Low-voltage carrier multi-configuration network time synchronization collaboration method

Abstract

The invention discloses a low-voltage carrier multi-configuration network time synchronization collaboration method, which is characterized in that network nodes are divided into a plurality of logic communication groups, and a periodic synchronization reference frame and a time slot distribution mechanism are adopted, so that intra-group high-precision synchronization and cross-group seamless forwarding are realized; by adopting the method, the synchronization precision is remarkably improved, and the reference node periodically broadcasts the synchronization frame and compensates the transmission delay, so that the clock skew of each node is reduced to be below millisecond level; flexible configuration and rapid reconstruction capability are realized, dynamic increase and decrease of nodes and real-time update of configuration are supported, manual intervention is not needed, and configuration switching time delay is less than 20 milliseconds; communication is high in reliability, time slot isolation reduces inter-group conflicts, and a cross-group forwarding mechanism ensures that the data transmission success rate is high; the compatibility is strong, the deployment is easy, only a synchronization frame and time slot mapping need to be added in an existing PLC link layer protocol, and primary equipment of a power grid does not need to be changed; the operation and maintenance cost is reduced, and the operation efficiency and stability of the power distribution network communication system are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of low-voltage power line carrier communication, and in particular to a low-voltage carrier multi-configuration network time synchronization and cooperation method. BACKGROUND

[0002] Low-voltage power line carrier (PLC) communication is widely used in power distribution network automation, intelligent meter reading, and distributed energy management due to its need for no additional wiring and low cost. In a typical PLC network, each node usually operates in a single configuration mode, which is difficult to adapt to the needs of dynamic changes in the scale of the power distribution network nodes and fluctuations in link quality.

[0003] The prior art usually relies on constant time slots or synchronization schemes based on power frequency zero point triggering, which can achieve basic communication alignment but has the following shortcomings: 1. Limited synchronization accuracy: traditional schemes lack link delay compensation, making it difficult to maintain millisecond-level alignment in complex topologies or long link environments; 2. Poor network scalability: under fixed configuration, nodes are added or removed, and link reconstruction requires manual reconfiguration of time slots and synchronization parameters, resulting in prolonged network reconstruction and high maintenance costs; 3. Weak anti-interference ability: single time slot allocation is prone to inter-group conflicts due to noise, load changes, and other factors, affecting communication reliability, especially when forwarding across groups, making it difficult to ensure data connectivity.

[0004] Therefore, there is an urgent need for a new method that can achieve high-precision, low-latency network-wide clock synchronization in low-voltage power line carrier networks while supporting multi-configuration flexible scheduling and cross-group cooperative communication to improve the robustness and maintainability of PLC networks. SUMMARY

[0005] This section aims to outline some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, abstract, and title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0006] Therefore, to solve the above technical problems, the present application provides the following technical solution: a low-voltage carrier multi-configuration network time synchronization and cooperation method, the method comprising the following steps: Step 1: dividing the nodes in the power line carrier communication network into multiple network configurations, each group consisting of at least one communication node; Step 2: selecting a synchronization reference node in each group, the reference node periodically sends a synchronization frame, and other nodes receive the synchronization frame and adjust the internal clock to achieve uniform clock synchronization within the network; Step three: define a network communication cycle according to the unified clock, the network cycle is divided into at least a plurality of time slots equal to the number of groups; each group is allocated one or more fixed time slots dedicated for communication within the group; Step four: in the corresponding time slot of each network cycle, the nodes belonging to the group transmit or receive data according to the time slot division rule; the nodes of each group can complete point-to-point or multi-hop communication using low-voltage power line carrier link in their time slots; Step five: the groups remain silent or in a listening state in non-simultaneous slots, when data needs to be transmitted across groups, in the time slot cycle of the target group, the nodes of the adjacent group act as a relay to forward the received data; Step six: after completing the data exchange of a network cycle, each group repeats the synchronization operation to ensure continuous clock alignment and time slot synchronization.

[0007] As a preferred scheme of the low-voltage carrier multi-group network time synchronization method, wherein: the synchronization reference node can be assumed by the master node or gateway node in each group, and each group periodically takes turns to serve as the reference source of the clock alignment of the whole network.

[0008] As a preferred scheme of the low-voltage carrier multi-group network time synchronization method, wherein: in step three, the length of each time slot and the time slot sequence of each group can be pre-configured or dynamically adjusted according to the network size or communication demand.

[0009] As a preferred scheme of the low-voltage carrier multi-group network time synchronization method, wherein: the time slot division adopts time division multiplexing, and different groups use the same carrier frequency band; the synchronization frame in step two is a low-voltage carrier signal frame, which contains timestamp or frame count information.

[0010] As a preferred scheme of the low-voltage carrier multi-group network time synchronization method, wherein: the node cooperative forwarding in step five includes the following processing: when a target node in a group cannot directly communicate, a neighboring group node with good link is selected as a relay, and the neighboring group node forwards data in its allocated time slot.

[0011] As a preferred scheme of the low-voltage carrier multi-group network time synchronization method, wherein: after the end of the group time slot, each group node enters a synchronization listening state to listen to the synchronization frames or transmission frames of other groups, so as to align the inter-group time and identify the cross-group communication demand.

[0012] As a preferred scheme of the low-voltage carrier multi-group network time synchronization method, wherein: the method further includes including the network configuration identification and time offset information of each node in the synchronization frame, so that a newly joined node can automatically obtain the current time slot configuration and join the synchronization clock.

[0013] As a preferred scheme of the low-voltage carrier multi-configuration network time synchronization method, wherein: the network can support dynamic increase and decrease of network nodes and addition of groups, and when the number of nodes or link conditions change, the network can adjust the network configuration during the synchronization period and complete the configuration update through the next synchronization frame.

[0014] As a preferred scheme of the low-voltage carrier multi-configuration network time synchronization method, wherein: the synchronization operation can adopt timestamp exchange in the link layer protocol or be realized by physical layer time slot offset measurement, and each node corrects the local timer through the synchronization information to realize millisecond-level time slot alignment.

[0015] As a preferred scheme of the low-voltage carrier multi-configuration network time synchronization method, wherein: in the group communication process, point-to-point or mesh link topology can be adopted, and the nodes send data in the preset carrier modulation mode in the group time slot to meet the communication rate requirement under different configurations.

[0016] The beneficial effects of the present application are: The present application divides the network nodes into multiple logical communication groups, and adopts periodic synchronization reference frame and time slot allocation mechanism to realize high-precision synchronization within the group and seamless forwarding across groups, and has the following significant advantages: The synchronization accuracy is significantly improved, the reference node periodically broadcasts the synchronization frame and compensates the transmission delay, so that the clock deviation of each node is reduced to below the millisecond level; the flexible configuration and fast reconstruction capability are provided, the dynamic increase and decrease of nodes and real-time update of configuration are supported without manual intervention, the configuration switching delay is less than twenty milliseconds; the communication has high reliability, the time slot isolation reduces the inter-group conflict, and the cross-group forwarding mechanism guarantees that the data transmission success rate is above 95%; the compatibility is strong and the deployment is easy, only the synchronization frame and time slot mapping need to be added in the existing PLC link layer protocol without changing the power grid primary equipment; in addition, the operation and maintenance cost can be reduced, the automatic configuration and synchronization management reduce the number of manual configuration and the maintenance period, and the operation efficiency and stability of the power distribution network communication system are improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them: Figure 1 The workflow diagram of the present application. DETAILED DESCRIPTION

[0018] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0019] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in other ways not described herein, and it is understood that the present application is not limited to the embodiments described herein. It is also understood that variations can be made in view of what is described herein without departing from the scope of the present application.

[0020] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is independent or alternative to other embodiments.

[0021] Embodiment 1 Reference Figure 1 For the first embodiment of the present application, a low-voltage carrier multi-configuration network time synchronization method is provided. The method is used for grouping nodes and time slot allocation in a low-voltage power line carrier communication network, and achieving unified clock of the whole network through periodic sending of synchronization frames by a synchronization reference node, so as to realize ordered intra-group communication and cross-group data forwarding in a multi-configuration network. The method flow of the embodiment will be described in detail below in combination with specific steps.

[0022] Step one: node grouping and time slot allocation; The nodes in the low-voltage power line carrier network are divided into multiple logical communication groups according to factors such as geographical location, communication demand or power grid topology, and each node in each group has a common group identifier.

[0023] A unique communication time slot is allocated to each group, and each group only occupies the carrier for communication in its allocated time slot to avoid interference between groups; the time slots of the groups do not overlap with each other, so that only one group can transmit data in the same time slot.

[0024] When the network is initialized or a node is changed, a time slot allocation table is generated and distributed to each node, which records the group ID and corresponding time slot number of each group; when a node joins the network, it automatically joins an existing group or forms a new group according to the node request and the current configuration, and obtains the group and time slot information to which the node belongs during the group configuration.

[0025] To support dynamic configuration update, one or more control time slots can be reserved for subsequent configuration adjustment or emergency communication without conflict with regular data time slots.

[0026] Step two: the synchronization reference node sends a synchronization frame; Select one or more nodes in the network as synchronization reference nodes, which have high-precision built-in clocks or external unified clock sources for the network time reference; The synchronization reference nodes send time synchronization frames at a predetermined period (e.g., once per communication period or multiple communication periods), which carry the current timestamp information of the reference nodes; After receiving the synchronization frame, other nodes extract the reference timestamp, compare it with the local clock time, calculate the clock deviation value, and adjust the local clock accordingly to achieve network-wide clock synchronization and unification; In the synchronization process, the influence of low-voltage power line transmission delay can be considered: the sending time tag is recorded in the synchronization frame, and the receiving node corrects the clock deviation according to the difference between the sending tag and the actual receiving time, improving the synchronization accuracy; The synchronization frame must contain the following key information: (1) Network configuration identification of the sending node (i.e., the group ID of the group it belongs to); (2) Current network cycle number; (3) Time slot configuration information (such as the total number of time slots in the current period, the starting offset or duration of each time slot, and the group ID corresponding to each time slot); (4) Precise timestamp of sending the synchronization frame (usually with microsecond-level precision).

[0027] Newly added nodes can obtain the current network configuration identification and time slot configuration information by listening to and successfully parsing any synchronization frame, and perform initial time synchronization with the timestamp. They can automatically join the group they belong to or initiate a new group application when necessary based on the group ID and time slot configuration.

[0028] Step three: communication period and time slot structure; Set a fixed length of the communication period, which is divided into multiple time periods (time slots); the number of time slots is generally corresponding to the number of communication groups, so that each group has at least one exclusive time slot in each period.

[0029] Each communication group occupies the carrier for data transmission in the corresponding time slot according to the pre-allocated time slot number; since the time slots are mutually exclusive, each group will not conflict with other groups when communicating in its own time slot, thereby ensuring the determinacy of group communication.

[0030] At the beginning of the communication period, the synchronization reference node can send a synchronization flag or wake-up signal to notify each group to start synchronization and communicate in the corresponding time slot; each group node activates the transmission and reception functions simultaneously when its time slot arrives to complete the communication in the time slot.

[0031] Backup time slots can be set as needed to carry burst data, configuration updates, or additional communication during network expansion, thereby improving network flexibility and robustness; Duration of the time slot ( The time slot order (Slot_Sequence) of each group is not fixed; the network management node (which can also be the synchronization reference node) will dynamically adjust it based on the following factors: (a) Changes in network size (increase or decrease in the number of nodes, increase or decrease in the number of groups); (b) Changes in communication requirements (estimated amount of data reported by nodes within each group). (c) Link quality assessment (e.g., signal-to-noise ratio (SNR), packet loss rate (PLR)); The adjustment algorithm can use the following formula to calculate the time slot duration: ; in, : Total network cycle duration; : Reserve time for synchronization frame transmission; : This refers to the time slot protection interval; Number of groups; Furthermore, priority is given to allocating longer time slots or better time slot positions to groups with large data volumes or high link quality requirements; the adjusted new time slot configuration is broadcast to all network nodes through synchronization frames or dedicated control frames (sent within the reserved control time slot).

[0032] Step 4: Data transmission within time slots and cross-group forwarding; Within a time slot allocated to a group, all nodes in that group send data frames according to actual communication needs. The recipients can be other nodes in the same group or nodes in different groups.

[0033] If the destination node of a data frame to be sent is not in this group, the relay node in this group that is adjacent to the target group will receive the data frame; the relay node will then forward the data frame to the target group in the subsequent time slot of its own group, thereby realizing cross-group communication.

[0034] The selection of which adjacent group node as a relay node is a key step. The source node (or group coordination node) makes a decision based on a pre-stored or real-time acquired link quality table (LQI Table). The table records the link quality indicators (such as received signal strength RSSI, signal-to-noise ratio SNR, historical communication success rate) of the nodes in the group to potential adjacent group nodes (usually referring to nodes with good physical location proximity or historical communication records). The selection criteria are: preferentially selecting adjacent group nodes with link quality indicators higher than a preset threshold (such as SNR > 15 dB, success rate > 90%) and whose group has the nearest upcoming time slot. For example, if the current time slot is for Group A, and the target node is in Group C, the node with the best link quality within Group B (whose time slot is after A and before C) is preferentially selected as the relay. The target group identifier and target node address need to be attached in the data frame.

[0035] After the adjacent group's relay node receives the cross-group data, it extracts the target group identifier and target node address in the data frame and continues to forward the data to the entry node of the target group in the next round of communication time slots, ensuring reliable delivery of the data to the target node.

[0036] The target group identifier and target node address can be attached in the data frame, allowing the relay node to accurately identify the forwarding target and schedule the corresponding forwarding operation according to the current time slot table.

[0037] Step five: listening or forwarding in non-group time slots; In the time slots of non-group, the nodes of the group enter the listening or standby state; the nodes within the group maintain carrier sensing to listen to the communication content of other groups.

[0038] If a data frame of another group is listened to and the destination of the frame belongs to the group (i.e., a node in the group is the target), the receiving or relay node of the group will receive the data frame and forward it in the subsequent time slot; if the frame destination is not within the group, the node continues to maintain the listening state.

[0039] Maintaining listening in non-group time slots allows nodes to capture possible cross-group communication requests and timely complete data forwarding and reception; if no relevant data is detected for a long time, the node can enter a low-power standby state to reduce energy consumption.

[0040] By listening and forwarding data in non-group time slots, each group node can achieve transparent relay of data, thereby enhancing the connectivity and reliability of inter-group communication.

[0041] Step six: dynamic adjustment of network configuration; Network supports dynamic adding and removing nodes and communication groups; when a new node joins, the node can apply to join an existing communication group or form a new group independently as a new group member, and is allocated corresponding time slots; when a node or the entire group exits the network, it can release its group identifier and time slot resources, and merge or reallocate the time slots of the remaining groups as appropriate.

[0042] When the network topology or communication requirements change, the system recalculates and updates the node grouping and time slot allocation scheme; the synchronization reference node or network management node generates a new configuration and distributes the update information to the entire network in the form of a broadcast control frame or an extended synchronization frame.

[0043] The trigger timing for dynamic configuration adjustment is usually: (1) detecting node joining / leaving events; (2) periodic configuration evaluation (e.g., every N network cycles); (3) link quality continuously deteriorating / optimizing beyond a threshold.

[0044] The adjustment process needs to be completed within a synchronization period: The management node broadcasts configuration update instructions (including new grouping scheme, new time slot table) in the control time slot or using the extended field of the synchronization frame. After all nodes receive the instructions, they complete local configuration updates (update group ID, time slot table, forwarding responsibility) before the next synchronization frame arrives. The configuration switching delay is defined as the time from the broadcast update instruction to the completion of local configuration update by all nodes, which can be controlled within 20 milliseconds by optimizing the instruction structure and processing flow (as described in the claims). After the update is completed, the new configuration takes effect immediately at the start of the next network cycle.

[0045] After receiving the configuration update information, each node updates the locally stored group ID and time slot table, adjusts its communication time slots and forwarding responsibilities to adapt to the new network configuration; in this way, the network can flexibly expand or shrink, and automatically balance the load of each group according to demand.

[0046] With dynamic configuration management, the present embodiment allows the network to flexibly add or remove communication groups according to operating conditions, and promptly coordinates the communication parameters of all nodes in the network after configuration changes, thereby maintaining the continuous and stable communication of the network.

[0047] The core of achieving millisecond-level (or lower) time slot alignment lies in the precise time synchronization mechanism, which can be implemented in one of the following two ways or in combination: Method one (link layer timestamp exchange): As described in step two, the synchronization frame carries a high-precision timestamp. The receiving node records the actual arrival time of the frame, extracts the sending timestamp in the frame. According to the known processing delay (which can be calibrated) and the estimated propagation delay (Based on distance or historical measurements) Calculate clock deviation ; Nodes based on Adjust the local clock. This method relies on precise timestamps and latency compensation.

[0048] Method 2 (Physical Layer Time Slot Offset Measurement): Nodes at the physical layer utilize specific synchronization headers of the carrier signal (such as preamble and start-of-frame delimiter, SFD) to perform precise arrival time detection. The receiving node measures the time generated by its local clock. Actual arrival time of the detected synchronization header tiny offset between - Real-time tracking and compensation of this through digital signal processing (such as correlators, phase-locked loops, and PLLs). This achieves precise alignment of time slot boundaries at the physical layer. This method is transparent to the link layer protocol and may offer higher accuracy.

[0049] The node uses the above synchronization information ( or The local timer is continuously adjusted to ensure that it accurately activates the send or receive function at the allocated time slot boundaries (Start_Slot, End_Slot), ultimately achieving millisecond-level (or even sub-millisecond-level) time slot alignment across the entire network.

[0050] Through the above implementation steps, this embodiment divides network nodes into multiple communication groups and assigns corresponding time slots. The synchronization reference node periodically sends synchronization frames containing rich configuration and time information to achieve a unified clock across the entire network, so that each communication cycle contains multiple time slots, and each group communicates within its assigned time slot. Within the time slot of its own group, nodes within the group send data and select the best neighboring group node to forward cross-group data based on link quality. In time slots outside its own group, nodes in each group enter a listening or forwarding state to obtain and forward relevant data. The network supports dynamic addition and removal of groups and real-time configuration updates, which can flexibly adjust group division and time slot allocation, and ensure millisecond-level time slot alignment through a precise synchronization mechanism (timestamp exchange or physical layer offset measurement).

[0051] Example 2 This is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that, in order to verify the beneficial effects of the above method, a comparative experiment was conducted to compare key performance indicators such as clock synchronization accuracy, intra-group throughput, cross-group forwarding success rate, and configuration dynamic switching latency in a multi-configuration network.

[0052] The experimental environment includes a low-voltage power distribution network simulation platform, 8 PLC communication terminals, 4 communication groups are constructed, and each group has 2 nodes; The experiment is run for 10 network cycles under "normal configuration method" (control group) and "multi-configuration time slot cooperative method" (experimental group) respectively, and part of the results are recorded as shown in the following table.

[0053] Table 1 Comparison of experimental results

[0054] Table notes: "Synchronization error" refers to the maximum deviation of the clock of each node relative to the reference node time; "In-group throughput rate" is the average value of the actual data transmission rate of each group in the allocated time slot; "Cross-group forwarding success rate" is the ratio of cross-group data arriving at the target node after relaying; "Configuration switching delay" refers to the time required from sending the configuration update control frame to completing the new time slot allocation in the entire network and entering the communication preparation state.

[0055] By comparison, it can be seen that: Synchronization accuracy is improved: the synchronization error of the experimental group under the fixed configuration is reduced to about 1.2 ms, which is about 79% higher than the 5.6 ms of the control group; Throughput performance is enhanced: under the same carrier conditions, the in-group throughput rate of the experimental group is about 8% higher than that of the control group on average; Reliability is improved: the cross-group forwarding success rate is improved from 80-85% in the control group to 95-99%; Dynamic configuration switching: In the test of dynamically increasing and decreasing groups, the system configuration switching delay is only about 14-16 ms, which can meet the demand of typical PLC network for fast reconstruction.

[0056] The time synchronization and communication cooperative method based on multi-configuration time slot cooperation proposed in the present application effectively reduces synchronization error and interference, improves reliable communication capability, and has millisecond-level dynamic configuration adjustment capability, which verifies the beneficial effects of the present application, and is significantly better than the traditional configuration-free or single-configuration PLC communication scheme.

[0057] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit it, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A low-voltage carrier multi-configuration network time synchronization coordination method, characterized in that: The method comprises the following steps: Step 1: divide nodes in a power line carrier communication network into multiple groups, each group comprising at least one communication node; Step 2: select a synchronization reference node in each group, which periodically sends a synchronization frame, and other nodes receive the synchronization frame and adjust the internal clock to achieve uniform clock synchronization in the network; Step 3: define a network communication period according to the uniform clock, and divide the network period into at least as many time slots as the number of groups; each group is allocated one or more fixed time slots for communication within the group; Step 4: in the corresponding time slot of each network period, nodes belonging to the group transmit or receive data according to the time slot division rule; nodes in each group can complete point-to-point or multi-hop communication using low-voltage power line carrier links within their time slots; Step 5: groups remain silent or in a listening state in non-simultaneous time slots, and when data needs to be transmitted across groups, nodes in adjacent groups act as relays to forward received data during the time slot period of the target group; Step 6: after completing a network period of data exchange, each group repeats the synchronization operation to ensure continuous clock alignment and time slot synchronization.

2. The low-voltage carrier multi-configuration network time synchronization coordination method of claim 1, wherein: The synchronization reference node can be a master node or a gateway node in each group, and each group periodically takes turns as the reference source for network clock alignment.

3. The low-voltage carrier multi-configuration network time synchronization coordination method of claim 2, wherein: In step 3, the length of each time slot and the time slot sequence of each group can be pre-configured or dynamically adjusted according to network size or communication requirements.

4. The low-voltage carrier multi-configuration network time synchronization coordination method of claim 3, wherein: The time slot division uses time division multiplexing, and different groups use the same carrier frequency band; the synchronization frame in step 2 is a low-voltage carrier signal frame containing timestamp or frame count information.

5. The low-voltage carrier multi-configuration network time synchronization coordination method of claim 4, wherein: The node cooperative forwarding in step 5 includes the following processing: when a target node in a group cannot directly communicate, select an adjacent group node with good link as a relay, and the adjacent group node forwards data in its allocated time slot.

6. The low-voltage carrier multi-configuration network time synchronization coordination method of claim 5, wherein: After the end of the group time slot, each group node enters a synchronization listening state to listen to synchronization frames or transmission frames of other groups to align the time between groups and identify cross-group communication requirements.

7. The low-voltage carrier multi-configuration network time synchronization coordination method of claim 6, wherein: The method further comprises including network configuration identification and time offset information of each node in the synchronization frame, so that newly added nodes automatically obtain the current time slot configuration and join the synchronization clock.

8. The low-voltage carrier multi-configuration network time synchronization coordination method of claim 7, wherein: The network can support dynamic addition or deletion of network nodes and addition of groups, and when the number of nodes or link conditions change, the network can adjust the network configuration during the synchronization period and complete the configuration update through the next synchronization frame.

9. The low-voltage carrier multi-configuration network time synchronization coordination method of claim 8, wherein: The synchronization operation can use timestamp exchange in the link layer protocol or be implemented by physical layer time slot offset measurement, and each node corrects the local timer through these synchronization information to achieve millisecond-level time slot alignment.

10. The low-voltage carrier multi-configuration network time synchronization coordination method of claim 9, wherein: In the process of communication within the group, point-to-point or mesh link topology can be used, and nodes transmit data in their group time slots through a preset carrier modulation method to meet the communication rate requirements under different configurations.

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