Wi-SUN network power adaptive control method for wireless meter reading

Abstract

A Wi-SUN network power adaptive control method for wireless meter reading comprises the following steps: assigning a Wi-SUN communication module of an intelligent electric meter in a meter box as a power coordinator, and assigning Wi-SUN communication modules of other intelligent electric meters in the meter box as terminal nodes; after the nodes are powered on, in the network construction process, the routing cost is adjusted by introducing a PC weight factor, and the node with the lowest routing cost is selected as a preferred father node to join the network, so that a terminal node preferentially selects the power coordinator of the meter box as the father node; the power coordinator sends a power control instruction in the meter box to the terminal node joining the network; the terminal node adjusts own transmitting power to be lower than conventional power; when the terminal node communicates with the node outside the meter box, the terminal node sends data to the power coordinator with limited power, and then the power coordinator sends the data to the upper-level node with high power. According to the invention, the problem of reliability conflict between near-end communication overload and long-distance communication in a high-density electric meter deployment scene is solved.

Description

Technical Field

[0001] This invention belongs to the field of wireless meter reading technology, and in particular relates to a Wi-SUN network power adaptive control method for wireless meter reading. Background Technology

[0002] Smart meters are the core terminals for user-side energy data collection, metering, and interaction in the power grid. Their deployment density is experiencing explosive growth, especially in urban residential areas and commercial complexes, where 10 to 30 smart meters are often installed in a single metal meter box, forming a typical high-density communication environment. Wi-SUN (Wireless Smart Ubiquitous Network) has become the mainstream technology solution for remote communication of smart meters due to its mesh topology self-healing capability, low power consumption, and wide coverage.

[0003] Existing smart meters based on Wi-SUN network technology generally employ a fixed transmit power design for their communication modules, typically around +30 dBm to achieve optimal communication distance. While this fixed transmit power design balances communication distance and power consumption requirements in low-density deployments, it reveals significant technical drawbacks in high-density integration within meter enclosures. For example, when smart meters are densely installed within metal enclosures (spacing <10 cm), the coupled RF signal strength between the communication modules can reach +15 dBm, far exceeding the receiver's maximum tolerable input power (typically -10 dBm), leading to LNA saturation and accelerated device aging. On the other hand, smart meters need to establish reliable communication with the regional concentrator, but the distance between the meter enclosure and the concentrator is usually considerable. This necessitates that the smart meter's communication module possess sufficient transmit power to overcome path loss and environmental interference. In high-density deployments, the need for high transmit power to ensure reliable communication with the regional concentrator and the avoidance of excessive transmit power leading to LNA saturation and device aging present a contradiction.

[0004] To address the aforementioned contradictions, some have proposed a partial adaptive power control scheme, but it still has significant limitations: First, it relies on a single parameter and global network information for decision-making, lacking the ability to identify scene differences. For example, if it only relies on Received Signal Strength Indication (RSSI) for unidirectional power adjustment, it cannot effectively distinguish whether the communication target is a neighboring node inside the meter box or an upper-level concentrator outside the meter box, leading to overload problems for short-range signals inside the meter box. Second, it lacks a local coordination mechanism at the meter box level, and the independent power decisions of each meter are prone to causing "power oscillations"—when one module reduces power, adjacent modules misjudge the communication quality as declining and increase power, forming an interference cycle. Summary of the Invention

[0005] The purpose of this invention is to provide a Wi-SUN network power adaptive control method for high-density deployment scenarios of smart meters. By designating a coordinator node within the meter box to achieve local power autonomy, it solves the conflict between near-end communication overload and long-distance communication reliability.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The Wi-SUN network power adaptive control method for wireless meter reading includes the following steps:

[0008] S1. In each meter box, one smart meter's Wi-SUN communication module is designated as the power coordinator, and the Wi-SUN communication modules of the remaining smart meters in the meter box are terminal nodes. The terminal nodes communicate and interact with the distribution area concentrator through the power coordinator. The nodes contained in the meter box include the power coordinator and the terminal nodes.

[0009] S2. After the node is powered on, calculate the routing cost and build the topology network. The steps are as follows:

[0010] S201. After the node is powered on, it reads the node type parameter of the local machine and sends PAS frames to the surrounding area at normal power; the PAS frame contains at least its own MAC address and node type identifier.

[0011] S202, Surrounding nodes respond to the PA frame with the same power; the PA frame includes at least the network name, network size, routing cost, received signal strength, its own MAC address, and node type identifier;

[0012] S203. After receiving PA frames from surrounding nodes, a node stores all surrounding nodes that responded with PA information as candidate parent nodes in a candidate parent node set. It then calculates the routing cost for itself and all nodes in the candidate parent node set, selects the node with the lowest routing cost as the preferred parent node, and joins the network. The routing cost PANcost = PANCost0 × PC_WEIGHT_FACTOR, where PANCost0 is the original routing cost and PC_WEIGHT_FACTOR is the PC weight factor.

[0013] S3. Perform power control within the meter box for nodes that have joined the network: The power coordinator sends a power control command within the meter box to the terminal node that has joined the network; Upon receiving the power control command, the terminal node adjusts its transmission power to be lower than the normal power; When communicating with nodes outside the meter box, the terminal node sends data to the power coordinator, which then sends it to the next higher level node.

[0014] In some embodiments, the transmit power of the power coordinator is greater than the transmit power of the terminal node after the transmit power is adjusted.

[0015] In some embodiments, the terminal node that receives the power control command from the meter box adjusts its own transmit power to -15dBm to 0dBm.

[0016] In some embodiments, the steps for calculating routing costs are as follows:

[0017] S203a. When a node receives a PA frame in response from a surrounding node, it records and stores the network name, network size, original routing cost PANCost0, received signal strength RSSI, MAC address, and node type in the received PA frame.

[0018] S203b. Determine the PC weight factor, calculate the new routing cost based on the PC weight factor, and save it. The rules for determining the PC weight factor are as follows:

[0019] ① If the node itself is an end node,

[0020] A) The received PA frame contains a PC identifier and RSSI ≥ -30dBm, PC_WEIGHT_FACTOR = 0.5~0.7;

[0021] B) The received PA frame contains a PC identifier and -50dBm≤RSSI<-30dBm, PC_WEIGHT_FACTOR=0.7~0.9;

[0022] C) The received PA frame contains a PC identifier and RSSI < -50dBm, PC_WEIGHT_FACTOR = 1.0;

[0023] D) The received PA frame contains a TN identifier or a C identifier, and PC_WEIGHT_FACTOR=1.0;

[0024] ② If the node itself is a power coordinator,

[0025] A) The received PA frame contains the C identifier, PC_WEIGHT_FACTOR = 0.5 to 0.8;

[0026] B) The received PA frame contains a PC identifier or a TN identifier, PC_WEIGHT_FACTOR = 1.0;

[0027] Newly powered nodes select the node with the lowest routing cost as their primary parent node and join the network. The remaining nodes in the candidate parent node set are arranged in order of routing cost from low to high and are selected as candidate parent nodes in turn.

[0028] In some embodiments, the method further includes the following steps: the power coordinator periodically exchanges information with its child nodes; if a child node does not receive information from its parent node within a set maintenance period, it is considered that the parent node is lost, and the remaining nodes are selected from the candidate parent node set in order of routing cost from low to high as its parent node.

[0029] In some embodiments, after designating a power coordinator as the primary power coordinator within the meter box, an additional terminal node is designated as a backup power coordinator to take over the function in the event of a failure of the primary power coordinator.

[0030] In some embodiments, when a backup power coordinator is available, the backup power coordinator takes over when the primary power coordinator fails, as follows:

[0031] When the backup power coordinator does not receive information from the primary power coordinator within a consecutive preset period and there is no candidate power coordinator, it initiates a PC takeover process, modifies its own node type parameter to PC, broadcasts a PC takeover request, obtains confirmation from the terminal nodes in the meter box, assumes the PC function, and resends power control commands to all terminal nodes.

[0032] In some embodiments, the Wi-SUN communication module includes: a storage unit, a communication unit, a computing unit, a power control unit, a security authentication unit, and a fault detection unit; the storage unit is used to store node type identifiers, Backup-PC parameters, PC weight factor tables, bin IDs, and power limit parameters; the communication unit is used to send and receive PAS / PA frames carrying node type identifiers; the computing unit is used to calculate routing costs based on the RSSI value and node type in the received PA frames; the power control unit is used to adjust the transmit power; the security authentication unit is used to verify the identity of the power operation and maintenance terminal and allow modification of the node type identifier; the fault detection unit is used to monitor the status of the primary power coordinator and trigger the backup power coordinator takeover process.

[0033] In some embodiments, the power control unit further includes a digital control attenuator for limiting the maximum output power upon receiving a power control command.

[0034] As can be seen from the above technical solutions, addressing the contradiction between near-end communication overload and long-distance communication reliability in existing technologies, this invention specifies a power coordinator within the meter box and introduces a PC weighting factor to calculate routing costs when constructing the topology network. This allows terminal nodes to select the power coordinator within their own meter box as the parent node, building a meter box-level power autonomy system. This achieves forced low-power communication within the meter box and unified proxy high-power backhaul for communication outside the meter box, solving the core pain point of Wi-SUN networks in high-density meter deployment. The power adaptive control method of this invention has the following beneficial effects:

[0035] 1) Eliminate near-end overload: The communication power in the meter box is forcibly reduced to -15dBm ~ 0dBm, and the signal strength of the TN receiver in the same meter box is controlled at -15dBm ~ 0dBm, which is far below the overload threshold of +10dBm of the RF chip, significantly reducing the risk of hardware failure.

[0036] 2) Ensure the reliability of long-distance communication: The PC, as a dedicated proxy node, uses high power by default to avoid communication interruptions caused by insufficient power in the TN.

[0037] 3) Enhance network topology stability: The PC weight factor mechanism ensures that the TN prioritizes the PC in the same box as the parent node, and the PC prioritizes the concentrator, forming a hierarchical network structure.

[0038] 4) Improve system reliability: In some embodiments, by setting up a backup power regulator, the Backup-PC failover mechanism ensures that a single point of failure does not affect the overall communication of the meter box, ensuring continuous network operation. Attached Figure Description

[0039] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 is a flowchart of the power adaptive control method according to an embodiment of the present invention;

[0041] Figure 2 A step-by-step diagram for constructing a network topology;

[0042] Figure 3 A flowchart illustrating the steps of power control within the meter box;

[0043] Figure 4 This is a schematic diagram illustrating the application of the method of the present invention in different scenarios.

[0044] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Detailed Implementation

[0045] The present invention will now be described in detail with reference to the accompanying drawings. In describing the embodiments of the present invention, for ease of explanation, the drawings illustrating the device structure will be partially enlarged, not according to general proportions. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of the present invention. It should be noted that the drawings are simplified and use non-precise proportions, intended only to facilitate and clearly illustrate the embodiments of the present invention. Additionally, in the description of this application, terms such as "first" and "second" are used only to distinguish descriptions and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Terms such as "positive," "negative," "bottom," "upper," "lower," "front," "rear," "left," and "right" indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, not indicating or implying that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0046] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] In a wireless meter reading network based on Wi-SUN network technology, each meter box contains several smart meters using Wi-SUN communication modules. To resolve the conflict between near-end communication overload and long-distance communication reliability in high-density deployment scenarios in existing technologies, the core idea of ​​this invention is to designate one smart meter's Wi-SUN communication module in each meter box as a Power Coordinator (PC), while the Wi-SUN communication modules of the remaining smart meters in the box serve as Terminal Nodes (TN). The network topology includes three types of nodes: Concentrators (C), Power Coordinators (PC), and Terminal Nodes (TN). When constructing the topology, a PC weighting factor is introduced to adjust routing costs based on an added node type identifier, enabling Terminal Nodes to select the Power Coordinator of their own meter box as their parent node. Terminal Nodes within the meter box communicate with the Concentrators through the Power Coordinator. When a terminal node joins the network, the power coordinator sends a power control command to it, forcibly reducing the communication power inside the meter box. When the terminal node communicates with the outside of the meter box, the power coordinator handles high-power forwarding on its behalf.

[0048] The node type parameter of the Wi-SUN communication module is set to TN by default at the factory, and the Backup-PC parameter is set to 0 by default, meaning the communication module is a terminal node by default, and the transmit power is set to +25dBm to +30dBm by default. When smart meters are installed in the distribution area, the node type identifier of the Wi-SUN communication module can be modified via a power maintenance terminal. This invention designates the Wi-SUN communication module of one smart meter in the meter box as a power coordinator. The power maintenance terminal can modify the node type identifier from TN to PC via infrared, Bluetooth, or NFC near-field communication. The modification process requires digital certificate authentication to ensure operational security. The node type of the Wi-SUN communication modules of the remaining smart meters remains unchanged, all being terminal nodes.

[0049] The Wi-SUN communication module in this embodiment includes a storage unit, a communication unit, a computing unit, a power control unit, a security authentication unit, and a fault detection unit. The storage unit stores parameters such as node type identifiers, Backup-PC parameters, PC weight factor tables, bin IDs, and power limit parameters. The communication unit transmits and receives PAS / PA frames carrying node type identifiers. The computing unit dynamically calculates the routing cost (PANCost) based on the RSSI value and node type in the received PA frames. The power control unit adjusts the transmit power according to the node type and communication target. The security authentication unit verifies the identity of the power maintenance terminal before allowing modification of the node type identifier. The fault detection unit monitors the master PC status and triggers the Backup-PC takeover process. The power control unit also includes a digital control attenuator for hardware-level limiting of the maximum output power (transmit power) upon receiving a power control command.

[0050] Figure 1 The flowchart of the method of the present invention is as follows: Figure 1 As shown, the Wi-SUN network power adaptive control method of the present invention is applied to the high-density deployment scenario of smart meters, and includes the following steps:

[0051] S1. In each meter box of the power distribution network, a Wi-SUN communication module of a smart meter is designated as a power coordinator, and the Wi-SUN communication modules of the remaining smart meters in the meter box are terminal nodes. The terminal nodes communicate and interact with the distribution area concentrator through the power coordinator. The nodes in the power distribution network include the power coordinator, terminal nodes, and distribution area concentrator, and the nodes in the meter box include the power coordinator and terminal nodes.

[0052] S2. After the node is powered on, calculate the routing cost and construct the network topology; such as Figure 2 As shown, the steps to construct the topology network are as follows:

[0053] S201. After the node is powered on, it reads the node type parameter of the local machine, and then sends PAS frames (PAN Advertisement Solicits) to the surrounding area at normal power to request network information (Personal Area Network, abbreviated as PAN); the PAS frame contains at least the MAC address of the sending node (newly powered-on node) and the node type identifier.

[0054] S202, Surrounding nodes respond to PA frames; Upon receiving a PSA frame, surrounding nodes record the MAC address and node type of the sending node, and respond to a PA frame (PAN Advertisement) with the same power; The PA frame contains network parameters, and also extends to carry node type and Received Signal Strength (RSSI), specifically the network name, network size, routing cost (PANCost0), Received Signal Strength (RSSI), and information such as the MAC address and node type of the sending node (the node responding to the PA frame);

[0055] S203. After a newly powered-on node receives PA frames from surrounding nodes, it calculates the routing cost, selects the node with the lowest routing cost as the preferred parent node, and joins the network.

[0056] Specifically, the routing cost is dynamically calculated based on the node type and RSSI. The specific steps are as follows:

[0057] S203a. When a node receives a PA frame in response from a surrounding node, it records and stores information such as the network name, network size, original routing cost (PANCost0), received signal strength (RSSI), MAC address of the sending node, and node type in the received PA frame.

[0058] S203b: Calculate the PC weight factor, calculate the new routing cost PANcost based on the PC weight factor, and save it;

[0059] PANcost = PANCost0 × PC_WEIGHT_FACTOR, where PANCost0 is the original routing cost and PC_WEIGHT_FACTOR is the PC weight factor;

[0060] The PC weighting factor, PC_WEIGHT_FACTOR, is dynamically determined based on the sender node type and RSSI, according to the following rules:

[0061] ① If the node (the newly powered-on node) itself is a terminal node (TN), then

[0062] A) The received PA frame contains a PC identifier (i.e., the node responding to the PA frame is the power coordinator) and RSSI ≥ -30dBm, PC_WEIGHT_FACTOR = 0.5~0.7;

[0063] B) The received PA frame contains a PC identifier and -50dBm≤RSSI<-30dBm, PC_WEIGHT_FACTOR=0.7~0.9;

[0064] C) The received PA frame contains a PC identifier and RSSI < -50dBm, PC_WEIGHT_FACTOR = 1.0;

[0065] D) The received and transmitted PA frames contain a TN identifier (i.e., the node responding to the PA frame is the terminal node) or a C identifier (i.e., the node responding to the PA frame is the area concentrator), PC_WEIGHT_FACTOR=1.0;

[0066] ② If the node (the newly powered node) itself is a power coordinator, then

[0067] A) The received PA frame contains the C identifier, PC_WEIGHT_FACTOR = 0.5 to 0.8;

[0068] B) The received PA frame contains a PC identifier or a TN identifier, PC_WEIGHT_FACTOR = 1.0;

[0069] The newly powered-on node stores all surrounding nodes that responded to the PA information as candidate parent nodes in the candidate parent node set, calculates the routing cost corresponding to itself and all nodes in the candidate parent node set, and then selects the node with the lowest routing cost as the preferred parent node to join the network; the remaining nodes in the candidate parent node set are arranged in order of routing cost from low to high and are selected as candidate parent nodes in turn; according to the above rules, based on the introduced PC weight factor, the terminal node will preferentially select the power coordinator as the preferred parent node, and the power coordinator will preferentially select the area concentrator as the preferred parent node;

[0070] S3. Perform power control on the nodes within the meter box after grid connection, such as... Figure 3 As shown, the steps are as follows:

[0071] When an end node joins the network, the power coordinator sends a power control command within the enclosure to the end node joining the network, fixing the transmit power of the end node joining the network to -15dBm to 0dBm, so that the transmit power is lower than the normal power; the power control command within the enclosure includes the following fields: command type identifier, maximum allowed transmit power value, limit duration, and unique identification ID of the enclosure;

[0072] Upon receiving the power control command from inside the meter box, the terminal node adjusts its own transmit power to -15dBm to 0dBm (reducing transmit power). When communicating with nodes outside the meter box, it sends data to the power coordinator with the power limited (-15dBm to 0dBm), and then the power coordinator sends it to the next-level node. The transmit power of the power coordinator is the normal power, which is greater than the transmit power of the terminal node after the transmit power is adjusted.

[0073] In this invention, during the network construction process, nodes adjust PANCost based on the PC weighting factor, ensuring that terminal nodes preferentially select the power coordinator within the same meter box as their parent node. When a terminal node joins the network, the power coordinator sends a power control command to it, forcing the communication power within the meter box to be limited to -15dBm to 0dBm. When a terminal node communicates with the outside of the meter box, the power coordinator uniformly proxies high-power (+25dBm to +30dBm) forwarding, thereby resolving the conflict between near-end communication overload and long-distance communication reliability in high-density smart meter deployment scenarios. This reduces hardware failure rates, extends equipment lifespan, and ensures wide-area network coverage quality. The power adaptive control method of this invention has advantages such as strong adaptability, flexible deployment, and no need to replace existing hardware, making it suitable for the construction of advanced metering systems (AMIs) in smart grids.

[0074] In some embodiments, to ensure normal network communication, the following steps are also included: the power coordinator periodically exchanges information with its child nodes; if a child node does not receive information from its parent node (power coordinator) within a set maintenance period (MAINTAIN_TIME), it is considered that the parent node has been lost, and the remaining nodes are selected from the candidate parent node set in order of routing cost as its parent node.

[0075] In some embodiments, to prevent communication failures when the power coordinator fails, after designating one power coordinator as the primary power coordinator in the meter box, an additional terminal node is designated as the backup power coordinator. That is, the “Backup-PC” parameter of the other terminal node is set to 1 through the power operation and maintenance terminal for takeover function when the primary PC fails. The “Backup-PC” parameter of the remaining terminal nodes is 0, which is the default “TN” working mode and is not a backup PC.

[0076] When a backup power coordinator is available, a PC node failover mechanism is also included. When the primary power coordinator fails, the backup power coordinator takes over, and the steps are as follows:

[0077] When the Backup Power Coordinator (Backup-PC) does not receive information from the Primary Power Coordinator within a consecutive preset period (such as 10 consecutive maintenance periods) and there is no candidate power coordinator, it initiates a PC takeover process, modifies its own "node type" parameter to "PC", broadcasts a PC takeover request, and after obtaining confirmation from a majority of terminal nodes in the meter box, it assumes the PC function and resends power control commands to all terminal nodes.

[0078] Figure 3 The diagram illustrates the application of the method of the present invention in three different scenarios. Figure 3 The illustrated topology includes three types of nodes: the distribution concentrator (C), the power coordinator (PC), and the terminal node (TN). Taking a residential substation scenario as an example, the distribution area deploys one concentrator and 12 meter boxes, with each meter box containing 15-25 smart meters.

[0079] All smart meters in the meter box have their Wi-SUN communication modules pre-configured at the factory with the following settings: the node type parameter is set to TN by default, and the Backup-PC parameter is set to 0 by default; the Wi-SUN concentrator module has its node type parameter fixed to C at the factory; and all Wi-SUN communication modules have their default transmit power set to +28dBm.

[0080] S1. Designate one smart meter's Wi-SUN communication module as a power coordinator in each meter box within the distribution area. Power maintenance personnel use a handheld terminal (such as a handheld maintenance device) via infrared / Bluetooth / NFC interface to modify the parameters of the designated Wi-SUN communication module, changing the node type of the selected Wi-SUN communication module from TN to PC. Meters located near the corner and relatively far from other smart meters in the same meter box can be preferentially selected as power coordinators. At the same time, an additional meter is designated in each meter box as a backup power coordinator, and its Backup-PC parameter is changed from 0 to 1. The modification process must be authenticated with a digital certificate to ensure operational security.

[0081] S2. After the node is powered on, the routing cost is calculated and the topology network is constructed.

[0082] S201, Power-on initialization; After the new meter is powered on or restarted, it first reads the node type and Backup-PC parameters of the local machine; Regardless of the type of node, it first sends a PAS frame at a normal power of +28dBm. The APS frame contains the local MAC address, node type identifier and Backup-PC status.

[0083] S202, Neighbor Discovery and Information Collection: After receiving a PAS frame, surrounding nodes record the sending node's MAC address, node type, and backup status, and respond to the PA frame with the same power.

[0084] S203. Dynamically calculate the new routing cost based on the PC weight factor;

[0085] If the newly powered-on node is TN, after receiving the PA frame, the PC weighting factor is dynamically calculated based on the sender node type and the received signal strength:

[0086] When a PA frame containing a PC identifier is received and RSSI ≥ -30dBm, PC_WEIGHT_FACTOR is set to 0.6;

[0087] When a PA frame containing a PC identifier is received and -50dBm≤RSSI<-30dBm, PC_WEIGHT_FACTOR is set to 0.8;

[0088] When a PA frame containing a PC identifier is received and RSSI < -50dBm, PC_WEIGHT_FACTOR is set to 1.0;

[0089] When a PA frame is received containing a TN or C identifier, PC_WEIGHT_FACTOR is set to 1.0;

[0090] Routing cost PANCost = PANCost0 × PC_WEIGHT_FACTOR;

[0091] If the newly powered-on node is a PC, upon receiving a PA frame, PC_WEIGHT_FACTOR is dynamically calculated based on the sender node type and the received signal strength.

[0092] When a PA frame containing the C identifier is received, PC_WEIGHT_FACTOR is set to 0.65;

[0093] When a PA frame is received containing a PC or TN identifier, PC_WEIGHT_FACTOR is set to 1.0;

[0094] Routing cost PANCost = PANCost0 × PC_WEIGHT_FACTOR.

[0095] Taking a specific test scenario as an example, a TN node within the meter box receives responses from three candidate parent nodes:

[0096] For PCs in the same table box: the original routing cost PANCost0=5, RSSI=-25dBm, then PC_WEIGHT_FACTOR=0.6, and the new routing cost PANCost=3;

[0097] For neighboring PC boxes: the original routing cost PANCost=6, RSSI=-42dBm, then PC_WEIGHT_FACTOR=0.8, and the new PANCost=4.8;

[0098] For a standard concentrator C: the original route PANCost=4, RSSI=-35dBm, then PC_WEIGHT_FACTOR=1.0, and the new route cost PANCost=4;

[0099] Arrange the routing costs corresponding to the three candidate parent nodes from low to high, 3 < 4 < 4.8, and select the PC in the same box with the lowest routing cost as the parent node;

[0100] After S3 and TN nodes join the network, they are allowed to perform autonomous power control within their enclosures: the PC sends an internal power control command to the TN node joining the network; after receiving the command, the TN node locks the upper limit of the transmit power to the range of -15dBm to 0dBm.

[0101] After power control is completed, the communication path in the network is as follows:

[0102] Internal communication within the meter box: When communicating between TN nodes, data transmission is performed using limited power (-15dBm ~ 0dBm);

[0103] External communication of the meter box: When the TN node needs to send data to the node outside the meter box, the data packet is sent to the PC with limited power (-15dBm ~ 0dBm);

[0104] After receiving the data, the PC retransmits it to the next higher-level node at high power (+25dBm ~ +30dBm).

[0105] PC node failover mechanism: PC nodes periodically exchange information with child nodes to maintain network connectivity; when a TN node does not receive information from its parent node (PC) within the set MAINTAIN_TIME period, it selects the remaining PC nodes from the candidate parent nodes in order of PANCost as the new parent node; the MAINTAIN_TIME period can be set according to the network size, usually for a 500-node area, the MAINTAIN_TIME period can be set to 1 hour.

[0106] When the Backup-PC does not receive information from the master PC node within 10 consecutive MAINTAIN_TIME cycles and there is no candidate PC node, it initiates a PC takeover process: changes its own node type parameter from TN to PC; broadcasts a PC takeover request; after obtaining confirmation from a majority of TN nodes in the meter box, it officially assumes the PC function; and resends power control commands to all TN nodes to ensure the continuous execution of the power policy.

[0107] Figure 3Figure a illustrates a scenario where the meter box and concentrator are close together, such as in an urban power distribution room, where the distance between the meter box and concentrator is less than 200 meters. When using the method of this invention for power control of the Wi-SUN communication module: firstly, one PC and one Backup-PC are designated in each meter box and configured via the maintenance terminal; during network construction, the PC in the meter box receives a PA frame from the concentrator C. Because it contains the C identifier, PC_WEIGHT_FACTOR=0.6, and PANCost is significantly reduced; the TN receives a PA frame from the PC in the same meter box, RSSI≈-25dBm, and PC_WEIGHT_FACTOR=0.6; the final network topology is formed: all PCs are directly connected to the concentrator C, and the TN is connected to the PC in its own meter box; the TN communication power within the meter box is maintained at -10dBm, and the communication power between the PC and the concentrator C is +28dBm. The network operates stably for 3 months without failure.

[0108] Figure 3 Figure b illustrates a scenario where the distance between the meter box and the concentrator is relatively far, such as in suburban power distribution networks. Some meter boxes are more than 500 meters away from the concentrator, resulting in severe signal attenuation. When using the method of this invention for power control of the Wi-SUN communication module: First, one PC and one Backup-PC are designated in each meter box and configured via the maintenance terminal. During network construction: The PC in the remote meter box (meter box A) receives a PA frame from concentrator C with RSSI < -85dBm and a high initial PANCost value. However, when it receives a PA frame from a neighboring meter box PC, RSSI ≈ -60dBm, and because the other party is a PC node, PC_WEIGHT_FACTOR = 1.0, the calculated route... The routing cost is lower than that of the concentrator C, meaning that the PAN cost of selecting a neighboring meter box PC as the parent node is lower than that of directly connecting to the concentrator. The final network topology forms a multi-level relay structure: remote meter box PC → neighboring meter box PC → concentrator C; data transmission path: TN (-10dBm) → this meter box PC (+28dBm) → neighboring meter box PC (+28dBm) → concentrator C; actual test results: while maintaining the safe power (-15dBm~0dBm) of each TN in the meter box, the overall network communication reliability reaches 99.2%.

[0109] Figure 3Figure c illustrates a PC node failover scenario, where the master PC in box A goes offline due to a power failure. In the initial phase (<10 maintenance cycles), the TNs in box A do not receive parent node information. Within the set maintenance cycle, the node with the lowest PANCost is selected from the candidate parent nodes, and some TNs switch to the PC node in box B as the new parent node. In the later phase (>10 maintenance cycles), according to the PC node failover mechanism, the Backup-PC in box A does not receive master PC information for 10 consecutive maintenance cycles, and there are no suitable candidate PC nodes. The Backup-PC initiates a takeover process, changing its node type to PC and broadcasting a PC takeover request. After obtaining confirmation from a majority of TNs in box A, it assumes the PC function and resends power control commands to all TNs, forcing the transmit power to be fixed at -15dBm to 0dBm. After network recovery, box A re-establishes an independent power autonomous unit, with communication interruption time <45 seconds.

[0110] In an isolated terminal node access scenario, such as at a temporary power monitoring point, there exists an isolated TN without a meter box. After powering on, the TN sends a PAS frame and receives multiple responses: PC node of meter box C: RSSI=-55dBm, PC_WEIGHT_FACTOR=0.85; TN node of meter box D: RSSI=-48dBm, PC_WEIGHT_FACTOR=1.0. After comparison using PANCost calculation, the isolated TN selects the PC of meter box C as its parent node. The PC of meter box C recognizes that the TN does not belong to its own meter box (verified by the meter box ID), but still allows it to join the network, without sending power control commands. The isolated TN maintains its default power of +28dBm, successfully accesses the network, and uploads data.

[0111] As can be seen from the above descriptions of several application scenarios, the method of the present invention can effectively solve the conflict between near-end communication overload and long-distance communication reliability in high-density deployment scenarios of smart meters, significantly extend the life of equipment, improve network stability, and does not require replacement of existing hardware, thus having good engineering practicality and economy.

[0112] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A Wi-SUN network power adaptive control method for wireless meter reading, characterized in that, Includes the following steps: S1. In each meter box, one smart meter's Wi-SUN communication module is designated as the power coordinator, and the Wi-SUN communication modules of the remaining smart meters in the meter box are terminal nodes. The terminal nodes communicate and interact with the distribution area concentrator through the power coordinator. The nodes contained in the meter box include the power coordinator and the terminal nodes. S2. After the node is powered on, calculate the routing cost and build the topology network. The steps are as follows: S201. After the node is powered on, it reads the node type parameter of the local machine and sends PAS frames to the surrounding area at normal power; the PAS frame contains at least its own MAC address and node type identifier. S202, Surrounding nodes respond to the PA frame with the same power; the PA frame includes at least the network name, network size, routing cost, received signal strength, its own MAC address, and node type identifier; S203. After receiving PA frames from surrounding nodes, a node stores all surrounding nodes that responded with PA information as candidate parent nodes in a candidate parent node set. It then calculates the routing cost for itself and all nodes in the candidate parent node set, selects the node with the lowest routing cost as the preferred parent node, and joins the network. The routing cost PANcost = PANCost0 × PC_WEIGHT_FACTOR, where PANCost0 is the original routing cost and PC_WEIGHT_FACTOR is the PC weight factor. S3. Perform power control within the meter box for nodes that have joined the network: The power coordinator sends a power control command within the meter box to the terminal node that has joined the network; Upon receiving the power control command, the terminal node adjusts its transmission power to be lower than the normal power; When communicating with nodes outside the meter box, the terminal node sends data to the power coordinator, which then sends it to the next higher level node.

2. The Wi-SUN network power adaptive control method as described in claim 1, characterized in that: The power coordinator's transmit power is greater than the terminal node's transmit power after adjustment.

3. The Wi-SUN network power adaptive control method as described in claim 1, characterized in that: Upon receiving the power control command from the meter box, the terminal node adjusts its own transmit power to -15dBm to 0dBm.

4. The Wi-SUN network power adaptive control method as described in claim 1, characterized in that: The steps to calculate routing costs are as follows: S203a. When a node receives a PA frame in response from a surrounding node, it records and stores the network name, network size, original routing cost PANCost0, received signal strength RSSI, MAC address, and node type in the received PA frame. S203b. Determine the PC weight factor, calculate the new routing cost based on the PC weight factor, and save it. The rules for determining the PC weight factor are as follows: ① If the node itself is an end node, A) The received PA frame contains a PC identifier and RSSI ≥ -30dBm, PC_WEIGHT_FACTOR = 0.5~0.7; B) The received PA frame contains a PC identifier and -50dBm≤RSSI<-30dBm, PC_WEIGHT_FACTOR=0.7~0.9; C) The received PA frame contains a PC identifier and RSSI < -50dBm, PC_WEIGHT_FACTOR = 1.0; D) The received PA frame contains a TN identifier or a C identifier, and PC_WEIGHT_FACTOR=1.0; ② If the node itself is a power coordinator, A) The received PA frame contains the C identifier, PC_WEIGHT_FACTOR = 0.5 to 0.8; B) The received PA frame contains a PC identifier or a TN identifier, PC_WEIGHT_FACTOR = 1.0; Newly powered nodes select the node with the lowest routing cost as their primary parent node and join the network. The remaining nodes in the candidate parent node set are arranged in order of routing cost from low to high and are selected as candidate parent nodes in turn.

5. The Wi-SUN network power adaptive control method as described in claim 1, characterized in that: It also includes the following steps: The power coordinator periodically exchanges information with its child nodes; if a child node does not receive information from its parent node within a set maintenance period, it is considered that the parent node has been lost, and the remaining nodes are selected from the candidate parent node set in order of routing cost from low to high as its parent node.

6. The Wi-SUN network power adaptive control method as described in claim 1, characterized in that: After designating one power coordinator as the primary power coordinator within the meter box, an additional terminal node is designated as the backup power coordinator to take over the function in the event of a failure of the primary power coordinator.

7. The Wi-SUN network power adaptive control method as described in claim 6, characterized in that: When a backup power coordinator is available, it will take over when the primary power coordinator fails, following the steps below: When the backup power coordinator does not receive information from the primary power coordinator within a consecutive preset period and there is no candidate power coordinator, it initiates a PC takeover process, modifies its own node type parameter to PC, broadcasts a PC takeover request, obtains confirmation from the terminal nodes in the meter box, assumes the PC function, and resends power control commands to all terminal nodes.

8. The Wi-SUN network power adaptive control method as described in claim 1, characterized in that: The Wi-SUN communication module includes: a storage unit, a communication unit, a computing unit, a power control unit, a security authentication unit, and a fault detection unit. The storage unit stores node type identifiers, Backup-PC parameters, a PC weight factor table, a table box ID, and power limit parameters. The communication unit transmits and receives PAS / PA frames carrying node type identifiers. The computing unit calculates routing costs based on the RSSI value and node type in the received PA frames. The power control unit adjusts the transmit power. The security authentication unit verifies the identity of the power operation and maintenance terminal and allows modification of the node type identifier. The fault detection unit monitors the status of the primary power coordinator and triggers the backup power coordinator takeover process.

9. The Wi-SUN network power adaptive control method as described in claim 8, characterized in that: The power control unit also includes a digital control attenuator for limiting the maximum output power upon receiving a power control command.

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