two frame lengths can be identified.

Furthermore, in the allocation table TBL1, one frame length may represent a bit value other than 4 bits. In general, when one frame length (the j is a positive integer) j represents the bit value of the bit, the number of WuID defined by one frame length and the number of one frame will 2 ^j pieces. Therefore, when one frame length represents a bit value of j bits and the WuID is defined by m frame lengths and the number of m frames, (2 ^j ) ^m WuIDs can be defined.

  FIG. 6 is a diagram showing a correspondence table showing the correspondence between frame length and data. Referring to FIG. 6, correspondence table TBL2 includes a frame length and data. The frame length and data are associated with each other.

  The frame length of 11.8 [ms] is associated with 0x0, the frame length of 12.1 [ms] is associated with 0x1, and the frame length of 12.4 [ms] is associated with 0x2. The frame length of 12.7 [ms] is associated with 0x3, the frame length of 13.0 [ms] is associated with 0x4, and the frame length of 13.3 [ms] is associated with 0x5. The frame length of 13.6 [ms] is associated with 0x6.

  The frame length of 13.9 [ms] is associated with 0x7, the frame length of 14.2 [ms] is associated with 0x8, and the frame length of 14.5 [ms] is associated with 0x9. A frame length of 14.8 [ms] is associated with 0xA, a frame length of 15.1 [ms] is associated with 0xB, and a frame length of 15.4 [ms] is associated with 0xC. The frame length of 15.7 [ms] is associated with 0xD, the frame length of 16.0 [ms] is associated with 0xE, and the frame length of 16.3 [ms] is 0xF. Is associated with. Each of 0x0 to 0xF consists of a 4-bit bit value.

  The control unit 14 and the wakeup signal determination unit 18 of each of the wireless nodes 1 to 7 hold a correspondence table TBL2. Then, the control unit 14 of each of the wireless nodes 1 to 7 calculates a hash value of the MAC address, and converts the calculated hash value into a frame length with reference to the correspondence table TBL2.

  The wakeup signal determination unit 18 of each of the wireless nodes 1 to 7 converts the frame length received from the wakeup signal reception unit 17 into data (bit value) with reference to the correspondence table TBL2.

  FIG. 7 is a configuration diagram of the routing table RT held by the route control unit 15 shown in FIG. Referring to FIG. 7, routing table RT includes a transmission destination, a next radio node, a hop count, and a Rank. The transmission destination, the next wireless node, the number of hops, and Rank are associated with each other.

  The transmission destination includes a wake-up signal, control packets DIO and DAO, and a MAC address MACadd of a wireless node that receives the packet. The next wireless node includes the MAC address MACadd_NB of the wireless node adjacent on the transmission side to the wireless node holding the routing table RT on the route to the transmission destination.

  The number of hops consists of the number of hops h from the wireless node holding the routing table RT to the destination wireless node. Rank indicates the degree of proximity of the transmission destination (wireless node) to the sink (= wireless node), and consists of r = 256 × j (= 256, 512, 768,...).

  FIG. 8 is a diagram illustrating an arrangement state of the wireless nodes 1 to 3 in the wireless sensor network 10 illustrated in FIG. 1.

  Referring to FIG. 8, radio nodes 1 to 3 have radio wave ranges REG1 to REG3, respectively. The wireless node 1 exists in a region where the two radio wave ranges REG1 and REG2 overlap. The wireless node 2 exists in an area where the three radio wave ranges REG1 to REG3 overlap. The wireless node 3 exists in a region where the two radio wave ranges REG2 and REG3 overlap.

  In this manner, in the state where there is a wireless node whose own radio wave range does not reach the sink (= wireless node 1), a path from each wireless node 2 to 7 to the sink (= wireless node 1) is constructed.

  A route construction method will be described. FIG. 9 is a flowchart for explaining an operation when a route is constructed. Referring to FIG. 9, when the operation of constructing a route is started, control unit 14 of wireless node 1 (= sink) receives a broadcast ID from route control unit 15 as a wakeup ID of the wakeup signal.

Then, the control unit 14 of the wireless node 1 calculates the hash value of the MAC address of the wireless node 2, 12-bit hash value _{a 1 a 2 a 3 a 4} a 5 a 6 a 7 a 8 a 9 a 10 a ₁₁ a ₁₂ is acquired. Table Consequently, the broadcast ID _{as a 9 a 10 a 11 a 12} = 0x2, a 5 a 6 a 7 a 8 = 0x0, a 1 a 2 a 3 a 4 = 0x3, 0xF, by 0x2,0x0,0x3 Is done.

  Thereafter, the control unit 14 of the wireless node 1 refers to the correspondence table TBL2, and the frame length FL1 of 16.3 [ms] corresponding to 0xF and the frame length FL2 of 12.4 [ms] corresponding to 0x2 , A frame length FL3 of 11.8 [ms] corresponding to 0x0 and a frame length FL4 of 12.7 [ms] corresponding to 0x3 are detected.

  Then, the control unit 14 of the wireless node 1 generates four wireless frames FR1 to FR4 having four frame lengths FL1 to FL4, respectively, and outputs them to the wireless communication unit 13.

  The radio communication unit 13 of the radio node 1 receives the four radio frames FR1 to FR4 from the control unit 14, modulates the received wakeup signal WuS including the four radio frames FR1 to FR4, and modulates the wake-up signal. The up signal WuS is broadcast via the antenna 11 (step S1).

  The wake-up signal receiving unit 17 of the wireless node 2 shifts to an activated state at regular intervals and confirms the presence or absence of received power via the antenna 12. Then, when detecting the received power, the wakeup signal receiver 17 of the wireless node 2 receives the wakeup signal WuS via the antenna 12, and based on the received radio waves of the received wakeup signal WuS, Frame lengths FL1 to FL4 are detected.

  More specifically, the wakeup signal receiving unit 17 of the wireless node 2 receives the wakeup signal via the antenna 12, and detects the received signal of the received wakeup signal at the sampling interval (= 10 μs). To obtain a bit string.

  After that, the wake-up signal receiving unit 17 of the wireless node 2 counts the number of “1” s from the beginning of the bit string, stops the counting when the bit value of the bit string becomes “0”, and stops the counting. The count value is set to the number N1 of “1” and the count value is reset. Thereafter, when the bit value of the bit string becomes “1”, the wake-up signal receiving unit 17 of the wireless node 2 counts the number of “1” until the bit value of the bit string becomes “0”, and the bit value of the bit string is When “0” is reached, the count is stopped, the count value when the count is stopped is set to the number N2 of “1”, and the count value is reset.

  The wake-up signal receiving unit 17 of the wireless node 2 repeats this operation until the end of the bit string to obtain four “1” numbers N1 to N4.

  Then, the wake-up signal receiver 17 of the wireless node 2 multiplies the number N1 by the sampling interval (= 10 μsec) to obtain a frame length of 16.3 [ms], and obtains the sampling interval (= 10 μsec) for the number N2. Multiplication is performed to obtain a frame length of 12.4 [ms], the number N3 is multiplied by a sampling interval (= 10 μs) to obtain a frame length of 11.8 [ms], and a sampling interval (= 10 μs) is obtained for the number N4. ) To obtain a frame length of 12.7 [ms].

  Then, the wakeup signal receiving unit 17 of the wireless node 2 performs a frame length of 16.3 [ms], a frame length of 12.4 [ms], a frame length of 11.8 [ms], and 12.7 [ms]. ] Is output to the wake-up signal determination unit 18.

  The wakeup signal determination unit 18 of the wireless node 2 has a frame length of 16.3 [ms], a frame length of 12.4 [ms], a frame length of 11.8 [ms], and 12.7 [ms]. The frame length is received from the wakeup signal receiving unit 17.

  Then, the wakeup signal determination unit 18 of the wireless node 2 refers to the correspondence table TBL2, detects 0xF corresponding to the frame length of 16.3 [ms], and corresponds to the frame length of 12.4 [ms]. 0x2 is detected, 0x0 corresponding to a frame length of 11.8 [ms] is detected, and 0x3 corresponding to a frame length of 12.7 [ms] is detected. Thereafter, the wakeup signal determination unit 18 of the wireless node 2 obtains a broadcast ID composed of a bit string by arranging 0xF, 0x2, 0x0, and 0x3 in a line.

  Then, the wakeup signal determination unit 18 of the wireless node 2 determines that the broadcast ID matches the previously held wakeup ID (= broadcast ID), generates an activation signal, generates the wireless communication unit 13, the control unit 14, Output to the route control unit 15 and the allocation unit 16. Thereby, the wireless node 2 shifts from the sleep state to the activated state (step S2).

  Thereafter, the control unit 14 of the wireless node 2 generates an activation notification including the MAC address of the wireless node 2 and outputs the generated activation notification to the wireless communication unit 13. The wireless communication unit 13 of the wireless node 2 receives the activation notification from the control unit 14, modulates the received activation notification, and broadcasts the modulated activation notification via the antenna 11.

  The wireless communication unit 13 of the wireless node 1 receives the activation notification via the antenna 11. Then, the control unit 14 of the wireless node 1 receives an activation notification from the wireless communication unit 13.

  When receiving the activation notification, the control unit 14 of the wireless node 1 detects that the wireless node 2 has shifted to the activated state.

  The path controller 15 of the wireless node 1 then sends the root address consisting of the MAC address MACadd1 of the wireless node 1 (= sink), the transmission destination consisting of the MAC address MACadd2 of the wireless node 2, and the wireless node 1 (= sink). A DIO1 = [MACadd1 / MACadd2 / MACadd1 / ESSID / 256/1] including a transmission source consisting of the MAC address MACadd1, an ID storage unit consisting of ESSID or PANID, a Rank consisting of 256, and a DTSN consisting of 1 is generated. Then, the generated DIO1 = [MACadd1 / MACadd2 / MACadd1 / ESSID / 256/1] is output to the control unit 14.

  The control unit 14 of the wireless node 1 receives DIO1 = [MACadd1 / MACadd2 / MACadd1 / ESSID / 256/1] from the path control unit 15 and receives the received DIO1 = [MACadd1 / MACadd2 / MACadd1 / ESSID / 256/1]. Is output to the wireless communication unit 13.

  The wireless communication unit 13 of the wireless node 1 receives DIO1 = [MACadd1 / MACadd2 / MACadd1 / ESSID / 256/1] from the control unit 14 and receives the received DIO1 = [MACadd1 / MACadd2 / MACadd1 / ESSID / 256/1]. Modulate. Then, the wireless communication unit 13 of the wireless node 1 transmits the modulated DIO1 = [MACadd1 / MACadd2 / MACadd1 / ESSID / 256/1] via the antenna 11 (step S3). Thereafter, the wireless node 1 shifts from the activated state to the sleep state.

  On the other hand, the wireless communication unit 13 of the wireless node 2 receives DIO1 = [MACadd1 / MACadd2 / MACadd1 / ESSID / 256/1] via the antenna 11 (step S4), and the received DIO1 = [MACadd1 / MACadd2 // MACadd1 / ESSID / 256/1] is output to the control unit 14.

  The control unit 14 of the wireless node 2 receives DIO1 = [MACadd1 / MACadd2 / MACadd1 / ESSID / 256/1] from the wireless communication unit 13 and receives the received DIO1 = [MACadd1 / MACadd2 / MACadd1 / 256 / ESSID / 256 / 1] is output to the route control unit 15.

  The path control unit 15 of the wireless node 2 receives DIO1 = [MACadd1 / MACadd2 / MACadd1 / ESSID / 256/1] from the control unit 14. Then, the path control unit 15 of the wireless node 2 detects that the root is the wireless node 1 with reference to the head address MACadd1 of the DIO1. Further, the path control unit 15 of the wireless node 2 refers to the second address MACadd2 of DIO1, and detects that the transmission destination of DIO1 is the wireless node 2. Further, the path control unit 15 of the wireless node 2 refers to the third address MACadd1 of DIO1, and detects that the transmission source of DIO1 is the wireless node 1 (= sink). Further, the path control unit 15 of the wireless node 2 takes out the Rank consisting of “256” and the DTSN consisting of “1” from the DIO 1 and holds them. Then, the path control unit 15 of the wireless node 2 detects that the number of hops from the wireless node 1 (= sink) to the wireless node 2 is “1” based on the Rank including “256”. This is because the “256” Rank is the minimum value of the Rank, and the wireless node 2 directly receives the Rank consisting of the minimum value “256” from the wireless node 1 (= sink). The path controller 15 of the wireless node 2 detects that the wireless node 1 (= sink) is the parent node of the wireless node 2 because the wireless node 1 (= sink) has the smallest Rank.

  Then, the route control unit 15 of the wireless node 2 stores MACadd1 in the transmission destination of the routing table RT, stores MACadd1 in the next wireless node, stores “1” in the hop count, and stores “256” in the Rank. Store. Then, the path control unit 15 of the wireless node 2 detects that the Rank of the wireless node 2 is “512” based on the Rank of “256”, and holds the Rank of “512”.

  Thereafter, since the path control unit 15 of the wireless node 2 receives DIO first, it detects that the DTSN has increased based on the DTSN consisting of “1” and determines to transmit DAO.

Then, the control unit 14 of the wireless node 2 generates a unicast ID as a wakeup ID of the wakeup signal in response to a request from the route control unit 15. Since DAO is transmitted to the wireless node 1, the control unit 14 of the wireless node 2 receives the MAC address MACadd 1 of the wireless node 1 from the path control unit 15. Then, the control unit 14 of the wireless node 2 calculates the hash value of the MAC address MACadd1, and the 12-bit hash value b ₁ b ₂ b ₃ b ₄ b ₅ b ₆ b ₇ b ₈ b ₉ b ₁₀ b ₁₁ b ₁₂ To get. As a result, unicast ID _{as b 9 b 10 b 11 b 12} = 0x5, b 5 b 6 b 7 b 8 = 0x2, b 1 b 2 b 3 b 4 = 0x8, the 0x1,0x5,0x2,0x8 expressed.

  After that, the control unit 14 of the wireless node 2 refers to the correspondence table TBL2, and has a frame length FL5 of 12.1 [ms] corresponding to 0x1 and a frame length FL6 of 13.3 [ms] corresponding to 0x5. , A frame length FL7 of 12.4 [ms] corresponding to 0x2 and a frame length FL8 of 14.2 [ms] corresponding to 0x8 are detected.

  Then, the control unit 14 of the wireless node 2 generates four wireless frames FR5 to FR8 having four frame lengths FL5 to FL8, respectively, and outputs them to the wireless communication unit 13.

  The wireless communication unit 13 of the wireless node 2 receives the four wireless frames FR5 to FR8 from the control unit 14, modulates the received wakeup signal WuS including the four wireless frames FR5 to FR8, and modulates the wake-up signal. The up signal WuS is broadcast via the antenna 11 (step S5).

  The wake-up signal receiving unit 17 of the wireless node 1 shifts to an activated state at regular intervals and confirms whether there is received power. Then, when detecting the received power, the wakeup signal receiving unit 17 of the wireless node 1 receives the wakeup signal WuS via the antenna 12, and based on the received radio wave of the received wakeup signal WuS, the method described above Detects four frame lengths FL5 to FL8. Then, the wakeup signal reception unit 17 of the wireless node 1 outputs the four frame lengths FL5 to FL8 to the wakeup signal determination unit 18.

  When the wakeup signal determination unit 18 of the wireless node 1 receives the four frame lengths FL5 to FL8 from the wakeup signal reception unit 17, the wakeup signal determination unit 18 refers to the correspondence table TBL2 and determines the four frame lengths FL5 to FL5 by the method described above. FL8 is converted into bit values 0x1, 0x5, 0x2, and 0x8, respectively, and a unicast ID is acquired.

  Then, the wakeup signal determination unit 18 of the wireless node 1 determines that the unicast ID matches the previously held wakeup ID, generates an activation signal, and generates the wireless communication unit 13, the control unit 14, and the path control unit 15. And output to the allocation unit 16. Thereby, the wireless node 1 shifts from the sleep state to the activated state (step S6).

  Thereafter, the wireless node 1 generates and broadcasts an activation notification by the same method as the wireless node 2.

  Then, in response to the activation notification transmitted from the wireless node 1, the path control unit 15 of the wireless node 2 includes “1”, the address of the parent node including the MAC address MACadd1, the transmission source including the MAC address MACadd2. DAO1 including “DAOSsequence” is generated and output to the control unit 14.

  The control unit 14 of the wireless node 2 receives DAO1 = [MACadd1 / MACadd2 / 1] from the path control unit 15 and outputs the received DAO1 = [MACadd1 / MACadd2 / 1] to the wireless communication unit 13.

  The wireless communication unit 13 of the wireless node 2 receives DAO1 = [MACadd1 / MACadd2 / 1] from the control unit 14 and modulates the received DAO1 = [MACadd1 / MACadd2 / 1]. Then, the wireless communication unit 13 of the wireless node 2 transmits the modulated DAO1 = [MACadd1 / MACadd2 / 1] via the antenna 11 (step S7).

  Thereafter, the wireless node 2 shifts from the activated state to the sleep state.

  The wireless communication unit 13 of the wireless node 1 receives DAO1 = [MACadd1 / MACadd2 / 1] via the antenna 11 (step S8), demodulates the received DAO1 = [MACadd1 / MACadd2 / 1], and controls the control unit 14 to output.

  The control unit 14 of the wireless node 1 receives DAO1 = [MACadd1 / MACadd2 / 1] from the wireless communication unit 13 and outputs the received DAO1 = [MACadd1 / MACadd2 / 1] to the path control unit 15.

  The path control unit 163 of the wireless node 1 receives DAO1 = [MACadd1 / MACadd2 / 1] from the control unit 14. Then, the path control unit 15 of the wireless node 1 detects that the wireless node 2 is a child node of the wireless node 1 with reference to the head address MACadd1 and the second address MACadd2 of the DAO1. This is because the wireless node 1 directly receives DAO 1 from the wireless node 2. Then, the route control unit 15 of the wireless node 2 stores the address MACadd2 in the destination of the routing table RT and the next wireless node, stores “1” in the number of hops, and stores “512” in the Rank. In this case, since the route control unit 15 of the wireless node 1 directly receives DAO 1 from the wireless node 2, it is understood that the number of hops from the wireless node 1 to the wireless node 2 is “1”. Further, since the number of hops from the wireless node 1 to the wireless node 2 is “1”, the route controller 15 of the wireless node 1 understands that the Rank of the wireless node 2 is “512”.

  Thereafter, the wireless node 2 performs the same operation as the operation of the wireless node 1 in step S1, and broadcasts the wakeup signal WuS (step S9).

  Then, the wireless node 3 shifts from the sleep state to the activated state by the same operation as the operation of the wireless node 2 in step S2 (step S10), and broadcasts an activation notification including the address MACadd3.

  Thereafter, when receiving the activation notification, the wireless node 2 transmits DIO by the same operation as the operation of the wireless node 1 in step S3 (step S11), and shifts from the activated state to the sleep state.

  The wireless node 3 receives the DIO (step S12), and stores the route information of the new route in the routing table RT by the same method as the wireless node 2 described above based on the received DIO. Further, the wireless node 3 detects that its own Rank is “768” based on the Rank (= 512) included in the received DIO, and holds the Rank including “768”. Further, the wireless node 3 detects that the numerical value of DTSN included in the received DIO is increasing, and determines to transmit DAO.

  Then, the wireless node 3 unicasts a wakeup signal WuS composed of a wireless frame having a frame length representing a unicast ID by the same operation as the operation of the wireless node 2 in step S5 (step S13).

  The wireless node 2 shifts from the sleep state to the activated state by the same operation as that in step S2 (step S14), and broadcasts an activation notification including the address MACadd2 of the wireless node 2.

  When receiving the activation notification, the wireless node 3 transmits DAO by the same operation as that in step S7 (step S15). Thereafter, the wireless node 3 shifts from the activated state to the sleep state.

  The wireless node 2 receives the DAO (step S16), determines that the received DAO is the latest by the method described above based on the DAOS sequence included in the DAO, and determines that the DAO should be transferred.

  Then, the wireless node 2 transmits a wakeup signal WuS composed of a wireless frame having a frame length representing a unicast ID by the same operation as the operation of step S5 (step S17).

  Then, the wireless node 1 shifts from the sleep state to the activated state by the same operation as that in step S6 (step S18), and broadcasts an activation notification including the address MACadd1 of the wireless node 1.

  After that, when receiving the activation notification, the wireless node 2 transmits DAO by the same operation as that in step S6 (step S19).

  The wireless node 1 receives the DAO (step S20), and since the address of the parent node of the DAO is MACadd2, and the transmission source is the MAC address MACadd3, the MAC address MACadd3 is stored in the transmission destination of the routing table RT. The MAC address MACadd2 is stored in the wireless node, “2” is stored in the hop count, “768” is stored in the Rank, and the routing table RT is updated. Note that the wireless node 1 has already stored in the routing table RT that the number of hops from itself to the wireless node 2 is “1” corresponding to the route having the wireless node 2 as a transmission destination. Therefore, it can be detected that the number of hops from itself to the wireless node 3 is “2”. The wireless node 1 has already been stored in the routing table RT corresponding to the route having the wireless node 2 as the transmission destination, so that the rank of the wireless node 2 is “512”. Since it is the wireless node 2, it can be detected that the Rank of the wireless node 3 is “768”.

  Thereafter, the wireless nodes 1 to 7 repeatedly execute the above-described operation, establish a route from the wireless node 1 to each of the wireless nodes 2 to 7, and create a routing table RT including route information of the established route. Then, the wireless node 1 creates and holds topology information indicating the topology state of the wireless nodes 1 to 7 based on the created routing table RT.

  As described above, in the wireless sensor network 10, when the route is first constructed, the wireless nodes 1 to 7 are shifted from the sleep state to the activated state using the MAC address that is the backup ID. This is because the wake-up ID (= WuID) defined by the frame length and the number of frames is not assigned to each of the wireless nodes 1 to 7.

  In the flowchart shown in FIG. 9, when transmitting DIO, the wireless node 1 broadcasts a wake-up signal to shift the wireless node 2 to the activated state, and then transmits DIO (see steps S1 to S3). And the wireless node 1 will transfer to a sleep state, if transmission of DIO is completed.

  In addition, when the wireless node 2 shifts to the activated state according to the wake-up signal, when receiving the DIO and transmitting DAO, the wireless node 1 unicasts the wake-up signal to shift the wireless node 1 to the activated state, and then DAO is transmitted (see steps S4, S5 and S7). When the wireless node 2 completes the DAO transmission, the wireless node 2 shifts to the sleep state.

  Further, when transmitting the DIO, the wireless node 2 broadcasts a wakeup signal to shift the wireless node 3 to the activated state, and then transmits the DIO (see steps S9 to S11). And the wireless node 2 will transfer to a sleep state, if transmission of DIO is completed.

  Further, when the wireless node 3 shifts to the activated state according to the wake-up signal, when receiving the DIO and transmitting DAO, the wireless node 3 unicasts the wake-up signal to shift the wireless node 2 to the activated state, and then DAO is transmitted (see steps S12, S13, S15). And the wireless node 3 will transfer to a sleep state, if transmission of DAO is completed.

  Further, when the wireless node 2 enters the activated state in response to the wake-up signal, when receiving the DAO and transferring the DAO, the wireless node 1 causes the wireless node 1 to enter the activated state by unicasting the wake-up signal, and then DAO is transmitted (see steps S16, S17, S19). When the wireless node 2 completes the DAO transmission, the wireless node 2 shifts to the sleep state.

  As described above, when each of the wireless nodes 1 to 3 shifts to the activated state, the wireless nodes 1 to 3 perform necessary operations and then shift to the sleep state. In the activated state, when the wireless node 2 needs to transfer the DAO received from the wireless node 3, the wireless node 2 shifts to the sleep state after completing the DAO transfer. As a result, the DAO transmitted from the wireless node 3 is quickly delivered to the wireless node 1. In other words, the wireless nodes 1 to 3 shift to the activated state only when necessary, perform necessary operations, and then shift to the sleep state.

  Therefore, the power consumption of the wireless nodes 1 to 7 can be minimized.

  FIG. 10 is a diagram showing an example of a topology constructed according to the flowchart shown in FIG.

  Referring to FIG. 10, steps S1 to S8 shown in FIG. 9 are executed, whereby wireless node 2 is connected to wireless node 1 (see (a) of FIG. 10).

  Thereafter, steps S9 to S20 shown in FIG. 9 are executed, whereby the wireless node 3 is connected to the wireless node 2 (see FIG. 10B).

  Then, by repeatedly executing steps S1 to S20 shown in FIG. 9, the wireless node 4 is connected to the wireless node 1 (see (c) of FIG. 10), the wireless node 5 is connected to the wireless node 4, The wireless node 6 is connected to the wireless node 4, and the wireless node 7 is connected to the wireless node 5 (see (d) of FIG. 10).

  When the wireless node 1 that is the sink creates the routing table RT, the wireless node 1 receives the control packet DAO created by each of the wireless nodes 2 to 7, and the control packet DAO is received in the received control packet DAO. The address of the parent node of the created wireless node (= any of wireless nodes 2 to 7) is stored. Therefore, the wireless node 1 can grasp the topology shown in FIG. 10D by sequentially receiving the control packet DAO created by each of the wireless nodes 2 to 7.

  As described above, in the wireless sensor network 10, there is no loop-like path, and a tree-structure topology is constructed according to the RPL.

  The wireless node 1 is a sink, and the parent node of the wireless nodes 2 and 4 is the wireless node 1. The wireless node 2 is a parent node of the wireless node 3, and the wireless node 4 is a parent node of the wireless nodes 5 and 6. Further, the wireless node 5 is a parent node of the wireless node 7.

  On the other hand, the wireless nodes 2 and 4 are child nodes of the wireless node 1, the wireless nodes 5 and 6 are child nodes of the wireless node 4, and the wireless node 7 is a child node of the wireless node 5.

  As a result, the wireless node 1 has two wireless nodes 2 and 4 as child nodes, the wireless node 2 has one wireless node 3 as a child node, and the wireless node 4 has two wireless nodes 5 and 6. As a child node, the wireless node 5 has one wireless node 7 as a child node.

  Therefore, the wireless node 1 (= sink) is arranged in the highest layer, the wireless nodes 2 and 4 are arranged in the second layer, the wireless nodes 3, 5, and 6 are arranged in the third layer, and the wireless node 7 is arranged in the first layer. Arranged in four layers.

  In this way, the wireless nodes 1 to 7 construct a topology having a hierarchical structure according to the RPL. In this topology, there is one parent node for each wireless node. Accordingly, the wireless nodes 1 to 7 are arranged in a tree shape from the highest layer to the lower layer.

  Further, when receiving a plurality of DIOs including Ranks having the same value, each wireless node calculates a transmission / reception probability that is the number of DIOs transmitted / received per unit time, and the calculated transmission / reception probability is maximum. The wireless node that transmitted the DIO is selected as the parent node.

  The flowchart shown in FIG. 9 is executed periodically (for example, every 30 minutes), or when a new wireless node enters the wireless sensor network 10, or the parent node of each wireless node 2-7 is changed. Or run when deleted. Further, the flowchart shown in FIG. 9 is executed when the topology changes.

  When a new wireless node enters the wireless sensor network 10, the newly entered wireless node broadcasts DIS, which is a DIO transmission request. Then, when the wireless node that has received DIS transmits DIO, the flowchart shown in FIG. 9 is executed, and a new topology is constructed.

  FIG. 11 is a diagram showing a specific example of the routing table RT shown in FIG. Note that the routing table RT-1 illustrated in FIG. 11 is the routing table RT in the wireless node 5 illustrated in FIG.

  Referring to FIG. 11, the routing table RT-1 of the wireless node 5 includes wireless nodes 1, 4, and 7 as transmission destinations. When the transmission destination is the wireless node 4 (MACadd4), the MAC address MACadd4 of the wireless node 4 is stored in the “next wireless node” corresponding to the transmission destination. Then, “1” is stored in the “hop count” corresponding to the transmission destination. In addition, “512” is stored in “Rank” corresponding to the transmission destination.

  The wireless node 5 receives the control packet DIO generated by the wireless node 4 from the wireless node 4, and detects that the transmission source included in the received control packet DIO is the wireless node 4 (= MACadd4). It is detected that the wireless node 4 is a wireless node adjacent to itself and that the number of hops to the wireless node 4 is “1”. Further, the wireless node 5 detects that “512” is stored in “Rank” included in the control packet DIO received from the wireless node 4, and the “Rank” of the wireless node 4 is “512”. Is detected. Therefore, the wireless node 5 can create route information on the first row of the routing table RT-1.

  When the wireless node 5 detects that “Rank” included in the control packet DIO received from the wireless node 4 is “512” and the “root address” included in the control packet DIO is MACadd1, It is detected that “Rank” of “768” is “768” (= 512 + 256). The wireless node 5 has its own “Rank” of “768”, and “Rank” increases by “256” for each hop. Therefore, “768” is divided by “256”, and the division result is obtained. The number of hops to the wireless node 1 (= 2) is obtained by subtracting “1” from “3”. Note that “1” is subtracted from the division result “3” because “Rank” of the wireless node 1 is “256”, and in order to obtain the number of hops, how many times “Rank” has increased is obtained. It is necessary. Further, since the “root address” is MACadd1, the wireless node 5 understands that “Rank” corresponding to the wireless node 1 as the transmission destination is “256”. Furthermore, since the wireless node 5 receives the control packet DIO from the wireless node 4 and the number of hops to the wireless node 1 is “2”, the “next wireless node” corresponding to the wireless node 1 as the transmission destination is It is detected that the wireless node 4 (= MACadd4). Therefore, the wireless node 5 can create route information on the second row of the routing table RT-1.

  Further, the wireless node 5 receives the control packet DAO from the wireless node 7, and based on the transmission source (= MACadd7) included in the received control packet DAO, the wireless node 7 is a child node adjacent to itself. Is detected. The “parent node address” included in the control packet DAO is MACadd5 (= wireless node 5), and the control packet DAO is a response to the control packet DIO, and is in the upstream direction (from each wireless node 2 to 7 to the wireless node). 1 (direction to 1). Accordingly, the wireless node 5 detects that the wireless node 7 is its own child node. Further, since the wireless node 5 directly receives the control packet DAO from the wireless node 7, it detects that the number of hops to the wireless node 7 is “1”. Further, the wireless node 5 detects that “Rank” of the wireless node 7 is “1024” because its “Rank” is “768” and the number of hops to the wireless node 7 is “1”. To do. Accordingly, the wireless node 5 can create route information on the third row of the routing table RT-1.

  When the wireless node 1 transmits a data packet including data to the wireless node 7, the wireless node 1 transmits route information from the wireless node 1 to the wireless node 7 (= wireless node 1 → wireless node 4 → wireless node 5 → A data packet including the wireless node 7) and data is generated and transmitted. Therefore, each of the wireless nodes 4 and 5 on the route indicated by the route information (= wireless node 1 → wireless node 4 → wireless node 5 → wireless node 7) is route information (= wireless node 1 → wireless node 4 → wireless). By referring to the node 5 → the wireless node 7), it is possible to store route information whose destination is a wireless node 2 hops away from itself in the routing table RT.

  As a result, each of the wireless nodes 2 to 7 can store, in the routing table RT, route information having all the wireless nodes constituting the wireless sensor network 10 as transmission destinations.

  Hereinafter, a method for assigning the wakeup ID (WuID) defined by the frame length and the number of frames to each of the wireless nodes 1 to 7 will be described.

(A) Wakeup ID assignment method 1
FIG. 12 is a diagram illustrating an example in which the wakeup ID is allocated to the wireless nodes 1 to 7 by the allocation method 1.

  When the route in the wireless sensor network 10 is constructed according to the flowchart shown in FIG. 9, the route control unit 15 of the wireless node 1 holds a topology indicating the arrangement state of the wireless nodes 1 to 7 in the wireless sensor network 10.

  Then, the route control unit 15 of the wireless node 1 outputs topology information indicating the topology to be held to the allocation unit 16.

  The allocation unit 16 of the wireless node 1 receives the topology information from the route control unit 15 and detects the total number (= 7) of the wireless nodes 1 to 7 configuring the wireless sensor network 10 based on the received topology information.

  After that, the allocation unit 16 of the wireless node 1 refers to the allocation table TBL1 and extracts seven wakeup IDs from the wakeup ID (WuID1) to the wakeup ID (WuID7). That is, the allocation unit 16 of the wireless node 1 has seven wakeup IDs (WuID1 to WuID7) so that the frame length sequentially increases from the wakeup ID (WuID1) defined by the shortest frame length and the smallest number of frames. To extract. The wakeup ID (WuID1) is referred to as “reference wakeup ID”.

  Then, the assignment unit 16 of the wireless node 1 randomly assigns the extracted seven wakeup IDs (WuID1 to WuID7) to the wireless nodes 1 to 7.

  As a result, for example, wakeup ID (WuID6), wakeup ID (WuID4), wakeup ID (WuID1), wakeup ID (WuID7), wakeup ID (WuID2), wakeup ID (WuID3), wakeup ID (WuID5) is assigned to each of the wireless nodes 1 to 7 (see FIG. 12).

  If the total number of wireless nodes constituting the wireless sensor network 10 is 20, the assignment unit 16 of the wireless node 1 extracts 20 wakeup IDs (= WuID1 to WuID20) from the assignment table TBL1. Then, the assignment unit 16 of the wireless node 1 randomly assigns 20 wakeup IDs (= WuID1 to WuID20) to the 20 wireless nodes. In this case, WuID1 to WuID16 are defined by one frame length and one frame number, and WuID17 to WuID20 are defined by two frame lengths and two frame numbers.

  As described above, the allocating unit 16 of the wireless node 1 detects the total number of wireless nodes constituting the wireless sensor network 10 and frames a number of WuIDs equal to the detected total number of wireless nodes from the reference wakeup ID (WuID1). The length or the frame length and the number of frames are extracted from the assignment table TBL1 so as to increase sequentially, and the extracted WuID is randomly assigned to the wireless nodes constituting the wireless sensor network 10.

  As a result, in the wireless sensor network 10, each wireless node is shifted from the sleep state to the active state using the wakeup ID defined by a shorter frame length and a smaller number of frames. Therefore, the wireless sensor network 10 is defined by a certain number of frames. The power consumption due to transmission of the wakeup ID and the power consumption due to reception of the wakeup ID can be reduced and each wireless node can be shifted from the sleep state to the activated state, compared with the case where the wakeup ID is used.

  When the allocation unit 16 of the wireless node 1 allocates seven wakeup IDs (WuID1 to WuID7) to the wireless nodes 1 to 7, the allocation result is output to the control unit 14.

  The control unit 14 of the wireless node 1 receives the allocation result from the allocation unit 16 and the topology information from the route control unit 15. Then, the control unit 14 of the wireless node 1 detects that the wireless node adjacent to the wireless node 1 is the wireless node 2 based on the topology information. Then, the control unit 14 of the wireless node 1 holds the wakeup ID (WuID6) assigned to the wireless node 1 and the wakeup ID (WuID4) assigned to the wireless node 2 based on the assignment result.

  Further, the control unit 14 of the wireless node 1 determines the wireless nodes 1, 3, 5 adjacent to the wireless node 2, the wireless nodes 2, 4, 6 adjacent to the wireless node 3, and the wireless node 4 based on the topology information. Wireless nodes 3 and 7 adjacent to each other, wireless node 2 adjacent to wireless node 5, wireless node 3 adjacent to wireless node 6, and wireless node 4 adjacent to wireless node 7 are detected.

  Then, based on the assignment result, the control unit 14 of the wireless node 1 wakes up ID (WuID4) assigned to the wireless node 2 and wakeup IDs (WuID6) assigned to the wireless nodes 1, 3 and 5, respectively. , Wakeup ID (WuID1) and wakeup ID (WuID2) are detected.

  Then, the control unit 14 of the wireless node 1 creates a WuID list 1 = [WuID2 / WuID6, WuID1, WuID2] including the wakeup ID (WuID4) and the wakeup ID (WuID6, WuID1, WuID2). The created WuID list 1 = [WuID2 / WuID6, WuID1, WuID2] is transmitted to the wireless node 2 via the wireless communication unit 13 and the antenna 11.

  Further, the control unit 14 of the wireless node 1 determines, based on the assignment result, the wakeup ID (WuID1) assigned to the wireless node 3 and the wakeup ID (WuID4) assigned to the wireless nodes 2, 4, 6 respectively. , Wakeup ID (WuID7) and wakeup ID (WuID3) are detected.

  Then, the control unit 14 of the wireless node 1 creates a WuID list 2 = [WuID1 / WuID4, WuID7, WuID3] including the wakeup ID (WuID1) and the wakeup ID (WuID4, WuID7, WuID3). The created WuID list 2 = [WuID1 / WuID4, WuID7, WuID3] is transmitted to the wireless node 3 via the wireless communication unit 13 and the antenna 11.

  Further, the control unit 14 of the wireless node 1 determines the wakeup ID (WuID7) assigned to the wireless node 4 and the wakeup ID (WuID1) assigned to the wireless nodes 3 and 7 based on the assignment result. An up ID (WuID5) is detected.

  Then, the control unit 14 of the wireless node 1 creates the WuID list 3 = [WuID7 / WuID1, WuID5] including the wakeup ID (WuID7) and the wakeup ID (WuID1, WuID5), and the created WuID list. 3 = [WuID7 / WuID1, WuID5] is transmitted to the wireless node 4 via the wireless communication unit 13 and the antenna 11.

  Furthermore, the control unit 14 of the wireless node 1 detects the wakeup ID (WuID2) assigned to the wireless node 5 and the wakeup ID (WuID4) assigned to the wireless node 2 based on the assignment result.

  Then, the control unit 14 of the wireless node 1 creates a WuID list 4 = [WuID2 / WuID4] including the wakeup ID (WuID2) and the wakeup ID (WuID4), and the created WuID list 4 = [WuID2]. / WuID4] is transmitted to the wireless node 5 via the wireless communication unit 13 and the antenna 11.

  Furthermore, the control unit 14 of the wireless node 1 detects the wakeup ID (WuID3) assigned to the wireless node 6 and the wakeup ID (WuID1) assigned to the wireless node 3 based on the assignment result.

  Then, the control unit 14 of the wireless node 1 creates a WuID list 5 = [WuID3 / WuID1] including the wakeup ID (WuID3) and the wakeup ID (WuID1), and the created WuID list 5 = [WuID3]. / WuID1] is transmitted to the wireless node 6 via the wireless communication unit 13 and the antenna 11.

  Furthermore, the control unit 14 of the wireless node 1 detects the wakeup ID (WuID5) assigned to the wireless node 7 and the wakeup ID (WuID7) assigned to the wireless node 4 based on the assignment result.

  Then, the control unit 14 of the wireless node 1 creates a WuID list 6 = [WuID5 / WuID7] including the wakeup ID (WuID5) and the wakeup ID (WuID7), and the created WuID list 6 = [WuID5]. / WuID7] is transmitted to the wireless node 7 via the wireless communication unit 13 and the antenna 11.

  Thus, when the wireless node 1 assigns the wakeup ID to each of the wireless nodes 1 to 7, the wakeup ID assigned to the wireless node (= any of the wireless nodes 2 to 7) and the wireless node (= wireless node) A WuID list including a wake-up ID assigned to a wireless node adjacent to any one of 2 to 7) is created and transmitted to the wireless node (= any of wireless nodes 2 to 7).

  The control unit 14 of each of the wireless nodes 2 to 7 receives the WuID list from the wireless node 1 and is assigned to the wakeup ID assigned to itself and the wireless node adjacent to itself based on the received WuID list. The wakeup ID is detected and held.

(B) Wakeup ID assignment method 2
When the route in the wireless sensor network 10 is constructed according to the flowchart shown in FIG. 9, the control unit 14 of the wireless nodes 1 to 7 measures the number of activations of the transition from the sleep state to the activated state in a desired time length. Then, the control units 14 of the wireless nodes 2 to 7 transmit the measured number of activations to the wireless node 1.

  The control unit 14 of the wireless node 1 receives the number of activations from the wireless nodes 2 to 7 and outputs the received number of activations and the number of activations measured by itself to the allocation unit 16.

  The allocation unit 16 of the wireless node 1 receives the number of activations of the wireless nodes 1 to 7 from the control unit 14. Then, based on the number of activations of the wireless nodes 1 to 7, the allocation unit 16 of the wireless node 1 moves from the wireless node with the largest number of activations to the wireless node with the smallest number of activations, from the reference wakeup ID to the frame length or A wakeup ID is assigned to each of the wireless nodes 1 to 7 so that the frame length and the number of frames sequentially increase.

  That is, the allocation unit 16 of the wireless node 1 allocates a wakeup ID (WuID) defined by a shorter frame length and a smaller number of frames as the number of activations increases.

  This will be described more specifically. When the activation times of the wireless nodes 1 to 7 are 10 times, 8 times, 7 times, 5 times, 1 time, 3 times, and 2 times, the assignment unit 16 of the wireless node 1 assigns WuID1 to WuID7 to the assignment table TBL1. WuID1 is assigned to wireless node 1, WuID2 is assigned to wireless node 2, WuID3 is assigned to wireless node 3, WuID4 is assigned to wireless node 4, WuID5 is assigned to wireless node 6, and WuID6 is assigned to wireless node 7. Assign WuID 7 to wireless node 5.

  If there are a plurality of wireless nodes having the same activation count, a wake-up ID is randomly assigned to the plurality of wireless nodes.

  As a result, it is possible to reduce the power consumption in the wireless node having a large number of activations and shift the wireless node from the sleep state to the activated state, compared with the case where the wakeup ID defined by a certain number of frames is used.

  When the wireless node 1 assigns the wake-up ID to the wireless nodes 1 to 7, the wireless node 1 transmits the WuID list to the wireless nodes 2 to 7 by the method described above.

(C) Wakeup ID assignment method 3
FIG. 13 is a diagram illustrating an example in which the wakeup ID is allocated to the wireless nodes 1 to 7 by the allocation method 3.

  When the route in the wireless sensor network 10 is constructed according to the flowchart shown in FIG. 9, the assignment unit 16 of the wireless node 1 receives the topology information from the route control unit 15.

  Then, the allocation unit 16 of the wireless node 1 detects a proximity index CLN indicating the proximity of each of the wireless nodes 1 to 7 from the wireless node 1 based on the topology information. The proximity index CLN may be the number of hops from the wireless node 1 or the Rank of each of the wireless nodes 1 to 7.

  When the allocation unit 16 of the wireless node 1 detects the proximity index CLN, the reference wakeup ID is directed from the wireless node closest to the sink (= wireless node 1) toward the wireless node farthest from the sink (= wireless node 1). The wakeup ID is assigned to the wireless nodes 1 to 7 so that the frame length or the frame length and the number of frames sequentially increase from (WuID1).

  That is, the allocating unit 16 of the wireless node 1 allocates a wakeup ID defined by a shorter frame length and a smaller number of frames as it is closer to the wireless node 1 (= sink), and is farther from the wireless node 1 (= sink). The wakeup ID specified by the longer frame length and the larger number of frames is assigned.

  The closer to the wireless node 1 (= sink), the greater the number of activations, and the farther from the wireless node 1 (= sink), the smaller the number of activations. Therefore, the closer to the wireless node 1 (= sync), the power consumption when shifting from the sleep state to the activated state can be reduced by using a wakeup ID defined by a shorter frame length and a smaller number of frames.

  When the wireless node 1 assigns the wake-up ID to the wireless nodes 1 to 7, the wireless node 1 transmits the WuID list to the wireless nodes 2 to 7 by the method described above.

(D) Wakeup ID assignment method 4
FIG. 14 is a diagram illustrating an example in which the wakeup ID is allocated to the wireless nodes 1 to 7 by the allocation method 4.

  When the route in the wireless sensor network 10 is constructed according to the flowchart shown in FIG. 9, the assignment unit 16 of the wireless node 1 receives the topology information from the route control unit 15.

  Then, the allocation unit 16 of the wireless node 1 detects the number of adjacent wireless nodes adjacent to each of the wireless nodes 1 to 7 based on the topology information. In the case illustrated in FIG. 14, the number of wireless nodes adjacent to the wireless node 1 is 1, the number of wireless nodes adjacent to the wireless node 2 is 3, and the number of wireless nodes adjacent to the wireless node 3. Is four, the number of wireless nodes adjacent to the wireless node 4 is one, the number of wireless nodes adjacent to the wireless node 5 is one, and the number of wireless nodes adjacent to the wireless node 6 is one. The number is one, and the number of wireless nodes adjacent to the wireless node 7 is one.

  When the assignment unit 16 of the wireless node 1 detects the number of adjacent wireless nodes for each of the wireless nodes 1 to 7, the wireless node 1 moves from the wireless node having the largest number of adjacent wireless nodes to the wireless node having the smallest number of adjacent wireless nodes. The wakeup IDs are assigned to the wireless nodes 1 to 7 so that the frame length or the number of frames and the number of frames sequentially increase from the reference wakeup ID (WuID1).

  More specifically, the assignment unit 16 of the wireless node 1 assigns a wake-up ID (WuID1) to the wireless node 3 having the largest number of adjacent wireless nodes, and the wireless node 2 having the second largest number of adjacent wireless nodes. A wakeup ID (WuID2) is assigned. Since the number of wireless nodes adjacent to the wireless nodes 1 and 4 to 7 is the same (= 1), the allocation unit 16 of the wireless node 1 randomly assigns WuID3 to WuID7 to the wireless nodes 1 and 4 to 7. assign.

  A wireless node with a large number of adjacent wireless nodes has a higher number of transitions from the sleep state to the activated state, and thus, as the number of adjacent wireless nodes increases, the number of adjacent wireless nodes is defined by a shorter frame length and a smaller number of frames. By assigning the wake-up ID, it is possible to reduce power consumption and shift from the sleep state to the activated state.

  When the wireless node 1 assigns the wake-up ID to the wireless nodes 1 to 7, the wireless node 1 transmits the WuID list to the wireless nodes 2 to 7 by the method described above.

(E) Wakeup ID assignment method 5
FIG. 15 is a diagram illustrating an example in which the wakeup ID is assigned to the wireless nodes 1 to 7 by the assignment method 5.

  When the route in the wireless sensor network 10 is constructed according to the flowchart shown in FIG. 9, the wireless communication unit 13 of each of the wireless nodes 1 to 7 receives the received signal strength RSSI when the control packet or the data packet is received from the adjacent wireless node. Is detected. In this case, when the wireless communication unit 13 of each of the wireless nodes 1 to 7 has a plurality of wireless links with adjacent wireless nodes, the wireless communication unit 13 detects the received signal strength RSSI for all of the plurality of wireless links.

  Then, the wireless communication unit 13 of each of the wireless nodes 1 to 7 outputs the detected received signal strength RSSI to the control unit 14.

  When receiving the received signal strength RSSI, the control unit 14 of the wireless node 1 outputs the received received signal strength RSSI to the assigning unit 16.

  When receiving the received signal strength RSSI, the control unit 14 of the wireless nodes 2 to 7 generates a packet PKT_RSSI including the received received signal strength RSSI and the MAC addresses of the wireless nodes 2 to 7, and generates the generated packet PKT_RSSI. It transmits to the wireless node 1 via the wireless communication unit 13. In this case, when transmitting the plurality of received signal strengths RSSI, the control units 14 of the wireless nodes 2 to 7 transmit the received signal strengths RSSI to the wireless node 1 in association with the adjacent wireless nodes.

  The wireless communication unit 13 of the wireless node 1 receives the packet PKT_RSSI from the wireless nodes 2 to 7, outputs the received packet PKT_RSSI to the control unit 14, and the control unit 14 outputs the packet PKT_RSSI to the allocation unit 16.

  When receiving the packet PKT_RSSI, the allocating unit 16 of the wireless node 1 extracts the received signal strength RSSI from the packet PKT_RSSI.

  In this case, the allocating unit 16 of the wireless node 1 receives the received signal strength RSSI (= −65 dBm) associated with the wireless node 1 as the received signal strength RSSI in the wireless node 2 and the received signal strength associated with the wireless node 3. The signal strength RSSI (= −70 dBm) and the received signal strength RSSI (= −60 dBm) associated with the wireless node 5 are extracted. Further, the allocating unit 16 of the wireless node 1 receives the received signal strength RSSI (= −70 dBm) associated with the wireless node 2 and the received signal associated with the wireless node 4 as the received signal strength RSSI in the wireless node 3. The strength RSSI (= −65 dBm) and the received signal strength RSSI (= −75 dBm) associated with the wireless node 6 are extracted. Further, the allocating unit 16 of the wireless node 1 receives the received signal strength RSSI (= −70 dBm) associated with the wireless node 3 as the received signal strength RSSI at the wireless node 4 and the received signal associated with the wireless node 7. The intensity RSSI (= -85 dBm) is taken out. Further, the allocating unit 16 of the wireless node 1 extracts the received signal strength RSSI (= −65 dBm) associated with the wireless node 2 as the received signal strength RSSI in the wireless node 5. Furthermore, the allocation unit 16 of the wireless node 1 extracts the received signal strength RSSI (= −70 dBm) associated with the wireless node 3 as the received signal strength RSSI in the wireless node 6. Furthermore, the allocating unit 16 of the wireless node 1 extracts the received signal strength RSSI (= −80 dBm) associated with the wireless node 4 as the received signal strength RSSI in the wireless node 7.

  Then, the allocating unit 16 of the wireless node 1 detects the smallest received signal strength RSSI for the wireless node having a plurality of wireless links. That is, the allocation unit 16 of the wireless node 1 detects a received signal strength RSSI of −70 dBm for the wireless node 2, detects a received signal strength RSSI of −75 dBm for the wireless node 3, and detects the received signal strength RSSI of the wireless node 4. , −85 dBm received signal strength RSSI is detected.

  Then, the allocating unit 16 of the wireless node 1 starts from the reference wakeup ID (WuID1) from the wireless node having the wireless link having the smallest received signal strength RSSI toward the wireless node having the wireless link having the largest received signal strength RSSI. The wakeup ID is assigned to the wireless nodes 1 to 7 so that the frame length or the frame length and the number of frames increase.

  More specifically, the assigning unit 16 of the wireless node 1 assigns a wakeup ID (WuID1) to the wireless node 4 having the wireless link with the smallest received signal strength RSSI, and the wireless link with the second smallest received signal strength RSSI. A wakeup ID (WuID2) is assigned to the wireless node 7 having The assigning unit 16 of the wireless node 1 assigns a wake-up ID (WuID3) to the wireless node 3 having the wireless link with the third smallest received signal strength RSSI, and has the wireless link with the fourth smallest received signal strength RSSI. Wakeup IDs (WuID4, WuID5) are randomly assigned to the wireless nodes 2 and 6. Further, the assigning unit 16 of the wireless node 1 assigns a wakeup ID (WuID6) to the wireless node 5 having the wireless link with the fifth smallest received signal strength RSSI, and the wireless node having the wireless link with the largest received signal strength RSSI. 1 is assigned a wakeup ID (WuID7).

  In this way, by assigning a wakeup ID (WuID) defined by a shorter frame length and a smaller number of frames to a radio node having a radio link having a small received signal strength RSSI, a radio link having a small received signal strength RSSI It is possible to reduce the probability that a wireless node having a failure to transition from the sleep state to the active state. Further, it is possible to reduce the overhead when the activation fails and the wakeup signal is retransmitted.

  Further, the allocating unit 16 of the wireless node 1 holds the threshold RSSI_REF of the received signal strength RSSI, and gives priority to a wireless node having a wireless link whose received signal strength RSSI is smaller than the threshold RSSI_REF. A wake-up ID (WuID) defined by a short frame length and a smaller number of frames may be assigned. In this case, when there are a plurality of radio nodes having radio links whose received signal strength RSSI is smaller than the threshold RSSI_REF, the wake-up ID ( WuID) is randomly assigned. In addition, when there are a plurality of radio nodes having radio links whose received signal strength RSSI is equal to or greater than the threshold RSSI_REF, the wake-up IDs (WuID) are arranged in the order of the short frame length and / or the few frames in the radio nodes. ) At random.

  The above-described effect can be obtained even when the wakeup ID (WuID) is assigned in this way.

  When the wireless node 1 assigns the wake-up ID to the wireless nodes 1 to 7, the wireless node 1 transmits the WuID list to the wireless nodes 2 to 7 by the method described above.

(F) Wake-up ID assignment method 6
When the route in the wireless sensor network 10 is constructed according to the flowchart shown in FIG. 9, the allocation unit 16 of the wireless node 1 wakes up the same wake to wireless nodes separated by h (h is an integer of 1 or more) hops based on the topology information. While assigning the up ID (WuID), the wakeup ID (WuID) is assigned so that the frame length or the frame length and the number of frames sequentially increase from the reference wakeup ID.

  When h = 1, in order to assign the same wakeup ID (WuID) to all the wireless nodes 1 to 7, all the wireless nodes adjacent to the wireless node that transmitted the wakeup signal shift from the sleep state to the activated state. .

  When h = 2, there is a possibility that a plurality of wireless nodes adjacent to the wireless node that has transmitted the wakeup signal shift from the sleep state to the activated state.

  When h = 3, only one wireless node adjacent to the wireless node that has transmitted the wakeup signal shifts from the sleep state to the activated state.

  FIG. 16 is a diagram illustrating an example in which a wakeup ID is assigned when h = 3. Referring to FIG. 16, when the wakeup ID (WuID1) is assigned to the wireless node 1, the wakeup ID (WuID1) is assigned to the wireless node 4 existing at a 3-hop position from the wireless node 1. The wireless node 6 exists at a position of 3 hops from the wireless node 1, but exists at a position of 2 hops less than 3 hops from the wireless node 4, so that the wakeup ID (WuID 1) is assigned to the wireless node 6. Absent.

  Since the wireless node 2 exists at a position one hop away from the wireless node 1, a wakeup ID (WuID2) different from the wakeup ID (WuID1) is assigned to the wireless node 2. Then, a wakeup ID (WuID2) is assigned to the wireless node 7 existing at a position of 3 hops from the wireless node 2.

  Since the wireless node 3 exists at a position one hop away from the wireless node 2, a wakeup ID (WuID3) different from the wakeup ID (WuID2) is assigned to the wireless node 3.

  Since the wireless node 5 exists at a 2-hop position from the wireless node 3, a wakeup ID (WuID4) different from the wakeup ID (WuID3) is assigned to the wireless node 5.

  Since the wireless node 6 exists at a position of 3 hops from the wireless node 5, a wakeup ID (WuID4) is assigned to the wireless node 6.

  As a result, when the wireless node 2 transmits WuID1, only the wireless node 1 is activated, and when the wireless node 7 transmits WuID1, only the wireless node 4 is activated.

  Further, when the wireless node 2 transmits WuiD4, only the wireless node 5 is activated, and when the wireless node 3 transmits WuID4, only the wireless node 6 is activated.

  Furthermore, when the wireless node 1 transmits WuID2, only the wireless node 2 is activated, and when the wireless node 4 transmits WuID2, only the wireless node 7 is activated.

  Furthermore, when the wireless node 3 transmits WuID2, only the wireless node 2 is activated, and when the wireless node 5 transmits WuID2, only the wireless node 2 is activated.

  Further, when the wireless node 6 transmits WuID3, only the wireless node 3 is activated, and when the wireless node 3 transmits WuID1, only the wireless node 4 is activated.

  Therefore, even if the same wakeup ID is assigned to wireless nodes that are three hops away, only one wireless node is activated.

  Even if the same wakeup ID is assigned to a radio node that is 3 hops away, only one radio node is activated. Therefore, even if the same wakeup ID is assigned to a radio node that is 4 hops away or more, one radio Only the node starts.

  In this way, by assigning the same wakeup ID to radio nodes that are h hops away from each other in the order of short frame length and / or low frame number, the frame length to be used can be shortened and the number of frames to be used can be reduced. .

  As a result, power consumption when starting up the wireless nodes 1 to 7 constituting the wireless sensor network 10 can be reduced.

  When the wireless node 1 assigns the wake-up ID to the wireless nodes 1 to 7, the wireless node 1 transmits the WuID list to the wireless nodes 2 to 7 by the method described above.

(G) Wakeup ID assignment method 7
FIG. 17 is a diagram illustrating an example in which the wakeup ID is allocated to the wireless nodes 1 to 7 by the allocation method 7.

  When the route in the wireless sensor network 10 is established according to the flowchart shown in FIG. 9, each of the wireless nodes 1 to 7 acquires the frame transmission number N. A method for obtaining the frame transmission number N will be described.

  The control unit 14 of each wireless node 1 to 7 has a sensor value (= data) collection period in the wireless sensor network 10, a transmission interval of control frames (DIO, DAO), and a tree size (total number of child nodes) obtained from the topology. The number N of frame transmissions is calculated based on the communication quality of the link.

  Here, the total number of child nodes is located in a lower hierarchy than the wireless node that calculates the frame transmission number N, and is sent to the sink (= wireless node 1) via the wireless node that calculates the frame transmission number N. This is the total number of wireless nodes that can transmit the value. Also, it is assumed that the sensor values transmitted from all the child nodes reach the wireless node that calculates the frame transmission number N within the sensor value collection cycle. Further, it is assumed that only the control packet DIO is transmitted among the control packets DIO and DAO. This is because when the sensor value is collected in the sink (= wireless node 1), the topology of the wireless sensor network 10 is stable and the control packet DAO is not transmitted. Further, the communication quality of the link consists of the arrival rate of the radio frame to the radio node for calculating the number N of frame transmissions, or a magnification using the received signal strength RSSI. The arrival rate of the radio frame is calculated from the past communication status, and the number of radio frames actually reached the radio node for calculating the number N of frame transmissions is the number of radio frames transmitted from the source radio node. Calculated by dividing.

  When calculating the number N of frame transmissions using this method, the control unit 14, for example, collects sensor values for 1 minute, the transmission interval of control frames for 5 minutes, the total number of 100 child nodes, Based on the arrival rate of 20%, the frame transmission number N of (60 × 100 + 12) /0.2=30060 [number / h] is calculated.

  The reason why the total number of child nodes is used in this method is that the sensor values are collected in the sink (= wireless node 1) existing at the highest level.

  Also, when the received signal strength RSSI is used as the communication quality of the link, if RSSI ≧ −20 dBm, the magnification is 1 ×, and if −50 dBm ≦ RSSI <−20 dBm, the magnification is 2 ×, −80 dBm If RSSI <−50 dBm, the magnification is 5 times, and if RSSI <−80 dBm, the magnification is 10 times. Therefore, the control unit 14, for example, based on a sensor value collection period of 1 minute, a control frame transmission interval of 5 minutes, a total number of 100 child nodes, and −50 dBm ≦ RSSI <−20 dBm, The frame transmission number N of (60 × 100 + 12) × 2 = 1,024 [pieces / h] is calculated.

  Thus, by calculating the number N of frame transmissions using the communication quality of the link, the number N of frame transmissions is always the number of radio frames reached, and the accuracy of the number N of frame transmissions can be improved.

  When calculating the number N of frame transmissions using the above-described method, the control unit 14 holds the sensor value collection period in advance, receives the control frame transmission interval from the path control unit 15, and receives the control frame transmission interval from the path control unit 15. The tree size (total number of child nodes) is obtained based on the received topology information.

  By calculating the frame transmission number N by the method described above, the frame transmission number N can be easily obtained.

  Further, the control unit 14 may receive the number N of frame transmissions actually measured by the wireless communication unit 13 from the wireless communication unit 13.

  By actually measuring the frame transmission number N, the frame transmission number N in accordance with the wireless sensor network 10 can be obtained.

  When the control unit 14 of the wireless node 1 acquires the frame transmission number N by the method described above, the control unit 14 outputs the acquired frame transmission number N to the allocation unit 16. Moreover, if the control part 14 of the radio | wireless nodes 2-7 acquires the frame transmission number N by the method mentioned above, the packet containing the acquired frame transmission number N will be produced | generated. Then, the control unit 14 of the wireless nodes 2 to 7 transmits the generated packet to the wireless node 1 (= sink) via the wireless communication unit 13 and the antenna 11.

  The wireless communication unit 13 of the wireless node 1 receives a packet including the frame transmission number N from the wireless nodes 2 to 7, demodulates the received packet, and outputs the demodulated packet to the control unit 14. The control unit 14 of the wireless node 1 receives the packet from the wireless communication unit 13, extracts the transmission source address and the frame transmission number N from the received packet, and sets the extracted transmission source address and frame transmission number N to each other. And output to the assigning unit 16.

  The allocating unit 16 of the wireless node 1 receives the transmission source address and the frame transmission number N from the control unit 14, and holds the received transmission source address and the frame transmission number N in association with each other.

  The frame transmission number N of the wireless nodes 1 to 7 is, for example, as shown in FIG. When the allocation unit 16 of the wireless node 1 collects the number N of frame transmissions of the wireless nodes 1 to 7, the reference wakeup ID is directed from the wireless node having the largest frame transmission number N toward the wireless node having the smallest frame transmission number N. The wakeup ID is assigned to the wireless nodes 1 to 7 so that the frame length or the frame length and the number of frames increase from (WuID1).

  More specifically, the assignment unit 16 of the wireless node 1 assigns a wakeup ID (WuID1) to the wireless node 2 having the largest number of frame transmissions N, and wakes up to the wireless node 3 having the second largest number of frame transmissions N. An ID (WuID2) is assigned. The allocation unit 16 of the wireless node 1 allocates a wakeup ID (WuID3) to the wireless node 4 having the third largest number of frame transmissions N, and wakes up ID (WuID3) to the wireless node 6 having the fourth largest number of frame transmissions N. Assign WuID4). Furthermore, the allocating unit 16 of the wireless node 1 assigns a wakeup ID (WuID5) to the wireless node 7 having the fifth largest number of frame transmissions N, and wakes up ID (WuID5) to the wireless node 5 having the sixth largest number of frame transmissions N. WuID6) is assigned, and a wakeup ID (WuID7) is assigned to the wireless node 1 with the smallest number N of frame transmissions.

  In this way, as the number N of frame transmissions increases, power consumption due to transmission and reception of wakeup IDs can be reduced by assigning a wakeup ID defined by a shorter frame length and a smaller number of frames.

  When the wireless node 1 assigns the wake-up ID to the wireless nodes 1 to 7, the wireless node 1 transmits the WuID list to the wireless nodes 2 to 7 by the method described above.

(H) Wakeup ID assignment method 8
FIG. 18 is a diagram illustrating an example in which the wakeup ID is assigned to the wireless nodes 1 to 7 by the assignment method 8.

  When the route in the wireless sensor network 10 is constructed according to the flowchart shown in FIG. 9, the assignment unit 16 of the wireless node 1 receives the topology information from the route control unit 15. Then, the allocation unit 16 of the wireless node 1 detects the total number of child nodes of the wireless nodes 1 to 7 based on the topology information.

  Then, the assignment unit 16 of the wireless node 1 moves from the wireless node having the largest total number of child nodes to the wireless node having the smallest total number of child nodes, from the reference wakeup ID (WuID1) to the frame length or the frame length and the number of frames. The wakeup ID is assigned to the wireless nodes 1 to 7 so as to increase.

  More specifically, the assignment unit 16 of the wireless node 1 assigns a wakeup ID (WuID1) to the wireless node 1 having the largest number of child nodes, and wakes up to the wireless node 2 having the second largest number of child nodes. An ID (WuID2) is assigned. The allocation unit 16 of the wireless node 1 allocates a wakeup ID (WuID3) to the wireless node 3 having the third largest total number of child nodes, and wakes up IDs (WuID3) to the wireless nodes 4 to 7 having the smallest total number of child nodes. WuID6, WuID4, WuID5, WuID7) are randomly assigned.

  In this way, the larger the total number of child nodes, the lower the power consumption due to the transmission and reception of the wakeup ID by assigning the wakeup ID defined by the shorter frame length and the smaller number of frames.

  When the wireless node 1 assigns the wake-up ID to the wireless nodes 1 to 7, the wireless node 1 transmits the WuID list to the wireless nodes 2 to 7 by the method described above.

  FIG. 19 is a flowchart for illustrating a method for assigning a wakeup ID according to the embodiment of the present invention.

  Referring to FIG. 19, when the operation for assigning the wakeup ID is started, the route control unit 15 of the wireless node 1 detects the topology indicating the arrangement state of the wireless nodes 1 to 7 constituting the wireless sensor net arc 10. (Step S21), and outputs the detected topology to the assigning unit 16.

  Then, the allocating unit 16 of the wireless node 1 receives the topology from the route control unit 15, and based on the topology information indicating the received topology, the total number of wireless nodes 1 to 7 constituting the wireless sensor network 10 and the sink (= The proximity index CLN indicating the degree of proximity from the wireless node 1), the number of adjacent wireless nodes adjacent to each of the wireless nodes 1 to 7, the number of hops between the wireless nodes, and the tree size (= total number of child nodes) Any one of them is detected, and the number of activations of each of the wireless nodes 1 to 7, the received signal strength RSSI of each of the wireless nodes 1 to 7, and the number N of frame transmissions of each of the wireless nodes 1 to 7 are collected (step S22).

  Thereafter, the allocation unit 16 of the wireless node 1 determines the frame length or the frame length and the number of frames from the reference wakeup ID defined by the shortest frame length and the smallest number of frames based on the detection result or the collection result in step S22. Allocation processing ASGN for assigning wakeup IDs to all the wireless nodes 1 to 7 so as to increase sequentially is executed (step S23).

  This completes the operation of assigning the wakeup ID.

  FIG. 20 is a flowchart showing the detailed operation of step S23 shown in FIG. Referring to FIG. 20, after step S22 of FIG. 19, the assignment unit 16 of the wireless node 1 determines whether the total number of wireless nodes has been detected (step S231).

  When it is determined in step S231 that the total number of radio nodes has been detected, the allocating unit 16 of the radio node 1 executes an allocation process ASGN based on the total number of radio nodes (step S232).

  On the other hand, when it is determined in step S231 that the total number of wireless nodes has not been detected, the assignment unit 16 of the wireless node 1 further determines whether or not the number of activations of the wireless node has been collected (step S233).

  When it is determined in step S233 that the number of activations of the wireless node has been collected, the allocation unit 16 of the wireless node 1 executes the allocation process ASGN from the wireless node with the largest number of activations to the wireless node with the smallest number of activations. (Step S234).

  On the other hand, when it is determined in step S233 that the number of activations of the wireless node has not been collected, the assignment unit 16 of the wireless node 1 further determines whether or not the proximity index CLN has been detected (step S235).

  When it is determined in step S235 that the proximity index CLN has been detected, the allocating unit 16 of the wireless node 1 transmits the wireless node farthest from the sink (= wireless node 1) from the wireless node closest to the sink (= wireless node 1). The allocation process ASGN is executed toward the node (step S236).

  On the other hand, when it is determined in step S235 that the proximity index CLN has not been detected, the assignment unit 16 of the wireless node 1 further determines whether or not the number of adjacent wireless nodes has been detected (step S237).

  When it is determined in step S237 that the number of adjacent wireless nodes has been detected, the assignment unit 16 of the wireless node 1 moves from the wireless node having the largest number of adjacent wireless nodes to the wireless node having the smallest number of adjacent wireless nodes. The allocation process ASGN is executed (step S238).

  On the other hand, when it is determined in step S237 that the number of adjacent wireless nodes has not been detected, the allocation unit 16 of the wireless node 1 further determines whether or not the received signal strength RSSI has been collected (step S239).

  When it is determined in step S239 that the received signal strength RSSI has been collected, the assigning unit 16 of the wireless node 1 selects a wireless link having the largest received signal strength RSSI from a wireless node having a wireless link having the smallest received signal strength RSSI. The allocation process ASGN is executed toward the wireless node that has it (step S240).

  On the other hand, when it is determined in step S239 that the received signal strength RSSI has not been collected, the allocation unit 16 of the wireless node 1 further determines whether or not the number of hops has been detected (step S241).

  When it is determined in step S241 that the number of hops has been detected, the assignment unit 16 of the wireless node 1 executes the assignment process ASGN while assigning the same wakeup ID to two wireless nodes having the number of hops of h ( Step S242).

  On the other hand, when it is determined in step S241 that the number of hops has not been detected, the assignment unit 16 of the wireless node 1 further determines whether or not the frame transmission number N has been collected (step S243).

  When it is determined in step S243 that the number N of frame transmissions has been collected, the assignment unit 16 of the wireless node 1 performs assignment processing from the wireless node having the largest number of frame transmissions N toward the wireless node having the smallest number of frame transmissions. ASGN is executed (step S244).

  On the other hand, when it is determined in step S243 that the number N of frame transmissions has not been collected, the allocating unit 16 of the wireless node 1 determines that the total number of child nodes has been detected, and starts from the wireless node having the largest total number of child nodes. The allocation process ASGN is executed toward the radio node having the smallest total number of child nodes (step S245).

  Then, after any of steps S232, S234, S236, S238, S240, S242, S244, and S245, the series of operations proceeds to “END” in FIG.

  Note that steps S231, S233, S235, S237, S239, S241, and S243 may be executed in any priority order.

  Further, without executing steps S231, S233, S235, S237, S239, S241, and S243, one step is arbitrarily selected from steps S232, S234, S236, S238, S240, S242, S244, and S246, and the selection is made. One step may be executed.

(J) Autonomous assignment of wakeup ID In the above description, it has been described that the wireless node 1 (= sink) assigns the wakeup ID to the wireless nodes 1 to 7, but in the embodiment of the present invention, the wireless node 1 to 7 may autonomously assign a wakeup ID.

  In the autonomous allocation of the wakeup ID described below, the allocated radio node ASGN_CPL for which the allocation of the wakeup ID is completed and the unallocated radio node ASGN_NonCPL for which the allocation of the wakeup ID is not completed are mixed. It is assumed.

  For example, this is a case where the wireless node newly enters the wireless sensor network 10 after the wakeup ID is assigned to the wireless nodes 1 to 7 using any one of the assignment methods 1 to 6 described above.

  When autonomous allocation of the wakeup ID is executed, each of the wireless nodes 2 to 7 has the same configuration as the wireless node 1 shown in FIG.

  The unallocated radio node ASGN_NonCPL transmits an allocation request message for requesting allocation of a wakeup ID (WuID). The allocation request message is represented by a bit string and a frame length. A set of frame lengths representing the allocation request message is determined in advance and stored in the allocation unit 16 and the wake-up signal determination unit 18 of each of the wireless nodes 1 to 7.

  Then, the radio nodes (unallocated radio node ASGN_NonCPL and allocated radio node ASGN_CPL) receive the allocation request message by the radio communication unit 13 or the wake-up signal receiving unit 17.

  When receiving the allocation request message by the radio communication unit 13, the radio nodes (unallocated radio node ASGN_NonCPL and allocated radio node ASGN_CPL) demodulate the received signal of the allocation request message and detect that the allocation request message has been received. .

  When the wireless node (unassigned wireless node ASGN_NonCPL and assigned wireless node ASGN_CPL) receives the assignment request message by the wake-up signal receiving unit 17, the wireless node detects the frame length of the received signal, and the detected frame length is assigned. When it matches the frame length representing the request message, it detects that the allocation request message has been received.

  When the wireless node (unassigned wireless node ASGN_NonCPL and assigned wireless node ASGN_CPL) receives the assignment request message in the sleep state, the wireless node always shifts from the sleep state to the activated state.

  When the unallocated radio node ASGN_NonCPL other than the unallocated radio node ASGN_NonCPL that has transmitted the allocation request message receives the allocation request message and detects the allocation request message, the operation of requesting allocation of the wakeup ID is temporarily stopped.

  When the assigned wireless node ASGN_CPL receives the assignment request message and shifts from the sleep state to the activated state, the assigned wireless node ASGN_CPL creates a wakeup ID list including its own wakeup ID and the wakeup ID of the wireless node adjacent to itself. To send.

  The assigned wireless node ASGN_CPL does not enter the sleep state until it receives an assignment completion message indicating that the assignment of the wakeup ID is completed.

  When the assigned wireless node ASGN_CPL in the activated state receives the assignment request message, it creates and transmits a wakeup ID list.

  The unallocated radio node ASGN_NonCPL that has transmitted the allocation request message waits for reception of the wakeup ID list for a certain period of time, and when the certain period of time has elapsed, retransmits the allocation request message until the number of allocation request message transmissions reaches a reference value. Here, the reason why the allocation request message is retransmitted is that there may be a wireless node that does not correctly receive the wakeup ID, or the wakeup ID list replies may collide.

  Further, when transmitting the allocation request message for the second and subsequent times, the unallocated radio node ASGN_NonCPL transmits the allocation request message including the information of the radio node that has already received the wakeup ID list in the payload. This is to alleviate the collision of packets due to the return of the wakeup ID list.

  When the collection of the wakeup ID list is completed, the unassigned wireless node ASGN_NonCPL is defined by the shortest frame length and the smallest number of frames in the wakeup IDs other than the wakeup ID included in the collected wakeup ID list. A wakeup ID is selected, and the selected wakeup ID is assigned to itself.

  When the unassigned wireless node ASGN_NonCPL assigns the wakeup ID to itself, it determines whether or not there is a wireless node to which the same wakeup ID is assigned between adjacent wireless nodes adjacent to the unassigned wireless node ASGN_NonCPL. That is, the unassigned wireless node ASGN_NonCPL determines whether or not a wake-up ID conflict has occurred between adjacent wireless nodes. When the unallocated radio node ASGN_NonCPL determines that there is a wakeup ID conflict between adjacent radio nodes, the unallocated radio node ASGN_NonCPL transmits a reassignment instruction that instructs reassignment of the wakeup ID to the adjacent radio node. In this case, the unallocated radio node ASGN_NonCPL selects an adjacent radio node that should not be reassigned with the wakeup ID, and transmits a reassignment instruction to an adjacent radio node other than the selected adjacent radio node.

  The unassigned radio node ASGN_NonCPL assigns a wakeup ID to itself and determines that there is no radio node to which the same wakeup ID is assigned among adjacent radio nodes. An assignment completion message including the wakeup ID assigned to the adjacent wireless node is generated and transmitted.

  The unallocated radio node ASGN_NonCPL that has received the allocation completion message resumes its allocation request.

  When the assigned wireless node ASGN_CPL receives a reassignment instruction when a wakeup ID conflict has occurred, the assigned wireless node ASGN_CPL waits until receiving a wakeup ID assignment completion message, or based on the received assignment completion message, Re-determine the wake-up ID. When the assigned wireless node ASGN_CPL re-determines its own wake-up ID, the assigned wireless node ASGN_CPL generates a change notification including the re-determined wake-up ID and transmits it to the adjacent wireless node.

  FIG. 21 is a diagram showing another correspondence table showing the correspondence between the frame length and the data. Referring to FIG. 21, correspondence table TBL3 includes a frame length and data. The frame length and data are associated with each other.

  The frame length of 11.5 [ms] is associated with 0x0, the frame length of 11.9 [ms] is associated with 0x1, and the frame length of 12.3 [ms] is associated with 0x2. The frame length of 12.7 [ms] is associated with 0x3, the frame length of 13.1 [ms] is associated with 0x4, and the frame length of 13.5 [ms] is associated with 0x5. The frame length of 13.9 [ms] is associated with 0x6.

  The frame length of 14.3 [ms] is associated with 0x7, the frame length of 14.7 [ms] is associated with 0x8, and the frame length of 15.1 [ms] corresponds to 0x9. A frame length of 15.5 [ms] is associated with 0xA, a frame length of 15.9 [ms] is associated with 0xB, and a frame length of 16.3 [ms] is associated with 0xC. The frame length of 16.7 [ms] is associated with 0xD, the frame length of 17.1 [ms] is associated with 0xE, and the frame length of 17.5 [ms] is 0xF. Is associated with.

The allocation unit 16 and the wakeup signal determination unit 18 of each of the wireless nodes 1 to 7 hold a correspondence table TBL3. Then, the allocating unit 16 of each of the wireless nodes 1 to 7 has a bit string (for example, c ₁ c ₂ c ₃ c ₄ c ₅ c ₆ c ₇ c ₈ c ₉ c ₁₀ c ₁₁ c ₁₂ indicating a wake-up ID allocation request. Are divided into c ₁ c ₂ c ₃ c ₄ , c ₅ c ₆ c ₇ c ₈ , c ₉ c ₁₀ c ₁₁ c _12, and the divided c ₁ c ₂ c ₃ c ₄ , c _{5 c 6 c 7 c 8,} c 9 c 10 c 11 c 12 each reference frame length correspondence table TBL3 the FL9, FL10, converted to FL10. Then, the allocating unit 16 of each of the wireless nodes 1 to 7 includes c ₁ c ₂ c ₃ c ₄ in the payload, and includes a radio frame FR9 having a frame length FL9 and c ₅ c ₆ c ₇ c ₈ in the payload. wherein, and, a radio frame FR10 having a frame length _FL10, include _{c 9} c ₁₀ c 11 c ₁₂ in the payload, and generates the radio frame FR11 having a frame length FL11. Then, the assignment unit 16 of each of the wireless nodes 1 to 7 sequentially transmits the wireless frames FR9 to FR11 via the control unit 14, the wireless communication unit 13, and the antenna 11. As a result, a wakeup ID assignment request message is transmitted.

The wake-up signal receiving unit 17 of each of the wireless nodes 1 to 7 sequentially receives the wireless frames FR9 to FR11 via the antenna 12, and based on the received signals of the received wireless frames FR9 to FR11, the frame is transmitted by the method described above. The lengths FL9 to FL11 are detected. Then, the wakeup signal receiving unit 17 of each of the wireless nodes 1 to 7 outputs the detected frame lengths FL9 to FL11 to the wakeup signal determining unit 18. The wakeup signal determination unit 18 of each of the wireless nodes 1 to 7 receives the frame lengths FL9 to FL11, and refers to the received frame lengths FL9 to FL11 with reference to the correspondence table TBL3, respectively, to the bit values c ₁ c ₂ c ₃ c _4. , C ₅ c ₆ c ₇ c ₈ , c ₉ c ₁₀ c ₁₁ c ₁₂ . Then, the wakeup signal determination unit 18 of each of the wireless nodes 1 to 7 arranges the bit values c ₁ c ₂ c ₃ c ₄ , c ₅ c ₆ c ₇ c ₈ , and c ₉ c ₁₀ c ₁₁ c ₁₂ in a line. It is detected that the bit string c ₁ c ₂ c ₃ c ₄ c ₅ c ₆ c ₇ c ₈ c ₉ c ₁₀ c ₁₁ c ₁₂ indicates a wake-up ID assignment request message, and an activation signal is transmitted to the wireless communication unit 13 and the control unit 14, output to the path control unit 15 and the allocation unit 16, and then output an allocation request message detection signal to the allocation unit 16. Then, the allocation unit 16 of each of the wireless nodes 1 to 7 detects that the wakeup ID allocation request message has been received based on the detection signal.

In addition, the wireless communication unit 13 of each of the wireless nodes 1 to 7 sequentially receives the wireless frames FR9 to FR11 via the antenna 11, demodulates the received signals of the received wireless frames FR9 to FR11, and generates a bit string c ₁ c _2. c ₃ c ₄ c ₅ c ₆ c ₇ c ₈ c ₉ c ₁₀ c ₁₁ c ₁₂ are output to the control unit 14. The control unit 14 of each of the wireless nodes 1 to 7 outputs the bit string c ₁ c ₂ c ₃ c ₄ c ₅ c ₆ c ₇ c ₈ c ₉ c ₁₀ c ₁₁ c ₁₂ received from the wireless communication unit 13 to the allocation unit 16. The allocation unit 16 detects that the wakeup ID allocation request message has been received based on the bit string c ₁ c ₂ c ₃ c ₄ c ₅ c ₆ c ₇ c ₈ c ₉ c ₁₀ c ₁₁ c ₁₂ .

  FIG. 22 is a flowchart for explaining an operation for autonomously assigning a wakeup ID. In addition, the flowchart shown in FIG. 22 is a flowchart explaining the operation | movement in unallocated radio | wireless node ASGN_NonCPL.

  Referring to FIG. 22, when a series of operations is started, allocation unit 16 of unallocated radio node ASGN_NonCPL sets n = 0 and transmits a wakeup ID list (WuID list) to the radio node. The wireless node information is initialized (step S31).

  Then, the allocating unit 16 of the unallocated radio node ASGN_NonCPL sends the WuID allocation request message including the information of the radio node that has transmitted the WuID list to the radio node to the control unit 14, the radio communication unit 13, and the antenna 11 by the method described above. (Step S32).

  Thereafter, the allocation unit 16 of the unallocated radio node ASGN_NonCPL sets n = n + 1 (step S33), and determines whether a WuID list has been received (step S34).

  When it is determined in step S34 that the WuID list has been received, the allocation unit 16 of the unallocated radio node ASGN_NonCPL updates information on the radio node that has transmitted the WuID list to the radio node (step S35).

  Then, when it is determined in step S34 that the WuID list has not been received, or after step S35, the allocation unit 16 of the unallocated radio node ASGN_NonCPL determines whether n <Nr (step S36). . Nr is the number of transmissions of the WuID assignment request message, and is set to 5 times, for example.

  When it is determined in step S36 that n <Nr, the series of operations returns to step S32, and steps S32 to S36 are repeatedly executed until it is determined in step S36 that n <Nr is not satisfied.

  When it is determined in step S36 that n <Nr is not satisfied, the allocating unit 16 of the unallocated radio node ASGN_NonCPL allocates a WuID to the radio node based on the received WuID list (step S37). More specifically, the allocation unit 16 of the unallocated radio node ASGN_NonCPL performs the wakeup ID defined by the shortest frame length and the minimum number of frames in the wakeup ID other than the wakeup ID included in the received WuID list. And assigns the selected wakeup ID to the wireless node.

  Thereafter, the allocation unit 16 of the unallocated radio node ASGN_NonCPL determines whether or not a WuID conflict has been detected between other radio nodes (step S38). That is, the allocation unit 16 of the unallocated radio node ASGN_NonCPL determines whether there is an adjacent radio node to which the same wake-up ID is allocated between adjacent radio nodes adjacent to the radio node based on the received WuID list. Determine.

  When it is determined in step S38 that a WuID conflict has been detected between other wireless nodes, the allocating unit 16 of the unallocated wireless node ASGN_NonCPL issues a WuID reassignment instruction to the control unit 14, the wireless communication unit 13, and the antenna 11 (Step S39).

  Then, when it is determined in step S38 that no WuID conflict has been detected between other wireless nodes, or after step S39, the allocating unit 16 of the unassigned wireless node ASGN_NonCPL wakes up the assigned wireless node. A WuID assignment completion message including the ID and the wakeup ID of the wireless node existing at a position one hop from the wireless node is generated, and the generated assignment completion message is transmitted to the control unit 14, the wireless communication unit 13, and the antenna 11. (Step S40). Thereby, a series of operation | movement is complete | finished.

  In step S34, the process may proceed to step S37 via “NO” in step S36 without determining that the WuID list has been received. In this case, the allocating unit 16 of the unallocated radio node ASGN_NonCPL does not hold the WuID list received from other radio nodes, but holds the allocation table TBL1. A wakeup ID defined by the frame length and the smallest number of frames is assigned to the wireless node. Thus, since the number of received WuID lists may be “0”, n = 0 is set as the number of transmissions n of the WuID assignment request message in step S31.

  FIG. 23 is a flowchart showing an interrupt routine by the unallocated radio node ASGN_NonCPL.

  Referring to FIG. 23, when the interrupt routine is disclosed, allocation unit 16 of unallocated radio node ASGN_NonCPL receives a WuID allocation request message from another radio node by the method described above (step S41).

  Then, the allocating unit 16 of the unallocated radio node ASGN_NonCPL interrupts the WuID allocation process in the radio node and waits (step S42).

  Thereafter, the allocating unit 16 of the unallocated radio node ASGN_NonCPL determines whether or not a timeout has been detected by determining whether or not a predetermined time has elapsed since the standby (step S43). The fixed time is set to 10 seconds, for example.

  When it is determined in step S43 that no timeout has been detected, the allocation unit 16 of the unallocated radio node ASGN_NonCPL further determines whether or not a WuID allocation completion message has been received (step S44).

  When it is determined in step S44 that the assignment completion message has not been received, the series of operations returns to step S42, and steps S42 to S43 are repeatedly executed until it is determined in step S44 that the assignment completion message has been received. Is done.

  When it is determined in step S43 that a timeout has been detected, or when it is determined in step S44 that an allocation completion message has been received, the series of operations transitions to “START” shown in FIG. S45), the operation of the interrupt routine ends.

  FIG. 24 is a flowchart for explaining the operation of the assigned wireless node that has received the wakeup ID assignment request message in the autonomous assignment of the wakeup ID.

  Referring to FIG. 24, when a series of operations is started, allocating unit 16 of allocated radio node ASGN_CPL receives a WuID allocation request message from another radio node (step S51).

  Then, the allocation unit 16 of the allocated radio node ASGN_CPL determines whether the WuID of the radio node has been detected in the allocation request message (step S52).

  When it is determined in step S52 that the WuID of the wireless node has not been detected in the allocation request message, the allocating unit 16 of the allocated wireless node ASGN_CPL receives the WuID of the wireless node and the position of one hop from the wireless node. A WuID list including the WuIDs of the wireless nodes existing in is generated, and the generated WuID list is transmitted (step S53).

  In step S52, when it is determined that the WuID of the wireless node is detected in the assignment request message, or after step S53, the assigned wireless node ASGN_CPL shifts to the sleep prohibited state (step S54), and the predetermined time has passed. It is determined whether or not a timeout has been detected by determining whether or not the time has elapsed (step S55). Also in this case, the fixed time is set to 10 seconds, for example.

  When it is determined in step S55 that no timeout has been detected, the allocation unit 16 of the allocated radio node ASGN_CPL further determines whether or not a WuID allocation completion message has been received (step S56).

  When it is determined in step S56 that a WuID assignment completion message has not been received, the series of operations returns to step S54, and steps S54 to S54 are performed until it is determined in step S56 that a WuID assignment completion message has been received. S56 is repeatedly executed.

  When it is determined in step S55 that a timeout has been detected, or when it is determined in step S56 that a WuID assignment completion message has been received, the assigned wireless node ASGN_CPL cancels the sleep inhibition state (step S55). S57). As a result, a series of operations is completed.

  When the allocated radio node ASGN_CPL determines in step S52 that the WuID of the radio node has not been detected in the allocation request message (see step S53), the allocated radio node ASGN_CPL is allocated to the allocated radio node ASGN_CPL. By transmitting the WuID and the WuID assigned to the adjacent radio node adjacent to the assigned radio node ASGN_CPL, the unassigned radio node ASGN_NonCPL has the same WuID as that of the assigned radio node ASGN_CPL and the assigned radio node ASGN_CPL. This is in order not to assign it to itself.

  In addition, when it is determined that the WuID of the wireless node is detected in the assignment request message or after step S53, the assigned wireless node ASGN_CPL shifts to the sleep prohibited state because the assigned wireless node ASGN_CPL times out. This is because a WuID assignment completion message can be received within a range that is not possible.

  FIG. 25 is a flowchart for explaining the operation of the assigned wireless node that has received the wakeup ID reassignment instruction in the autonomous assignment of the wakeup ID.

  Referring to FIG. 25, when a series of operations is started, allocating unit 16 of allocated radio node ASGN_CPL receives a WuID reassignment instruction (step S61). Then, the allocation unit 16 of the allocated radio node ASGN_CPL waits until it receives a WuID allocation completion message (step S62).

  Thereafter, the allocation unit 16 of the allocated radio node ASGN_CPL determines whether or not a WuID allocation completion message has been received (step S63).

  When it is determined in step S63 that the WuID assignment completion message has not been received, the series of operations returns to step S62, and steps S62 and S63 are performed until it is determined in step S63 that a WuiD assignment completion message has been received. Is repeatedly executed.

  If it is determined in step S63 that the WuID assignment completion message has been received, the assigning unit 16 of the assigned wireless node ASGN_CPL performs reassignment of WuID based on the received information (step S64).

  Then, the allocation unit 16 of the allocated radio node ASGN_CPL generates a WuID change notification including the wakeup ID reassigned to the radio node and the wakeup ID assigned to the radio node adjacent to the radio node, Send the generated change notification. Then, the assigned radio node ASGN_CPL cancels the sleep prohibition state (step S65). As a result, a series of operations is completed.

  By repeatedly executing the flowcharts shown in FIGS. 22 to 25 described above, the wakeup ID is assigned to the unassigned radio node SGN_NonCPL.

  As shown by the flowcharts of FIGS. 22 to 25, in the autonomous assignment of the wakeup ID, the unassigned wireless node SGN_NonCPL receives the WuID list from the other wireless nodes by transmitting a wakeup ID assignment request message. At the same time (see “YES” in steps S32 and S34 in FIG. 22, S35), a WuID reassignment instruction is transmitted when a conflict in WuID is detected (“YES” in step S38 in FIG. 22, see S39). The assigned wireless node ASGN_CPL receives the WuID assignment request message, and when the assignment request message does not include its own WuID, transmits the WuID list including its own WuID and its own neighboring wireless node WuID ( (Refer to “NO” in steps S51 and S52 of FIG. 24, S53).

  As a result, the unassigned radio node SGN_NonCPL can collect the WuID list from the assigned radio node ASGN_CPL, and is defined by the shortest frame length and the smallest number of frames among the wakeup IDs not included in the collected WuID list. Assigned wakeup IDs to itself.

  Therefore, when the autonomous assignment of the wakeup ID is completed, a wakeup ID defined by a shorter frame length and a smaller number of frames can be assigned to the wireless nodes constituting the wireless sensor network 10.

  In addition, when the assigned wireless node ASGN_CPL receives a WuID reassignment instruction, the assigned wireless node ASGN_CPL waits until a WuID assignment completion message is received. (Refer to steps S61, S62, S63, S64, S65 in FIG. 25).

  As a result, the assigned radio node ASGN_CPL performs the reassignment of the wakeup ID after the assignment of the wakeup ID in the unassigned radio node SGN_NonCPL is completed.

  Therefore, further conflicts of the wakeup ID can be suppressed.

  FIG. 26 is a diagram illustrating an operation of starting a wireless node. Referring to FIG. 26, wireless node 2 has wake-up ID = WuID2. WuID2 is defined by a frame length of 12.8 [ms] and the number of one frame (see allocation table TBL1).

  When the wireless node 1 activates the wireless node 2, the control unit 14 of the wireless node 1 generates one wireless frame FR12 having a frame length of 12.8 [ms], and the generated wireless frame FR12 is wirelessly transmitted. Output to the communication unit 13. The wireless communication unit 13 of the wireless node 1 modulates the wireless frame FR12 and transmits the modulated wireless frame FR12 via the antenna 11.

  The wake-up signal receiving unit 17 of the wireless node 2 receives the wireless frame FR12 via the antenna 12, and based on the received signal of the received wireless frame FR12, the frame length of 12.8 [ms] is obtained by the above-described method. Is detected. Then, the wakeup signal reception unit 17 of the wireless node 2 outputs the detected frame length of 12.8 [ms] to the wakeup signal determination unit 18.

  The wakeup signal determination unit 18 of the wireless node 2 receives the frame length of 12.8 [ms] from the wakeup signal reception unit 17, and the WuID2 frame that the received frame length of 12.8 [ms] holds in advance. It is detected that the number of frames of the received radio frame FR12 matches the length and the number of frames (= 1) matches the number of frames of WuID2. Then, the wakeup signal determination unit 18 of the wireless node 2 generates an activation signal and outputs it to the wireless communication unit 13, the control unit 14, the route control unit 15, and the allocation unit 16. As a result, the wireless node 2 shifts from the sleep state to the activated state.

  If an error occurs in the wakeup ID (WuID), each of the wireless nodes 1 to 7 activates the adjacent wireless node using the MAC address as the backup ID.

  Examples of cases where an error has occurred in the wake-up ID (WuID) include a case where some wireless nodes have failed to receive the allocation change notification and a case where the activation of the activation target wireless node has failed continuously. It is done.

  When the adjacent wireless node is activated using the MAC address as the backup ID, the control unit 14 of the wireless node 1 calculates the hash value of the MAC address, and refers to the bit string of the calculated hash value with reference to the correspondence table TBL2 Converting to at least one frame length and generating at least one radio frame having the converted at least one frame length. Then, the control unit 14 of the wireless node 1 transmits the generated at least one wireless frame via the wireless communication unit 13 and the antenna 11.

  The wake-up signal receiving unit 17 of the wireless node 2 receives at least one radio frame via the antenna 12, and based on the received signal of the received at least one radio frame, at least one radio frame is received by the method described above. The frame length is detected, and the detected at least one frame length is output to the wakeup signal determination unit 18.

  The wakeup signal determination unit 18 of the wireless node 2 receives at least one frame length from the wakeup signal reception unit 17, converts the received at least one frame length into a bit value with reference to the correspondence table TBL2, and performs MAC processing. Get the address. Then, the wakeup signal determination unit 18 of the wireless node 2 generates an activation signal when the acquired MAC address matches the held MAC address, and the wireless communication unit 13, the control unit 14, and the path control unit 15 (to the allocating unit 16 when the allocating unit 16 is provided). As a result, the wireless node 2 is activated. Then, when the wireless node 2 is activated, the control unit 14 of the wireless node 2 transmits a wakeup ID (WuID) assigned to the wireless node 2 to the wireless node 1 (= adjacent wireless node).

  Then, the control unit 14 of the wireless node 1 receives the wakeup ID (WuID) from the wireless node 2, holds the received wakeup ID (WuID), and updates the wakeup ID of the wireless node 2.

  As a result, the new wake-up ID (WuID) of the wireless node 2 can be shared.

  After the wake-up ID is assigned to the wireless nodes 1 to 7 by the various methods described above, the wireless nodes 1 to 7 use the assigned wake-up ID to activate the adjacent wireless node by the operation shown in FIG. Control packets DIO and DAO are transmitted and received, and the flowchart shown in FIG. 9 is executed. Thereby, the route in the wireless sensor network 10 is maintained.

  As a result, the power consumption and wakeup ID (WuID) when transmitting the wakeup ID (WuID) are compared with the case where the wakeup ID defined by the same number of frames is assigned to all of the wireless nodes 1 to 7. The power consumption at the time of reception can be reduced and the route in the wireless sensor network 10 can be maintained.

  FIG. 27 is a flowchart for explaining the sensor value transfer operation in the wireless sensor network 10 shown in FIG. A wakeup ID (WuID3) is assigned to the wireless node 1 by the method described above. It is assumed that a wakeup ID (WuID5) is assigned to the wireless node 2.

  Referring to FIG. 27, when receiving the activation time from the built-in timer, control unit 14 of wireless node 3 shifts to the activation state and shifts radio communication unit 13 and path control unit 15 to the activation state. As a result, the wireless node 3 shifts to the activated state.

  And the control part 14 of the radio | wireless node 3 controls a sensor (not shown) so that a sensor value may be detected.

  After that, when receiving a sensor value from a sensor (not shown), the control unit 14 of the wireless node 3 routes the parent node of the wireless node 3 to transmit the received sensor value to the wireless node 1 (= sink). The control unit 15 is inquired.

  Then, the control unit 14 of the wireless node 3 receives the address MACadd2 of the wireless node 2 that is the parent node of the wireless node 3 from the route control unit 15.

  Then, the control unit 14 of the wireless node 3 detects the wake-up ID (WuID5) of the wireless node 2 corresponding to the MAC address MACadd2, and generates one wireless frame having a frame length of 18.8 [ms]. . Then, the control unit 14 of the wireless node 3 outputs a wakeup signal WuS including the generated wireless frame to the wireless communication unit 13.

  The wireless communication unit 13 receives the wakeup signal WuS from the control unit 14, modulates the received wakeup signal WuS, and transmits the modulated wakeup signal WuS via the antenna 11 (step S71).

  Then, the wireless node 2 shifts from the sleep state to the activated state according to the wake-up signal WuS from the wireless node 3 by the same operation as described in FIG. 26 (step S72), and sets the address MACadd2 of the wireless node 2 Broadcast startup notifications that contain it.

  Upon receiving the activation notification, the wireless node 3 detects that the wireless node 2 has been activated. Then, the control unit 14 of the wireless node 3 transmits a packet including the address MACadd1 of the wireless node 1 (= sink), the address MACadd2 of the wireless node 2 that transmitted the activation notification, the address MACadd3 of the wireless node 3, and the sensor value. PKT1 = [MACadd1 / MACadd2 / MACadd3 / sensor value] is generated, and the generated packet PKT1 = [MACadd1 / MACadd2 / MACadd3 / sensor value] is output to the wireless communication unit 13. The wireless communication unit 13 of the wireless node 3 receives the packet PKT1 = [MACadd1 / MACadd2 / MACadd3 / sensor value] from the control unit 14, modulates the received packet PKT1, and transmits the modulated packet PKT1 via the antenna 11. Transmit (step S73). Thereafter, the wireless node 3 shifts from the activated state to the sleep state.

  The wireless node 2 receives the packet PKT1 = [MACadd1 / MACadd2 / MACadd3 / sensor value] from the wireless node 3 (step S74). Then, the wireless node 2 detects that the leading address of the packet PKT1 is the address MACadd1 of the wireless node 1, and detects that the packet PKT1 should be transferred to the wireless node 1.

  Then, the wireless node 2 transmits a wake-up signal WuS including one wireless frame having a frame length of 14.8 [ms] by the same operation as the operation of the wireless node 3 in step S71 (step S75). In response to the wake-up signal WuS from the wireless node 2, the wireless node 1 shifts from the sleep state to the activated state by the same operation as the operation of the wireless node 2 in step S72 (step S76), and the address MACadd1 of the wireless node 1 Broadcast a startup notification containing.

  Upon receiving the activation notification, the wireless node 2 generates a packet PKT2 = [MACadd1 / MACadd1 / MACadd3 / sensor value] in which the address MACadd2 of the packet PKT1 = [MACadd1 / MACadd2 / MACadd3 / sensor value] is changed to the address MACadd1. The generated packet PKT2 = [MACadd1 / MACadd1 / MACadd3 / sensor value] is transmitted (step S77). Then, the wireless node 2 shifts from the activated state to the sleep state.

  The wireless node 1 receives the packet PKT2 = [MACadd1 / MACadd1 / MACadd3 / sensor value] from the wireless node 2 (step S78). Then, the control unit 14 of the wireless node 1 extracts the transmission source address MACadd3 and sensor value from the received packet PKT2, and holds the extracted address MACadd3 and sensor value in association with each other.

  Thereafter, the wireless node 2 shifts from the sleep state to the activated state by a timer interrupt, and receives a sensor value from a sensor (not shown). Then, the wireless node 2 transmits a wake-up signal WuS composed of one wireless frame having a frame length of 14.8 [ms] by the same operation as the operation of the wireless node 3 in step S71 (step S79).

  The wireless node 1 shifts from the sleep state to the activated state in response to the wake-up signal WuS from the wireless node 2 (step S80), and broadcasts an activation notification including the address MACadd1 of the wireless node 1.

  Upon receiving the activation notification, the wireless node 2 transmits a packet PKT3 = [MACadd1 / MACadd1 / MACadd2 / sensor value] including the sensor value by the same operation as the operation of the wireless node 3 in step S73 (step S81).

  The wireless node 1 receives the packet PKT3 = [MACadd1 / MACadd1 / MACadd2 / sensor value] (step S82). Then, the control unit 14 of the wireless node 1 extracts the transmission source address MACadd2 and the sensor value from the packet PKT3, and holds the extracted transmission source address MACadd2 and the sensor value in association with each other.

  In this way, according to the flowchart shown in FIG. 27, the sensor values detected by the wireless nodes 2 to 7 are transmitted to the wireless node 1 (= sink) and held in the wireless node 1 (= sink).

  In the flowchart shown in FIG. 27, when transmitting the sensor value, the wireless node 3 unicasts the wakeup signal to shift the wireless node 2 to the activated state, and then transmits the sensor value (see steps S71 to S73). ). And the wireless node 3 will transfer to a sleep state, if transmission of a sensor value is completed.

  In addition, when the wireless node 2 transitions to the activated state in response to the wake-up signal, the wireless node 1 receives the sensor value and transfers the sensor value, unicasts the wake-up signal to cause the wireless node 1 to transition to the activated state, Thereafter, the sensor value is transmitted (see steps S75, S76, S77). And the wireless node 2 will transfer to a sleep state, if the transfer of a sensor value is completed.

  Further, when transmitting the sensor value detected by itself, the wireless node 2 unicasts the wakeup signal to shift the wireless node 1 to the activated state, and then transmits the sensor value (see steps S79 to S81). . And the wireless node 2 will transfer to a sleep state, if transmission of a sensor value is completed.

  As described above, when the wireless nodes 1 to 3 perform the necessary operations in the transmission and transfer operations of the sensor values to the wireless node 1 and then perform necessary operations, the wireless nodes 1 to 3 shift to the sleep state. In the activated state, when transferring the sensor value received from the wireless node 3, the wireless node 2 shifts to the sleep state after completing the transfer of the sensor value. As a result, the sensor value transmitted from the wireless node 3 is quickly delivered to the wireless node 1. In other words, the wireless nodes 1 to 3 shift to the activated state only when necessary, perform necessary operations, and then shift to the sleep state.

  Each of the wireless nodes 1 to 3 uses the wakeup ID assigned by the above-described method when the transmission destination is shifted from the sleep state to the activated state.

  Therefore, in the transmission and transfer operations of the sensor value to the wireless node 1, it is possible to reduce the power consumption during transmission and reception of the wakeup ID.

  In the embodiment of the present invention, the operations of the wireless nodes 1 to 7 described above may be executed by a program.

  In this case, each of the wireless nodes 1 to 7 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Randum Access Memory).

  The ROM stores a program PROG1 including steps S1, S3, S6, S8, S18, and S20 shown in FIG. 9, and steps S2, S4, S5, S7, S9, S11, S14, S16, S17, and S19 shown in FIG. 9, program PROG3 consisting of steps S10, S12, S13 and S15 shown in FIG. 9, steps S21 to S23 shown in FIG. 19, and program PROG4 consisting of steps S231 to S245 shown in FIG. 20, and step S31 shown in FIG. Program SPROG5 consisting of S40, Steps S31 to S40 shown in FIG. 22 and Program PROG6 consisting of Steps S41 to S45 shown in FIG. 23, Program PROG7 consisting of Steps S51 to S57 shown in FIG. 24, Step S61 shown in FIG. Program PROG8 consisting of 65, program PROG9 consisting of steps S71 and S73 shown in FIG. 26, program PROG10 consisting of steps S72, S74, S75, S77, S79 and S81 shown in FIG. 27, steps S76, S78 and S80 shown in FIG. , S82, a program PROG11, an allocation table TBL1, and a correspondence table TBL2,3 are stored.

  The CPU reads and executes one of the programs PROG1 to PROG11 stored in the ROM.

  When the CPU executes the program PROG4 and assigns the wakeup ID, the CPU reads the assignment table TBL1 from the ROM and refers to it.

  Further, when executing the program PROG5 or the program PROG6 and autonomously assigning the wakeup ID, the CPU reads the reference table TBL3 from the ROM and refers to it.

  Further, when executing any one of the programs PROG1 to PROG3 and PROG9 to PROG11, the CPU reads the reference table TBL2 from the ROM and refers to it when the wireless node is activated using the MAC address as the backup ID.

  Further, the CPU calculates a hash value of the MAC address using the RAM.

  Thus, any of the programs PROG1 to PROG11 is a program for causing the computer (CPU) to execute the operations of the wireless nodes 1 to 7.

  And even when the operation of each of the wireless nodes 1 to 7 is executed by a program, the various effects described above can be enjoyed.

  In the above, the present invention has been described by taking the wireless sensor network 10 as an example. However, the present invention is not limited to this, and the present invention may be applied to any wireless network. .

  In the above description, the example in which the wireless nodes 1 to 7 constituting the wireless sensor network 10 are assigned the wireless nodes 1 to 7 with the wake-up ID (WuID) for shifting from the sleep state to the activated state has been described. In the embodiment of the invention, not limited to this, identification information (= ID) for shifting the wireless nodes 1 to 7 constituting the wireless sensor network 10 from the activated state to the sleep state is assigned to the wireless nodes 1 to 7. May be. Then, shifting each of the wireless nodes 1 to 7 from the sleep state to the activated state, and shifting each of the wireless nodes 1 to 7 from the activated state to the sleep state is equivalent to controlling each of the wireless nodes 1 to 7. To do.

  Therefore, in the embodiment of the present invention, the wireless nodes 1 to 7 are generally defined by the frame length and the number of frames and the identification information for controlling the wireless nodes 1 to 7 is determined by the method described above. Anything can be assigned.

  As a result, the wakeup ID (= WuID) constitutes “identification information” for controlling the wireless node, and the above-described reference wakeup ID (= WuID1) constitutes “reference identification information”.

  Further, the above-mentioned “number of activations” corresponds to “number of times of control” or “number of times of being controlled”.

  Furthermore, the activation notification transmitted by the wireless node activated by the wakeup ID corresponds to a notification indicating that each wireless node is in a controllable state.

  Furthermore, the assignment request for the wakeup ID corresponds to an assignment request for identification information for controlling the wireless node.

  Further, the wakeup ID list corresponds to an identification information list.

  Further, when identification information (= ID) for shifting the wireless nodes 1 to 7 from the activated state to the sleep state is assigned to the wireless nodes 1 to 7, the wake-up signal receiving unit 17 and the wake of each wireless node 1 to 7 are assigned. The up signal determination unit 18 operates even when the wireless nodes 1 to 7 are activated.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to a radio apparatus, a radio communication system including the radio apparatus, and a program executed in the radio apparatus.

  1 to 7 wireless nodes, 10 wireless sensor networks, 11 and 12 antennas, 13 wireless communication units, 14 control units, 15 route control units, 16 allocation units, 17 wakeup signal reception units, and 18 wakeup signal determination units.

Claims (23)

Detecting a topology indicating an arrangement state of wireless devices constituting a wireless network, and based on topology information indicating the detected topology, the total number of wireless devices constituting the wireless network, included in the wireless devices constituting the wireless network And a proximity index indicating the degree of proximity from the first wireless device that collects data from other wireless devices, the number of adjacent wireless devices adjacent to the wireless devices that constitute the wireless network, and each wireless device Any of the number of hops between them and the total number of child nodes existing in a lower layer than each wireless device constituting the wireless network and located at one hop or more from each wireless device constituting the wireless network Detecting means for detecting
One of the number of times of control, which is the number of times the wireless device is controlled in a desired time length, the received signal strength in each wireless device, and the number of frames transmitted, which is the number of frames transmitted in the desired time length in each wireless device. Collection means to collect;
Based on either the detection result by the detection means or the collection result by the collection means, the frame length or the frame length and the number of frames sequentially increase from the reference identification information defined by the shortest frame length and the smallest number of frames. A wireless device comprising: an assigning unit that executes assignment processing for assigning identification information for controlling the wireless device to all wireless devices constituting the wireless network.   2. The allocation unit according to claim 1, wherein when the number of times of control is collected by the collection unit, the allocation unit executes the allocation process from a wireless device having the largest number of times of control toward a wireless device having the smallest number of times of control. Wireless devices.   The wireless device according to claim 1, wherein when the total number of the wireless devices is detected by the detecting unit, the allocating unit executes the allocation process based on the total number of the wireless devices.   The allocating unit executes the allocating process from a wireless device closest to the first wireless device to a wireless device farthest from the first wireless device when the proximity index is detected by the detecting unit. The wireless device according to claim 1.   The allocating unit executes the allocating process from a wireless device having the largest number of neighboring wireless devices to a wireless device having the smallest number of neighboring wireless devices when the neighboring wireless device is detected by the detecting unit. The wireless device according to claim 1.   The assigning means, when the received signal strength is collected by the collecting means, from the wireless device having the wireless link having the smallest received signal strength toward the wireless device having the wireless link having the largest received signal strength. The radio apparatus according to claim 1, which executes an allocation process.   The assigning means assigns the assignment process while assigning the same identification information to two wireless devices whose number of hops is equal to or greater than h (h is an integer equal to or greater than 1) when the number of hops is detected by the detection means. The wireless device according to claim 1, wherein:   The assigning means, when the number of frame transmissions is collected by the collecting means, executes the assignment processing from a wireless device having the largest number of frame transmissions to a wireless device having the smallest number of frame transmissions. The wireless device according to 1.   The allocation unit executes the allocation process from a wireless device having the largest total number of child nodes to a wireless device having the smallest total number of child nodes when the total number of child nodes is detected by the detection unit. The wireless device according to claim 1. A wireless device that controls another wireless device using the identification information assigned by the wireless device according to any one of claims 1 to 9,
Holding means for holding first identification information assigned to the wireless device and second identification information assigned to an adjacent wireless device adjacent to the wireless device;
A number of first radio frames having a frame length defining the second identification information and equal to the number of frames defining the second identification information are generated, and the generated first radio frames are First transmitting means for transmitting;
A second transmission means for transmitting data when receiving the first notification indicating that the adjacent wireless device is in a controllable state after the first wireless frame is transmitted by the first transmission means; A wireless device comprising:   When an error occurs in the second identification information, the first transmission unit generates a second radio frame having a frame length representing a MAC address of the adjacent radio device as a backup ID, and generates the second radio frame The wireless device according to claim 10, wherein the wireless device transmits a second wireless frame. A radio | wireless communications system provided with the radio | wireless apparatus of any one of Claims 1-11. The detecting means detects the topology indicating the arrangement state of the wireless devices constituting the wireless network, and based on the topology information indicating the detected topology, the total number of wireless devices constituting the wireless network, the wireless devices constituting the wireless network Included, and a proximity index indicating the degree of proximity from the first wireless device that collects data from other wireless devices, the number of adjacent wireless devices adjacent to the wireless device constituting the wireless network, and each wireless device Either the number of hops between the devices, or the total number of child nodes existing in a lower layer than each wireless device constituting the wireless network and located at a position of 1 hop or more from each wireless device constituting the wireless network A first step of detecting;
  The number of times the collection means controls the radio device in a desired time length, the received signal strength in each radio device, and the number of frames transmitted in the desired time length in each radio device. A second step of collecting either;
  The allocation means sequentially increases the frame length or the frame length and the number of frames from the reference identification information defined by the shortest frame length and the smallest number of frames based on either the detection result by the detection means or the collection result by the collection means. A program for causing a computer to execute a third step of executing assignment processing for assigning identification information for controlling a wireless device to all wireless devices constituting the wireless network. In the third step, when the number of times of control is collected by the collecting means in the third step, the assigning means executes assignment processing from the wireless device having the largest number of times of control toward the wireless device having the smallest number of times of control. A program for causing a computer according to claim 13 to execute the program. 14. The computer according to claim 13, wherein the assigning unit executes the assigning process based on the total number of the wireless devices when the total number of the wireless devices is detected by the detecting unit in the third step. A program to make it run. In the third step, when the proximity index is detected by the detection unit, the allocating unit changes from a wireless device closest to the first wireless device to a wireless device farthest from the first wireless device. The program for making a computer run of Claim 13 which performs the said allocation process toward this. In the third step, when the neighboring wireless device is detected by the detecting unit, the allocating unit changes from a wireless device having the largest number of neighboring wireless devices to a wireless device having the smallest number of neighboring wireless devices. The program for making a computer run of Claim 13 which performs the said allocation process toward this. In the third step, when the received signal strength is collected by the collecting unit, the allocating unit sends a radio link having the largest received signal strength from a wireless device having a radio link having the smallest received signal strength. The program for making a computer perform of the said allocation process which performs the said allocation process toward the radio | wireless apparatus which has. In the third step, when the number of hops is detected by the detection means in the third step, the allocating means is identical to the two wireless devices having the hop count of h (h is an integer of 1 or more) hops or more. 14. The program for causing a computer to execute the assignment process while assigning information. In the third step, when the number of frame transmissions is collected by the collecting unit in the third step, the allocating unit assigns the allocation from the wireless device having the largest number of frame transmissions to the wireless device having the smallest number of frame transmissions. The program for making a computer run of Claim 13 which performs a process. In the third step, when the total number of the child nodes is detected by the detection unit, the allocating unit moves from a wireless device having the largest total number of child nodes to a wireless device having the smallest total number of child nodes. The program for causing a computer according to claim 13 to execute the allocation process. A program for causing a computer to execute control of another wireless device using identification information assigned by causing the computer to execute the program according to any one of claims 13 to 21.
  A fourth step in which holding means holds the first identification information assigned to the wireless device and the second identification information assigned to an adjacent wireless device adjacent to the wireless device;
  The first transmission means generates a number of first radio frames having a frame length that defines the second identification information and equal to the number of frames that defines the second identification information. A fifth step of transmitting the first radio frame,
  When the second transmission unit receives the first notification indicating that the adjacent radio apparatus is in a controllable state after the first radio frame is transmitted by the first transmission unit, the second transmission unit transmits data. A program for causing a computer to execute the sixth step. When an error has occurred in the second identification information, the first transmission means has a second radio frame having a frame length representing a MAC address of the adjacent radio device as a backup ID in the fifth step. 23. The program for causing a computer to execute the method according to claim 22, wherein the generated second radio frame is transmitted.

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