JP6064198B2 - Wireless network system and safety confirmation system using the same - Google Patents

Description

  The present invention relates to a wireless network system and a safety confirmation system using the same. In particular, the present invention relates to a radio network system that can be suitably used for a safety confirmation system by reducing power consumption of a node, and a safety confirmation system using the same.

Conventionally, various safety confirmation systems for confirming the safety of elderly people living alone have been proposed (see, for example, Patent Documents 1 and 2).
The safety confirmation system detects these by, for example, pressing a button provided on a terminal installed in the safety confirmation target person's home or detecting the movement of the safety confirmation target person with a sensor. The signal is configured to be transmitted to the management server via the network. When the detection signal is received by the management server, a watcher such as a local government that manages the management server can confirm the safety of the safety confirmation target person. On the other hand, if the detection signal is not received by the management server for a certain period, it is possible that an abnormality has occurred in the safety confirmation target person, and appropriate measures such as rushing to the safety confirmation target person's house can be taken.

  In the safety confirmation system described above, it is preferable to use a wireless network as a network for transmitting and receiving detection signals from the viewpoint of convenience of handling. In particular, when transmitting and receiving a detection signal generated when a safety confirmation target person presses a button included in the terminal, it is desirable to use a wireless network in that the safety confirmation target person can freely carry the terminal.

A so-called multi-hop wireless network is known as a wireless network (see, for example, Patent Documents 3 and 4).
A multi-hop wireless network is a network excellent in ease of installation and flexibility that is spontaneously constructed by small wireless terminals (nodes) and can easily cope with movement and increase of nodes. In this respect, it is considered suitable as a wireless network used for the safety confirmation system.
However, since the nodes constituting the multi-hop wireless network are driven by a battery as a power source, in order to reduce the replacement frequency, it is a problem to reduce the power consumption of the nodes. In particular, when used in the safety confirmation system described above, it is necessary to reduce labor by reducing the frequency with which safety confirmation subjects such as elderly people replace batteries as much as possible. Therefore, it is extremely important to reduce power consumption. It is a problem.

JP 2007-179378 A JP 2012-89106 A JP 2010-231666 A JP 2010-233011 A

  An object of the present invention is to provide a radio network system that can be suitably used in a safety confirmation system by reducing power consumption of a node, and a safety confirmation system using the same.

In order to solve the above-mentioned problem, the present inventor detects various kinds of information, and transmits the detected information as a data packet to the outside wirelessly, receives the data packet, and receives the received data packet. Consider a wireless network system that includes a base station node that transmits to the outside wirelessly, and a relay node that relays the end node and the base station node wirelessly and transmits data packets transmitted from the end node to the base station node. did.
The terminal node is provided with a button for the safety confirmation target person to press, for example. When the safety confirmation subject presses this button, information indicating that the button has been pressed (corresponding to the detected information) is wirelessly transmitted as a data packet from the end node and received by the base station node via the relay node. It will be. Since the base station node wirelessly transmits the received data packet to the outside, the base station node may receive it by, for example, a management server managed by a watcher. If such a wireless network system is used, a watcher of a local government or the like that manages the management server can confirm the safety of the safety confirmation target person.

Here, when using the above-described wireless network system for safety confirmation, the present inventor has the following two timings (1) and (2) as the timing for transmitting the information detected by the end node as a data packet. We thought it important to have a case.
(1) A data packet is transmitted at the timing of detecting information (irregular). Specifically, for example, when a safety confirmation subject presses a button provided at a terminal node, a data packet indicating information that the button is pressed is transmitted.
(2) A data packet is transmitted at predetermined time intervals (periodically). For example, at every predetermined time interval, a data packet indicating an integrated value of the number of times a button provided in the terminal node is pressed during this time interval is transmitted.
The case of (1) is provided in order to immediately notify the base station node and thus the management server of the safety confirmation target person's operation (for example, pressing a button).
On the other hand, the case (2) is provided in order to confirm the operation of each node constituting the wireless network system (confirm whether data packets are normally transmitted / received). In addition, for example, by comparing the integrated values transmitted at predetermined time intervals (the integrated value of the number of times the button is pressed), the button press that is not normally notified to the parent node due to transmission / reception failure is detected. This is also because there is a difference in the integrated value but the button is not pressed.

In both cases (1) and (2), when the transmission / reception of the data packet fails, that is, when the data packet transmitted from the end node is not received by the base station node, this kind of wireless network As is generally done in the system, (a) retransmitting data packets from the end node, and (b) re-searching the path for transmitting data packets from the end node to the base station node (most communication) It is conceivable to search for a route with good quality.
When either of the operations (a) and (b) is performed, since data packets are transmitted and received a plurality of times, the power consumption of the node increases and the battery life is shortened (FIG. 5A). )reference).
When the operation (b) is executed, the data packet transmission / reception cannot be performed because the route for transmitting the data packet is not fixed while the operation is being executed. The cause of the failure of data packet transmission / reception is the instantaneous deterioration of the radio wave condition, and it is also conceivable that the situation will immediately recover. However, even if the radio wave condition immediately recovers, if the operation of (b) is being executed, the data packet cannot be transmitted / received even in the case of (1), so that the safety confirmation target person feels inconvenience. At the same time, there is a problem that urgent information cannot be transmitted.

Therefore, the present inventor has further studied and, when using the wireless network system for safety confirmation, it is considered that at least one base station node should be provided in the safety confirmation target person's house, Since the number of nodes and relay nodes is considered to be small, we focused on the low need for route re-search.
That is, when the transmission / reception of the data packet fails, the above operations (a) and (b) are not performed in both cases (1) and (2), but in the case (1) above, It was considered sufficient to execute only the operation (a) (see FIG. 5B).

The present invention has been completed based on the knowledge of the present inventors.
That is, in order to solve the above-mentioned problem, the present invention detects various types of information, receives a terminal packet that wirelessly transmits the detected information as a data packet to the outside, receives the data packet, and receives the received data packet. A base station node for wirelessly transmitting to the outside, a relay node for wirelessly relaying the terminal node and the base station node, and transmitting a data packet transmitted from the terminal node to the base station node, The terminal node performs a first operation for transmitting the data packet at a timing when the information is detected and a second operation for transmitting the data packet at a predetermined time interval regardless of the timing at which the information is detected. And if the data packet transmitted by the second operation of the end node is not received by the base station node, The end node retransmits the data packet and re-searches a route for transmitting the data packet from the end node to the base station node, and the data packet transmitted by the first operation of the end node is If not received by the base station node, the end node only retransmits the data packet without re-searching the route for transmitting the data packet from the end node to the base station node. A wireless network system is provided.

According to the wireless network system of the present invention, when the data packet transmitted from the end node is not received by the base station node (when transmission / reception of the data packet fails), both the first operation and the second operation are performed. The route is not searched again, but the route is searched again only in the second operation.
Therefore, the power consumption of the node can be reduced, and a radio network system suitable for use in the safety confirmation system is provided.
In addition, when the transmission / reception of a data packet fails due to the instantaneous deterioration of the radio wave condition, the first operation can be executed as soon as the radio wave condition is recovered, so it is easy to use and can transmit urgent information. .

  In order to solve the above problem, the present invention provides the wireless network system arranged in the home of the safety confirmation target and the management server that receives the data packet transmitted from the base station node of the wireless network system. The terminal node of the wireless network system is also provided as a safety confirmation system that detects safety information of a safety confirmation target person.

According to the safety confirmation system according to the present invention, a watcher such as a local government that manages the management server can confirm the safety information of the safety confirmation target person transmitted from the end node.
Further, according to the safety confirmation system according to the present invention, the advantages of the wireless network system according to the present invention described above are utilized.
That is, since it is possible to reduce the power consumption of the node, the frequency of replacement of the battery by a safety confirmation target person such as an elderly person can be reduced, and the labor can be reduced.
In addition, when transmission / reception of a data packet fails due to a momentary deterioration in radio wave condition, the first operation can be executed as soon as the radio wave condition recovers. Will not be able to transmit.

  ADVANTAGE OF THE INVENTION According to this invention, the radio | wireless network system which can be used suitably for a safety confirmation system by reducing the power consumption of a node, and a safety confirmation system using the same are provided.

FIG. 1 is a schematic configuration diagram of a safety confirmation system according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a schematic configuration of a terminal node, a base station node, and a relay node that configure the wireless network illustrated in FIG. FIG. 3 is a time chart for explaining an example of a route re-search method in the wireless network shown in FIG. FIG. 4 is a time chart for explaining another example of a route re-search method in the wireless network shown in FIG. FIG. 5 is a time chart for explaining the relationship between the operation of the end node and the power consumption.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings as appropriate.
FIG. 1 is a schematic configuration diagram of a safety confirmation system according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a schematic configuration of a terminal node, a base station node, and a relay node that configure the wireless network illustrated in FIG. 2A is a plan view of the end node, FIG. 2B is a block diagram of the end node, FIG. 2C is a block diagram of the relay node, and FIG. 2D is a block of the base station node. The figure is shown.
As shown in FIG. 1, the safety confirmation system 100 according to the present embodiment includes a wireless network system 10 and a management server 20. In this embodiment, the wireless network system 10 is arranged for each of the premises of a plurality of safety confirmation subjects. The management server 20 is managed by a watcher such as a local government. FIG. 1 shows an example in which wireless network systems 10a, 10b, and 10c are arranged in the homes of three persons, who are safety confirmation subjects A, B, and A, respectively. Is the same configuration.

  The radio network system 10 according to the present embodiment includes a terminal node 1, a base station node 2, and relay nodes 3 (3a, 3b, 3c). In the example shown in FIG. 1, three relay nodes 3 are provided. However, the present invention is not limited to this, and it is only necessary to provide one or more relay nodes 3, and each wireless network system 10a. -10c may have a different number of relay nodes 3. In addition, the base station node 2 may also function as the relay node 3 (in this case, the wireless network system 10 actually includes only the terminal node 1 and the base station node 2).

As shown in FIG. 2B, the end node 1 is a control unit that executes a variety of arithmetic processing on the button 11 for the safety confirmation target person to press and the data obtained by pressing the button 11. MPU 12, a timer 13 that provides time data for arithmetic processing in the MPU 12, a wireless chip 14 that performs wireless transmission / reception in accordance with instructions from the MPU 12, a ROM 15 that stores arithmetic processing procedures in the MPU 12, and arithmetic in the MPU 12 A RAM 16 is provided for executing data exchange for processing.
With the above configuration, the end node 1 has a function of detecting information that the safety confirmation subject has pressed the button 11 and wirelessly transmitting the detected information to the outside as a data packet by the wireless chip 14.

  Specifically, as illustrated in FIG. 2A, the terminal node 1 is provided with three buttons 11 a to 11 c that are pressed by the safety confirmation target person. For example, the button 11 a is a button for “emergency”, the button 11 b is a button for “greeting”, the button 11 c is a button for “listening”, and the person to whom safety confirmation is to be made is incorrect around each button 11. The meaning of each button 11 is displayed in characters so as not to be pressed. When the safety confirmation person presses one of these buttons 11a to 11c, a data packet indicating information indicating that one of the buttons 11a to 11c is pressed is wirelessly transmitted from the end node 1. For example, a data packet indicating information indicating that the button 11b has been pressed is wirelessly transmitted and received by the management server 20, whereby a watcher such as a local government can confirm the safety of the safety confirmation target person. In addition, a data packet indicating information indicating that the button 11a or 11c has been pressed is wirelessly transmitted and received by the management server 20, so that a watcher of the local government or the like can take an appropriate measure for the safety confirmation target person. Is possible. The reason why both the buttons 11a and 11c are provided is to identify the degree of urgency that requires treatment (it can be identified that the degree of urgency is higher when the button 11A is pressed).

The end node 1 transmits a data packet at the timing when information is detected (ie, when the button 11 is pressed), and every predetermined time interval (for example, every 5 minutes) regardless of the timing at which the information is detected. And a second operation for transmitting a data packet.
In the first operation, a data packet indicating information indicating which of the buttons 11a to 11c is pressed is transmitted.
In the second operation, a data packet indicating an integrated value of the number of times each button 11a to 11c is pressed during a predetermined time interval is transmitted.

As shown in FIG. 2B, the relay node 3 has the same configuration as the end node 1 except that the relay node 3 does not include the button 11. That is, the relay node 3 includes an MPU 12, a timer 13, a wireless chip 14, a ROM 15, and a RAM 16.
With the above configuration, the relay node 3 has a function of relaying the terminal node 1 and the base station node 2 wirelessly and transmitting the data packet transmitted from the terminal node 1 to the base station node 2 by the wireless chip 14.

As shown in FIG. 2C, the base station node 2 includes an MPU 12, a timer 13, a wireless chip (first wireless chip) 14, a ROM 15, and a RAM 16, similarly to the relay node 3. Yes. Further, the base station node 2 includes a second wireless chip 21 that performs wireless transmission / reception in accordance with an instruction from the MPU 12. The first wireless chip 14 is responsible for transmission / reception of data packets with the relay node 3 or the terminal node 1, and the second wireless chip 21 is responsible for transmission / reception of data packets with the management server 20.
With the above configuration, the base station node 2 receives the data packet transmitted from the relay node 3 (transmitted from the terminal node 1) by the first wireless chip 14, and the received data packet is transmitted to the second wireless packet. The chip 21 has a function of transmitting to the outside wirelessly.

  The management server 20 receives the data packet transmitted from the base station node 2 of the wireless network system 10. As shown in FIG. 1, when there are a plurality of wireless network systems 10, data packets transmitted from the base station node 2 of each wireless network system 10 are received.

  For wireless transmission / reception (that is, wireless transmission / reception between the terminal node 1, the relay node 3, and the base station node 2) in the wireless network system 10 carried by the wireless chip (first wireless chip) 14. For example, a wireless communication standard conforming to IEEE 802.15.4 using the 2.4 GHz band can be used. In addition, for wireless transmission and reception between the base station 2 and the management server 20 that the second wireless network 21 serves, for example, a wireless communication method called DCR (Digital Convenience Radio) can be used.

In the safety confirmation system 100 having the above-described configuration, when the transmission / reception of the data packet by the first operation and the second operation of the end node 1 described above in the wireless network system 10 fails (the transmission is performed by the second operation of the end node 1). The operation has the greatest feature in the case where the received data packet is not received by the base station node 2.
That is, if the data packet transmitted by the second operation of the end node 1 is not received by the base station node 2, the end node 1 retransmits the data packet and transmits data from the end node 1 to the base station node 2. Re-search the route to send the packet. On the other hand, if the data packet transmitted by the first operation of the end node 1 is not received by the base station node 2, the end node 1 re-searches the route for transmitting the data packet from the end node 1 to the base station node 2. Without retransmitting the data packet.
Hereinafter, this feature point will be described in detail.

In the wireless network system 100 shown in FIG. 1, the route for transmitting data packets from the terminal node 1 to the base station node 2 follows the order of the terminal node 1, the relay node 3a, the relay node 3b, and the base station node 2. Assuming that When transmission / reception of a data packet fails in the wireless network system 10, the following three cases can be considered in the above example.
(I) A case where transmission / reception of a data packet between the end node 1 and the relay node 3a fails.
(Ii) A case where data packet transmission / reception between the relay node 3a and the relay node 3b fails.
(Iii) A case where data packet transmission / reception between the relay node 3b and the base station node 2 fails.
In this specification, the case (i) will be mainly described as an example.

In both cases of the first operation and the second operation, the data packet is transmitted from the end node 1 to the relay node 3a. When the relay node 3a normally receives the data packet, the relay node 3a transmits an Acknowledge signal (hereinafter referred to as Ack) to the terminal node 1. The terminal node 1 considers that the transmission of the data packet to the relay node 3a is successful when the Ack is received.
On the other hand, when Ack cannot be received within a certain timeout period (for example, several milliseconds), it is considered that transmission of the data packet to the relay node 3a has failed, and the end node 1 retransmits the data packet. The retransmission of the data packet is executed in the same manner when the transmission / reception of the data packet in the first operation fails or when the transmission / reception of the data packet in the second operation fails. In the case (ii), the same operation is performed between the relay nodes 3a and 3b, and in the case (iii), the same operation is performed between the relay node 3b and the base station node 2. .
If the Ack cannot be received even after retransmitting the data packet a certain number of times (for example, about 10 times or less), a route for transmitting the data packet from the terminal node 1 to the base station node 2 only in the case of the second operation. I will search again. Hereinafter, this route re-search method will be described mainly using a method of searching for a parent node of the terminal node 1 as an example.

FIG. 3 is a time chart for explaining an example of a route re-search method in the wireless network shown in FIG.
As illustrated in FIG. 3, the relay nodes 3 a to 3 c each transmit a routing (RTE) packet at a constant time interval (for example, 60 sec). In this RTE packet, as the information of the relay node 3 itself that is transmitting the RTE packet, the identifier of the relay node 3 that is the parent node of the relay node 3 and the communication quality with the base station node 2 are indicated. Parameters to be expressed (communication cost with the base station node 2), the number of hops to the base station node 2 (how many relays are required), and the like are included. The RTE packet includes information on the relay node 3 located in the vicinity of the relay node 3 that is transmitting the RTE packet (hereinafter referred to as “peripheral node”), as an identifier of the peripheral node, A parameter (communication cost between peripheral nodes) indicating communication quality between the nodes is included.

  The terminal node 1 can acquire the candidate of the parent node located around the terminal node 1 by receiving the RTE packet transmitted from each relay node 3. When RTE packets are received from a plurality of relay nodes 3 (in the example shown in FIG. 3, RTE packets are received from all the relay nodes 3a to 3c), the end node 1 receives the RTE packets from the relay node 3 that has received the RTE packets. The relay node 3 considered to be able to perform the best communication is selected and set as its own parent node. Specifically, the end node 1 determines the communication cost between the end node 1 and the relay node 3 (which is held as information by the end node 1 itself), the relay node 3 and the base station node 2 The relay node 3 having the smallest value is set as its own parent node.

In the example shown in FIG. 3, the time interval (for example, 60 sec) + α (for example, 10 sec) at which RTE packets are transmitted so that the end node 1 can receive RTE packets transmitted from all the relay nodes 3 located in the vicinity. Wait for reception. The end node 1 then selects the parent node as described above, and transmits a connection confirmation packet to the parent node. With the above operation, the search for the parent node of the terminal node 1 is completed.
In addition, the re-search of the route between the relay node 3 set as the parent node of the end node 1 as described above and the other relay node 3 or the base station node 2 is also executed in the same procedure. However, each relay node 3 periodically transmits and receives RTE packets, unlike the end node 1 which is in a state of receiving RTE packets only when a route is re-searched. For this reason, each relay node 3 does not execute the operation of receiving the RTE packet again when re-searching the route, and the communication cost next to the relay node 3 or the base station node 2 that has become the parent node before the re-search. Therefore, the relay node 3 or the base station node 2 having a small size is selected as the parent node.

FIG. 4 is a time chart for explaining another example of a route re-search method in the wireless network shown in FIG.
In the example illustrated in FIG. 3, the terminal node 1 receives only the RTE packets transmitted from each relay node 3 at a constant time interval, thereby acquiring only the candidate of the parent node located around the terminal node 1. . However, as shown in FIG. 4, by transmitting an RTE request for requesting transmission of an RTE packet from the end node 1 and receiving an RTE packet transmitted from the relay node 3 that has received the RTE request, It is also possible to adopt a method for acquiring a candidate for a parent node located in The operation after acquiring the candidate of the parent node is the same as the example shown in FIG. 3. By selecting the parent node and transmitting the connection confirmation packet to this parent node, the parent node of the end node 1 is obtained. The node search is complete.
According to the method shown in FIG. 4, since the end node 1 can receive RTE packets transmitted from all the relay nodes 3 located in the vicinity in a short time, the power consumption of the end node 1 compared to the method shown in FIG. Is preferable in terms of reduction.

As described above, according to the wireless network system 10 according to the present embodiment, when the data packet transmitted from the end node 1 is not received by the base station node 2 (when transmission / reception of the data packet fails). The route is not re-searched in both the first operation and the second operation, but the route is re-searched only in the second operation. Therefore, the power consumption of each node such as the terminal node 1 can be reduced.
Moreover, according to the safety confirmation system 100 according to the present embodiment, a watcher of a local government or the like that manages the management server 20 confirms the safety information of the safety confirmation target person transmitted from the end node 1 to the management server 20. Can do. Further, according to the safety confirmation system 100 according to the present embodiment, the advantages of the wireless network system 10 described above are utilized. That is, since it is possible to reduce the power consumption of each node, the frequency of replacement of the battery by the safety confirmation target person such as an elderly person can be reduced, and the labor can be reduced. In addition, when transmission / reception of a data packet fails due to a momentary deterioration in radio wave condition, the first operation can be executed as soon as the radio wave condition recovers. Will not be able to transmit.

DESCRIPTION OF SYMBOLS 1 ... Terminal node 2 ... Base station node 3, 3a, 3b, 3c ... Relay node 10, 10a, 10b, 10c ... Wireless network system 20 ... Management server 100 ... Safety confirmation system

Claims (2)

A terminal node that detects various types of information and wirelessly transmits the detected information to the outside as a data packet;
A base station node that receives the data packet and wirelessly transmits the received data packet to the outside;
A relay node that wirelessly relays between the terminal node and the base station node, and transmits a data packet transmitted from the terminal node to the base station node;
The terminal node performs a first operation for transmitting the data packet at a timing when the information is detected and a second operation for transmitting the data packet at a predetermined time interval regardless of the timing at which the information is detected. And
If the data packet transmitted by the second operation of the end node is not received by the base station node, the end node retransmits the data packet and from the end node to the base station node Re-searching the route for transmitting the data packet;
If the data packet transmitted by the first operation of the end node is not received by the base station node, the end node reroutes the data packet from the end node to the base station node. A wireless network system characterized by only retransmitting the data packet without searching. The wireless network system according to claim 1, wherein the wireless network system is disposed in a premises of a safety confirmation target person,
A management server that receives the data packet transmitted from the base station node of the wireless network system,
The safety confirmation system, wherein the terminal node of the wireless network system detects safety information of a safety confirmation target person.

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