A method and apparatus for adjusting beacon period in a HPLC dual-mode system

Abstract

The application discloses a beacon period adjusting method of HPLC dual-mode system, which comprises the following steps: only allocating time slots for part of nodes in a beacon period, continuously allocating time slots for nodes without time slots in subsequent beacon periods until all nodes are allocated time slots. Considering that a node is allocated a time slot, its ancestor nodes must be allocated time slots in the same beacon frame, and the principle of beacon period adjustment is that a time slot period is allocated in a CCO sub-tree unit, and all nodes on the sub-tree must be allocated in a time slot period of a beacon frame. The method can avoid the problem that packet transmission fails and the whole beacon frame is invalid due to too long beacon frame, and improve the reliability of the system; on the other hand, short beacon frame can reduce the time delay of service transmission; only part of nodes obtain CSMA time slot window in a beacon period, and the conflict caused by a large number of nodes competing for CSMA time slots is avoided. The application also provides a beacon period adjusting device of HPLC dual-mode system.

Description

Technical Field

[0001] This invention belongs to the field of power line carrier communication technology, and more specifically, relates to a beacon period adjustment method and apparatus for an HPLC dual-mode system. Background Technology

[0002] High Power Line Carrier (HPLC) communication is a broadband power line carrier technology for data transmission over low-voltage power lines. Using power lines as the communication medium, it enables the aggregation, transmission, and interaction of electricity consumption information from low-voltage power users into a communication network. Compared to traditional low-speed narrowband power line carrier technology, HPLC offers a larger bandwidth and higher transmission rate, meeting the higher demands of low-voltage power line carrier communication.

[0003] High-speed radio frequency (HRF) technology is a low-power, flexible wireless communication method. Introducing RF into single-mode HPLC technology helps avoid interference and noise in the power environment, effectively addressing the shortcomings of single-mode HPLC and improving the reliability of communication transmission. Dual-mode HPLC, based on wired HPLC and high-speed wireless HRF, fully leverages the advantages of both communication methods while compensating for their respective shortcomings. It offers advantages such as low power consumption and low cost, providing a flexible, high-speed, stable, and reliable dual-channel communication network for power Internet of Things (IoT) transmission.

[0004] For an electricity information collection and communication system, the various communication nodes form a communication network. The Central Coordinator (CCO) acts as the master node, responsible for network control, network maintenance, and management; it is the communication unit on the concentrator. The remaining nodes in the network act as slave nodes, serving as communication units on the electricity meters or collectors. Some of these devices act as proxy coordinators (PCOs) between the CCO and other stations (STAs). The topology of the dual-mode HPLC communication network, composed of all communication units, is a multi-level, tree-like structure with the CCO as the root, the PCO as the relay proxy, and all STAs connected.

[0005] The dual-mode HPLC communication network uses a beacon frame-based channel access mechanism. The Control Center (CCO) periodically sends beacon frames, which contain beacon time slots, TDMA time slots, and CSMA time slots allocated by the CCO within the beacon period. All communication nodes in the network must adhere to the time slots allocated by the CCO for channel access.

[0006] In a dual-mode HPLC communication network, there are three types of beacon frames: central beacon, proxy beacon, and discovery beacon. Beacon frames must be transmitted within beacon time slots. Beacon time slots are allocated by the CCO (Content Control Operator), specifying the corresponding time slot available to each STA (Station). The central beacon and proxy beacon must be transmitted within each beacon cycle. The central beacon contains the CCO's time slot allocation results, determining how and in which stations access the network. The proxy beacon primarily relays the central beacon, while the discovery beacon is mainly used to discover hidden, unconnected nodes in the vicinity. The beacon frame structure in a dual-mode HPLC communication network is as follows: Figure 1 ,exist Figure 1 In the diagram, A, B, and C identify phases A, B, and C of the power line, respectively, and TEI2 to TEI5 are node identifiers. Central beacons, proxy beacons, and discovery beacons are transmitted on both the power line carrier and the radio channel. Beacon time slots are used to transmit beacon frames, Time Division Multiple Access (TDMA) time slots are used for designated nodes to transmit service messages, and Carrier Sense Multiple Access (CSMA) time slots are used for inter-node contention for service transmission. Figure 1 The central beacon needs to be transmitted separately on the three phase lines ABC, therefore the central beacon time slots of the three CCOs need to be divided.

[0007] HPLC beacons and high-speed wireless beacons share the same beacon mechanism and data structure, which allows the central beacon and proxy beacon of the carrier to be converted into standard beacon frames and simplified beacon frames of the wireless, while the standard beacon frames of the wireless can be converted into proxy beacon frames and discovery beacon frames. In dual-mode HPLC communication networks, because the HRF link rate is lower than the HPLC link rate, a message of the same length occupies a longer time slot on the HRF link than on the HPLC link. Therefore, a standard beacon frame occupies the HPLC beacon time slots of multiple nodes on the HRF channel. Long beacon time slots will consume too much system bandwidth, resulting in a reduction in service bandwidth and an increase in network forwarding latency. Therefore, for wireless beacons, it is necessary to send simplified beacon frames as much as possible.

[0008] The standard uses a method that prioritizes the reuse of carrier beacon time slots in radio beacon frames, meaning that one node transmits beacons on a high-speed carrier while another node transmits beacons on a radio. Figure 1 This reflects the type and timing of beacon frames sent by nodes within a beacon cycle. The State Grid standard stipulates that beacon time slot allocation follows a network hierarchy, with the lowest-level proxy nodes (PCOs) sending proxy beacon frames first, and finally, the outer leaf nodes (STAs) sending discovery beacon frames and simplified radio beacon frames. Therefore... Figure 1The upper time slot distribution is actually the arrangement of nodes to send beacon frames in an orderly manner according to the TDMA method. Summary of the Invention

[0009] The technical problem to be solved: With the continuous advancement of the State Grid's digitalization, the number of nodes in the network is constantly increasing. In this situation, if all nodes that need to send beacons are placed in a single period by increasing the beacon period, problems arise: Firstly, allocating all node time slots within a single beacon period may lead to scheduling issues. Secondly, long messages need to be transmitted in packets at the physical layer, making them susceptible to sudden interference and reducing communication reliability. Furthermore, with an increased number of nodes in a beacon frame, the longer beacon time slots occupy time, resulting in a later start time for CSMA time slots, inevitably leading to a reduction in CSMA time slots, increasing the risk of transmission conflicts, and consequently affecting data transmission latency. Overall, with the increase in the number of nodes, without adjusting the beacon period, network reliability and transmission latency will be difficult to guarantee, significantly impacting the quality of digitalization, especially the development of in-depth applications.

[0010] To achieve the above objectives, according to one aspect of the present invention, a beacon period adjustment method for an HPLC dual-mode system is provided, wherein time slots are allocated to only some nodes in a beacon period, and time slots are allocated to nodes that have not been allocated time slots in subsequent beacon periods until all nodes are allocated time slots. Considering that a node is allocated a time slot, its ancestor node must have been allocated a time slot in the same beacon frame first.

[0011] In one embodiment of the present invention, the principle of beacon period adjustment is as follows: time slot periods are allocated in units of CCO subtrees, and all nodes in a subtree must be allocated a time slot period of a beacon frame.

[0012] In one embodiment of the present invention, the method includes: (1) Determine the beacon period length T_Beacon, and the threshold number of beacon time slots it contains is T_threshold, both of which are the number of time slots; (2) Allocate time slots for beacon period P(i). For the first beacon period i=1, select a CCO subtree for beacon period P(i) and confirm the beacon time slots of the selected subtree nodes. (3) Determine the CSMA slot length of the beacon frame, form the beacon frame, and send it; (4) Start the time slot allocation for the next beacon period P(i+1) and go to step (2) until all subtrees are allocated.

[0013] In one embodiment of the present invention, the subtree selection method in step (2) is as follows: Find the subtree SubTree1 with the largest number of unselected child nodes among the direct proxy nodes of the CCO, and arrange time slots according to levels on this subtree to obtain the number of time slots SubT1; If SubT1 exceeds the predetermined threshold T_threshold, only one subtree can be allocated in this beacon frame, and no other subtrees need to be selected.

[0014] In one embodiment of the present invention, if SubT1 is within the predetermined threshold T_threshold, select the next node tree SubTree2 with the largest number of child nodes to allocate time slots according to levels. At this time, the allocation rule is to allocate according to the levels of the two subtrees from top to bottom; if the total number of time slots SubT(i)=∑SubTj obtained exceeds the specified threshold T_threshold, indicating that the time slot allocation fails, then select the next node tree SubTree3 with the largest number of child nodes of the CCO for time slot allocation; repeat this process until no subtree can be arranged under the specified threshold, that is, (SubT(i)=∑SubTj)<T_threshold, where j is the number of selected subtrees.

[0015] In one embodiment of the present invention, in step (3), the CSMA time slot length T_CSMA(i)=T_Beacon - SubT(i).

[0016] In one embodiment of the present invention, in step (2), when selecting a subtree, non-leaf nodes are arranged according to levels from top to bottom of the subtree, and then leaf nodes are arranged.

[0017] In one embodiment of the present invention, if all proxy nodes on the subtree can communicate with their directly connected child nodes through a high-speed carrier, a reduced beacon frame is sent on the wireless channel.

[0018] In one embodiment of the present invention, if the proxy nodes on the subtree can only communicate with their directly connected child nodes wirelessly, when arranging time slots, nodes that only send reduced beacon frames on the subtree are inserted as much as possible. If the requirements cannot be met, time slots for sending wireless standard beacon frames are inserted.

[0019] According to another aspect of the present invention, there is also provided a device for adjusting the beacon period of an HPLC dual-mode system, including at least one processor and a memory. The at least one processor and the memory are connected through a data bus. The memory stores instructions executable by the at least one processor. After being executed by the processor, the instructions are used to complete the method for adjusting the beacon period of the HPLC dual-mode system.

[0020] Generally speaking, compared with the prior art through the above technical solutions conceived by the present invention, the following beneficial effects are achieved: When there are too many network nodes to complete the allocation within a single period, or when the beacon period is too long, a shorter beacon period is formed by allocating only a subset of nodes to a single beacon frame. This avoids the problem of losing some packets and rendering the entire beacon frame invalid due to the fragmented transmission of long beacon frames, thus improving system reliability. Furthermore, shorter beacon frames reduce service transmission latency. Moreover, since only a subset of nodes obtain CSMA time slot windows within a single beacon period, conflicts arising from a large number of nodes competing for CSMA time slots are avoided. Attached Figure Description

[0021] Figure 1 This is a diagram of the beacon frame structure in an HPLC dual-mode system; Figure 2 This is a flowchart of the beacon cycle adjustment method for the HPLC dual-mode system in this embodiment; Figure 3 This is the communication node topology tree of this embodiment; the solid lines in the figure represent HPLC channels, and the dashed lines represent... The line represents the HRF channel; Figure 4 This is an embodiment of the solution. Figure 3 The first subtree time slot allocation diagram of the communication node topology tree in the diagram; Figure 5 This is the communication node topology tree of this embodiment; the solid lines in the figure represent HPLC channels, and the dashed lines represent... The line represents the HRF channel; Figure 6 This is an embodiment of the solution. Figure 5 The first subtree time slot allocation diagram of the communication node topology tree in the diagram; Figure 7 This is an embodiment of the solution. Figure 5 The time slot allocation diagram of the first and second subtrees of the communication node topology tree; Figure 8 This is an embodiment of the solution. Figure 5 The time slot allocation diagram of the first and third subtrees of the communication node topology tree; Figure 9 These are two beacon cycle structure diagrams formed by the embodiments of this scheme. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0023] To solve this problem, the beacon period is adjusted, that is: in one beacon period, time slots are only allocated to some nodes, and in subsequent beacon periods, time slots are allocated to the nodes that have not been allocated time slots until all nodes are allocated time slots. Considering that a node is allocated a time slot, its ancestor nodes must be allocated time slots in the same beacon frame first. The basic principle of beacon period adjustment is: select to allocate the time slot period in units of the subtrees of the CCO, and all nodes on a subtree must be allocated a time slot period of a beacon frame.

[0024] The present invention provides a method for adjusting the beacon period of an HPLC dual-mode system, including the following steps: (1) Determine the beacon period length T_Beacon, and the threshold of the number of beacon time slots it contains is T_threshold, both in the unit of the number of time slots; (2) Allocate time slots for the beacon period P(i), for the first beacon period i = 1; select the CCO subtree for the beacon period P(i), and confirm the beacon time slots of the nodes of the selected subtree; Specifically, the subtree selection method is as follows: Find the subtree SubTree1 with the largest number of unselected child nodes among the direct proxy nodes of the CCO, arrange the time slots hierarchically on this subtree, and obtain the number of time slots SubT1; If SubT1 exceeds the predetermined threshold T_threshold, only one subtree can be allocated in this beacon frame, and no other subtrees need to be selected.

[0025] Furthermore, if SubT1 is within the predetermined threshold T_threshold, then select the next node tree SubTree2 with the largest number of child nodes to allocate time slots hierarchically. At this time, the allocation rule is to allocate according to the hierarchy of the two subtrees from top to bottom; if the total number of time slots SubT(i)=∑SubTj obtained exceeds the specified threshold T_threshold, indicating that the time slot allocation fails, then select the next node tree SubTree3 with the largest number of child nodes of the CCO to allocate time slots; repeat this process until no subtree can be arranged under the specified threshold, that is, (SubT(i)=∑SubTj)<T_threshold, and j is the number of the selected subtree.

[0026] Furthermore, when selecting subtrees, arrange the non-leaf nodes hierarchically from top to bottom for the subtrees, and then arrange the leaf nodes.

[0027] (3) Determine the CSMA time slot length of this beacon frame, form a beacon frame and send it; (4) Start the time slot allocation for the next beacon period P(i + 1), and go to step (2) until all subtrees are allocated.

[0028] Furthermore, such as Figure 2 The diagram shown is a flowchart illustrating a beacon cycle adjustment method for an HPLC dual-mode system according to an embodiment of the present invention, comprising the following steps: S100 determines the beacon period length T_Beacon, which contains a beacon time slot threshold of T_threshold, both in units of time slots; Typically, a carrier beacon slot length T_Slot is around 20ms. If 100 nodes are arranged within the beacon period, CSMA slots can only be arranged after 2 seconds, meaning service data can only be sent after 2 seconds. To reduce service latency, a suitable beacon period length T_Beacon = 200, and a recommended threshold for the number of beacon slots is T_threshold = 100.

[0029] S101 allocates time slots for beacon period P(i), selects a CCO subtree for beacon period P(i) (for the first beacon period i=1), and confirms the beacon time slots of the selected subtree nodes. The subtree selection method is as follows: Specifically, find the subtree SubTree(j) with the most unselected child nodes from the direct-connected agent nodes of CCO, arrange time slots hierarchically on the subtree to obtain the number of time slots SubT(i), and add the subtree to the subtree list A; S102 Check if the total number of time slots SubT(i) exceeds T_threshold. If yes, go to S104; otherwise, go to S103. S103 Add SubTree(j) to the subtree list A; S104 Check if there is a subtree with unallocated time slots. If there is no subtree to choose from, proceed to S106; otherwise, proceed to S105. S105 Take a subtree SubTree(j) from the unallocated subtrees, and allocate SubTree(j) and the subtrees in the subtree list A according to the hierarchical order of multiple subtrees from top to bottom to obtain the total number of time slots SubT(i); go to S102.

[0030] S106 determines the CSMA slot length of the beacon frame: CSMA slot length T_CSMA(i) = T_Beacon - SubT(i); S107 arranges the selected subtree into time slots, forms a beacon frame, and sends it. Then, it resets selection list A to empty.

[0031] S108 If there are still subtrees without allocated time slots, start the time slot allocation for the next beacon period P(i+1), and repeat S101~S107 until all subtrees are allocated.

[0032] Furthermore, the present invention also provides an HPLC dual-mode system beacon cycle adjustment device, including at least one processor and a memory, wherein the at least one processor and the memory are connected via a data bus, and the memory stores instructions that can be executed by the at least one processor, wherein the instructions, after being executed by the processor, are used to complete the HPLC dual-mode system beacon cycle adjustment method.

[0033] Furthermore, the following, in conjunction with the appendix Figures 3-9 To illustrate the technical solution of this invention, in this embodiment, for easier explanation of the principle, it is assumed that T_Beacon=22 and T_threshold=11. The number of carrier beacon time slots occupied by a standard wireless beacon frame is related to the ratio of carrier rate to wireless rate. Typically, the carrier rate can reach 1Mbps, while the wireless channel rate can reach 200Kbps. One wireless standard beacon occupies 5-6 carrier beacon time slots. In this embodiment, for simplicity, it is assumed that one wireless standard beacon occupies 2 carrier beacon time slots. (Example...) Figure 4 In the diagram, the carrier beacon row indicates the time slot distribution on the HPLC channel, and the radio beacon row indicates the time slot distribution on the HRF channel. In all time slot allocation diagrams, the numbered box X represents the time slot allocated to node TEX; the numbered box X in the carrier beacon row represents the time slot allocated to node TEX on the carrier channel; and the numbered box X in the radio beacon row represents the time slot allocated to node TEX on the radio channel. The method specifically includes: (1) Find the node with the most child nodes from the direct-connection proxy nodes of CCO, and arrange time slots hierarchically on this subtree; the specific arrangement rules are as follows: (1.1) If the number of beacon slots SubT(1) of the first subtree SubTree1 in the beacon frame already exceeds the threshold T_threshold, then there is no need to select another subtree, and the subtree SubTree1 can be directly used as the beacon frame for transmission. For example, in... Figure 3 Selecting subtrees TE1TE2TE5TE6TE7TE10TE11TE12TE14TE15 typically follows the rule of arranging non-leaf nodes (TE1TE2TE5TE6TE7TE11TE12) and then leaf nodes (TE10TE14TE15) from top to bottom. Time slots are then allocated to this subtree as follows: Figure 4 As shown, the time slot SubT(1) (=13) occupied by this subtree exceeds T_threshold (=11), therefore it is directly used as... Figure 4 The allocated time slots are used to form beacon frames for transmission; it should be noted that, in Figure 4In addition to the 12 time slots in the first row, SubT(1) also includes a radio simplified beacon frame time slot allocated by node TE15 within the CSMA time slot, so there are a total of 13 time slots.

[0034] (1.2) If the number of beacon slots SubT(1) is within the threshold T_threshold, then select the next node tree SubTree2 with the most child nodes. Allocate slots between SubTree1 and SubTree2 according to the rule of first allocating non-leaf nodes and then leaf nodes. If slots cannot be filled within the predetermined beacon period, it indicates that slot allocation has failed. Figure 5 First, select the first subtree SubTree1 (TE1TE2TE5TE8TE10) to obtain the time slot arrangement as follows: Figure 6 ,exist Figure 6 Three time slots are allocated to node TE5, one of which is a carrier time slot on the carrier channel. Node TE5 is connected to node TE8 wirelessly. At this time, it needs to send a wireless standard beacon frame on the wireless channel. According to the previous settings, one wireless standard beacon frame occupies two carrier beacon time slots (within this subtree, node TE5 is the parent node of TE8, and nodes TE8 and TE10 can only be sent after TE5 has finished sending; since TE5 is connected to TE8 wirelessly, TE5 needs to send a wireless standard beacon frame, which is assumed to occupy two carrier beacon slots, so TE5 occupies two time slots on the wireless channel and one time slot on the carrier channel, for a total of three time slots). At this time, the number of time slots SubT(1) (=10) is within the threshold T_threshold (=11). Then, the next subtree SubTree2 (TE1TE3TE6TE9) is selected, and together with the previously selected subtree SubTree1, time slots are allocated according to the rule of allocating non-leaf nodes first and then leaf nodes, forming a time slot allocation as follows. Figure 7 The total number of time slots, SubT(1) (=12), exceeds the threshold T_threshold=11, therefore Subtree SubTree2 cannot be selected. The next child node tree, SubTree3 (TE1TE4TE7), is selected. SubTree3 and SubTree1 are then allocated time slots according to the rule of first allocating non-leaf nodes and then leaf nodes, as shown in the time slot diagram. Figure 8 The total number of time slots is SubT(1) (=11), which is less than or equal to the threshold T_threshold (=11), so the two subtrees can be arranged in one beacon; (1.3) If all agent nodes on a subtree can communicate with their directly connected child nodes via high-speed carriers, then a simplified beacon frame is sent over the wireless channel; Figure 3 The time slot arrangement of neutron tree TE1TE2TE5TE6TE7TE10TE11TE12TE14TE15 is as follows: Figure 4According to the time slot allocation rules, Figure 3 The middle node TE6 and node TE11 are connected by both a carrier channel and a wireless channel. Therefore, only the simplified wireless beacon (occupying 1 time slot) needs to be transmitted on the wireless channel of node TE6. Figure 4 The 6-mark box above the wireless beacon row indicates the simplified beacon time slot of node TE6 on the wireless channel.

[0035] (1.4) If the proxy node on the subtree can only communicate with its directly connected child node via wireless, then when scheduling time slots, try to insert nodes on the subtree that only send simplified beacon frames. If this requirement cannot be met, then insert time slots that send wireless standard beacon frames. Figure 5 The time slot arrangement of the subtrees TE1, TE2, TE5, TE8, and TE10 is as follows: Figure 6 Since there is only a radio channel between nodes TE5 and TE8, and the simplified radio beacon frame only contains CSMA information and not the time slot information of other nodes, node TE5 can only send standard radio beacon frames and not simplified radio beacon frames on the radio channel. At this time, TE5 sends standard beacon frames (occupying 2 time slots) on the radio channel. Figure 6 The two 5-marked boxes above the wireless beacon row indicate the standard beacon time slot of node TE5 on the wireless channel.

[0036] (2) Determine the CSMA slot of the beacon frame; T_CSMA(i) = T_Beacon - SubT(i) =22-11=11; (3) Determine the beacon period of the beacon frames to be sent in this round based on the number of beacon slots and the CSMA slot length; (4) For the selection of subtrees in the next round of beacon frames, process 1-3 is repeated again in the subtrees that have not been allocated time slots; (5) Once all subtrees have been allocated, the beacon periodic adjustment process ends.

[0037] Figure 9 The example describes the time slot allocation diagram for the final two beacon cycles.

[0038] This embodiment only shows that within 2 beacon cycles, the minimum number of beacon cycles that can be allocated to all nodes is 1, and the maximum is the number of subtrees of the CCO node.

[0039] Furthermore, the present invention also provides a beacon period adjustment device for an HPLC dual-mode system, including at least one processor and a memory, wherein the at least one processor and the memory are connected via a data bus, and the memory stores instructions that can be executed by the at least one processor. After being executed by the processor, the instructions are used to complete the HPLC dual-mode system beacon period adjustment method.

[0040] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for adjusting the beacon cycle in an HPLC dual-mode system, characterized in that, Only allocate time slots for some nodes in one beacon period, and continue to allocate time slots for the nodes that have not been allocated time slots in subsequent beacon periods until all nodes have been allocated time slots. Considering that a node is allocated a time slot, its ancestor node must be allocated a time slot in the same beacon frame first; the principle of beacon period adjustment is: select to allocate the time slot period in units of the subtree of the CCO, and all nodes on a subtree must be allocated a time slot period of a beacon frame; the method includes: (1)Determine the length T_Beacon of the beacon period, and the threshold of the number of beacon time slots it contains is T_threshold, and the unit is the number of time slots; (2)Allocate time slots for the beacon period P(i). For the first beacon period i = 1; select the CCO subtree for the beacon period P(i), and confirm the beacon time slots of the nodes of the selected subtree; (3)Determine the CSMA time slot length of this beacon frame, form a beacon frame and send it; (4)Start the time slot allocation of the next beacon period P(i + 1), and go to step (2) until all subtrees are allocated.

2. The beacon cycle adjustment method for an HPLC dual-mode system as described in claim 1, characterized in that, The method for subtree selection in step (2) is as follows: Find the subtree SubTree1 with the largest number of unselected child nodes among the direct proxy nodes of the CCO, arrange the time slots hierarchically on this subtree, and obtain the number of time slots SubT1; If SubT1 exceeds the predetermined threshold T_threshold, only one subtree can be allocated in this beacon frame, and there is no need to select other subtrees.

3. The beacon cycle adjustment method for an HPLC dual-mode system as described in claim 2, characterized in that, If SubT1 is within the predetermined threshold T_threshold, select the next node tree SubTree2 with the largest number of child nodes to allocate time slots hierarchically. At this time, the allocation rule is to allocate according to the hierarchy of the two subtrees from top to bottom; If the total number of time slots SubT(i)=∑SubTj obtained exceeds the specified threshold T_threshold, indicating that the time slot allocation fails, then select the next node tree SubTree3 with the largest number of child nodes of the CCO for time slot allocation; repeat this process until no subtree can be arranged within the specified threshold, that is, (SubT(i)=∑SubTj)<T_threshold, and j is the number of selected subtrees.

4. The beacon cycle adjustment method for an HPLC dual-mode system as described in claim 3, characterized in that, In step (3), the CSMA time slot length T_CSMA(i)= T_Beacon - SubT(i).

5. The beacon cycle adjustment method for an HPLC dual-mode system as described in claim 1, characterized in that, In step (2), when selecting a subtree, arrange the non-leaf nodes hierarchically from top to bottom of the subtree, and then arrange the leaf nodes.

6. The beacon cycle adjustment method for an HPLC dual-mode system as described in claim 1, characterized in that, If all proxy nodes on the subtree can communicate with their direct child nodes through a high-speed carrier, send a reduced beacon frame on the wireless channel.

7. The beacon cycle adjustment method for an HPLC dual-mode system as described in claim 1, characterized in that, If the proxy nodes on the subtree can only communicate with their direct child nodes wirelessly, try to insert the nodes that only send reduced beacon frames on the subtree when arranging time slots. If the requirements cannot be met, insert the time slots for sending wireless standard beacon frames.

8. A device for adjusting the beacon period of an HPLC dual-mode system, characterized in that: The system includes at least one processor and a memory, which are connected via a data bus. The memory stores instructions that can be executed by the at least one processor. After being executed by the processor, the instructions are used to complete the HPLC dual-mode system beacon cycle adjustment method according to any one of claims 1-7.

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