JP6996702B2 - Wireless communication method - Google Patents

Description

The present invention relates to a wireless communication method in a tree-type network in which data is transmitted / received between two or more nodes arranged with a collection control station as a root.

In recent years, in wireless networks, communication devices compliant with the IEEE 802.15.4 standard, which are small in size, inexpensive, and capable of performing low-output digital wireless communication, have been used. In a network compliant with the IEEE 802.15.4 standard, as shown in FIG. 6, a tree type composed of CS (Collection station) 71, which is a collection control station, and one or more nodes 72-1 to 72-4. Topology is adopted. In the tree-type topology, the lower node 72 transmits data to the higher node 72 or CS71 as needed (see, for example, Patent Documents 1 to 3).

In such a tree-type topology, as shown in FIG. 6, it is common that the node 72 is connected to the CS71 via the wireless link 73.

FIG. 7 shows an example of a time chart in the case of transmitting data from lower nodes 72-3 and 72-4 to CS71. The CS71 and each node 72 are assigned an active period (communication period) T1 and a sleep period T2 within the basic interval (intermittent standby cycle) T, respectively. In the communication period T1, wireless communication becomes possible, and in the sleep period T2, the receiving side shifts to the sleep state, so that wireless communication cannot be performed with each other. By intentionally providing the sleep period T2 within the basic interval T, the power consumption can be reduced, and the power consumption of the entire system can be suppressed.

When data is transmitted from the node 72-3 to the CS71, the node 72-1 is relayed from the node 72-3 to become the route of the CS71. In such a case, the upper node 72-1 is the master and the lower node 72-3 is the slave between the node 72-3 and the node 72-1 above the node 72-3. Similarly, between the nodes 72-1 and CS71, the CS71 as the upper node is the master and the lower node 72-1 is the slave. In such a relationship between the master and the slave, the higher master determines the timing of the communication period T1 at the basic interval T, and the lower slave determines the data according to the timing of the communication period T1 determined on the master side. It will be sent.

Under such a rule, in FIG. 7, the node 72-3 first transmits the data D81 generated at the timing t91 in accordance with the communication period T1 of the node 72-1 as the master starting at the timing t92. Upon receiving this data D81, the node 72-1 transmits the data D81 in accordance with the communication period T1 of the CS71 as the master starting at the timing t93. As a result, the CS71 can receive the data D81 within the communication period T1 set by itself.

Similarly, when data is transmitted from the node 72-4 to the CS71, the node 72-4 relays the node 72-1 and becomes the route of the CS71. The node 72-4 transmits the data D82 generated at the timing t94 in accordance with the communication period T1 of the node 72-1 as the master starting at the timing t95. Upon receiving the data D82, the node 72-1 transmits the data D82 in accordance with the communication period T1 of the CS71 as the master starting at the timing t96. As a result, the CS71 can receive the data D82 within the communication period T1 set by itself.

The CS71 can collect all the data from each node 72 in the tree-type network based on the above-mentioned wireless communication processing operation method.

Japanese Unexamined Patent Publication No. 2015-198333 Japanese Unexamined Patent Publication No. 2014-23085 Japanese Unexamined Patent Publication No. 2014-103580

By the way, in the above-mentioned conventional tree-type topology, when the node 72 senses various data like a sensor and collects the data in the CS71, the data may not be urgently competing for every second. Since most of the data is transmitted in accordance with the periodic standby communication period T1 defined by the higher-level node 72 or CS71 as described above, no particular problem occurs.

On the other hand, when the node 72 plays a role as an actuator, that is, when a so-called control system for controlling to stop the valve or controlling to close the gas pipe is added, the control system is applied from the CS71. There is a case where the control system data for controlling this is transmitted to the node 72 of the above. The data D83 of this control system may sometimes be required to stop the valve in an emergency or to stop the gas pipe in an emergency, and may have to transmit the so-called urgent data D83 to the node 72. ..

That is, in the bidirectional communication of the uplink data communication from the node 72 to the CS71 and the downlink data communication from the CS71 to the node 72, the data collection and control by the CS71 have different expected transmission qualities in the first place.

In such uplink data communication and downlink data communication in which the transmission qualities expected from each other are different, the wireless communication methods and communication standards in the nodes 72-1 to 72-4 are often different from each other, and the wireless link 73 corresponds to this. Similarly, the wireless communication methods and communication standards of -1 to 73-4 are often different from each other. For this reason, it is common for the CS71 to be provided with a gateway device 74 in order to perform wireless communication via wireless links 73-1 to 73-4, which may have different communication standards. That is, even if the wireless links 73-1 to 73-4 may have different communication standards, it is possible to perform desired communication with one CS71 by performing various conversions through the gateway device 74. It becomes.

However, the fact that the gateway device 74 must be prepared according to each communication standard of the wireless links 73-1 to 73-4 significantly impairs the ease of installation of the system and reduces the cost of the entire system. This will not be possible, and in turn, it will be an obstacle to the widespread use of the system in society.

Therefore, the present invention has been devised in view of the above-mentioned problems, and an object thereof is a tree type in which data is transmitted / received between two or more nodes arranged with a collection control station as a root. Since the communication quality expected of nodes in a network varies widely, a wireless communication method that can establish a wireless link without installing a gateway device on the collection control station side even if the communication standard is diverse. Is to provide.

In order to solve the above-mentioned problems, the present inventors, when transmitting and receiving data between two or more nodes arranged with the collection control station as the root, the above-mentioned collection control station on the receiving side may perform the above-mentioned. During uplink data communication from each node to the collection control station, a periodic synchronization signal is transmitted, a communication period for periodic standby is provided immediately after that, and a gateway for uplink data communication with each node. The device is omitted, and the standby communication period of the collection control station and / or the communication period for data transmission of each node is adjusted and acquired in advance according to the communication method of uplink data by each node on the transmitting side. We have invented a wireless communication method that can match the communication period for standby with the communication period for data transmission .

The wireless communication method according to claim 1 is a wireless communication method in a tree-type network in which data is transmitted / received between two or more nodes arranged with a collection control station as a root. During uplink data communication from each of the above nodes to the collection control station, a periodic synchronization signal is transmitted, a communication period for periodic standby is provided immediately after that, and uplink data communication is performed with each of the above nodes. The gateway device is omitted, and the standby communication period of the collection control station and / or the communication period for data transmission of each node is adjusted in advance according to the communication method of uplink data by each node on the transmitting side. It is characterized in that the communication period for standby is matched with the acquired communication period for data transmission .

The wireless communication method according to claim 2 continuously transmits an information notification signal including information about a communication period for data transmission from the node in the invention according to claim 1 , and sets the standby communication period. The feature is that the collection control station that receives the information notification signal acquires information on the communication period for data transmission, and matches the communication period for standby with the acquired communication period for data transmission. do.

The wireless communication method according to claim 3 has a reception window period for receiving a synchronization signal transmitted from the collection control station at the node on the transmitting side in the invention according to claim 1 or 2 . When the synchronization signal is received via the window period, the communication period for data transmission is matched with the communication period for standby immediately after the synchronization signal.

The wireless communication method according to claim 4 is a wireless communication method in a tree-type network in which data is transmitted / received between two or more nodes arranged with a collection control station as a root, and the collection control station on the receiving side is described above. During uplink data communication from each node to the collection control station, a periodic synchronization signal is transmitted, a communication period for periodic standby is provided immediately after that, and a gateway for uplink data communication with each node. The device is omitted, and the standby communication period of the collection control station and / or the communication period for data transmission of each node is adjusted and acquired in advance according to the communication method of uplink data by each node on the transmitting side. The first method of adjusting the communication period for standby to the communication period for data transmission, and an information notification signal including information on the communication period for data transmission are continuously transmitted from the node for standby. Information on the communication period for data transmission is acquired by the collection control station that has received the information notification signal via the communication period of, and the communication period for standby is adjusted to the acquired communication period for data transmission. When the second method and the reception window period for receiving the synchronization signal transmitted from the collection control station at the node on the transmission side are provided and the synchronization signal is received through the reception window period, the synchronization signal is received. A third method for adjusting the communication period for data transmission to the standby communication period immediately after the synchronization signal is prepared in advance, and the first method to the above node adopted by the node for uplink data communication. It is characterized in that data is received at the collection control station based on any of the third methods.

The wireless communication method according to claim 5 is a wireless communication method in a tree-type network in which data is transmitted / received between two or more nodes. In the receiving side node, the transmitting side node to the receiving side node. During uplink data communication to, a periodic synchronization signal is transmitted, a communication period for periodic standby is provided immediately after that, and a gateway device for uplink data communication with each of the above nodes is omitted, and the above transmission is performed. For data transmission acquired in advance by adjusting the standby communication period of the receiving node and / or the data transmission communication period of the transmitting node according to the communication method of uplink data by the side node. It is characterized in that the above-mentioned standby communication period is matched with the communication period of .

According to the present invention having the above-described configuration, regardless of which communication method is adopted, the collection control station transmits a periodic synchronization signal and provides a periodic standby communication period immediately after that. Perform operations in common. On the contrary, it is possible to freely respond to the operation of this collection control station, which is commonly performed, regardless of the method adopted by the node. If the node adopts the first method, adjust in advance so that the communication period for standby and the communication period for data transmission overlap each other between the collection control station and the node. As a result, the data can be received without any special control on the collection control station side. If the node adopts the second method, data can be received by setting the standby communication period based on the information regarding the data transmission communication period included in the received information notification signal. can. Furthermore, if the node adopts the third method, the node reads the synchronization signal transmitted from the collection control station and automatically adjusts the communication period for data transmission to the communication period for standby. In particular, data can be received without any special control on the collection control station side.

Data can be received by the collection control station based on any of the first to third methods adopted by the node in performing uplink data communication. In other words, the collection control station side can freely receive data according to any of the first method to the third method regardless of whether the node adopts the first method to the third method.

In particular, the node may be connected to a control system device as described above, or may be connected to a sensor device, and the wireless communication method and communication standard are often different from each other. Therefore, the communication method is not always unified among the nodes, and one node may adopt the first method and another node may adopt the third method. Even when the communication method adopted between the nodes is not unified between the first method and the third method as described above, according to the present invention, the data is freely received by the collection control station side in accordance with the communication method. It becomes possible. Therefore, since the system configuration can include the functions of the gateway device, it is possible to omit connecting the gateway device at the collection control station. Therefore, according to the present invention, when constructing a system, it is not necessary to install gateway devices corresponding to the wireless communication method and communication standard adopted by each node, thereby improving the ease of installation of the system. It is possible to reduce the cost of the entire system.

It is a schematic diagram which shows the example of the wireless communication system to which this invention is applied. It is a figure which shows the example which actually connected the water level sensor and the electric valve to a node. It is a figure for demonstrating the 1st method for adjusting a communication period. It is a figure for demonstrating the 2nd method for adjusting a communication period. It is a figure for demonstrating the 3rd method for adjusting a communication period. It is a figure which shows the example of the network which conforms to the standard of IEEE802.15.4. It is a figure for demonstrating the problem of the prior art.

First Embodiment Hereinafter, the wireless communication method as the first embodiment of the present invention will be described in detail. FIG. 1 is a schematic diagram showing an example of a wireless communication system 1 to which the present invention is applied. The wireless communication system 1 includes two or more nodes 3-1, 3-2, 3-3 rooted at a collection control station (Collection Station: hereinafter referred to as CS) 2 as a wireless communication terminal, and is a so-called tree type. Topology is adopted. In this wireless communication system 1, a lower-level node 3 performs uplink data communication toward a higher-level node 3 or CS2. Further, in the wireless communication system 1, the higher-level node 3 and CS2 perform downlink data communication toward the lower-level node 3.

The CS2 is the highest-level master device, and collects data wirelessly transmitted by uplink data communication from each node 3-1 to 3-3. The CS2 also plays a role as a central control unit for controlling the entire wireless communication system 1, and performs downlink data communication of control system data to a specific node 3. It is premised that no so-called gateway device is connected to this CS2, or that the function of this gateway device is not implemented inside at all.

Node 3 is a general term for devices capable of transmitting and receiving data such as transmission and relay of data, and is, for example, a communication device compliant with the standard of IEEE 802.15.4. The node 3 may be embodied as a sensor that senses predetermined data and transmits it wirelessly, for example, a mobile phone, a smartphone, a tablet terminal, a wearable terminal, a notebook personal computer (PC), or the like. It may be embodied as a terminal device capable of wireless communication such as. Further, the node 3 may be connected to a control system such as an actuator, or may be connected to various sensors.

The example of FIG. 2 shows an example in which the water level sensor 31 is actually connected to the node 3-1 and the electric valve 32 is connected to the node 3-2. Incidentally, in the example of FIG. 2, a programmable logic controller (PLC) 33 may be connected to CS2 to control the control of the entire system. Although such a PLC 33 may be connected to play a role as the CS2, the CS2 itself may operate as the PLC 33 by mounting the function of the PLC 33 on the CS2 side.

Further, CS2 may be configured to perform wireless communication with CS2'in another network. The PLC 33'is also connected to the CS2', and the PLC 33'is connected to the public communication network 36 including the telephone communication network, but the CS2 is also connected to the public communication network 36. May be good.

Further, as an alternative to controlling the electric valve 32 as a control system connected to the node 3-2, for example, control for stopping the valve, control for the robot, or control for stopping the gas can be performed. It may be embodied as a possible device. If the node 3 is embodied as an actuator including a control system, various control operations should be executed based on the control data transmitted from CS2 via the other node 3 for downlink data. It becomes.

In the present embodiment, as shown in the wireless communication system 1 shown in FIG. 1, a case where four nodes 3-1, 3-2, and 3-3 are arranged under CS2 will be described as an example. However, it is not limited to this. That is, the node 3 arranged in the lower link of CS2 may have a tree structure composed of any branching pattern as long as it causes CS2 to collect data, and may have any number of nodes of 2 or more. It may be configured. Further, the node 3 may be further arranged in the further lower link of the nodes 3-1 to 3-3.

Next, a processing operation method of the wireless communication system 1 to which the present invention is applied will be described. The CS2 and / or each node 3 adjusts the communication period according to the communication method of the uplink data by each node 3 on the transmitting side in the wireless communication system 1. In adjusting the communication period, any one of the first method, the second method, and the third method described below is used.

In the first method, as shown in FIG. 3, in the process of performing uplink data communication from each node 3 to CS2, CS2 transmits a periodic synchronization signal S1 and is for periodic standby immediately after that. Communication period S2 is provided. In CS2, only this communication period S2 is the active period, but in the other inactive periods, the power consumption of the entire device is suppressed by shifting to the sleep state.

As shown in FIG. 3, the node 3 on the data transmission side is periodically provided with a standby communication period S3. The standby communication period S3 may be periodically provided at each predetermined basic time interval in the node 3. When the data to be actually transmitted occurs at the timing t1, it is transmitted to CS2 via the communication period S4 for data transmission. The communication period S4 for data transmission will be described by taking as an example the case where it is set immediately after the communication period S3 for standby, but the present invention is not limited to this, and the communication period S4 is freely set in the node 3. It may have been done.

When data to be transmitted occurs at timing t1, the data is directed to CS2 in the data transmission communication period S4 immediately after the next standby communication period S3 at which the basic time interval including this timing t1 ends. Will be sent. At this time, the CS2 side acquires in advance at what timing the communication period S4 for data transmission can occur. If the communication period S4 for data transmission is set immediately after the next standby communication period S3 at the end of the basic time interval, CS2 itself recognizes that fact in advance. The CS2 may acquire that fact from the node 3 in advance before the operation of this system. At this time, the CS2 may acquire the communication period S4 itself for data transmission from the node 3 in advance, or obtain information such as the standby communication period S3 and the basic time interval in advance. The communication period S4 for data transmission may be estimated from the communication period S4.

The CS2 provides its own standby communication period S2 in accordance with the acquired communication period S4 for data transmission. As a result, an overlapping time occurs between the communication period S4 for data transmission and the communication period S2 for standby. As a result, the CS2 can receive data from the data transmission communication period S4 in the standby communication period S2. The CS2 may extend or extend the standby communication period S2 according to the communication period S4 to be matched. It is not essential that the standby communication period S2 and the data transmission communication period S4 completely overlap, and it is sufficient that at least a part of the communication period S2 matches in time.

In the above description of the first method, the case where the CS2 side acquires the communication period S4 for data transmission in advance and then adds the communication period S2 for standby to this is described as an example, but the explanation is limited to this. It is not something that will be done. The node 3 side may acquire the standby communication period S2 from the CS and match it with the data transmission communication period S4.

In any case, it is based on any method as long as the standby communication period S2 and the data transmission communication period S4 are adjusted in advance so as to overlap each other between CS2 and node 3. It may be a thing.

The second method is a method in which only the CS2 side is obliged to adjust the communication period S2 for its own standby. As shown in FIG. 4, the CS2 transmits a periodic synchronization signal S1 and is provided with a periodic standby communication period S2 immediately after that, which is the same as the first method.

As shown in FIG. 4, the node 3 on the data transmission side continuously transmits the information notification signal S5 when the data to be transmitted to the CS2 is generated at the time point t1. Each information notification signal S5 contains information regarding the communication period S4 for subsequent data transmission. The information regarding the communication period S4 may include information regarding how many seconds after the transmission or reception of the information notification signal S5 the communication period S4 comes. For example, the information notification signal S5 located at the head contains information that the communication period S4 comes after 1 second, and the following information notification signal S5 has the communication period S4 after 0.9 seconds. Information to that effect is included, and further, the information notification signal S5 that follows contains information that the communication period S4 will come after 0.8 seconds. As the information notification signal becomes later in time series, the interval from the communication period S4 for data transmission becomes shorter, but such information is included in each information notification signal S5.

The node 3 receives this information notification signal S5 via the standby communication period S2. Since the communication period S2 is set periodically, the communication period S2 may not be set and a sleep state may occur depending on the time zone. However, in the node 3, the information notification signal S5 is continuously transmitted over a plurality of times so that the transmission time at least once coincides with the communication period S2. As a result, the CS2 can receive the information notification signal S5 from the node 3 via the communication period 2.

Upon receiving the information notification signal S5, CS2 decodes the information contained therein. As a result, the CS2 can determine how many seconds after the transmission or reception of the information notification signal S5 the communication period S4 comes. Then, the standby communication period S2 is newly set so that at least a part thereof overlaps with the determined data transmission communication period S4 in time. If it is determined in the information notification signal S5 that the communication period S4 will come 0.8 seconds after the reception, the standby communication period S2 is set 0.8 seconds after the reception to match this. As a result, the CS2 can receive data from the data transmission communication period S4 in the standby communication period S2. The CS2 may extend or extend the standby communication period S2 according to the communication period S4 to be matched.

The third method is a method in which only the node 3 side is obliged to adjust the communication period S4 for its own data transmission. As shown in FIG. 5, the CS2 transmits a periodic synchronization signal S1 and provides a periodic standby communication period S2 immediately after that, which is the same as the first and second methods.

As shown in FIG. 5, the node 3 on the data transmission side is provided with a reception window period S6. The reception window period S6 is a period for receiving the synchronization signal S1 transmitted from CS2. The node 3 starts the detection of the synchronization signal S1 by setting the reception window period S6 after the data to be transmitted to the CS2 is generated at the time point t1.

Since the synchronization signal S1 transmitted from the CS2 is periodically transmitted, the synchronization signal S1 can always be received at a certain timing by setting the reception window period S6 and continuously detecting the synchronization signal S1. can. Since the standby communication period S2 continues immediately after the synchronization signal S1, the node 3 sets the communication period S4 for data transmission immediately after receiving the synchronization signal S1. As a result, the CS2 can receive data from the communication period S4 for data transmission in the communication period S2 for standby. The CS2 may extend or extend the standby communication period S2 according to the communication period S4 to be matched.

Regardless of which method the node 3 adopts, the CS2 commonly performs an operation of transmitting a periodic synchronization signal S1 and providing a periodic standby communication period S2 immediately after that. On the contrary, it is possible to freely respond to the common operation of CS2 regardless of the method adopted by the node 3. If the node 3 adopts the first method, the CS2 and the node 3 are adjusted in advance so that the standby communication period S2 and the data transmission communication period S4 overlap each other in time. By setting the data, the data can be received without any special control on the CS2 side. If the node 3 adopts the second method, the data is stored by setting the standby communication period S2 based on the information regarding the data transmission communication period S4 included in the received information notification signal S5. Can be received. Further, if the node 3 adopts the third method, the node 3 reads the synchronization signal S1 transmitted from the CS2 and automatically adjusts the communication period S4 for data transmission to the communication period S2 for standby. Therefore, the data can be received without any special control on the CS2 side.

It is possible to receive data in CS2 based on any of the first to third methods adopted by the node 3 in performing uplink data communication. In other words, the CS2 side can freely receive data regardless of whether the node 3 adopts any of the first method to the third method.

In particular, the node 3 may be connected to a control system device or a sensor device as described above, and often have different wireless communication methods and communication standards. Therefore, the communication method is not always unified among the nodes 3, and one node 3 may adopt the first method and the other node 3 may adopt the third method. .. That is, since the communication quality expected at the node varies widely, the communication standard may vary. Even when the communication method adopted between the nodes 3 is not unified between the first method and the third method as described above, according to the present invention, data can be freely received on the CS2 side in accordance with the communication method. Is possible. Therefore, since the system configuration can include the functions of the gateway device, it is possible to omit connecting the gateway device in CS2. Therefore, according to the present invention, when constructing a system, it is not necessary to install gateway devices corresponding to the wireless communication method and communication standard adopted by each node 3, thereby improving the ease of installation of the system. This makes it possible to reduce the cost of the entire system.

The present invention is not limited to the above-described embodiment. For example, if two or more nodes 3-1 to 3-3 rooted in CS2 are all the first method, data is transmitted and received between CS2 and nodes 3-1 to 3-3 based on the first method. After that, the uplink data communication may be performed based only on the first method. If two or more nodes 3-1 to 3-3 rooted in CS2 are all in the second method, data is transmitted and received between CS2 and nodes 3-1 to 3-3 based on the second method. After that, uplink data communication may be performed based only on the second method. If two or more nodes 3-1 to 3-3 rooted in CS2 are all in the third method, data is transmitted and received between CS2 and nodes 3-1 to 3-3 based on the third method. After that, uplink data communication may be performed based only on the third method.

The CS2 may determine in advance whether or not all the nodes 3-1 to 3-3 are unified by any of the first method to the third method. As a result, if all the nodes 3-1 to 3-3 are any of the first method to the third method, uplink data communication is performed between the node 3 and CS2 based on the unified method. Become.

Further, the above-mentioned node 3 may be a concept including CS2. That is, the processing performed in each node 3 may be performed in CS2, or the processing performed in CS2 may be performed in node 3. Further, CS2 may be replaced with so-called node 3.

Of course, each of the above-mentioned processes can be similarly applied to the communication between CS2 and the node 3 and the communication between the nodes 3.

Further, according to the present invention having the above-mentioned configuration, CS2 may be omitted, or it may be applied in communication between two or more nodes 3. In such a case, CS2 is replaced by the node on the receiving side, and node 3 becomes the node on the transmitting side. Each process in CS2 and node 3 described above is executed as it is in the node on the receiving side and the node on the transmitting side.

1 Wireless communication system 2 CS
3 node 31 water level sensor 32 electric valve 33 PLC
36 Public communication network

Claims (5)

In a wireless communication method in a tree-type network that sends and receives data between two or more nodes arranged with a collection control station as the root.
The collection control station on the receiving side transmits a periodic synchronization signal at the time of uplink data communication from each node to the collection control station, and provides a periodic standby communication period immediately after that, and also provides the above-mentioned communication period for standby. Omitting the gateway device for uplink data communication with each node,
Adjust the standby communication period of the collection control station and / or the communication period for data transmission of each node according to the communication method of uplink data by each node on the transmitting side.
A wireless communication method characterized in that the communication period for standby is matched with the communication period for data transmission acquired in advance . An information notification signal including information on the communication period for data transmission is continuously transmitted from the node.
Information on the communication period for data transmission is acquired by the collection control station that has received the information notification signal via the communication period for standby, and the communication for standby is performed during the acquired communication period for data transmission. The wireless communication method according to claim 1 , wherein the period is adjusted. A reception window period for receiving the synchronization signal transmitted from the collection control station is provided at the node on the transmission side, and when the synchronization signal is received through the reception window period, immediately after the synchronization signal. The wireless communication method according to claim 1 or 2 , wherein the communication period for data transmission is combined with the communication period for standby following. In a wireless communication method in a tree-type network that sends and receives data between two or more nodes arranged with a collection control station as the root.
The collection control station on the receiving side transmits a periodic synchronization signal at the time of uplink data communication from each node to the collection control station, and provides a periodic standby communication period immediately after that, and also provides the above-mentioned communication period for standby. Omitting the gateway device for uplink data communication with each node,
Adjust the standby communication period of the collection control station and / or the communication period for data transmission of each node according to the communication method of uplink data by each node on the transmitting side.
The first method of matching the communication period for standby with the communication period for data transmission acquired in advance, and
The data transmission is performed by the collection control station that continuously transmits an information notification signal including information on the communication period for data transmission from the node and receives the information notification signal via the standby communication period. The second method of acquiring information on the communication period and matching the acquired communication period for data transmission with the communication period for standby, and
When the reception window period for receiving the synchronization signal transmitted from the collection control station is provided in the node on the transmission side and the synchronization signal is received through the reception window period, immediately after the synchronization signal. Prepare in advance a third method that matches the communication period for data transmission with the communication period for standby following.
A wireless communication method characterized in that data is received by the collection control station based on any one of the first method to the third method adopted by the node in performing uplink data communication. In a wireless communication method in a tree-type network that sends and receives data between nodes arranged over two or more.
At the receiving node, a periodic synchronization signal is transmitted at the time of uplink data communication from the transmitting node to the receiving node, and a periodic standby communication period immediately following the transmission is provided, and each of the above is provided. Omitting the gateway device for uplink data communication with the node,
Adjust the standby communication period of the receiving node and / or the data transmission communication period of the transmitting node according to the uplink data communication method of the transmitting node.
A wireless communication method characterized in that the communication period for standby is matched with the communication period for data transmission acquired in advance .

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