Data transmission method, apparatus, system, electronic device, and storage medium

Abstract

The application provides a data transmission method, device, system, electronic equipment and storage medium, and relates to the technical field of communication. The method comprises the following steps: after determining that a target destination advertising object (DAO) corresponding to a target sub-node is acquired, acquiring a target return time interval of the target sub-node in a next data return period according to address information of the target sub-node; generating a destination advertising object acknowledgement (DAO-ACK) of the target sub-node based on timestamp information of a current time and the target return time interval, and sending the DAO-ACK to the target sub-node, so that the target sub-node determines a data return time through the target return time interval after completing time correction according to the timestamp information. The application avoids packet collision caused by the fact that all sub-nodes return data at adjacent times, and improves the success rate of returned data.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a data transmission method, apparatus, system, electronic device, and storage medium. Background Technology

[0002] Low-power and lossy wireless networks (LLNs) are characterized by low power consumption and limited storage resources, and are currently widely used in transportation, industry, and power sectors.

[0003] Existing LLNs networks primarily consist of embedded devices with limited power, storage space, and processing capabilities (such as smart meters in smart grids). These devices, acting as nodes in the LLN network, send relevant data to gateway nodes, essentially reporting data to the gateway. For example, the gateway node of a smart meter box sends electricity bill information, which is then sent to a server for analysis. To reduce costs, external batteries are typically used for power, allowing these devices to remain in sleep mode for most of the time, except for periodically reporting data to the gateway node, thus conserving battery power.

[0004] However, if the time intervals for data reporting between devices are too close together, packet collisions can easily occur, leading to packet loss. The cost of resending after a failure not only increases battery consumption and shortens device lifespan, but also significantly reduces the success rate of individual child nodes (such as smart meters) within the reporting time limit. Therefore, there is an urgent need for a data transmission method, device, system, electronic device, and storage medium to solve these problems. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a data transmission method, apparatus, system, electronic device and storage medium.

[0006] This invention provides a data transmission method applied to a root node, comprising: After determining the target broadcast object (DAO) corresponding to the target child node, the target reporting time interval of the target child node in the next data reporting cycle is obtained based on the address information of the target child node. Based on the current timestamp information and the target reporting time interval, a DAO-ACK is generated for the target child node, and the DAO-ACK is sent to the target child node so that the target child node can determine the data reporting time through the target reporting time interval after completing time synchronization based on the timestamp information.

[0007] According to a data transmission method provided by the present invention, the step of obtaining the target reporting time interval of the target child node in the next data reporting cycle based on the address information of the target child node includes: Obtain the Media Access Control (MAC) address of the target child node; The MAC address is hashed using a hash algorithm to obtain the hash value corresponding to the MAC address; Based on the hash value, the target return time interval for the target child node in the next data return cycle is determined.

[0008] According to a data transmission method provided by the present invention, determining the target return time interval of the target child node in the next data return cycle based on the hash value includes: Based on the preset return period duration and interval unit duration, the data return period is divided into multiple return time intervals, and each of the return time intervals is marked with a corresponding return time interval number in chronological order. Using the hash value, a modulo operation is performed on the number of the multiple return time intervals, and based on the return time interval sequence number corresponding to the modulo result, the target return time interval of the target child node in the next data return cycle is determined from the multiple return time intervals.

[0009] According to a data transmission method provided by the present invention, generating DAO-ACK information for the target child node based on the timestamp information of the current moment and the target report time interval includes: Based on the timestamp information and the target return time interval, add the timestamp field and the return time interval field to the pre-sent DAO-ACK to generate the DAO-ACK for the target child node.

[0010] According to a data transmission method provided by the present invention, the step of adding a timestamp field and a return time interval field to the pre-sent DAO-ACK based on the timestamp information and the target return time interval to generate the DAO-ACK of the target child node includes: Based on the timestamp information, determine the timestamp encoding type and timestamp encoding length; Based on the target return time interval, determine the return time interval encoding type and the return time interval encoding length; The timestamp field is constructed based on the timestamp encoding type and the timestamp encoding length; The return time interval field is constructed based on the return time interval encoding type and the return time interval encoding length; Add the timestamp field and the return time interval field to the Option of the pre-sent DAO-ACK to generate the DAO-ACK for the target child node.

[0011] According to a data transmission method provided by the present invention, before dividing the data return period into multiple return time intervals based on a preset return period duration and an interval unit duration, the method further includes: The type of hash algorithm and the number of reward time intervals are determined based on the number of child nodes in the wireless low-power lossy network.

[0012] According to a data transmission method provided by the present invention, before obtaining the target return time interval of the target child node in the next data return cycle based on the address information of the target child node, the method further includes: Confirm the transmission mode of the wireless low-power lossy network; If the transmission mode is non-storage mode, obtain the DAO sent by the target child node.

[0013] According to a data transmission method provided by the present invention, obtaining the DAO sent by the target child node includes: Broadcast a directed acyclic graph information object (DIO) for the target node, so that after the target child node obtains the DIO, it can determine the parent node of the target child node in the target directed acyclic graph (DODAG) for the target node, wherein the target directed acyclic graph (DODAG) for the target node is the DODAG corresponding to the root node. The parent node obtains the DAO sent by the target child node.

[0014] The present invention also provides a data transmission method applied to a child node, comprising: Obtain the Destination Broadcast Object Acknowledgment (DAO-ACK) sent by the target node, where the target node is the target root node or target parent node corresponding to the child node; The DAO-ACK is parsed to obtain timestamp information and target return time interval, wherein the timestamp information is the timestamp when the target node generates the DAO-ACK, and the target return time interval is obtained by the target node based on the address information of the child node; The time is synchronized using the timestamp information, and after the time synchronization is completed, the data return time in the next data return cycle is determined based on the target return time interval. When the current time is the data reporting time, send the reporting data to the target node.

[0015] According to a data transmission method provided by the present invention, obtaining the DAO-ACK information sent by the target node includes: Broadcast a Directed Acyclic Graph Information Request (DIS) for the destination node, so that the neighboring nodes corresponding to the child node, upon receiving the DIS, will send their respective Directed Acyclic Graph Information Objects (DIOs) for the destination node to the child node. Based on the received DIOs, determine the target parent node; Send the target broadcast object (DAO) to the target parent node and obtain the DAO-ACK sent by the target parent node or the DAO-ACK sent by the target root node.

[0016] According to a data transmission method provided by the present invention, parsing the DAO-ACK to obtain timestamp information includes: Obtain the transmission mode of wireless low-power lossy networks; If the transmission mode is storage mode, the DAO-ACK is parsed to obtain the first timestamp information, which is the timestamp when the target parent node generates the DAO-ACK.

[0017] According to a data transmission method provided by the present invention, the method further includes: If the transmission mode is non-storage mode, the DAO-ACK is parsed to obtain the second timestamp information, which is the timestamp when the target root node generates the DAO-ACK.

[0018] According to a data transmission method provided by the present invention, the target reporting time interval is determined by the target node performing a hash operation on the media access control MAC address of the child node, and based on the obtained hash value, the reporting time interval of the child node in the next data reporting cycle.

[0019] According to a data transmission method provided by the present invention, determining the data return time within the next data return cycle based on the target return time interval includes: Obtain the number of time intervals for the next data return cycle. The number of time intervals for the data return cycle is obtained by dividing the data return cycle based on a preset return cycle duration and interval unit duration. The target return time interval sequence number is determined by the target node based on the hash value corresponding to the MAC address of the child node, performing a modulo operation on the number of multiple return time intervals, and determining the sequence number from multiple return time intervals based on the modulo result; the return time interval sequence number is obtained by the target node marking each of the return time intervals with a corresponding sequence number in chronological order. Based on the return time interval number and the start time of the next data return period, the data return time within the next data return period is determined.

[0020] According to a data transmission method provided by the present invention, after sending the return data to the target node when the current time is the data return time, the method further includes: Upon completion of the data reporting task for the current data reporting cycle, a first input is received, which includes an operation to execute a dormant state. In response to the first input, the sleep state is executed, and when the data report time of the next data report cycle arrives, the sleep state is switched to the working state.

[0021] The present invention also provides a data transmission device applied to a root node, comprising: The time interval grouping module is used to obtain the target reporting time interval of the target child node in the next data reporting cycle based on the address information of the target child node after determining that the target broadcast object (DAO) corresponding to the target child node has been obtained. The confirmation information generation module is used to generate a DAO-ACK for the target child node based on the timestamp information of the current time and the target reporting time interval, and send the DAO-ACK to the target child node so that the target child node can determine the data reporting time through the target reporting time interval after completing the time synchronization based on the timestamp information.

[0022] The present invention also provides a data transmission device applied to a child node, comprising: The receiving module is used to obtain the DAO-ACK acknowledgment information sent by the target node, wherein the target node is the target root node or the target parent node corresponding to the child node; The parsing module is used to parse the DAO-ACK to obtain timestamp information and target return time interval, wherein the timestamp information is the timestamp when the target node generates the DAO-ACK, and the target return time interval is obtained by the target node based on the address information of the child node; The time synchronization module is used to synchronize the time using the timestamp information, and after the time synchronization is completed, to determine the data return time in the next data return cycle based on the target return time interval; The data reporting module is used to send reporting data to the target node when the current time is the data reporting time.

[0023] The present invention also provides a data transmission system, including a root node applied to the above-described data transmission device, and child nodes applied to the above-described data transmission device.

[0024] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the data transmission method as described above.

[0025] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the data transmission method as described above.

[0026] The data transmission method, apparatus, system, electronic device, and storage medium provided by this invention perform time synchronization and report interval grouping for child nodes in a wireless low-power lossy network by using the control packet DAO-ACK in the wireless low-power lossy network routing protocol. This eliminates the need to increase the burden on the wireless low-power lossy network through additional broadcast or unicast packet methods, ensuring that the report data of each child node in the DODAG is evenly distributed within the specified time interval. This avoids packet collisions caused by all child nodes reporting data in adjacent time periods, thereby improving the success rate of report data. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 One of the flowcharts of the data transmission method provided by the present invention; Figure 2 This is a structural diagram of the wireless low-power lossy network provided by the present invention; Figure 3 A schematic diagram illustrating the process of dividing the return time interval provided by the present invention; Figure 4 A schematic diagram of the modified DAO-ACK packet structure provided by this invention; Figure 5A schematic diagram illustrating the data interaction process between the root node and child nodes provided by the present invention; Figure 6 The second schematic diagram of the data transmission method provided by the present invention; Figure 7 This is one of the structural schematic diagrams of the data transmission device provided by the present invention; Figure 8 This is a second schematic diagram of the structure of the data transmission device provided by the present invention; Figure 9 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0030] In LLNs networks, a destination-oriented directed acyclic graph (DODAG) topology is constructed and maintained using the Routing Protocol for Low Power and Lossy Networks (RPL). This topology originates from the root node of a specified RPL network and is constructed using an objective function (OF) according to certain objectives (such as shortest path, measured by latency, bandwidth, and cost). Since LLNs networks generally do not predefine the destination of a particular sending node, nodes within the network must discover other nodes themselves and establish communication according to RPL network rules. Therefore, RPL routing utilizes the DODAG to aggregate all outgoing channels from all nodes within the network topology to the specified root node, while external information also enters from the root node and is distributed to nodes within the network. In the RPL network, each node corresponds to only one DODAG in an RPLInstance. An RPL instance includes one or more DODAGs. Each RPL Instance operates independently of other RPL Instances, has a unique RPL Instance ID, and all DODAGs within the same RPL Instance use the same OF to calculate their Rank value.

[0031] Root nodes are typically network boundary routers, such as gateway nodes in smart meters or smart water meters. They receive data periodically reported by their child nodes, which then transmit the collected data to the root node via a wireless network, depending on the application scenario. Routing information in RPL networks, on the other hand, is propagated intermittently via broadcast beacons and trickle timers.

[0032] In an RPL network, each node has a designated Rank, calculated using a pre-defined OF (Order of Decision) and increasing as child nodes move further away from the root node. Child nodes use DODAG (Directed Directed Request) to send datagrams to the root node, selecting the shortest path as the routing criterion. DODAG is established based on control packets transmitted between child nodes in the RPL network, including DODAG Information Solicitation (DIS), DODAG Information Object (DIO), Destination Advertisement Object (DAO), and Destination Advertisement Object Acknowledgement (DAO-ACK).

[0033] Specifically, DIS can be used to request DIO from RPL nodes, similar to the router request specified in the IPv6 (Internet Protocol Version 6) neighbor discovery protocol, allowing each node to probe the neighborhood of nearby DODAGs via DIS; The information carried by DIO allows nodes to discover RPL instances and understand their parameter configurations. It can help nodes find suitable RPL instances, select a set of DODAG parent nodes, determine the optimal parent node, and finally join the corresponding DODAG. DAOs are used to transmit propagation destination information for the uplink path in a DODAG and record information about the nodes traversed along the path, thereby populating the routing table of the parent node. Uplink transmission in the RPL network includes both stored and non-stored modes. In stored mode, the DAO is unicast from the child node to the selected parent node; in non-stored mode, the DAO is unicast to the root node of its corresponding DODAG graph. Additionally, DAOs are optional in case of explicit requests or errors, and the destination node sends a returned DAO-ACK to the sender (child node) of the DAO for acknowledgment. DAO-ACK is sent as a unicast packet by the DAO receiver (parent node or root node) in response to the received unicast DAO.

[0034] In current LLNs networks, RPL network routing technology is often used to construct the basic network topology. An RPL instance is formed within a field, and nodes within the field select the best parent node based on OF (Optical Frequency) to join, ultimately forming multiple DODAGs. Child nodes, as intelligent devices, have different functions depending on their location. For example, after collecting data from sensors such as electricity or water meters, they periodically report the data to the root node. The root node acts as a gateway, collecting and summarizing the data before sending it to the backend server for analysis. Since child nodes mainly consist of devices with limited power, storage space, and processing capabilities, they often remain in sleep mode to conserve battery power. When the data reporting times between child nodes are too frequent, packet collisions and packet loss can easily occur, significantly reducing the data reporting success rate and wasting node resources.

[0035] Figure 1 This is one of the flowcharts illustrating the data transmission method provided by the present invention, such as... Figure 1 As shown, the present invention provides a data transmission method applied to the root node, comprising: Step 101: After determining that the target broadcast object (DAO) corresponding to the target child node has been obtained, the target reporting time interval of the target child node in the next data reporting cycle is obtained according to the address information of the target child node. In this invention, the root node in the RPL network protocol is used as the execution subject for explanation. It should be noted that in this embodiment, the transmission mode is non-storage mode, which allows the root node to obtain the DAO through the parent node corresponding to the target child node, and then send the DAO-ACK containing the time synchronization information and the report interval information to the child node.

[0036] In this embodiment, after the root node completes its configuration, it broadcasts a DIO containing DODAG graph configuration information (e.g., DODAG ID information, OF, and existing node Rank values) to each node in the network. Upon receiving the DIO, each node determines whether to join the DODAG based on the relevant information in the DIO. Further, after deciding to join the DODAG, each node calculates its own Rank value based on the previously set OF and broadcasts the calculated Rank value through the DIO. This allows other nodes in the DODAG to also calculate their own Rank values ​​upon receiving the DIO. Then, by comparing the shortest path to the root node (i.e., the one with the least cost), the optimal parent node is selected, and the DAO is unicast to this parent node. Subsequently, this parent node, in non-storage mode, forwards the DAO unicast by the target child node to the root node based on its own routing table information.

[0037] Furthermore, since DAO is an improvement on ICMPv6 (Internet Control Message Protocol version 6), the relevant fields of DAO also contain source address information (such as the MAC address and IP information of the target child node). When the root node receives the DAO, it can calculate the return time interval of the target child node based on this address information. This ensures that there is a certain time interval between child nodes in different return time intervals when they report data to the root node, which can minimize packet collisions.

[0038] It should be noted that in this invention, for a node that has been added to the DODAG, if it receives a DIO sent by a neighboring node again, and if it obtains a lower Rank value through OF calculation, it will change its position in the DODAG, update its parent node information, and send the DAO to the root node again through the new parent node.

[0039] Step 102: Based on the timestamp information of the current moment and the target reporting time interval, generate the DAO-ACK of the target child node and send the DAO-ACK to the target child node so that the target child node can determine the data reporting time through the target reporting time interval after completing the time synchronization according to the timestamp information.

[0040] In this invention, Figure 2 The structural diagram of the wireless low-power lossy network provided by this invention can be referred to. Figure 2 As shown, a child node (such as node 3) sends a DAO to the root node through its parent node (such as node 1). Upon receiving the DAO, the root node first adds a timestamp to the corresponding field of the DAO-ACK to be sent using the Network Time Protocol (NTP), thus transmitting a time message packet to the child node. This allows the target child node receiving the timestamp to perform time synchronization. Simultaneously, the relevant information about the target reporting time interval obtained in step 101 is also added to the corresponding field of the DAO-ACK to be sent, thus sending the constructed DAO-ACK to the target child node. After parsing the received DAO-ACK, the target child node corrects its local clock and determines its own reporting time based on the target reporting time interval. For example, if the interval between reporting time intervals is 1 second, and the target reporting time interval is the 10th interval, the target child node will begin reporting data 10 seconds after the start time of the next data reporting cycle.

[0041] The data transmission method provided by this invention uses the control packet DAO-ACK in the wireless low-power lossy network routing protocol to perform time synchronization and report interval grouping for child nodes in the wireless low-power lossy network. This eliminates the need to increase the burden on the wireless low-power lossy network through additional broadcast or unicast packet methods, and ensures that the report data of each child node in the DODAG is evenly distributed within the specified time interval, avoiding packet collisions caused by all child nodes reporting data in adjacent time periods, and improving the success rate of report data.

[0042] Based on the above embodiments, the step of obtaining the target return time interval of the target child node in the next data return cycle according to the address information of the target child node includes: Obtain the Media Access Control (MAC) address of the target child node; The MAC address is hashed using a hash algorithm to obtain the hash value corresponding to the MAC address; Based on the hash value, the target return time interval for the target child node in the next data return cycle is determined.

[0043] In this invention, a hash function is used to perform hash calculations on the Media Access Control (MAC) address of the target child node, thereby obtaining the hash value corresponding to the MAC address. Hash algorithms typically use a short string of random letters and numbers to represent the hash value, compressing messages or data into a digest, reducing data volume, and fixing the data format. Because the data is shuffled and mixed, hash collisions are minimized in the input domain. Accordingly, in this invention, since the MAC address is converted into a hash value, different nodes correspond to different hash values. Furthermore, based on this hash value, the data return times of each child node can be grouped, such as by establishing a group list corresponding to each hash value. Preferably, in one embodiment, each child node can be divided into a corresponding return time interval by performing a modulo operation on the hash value according to a preset return period duration. In another embodiment, hash calculations can also be performed based on the IP address information of the target child node; the specific process can be referred to the process of hash calculation using the MAC address in this invention.

[0044] Based on the above embodiments, determining the target return time interval of the target child node in the next data return cycle according to the hash value includes: Based on the preset return period duration and interval unit duration, the data return period is divided into multiple return time intervals, and each of the return time intervals is marked with a corresponding return time interval number in chronological order. Using the hash value, a modulo operation is performed on the number of the multiple return time intervals, and based on the return time interval sequence number corresponding to the modulo result, the target return time interval of the target child node in the next data return cycle is determined from the multiple return time intervals.

[0045] In this invention, after the root node receives the DAO forwarded by the target child node through the corresponding parent node, the root node groups the data report time of the target child node according to the MAC address of the target child node. The purpose of this grouping is to disperse the report time of all child nodes in the same DAO and avoid the report time of the child nodes being too dense.

[0046] Furthermore, in one embodiment, a 256-bit hash value is generated by applying a hash algorithm (SHA-256 algorithm is used in this embodiment) to the MAC address of the target child node. Then, the preset reporting period is determined to be 1 hour, that is, each node reports data once every 1 hour. At the same time, the interval unit duration is set to 1 second, that is, 3600 seconds in one data reporting period correspond to 3600 reporting time intervals, and the intervals are sorted in chronological order, such as the 5th second corresponding to the 5th interval. Next, the generated 256-bit hash value is MOD 3600, thereby dispersing the hash value into the interval of 0-3599 seconds, and each interval is numbered in chronological order. Figure 3 A schematic diagram illustrating the process of dividing the return time interval provided by this invention can be referred to. Figure 3 As shown, Figure 3 The MAC address fe:92:bf:e9:fb:69 is hashed, and the resulting hash value is MOD3600. The final interval is 43, which also corresponds to the time sequence 43 (that is, the child node of this MAC address pair starts reporting data at the 43rd second of the current data reporting cycle). This ensures that the child nodes do not send data densely at the same time. Finally, the reporting time interval sequence number of the child node is added to the DAO-ACK and sent to the child node.

[0047] Based on the above embodiments, generating the DAO-ACK information for the target child node based on the current timestamp information and the target report time interval includes: Based on the timestamp information and the target return time interval, add the timestamp field and the return time interval field to the pre-sent DAO-ACK to generate the DAO-ACK for the target child node.

[0048] In this invention, the existing DAO-ACK is improved by adding a timestamp field and a report time interval field to the corresponding fields. This eliminates the need for the root node to perform time synchronization and grouping of report times through additional broadcast or unicast, thereby reducing the load on the LLNs network and enabling all child nodes in each DODAG to accurately report data within various corresponding time intervals.

[0049] Based on the above embodiments, the step of adding a timestamp field and a return time interval field to the pre-sent DAO-ACK according to the timestamp information and the target return time interval to generate the DAO-ACK for the target child node includes: Based on the timestamp information, determine the timestamp encoding type and timestamp encoding length; Based on the target return time interval, determine the return time interval encoding type and the return time interval encoding length; The timestamp field is constructed based on the timestamp encoding type and the timestamp encoding length; The return time interval field is constructed based on the return time interval encoding type and the return time interval encoding length; Add the timestamp field and the return time interval field to the Option of the pre-sent DAO-ACK to generate the DAO-ACK for the target child node.

[0050] RFC 6550 does not define any field content that needs to be carried by the Option in the existing DAO-ACK. Figure 4 A schematic diagram of the modified DAO-ACK packet structure provided by the present invention can be referred to. Figure 4 As shown, in this invention, based on the Linux timestamp of the root node, the Linux timestamp information and Group ID (i.e., the reporting time interval sequence number) are filled into the corresponding area of ​​the Option option in the DAO-ACK control packet. Specifically, refer to... Figure 4As shown, in the Option field, firstly, a 1-byte Option type needs to be set. In this embodiment, 0xA1 is defined as the Linux timestamp information, and 0xA2 is defined as the Group ID (this Group ID corresponds to the 0-3599 second reporting time interval). Next, a 1-byte Option length is set, where the Option length for the Linux timestamp information is 0x04, and the Group ID is 0x02. Finally, the corresponding values ​​are filled into the Optiondata field according to the type, i.e., the corresponding timestamp information and the reporting time interval sequence number are filled in. Since this modifies the Option in the existing DAO-ACK, it will not affect other fields, ensuring that the child node can quickly parse and obtain the relevant information in the DAO-ACK after receiving it.

[0051] Based on the above embodiments, before dividing the data return period into multiple return time intervals based on the preset return period duration and interval unit duration, the method further includes: The type of hash algorithm and the number of reward time intervals are determined based on the number of child nodes in the wireless low-power lossy network.

[0052] In this invention, corresponding hash algorithms and return time intervals can be set according to actual application scenarios. For example, in the case of a scenario with a large number of child nodes, the hash algorithm can be SHA-512, and the return time interval can be divided into as many intervals as possible (set the preset return period to 2 hours, the interval unit duration to 1 second, that is, there are 7200 return time intervals), so that each child node can return data in different time return intervals as much as possible, reducing the possibility of packet collision.

[0053] Based on the above embodiments, before obtaining the target return time interval of the target child node in the next data return cycle according to the address information of the target child node, the method further includes: Confirm the transmission mode of the wireless low-power lossy network; If the transmission mode is non-storage mode, obtain the DAO sent by the target child node.

[0054] In this invention, before the root node receives the DAO information sent by the target child node through the parent node, it first needs to confirm the current transmission mode of the LLNs network. When the current transmission mode is confirmed to be non-storage mode, the root node obtains the DAO information, triggers the time synchronization and packet processing, and fills the corresponding information into the corresponding fields in the DAO-ACK.

[0055] In one embodiment, if the transmission mode is storage mode, although the root node does not receive the DAO information of the target child node, the parent node corresponding to the target child node can also perform corresponding time synchronization and grouping processing based on the received DAO information. Compared with the root node, the efficiency and time synchronization accuracy of the parent node will be reduced. However, in some scenarios where there are few child nodes, the parent node can still complete the time synchronization and grouping process well.

[0056] Based on the above embodiments, obtaining the DAO sent by the target child node includes: Broadcast a directed acyclic graph information object (DIO) for the target node, so that after the target child node obtains the DIO, it can determine the parent node of the target child node in the target directed acyclic graph (DODAG) for the target node, wherein the target directed acyclic graph (DODAG) for the target node is the DODAG corresponding to the root node. The parent node obtains the DAO sent by the target child node.

[0057] In this invention, reference may be made to Figure 2 As shown, the root node broadcasts a DIO. When the target child node receives the DIO, it determines whether to add it to the DODAG within the DIO and calculates the Rank value using OF to decide which parent node to unicast the DAO to (i.e., determine the optimal parent node). Then, the child node unicasts the DAO to the parent node, and in non-storage mode, it reaches the root node through the parent node. Since the root node is usually a gateway that can synchronize time via NTP, it has accurate time. When the root node receives the DAO, it calculates the received target child node's MAC address to obtain the corresponding Group ID, and finally fills the timestamp and Group ID into the DAO-ACK and sends it to the target child node. Figure 5 This is a schematic diagram of the data interaction process between the root node and child nodes provided by the present invention. For the specific process, please refer to... Figure 5 As shown.

[0058] Figure 6 This is a second flowchart illustrating the data transmission method provided by the present invention, as shown below. Figure 6 As shown, the present invention provides a data transmission method applied to a child node, comprising: Step 601: Obtain the Destination Broadcast Object Acknowledgment (DAO-ACK) sent by the target node, wherein the target node is the target root node or target parent node corresponding to the child node; Step 602: Parse the DAO-ACK to obtain timestamp information and target return time interval, wherein the timestamp information is the timestamp when the target node generates the DAO-ACK, and the target return time interval is obtained by the target node based on the address information of the child node; Step 603: Perform time synchronization using the timestamp information, and after time synchronization is completed, determine the data return time within the next data return cycle based on the target return time interval; Step 604: When the current time is the data report time, send the report data to the target node.

[0059] In this invention, the child node in the RPL network protocol is used as the execution subject for explanation. The child node broadcasts a DIS to its nearby neighboring nodes. Upon receiving the DIS, the neighboring nodes unicast a DIO to the child node. The child node then determines which parent node to unicast a DAO to based on the received DIO. Each node, upon receiving the DIO, uses the relevant information in the DIO to determine whether to join the DODAG. Further, after deciding to join the DODAG, each node calculates its own Rank value based on the previously set OF and broadcasts the calculated Rank value via DIO. Other nodes in the DODAG, upon receiving the DIO, also calculate their own Rank values. They then compare the shortest path to the root node (i.e., the one with the least cost) to select the optimal parent node (the target parent node) and unicast the DAO to this target parent node. This target parent node, in non-storage mode, forwards the unicast DAO from the child node to the target root node based on its routing table information. It should be noted that if the current transmission mode is storage mode, the unicast DAO is only sent to the target parent node.

[0060] Furthermore, the relevant fields of the DAO contain source address information (such as the MAC address and IP information of the target child node). When the target root node or target parent node receives the DAO, it calculates the reporting time interval of the target child node based on this address information, and then generates the corresponding DAO-ACK and sends it to the child node. This ensures that there is a certain time interval between the child nodes reporting data to the root node under different reporting time intervals, which can minimize packet collisions.

[0061] Furthermore, the child node parses the received DAO-ACK, performs time synchronization processing based on the timestamp information obtained from the parsing, completes the correction of the local clock, and determines its own reporting time according to the target reporting time interval. For example, if the interval length of the reporting time interval is 1 second, and the target reporting time interval is the 10th interval, then the target child node will start reporting data 10 seconds after the start time of the next data reporting cycle.

[0062] The data transmission method provided by this invention uses the control packet DAO-ACK in the wireless low-power lossy network routing protocol to perform time synchronization and report interval grouping for child nodes in the wireless low-power lossy network. This eliminates the need to increase the burden on the wireless low-power lossy network through additional broadcast or unicast packet methods, and ensures that the report data of each child node in the DODAG is evenly distributed within the specified time interval, avoiding packet collisions caused by all child nodes reporting data in adjacent time periods, and improving the success rate of report data.

[0063] Based on the above embodiments, obtaining the DAO-ACK message sent by the target node includes: Broadcast a Directed Acyclic Graph Information Request (DIS) for the destination node, so that the neighboring nodes corresponding to the child node, upon receiving the DIS, will send their respective Directed Acyclic Graph Information Objects (DIOs) for the destination node to the child node. Based on the received DIOs, determine the target parent node; Send the target broadcast object (DAO) to the target parent node and obtain the DAO-ACK sent by the target parent node or the DAO-ACK sent by the target root node.

[0064] In this invention, a child node broadcasts a DIS to nearby neighboring nodes to find and join a neighboring DODAG. After receiving the DIS, the neighboring node unicasts a DIO to the child node. Then, the child node determines which parent node to unicast a DAO to based on the received DIO, i.e., it determines the target parent node. In non-storage mode, the unicast DAO will be forwarded to the target root node through the target parent node, thereby obtaining the DAO-ACK sent by the target parent node or the target root node.

[0065] Based on the above embodiments, the step of parsing the DAO-ACK to obtain timestamp information includes: Obtain the transmission mode of wireless low-power lossy networks; If the transmission mode is storage mode, the DAO-ACK is parsed to obtain the first timestamp information, which is the timestamp when the target parent node generates the DAO-ACK.

[0066] Based on the above embodiments, the method further includes: If the transmission mode is non-storage mode, the DAO-ACK is parsed to obtain the second timestamp information, which is the timestamp when the target root node generates the DAO-ACK.

[0067] In this invention, the timestamp information obtained by the child node can be either the time of the target parent node or the time of the target root node. For different transmission modes, both of the above methods can complete the time synchronization of the child node and the determination of the reporting time interval without the need for additional transmission mode switching operations.

[0068] Based on the above embodiments, the target return time interval is determined by the target node performing a hash operation on the media access control MAC address of the child node, and based on the obtained hash value, the return time interval of the child node in the next data return cycle.

[0069] In this invention, the MAC address of the child node is converted into a hash value. Further, based on this hash value, the data return times of each child node can be grouped, such as by establishing a group list corresponding to each hash value. Preferably, in one embodiment, each child node can be divided into a corresponding return time interval by performing a modulo operation on the hash value according to a preset return period. After the child node completes parsing the received DAO-ACK, the data return time can be accurately determined based on the return time interval.

[0070] Based on the above embodiments, determining the data return time within the next data return cycle according to the target return time interval includes: Obtain the number of time intervals for the next data return cycle. The number of time intervals for the data return cycle is obtained by dividing the data return cycle based on a preset return cycle duration and interval unit duration. The target return time interval sequence number is determined by the target node based on the hash value corresponding to the MAC address of the child node, performing a modulo operation on the number of multiple return time intervals, and determining the sequence number from multiple return time intervals based on the modulo result; the return time interval sequence number is obtained by the target node marking each of the return time intervals with a corresponding sequence number in chronological order. Based on the return time interval number and the start time of the next data return period, the data return time within the next data return period is determined.

[0071] In this invention, the child node first determines the total number of return time intervals within its own data return cycle. Since each return time interval is divided according to time order, the target return time interval is obtained through parsing. According to the data order, the corresponding target return time interval number is obtained from all return time intervals, that is, the data return time of the child node is determined when the start time of the next data return cycle arrives. Specifically, in this embodiment, after obtaining the MAC address, the root node generates a 256-bit hash value by applying the SHA-256 algorithm to the MAC address of the child node. Then, it sets the node to report data once every hour, and sets the interval unit duration to 1 second. That is, 3600 seconds in one data reporting cycle correspond to 3600 reporting time intervals, and the intervals are sorted in chronological order, such as the 5th second corresponding to the 5th interval. Next, the generated 256-bit hash value is MOD 3600, thereby dispersing the hash value into the interval of 0-3599 seconds. Each interval is numbered in chronological order. When the child node obtains the reporting time interval information from DAO-ACK, it will only send data in its corresponding time interval, ensuring that the child nodes do not send data densely at the same time.

[0072] Based on the above embodiments, after sending the report data to the target node when the current time is the data report time, the method further includes: Upon completion of the data reporting task for the current data reporting cycle, a first input is received, which includes an operation to execute a dormant state. In response to the first input, the sleep state is executed, and when the data report time of the next data report cycle arrives, the sleep state is switched to the working state.

[0073] In this invention, the child node determines the data reporting time for the next cycle based on the reporting time interval, and remains in a dormant state until the next cycle arrives, thereby improving and reducing additional power consumption.

[0074] The data transmission device provided by the present invention will be described below. The data transmission device described below can be referred to in correspondence with the data transmission method described above.

[0075] Figure 7 One of the structural schematic diagrams of the data transmission device provided by the present invention is shown below. Figure 7As shown, the present invention provides a data transmission device applied to a root node, including a time interval grouping module 701 and an acknowledgment information generation module 702. The time interval grouping module 701, after determining that the target broadcast object (DAO) corresponding to the target child node has been obtained, acquires the target reporting time interval of the target child node in the next data reporting cycle based on the address information of the target child node. The acknowledgment information generation module 702, based on the timestamp information of the current moment and the target reporting time interval, generates a DAO-ACK acknowledgment information for the target child node and sends the DAO-ACK to the target child node, so that the target child node can determine the data reporting time through the target reporting time interval after completing time synchronization based on the timestamp information.

[0076] In this invention, the data transmission device is located at the root node, and can cooperate with the root node to complete the process of receiving DAO and sending DAO-ACK. It should be noted that in this embodiment, the transmission mode is a non-storage mode, which allows the root node to obtain the DAO through the parent node corresponding to the target child node, and then send the DAO-ACK containing time synchronization information and report interval information to the child node.

[0077] Specifically, after the root node completes its configuration, it broadcasts a DIO containing DODAG graph configuration information (e.g., DODAG ID, OF, and existing node Rank values) to all nodes in the network. Upon receiving the DIO, each node determines whether to join the DODAG based on the relevant information in the DIO. Furthermore, after deciding to join the DODAG, each node calculates its own Rank value based on the previously set OF and broadcasts the calculated Rank value via the DIO. This allows other nodes in the DODAG to receive the DIO and also calculate their own Rank values. Then, by comparing the shortest path to the root node (i.e., the one with the least cost), the optimal parent node is selected, and the DAO is unicast to this parent node.

[0078] Furthermore, after the root node receives the DAO, the time interval grouping module 701 calculates the return time interval of the target child node based on the address information. This ensures that there is a certain time interval between child nodes in different return time intervals when they report data to the root node, minimizing packet collisions. It should be noted that in this invention, for a node already added to the DODAG, if it receives another DIO from a neighboring node and obtains a lower Rank value through OF calculation, it will change its position in the DODAG, update its parent node information, and send the DAO to the root node again through the new parent node.

[0079] In this invention, the confirmation information generation module 702 adds timestamp information to the corresponding fields of the DAO-ACK to be sent, thereby transmitting time message packets to the child nodes, enabling the target child nodes receiving the timestamp information to perform time synchronization processing. Simultaneously, the confirmation information generation module 702 also adds relevant information about the target reporting time interval to the corresponding fields of the DAO-ACK to be sent, thereby sending the constructed DAO-ACK to the target child nodes. After the target child node parses the received DAO-ACK, it completes local clock correction and determines its own reporting time based on the target reporting time interval. For example, if the interval between reporting time intervals is 1 second, and the target reporting time interval is the 10th interval, then the target child node begins reporting data 10 seconds after the start time of the next data reporting cycle.

[0080] The data transmission device provided by this invention performs time synchronization and report interval grouping for child nodes in a wireless low-power lossy network through the control packet DAO-ACK in the wireless low-power lossy network routing protocol. This eliminates the need to increase the burden on the wireless low-power lossy network through additional broadcast or unicast packet methods, so that the report data of each child node in the DODAG is evenly distributed within the specified time interval, avoiding packet collisions caused by all child nodes reporting data in adjacent time periods, and improving the success rate of report data.

[0081] Figure 8 This is a second schematic diagram of the structure of the data transmission device provided by the present invention, as shown below. Figure 8 As shown, the present invention provides a data transmission device applied to a child node, including a receiving module 801, a parsing module 802, a time synchronization module 803, and a data reporting module 804. The receiving module 801 is used to acquire DAO-ACK confirmation information sent by a target node, where the target node is the target root node or target parent node corresponding to the child node. The parsing module 802 is used to parse the DAO-ACK to obtain timestamp information and a target reporting time interval. The timestamp information is the timestamp when the target node generates the DAO-ACK, and the target reporting time interval is obtained by the target node based on the address information of the child node. The time synchronization module 803 is used to synchronize the time using the timestamp information, and after synchronization, determines the data reporting time within the next data reporting cycle based on the target reporting time interval. The data reporting module 804 is used to send reporting data to the target node when the current time is the data reporting time.

[0082] In this invention, the data transmission device is located at the child node and can cooperate with the child node to complete the process of receiving and parsing DAO-ACK. Specifically, when the target root node or target parent node receives the DAO, it calculates the child node's report time interval based on the address information in the DAO, and then generates the corresponding DAO-ACK. When the receiving module 801 receives the DAO-ACK, the parsing module 802 parses the received DAO-ACK, so that the time synchronization module 803 performs time synchronization processing based on the parsed timestamp information to complete the correction of the local clock. At the same time, it determines its own report time based on the target report time interval. For example, if the interval length of the report time interval is 1 second, and the target report time interval is the 10th interval, then the target child node starts reporting data 10 seconds after the start time of the next data report cycle. Finally, the data report module 804 reports data to the root node in the corresponding report time interval, so that there is a certain time interval between each child node, which can minimize packet collisions.

[0083] The data transmission device provided by this invention performs time synchronization and report interval grouping for child nodes in a wireless low-power lossy network through the control packet DAO-ACK in the wireless low-power lossy network routing protocol. This eliminates the need to increase the burden on the wireless low-power lossy network through additional broadcast or unicast packet methods, so that the report data of each child node in the DODAG is evenly distributed within the specified time interval, avoiding packet collisions caused by all child nodes reporting data in adjacent time periods, and improving the success rate of report data.

[0084] The present invention also provides a data transmission system, including a root node applied to the data transmission apparatus of the above embodiments, and a child node applied to the data transmission apparatus of the above embodiments.

[0085] In this invention, a child node broadcasts a DIS to its nearest neighboring nodes. Upon receiving the DIS, a neighboring node unicasts its own DIO to the child node. The child node then determines which parent node to unicast a DAO to based on the received DIO, thus identifying the target parent node. In non-storage mode, the unicast DAO is forwarded to the root node via the target parent node. Since the root node has accurate time, it can synchronize its time via NTP. Therefore, upon receiving the DAO, the root node hashes the received child node's MAC address and modulo the hash value with the total data in the reporting time interval to obtain the Group ID (reporting time interval sequence number) corresponding to the MAC address. This ensures that the child node and other child nodes do not send data at the same time as much as possible. Finally, the root node fills the time synchronization information and reporting time interval information into the DAO-ACK and sends it to the child node.

[0086] The data transmission system provided by this invention uses the control packet DAO-ACK in the wireless low-power lossy network routing protocol to perform time synchronization and report interval grouping for child nodes in the wireless low-power lossy network. This eliminates the need to increase the burden on the wireless low-power lossy network through additional broadcast or unicast packet methods, ensuring that the report data of each child node in the DODAG is evenly distributed within the specified time interval. This avoids packet collisions caused by all child nodes reporting data in adjacent time periods, thereby improving the success rate of report data.

[0087] Figure 9 This is a schematic diagram of the structure of the electronic device provided by the present invention, such as... Figure 9 As shown, the electronic device may include: a processor 901, a communications interface 902, a memory 903, and a communication bus 904. The processor 901, communications interface 902, and memory 903 communicate with each other via the communication bus 904. The processor 901 can call logical instructions in the memory 903 to execute a data transmission method. This method includes: after determining that the target broadcast object (DAO) corresponding to the target sub-node has been obtained, obtaining the target reporting time interval of the target sub-node in the next data reporting cycle based on the address information of the target sub-node; generating a DAO-ACK acknowledgment message for the target sub-node based on the timestamp information of the current moment and the target reporting time interval, and sending the DAO-ACK to the target sub-node so that the target sub-node can determine the data reporting time through the target reporting time interval after completing time synchronization based on the timestamp information. Alternatively, obtain the DAO-ACK confirmation information sent by the target node, where the target node is the target root node or target parent node corresponding to the child node; parse the DAO-ACK to obtain timestamp information and target report time interval, wherein the timestamp information is the timestamp when the target node generates the DAO-ACK, and the target report time interval is obtained by the target node based on the address information of the child node; perform time synchronization using the timestamp information, and after time synchronization is completed, determine the data report time in the next data report cycle based on the target report time interval; when the current time is the data report time, send report data to the target node.

[0088] Furthermore, the logical instructions in the aforementioned memory 903 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0089] On the other hand, the present invention also provides a computer program product, the computer program product including a computer program stored on a non-transitory computer-readable storage medium, the computer program including program instructions, when the program instructions are executed by a computer, the computer is able to execute the data transmission method provided by the above methods, the method including: after determining that the DAO corresponding to the target sub-node has been obtained, obtaining the target reporting time interval of the target sub-node in the next data reporting cycle according to the address information of the target sub-node; generating DAO-ACK of the target sub-node based on the timestamp information of the current time and the target reporting time interval, and sending the DAO-ACK to the target sub-node, so that the target sub-node can determine the data reporting time through the target reporting time interval after completing time synchronization according to the timestamp information; Alternatively, obtain the DAO-ACK confirmation information sent by the target node, where the target node is the target root node or target parent node corresponding to the child node; parse the DAO-ACK to obtain timestamp information and target report time interval, wherein the timestamp information is the timestamp when the target node generates the DAO-ACK, and the target report time interval is obtained by the target node based on the address information of the child node; perform time synchronization using the timestamp information, and after time synchronization is completed, determine the data report time in the next data report cycle based on the target report time interval; when the current time is the data report time, send report data to the target node.

[0090] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the data transmission method provided in the above embodiments. The method includes: after determining that the DAO corresponding to the target child node has been obtained, obtaining the target reporting time interval of the target child node in the next data reporting cycle according to the address information of the target child node; generating DAO-ACK of the target child node based on the timestamp information of the current moment and the target reporting time interval, and sending the DAO-ACK to the target child node so that the target child node can determine the data reporting time through the target reporting time interval after completing time synchronization according to the timestamp information; Alternatively, obtain the DAO-ACK confirmation information sent by the target node, where the target node is the target root node or target parent node corresponding to the child node; parse the DAO-ACK to obtain timestamp information and target report time interval, wherein the timestamp information is the timestamp when the target node generates the DAO-ACK, and the target report time interval is obtained by the target node based on the address information of the child node; perform time synchronization using the timestamp information, and after time synchronization is completed, determine the data report time in the next data report cycle based on the target report time interval; when the current time is the data report time, send report data to the target node.

[0091] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0092] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A data transmission method, characterized in that, Applied to the root node, including: In the case of non-storage mode transmission mode in wireless low-power lossy network, the target broadcast object (DAO) sent by the target child node is obtained through the parent node corresponding to the target child node; After determining the target broadcast object (DAO) corresponding to the target child node, the target reporting time interval of the target child node in the next data reporting cycle is obtained based on the address information of the target child node. Based on the current timestamp information and the target reporting time interval, a DAO-ACK is generated for the target child node, and the DAO-ACK is sent to the target child node so that the target child node can determine the data reporting time through the target reporting time interval after completing time synchronization based on the timestamp information. The step of obtaining the target return time interval of the target child node in the next data return cycle based on the address information of the target child node includes: Obtain the Media Access Control (MAC) address of the target child node; The MAC address is hashed using a hash algorithm to obtain the hash value corresponding to the MAC address; Based on the hash value, the target return time interval for the target child node in the next data return cycle is determined.

2. The data transmission method according to claim 1, characterized in that, The step of determining the target return time interval for the target child node in the next data return cycle based on the hash value includes: Based on the preset return period duration and interval unit duration, the data return period is divided into multiple return time intervals, and each of the return time intervals is marked with a corresponding return time interval number in chronological order. Using the hash value, a modulo operation is performed on the number of the multiple return time intervals, and based on the return time interval sequence number corresponding to the modulo result, the target return time interval of the target child node in the next data return cycle is determined from the multiple return time intervals.

3. The data transmission method according to claim 1, characterized in that, The generation of DAO-ACK information for the target child node based on the current timestamp information and the target return time interval includes: Based on the timestamp information and the target return time interval, add the timestamp field and the return time interval field to the pre-sent DAO-ACK to generate the DAO-ACK for the target child node.

4. The data transmission method according to claim 3, characterized in that, The step of adding a timestamp field and a return time interval field to the pre-sent DAO-ACK based on the timestamp information and the target return time interval to generate the DAO-ACK for the target child node includes: Based on the timestamp information, determine the timestamp encoding type and timestamp encoding length; Based on the target return time interval, determine the return time interval encoding type and the return time interval encoding length; The timestamp field is constructed based on the timestamp encoding type and the timestamp encoding length; The return time interval field is constructed based on the return time interval encoding type and the return time interval encoding length; Add the timestamp field and the return time interval field to the Option of the pre-sent DAO-ACK to generate the DAO-ACK for the target child node.

5. The data transmission method according to claim 2, characterized in that, Before dividing the data return period into multiple return time intervals based on a preset return period duration and interval unit duration, the method further includes: The type of hash algorithm and the number of reward time intervals are determined based on the number of child nodes in the wireless low-power lossy network.

6. The data transmission method according to claim 1, characterized in that, Before obtaining the target return time interval of the target child node in the next data return cycle based on the address information of the target child node, the method further includes: Confirm the transmission mode of the wireless low-power lossy network; If the transmission mode is non-storage mode, obtain the DAO sent by the target child node.

7. The data transmission method according to claim 6, characterized in that, The step of obtaining the DAO sent by the target child node includes: Broadcast a directed acyclic graph information object (DIO) for the target node, so that after the target child node obtains the DIO, it can determine the parent node of the target child node in the target directed acyclic graph (DODAG) for the target node, wherein the target directed acyclic graph (DODAG) for the target node is the DODAG corresponding to the root node. The parent node obtains the DAO sent by the target child node.

8. A data transmission method, characterized in that, Applied to child nodes, including: In the case of non-storage mode transmission mode in wireless low-power lossy network, the target broadcast object DAO is sent to the target parent node; Obtain the Destination Broadcast Object Acknowledgment (DAO-ACK) sent by the target node, where the target node is the target root node or target parent node corresponding to the child node; The DAO-ACK is parsed to obtain timestamp information and target return time interval, wherein the timestamp information is the timestamp when the target node generates the DAO-ACK; the target return time interval is obtained by the target node based on the address information of the child node. The time is synchronized using the timestamp information, and after the time synchronization is completed, the data return time in the next data return cycle is determined based on the target return time interval. When the current time is the data reporting time, send the reporting data to the target node; The target reporting time interval is determined by the target node performing a hash operation on the media access control MAC address of the child node, and based on the obtained hash value, the reporting time interval of the child node in the next data reporting cycle.

9. The data transmission method according to claim 8, characterized in that, The acquisition of the DAO-ACK acknowledgment information sent by the target node includes: Broadcast a Directed Acyclic Graph Information Request (DIS) for the destination node, so that the neighboring nodes corresponding to the child node, upon receiving the DIS, will send their respective Directed Acyclic Graph Information Objects (DIOs) for the destination node to the child node. Based on the received DIOs, determine the target parent node; Send the target broadcast object (DAO) to the target parent node and obtain the DAO-ACK sent by the target parent node or the DAO-ACK sent by the target root node.

10. The data transmission method according to claim 8, characterized in that, The step of parsing the DAO-ACK to obtain timestamp information includes: Obtain the transmission mode of wireless low-power lossy networks; If the transmission mode is storage mode, the DAO-ACK is parsed to obtain the first timestamp information, which is the timestamp when the target parent node generates the DAO-ACK.

11. The data transmission method according to claim 10, characterized in that, The method further includes: If the transmission mode is non-storage mode, the DAO-ACK is parsed to obtain the second timestamp information, which is the timestamp when the target root node generates the DAO-ACK.

12. The data transmission method according to claim 9, characterized in that, Determining the data return time within the next data return cycle based on the target return time interval includes: Obtain the number of time intervals for the next data return cycle. The number of time intervals for the data return cycle is obtained by dividing the data return cycle based on a preset return cycle duration and interval unit duration. The target return time interval sequence number is determined, wherein the target return time interval sequence number is obtained by the target node performing a modulo operation on the number of multiple return time intervals based on the hash value corresponding to the MAC address of the child node, and determining the sequence number from multiple return time interval sequence numbers based on the modulo result; the return time interval sequence number is obtained by the target node marking each of the return time intervals with a corresponding sequence number in chronological order. Based on the return time interval number and the start time of the next data return period, the data return time within the next data return period is determined.

13. The data transmission method according to any one of claims 8 to 12, characterized in that, After sending the data report to the target node at the current time being the data report time, the method further includes: Upon completion of the data reporting task for the current data reporting cycle, a first input is received, which includes an operation to execute a dormant state. In response to the first input, the sleep state is executed, and when the data report time of the next data report cycle arrives, the sleep state is switched to the working state.

14. A data transmission device, characterized in that, Applied to the root node, for implementing the data transmission method as described in any one of claims 1 to 7.

15. A data transmission device, characterized in that, Applied to child nodes to implement the data transmission method as described in any one of claims 8 to 13.

16. A data transmission system, characterized in that, This includes the root node applied to the data transmission device of claim 14, and the child nodes applied to the data transmission device of claim 15.

17. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the data transmission method as described in any one of claims 1 to 7, or the data transmission method as described in any one of claims 8 to 13.

18. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the data transmission method as described in any one of claims 1 to 7, or the data transmission method as described in any one of claims 8 to 13.

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