A method for reporting measurement switch events based on dual-mode communication confirmation

Abstract

The application discloses a kind of based on double mode communication confirmation's measurement switch event frame reporting method, for the low utilization of whole package retransmission channel in the existing power distribution terminal mass event reporting, single-link confirmation reliability is insufficient, lack of power failure continuation and service scheduling capability problem, the application is by generating the event level envelope containing unique event identification and total frame number, event load is split into carrying event identification and frame serial number multiple event frames and is sent by main communication link;Again by main, standby double mode link receives the confirmation message containing confirmation bitmap, is positioned missing frame according to confirmation bitmap and only to missing frame executes make-up.This application can realize the efficient, reliable reporting of mass event, also has breakpoint continuation, priority scheduling and double mode redundancy ability, can be applicable to the event transmission demand of distribution internet of things measurement switch.

Description

Technical Field

[0001] This invention relates to the fields of power grid distribution automation and Internet of Things communication technology, and in particular to a method for frame-based reporting of measurement switch events based on dual-mode communication confirmation. Background Technology

[0002] With the continuous advancement of the construction of the distribution network Internet of Things (IoT), the measurement switches in distribution substations have evolved from simple on / off control and electrical parameter acquisition to multi-functional applications such as edge sensing, fault recording, and event tracing. Among these, dual-mode communication technology, consisting of high-speed power line carrier and low-power wireless, has become the mainstream access solution for distribution terminals due to its dual-link redundancy. Currently, distribution terminal event reporting mostly adopts whole-packet transmission and link-layer automatic retransmission mechanisms. In high-capacity event reporting scenarios, this results in low channel utilization and insufficient transmission reliability, making it difficult to meet the operation and maintenance needs of smart distribution networks.

[0003] CN121125574A discloses a traffic load monitoring and management method for power communication networks. This method achieves traffic load control of the backbone communication network through DPI deep packet analysis, time sliding window feature extraction, anomaly detection and tracing, and load regulation decision-making. However, this method mainly focuses on link-level load monitoring and global scheduling on the network side, without addressing the optimization of event reporting transmission mechanisms on the distribution terminal side; it also does not design framed transmission and selective retransmission strategies for large-capacity events, and cannot solve the problem of channel resource waste caused by single-frame bit error triggering whole packet retransmission; at the same time, it lacks the ability to adapt to power distribution scenarios such as dual-mode link dual-channel acknowledgment reception and terminal power failure interruption resumption.

[0004] CN113840331A discloses a data transmission method and network system. This scheme improves transmission bandwidth through multi-physical interface aggregation and switches to an independent interface or uses multi-interface load balancing transmission when an abnormality is detected in the aggregated interface, ensuring link availability. However, this scheme is designed for general network access scenarios and does not adapt to the service characteristics of measurement switch event reporting; it only implements link-level fault switching and does not establish frame-level acknowledgment feedback and selective retransmission mechanisms, resulting in insufficient channel utilization and reliability for large-capacity data transmission; at the same time, it lacks essential transmission control capabilities for power distribution terminals, such as event-level priority scheduling, receiver idempotency verification, and protocol conversion verification.

[0005] CN102883370B discloses a distributed data transmission method for power line monitoring based on wireless sensor networks. This method achieves energy load balancing of nodes in a chain-like sensor network through distributed relay selection, time-slice allocation, and tiered upload scheduling. However, this method is only geared towards terminal energy consumption optimization scenarios in wireless sensor networks and does not cover the event reporting requirements of dual-mode communication in distribution substations. It adopts a whole-packet transmission mechanism without frame encapsulation or bitmap-based acknowledgment retransmission capabilities, resulting in low efficiency for large-capacity event transmission. It also lacks mechanisms such as dual-link redundant acknowledgment, event priority scheduling, and power-off resume transmission, making it difficult to adapt to the high-capacity, high-reliability event reporting scenarios of measurement switches.

[0006] In summary, none of the above solutions have developed a specific optimization plan for the high-capacity event reporting scenario of power distribution measurement switches. They generally suffer from problems such as low channel utilization for whole packet retransmission, insufficient reliability of single-link confirmation feedback, and lack of power failure breakpoint resume transmission and priority scheduling mechanisms, which cannot meet the needs of efficient and reliable reporting of measurement switch events under the power distribution Internet of Things. Summary of the Invention

[0007] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0008] In view of the aforementioned existing problems, this invention is proposed. Therefore, this invention provides a frame-based reporting method for measurement switch events based on dual-mode communication confirmation, to solve the problems mentioned in the background art.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for frame-based reporting of measurement switch events based on dual-mode communication confirmation, comprising: S1: In the measurement switch or its communication unit, an event-level envelope is generated for the detected event. The event-level envelope contains a unique event identifier and the total number of frames corresponding to the event. S2: Divide the event payload data into multiple event frames, each event frame containing the event identifier and frame number; S3: Send the multiple event frames to the receiving end through the main communication link; S4: Receive an acknowledgment message for the event identifier via the main communication link or the backup communication link. The acknowledgment message contains an acknowledgment bitmap, which indicates that the event frame has been successfully received. S5: Based on the confirmation bitmap, identify the missing event frames that were not successfully received, and perform a retransmission operation only on the missing event frames.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention adopts a framed transmission and bitmap-based selective retransmission mechanism to split the event payload exceeding the maximum transmission unit into independent event frames. By confirming the bitmap, the lost or damaged single frame is accurately located, and only the missing frame is retransmitted. This avoids the bandwidth waste caused by single frame errors triggering full retransmission in traditional whole packet transmission, and improves the channel utilization rate for reporting large-capacity events such as fault recording.

[0011] 2. This invention adopts a dual-mode dual-channel acknowledgment and dynamic link retransmission strategy, which supports simultaneous monitoring of acknowledgment messages of the primary and backup communication links and removes the binding restriction of the transmitting and receiving links. When the communication quality of the primary link is lower than a preset threshold, it automatically switches to the backup link to perform retransmission. By utilizing the complementary channel characteristics of high-speed power line carrier and low-power wireless, it effectively avoids one-way interference and link failure in power distribution scenarios and improves the success rate of event reporting in complex environments.

[0012] 3. In addition, the present invention also uses non-volatile memory to solidify the transmission status log, so that the transmission can be directly resumed from the breakpoint after the device is powered off and restarted, avoiding the repeated transmission of the whole packet; at the same time, it implements preemptive queue scheduling based on event priority to ensure that high-priority emergency events such as trip alarms occupy channel resources first, which can adapt to the operating characteristics of multiple services concurrently in measurement switches and power grids prone to flashover. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the 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. Wherein: Figure 1 This is a flowchart illustrating the overall process of a frame-based reporting method for measurement switch events based on dual-mode communication confirmation, according to an embodiment of the present invention. Detailed Implementation

[0014] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0015] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0016] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0017] Furthermore, in the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply 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 invention. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] Example 1

[0019] Reference Figure 1 This is the first embodiment of the present invention, which provides a method for frame-based reporting of measurement switch events based on dual-mode communication confirmation, including: S1: In the measurement switch or its communication unit, an event-level envelope is generated for the detected event. The event-level envelope contains a unique event identifier and the total number of frames corresponding to the event.

[0020] Specifically, in the distribution substation scenario of a smart grid, measurement switches (such as smart circuit breakers and smart meters) are typically used to collect real-time data on the grid's operating status. When an anomaly or sudden change in the grid's state occurs, the edge computing module of the measurement switch triggers an event monitoring mechanism. To ensure the integrity of event data and prevent out-of-order delivery and loss in a dual-mode communication environment, this invention introduces event-level envelope technology. This event-level envelope provides a global metadata description for the entire event data packet.

[0021] Furthermore, when the detected event originates from a record in the first communication protocol (e.g., the traditional DL / T 645 protocol), since the data structure of the traditional protocol is often not suitable for the efficient framing transmission requirements of modern IoT dual-mode communication, the communication unit of the measurement switch will first execute protocol conversion logic to convert the event record in the first communication protocol into an event object in the second communication protocol (e.g., the object-oriented DL / T 698.45 protocol). Simultaneously, to ensure data consistency before and after conversion and to prevent data tampering or loss during edge-side conversion, the system will extract the payload data of the converted event object and generate a conversion summary. The generation process is as follows: The original event byte stream under the first communication protocol is XORed with the event object byte stream under the second communication protocol. Specifically, when the two byte streams are of different lengths, the shorter byte stream is padded with zeros (or circularly padded) to align its length, based on the length of the longer byte stream. Then, an XOR operation is performed byte by byte, and the timestamp of the conversion is appended. Finally, the concatenated data is input into a secure hash algorithm (e.g., SHA-256) for calculation, and the output is the conversion digest.

[0022] Then, the conversion summary and the protocol information used to identify the first and second communication protocols will be recorded together in an event-level envelope for the receiving end to trace and verify against counterfeiting.

[0023] Furthermore, in order to accurately distinguish and reassemble concurrent events from different measurement switches and at different times at the receiving end (e.g., a distribution concentrator or a master station system), a globally unique event identifier must be assigned to each event.

[0024] Specifically, the system takes the physical MAC address of the measurement switch (to ensure spatial uniqueness), the timestamp of the event (to ensure temporal uniqueness), and the monotonically increasing event sequence number maintained locally by the measurement switch (to prevent conflicts caused by multiple concurrent events within the same millisecond) as input parameters. Then, these three input parameters are concatenated into binary data. The concatenated data is then fed into a hash algorithm (e.g., MD5) to generate a fixed-length hash digest. The first N bytes (e.g., the first 4 bytes) of this hash digest are extracted as a feature code. Finally, this feature code is Base62 encoded. The final output is a short, fixed-length alphanumeric combination as a unique event identifier.

[0025] It should be noted that this processing method can reduce the overhead of the communication message header while ensuring uniqueness.

[0026] Furthermore, since the event load data reported by the measurement switches (e.g., advanced events containing fault waveform data) is often large, exceeding the MTU (Maximum Transmission Unit) of the dual-mode communication network, the load data must be segmented. Specifically, when generating the envelope, the total number of frames corresponding to the event needs to be calculated in advance. The calculation rules for the total number of frames are as follows: First, obtain the minimum common maximum transmission unit negotiated by the current dual-mode communication network (to ensure frame size compatibility during primary / backup link switching), and subtract the fixed frame header overhead (including frame sequence number, event identifier, etc.) and security check overhead (e.g., CRC checksum) for a single event frame to obtain the single-frame payload capacity. Then, divide the total payload data byte length of the event object by this single-frame payload capacity. If a remainder exists, it means the remaining data is insufficient for a complete data frame, but still requires a separate frame sequence number for transmission. Therefore, round up the division result; the final value is the total number of frames corresponding to that event.

[0027] Furthermore, in addition to the above information, the event-level envelope of this invention also includes: event type, event occurrence time, measurement switch address, and priority information for identifying event priority. To achieve reasonable resource scheduling in subsequent transmission queues, a dynamic priority evaluation logic is built into the communication unit. Its evaluation rules are as follows: First, a baseline weight is assigned based on the event type (e.g., the baseline weight for a short-circuit trip event is much greater than that for a regular over-limit alarm event). Then, the time difference between the current time and the event occurrence time is calculated (i.e., the event's local latency). For time-sensitive events, the longer the latency, the more dynamically the system amplifies its baseline weight according to a preset growth factor, thereby increasing its priority and forcibly preempting the channel for reporting; conversely, for expired or invalid events, their priority is reduced.

[0028] In this embodiment, the formula for calculating the dynamic priority is:

[0029] in, For dynamic priority weights, The baseline weights assigned based on event type. For the current time, The time when the event occurred. This refers to the residence time, and K is the preset growth coefficient.

[0030] Furthermore, the measurement switch encapsulates the unique event identifier, total number of frames, event type, event occurrence time, measurement switch address, dynamic priority information, and protocol conversion summary obtained above together to form an event-level envelope.

[0031] S2: Divide the event payload data into multiple event frames, each of which contains an event identifier and a frame number.

[0032] Specifically, after S1 generates the global event-level envelope, the communication unit of the measurement switch needs to physically segment and encapsulate the actual event payload data (i.e., the byte stream of the converted second communication protocol event object). Due to the complex channel environment of dual-mode communication networks (high-speed power line carrier and low-power wireless), with its burst noise and multipath fading, transmitting large amounts of event data as a whole would lead to retransmission of the entire massive data packet in the event of a local error, wasting channel resources. Therefore, this invention uses framing to break down large chunks of payload data into smaller units. The specific segmentation and encapsulation process is as follows: Furthermore, the communication unit first extracts the total payload data byte stream of the event to be sent from memory. Based on the single-frame effective payload capacity and the total number of frames determined in S1, the byte stream is segmented using a sequential truncation method. The specific segmentation rules are as follows: For most of the preceding event frames, a full-load strategy is adopted, that is, the length of the load data allocated to them is equal to the effective load capacity of a single frame; while for the last event frame, it is allocated the remaining unsegmented tail data.

[0033] It should be explained that the single-frame effective payload capacity here is the net payload limit derived from the MTU of the current dual-mode network's primary and backup links after deducting necessary protocol overhead. Fixed-length segmentation according to the above segmentation rules ensures that the segmented physical frames will not undergo secondary fragmentation at the network layer on any communication link, maximizing channel utilization of a single frame while guaranteeing the determinism and continuity of data slices.

[0034] Furthermore, after the payload data is segmented, an independent frame header needs to be assembled for each payload data block. In this process, to meet the characteristics of connectionless and asynchronous transmission under dual-mode communication, the frame header of each event frame must contain two core elements: a unique event identifier and a frame sequence number.

[0035] Specifically, the unique event identifier generated in S1 is written into the header of each frame. It is important to emphasize that in a dual-mode network, due to the dynamic switching of the primary and backup links (PLC and RF) or the dynamic changes in mesh network routing, multiple event frames belonging to the same event may arrive at the receiver at different times via different physical paths (i.e., out-of-order arrival). Therefore, embedding the same event identifier in each slice allows the receiver to accurately assign scattered frames to their corresponding event contexts without maintaining a synchronized session connection.

[0036] Furthermore, the system assigns an incrementing frame number to each event frame according to the order of data segmentation and writes it into the frame header. This frame number is not only used for the sequential arrangement of data reassembly at the receiving end, but also serves as a direct mapping basis for the subsequent generation of the acknowledgment bitmap by the receiving end (e.g., the event frame with frame number 3 will directly correspond to the state of the 3rd bit in the acknowledgment bitmap).

[0037] Meanwhile, to support subsequent accurate retransmission (i.e., selective retransmission), it is also necessary to ensure that the receiving end can independently verify the correctness of each event frame. Therefore, the system in this invention does not perform global verification of the entire event data, but instead performs independent CRC (Cyclic Redundancy Check) code calculation on the assembled frame header and payload data block, and appends the generated check code to the end of the specific frame to form a complete event frame.

[0038] It should be noted that during transmission, if a single bit flip or local interference occurs, the receiving end can immediately determine whether the specific frame is corrupted by using the CRC code at the end of the frame upon receipt. If it is corrupted or lost, the receiving end only needs to set the position corresponding to the frame sequence number to zero in the acknowledgment bitmap. The measurement switch can then accurately locate and retransmit only the corrupted event frame, without needing to retransmit other correctly received frames, thereby saving bandwidth resources in dual-mode communication.

[0039] Furthermore, after encapsulating all the aforementioned event frames, this group of event frames is pushed into the underlying transmission buffer of the communication unit. During this process, these event frames will automatically inherit the priority information evaluated by the event-level envelopes in S1. When the underlying MAC layer engages in channel contention (e.g., CSMA / CA mechanism), these frames belonging to the same high-priority event will be treated as a cluster, giving priority to preempting transmission time slots, thereby ensuring that slice data of emergency events (e.g., tripping waveform recording) can enter the transmission process as quickly as possible.

[0040] S3: Send multiple event frames to the receiving end via the main communication link.

[0041] It should be noted that after the physical framing and encapsulation of S2 are completed, the event frame will enter the waiting-to-send stage of the underlying communication module. Due to the complex environment of the smart grid distribution substation, the measuring switches may face sudden power outages at any time, and the network is often accompanied by massive amounts of periodic data collection concurrently. In order to ensure the reliable and timely delivery of high-priority events, the system needs to perform state solidification and queue scheduling operations before actually executing physical transmission.

[0042] Furthermore, before S3 actually transmits, the measurement switch or its communication unit will establish an independent breakpoint resume log for the event to be transmitted in its internal non-volatile memory (e.g., NVRAM or Flash). The data structure of this log not only includes the event-level envelopes generated in S1, but also maintains two dynamically updated sets of status identifiers, namely the transmission bitmap and the acknowledgment bitmap.

[0043] Then, based on the total number of frames the event is divided into, the system initializes a binary transmission bitmap of corresponding length in memory. Initially, all bits in the bitmap are set to 0 (representing no transmission). During subsequent transmission, whenever a specific event frame is successfully pushed into the physical layer and transmission is completed, the system flips the corresponding bit in the transmission bitmap to 1 (representing transmission).

[0044] It's important to explain that storing the transmission status in real-time as a bitmap in non-volatile memory is primarily intended to address device interruptions and restarts in power grid environments. When a measurement switch suddenly loses power while transmitting long message events (e.g., large waveform files), the restarted initialization process prioritizes reading the resume log from that point. By comparing the transmission bitmap and the acknowledgment bitmap, the system can accurately identify which frames were not yet transmitted and which frames were transmitted but not acknowledged before the power outage, thus directly resuming transmission or retransmission from the point of interruption. This method effectively avoids full packet retransmissions due to power outages, saving channel bandwidth.

[0045] Furthermore, in multi-task concurrent measurement switches, the MAC (Media Access Control) layer of the communication unit maintains a transmission buffer queue. Before the S3 actually transmits, the system needs to dynamically sort the event frames of different events in the transmission queue according to the priority information in the event-level envelopes. To prevent low-priority, high-volume tasks (e.g., periodic power freeze reporting) from blocking emergency events (e.g., short-circuit trip alarms), the system has a built-in preemptive scheduling logic. Specifically, the scheduler calculates a dynamic scheduling weight for each event frame cluster entering the queue. The evaluation rule for this weight integrates the following three dimensions: Baseline Priority: The initial priority assigned to the event-level envelope in S1 is read directly. The higher the priority of an event, the greater its base weight.

[0046] Business type bias: Logically distinguish between sudden event data and periodic polling data, and assign a fixed high weight compensation to sudden event data to ensure that event-type business is superior to periodic business overall.

[0047] Waiting time anti-congestion amplification: Real-time monitoring of the dwell time of each event frame in the transmission queue. For emergency alarm events, their scheduling weight increases rapidly with the increase of waiting time; while for ordinary events, the waiting time has a minimal impact on the weight. The purpose of this weight adjustment is to forcibly break any potential congestion in the underlying channel, ensuring that emergency events do not experience uncontrollable delays due to queuing.

[0048] Conflict handling logic: The scheduler sorts the queues in descending order based on the calculated dynamic weights. When a high-priority event frame conflicts with a low-priority data transmission task, the scheduler triggers a soft interrupt. If the underlying channel is idle, the high-priority frame will directly enter the transmission process; if a low-priority frame is being transmitted at the physical layer, the system waits for the current frame to complete transmission before immediately preempting the next TXOP (transmission opportunity), thus ensuring that the urgent event frame cluster is injected into the channel with minimal delay.

[0049] Furthermore, after completing the above log recording and queue scheduling, the system will officially send multiple event frames to the receiving end through the main communication link.

[0050] Specifically, in this embodiment, the main communication link is preferably an HPLC (High-Speed ​​Power Line Carrier) communication link. This is because, compared to low-power wireless links, HPLC communication links rely on physical power lines and have physical characteristics such as high bandwidth and relatively stable anti-interference capabilities, resulting in higher transmission efficiency for large-capacity continuous data (e.g., multiple segmented event frames). The specific transmission process is as follows: The HPLC baseband chip of the communication unit sequentially extracts event frames from the scheduling queue. Before transmission, it executes CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) mechanism to listen for the power line channel status. After confirming that the channel is idle, it modulates the digital bitstream of the event frames into a high-frequency analog signal and couples it into the power line for burst transmission to the receiving end of the distribution area (e.g., a concentrator). Each time an event frame is successfully injected into the physical layer, the system synchronously updates the corresponding state of the transmission bitmap in the non-volatile memory.

[0051] S4: Receive an acknowledgment message for the event identifier via the main communication link or the backup communication link. The acknowledgment message contains an acknowledgment bitmap, which indicates that the event frame has been successfully received.

[0052] Specifically, after the measurement switch in S3 injects the event frame cluster into the channel, due to the complexity of the physical environment of the distribution area (e.g., burst impulse noise on power lines, multipath fading in low-power wireless channels), some event frames will inevitably experience bit errors or be lost during transmission. In order to achieve breakpoint resumption rather than inefficient full packet retransmission, it is necessary to rely on the acknowledgment messages fed back by the receiving end (e.g., the distribution area concentrator or edge computing gateway).

[0053] Furthermore, after the receiving end captures an event frame through the underlying physical link, it extracts the event identifier and frame sequence number from the frame header. The receiving end allocates a reassembly buffer in memory for each newly arrived event identifier and initializes a receive state array with all initial states set to 0 based on the total number of frames. The processing rules involved are as follows: For each arriving event frame, the receiver first calculates its CRC code. If the check passes, the bit corresponding to the frame sequence number in the acknowledgment bitmap is set to 1, indicating that the frame has been received completely and correctly; if the frame is missing or the check fails, the corresponding bit remains 0.

[0054] Furthermore, to prevent the same event from being processed repeatedly due to network retransmissions, the receiving end also uses the event identifier, measurement switch address, event occurrence time, and event frame payload summary to perform an idempotency check on the reassembled event. If it is determined to be a duplicate report, the redundant payload is directly discarded, but an acknowledgment message containing the latest acknowledgment bitmap will still be forcibly replied to assist the sending end (measurement switch) in clearing the transmission queue.

[0055] Simultaneously, at the measurement switch terminal, after completing the S3 transmission action, the communication unit immediately enters a waiting-for-acknowledgment state. Traditional single-mode communication often can only wait for a reply on the original transmission link; once this link experiences persistent congestion, the acknowledgment message will not be delivered. Therefore, this invention employs a method that simultaneously monitors both the primary and backup communication links.

[0056] Specifically, after the communication unit of the measurement switch finishes transmitting, it keeps both the coupling receiving circuit of the main communication link (i.e., HPLC) and the radio frequency receiving circuit of the backup communication link (i.e., HRF) active simultaneously. This is because the dual-mode network of the smart grid has asymmetric characteristics; that is, a good quality main link from node A to node B does not necessarily mean that the quality of the main link from node B to node A is equally good (there may be unidirectional noise sources). Therefore, when the receiving end sends an acknowledgment message, it dynamically selects the optimal link to send the acknowledgment message based on its own routing table and channel assessment. Thus, when the measurement switch performs concurrent listening operations in dual mode, it can capture the acknowledgment message with the highest probability and lowest latency, thereby breaking the traditional fixed method of "the path from which it sends must be the path from which it receives".

[0057] Furthermore, if the receiving end does not receive any event frames, or if all acknowledgment messages sent by the receiving end are completely lost in the dual-mode channel, the measurement switch will face the risk of indefinite waiting. Therefore, when the main communication link times out or fails to receive acknowledgment messages, the system needs to implement an active backoff strategy. In this process, to adapt to the dynamically changing power grid channel, this invention preferably adopts a dynamic adaptive timeout threshold. This threshold is not a fixed constant, but is calculated by comprehensively considering three parameters: first, the average round-trip time between the measurement switch and the receiving end in the past (reflecting the current network congestion baseline); second, the fluctuation difference of the historical round-trip time (reflecting channel stability); and third, the fixed hardware time consumed by the receiving end to process frame reassembly and generate bitmaps. The system achieves a balance between fast retransmission and avoiding false timeouts by assigning different weights to the first two parameters.

[0058] In this embodiment, the dynamic adaptive timeout threshold The calculation formula is:

[0059] in, This is the historical average round-trip time. The basic weighting coefficient (e.g., 1.2); This represents the fluctuation difference in historical round-trip time. This is the penalty weighting coefficient (e.g., 2.0). This is the fixed hardware time required for the receiver to process frame reassembly. The calculated value is the dynamic adaptive timeout threshold for the current moment.

[0060] Specifically, the calculation process for the dynamic adaptive timeout threshold in this proactive fallback strategy is as follows: First, the inputs include the average round-trip time (RTT) of historical communication between the measurement switch and the receiver, the fluctuation difference of historical RTT, and the fixed hardware time consumed by the receiver in processing frame reassembly. Then, the system uses a combination of weighted summation and dynamic compensation. Specifically, a base weight is assigned to the average RTT (e.g., a weight coefficient of 1.2 to reserve space for basic network fluctuations), and a penalty weight is assigned to the fluctuation difference (e.g., a weight coefficient of 2.0, which amplifies the timeout threshold to avoid frequent false retransmissions when the network is extremely unstable). The sum of the weighted products of these two factors is then added to the fixed hardware time. The calculated value is the dynamic adaptive timeout threshold for the current moment. If the hardware timer inside the measurement switch exceeds this threshold without receiving an acknowledgment message, a downlink failure in the main communication link is determined. At this time, the measurement switch will switch to the backup communication link and actively send an acknowledgment request message to the receiver. This request message only contains an event identifier and does not contain large amounts of payload data. Once the receiving end receives the request on the backup link, it will immediately encapsulate the acknowledgment bitmap of the event maintained in its memory and return it along the backup link.

[0061] It is important to note that if the receiving end cannot find the reassembly context corresponding to the event identifier in its memory when it receives the acknowledgment request message (i.e., the main communication link message is completely lost and no event frames have been received), the receiving end will generate an initial acknowledgment bitmap filled with all zeros, or return along the backup link with an abnormal acknowledgment message carrying the event not found flag. After the measurement switch receives this all-zero bitmap or abnormal message, it determines that all event frames are missing and then triggers the retransmission of all event frames on the backup link.

[0062] Furthermore, once the measurement switch successfully receives the acknowledgment message via any of the above methods (passive listening or active request, main link or backup link), the microprocessor of the communication unit extracts the event identifier from the message to match the local context and parses out the acknowledgment bitmap. Subsequently, the system performs a bitwise logical comparison between the received acknowledgment bitmap and the transmission bitmap stored in the non-volatile memory (breakpoint resume log) in S3, thereby providing reliable data input for subsequent accurate location of missing frames and selective retransmission.

[0063] S5: Based on the confirmation bitmap, identify the missing event frames that were not successfully received, and perform a retransmission operation only on the missing event frames.

[0064] Specifically, in the traditional ARQ (Automatic Repeat Request) mechanism, once packet loss occurs, the sender often uses a backseat of N frames or retransmission of the entire packet. This results in significant waste of channel resources in dual-mode communication networks of distribution areas with limited bandwidth and frequent interference. Therefore, this invention employs a bitmap-based precise selective retransmission mechanism. After the measurement switch receives the acknowledgment message in S4, it will perform the location of the missing frame and dynamic link retransmission operation.

[0065] Furthermore, the microprocessor of the measurement switch extracts the acknowledgment bitmap received in S4 and reads the current event's transmission bitmap from the breakpoint resume log in the local non-volatile memory. To achieve the most efficient missing frame localization under the limited computing power of the edge computing node (measurement switch), the system uses a low-level bit-by-bit logic comparison rule to generate the missing state bitmap.

[0066] Specifically, the input data for this comparison rule consists of a locally recorded transmit bitmap (recording frames injected into the physical channel) and a receiver's acknowledgment bitmap (recording frames successfully received and verified). The processing rule is that the system performs a bit-by-bit logical comparison of these two bitmaps. The determination condition is: a frame is considered missing only if its status in the local record is "sent" and its status at the receiver is "unacknowledged." The output data is a missing status bitmap, where the bits marked as valid (set to 1) directly correspond to the sequence number of the event frame that needs to be retransmitted.

[0067] It should be noted that, through this bit state comparison logic based on pure hardware, compared with the traditional array traversal query, its execution cycle can not only be shortened, but also the CPU load of the measurement switch can be reduced, enabling the system to lock all the frame sequence numbers that need to be resent in a timely manner.

[0068] Furthermore, after identifying the missing event frame, the present invention does not blindly retransmit it directly on the original main communication link (i.e., HPLC). Instead, it considers the abrupt changes in the physical environment of the distribution station area (e.g., a large motor suddenly starting, causing continuous strong pulse noise on the power line). If the main link has already fallen into attenuation, continuing to retransmit on the original link will only lead to continuous failures. Therefore, before performing the retransmission operation, the system first extracts multi-dimensional operating parameters of the current main communication link to perform a comprehensive communication quality assessment. These multi-dimensional operating parameters include the historical confirmation success rate of the main link (range 0~100%), the confirmation round-trip time of the current event frame, and the number of retries for the current event. The communication quality assessment rules are as follows: The system employs a baseline deduction scoring model. First, the percentage of historical confirmation success rates is used as the base reliability score (out of 100). Then, a dynamic penalty mechanism is introduced: when the confirmation round-trip delay exceeds a preset normal delay threshold, a non-linear exponential penalty score is calculated for the excess portion (reflecting severe channel congestion). Simultaneously, the number of retries is multiplied by a preset single-retry deduction coefficient to obtain a linear penalty score. Specifically, this results in a comprehensive quality score. The calculation formula can be expressed as: ;in, This is the percentage of historical confirmed success rate (i.e., the baseline reliability score). For the currently confirmed round-trip delay, This is the normal delay threshold. The preset exponential penalty coefficient (when At that time, the penalty was scored as 0). This is the number of retries already made. This is the deduction factor for a single retry. Finally, the overall quality score of the current main communication link is calculated.

[0069] Furthermore, the calculated overall quality score of the main communication link is compared with a preset health threshold (e.g., 60 points), and different retransmission routing strategies are executed accordingly: Strategy A (Retransmission via the original link): If the overall quality score is greater than or equal to the preset threshold, it indicates that although occasional packet loss occurred on the main communication link, the overall channel quality remains healthy. In this case, the system continues to retransmit the missing event frames via the main communication link.

[0070] Strategy B (Heterogeneous Link Switchover and Retransmission): If the overall quality score is less than the preset threshold, it indicates that the main communication link has suffered severe degradation or persistent congestion. In this case, the system triggers the heterogeneous link switching mechanism and decisively switches the retransmission data stream to the backup communication link for transmission.

[0071] It should be noted that conducted interference on power lines typically does not affect the propagation of radio electromagnetic waves in space. Therefore, the aforementioned dynamic assessment and switching operations can bypass local physical interference sources, thereby improving the success rate and real-time performance of emergency reporting.

[0072] Furthermore, after determining the retransmission link, the communication unit of the measurement switch will traverse the local cache according to the missing status bitmap and extract only the missing event frames. It is particularly important to emphasize that during repackaging and transmission, the system will maintain the event identifier and frame sequence number of the original event frame unchanged. After the retransmission frame is sent to the receiving end through the selected link, the receiving end will directly fill the missing positions in the corresponding reassembly buffer in its memory with these late retransmission frames based on the event identifier in the frame header, and trigger the transmission of an acknowledgment message again. After receiving the new acknowledgment message, the measurement switch repeats the above comparison logic and updates the breakpoint resumption log. Until the missing status bitmap no longer contains any missing markers (i.e., all frames have been successfully acknowledged), the system determines that the event frame reporting is complete, then clears the local cache, releases memory resources, and throws an asynchronous interrupt signal indicating successful event reporting to the upper-layer application, forming a complete business process.

[0073] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for frame-based reporting of measurement switch events based on dual-mode communication confirmation, characterized in that, include: S1: In the measurement switch or its communication unit, an event-level envelope is generated for the detected event. The event-level envelope contains a unique event identifier and the total number of frames corresponding to the event. The unique event identifier is obtained by concatenating the physical MAC address of the measurement switch, the event occurrence timestamp, and the monotonically increasing event sequence number maintained locally by the measurement switch, and then extracting and encoding it through a hash digest. The total number of frames is obtained by deducting the fixed frame header overhead and security check overhead of the event frame from the minimum common maximum transmission unit negotiated by the current dual-mode communication network to obtain the effective payload capacity of a single frame. The effective payload capacity of a single frame is then rounded up according to the length of the event payload data bytes. S2: Divide the payload data of the event into multiple event frames. Each event frame contains the event identifier and frame sequence number, as well as an independent CRC checksum. The frame sequence number corresponds to the bit bits of the acknowledgment bitmap generated by the receiving end. Before executing S3, a breakpoint resume log is established for the event in the non-volatile memory of the measurement switch or its communication unit. The breakpoint resume log is used to record the event-level envelope, the sending bitmap of the sent event frame, and the confirmation bitmap of the confirmed event frame. S3: The multiple event frames are sent to the receiving end via a high-speed power line carrier communication link, which serves as the main communication link, and the transmission bitmap is updated after each event frame is successfully pushed into the physical layer. S4: Receive an acknowledgment message for the event identifier via the main communication link or a high-speed low-power wireless communication link used as a backup communication link. The acknowledgment message includes an acknowledgment bitmap, which indicates an event frame that has been successfully received. After the multiple event frames are sent, the acknowledgment messages of both the main communication link and the backup communication link are monitored simultaneously. When the main communication link times out or fails to receive the acknowledgment message, the system switches to the backup communication link and actively sends an acknowledgment request message containing only the event identifier to request the receiving end to return the acknowledgment bitmap corresponding to the event identifier. S5: Perform a bitwise logical comparison between the received acknowledgment bitmap and the sending bitmap in the breakpoint resume log. Only when an event frame is in the state of sent in the sending bitmap and in the state of unacknowledged in the acknowledgment bitmap is the event frame determined to be a missing event frame, and a missing state bitmap is generated. Only the missing event frames corresponding to the missing state bitmap are resent. When the communication quality of the main communication link is lower than a preset threshold, the missing event frame is resent through the backup communication link, and the event identifier and frame sequence number of the original event frame remain unchanged during resentment.

2. The method for frame-based reporting of measurement switch events based on dual-mode communication confirmation as described in claim 1, characterized in that, The event-level envelope also includes: Event type, event occurrence time, measurement switch address, and priority information used to identify event priority; The receiving end uses the event identifier, measurement switch address, event occurrence time, and event frame payload digest to perform idempotency judgment on the recombined event and merge duplicate reported events.

3. The method for frame-based reporting of measurement switch events based on dual-mode communication confirmation as described in claim 1, characterized in that, The determination of whether the main communication link receives an acknowledgment message timeout or failure is based on a dynamic adaptive timeout threshold. This dynamic adaptive timeout threshold is obtained by combining the average round-trip time of historical communication between the measurement switch and the receiving end, the fluctuation difference of historical round-trip time, and the fixed hardware time consumed by the receiving end in processing frame reassembly and generating bitmaps.

4. The method for frame-based reporting of measurement switch events based on dual-mode communication confirmation as described in claim 2, characterized in that, Before S3, it also includes: Based on the priority information in the event-level envelopes, the event frames of different events are sorted into sending queues; When a conflict occurs between the event frame of a high-priority event and the transmission task of low-priority periodic data, the event frame of the high-priority event is scheduled to enter the transmission process first; if the low-priority periodic data is being transmitted at the physical layer, it waits for the current single frame to be transmitted and then seizes the next transmission opportunity.

5. The method for frame-based reporting of measurement switch events based on dual-mode communication confirmation as described in claim 1, characterized in that, When the detected event originates from a record of the first communication protocol, step S1 further includes: The event records of the first communication protocol are converted into event objects of the second communication protocol, and the payload data of the event objects is used to segment the payload data; The event-level envelope also records protocol information for identifying the first and second communication protocols, as well as a conversion digest for verifying conversion consistency.

6. The method for frame-based reporting of measurement switch events based on dual-mode communication confirmation as described in claim 1, characterized in that, The criteria for judging the communication quality of the main communication link include: The confirmation success rate of historical confirmation messages is used as the base score; When the current confirmed round-trip delay exceeds a preset threshold, an exponential penalty score is calculated based on the excess. Calculate the linear penalty score based on the current number of retries; The comprehensive quality score is obtained by subtracting the exponential penalty score and the linear penalty score from the base score. When the comprehensive quality score is lower than the preset health threshold, the communication quality of the main communication link is determined to be lower than the preset threshold.

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