Power line carrier and wireless communication hybrid network self-organizing scheduling method

Abstract

The invention relates to a self-organizing scheduling method for a power line carrier and wireless communication hybrid network. The node equipment of the method has a unique address and has two communication functions. The method comprises the steps of performing self-learning identification on nodes of the same power carrier link, judging whether the nodes are in the same link or not and determining the number of core nodes; a core node is selected for each link, a total score is obtained by calculating power carrier quality, wireless communication and power carrier position score weighting, and the link with the highest total score is selected; each core node corresponds to an independent wireless communication network and is responsible for interaction; and after the hybrid network runs, dynamically adjusting core node and index weights according to changes. The calculation method of each score index is clear, and variable coefficient adjustment weight can be calculated according to a time period. According to the method, data conflict and packet loss can be avoided, the system load is reduced, the link communication mechanism is optimized, the optimal core node is selected during complex link deployment, and effective transmission of data is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of Internet of Things hybrid networking, and specifically to a self-organizing scheduling method for a hybrid network of power line carrier and wireless communication. Background Art

[0002] Power line carrier communication, with the English full name Power Line Carrier Communication and abbreviated as PLC, is a technology that uses power lines as a transmission medium to achieve data communication. Those skilled in the art also commonly use names such as power line carrier communication and power line communication for this technology, which belong to the same technical concept under the premise of using the same technical principle. Power line carrier communication also includes: ground wire carrier communication and split conductor carrier communication.

[0003] Its principle is: power system communication with the transmission line as the transmission medium of the carrier signal. Since the transmission line has a very firm support structure and is equipped with more than 3 conductors, generally three-phase good conductors and one or two overhead ground wires, when the transmission line conveys the power frequency current, it is used to transmit the carrier signal, which is both economical and very reliable.

[0004] It should be noted that PLC is also the abbreviation of Programmable Logic Controller, and its English full name is Programmable Logic Controller. The present invention does not involve the technical content of Programmable Logic Controller, and the two should not be confused.

[0005] Usually, there is only one set of data for the uplink and downlink of a power line carrier communication link at the same time. The size of the data content of this set can be determined according to the performance of the hardware devices participating in the communication, but reasonable communication scheduling is required when multiple devices generate communication data simultaneously to achieve it.

[0006] Affected by the inherent characteristics of the transmission medium, i.e., the power line, the following problems exist in the power line carrier communication system: When performing communication scheduling, it is necessary to consider that the power line carrier communication devices at different installation positions have different net attenuation when communicating with other devices or communicating with the gateway or central processing device, which means that the data forwarding performance of not every device necessarily meets the communication requirements. Power line carrier communication is also affected by the inherent frequency stability and noise of the power line.

[0007] When considering the interaction between power line carrier communication and other communication method devices, it is also necessary to consider the impact of power line differential and junction on the hybrid communication system of multiple communication methods.

[0008] The signal-to-noise ratio (SNR) of power carrier communication is defined as the ratio of useful signal power to noise power. Noise power includes: background noise such as steady-state noise from electrical equipment, pulse noise, narrowband interference such as wireless frequency band crosstalk, and channel attenuation such as signal attenuation caused by power line impedance changes. SNR can determine the reliability and rate of data transmission.

[0009] The net attenuation of a channel refers to the difference between the input level value at the initial end of the carrier channel and the output level value at its terminal, that is, the total attenuation in one transmission direction minus the net attenuation of the total gain.

[0010] Stability is a quality indicator that measures the stability of a channel. When the total gain of the loop formed by the two transmission directions exceeds the comprehensive loop attenuation, the channel becomes unstable and will produce ringing, which seriously interferes with the signal, overloads the line, and even interferes with other channels.

[0011] Tandem connection is to combine two or more transmission paths into one path. Differential connection is to separate one transmission path into two or more transmission paths. Differential connection refers to the combination of differential connection and tandem connection. Differential connection and tandem connection are two inverse processes. If it is a differential connection device, it can complete these two reversible processes at the same time. Summary of the invention

[0012] Based on the problems mentioned in the background technology, a communication scheduling method needs to be designed in the system of hybrid networking of power carrier communication and wireless communication to ensure that the communication data and signals can be transmitted to the target device in a timely and effective manner when the power carrier communication and wireless communication interact with each other. At the same time, the overall load of data interaction in the hybrid networking system is reduced, the communication work mechanism of the power carrier communication link is optimized, and the equipment performance and link data transmission efficiency are balanced.

[0013] like Figure 1 and Figure 2 As shown, a self-organizing scheduling method for a hybrid network of power carrier and wireless communication includes a node device for running the method, which has a unique device address and has power carrier communication and wireless communication functions; and also includes the following steps: S1. The node devices of the same power carrier link self-learn to identify each other, determine whether they are in the same link, and the number of core nodes that need to be selected for the same link; S2. Select the core node for each power carrier link, calculate the power carrier quality score, wireless communication score, and power carrier location score, and calculate the total score by weighting each score. The node with the highest total score is selected as the core node; S3. Each selected core node corresponds to an independent wireless communication network and is responsible for communicating and interacting with the wireless network; S4. After the hybrid network runs, dynamically adjust the core nodes according to network changes, and dynamically adjust the weight coefficient of each index of the core nodes; The S2 step includes the following contents: The power line carrier quality score includes: signal-to-noise ratio index, net attenuation index, stability index, and the power line carrier quality score is calculated by weighted synthesis of each index; The wireless communication score includes: the coverage ratio of the node communication hop count; The power line carrier position score is to select corresponding indicators for score evaluation according to the transmission direction of wireless communication data in the power line carrier link and the communication function position of the transmission node in the link, including: the convergence network index H i , or the differential network index D i , or the differential connection cooperation index B i , where i represents the node device address.

[0014] The reason for identifying the number of core nodes to be selected in the S1 step is that a hybrid networking system of power line carrier communication and wireless communication is required. The main purpose is for wireless communication deployment and maintenance, which are simple, but in the case of cement walls and metal doors in the installation environment, it will affect wireless communication transmission. If the installation environment is basically closed, the wireless communication network within the closed-loop area is independent. At this time, power line carrier communication can make up for this deficiency by transmitting data through power lines, and the data is transmitted outside the closed-loop area. Power line carriers can connect multiple independent wireless communication networks. In order for the data of each independent wireless communication network to be effectively transmitted, a core node should be selected for each corresponding independent network to interact with it.

[0015] The weighted calculation described in the S2 step uses weight coefficients preset according to factors such as the actual project and network topology. The preset weight coefficients will be dynamically adjusted and optimized in the S4 step. The dynamic adjustment of the weight coefficients in the S4 step can not only cope with changes in the network topology, or the replacement, addition, or deletion of node devices, but also meet the further correction of the results of weighted calculation with the preset weights.

[0016] The index content of the power line carrier quality score calculation described in step S2 mainly targets the embedded hardware performance of each node. Due to the use of different electronic components, the index values of signal-to-noise ratio, net attenuation, stability, etc. may be different for different node devices even at the same location. The wireless communication score mainly refers to the ability of the power line carrier node device to interact with the wireless communication network. In addition to the communication hop coverage ratio, one or a combination of factors such as the communication success rate per unit time and the signal strength attenuation per unit distance can be used for evaluation. This method mainly uses the wireless communication network hop coverage ratio, considering that when the data of the power line carrier communication network system needs to be transmitted to the wireless communication network, data synchronization can be carried out efficiently and quickly. The power line carrier position score mainly considers the differential, convergence, and bridging situations generated by the node device when data travels upstream and downstream in the power line.

[0017] Preferably, the calculation steps of the signal-to-noise ratio index are as follows: Use the built-in function of the power line carrier module to measure SNR; measure it once every period of time, select the minimum value SNR_min and the maximum value SNR_max, and take the average value of multiple measurements; convert the SNR value to dB, i.e., SNR_dB = 10 * log10(SNR); perform SNR normalization, and the signal-to-noise ratio index SNR_normalized = (SNR_db - SNR_min) / (SNR_max - SNR_min).

[0018] Preferably, the calculation steps of the power line carrier net attenuation index NA are as follows: First, calculate the average net attenuation of the node: NA_avg = Σ(net attenuation with other nodes) / number of nodes, and then perform normalization processing NA_normalized = 1 - (NA_avg - NA_min) / (NA_max - NA_min), where NA_min and NA_max are the preset minimum and maximum acceptable net attenuation values.

[0019] Preferably, the power line carrier stability index PS is calculated using the Allan variance σ²(τ), PS = 10 *log 10 (σ²_ref / σ²_measured). Where: σ²_ref is the reference Allan variance, and σ²_measured is the actually measured Allan variance; for N consecutive measurement values with a sampling interval of τ, the calculation formula for the Allan variance is: σ²(τ) = 1 / (2(N - 1)) * Σ[y(i + 1) - y(i)]². Where y(i) is the average frequency in the i-th measurement period.

[0020] Preferably, the wireless communication score adopts the coverage ratio of the number of node communication hops, and the steps include: firstly perform a breadth-first search and record the number of new nodes that can be reached by each hop; calculate the cumulative coverage ratio: HCR = Σ(w_i * Nodes_i / Total_Nodes); i ranges from 1 to max_hops value, and max_hops can be set to 3 or half of the network diameter, whichever is smaller; wherein: Nodes_i is the number of newly added reachable nodes in the i-th hop, Total_Nodes is the total number of nodes in the network, and w_i is a weight factor, which can be set to w_i = 1 / i, indicating that the closer the hop number, the greater the weight of the node. In the weight factor w_i described in this formula step, i is the number of the i-th hop, which is also used as the factor w_i.

[0021] Preferably, the calculation formula for the tandem network index is Where T i,j is the flow data at node i of the j-th branch, n is the total number of branches, m is the number of all nodes of the branch connected to node k, T k,j is the flow data at the j-th branch node k, and the denominator of the calculation formula represents the total flow of all branches as a whole.

[0022] Preferably, the differential network index calculation formula is ,in is the flow rate of the kth output path of node i, nout is the number of output paths, is the flow rate of the input channel, is the mean flow rate of the output channel, and δout is the standard deviation of the flow rate of the output channel.

[0023] Preferably, the differential connection coordination index calculation formula is , ε is a very small constant to prevent the denominator from being zero.

[0024] Preferably, the power carrier location score evaluation includes: Hi ≈ Di Time Bi ≈1, the differential connection coordination index is selected for evaluation; when Hi > Di and Bi Approaching 0, the tandem network index is used for evaluation; Di > Hi and Bi Approaching 0, select differential network indicator evaluation.

[0025] Preferably, according to the set time period, calculate the coefficient of variation CV of each index; adjust the corresponding weight wi according to CV: wi_new = wi_old * (1 + CVi / sum(CV)); for each type of score that contains multiple indexes, after normalization adjustment, make the sum of the weight coefficients of each index equal to 1. In the corresponding weight wi described in the steps of this formula, i is the corresponding weight number, which can be set according to the specific application situation. wi_new is the specific corresponding weight value to be adjusted to, and wi_old is the corresponding weight value before being adjusted by CV.

[0026] All devices on the same power carrier link need to interact with the data of the devices that only communicate wirelessly around them during the same time period, and the data is the same. This method can avoid the channel occupation and data conflict caused by the devices on the same power carrier link repeatedly sending data to the wireless communication devices that need to interact around them. Generally, the data transmitted by the devices that only communicate wirelessly to a certain power carrier link during the same time period is unique. Within a certain time after receiving the data on this interaction link, uploading and downloading data can avoid packet loss caused by scheduling failure or failure caused by the influence of the inherent interference of the power carrier through this method. Another beneficial effect of this method is that when the deployment of the power carrier link is relatively complex, that is, there are many differential and branch connection branches, the optimal core node can be selected to take into account the data communication of the main link and the branch. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic Diagram of the Method Flow of the Present Invention Figure 1 。

[0028] Figure 2 Schematic Diagram of the Method Flow of the Present Invention Figure 2 。

[0029] Figure 3 It is a schematic diagram of Embodiment 1 of the present invention.

[0030] Figure 4 It is a schematic diagram of Embodiment 2 of the present invention.

[0031] Figure 5 It is a schematic diagram of Embodiment 3 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] In order to realize the communication scheduling of the system composed of the power carrier communication network and the wireless communication hybrid network, there should be several devices in the power carrier communication network that simultaneously have the communication modules of both networks, and such devices are used as nodes in the overall system. Other devices that only have the power carrier communication module are generally only used as data receiving devices.

[0033] After the installation of power line carrier communication and wireless communication devices is completed, the technology of the present invention can save the work of debugging personnel during the debugging stage. The overall system will automatically identify the device addresses of the power line carrier communication link nodes and whether they are on the same link. It can automatically identify how many core nodes need to be selected. And for the purpose of selecting core nodes, it automatically runs a program method and selects the results through scoring. The system also supports dynamic adjustment of the weight parameters in the scoring process and dynamic adjustment of the core nodes.

[0034] In the hybrid network system, devices belonging to the wireless communication network can automatically identify and determine their relative positions and unique device addresses through broadcast communication, which is convenient for the operation of the method described in the present invention. When selecting core nodes, the relative positions of wireless communication devices and the addresses corresponding to the positions can help the nodes calculate the hop count coverage ratio.

[0035] In order to better automatically discover whether node devices are on the same link, each node is equipped with a wireless communication module, such as a Bluetooth or Wi-Fi module, and a power line carrier communication module. After the node runs, in order to identify whether it is on the same link, that is, whether it communicates through the same power line, the following steps are executed: The node device generates a unique identifier: Use a hardware address such as a MAC address, or directly bind a unique device address when the node device is programmed. The address and a random number are combined to generate an identifier. The identifier can also add an identification bit for the device type to distinguish devices around that only have wireless communication functions.

[0036] Each node broadcasts through the power line carrier communication module, and the content includes: the identifier and the current timestamp; Generate a list of neighboring nodes: Record the node information received in the broadcast, including the last communication time; Since power line carrier communication can only interact with a group of data at the same time, that is, one group of data for uplink or downlink. Therefore, when performing the above steps, there may be a situation of data transfer queuing. When queuing occurs, the data is transmitted in order of the identifier value size, and it can be that the data with a smaller identifier value is transmitted first; After a period of time, all node devices on the same link will complete a list of other node devices on the same link, and this list will be used when selecting core nodes later.

[0037] Other devices that only have power line carrier communication functions will not generate interfering data during the operation of this method. This identification of node devices on the same link is to reduce data conflicts after selecting core nodes. A power line carrier communication link can have many nodes, but only the core nodes are responsible for interacting with the surrounding wireless communication network, avoiding repeated data transmission and queuing occupying communication.

[0038] Perform list verification on the entire link: Use timestamp data. Calculate the node broadcast time interval δt, construct the cumulative distribution function, calculate the link similarity through the function, and then perform clustering analysis to confirm the final list.

[0039] Construction of the cumulative distribution function CDF: Divide the time interval into N intervals, such as N = 100. For each interval i, calculate CDF(i) = P(δt ≤ i*Δt), where Δt is the interval width. CDF update: Update the CDF every time M new packets are received, such as M = 100. Update the CDF using the exponential decay factor α: CDF_new(i) = α * CDF_old(i) + (1 - α) * CDF_current(i), where α can be set to 0.9, and CDF_current is the CDF of the current M packets.

[0040] When calculating the link similarity, first perform CDF exchange: Each node broadcasts its own CDF information every time T, such as T = 5 min. Then perform the Kolmogorov - Smirnov test: For two CDFs, such as F1 and F2, calculate: D = max|F1(i) - F2(i)|, i = 1, 2, ..., N. The similarity S = 1 - D. Link determination: If S > S_threshold, such as S_threshold = 0.95, then the two nodes are considered to be on the same link.

[0041] The calculation process can perform hierarchical clustering through python software and obtain it using the UPGMA algorithm. The full English name of UPGMA is Unweighted Pair Group Method with Arithmetic Mean.

[0042] The purpose of performing list verification is to prevent the situation where node data is not effectively queued and is directly lost due to conflicts, resulting in data omission. At the same time, avoid data crosstalk and identifier changes that may occur in extremely rare cases.

[0043] As Figure 2 shown, the power line carrier quality score is represented by PQ, which is the abbreviation of Power line carrier quality score. It is mainly the influence of some inherent parameters of the power line carrier on power line carrier communication after the node device is installed and running. It mainly includes the signal - to - noise ratio score, the power line carrier net attenuation score, and the power line carrier stability score.

[0044] Preferably, PQ = 0.3 * SNR_normalized + 0.4 * NA_normalized + 0.3*PS_Normalized. This embodiment considers that: the weight of SNR is 0.3, reflecting the anti-interference ability. The weight of net attenuation accounts for 0.4, reflecting the performance of interactive communication on the same link. The weight of stability is 0.3, providing network characteristic information. Among them, SNR_normalized is the normalized signal-to-noise ratio index, NA_normalized is the normalized net attenuation index, and PS_Normalized is the normalized power line carrier stability index. The numerical values of the weight coefficients can be corrected via step S4 after the initial method run.

[0045] SNR measurement of signal-to-noise ratio: First, use the built-in signal-to-noise ratio measurement function of the power line carrier module to measure the specific SNR; measure once every 1 second and take the average of 10 measurements; convert SNR to dB measurement method: SNR_dB = 10 * log10(SNR); perform SNR normalization: SNR_normalized = (SNR_db - SNR_min) / (SNR_max - SNR_min).

[0046] In the normal implementation case, SNR_min = 0 dB, SNR_max = 50 dB. The specific numerical values can be adjusted according to the actual situation.

[0047] The purpose of measuring SNR is that SNR directly reflects the quality of the communication channel. A higher SNR means better signal quality and more reliable communication.

[0048] In an actual communication system, the values of SNR may span several orders of magnitude. For example, a good normal signal may be 1000 times that of the noise, while a poor signal may only be 1.1 times stronger than the noise. Directly using these ratios is not convenient for comparison and calculation. dB is a logarithmic unit that can compress a large range of ratios into a smaller range. This makes it easier to compare and process SNR values of different orders of magnitude.

[0049] The purpose of SNR normalization is to unify the measurement standard. The SNR ranges may be different for different devices or environments. After normalization, they can be compared within the range of 0-1. It is convenient to combine with other indicators for operation. The normalized SNR can be directly combined with other indicators within the range of 0-1. It improves comparability, and the communication quality between different nodes can be directly compared. It simplifies the calculation. In the comprehensive score, the scales of various indicators are the same, and the weight allocation is more intuitive.

[0050] The evaluation of the net attenuation of the power line carrier is represented by NA, which is the abbreviation of English Net Attenuation.

[0051] Net attenuation measurement method: The sending node sends a test signal with a known power. The receiving node measures the power of the received signal. Net attenuation = transmitted power - received power, unit: dB. Measure all directly communicable nodes in the network regularly.

[0052] Calculate the average net attenuation of the node: NA_avg = Σ(net attenuation with other nodes) / number of nodes Normalization: NA_normalized = 1 - (NA_avg - NA_min) / (NA_max - NA_min). Where NA_min and NA_max are the preset minimum and maximum acceptable net attenuation values, and the specific values are calculated according to the actual project.

[0053] Power Line Stability score PS, the abbreviation of English Power Line Stability: Preferably, the Allan variance used to measure frequency stability is adopted. Evaluate the frequency stability and phase noise of the signal, which has a direct impact on communication quality.

[0054] Collect the frequency measurement data of the power line communication system. Select an appropriate τ value, usually starting from the characteristic time scale of the system. Calculate the Allan variance σ²(τ). Compare the calculated Allan variance with a predetermined reference value to obtain PS_Score. Apply a normalization function to obtain the final PS_Normalized.

[0055] For N consecutive measurement values with a sampling interval of τ, the calculation formula for the sample Allan variance is: σ²(τ) = 1 / (2(N - 1)) * Σ[y(i + 1) - y(i)]². Where y(i) is the average frequency in the i-th measurement period.

[0056] We can design the following scoring formula based on the Allan variance: PS = 10 * log 10 (σ²_ref / σ²_measured). Where: σ²_ref is the reference Allan variance, which can be set based on system requirements, and σ²_measured is the actually measured Allan variance.

[0057] To normalize the score to the 0 - 1 range, we can use the following normalization function: PS_Normalized =1 / (1 + e^(-k * (NA_Score - threshold))). Where: k is the parameter to adjust the steepness of the curve, and threshold is the middle value of the score.

[0058] The threshold is usually determined based on historical data or system specifications. A commonly used method is to use the median, which can reduce the influence of outliers and obtain a value representing typical performance.

[0059] The selection of k is usually based on experience and system requirements. One calculation method is: k = -ln(1 / 0.99 - 1) / (x_max - threshold). Where: x_max is the maximum PS_Score value where 99% of the expected data is to fall. This formula ensures that when the PS_Score reaches x_max, the PS_Normalized is approximately 0.99.

[0060] The wireless communication score WS, which is the abbreviation of Wireless communication score. Preferably, it is calculated through the hop coverage ratio HCR index, where HCR is the abbreviation of Hop Coverage Ratio. Calculate the ratio of nodes that can be reached through different hop counts starting from this node. The detailed steps are as follows: First, perform a breadth-first search and record the number of new nodes that can be reached in each hop. Calculate the cumulative coverage ratio: HCR = Σ(w_i * Nodes_i / Total_Nodes), i = 1 to max_hops. Where: Nodes_i is the number of newly reachable nodes in the i-th hop, Total_Nodes is the total number of nodes in the network, w_i is the weight factor, which can be set as w_i = 1 / i, indicating that nodes closer in hop count have a greater weight, and max_hops can be set to 3 or half of the network diameter, taking the smaller value.

[0061] The wireless communication score can also include relative index measurements such as signal strength and communication success rate. The present invention preferably uses HCR because when a node device interacts with a wireless communication device, the more devices that can interact, the better. After selecting such a node as the core node, in subsequent use, it can more efficiently obtain data from the wireless communication network source and save the routing communication time from other wireless communication devices to the node device.

[0062] Such as Figure 3 , Figure 4 , Figure 5 As shown. Due to the wall, the signal transmission of the wireless communication network can only reach the nodes on its own nearest power line carrier network, that is, the nodes on the side closer to itself after being separated by the wall.

[0063] Such as Figure 3As shown, the node devices that can directly perform wireless communication in wireless communication network A are 1, 2, 3, and 5. The node devices that can directly perform wireless communication in wireless communication network B are 4, 6, and 7. After the node devices 1 - 7 on the power line carrier link identify that they are on the same link, they will also determine to select 2 core nodes to communicate with wireless communication networks A and B respectively.

[0064] Regarding the power line carrier position score, taking Figure 3 as an example, when node 1 transmits data to nodes 3, 4, and 5, it is differential. When nodes 3, 4, and 5 transmit data to 1, it is a convergence. When wireless communication network B first transmits data to the power line carrier communication network and then the data is transmitted to wireless communication network A through the power line carrier link, in this data transmission direction, it is preferably evaluated using the convergence network index to select the core node from nodes 4, 6, and 7. In the opposite data transmission direction, wireless communication network A first transmits data to the power line carrier communication network and then to wireless communication network B. In this data transmission direction, it is preferably evaluated using the differential network index to evaluate and select the core node from nodes 1 and 2.

[0065] In the above - mentioned situation, in the step of calculating the hop - count coverage ratio of the wireless communication score, the number of core nodes can be identified and selected. In this implementation, during the hop - count coverage ratio detection process, the node devices record the wireless communication device addresses to form a data set. At the stage when each node starts the step of broadcasting to select the core node, the node will directly discover the recorded wireless communication device address data set, and the data sets have no intersection. At this time, the corresponding number of core nodes is selected according to the number of non - intersecting data sets. For example, the device address data sets of wireless communication network A and wireless communication network B have no intersection, and it is identified that 2 core nodes need to be selected.

[0066] Such as Figure 4 shown, wireless communication network C is basically isolated by walls around it. When it performs wireless communication interaction, it can only communicate with nodes 12 and 13. When node 12 transmits data to nodes 16, 17, and 18, it is differential. When node 13 transmits data to nodes 14 and 15, it is also differential. When nodes 12 and 13 transmit data to 11, it is a convergence. In this case, nodes 12 and 13 evaluate the power line carrier position score and preferably use the differential cooperation index.

[0067] Based on Figure 4 the node devices, if the installation position of the power line carrier link has changed, assuming it becomes as Figure 5In the illustrated embodiment, at this time, the nodes that the wireless communication network C can communicate with are 11, 12, and 17. When node 12 is assumed to be the core node, the data it transmits is equivalent to being differenced twice. For example, the first difference of node 12 is to nodes 16, 17, 13, and 11, and the second difference is to nodes 14 and 15 after node 13. In this case, if it is found that the scores are too close after the differential cooperation index evaluation, the differential network index evaluation can be used once more.

[0068] Core node selection process: Each node calculates its own score and broadcasts it to other nodes on the same power carrier link. The node collects all score information and selects the node with the highest score as the core node. If the scores are the same, the node with the smaller ID is selected. The election result is broadcast to all nodes.

[0069] To adapt to the dynamic changes of the network, we adopt the following dynamic adjustment mechanism: When the following events are detected, the score recalculation can be triggered: First, the network topology changes, such as Figures 4 to 5 the situation shown by the change in the installation location of the device. Second, the network state changes, such as significant changes in the convergence or differential network voltage exceeding the preset threshold, or the access, offline, or replacement of nodes or devices with only power carrier communication capabilities; Adopt a smoothing process for the dynamic adjustment mechanism: Use the Exponential Moving Average (EMA) to smooth the change of the PI score: PI_EMA = α * PI_current + (1 - α) * PI_previous. Where α is set to 0.3, indicating that the newly calculated PI accounts for 30% of the weight; Threshold trigger mechanism: Only when the difference between the newly calculated PI_EMA and the PI_EMA of the current core node exceeds the preset threshold, such as 10%, is the replacement of the core node considered.

[0070] Through this optimized system, it is thus possible to better adapt to complex network structures and dynamic changes.

[0071] The weights can be self-organized and adjusted by the system according to the calculation of the coefficient of variation: Regularly, such as every 7 days, calculate the coefficient of variation CV of each score index: CV = standard deviation / mean. Adjust the weights according to CV: wi_new = wi_old * (1 + CVi / sum(CV)). wi_new represents the adjusted weight, wi_old represents the original weight coefficient, sum(CV) represents the simple sum of the coefficients of variation, and i represents the corresponding score index number.

[0072] The purpose of introducing the coefficient of variation CV is to reflect the volatility of the indicators. CV measures the degree of dispersion of the data. A high CV indicates that the indicator varies greatly in the network. Indicators with large variations may have a more important impact on the network state and should receive more attention. By increasing the weights of indicators with large fluctuations, the system can respond more sensitively to network changes and make adaptive adjustments. Balance stability and sensitivity: retain the influence of the original weights wi_old, and at the same time introduce appropriate dynamic adjustments. For each type of score that contains multiple indicators, after normalization adjustment, the sum of the weight coefficients of each indicator is 1.

[0073] This implementation method can make the weights automatically adapt to the network situation: if an indicator varies greatly in the network, it may mean that the communication quality is unstable, and the system will automatically increase its weight to monitor and respond to this situation more closely. On the contrary, if an indicator is very stable, its weight will be relatively reduced, making the system pay more attention to other aspects that may have problems.

Claims

1. A self-organizing scheduling method for a hybrid power line carrier and wireless communication network, including node devices that run the method, having a unique device address and both power line carrier communication and wireless communication capabilities; characterized in that, It also includes the following steps: S1. The node devices on the same power carrier link perform self-learning and mutual recognition to determine whether they are on the same link and the number of core nodes to be selected on the same link; S2. Each power carrier link selects core nodes by calculating the power carrier quality score, wireless communication score, and power carrier position score, and calculating the total score by weighted calculation of each score. The one with the highest total score is used as the core node; S3. Each selected core node corresponds to an independent wireless communication network and is responsible for communicating and interacting with this wireless network; S4. After the hybrid network runs, the core nodes are dynamically adjusted according to network changes, and the weight coefficients of each index of the core nodes are dynamically adjusted; The S2 step includes the following contents: The power carrier quality score includes: signal-to-noise ratio index, net attenuation index, and stability index. The power carrier quality score is calculated by weighted synthesis of each index; The wireless communication score includes: node communication hop count coverage ratio; The power line carrier position score is evaluated by selecting corresponding indicators according to the transmission direction of wireless communication data in the power line carrier link and the communication function position of the transmission node in the link, including: the convergence network indicator H i , or the differential network indicator D i , or the differential connection coordination indicator B i , where i represents the node device address.

2. The self-organizing scheduling method for a hybrid power line carrier and wireless communication network according to claim 1, characterized in that, The calculation steps of the signal-to-noise ratio index are as follows: Use the built-in function of the power carrier module to measure SNR; measure it once every period of time, select the minimum value SNR_min and the maximum value SNR_max, and take the average value of multiple measurements; convert the SNR value to dB, that is, SNR_dB = 10 * log10(SNR); perform SNR normalization, and the signal-to-noise ratio index SNR_normalized = (SNR_db - SNR_min) / (SNR_max - SNR_min).

3. A self-organizing scheduling method for a power line carrier and wireless communication hybrid network according to claim 1, characterized in that The calculation steps of the net attenuation index NA are as follows: First calculate the average net attenuation of the node: NA_avg = Σ(net attenuation with other nodes) / number of nodes, and then perform normalization processing NA_normalized = 1 - (NA_avg - NA_min) / (NA_max - NA_min), where NA_min and NA_max are the preset minimum and maximum acceptable net attenuation values.

4. A self-organizing scheduling method for a hybrid power line carrier and wireless communication network according to claim 1, characterized in that The stability index PS is calculated using the Allan variance σ²(τ), and PS = 10 * log 10 (σ²_ref / σ²_measured). Where: σ²_ref is the reference Allan variance, and σ²_measured is the actually measured Allan variance; for N consecutive measurement values with a sampling interval of τ, the calculation formula for the Allan variance is: σ²(τ) = 1 / (2(N - 1)) * Σ[y(i + 1) - y(i)]². Where, y(i) is the average frequency in the i-th measurement period.

5. A self-organizing scheduling method for a power line carrier and wireless communication hybrid network according to claim 1, characterized in that The wireless communication score uses the node communication hop count coverage ratio. The steps include: First perform breadth-first search and record the number of new nodes that can be reached in each hop; calculate the cumulative coverage ratio: HCR = Σ(w_i * Nodes_i / Total_Nodes); i ranges from 1 to the value of max_hops, and max_hops can be set to 3 or half of the network diameter, taking the smaller value; where: Nodes_i is the number of newly reachable nodes in the i-th hop, Total_Nodes is the total number of network nodes, and w_i is the weight factor, which can be set to w_i = 1 / i, indicating that the nodes closer to the hop have a greater weight.

6. The self-organizing scheduling method for a hybrid power line carrier and wireless communication network according to claim 1, characterized in that The calculation formula for the tandem network metrics is where T i,j is the traffic data at node i of the j-th branch, n is the total number of branches, m is the number of all nodes of the branches connected to node k, and T k,j is the traffic data at node k of the j-th branch, and the denominator part of the calculation formula represents the total traffic of all branches as a whole.

7. A self-organizing scheduling method for a power line carrier and wireless communication hybrid network according to claim 1, characterized in that, The calculation formula for the differential network metrics is , where is the flow of the k-th output path of node i, nout is the number of output paths,[ is the flow of the input path,[ is the average value of the flow of the output path, and δout is the standard deviation of the flow of the output path.[ 8. A self-organizing scheduling method for a hybrid power line carrier and wireless communication network according to claim 1, characterized in that, The differential connection coordination index calculation formula is: , ε is a very small constant to prevent the denominator from being zero.

9. A self-organizing scheduling method for a power line carrier and wireless communication hybrid network according to claim 1, characterized in that, The power carrier position score evaluation includes: when Hi ≈ Di that is Bi ≈1, select the differential connection cooperation index for evaluation; when Hi > Di and Bi approaches 0, select the convergent network index for evaluation; when Di > Hi and Bi approaches 0, select the differential network index for evaluation.

10. The self-organizing scheduling method for a power line carrier and wireless communication hybrid network according to claim 1, wherein Calculate the coefficient of variation CV of each index according to the set time period; adjust the corresponding weight wi according to CV: wi_new = wi_old * (1 + CVi / sum(CV)); for each type of score containing multiple indexes, after normalization adjustment, the sum of the weight coefficients of each index is 1.

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